{"title":"Remote Sensing Image Captioning with Continuous Output Neural Models","authors":"R. Ramos, Bruno Martins","doi":"10.1145/3474717.3483631","DOIUrl":"https://doi.org/10.1145/3474717.3483631","url":null,"abstract":"Remote sensing image captioning involves generating a concise textual description for an input aerial image. Most previous methods are based on neural encoder-decoder models trained to generate a sequence of discrete outputs with the standard cross-entropy token-level loss. This paper explores an alternative method based on continuous outputs, generating sequences of embedding vectors instead of directly predicting discrete word tokens. We argue that continuous outputs can facilitate the optimization of semantic similarity, as opposed to exact word-by-word matches. It also facilitates the use of loss functions that compare different views of the data. This includes comparing representations for individual tokens and for the entire captions, and also comparing captions against intermediate image representations. We experimentally compared discrete versus continuous output methods over the RSICD dataset, extensively used in the area. Results show that continuous outputs can indeed lead to better results, and our approach performs competitively with the state-of-the-art model in the area.","PeriodicalId":340759,"journal":{"name":"Proceedings of the 29th International Conference on Advances in Geographic Information Systems","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126574930","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. Carniel, Felippe Galdino, J. S. Philippsen, Markus Schneider
{"title":"Handling Fuzzy Spatial Data in R Using the fsr Package","authors":"A. Carniel, Felippe Galdino, J. S. Philippsen, Markus Schneider","doi":"10.1145/3474717.3484255","DOIUrl":"https://doi.org/10.1145/3474717.3484255","url":null,"abstract":"GIS and spatial data science (SDS) tools have been recently approaching each other by establishing bridge technologies between them. R as one of the most prominent programming languages used in SDS projects has been granted access to GIS infrastructure, while R scripts can be integrated and executed in GIS functions. Unfortunately, the treatment of spatial fuzziness has so far not been considered in SDS projects and bridge technologies due to a lack of software packages that can handle fuzzy spatial objects. This paper introduces an R package named fsr as an implementation of the fuzzy spatial data types, operations, and predicates of the Spatial Plateau Algebra that is based on the abstract Fuzzy Spatial Algebra. This R package solves the problem of constructing fuzzy spatial objects as spatial plateau objects from real datasets and describes how to conduct exploratory spatial data analysis by issuing geometric operations and topological predicates on fuzzy spatial objects. Further, fsr provides the possibility of designing fuzzy spatial inference models to discover new findings from fuzzy spatial objects. It optimizes the inference process by deploying the particle swarm optimization to obtain the point locations with the maximum or minimum inferred values that answer a specific user request.","PeriodicalId":340759,"journal":{"name":"Proceedings of the 29th International Conference on Advances in Geographic Information Systems","volume":"293 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131832401","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":"STAR","authors":"Zhida Chen, Gao Cong, Walid G. Aref","doi":"10.1145/3474717.3484265","DOIUrl":"https://doi.org/10.1145/3474717.3484265","url":null,"abstract":"The proliferation of mobile phones and location-based services has given rise to an explosive growth in spatial data. In order to enable spatial data analytics, spatial data needs to be streamed into a data stream warehouse system that can provide real-time analytical results over the most recent and historical spatial data in the warehouse. Existing data stream warehouse systems are not tailored for spatial data. In this paper, we introduce the STAR (Spatial Data Stream Warehouse) system. STAR is a distributed in-memory data stream warehouse system that provides low-latency and up-to-date analytical results over a fast-arriving spatial data stream. STAR supports queries that are composed of aggregate functions and ad hoc query constraints over spatial, textual, and temporal data attributes. STAR implements a cache-based mechanism to facilitate the processing of queries that collectively utilizes the techniques of query-based caching (i.e., view materialization) and object-based caching. Extensive experiments over real data sets demonstrate the superior performance of STAR over existing systems.","PeriodicalId":340759,"journal":{"name":"Proceedings of the 29th International Conference on Advances in Geographic Information Systems","volume":"9 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114019578","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}
Xiaowei Mao, Tianyu Cai, Wenchuang Peng, Huaiyu Wan
{"title":"Estimated Time of Arrival Prediction via Modeling the Spatial-Temporal Interactions between Links and Crosses","authors":"Xiaowei Mao, Tianyu Cai, Wenchuang Peng, Huaiyu Wan","doi":"10.1145/3474717.3488373","DOIUrl":"https://doi.org/10.1145/3474717.3488373","url":null,"abstract":"The ACM SIGSPATIAL GIS CUP 2021 focuses on Estimated Time of Arrival (ETA) prediction, which is important to the travel scheduling and decision-making of ride-hailing platforms. Accurate ETA prediction is very challenging since ETA is affected by many heterogeneous influencing factors, including static features (e.g., number of links) and dynamic features (e.g., real-time road conditions). Meanwhile, ETA can also be affected by complex spatial-temporal dependencies between links and crosses in the route. To tackle the above challenges, we propose a deep learning method based on the Wide-Deep-Recurrent (WDR) architecture while modeling the interactions between links and crosses. We adopt Neural Factorization Machines (NFM) to memorize the historical patterns and a multiple layer perceptron (MLP) to integrate various heterogeneous influencing factors. We also model links and crosses jointly to learn their spatial-temporal dependencies in the route. Extensive experiments conducted on a real dataset show that our method achieves a high prediction accuracy. The source code is available at: https://github.com/wanhuaiyu/WDR-LC.","PeriodicalId":340759,"journal":{"name":"Proceedings of the 29th International Conference on Advances in Geographic Information Systems","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121973507","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":"TrajNet","authors":"Sumanto Dutta","doi":"10.1145/3474717.3486806","DOIUrl":"https://doi.org/10.1145/3474717.3486806","url":null,"abstract":"Discovering anomalous trajectory becomes an essential task in various research and industrial domains in recent years. Unsupervised learning techniques have been used frequently to find an anomaly in trajectory. These methods fail to detect an outlier in highly correlated trajectory data. In general, the supervised approach is found to be more efficient compared to unsupervised learning in many domains. In this article, to detect outliers in vehicle trajectory data, a supervised learning technique is proposed called TrajNet. TrajNet work with a limited number of labelled trajectories exploiting capsule network-based one-shot learning. The experiments are conducted with a publicly available Geolife GPS trajectory dataset, and the preliminary results are very encouraging.","PeriodicalId":340759,"journal":{"name":"Proceedings of the 29th International Conference on Advances in Geographic Information Systems","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115454072","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":"Point in Polygon Tests Using Hardware Accelerated Ray Tracing","authors":"Moritz Laass","doi":"10.1145/3474717.3486796","DOIUrl":"https://doi.org/10.1145/3474717.3486796","url":null,"abstract":"Recent generations of GPUs have seen the introduction of hardware-accelerated ray tracing algorithms that are suitable for real-time use. They provide hardware for massively parallel ray-geometry intersection computations, indicating a highly optimized spatial data structure derived from arbitrary triangle-based geometries. Spatial join is an ubiquitous problem in spatial databases, GIS applications, spatial statistics, and similar applications. On a fundamental level, spatial joins are based on point in polygon tests (PIP). We suggest exploiting the capabilities of ray tracing hardware to perform fast parallel point in polygon tests in order to implement hardware-accelerated spatial joins.","PeriodicalId":340759,"journal":{"name":"Proceedings of the 29th International Conference on Advances in Geographic Information Systems","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130293535","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}
Yifang Yin, An Tran, Ying Zhang, Wenmiao Hu, Guanfeng Wang, Jagannadan Varadarajan, Roger Zimmermann, See-Kiong Ng
{"title":"Multimodal Fusion of Satellite Images and Crowdsourced GPS Traces for Robust Road Attribute Detection","authors":"Yifang Yin, An Tran, Ying Zhang, Wenmiao Hu, Guanfeng Wang, Jagannadan Varadarajan, Roger Zimmermann, See-Kiong Ng","doi":"10.1145/3474717.3483917","DOIUrl":"https://doi.org/10.1145/3474717.3483917","url":null,"abstract":"Automatic inference of missing road attributes (e.g., road type and speed limit) for enriching digital maps has attracted significant research attention in recent years. A number of machine learning based approaches have been proposed to detect road attributes from GPS traces, dash-cam videos, or satellite images. However, existing solutions mostly focus on a single modality without modeling the correlations among multiple data sources. To bridge the gap, we present a multimodal road attribute detection method, which improves the robustness by performing pixel-level fusion of crowdsourced GPS traces and satellite images. A GPS trace is usually given by a sequence of location, bearing, and speed. To align it with satellite imagery in the spatial domain, we render GPS traces into a sequence of multi-channel images that simultaneously capture the global distribution of the GPS points, the local distribution of vehicles' moving directions and speeds, and their temporal changes over time, at each pixel. Unlike previous GPS based road feature extraction methods, our proposed GPS rendering does not require map matching in the data preprocessing step. Moreover, our multimodal solution addresses single-modal challenges such as occlusions in satellite images and data sparsity in GPS traces by learning the pixel-wise correspondences among different data sources. Extensive experiments have been conducted on two real-world datasets in Singapore and Jakarta. Compared with previous work, our method is able to improve the detection accuracy on road attributes by a large margin.","PeriodicalId":340759,"journal":{"name":"Proceedings of the 29th International Conference on Advances in Geographic Information Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130361980","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}
Andreas S. Andersen, Andreas D. Christensen, Philip Michaelsen, Shpend Gjela, K. Torp
{"title":"AIS Data as Trajectories and Heat Maps","authors":"Andreas S. Andersen, Andreas D. Christensen, Philip Michaelsen, Shpend Gjela, K. Torp","doi":"10.1145/3474717.3484208","DOIUrl":"https://doi.org/10.1145/3474717.3484208","url":null,"abstract":"All large ships are by international law required to provide their position, speed, and course while sailing. This data is called AIS data. Several maritime organizations make this data freely available. In this paper, we present two approaches to querying AIS data. The first approach combines the individual AIS data records into trajectories and the second approach is to combine many trajectories into heat maps. The first approach is well suited, e.g., to find the complete route of a few ships or study how many ships are navigating in a smaller area known to be complicated to sail. The heat-map approach is particularly well suited to provide an overview of ship movements in large areas. For the trajectory approach, we introduce and define a novel way to query AIS data called a trident query. This query type is developed in close collaboration with domain experts. The core idea with a trident query is to visualize route choices. The heat-map approach works both for user-defined areas and for predefined Areas Of Interest (AOI) cells. The trajectory approach is difficult to scale and we show how the trajectories can be simplified to make querying and visualization more efficient. We present data on a map and statistical details are provided in graphs and tables, e.g., the distribution of ship types and ship dimensions (length, width, and draught). End-users can filter on attributes such as ship IDs, ship types, and ship dimensions for both the trajectory and heap-map approaches.","PeriodicalId":340759,"journal":{"name":"Proceedings of the 29th International Conference on Advances in Geographic Information Systems","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128604626","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":"Scalable Spatio-Temporal Top-k Community Interactions Query","authors":"Abdulaziz Almaslukh, Yongyi Liu, A. Magdy","doi":"10.1145/3474717.3483962","DOIUrl":"https://doi.org/10.1145/3474717.3483962","url":null,"abstract":"The excessive amount of data that online users produce through social media platforms provides valuable insights about users and communities at scale. Existing techniques have not fully exploited such data to help practitioners perform a deep analysis of large online communities. Lack of scalability hinders analyzing communities of large sizes and requires tremendous system resources and unacceptable runtime. This paper introduces a new analytical query that reveals the top-k posts of interest of a given user community over a period of time and in a certain location. We propose a novel indexing framework that captures the interactions of community users to provide a low query latency. Moreover, we propose efficient query algorithms that utilize the index content to prune the search space. The extensive experimental evaluation on real data has shown the superiority of our techniques and their scalability to support large online communities.","PeriodicalId":340759,"journal":{"name":"Proceedings of the 29th International Conference on Advances in Geographic Information Systems","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121424824","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":"Attention-Based Spatial Interpolation for House Price Prediction","authors":"Darniton Viana, Luciano Barbosa","doi":"10.1145/3474717.3484257","DOIUrl":"https://doi.org/10.1145/3474717.3484257","url":null,"abstract":"Estimating the market price of a house is important for many businesses such as real estate and mortgage lending companies. The price of a house depends not only on its structural features (e.g. area and number of bedrooms) but also on the spatial context where it is located. In this work we estimate the price of a house based solely on its structural features and the characteristics and price of its neighbors. For that, we propose a hybrid attention mechanism that weights neighbors based on their similarity to the house in terms of structural features and geographic location. For the structural features, we apply an euclidean-based attention and, for the geographic location, we propose an attention layer based on a radial basis function kernel. Those attention mechanisms are then used by a neural network regressor to predict the price of a house and to generate a vector representation of the house based on its implicit context: the house embedding, which can be used as a feature set by any regressor to perform house price prediction. We have performed an extensive experimental evaluation on real-world datasets that shows that: (1) regressors using house embedding obtained the best results on all 4 datasets, outperforming baseline models; (2) the learned house embedding improves the performance of the evaluated regressors in almost all scenarios in comparison to raw features; and (3) simple regressor models such as Linear Regression using house embedding achieved comparable results to more competitive algorithms (e.g. Random Forest and Xgboost).","PeriodicalId":340759,"journal":{"name":"Proceedings of the 29th International Conference on Advances in Geographic Information Systems","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117235189","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}