• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.443-453
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• 2013

The hybrid test is one of the most advanced test methods to predict the structural dynamic behavior with the interaction between a physical substructure and a numerical modeling in the hybrid control system. The purpose of this study is to perform the multi-directional dynamic test of a steel frame structure with the real-time hybrid system and to evaluate the validation of the results. In this study, FEAPH, nonlinear finite element analysis program for hybrid only, was developed and the hybrid control system was optimized. The inefficient computational time was improved with a fixed number iteration method and parallel computational techniques used in FEAPH. Furthermore, the previously used data communication method and the interface between a substructure and an analysis program were simplified in the control system. As the results, the total processing time in real-time hybrid test was shortened up to 10 times of actual measured seismic period. In order to verify the accuracy and validation of the hybrid system, the linear and nonlinear dynamic tests with a steel framed structure were carried out so that the trend of displacement responses was almost in accord with the numerical results. However, the maximum displacement responses had somewhat differences due to the analysis errors in material nonlinearities and the occurrence of permanent displacements. Therefore, if the proper material model and numerical algorithms are developed, the real-time hybrid system could be used to evaluate the structural dynamic behavior and would be an effective testing method as a substitute for a shaking table test.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.7
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• pp.778-787
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• 1999

이제까지 대부분의 다중 에이전트 시스템에서는 에이전트 사회에 속한 모든 응용 에이전트를 작업 요청에 관계없이 처음부터 구동시킨다고 가정하였다. 이러한 에이전트 정적 구동 방법은 에이전트 관리를 단순하게 해주는 이점을 제공하지만 워크플로우 관리나 전자상거래와 같이 매우 많은 수의 에이전트로 구성되는 응용 분야에서는 시스템 과부하와 자원의 낭비 등 많은 문제점을 초래한다. 동적 에이전트 관리는 이에 대한 해결책으로 아주 많은 수의 에이전트를 포함하는 다중 에이전트 시스템에서 현재 수행중인 작업에 관련된 에이전트만을 선별하여 구동시키고, 작업이 끝난 에이전트는 종료시킴으로써 자원의 낭비를 막고 에이전트간의 상호작용 시에 요구되는 에이전트 통신의 복잡도 부담을 감소시키는 효과를 낸다. 본 논문에서는 자바로 에이전트 관리 시스템을 구현하고, 이 관리 시스템을 통해 각기 다른 언어로 개발된 응용 에이전트가 분산된 환경에서 상호 협력을 통해 작업을 수행할 수 있는 기법을 제안한다. 사용자나 다른 에이전트의 요청으로 에이전트를 동적으로 수행시키기 위해 다른 언어로의 확장을 가능하게 하는 Java Native Interface(JNI)를 사용한 기술 및 이러한 이질적인 에이전트간의 원활한 통신을 위해서 KQML 언어 인터페이스를 통한 통신 기능을 제안한다. 이질적 에이전트의 동적 관리를 가능하게 함으로써 다중 에이전트 시스템의 자원 이용 효율성과 확장성을 높이고 다양한 환경 변화에 대한 적응성과 개선된 협동능력을 제공한다.Abstract It has been assumed that all application agents in a multi-agent system are pre-invoked and remain active regardless of whether they are actually used. Although this kind of static agent invocation simplifies the management of agents, it causes several problems such as the system overload and a waste of resources, especially in the areas of the workflow management and the electronic commerce that consist of tens and even hundreds of application agents. A solution for these problems is the scheme of dynamic agent management that selectively invokes only agents that are actually requested and terminates them when they are no longer needed. This method prevents a waste of system resources and alleviates the complexity of agent communications.This paper proposes an agent management system implemented in Java that supports interactions between application agents that are developed using different languages. Dynamic agent invocation is accomplished by Java Native Interface(JNI) that links two heterogeneous methods, and by KQML language interface that facilitates the communications between heterogeneous agents. This scheme of dynamic agent management provides efficient resource usage, easy extensibility, dynamic adaptibility to changes in the environment, and improved cooperation.

• Convergence Security Journal
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• v.11 no.4
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• pp.51-58
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• 2011

Due to the digital technology, the TV broadcasting platform is evolving to the digital-TV, which is supporting data broadcasting service. Although the data broadcasting services (i.e., games, wether information, stock trading service) provide rich entertainment to viewers, they make the operation manners of digital-TV so complex that some viewers feel difficulty in using their TV sets. Several researches have been performed to address the problem by improving the functions of EPG such as searching and reserving programs, applying gesture and voice recognition technologies to operating EPG, guiding the design of the EPG's user interface, and developing agents helping EPG to behave intelligently. A research, however, that tries to address the problem that viewers have different familiarities with IT services has not been performed yet. The paper tackles the problem by letting a viewer to choose an EPG configuration (among the several EPG configurations provided by a broadcasting network) and designing an EPG that implements an EPG configuration based on the choice.

• Journal of Internet Computing and Services
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• v.3 no.5
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• pp.31-39
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• 2002

A rapid growth of internet and sudden increase of multimedia data demands for high-speed transfer media and if optimizec usage from the interface system. To achieve this level of network bandwidth, multiple NICs for support of high-speed network bandwidth have been developed and studied. Furthermore, the use of multiple NICs can provide high-speed LAN environment without large network environment modification, supports backward compatibility of current system and reduce overhead. However. if system failure is caused by SPOF(Single Point of Failure) fault of large-capacity multiple NICs, incredible loss will be met because it services large capacity of multimedia data, Therefore, to prevent loss coming from faults, we describe 'Fault tolerance of multiple NICs', which use the fault prevention mechanism. Considering inefficiency of availability and serviceability that is occurred with existing TMR, Primary-Standby approach and Watchdog time mechanism, we propose and design the efficient fault tolerance mechanism, which minimize down time as changing of detection period dynamically. Consequently, the fault tolerance mechanism proposed for reducing overhead time when the fault is occurred, should minimize system downtime overall.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.715-718
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• 2009

Time series data is a sequence of data points, measured typically at successive, spaced at time intervals. Many devices for an efficient exploration is developed according as the items of time series data increase. Among these devices, there is a Timebox widget as a representative device of dynamic query for interactive data exploration. Timeboxes are rectangular query region of interest. The users can draw the region of interest using simple mouse manipulation and the query result sets is displayed. But there is a limitation to represent the concrete query region and Timeboxes visualize the query region inconsistent with the mental model of users. To resolve these problems, we propose a new device called DQB(Dynamic Query Band). DQB is a qeury region consisting of user defined polyline with a thickness on time series data. This device is possible to concretely specify the query region. Also, it provides a simple and convenient interface and a good conceptual model.

• The KIPS Transactions:PartA
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• v.11A no.3
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• pp.149-156
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• 2004

As software is large and sophisticate, in order to increase the productivity and efficiency of programs in programming development environments, it is necessary to support the integrated system that offers user interface integrated editing, compiling, debugging, and running steps. The key tool in such environments is an incremental translation. In this paper, in order to increase the productivity and reusability of software, the goal is to construct the integrated incremental interpretation system that supports friendly user interface with editor, debugger, and incremental interpreter. We define the new object-oriented language, IMPLO(IMPerative Language with Object) using EBNF notation, and construct the integrated incremental interpretation system using incremental interpreter of the language. To do so, we extend attribute grammars for specifying static semantics and present new action equations to describe the dynamic semantics. We executed the incremental interpretation by using analyzing the dynamic semantics and then implemented integrated incremental interpretation system with editor and debugger in C, Lex and Yacc using X windows on SUN. We obtain about 50％ speedups in case of incremental execution time for example programs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.19-24
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• 2018

The IP Multimedia Subsystem(IMS) is an architectural framework for delivering IP multimedia services to mobile users. In order to guarantee the reliability and Quality of Service(QoS) of a variety of multimedia services, we need a new evolutionary approach that maintains the IMS based signaling platform which can perform the processing of flow through distributed controllers. Software Defined Network(SDN) is an architecture purporting to be distributed, dynamic, cost-effectives as well as adapting and seeking to be suitable for the high-bandwidth, dynamic nature of today's applications. It requires some methods for the control plane to communication with the data plane. One of such mechanisms is OpenFlow which is a prominent standard protocol and interface that is responsible for managing the network resources by using the remote SDN controller. In this paper, we propose a straightforward approach for integrating SDN technology together with the IMS architecture. Therefore we propose and construct a combined architecture model that performs flow processing using OpenFlow via the IMS based signaling platform, which maintains the existing telecom call service. Additionally, we describe some relevant experimentation results from the proposed architecture.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.3
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• pp.241-253
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• 2003

SCA (Software Communication Architecture), which has been adopted as a SDR(Software Defined Radio) Forum standard, provides a framework that successfully exploits common design patterns of embedded systems software. However, the SCA is inadequate as a component framework since it does not explicitly specify (1) a component model that defines how to express a component interface and how to implement it, (2) a package model that defines what and how to package in deployment units, and (3) a deployment model that defines the deployment environment and deployment process. In this paper, we propose a SCA-based component framework for SDR. Specifically, we present (1) a component model that defines a component as a specialized CORBA object that implements object management functionality, (2) a package model exploiting the existing XML descriptors of the SCA, and (3) a deployment model that defines a SCA-based deployment environment, a boot-up process that restores the deployment state, and a deployment process that supports lazy application instantiation and dynamic component replacement.

• Journal of Advanced Navigation Technology
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• v.2 no.2
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• pp.132-142
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• 1998

In optical scanning holography, 3-D holographic information of an object is generated by 2-D active optical scanning. The optical scanning beam can be a time-dependent Gaussian apodized Fresnel zone plate. In this technique, the holographic information manifests itself as an electrical signal which can be sent to an electron-beam-addressed spatial light modulator for coherent image reconstruction. This technique can be applied to 3-D optical remote sensing especially for identifying flying objects. In this paper, we first briefly review optical scanning holography and analyze the resolution achievable with the system. We then present mathematical expression of real and virtual image which are responsible for holographic image reconstruction by using Gaussian beam profile.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1055-1060
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• 2009

In this paper, we design an e-Learning system for the Driver's License Teste studying through the Internet. The proposed system make users to be arrived at the goal for the license in a shorter time by offering learning contents and items according to the item-responses made by the users based on the Item Response Theory. Moreover we design the scheme to give the optimum items and the most necessary content to the user during the learning procedure in the form of concept-based objects. All the items in the problem bank DB maintain their difficulties, discriminations, and guessing parameters as is the case of 3-parameter logistic model. In addition user profile DB stores users' status informations, item responses, and ability parameters. Using these structures and combining agents, we can offer the optimum learning process or dynamic personalized studying structure to the user. We can construct interface agent and content selection and feedback agent with the DB's described above. User can study without any awareness of system operations or personal fitting scheme.