Tourism Guided Information System for Location-Based Services

Transcription

1 Tourism Guided Information System for Location-Based Services Chang-Won Jeong 1, Yeong-Jee Chung 2, Su-Chong Joo, 2 and Joon-whoan Lee 1 1 Research Center for Advanced LBS Technology of Chonbuk National University, Korea 2 College of Electrical, Electronic and Information Engineering, Wonkwang University, Korea {mediblue, chlee}@chonbuk.ac.kr, {yjchung, scjoo}@wonkwang.ac.kr Abstract. Mobile information community develops quickly, as mobile telecommunication technology matches to the third generation. XML-based GIS becomes a global standard and the foundation. Recent developed Geography Markup Language (GML) allows integration of GIS location-based services, telematics, and intelligent transportation systems. In this paper, we propose a tourism information system for supporting the location based service of GIS applications. The system implements thin-client/server technology for mobile Web mapping service. The system includes traditional GIS system for navigation service and location finder POI services. The system for location and POI determination with design concerns are presented. An experimental user interface of PDA within the system is illustrated for the system procedures. Keywords: GML, LBS, Mobile tourism service, GIS, SVG. 1 Introduction Web becomes a popular tool for information distribution and Web based geographic Information Systems (GIS) are rapidly deployed to applications [1]. Since wireless networks enable new infrastructure for mobile services, Location Based Service (LBS) for mobile users begin to track and measure the user position for providing better service performance [2,3]. Therefore, the LBS urgently need a mapping information system, together with conventional GIS services and infrastructures. LBS based tourism information system may contain tour planning, navigation support to yellow page services, and commerce [4]. To generate interactive maps is an important component in today s tourism information system. Since existing GIS services were developed independently, there is no interoperability to support diverse map formats. Recently developed GML is a new methodology to deal with geographic information sharing. GML is an XML encoding for transport and storage of geographic information, including both spatial and nonspatial properties of geographic feature [5-7]. GML is important to draw some clear distinctions between geographic data and graphic interpretations of the data, as it appears on a map or other form of visualization. To generate a map with GML data, one must follow GML standards and coded into a suitable graphical presentation. In H.T. Shen et al. (Eds.): APWeb Workshops 2006, LNCS 3842, pp , Springer-Verlag Berlin Heidelberg 2006

2 750 C.-W. Jeong et al. general, GML data are coded into an XML graphical format using SVG (Scalable Vector Graphics), VML (Vector Markup Language), X3D technologies. In the past, people developed some prototype for distributing vector data on Internet. These protocols are complementarily based on GML and SVG. GML is used for string and distributing geographic data, while SVG is for presenting data [8, 9]. When a request to a map is performed, a GML file is created and to be translated into an SVG file. This step may also perform some generalization transformations. Portable devices, such as cellular phones, GPS devices, PDAs, and Palm, georeferenced information (GRI) are undergoing a significant change. The change is driven by software systems such as ESRI [10], MapInfo [11], Intergraph [12] and AutoDesk [13] which allow us publish geographical data online. However, the data and software systems are proprietary and completely controlled by vendors. The maps in image formats or in embedded objects are not interoperable; hence forming an obstacle of integrating searched results from different systems together. The LBS is an integrated technology in telecommunication and GIS. LBS was developed based on that a portable device sends its location information to a gateway; the gateway search through its database to find the most relevant information near the location and sends it back to the client for further use. However, a problem in this technology is that the gateway must maintain a centralized GRI database to support queries. XML-based data integration architectures become popular since XML is a kind of text-based protocol that is easily processed and exchanged between users. GML, an extension of XML and proposed by OGC is to solve the GRI interoperability problem. Several spatial data types, such as points, poly-lines and polygons, as well as earth projection types are defined in GML DTD. Any software that supports GML can use geographical data in a GML document. An XML-based spatial data mediation infrastructure for global interoperability study is conducted in San Diego Supercomputer Center [13]. This paper suggests a thin client/server information system for LBS. It was experimented in within a small region. Section 2 describes a general overview of the information system. Section 3 shows the servicing procedures respectively. The proposed prototype implementation is described in Section 4; followed by a conclusion and future works. 2 Proposed System Architecture The overall architecture of our proposed system is illustrated in Fig. 1. The system architecture is structured by the following. The architecture serves as a generic infrastructure that can be applied to other LBS applications. Therefore, a well-formed interface has to be provided that allows the appropriate use of the services for the different applications. The system adopts a three-tier architecture. The first is a client tier. Each client has two components: GPS and Service agents. GPS agent provides the physical location of a user to the TM (Transverse Mercator) [14]. GPS receiver with deferential correction (DGPS) is used to determine location and to track the path of travel. Position information is provided for mapping. The Service agent supports geographical view utilities based on Map and POI.

3 Tourism Guided Information System for Location-Based Services 751 The second is a mediator. Whenever the mediator receives a request from a client, it first determines which service manager is related to map and divided a query into a sub-queries. The mediator then finds the corresponding map in its database. Mediator has a service manager which consists of four modules (in Fig.1); mainly a GIS-based solution; DXF to SVG/GML translating, collecting, storing, and searching and retrieving maps. The third is the database tier. It supports data management of spatial or non-spatial data. For a POI service, database contains object identification, name for map presentation, coordination system, and additional information entities.g The roles of each component in the thin client and server are described like below. Fig. 1. Proposed System Architecture Thin client side - Service Manager: total management services invoked by a Web service, controlling the process of response message, and monitoring each component. - NMEA Parser: extracting valid information fetched from NMEA information of GPS receiver. - WGS84 to Bessel Translator: translating Bessel to WGS84 (using Molodensky- Badekas model). - Bessel to TM Translator: translating Transverse Mercator. - Position Manager: managing with log file and user position tracking. - User Interface: providing two-way communication between GPS agent and users. - Map Viewer: supporting SVG and GML displays - Embedded Browser: providing additional POI information based on HTML - Event Manager: managing all layer controls and POI events. Server side - Service Manager: managing service modules; receiving the service requests from client, and then returns the information of the created XML byte stream to service agents. - DXF Parser: translating DXF file into Tag Tree.

4 752 C.-W. Jeong et al. - XML Generator: generating well-formed XML document in a tag tree. - ML Translator: translating markup language using XSLT schema which is suitable for client GIS environments (SVG, GML, etc.). - POI Manager: extracting a POI information requested from client. 3 Service Procedure The workflow of both control commands and information contents are described in Fig. 2. Step 1 performs an acquisition of location information; Step 2 request from the client reaches a service manager by the means of the XML soap/http protocol through the communication layer. Selected position information is sent to the service manager. Steps 3-5 are executed under POI environments using client s selection, upon the given position information in Step 2. This step filters a map of service area. In Step 6, the response information with the XML byte stream is collected from the Service manager. The generated data is passed to the communication layer for further transformation to an appropriate format. Figure 3 shows a Message Flow for representing the whole management procedures mentioned above. Fig. 2. Service Flow Fig. 3. Message Flow G

5 Tourism Guided Information System for Location-Based Services Implementation of the Tourism Information System for LBS A prototyped implementation of the Tourism information system for LBS is implemented for the explanation of the system mechanism. The main implementation goal is to process spatial data, and to handle both the geometry and the properties of the geographical elements; this allows the various data providers to share heterogeneous datasets and the users to access the data in a completely transparent way. The processing of XML/GML documents and their visualizations in a graphical way with the interaction of the user is depicted. Since the GML data structure is XML compliant, it can be transformed in a SVG format for easily to be displayed on a Web browser with SVG viewing utility. The physical environment for implementation is shown in Figure 4. We constructed a Web service using a computer with Windows 2003 server. Net framework for interacting among components and/or service objects. The model components of the client and the server are implemented by C# language. Information of the POI is constructed to a relational database. These databases are managed by the MS SQL The Prototyped Implementation Environment as shown in Figure 4 presents the executing results of the navigation service and an example of the POI services in the system are provided. For displaying the procedures and the executing results of services on our system, a GUI-window interface is designed. Fig. 4. Service Configuration To demonstrate the operation of the service, a small part of Jeonju-City was selected and spatial data and POI information were converted from a GIS format of DXF to SVG. The client side supported zoom in/zoom out and full extent of geometric data for visualization and POI listing of textural data. Selected POI results were overlapped on base maps that were given from the other GML data, or directly from flat geographical data files as well as spatial databases.

6 754 C.-W. Jeong et al. Fig. 5. The map of Han-Ok Village with the Korean traditional houses in Jeonju-city and POI information G Figure 5 illustrates the screens displayed on the PDA. Click setting button of first phase of Figure 5, after pointing which one you like, you fill the choosing POI out in check space, and then click WMSCall button. One can see the map and POI information corresponding to a given service. These GUI is displaying user position by red dot on the base map in PDA, and then, selecting the POI displayed on the map. And these screens are displayed in first page and user can browse the map and select the POI to be displayed in GUI. And then it shows the related information with the position information as results executed by the UI event. As mentioned before, all processes in this system, either spatial analysis or invoking XML-based map contents are carried out in the server side and just a response in XML form is sent to client. XML parsers in client side interpret the XML contents and a service agent displays the spatial data and/or POI information s in the form of image and texts. Fig. 6 shows the map of small area query results returned from server. Fig. 6. Map of area showing GML and SVG G

7 Tourism Guided Information System for Location-Based Services Conclusions and Future Work Many WMS (Web Mapping Services) and POI (Point of Interest) based services begin to function in mobile GIS with the fast development of wireless devices. Location based services play a signification part in wireless application. With increasing the bandwidth of wireless communication, LBS systems are feasible for wireless users want to gain more. This paper described a thin client/server information system for location based service. System was implemented in a small area. This paper serves as a case study tries to expose the potential of wireless technology to serve LBSs. The future study focuses on an object-oriented database system capable for large spatial dataset. Acknowledgments This research was supported by University IT Research Center Project. References 1. Shekhar, S., Vatasavi, R.R., Sahay, N., Burk, T. E., Lime, S.: WMS and GML based Interoperable Web Mapping System. In proceedings of the 9th ACM International Symposium on Advances in Geographic Information Systems. ACMGIS 2001 (Nov. 2001), ISBN Zipf, A., Malaka, R.: Developing Location Based Services (LBS) for tourism The service providers view. In: Sheldon, P., Wober, K. and Fesenmaier D. (Eds.): Information and Communication Technologies in TOURISM Proceedings of ENTER 2001, 8 th International Conference. Montreal. Springer Computer Science. Wien, NewYork Schmidt-Belz, B., Makelainen, M., Nick, A., Poslad, S.: Intelligent Brokering of Tourism Services for Mobile Users. ENTER January (2002) Innsbruck 4. Stephanidis, C., Paramythis, A., Sfyrakis, M., Stergou, A., Maou, N., Leventis, A., Paparoulis, G., & Kaagiannidis, C., (1998). Adaptable and Adaptive User Interfaces for Disabled Users in the AVANTI Project. In S. Trigila, A. Mullery, M. Campolargo, H. Vanderstraeten & M. Mampaey(Eds.), Intelligence in Services and Network: Technology for Ubiquitous Telecommunications Services Proceedings of the 5 th International Conference on Intelligence in Services and Networks (IS&N 98), Antwerp, Belgium, OpenGIS Consortium, Geography Markup Language, 6. Open GIS Consortium, Simple Feature Specification, specs/?page=specs 7. W3Consortium, XML, 8. SVG Explorer of GML Data, Bonati L. P., Fortunati L., Fresta G. (2003) 9. Making maps with Geography Markup Language(GML), Lake R., Galdos Systems Inc, October (2000) 10. MapInfo, InterGraph, AutoDesk, GML3.0 specification, Welcome to CommLinx Solutions - GPS Tracking Systems, commlinx. com.au/default.htm 15. Lehto L., Standards-Based Service Architecture for Mobile Map Applications, 5th AGILE Conference on Geographical Information Science, Palma (Balearic Islands, Spain) April (2002)