• Proceedings of the Korea Information Processing Society Conference
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• 2003.05c
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• pp.2205-2208
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• 2003

대부분의 인터넷 서비스는 일대일 전송방식의 best-effort를 지향하는 유니캐스트(Unicast)가 보편화 되어있다. 하지만, 다자간 통신 서비스는 고려하지 않아 망 자원 이용측면에서 매우 비효율적이다. 최근, 인터넷방송이나 소프트웨어 분배, 원격 화상회의, 다중사용자 게임, 증권시세 정보서비스 등 다자간 멀티미디어 서비스가 주요 인터넷 사업으로 각광을 밭으면서, 멀티캐스트(Multicast) 전송기술의 사용범위가 점차 증가되고 있다. 멀티캐스트는 그룹참가자의 가입과 탈퇴가 빈번한 특징이 있어 키 전달 과정에서 네트워크의 과부하를 초래한다. 본 논문에서는 빈번하게 생성되는 그룹 키의 길이를 축소시켜 메시지의 생성과정을 단축하고, 독립된 그룹간 통신에 사용되는 유니캐스트에 IPSec(Internet Protocol Security Protocol)을 적용시켜 보다 안전하게 구간의 접근제어와 무결성 및 기밀성을 보장하는 SDKD(Secure Dynamic Key Distribution)를 제안한다.

• Journal of The Korean Association of Information Education
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• v.10 no.2
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• pp.209-217
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• 2006

For its maximum impact on the scene of school as the educational equipment, it is necessary to understand equipmental characteristics of PDA and study the basis for utilizing it educationally. In this point of view, to inquire how PDA is helpful for education more than PC, the typical educational equipment in the past, PDA-based English vocabulary learning game is developed in this study, and after that it is applied on the scene of education. The result of study showed PDA can access the content more easily than PC, and learners expressed more curiosity and expectation of PDA than PC in a recent poll. In addition, under the condition of learner's voluntary use, the present study has found that learning with PDA is helpful to enhance the academic achievement more than one with PC.

• Journal of Environmental Policy
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• v.7 no.3
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• pp.41-61
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• 2008

Although the size of the organic food market in Korea has increased significantly, its further development is hampered by the information asymmetry between the producers and consumers of organic food. It isn't just about revitalizing the market; it's also about Korean farmers surviving an era of trade liberalization. In order to produce more value-added products, the information asymmetry issue has to be resolved regarding the organic food market and other agricultural credence goods such as Han-woo(Korean beef). Therefore, measuring information asymmetry has become a central issue. One way to measure asymmetry is to use Game Theory. However, in practice, estimating payoffs at the industry level is hard to accomplish, and even when it is possible, the reliability of the estimated payoffs is not guaranteed. As an alternative, the concept of Information Entropy(disorder level of information), developed by Shannon(1948), was used in this study. It is proposed that this measure should be used when assessing the level of information asymmetry in the Korean organic food market. Using recent data, it was found that information entropy in the Korean organic food market has been decreasing constantly since 2003. Therefore, it was proposed that measures should be adopted by the government to improve the certification system of organic food.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.3
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• pp.71-80
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• 2019

The Fourth Industrial Revolution, centered on intelligence and information, began to take hold in 2016. This study uses virtual reality technology, which is the most popular technology of the Fourth Industrial Revolution. The purpose of this study is to explore a Virtual Walk-through method, which can be easily applied to landscape architecture. At present, virtual reality technology is widely used in the fields of games, emergency training, and architectural design. However, in the field of landscape architecture, it is still in the development stage. In addition, most of the traditional ways to display virtual reality use 2D images, but such methods have some limitations. Therefore, this research addresses the three stages of "design-exhibition-experience" and puts forward a new simple method called 'Virtual Walk-through' that breaks from traditional landscape design exhibitions. The results show that compared with traditional methods, virtual reality has many advantages, such as the freedom of experience, a diversity of viewing angles, information supply, interaction, etc. It can show high quality images and effects, which are suitable for landscape design. It provides an evaluation method for garden design that can be utilized in the future. It is simple and has value as it can reflect the method and the expected effects. Virtual reality technology can bring an infinite number of prospects to the development of landscape architecture.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.667-669
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• 2003

최근 휴대폰, PDA(Personal Digital Assistants) 등 이동 단말기의 발전으로 개인 정보 관리 위주로만 사용하던 이동 단말기의 역할이 게임, 원격 감시 분야 등 여러 분야로 확대되었다. 원격 감시 분야의 경우, 초기에는 하드웨어의 단순한 유선 연결만을 이용하여 감시 하였다. 원격 감시 기술은 인터넷 등장과 함께 급속도로 발전, 보급되었고 웹으로도 원격 감시를 할 수 있게 되었다. 하지만, 웹을 이용한 방식은 공간과 시간의 제약이 있다. 이러한 문제점을 해결하기 위해 무선 인터넷이 가능한 이동 단말기와 원격 감시 분야를 접목시킴으로써 공간과 시간 제약 없이 원격 감시를 할 수 있게 된다. 이동 단말기에는 원격 감시 소프트웨어가 탑재된다. 소프트웨어를 통해 서버에 접근할 때는 사용자인증을 하여 영상에 대한 보안성을 높였다. 이 때 서버와 이동 단말기 간의 통신은 영상과 제어 메시지를 통하여 수행하게 된다. 본 논문에서는 사용자가 지속적으로 증가하고 있는 이동 단말기인 PDA에 원격 감시 소프트웨어를 탑재하여 가정 또는 공장 등에 있는 서버와 영상, 제어 메시지를 통하여 감시와 제어를 할 수 있는 원격 감시 시스템의 구조를 제안한다.

• The Journal of the Korea Contents Association
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• v.17 no.5
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• pp.520-528
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• 2017

In this paper, we analyze semantics on mudras of Sahasra-bhuja Avalokitesvara and implement visual content as its application. The mudras are described in the Odaejineunjib that is a tangible cultural property. The semantics analysis on the mudras are essential for understanding the meaning of the 42 Hands(mudras) that present symbolic difference of hands holding on various items. So, in this paper, we analyze the semantics on the 42 Hands according to 5 parts which are basic classification of Honored Ones on Esoteric Buddhism. We implemented a visual contents showing Avalokitesvara according to semantics on the 42 Hands. And, in the process, we are able to provide the public with easy accessibility on mudras of Sahasra-bhuja Avalokitesvara. Applications of the mudras are as follows; game contents, traditional cultural contents, etc.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.990-993
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• 2019

인공지능(AI)은 최근 다양한 산업과 사회에서 패러다임을 바꾸고 있지만, 최첨단 AI 가 제조업에서는 즉각적인 성과를 보이지 못 하고 있다. 다시 말해, Industry 4.0 시점에서 기존의 접근 방법과 차별화되는 실용적인 방법론이 필요하다. 여기서 중요한 점은 '어떤' 데이터를 '어떻게' 활용하여 '어느' 부분에 적용할 것 인가이다. 제조업은 게임과 같이 가상의 캐릭터가 하나의 객체 단위로 구동되는 것이 아니라 수많은 하드웨어가 물리적으로 조합되어 연동한다. 따라서, 현실 세계에서는 물리적 마모, 고장 등으로 인해 엔지니어의 개입 없이 수천만 번 이상의 반복 학습이 불가능하다. 또, 제조업은 학습을 위한 방대한 양의 데이터를 수집하고 레이블링 하는 것이 매우 어렵다. 이 두 가지 한계를 극복할 수 있는 방법은 현실과 매우 유사한 환경을 시뮬레이션으로 재연 후 강화 학습을 사용하는 것이다. 제조 분야에서 아주 복잡한 환경 중 하나로 이송 설비가 있으며, 본 논문에서는 그리드 분류 시스템을 개발하고 강화 학습을 적용시킬 수 있는 환경을 설계한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.2
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• pp.127-133
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• 2019

Since frequent item extraction so far requires searching for patterns and traversal for the FP-Tree, it is more likely to store the mining data in a tree and thus CPU time is required for its searching. In order to overcome these drawbacks, in this paper, we provide each item with its location identification of transaction data without relying on conditional FP-Tree and convert transaction data into 2-dimensional position information look-up table, resulting in the facilitation of time and spatial accessibility. We propose an algorithm that considers the mapping scheme between the location of items and items that guarantees the linear time complexity. Experimental results show that the proposed method can reduce many execution time and memory usage based on the data set obtained from the FIMI repository website.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.4
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• pp.77-89
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• 2001

Recently, with the explosive growth of communication technologies, group oriented services such as teleconference and multi-player game are increasing. Access control to information is handled by secret communications with group keys shared among members, and efficient updating of group keys is vital to such secret communications of large and dynamic groups. In this paper, we employ (2,4)-tree as a key tree, which is one of height balanced trees, to reduce the number of key updates caused by join or leave of members. Especially, we use CBT(Core Based Tree) to gather network configurations of group members and reflect this information to key tree structure to update group keys efficiently when splitting or merging of subgroups occurs by network failure or recovery.

• Journal of the Korea Society for Simulation
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• v.18 no.1
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• pp.53-62
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• 2009

The real data obtained from field exercises has a crucial role in modeling and simulation of a combat or a wargame. This becomes an important input especially in analyzing weapon systems realization. Many existing models have been using the mean value of the time between each fire. The firing data can be incorporated into a known probability distribution or used directly as an empirical distribution. Data of field exercises are very useful instead of the real combat outcomes. This study finds a new modeling approach and techniques to compare the data with the previously generated outcomes. This fundamental research work will continue to consider more of the various weapon systems, the sizes, and other tactical aspects.