• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제6권2호
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• pp.53-62
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• 2002

In this paper we analyze the behavior of linear multiple attractor cellular automata having two-predecessors.

• 대한수학회보
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• 제33권2호
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• pp.303-310
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• 1996

The Gottlieb group of a compact connected ANR X, G(X), consists of all $\alpha \in \prod_{1}(X)$ such that there is an associated map $A : S^1 \times X \to X$ and a homotopy commutative diagram $$ S^1 \times X \longrightarrow^A X $$ $$incl \uparrow \nearrow \alpha \vee id $$ $$ S^1 \vee X $$.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.220-223
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• 2002

The digital logic systems(DLS) is classified into digital combinational logic systems(CDLS) and digital sequential logic systems(SDLS). This paper presents a method of constructing the digital sequential logic systems without feedback. Firstly we assign all elements in Finite Fields to P-valued digit codes using mathematical properties of Finine Fields. Also, we discuss the operarional properties of the building block T-gate that is used to realizing digital sequential logic systems over Finite Fields. Then we realize the digital sequential logic systems without feedback. This digital sequential logic systems without feedback is constructed ny following steps. Firstly, we assign the states in the state-transition diagram to state P-valued digit dodo, then we obtain the state function and predecessor table that is explaining the relationship between present state and previous states. Next, we obtained the next-state function and predecessor table. Finally, we realize the circuit using T-gate and decoder.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2004년도 추계학술대회 및 정기총회
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• pp.304-316
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• 2004

When new services are introduced, one of the drivers for market performance of them is the interactions among existing and new services. They are characterized by the substitution or complementary effects among existing and new service or the cannibalization of existing services by new services. This paper analyzes these issues in the telecommunications service industry context. To analyze them, a simple graphical tool or State Transition Diagram(STD) is developed and used. The diagram helps to clearly represent and explain the substitution, complement and cannibalization impact. Then, using the face-to-face survey of 1,200 people, a new wireless internet access service or WiBro is analyzed to identify the substitution/complement and cannibalization impacts in relation with the other competing services. Additionally, the important factors explaining customer subscription and substitution behavior are identified. The analysis results indicate that males, students or on-line game users are more likely to subscribe WiBro. Also, among the potential WiBro subscribers, customers who are less satisfied with the existing fixed line broadband internet access services are more likely to stop subscribing the fixed line service, which implies substitution by a new service. Additionally, this raises the issue of cannibalization if the existing and new services are provided by the same company. In fact we find the cannibalization effect is more serious for the cost sensitive group. We believe that our tool, approach, analysis results and their implications would be very helpful to devise a winning strategy for the new services in the highly uncertain telecommunications business environment.

• 대한화학회지
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• 제50권1호
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• pp.65-78
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• 2006

연구에서는 언 빨래가 마르는 현상을 승화라고 생각하는지, 그리고 이를 상평형 그림으로 표현할 수 있는지에 대한 중등학교 화학 교사들의 인식을 알아보았다. 53명의 교사들을 선정하여 이 연구에서 개발한 설문 및 면담을 실시하였다. 또한 사범대학 물리화학 전공 교수 2인과 분석화학 전공 교수 1인에게도 면담을 실시하여 교사 교육을 담당하는 교수의 승화에 대한 생각을 알아보았다. 연구 결과, 설문 응답한 53명의 교사 중 41명이 승화 현상이라고 답하였다. 승화라고 생각하는 교사들은 대부분 고체에서 기체로 상태변화가 일어나기 때문이라고 응답하였으며, 승화가 아니라고 생각한 교사들은 상평형 그림에서 외부압이 1기압일 때 승화가 일어날 수 없는 조건이라고 응답하였다. 17명의 교사는 언 빨래가 마르는 현상을 상평형 그림에 표현할 수 있다고 생각하였으며, 34명이 나타낼 수 없다고 응답하였다. 그러나 대부분 상평형 그림에 언 빨래가 마르는 현상을 과학적으로 설명하는 것에 대해 혼란스러워하였으며, 학생들을 가르치면서도 어려움을 겪는다고 응답하였다.

• The Korean Journal of Ecology
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• 제16권1호
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• pp.75-91
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• 1993

Structure and dynamics of Abies koreana community in Mt. Gaya were studied to provide the basic data for conservation of Abies koreana community, an endemic species in Korea. A. koreana community of this study site was composed of tree layer (4~7m), subtree layer (2~4m), shrub layer (1~2m), and herb layer (below 1m). The heights of tree and subtree layers were low. Floristic composition showed that this study site was subalpine and dry site. In frequency distribution diagram of diameter classes of major species consisting of A. koreana community, those of both A. koreana and other species showed reverse J-shaped types. From these results, it was estimated that A. koreana community of this site might be maintained continuously as a stable climax state like present state. In the spatal distribution diagram of major species, saplings of A. koreana were established under the canopy of A. koreana and Pinus koraiensis and under the dead tree of A. koreana. From these results, it was known that A. koreana saplings were recruited before the community was disturbed and regeneration was accomplished by advance regeneration pattern, in which these saplings established before occurrence of disturbance fill with open site originated from death of mature tree. Growth of annual rings was variable among individuals, it was estimated that such variation was originated in that growth of each individual relates to microclimatic conditions rather than macroclimatic ones. Ecological longevity of A. koreana in this study site estimated by disturbance types and age of dead trees was about 120 years.

• 대한인간공학회지
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• 제33권2호
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• pp.77-86
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• 2014

Objective: The purpose of this study is to grasp the fundamental structure of incident occurrence in nuclear organizations based on system thinking, and analyze how various causes are interrelated in terms of the causal loop diagram. Background: The recent domestic and overseas nuclear power plant-related incidents and accidents are directly or indirectly associated with safety culture, and thus effective plans for the improvement of safety culture are being called for. While the safety of a nuclear power plant is highly dependent upon technology and equipment, the utilization, maintenance and inspection of the technology and equipment are conducted by workers of the nuclear power plant. Method: Methodology of system thinking perspective using causal loop analysis. Results: As a result of the analysis, first, it turned out that the fundamental cause of incident occurrence in nuclear organizations is time constraint. Second, if a workload of workers increases, their adherence to regulations and procedures comes to be reduced due to time constraint. Third, it is needed, through organizational learning education, to increase actions made from thoughts considering safety as the utmost priority in advance. Fourth, it is necessary to improve professionalism by enhancing educational programs for new workers, and to develop various scenarios with which they can cope with certain situations. Application: This paper provides a base for system dynamics simulation model for future study.

• Progress in Superconductivity
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• 제3권1호
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• pp.5-12
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• 2001

Our experimental research focuses on manipulating pinning deflects to alter the phase diagram of vortex matter, creating new vortex phases. Vortex matter offers a unique opportunity for creating and studying these novel phase transitions through precise control of thermal, pinning and elastic energies. The vortex melting transition in untwinned YB $a_2$C $u_3$ $O_{7-}$ $\delta$/ crystals is investigated in the presence of disorder induced by particle irradiation. We focus on the low disorder regime, where a glassy state and a lattice state can be realized in the same phase diagram. We follow the evolution of the first order vortex melting transition line into a continuous transition line as disorder is increased by irradiation. The transformation is marked by an upward shift in the lower critical point on the melting line. With columnar deflects induced by heavy ion irradiation, we find a second order Bose glass transition line separating the vortex liquid from a Bose glass below the lower critical point. Furthermore, we find an upper threshold of columnar defect concentration beyond which the lower critical point and the first order melting line disappear together. With point deflect clusters induced by proton irradiation, we find evidence for a continuous thermodynamic transition below the lower critical point..

• 한국통신학회논문지
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• 제33권10A호
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• pp.972-979
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• 2008

양방향 중계 채널 (two-way relay channel)은 2개의 단말이 중계기 (relay)의 도움을 받아 양방향의 정보를 주고 받는 협력 통신 (cooperative communication) 채널이다. 기존의 협력 통신에서는 중계기가 시간 또는 주파수 자원을 나누어 양방향으로 신호를 송신하지만, 네트워크 부호화 (network coding)를 사용한 양방향 중계 채널에서는 중계기가 동일 자원을 사용하여 두 단말로 신호를 동시에 송신하므로 기존 기법보다 높은 통신용량을 얻을 수 있다. 본 논문에서는 ARQ환경에서 네트워크 부호화를 사용한 헙력통신 프로토콜을 보이고, 이를 스테이트 다이어그램 (state diagram) 을 이용하여 성능을 분석하였다.

• 한국통신학회논문지
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• 제39C권9호
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• pp.782-788
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• 2014

본 논문은 무선 네트워크에서 하나의 단말기가 복수의 인터페이스를 이용하여 상이한 액세스 네트워크에 접속할 때 QoS에 따른 플로우 이동성 지원을 위한 방안을 제안한다. 이를 위해서 PBU/PBA 메시지의 확장 및 LMA에 추가적인 QoS request 메시지 절차 추가하였다. 제안한 방법을 통해 LMA가 이동할 네트워크에 대한 QoS정보를 수집하고 플로우 이동을 결정하여 사용자에게 네트워크 상황에 따른 최적의 서비스를 제공할 수 있다. 제안한 방안은 state transition diagram을 이용하여 수행 여부를 확인하였다.