• KIISE Transactions on Computing Practices
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• v.20 no.12
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• pp.688-693
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• 2014

With the advent of ubiquitous environments, the smart phone has come into wide use and the demand for various content increases. Thus, in order to efficiently utilize limited resources cognitive radio technology is regarded as a possible solution. Besides spectrum sensing or access schemes, the provision of VoIP traffic service for secondary users with limited spectrum resources is a very important issue. In this paper, a resource allocation and control system for VoIP QoS provision in cognitive radio networks is proposed. Firstly, as the system model, the time structure of the network is addressed and, according to the structure, a bandwidth broker is proposed. In addition, based on available bandwidth estimated by the bandwidth broker, a connection admission control for secondary users is developed. It is demonstrated that the provision of VoIP QoS is greatly affected by channel utilization, the number of channels, and the length of timeslot.

• Information and Communications Magazine
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• v.30 no.4
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• pp.7-15
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• 2013

본고에서는 최근 클라우드 컴퓨팅 기술에서 이슈가 되고 클라우드 서비스 브로커(Cloud Service Broker) 기술 및 관련 기술동향을 살펴보고 실제 구현을 진행중인 사례를 분석 함으로서 클라우드 서비스 브로커 기술에 대한 전반적인 내용을 살펴보고자 한다.

• Korean Journal of Computational Design and Engineering
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• v.9 no.4
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• pp.361-372
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• 2004

Collaborative and distributed engineering web services are emerging as a viable alternative to the traditional design and engineering process automation. Existing approaches have limitations in supporting long-running engineering transactions, automatic engineering process orchestration and choreography, synchronous and asynchronous conversation, and geometric abstraction for transmission and sharing. In this paper, we present a process-centric engineering web service methodology to overcome these limitations by utilizing BPEL-based (Business Process Execution Language) process templates and coordination broker-based conversation support. This paper discusses the synchronization of engineering web services which can be either peer-centric or process-centric to support long-running engineering transactions and conversation. The process orchestration and choreography broker works as a service dispatching and aggregation mediator for executing process templates, which enables the individual activity or the engineering process to dynamically select and invoke one of the alternative web services through the run-time process brokering. Further, the paper presents how to support collaboration over the running process using conversation policy.

• Convergence Security Journal
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• v.5 no.3
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• pp.15-22
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• 2005

The spread of Internet and the appear of Downsizing, SI(System Integration) is chaning centralized computing to distributed computing. Also distributed computing is rapidly changing to Ubiquitous computing escape from hard wire connected network. CORBA(Common Object Request Broker Architecture) is a middleware that used for smoothness communication between application program and operation system in a different environment. However distributed computing environment is not safe from the danger, the attack like virus, worm is too intellectual and variety. In this paper, we design a new DB security model and suggest efficiency of it in Ubiquitous environment base on CSS(CORBA Security Service) that present ed from OMG(Object Management Group).

• Journal of the Korea Society of Computer and Information
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• v.10 no.4 s.36
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• pp.337-344
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• 2005

UDDI server is the web services registry enabling users to register and search for web services. However, the existing UDDI servers do not provide any information about web services qualify. We designed and developed a UDDI broker system which actively monitors and analyses the qualify of web services. The analysis results are presented to users in statistical figures and graphs. With this information a user can select a web service that meets his/her needs. Availability, performance, and stability were the metrics used for the service qualify measurement and analysis.

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.24 no.3 s.202
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• pp.35-42
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• 2006

본 논문에서는 내장형 소프트웨어 시스템, 특히 로봇 소프트웨어를 위한 self-managed 소프트웨어 개발 프레임워크로서 SHAGE 프레임워크를 제안하였다. SHAGE 프레임워크는 소프트웨어를 실행시간에 동적으로 변경시킬 수 있도록 지원하는 여러 모듈로 구성되어 있다. Observer가 외부 상황을 관찰하고 관찰된 상황이 Architecture Broker로 전달되면 후보 아키텍처 재구성 전략을 검색하고 Component Broker가 구체화 컴포넌트들을 검색한 후 상황에 적절한 아키텍처 재구성 전략과 컴포넌트 구성을 Decision Maker가 선택한다. Reconfigurator가 선택된 전략과 컴포넌트 구성을 기초로 로봇의 아키텍처를 재구성한다. 적응행위를 Evaluator가 평가하고 그 결과를 Learner가 축적하여 나중에 Decision Maker가 사용할 수 있게 한다. 프레임워크의 효용성을 확인하기 위해서 실제 로봇을 이용한 사례연구를 수행하였고, 이 실험을 통해 적응 과정을 확인하였다. 로봇은 상황과 사용자의 피드백에 적응하였다.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.190-192
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• 1998

이동에이전트를 위한 이동객체(mobile agent)와 이를 지원해주는 이동객체서버(mobile object system)를 설계하고 이러한 요소들을 제어하고 관리하는 이동객체 시스템(mobile object system)을 Java로 구현한다. 또, 시스템 내의 이동객체를 비롯한 모든 객체들간의 객체 요청(object request)을 유연하게 중계하고 이들간의 통신을 담당하는 ORB (Object Request Broker)를 TCP/IC상에서 Java 로 구현하고 이동 에이젼트 시스템을 쉽게 구측할수 있는 앱스트랙션(abstraction)과 API를 제공한다. 이 시스템은 네이밍 서비스(naning service)와 푸쉬형 이벤트 서비스(push-event service)등을 기본적으로 지원한다.

• The Journal of Korean Association of Computer Education
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• v.9 no.4
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• pp.63-74
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• 2006

A molecular docking is thc process of reducing an unmanageable number of compounds to a limited number of compounds for the target of interest by means of computational simulation. And it is one of a large scale scientific application that requires large computing power and data storage capability. Previous applications or software for molecular docking were developed to be run on a supercomputer, a workstation, or a cluster computer. However the virtual screening using a supercomputer has a problem that a supercomputer is very expensive and the virtual screening using a workstation or a cluster-computer requires a long execution time. Thus we propose Grid service based molecular docking application. We designed a resource broker and a data broker for supporting efficient molecular docking service and developed various services for molecular docking.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.6
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• pp.1131-1141
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• 2013

Most of the single server model of cloud computing services have problems that are hard to solve, such as a service availability, insider attack, and vendor lock-in, etc. To solve these problems, the research about multicloud has emerged. Multicloud model can supplement previous cloud model's weakness and provides new services to user. In this paper, we focus on a user authentication problem in multicloud model and propose a scheme to resolve it. We define a cloud broker-based multicloud model. And we propose an authentication protocol that is applicable at presented model. The proposed scheme can provide service transparency to user and prevent an impersonation attack by service provider.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.7
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• pp.23-29
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• 2012

A single line diagram is a graphic user interface to represent electrical connectivity between power equipments in distribution automation systems. This paper proposes a new single line auto-drawing technique based on the service oriented architecture. Web service, CIM(Common Information Model) and SVG(Scalable Vector Graphics) are adopted to implement SOA concept. A web service demo system was established which is configured with the service provider, consumer and broker to verify the feasibility of this study.