المؤلفون: Zuo, Tianyu, Tang, Xueyan, Lee, Bu Sung

مصطلحات موضوعية: Computer Science - Data Structures and Algorithms

الوصف: This paper studies an online replication problem for distributed data access. The goal is to dynamically create and delete data copies in a multi-server system as time passes to minimize the total storage and network cost of serving access requests. We study the problem in the emergent learning-augmented setting, assuming simple binary predictions about inter-request times at individual servers. We develop an online algorithm and prove that it is ($\frac{5+\alpha}{3}$)-consistent (competitiveness under perfect predictions) and ($1 + \frac{1}{\alpha}$)-robust (competitiveness under terrible predictions), where $\alpha \in (0, 1]$ is a hyper-parameter representing the level of distrust in the predictions. We also study the impact of mispredictions on the competitive ratio of the proposed algorithm and adapt it to achieve a bounded robustness while retaining its consistency. We further establish a lower bound of $\frac{3}{2}$ on the consistency of any deterministic learning-augmented algorithm. Experimental evaluations are carried out to evaluate our algorithms using real data access traces.
Comment: The formal version of this draft will appear in ACM SPAA'24 conference

الوصول الحر: http://arxiv.org/abs/2404.16489Test

المؤلفون: Schläpfer, Markus, Chew, Hong Jun, Yean, Seanglidet, Lee, Bu-Sung

مصطلحات موضوعية: Electrical Engineering and Systems Science - Systems and Control

الوصف: The vehicle-to-grid (V2G) concept utilises electric vehicles as distributed energy storage and thus may help to balance out the intermittent availability of renewable energy sources such as photovoltaics. V2G is therefore considered to play an important role for achieving low-carbon energy and transportation systems in cities. However, the adequate planning of city-wide V2G infrastructures requires detailed knowledge of the aggregate mobility patterns of individuals and also needs to keep track with ongoing developments of urban transportation modes. Here, we introduce an initial framework that infers population-wide mobility patterns from anonymised mobile phone location data and subsequently superimposes a vehicle charging and discharging scheme. The framework allows for the estimation of the aggregate V2G energy supply and demand at fine-grained spatial and temporal scales under a given electric vehicle usage scenario. This information provides an adequate basis for assessing the role of V2G in the context of maximising the deployment of photovoltaics, as well as for the sizing and placement of the required vehicle (dis)charging infrastructure. The proposed framework is applied to Singapore as a case study.

الوصول الحر: http://arxiv.org/abs/2112.15006Test

المؤلفون: Lwin, May O., Yang, Shanshan, Sheldenkar, Anita, Yang, Xinghao, Lee, Bu Sung Francis

المساهمون: National Medical Research Council, Ministry of Health -Singapore

المصدر: Computers in Human Behavior Reports ; volume 13, page 100361 ; ISSN 2451-9588

مصطلحات موضوعية: Artificial Intelligence, Cognitive Neuroscience, Computer Science Applications, Human-Computer Interaction, Applied Psychology, Neuroscience (miscellaneous)

الإتاحة: https://doi.org/10.1016/j.chbr.2023.100361Test
https://api.elsevier.com/content/article/PII:S2451958823000945?httpAccept=text/xmlTest
https://api.elsevier.com/content/article/PII:S2451958823000945?httpAccept=text/plainTest

المؤلفون: Steentoft, Aike Alexander, Poorthuis, Ate, Lee, Bu-Sung, Schläpfer, Markus

مصطلحات موضوعية: Physics - Physics and Society, Computer Science - Social and Information Networks

الوصف: As cities grow, certain neighborhoods experience a particularly high demand for housing, resulting in escalating rents. Despite far-reaching socioeconomic consequences, it remains difficult to predict when and where urban neighborhoods will face such changes. To tackle this challenge, we adapt the concept of `bioindicators', borrowed from ecology, to the urban context. The objective is to use an `indicator group' of people to assess the quality of a complex environment and its changes over time. Specifically, we analyze 92 million geolocated Twitter records across five US cities, allowing us to derive socio-economic user profiles based on individual movement patterns. As a proof-of-concept, we define users with a `high-income-profile' as an indicator group and show that their visitation patterns are a suitable indicator for expected future rent increases in different neighborhoods. The concept of indicator groups highlights the potential of closely monitoring only a specific subset of the population, rather than the population as a whole. If the indicator group is defined appropriately for the phenomenon of interest, this approach can yield early predictions while simultaneously reducing the amount of data that needs to be collected and analyzed.
Comment: 20 pages, 6 figures

الوصول الحر: http://arxiv.org/abs/1712.08924Test

المؤلفون: Yean, Seanglidet, Goh, Wayne, Lee, Bu-Sung, Oh, Hong Lye

المساهمون: School of Computer Science and Engineering, Singtel Cognitive and Artificial Intelligence Lab (SCALE@NTU)

مصطلحات موضوعية: Engineering::Computer science and engineering, Indoor Localisation, Generative Adversarial Networks

الوصف: For indoor localisation, a challenge in data-driven localisation is to ensure sufficient data to train the prediction model to produce a good accuracy. However, for WiFi-based data collection, human effort is still required to capture a large amount of data as the representation Received Signal Strength (RSS) could easily be affected by obstacles and other factors. In this paper, we propose an extendGAN+ pipeline that leverages up-sampling with the Dirichlet distribution to improve location prediction accuracy with small sample sizes, applies transferred WGAN-GP for synthetic data generation, and ensures data quality with a filtering module. The results highlight the effectiveness of the proposed data augmentation method not only by localisation performance but also showcase the variety of RSS patterns it could produce. Benchmarking against the baseline methods such as fingerprint, random forest, and its base dataset with localisation models, extendGAN+ shows improvements of up to 23.47%, 25.35%, and 18.88% respectively. Furthermore, compared to existing GAN+ methods, it reduces training time by a factor of four due to transfer learning and improves performance by 10.13%. ; Agency for Science, Technology and Research (A*STAR) ; Nanyang Technological University ; Published version ; This research was funded by Singtel Cognitive and Artificial Intelligence Lab for Enterprises (SCALE@NTU), which is a collaboration between Singapore Telecommunications Limited (Singtel) and Nanyang Technological University (NTU) that is supported by A*STAR under its Industry Alignment Fund (LOA Award number: I1701E0013).

وصف الملف: application/pdf

العلاقة: I1701E0013; Sensors; Yean, S., Goh, W., Lee, B. & Oh, H. L. (2023). extendGAN+: transferable data augmentation framework using WGAN-GP for data-driven indoor localisation model. Sensors, 23(9), 4402-. https://dx.doi.org/10.3390/s23094402Test; https://hdl.handle.net/10356/169535Test; 2-s2.0-85159216576; 23; 4402

الإتاحة: https://doi.org/10.3390/s23094402Test
https://hdl.handle.net/10356/169535Test

المؤلفون: Potort, Francesco, Torres-Sospedra, Joaquín, Quezada Gaibor, Darwin, Jiménez, Antonio Ramón, Seco, Fernando, Perez-Navarro, Antoni, Ortiz, Miguel, Zhu, Ni, Renaudin, Valerie, Ichikari, Ryosuke, Shimomura, Ryo, Kaichi, Tomoya, Zhou, Baoding, Liu, Xu, Gu, Zhining, Yang, Chengjing, Wu, Zhiqian, Xie, Doudou, Huang, Can, Zheng, Lingxiang, Peng, Ao, Jin, Ge, Wang, Qu, Luo, Haiyong, Xiong, Hao, Bao, Linfeng, Zhang, Pushuo, Zhao, Fang, Yu, Chia-An, Hung, Chung-Hao, Antsfeld, Leonid, Chidlovskii, Boris, Jiang, Haitao, Xia, Ming, Yan, Dayu, Li, Yuhang, Dong, Yitong, Silva, Ivo, Pendão, Cristiano, Meneses, Filipe, Nicolau, Maria João, Costa, António, Moreira, Adriano, De Cock, Cedric, Plets, David, Opiela, Miroslav, Dzama, Jakub, Zhang, Liqiang, Li, Hu, Chen, Boxuan, Liu, Yu, Yean, Seanglidet, Lim, Bo Zhi, Teo, Wei Jie, Lee, Bu Sung, OH, HL, ohta, nozomu, Nagae, Satsuki, Kurata, Takeshi, dongyan, wei, Ji, Xinchun, Zhang, Wenchao, Kram, Sebastian, Stahlke, Maximilian, Mutschler, Christopher, Crivello, Antonino, Barsocchi, Paolo, GIROLAMI, MICHELE, Palumbo, Filippo, Chen, Ruizhi, Wu, Yuan, Li, Wei, Yu, Yue, Xu, Shihao, Huang, Lixiong, Liu, Tao, Kuang, Jian, Niu, Xiaoji, Yoshida, Takuto, Nagata, Yoshiteru, Fukushima, Yuto, Fukatani, Nobuya, Hayashida, Nozomi, Asai, Yusuke, Urano, Kenta, Ge, Wenfei, Lee, Nien-Ting, Fang, Shih-Hau, Jie, You-Cheng, Young, Shawn-Rong, Chien, Ying-Ren, Yu, Chih-Chieh, Ma, Chengqi, Wu, Bang, Zhang, Wei, Wang, Yankun, Fan, Yonglei, Poslad, Stefan, Selviah, David, Wang, Weixi, Yuan, Hong, Yonamoto, Yoshitomo, Yamaguchi, Masahiro

المساهمون: Universitat Oberta de Catalunya (UOC)

مصطلحات موضوعية: indoor positioning and navigation, evaluation, smartphone-based positioning, foot-mounted IMU, positioning in industrial scenarios and factories, vehicle-positioning, navegación y posicionamiento en interiores, evaluación, posiciónamiento basado en teléfonos inteligentes, IMU con patas, posicionamiento en escenarios industriales y fábricas, posicionamiento del vehículo, navegació i posicionament en interiors, evaluació, posicionament basat en teléfons inteligents, IMU amb cames, posicionament en escenaris industrials i fabriques, posicionament del vehicle, electronics in navigation, electrònica en la navegació, electrónica en la nevagación

الوصف: Every year, for ten years now, the IPIN competition has aimed at evaluating real-world indoor localisation systems by testing them in a realistic environment, with realistic movement, using the EvAAL framework. The competition provided a unique overview of the state-of-the-art of systems, technologies, and methods for indoorpositioning andnavigationpurposes.Throughfaircomparison of the performance achieved by each system, the competition was able to identify the most promising approaches and to pinpoint the most critical working conditions. In 2020, the competition included 5 diverse off-site off-site Tracks, each resembling real use cases and challenges for indoor positioning. The results in terms of participation and accuracy of the proposed systems have been encouraging. The best performing competitors obtained a third quartile of error of 1m for the Smartphone Track and 0.5m for the Footmounted IMU Track. While not running on physical systems, but only as algorithms, these results represent impressive achievements

وصف الملف: application/pdf

العلاقة: IEEE Sensors Journal, 2022, 22(6); https://www.doi.org/10.1109/JSEN.2021.3083149Test; http://hdl.handle.net/10609/147005Test

الإتاحة: https://doi.org/10.1109/JSEN.2021.3083149Test
http://hdl.handle.net/10609/147005Test

المؤلفون: Potorti, Francesco, Torres-Sospedra, Joaquín, Quezada-Gaibor, Darwin, Jimenez, Antonio Ramon, Seco, Fernando, Perez-Navarro, Antoni, Ortiz, Miguel, Zhu, Ni, Renaudin, Valerie, Ichikari, Ryosuke, Shimomura, Ryo, Ohta, Nozomu, Nagae, Satsuki, Kurata, Takeshi, Wei, Dongyan, Ji, Xinchun, Zhang, Wenchao, Kram, Sebastian, Stahlke, Maximilian, Mutschler, Christopher, Crivello, Antonino, Barsocchi, Paolo, Girolami, Michele, Palumbo, Filippo, Chen, Ruizhi, Wu, Yuan, Li, Wei, Yu, Yue, Xu, Shihao, Huang, Lixiong, Liu, Tao, Kuang, Jian, Niu, Xiaoji, Yoshida, Takuto, Nagata, Yoshiteru, Fukushima, Yuto, Fukatani, Nobuya, Hayashida, Nozomi, Asai, Yusuke, Urano, Kenta, Ge, Wenfei, Lee, Nien-Ting, Fang, Shih-Hau, Jie, You-Cheng, Young, Shawn-Rong, Chien, Ying-Ren, Yu, Chih-Chieh, Ma, Chengqi, Wu, Bang, Zhang, Wei, Wang, Yankun, Fan, Yonglei, Poslad, Stefan, Selviah, David R., Wang, Weixi, Yuan, Hong, Yonamoto, Yoshitomo, Yamaguchi, Masahiro, Kaichi, Tomoya, Zhou, Baoding, Liu, Xu, Gu, Zhining, Yang, Chengjing, Wu, Zhiqian, Xie, Doudou, Huang, Can, Zheng, Lingxiang, Peng, Ao, Jin, Ge, Wang, Qu, Luo, Haiyong, Xiong, Hao, Bao, Linfeng, Zhang, Pushuo, Zhao, Fang, Yu, Chia-An, Hung, Chun-Hao, Antsfeld, Leonid, Silva, Ivo Miguel Menezes, Pendão, Cristiano Gonçalves, Meneses, Filipe, Nicolau, Maria João, Costa, António, Moreira, Adriano, Cock, Cedric De, Plets, David, Opiela, Miroslav, Jakub Džama, Zhang, Liqiang, Li, Hu, Chen, Boxuan, Liu, Yu, Yean, Seanglidet, Lim, Bo Zhi, Teo, Wei Jie, Lee, Bu Sung, Oh, Hong Lye

مصطلحات موضوعية: Sensor phenomena and characterization, Indoor navigation, Testing, Standards, Satellite broadcasting, Recurrent neural networks, Received signal strength indicator, Indoor positioning and navigation, evaluation, smartphone-based positioning, foot-mounted IMU, positioning in industrial scenarios and factories, vehicle-positioning, Ciências Naturais::Ciências da Computação e da Informação, Science & Technology

الوصف: Every year, for ten years now, the IPIN competition has aimed at evaluating real-world indoor localisation systems by testing them in a realistic environment, with realistic movement, using the EvAAL framework. The competition provided a unique overview of the state-of-the-art of systems, technologies, and methods for indoor positioning and navigation purposes. Through fair comparison of the performance achieved by each system, the competition was able to identify the most promising approaches and to pinpoint the most critical working conditions. In 2020, the competition included 5 diverse off-site off-site Tracks, each resembling real use cases and challenges for indoor positioning. The results in terms of participation and accuracy of the proposed systems have been encouraging. The best performing competitors obtained a third quartile of error of 1 m for the Smartphone Track and 0.5 m for the Foot-mounted IMU Track. While not running on physical systems, but only as algorithms, these results represent impressive achievements. ; Track 3 organizers were supported by the European Union’s Horizon 2020 Research and Innovation programme under the Marie Skłodowska Curie Grant 813278 (A-WEAR: A network for dynamic WEarable Applications with pRivacy constraints), MICROCEBUS (MICINN, ref. RTI2018-095168-B-C55, MCIU/AEI/FEDER UE), INSIGNIA (MICINN ref. PTQ2018-009981), and REPNIN+ (MICINN, ref. TEC2017-90808-REDT). We would like to thanks the UJI’s Library managers and employees for their support while collecting the required datasets for Track 3. Track 5 organizers were supported by JST-OPERA Program, Japan, under Grant JPMJOP1612. Track 7 organizers were supported by the Bavarian Ministry for Economic Affairs, Infrastructure, Transport and Technology through the Center for Analytics-Data-Applications (ADA-Center) within the framework of “BAYERN DIGITAL II. ” Team UMinho (Track 3) was supported by FCT—Fundação para a Ciência e Tecnologia within the R&D Units Project Scope under Grant UIDB/00319/2020, and the Ph.D. ...

وصف الملف: application/pdf

العلاقة: info:eu-repo/grantAgreement/EC/H2020/813278/EU; info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F00319%2F2020/PT; info:eu-repo/grantAgreement/FCT/POR_NORTE/PD%2FBD%2F137401%2F2018/PT; https://ieeexplore.ieee.org/document/9439493Test; F. Potortì et al., "Off-Line Evaluation of Indoor Positioning Systems in Different Scenarios: The Experiences From IPIN 2020 Competition," in IEEE Sensors Journal, vol. 22, no. 6, pp. 5011-5054, 15 March15, 2022, doi:10.1109/JSEN.2021.3083149.; https://hdl.handle.net/1822/82092Test

الإتاحة: https://doi.org/10.1109/JSEN.2021.3083149Test
https://hdl.handle.net/1822/82092Test

المؤلفون: Lim, Yun Jie, Yean, Seanglidet, Lee, Bu Sung, Edwards, Peter

المصدر: Procedia Computer Science ; volume 201, page 390-397 ; ISSN 1877-0509

مصطلحات موضوعية: General Earth and Planetary Sciences, General Environmental Science

الإتاحة: https://doi.org/10.1016/j.procs.2022.03.052Test
https://api.elsevier.com/content/article/PII:S1877050922004653?httpAccept=text/xmlTest
https://api.elsevier.com/content/article/PII:S1877050922004653?httpAccept=text/plainTest

المؤلفون: Banerjee, Abhik, Agarwal, Rachit, Gauthier, Vincent, Yeo, Chai Kiat, Afifi, Hossam, Lee, Bu Sung

مصطلحات موضوعية: Computer Science - Networking and Internet Architecture

الوصف: Motivated by the benefits of small world networks, we propose a self-organization framework for wireless ad hoc networks. We investigate the use of directional beamforming for creating long-range short cuts between nodes. Using simulation results for randomized beamforming as a guideline, we identify crucial design issues for algorithm design. Our results show that, while significant path length reduction is achievable, this is accompanied by the problem of asymmetric paths between nodes. Subsequently, we propose a distributed algorithm for small world creation that achieves path length reduction while maintaining connectivity. We define a new centrality measure that estimates the structural importance of nodes based on traffic flow in the network, which is used to identify the optimum nodes for beamforming. We show, using simulations, that this leads to significant reduction in path length while maintaining connectivity.
Comment: Submitted to IEEE Transactions on Vehicular Technology

الوصول الحر: http://arxiv.org/abs/1203.1185Test

المؤلفون: Agarwal, Rachit, Banerjee, Abhik, Gauthier, Vincent, Becker, Monique, Yeo, Chai Kiat, Lee, Bu Sung

مصطلحات موضوعية: Computer Science - Networking and Internet Architecture

الوصف: It is highly desirable and challenging for a wireless ad hoc network to have self-organization properties in order to achieve network wide characteristics. Studies have shown that Small World properties, primarily low average path length and high clustering coefficient, are desired properties for networks in general. However, due to the spatial nature of the wireless networks, achieving small world properties remains highly challenging. Studies also show that, wireless ad hoc networks with small world properties show a degree distribution that lies between geometric and power law. In this paper, we show that in a wireless ad hoc network with non-uniform node density with only local information, we can significantly reduce the average path length and retain the clustering coefficient. To achieve our goal, our algorithm first identifies logical regions using Lateral Inhibition technique, then identifies the nodes that beamform and finally the beam properties using Flocking. We use Lateral Inhibition and Flocking because they enable us to use local state information as opposed to other techniques. We support our work with simulation results and analysis, which show that a reduction of up to 40% can be achieved for a high-density network. We also show the effect of hopcount used to create regions on average path length, clustering coefficient and connectivity.
Comment: Accepted for publication: Special Issue on Security and Performance of Networks and Clouds (The Computer Journal)

الوصول الحر: http://arxiv.org/abs/1111.4807Test