• Journal of KIISE:Computing Practices and Letters
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• v.13 no.1
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• pp.35-45
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• 2007

The log data collected from mobile devices contains diverse meaningful and practical personal information. However, this information is usually ignored because of its limitation of memory capacity, computation power and analysis. We propose a novel method that detects landmarks of meaningful information for users by analyzing the log data in distributed modules to overcome the problems of mobile environment. The proposed method adopts Bayesian probabilistic approach to enhance the inference accuracy under the uncertain environments. The new cooperative modularization technique divides Bayesian network into modules to compute efficiently with limited resources. Experiments with artificial data and real data indicate that the result with artificial data is amount to about 84% precision rate and about 76% recall rate, and that including partial matching with real data is about 89% hitting rate.

• Journal of KIISE:Software and Applications
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• v.34 no.8
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• pp.752-762
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• 2007

The PSP (Personal Software Process) is developed to help developers make high-quality products through improving their personal process. With consistent measurement and analysis activity that the PSP suggests, developers can identify process deficiencies and make reliable estimates on effort and quality. However, due to the high-overhead and context-switching problem of manual data recording, developers have difficulties in collecting reliable data, which can lead wrong analysis results. On the other hand, the paper-based process guides of the PSP are inconvenient to navigate its process information and difficult to attach additional information. In this paper, we introduce a PSP supporting tool developed to handle these problems. The tool provides automated data collection facilities to help acquire reliable data, an EPG (Electronic Process Guide) for the PSP to provide easy access and navigation of the process information, and an experience repository to store development experience as additional information about the process.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.4
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• pp.264-274
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• 2006

Recently, a variety of organizations including enterprises tend to try to use reporting tools as a data analysis tool for decision making support because reporting tools are capable of formatting data flexibly. Traditional reporting tools have thin-client structure in which all of dynamic documents are generated in the server side. This structure enables reporting tools to avoid repetitive process to generate dynamic documents, when many clients intend to access the same dynamic document. However, generating dynamic documents for data analysis doesn't consider a number of potential readers and increases requests to the server by making clients input various parameters at short intervals. In the structure of the traditional reporting tools, the increase of these requests leads to the increase of processing load in the server side. Thus, we present the reporting tool that can generate dynamic documents at the client side. This reporting tool has a processing mechanism to deal with a number of data despite the limited memory capacity of the client side.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.5
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• pp.510-519
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• 2002

The OpenGIS Consortium has proposed a new web-mapping technology to support interoperability in web GIS environment by developing the specifications of MapServer and GML. In this environment, the MapServer transforms legacy spatial data into GML data, and clients display them on standard web browsers. This web-mapping testbed proposes methods for discovering, accessing, integrating and displaying GIS information except processing of spatial operations which are essential services in GIS environment. This paper proposes the method for executing spatial operations on GML data which are overlays of different map layers in legacy data servers. To support spatial operations on GML data in web GIS environment, this paper designs and implements GDOM based on the W3C's DOM Specifications and OGC's Simple Features Specifications. This paper shows the specifications and implementation of GDOM and the process of spatial operations in web-mapping testbed environment.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.5
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• pp.498-509
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• 2001

Collaborative systems allow users, who may be far removed from each other geographically, to do collaborative work such as 3D animation, computer game, and industrial design in a single virtual space. This paper describes our experience to develop a collaborative system framework that aims at expanding the some functions of a stand-alone visual modeling tool, called 3D Studio Max, into those of the distributed collaborative working environments. The paper mainly deals with design and implementation of a 3D shared-object Plug-In with respect to the 3D Studio Max Plug-In Software Development Kit in the distributed collaborative system developed by the authors. There are two major functions of the proposed scheme; one is to write 3D object-information to the shared memory after extracting it from the 3D Studio Max, the other is to create 3D objects after retrieving them from the shared memory. Also, the proposed scheme provides a simple way of storing 3D objects that have variable size, by means of shared memory which located in between the collaborative system clients and 3D studio Max. One of the remarkable virtures of the Plug-In is to reduce a considerable amount of shared object data which in consequence can mitigate the network overhead. This can be achieved by the fact that the system is able to extract a minimum amount of 3D objects that are required to transmit. Also, using the proposed scheme, user can facilitate 3D Studio Max into distributed collaborative working environments. This, in consequence give many benefits such as saving time as well as eliminating space constraints in the course of 3D modeling when we are under industrial design process.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.4
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• pp.334-348
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• 2005

The goal of next generation digital broadcasting is offering the interaction among consumers and providers as well as variety services. One of the important factors for this new broadcasting environment keeps the interoperability among providers and consumers since the environment is distributed. Therefore a standard metadata for digital broadcasting is required and TV-Anytime metadata is one of the metadata standards for digital broadcasting. The terminal nodes of TV-Anytime metadata are defined by using MPEG-7 metadata. MPEG-7 metadata is standard metadata for describing multimedia content. Therefore, if we use the MPEG-7 metadata for describing broadcasting content can offer multimedia search services like content-based search by the extension of metadata. The efficient management system for these metadata is important for offering the services with high Duality on real broadcasting environment TV-Anytime metadata and MPEG-7 metadata are technically defined using a single XML schema, so its instances are XML data. Currently, a lot of systemsfor managing XML data are proposed in many researchers and we can expect to adapt these systems for managing broadcasting metadata. But the methods used in these systems are not specific methods for managing broadcasting metadata because of methods for general-purpose. In this paper, we find the properties of broadcasting metadata and develop an efficient metadata management system that is based on the found properties. Since our systemis implemented on real broadcasting environment, we expect that the system is most efficient and suitable. Also our system is interoperable since we use XQuery as query language for querying broadcasting metadata.

• Journal of KIISE:Databases
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• v.33 no.7
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• pp.715-726
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• 2006

Web service technologies provide a standard means for interoperation and integration of heterogeneous applications distributed over the Internet. For efficient execution of hierarchically interacting composite web services, this paper proposes an approach to distribute web service invocations over peer systems effectively, exploiting intensional XML data embedding external service calls as a result of well services. A cost-based optimization problem on the execution of web services using intensional results was formalized, and a heuristic search method to find an optimal solution and a greedy algorithm to generate an efficient invocation plan quickly were suggested in this paper. Experimental evaluation shows that the proposed greedy algorithm provides near-optimal solutions in an acceptable time even for a large number of Web services.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.88-90
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• 2001

최근 웹 확산에 따른 일반인들의 인터넷 이용이 급증하였고 이에 따른 정보 기술도 빠르게 변화하고 있다. GIS 분야에서도 시대의 흐름에 맞춰 지리정보 데이타를 웹상에서 제공하는 웹 GIS 분야가 등장하게 되었다. 그러나, 상호 이질적인 지리정보 데이타를 웹 기반 분산 환경에서 서비스하기 위해 표준 인터페이스와 각각의 웹 서비스 모델을 정의한 통합 시스템이 요구되고 있다. OGC(OpenGIS Consortium)에서는 기존 OpenGIS(Open Geodata Interoperabillty Specification)의 상호운용성을 웹 환경에서 지원하고, 또한 상호이질석인 지리정보의 접근을 위해 새로운 웹 맵 서버인터페이스 구현 명세(Web Map Server Interface Implementation Specification)를 제안하였다. 웹 맵 서버 인터페이스 구현 명세는 웹상에서 공간 질의를 처리하기 위안 URL 컴포넌트를 정의하고 있으며, URL 형식의 클라이언트 질의를 수행한 결과를 웹 브라우저에서 이미지 포맷으로 지리정보를 제공한다. 본 논문에서는 OGC가 최근 제안한 XML(eXtendible Markup Language)기반의 표준 공간 데이터 포맷인 GML(Geography Markup Language)과 웹 맵 서버 인터페이스를 이용해 분산된 지리정보 데이터를 웹 브라우서를 통하여 서비스할 수 있는 웹 맵 서버를 설계 및 구현하였다. 따라서 클라이언트는 본 논문에서 개발한 웹 맵 서버를 통하여 별도의 응용 프로그램을 개발하지 않고도 다양한 GIS 시버들의 종류와 위치에 관계없이 표준 인터페이스를 통해 이를 GIS 서버들로부터 공간 데이터를 접근할 수 있다.

• The KIPS Transactions:PartD
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• v.12D no.4 s.100
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• pp.531-542
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• 2005

In this paper, we propose the MDBMS(Multi-DataBase Management System) which integrates the LDBMSs(Local DataBase Systems) with heterogeneous environment into distributed system and provides global users with rapidly query process. For designing the MDBMS, we define the functions of components and design the interaction among them. In a point of view of the global view manager in components, we describe the following 3 cases; (1)the case which the results for the global query are all stored to the global view repository, (2)the case which no result exists in the global view repository, and (3)the case which the partial results we stored to the global view repository. By comparing above cases, we establish the functionalities of our MDBMS through the sequence diagram including the interlace of among objects and the method calling. Finally, we propose the model designed in the concrete by showing the executing procedures of each function using sample query on established functions mentioned above.

• Journal of KIISE:Databases
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• v.32 no.3
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• pp.254-262
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• 2005

This paper presents a new sequential indexing method called segment-page indexing (SP-indexing) for multidimensional range queries. The design objectives of SP-indexing are twofold:(1) improving the range query performance of multidimensional indexing methods (MIMs) and (2) providing a compromise between optimal index clustering and the full index reorganization overhead. Although more than ten years of database research has resulted in a great variety of MIMs, most efforts have focused on data-level clustering and there has been less attempt to cluster indexes. As a result, most relevant index nodes are widely scattered on a disk and many random disk accesses are required during the search. SP-indexing avoids such scattering by storing the relevant nodes contiguously in a segment that contains a sequence of contiguous disk pages and improves performance by offering sequential access within a segment. Experimental results demonstrate that SP-indexing improves query performance up to several times compared with traditional MIMs using small disk pages with respect to total elapsed time and it reduces waste of disk bandwidth due to the use of simple large pages.