• International Journal of Safety
• /
• v.2 no.1
• /
• pp.50-56
• /
• 2003

There are a lot of uncertainties in the severe accident phenomena and scenarios in nuclear power plants (NPPs) and one of the major issues for severe accident management is the reduction of these uncertainties. The severe accident management aid system using Probabilistic Safety Assessments (PSA) technology is developed for the management staff in order to reduce the uncertainties. The developed system includes the graphical display for plant and equipment status, previous research results by a knowledge-base technique, and the expected plant behavior using PSA. The plant model used in this paper is oriented to identify plant response and vulnerabilities via analyzing the quantified results, and to set up a framework for an accident management program based on these analysis results. Therefore the developed system may playa central role of information source for decision-making for severe accident management, and will be used as a training tool for severe accident management.

• Proceedings of the KIEE Conference
• /
• 2006.07a
• /
• pp.27-28
• /
• 2006

최근 변전소 자동화 시스템에서 가장 큰 관심사는 종래의 인간의 개입을 최소화 할 수 있는 통합화, 자동화, 원격 감시화이다. 즉 변전소를 구성하는 장비들은 서로 다른 구조와 통신방식에서 벗어나 IEC61850 표준규격에서 제안하는 객체 모델링 및 통신프로토콜을 이용한 마이크로프로세서 기반의 IED를 개발하여 상호운용성을 확보하는 것이다. 본 연구에서는 IEC61850기반의 간단한 과전류 계전 IED(OCR)를 개발하고 그 구현방법을 설명하였다. 구현을 위해 상용보드인 MVME5100에 실시간 운영체제인 VxWorks를 포팅하여 MMS(Manufacturing Message Specification), SMV(Sampled multicast value) GOOSE(Generic object oriented substation event) 통신모듈을 탑재하였고 과전류 계전 요소들을 논리장치 및 논리노드로 구현하였다. 또한 전력계통 시뮬레이터인 Hypersim을 이용하여 IEC61850기반의 리클로저, 액츄에이터, 병합장치를 구현하고 과전류 계전 IED의 성능을 검증하였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2007.05a
• /
• pp.757-760
• /
• 2007

최근 각 기업과 공공기관들의 서비스들은 웹 서비스 기반으로 구축되고 있다. 이러한 여러 서비스들을 혼합한 협업적 웹 서비스 환경에서 서비스에 대한 프로세스 관리, 서비스 상태 체크, 서비스 과금을 위한 과금 요소 추출등을 위한 모니터링이 필요하다. 이에 본 논문에서는 효과적인 모니터링을 위하여 이벤트 기반의 협업적 웹 서비스 관리 모니터링 구조와 방법을 제시한다. SOA (Service Oriented Architecture) 기반의 협업적 웹 서비스 개발 생명주기를 단계별로 검토하여 관리 모니터링의 관점에서 필요한 요구사항들을 찾아내고, 이를 기반으로 협업적 웹 서비스 관리를 위한 이벤트 기반의 관리 모니터링 시스템 아키텍처를 제시한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2007.05a
• /
• pp.225-228
• /
• 2007

차세대 보험시스템에서 지향하는 실시간 기업(RTE: Real Time Enterprise) 서비스가 오픈 프레임 플랫폼 기반의 다운사이징으로 구체화됨에 따라 서비스 지향 아키텍처(SOA: Service Oriented Architecture)와 이벤트 기반 아키텍처(EDA: Event Driven Architecture)가 비즈니스 어플리케이션을 변화시키는 주요한 설계 스타일로 등장하게 되었다. 이에 따라 엔터프라이즈 서비스 버스를 통한 서비스 흐름이 업무 서비스간 유연한 결합이 되도록 프로세스 관리 목적에 부합하는 연계성 방안이 필요하게 되었다. 본 연구에서는 이러한 설계 스타일의 SOA 구현방식에 있어서 비즈니스 프로세스관리(BPM: Business Process Management)에 대한 비즈니스 측면과 IT 측면의 연계성 방안을 마련하였다. 이 방안을 도출하기 위하여 관련 디자인 패턴을 연구한 후 BPM 솔루션을 활용하여 연계테스트를 통한 검증을 수행하였고, 이러한 분석결과는 향후 SOA 로 차세대프로젝트를 진행하려는 이용자들에게 아키텍처 수립 및 시스템 개발에 필요한 효율적인 방안을 제공할 수 있을 것이다.

• Journal of the Korea Society for Simulation
• /
• v.4 no.2
• /
• pp.1-16
• /
• 1995

The performance of a computer system depends on the system architecture and workload, and the high performance required in many applications can be achieved by the scalability of the system architecture and workload. This paper presents scalable workload, a performance metric of scalable speedup and hierarchical modeling for the scalable computer system as well as the development of the object-oriented simulator spmplC++ Which is an advanced C++ version of the discrete event-driven simulation environment smplE. In addition, this paper presents two examples of applying scalable speedup, hierarchical modeling and simulator smplC++ to analyze the performance effect of the sclcbility in a multiprocessor system and a network-based client/server system.

• Journal of the Korea Society for Simulation
• /
• v.5 no.2
• /
• pp.25-40
• /
• 1996

Modeling of systems for intensive knowledge-based processing requires a modeling methodology that makes efficient access to the information in huge data base models. The proposed level access mothodology is a modeling approach applicable to systems where data is stored in a hierarchical and modular modules of active memory cells(processor/memory pairs). It significantly reduces the effort required to create discrete event simulation models constructed in hierarchical, modular fashion for above application. Level access mothodology achieves parallel access to models within the modular, hierarchical modules(clusters) by broadcasting the desired operations(e.g. querying information, storing data and so on) to all the cells below a certain desired hierarchical level. Level access methodology exploits the capabilities of object-oriented programming to provide a flexible communication paradigm that combines port-to-port coupling with name-directed massaging. Several examples are given to illustrate the utility of the methodology.

• Journal of information and communication convergence engineering
• /
• v.6 no.1
• /
• pp.59-63
• /
• 2008

The methods or algorithms which can accelerate simulation speed became of great importance, as the modeling and simulation methodology for discrete event systems is used in many areas such as model validation/verification and performance evaluation. This paper proposes a tool named, DEVSIF composer. The tool is made of an automated compiled simulation technology and it builds a new composed model which can be executed much fast by composing the component models together. Models are described by our new specification language DEVSIF, which is compatible with object-oriented language and supports representation of a hierarchical model structure. Experimental results demonstrates that DEVSIF composer enhances the simulation speed of a transformed DEVS model 5 times faster than that of the original ones in average.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.9 no.1
• /
• pp.1-9
• /
• 2014

As Android platform and its applications are widely used, it is necessary to assure the reliability and safety of Android applications. The capture and replay technique is widely used for reproducing the crashes in Java applications. In this paper, we adapt the context-based capture and replay technique to Android applications by considering Android activity structure and its GUI characteristics. Our capture and replay technique uses probe code insertion based on AspectJ for minimizing the original code change and for enhancing the efficiency and reusability of the probe codes. For proving the efficiency of our technique, we provide a case study and execution overhead comparisons with related works, in which our approach has merits in GUI oriented Android applications with relatively low execution overhead.

• Journal of the Korean housing association
• /
• v.1 no.1
• /
• pp.37-48
• /
• 1990

The objective of this study is to suggest a housing life cycle of Korean families which adds to the establishment of reasonable housing standards and to the prediction of fufure-oriented family housing behavior by reviewing published papers. Following model is suggested as a housing life cycle suitable to assess the family housing behavior in Korea. 1st stage : period of house searching 2nd stage : period of house changing 3rd stage : period of house stabilizing \circled1 size enlargement phase \circled2 quality improvement phase \circled3 stable settlement phase 4th siage : period of house contracting 5th stage : period of house depending Since the proposed model is hypothetical, it must be tested and modified by the extensive social survey research on the real housing event history.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.193-194
• /
• 2008

IEC 61850 기반의 변전소자동화시스템이 세계적으로 많은 관심을 가지면서 IEC 61850 프로토콜 기반의 IED(Intelligent Electronic Device) 개발을 위해 전 세계적으로 많은 노력이 진행되고 있다. 본 연구에서는 IEC 61850 표준규격에서 제안하는 객체 모델링 및 통신프로토콜을 이용하여 2권선 변압기 보호용 IED를 개발하고 그 구현방법을 설명하였다. 구현을 위해 리눅스 OS(Operation System)가 포팅된 통신보드에 MMS(Manufacturing Message Specification), GOOSE(Generic object oriented substation event) 통신모듈을 탑재하였고 데모 시스템을 구성하여 성능을 검증하였다.