• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.6 no.2
• /
• pp.53-62
• /
• 2002

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

• Bulletin of the Korean Mathematical Society
• /
• v.33 no.2
• /
• pp.303-310
• /
• 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 $$ S^1 \times X \longrightarrow^A X $$ $$incl \uparrow \nearrow \alpha \vee id $$ $$ S^1 \vee X $$.

• Proceedings of the IEEK Conference
• /
• 2002.07a
• /
• pp.220-223
• /
• 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.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2004.10a
• /
• pp.304-316
• /
• 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.

• Journal of the Korean Chemical Society
• /
• v.50 no.1
• /
• pp.65-78
• /
• 2006

study identified secondary school chemistry major teachers' perceptions of sublimation related to the drying phenomenon of frozen wash and representation of the phenomenon on phase diagram. The subjects were 53 teachers for the questionnaire developed for this study, and interviews. The two professors who majored physical chemistry and one professor who majored analytical chemistry at teacher's college were interviewed for teacher educators' perceptions of sublimation. The results showed that forty one teachers among fifty three teachers thought that the drying phenomenon was sublimation. The most teachers who thought that the phenomenon was sublimation responded as a reason that solid state changes to gas state. The teachers who thought that the phenomenon was not sublimation responded as a reason that the 1 atm of air pressure was not the condition of sublimation. Seventeen teachers thought that the drying phenomenon of frozen wash could be represented on phase diagram, but thirty four teachers thought that it could not. But most teachers confused the scientific representation of the phenomenon, and felt difficulties to teach the contents to students.

• The Korean Journal of Ecology
• /
• v.16 no.1
• /
• pp.75-91
• /
• 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.

• Journal of the Ergonomics Society of Korea
• /
• v.33 no.2
• /
• pp.77-86
• /
• 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
• /
• v.3 no.1
• /
• pp.5-12
• /
• 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..

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.10A
• /
• pp.972-979
• /
• 2008

Two-way relay channel is a bidirectional cooperative communication channel that two terminals communicate each other with the help of a relay. In the previous cooperative communication schemes, a relay uses two divided resources for bidirectional transmission. When a network coding is used at a relay, the relay can transmit bidirectional data to two terminals simultaneously using one resource only. Thus the throughput of this scheme is greater than that of the previous scheme. In this paper, we showa two-way cooperative ARQ protocol using network coding and the throughput of this protocol is analyzed using a state diagram.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39C no.9
• /
• pp.782-788
• /
• 2014

In this paper, we propose a scheme for the support of flow mobility according to a QoS condition when a mobile node with multiple wireless interface moves and attaches to a different access network. For this purpose, we extend the fields of the PBU/PBA message and add an additional request procedures. Through the proposed scheme, we can provide the best service in according to the network conditions of the next access network based on the measured QoS values by LMA. Finally we consider the state transition diagram of our proposed scheme and confirm its operation.