• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.5
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• pp.54-63
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• 2000

We present a multi-resolution block matching algorithm (BMA) for fast motion estimation At the coarsest level, a motion vector (MV) having minimum matching error is chosen via a full search, and a MV with minimum matching error is concurrently found among the MVs of the spatially adjacent blocks Here, to examine the spatial MVs accurately, we propose an efficient method for searching full resolution MV s without MV quantization even at the coarsest level The chosen two MV s are used as the initial search centers at the middle level At the middle level, the local search is performed within much smaller search area around each search center If the method used at the coarsest level is adopted here, the local searches can be done at integer-pel accuracy A MV having minimum matching error is selected within the local search areas, and then the final level search is performed around this initial search center Since the local searches are performed at integer-pel accuracy at the middle level, the local search at the finest level does not take an effect on the overall performance So we can skip the final level search without performance degradation, thereby the search speed increases Simulation results show that in comparison with full search BMA, the proposed BMA without the final level search achieves a speed-up factor over 200 with minor PSNR degradation of 02dB at most, under a normal MPEG2 coding environment Furthermore, our scheme IS also suitable for hardware implementation due to regular data-flow.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.8
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• pp.455-476
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• 2006

An avatar script language consists of commands set which is used to control avatar behaviors in cyberspace. The script language should be abstract from complex low-level concepts, so that a user can write down a scenario script easily without concerning about physical motion parameters. Also, the script should be defined in a standard format and structure to allow reusing in various implementation tools. In this paper, a layered script language is proposed for avatar behavior representation and control, which consists of task-level behavior, high-level motion and primitive motion script language. The script language of each layer represents behavior elements for a scenario scripting interface, an avatar motion sequence, and geometric information of implementation environment, respectively. Therefore, a user can create a scenario script by abstract behavior interface and a script can be applied to various implementations by the proposed translating process. A presentation domain is chosen for applying the proposed script language and the implementation result shows that the script is flexibly applied in several applications.

• Journal of the Economic Geographical Society of Korea
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• v.10 no.2
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• pp.182-196
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• 2007

EU has pursued of the economic growth and the promotion of jobs by a free movement of workers. The free labour mobility brings a sustainable economic development through the creating jobs and the acquisition of a new knowledge and technology, but it also produces the geographical unequality of the movement of workers. And the enlargement of the EU redistributes geographically the flow of labour mobility. The flow of labour movement within EU changes to the structure of mobility that moves from the North to the North instead of the movement from the South to the North as an economic development in the South and an economic transformation to the service and hightech industry in the North. The mobility of unskilled workers has diminished, but the mobility of expert workers has increased. The flow of labour movement within EU has a structure hierarchic that the experts labour move from the North to the North, and the unskilled labour move from the South to the North and from the northern Africa to the South of Europe.

• The Transactions of the Korea Information Processing Society
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• v.4 no.9
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• pp.2289-2298
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• 1997

This paper proposes a new method to recognize map. In order to minimize the ripple effect of one recognition result affecting another, the structural information is represented with a hierarchical model. and the model is used in both the recognition and verification process. Furthermore, lines related to an entity are searched in a used in both the recognition and verification process. Furthermore, lines related to an entity are searched in a reduced search space by defining some relations between lines. When there is a mis-recognition after verificaiton, recognition process will be retired. In the process, the accurate result can obtained through the change of the parameter values used in the algorithm. As a result, the search space is reduced effectively, and even objects that embodies the broken lines and the crossed lines are recognized.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.688-690
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• 2004

최근 전자화된 문서 영상을 효율적으로 관리하고 검색하기 위한 문서구조분석 방법과 문서의 자동 분류에 관한 많은 연구가 발표되고 있다. 본 논문에서는 NMF(non-negative matrix factorization) 알고리즘을 사용하여 폰트를 자동으로 분류하는 방법을 제안한다. 제안된 방법은 폰트의 구분 특징들이 공간적으로 국부성을 가지는 부분으로 표현될 수 있다는 가정을 바탕으로, 전체의 폰트 이미지들로부터 각 폰트들의 구분 특징인 부분을 학습하고, 학습된 부분들을 특징으로 사용하여 폰트를 분류하는 방법이다. 학습된 폰트의 특징들은 계층적 군집화 알고리즘을 이용하여 템플릿을 생성하고, 테스트 패턴을 분류하기 위하여 템플릿 패턴과의 EMD(earth mover's distance)를 사용한다. 실험결과에서 폰트 이미지들의 공간적으로 국부적인 특징들이 조사되고, 그 특징들의 폰트 식별을 위한 적절성을 보였다. 제안된 방법이 기존의 문자인식. 문서 검색 시스템들의 전처리기로 사용되면. 그 시스템들의 성능을 향상시킬 것으로 기대된다.

• Journal of KIISE:Software and Applications
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• v.30 no.1_2
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• pp.103-116
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• 2003

States explosion due to composition of spaces of data, temporal, and locational values is one of the well-known critical problems which cause difficulty in understanding and analysing real-time systems specified with state-based formal methods. In order to overcome this problem, this paper presents an abstraction method for state minimization based on an abstraction in system specification and an abstraction in system execution. The first is named the syntactic in system specification and an abstraction in system execution. The first is named the syntactic abstraction, through which the patterns of the unconditionally internalized computation and the repetition and selection structures are abstracted. The latter is named the semantic abstraction, through which the patterns of the execution space represented with data. Through the abstractions, the components of a system in specification and execution model is hierarchically organized. The system can be analyzed briefly in the upper level in an skeleton manner with low complexity. The system, however, can be abstraction method for the state minimization and the decrease in analysis complexity through the abstraction with examples.

• Journal of the Korea Society for Simulation
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• v.17 no.3
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• pp.35-44
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• 2008

Facility location problem is an important subject in many areas of modern business environment. In this paper, we deal with uncapacitated and multi-period facility location problem where the object is a maximization of total profit within predetermined cost. We assume that all demand have to be met. Particularly, we represent various types of customer based on four well-known urban spatial structures to represent a spread of customers. Those are concentric zone model, sector model, multiple nuclei model and star model respectively. We apply to the genetic algorithm to simulate a large scaled problem and develop simulator. We analyze both optimal numbers and locations of facilities for each urban structure. Furthermore, we examine the appropriate time to further expansion of the facilities in the planning horizon. The experimental results show that the developed algorithm can be applied effectively to the facility location problem in the various types of urban area.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.626-626
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• 2015

본 연구에서는 하천공간정보의 웹서비스를 위해 SOAP(Simple Object Access Protocol) API 및 REST(Representation State Transfer) API로 제공하는 HydroG-OneFlow 웹서비스를 개발하였다. HydroG-OneFlow는 GML 기반의 서비스를 제공하며 GetBasin, GetGeoVariable 및 GetData 등의 기본서비스로 구성된다. GML은 GIS S/W의 벡터 GML 포맷과 공간정보 오픈플랫폼 서비스인 브이월드 데이터 API에서 제공하는 GML 포맷을 참고하여 하천공간 벡터정보를 제공할 수 있도록 GML을 구성하였다. GDM 공간 데이터에 대한 벡터정보 ML 수용 수준을 향상시킬 수 있도록 벡터구조의 점, 선, 면 정보에 대하여 GML의 PointPropertyType, CurvePropertyType, SurfacePropertyType을 도입하였다. 또한 일반적인 공간자료에서는 Multi 객체에 대한 지원도 필요하다. 현 GDM 데이터베이스에서도 OGC 표준의 MultiPoint, MultiLineString, MultiPolygon을 지원하고 있다. 이를 위하여 GML의 상응 요소인MultiPointPropertyType, MultiCurvePropertyType, MultiSurfacePropertyType을 하천공간정보 벡터 스키마에 도입하여 활용하였다. 클라이언트 서버 통신은 메시지 교환프로토콜인 SOAP을 사용하여 서버의 객체를 직접 호출하여 이루어진다. 서버는 서버의 제공 서비스를 WSDL(Web Service Description Language)를 통하여 게시하고 클라이언트는 이 기준(Criteria)을 참고하여 접근한다. GetData의 경우 Type(GRID or VECTOR), GDM(Geospatial Data Model) 여부(true or false), LayerName, BasinID, GenTime을 인자로 받아 GeoData에서 검색된 정보를 반환한다. SOAP버전은 1.1과 1.2를 지원하여 접근하는 클라이언트에서 선택할 수 있도록 개발하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.2
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• pp.180-185
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• 2003

This paper proposes an intelligent navigation algorithm for multiple mobile robots under unknown dynamic environment. The proposed algorithm consists of three basic parts as follows. The first part based on the fuzzy rule generates the turning angle and moving distance of the robot for goal approach without obstacles. In the second part, using both fuzzy and neural network, the angle and distance of the robot to avoid collision with dynamic and static obstacles are obtained. The final adjustment of the weighting factor based on fuzzy rule for moving and avoiding distance of the robots is provided in the third stage. The experiments which demonstrate the performance of the proposed intelligent controller is described.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.28-30
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• 2001

동적 캐시 그룹 구성 정책으로 중첩된 그룹 캐시 구조가 제시되면서 중첩 캐시의 운영 방안에 대한 연구가 필요하게 되었다. 그 기반 연구로 계층 캐시의 효율적 캐시 분배 정책을 그대로 살리되 중첩 그룹 캐시를 이용하는 방안으로 그룹 내 멀티캐스팅 페이지 분배 정책이 제시되고 있다. 그러나 그룹내의 모든 캐시에 해당 페이지를 분배하는 방안은 불필요한 저장 공간 낭비를 가져올 뿐 아니라 그룹 내 통신량 증가라는 문제점을 내포하고 있다. 따라서 본 논문에서는 그룹 내 캐시의 역할을 두 개의 기능으로 나누어 보다 효율적 페이지 분배와 그룹 유지 운영 방안을 제시하려 한다. 또한 중첩 그룹 캐시에서 제기되는 요청 진행 방향 문제에 대한 해결 방안으로 그를 아이디를 활용한 진행 방향 테이블 운영 방안을 제시하려 한다.