• The KIPS Transactions:PartA
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• v.14A no.1 s.105
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• pp.63-72
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• 2007

This paper introduces a load-balancing algorithm focusing on distributing web requests evenly into the web cluster servers. The load-balancing algorithms based on conventional periodic load-information update mechanism are not suitable for dynamic page applications, which are common in Cyber Foraging services, due to the problems caused by periodic synchronized load-information updating and the difficulties of work load estimation caused by embedded executing scripts of dynamic pages. Update-on-Finish algorithm solves this problem by using non-periodic load-update mechanism, and the web switch knows the servers' real load information only after their reporting and then distributes new loads according to the new load-information table, however it results in much communication overhead. Our proposed mechanism improve update-on-finish algorithm by using K-Percents-Finish mechanism and thus largely reduce the communication overhead. Furthermore, we consider the different capabilities of servers with a threshold Ti value and propose a load-balancing algorithm for servers with various capabilities. Simulation results show that the proposed K-Percents-Finish Reporting mechanism can at least reduce 50% communication overhead than update-on-finish approach while sustaining better load balancing performance than periodic mechanisms in related work.

• Journal of Intelligence and Information Systems
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• v.11 no.3
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• pp.1-23
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• 2005

Personalized reminder systems have to identify the user's current needs dynamically and proactively based on the user's current context. However, need identification methodologies and their feasible architectures for personalized reminder systems have been so far rare. Hence, this paper aims to propose a proactive need awaring mechanism by applying agent, semantic web technologies and RFID-based context subsystem for a personalized reminder system which is one of the supporting systems for a robust ubiquitous service support environment. RescorlaWagner model is adopted as an underlying need awaring theory. We have created a prototype system called NAMA(Need Aware Multi-Agent)-RFID, to demonstrate the feasibility of the methodology and of the mobile settings framework that we propose in this paper. NAMA considers the context, user profile with preferences, and information about currently available services, to discover the user's current needs and then link the user to a set of services, which are implemented as web services. Moreover, to test if the proposed system works in terms of scalability, a simulation was performed and the results are described.

• Journal of Korea Multimedia Society
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• v.2 no.4
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• pp.430-437
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• 1999

In this paper, client/server model for remote conveyor control and monitoring system Is designed and implemented to simulate the product line of vehicles. The client system located at the monitoring office is using a web applet based system, and sends some commands to the server system which guards and controls the conveyer system. The commands is delivered to the server system, the driver software existing in the server controls the conveyer system directly.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.923-930
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• 2003

최근의 정보기술의 급속한 발전과 더불어 대형사업의 성공 및 실패할 확률을 고려한 프로젝트 위험분석 연구가 널리 연구되고 있다. 특히 정보시스템을 기반으로 발전되고 있는 SCM(Supply Chain Management)의 구축사업은 복잡하고 대형프로젝트들로서 계획 초기부터 운영단계에 이르기까지 사업의 성공 및 실패할 확률을 예측함은 매우 중요하다. 본 연구에서는 이러한 SCM구축사업의 위험분석을 위하여 다 속성(Multi-Attribute)구조를 가지는 분석 방법과, 구축사업의 비용, 기간 및 고객 서비스능력 등을 고려한 위험 분석모델을 개발하였으며, 두 가지 방법을 사용하였다. : 1) AHP 방법을 이용한 가중치 방법, 2) SCM 네트웍을 구축하고 방법을 사용하였다. 또한 이를 위한 전산프로그램을 개발하고 실례를 들고 그 결과를 보였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1747-1750
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• 2003

The development of a Web-based powertrain performance simulation system is introduced. The development approach of system architecture and each module is introduced along with the H/W and S/W used. The interface with all users is developed via a JAVA applet. The powertrain modeling and other job history data of a user is managed systematically on the server by database to increase the reusability of the data. A self-developed program using object-oriented programming is used as a solver for the performance simulation. The graph tool for the analysis of simulation results has the collaboration support developed based on JAVA so that synchronous users can view the same result. As a result, the powertrain simulation is possible only with Web-browser for the user and the collaboration support among the relevant engineers is possible.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.147-149
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• 2000

프로세서와 네트워크의 발달로 클러스터 시스템은 웹 기반 응용분야 등에서 수요가 증가하고 있다. 화상회의, VOD, 온라인 게임, 상품 및 주식거래 등과 같은 실시간 서비스를 제공하기 위해 클러스터 시스템에서의 라우팅은 결함이 발생한 경우에도 마감시간 안에 실시간 연결이 이루어져야 한다. 본 논문에서는 여러 개의 노드로 구성되어 있으며, 동일한 작업을 수행하는 노드들이 그룹을 이룬 클러스터 시스템에서 백업 채널과 백업 노드를 예약하는 결함 허용 실시간 연결방법을 제안하고 신뢰도를 분석한다. 또한 일반 네트워크 환경의 라우팅만을 사용한 시스템과 백업 채널을 사용하는 시스템의 QoS를 비교하기 위해 시뮬레이션을 수행한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.41-44
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• 2012

Extensible Markup Language(XML)는 데이터 저장, 웹 서비스, 팟캐스팅, 신디케이션과 같은 분야에서 널리 사용되는 언어이다. XML 문서를 사용하기 위해서는 반드시 XML 문서에 대한 파싱이 이루어져야 하기 때문에 여러 연구들이 제안되었다. 스트림 기반 파서인 Roll-Back Streaming XML(RBStreX) 파서는 파싱의 흐름을 되돌리는 Roll-Back을 제안하였지만, 특정 노드를 검색할 때 발생되는 오버헤드를 해결하지 못하였다. 본 논문에서는 특정 노드에 대한 검색 기능을 지원하는 새로운 구조의 하드웨어 스트리밍 파서를 제안하였고, 시뮬레이션을 통하여 하드웨어의 동작 검증을 하였다. 제안된 구조는 RBStreX 파서와 비교하여 소프트웨어 오버헤드가 없으며 하드웨어 사이클도 반 정도로 감소시키는 성능향상을 얻는다.

• Convergence Security Journal
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• v.23 no.2
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• pp.103-113
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• 2023

In recent years, Unmanned Aerial Vehicles (UAV) have been widely used in various industries. However, as the depend ence on UAV increases rapidly, concerns about the security and safety of UAV are growing. Currently, various vulnerabili ties such as stealing the control right of the UAV or the right to communicate with the UAV in the web application are being disclosed. However, there is a lack of research related to the security of UAV. Therefore, in this paper, a study was conducted to determine whether the packet data was normal or abnormal by collecting packet data of an unmanned aerial vehicle in a HITL(Hardware In The Loop) simulation environment similar to the real environment. In addition, this paper proposes a method for reducing computational cost in the modeling process and increasing the ease of data interpretation, a machine learning-based anomaly detection model that detects abnormal data by learning only normal data, and optimized hyperparameter values.

• The KIPS Transactions:PartC
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• v.13C no.6 s.109
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• pp.785-794
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• 2006

Nowadays, Internet is used worldwide and network traffic is increasing dramatically. Much of Internet traffic is due to the web applications. And I propose a new cooperative web caching scheme, called DCOORD which tries to minimize the overall cost of Web caching. DCOORD reduces the communication cost by coordinating the objects which are cached at each cache server. In this paper, I compare the Performance of DCOORD with two well-known cooperative Web caching schemes, ICP and CARP, using trace driven simulation. In order to reflect the cost factor in the network communication, I used the CSR(Cost-Saving Ratio) as our performance metric, instead of the traditional hit ratio. The performance evaluations show that DCOORD is more cost effective than ICP and CARP.

• Journal of Internet Computing and Services
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• v.17 no.4
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• pp.115-125
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• 2016

Recently, many attentions have been paid to conducting convergence research across diverse disciplines. Along with this convergence era, an IT-based multi-disciplinary convergence project, called EDISON (EDucation-research Integrated Simulation On the Net), has been launched to support the studies of researchers engaged in several computational science and engineering (CSE) fields and to boost learning motivations of CSE students. Since 2011, we have been successfully carrying out the EDISON project. EDISON as a cyber-learning platform enables CSE researchers to share their own high-performance computing (HPC) simulation softwares developed to solve their research problems accompanying large-scale computation and I/O and users to run the softwares with little constraints on the web. Also, the EDISON platform has been utilized as lecture material by many universities in Korea. This article introduces the construction and service statistics of this EDISON platform. Specifically, we explicate several distinctions between EDISON and existing other HPC service platforms and discuss a three-layered technical architecture of the EDISON platform. We then present the up-to-date service statistics of EDISON over the past four years. Finally, we conclude this article and describe future plans.