• 공학교육연구
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• 제17권2호
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• pp.50-58
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• 2014

This study reviews recently developed perspectives within Science and Technology Studies (STS) and engineering education including engineering ethics and engineering design, focusing on defining why interdisciplinary collaboration between those two areas is required and how it can be realized. The disconnection between those areas is closely related to the chronic diseases that has brought the mono-disciplinary, segmented educational system of 20th century: fragmented perception of reality and gradual loss of academic influence. This study consists of two sections: the first section reviews new movements among STS, engineering ethics and engineering design; the second section analyses how their combination is developing and what significance it represents. Recently, some scholars attach more importance to scalable scholarship of STS, that is, strategic expansion of the range of STS. This kind of attempts is gradually producing satisfactory results as it is combined with innovative efforts arising from the field of engineering education. This study emphasizes that, when STS and engineering education are combined and interact more with each other, it will broaden our prospects about engineering and society; it will, particularly, contribute to enhance our engineering education.

• 디지털융복합연구
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• 제11권12호
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• pp.453-458
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• 2013

무선 LAN 환경에서는 최대한 안전한 것이 가장 중요하다. 표준 802.11 보안은 매우 네트워크 공격에 대해 매우 많은 취약점을 가지고 있다. IEEE 에서는 이러한 취약점에 대해서 보안을 하기 위해 많은 메커니즘을 만들지만, 무선 LAN의 특성인 공중에 브로드 캐스트 하는 방식 때문에 다른 환경의 네트워크 보다 많은 정보가 유출 될 수 있다. 무선 LAN 환경에서 해당 인증 이후에 무선 LAN에 접근 할 수 있기 때문에 이러한 인증 과정이 중요한 것이다. 하지만 인증 과정에는 안전적인 메커니즘이 사용하지만, 근본적인 최대한의 정보 노출을 줄이는 방법에 대해서는 언급하지 않고 있는 실태이다. 해당 연구에서는 무선 LAN의 인증과 인증 해제 방법과 이에 대한 취약점에 대해서 설명하고, 해당 취약점에 대한 보안 방법을 제시한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.658-662
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• 2004

This paper proposes an orthogonal reception structure for OS/SS communication with time-shifted m-sequences, and compares the performances of the proposed and conventional receiver. This structure provides two important characteristics to reference user signal with not only increment of auto-correlation value but also cancel of the cross-correlation value out to zero between the reference user and other user signals. In addition, the structure can be easily implemented with the conventional receiver adding an additional integrator path in parallel and an adder that sums the conventional path output and the new path output signal. Hence, the proposed structure can be applied for channel impulse response measurement, and efficiently used for multi-user interference signal cancellation and channel capacity increment by flexible structural inter-working operation, connection or disconnection, of the new path to conventional receiver structure.

• 한국보육지원학회지
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• 제12권6호
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• pp.1-17
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• 2016

This study aimed to investigate the effects of shyness of 3 to 5-year-olds and the teacher-child relationship on peer play behaviors. For this purpose, a survey was conducted targeting 33 teachers working with 277 three to five-year-olds at child care centers located in Chungbuk, Korea. SPSS 19.0 was used to implement exploratory analyses and hierarchical regression analysis. It was found that children with low sociability and thoes with close relationships with teachers indicated the least play disruption. Children whose assertiveness and sociability were low and whose relationships with teachers were close were likely to do the most play interaction. However, regardless of the level of the lack of assertiveness and of the lack of sociability, children with close relationships with teachers had a higher level of play interaction. Children with a higher level of lack of sociability and in conflict relationships with teachers had a higher level of play disconnection. Findings of this study highlight the importance of considering the interplay of children's shyness and teacher-child relationships in the development of peer play behaviors.

• 한국군사과학기술학회지
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• 제21권5호
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• pp.640-648
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• 2018

Time division wireless communication in tactical MANET is attractive to deliver both high data rates and long-range coverage, and to provide scheduled QoS to mission participants. This paper is about the time synchronization issue of multi-mission USV in tactical MANET. As USV communication coverage becomes longer, the synchronization error also becomes higher; therefore, which results in link disconnection, and consequent failures of reconnection because base station cannot configure necessary parameters over long-distant terminal. We propose a range adaptive time synchronization method to compensate for synchronization errors. The issue of long-range time synchronization problem was identified during maritime communication tests, and we verified the proposed method through analyses of both indoor and outdoor test results.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권7호
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• pp.384-390
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• 1999

This paper describes a new ac-to-dc power converter using a multilevel converter. A conventional multilevel ac-to-dc converter has large output dc filter capacitors. When a short circuit happens in a load, the stored energy in the capacitors should be discharged through the load with a high short circuit current. The high current may cause considerable damage to the capacitors and the load. The output dc capacitors of the proposed converter do not discharge even under load short circuit condition. In the case of a load short circuit, the capacitors become a floating state immediately and remain in the state. Then the stored capacitor energy is supplied to the load again as soon as the short circuit has been cleared. Therefore, the rising time of the load voltage can be significantly reduced. This feature satisfies the requirement of a power supply for a load with frequent short circuits. The proposed converter has the characteristics of a simplified structure, a reduced cost, weight, and volume compared with conventional power supplies with frequent output short circuits. Experimental results are presented to verify the usefulness of the proposed converter.

• 수산해양기술연구
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• 제36권2호
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• pp.126-131
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• 2000

본 연구에서는 장어 통발어선 자동화 조업장치 개발의 첫 단계로서 통발을 모릿줄에 기계적으로 연결, 분리할 수 있는 장치인 집게식 통발연결장치 및 통발자동분리장치를 개발하여 해상성능실험을 실시하였다. 본 연구에서 얻어진 결과를 요약하면 다음과 같다. 1. 집게식 통발연결장치가 무른 꼬임 트와인 고다리 및 된 꼬임 트와인 고다리에 각각 연결되었을 때, 그 사이의 최대 인장하중은 각각 1379 N및 1,603 N 이었다. 2. 집게식 통발연결장치에 대한 해상성능시험 결과 성능이 양호함을 확인하였으며, 통발 회수율은 100% 이었다. 3. 통발자동분리장치에 대한 해상성능시험 결과 성능이 양호함을 확인하였으며, 통발 분리율은 100% 이었다.

• 한국식물병리학회지
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• 제2권3호
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• pp.158-164
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• 1986

Fusarium oxysporum f. sp. fragariae에 의한 딸기 시들음병에 감염된 딸기 식물의 병태조직학적 특징을 광학현미경으로 조사한 결과 자연 또는 인공 감염된 뿌리, 관부, 잎자루 및 포복지의 도관내에는 본 병균의 균사와 대형, 소형 분생포자가 관찰되었으며, 이들 균체에 의한 도관의 폐쇄와 유관속내에 형성된 강(Cavity)이 관찰되었으나 다른 분화형에서 볼 수 있는 도관유조직의 비대현상, 분충체 및 pectin 물질에 의한 도관폐쇄는 관찰할 수 없었다. 따라서 딸기 시들음병의 위조발생은 균체에 의한 도관의 폐쇄가 중요한 요인으로 생각되었다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.822-828
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• 2005

Customer satisfaction becomes one of the important managerial concerns associated with corporate competency in current competitive environment for Internet communication service companies. Hence, it is demanding to improve a company's customer satisfaction through the total quality management perspective. In practice, engineers as well as the management hope to find major quality characteristics with Internet communication network that is closely related to customer satisfaction, consequently aiming to the raise of their company's customer satisfaction. This paper presents an empirical relationship analysis between network quality characteristics and customer satisfaction on Internet communication. Methodologically, the relationship analysis framework is based on the regression variable selection procedures. In this framework, it is implemented that; 1) iterative model building; and 2) consistent criteria application to statistical tests for selecting significant variables. A case study shows that; 1) the customer satisfaction on the network connection seems to be more closely related to the network quality characteristics compared with the customer satisfaction on the network speed; and 2) the download disconnection rate has relatively evident relationship with the customer satisfaction on the network connection.

• 한국군사과학기술학회지
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• 제10권1호
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• pp.44-54
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• 2007

In the military field, according to the MIL-STD-188-220, which is an Ad-Hoc communication protocol used for sending out or receiving data and voice smoothly among nodes in the situation that wireless communication nodes move arbitrarily, data communication is cut off because nodes can not know topology changes perpetually in the link disconnection state due to node movement in the case that transmitters do not confirm whether data is delivered to receivers or not, and transmit only the data having routine precedence continuously. In order to solve this problem, we have proposed the technique that makes efficient data communication possible by achieving a rapid topology change detection and link information update using TEST frame. We have analyzed TEST frame application effects in the two aspects of the topology update delay time and the data transmission success ratio.