• Journal of the Korea Society of Computer and Information
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• v.15 no.7
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• pp.33-40
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• 2010

The hand over between different radio access networks, especially where their coverage overlaps, suffers various complications since the different access networks provide different service characteristics. In this paper, it is about the system which can control the wireless LAN network management system and the wireless LAN access point of variety vendor which is in different areas. Successful development of mobile sink wireless LAN network management system which supports multi-vendor devices and have center-local interoperability structure. In proposed system, speed of the mobile station give about 10% improvement when the map domain size is 5 than the existing system. Through a data plane and management system of message way, it give a stability system and consistency network.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.523-526
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• 1998

In an ongoing project at ETRI-CSTL, A debugger for distributed programs that run on a varied collection of machines is being built. To build such debugger, a clientserver model is incorporated. This strategy enables us to provide a unified user interface and isolate debugger core from the user interface. Several debugging servers running on a diverse set of platforms permit the implementation of a distributed debugger for heterogeneous environment, and the single debugging client provides unified debugging concept and graphical user interface over various servers. Also, the precise specification of the interaction protocol between the client and server facilitates client to be paired with a variety of server implementantations. This paper describes the design and implementation of our debugger, concentrating on the system architecture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2707-2712
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• 2012

Desktop-based computing environment is changed into mobile computing using smart phone and cloud computing providing common behavior and big data by network. Because of this transformation software development and operating environment is changed into heterogeneous distributed environment. As a result, dynamic service composition or changement is required. However, there is few research of techniques supporting service composition or changement dynamically in this situation. This paper suggests a technique for customizing services dynamically of mobile applications based on android platform. Especially we propose a customization technique of service by applying ontology technique to improve sharing and reuse of service. We applied proposed technique into meeting notification system, and obtain that it can be customized into various services such as email, sms, twitter service, and so on.

• KIISE Transactions on Computing Practices
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• v.23 no.9
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• pp.517-534
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• 2017

This paper proposes an Internet of Things (IoT) middleware called Middleware for Cooperative Interaction of Things (MinT). MinT supports a fully distributed IoT environment in which IoT devices directly connect to peripheral devices, easily constructing a local or global network and sharing their data in an energy efficient manner. MinT provides a sensor abstract layer, a system layer and an interaction layer. These layers enable integrated sensing device operations, efficient resource management, and interconnection between peripheral IoT devices. In addition, MinT provides a high-level API, allowing easy development of IoT devices by developers. We aim to enhance the energy efficiency and performance of IoT devices through the performance improvements offered by MinT resource management and request processing. The experimental results show that the average request rate increased by 25% compared to existing middlewares, average response times decreased by 90% when resource management was used, and power consumption decreased by up to 68%. Finally, the proposed platform can reduce the latency and power consumption of IoT devices.

• The KIPS Transactions:PartA
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• v.10A no.6
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• pp.651-656
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• 2003

Emerging technologies, such as multimedia and mobile computing, require that middleware platforms can support high adaptability in order to provide more flexible services in heterogeneous environments. To support high quality of service in distributed wired/wireless environments, it will be necessary for applications and middleware to be aware of changes in users requirements as well as environmental conditions, also to be able to adapt their behaviour as such changes. According to the needs of adaptability supporting in middleware, we structure a component-based, mobile agents framework in base level and meta level by using reflection. We propose concepts of meta agents and meta-service agents that are able to reflect changes made by mobile agents to the system. At the meta level of our framework, meta agents monitor execution of mobile agents and it is possible to provide dynamic adaptation of users requirements, deployment of application services and service customization with meta agents and meta-service agents.

• The KIPS Transactions:PartA
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• v.14A no.7
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• pp.409-420
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• 2007

Software adaptation may be required to interact between heterogeneous platforms and to react to rapid change of environment in ubiquitous computing. Web service provides a way to use heterogeneous and distributed services or resources to utilize and organize them. But it is not easy to retrieve appropriate services when we search services because web service lacks of semantic information. Semantic web service provides additional information of services, but it does not support a method to match them in various ways. We can adapt and extend web applications by using web service, but a method for management and administration is still needed. Therefore in this paper, we propose a framework for dynamic growing of web service applications based on ESB(Enterprise Service Bus) and agent and provide a prototype to show its usefulness.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06c
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• pp.127-129
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• 2006

최근 대부분 기업들 환경에서의 정보 시스템들은 지역적으로 분산되어 있으며 다양한 형태로 구성되어 있으므로, 사용자 의사 결정을 지원하는데 필요한 통합된 정보를 얻는 것은 어려운 일이다. 따라서 이러한 문제를 효율적으로 정보 검색에 적용하기위해 사용자에게 단일 인터페이스를 제공하고, 이기종 시스템들 간에 구축된 데이터베이스 시스템들은 각각 독립성을 유지하면서 하나의 인터페이스처럼 투명성을 제공할 필요성이 있다. 이를 위해 ISO/IEC 11179에서 연구 중인 XMDR의 개념을 이용하여 정보검색에서 발생하는 "의미적 상호운용성(semantic interoperability)"이라는 문제점을 해결하고 이 XMDR에 지식 인스턴스 계층을 통한 지식공유를 가능하게 함으로써 단순 검색의 한계점을 극복할 수 있도록 한다. 본 논문에서는 데이터 표현에 사용되는 명칭, 속성, 관계성에 대한 이질적인 문제를 해결하기 위한 표준 온톨로지, 각 레거시 시스템을 연결하는 중간자(mediation)역할을 수행하는 로케이션 온톨로지, 지식공유가 가능하도록 하는 지식 인스턴스 계층으로 구성하는 방법을 제안한다. 또한 지식 인스턴스 계층은 협업적인 검색 환경하에서 각각의 정보시스템에서 다양한 형태의 지식을 공유 및 통합에 있어 구조화 되지 않은 지식들을 어떻게 공유할 것인가에 대한 개념적인 모델을 제시한다.

• Spatial Information Research
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• v.22 no.2
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• pp.63-71
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• 2014

Ocean leisure sports have recently emerged as one of so-called blue ocean industries. They are sensitive to diverse environmental conditions such as current, temperature, and salinity, which can increase needs of forecasting data as well as in-situ observations for the ocean. In this context, a Web-based geovisualization system for coastal information produced by model forecasts was implemented for use in supporting various ocean activities. First, FVCOM(Finite Volume Coastal Ocean Model) was selected as a forecasting model, and its data was preprocessed by a spatial interpolation and sampling library. The interpolated raster data for water surface elevation, temperature, and salinity were stored in image files, and the vector data for currents including speed and direction were imported into a distributed DBMS(Database Management System). Web services in REST(Representational State Transfer) API(Application Programming Interface) were composed using Spring Framework and integrated with desktop and mobile applications developed on the basis of hybrid structure, which can realize a cross-platform environment for geovisualization.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.181-188
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• 2014

Heterogeneous physical systems and computational devices are incorporated on a large-scale in a CPS (cyber-physical system) environment. Simulations can be useful for the reliable behaviors of CPSs. Time synchronization is one of major technical issues for the simulations. In the CPS, distributed systems control themselves by interacting with each other during runtime. When some simulation models have high complexity, wrong control commands as well as incorrect data can be exchanged due to the time error. We propose a time synchronization algorithm for the hybrid model that has characteristics of both continuous time systems and discrete event systems. In addition, we develop a CPS simulator based on our algorithm. For the verification of the algorithm and the execution of the simulator, we develop an example hybrid model and simulate considering user controls as well as interactions among the distributed systems.

• Journal of Convergence for Information Technology
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• v.9 no.7
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• pp.1-7
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• 2019

With the recent commercialization of the next generation of wireless 5G in everyday life, many changes have been made to organizations, industries and businesses of various sizes in various fields. However, although the improved speed and latency of 5G has improved, improvements in encryption, authentication and privacy are still required. In this paper, multiple groups of information management techniques are proposed to efficiently protect users' privacy in the heterogeneous environment of 5G. The proposed technique aims to allow distributed management of users' privacy links by clouding the privacy information generated by different heterogeneous devices to efficiently interface with different groups. Suggestion techniques process user-specific privacy information independently in a virtual space so that users can periodically synchronize their privacy information.