Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems最新文献_第3页

Regionally influential users in location-aware social networks 在位置感知社交网络中具有区域影响力的用户

Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems Pub Date : 2014-11-04 DOI: 10.1145/2666310.2666489

Panagiotis Bouros, Dimitris Sacharidis, Nikos Bikakis

引用次数: 27

Group nearest neighbor queries in the presence of obstacles 在存在障碍物的情况下对最近邻查询进行分组

Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems Pub Date : 2014-11-04 DOI: 10.1145/2666310.2666484

Nusrat Sultana, T. Hashem, L. Kulik

引用次数: 18

Quality control from the perspective of a near-real-time, spatial-temporal data aggregator and (re)distributor 从近实时、时空数据聚合和(再)分发的角度进行质量控制

Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems Pub Date : 2014-11-04 DOI: 10.1145/2666310.2666426

D. Galarus, R. Angryk

引用次数: 8

Efficient spatial query processing for big data 面向大数据的高效空间查询处理

Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems Pub Date : 2014-11-04 DOI: 10.1145/2666310.2666481

Kisung Lee, R. Ganti, M. Srivatsa, Ling Liu

引用次数: 66

Online event clustering in temporal dimension 时间维在线事件聚类

Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems Pub Date : 2014-11-04 DOI: 10.1145/2666310.2666393

Hoang Thanh Lam, E. Bouillet

{"title":"Online event clustering in temporal dimension","authors":"Hoang Thanh Lam, E. Bouillet","doi":"10.1145/2666310.2666393","DOIUrl":"https://doi.org/10.1145/2666310.2666393","url":null,"abstract":"This work is motivated by a real-life application that exploits sensor data available from traffic light control systems currently deployed in many cities around the world. Each sensor consists of an induction loop that generates a stream of events triggered whenever a metallic object e.g. car, bus, or a bicycle, is detected above the sensor. Because of the red phase of traffic lights objects are usually divided into groups that move together. Detecting these groups of objects as long as they pass through the sensor is useful for estimating the status of the toad networks such as car queue length or detecting traffic anomalies. In this work, given a data stream that contains observations of an event, e.g. detection of a moving object, together with the timestamps indicating when the events happen, we study the problem that clusters the events together in real-time based on the proximity of the event's occurrence time. We propose an efficient real-time algorithm that scales up to the large data streams extracted from thousands of sensors in the city of London. Moreover, our algorithm is better than the baseline algorithms in terms of clustering accuracy. We demonstrate motivations of the work by showing a real-life use-case in which clustering results are used for estimating the car queue lengths on the road and detecting traffic anomalies.","PeriodicalId":153031,"journal":{"name":"Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130825091","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}

引用次数: 1

Efficient computation and simplification of discrete morse decompositions on triangulated terrains 三角地形上离散莫尔斯分解的高效计算与简化

Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems Pub Date : 2014-11-04 DOI: 10.1145/2666310.2666412

Riccardo Fellegara, F. Iuricich, L. Floriani, K. Weiss

{"title":"Efficient computation and simplification of discrete morse decompositions on triangulated terrains","authors":"Riccardo Fellegara, F. Iuricich, L. Floriani, K. Weiss","doi":"10.1145/2666310.2666412","DOIUrl":"https://doi.org/10.1145/2666310.2666412","url":null,"abstract":"We consider the problem of efficient computing and simplifying Morse complexes on a Triangulated Irregular Network (TIN) based on discrete Morse theory. We develop a compact encoding for the discrete Morse gradient field, defined by the terrain elevation, by attaching it to the triangles of the TIN. This encoding is suitable to be combined with any TIN data structure storing just its vertices and triangles. We show how to compute such gradient field from the elevation values given at the TIN vertices, and how to simplify it effectively in order to reduce the number of critical elements. We demonstrate the effectiveness and scalability of our approach over large terrains by developing algorithms for extracting the cells of the Morse complexes as well as the graph joining the critical elements from the discrete gradient field. We compare implementations of our approach on a widely-used and compact adjacency-based topological data structure for a TIN and on a compact spatio-topological data structure that we have recently developed, the PR-star quadtree.","PeriodicalId":153031,"journal":{"name":"Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"154 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131979305","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}

引用次数: 21

City nexus: discovering pairs of jointly-visited locations based on geo-tagged posts in social networks 城市联系:根据社交网络上的地理标记帖子发现共同访问过的地点

Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems Pub Date : 2014-11-04 DOI: 10.1145/2666310.2666378

Y. Kanza, Elad Kravi, Uri Motchan

引用次数: 16

Extracting stay regions with uncertain boundaries from GPS trajectories: a case study in animal ecology 从GPS轨迹中提取边界不确定的停留区:动物生态学的案例研究

Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems Pub Date : 2014-11-04 DOI: 10.1145/2666310.2666417

M. Damiani, H. Issa, F. Cagnacci

{"title":"Extracting stay regions with uncertain boundaries from GPS trajectories: a case study in animal ecology","authors":"M. Damiani, H. Issa, F. Cagnacci","doi":"10.1145/2666310.2666417","DOIUrl":"https://doi.org/10.1145/2666310.2666417","url":null,"abstract":"In this paper we present a time-aware, density-based clustering technique for the identification of stay regions in trajectories of low-sampling-rate GPS points, and its application to the study of animal migrations. A stay region is defined as a portion of space which generally does not designate a precise geographical entity and where an object is significantly present for a period of time, in spite of relatively short periods of absence. Stay regions can delimit for example the residence of animals, i.e. the home-range. The proposed technique enables the extraction of stay regions represented by dense and temporally disjoint sub-trajectories, through the specification of a small set of parameters related to density and presence. While this work takes inspiration from the field of animal ecology, we argue that the approach can be of more general concern and used in perspective in different domains, e.g. the study of human mobility over large temporal scales. We experiment with the approach on a case study, regarding the seasonal migration of a group of roe deer.","PeriodicalId":153031,"journal":{"name":"Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129147569","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}

引用次数: 30

A framework for trajectory segmentation by stable criteria 基于稳定准则的弹道分割框架

Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems Pub Date : 2014-11-04 DOI: 10.1145/2666310.2666415

Sander P. A. Alewijnse, K. Buchin, M. Buchin, A. Kölzsch, H. Kruckenberg, M. A. Westenberg

{"title":"A framework for trajectory segmentation by stable criteria","authors":"Sander P. A. Alewijnse, K. Buchin, M. Buchin, A. Kölzsch, H. Kruckenberg, M. A. Westenberg","doi":"10.1145/2666310.2666415","DOIUrl":"https://doi.org/10.1145/2666310.2666415","url":null,"abstract":"We present an algorithmic framework for criteria-based segmentation of trajectories that can efficiently process a large class of criteria. Criteria-based segmentation is the problem of subdividing a trajectory into a small number of parts such that each part satisfies a global criterion. Our framework can handle criteria that are stable, in the sense that these do not change their validity along the trajectory very often. This includes both increasing and decreasing monotone criteria. Our framework takes O(n log n) time for preprocessing and computation, where n is the number of data points. It surpasses the two previous algorithmic frameworks on criteria-based segmentation, which could only handle decreasing monotone criteria, or had a quadratic running time, respectively. Furthermore, we develop an efficient data structure for interactive parameter selection, and provide mechanisms to improve the exact position of break points in the segmentation. We demonstrate and evaluate our framework by performing case studies on real-world data sets.","PeriodicalId":153031,"journal":{"name":"Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115523567","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}

引用次数: 33

Top-k point of interest retrieval using standard indexes 使用标准索引检索Top-k兴趣点

Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems Pub Date : 2014-11-04 DOI: 10.1145/2666310.2666399

Anders Skovsgaard, Christian S. Jensen

{"title":"Top-k point of interest retrieval using standard indexes","authors":"Anders Skovsgaard, Christian S. Jensen","doi":"10.1145/2666310.2666399","DOIUrl":"https://doi.org/10.1145/2666310.2666399","url":null,"abstract":"With the proliferation of Internet-connected, location-aware mobile devices, such as smartphones, we are also witnessing a proliferation and increased use of map-based services that serve information about relevant Points of Interest (PoIs) to their users. We provide an efficient and practical foundation for the processing of queries that take a keyword and a spatial region as arguments and return the k most relevant PoIs that belong to the region, which may be the part of the map covered by the user's screen. The paper proposes a novel technique that encodes the spatio-textual part of a PoI as a compact bit string. This technique extends an existing spatial encoding to also encode the textual aspect of a PoI in compressed form. The resulting bit strings may then be indexed using index structures such as B-trees or hashing that are standard in DBMSs and key-value stores. As a result, it is straightforward to support the proposed functionality using existing data management systems. The paper also proposes a novel top-k query algorithm that merges partial results while providing an exact result. An empirical study with real-world data indicates that the proposed techniques enable excellent indexing and query execution performance on a standard DBMS.","PeriodicalId":153031,"journal":{"name":"Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114398305","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}

引用次数: 7