地點相關服務(Location-Dependent Service) 是近來相當熱門的一項研究，它可以有效減少傳送至資料頻寬或顯示能力有限裝置的資料量，簡單來說，地點相關加值服務就是根據使用者的位置來搜尋資訊，進而提供加值服務。加值服務主要的重點在於必須先能提供位置相關的資訊(Location-Dependent Information)，然後才能根據提供的資訊進一步做加值服務。本篇論文提出GSM手機為定位來源的定位方法，一個可以利用道路鄰近圖去尋找地點相關資訊的演算法，以及一個針對黃頁資料的所設計的資料模型(Semantic Data Model)，可以使黃頁資料的取得更加有效率。
電子黃頁資料的利用在地點相關服務及行動商務(mobile commerce)上扮演一個相當重要的角色，它包含了繁多且複雜的資料，如空間上、時間上及語意上(semantic)各方面，良好的資料表達將有助於黃頁資料的取得。它包含有實體資料層(Data Layer)、時間空間層(Spatial-Temporal Layer)與服務類別層(Category Layer)。
此系統已在Wireless Application Protocol (WAP)環境上實行，搜尋結果以Wireless Markup Language (WML)格式呈現。

The location-dependent service can greatly reduce information loading on limited network bandwidth and display appropriate information on limited screen size, which is important in mobile commerce. This paper proposes a novel framework for location-aware information system that is suitable to operate in mobile environment. There is a locating module that can obtain user’s location by GSM cellular network. A neighborhood graph is proposed to represent spatial information. A graph search algorithm is proposed to find location-dependent results from the neighborhood graph. And we also proposed a Semantic Data Model can handle the yellow page data with a good structure, then the system can get the yellow page information in an efficient way.
Electronic yellow page plays an important role in location-dependent service and mobile commerce. It includes rich and complex information that has spatial, temporal, and semantic aspects. Semantic modeling of yellow pages is necessary for efficient and intelligent retrieval. This paper proposes a semantic model to represent the rich information in yellow pages. The model has data layer, spatial-temporal layer, and category layer. Data layer has relational schema to store yellow page records. Spatial-temporal layer adopts graph structure to encode spatial and temporal information. Category layer represents the hierarchical relationship among categories and companies. Semantic relations, such as competition, cooperation, and branch are represented in category layer.
The system is implementation with Wireless Application Protocol (WAP). Search results are organized as dynamic documents, which are Wireless Markup Language (WML) cards and decks.

Abstract---------i
Content---------v
List of Figures---------vi
List of Tables---------vii
Chapter 1 Introduction---------1
1.1 Research motivation---------3
1.2 Concept of “location-dependent service---------5
1.3 Related Works---------5
Chapter 2 The Semantic Data Model---------9
2.1 Spatial-temporal layer---------9
2.1.1 Spatial relationship---------10
2.1.2 Temporal relationship---------11
2.2 Category layer---------12
2.3 Data layer---------13
Chapter 3 The Location-dependent information system---------16
3.1 Databases---------16
3.1.1 Base station database---------17
3.1.2 Road database---------18
3.1.3 Yellow page database---------22
3.2 The search algorithm---------24
3.3 Locating module---------28
3.3.1 Techniques of positioning GSM telephones---------29
3.4 Dynamic documents---------32
Chapter 4 The Implementation---------34
4.1 Experimental result---------34
4.2 Analysis---------38
Chapter 5 Conclusions---------39
Reference---------41

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