• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1597-1600
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• 2004

본 논문에서는 RMCP(Relayed Multicast Control Protocol)[1]를 이용하여 효율적으로 미디어 스트림을 전송할 수 있도록 구현하기 위한 구조를 소개한다. 일반적으로 IP 멀티캐스팅 서비스를 구현하기 위하여 멀티캐스팅 라우터를 이용하여 여러 수신자들에게 서비스를 제공하여 준다. 그러나 멀티캐스팅 라우터를 이용하여 멀티캐스팅 서비스를 구현할 때, 사업적, 기술적 측면에서 많은 문제점을 가지게 된다. 이러한 문제점을 보완하고자 응용 계층에서 중계 기능을 제공하며, 기존에 있는 네트웍 망을 그대로 이용하면서, 멀티 캐스트 서비스를 제공한다. 본 논문에서는 이러한 멀티캐스트 전송 방법을 이용한 멀티캐스트 응용 프로그램을 개발하기 위하여 고려해야 할 사항들을 설명한다. 차후 이 구조 기반으로 실제적으로 미디어 스트림을 전송하는 프로그램을 구현하고자 한다.

• Journal of the Korea Society for Simulation
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• v.18 no.4
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• pp.117-125
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• 2009

Recently the intelligent agent systems have been emerged as one of key issues for developing the defense M&S systems. However, most conventional agent architecture of M&S systems utilize the script-based models and can only deal with the individual behaviors so that they cannot suitably describe the precise tactical/strategic behavior and/or complex warfare environment. To overcome these problems, we have proposed the hierarchical multi-agent system architecture that is able to intelligently cope with the complex missions based on the functional role of each agent on the hierarchy such as an intelligence officer, captain, warship commander. Several simulation tests performed on 2:2 warship warfare models will illustrate our techniques.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1101-1104
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• 2006

다가올 미래에는 유비쿼터스 컴퓨팅과 유비쿼터스 네트워크를 통해 새롭고 다양한 서비스가 창출될 것이다. 특히, 언제 어디서나 사람과 사물 같은 객체의 위치를 인식하고, 이를 기반으로 유용한 서비스를 제공하는 유비쿼터스 위치기반 서비스가 중요한 서비스로 대두되고 있다. 이에 관해 Cricket, Ubisense 등의 많은 연구가 진행되고 있지만, 노드들로만 구성된 네트워크를 이용하기 때문에 위치추적과 같은 복잡한 연산을 수행하는데 적합하지 않다. 본 연구는 위치인식이 가능하고, 계산 능력이 높은 게이트웨이 노드를 구현하여 복잡한 연산을 가능하게 하였다. 이를 이용하여 무선 센서 네트워크 환경에서 계층적 구조의 다목적 기능을 가진 시스템을 구축하고 평가하였다.

• Archives of design research
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• v.17 no.1
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• pp.163-178
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• 2004

In this study, in order to achieve the before-mentioned study purpose, the importance of developing the new product, the relationship with the design, and the design element for developing the new product were considered. In order to extract the importance of the design element which is applied to the development of the new product design, the research model about the induction of the priority was created, the evaluation items were instituted, and the demonstrative research approach was performed in order to recognize the relationship among those elements. Firstly, in the process of selecting the items for the application, 14 evaluation elements which were extracted through the advanced study data were grouped in 4 kinds of dimensions, and the properties which are related with the Digital TV product were composed up of 36 items. Through the factor analysis, by decreasing the detailed standard for the evaluation of 36 items, the parsimony was secured, and the characteristics which the various items contain induced into one factor. Secondly, the detailed factors which were united into one factor went under the paired comparison as one by one through AHP again, and then the importance degree was generated. First of all, as the first stage of AHP, the decision making factors which affect the whole achievement of purpose of the decision making were classified as in a hierarchical style. From these research results, it was known that the functional factor and esthetic factor in the process of designing the new product are the major affecting variables, and it was confirmed that in case of the Digital TV products group, the factors such as the high quality of picture, big screen, user interface, sound, product reliability, style, size, indoor reproduction, and guarantee are the main factors which influence the need of the consumers in purchasing products.

• Membrane Journal
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• v.26 no.6
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• pp.421-431
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• 2016

Novel membrane technologies that harness ordered nanostructures have recently received much attention because they allow for high permeability due to their reduced flow resistance while also maintaining high selectivity due to their isoporous characteristics. In particular, the opaline structure (made from the self-assembly of colloidal particles) and its inverted form (inverse-opal) have shown strong potential for membrane applications on account of several advantages in processing and the resulting membrane properties. These include controllability over the pore size and surface functional moieties, which enable a wide range of applications ranging from size-exclusive separation to catalytically-reactive membranes. Furthermore, when combined with multiscale architecturing strategies, inverse-opal-structured membranes can be designed to have specific pores or channel structures. These materials are anticipated to be utilized for next-generation, high-performance, and high-value-added functional membranes. In this review article, various types of inverse-opal-structured membranes are reviewed and their functionalization through hierarchical structuring will be comprehensively investigated and discussed.

• Journal of Internet Computing and Services
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• v.5 no.5
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• pp.27-37
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• 2004

The existing ad hoc network protocols suffer the scalability problem due to the inherent characteristics of node mobility. Cluster-based routing protocols divide the member nodes into a set of clusters and perform a hierarchical routing between these clusters. This hierarchical feature help to improve the scalability of ad hoc network routing. However, previous k-hop cluster-based routing protocols face another problems, that is, control overhead of the cluster headers. This paper proposes a novel k-hop cluster-based routing scheme with delegation functions for mobile ad hoc networks. The scheme employs is based on tree topology to manage cluster members in effectively. The cluster headers do not manage the routing table for whole members, while the header keeps the routing table for its neighbor members and the member list for one hop over nodes within k-hop cluster. Then the in-between leveled nodes manage the nested nodes which is structured in the lower level. Therefore, the proposed mechanism can reduce some control overhead of the cluster leaders.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.6
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• pp.801-808
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• 1999

지금까지, 전기통신망과 장비들의 관리에 대해서는 많은 연구들이 진행되었지만, TMN 상위 계층의 서비스 관리와 비즈니스 관리에 대한 연구는 많이 수행되지 못했다. 최근 전세계적으로 TMN 상위 계층의 관리기능 구현을 위해서 CORBA 기술을 적용하고자하는 관심이 증가하고 있다. 본 논문에서는, 정보모델과 상호운용에 관한 TMN과 CORBA의 주요특징들을 비교하고, TMN 프레임웍와 효율적인 CORBA 기술 연동을 위한 플랫폼 구조를 제안한다. 제안된 구조에서, TMN 관리 정보를 CORBA IDL 인터페이스로 변환해주는 GDMO/ASN.1 - CORBA IDL 변환기가 고안, 구현되었고, JIDM의 상호 작용 변환의 구현을 위해서 TMN/CORBA 게이트웨이 또한 고안되었다. 그리고 이러한 기능의 확장을 위해서 모듈 형식으로 라이브러리들과 코드 생성기들이 설계, 구현되었다.Abstract Up to now, a lot of efforts have been made for the management of telecommunication networks and equipment, but less effort has been made for the realization of higher-layer service and business management. There are recently worldwide growing interests for applying CORBA technology for the realization of higher layer Telecommunication Management Network (TMN) management functions. In this paper, we compare the features of TMN and CORBA with respect to information model, and operational behavior. And then, we propose a platform architecture for the efficient integration of CORBA technology within TMN framework. Within platform architecture, GDMO/ASN.1 to IDL translator has been designed and implemented for translating TMN management information into CORBA IDL interface. The TMN/CORBA gateway is also designed for realization of the interaction translation specification of JIDM task force. The libraries and code generators have been designed and implemented in a modular fashion to provide the functional extensibility.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.679-681
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• 1999

최근 웹의 폭발적인 성장으로 인하여 웹을 교육의 매개체로 활용하려는 노력이 활성화되고 있다. 그러나 현재 대부분의 웹 기반 교육 시스템들은 대체로 수동적이며, 정적인 하이퍼텍스트 위주이기 때문에, 학습상황을 수시로 점검할 수 있는 상호작용기능이 부족하고, 특정 학습자의 학습결과에 따른 동적인 학습환경의 제시가 어렵다. 일반적으로 웹기반 교육시스템은 다양한 지식계층의 사람들에게 노출되어 있기 때문에 보다 상세한 학습전략이 요구되며, 따라서 최근에는 기존의 지능형 교수시스템(Intelligent Tutoring System: ITS)에서 연구된 풍부한 기술들을 웹 환경에 도입함으로서 보다 지능적이며 적응력 있는 시스템개발에 관한 연구가 활성화되고 있다. 본 연구에서는 이러한 웹 기반 교육시스템에서의 문제점들을 해소하기 위한 한가지 방안으로 ITS의 동적 교수계획기법을 웹 기반 시스템에 도입한다. 문제영역으로 C 프로그래밍 언어 학습을 선정하여 이를 웹 기반 교수시스템으로 설계하고 구현하였다. 또한 기존 시스템들의 서버 집중형 구조에서 탈피하여 CORBA를 이용한 분산기반구조로 시스템 개발에 접근하였다.

• KDI Journal of Economic Policy
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• v.13 no.4
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• pp.59-90
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• 1991

The purpose of this paper is to determine whether the rate schedule of the Korean income tax system embodies the theoretically desirable distribution of the tax burden by income classes. The paper follows the approach of Young (1990) who has estimated the utility function and calculated the magnitude of sacrifice, i.e., the tax burden. The main point of the study is to estimate the utility function. The estimation results may differ if different data sets are used. Therefore, this paper employs the effective as well as the nominal tax rate schedule. The findings derived in this paper are 1) that the effective rate schedule is more appropriate in estimating the utility function; 2) that the middle class has born the relatively heavier burden over time; 3) that the current income tax credit scheme curtails the tax burden on the middle class while intensifying the tax burden of the lower and upper income classes; 4) that reducing the amount of deduction moves the distribution of tax burdens by income classes closer to the theoretically desirable model; 5) that the rate schedule of the Korean income tax system, particularly in 1991, did not conform to the desired model as did the tax systems of developed countries such as the United States, Italy, Japan, and Germany.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.8
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• pp.23-32
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• 2007

We propose a group-based security scheme for hierarchical wireless sensor networks. We model the network for secure routing with 3-tier sensor network comprised of three types of nodes: Base Station, Group Dominator and ordinary Sensor Nodes. Group-based deployment is performed using Gaussian (normal) distribution and show that more than 85% network connectivity can be achieved with the proposed model. The small groups with pre-shared secrets form the secure groups where group dominators form the backbone of the entire network. The scheme is devised for dealing with sensory data aggregated by groups of collocated sensors; i.e., local sensed data are collected by the dominating nodes and sent an aggregated packet to the base station via other group dominators. The scheme is shown to be light-weight, and it offers a stronger defense against node capture attacks. Analysis and simulation results are presented to defend our proposal. Analysis shows that robustness can significantly be improved by increasing the deployment density using both the dominating and/or ordinary sensor nodes.