Sezaki Laboratory
Institute of Industrial Science / Center for Spatial Information Science in The University of Tokyo
Institute of Industrial Science / Center for Spatial Information Science in The University of Tokyo
2021 |
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Journal Articles |
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| 1. | Wataru Sasaki, Yuuki Nishiyama, Tadashi Okoshi, Jin Nakazawa Investigating the occurrence of selfie-based emotional contagion over social network Journal Article Open Access In: Social Network Analysis and Mining, 11 , pp. 8, 2021, ISSN: 1869-5450. Abstract | BibTeX | タグ: Emotional contagion ·, Mobile sensing ·, Social content sharing, Social network · | Links: @article{Sasaki2021, title = {Investigating the occurrence of selfie-based emotional contagion over social network}, author = {Wataru Sasaki and Yuuki Nishiyama and Tadashi Okoshi and Jin Nakazawa}, url = {http://link.springer.com/10.1007/s13278-020-00712-0}, doi = {10.1007/s13278-020-00712-0}, issn = {1869-5450}, year = {2021}, date = {2021-01-01}, journal = {Social Network Analysis and Mining}, volume = {11}, pages = {8}, publisher = {Springer}, abstract = { Happiness is obviously one of the most fundamental essence that affects many aspects of our lives. Past research found that happiness of one person affects that of other people. What occurs under this propagation of emotion is called “emotional contagion,” a phenomenon wherein through perception, people experience the same emotion expressed by someone when communicating with them. Although online communication is increasing due to growth of mobile computing, emotional contagion on online communication is not well studied yet. Particularly, it is not yet clear if emotional contagion among people occurs through selfie photographs posted on the social network media. We implemented “SmileWave,” the social networking system for investigating selfie-based emotional contagion. The key feature of SmileWave is detecting “smile degree” in user’s posting selfies and in reactive facial expressions when the user is viewing the posted photographs from others. Our in-the-wild user studies with 38 participants for 2 weeks revealed the occurrence of selfie-based emotional contagion over the social network, based on the results that the users’ smile degree improved (15% on average) when the user looked at posted selfie photographs. },keywords = {Emotional contagion ·, Mobile sensing ·, Social content sharing, Social network ·}, pubstate = {published}, tppubtype = {article} } <p>Happiness is obviously one of the most fundamental essence that affects many aspects of our lives. Past research found that happiness of one person affects that of other people. What occurs under this propagation of emotion is called “emotional contagion,” a phenomenon wherein through perception, people experience the same emotion expressed by someone when communicating with them. Although online communication is increasing due to growth of mobile computing, emotional contagion on online communication is not well studied yet. Particularly, it is not yet clear if emotional contagion among people occurs through selfie photographs posted on the social network media. We implemented “SmileWave,” the social networking system for investigating selfie-based emotional contagion. The key feature of SmileWave is detecting “smile degree” in user’s posting selfies and in reactive facial expressions when the user is viewing the posted photographs from others. Our in-the-wild user studies with 38 participants for 2 weeks revealed the occurrence of selfie-based emotional contagion over the social network, based on the results that the users’ smile degree improved (15% on average) when the user looked at posted selfie photographs.</p> |
Inproceedings |
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| 2. | Hidenaga Ushijima, Shota Ono, Yuuki Nishiyama, Kaoru Sezaki Towards Infectious Disease Risk Assessment in Taxis using Environmental Sensors Inproceedings In: Distributed, Ambient and Pervasive Interactions, Springer International Publishing, Cham, 2021. Abstract | BibTeX | タグ: CO2, COVID-19, Mobile sensing, Public Transportation @inproceedings{taxi_co2_20201, title = {Towards Infectious Disease Risk Assessment in Taxis using Environmental Sensors}, author = {Hidenaga Ushijima and Shota Ono and Yuuki Nishiyama and Kaoru Sezaki}, year = {2021}, date = {2021-01-01}, booktitle = {Distributed, Ambient and Pervasive Interactions}, publisher = {Springer International Publishing}, address = {Cham}, abstract = {The spread of Coronavirus disease of 2019 (COVID-19) has reaffirmed the importance of ventilation in enclosed public spaces. Studies on air quality in public spaces such as classrooms, hospitals, and trains have been conducted in the past. However, the interior of a taxi, where an extremely small space is shared with an unspecified number of people, has not been sufficiently studied. This is a unique environment where ventilation is important. This study compared ventilation meth-ods focusing on the CO2 concentration in the cabin, and evaluated the frequency of ventilation in an actual taxi using sensing technology}, keywords = {CO2, COVID-19, Mobile sensing, Public Transportation}, pubstate = {published}, tppubtype = {inproceedings} } The spread of Coronavirus disease of 2019 (COVID-19) has reaffirmed the importance of ventilation in enclosed public spaces. Studies on air quality in public spaces such as classrooms, hospitals, and trains have been conducted in the past. However, the interior of a taxi, where an extremely small space is shared with an unspecified number of people, has not been sufficiently studied. This is a unique environment where ventilation is important. This study compared ventilation meth-ods focusing on the CO2 concentration in the cabin, and evaluated the frequency of ventilation in an actual taxi using sensing technology |
2020 |
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Journal Articles |
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| 3. | Elina Kuosmanen, Florian Wolling, Julio Vega, Valerii Kan, Yuuki Nishiyama, Simon Harper, Kristof Van Laerhoven, Simo Hosio, Denzil Ferreira Smartphone-Based Monitoring of Parkinson Disease: Quasi-Experimental Study to Quantify Hand Tremor Severity and Medication Effectiveness Journal Article Open Access In: JMIR Mhealth Uhealth, 8 (11), pp. e21543, 2020, ISSN: 2291-5222. Abstract | BibTeX | タグ: hand tremor, mobile health, Parkinson disease, smartphone | Links: @article{info:doi/10.2196/21543, title = {Smartphone-Based Monitoring of Parkinson Disease: Quasi-Experimental Study to Quantify Hand Tremor Severity and Medication Effectiveness}, author = {Elina Kuosmanen and Florian Wolling and Julio Vega and Valerii Kan and Yuuki Nishiyama and Simon Harper and Kristof Van Laerhoven and Simo Hosio and Denzil Ferreira}, url = {http://www.ncbi.nlm.nih.gov/pubmed/33242017}, doi = {10.2196/21543}, issn = {2291-5222}, year = {2020}, date = {2020-11-26}, journal = {JMIR Mhealth Uhealth}, volume = {8}, number = {11}, pages = {e21543}, abstract = {Background: Hand tremor typically has a negative impact on a person's ability to complete many common daily activities. Previous research has investigated how to quantify hand tremor with smartphones and wearable sensors, mainly under controlled data collection conditions. Solutions for daily real-life settings remain largely underexplored. Objective: Our objective was to monitor and assess hand tremor severity in patients with Parkinson disease (PD), and to better understand the effects of PD medications in a naturalistic environment. Methods: Using the Welch method, we generated periodograms of accelerometer data and computed signal features to compare patients with varying degrees of PD symptoms. Results: We introduced and empirically evaluated the tremor intensity parameter (TIP), an accelerometer-based metric to quantify hand tremor severity in PD using smartphones. There was a statistically significant correlation between the TIP and self-assessed Unified Parkinson Disease Rating Scale (UPDRS) II tremor scores (Kendall rank correlation test: z=30.521, P<.001, $tau$=0.5367379; n=11). An analysis of the ``before'' and ``after'' medication intake conditions identified a significant difference in accelerometer signal characteristics among participants with different levels of rigidity and bradykinesia (Wilcoxon rank sum test, P<.05). Conclusions: Our work demonstrates the potential use of smartphone inertial sensors as a systematic symptom severity assessment mechanism to monitor PD symptoms and to assess medication effectiveness remotely. Our smartphone-based monitoring app may also be relevant for other conditions where hand tremor is a prevalent symptom.}, keywords = {hand tremor, mobile health, Parkinson disease, smartphone}, pubstate = {published}, tppubtype = {article} } Background: Hand tremor typically has a negative impact on a person's ability to complete many common daily activities. Previous research has investigated how to quantify hand tremor with smartphones and wearable sensors, mainly under controlled data collection conditions. Solutions for daily real-life settings remain largely underexplored. Objective: Our objective was to monitor and assess hand tremor severity in patients with Parkinson disease (PD), and to better understand the effects of PD medications in a naturalistic environment. Methods: Using the Welch method, we generated periodograms of accelerometer data and computed signal features to compare patients with varying degrees of PD symptoms. Results: We introduced and empirically evaluated the tremor intensity parameter (TIP), an accelerometer-based metric to quantify hand tremor severity in PD using smartphones. There was a statistically significant correlation between the TIP and self-assessed Unified Parkinson Disease Rating Scale (UPDRS) II tremor scores (Kendall rank correlation test: z=30.521, P<.001, $tau$=0.5367379; n=11). An analysis of the ``before'' and ``after'' medication intake conditions identified a significant difference in accelerometer signal characteristics among participants with different levels of rigidity and bradykinesia (Wilcoxon rank sum test, P<.05). Conclusions: Our work demonstrates the potential use of smartphone inertial sensors as a systematic symptom severity assessment mechanism to monitor PD symptoms and to assess medication effectiveness remotely. Our smartphone-based monitoring app may also be relevant for other conditions where hand tremor is a prevalent symptom. |
| 4. | Tammy Chung, Sang Won Bae, Eun-Young Mun, Brian Suffoletto, Yuuki Nishiyama, Serim Jang, Anind K Dey Mobile Assessment of Acute Effects of Marijuana on Cognitive Functioning in Young Adults: Observational Study Journal Article Open Access In: JMIR Mhealth Uhealth, 8 (3), pp. e16240, 2020, ISSN: 2291-5222. Abstract | BibTeX | タグ: cannabis, cell phone, cognition, marijuana, memory, short-term | Links: @article{info:doi/10.2196/16240, title = {Mobile Assessment of Acute Effects of Marijuana on Cognitive Functioning in Young Adults: Observational Study}, author = {Tammy Chung and Sang Won Bae and Eun-Young Mun and Brian Suffoletto and Yuuki Nishiyama and Serim Jang and Anind K Dey}, url = {http://www.ncbi.nlm.nih.gov/pubmed/32154789}, doi = {10.2196/16240}, issn = {2291-5222}, year = {2020}, date = {2020-03-10}, journal = {JMIR Mhealth Uhealth}, volume = {8}, number = {3}, pages = {e16240}, abstract = {Background: Mobile assessment of the effects of acute marijuana on cognitive functioning in the natural environment would provide an ecologically valid measure of the impacts of marijuana use on daily functioning. Objective: This study aimed to examine the association of reported acute subjective marijuana high (rated 0-10) with performance on 3 mobile cognitive tasks measuring visuospatial working memory (Flowers task), attentional bias to marijuana-related cues (marijuana Stroop), and information processing and psychomotor speed (digit symbol substitution task [DSST]). The effect of distraction as a moderator of the association between the rating of subjective marijuana high and task performance (ie, reaction time and number of correct responses) was explored. Methods: Young adults (aged 18-25 years; 37/60, 62% female) who reported marijuana use at least twice per week were recruited through advertisements and a participant registry in Pittsburgh, Pennsylvania. Phone surveys and mobile cognitive tasks were delivered 3 times per day and were self-initiated when starting marijuana use. Completion of phone surveys triggered the delivery of cognitive tasks. Participants completed up to 30 days of daily data collection. Multilevel models examined associations between ratings of subjective marijuana high (rated 0-10) and performance on each cognitive task (reaction time and number of correct responses) and tested the number of distractions (rated 0-4) during the mobile task session as a moderator of the association between ratings of subjective marijuana high and task performance. Results: Participants provided 2703 data points, representing 451 reports (451/2703, 16.7%) of marijuana use. Consistent with slight impairing effects of acute marijuana use, an increase in the average rating of subjective marijuana high was associated with slower average reaction time on all 3 tasks---Flowers (B=2.29; SE 0.86; P=.008), marijuana Stroop (B=2.74; SE 1.09; P=.01), and DSST (B=3.08; SE 1.41; P=.03)---and with fewer correct responses for Flowers (B=−0.03; SE 0.01; P=.01) and DSST (B=−0.18; SE 0.07; P=.01), but not marijuana Stroop (P=.45). Results for distraction as a moderator were statistically significant only for certain cognitive tasks and outcomes. Specifically, as hypothesized, a person's average number of reported distractions moderated the association of the average rating of subjective marijuana high (over and above a session's rating) with the reaction time for marijuana Stroop (B=−52.93; SE 19.38; P=.006) and DSST (B=−109.72; SE 42.50; P=.01) and the number of correct responses for marijuana Stroop (B=−0.22; SE 0.10; P=.02) and DSST (B=4.62; SE 1.81; P=.01). Conclusions: Young adults' performance on mobile cognitive tasks in the natural environment was associated with ratings of acute subjective marijuana high, consistent with slight decreases in cognitive functioning. Monitoring cognitive functioning in real time in the natural environment holds promise for providing immediate feedback to guide personal decision making.}, keywords = {cannabis, cell phone, cognition, marijuana, memory, short-term}, pubstate = {published}, tppubtype = {article} } Background: Mobile assessment of the effects of acute marijuana on cognitive functioning in the natural environment would provide an ecologically valid measure of the impacts of marijuana use on daily functioning. Objective: This study aimed to examine the association of reported acute subjective marijuana high (rated 0-10) with performance on 3 mobile cognitive tasks measuring visuospatial working memory (Flowers task), attentional bias to marijuana-related cues (marijuana Stroop), and information processing and psychomotor speed (digit symbol substitution task [DSST]). The effect of distraction as a moderator of the association between the rating of subjective marijuana high and task performance (ie, reaction time and number of correct responses) was explored. Methods: Young adults (aged 18-25 years; 37/60, 62% female) who reported marijuana use at least twice per week were recruited through advertisements and a participant registry in Pittsburgh, Pennsylvania. Phone surveys and mobile cognitive tasks were delivered 3 times per day and were self-initiated when starting marijuana use. Completion of phone surveys triggered the delivery of cognitive tasks. Participants completed up to 30 days of daily data collection. Multilevel models examined associations between ratings of subjective marijuana high (rated 0-10) and performance on each cognitive task (reaction time and number of correct responses) and tested the number of distractions (rated 0-4) during the mobile task session as a moderator of the association between ratings of subjective marijuana high and task performance. Results: Participants provided 2703 data points, representing 451 reports (451/2703, 16.7%) of marijuana use. Consistent with slight impairing effects of acute marijuana use, an increase in the average rating of subjective marijuana high was associated with slower average reaction time on all 3 tasks---Flowers (B=2.29; SE 0.86; P=.008), marijuana Stroop (B=2.74; SE 1.09; P=.01), and DSST (B=3.08; SE 1.41; P=.03)---and with fewer correct responses for Flowers (B=−0.03; SE 0.01; P=.01) and DSST (B=−0.18; SE 0.07; P=.01), but not marijuana Stroop (P=.45). Results for distraction as a moderator were statistically significant only for certain cognitive tasks and outcomes. Specifically, as hypothesized, a person's average number of reported distractions moderated the association of the average rating of subjective marijuana high (over and above a session's rating) with the reaction time for marijuana Stroop (B=−52.93; SE 19.38; P=.006) and DSST (B=−109.72; SE 42.50; P=.01) and the number of correct responses for marijuana Stroop (B=−0.22; SE 0.10; P=.02) and DSST (B=4.62; SE 1.81; P=.01). Conclusions: Young adults' performance on mobile cognitive tasks in the natural environment was associated with ratings of acute subjective marijuana high, consistent with slight decreases in cognitive functioning. Monitoring cognitive functioning in real time in the natural environment holds promise for providing immediate feedback to guide personal decision making. |
| 5. | Shota Ono, Taku Yamazaki, Takumi Miyoshi, Kaoru Sezaki Mobile-assisted ad hoc networking architecture based on location information Journal Article Open Access In: IEICE Communications Express, 9 (3), pp. 94-99, 2020. Abstract | BibTeX | タグ: Ad hoc network, device-to-device communication, location information, mobile network, relay range | Links: @article{ShotaOno20202019XBL0152, title = {Mobile-assisted ad hoc networking architecture based on location information}, author = {Shota Ono and Taku Yamazaki and Takumi Miyoshi and Kaoru Sezaki}, doi = {10.1587/comex.2019XBL0152}, year = {2020}, date = {2020-01-01}, journal = {IEICE Communications Express}, volume = {9}, number = {3}, pages = {94-99}, abstract = {This letter proposes a mobile-assisted ad hoc networking architecture based on location information. The proposed architecture comprises the location layer and ad hoc layer. The location layer performs to manage the locations of nodes and to determine the area of ad hoc network virtually based on locations via mobile networks. The ad hoc layer performs to establish an actual route based on the virtual area and to send data along the established route via local networks. The proposed architecture achieves the significant reduction of the unnecessary packets and the improvement of the packet arrival rate.}, keywords = {Ad hoc network, device-to-device communication, location information, mobile network, relay range}, pubstate = {published}, tppubtype = {article} } This letter proposes a mobile-assisted ad hoc networking architecture based on location information. The proposed architecture comprises the location layer and ad hoc layer. The location layer performs to manage the locations of nodes and to determine the area of ad hoc network virtually based on locations via mobile networks. The ad hoc layer performs to establish an actual route based on the virtual area and to send data along the established route via local networks. The proposed architecture achieves the significant reduction of the unnecessary packets and the improvement of the packet arrival rate. |
Inproceedings |
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| 6. | 山下陸, 西山勇毅, 小松寛弥, 川原圭博 BLEビーコンを用いた屋内位置推定システムの設計と実装 Inproceedings In: 研究報告ユビキタスコンピューティングシステム（UBI）, pp. 1–7, 情報処理学会, 2020, ISBN: 2188-8698. Abstract | BibTeX | タグ: COVID-19, 屋内位置情報, 接触検知 | Links: @inproceedings{weko_208650_1, title = {BLEビーコンを用いた屋内位置推定システムの設計と実装}, author = {山下陸 and 西山勇毅 and 小松寛弥 and 川原圭博}, url = {http://id.nii.ac.jp/1001/00208548/ https://mocha.t.u-tokyo.ac.jp/}, isbn = {2188-8698}, year = {2020}, date = {2020-12-01}, booktitle = {研究報告ユビキタスコンピューティングシステム（UBI）}, volume = {2020-UBI-68}, number = {8}, pages = {1--7}, publisher = {情報処理学会}, abstract = {現在，我々は大学キャンパスでの COVID-19 感染対策，そして，ポストコロナ時代における望ましい位置情報インフラの構築を目指している．ユーザーのプライバシーに配慮し，講義で活用する教室や図書館等の 181 のスペースに 200 の Bluetooth ビーコンを設置した．ビーコンが発する ID をスマートフォンで検知し，ユーザの部屋への入退室を判定する．ユーザの位置情報はサーバーサイドに集約された後，ユーザの同意に基づいたルールで，ニーズに応じた位置情報の開示が可能になっている．設置したビーコンをもとにキャンパス内で位置情報の取得予備実験を行ったところ，室内を隔てる壁の材質によっては電波の減衰率が大きく異なることや，大学の施設管理データベースの登録情報が実態を反映していないことなどが明るみになった．本稿では，MOCHA と名付けた本システムの設計と実装，システムアーキテクチャや利用規約を制定する際のポイントについて共有する． We are currently working to build the desirable location infrastructure on university campus to combat COVID-19 and also in the post-corona era. In consideration of the user privacy, we have installed 200 Bluetooth beacons in 181 spaces, including the libraries and the classrooms used for the lectures. The IDs emitted by the beacons are detected by a smartphone to determine the user's entering and exiting the room. After the user's location information is collected on the server side, rules based on the user's consent enable the location information to be disclosed according to their needs. A preliminary experiment of the location information acquisition in the campus using the beacons revealed that the attenuation rate of radio waves differs greatly depending on the material of the wall, and the information registered in the facility management database of the university does not reflect the reality. In this paper, we share the design and implementation of our system, named MOCHA, and the key points for establishing the system architecture and terms of use.}, keywords = {COVID-19, 屋内位置情報, 接触検知}, pubstate = {published}, tppubtype = {inproceedings} } 現在，我々は大学キャンパスでの COVID-19 感染対策，そして，ポストコロナ時代における望ましい位置情報インフラの構築を目指している．ユーザーのプライバシーに配慮し，講義で活用する教室や図書館等の 181 のスペースに 200 の Bluetooth ビーコンを設置した．ビーコンが発する ID をスマートフォンで検知し，ユーザの部屋への入退室を判定する．ユーザの位置情報はサーバーサイドに集約された後，ユーザの同意に基づいたルールで，ニーズに応じた位置情報の開示が可能になっている．設置したビーコンをもとにキャンパス内で位置情報の取得予備実験を行ったところ，室内を隔てる壁の材質によっては電波の減衰率が大きく異なることや，大学の施設管理データベースの登録情報が実態を反映していないことなどが明るみになった．本稿では，MOCHA と名付けた本システムの設計と実装，システムアーキテクチャや利用規約を制定する際のポイントについて共有する． We are currently working to build the desirable location infrastructure on university campus to combat COVID-19 and also in the post-corona era. In consideration of the user privacy, we have installed 200 Bluetooth beacons in 181 spaces, including the libraries and the classrooms used for the lectures. The IDs emitted by the beacons are detected by a smartphone to determine the user's entering and exiting the room. After the user's location information is collected on the server side, rules based on the user's consent enable the location information to be disclosed according to their needs. A preliminary experiment of the location information acquisition in the campus using the beacons revealed that the attenuation rate of radio waves differs greatly depending on the material of the wall, and the information registered in the facility management database of the university does not reflect the reality. In this paper, we share the design and implementation of our system, named MOCHA, and the key points for establishing the system architecture and terms of use. |
| 7. | 日隈壮一郎, 西山勇毅, 瀬崎薫 スマートフォンのGPS信号受信強度を用いた紫外線量推定手法に関する研究 Inproceedings In: CSIS DAYS 2020, Center for Spatial Information Science, The University of Tokyo, オンライン, 2020. BibTeX | タグ: GPS信号受信状態, モバイルセンシング, 紫外線量推定 @inproceedings{日隈壮一郎2020b, title = {スマートフォンのGPS信号受信強度を用いた紫外線量推定手法に関する研究}, author = {日隈壮一郎 and 西山勇毅 and 瀬崎薫}, year = {2020}, date = {2020-11-21}, booktitle = {CSIS DAYS 2020}, publisher = {Center for Spatial Information Science, The University of Tokyo}, address = {オンライン}, keywords = {GPS信号受信状態, モバイルセンシング, 紫外線量推定}, pubstate = {published}, tppubtype = {inproceedings} } |
| 8. | 牛島秀暢, 西山勇毅, 小野翔多, 瀬崎薫 環境センサを用いたタクシー車室内における感染症リスク評価に関する一検討 Inproceedings Award In: 研究報告高度交通システムとスマートコミュニティ（ITS）, pp. 1–6, 情報処理学会, 2020, ISSN: 2188-8965. Abstract | BibTeX | タグ: 二酸化炭素, 感染症対策, 車内環境センシング | Links: @inproceedings{mbl_co2, title = {環境センサを用いたタクシー車室内における感染症リスク評価に関する一検討}, author = {牛島秀暢 and 西山勇毅 and 小野翔多 and 瀬崎薫}, url = {http://id.nii.ac.jp/1001/00207785/}, issn = {2188-8965}, year = {2020}, date = {2020-11-17}, booktitle = {研究報告高度交通システムとスマートコミュニティ（ITS）}, volume = {2020-ITS-83}, number = {10}, pages = {1--6}, publisher = {情報処理学会}, abstract = {COVID-19の感染拡大により，公共空間や飲食業などの対面サービスにおいて，持続的かつ安全で低コストな感染症への対策が求められている．これまでは，密閉，密集，密接の三密と呼ばれる状態が感染リスクがあるとされ，換気の徹底などが推奨されてきたが，その効果を定量的に計測する事は極めて困難である．本研究では，タクシーという密閉空間の状態を複数の環境センサを用いて計測し，感染症リスクを定量的に分析する．}, keywords = {二酸化炭素, 感染症対策, 車内環境センシング}, pubstate = {published}, tppubtype = {inproceedings} } COVID-19の感染拡大により，公共空間や飲食業などの対面サービスにおいて，持続的かつ安全で低コストな感染症への対策が求められている．これまでは，密閉，密集，密接の三密と呼ばれる状態が感染リスクがあるとされ，換気の徹底などが推奨されてきたが，その効果を定量的に計測する事は極めて困難である．本研究では，タクシーという密閉空間の状態を複数の環境センサを用いて計測し，感染症リスクを定量的に分析する． |
| 9. | Yuuki Nishiyama, Takuro Yonezawa, Kaoru Sezaki SelfGuard: Semi-Automated Activity Tracking for Enhancing Self-Protection against the COVID-19 Pandemic Inproceedings In: the 18th ACM Conference on Embedded Networked Sensor Systems (SenSys '20), COVID-19 Pandemic Response, Virtual Event, Japan , pp. 780–781, Association for Computing Machinery, New York, NY, USA, 2020, ISBN: 978-1-4503-7590-0/20/11. Abstract | BibTeX | タグ: COVID-19, GPS, Mobile sensing, Self-Tracking | Links: @inproceedings{sensys2020_selfguard, title = {SelfGuard: Semi-Automated Activity Tracking for Enhancing Self-Protection against the COVID-19 Pandemic}, author = {Yuuki Nishiyama and Takuro Yonezawa and Kaoru Sezaki}, url = {https://youtu.be/KYmvCHl_U7g}, doi = {10.1145/3384419.3430592}, isbn = {978-1-4503-7590-0/20/11}, year = {2020}, date = {2020-11-16}, booktitle = {the 18th ACM Conference on Embedded Networked Sensor Systems (SenSys '20), COVID-19 Pandemic Response, Virtual Event, Japan }, number = {2}, pages = {780–781}, publisher = {Association for Computing Machinery}, address = {New York, NY, USA}, abstract = {Contagious diseases like COVID-19 spread periodically and threaten our lives. Self-protection, such as washing hands, wearing a mask, and staying home, are simple and practical solutions to safeguard against these diseases. Most governments and health departments recommend that people maintain self-protection. Although continuous self-protection effectively prevents the spread of infection, only the intent to self-protect is unsustainable in the long term. In this study, we design, develop, and deploy an application to track users' daily activities semi-automatically and enhance self-protection behavior using mobile sensing and gamified feedback techniques. Currently, more than 324 people have installed the app via AppStore, and 52 users have shared their activity data to our research group.}, keywords = {COVID-19, GPS, Mobile sensing, Self-Tracking}, pubstate = {published}, tppubtype = {inproceedings} } Contagious diseases like COVID-19 spread periodically and threaten our lives. Self-protection, such as washing hands, wearing a mask, and staying home, are simple and practical solutions to safeguard against these diseases. Most governments and health departments recommend that people maintain self-protection. Although continuous self-protection effectively prevents the spread of infection, only the intent to self-protect is unsustainable in the long term. In this study, we design, develop, and deploy an application to track users' daily activities semi-automatically and enhance self-protection behavior using mobile sensing and gamified feedback techniques. Currently, more than 324 people have installed the app via AppStore, and 52 users have shared their activity data to our research group. |
| 10. | Zengyi Han Context Aware Photo Protection for In-SituSharing Inproceedings In: MobileHCI '20: Proceedings of the 22nd International Conference on Human-Computer Interaction with Mobile Devices and Services (Doctoral Consortium), Virtual Event, Germany, 2020. Abstract | BibTeX | タグ: Context-Aware, Face Recognition, In-situ Photo Sharing, smartphone @inproceedings{han2020_mobilehci, title = {Context Aware Photo Protection for In-SituSharing}, author = {Zengyi Han}, year = {2020}, date = {2020-10-05}, booktitle = {MobileHCI '20: Proceedings of the 22nd International Conference on Human-Computer Interaction with Mobile Devices and Services (Doctoral Consortium), Virtual Event, Germany}, abstract = {People nowadays are getting used to using mobile phones for daily photography, and sharing these precious moments online or in-situ with their friends. However, there is a potential risk of privacy leakage during the in-situ photo-sharing process. To address this risk, we proposeOASIS, a cOntext Aware photoprotection for in-SItuSharing behavior: using the front camera to tell different viewers, OASIScustomize viewer’s photo gallery seamlessly between different viewers according to the context of the photo. In this way, we can provide viewers with a good sharing experience while protecting the privacy of the owner. The paper is presented at MobileHCI 2020 Doctoral Consortium.}, keywords = {Context-Aware, Face Recognition, In-situ Photo Sharing, smartphone}, pubstate = {published}, tppubtype = {inproceedings} } People nowadays are getting used to using mobile phones for daily photography, and sharing these precious moments online or in-situ with their friends. However, there is a potential risk of privacy leakage during the in-situ photo-sharing process. To address this risk, we proposeOASIS, a cOntext Aware photoprotection for in-SItuSharing behavior: using the front camera to tell different viewers, OASIScustomize viewer’s photo gallery seamlessly between different viewers according to the context of the photo. In this way, we can provide viewers with a good sharing experience while protecting the privacy of the owner. The paper is presented at MobileHCI 2020 Doctoral Consortium. |
| 11. | Shota Ono, Fuga Kikuchi, Taku Yamazaki, Takumi Miyoshi, Kaoru Sezaki An Information Sharing Method Using P2P and V2V Communications in VANET Inproceedings Open Access In: IEEE International Conference on Consumer Electronics - Taiwan (ICCE-TW 2020), 2020. Abstract | BibTeX | タグ: P2P, V2V, VANET | Links: @inproceedings{ono_iccetw2020, title = {An Information Sharing Method Using P2P and V2V Communications in VANET}, author = {Shota Ono and Fuga Kikuchi and Taku Yamazaki and Takumi Miyoshi and Kaoru Sezaki}, url = {https://edas.info/showManuscript.php?m=1570630496&ext=pdf&random=1117285026&type=stamped http://www.icce-tw.org/index.html}, year = {2020}, date = {2020-09-28}, booktitle = {IEEE International Conference on Consumer Electronics - Taiwan (ICCE-TW 2020)}, abstract = {For realizing information sharing among vehicles, various methods based on P2P (peer-to-peer) and V2V (vehicle-to-vehicle) communications have been proposed. However, in a case of using a P2P-based method, the network load of a source vehicle will increase due to the increase of receivers. On the other hand, in a case of using a V2V-based method, vehicles cannot communicate with each other if vehicles are far apart. In this paper, we propose an information sharing method among vehicles based on V2V and P2P communications.}, keywords = {P2P, V2V, VANET}, pubstate = {published}, tppubtype = {inproceedings} } For realizing information sharing among vehicles, various methods based on P2P (peer-to-peer) and V2V (vehicle-to-vehicle) communications have been proposed. However, in a case of using a P2P-based method, the network load of a source vehicle will increase due to the increase of receivers. On the other hand, in a case of using a V2V-based method, vehicles cannot communicate with each other if vehicles are far apart. In this paper, we propose an information sharing method among vehicles based on V2V and P2P communications. |
| 12. | 日隈壮一郎, 西山勇毅, 瀬崎薫 GPS信号受信状態を用いた紫外線量推定手法の検討 Inproceedings In: 2020 IEICE Society Conference, The Institute of Electronics, Information and Communication Engineers, オンライン, 2020. BibTeX | タグ: GPS信号受信状態, モバイルセンシング, 紫外線量推定 @inproceedings{日隈壮一郎2020, title = {GPS信号受信状態を用いた紫外線量推定手法の検討}, author = {日隈壮一郎 and 西山勇毅 and 瀬崎薫}, year = {2020}, date = {2020-09-16}, booktitle = {2020 IEICE Society Conference}, publisher = {The Institute of Electronics, Information and Communication Engineers}, address = {オンライン}, keywords = {GPS信号受信状態, モバイルセンシング, 紫外線量推定}, pubstate = {published}, tppubtype = {inproceedings} } |
| 13. | Soichiro Higuma, Yuuki Nishiyama, Kaoru Sezaki Towards Estimating UV Light Intensity Using GPS Signal Strength Inproceedings In: Adjunct Proceedings of the 2020 ACM International Joint Conference on Pervasive and Ubiquitous Computing and Proceedings of the 2020 ACM International Symposium on Wearable Computers, pp. 684–687, Association for Computing Machinery, Virtual Event, Mexico, 2020, ISBN: 9781450380768. Abstract | BibTeX | タグ: Estimation, GPS Signal Reception, Mobile sensing, UV | Links: @inproceedings{10.1145/3410530.3414434, title = {Towards Estimating UV Light Intensity Using GPS Signal Strength}, author = {Soichiro Higuma and Yuuki Nishiyama and Kaoru Sezaki}, url = {https://doi.org/10.1145/3410530.3414434 https://youtu.be/qsuyUv47M6E https://github.com/sezakilab/M5Stack_UVLogger}, doi = {10.1145/3410530.3414434}, isbn = {9781450380768}, year = {2020}, date = {2020-09-12}, booktitle = {Adjunct Proceedings of the 2020 ACM International Joint Conference on Pervasive and Ubiquitous Computing and Proceedings of the 2020 ACM International Symposium on Wearable Computers}, pages = {684–687}, publisher = {Association for Computing Machinery}, address = {Virtual Event, Mexico}, series = {UbiComp-ISWC '20}, abstract = {Due to recent urbanization and changing lifestyles, many people have been spending more time indoors. Hence, they tend to receive less direct sunlight than ever before. Although excessive/inadequate UV exposure can be harmful to human health leading to illnesses such as skin cancer, spots, or depression, moderate UV exposure is necessary for vitamin D production in the body. Therefore, estimating UV exposure with a commonly used device is useful for maintaining a healthy lifestyle from excessive/inadequate UV exposure in our daily life. In this study, we aim to estimate UV exposure, and to this end, we used the GPS signal strength (C/No) collected from an off-the-shelf smartphone for exploring the relationship between UV values and C/No. We conducted an experiment and measured UV values and C/No from 10 places in two different situations. From the results, we observed a significant correlation (R2 more than 0.87) between UV values and C/No when all the data were divided by the sun/shade condition. This result supports the fact that UV values potentially can be inferred from C/No to some degree if the sun/shade condition can be detected.}, keywords = {Estimation, GPS Signal Reception, Mobile sensing, UV}, pubstate = {published}, tppubtype = {inproceedings} } Due to recent urbanization and changing lifestyles, many people have been spending more time indoors. Hence, they tend to receive less direct sunlight than ever before. Although excessive/inadequate UV exposure can be harmful to human health leading to illnesses such as skin cancer, spots, or depression, moderate UV exposure is necessary for vitamin D production in the body. Therefore, estimating UV exposure with a commonly used device is useful for maintaining a healthy lifestyle from excessive/inadequate UV exposure in our daily life. In this study, we aim to estimate UV exposure, and to this end, we used the GPS signal strength (C/No) collected from an off-the-shelf smartphone for exploring the relationship between UV values and C/No. We conducted an experiment and measured UV values and C/No from 10 places in two different situations. From the results, we observed a significant correlation (R2 more than 0.87) between UV values and C/No when all the data were divided by the sun/shade condition. This result supports the fact that UV values potentially can be inferred from C/No to some degree if the sun/shade condition can be detected. |
| 14. | Yuuki Nishiyama, Denzil Ferreira, Wataru Sasaki, Tadashi Okoshi, Jin Nakazawa, Anind K Dey, Kaoru Sezaki Using IOS for Inconspicuous Data Collection: A Real-World Assessment Inproceedings In: Adjunct Proceedings of the 2020 ACM International Joint Conference on Pervasive and Ubiquitous Computing and Proceedings of the 2020 ACM International Symposium on Wearable Computers, pp. 261–266, Association for Computing Machinery, Virtual Event, Mexico, 2020, ISBN: 9781450380768. Abstract | BibTeX | タグ: Effective Data Collection, iOS, Mobile Crowd sensing, Mobile Sensing Toolkit, Real-world Assessment | Links: @inproceedings{10.1145/3410530.3414369, title = {Using IOS for Inconspicuous Data Collection: A Real-World Assessment}, author = {Yuuki Nishiyama and Denzil Ferreira and Wataru Sasaki and Tadashi Okoshi and Jin Nakazawa and Anind K Dey and Kaoru Sezaki}, url = {https://doi.org/10.1145/3410530.3414369 https://github.com/tetujin/AWAREFramework-iOS}, doi = {10.1145/3410530.3414369}, isbn = {9781450380768}, year = {2020}, date = {2020-09-12}, booktitle = {Adjunct Proceedings of the 2020 ACM International Joint Conference on Pervasive and Ubiquitous Computing and Proceedings of the 2020 ACM International Symposium on Wearable Computers}, pages = {261–266}, publisher = {Association for Computing Machinery}, address = {Virtual Event, Mexico}, series = {UbiComp-ISWC '20}, abstract = {Mobile Crowd Sensing (MCS) is a method for collecting multiple sensor data from distributed mobile devices for understanding social and behavioral phenomena. The method requires collecting the sensor data 24/7, ideally inconspicuously to minimize bias. Although several MCS tools for collecting the sensor data from an off-the-shelf smartphone are proposed and evaluated under controlled conditions as a benchmark, the performance in a practical sensing study condition is scarce, especially on iOS. In this paper, we assess the data collection quality of AWARE iOS, installed on off-the-shelf iOS smartphones with 9 participants for a week. Our analysis shows that more than 97% of sensor data, provided by hardware sensors (i.e., accelerometer, location, and pedometer sensor), is successfully collected in real-world conditions, unless a user explicitly quits our data collection application.}, keywords = {Effective Data Collection, iOS, Mobile Crowd sensing, Mobile Sensing Toolkit, Real-world Assessment}, pubstate = {published}, tppubtype = {inproceedings} } Mobile Crowd Sensing (MCS) is a method for collecting multiple sensor data from distributed mobile devices for understanding social and behavioral phenomena. The method requires collecting the sensor data 24/7, ideally inconspicuously to minimize bias. Although several MCS tools for collecting the sensor data from an off-the-shelf smartphone are proposed and evaluated under controlled conditions as a benchmark, the performance in a practical sensing study condition is scarce, especially on iOS. In this paper, we assess the data collection quality of AWARE iOS, installed on off-the-shelf iOS smartphones with 9 participants for a week. Our analysis shows that more than 97% of sensor data, provided by hardware sensors (i.e., accelerometer, location, and pedometer sensor), is successfully collected in real-world conditions, unless a user explicitly quits our data collection application. |
| 15. | Yuuki Nishiyama, Denzil Ferreira, Yusaku Eigen, Wataru Sasaki, Tadashi Okoshi, Jin Nakazawa, Anind K Dey, Kaoru Sezaki iOS Crowd-Sensing Won't Hurt a Bit!: AWARE Framework and Sustainable Study Guideline for iOS Platform Inproceedings Self Archive In: Streitz, Norbert; Konomi, Shiníchi (Ed.): Distributed, Ambient and Pervasive Interactions, pp. 223–243, Springer International Publishing, Cham, 2020, ISBN: 978-3-030-50344-4. Abstract | BibTeX | タグ: Data Collection Rate, Guideline, iOS, Mobile Sensing Framework, Sustainable Sensing | Links: @inproceedings{10.1007/978-3-030-50344-4_17, title = {iOS Crowd-Sensing Won't Hurt a Bit!: AWARE Framework and Sustainable Study Guideline for iOS Platform}, author = {Yuuki Nishiyama and Denzil Ferreira and Yusaku Eigen and Wataru Sasaki and Tadashi Okoshi and Jin Nakazawa and Anind K Dey and Kaoru Sezaki}, editor = {Norbert Streitz and Shiníchi Konomi}, url = {https://www.yuukinishiyama.com/2020/07/25/hcii2020/ https://www.yuukinishiyama.com/wp-content/uploads/2020/07/AWARE-iOS_HCII2020_preprint.pdf https://github.com/tetujin/aware-client-ios-v2 https://github.com/tetujin/AWAREFramework-iOS}, doi = {10.1007/978-3-030-50344-4_17}, isbn = {978-3-030-50344-4}, year = {2020}, date = {2020-07-10}, booktitle = {Distributed, Ambient and Pervasive Interactions}, pages = {223--243}, publisher = {Springer International Publishing}, address = {Cham}, abstract = {The latest smartphones have advanced sensors that allow us to recognize human and environmental contexts. They operate primarily on Android and iOS, and can be used as sensing platforms for research in various fields owing to their ubiquity in society. Mobile sensing frameworks help to manage these sensors easily. However, Android and iOS are constructed following different policies, requiring developers and researchers to consider framework differences during research planning, application development, and data collection phases to ensure sustainable data collection. In particular, iOS imposes strict regulations on background data collection and application distribution. In this study, we design, implement, and evaluate a mobile sensing framework for iOS, namely AWARE-iOS, which is an iOS version of the AWARE Framework. Our performance evaluations and case studies measured over a duration of 288 h on four types of devices, show the risks of continuous data collection in the background and explore optimal practical sensor settings for improved data collection. Based on these results, we develop guidelines for sustainable data collection on iOS.}, keywords = {Data Collection Rate, Guideline, iOS, Mobile Sensing Framework, Sustainable Sensing}, pubstate = {published}, tppubtype = {inproceedings} } The latest smartphones have advanced sensors that allow us to recognize human and environmental contexts. They operate primarily on Android and iOS, and can be used as sensing platforms for research in various fields owing to their ubiquity in society. Mobile sensing frameworks help to manage these sensors easily. However, Android and iOS are constructed following different policies, requiring developers and researchers to consider framework differences during research planning, application development, and data collection phases to ensure sustainable data collection. In particular, iOS imposes strict regulations on background data collection and application distribution. In this study, we design, implement, and evaluate a mobile sensing framework for iOS, namely AWARE-iOS, which is an iOS version of the AWARE Framework. Our performance evaluations and case studies measured over a duration of 288 h on four types of devices, show the risks of continuous data collection in the background and explore optimal practical sensor settings for improved data collection. Based on these results, we develop guidelines for sustainable data collection on iOS. |
| 16. | 牛島秀暢, 青木俊介, 西山勇毅, 瀬崎薫 Non-Negative Tensor Factrization を用いたドックレス型マイクロモビリティの利用形態分類手法の検討 Inproceedings AwardSelf Archive In: 研究報告高度交通システムとスマートコミュニティ（ITS）, pp. 1–8, 情報処理学会, 2020, ISSN: 2188-8965. Abstract | BibTeX | タグ: e-scooter, ITS, Micromobility, Mobility-as-a-Service, 都市コンピューティング | Links: @inproceedings{ushijima2020_its, title = {Non-Negative Tensor Factrization を用いたドックレス型マイクロモビリティの利用形態分類手法の検討}, author = {牛島秀暢 and 青木俊介 and 西山勇毅 and 瀬崎薫}, url = {http://id.nii.ac.jp/1001/00204626/ https://www.mcl.iis.u-tokyo.ac.jp/wp-content/uploads/2020/08/ITS81.pdf }, issn = {2188-8965}, year = {2020}, date = {2020-05-21}, booktitle = {研究報告高度交通システムとスマートコミュニティ（ITS）}, journal = {研究報告モバイルコンピューティングとパーベイシブシステム (MBL)}, volume = {2020-ITS-81}, number = {1}, pages = {1--8}, publisher = {情報処理学会}, abstract = {交通やインフラ，スマートフォンなどから得られる様々なデータを統合的に利活用し，都市計画の継続的な改善に役立てるという都市コンピューティングが注目されている．都市コンピューティングは少子高齢化と過疎化が進行する日本においても公共インフラを有効活用し都市を維持するためにも有効である．限られた公共インフラを活用するためには人々の移動目的を推定し，交通リソースを最適化する必要があるが，既存の IC カードなどの交通データでは推定粒度に限界があった．こうした状況の中，特定の返却場所を持たないドックレス型のマイクロモビリティが急速に普及している．ドックレス型マイクロモビリティは平均移動距離が 500m 程度と短く，直接目的地に向かうため，より詳細な移動行動が検出可能である．本研究では，マイクロモビリティが都市空間で離散的に分布する点に着目した．そして，細かく単発的な移動行動を大域的に分析することで潜在的な移動パターンがあることを，Non-Negative Tensor Factrization と呼ばれる教師なし学習を用いることで明らかにした．}, keywords = {e-scooter, ITS, Micromobility, Mobility-as-a-Service, 都市コンピューティング}, pubstate = {published}, tppubtype = {inproceedings} } 交通やインフラ，スマートフォンなどから得られる様々なデータを統合的に利活用し，都市計画の継続的な改善に役立てるという都市コンピューティングが注目されている．都市コンピューティングは少子高齢化と過疎化が進行する日本においても公共インフラを有効活用し都市を維持するためにも有効である．限られた公共インフラを活用するためには人々の移動目的を推定し，交通リソースを最適化する必要があるが，既存の IC カードなどの交通データでは推定粒度に限界があった．こうした状況の中，特定の返却場所を持たないドックレス型のマイクロモビリティが急速に普及している．ドックレス型マイクロモビリティは平均移動距離が 500m 程度と短く，直接目的地に向かうため，より詳細な移動行動が検出可能である．本研究では，マイクロモビリティが都市空間で離散的に分布する点に着目した．そして，細かく単発的な移動行動を大域的に分析することで潜在的な移動パターンがあることを，Non-Negative Tensor Factrization と呼ばれる教師なし学習を用いることで明らかにした． |
| 17. | 日隈壮一郎, 西山勇毅, 瀬崎薫 GPS 信号受信状態を用いた紫外線量推定手法の検討 Inproceedings Award In: 研究報告ユビキタスコンピューティングシステム (UBI), pp. 1–7, 情報処理学会, 2020, ISSN: 2188-8698. Abstract | BibTeX | タグ: GPS信号受信状態, モバイルセンシング, 紫外線量推定 | Links: @inproceedings{higuma2020_ubi66, title = {GPS 信号受信状態を用いた紫外線量推定手法の検討}, author = {日隈壮一郎 and 西山勇毅 and 瀬崎薫}, url = {http://id.nii.ac.jp/1001/00204523/}, issn = {2188-8698}, year = {2020}, date = {2020-05-18}, booktitle = {研究報告ユビキタスコンピューティングシステム (UBI)}, journal = {研究報告ユビキタスコンピューティングシステム (UBI)}, volume = {2020-UBI-66}, number = {5}, pages = {1--7}, publisher = {情報処理学会}, abstract = {近年の都市構造の変容と急激なライフスタイルの変化に伴い，人間が屋内で過ごす時間は長時間化し，逆に屋外で直射日光を浴びる時間は年々短くなっている．過度な紫外線の被曝は皮膚癌やシワ，シミの発生可能性を高めるが，一方で適度な紫外線被曝は体内でのビタミン D の生成に必要不可欠である．また，基本的に野菜に含まれていないビタミン D の不足は，カルシウム不足や低カルシウム血症，骨の軟化やうつ病などに繋がる危険性があり，長期的な健康管理において，紫外線被曝量の管理は重要である．しかしながら，紫外線センサを常に携帯することはユーザの負担が大きく，長期的な利用には日常的に計測または推定可能な手法が必要である．そこで本研究では，スマートフォンに搭載された GPS モジュールを用いて，GPS 信号の受信状態から紫外線量を推定する手法の検討を行う．}, keywords = {GPS信号受信状態, モバイルセンシング, 紫外線量推定}, pubstate = {published}, tppubtype = {inproceedings} } 近年の都市構造の変容と急激なライフスタイルの変化に伴い，人間が屋内で過ごす時間は長時間化し，逆に屋外で直射日光を浴びる時間は年々短くなっている．過度な紫外線の被曝は皮膚癌やシワ，シミの発生可能性を高めるが，一方で適度な紫外線被曝は体内でのビタミン D の生成に必要不可欠である．また，基本的に野菜に含まれていないビタミン D の不足は，カルシウム不足や低カルシウム血症，骨の軟化やうつ病などに繋がる危険性があり，長期的な健康管理において，紫外線被曝量の管理は重要である．しかしながら，紫外線センサを常に携帯することはユーザの負担が大きく，長期的な利用には日常的に計測または推定可能な手法が必要である．そこで本研究では，スマートフォンに搭載された GPS モジュールを用いて，GPS 信号の受信状態から紫外線量を推定する手法の検討を行う． |
| 18. | 小野翔多, 山崎託, 三好匠, 瀬崎薫 MANETにおけるノードの通信負荷に基づく経路構築手法 Inproceedings In: 電子情報通信学会 電子情報通信学会総合大会, 広島大学東広島キャンパス, 2020. Abstract | BibTeX | タグ: AODV, MANET, 通信負荷 | Links: @inproceedings{, title = {MANETにおけるノードの通信負荷に基づく経路構築手法}, author = {小野翔多 and 山崎託 and 三好匠 and 瀬崎薫}, url = {http://www.ieice-taikai.jp/2020society/jpn/}, year = {2020}, date = {2020-03-20}, booktitle = {電子情報通信学会 電子情報通信学会総合大会}, address = {広島大学東広島キャンパス}, abstract = {MANET（Mobile ad-hoc network）は，無線通信を用いることで自律分散的なネットワークを構築することが可能である．しかし，経路構築時に経路要求をフラッディングするため，通信資源を消費する．この問題に対して，位置情報に基づき仮想的な領域を作成し，不必要な制御メッセージを抑制する手法が提案されている．しかし，多くの近傍ノードを持つノードが経路に選択されやすく，ノードの通信負荷に偏りが生じる．本稿では，各ノードの通信負荷を分散するための経路構築手法を提案する．}, keywords = {AODV, MANET, 通信負荷}, pubstate = {published}, tppubtype = {inproceedings} } MANET（Mobile ad-hoc network）は，無線通信を用いることで自律分散的なネットワークを構築することが可能である．しかし，経路構築時に経路要求をフラッディングするため，通信資源を消費する．この問題に対して，位置情報に基づき仮想的な領域を作成し，不必要な制御メッセージを抑制する手法が提案されている．しかし，多くの近傍ノードを持つノードが経路に選択されやすく，ノードの通信負荷に偏りが生じる．本稿では，各ノードの通信負荷を分散するための経路構築手法を提案する． |
| 19. | 菊地風雅, 山崎託, 三好匠, 小野翔多 P2P通信とV2V通信を併用した車車間情報配信手法 Inproceedings In: 電子情報通信学会 電子情報通信学会総合大会, 広島大学東広島キャンパス, 2020. Abstract | BibTeX | タグ: P2P, V2V, VANET, 車車間通信 | Links: @inproceedings{, title = {P2P通信とV2V通信を併用した車車間情報配信手法}, author = {菊地風雅 and 山崎託 and 三好匠 and 小野翔多}, url = {http://www.ieice-taikai.jp/2020society/jpn/}, year = {2020}, date = {2020-03-19}, booktitle = {電子情報通信学会 電子情報通信学会総合大会}, address = {広島大学東広島キャンパス}, abstract = {車両間で通信する方法には，直接通信を用いた車車間通信（V2V通信）と移動体通信網を用いたピアツーピア通信（P2P通信）がある．V2V通信では，マルチホップ通信を用いることで車車間アドホックネットワーク（VANET）を構築し，情報を共有する． しかし，車両間の距離が遠い場合は情報が不達となる． P2P通信では，移動体通信網を用いて車両間の距離に依らずに直接情報を共有することができる．しかし，接続する車両数が多くなると移動体通信網や配信元車両への負荷が増大する． 本研究では，分断された車両群に対応するため，V2V通信とP2P通信を併用した情報配信手法を提案する．}, keywords = {P2P, V2V, VANET, 車車間通信}, pubstate = {published}, tppubtype = {inproceedings} } 車両間で通信する方法には，直接通信を用いた車車間通信（V2V通信）と移動体通信網を用いたピアツーピア通信（P2P通信）がある．V2V通信では，マルチホップ通信を用いることで車車間アドホックネットワーク（VANET）を構築し，情報を共有する． しかし，車両間の距離が遠い場合は情報が不達となる． P2P通信では，移動体通信網を用いて車両間の距離に依らずに直接情報を共有することができる．しかし，接続する車両数が多くなると移動体通信網や配信元車両への負荷が増大する． 本研究では，分断された車両群に対応するため，V2V通信とP2P通信を併用した情報配信手法を提案する． |
| 20. | 神村潤, 西山勇毅, 瀬崎薫 スマートフォンセンサを用いた気分情報を基にした都市空間評価手法に向けて Inproceedings In: 電子情報通信学会 電子情報通信学会総合大会, 広島大学東広島キャンパス, 2020. BibTeX | タグ: | Links: @inproceedings{kamimura2020_2020Soc, title = {スマートフォンセンサを用いた気分情報を基にした都市空間評価手法に向けて}, author = {神村潤 and 西山勇毅 and 瀬崎薫}, url = {http://www.ieice-taikai.jp/2020society/jpn/}, year = {2020}, date = {2020-03-17}, booktitle = {電子情報通信学会 電子情報通信学会総合大会}, address = {広島大学東広島キャンパス}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
| 21. | 西山勇毅, 佐々木航, 栄元優作, 本木悠介, 大越匡, 中澤仁, 瀬崎薫 In-the-Wild実験におけるiOS用モバイルセンシングフレームワークの性能評価 Inproceedings In: 電子情報通信学会技術研究報告: 信学技報, pp. 127-132, ライフインテリジェンスとオフィス情報システム(LOIS) 電子情報通信学会, 大濱信泉記念館（石垣島） , 2020, ISSN: 0913-5685. Abstract | BibTeX | タグ: AWARE, In-the-Wildセンシング, iOS, ガイドライン, センシング基盤, フレームワーク, モバイルセンシング | Links: @inproceedings{Nishiyama2020_LOIS, title = {In-the-Wild実験におけるiOS用モバイルセンシングフレームワークの性能評価}, author = {西山勇毅 and 佐々木航 and 栄元優作 and 本木悠介 and 大越匡 and 中澤仁 and 瀬崎薫}, url = {https://www.ieice.org/ken/index/ieice-techrep-119-477.html}, issn = {0913-5685}, year = {2020}, date = {2020-03-11}, booktitle = {電子情報通信学会技術研究報告: 信学技報}, volume = {119}, number = {477}, pages = {127-132}, publisher = {電子情報通信学会}, address = {大濱信泉記念館（石垣島） }, organization = {ライフインテリジェンスとオフィス情報システム(LOIS)}, abstract = {ユーザの携帯端末より収集したセンサデータを用いて，人や集団・空間の状態を理解するモバイルセンシングは，情報科学だけでなく社会科学や公衆衛生など様々な分野で利用されている．モバイルセンシングを容易に実現するツールは多数提案されており，それらは研究室内実験など「コントール環境」での性能評価は行われている．しかし，実際の被験者にシステムを配布し実験を行う「In-the-Wild環境」における性能評価は行われていない．特にAndroidに比べiOSは制約が多く，制約を無視した設定はデータ収集率の低下を招くため，適切な設定を明らかにする必要がある． そこで本研究では，iOS用モバイルセンシングフレームワーク（{it AWARE-iOS}）を用いて，1週間のIn-the-Wild環境実験を10人の被験者を対象に行い，その際の{it AWARE-iOS}のデータ収集性能及びバッテリ消費を評価した．その結果，最も収集率が高い可能性のある設定（ESM＋SPN）では，ユーザが{it AWARE-iOS}を強制終了しない限り95%以上のデータを収集可能であり，平均11.39時間の起動が可能であることが明らかになった． }, keywords = {AWARE, In-the-Wildセンシング, iOS, ガイドライン, センシング基盤, フレームワーク, モバイルセンシング}, pubstate = {published}, tppubtype = {inproceedings} } ユーザの携帯端末より収集したセンサデータを用いて，人や集団・空間の状態を理解するモバイルセンシングは，情報科学だけでなく社会科学や公衆衛生など様々な分野で利用されている．モバイルセンシングを容易に実現するツールは多数提案されており，それらは研究室内実験など「コントール環境」での性能評価は行われている．しかし，実際の被験者にシステムを配布し実験を行う「In-the-Wild環境」における性能評価は行われていない．特にAndroidに比べiOSは制約が多く，制約を無視した設定はデータ収集率の低下を招くため，適切な設定を明らかにする必要がある． そこで本研究では，iOS用モバイルセンシングフレームワーク（{it AWARE-iOS}）を用いて，1週間のIn-the-Wild環境実験を10人の被験者を対象に行い，その際の{it AWARE-iOS}のデータ収集性能及びバッテリ消費を評価した．その結果，最も収集率が高い可能性のある設定（ESM＋SPN）では，ユーザが{it AWARE-iOS}を強制終了しない限り95%以上のデータを収集可能であり，平均11.39時間の起動が可能であることが明らかになった． |
| 22. | Chenwei Song, Masaki Ito, Yuuki Nishiyama, Kaoru Sezaki Mobile Sensing of Pedestrian Mobility and its Assessment Inproceedings In: IEICE Tech. Rep., pp. 121–126, Life Intelligence and Office Information Systems (LOIS) IEICE Technical Committee, 2020, ISBN: 0913-5685. Abstract | BibTeX | タグ: Bluetooth, Crowd detection, Human mobility | Links: @inproceedings{Chenwei2020_LOIS, title = {Mobile Sensing of Pedestrian Mobility and its Assessment}, author = {Chenwei Song and Masaki Ito and Yuuki Nishiyama and Kaoru Sezaki}, url = {https://www.ieice.org/ken/paper/20200312h1vo/eng/}, isbn = {0913-5685}, year = {2020}, date = {2020-03-04}, booktitle = {IEICE Tech. Rep.}, volume = {119}, number = {477}, pages = {121--126}, publisher = {IEICE Technical Committee}, organization = {Life Intelligence and Office Information Systems (LOIS)}, abstract = {We propose a client-server system that provides crowd detection and mobility information. Our proposed system has the advantages of low cost and location flexibility without pre-deployed, as long as there is a sufficient number of users involved. We conducted several experiments in real environments to determine the feasibility, accuracy and applicable environment of the system. The result shows that the system can effectively capture the flow of people in the experimental area. In some cases, under the same environment, it can obtain almost the same mobility tracking information from fewer participating users than the GPS method. }, keywords = {Bluetooth, Crowd detection, Human mobility}, pubstate = {published}, tppubtype = {inproceedings} } We propose a client-server system that provides crowd detection and mobility information. Our proposed system has the advantages of low cost and location flexibility without pre-deployed, as long as there is a sufficient number of users involved. We conducted several experiments in real environments to determine the feasibility, accuracy and applicable environment of the system. The result shows that the system can effectively capture the flow of people in the experimental area. In some cases, under the same environment, it can obtain almost the same mobility tracking information from fewer participating users than the GPS method. |
| 23. | Shota ono, Taku Yamazaki, Takumi miyoshi 移動体通信併用形MANETにおける通信負荷に基づく経路構築手法 Inproceedings In: 電子情報通信学会 信学技報, 大濱信泉記念館（石垣島）, 2020. Abstract | BibTeX | タグ: MANET, モバイルネットワーク, 位置情報, 負荷分散 @inproceedings{, title = {移動体通信併用形MANETにおける通信負荷に基づく経路構築手法}, author = {Shota ono and Taku Yamazaki and Takumi miyoshi}, year = {2020}, date = {2020-02-24}, booktitle = {電子情報通信学会 信学技報}, address = {大濱信泉記念館（石垣島）}, abstract = {移動可能な無線ノード間で自律分散的なネットワークを形成するMANET（Mobile ad-hoc network）では，通信要求に応じて経路を構築するルーティングプロトコルが広く検討されている．しかし，これらのプロトコルでは，経路構築時に制御メッセージをネットワーク全体にフラッディングするため，通信資源を大量に消費する．この問題に対して，著者らは，移動体通信を用いてMANETを構築するための仮想領域を作成する移動体通信併用形MANETを提案している．この手法では，仮想領域内に制御メッセージの送信を制限することでネットワーク負荷を低減できるが，多くのノードが近傍に存在するノードが経路に選択されやすいため，ノード間の通信負荷に偏りが生じる． 本稿では，移動体通信併用形MANETにおいて，各ノードの通信負荷を分散させるための経路構築手法を提案する． また，シミュレーションにより，既存の経路制御手法と提案手法の比較を行い，有効性を評価する．}, keywords = {MANET, モバイルネットワーク, 位置情報, 負荷分散}, pubstate = {published}, tppubtype = {inproceedings} } 移動可能な無線ノード間で自律分散的なネットワークを形成するMANET（Mobile ad-hoc network）では，通信要求に応じて経路を構築するルーティングプロトコルが広く検討されている．しかし，これらのプロトコルでは，経路構築時に制御メッセージをネットワーク全体にフラッディングするため，通信資源を大量に消費する．この問題に対して，著者らは，移動体通信を用いてMANETを構築するための仮想領域を作成する移動体通信併用形MANETを提案している．この手法では，仮想領域内に制御メッセージの送信を制限することでネットワーク負荷を低減できるが，多くのノードが近傍に存在するノードが経路に選択されやすいため，ノード間の通信負荷に偏りが生じる． 本稿では，移動体通信併用形MANETにおいて，各ノードの通信負荷を分散させるための経路構築手法を提案する． また，シミュレーションにより，既存の経路制御手法と提案手法の比較を行い，有効性を評価する． |
| 24. | 栄元優作, 佐々木航, 西山勇毅, 大越匡, 中澤仁 モバイルコンピューティングによるエモーショナル・イーティングの検知 Inproceedings In: 研究報告ユビキタスコンピューティングシステム (UBI), pp. 1–8, 情報処理学会, 2020, ISSN: 2188-8698. Abstract | BibTeX | タグ: エモーショナル・イーティング, スマートフォン, モバイルセンシング, 情動的摂食, 機械学習, 行動推定 | Links: @inproceedings{eigen2020_ubi65, title = {モバイルコンピューティングによるエモーショナル・イーティングの検知}, author = {栄元優作 and 佐々木航 and 西山勇毅 and 大越匡 and 中澤仁}, url = {http://id.nii.ac.jp/1001/00203697/}, issn = {2188-8698}, year = {2020}, date = {2020-01-01}, booktitle = {研究報告ユビキタスコンピューティングシステム (UBI)}, volume = {2020}, number = {39}, pages = {1--8}, publisher = {情報処理学会}, abstract = {ストレスや感情の変化に左右された食行動はエモーショナル・イーティングと呼ばれる．エモーショナル・イーティングが発生する原因として，ストレスや生活習慣の乱れによる自律神経やホルモンバランスの乱れがあげられる．したがって，自律神経の活性度やホルモン分泌量を継続して観察・分析することで，エモーショナル・イーティングの発生を予期することが可能である．しかし，それらの計測には特殊な生体センサが必要であり，また長時間の使用は負担が大きい．本研究では，ユーザが日常的に利用しており，かつ利用者の行動パターンの特徴が表れるスマートフォンのセンサ情報と機械学習を組み合わせることで，エモーショナルイーティングの検知に取り組む．そして，スマートフォンのセンサデータと食生活データを収集する SEED システムを構築し，収集データからエモーショナル・イーティングを検知する機械学習モデルを作成した．本システムを用いて 60 人の被験者から 28 日間のデータを収集したところ，87.5% の精度でエモーショナル・イーティングを検知することに成功した．}, keywords = {エモーショナル・イーティング, スマートフォン, モバイルセンシング, 情動的摂食, 機械学習, 行動推定}, pubstate = {published}, tppubtype = {inproceedings} } ストレスや感情の変化に左右された食行動はエモーショナル・イーティングと呼ばれる．エモーショナル・イーティングが発生する原因として，ストレスや生活習慣の乱れによる自律神経やホルモンバランスの乱れがあげられる．したがって，自律神経の活性度やホルモン分泌量を継続して観察・分析することで，エモーショナル・イーティングの発生を予期することが可能である．しかし，それらの計測には特殊な生体センサが必要であり，また長時間の使用は負担が大きい．本研究では，ユーザが日常的に利用しており，かつ利用者の行動パターンの特徴が表れるスマートフォンのセンサ情報と機械学習を組み合わせることで，エモーショナルイーティングの検知に取り組む．そして，スマートフォンのセンサデータと食生活データを収集する SEED システムを構築し，収集データからエモーショナル・イーティングを検知する機械学習モデルを作成した．本システムを用いて 60 人の被験者から 28 日間のデータを収集したところ，87.5% の精度でエモーショナル・イーティングを検知することに成功した． |
2019 |
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Journal Articles |
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| 25. | Yuichi Nakamura, Masaki Ito, Kaoru Sezaki Optimal Mobility Control of Sensors in the Event of a Disaster Journal Article Open Access In: Journal of Disaster Research, 14 (3), pp. 500-507, 2019. Abstract | BibTeX | タグ: active sensing, disaster prevention, participatory sensing | Links: @article{YuichiNakamura2019, title = {Optimal Mobility Control of Sensors in the Event of a Disaster}, author = {Yuichi Nakamura and Masaki Ito and Kaoru Sezaki}, doi = {10.20965/jdr.2019.p0500}, year = {2019}, date = {2019-01-01}, journal = {Journal of Disaster Research}, volume = {14}, number = {3}, pages = {500-507}, abstract = {Disasters have caused serious damage on human beings throughout their long history. In a major natural disaster such as an earthquake, a key to mitigate the damage is evacuation. Evidently, secondary collateral disasters is account for more casualty than the initial one. In order to have citizens to evacuate safely for the sake of saving their lives, collecting information is vital. However at times of a disaster, it is a difficult task to gain environmental information about the area by conventional way. One of the solutions to this problem is crowd-sensing, which regards citizens as sensors nodes and collect information with their help. We considered a way of controlling the mobility of such sensor nodes under limitation of its mobility, caused by road blockage, for example. Aiming to make a mobility control scheme that enables high-quality information collection, our method uses preceding result of the measurement to control the mobility. Here it uses kriging variance to do that. We evaluated this method by simulating some measurements and it showed better accuracy than baseline. This is expected to be a method to enable a higher-quality input to the agent-based evacuation simulation, which helps to guide people to evacuate more safely.}, keywords = {active sensing, disaster prevention, participatory sensing}, pubstate = {published}, tppubtype = {article} } Disasters have caused serious damage on human beings throughout their long history. In a major natural disaster such as an earthquake, a key to mitigate the damage is evacuation. Evidently, secondary collateral disasters is account for more casualty than the initial one. In order to have citizens to evacuate safely for the sake of saving their lives, collecting information is vital. However at times of a disaster, it is a difficult task to gain environmental information about the area by conventional way. One of the solutions to this problem is crowd-sensing, which regards citizens as sensors nodes and collect information with their help. We considered a way of controlling the mobility of such sensor nodes under limitation of its mobility, caused by road blockage, for example. Aiming to make a mobility control scheme that enables high-quality information collection, our method uses preceding result of the measurement to control the mobility. Here it uses kriging variance to do that. We evaluated this method by simulating some measurements and it showed better accuracy than baseline. This is expected to be a method to enable a higher-quality input to the agent-based evacuation simulation, which helps to guide people to evacuate more safely. |
| 26. | 栄元優作, 西山勇毅, 大越匡, 中澤仁 HealthyStadium: 他者評価とゲーミフィケーションを用いた食習慣改善ソーシャルメディア Journal Article In: 情報処理学会論文誌, 60 (10), pp. 1881-1895, 2019, ISSN: 1882-7764. Abstract | BibTeX | タグ: ゲーミフィケーション, ソーシャルメディア, 食事記録, 食生活 | Links: @article{170000180547b, title = {HealthyStadium: 他者評価とゲーミフィケーションを用いた食習慣改善ソーシャルメディア}, author = {栄元優作 and 西山勇毅 and 大越匡 and 中澤仁}, url = {https://ci.nii.ac.jp/naid/170000180547/en/}, issn = {1882-7764}, year = {2019}, date = {2019-01-01}, journal = {情報処理学会論文誌}, volume = {60}, number = {10}, pages = {1881-1895}, abstract = {生活習慣病は，生活習慣が発症原因に深く関与する疾患の総称であり，癌などの三大死因の発症リスクを高める危険性がある．特に食事は，人間活動に必須であり日常的に行われるが，高カロリー・栄養バランスの悪い食事は生活習慣病につながる可能性が高い．健康な食生活を目指すために，主にモバイルデバイスに食事内容を記録する手法が利用されるが，栄養素の計算・記録負荷が大きく，また利用者がつねに能動的に記録を行う必要があり，継続利用には利用者個人の動機に依存する傾向がある．本研究では，これまでの食事内容の記録手法に「グループでのゲーム要素」および「食事内容に対する他者の評価」を加えることで，グループ全体での低負荷での食事の行動変容を促進する新たな記録手法，HealthyStadiumを提案する．HealthyStadiumはグループ内において食事画像の共有および，その健康度合いで対戦するソーシャルメディアである．健康度合いの評価は，1人1票の投票形式で行われ投票数の多い方が勝利となる．本アプリケーションを用いて，大学生10人を対象に28日間にわたる評価実験を実施した．既存の記録アプリケーションと比較して，HealthyStadiumでは食事の記録回数が20%上昇し，記録負担が低減した．さらに，行動変容ステージモデルの評価指数の1つである自己効力感を増加させる効果を確認できた． Lifestyle-related diseases are a general term for diseases in which lifestyle is deeply involved in the pathogenesis, and there is a risk of raising the risk of developing three major causes of death such as cancer. Diet, in particular, is essential for human activities and is carried out on a daily basis, but diets with high calorie and poor nutritional balance are likely to lead to lifestyle diseases. To aim for healthy eating habits, a method of recording dietary contents in mobile devices is mainly used, but calculation of nutrients and recording load are large and it is required to always positively record, so there is a tendency to depend on the motivation of individual users for continuous use. In this research, we propose “HealthyStadium”, a new recording method to promote eating behavior change in the whole group by adding “game element in group” and “evaluation of others to meal contents” to the existing recording method. HealthyStadium is a social media which shares meal photo in the group and makes users fight with its health degree. Evaluation of the degree of health is done by voting one by one person, and users with many votes win. Using this application, we conducted an evaluation experiment for 10 university students over 28 days. Compared with the existing recording application, the number of meals recordings increased by 20% in HealthyStadium, and the burden of the recording was alleviated. Furthermore, the self-efficacy which is one of the evaluation indexes of the behavior change stage model was also improving.}, keywords = {ゲーミフィケーション, ソーシャルメディア, 食事記録, 食生活}, pubstate = {published}, tppubtype = {article} } 生活習慣病は，生活習慣が発症原因に深く関与する疾患の総称であり，癌などの三大死因の発症リスクを高める危険性がある．特に食事は，人間活動に必須であり日常的に行われるが，高カロリー・栄養バランスの悪い食事は生活習慣病につながる可能性が高い．健康な食生活を目指すために，主にモバイルデバイスに食事内容を記録する手法が利用されるが，栄養素の計算・記録負荷が大きく，また利用者がつねに能動的に記録を行う必要があり，継続利用には利用者個人の動機に依存する傾向がある．本研究では，これまでの食事内容の記録手法に「グループでのゲーム要素」および「食事内容に対する他者の評価」を加えることで，グループ全体での低負荷での食事の行動変容を促進する新たな記録手法，HealthyStadiumを提案する．HealthyStadiumはグループ内において食事画像の共有および，その健康度合いで対戦するソーシャルメディアである．健康度合いの評価は，1人1票の投票形式で行われ投票数の多い方が勝利となる．本アプリケーションを用いて，大学生10人を対象に28日間にわたる評価実験を実施した．既存の記録アプリケーションと比較して，HealthyStadiumでは食事の記録回数が20%上昇し，記録負担が低減した．さらに，行動変容ステージモデルの評価指数の1つである自己効力感を増加させる効果を確認できた． Lifestyle-related diseases are a general term for diseases in which lifestyle is deeply involved in the pathogenesis, and there is a risk of raising the risk of developing three major causes of death such as cancer. Diet, in particular, is essential for human activities and is carried out on a daily basis, but diets with high calorie and poor nutritional balance are likely to lead to lifestyle diseases. To aim for healthy eating habits, a method of recording dietary contents in mobile devices is mainly used, but calculation of nutrients and recording load are large and it is required to always positively record, so there is a tendency to depend on the motivation of individual users for continuous use. In this research, we propose “HealthyStadium”, a new recording method to promote eating behavior change in the whole group by adding “game element in group” and “evaluation of others to meal contents” to the existing recording method. HealthyStadium is a social media which shares meal photo in the group and makes users fight with its health degree. Evaluation of the degree of health is done by voting one by one person, and users with many votes win. Using this application, we conducted an evaluation experiment for 10 university students over 28 days. Compared with the existing recording application, the number of meals recordings increased by 20% in HealthyStadium, and the burden of the recording was alleviated. Furthermore, the self-efficacy which is one of the evaluation indexes of the behavior change stage model was also improving. |
| 27. | Shin’ichi Konomi, Tomoyo Sasao, Simo Hosio, Kaoru Sezaki Using ambient WiFi signals to find occupied and vacant houses in local communities Journal Article Open Access In: Journal of Ambient Intelligence and Humanized Computing, 10 (2), pp. 779–789, 2019. Abstract | BibTeX | タグ: Ambient WiFi signals, Civic computing, localization, Vacant houses | Links: @article{konomi2019using, title = {Using ambient WiFi signals to find occupied and vacant houses in local communities}, author = {Shin’ichi Konomi and Tomoyo Sasao and Simo Hosio and Kaoru Sezaki}, doi = {10.1007/s12652-018-0899-8}, year = {2019}, date = {2019-01-01}, journal = {Journal of Ambient Intelligence and Humanized Computing}, volume = {10}, number = {2}, pages = {779--789}, publisher = {Springer}, abstract = {In many countries, the population is either declining or rapidly concentrating in big cities, which causes problems in the form of vacant houses. It is often challenging to keep track of the locations and the conditions of vacant houses, and for example in Japan, costly manual field studies are employed to map the occupancy situation. In this paper, we discuss a technique to infer the locations of occupied and vacant houses based on ambient WiFi signals. Our technique collects Received Signal Strength Indicator (RSSI) data based on opportunistic smartphone sensing, constructs hybrid networks of WiFi access points, and analyzes their geospatial patterns based on statistical shape modeling. In situ experiments in two residential neighborhoods show that the proposed technique can successfully detect occupied houses and substantially outperform a simple triangulation-based method in one of the neighborhoods. We also argue that the proposed technique can significantly reduce the cost of field surveys to find vacant houses as the number of potential houses to be inspected decreases.}, keywords = {Ambient WiFi signals, Civic computing, localization, Vacant houses}, pubstate = {published}, tppubtype = {article} } In many countries, the population is either declining or rapidly concentrating in big cities, which causes problems in the form of vacant houses. It is often challenging to keep track of the locations and the conditions of vacant houses, and for example in Japan, costly manual field studies are employed to map the occupancy situation. In this paper, we discuss a technique to infer the locations of occupied and vacant houses based on ambient WiFi signals. Our technique collects Received Signal Strength Indicator (RSSI) data based on opportunistic smartphone sensing, constructs hybrid networks of WiFi access points, and analyzes their geospatial patterns based on statistical shape modeling. In situ experiments in two residential neighborhoods show that the proposed technique can successfully detect occupied houses and substantially outperform a simple triangulation-based method in one of the neighborhoods. We also argue that the proposed technique can significantly reduce the cost of field surveys to find vacant houses as the number of potential houses to be inspected decreases. |
Book Chapters |
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| 28. | Chenwei Song, Masaki Ito, Kaoru Sezaki Capturing People Mobility with Mobile Sensing Technology for Disaster Evacuation Book Chapter In: Streitz, Norbert; Konomi, Shiníchi (Ed.): Distributed, Ambient and Pervasive Interactions, 11587 , pp. 187–198, Springer International Publishing, Cham, 2019, ISBN: 978-3-030-21935-2. Abstract | BibTeX | タグ: Bluetooth, Capture mobility, Crowd detection | Links: @inbook{10.1007/978-3-030-21935-2_15, title = {Capturing People Mobility with Mobile Sensing Technology for Disaster Evacuation}, author = {Chenwei Song and Masaki Ito and Kaoru Sezaki}, editor = {Norbert Streitz and Shiníchi Konomi}, doi = {10.1007/978-3-030-21935-2_15}, isbn = {978-3-030-21935-2}, year = {2019}, date = {2019-06-07}, booktitle = {Distributed, Ambient and Pervasive Interactions}, volume = {11587}, pages = {187--198}, publisher = {Springer International Publishing}, address = {Cham}, series = {Lecture Notes in Computer Science}, abstract = {In this paper, we propose a client-server-service-based system that provides crowd detection and mobility capture. Crowd detection is to detect and calculate the density of crowds within a specified area. Mobility capture is to track the direction of the people. If a warning mechanism is added, the system can prevent or dissolve the crowd to avoid accidents in public places by sending alerts when the detected number of people exceeds a certain set percentage. The technology also plays a big role after the disaster, by calculating the path with relatively small population density in the disaster area, the high-density crowd can be led to a safe area avoiding secondary injury by crowding. Compared to common methods, such as cameras, our proposed system has the advantages of low cost and location flexibility. The system can detect any area without pre-deployed, as long as there is a sufficient number of users involved. In this article, we conducted several experiments in real environments to determine if the system can accurately capture crowd information and route tracking.}, keywords = {Bluetooth, Capture mobility, Crowd detection}, pubstate = {published}, tppubtype = {inbook} } In this paper, we propose a client-server-service-based system that provides crowd detection and mobility capture. Crowd detection is to detect and calculate the density of crowds within a specified area. Mobility capture is to track the direction of the people. If a warning mechanism is added, the system can prevent or dissolve the crowd to avoid accidents in public places by sending alerts when the detected number of people exceeds a certain set percentage. The technology also plays a big role after the disaster, by calculating the path with relatively small population density in the disaster area, the high-density crowd can be led to a safe area avoiding secondary injury by crowding. Compared to common methods, such as cameras, our proposed system has the advantages of low cost and location flexibility. The system can detect any area without pre-deployed, as long as there is a sufficient number of users involved. In this article, we conducted several experiments in real environments to determine if the system can accurately capture crowd information and route tracking. |
Inproceedings |
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| 29. | 大越匡, 西山勇毅, 佐々木航, 栄元優作, 中澤仁 人の限定合理性を超越した行動変容支援に向けた情報プラッ トフォームの設計 Inproceedings In: 研究報告ユビキタスコンピューティングシステム（UBI）, pp. 1–6, 情報処理学会, 2019, ISSN: 2188-8698. Abstract | BibTeX | タグ: 情報システム, 情報提示, 行動変容, 限定合理性 | Links: @inproceedings{tadashi2019_ubi, title = {人の限定合理性を超越した行動変容支援に向けた情報プラッ トフォームの設計}, author = {大越匡 and 西山勇毅 and 佐々木航 and 栄元優作 and 中澤仁}, url = {http://id.nii.ac.jp/1001/00200838/}, issn = {2188-8698}, year = {2019}, date = {2019-12-03}, booktitle = {研究報告ユビキタスコンピューティングシステム（UBI）}, volume = {2019-UBI-64}, number = {8}, pages = {1--6}, publisher = { 情報処理学会}, series = {UBI64}, abstract = {ユビキタスコンピューティングシステムとして，例えば睡眠，食事，運動，学びといった人の多くの行動における行動変容を支援するための研究が数多くなされてきた一方，現状の取り組みは，人間が合理的であろうとするが種々の能力の限界によって限られた合理性しかもてない「限定合理性」(bounded rationality）を超えて人間を支援できていない．本研究では，この限定合理性を超越する情報技術の実現を目指し，その概念を整理し，解決手法における方針と情報アーキテクチャへの要件を明らかにする．}, keywords = {情報システム, 情報提示, 行動変容, 限定合理性}, pubstate = {published}, tppubtype = {inproceedings} } ユビキタスコンピューティングシステムとして，例えば睡眠，食事，運動，学びといった人の多くの行動における行動変容を支援するための研究が数多くなされてきた一方，現状の取り組みは，人間が合理的であろうとするが種々の能力の限界によって限られた合理性しかもてない「限定合理性」(bounded rationality）を超えて人間を支援できていない．本研究では，この限定合理性を超越する情報技術の実現を目指し，その概念を整理し，解決手法における方針と情報アーキテクチャへの要件を明らかにする． |
| 30. | Yao Sun, Masaki Ito, Kaoru Sezaki Channel Capacity Analysis of Diffusive DNA based Molecular Communication Inproceedings In: 2019 IEEE Wireless Communications and Networking Conference (WCNC), pp. 1-6, IEEE, Marrakesh, Morocco, Morocco, 2019, ISBN: 978-1-5386-7646-2. Abstract | BibTeX | タグ: channel capacity analysis, diffusion-based channel, DNA-based information packet, Molecular Communication | Links: @inproceedings{8885693, title = {Channel Capacity Analysis of Diffusive DNA based Molecular Communication}, author = {Yao Sun and Masaki Ito and Kaoru Sezaki}, doi = {10.1109/WCNC.2019.8885693}, isbn = {978-1-5386-7646-2}, year = {2019}, date = {2019-10-31}, booktitle = {2019 IEEE Wireless Communications and Networking Conference (WCNC)}, pages = {1-6}, publisher = {IEEE}, address = {Marrakesh, Morocco, Morocco}, abstract = {In this paper, we present a diffusion-based molecular communication using DNA molecules as data packets. In particular, we design a scheme utilizing the two types of nucleobase pairs to represent binary bits so that a bit sequence can be encoded onto a single DNA molecule. Therefore, the DNA molecule can be used as a data packet. Because of the stochastic character of the diffusion process and the variation of DNA diffusion coefficient correlated to the size of the molecule, namely number of base pairs composing the DNA fragment, the uncertainty of arrival order is a crucial factor that influences the reliable transmission. By modeling the observation window and focus slot, we concentrate on the order of the arriving DNA sequences. Based on the probability of each state, we derive the channel capacity of the proposed diffusive DNA based molecular communication. We also testify the effect of some parameters on the channel capacity, including base pair number, communication distance, and time slot width. Furthermore, the analysis shows that due to the high-density information encoded onto the DNA molecule, the proposed diffusive DNA based molecular communication has a higher channel capacity than other diffusion-based molecular communication.}, keywords = {channel capacity analysis, diffusion-based channel, DNA-based information packet, Molecular Communication}, pubstate = {published}, tppubtype = {inproceedings} } In this paper, we present a diffusion-based molecular communication using DNA molecules as data packets. In particular, we design a scheme utilizing the two types of nucleobase pairs to represent binary bits so that a bit sequence can be encoded onto a single DNA molecule. Therefore, the DNA molecule can be used as a data packet. Because of the stochastic character of the diffusion process and the variation of DNA diffusion coefficient correlated to the size of the molecule, namely number of base pairs composing the DNA fragment, the uncertainty of arrival order is a crucial factor that influences the reliable transmission. By modeling the observation window and focus slot, we concentrate on the order of the arriving DNA sequences. Based on the probability of each state, we derive the channel capacity of the proposed diffusive DNA based molecular communication. We also testify the effect of some parameters on the channel capacity, including base pair number, communication distance, and time slot width. Furthermore, the analysis shows that due to the high-density information encoded onto the DNA molecule, the proposed diffusive DNA based molecular communication has a higher channel capacity than other diffusion-based molecular communication. |
| 31. | Elina Kuosmanen, Valerii Kan, Julio Vega, Aku Visuri, Yuuki Nishiyama, Anind K Dey, Simon Harper, Denzil Ferreira Challenges of Parkinson's Disease: User Experiences with STOP Inproceedings In: Proceedings of the 21st International Conference on Human-Computer Interaction with Mobile Devices and Services, Association for Computing Machinery, Taipei, Taiwan, 2019, ISBN: 9781450368254. Abstract | BibTeX | タグ: empirical evaluation, logging, Parkinson's disease, smartphone | Links: @inproceedings{10.1145/3338286.3340133b, title = {Challenges of Parkinson's Disease: User Experiences with STOP}, author = {Elina Kuosmanen and Valerii Kan and Julio Vega and Aku Visuri and Yuuki Nishiyama and Anind K Dey and Simon Harper and Denzil Ferreira}, url = {https://doi.org/10.1145/3338286.3340133}, doi = {10.1145/3338286.3340133}, isbn = {9781450368254}, year = {2019}, date = {2019-10-05}, booktitle = {Proceedings of the 21st International Conference on Human-Computer Interaction with Mobile Devices and Services}, publisher = {Association for Computing Machinery}, address = {Taipei, Taiwan}, series = {MobileHCI '19}, abstract = {Parkinson's disease (PD) is the second most common neurodegenerative disorder, impacting an estimated seven to ten million people worldwide. Measuring the symptoms and progress of the disease, and medication effectiveness is currently performed using subjective measures and visual estimation. We developed and evaluated a mobile application, STOP for tracking hand's motor symptoms, and a medication journal for recording medication intake. We followed 13 PD patients from two countries for a 1-month long real-world deployment. We found that PD patients are willing to use digital tools, such as STOP, to track their medication intake and symptoms, and are also willing to share such data with their caregivers and medical personnel to improve their own care.}, keywords = {empirical evaluation, logging, Parkinson's disease, smartphone}, pubstate = {published}, tppubtype = {inproceedings} } Parkinson's disease (PD) is the second most common neurodegenerative disorder, impacting an estimated seven to ten million people worldwide. Measuring the symptoms and progress of the disease, and medication effectiveness is currently performed using subjective measures and visual estimation. We developed and evaluated a mobile application, STOP for tracking hand's motor symptoms, and a medication journal for recording medication intake. We followed 13 PD patients from two countries for a 1-month long real-world deployment. We found that PD patients are willing to use digital tools, such as STOP, to track their medication intake and symptoms, and are also willing to share such data with their caregivers and medical personnel to improve their own care. |
| 32. | Shota ono, Taku Yamazaki, Takumi miyoshi Relay Node Controlled Routing Based on Location Information for Mobile-Assisted Ad Hoc Networks Inproceedings In: 2019 IEICE General Conference English Session, waseda university, 2019. Abstract | BibTeX | タグ: AODV, location information, MANET, mobile network @inproceedings{, title = {Relay Node Controlled Routing Based on Location Information for Mobile-Assisted Ad Hoc Networks}, author = {Shota ono and Taku Yamazaki and Takumi miyoshi}, year = {2019}, date = {2019-03-21}, booktitle = {2019 IEICE General Conference English Session}, address = {waseda university}, abstract = {In a mobile ad hoc network (MANET), general ad hoc routing protocols cause the traffic load due to control messages in route discovery process. To alleviate this, location-based routing protocols reduce them in the route discovery process. However, they degrade the performance due to movement of nodes since it is difficult to track the locations by only exchanging messages locally. To address the above issue, assuming the applications of MANET in urban areas, this paper proposes a relay node controlled ad-hoc routing which reduces the control messages based on location information obtained from a server via mobile networks.}, keywords = {AODV, location information, MANET, mobile network}, pubstate = {published}, tppubtype = {inproceedings} } In a mobile ad hoc network (MANET), general ad hoc routing protocols cause the traffic load due to control messages in route discovery process. To alleviate this, location-based routing protocols reduce them in the route discovery process. However, they degrade the performance due to movement of nodes since it is difficult to track the locations by only exchanging messages locally. To address the above issue, assuming the applications of MANET in urban areas, this paper proposes a relay node controlled ad-hoc routing which reduces the control messages based on location information obtained from a server via mobile networks. |
| 33. | Yao Sun, Masaki Ito, Kaoru Sezaki Buffer Aided Receiver for Diffusive DNA Based Molecular Communication Inproceedings Award In: IEICE General Conference 2019, Japan, 2019. BibTeX | タグ: Diffusive DNA, Molecular Communication | Links: @inproceedings{yao2019, title = {Buffer Aided Receiver for Diffusive DNA Based Molecular Communication}, author = {Yao Sun and Masaki Ito and Kaoru Sezaki}, url = {https://www.ieice.org/cs/ns/jpn/es-awards.html}, year = {2019}, date = {2019-03-20}, publisher = {IEICE General Conference 2019}, address = {Japan}, keywords = {Diffusive DNA, Molecular Communication}, pubstate = {published}, tppubtype = {inproceedings} } |
| 34. | 小野翔多, 山崎託, 三好匠 端末の位置情報に基づいた中継端末限定形アドホックルーティング Inproceedings In: 電子情報通信学会 信学技報, 沖縄コンベンションセンター, 2019. Abstract | BibTeX | タグ: AODV, MANET, モバイルネットワーク, 位置情報 @inproceedings{, title = {端末の位置情報に基づいた中継端末限定形アドホックルーティング}, author = {小野翔多 and 山崎託 and 三好匠}, year = {2019}, date = {2019-02-25}, booktitle = {電子情報通信学会 信学技報}, address = {沖縄コンベンションセンター}, abstract = {MANET（Mobile ad hoc network）では，電波干渉や端末の移動による動的なトポロジーの変化によってパケット到達率が低下する問題がある． 更に，一般的なオンデマンド形の経路制御では，通信要求発生時に宛先端末との経路を構築することから，宛先端末探索のための経路要求をネットワーク全体にフラッディングする必要があり，通信資源を過剰に消費する問題がある． この問題に対し，端末の位置情報に基づき冗長な経路要求の転送を抑制する手法が提案されている． しかし，従来手法では，各端末が，MANET内での通信を通じて位置情報を事前に共有する必要があるため，適切な位置情報の共有が困難である問題や位置情報を共有するために通信資源を消費する問題がある． そこで，本稿では，移動体通信を通じて各端末の位置情報の共有や管理を行い，得られた位置情報に基づき中継端末を制限する経路制御手法を提案する． また，シミュレーションにより，既存の経路制御手法と提案手法の比較を行い有効性を評価する． }, keywords = {AODV, MANET, モバイルネットワーク, 位置情報}, pubstate = {published}, tppubtype = {inproceedings} } MANET（Mobile ad hoc network）では，電波干渉や端末の移動による動的なトポロジーの変化によってパケット到達率が低下する問題がある． 更に，一般的なオンデマンド形の経路制御では，通信要求発生時に宛先端末との経路を構築することから，宛先端末探索のための経路要求をネットワーク全体にフラッディングする必要があり，通信資源を過剰に消費する問題がある． この問題に対し，端末の位置情報に基づき冗長な経路要求の転送を抑制する手法が提案されている． しかし，従来手法では，各端末が，MANET内での通信を通じて位置情報を事前に共有する必要があるため，適切な位置情報の共有が困難である問題や位置情報を共有するために通信資源を消費する問題がある． そこで，本稿では，移動体通信を通じて各端末の位置情報の共有や管理を行い，得られた位置情報に基づき中継端末を制限する経路制御手法を提案する． また，シミュレーションにより，既存の経路制御手法と提案手法の比較を行い有効性を評価する． |
| 35. | Chenwei Song, Masaki Ito, Yuuki Nishiyama, Kaoru Sezaki Using Mobile Sensing Technology for Capturing People Mobility Information Inproceedings In: Proceedings of the 3rd ACM SIGSPATIAL International Workshop on Prediction of Human Mobility, pp. 33–40, Association for Computing Machinery, Chicago, IL, USA, 2019, ISBN: 9781450369640. BibTeX | タグ: Bluetooth, Crowd detection, Human mobility | Links: @inproceedings{10.1145/3356995.3364541, title = {Using Mobile Sensing Technology for Capturing People Mobility Information}, author = {Chenwei Song and Masaki Ito and Yuuki Nishiyama and Kaoru Sezaki}, url = {https://doi.org/10.1145/3356995.3364541}, doi = {10.1145/3356995.3364541}, isbn = {9781450369640}, year = {2019}, date = {2019-01-01}, booktitle = {Proceedings of the 3rd ACM SIGSPATIAL International Workshop on Prediction of Human Mobility}, pages = {33–40}, publisher = {Association for Computing Machinery}, address = {Chicago, IL, USA}, series = {PredictGIS’19}, keywords = {Bluetooth, Crowd detection, Human mobility}, pubstate = {published}, tppubtype = {inproceedings} } |
| 36. | Takuro Yonezawa, Yuuki Nishiyama, Kei Hiroi, Nobuo Kawaguchi Capturing Subjective Time as Context and It’s Applications (Poster) Inproceedings In: Proceedings of the 17th Annual International Conference on Mobile Systems, Applications, and Services, pp. 647–648, Association for Computing Machinery, Seoul, Republic of Korea, 2019, ISBN: 9781450366618. Abstract | BibTeX | タグ: context-awareness, experience sampling method, subjective time | Links: @inproceedings{10.1145/3307334.3328719, title = {Capturing Subjective Time as Context and It’s Applications (Poster)}, author = {Takuro Yonezawa and Yuuki Nishiyama and Kei Hiroi and Nobuo Kawaguchi}, url = {https://doi.org/10.1145/3307334.3328719}, doi = {10.1145/3307334.3328719}, isbn = {9781450366618}, year = {2019}, date = {2019-01-01}, booktitle = {Proceedings of the 17th Annual International Conference on Mobile Systems, Applications, and Services}, pages = {647–648}, publisher = {Association for Computing Machinery}, address = {Seoul, Republic of Korea}, series = {MobiSys ’19}, abstract = {We propose an integrated framework for sensing, recognizing and utilizing of subjective time as context. Various studies on experimental psychology have showed several factors which affects subjective time. Those factors should be partially captured by ubiquitous sensors such as smartphones and wearable devices, therefore, we tackle to create common and individual model for subjective time based on the sensor data. We report our first prototype implementation for the framework based on AWARE framework with adding experience sampling method for subjective time recognition. In addition, we discuss potential applications which leveraging advantages of subjective time as context.}, keywords = {context-awareness, experience sampling method, subjective time}, pubstate = {published}, tppubtype = {inproceedings} } We propose an integrated framework for sensing, recognizing and utilizing of subjective time as context. Various studies on experimental psychology have showed several factors which affects subjective time. Those factors should be partially captured by ubiquitous sensors such as smartphones and wearable devices, therefore, we tackle to create common and individual model for subjective time based on the sensor data. We report our first prototype implementation for the framework based on AWARE framework with adding experience sampling method for subjective time recognition. In addition, we discuss potential applications which leveraging advantages of subjective time as context. |
| 37. | Yuichi Nakamura, Masaki Ito, Kaoru Sezaki Mobility Control of Mobile Sensing for Time-Varying Parameter Inproceedings In: Proceedings of the 20th International Workshop on Mobile Computing Systems and Applications, pp. 159, Association for Computing Machinery, Santa Cruz, CA, USA, 2019, ISBN: 9781450362733. BibTeX | タグ: active sensing, kriging, Mobile sensing, sensor networks | Links: @inproceedings{10.1145/3301293.3309553, title = {Mobility Control of Mobile Sensing for Time-Varying Parameter}, author = {Yuichi Nakamura and Masaki Ito and Kaoru Sezaki}, url = {https://doi.org/10.1145/3301293.3309553}, doi = {10.1145/3301293.3309553}, isbn = {9781450362733}, year = {2019}, date = {2019-01-01}, booktitle = {Proceedings of the 20th International Workshop on Mobile Computing Systems and Applications}, pages = {159}, publisher = {Association for Computing Machinery}, address = {Santa Cruz, CA, USA}, series = {HotMobile ’19}, keywords = {active sensing, kriging, Mobile sensing, sensor networks}, pubstate = {published}, tppubtype = {inproceedings} } |
| 38. | Elina Kuosmanen, Valerii Kan, Julio Vega, Aku Visuri, Yuuki Nishiyama, Anind K Dey, Simon Harper, Denzil Ferreira Challenges of Parkinson’s Disease: User Experiences with STOP Inproceedings In: Proceedings of the 21st International Conference on Human-Computer Interaction with Mobile Devices and Services, Association for Computing Machinery, Taipei, Taiwan, 2019, ISBN: 9781450368254. Abstract | BibTeX | タグ: empirical evaluation, logging, Parkinson’s disease, smartphone | Links: @inproceedings{10.1145/3338286.3340133, title = {Challenges of Parkinson’s Disease: User Experiences with STOP}, author = {Elina Kuosmanen and Valerii Kan and Julio Vega and Aku Visuri and Yuuki Nishiyama and Anind K Dey and Simon Harper and Denzil Ferreira}, url = {https://doi.org/10.1145/3338286.3340133}, doi = {10.1145/3338286.3340133}, isbn = {9781450368254}, year = {2019}, date = {2019-01-01}, booktitle = {Proceedings of the 21st International Conference on Human-Computer Interaction with Mobile Devices and Services}, publisher = {Association for Computing Machinery}, address = {Taipei, Taiwan}, series = {MobileHCI ’19}, abstract = {Parkinson's disease (PD) is the second most common neurodegenerative disorder, impacting an estimated seven to ten million people worldwide. Measuring the symptoms and progress of the disease, and medication effectiveness is currently performed using subjective measures and visual estimation. We developed and evaluated a mobile application, STOP for tracking hand's motor symptoms, and a medication journal for recording medication intake. We followed 13 PD patients from two countries for a 1-month long real-world deployment. We found that PD patients are willing to use digital tools, such as STOP, to track their medication intake and symptoms, and are also willing to share such data with their caregivers and medical personnel to improve their own care.}, keywords = {empirical evaluation, logging, Parkinson’s disease, smartphone}, pubstate = {published}, tppubtype = {inproceedings} } Parkinson's disease (PD) is the second most common neurodegenerative disorder, impacting an estimated seven to ten million people worldwide. Measuring the symptoms and progress of the disease, and medication effectiveness is currently performed using subjective measures and visual estimation. We developed and evaluated a mobile application, STOP for tracking hand's motor symptoms, and a medication journal for recording medication intake. We followed 13 PD patients from two countries for a 1-month long real-world deployment. We found that PD patients are willing to use digital tools, such as STOP, to track their medication intake and symptoms, and are also willing to share such data with their caregivers and medical personnel to improve their own care. |
| 39. | Chenwei Song, Masaki Ito, Kaoru Sezaki Crowd Information System Utilizing Smartphone Bluetooth Inproceedings In: The Institute of Electronics, Information and Communication Engineers, 2019. BibTeX | タグ: @inproceedings{Song2019-kl, title = {Crowd Information System Utilizing Smartphone Bluetooth}, author = {Chenwei Song and Masaki Ito and Kaoru Sezaki}, year = {2019}, date = {2019-01-01}, journal = {IEICE Conferences Archives}, publisher = {The Institute of Electronics, Information and Communication Engineers}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
| 40. | Shota Ono, Taku Yamazaki, Takumi Miyoshi, Kaoru Sezaki Location-based Flooding Area Restriction for Mobile-assisted Ad Hoc Networks Inproceedings In: 2019 20th Asia-Pacific Network Operations and Management Symposium, Institute of Electrical and Electronics Engineers Inc., 2019, (20th Asia-Pacific Network Operations and Management Symposium, APNOMS 2019 ; Conference date: 18-09-2019 Through 20-09-2019). Abstract | BibTeX | タグ: Mobile ad hoc networks, Receivers, Relays, Routing protocols, Servers, Topology | Links: @inproceedings{7561f51ea85a49728fc32d70873932fe, title = {Location-based Flooding Area Restriction for Mobile-assisted Ad Hoc Networks}, author = {Shota Ono and Taku Yamazaki and Takumi Miyoshi and Kaoru Sezaki}, doi = {10.23919/APNOMS.2019.8892856}, year = {2019}, date = {2019-01-01}, booktitle = {2019 20th Asia-Pacific Network Operations and Management Symposium}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, series = {2019 20th Asia-Pacific Network Operations and Management Symposium: Management in a Cyber-Physical World, APNOMS 2019}, abstract = {In mobile ad hoc networks, radio interference and mobility of nodes may degrade the packet arrival rate due to the dynamic topological change. Then, traditional reactive routing protocols may cause huge network resource consumption due to the route request flooding for discovering the destination. To solve the above issue, flooding area restriction methods can reduce the unnecessary control messages to narrow the flooding area based on the location information. However, each node must share location information before sending route requests via control messages. Besides, it is also difficult to share the correct location information of nodes due to the mobility of nodes. This paper proposes a flooding area restriction method to reduce the unnecessary control messages to determine the flooding area by sharing the location information via a mobile network. In addition, computer simulations reveal the effectiveness of the proposed method in comparison with a traditional routing protocol.}, note = {20th Asia-Pacific Network Operations and Management Symposium, APNOMS 2019 ; Conference date: 18-09-2019 Through 20-09-2019}, keywords = {Mobile ad hoc networks, Receivers, Relays, Routing protocols, Servers, Topology}, pubstate = {published}, tppubtype = {inproceedings} } In mobile ad hoc networks, radio interference and mobility of nodes may degrade the packet arrival rate due to the dynamic topological change. Then, traditional reactive routing protocols may cause huge network resource consumption due to the route request flooding for discovering the destination. To solve the above issue, flooding area restriction methods can reduce the unnecessary control messages to narrow the flooding area based on the location information. However, each node must share location information before sending route requests via control messages. Besides, it is also difficult to share the correct location information of nodes due to the mobility of nodes. This paper proposes a flooding area restriction method to reduce the unnecessary control messages to determine the flooding area by sharing the location information via a mobile network. In addition, computer simulations reveal the effectiveness of the proposed method in comparison with a traditional routing protocol. |
Technical Reports |
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| 41. | 中村裕一, 伊藤昌毅, 瀬崎薫 時間変化する環境情報に対する内挿の信頼度を用いたセンサーノードの配置決定 Technical Report 東京大学生産技術研究所, 東京大学生産技術研究所, 東京大学空間情報科学研究センター／東京大学生産技術研究所 (11), 2019, ISSN: 2188-8698. Abstract | BibTeX | タグ: | Links: @techreport{weko_194609_1, title = {時間変化する環境情報に対する内挿の信頼度を用いたセンサーノードの配置決定}, author = {中村裕一 and 伊藤昌毅 and 瀬崎薫 }, url = {http://id.nii.ac.jp/1001/00194520/}, issn = {2188-8698}, year = {2019}, date = {2019-02-25}, number = {11}, institution = {東京大学生産技術研究所, 東京大学生産技術研究所, 東京大学空間情報科学研究センター／東京大学生産技術研究所}, abstract = {近年スマートフォンの普及に見られるように半導体技術が進歩しており，参加型センシングをはじめとするセンシングシステムの活用に注目が集まっている．しかし，各ノードが動くような系において最適な測定を可能にするようなセンサの配置決定について，確立した方法は少ない．そこで本研究では，センサーノードでの測定データを空間的に内挿しながら，各点における内挿の信頼度を計算しそれをもとに次回の測定でのセンサーの配置を決定する方法を提案する．本稿では，実際に時間変化するスカラー場を作りその上でのセンサーノードたちの挙動をシミュレーションし，提案手法でのノードの配置決定が有用かを検討する． As the semiconductor technology advances, which can be seen in the recent spread of smart-phones, sensing system including participatory sensing has attracted great attention these days. However, there is few established ways of such a determination of positioning of sensor nodes that enables the optimal measurement with regard to the confidence of interpolation. This study proposes a method to determine the optimal positioning of sensor nodes after sets of measurement at each point, by using the result of interpolation of that set of measurement. In this paper, we will show whether that method is valid by simulating a time-varying scaler field and sensor nodes on it.}, keywords = {}, pubstate = {published}, tppubtype = {techreport} } 近年スマートフォンの普及に見られるように半導体技術が進歩しており，参加型センシングをはじめとするセンシングシステムの活用に注目が集まっている．しかし，各ノードが動くような系において最適な測定を可能にするようなセンサの配置決定について，確立した方法は少ない．そこで本研究では，センサーノードでの測定データを空間的に内挿しながら，各点における内挿の信頼度を計算しそれをもとに次回の測定でのセンサーの配置を決定する方法を提案する．本稿では，実際に時間変化するスカラー場を作りその上でのセンサーノードたちの挙動をシミュレーションし，提案手法でのノードの配置決定が有用かを検討する． As the semiconductor technology advances, which can be seen in the recent spread of smart-phones, sensing system including participatory sensing has attracted great attention these days. However, there is few established ways of such a determination of positioning of sensor nodes that enables the optimal measurement with regard to the confidence of interpolation. This study proposes a method to determine the optimal positioning of sensor nodes after sets of measurement at each point, by using the result of interpolation of that set of measurement. In this paper, we will show whether that method is valid by simulating a time-varying scaler field and sensor nodes on it. |
2018 |
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Journal Articles |
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| 42. | Shunsuke Aoki, Kaoru Sezaki, Nicholas Jing Yuan, Xing Xie BusBeat: Early Event Detection with Real-Time Bus GPS Trajectories Journal Article In: IEEE Transactions on Big Data, pp. 1-1, 2018, ISSN: 2372-2096. Abstract | BibTeX | タグ: Event detection, GPS trajectory, Location knowledge, Smart city, Spatial data mining, Urban computing | Links: @article{8476163, title = {BusBeat: Early Event Detection with Real-Time Bus GPS Trajectories}, author = {Shunsuke Aoki and Kaoru Sezaki and Nicholas Jing Yuan and Xing Xie}, doi = {10.1109/TBDATA.2018.2872532}, issn = {2372-2096}, year = {2018}, date = {2018-09-28}, journal = {IEEE Transactions on Big Data}, pages = {1-1}, abstract = {Large-scale events attracting many participants might have a strong negative impact on productivity, mobility, comfort, and safety. Within the few years, serious accidents led by congestion have occurred multiple times, especially during sports events, religious ceremonies, festivals, and so on.To alleviate these serious accidents, predicting the occurrence of a large-scale event is much significant. In fact, when we know an event occurrence in advance, some of those who are not interested in the event might change their plans and/or might take a detour to avoid to get involved in a heavy congestion. In this paper, we present an early event detection technique named BusBeat. BusBeat uses GPS trajectory data collected from periodic-cars, that are vehicles periodically traveling on a pre-scheduled route with a pre-determined departure time, such as a transit bus, shuttle, garbage truck, or municipal patrol car. In addition, BusBeat uses Time-dependent Congestion Network to detect geo-spatial events. BusBeat achieves early event detection without incurring any privacy invasion, by using the continuous trajectories of periodic-cars, that provide the real-time traffic flow and speed. We evaluate our BusBeat using over 7,000-bus data collected in Beijing for 5 months and compare with the check-in data collected from a social network service.}, keywords = {Event detection, GPS trajectory, Location knowledge, Smart city, Spatial data mining, Urban computing}, pubstate = {published}, tppubtype = {article} } Large-scale events attracting many participants might have a strong negative impact on productivity, mobility, comfort, and safety. Within the few years, serious accidents led by congestion have occurred multiple times, especially during sports events, religious ceremonies, festivals, and so on.To alleviate these serious accidents, predicting the occurrence of a large-scale event is much significant. In fact, when we know an event occurrence in advance, some of those who are not interested in the event might change their plans and/or might take a detour to avoid to get involved in a heavy congestion. In this paper, we present an early event detection technique named BusBeat. BusBeat uses GPS trajectory data collected from periodic-cars, that are vehicles periodically traveling on a pre-scheduled route with a pre-determined departure time, such as a transit bus, shuttle, garbage truck, or municipal patrol car. In addition, BusBeat uses Time-dependent Congestion Network to detect geo-spatial events. BusBeat achieves early event detection without incurring any privacy invasion, by using the continuous trajectories of periodic-cars, that provide the real-time traffic flow and speed. We evaluate our BusBeat using over 7,000-bus data collected in Beijing for 5 months and compare with the check-in data collected from a social network service. |
| 43. | Yu Nakayama, Kaoru Sezaki Per-Flow Throughput fairness in ring aggregation network with multiple edge routers Journal Article Open Access In: Big Data and Cognitive Computing, 2 (3), pp. 17, 2018. Abstract | BibTeX | タグ: | Links: @article{nakayama2018per, title = {Per-Flow Throughput fairness in ring aggregation network with multiple edge routers}, author = {Yu Nakayama and Kaoru Sezaki}, url = {https://doi.org/10.3390/bdcc2030017}, doi = {10.3390/bdcc2030017}, year = {2018}, date = {2018-07-18}, journal = {Big Data and Cognitive Computing}, volume = {2}, number = {3}, pages = {17}, publisher = {Multidisciplinary Digital Publishing Institute}, abstract = {Ring aggregation networks are often employed by network carriers because of their efficiency and high fault tolerance. A fairness scheme is required in ring aggregation to achieve per-flow throughput fairness and bufferbloat avoidance, because frames are forwarded along multiple ring nodes. N Rate N + 1 Color Marking (NRN + 1CM) was proposed to achieve fairness in ring aggregation networks consisting of Layer-2 Switches (SWs). With NRN + 1CM, frames are selectively discarded based on color and the frame-dropping threshold. To avoid the accumulation of a queuing delay, frames are discarded at upstream nodes in advance through the notification process for the frame-dropping threshold. However, in the previous works, NRN + 1CM was assumed to be employed in a logical daisy chain topology linked to one Edge Router (ER). The currently available threshold notification process of NRN + 1CM cannot be employed for ring networks with multiple ERs. Therefore, this paper proposes a method for applying NRN + 1CM to a ring aggregation network with multiple ERs. With the proposed algorithm, an SW dynamically selects the dropping threshold to send in order to avoid excess frame discarding. The performance of the proposed scheme was confirmed through computer simulations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Ring aggregation networks are often employed by network carriers because of their efficiency and high fault tolerance. A fairness scheme is required in ring aggregation to achieve per-flow throughput fairness and bufferbloat avoidance, because frames are forwarded along multiple ring nodes. N Rate N + 1 Color Marking (NRN + 1CM) was proposed to achieve fairness in ring aggregation networks consisting of Layer-2 Switches (SWs). With NRN + 1CM, frames are selectively discarded based on color and the frame-dropping threshold. To avoid the accumulation of a queuing delay, frames are discarded at upstream nodes in advance through the notification process for the frame-dropping threshold. However, in the previous works, NRN + 1CM was assumed to be employed in a logical daisy chain topology linked to one Edge Router (ER). The currently available threshold notification process of NRN + 1CM cannot be employed for ring networks with multiple ERs. Therefore, this paper proposes a method for applying NRN + 1CM to a ring aggregation network with multiple ERs. With the proposed algorithm, an SW dynamically selects the dropping threshold to send in order to avoid excess frame discarding. The performance of the proposed scheme was confirmed through computer simulations. |
| 44. | Yu Nakayama, Kazuki Maruta, Takuya Tsutsumi, Kaoru Sezaki Optically Backhauled Moving Network for Local Trains: Architecture and Scheduling Journal Article Open Access In: IEEE Access, 6 , pp. 31023-31036, 2018, ISSN: 2169-3536. Abstract | BibTeX | タグ: Communication networks, mobile communication, optical fiber networks | Links: @article{8374407, title = {Optically Backhauled Moving Network for Local Trains: Architecture and Scheduling}, author = {Yu Nakayama and Kazuki Maruta and Takuya Tsutsumi and Kaoru Sezaki}, doi = {10.1109/ACCESS.2018.2844865}, issn = {2169-3536}, year = {2018}, date = {2018-06-07}, journal = {IEEE Access}, volume = {6}, pages = {31023-31036}, publisher = {IEEE}, abstract = {The concept of moving cell in cellular systems has been discussed for 5G group mobility where rapidly moving platforms such as trains carry a large number of user terminals. It has been considered to employ wireless backhaul for moving cell, the problem of which is its limited and unstable bandwidth. To realize high bandwidth with wireless backhaul, a large number of base stations (BSs) are required along the railway. Therefore, this paper proposes the concept of optically backhauled moving network (OBMN) for local trains to efficiently provide backhaul links for local trains. In the OBMN, an autonomous BS (ABS) is set on the top of a train and is connected to a gateway via optical backhaul. While the user terminals onboard move, the ABS set on the train always satisfies the moving demands through high-bandwidth optical backhaul. The effectiveness of the proposed architecture and scheduling was confirmed by examining two case studies in the suburban and urban areas in Tokyo. The number of required BSs and deployment cost are reduced by half with the proposed OBMN compared with the existing static deployment.}, keywords = {Communication networks, mobile communication, optical fiber networks}, pubstate = {published}, tppubtype = {article} } The concept of moving cell in cellular systems has been discussed for 5G group mobility where rapidly moving platforms such as trains carry a large number of user terminals. It has been considered to employ wireless backhaul for moving cell, the problem of which is its limited and unstable bandwidth. To realize high bandwidth with wireless backhaul, a large number of base stations (BSs) are required along the railway. Therefore, this paper proposes the concept of optically backhauled moving network (OBMN) for local trains to efficiently provide backhaul links for local trains. In the OBMN, an autonomous BS (ABS) is set on the top of a train and is connected to a gateway via optical backhaul. While the user terminals onboard move, the ABS set on the train always satisfies the moving demands through high-bandwidth optical backhaul. The effectiveness of the proposed architecture and scheduling was confirmed by examining two case studies in the suburban and urban areas in Tokyo. The number of required BSs and deployment cost are reduced by half with the proposed OBMN compared with the existing static deployment. |
| 45. | 日向慧, 伊藤昌毅, 岩井将行, 瀬崎薫 スマートフォンの気圧センサを用いた地下鉄での位置推定手法 Journal Article Open Access In: 電子情報通信学会論文誌 B, 101 (5), pp. 347–356, 2018. Abstract | BibTeX | タグ: スマートフォン, 位置推定, 地下鉄, 気圧 | Links: @article{日向慧2018スマートフォンの気圧センサを用いた地下鉄での位置推定手法, title = {スマートフォンの気圧センサを用いた地下鉄での位置推定手法}, author = {日向慧 and 伊藤昌毅 and 岩井将行 and 瀬崎薫}, url = {http://220.110.251.211/bin/pdf_link.php?category=B&lang=J&year=2018&fname=j101-b_5_347&abst=}, year = {2018}, date = {2018-05-01}, journal = {電子情報通信学会論文誌 B}, volume = {101}, number = {5}, pages = {347--356}, publisher = {The Institute of Electronics, Information and Communication Engineers}, abstract = {近年，走行中の地下鉄でもインターネットが利用できるようになり，乗客は常に最新の情報を取得できるようになった．電車の位置情報と組み合わせることで，乗客により便利なサービスの提供が可能となるが，位置の取得方法が課題となっている．地下鉄ではGPSやWi-Fiを用いた正確な位置の取得が不可能であり，全車両に装置を設置する方法は費用などの問題で現実的ではない．そこで，乗客のもつスマートフォンに搭載された様々なセンサを用いることで，電車の移動状態（走行中か停車中か）や位置を推定する研究が行われている．本研究では，スマートフォンに搭載された気圧センサのみを用いて，計測した気圧の変化から電車の移動状態と，停車判定時の気圧から求めた標高から最後の停車駅を推定することで，電車が現在どの駅または駅間にいるのかを推定する．これにより，乗客の現在地にもとづいた情報を提供するようなサービスの開発が可能になる．}, keywords = {スマートフォン, 位置推定, 地下鉄, 気圧}, pubstate = {published}, tppubtype = {article} } 近年，走行中の地下鉄でもインターネットが利用できるようになり，乗客は常に最新の情報を取得できるようになった．電車の位置情報と組み合わせることで，乗客により便利なサービスの提供が可能となるが，位置の取得方法が課題となっている．地下鉄ではGPSやWi-Fiを用いた正確な位置の取得が不可能であり，全車両に装置を設置する方法は費用などの問題で現実的ではない．そこで，乗客のもつスマートフォンに搭載された様々なセンサを用いることで，電車の移動状態（走行中か停車中か）や位置を推定する研究が行われている．本研究では，スマートフォンに搭載された気圧センサのみを用いて，計測した気圧の変化から電車の移動状態と，停車判定時の気圧から求めた標高から最後の停車駅を推定することで，電車が現在どの駅または駅間にいるのかを推定する．これにより，乗客の現在地にもとづいた情報を提供するようなサービスの開発が可能になる． |
| 46. | 近藤亮磨, 伊藤昌毅, 小林亘, 岩井将行, 森川博之 大規模ストリーミング雨量レーダデータの柔軟な高速アクセスを実現する Web データベースシステム Journal Article In: 電子情報通信学会論文誌 D, 101 (4), pp. 669–680, 2018, ISSN: 1881-0225. Abstract | BibTeX | タグ: Webデータベース, アクセス, ストリーミング, レーダ, 大規模, 雨量 | Links: @article{近藤亮磨2018大規模ストリーミング雨量レーダデータの柔軟な高速アクセスを実現する, title = {大規模ストリーミング雨量レーダデータの柔軟な高速アクセスを実現する Web データベースシステム}, author = {近藤亮磨 and 伊藤昌毅 and 小林亘 and 岩井将行 and 森川博之}, url = {https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201802248698273772}, issn = {1881-0225}, year = {2018}, date = {2018-04-01}, journal = {電子情報通信学会論文誌 D}, volume = {101}, number = {4}, pages = {669--680}, publisher = {The Institute of Electronics, Information and Communication Engineers}, abstract = {日本各地に配備され,250mメッシュ・1分ごとに雨量を観測するレーダネットワークから得られるリアルタイムの雨量情報は,広範囲な流出解析や気象解析だけでなく,局地的な降雨情報を抽出することで身近な生活をより快適で安全にするために役立てられる。例えば,道路冠水予測,屋外イベントの中止の案内,洗濯物の取り入れのタイミングだけでなく,降雨量を考慮したルートによるナビゲーションや車での送迎の提案などを,スマートフォンを通して個人に通知をするようなアプリへの期待は高まっている。更にレーダから得られる降雨量は,積算することで近年特に求められている局地的な都市部での内水氾濫対策など市町村レベルの都市防災への活用も期待されている。こういった広域の雨量情報を必要としない場合においても,現在の雨量レーダデータは関東全域など広域がまとめられたバイナリ形式か降雨量が地図化された画像形式にて一括で一方的にストリーミングデータとして受け取ることしかできない。このようなユーザが必要としていない範囲を含む広範囲なデータ配信方法は,身近な活用においては受信側のデータ処理や解釈をより煩雑としてしまう。局地的な雨量情報を用いたマッシュアップや個人個人のニーズに応える多様なアプリの実現を促進するためには,ユーザが必要とする範囲の雨量データを切り出し提供するWeb APIと,その基盤となる膨大なストリーミングデータを高速かつ柔軟に処理できるデータベースシステムが必要である。そこで我々は,ストリーミングデータの高速なストア処理を実現しつつ,クエリを複数矩形の組み合わせで表現することで様々な地理形状での範囲取得を実現するXRAIN WebDBシステムをアレーデータベースを応用して開発した。本論文では更に,マッシュアップにより容易なウェブ上でのデータ活用を目指すWeb APIを提案する。本XRAIN WebDBシステムの評価として,実際のXバンドMP雨量レーダのデータを用いて評価を行い,提案システムが局地的な範囲での雨量レーダの活用において有用であることを示す。}, keywords = {Webデータベース, アクセス, ストリーミング, レーダ, 大規模, 雨量}, pubstate = {published}, tppubtype = {article} } 日本各地に配備され,250mメッシュ・1分ごとに雨量を観測するレーダネットワークから得られるリアルタイムの雨量情報は,広範囲な流出解析や気象解析だけでなく,局地的な降雨情報を抽出することで身近な生活をより快適で安全にするために役立てられる。例えば,道路冠水予測,屋外イベントの中止の案内,洗濯物の取り入れのタイミングだけでなく,降雨量を考慮したルートによるナビゲーションや車での送迎の提案などを,スマートフォンを通して個人に通知をするようなアプリへの期待は高まっている。更にレーダから得られる降雨量は,積算することで近年特に求められている局地的な都市部での内水氾濫対策など市町村レベルの都市防災への活用も期待されている。こういった広域の雨量情報を必要としない場合においても,現在の雨量レーダデータは関東全域など広域がまとめられたバイナリ形式か降雨量が地図化された画像形式にて一括で一方的にストリーミングデータとして受け取ることしかできない。このようなユーザが必要としていない範囲を含む広範囲なデータ配信方法は,身近な活用においては受信側のデータ処理や解釈をより煩雑としてしまう。局地的な雨量情報を用いたマッシュアップや個人個人のニーズに応える多様なアプリの実現を促進するためには,ユーザが必要とする範囲の雨量データを切り出し提供するWeb APIと,その基盤となる膨大なストリーミングデータを高速かつ柔軟に処理できるデータベースシステムが必要である。そこで我々は,ストリーミングデータの高速なストア処理を実現しつつ,クエリを複数矩形の組み合わせで表現することで様々な地理形状での範囲取得を実現するXRAIN WebDBシステムをアレーデータベースを応用して開発した。本論文では更に,マッシュアップにより容易なウェブ上でのデータ活用を目指すWeb APIを提案する。本XRAIN WebDBシステムの評価として,実際のXバンドMP雨量レーダのデータを用いて評価を行い,提案システムが局地的な範囲での雨量レーダの活用において有用であることを示す。 |
| 47. | Tomoya Kitazato, Miku Hoshino, Masaki Ito, Kaoru Sezaki Detection of Pedestrian Flow Using Mobile Devices for Evacuation Guiding in Disaster Journal Article Open Access In: Journal of Disaster Research, 13 (2), pp. 303-312, 2018. Abstract | BibTeX | タグ: crowd sensing, evacuation guidance, Mobile sensing | Links: @article{articleb, title = {Detection of Pedestrian Flow Using Mobile Devices for Evacuation Guiding in Disaster}, author = {Tomoya Kitazato and Miku Hoshino and Masaki Ito and Kaoru Sezaki}, url = {https://www.jstage.jst.go.jp/article/jdr/13/2/13_303/_article/-char/ja}, doi = {10.20965/jdr.2018.p0303}, year = {2018}, date = {2018-03-20}, journal = {Journal of Disaster Research}, volume = {13}, number = {2}, pages = {303-312}, abstract = {In March 2011, the Great East Japan Earthquake occurred, killing approximately 20,000 people. Previous research has shown that evacuation start time and evacuation behavior are related to the disaster survival rate: immediate evacuation increases the survival rate and evacuation-disruption caused by traffic congestion decreases it. Therefore, it can be assumed that guiding people to safe locations will increase the survival rate. The detection of the human mobility flow is a key to rescuing more people, because its analysis can help determine the appropriate evacuation routes toward which people should be guided. The objective of our research is to develop a system for detecting the human mobility flows in a disaster scenario. We analyzed the requirements of human mobility flow detection for disaster evacuation guidance. In this paper, we propose a crowd sensing system that uses Bluetooth for recognizing human mobility flows. By detecting Bluetooth devices carried by pedestrians, the congestion degree can be estimated. Further, the devices’ movements can be detected by observing the received signal strength indicator (RSSI) of Bluetooth Low Energy (LE) beacons carried by pedestrians. The results of experimental evaluations of these two methods verify their usefulness. Our methods can estimate the congestion degree, as well as the velocity of walking pedestrians.}, keywords = {crowd sensing, evacuation guidance, Mobile sensing}, pubstate = {published}, tppubtype = {article} } In March 2011, the Great East Japan Earthquake occurred, killing approximately 20,000 people. Previous research has shown that evacuation start time and evacuation behavior are related to the disaster survival rate: immediate evacuation increases the survival rate and evacuation-disruption caused by traffic congestion decreases it. Therefore, it can be assumed that guiding people to safe locations will increase the survival rate. The detection of the human mobility flow is a key to rescuing more people, because its analysis can help determine the appropriate evacuation routes toward which people should be guided. The objective of our research is to develop a system for detecting the human mobility flows in a disaster scenario. We analyzed the requirements of human mobility flow detection for disaster evacuation guidance. In this paper, we propose a crowd sensing system that uses Bluetooth for recognizing human mobility flows. By detecting Bluetooth devices carried by pedestrians, the congestion degree can be estimated. Further, the devices’ movements can be detected by observing the received signal strength indicator (RSSI) of Bluetooth Low Energy (LE) beacons carried by pedestrians. The results of experimental evaluations of these two methods verify their usefulness. Our methods can estimate the congestion degree, as well as the velocity of walking pedestrians. |
| 48. | Kazuhiko W Nakamura, Ryuichi Watanabe, Akio Fujiwara, Kaoru Saito, Hill Hiroki Kobayashi, Kaoru Sezaki Plant Phenology Observation by Students Using Time-Lapse Images: Creation of the Environment and Examination of Its Adequacy Journal Article Open Access In: Environments, 5 (1), pp. 7, 2018. Abstract | BibTeX | タグ: climate change, Cyberforest, environmental education, phenology | Links: @article{nakamura2018plant, title = {Plant Phenology Observation by Students Using Time-Lapse Images: Creation of the Environment and Examination of Its Adequacy}, author = {Kazuhiko W Nakamura and Ryuichi Watanabe and Akio Fujiwara and Kaoru Saito and Hill Hiroki Kobayashi and Kaoru Sezaki}, url = {https://doi.org/10.3390/environments5010007}, doi = {10.3390/environments5010007}, year = {2018}, date = {2018-01-02}, journal = {Environments}, volume = {5}, number = {1}, pages = {7}, publisher = {Multidisciplinary Digital Publishing Institute}, abstract = {For environmental education about climate change issues, selecting events that are already encountered by people as teaching materials is considered effective. Consideration of changes in leafing dates over time provides a useful tool, in particular when children themselves observe plant phenology, which can be achieved using time-lapse imagery. We postulated that creating an environment where this process can be conducted at school would give children a readiness of behavior toward resolution of climate change issues. Verification of how adequately children can undertake the observations is key to establishing the methodology’s effectiveness. In this research, we used time-lapse images from Shiga Heights, Nagano prefecture, Japan, that were taken once per day from 1987 to 2004; in each year from this series, we used the images taken from 27 May to 15 June, inclusive, as these were the dates during which leafing was expected. We created observation sheets and made these and the time-lapse images available for students on the Internet. As a result of our analysis of observations made by 543 students using the observation sheets, we determined that the method had sufficient adequacy for education. }, keywords = {climate change, Cyberforest, environmental education, phenology}, pubstate = {published}, tppubtype = {article} } For environmental education about climate change issues, selecting events that are already encountered by people as teaching materials is considered effective. Consideration of changes in leafing dates over time provides a useful tool, in particular when children themselves observe plant phenology, which can be achieved using time-lapse imagery. We postulated that creating an environment where this process can be conducted at school would give children a readiness of behavior toward resolution of climate change issues. Verification of how adequately children can undertake the observations is key to establishing the methodology’s effectiveness. In this research, we used time-lapse images from Shiga Heights, Nagano prefecture, Japan, that were taken once per day from 1987 to 2004; in each year from this series, we used the images taken from 27 May to 15 June, inclusive, as these were the dates during which leafing was expected. We created observation sheets and made these and the time-lapse images available for students on the Internet. As a result of our analysis of observations made by 543 students using the observation sheets, we determined that the method had sufficient adequacy for education. |
| 49. | Hill Hiroki Kobayashi, Keijiro Nakagawa, Ko Makiyama, Yuta Sasaki, Hiromi Kudo, Baburam Niraula, Kaoru Sezaki Animal-to-Animal Data Sharing Mechanism for Wildlife Monitoring in Fukushima Exclusion Zone Journal Article Open Access In: Multimodal Technologies and Interaction, 2 (3), pp. 40, 2018, ISSN: 2414-4088. Abstract | BibTeX | タグ: nature conservation, sensor networks, wearable interfaces | Links: @article{kobayashi2018animal, title = {Animal-to-Animal Data Sharing Mechanism for Wildlife Monitoring in Fukushima Exclusion Zone}, author = {Hill Hiroki Kobayashi and Keijiro Nakagawa and Ko Makiyama and Yuta Sasaki and Hiromi Kudo and Baburam Niraula and Kaoru Sezaki}, url = {https://www.mdpi.com/2414-4088/2/3/40}, doi = {10.3390/mti2030040}, issn = {2414-4088}, year = {2018}, date = {2018-01-01}, journal = {Multimodal Technologies and Interaction}, volume = {2}, number = {3}, pages = {40}, publisher = {Multidisciplinary Digital Publishing Institute}, abstract = {We propose an animal-to-animal data sharing mechanism that employs wildlife-borne sensing devices to expand the size of monitoring areas in which electricity, information, and road infrastructures are either limited or nonexistent. With the proposed approach, monitoring information can be collected from remote areas in a safe and cost-effective manner. To substantially prolong the life of a sensor node, the proposed mechanism activates the communication capabilities only when there is a plurality of animals; otherwise, the sensor node remains in a sleep state. This study aimed to achieve three objectives. First, we intend to obtain knowledge based on the actual field operations within the Fukushima exclusion zone. Second, we attempt to realize an objective evaluation of the power supply and work base that is required to properly evaluate the proposed mechanism. Third, we intend to acquire data to support wildlife research, which is the objective of both our present (and future) research.}, keywords = {nature conservation, sensor networks, wearable interfaces}, pubstate = {published}, tppubtype = {article} } We propose an animal-to-animal data sharing mechanism that employs wildlife-borne sensing devices to expand the size of monitoring areas in which electricity, information, and road infrastructures are either limited or nonexistent. With the proposed approach, monitoring information can be collected from remote areas in a safe and cost-effective manner. To substantially prolong the life of a sensor node, the proposed mechanism activates the communication capabilities only when there is a plurality of animals; otherwise, the sensor node remains in a sleep state. This study aimed to achieve three objectives. First, we intend to obtain knowledge based on the actual field operations within the Fukushima exclusion zone. Second, we attempt to realize an objective evaluation of the power supply and work base that is required to properly evaluate the proposed mechanism. Third, we intend to acquire data to support wildlife research, which is the objective of both our present (and future) research. |
| 50. | Yu Nakayama, Kaoru Sezaki Requirement Modeling Language for the Dynamic Node Integration Problem of Telecommunication Network Journal Article In: IEICE Transactions on Communications, 101 (6), pp. 1379–1387, 2018. Abstract | BibTeX | タグ: dynamic model, network optimization, networks, requirement | Links: @article{nakayama2018requirement, title = {Requirement Modeling Language for the Dynamic Node Integration Problem of Telecommunication Network}, author = {Yu Nakayama and Kaoru Sezaki}, url = {https://doi.org/10.1587/transcom.2017EBP3248}, doi = {10.1587/transcom.2017EBP3248}, year = {2018}, date = {2018-01-01}, journal = {IEICE Transactions on Communications}, volume = {101}, number = {6}, pages = {1379--1387}, publisher = {The Institute of Electronics, Information and Communication Engineers}, abstract = {Efficiently locating nodes and allocating demand has been a significant problem for telecommunication network carriers. Most of location models focused on where to locate nodes and how to assign increasing demand with optical access networks. However, the population in industrialized countries will decline over the coming decades. Recent advance in the optical amplifier technology has enabled node integration; an excess telecommunication node is closed and integrated to another node. Node integration in low-demand areas will improve the efficiency of access networks in this approaching age of depopulation. A dynamic node integration problem (DNIP) has been developed to organize the optimal plan for node integration. The problem of the DNIP was that it cannot consider the requirements of network carriers. In actual situations, network carriers often want to specify the way each node is managed, regardless of the mathematical optimality of the solution. This paper proposes a requirement modeling language (RML) for the DNIP, with which the requirements of network carriers can be described. The described statements are used to solve the DNIP, and consequently the calculated optimal solution always satisfies the requirements. The validity of the proposed method was evaluated with computer simulations in a case study.}, keywords = {dynamic model, network optimization, networks, requirement}, pubstate = {published}, tppubtype = {article} } Efficiently locating nodes and allocating demand has been a significant problem for telecommunication network carriers. Most of location models focused on where to locate nodes and how to assign increasing demand with optical access networks. However, the population in industrialized countries will decline over the coming decades. Recent advance in the optical amplifier technology has enabled node integration; an excess telecommunication node is closed and integrated to another node. Node integration in low-demand areas will improve the efficiency of access networks in this approaching age of depopulation. A dynamic node integration problem (DNIP) has been developed to organize the optimal plan for node integration. The problem of the DNIP was that it cannot consider the requirements of network carriers. In actual situations, network carriers often want to specify the way each node is managed, regardless of the mathematical optimality of the solution. This paper proposes a requirement modeling language (RML) for the DNIP, with which the requirements of network carriers can be described. The described statements are used to solve the DNIP, and consequently the calculated optimal solution always satisfies the requirements. The validity of the proposed method was evaluated with computer simulations in a case study. |