• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.11
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• pp.1500-1506
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• 2020

In this paper, we study a scheduling problem based on reinforcement learning for overlay device-to-device (D2D) communication networks. Even though various technologies for D2D communication networks using Q-learning, which is one of reinforcement learning models, have been studied, Q-learning causes a tremendous complexity as the number of states and actions increases. In order to solve this problem, D2D communication technologies based on Deep Q Network (DQN) have been studied. In this paper, we thus design a DQN model by considering the characteristics of wireless communication systems, and propose a distributed scheduling scheme based on the DQN model that can reduce feedback and signaling overhead. The proposed model trains all parameters in a centralized manner, and transfers the final trained parameters to all mobiles. All mobiles individually determine their actions by using the transferred parameters. We analyze the performance of the proposed scheme by computer simulation and compare it with optimal scheme, opportunistic selection scheme and full transmission scheme.

• Journal of the Korea Society of Computer and Information
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• v.19 no.9
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• pp.21-31
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• 2014

Singular value decomposition (SVD) has been widely used to identify unique features from a data set in various fields. However, a complex matrix calculation of SVD requires tremendous computation time. This paper improves the performance of a representative one-sided block Jacoby algorithm using a two-dimensional (2D) multi-core system. In addition, this paper explores an optimal multi-core system by varying the number of processing elements in the 2D multi-core system with the same 400MHz clock frequency and TSMC 28nm technology for each matrix-based one-sided block Jacoby algorithm ($128{\times}128$, $64{\times}64$, $32{\times}32$, $16{\times}16$). Moreover, this paper demonstrates the potential of the 2D multi-core system for the one-sided block Jacoby algorithm by comparing the performance of the multi-core system with a commercial high-performance graphics processing unit (GPU).

• Journal of the Korea Society of Computer and Information
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• v.19 no.9
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• pp.151-160
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• 2014

Recently enterprises, which posses high-speed internet and high-performance computers, have tried to use MIS(management information systems) to deal with whole task efficiently. This study considers design of menu navigation using SNA(social network analysis) to be able to move between menus of MIS efficiently. We extracted the important menu lists through the high SNA measures such as degree centrality, betweenness centrality and closeness centrality, developed web-pages and investigated its application. The findings will be used for design of web menu navigation and guide of strategic planning for MIS.

• Proceedings of the ESK Conference
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• 1998.04a
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• pp.1-6
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• 1998

의복은 사람의 신체적인 특징에잘 맞고 심리적으로 만족을 주는 것이어야 한다. 식죽(1989)은 인간관계와 사회구조가 복잡하게 서로 얽혀 이루어진 현대사회에서는 의복에대한 욕구는 다면적이고 모든 기능을 동시에갖는 것이 요구되어진다고 하였고 정삼호(1988)는 성인여성들은 연려이 증가함에 따라 나타나는 체형변화를 의복으로 최대한 보완할 수 있는 디자인을 선택하여 다른 사람들에게 의복을 통해 자기 자신을 표현함으로서 심리적으로 안정감을 얻으려고 노력한다고 하였다. 따라서, 의복 착용 자가 의복을 통해얻는 심리적 만족도는 신체적 만족도와 관련되어 형성된다고 할 수 있으며 또한 신체 적 만족도는 체형과 관련되어 형성된다고 할 수 있다 (정재은,1992). 이에 신체적 만족도와 의복행동 및 체형에 관한 연구가 많이 이루어지고 있다. 이옥연(1984), 식죽(1988), Labat-Delong(1990), 김용숙 (1990), Shim(1991), 구자명.이명희(1994), 고애란.김양진(1996) 등은 신체 만족도와 의복행동간에 관련 이 있음을 밝혔으며, 임숙자(1986), 김양진.강혜원(1992)은 신체의 결함을 의복으로 보완하고자 하는 경향이 있다고 하였고, 김정숙(1984)은 자신에게 어울리는 의복을 선택하므로써 안정감을 갖게된다고 하였다. 또한, Douty. Brannon(1984)은 여성은 마른것을 선호한다고 하였고 Clayton 등(1987)은 의복 착용자의 체형에 따라 의복 유행성 지각이 다름을 밝혔다. 그러나, 이에관한 대부분의 연구들은 심리 학적 입장에서 행하여진 연구로 신체의 종합적인 만족도, 선호를 취급하고 있을 뿐 신체각 부위의 만족 도나 선호에 관한 자세한 고찰을 하고 있지 않으며 자신의 신체에 대한 인식도 및 실제체형과의 비교는 이루어지고 있지 않다. 이에, 신체 각 부위에 대한 인식도 및 실제 신체 측정치와 만족도와의 관계 및 이상형에 대해 구체적으로 파악할 필요가 있다. 또한, 신체에 대한 이상형은 시대의 여러 여건에 따라서 변화할 수 있으므로 의복 착용자가 의복을 통해서 표현하고자 하는 이상형의 시대적 변화를 살펴볼 필요가 있다. 따라서 본 연구에서는 신체에 대한 인식도 및 만족도, 이상형에 대한 설문지 조사와 신체측정을 통하여 신체 크기에대한 만족도를 객관적인 척도로 고찰하고, 이상형과 실제 체형에 관하여 고찰하고자 한다. 도한, 1992년도 자료와의 비교를 통하여 시대에 따른 신체만족도와 이상형의 변화를 파악하고자 한다. 이를 기초로 한 의복원형 제작 및 의복 디자인에 대한 연구를 통해 의복의 맞음새가 좋을뿐만 아니라 의복착용자들 에게 심리적 만족을 줄 수 있는 의복 제작에 도움이 될 수 있을 것이다.

• Korean Institute of Interior Design Journal
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• v.26 no.3
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• pp.45-54
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• 2017

A social phenomenon that occurs in a physical space is said to be a complex system. However, space syntax, which is commonly employed by researchers to identify such social phenomena, has various limitations in interpreting their complexity. On the other hand, agent-based modeling considers a variety of factors including the personality of the agent, objective-oriented work flows, estimation according to time flows and better prediction of space use through diverse parameters depending the situation, as well as the characteristics of the space. The agent-based method thus has the potentials to be developed as an alternative to space syntax techniques. In particular, discrete event driven simulation(DEVS), which is part of the agent-based modeling method, embraces the concept of networks just like space syntax, which allows a possible theoretical linkage in the future. This study suggests a procedural model of agent-based DEVS reflecting two different connection methods, i.e. connections between adjacent areas and those of the entire space, and attempts to identify the relationship between the local and regional indices of space syntax. A number of spaces were selected as examples-one for a preliminary experiment and eight modified for the main experiment-and space syntax and DEVS were applied to each of them. The comparative analysis of the results led to the conclusions as follows: 1) Adjacent connections were closely related to local indices, while the whole-space approach to regional indices. Local integration shows both characteristics. 2) Observation of the time flow model indicated a faster convergence with the range of 1 to 3-fold of the total time of one lap, with the error of less than 10%. 3) The heat map analysis showed more obvious characteristics of using the space for the entire space rather than adjacent connections. 4) Space syntax shows higher eligibility than ABM.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.249-255
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• 2017

Recently, among smart phone functions, cameras are one of the most popular functions and have become one of the most influential functions for purchasing smartphones. However, the basic camera application of the smart phone has a complicated user environment, which is causing many difficulties for the first time user. In this study, Galaxy S7, which is the newest Galaxy S series among the most used Galaxy S series in Korea, was selected and the usability test of the camera application was limited to shooting and editing sharing functions. As a result, first, improvement of icon graphic and label of text form should be provided at the same time to increase the recognition rate and attention of the icon. Second, it is necessary to simplify the structure and provide an intuitive interface in order to facilitate access to various modes and functions. Third, it is necessary to simplify the provision of personalized customized menus or functions in the development of the camera application because it causes a high failure rate and inconvenience in the special functions which are not widely used.

• Archives of design research
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• v.13 no.3
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• pp.29-38
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• 2000

Human has been living in the relation with diverse artifacts ranging from simple tools to complex systems. The relation is an interaction between user and product with input and output process to achieve a certain goals. Natural inter-connection is very important to this interaction. The visualized operation and the dear feedback of product play a critical role in making input and output distinct at both sides. So product innovation means removing mental and physical loads between product and user based on understanding and analyzing interaction. This study proposes the interaction grid as a framework to visualize the interaction. The interaction grid is the format to describe the input and output process between user and product. Modeling and analysis of interaction is based on the interaction grid. Finally, this study discusses the idea exploration method for product innovation with interaction grid, and develops prototype of interaction analysis system for supporting idea exploration.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5B
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• pp.573-581
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• 2011

The underwater channel is known to offer poor communications channel. The channel medium is highly absorptive and the transmission bandwidth is limited. In addition, the channel is highly frequency selective; the degree of selectiveness depends on a detailed geometry of the channel. Furthermore, the response changes over time as the channel conditions affecting the response such as water temperature, sea surface wind and salinity are time-varying. The transceiver design to deal with the frequency and time selective channel, therefore, becomes very challenging. It has been known that deep fading at certain specific sub-carriers are detrimental to OFDM systems. To mitigate this negative effect, the proposed coded OFDM system employs an LDPC code based modulation. In this paper, we aim 1) to provide a detailed underwater channel model; 2) to design a robust LDPC coded OFDM system; 3) to test the proposed system under a variety of channel conditions enabled by the channel model.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2968-2974
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• 2015

Method for finding the attractors is the important object to investigate in the linear/additive CA because it is a primary interest in applications like pattern recognition, pattern classification, design of associative memory and query processing etc. But the research has been so far mostly concentrated around linear/additive CA and it is not enough to modelize the complex real life problem. So nonlinear CA is demanded to devise effective models of the problem and solutions around CA model. In this paper we introduce CLT as an upgraded version of RMT and provide the process for finding the attractors and nonreachable states effectively through the CLT.

• Archives of design research
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• v.15 no.4
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• pp.253-262
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• 2002

Without the involvement of time in animation, it cannot be possible to create movement. Therefore, tine is the important element to create animation. In animation, the expression of the emotion of character is more complicate than the appearance. Time is one of element to use for express of the emotion. It can be divided two types of time as the real time and the animation time broadly. The real time has linear, irreversible and analogue form which is in our daily life. And the animation time has multi-direction, reversible, and digital form which can be detected in the movie. For the animation time, there are many types of time that are the running time, the production time, the subjective time, the objective time, the ambiguous time and the universal time etc. This study is to extend and enrich the express as film language through various types of times in animation. Time is one of important element that can be useful method for expressing many unique scenes in film art as film language.