• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.4
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• pp.23-30
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• 2000

Cogeneration systems are seen as a significant innovation for dispersed energy generation since they are both environmentally friendly and has comparatively high degrees of efficiency. It is especially suited for the decentralized provision of electricity and heat. However, it causes operational problems such as voltage regulation, voltage variation, protection and safety. Especially, it is expected that the interconnection/disconnection operation of cogeneration system has an effect on distribution voltage regulation and variation. Recently, with the increased use of customer-owned computers and other sensitive electronic equipment, electric power quality has become an important concerns. Therefore, the voltage quality problems with cogeneration system should be investigated because the voltage quality is an important part of electrical power quality. In this paper, the momentary voltage dips associated with the interconnection/disconnection operation of cogeneration system are analyzed, including restraint solutions at the customer level. In addition, the unit capacity of cogeneration systems per feeder are evaluated from the view point of momentary voltage variations. The results of this paper are useful analysis data for interconnection standards/guidelines of cogeneration systems and dispersed generation (DG)

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.7
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• pp.1634-1642
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• 2014

Mobile RFID system, that consists of the existing RFID reader mounted on the mobile devices such as smartphones, is able to provide the users a variety of services and convenience. But security of mobile RFID system is too weak like the existing RFID system. In this paper, the mobile RFID mutual authentication protocol with high level of security is proposed to overcome the troubles such as cryptographic protocols in the existing RFID system responding with the same value in every authentication procedure and the exposure in the exchange of messages. The proposed protocol exchanges messages unexposed by using the random numbers generated in the mutual authentication between the tag and the reader and making numbers coded with the symmetric key. Besides, the protocol uses the mutual authentication utilizing OTP by considering the characteristics of the reader embedded in mobile devices in the mutual authentication process between the reader and the server. Because changed message in every authentication, which produces safe from spoofing attacks and replay attacks, etc.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.271-274
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• 2013

Considering the recent trend highlighting the importance of STEAM education, the purpose of this study is to develop scientific research activities and STEAM technology material using the smart device sensor. Drawing a picture on a map with GPS drawing application which contains elements such as IT, geographic information, sports and arts, we intent not just to install a smartphone application but also to get synergic effects and help with real cartography and geographic classes which are not experienced in the middle school curriculum, by using the functions of a smart device. Through the development of STEAM teaching material, we intended to provide a clear direction towards advancement by developing creative teaching data and teaching models which encourage students to improve their interest and creativity in science, technology, engineering, art, and mathematics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.491-494
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• 2017

Recently, IoT has been supported by ICT technology with a variety of ICT powers. In May 2014, Information and Communication Strategy Committee announced the 'Basic plan for Internet of Things'. Also on Febuary 24 this SAME year, KISA(Korea Internet&Security Agency) provides many projects related to IoT, such as announcement of 'K-Global Project' for start-up and venture support related to IoT and ICT companies. In contrast to the various services of Internet of Things, when a connection is made between object-to-object or person-to-object wired and wireless networks, security threats have occurred in the process of communication. We analyzed these kinds of security threats related to Internet of things, and gave a consideration for requirement.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.607-608
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• 2016

Recently using a variety of sensors sensing the virtual(Virtual Sensing) technology that extracts specific data has been applied to IoT service interface. The utilization of such sensors while increasing IoT (Internet of Things) environmental sensor is an essential element. However, used in the IoT to the environment, while the increase in utilization of a specific sensor utilization falling sensors is generated. In this paper, we design unnecessary sensors removal algorithm as a way to solve this problem. Through the utilization of poor power to block the sensor can reduce the power consumption and user sensor control service through the monitoring by blocking the use of the sensor is considered that there can be provided a more effective and convenient.

• The KIPS Transactions:PartD
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• v.8D no.5
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• pp.553-560
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• 2001

Bioinformatics is a discipline to support biological experiment projects by storing, managing data arising from genome research. In can also lead the experimental design for genome function prediction and regulation. Among various approaches of the genome research, the proteomics have been drawing increasing attention since it deals with the final product of genomes, i.e., proteins, directly. This paper proposes a data mining technique to predict the structural characteristics of a given protein group, one of dominant factors of the functions of them. After explains associations among amino acid subsequences in the primary structures of proteins, which can provide important clues for determining secondary or tertiary structures of them, it defines a sequence association rule to represent the inter-subsequences. It also provides support and confidence measures, newly designed to evaluate the usefulness of sequence association rules, After is proposes a method to discover useful sequence association rules from a given protein group, it evaluates the performance of the proposed method with protein sequence data from the SWISS-PROT protein database.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8B
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• pp.687-694
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• 2012

In OFDMA-based cellular system, inter-cell interference (ICI) reduces system capacity by aggravating receiving performance of the users located in edge of the cell. Therefore, to mitigate ICI is very important issue in cellular system. To deal with ICI problem, fractional frequency reuse (FFR) is introduced. FFR is an interference management technique. It separates each cell into inner cell and outer cell. Then, it allocates whole system bandwidth to inner cell and different frequency partition to each sector of outer cell. By doing this, outer cell users can ignore interferences from adjacent cells. So, the receiving performance of the cell edge users can be fairly increased. However, using FFR technique has a fatal side effect. In order to use different frequency partition among three sectors of outer cell, they can use only a third of the whole system bandwidth. Then, the reduction of available bandwidth reduces the system throughput directly. To solve this problem, we propose a new FFR method that allocates partially overlapped frequency partition to each sector of outer cell. And then, we suggest a proper overlapping ratio for practical cellular system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.209-215
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• 2011

Roundabout has circular traffic island in the intersection center and is kind of intersection where the automobile bypass circular traffic island. In Korea, the provisional Roundabouts Design Guidelines were published in 2004 by MLTM (Ministry of Land, Transport and Maritime Affairs). This guideline did not discussed domestic traffic circumstance. It just only introduced foreign instances and their guidelines. In addition, the recent National Competitiveness roundabouts as part of the green growth has been concentrated on the interest. In this paper, 90 degree of the 4-legged roundabout was compared with 72 degree, 45 degree, and 30 degree 5-legged roundabouts by micro simulation VISSIM. As a result of analysis, average travel time is decreased when the inscribed circle diameter become bigger the roundabout. 5-legged roundabout until 2,000 volume per hour evaluated to be similar effect at 90 degree of 4-legged roundabout.

• Journal of Convergence for Information Technology
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• v.10 no.8
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• pp.173-178
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• 2020

In the near future, as artificial intelligence and computing network technology develop, collaboration with artificial intelligence (AI) will become important. In an AI society, the ability to communicate and collaborate among people is an important element of talent. To do this, it is necessary to understand how artificial intelligence based on computer science works. An algorithmic education focused on problem solving and learning is efficient for computer science education. In this study, the results of an assessment of computational thinking at the beginning of the semester, a satisfaction survey at the end of the semester, and academic performance were compared and analyzed for 28 students who received algorithmic education focused on problem-solving learning. As a result of diagnosing students' computational thinking and problem-solving learning, teaching methods, lecture satisfaction, and other environmental factors, a correlation was found, and regression analysis confirmed that problem-solving learning had an effect on improving lecture satisfaction and computational thinking ability. For algorithmic education, if you pursue a problem-solving learning technique and a way to improve students' satisfaction, it will help students improve their problem-solving skills.

• Journal of Global Scholars of Marketing Science
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• v.4
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• pp.111-131
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• 1999

본 연구는 인터넷 쇼핑시이트의 웹디지인 구성형식에 띠른 소비자의 쇼핑 프로세스의 차이점을 밝히고, 인터넷 쇼핑 사이트에 대한 소비자 만족도와 그 차원을 규명하고, 인터넷 편의성, 만족도 및 구매의도와의 관계를 조사하였다. 본 연구는 설문지조사법과 관찰법을 이용히여 인터넷을 사용하는 소비자로, 남여 대학생 101명을 편의추출히여 조사를 실시하였고, 자료분석방법으로는 기술통계, paired t-test, 요인분석, 회귀분석을 실시하였다. 연구 결과 첫째, 대부분의 응답자들이 인터넷사용과 인터넷 쇼핑에 어려움을 느끼지 않았으며, 인터넷 정보의 질은 소비자들이 기대수준에 미치지 못하는 것으로 나타났다. 또한 상품정보 제공 시 사진과 설명을 동시에 사용하는 것을 선호하고 상품 홈페이지 구성의 중요도 중 속도와 정보의 질을 중요시 여기는 것으로 나타났다. 둘째, 인터넷 쇼핑 프로세스의 관찰 결과 처음 쇼핑을 시도할 경우 인석하기 쉬운 기능키나 단어로 된 메뉴를 이용하는 경우가 대부분이며, 쇼핑 과정은 대부분 10번의 클릭으로 이루어졌고, 쇼핑과정 동안 쇼핑에 재미를 느끼지 못하는 경우도 많았으며 마음에 들지 않거나 선호하는 상품이 없는 경우 쇼핑을 중단하는 것이 대부분이었다. 그리고 매장구성은 텍스트보다는 그림을 선호하는 경우가 많았다. 셋째, 인터넷 쇼핑에 대한 소비자 만족요소 중에 '직접 가지 않아도 되는 것'과 '시간, 장소에 구애받지 않는다'는 항목에 대한 만족도가 높게 나타났으나 상품의 구색이나 가격, 유통업자 및 상품의 신뢰도 요인에 대한 만족도가 낮게 나타났으며 만족/불만족 요인으로는 주문처리의 정확성/다양성, 인터넷 쇼핑의 편의성, 상품의 다양성/신뢰성, 주문 방법의 편의/경제성, 쇼핑 방법의 용이성의 5가지 요인으로 나타났다. 넷째, 인터넷 편의성은 소비자 만족에 영향을 미치지 않는 것으로 나타났으나, 인터넷 쇼핑의 만족은 구매의도에 영향을 주는 것으로 나타났다. 쇼핑의 만족도가 높을수록 구매의도가 높은 것으로 나타났고, 상품의 다양성/신뢰성 요인에 대한 만족도가 높을수록 구매의도가 가장 높아지는 것으로 조사되었다. 인터넷 쇼핑 사이트에서 소비자들은 전형적인 의복구매행동과 유사하거나 오히려 더 많은 정보와 서비스롤 요구하는 것으로 나타났다. 직접 보지 못하고 구매해야 한다는 데 대한 두려움과 거부감을 많이 나타내고 쇼핑 시 즐거움에 대한 중요도도 높게 나타났다.