{"title":"Location-based social networking for obtaining personalised driving advice","authors":"Abdullah AlDwyish, E. Tanin, S. Karunasekera","doi":"10.1145/2820783.2820789","DOIUrl":"https://doi.org/10.1145/2820783.2820789","url":null,"abstract":"Major navigation companies have resorted to crowdsourcing for obtaining traffic data to improve their services. In fact, a new generation of navigation systems are emerging for the sole purpose of connecting drivers on the road (Waze.com) so that they benefit from each other. The focus of these efforts is on real-time traffic estimation. While obtaining real-time data is desirable and has great benefits, it is still limited, given the potential of the detailed individual data from drivers. For example, commuters in a city have valuable knowledge about their city as a result of their daily commute over many years. Using drivers as mere traffic sensors and aggregating their data desposes off any human knowledge that exists in their choices. In this work, we demonstrate a social navigation system that can help drivers avoid road incidents using expert advice in real-time without explicitly consulting drivers but through an automated system built on top of a location-based social network. In our system, we do not aggregate data from individual users and we instead outsource the task of finding a route that best avoids incidents by looking up drivers' old choices.","PeriodicalId":241302,"journal":{"name":"Proceedings of the 23rd SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117317369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ji Zhang, Wei-Shinn Ku, Xunfei Jiang, X. Qin, Min-Te Sun, Hua Lu
{"title":"A framework for multi-criteria optimal location selection","authors":"Ji Zhang, Wei-Shinn Ku, Xunfei Jiang, X. Qin, Min-Te Sun, Hua Lu","doi":"10.1145/2820783.2820784","DOIUrl":"https://doi.org/10.1145/2820783.2820784","url":null,"abstract":"In this demonstration, we present a visualization system offering two advanced solutions that can efficiently address a novel multi-criteria optimal location query by using Overlapping Voronoi Diagrams (OVDs). Our system not only displays an example that applies the advanced solutions to a practical optimal location query, but also visualizes the process of query evaluation by using the solutions, which can help users better understand the two solutions in a more intuitive way. The Real Region as Boundary (RRB) approach calculates real regions of overlapped Voronoi cells, while the Minimum Bounding Rectangle as Boundary (MBRB) approach approximates the cells by their MBRs to simplify region overlapping calculation. For efficient query evaluation and better demonstration, global and local datasets are managed separately and only the local dataset is displayed in a limited visualization area. User interactions are provided in diverse manners in our system by using the Standard Widget Toolkit (SWT) and Open Graphics Library (OpenGL).","PeriodicalId":241302,"journal":{"name":"Proceedings of the 23rd SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"29 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120916383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Design and representation of complex objects in database systems","authors":"Lin Qi, Huiyuan Zhang, Markus Schneider","doi":"10.1145/2820783.2820842","DOIUrl":"https://doi.org/10.1145/2820783.2820842","url":null,"abstract":"In recent decades, applications like geospatial, genomic, and multimedia have made use of very large and diverse application objects such as spatial networks and protein structures. These objects are complex in the sense that they are highly structured and of variable size. Storing, accessing and manipulating them in a standard and efficient manner is very challenging. The state-of-the-art solutions handle such objects by using file system formats like HDF and XML, serialization technique like Protocol Buffers and BLOB data type in databases. However, specialized file format solutions lack any well established database system features, and neither a uniform concept nor mechanisms exist for supporting complex objects for BLOBs. In this article, a novel and database-friendly framework of specifying and interpreting complex objects is proposed. Empirical studies have shown that our approach outperforms prevailing methods with efficient processing time and less storage consumption.","PeriodicalId":241302,"journal":{"name":"Proceedings of the 23rd SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115533403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Task matching and scheduling for multiple workers in spatial crowdsourcing","authors":"Dingxiong Deng, C. Shahabi, Linhong Zhu","doi":"10.1145/2820783.2820831","DOIUrl":"https://doi.org/10.1145/2820783.2820831","url":null,"abstract":"A new platform, termed spatial crowdsourcing, is emerging which enables a requester to commission workers to physically travel to some specified locations to perform a set of spatial tasks (i.e., tasks related to a geographical location and time). The current approach is to formulate spatial crowdsourcing as a matching problem between tasks and workers; hence the primary objective of the existing solutions is to maximize the number of matched tasks. Our goal is to solve the spatial crowdsourcing problem in the presence of multiple workers where we optimize for both travel cost and the number of completed tasks, while taking the tasks' expiration times into consideration. The challenge is that the solution should be a mixture of task-matching and task-scheduling, which are fundamentally different. In this paper, we show that a baseline approach that performs a task-matching first, and subsequently schedules the tasks assigned per worker in a following phase, does not perform well. Hence, we add a third phase in which we iterate back to the matching phase to improve the assignment per the output of the scheduling phase, and thus further improves the quality of matching and scheduling. Even though this 3-phase approach generates high quality results, it is very slow and does not scale. Hence, to scale our algorithm to large number of workers and tasks, we propose a Bisection-based framework which recursively divides all the workers and tasks into different partitions such that assignment and scheduling can be performed locally in a much smaller and promising space. Our experiments show that this approach is three orders of magnitude faster than the 3-phase approach while it only sacrifices 4% of the results' quality.","PeriodicalId":241302,"journal":{"name":"Proceedings of the 23rd SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115274592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuhong Li, Yu Zheng, Shenggong Ji, Wenjun Wang, Leong Hou U, Zhiguo Gong
{"title":"Location selection for ambulance stations: a data-driven approach","authors":"Yuhong Li, Yu Zheng, Shenggong Ji, Wenjun Wang, Leong Hou U, Zhiguo Gong","doi":"10.1145/2820783.2820876","DOIUrl":"https://doi.org/10.1145/2820783.2820876","url":null,"abstract":"Emergency medical service provides a variety of services for those in need of emergency care. One of the major challenges encountered by emergency service providers is selecting the appropriate locations for ambulance stations. Prior works measure spatial proximity under Euclidean space or static road network. In this paper, we focus on locating the ambulance stations by using the real traffic information so as to minimize the average travel-time to reach the emergency requests. To this end, we estimate the travel-time of road segments using real GPS trajectories and propose an efficient PAM-based refinement for the location problem. We conduct extensive experimental evaluations using real emergency requests collected from Tianjin, and the result shows that the proposed solution can reduce the travel-time to reach the emergency requests by 29.9% when compared to the original locations of ambulance stations.","PeriodicalId":241302,"journal":{"name":"Proceedings of the 23rd SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114185127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Flag-verify-fix: adaptive spatial crowdsourcing leveraging location-based social networks","authors":"U. Hassan, E. Curry","doi":"10.1145/2820783.2820870","DOIUrl":"https://doi.org/10.1145/2820783.2820870","url":null,"abstract":"This paper introduces the flag-verify-fix pattern that employs spatial crowdsourcing for city maintenance. The patterns motivates the need for appropriate assignment of dynamically arriving spatial tasks to a pool for workers on the ground. The assignment is aimed at maximizing the coverage of tasks spread over spatial locations; however, the coverage depends of willingness of workers to perform tasks assigned to them. We introduce the maximum coverage assignment problem that formulates two design issues of dynamic assignment. The quantity issue determines the number of worker required for a task and selection issue determines the set of workers. We propose an adaptive algorithm that uses location diversity based on a location-based social network to address the quantity issue and employs Thompson sampling for selecting the workers by learning their willingness. We evaluate the performance of the proposed algorithm in terms of coverage and number of assignments using real world datasets. The results show that our proposed algorithm achieves 30%--50% more coverage than the baseline algorithms, while requiring less workers per task.","PeriodicalId":241302,"journal":{"name":"Proceedings of the 23rd SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114542650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Piyush Kumar, Tathagata Mukherjee, E. Pasiliao, Liqin Xu
{"title":"Cheap approximate localization using FM radio","authors":"Piyush Kumar, Tathagata Mukherjee, E. Pasiliao, Liqin Xu","doi":"10.1145/2820783.2820868","DOIUrl":"https://doi.org/10.1145/2820783.2820868","url":null,"abstract":"In this paper, we present a coarse and passive localization system for GPS-denied environments. Our system is based on a cheap software defined radio (SDR) costing less than $25, which is used to listen to broadcast signals from local FM Radio stations. We show that the hardware and associated algorithms are capable of localizations with average errors of less than 5 miles, without requiring a fingerprinting or crowd sourcing approach. The algorithm is based on a large-scale simulation based map building phase and a query phase. We use 924 power spectra distributed over more than 200 miles for experimentally validating our query algorithm. Our average localization error is less than 5 miles.","PeriodicalId":241302,"journal":{"name":"Proceedings of the 23rd SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"155 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124354853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"coMobile: real-time human mobility modeling at urban scale using multi-view learning","authors":"Desheng Zhang, Juanjuan Zhao, Fan Zhang, T. He","doi":"10.1145/2820783.2820821","DOIUrl":"https://doi.org/10.1145/2820783.2820821","url":null,"abstract":"Real-time human mobility modeling is essential to various urban applications. To model such human mobility, numerous data-driven techniques have been proposed. However, existing techniques are mostly driven by data from a single view, e.g., a transportation view or a cellphone view, which leads to over-fitting of these single-view models. To address this issue, we propose a human mobility modeling technique based on a generic multi-view learning framework called coMobile. In coMobile, we first improve the performance of single-view models based on tensor decomposition with correlated contexts, and then we integrate these improved single-view models together for multi-view learning to iteratively obtain mutually-reinforced knowledge for real-time human mobility at urban scale. We implement coMobile based on an extremely large dataset in the Chinese city Shenzhen, including data about taxi, bus and subway passengers along with cellphone users, capturing more than 27 thousand vehicles and 10 million urban residents. The evaluation results show that our approach outperforms a single-view model by 51% on average.","PeriodicalId":241302,"journal":{"name":"Proceedings of the 23rd SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116827012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Asahara, Nobuo Sato, Masatsugu Nomiya, Satomi Tsuji
{"title":"LiDAR-based pedestrian-flow analysis for crowdedness equalization","authors":"A. Asahara, Nobuo Sato, Masatsugu Nomiya, Satomi Tsuji","doi":"10.1145/2820783.2820805","DOIUrl":"https://doi.org/10.1145/2820783.2820805","url":null,"abstract":"A highly practical use case of pedestrian-track analysis by using LiDAR is presented in this paper. Many problems are caused by heavy crowdedness in the management of public facilities, i.e., shopping malls, airports, and so on. One solution is crowdedness equalization by controlling pedestrian flow. We conducted two experimental demonstrations at technical exhibitions to find that factors that determine pedestrian flow. Pedestrian tracks were obtained at an exhibition in 2013 by using a LiDAR-based pedestrian-tracking system first. As a result, new knowledge was gained; the layout of a technical exhibition should be designed to bend the path of a pedestrian flow toward areas where their attention is desired to be. The layout of an exhibition in 2014 was designed to bend the pedestrian path many times so that pedestrians' attention was located diversely. Therefore, pedestrian tracks were successfully obtained; as a result, it was confirmed that crowdedness was successfully equalized.","PeriodicalId":241302,"journal":{"name":"Proceedings of the 23rd SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"125 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116216734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Toponym disambiguation in online social network profiles","authors":"Mohammad Ghufran, Gianluca Quercini, N. Bennacer","doi":"10.1145/2820783.2820812","DOIUrl":"https://doi.org/10.1145/2820783.2820812","url":null,"abstract":"In online social networks individuals are given the option to reveal on their online profiles some personal information about themselves including, among others, their home location that, if specified, is typically referred to with a toponym. A toponym disclosed by an individual on her profile, or self-reported toponym (e.g., \"London\"), is often ambiguous and may be interpreted as the name of different geographic locations (\"London, U.K.\", \"London, Ontario, Canada\", \"London, Arkansas, USA\"). The determination of the right interpretation of a self-reported toponym is challenging because the profile of an individual usually lacks the contextual information that can be used to disambiguate the toponym. In this paper, we propose LocusRank, an algorithm for the disambiguation (or resolution) of the self-reported toponyms in online social network profiles. More precisely, LocusRank chooses the right interpretation of a self-reported toponym of an individual by using the (possibly ambiguous) self-reported toponyms of her friends. Besides, LocusRank can also be used to infer with good accuracy the home location of profiles that do not even have a self-reported toponym. We evaluated LocusRank with good results on a dataset of profiles obtained from two real social networks, namely Flickr and LiveJournal.","PeriodicalId":241302,"journal":{"name":"Proceedings of the 23rd SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121566415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}