查看更多>>摘要：Public Map Service Platforms(PMSPs)provide embedded map services in domains such as forests and rivers.Users from different domains(Domain Users)prefer specific spatial features,and extracting the Browsing Interests of Domain Users(BIDUs)can help elucidate users'access intentions and provide suitable recommendations.Previous research has found that access frequency of spatial features is an indicator of users'browsing interests;however,high-frequency spatial features are sparsely distributed,resulting in inaccurate extraction of brows-ing interests.Our objective is to model the spatial co-occurrence of spatial features and employ BIDUs extraction to address this limitation.First,to extract spatial features in tiles,we proposed a k-nearest neighbor method for Point-of-Interest(POI)extraction and a template-based method for Land Uses/Land Covers extraction.Then,we developed the word2vec model to construct a POI semantic space to quantify spatial co-occurrence and employed multi-domain user classification to verify its effectiveness.Finally,a combined word2vec and singular value decomposition model is proposed to perform topic extraction as a representation of BIDUs.Compared with the baseline models,the proposed model integrates spatial co-occurrence from massive POIs to achieve high-accuracy BIDU extraction.Our findings can help construct domain user profiles and support the development of intelligent PMSPs.
查看更多>>摘要：The capsule robot has become an important tool in covering the entire spectrum of digestive tract disease diagnosis.To achieve magnetic capsule-robot localization,the Levenberg-Marquardt(LM)algorithm has become a mainstream approach that provides accurate solu-tions in the general case.In practice,however,to meet the requirements of wearability,fewer sensors and lower power consumption are required.When the number of sensor observations becomes smaller,local convergences and outliers may occur in positioning results.To mitigate this issue,this paper makes two contributions to enhance the robustness of capsule-endoscope positioning,especially when the quality of magnetic observations is low.First,it proposes a two-step approach that initializes the capsule attitude by using inertial measure-ments before estimating the position.Second,it presents an improved LM-based positioning algorithm based on vest-type magnetic sensor arrays.Furthermore,to verify the proposed approach,a vest-type wearable device with two low-cost magnetometer arrays is designed.Test results have shown the effectiveness of the proposed LM method in enhancing position-ing when there is a lack of observations.
查看更多>>摘要：Spatial equity in access to urban services is a significant element of sustainable urban planning.To date,a service-based index is used to measure service attractiveness,considering attrac-tiveness as a static concept.While from the user side view,service attractiveness is a dynamic concept related to the variation of different opportunities of users to use the services and capacities.In this paper,a user-based method for measuring service attractiveness is proposed.In this approach,the attractiveness of service for a user is modeled as a function of the user's Travel Times(TT),Free Times(FTs),park size and relative positions of the user,local demanding population,and service.Then,the inequity of attractiveness of services for different users has been examined using three inequity indices including the Duration of Use(DU),Frequency of Visit(FV),and the Chance of Space Choice(CSC).The proposed method is applied to urban regional parks of Tehran municipality.Traffic Analysis Zones(TAZs)and regional parks are respectively regarded as the users and services.In addition to considering inequity of access to the first closest park,the additional cost of accessing to the other two closest parks is also considered.Results show that the proposed method leads to the exploration of the existing inequities of DU,FV,and CSC among residents in local scales,whereas in the service-based method,all users of a service are highlighted with a single value of attractiveness.Comparison of the user-based and service-based attractiveness indices show significant differences.As an example,user-based attractiveness values of about 14%and 20%of TAZs are respectively 5 and 3 square meters more than that of the service-based attractiveness index.However,the service-based method is suitable for regional-scale comparison of the inequities.Therefore,the proposed index can complement the service-based index for inequity mapping and manage-ment in varying scales.
查看更多>>摘要：In recent years,decision support systems(DSSs)have successfully deployed ontologies in their architecture.The result of such a use is information systems that assist users and organizations in semi-structured decision-making activities.Visitors from throughout Iran travel to different cities and regions every year,and they need help making their choices.Some of these tourists are unable to visit the beautiful areas of the destination city due to a lack of awareness.In this study,we design an ontology-based spatial DSS to find entertainment and tourism centers in Arak,Iran.The objective is to provide users with recommendations appropriate for the location,time,age group,type of activity,and other factors.In this model,the demands and concerns of tourists have been managed by creating a domain Web Ontology Language(OWL)for entertainment centers as a knowledge base in the Protégé environment.The developed web-based DSS operates on a client-server architecture using technologies such as Werkzeug and Flask.As a result,it makes it possible to ontology reasoning based on the HermiT engine to choose the right center and conduct a semantic search on classes related to the appropriate point of interest.The main distinction between the proposed methodology and the previous studies on spatial DSS is that criteria are object properties in an ontology.Therefore,decision support relies on real-time reasoning rather than transforming criteria into geospatial layers.The evaluation results confirmed efficient interaction with this system,purposeful information retrieval,and rapid decision-making process.The results also indicated that searching for a POI(point of interest)in the study area using the developed system is at least 30%more successful than a search engine or social media.Moreover,to overcome the cold start problem,the proposed technique might be utilized in conjunction with the POI recommender systems.
查看更多>>摘要：Mixed reality technology has been increasingly used for navigation.While most MR-based navigation systems are currently based on hand-held devices,for example,smartphones,head-mounted MR devices have become more and more popular in navigation.Much research has been conducted to investigate the navigation experience in MR.However,it is still unclear how ordinary users react to the first-person view and FOV(field of view)-limited navigation experience,especially in terms of spatial learning.In our study,we investigate how visualization in MR navigation affects spatial learning.More specifically,we test two related hypotheses:incorrect virtual information can lead users into incorrect spatial learning,and the visualization style of direction can influence users'spatial learning and experience.We designed a user interface in Microsoft HoloLens 2 and conducted a user study with 40 participants.The user study consists of a walking session in which users wear Microsoft HoloLens 2 to navigate to an unknown destina-tion,pre-and post-walking questionnaires,sketch map drawing,and a semi-structured interview about the user interface design.The results provide preliminary confirmation that users'spatial learning can be misled by incorrect information,even in a small study area,but this misleading effect can be compensated by considerate visualization,for example,including lines instead of using only arrows as direction indicators.Arrows with or without lines as two visualization alternatives also influenced the user's spatial learning and evaluation of the designed elements.Besides,the study shows that users'preferences for navigation interfaces are diverse,and an adaptable interface should be provided.The results contribute to the design of head-mounted MR-based navigation interfaces and the application of MR in navigation in general.
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