• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.173-187
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• 2004

The horizon of using GIS technologies can be expanded to analyzing spatial changes by time in reality. Traditional GIS technologies usually use maps for a snapshot aspect of spatial information. Limitations of the present GIS technologies in terms of dealing with spatial changes require more solutions for collecting, processing and analyzing spatial data with time. Traditional GIS technologies include Temporal GIS, Real-time GIS and Virtual GIS respectively but those are not capable enough to represent spatial change in an overall perspective. By reflecting dynamic changes the current GIS technologies can be more useful and valuable than before. This study assumes that '4D GIS', a composite of temporal, realtime and virtual GIS technology, will open a new horizon for the future sophisticated GIS applications. By identifying a technology application model for 4D GIS the new concept of 4D GIS can be clarified. The model is established by combining dynamic spatial information types and applicable 4D GIS technologies, which are identified from the most current 4D application and research efforts. The technology application model for 4D GIS can be expected to contribute to efficient in planning for 4D GIS technology development in the future.he future.

• Spatial Information Research
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• v.13 no.3 s.34
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• pp.221-237
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• 2005

This study attempts at building a GIS computing environment that incorporates object-relational spatio-temporal database for the time geography model with space-time path, space-time prism and space-time accessibility. The proposed computing environment is composed of ( i ) mobile GIS application for collecting spatio-temporal trajectory data of an individual, ( ii ) spatio-temporal database server that includes time geography model, and (iii) geovisualization client that performs time geographic queries to the spatio-temporal database. The spatio-temporal trajectory data collected by GPS-PDA client is automatically processed and sent to server through data management middleware. The spatio-temporal database implemented by extending a generic DBMS provides spatio-temporal objects, functions, and SQL. The geovisualization client illustrates 3D visual results of the queries about space-time path, space-time prism, and space-time accessibility. This study confirms the possibility of integrating mobile GIS and DBMS for time geography model, and it presents the appropriate database model with spatio-temporal objects and functions that may handle very large data for time geography application.

• Spatial Information Research
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• v.12 no.1
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• pp.1-12
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• 2004

The 3-dimensional GIS data provider system manages and retrieves 2, 3-dimensional spatial and time data. This system provides the standard interfaces which help developers to omit additional works to do modify or convert a format of 2 or 3-dimensional spatial data, which has been already accumulated, into that dependent on a specified system. This system consists of a data provider and data access component. The former deals with the connections with some databases and manages the meta data, so that the various GIS or software can access to 3-dimensional spatial and time data via the same method, and the latter takes charge of index management and spatial operations on GIS data for consumers. The system offers the diverse spatial operations and analysis functions for 3-dimensional GIS.

• Spatial Information Research
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• v.8 no.2
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• pp.183-189
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• 2000

According to Oriental perspective on Universe, all systems become complete when three elements namely time, space, and human are all present. The only computer technology which can integrate these three elements is GIS. The current GIS database and system architecture, however, mainly concentrate on managing and analyzing spatial data without considering temporal and human elements. Despite the limitations, it is certain that GIS technology will develop into a unity within which the three elements of time, space and human are integrated. On the other hand, with the rapid acceptance of Internet technology, a new small universe that can be called "cyber world" is emerging. However, the current small univers created by internet is only a half-universe which does not include the concept of space. The creation of "cyber nation" which truly reflects our living environment in computer and information communication networks can only be achievedthrough the integration of GIS and Internet. Currently, many countries are heavily investing in GIS. Based on the magnitude of investments, we can expect that the concept of "cyber nation" will further develop into "cyber world" where the search for information on any part of global village is possible with the simple use of mobile phone regardless of time or location. If so, it might be possible to create a "Digitopia", a digital utopia in cyber space. A new world is opening by the integration of GIS and Internet.is opening by the integration of GIS and Internet.

• Journal of Internet Computing and Services
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• v.1 no.1
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• pp.73-86
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• 2000

The Geographic Information System (GIS) is a system that collects, stores, analyzes and processes geographic object data existing in space. The GIS is widely used in application fields related to geography such as city planning, land-register management, forest resources management, etc. The importance and necessity of the GIS have been well demonstrated, and therefore many studies on this system have been carried out. However, most of those studies have just treated geographic information as spatial information, but have not considered or have overlooked changes of spatial data dependent on time. For example, transportation information management and atmospheric phenomena forecast, have not exactly reflected the actual world which changes with the flow of time. In this thesis, a temporal GIS is established to effectively and precisely process information on space objects changing with time and a database is built up in reference to changes in water temperature and salinity. And the isotherm and isohaline forecast system implemented to support graphical tool.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.51-60
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• 2004

In open GIS environment, a GIS client can access spatial data in different types of GIS sowers with the same Interfaces. This means that open GIS components software ensures the interoperability throughout the heterogeneous GIS servers. The user response time, however, tends to be increased, if the client makes use of the standard interfaces for data accesses that can ensure interoperability. This is because the format of spatial data accessed from a specific GIS server must be transformed into common format, such as Rowset in OLE/DB, which is compatible with the standard interfaces. In this paper, we develop efficient techniques for data buffering in GIS client to reduce the response time. We design the buffer management method, which Is based on the space partitioning, and Integrate buffer management components into MapBase, an open GIS component software. And we also, show that buffer management proposed in this paper yields significant performance improvement in GIS client.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.4
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• pp.323-330
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• 2003

GIS-based applications for route guidance are increasingly developed recently, but most of them are for self$.$driven cars. Although some of them are intended for public transportation, they show limitations in dealing with time constraints problems taken place in transfer areas. Developing a public transportation guidance system requires the fallowing aspects: (i) people may change transportation means not only within the same type but also among different modes such as between buses and subways, and (ii) the system should take into account the time taken in transfer from one mode to the other. This study suggests the framework for developing a public transportation guidance system that generates optimized paths in the transportation network of mixed means including buses, subways and other modes. For this study, the Genetic Algorithms are used to find the best routes that take into account transfer time and other service-time constraints. The method for constructing the data structure in the GIS was also suggested.

• The Journal of the Korea Contents Association
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• v.6 no.12
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• pp.121-127
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• 2006

As information technologies are improving, geographical information system (GIS) technologies are also developing rapidly and demands for spatial analysis with GIS are increasing. Particularly, the spatial analyses with GIS researches have been noted rather than general GIS researches. However, most GIS researches focus on space dimension: a density-based clustering method (DBSCAN) or a DBSCAN algorithm using region expressed as Weight (DBSCAN-W) but the importance of rational decision making based on time dimension has been neglected. This study adopts system dynamics in order to put time dimension in GIS-based optimum allocation.

• Proceedings of the Korea Contents Association Conference
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• 2003.11a
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• pp.440-444
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• 2003

It was investigated to find the concept of the distance teaming, its characteristics and components, and to present successful strategies for the development of the GIS(Geographic Information Systems) programs for the online university. The elements of these successful strategies would be as follows. The models considered for the educational environment and characteristics, relationships between professor and student, community constructions for sharing the educational information, various courses based on the level, and linkages among various GIS programs.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10a
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• pp.278-280
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• 1999

실시간 GIS 응용 프로그램에서는 기존의 GIS 시스템과는 달리 동적인 공간데이터가 신뢰성을 위해 일정한 시간 내에 갱신되어야 유효성을 유지하며, 사용자가 요청하는 질의는 일정 시간 내에 처리되어야 하는 시간제약조건을 갖는다. 이러한 GIS응용프로그램을 지원하기 위한 실시간 공간데이터베이스 시스템에서는 기존의 실시간 데이터베이스 시스템에서 고려되지 않은 동적 실시간 공간데이터와 실시간 공간질의에 대한 처리가 필요하며 질의 처리 시 실시간 데이터와 실시간트랜잭션의 시간제약조건의 만족을 초대화하기 위한 고려가 필요하다. 본 논문에서는 실시간 공간질의 처리 시 예측성을 최대화 하기 위해 질의에서 빈번히 사용되는 데이터를 주기억상주 데이터베이스에 저장하였고, 실시간 공간데이터의 관리를 위하여 공간질의어를 확장하였다. 또한 실시간 공간질의 처리 시에 실시간 데이터와 실시간트랜잭션의 시간제약조건을 최대한 만족시키기 위해 공간질의 분석과 연산 순서의 재배치 기법을 사용하였다.