• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5C
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• pp.445-453
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• 2010

Because of heavy computational overheads, the use of public key cryptosystem in Wireless Sensor Networks seems unfeasible. But some recent researches show that certain public key cryptosystem can be used in WSN, in which the key and data size, power consumption is relatively small. The NTRU cryptosystem is suggested as one of the candidates of public key cryptosystems which can be used in wireless sensor networks. In this paper, we propose an efficient key agreement scheme using NTRU and we show that it can be used in wireless sensor networks.

• Journal of Korea Game Society
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• v.6 no.3
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• pp.3-12
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• 2006

Path-finding, one of the traditional Game A.I. problems, becomes an important issue to make games more realistic. Due to the limited resources in the computer system, path-finding systems sometimes produce a simplified and unrealistic path. The most relent researches have been focused on the path-finding avoiding only static obstacles. Various moving obstacles are however deployed in real games, a method avoiding those obstacles and producing a smooth path is necessary. In this paper, navigation mesh is used to represent 3D space and its topological characteristics are used for path-finding. Intellectual repulser and attractor are also used to avoid moving obstacles and to find an optimal path. We have evaluated the path produced by the method proposed in this paper and verified its usability in real game.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10c
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• pp.179-184
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• 2007

EPCglobal 네트워크란 EPC(Electronic Product Code)와 RFID(Radio Frequency Identification) 기술을 바탕으로 제품에 식별번호를 부여하고 정보를 저장할 수 있는 공간을 네트워크로 연동하여 공급자, 수요자, 소비가 제품에 관련된 정보를 알 수 있게 해주는 시스템을 말한다. 또한 EPCglobal 네트워크 아키텍처 프레임워크(EPCglobal network architecture framework)는 EPC를 사용하여 공급과 유통망 강화라는 업체간의 공동 목표를 위한 서비스하는 것이다. EPCglobal 네트워크 아키텍처 중 EPCIS(EPC Information System) 수집 애플리케이션, EPCIS 접근 애플리케이션에서 이벤트 정의 시 공통적인 의사소통을 위한 표준 어휘 정의가 필수적이며, 그 어휘 종류에는 표준 어휘(standard vocabulary)와 사용자어휘(user vocabulary)가 있다. 이 논문은 이 가운데 EPCglobal 네트워크 아키텍처의 표준 어휘 정의에 초점을 두고, 사용자 어휘는 부분적으로 정의하고자 한다. 따라서 이 논문은 EPCglobal 네트워크 프레임 아키텍처의 이벤트 정의 시 사용될 표준 어휘를 제안하고, XML 구현을 통해 실제 사용 가능한 환경을 제공할 것이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.580-581
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• 2018

In order to reduce end-to-end delay in EH-WSN (energy harvestin wireless sensor netowk), medium access control protocols using multi-hop routing technique have been studied. In a real environment, there are many situations where it is difficult to harvest enough energy than the energy consumed. Therefore, it is required to design a MAC protocol that allows nodes to reliably relay data without exhausting power in multi-hop transmission. In this paper, we propose a power-efficient MAC protocol that can select the relay node according to the residual power and the energy collection rate to increase network lifetime.

• Annual Conference of KIPS
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• 2011.11a
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• pp.1218-1221
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• 2011

전 세계적으로 인터넷 보급률이 높아지고 전자상거래가 활발해지면서 직접 발품을 팔아가며 보다 비싼 가격에 물건을 구입하는 일보다는 인터넷몰을 이용하여 제품을 구매하는 일이 늘어나고 있다. 특히 인터넷몰 중에서도 의류를 판매하는 인터넷 쇼핑몰은 새로운 산업으로 각광받으며 하루가 다르게 새로운 사이트가 우후죽순 생겨나고 있다. 자리에 앉아 직원의 직접적인 홍보에 대한 부담을 갖지 않고 차분히 제품을 싼 가격에 구입할 수 있다는 이점을 갖고 있는 인터넷 쇼핑몰이지만 직접 제품을 눈으로 확인하지 못하기 때문에 실제 제품과 동일한 제품인지 조작된 사진인지의 여부를 확인하기 힘들고 직원과의 상담 역시 전화나 인터넷을 통해 진행되기 때문에 환불이나 교환과 같은 의사소통에 문제가 생기고는 한다. 이에 본 논문에서는 오피니언 마이닝을 통해 웹 서버에 저장되어 있는 수많은 쇼핑몰의 리뷰를 정리하고 각 사이트의 서비스, 품질 등에 대한 평가를 카테고리 별로 분석하여 소비자가 현명하고 효율적인 소비 결정을 내릴 수 있도록 도울 방법을 제안하고자 한다.

• Korean Association of Arts Management
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• no.52
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• pp.75-105
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• 2019

In studying culture consumption today, it is essential to understand and analyze the actual visitors' experiences in detail. This is deeply related to the fact that we can utilize subjective experience records that were previously inaccessible as data since plenty of people actually record many performance experiences in the media space such as social media. This study attempts to examine what elements actually consists of people's performance experience based on actual expression of the performance experience that exists online. For this, we collected two types of data. First, we collected posts which required performance recommendation on online platforms such as Jisik-In and Cafes to see how people describe what they want and analyzed data focusing on the modifiers. Results show that people mainly use modifiers that reflect the specific situation of the individual such as companion or age. In addition we analyzed how the experience was described after the show through the review posts of ticket booking site. Results show how expressions are centered around companions, revisit intentions, and viewing experiences besides elements such as story and music, which have been known as main satisfaction elements of performance experience in previous studies. In addition, we discussed the practical implications and limitations of the study as well as the theoretical discussion.

• Journal of the Korea Convergence Society
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• v.8 no.1
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• pp.19-23
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• 2017

Energy is a vital resource for the economic growth and the social development for any country. As the industry becomes more sophisticated and the economy more grows, the electricity demand is increasing. So forecasting electricity demand is an important for electricity suppliers. Forecasting electricity demand makes it possible to distribute electricity demand. As the market for Negawatt market began to grow in Korea from 2014, the prediction of electricity consumption demand becomes more important. Moreover, power consumption forecasting provides a way for demand management to be directly or indirectly participated by consumers in the electricity market. We use Genetic Algorithms to predict the energy demand of the fishing industry in Jeju Island by using GDP, per capita gross national income, value add, and domestic electricity consumption from 1999 to 2011. Genetic Algorithm is useful for finding optimal solutions in various fields. In this paper, genetic algorithm finds optimal parameters. The objective is to find the optimal value of the coefficients used to predict the electricity demand and to minimize the error rate between the predicted value and the actual power consumption values.

• Journal of Food Hygiene and Safety
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• v.16 no.4
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• pp.295-299
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• 2001

This study was performed to survey and evaluate the contents of caffeine in commercial palatability foods by HPLC. The contents of caffeine in commercial palatability foods were 9.0~49.2 mg in black tea, 35.9~141.4 mg in coffee, 12.4~48.0 mg in green tea, 7.1 ~16.5 mg in brown rice green tea, 22.8 mg in cocoa tea, 10.3~25.0 mg in cola and 10.0~48.2 mg in ice bar(coffee) respectively. The contents of caffeine extracted from black tea, coffee(roasted beans) and green tea were rapidly increased for five minutes from the extraction initiation, and were not nearly changed after ten minutes. Moreover, the caffeine contents were increased until 10$0^{\circ}C$ of extraction temperature.

• The Journal of the Korea Contents Association
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• v.16 no.6
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• pp.236-247
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• 2016

Considering the prevalent use of mobile devices and the mobile Internet in Korea, there should be open doors for retailers to a different type of distribution if they could find out what makes consumers satisfied with m-commerce sites as well as what makes consumers purchase from m-commerce sites. Therefore, we explored: 1) the antecedents of satisfaction with m-commerce sites and 2) the determinants of purchasers vs. browsers of m-commerce. As possible antecedents of the two dependent variables, the following were utilized in the current study: the Technology Acceptance Model (TAM), perceived shopping values, and interactivity. According to the results of this study, these variables related to the performance of mobile commerce sites (Perceived ease of use, Perceived usefulness, Synchronicity, Richness of content, and Contextual services) significantly affected satisfaction with m-commerce sites. On the other hand, the most important discriminator of an m-commerce purchaser vs. a browser was human-oriented interactivity, especially interpersonal communication among users. With the help of information technology.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.7
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• pp.757-766
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• 2014

In this paper, economic loss due to high power electromagnetic pulse is estimated and the methodology used for calculating its impacts is suggested using a macro approach. In order to investigate the most critical infrastructure for the high power electromagnetic pulse assault, the vulnerability assessment that provides information on the threats of concern is conducted. As a result, this study concentrates on the electric power networks. The presented assessment model is considered with gross domestic product (GDP) and energy consumption when the electric power networks are damaged due to high power electromagnetic pulse. In addition, economic losses are calculated by the extent of damages considering different types of the high power electromagnetic pulse assault generated by nuclear and man-made weapon. Through the estimation of these damages, the resulted economic loss will be compared with the protection cost. Consequently, protection of the vulnerable infrastructures can be prepared against electromagnetic pulse attack.