• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2370-2387
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• 2000

This paper proposes a new design strategy that can overcome limitations of two existing approaches, focusing on performance and scalability issues among various architectural issues which must be considered in designing workflow systems. In the proposed approach, we suggest to introduce 'delegation model' which corresponds to the high-level strategy utilizing the fundamental characteristics of mobile agents, after establishing a mobile agent-based workflow system architecture focused on performance and scalability. We point out three major issues that should be considered in this approach and propose a 3-tier mobile agent-based workflow system architecture that effectively reflects these considerations. Also, we show that the new approach can provide better performance and scalability than existing ones - approaches based on the client-server paradigm and other approaches based on mobile agent paradigm represented by DartFlow system - by evaluating performance of the proposed architecture through the GSPN simulation.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.388-390
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• 2001

본 논문은 변형성과 재 사용성이 우수한 컴포넌트 기반의 어플리케이션 서버 플랫폼을 구현하는데 필수적인 기술인, 워크플로우 관리 기술의 Built-Time 부분의 설계 및 구현을 다룬다. 워크 플로우 관리 시스템의 기능은 크게 Build-Time 부분과 Run-Time 부분으로 나누어서지는데, Build-Time 부분은 워크플로우프로세스를 사용하기 전에 정의하는 관점에서 기능을 수행하고 Run-Time 부분은 설정된 워크플로우 프로세스 정의에 따라 프로세스를 실제로 동작시키는 관점에서 기능을 수행한다. Run-Time 부분은 워크플로우 관리 시스템의 핵심 부분인 워크플로우 엔진 모듈을 포함하고 있다. 본 논문은 Build-Time 부분을 다룬다. 본 논문에서는 우리가 구현한 워크플로우 관리 시스템의 다양한 형태의 프로세스를 지원하는 프로세스 정의 모델과 그에 대한 XML 구조의 설계 및 프로세스 정의에 대한 객체를 설계하고 구현하였다.

• Journal of Korea Multimedia Society
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• v.4 no.5
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• pp.377-389
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• 2001

It has a tendency to build Workflow Systems based on the web with the spread of web environment. The important function in Workflow Systems are to automatize job flow according to the predefined regulations, procedures or conditions. Hence, there needs to consider excluding passive jobs, supporting GUI and a migratory information processing for information flow. Distributed Workflow System for workflow of a distributed service system should perform transfer control and Fault-Tolerance between tasks based on process logic, and real time processing. However, the existing mail systems being used are just for transmission and it doesn't fit to automatize job flow. To solve the matter, there needs a Distributed Workflow Engine to design workflow and automatize its control. In this paper, we design a web browser with graphic interface using web mail, a browser creating a script code for a procedural performance. Also, we design a Process-engine has a Preprocessor which tolerates process scheduler for task transaction or server node's faults on distributed environment. The proposed system enhances the reliability and usability of a system reduces the cost rather than a workflow system based on database, for they execute as proxy for a server's fault or suers' absence.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.333-336
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• 2000

As developing W industry, Enterprise environments are changed fast. As activeness is focused on an important factor in enterprise environment, mobile computing environment is being more popular. Workflow systems should be adapted to these changes because it takes change of automation of enterprise. So in this paper, I suppose an adaptive workflow system which covers all the types of client systems including mobile hosts and processes their works by capacity of each client

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.1255-1258
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• 2012

클라우드 컴퓨팅에서 사용되는 웹 서비스들은 워크플로우에 따라 서비스가 설계되어 조합된다. 대표적인 웹서비스 명세언어인 BPEL의 검증방법에는 Petri nets, Abstract State Machine(ASM), BPE-Calculus 등이 존재한다. 하지만 기존의 방법은 설계와 검증이 분리되어 있어 일관성이 부족하고, 시각화 문제, 동일성, 시간에 대한 제약조건의 문제점이 존재한다. 이에 대한 해결방안으로 이동성, 재구성성, 동일성, 시간속성 등의 새로운 분석 방법을 제시하는 Onion 언어가 제안되었다. 본 논문은 BPEL로 명세된 서비스를 Onion 시스템에 적용시키기 위한, 변환 과정에 대해서 다룬다. 이에 대한 과정으로 BPEL의 액티비티를 Onion으로 변환하고, 워크플로우 패턴을 적용하여, 3 가지 패턴을 Onion OVL로 변환을 적용하였다. 이를 통하여 BPEL을 Onion OVL로 변환하는데 문제가 없음을 보였으며, 효율적인 표현이 가능함을 보였다. 추후 Onion 시스템의 컴포넌트로 적용하여, BPEL로 작성된 서비스를 Onion 시스템을 통해 분석/검증할 수 있다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.67-74
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• 2009

This paper presents a method of improving the service availability by distributing the traffic of voice/data calls over the multi-layer cells in a mobile communication network. The traffic model is described and the call handling performance is analyzed. In our method, a fast moving call is moved to and serviced in the upper layer cell. A call is also moved upward when an overflow occurs. But unlike other methods, the call that is moved upward in the overflow case is the one which has the longest sojourn time in the cell. Moreover, when the call that was moved upward due to overflow condition stays longer than a certain period of time in the upper layer cell, the system moves the call back to the lower layer in order to save the more expensive resources of the upper layer cell. Call handling performance of this method evaluated from M/M/C/K models shows clear improvement with respect to call blocking probability and forced termination probability.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6B
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• pp.592-599
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• 2011

Proxy Mobile IPv6 (PMIPv6) is the network-based mobility management protocol that network supports the mobility of mobile node (MN) on behalf of the MN. In PMIPv6, a multi-homed MN can connect to the PMIPv6 domain by using only one interface even though it has multiple interfaces. It would be efficient when such a multi-homed MN connects to the PMIPv6 domain by using all of its interfaces. If such a multi-homed MN utilizes all of its interfaces, flow mobility can be provided that the MN handovers one or more flows from one interface to another without re-establishing session. In this paper, we propose the flow-based mobility management protocol by considering the intention of the user. The Router Advertisement (RA) message is used in order for the PMIPv6 domain to inform that the MN can utilize the flow mobility. The proposed mechanism is evaluated by analyzing signaling overhead and handover latency, and the numerical results show that the performance is affected by mobility speed of the MN and the failure probability of the wireless link.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.177-180
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• 2013

유비쿼터스시대의 핵심기기로 중요성을 더해 가고 있는 이동전화와 무선인터넷기술의 발전은 현대 비즈니스 환경의 급격한 변화와 함께 광고활동에도 많은 변화와 새로운 기회를 제공하고 있다. 무궁이 변화하는 환경 속에서 소비자 행동을 새롭게 파악할 수 있는 플로우를 중심으로 살펴보았고, 이용자들의 광고 회피로 인해 광고 효율성이 점차 낮아지고 있는 현 시점에서 광고태도에 따른 회피 현상들을 통계프로그램 SPSS와 AMOS를 통해 분석하였다. 이에 따른 결과는 휴대폰 사용자의 플로우가 상태일 때 모바일 광고효과인 광고태도에 긍정적인 영향을 미치는 것으로 나타났고, 광고태도는 광고회피에 영향을 미친다는 연구 결과가 나왔다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.9
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• pp.782-788
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• 2014

In this paper, we propose a scheme for the support of flow mobility according to a QoS condition when a mobile node with multiple wireless interface moves and attaches to a different access network. For this purpose, we extend the fields of the PBU/PBA message and add an additional request procedures. Through the proposed scheme, we can provide the best service in according to the network conditions of the next access network based on the measured QoS values by LMA. Finally we consider the state transition diagram of our proposed scheme and confirm its operation.

• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.401-407
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• 2019

SDN(Softeware Defined Networking) has emerged to address the rapidly growing demand for cloud computing and to support network virtualization services. Therefor many companies and organizations have taken SDN as a next-generation network technology. However, unlike the wired network where the SDN is originally designed, the SDN in the wireless network has a restriction that it can not provide the mobility of the node. In this paper, we extended existing openflow protocol of SDN and developed SDN-based network platform, which enables the SDN controller to manage the radio resources of its network and support the mobility of the nodes. The mobility support function of this paper has the advantage that a node in the network can move using its two or more wireless interfaces by using the radio resource management function of the SDN controller. In order to test the functions implemented in this paper, we measured parameters related to various transmission performance according to various mobile experiments, and compared parameters related to performance using one wireless interface and two interfaces. The SDN-based network platform proposed in this paper is expected to be able to monitor the resources of wireless networks and support the mobility of nodes in the SDN environment.