• Journal of KIISE:Computer Systems and Theory
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• v.33 no.7
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• pp.370-379
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• 2006

Computational grid provides the environment which integrates v 따 ious computing resources. Grid environment is more complex and various than traditional computing environment, and consists of various resources where various software packages are installed in different platforms. For more efficient usage of computational grid, therefore, some kind of integration is required to manage grid resources more effectively. In this paper, a global scheduler is suggested, which integrates grid resources at meta level with applying various scheduling policies. The global scheduler consists of a mechanical part and three policies. The mechanical part mainly search user queues and resource queues to select appropriate job and computing resource. An algorithm for the mechanical part is defined and optimized. Three policies are user selecting policy, resource selecting policy, and executing policy. These can be defined newly and replaced with new one freely while operation of computational grid is temporarily holding. User selecting policy, for example, can be defined to select a certain user with higher priority than other users, resource selecting policy is for selecting the computing resource which is matched well with user's requirements, and executing policy is to overcome communication overheads on grid middleware. Finally, various algorithms for user selecting policy are defined only in terms of user fairness, and their performances are compared.

• Journal of IKEEE
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• v.18 no.1
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• pp.140-145
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• 2014

OPC UA(IEC62541) is a communication protocol for SG(Smart Grid) application platform. It was standardized by IEC TC57 group in December 2012. The IEC61850 has been used in Digital Substation Systems and Smart Distributed Systems. The DNP3.0 has been used for device's data collection/control in Distributed Systems. The DLMS/COSEM has been used to control metering and collect information in the Smart Metering. The top-level SG management platform needs an independent middleware to manage transparently the Power Information Technology, including the IEC61850, DNP3.0, DLMS/COSEM. In this paper, we propose the SDG(Scada Data Gateway) platform. It manages Power Information Technology based Digital Substation Systems and Smart Distributed systems, Smart Metering through OPC UA.

• Journal of Korea Multimedia Society
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• v.24 no.8
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• pp.1101-1113
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• 2021

The rapid growth of sense-and-respond applications and the emerging cloud computing model present a new challenge: providing publish/subscribe middleware as a scalable and elastic cloud service. The publish/subscribe interaction model is a promising solution for scalable data dissemination over wide-area networks. In addition, there have been some work on the publish/subscribe messaging paradigm that guarantees reliability and availability in the face of node and link failures. These publish/subscribe systems are commonly used in information-centric networks and edge-fog-cloud infrastructures for IoT. The IoT has an edge-fog cloud infrastructure to efficiently process massive amounts of sensing data collected from the surrounding environment. In this paper. we propose a quorum-based hierarchical fault-tolerant publish/subscribe systems (QHFPS) to enable reliable delivery of messages in the presence of link and node failures. The QHFPS efficiently distributes IoT messages to the publish/subscribe brokers in fog overlay layers on the basis of proposing extended stepped grid (xS-grid) quorum for providing tolerance when faced with node failures and network partitions. We evaluate the performance of QHFPS in three aspects: number of transmitted Pub/Sub messages, average subscription delay, and subscritpion delivery rate with an analytical model.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.16 no.4
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• pp.75-82
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• 2008

As the number of passengers and the amount of cargo is getting increased, the traffic of aircraft and moving vehicle at an airport is getting busy. Especially, due to the heavy traffic of moving vehicles in the area of airside, the safety management of them is getting important. The study has been performed for suggesting improved methods in order to reduce safety accidents between aircraft and moving vehicles by introducing a safety management system for moving vehicles in airside of an airport. In order to improve the level of safety with the efficient management of moving vehicles in airside, the analysis of the domestic and international trends of the related technology and regulations has been performed. As a result, the conceptual design of safety management system has been suggested by utilizing the location information technology and four layers (hardware, network, middleware and application) approaches of safety management system.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.237-238
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• 2012

기존의 기업 응용 프로그램들은 스마트폰의 성능 이상의 처리를 요구하는 데스크탑 환경에서 동작하였고 또한 기업의 시스템들은 스마트폰과의 연동과는 적합하지 않았다. 스마트폰 시장의 폭발적인 성장과 함께 일부 기업 업무처리가 스마트폰으로 이동하는 추세에서 이러한 문제들을 해결하기 위한 모바일 플랫폼으로 온-디멘드 클라우드 리소스를 이용한 개방형 모바일 클라우드(Open Mobile Cloud 이하 OMC) 플랫폼이 제안되었다. 본 논문에서는 OMC 플랫폼에서의 어플리케이션 리파지토리의 역할과 구조를 제안한다. 해당 플랫폼에서 리파지토리로의 요구사항으로는 VApp과 HApp의 버전 관리 및 배포가 있다. 또한 확장성, 독립성, 신뢰성 및 고 가용성의 리파지토리를 만족할 수 있는 구조 연구를 통해 이를 시험적으로 구현한 OMC App Repository를 소개한다. 또한 결론에서는 OMC 플랫폼에서 리파지토리를 이용한 추후 연구에 대해서도 다루고 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.232-233
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• 2012

여러 모바일 플랫폼들이 등장함에 따라 플랫폼 별로 어플리케이션을 따로 제작하고 따로 관리해야 하는 불편함과 대부분의 개발 환경이 PC 환경이기 때문에 이동 중에는 어플리케이션을 개발할 수 없는 문제점을 해결하기 위해 한번의 소스 코딩만으로 여러 플랫폼에서 적용이 가능하도록 해주며 이동하면서 어플리케이션 개발을 가능케 해주는 모바일 스튜디오의 구조를 제안하고자 한다.

• The KIPS Transactions:PartD
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• v.13D no.7 s.110
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• pp.1009-1016
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• 2006

Under foundational precepts of Grid computing, two important requirements that all Grid application systems should satisfy are to accommodate the dynamic nature of Virtual Organizations (VOs), and to enforce different levels of security among different VOs. For the research described in this paper, we developed two different use-case scenarios addressing the two requirements, and then showed how the requirements can be met by implementing a Grid information retrieval (GIR) system prototype. The dynamic nature of VO applies not only to increasing and decreasing number of users, but also to the dynamically changing requirement of computing power among the different subcomponents that consist in overall system configuration. This implies that a request to increase computing power by a certain subcomponent can be satisfied by other idling subcomponents taking advantage of overall system flexibility. This paper describes how we implemented a Grid IR system using VO and security mechanisms provided by Globus toolkit 3.0, and shows how GIR system scalability and security can be improved for dynamic VOs. In order to manage different VOs, we implemented VO management service (VOMS), and registered it to Globus as an additional service.

• Journal of IKEEE
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• v.22 no.4
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• pp.1073-1078
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• 2018

As interest in the 4th Industrial Revolution increases, the CPS, in which things existing in the reality and things existing in the virtual interact with each other, is attracting attention as an important technology. Complex systems such as electric vehicles, autonomous driving, smart factories, and smart grid system are considered as core technology fields of the 4th Industrial Revolution, and many types of research have been conducted to develop it. The reliability of the system is directly related to the safety of people in case of the autonomous driving, and verification of the actual vehicle's hardware and software of ADAS is essential. In this paper, we proposed distributed simulation middleware supporting HILS for reliable verification of the complex hybrid systems.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.421-433
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• 2012

AMGA service, which is one of the EMI gLite middleware components, is widely used for analysis of distributed large scale experiments data as metadata repository by scientific and technological researchers and the use of AMGA is extended farther to include general industries needing metadata Catalogue as well. However AMGA, based unix and Grid UI, has the weakness of being absence of general-purpose user interfaces in comparison to other commercial database systems and that's why it's difficult to use and diffuse it although it has the superiority of the functionality. In this paper, we developed AMGA GUI toolkit to provide work convenience using object-oriented modeling language(UML). Currently, AMGA has been used as the main component among many user communities such as Belle II, WISDOM, MDM, and so on, but we expect that this development can not only lower the barrier to entry for AMGA beginners to use it, but lead to expand the use of AMGA service over more communities.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.6
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• pp.1273-1293
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• 2010

Immune-inspired intrusion detection is a promising technology for network security, and well known for its diversity, adaptation, self-tolerance, etc. However, scalability and coverage are two major drawbacks of the immune-inspired intrusion detection systems (IIDSes). In this paper, we propose an IIDS framework, named GEP-IIDS, with improved basic system elements to address these two problems. First, an additional bio-inspired technique, gene expression programming (GEP), is introduced in detector (corresponding to detection rules) representation. In addition, inspired by the avidity model of immunology, new avidity/affinity functions taking the priority of attributes into account are given. Based on the above two improved elements, we also propose a novel immune algorithm that is capable of integrating two bio-inspired mechanisms (i.e., negative selection and positive selection) by using a balance factor. Finally, a pruning algorithm is given to reduce redundant detectors that consume footprint and detection time but do not contribute to improving performance. Our experimental results show the feasibility and effectiveness of our solution to handle the scalability and coverage problems of IIDS.