• Journal of applied mathematics & informatics
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• 제34권5_6호
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• pp.495-508
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• 2016

A singularly perturbed reaction-diffusion fourth-order ordinary differential equation(ODE) with discontinuous source term is considered. Due to the discontinuity, interior layers also exist. The considered problem is converted into a system of weakly coupled system of two second-order ODEs, one without parameter and another with parameter ε multiplying highest derivatives and suitable boundary conditions. In this paper a computational method for solving this system is presented. A zero-order asymptotic approximation expansion is applied in the second equation. Then, the resulting equation is solved by the numerical method which is constructed. This involves non-overlapping Schwarz method using Shishkin mesh. The computation shows quick convergence and results presented numerically support the theoretical results.

• 한국정밀공학회지
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• 제17권10호
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• pp.41-48
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• 2000

Manufacturing devices must be integrated for constructing CIM environment, but integration of heterogeneous system meets several economical and technological difficulties. In this case, MMS(Manufacturing Message Specification) can be an effective method, but it has problems which MMS products are generally very expensive and majority of the existing manufacturing devices do not support MMS. This paper describes the development of a gateway for Non-MMS-Compatible CNC machine tools to serve MMS and the implementation of OSI(Open System Interconnection) upper layer on TCP/IP. The developed system is applied to construct cell controller with heterogeneous devices under CIM environment and to evaluate interoperability and portability.

• 한국진공학회지
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• 제6권S1호
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• pp.80-88
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• 1997

The attempt to enhance the strength of materials has been an important subject for materials engineering and scientists. The strength of materials is termed as the ability to support high load without excessive deformation and without breaking catastrophically. The control of dislocation densities and barriers to the movement of dislocations have been considered to be the important methods for the strengthening materials. One of the approaches is mechanical blocking of dislocations by alternately depositing material layers. The typical structure of materials is multilayered and laminated composites. The thickness of each layer is typically in the range of nanometer. Ton avoid confusion with other terminology they may be defined as microlaminate composite materials. The manufacturing process of multilayered laminate structure will be introduced. And the current theoretical theories will be reviewed in view of strengthening of microlaminte composite materials.

• 한국정보처리학회논문지
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• 제6권11S호
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• pp.3379-3389
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• 1999

Important network application services have been rapidly increased along with the growth of the Internet. So, it is desirable for such applications to serve transparently, continuously and safely even if the network is temporally disconnected or certain hosts running those services are crashed down. To satisfy such requirementes, many group communication systems have been developed; but, those systems restrict its range within a single LAN or directly interconnected LAN environments since the communication through the Internet is too slow and too unreliable to support group communication. As of now, it is expected the Internet is going to e sufficiently fast and reliable in the near communication system, named FACE(Java Advanced Communication Environment), supporting Extended Virtual which is a basic communication layer, RPGS(Reliable Process Group Service) which manages application process groups, and JACE API for developing Java application services and clients programs. In addition, an experimental replicated object space is developed as an application of the JACE system.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (3)
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• pp.211-213
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• 2004

차세대 인터넷 사용자들을 위해서는 이동하면서 연속적으로 인터넷에 접속하고 통신할 수 있도록 지원하는 것이 필수적이다. 현재까지 Mobile IT를 기점으로 다양한 네트워크 계층에서의 이동성 지원 프로토콜들이 제안되어 왔다. 그런데 최근에는 네트워크 계층에서의 이동성 지원과는 전혀 다른 접근 방식으로서, 트랜스포트 계층에서 이동성을 지원하는 방안이 언급되고 있다. 트랜스포트 계층에서의 이동성 지원은 기존 네트워크 계층에서의 이동성 지원 방안처럼 코어 네트워크에 홈 에이전트나 외부 에이전트와 같은 특별한 엔터티들의 추가를 요구하지 않기 때문에 디플로이가 상대적으로 용이하며, 종단 간 이동성을 지원할 수 있기 때문에 네트워크 계층에서의 이동성 지원 방안에서 발생하는 터널링 오버헤드나 비효율적인 라우팅 문제를 피할 수 있다. 이에 본 논문에서는 차세대 인터넷 환경인 IPv6 네트워크에서 WLAN 기반의 트랜스포트 계층 이동성 지원 방안을 제안한다 시뮬레이션을 통하여 제안하는 방안이 네트워크 계층에서의 이동성 지원과 대등한 성능을 보임을 확인하였고, 특히 이동 노드의 속도가 빠를 때 새로운 네트워크에서의 IT 주소 획득 시간이 길 때, 네트워크 계층에서의 이동성 지원 방안보다 더 좋은 성능을 제공함을 볼 수 있었다.

• BMB Reports
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• 제33권4호
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• pp.289-293
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• 2000

Annexin I is a 37 kDa member of the annexin family of calcium-dependent phospholipid binding proteins. Annexin I plays regulatory roles in various cellular processes including cell proliferation and differentiation. Recently we found that annexin I is a heat shock protein (HSP) and displays a chaperone-like function. In this paper we investigated the function of annexin I as an ATPase using 1 to 32 amino acids deleted annexin I (${\Delta}-annexin$ I). ${\Delta}-Annexin$ I hydrolyzed ATP as determined by thin layer chromatography. The ability of ATP hydrolysis was inhibited by ADP, GTP and GDP, but not by the AMP, GMP and cAMP. In view of the ATP hydrolyzing function of HSP, the results support the function of annexin I as a HSP.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(A)
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• pp.361-364
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• 2011

Nowadays, an explosive increase of mobile devices has triggered a lot of research into radio resource management. Therefore, many studies have been done and still underway to use this limited resource efficiently. However, most of the existing studies focused on efficiency in mac layer. In this paper, I proposed a timer to manage radio resource, which refreshes the timer's values based on the number of connections dynamically. This dynamic timer enables Base Station (BS) to be able to manage available radio resources efficiently and accommodate much more Mobile Stations (MSs). Simulation result showed that BS with dynamic timer could accommodate the MS about 30% more, compared with BS with a static timer in terms of radio resource management. Dynamic timer is not restricted to any specific network standard. So its mechanism is practical and implementable without changing the original standard, which can contribute to service providers by increasing capability that BS can support.

• 수산해양교육연구
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• 제17권1호
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• pp.76-85
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• 2005

GIS (Geographic Information Systems) technology is a necessary function to support location based on service by using GPS in the mobile environment. These mobile systems have basic functional limitations such as a low rate of processing, limited memory capacity, and small screen size. Because of these limitations, most of the mobile systems require development of a reduced digital map to overcome problems with large-volume spatial data. In this paper, we suggest using the reduced digital map format in order to use location based on service in a PDA environment. The processing of the proposed data format consists of map generation, redefinition of layers, creating polygons, and format conversion. The proposed data format reduces the data size by about 98% comparing with DXF format based on the digital map of Busan.

• 전자통신동향분석
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• 제14권6호통권60호
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• pp.51-63
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• 1999

IPSEC (Internet Protocol Security) is a network layer security protocol that is designed to support secure TCP/IP environment over the Internet considering flexibility, scalability, and interoperability. IPSEC primarily supports security among hosts rather than users unlike the other security protocols. Recently, IPSEC is emphasized as one of the important security infrastructures in the NGI (Next Generation Internet). It also has suitable features to implement VPN (Virtual Private Network) efficiently and its application areas are expected to grow rapidly. In this paper, the basic concepts and related standard documents of IPSEC will be introduced.

• 한국전자파학회논문지
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• 제10권4호
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• pp.487-497
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• 1999

본 논문에서는 무선 ATM 전송을 위한 MC-COMA 시스댐의 성능을 시융레이션을 통하여 분석하였다. 설 계된 MC-COMA 시스템은 5GHz 주파수대에서 약 18.2 MHz의 대역폭을 사용하여 25 Mbps의 데이터를 지원 하며, Wireless ATM Working Group(WATM WG)에서 제안한 무선 물리 계층의 규격을 만족한다. 채널 부 호화 방법으로서 컨볼루션 부호, TCM. 그리고 Turbo TCM(T-TCM)을 각각 적용하여 성능을 비교 분석한 다 실험 결과로부터 T-TCM을 적용한 경우. 반복 복호를 수행함에 따라 가장 우수한 성능을 보임을 알 수 였다.