• 대한기계학회논문집A
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• 제25권1호
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• pp.61-69
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• 2001

EFP(Fitness For Purpose) type defect assessment methodologies based on ECA(Engineering Critical Analysis) have been established and are in use for the structural integrity evaluation of gas pipelines. ECA usually includes the fracture mechanics analysis, and it is assumed that the J-integral uniquely characterizes the crack-tip stress-strain field. However, it has been proven that the J-integral alone can not be sufficient to characterize the crack-tip field under low levels of constraint with a single parameter. Since pipeline structures are made of ductile material, locally loaded in tension, cracks may experience low level of constraint, and therefore, J-dominance will be lost. For this reason, the level of constraint must be quantified to establish a precise assessment procedure for pipeline defects. The objective of this paper is to investigate the fracture behavior of a crack in gas pipeline(KS D 3507) by quantifying the level of constraint. For this purpose, tensile tests and CTOD tests were performed at room temperature(24$\^{C}$) and low temperature(-40$\^{C}$) to obtain the material properties. J-Q analyses were performed for SENB and SENT specimens based on 2-D finite element analyses, in order to investigate the in-plane constraint effects on pipeline defects. For precise assessment of cracks, especially shallow cracks, in KS D 3507 pipeline, constraint effect must be considered.

• 제어로봇시스템학회논문지
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• 제15권11호
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• pp.1150-1156
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• 2009

The spread of wireless Internet technology development and applications with location information in the form of location-based services are more varied. In particular, where you recognize the location of objects such as people and things, and to provide valuable services based on ubiquitous, location-based services (Ubiquitous Location Based Services: u-LBS) is emerging as an important service. In this paper precise location data to the car crash through the location and offers related service system. In this paper the precise location tracking proposed by the concept of the Rail, road, to extract the location Data Matching Data and the current location is obtained. System used in GPS Packet and information about the location of the vehicle collision and the collision time, the vehicle consists of NodeID is about. Using these data, a packet is to be created when the conflict between vehicles in the vehicle will be sent to Gateway. Gateway to the packets that were sent from the Server to determine whether the conflict is that in an emergency situation, Emergency Center for location information and let me know whether or not the conflict will be measured. Also, for those on the outside of an emergency such as a family related to the wireless terminal wireless (PDA, cell phone) is to let me know. Server get into the conflict that was configured to store information on the Database. Additionally, the proposed u-LBS system to verify the validity of the experiment was performed.

• 한국산학기술학회논문지
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• 제12권6호
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• pp.2815-2822
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• 2011

무선 센서 네트워크에서 클러스터링 기법은 클러스터를 형성하여 데이터를 병합한 후 한 번에 전송해서 에너지를 효율적으로 사용하는 기법이다. 본 논문에서는 클러스터 그룹 모델을 이용한 계층적 불균형 클러스터링 기법을 제안한다. 이 기법은 전체 네트워크를 두 개의 계층으로 나누어 클러스터 그룹으로 형성된 2계층의 데이터를 병합해서 1계층으로 보내고, 다시 1계층에서 데이터를 병합하여 기지국으로 보낸다. 이와 같이 제안된 기법은 다중 홉 통신 구조와 클러스터 그룹 모델을 같이 이용함으로써 전체 에너지 소모량을 줄인다. 이러한 방식은 다중 홉 통신이지만 불균형 클러스터를 구축하여 핫 스팟 문제를 어느 정도 해결하고 있다. 실험을 통하여 제안된 계층적 불균형 클러스터링 기법이 이전의 클러스터링 기법보다 네트워크 에너지 효율이 향상되었음을 보였다.

• 무역상무연구
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• 제58권
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• pp.237-263
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• 2013

Traditionally, a L/C (letter of credit) has been known as a relatively low risk method of payment. This is why L/C has been used in international trade. However, L/C has a number of weak points such as high cost, long processing time, and complicated documents. Using an electronic L/C is one way to solve those weak points. In Korea, there are two types of electronic L/C. One is the EDI (Electronic Data Interchange) based L/C and the other one is the XML (Extensible Markup Language) based L/C. The former, established in 1990's, is sent from banks to the beneficiary solely through VAN (Value Added Network, KTNET) operators. On the other hand the latter, started in 2005, is sent from banks to KFTC (Korea Financial Telecommunications & Clearings Institute) for management of the L/C balance, as well as to KTNET. So far, paper L/C and EDI based L/C have been used overwhelmingly instead of XML based L/C in spite of the aforesaid disadvantages. In this paper, the authors examined empirically why the users of electronic L/C were reluctant to use XML based L/C. The results are as follows. First, the users of paper L/C were more dissatisfied than the users of electronic L/C due to many factors such as cost, the time required, and information reuse. Second, the users who have more experience with XML based L/C wanted to adopt integrated management with EDI based L/C more than the users who had not experienced XML based L/C. Third, the users who had used more than one form of L/C wanted to adopt integrated management to EDI and XML based L/C more than the users who had only used one form of L/C. Therefore, the authority for electronic L/C should consider a change of the policy from the XML based electronic L/C oriented to integrated management of the various types of L/C.

• 한국도서관정보학회지
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• 제36권3호
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• pp.213-231
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• 2005

연행록은 17세기부터 19세기에 이르기까지 중국의 연경을 사행하고 돌아 온 사행사의 일원에 의해 쓰여진 기록이다. 이익모가 저술한 병진연행록은 사은겸동지사 서상관인 이익모가 1796년 11월 24일부터 익년 3월 7일까지 매일 매일의 일정을 생생하게 기록한 연행록이다. 이 연행록은 임기중의 $\ulcorner$연행록전집${\lrcorner}$ 에도 누락된 새로 발견된 연행록이며, 전라남도 장흥군 용산면 상금리(금곡)에 위치한 수원 백씨 종가에서 새로 발견되었다. 특히 병진연행록은 청의 건륭황제(고종)가 옹염(인종)에게 선위 의식을 거행한 후 첫 번째에 해당하는 정규 사절단의 공식 기록이라는 역사적 의미를 담고 있는 중요한 문헌이다. 이 연구는 이익모의 연행록에 대하여 서지적 특징과 연행록의 필사시기 및 수원 백씨 종가에 입수된 과정, 그리고 연행록에 수록된 내용을 중심으로 병진 사행의 3사신, 북경까지의 왕복 노정 및 북경에서의 체류 일정 등에 대해 살펴보았다.

• 한국콘텐츠학회논문지
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• 제9권11호
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• pp.90-99
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• 2009

본 논문에서는 RFID 기술 중 리더와 능동형 태그간 900MHz 대역을 사용하여 RFID EPC global network 교육용 시스템을 구현하였다. 능동형 태그와 리더의 설계를 임베디드 환경에서 제시하였으며 리더와 접속 가능한 서버의 소프트웨어 개발은 PC 윈도우 운영체제 환경에서 실현하였다. 개발 환경으로는 리더와 태그의 프로세서로 ATmega128를 사용하였고, 개발 언어는 C 언어로, 이를 제어하기 위하여 AVR 컴파일러가 사용되었다. 서버인 PC에서는 비주얼 스튜디오상의 비주얼 C++ 언어가 사용되었다. 시스템은 PC에서는 리더를 통해 EPC global 데이터가 포함되어 있는 태그를 붙여 관리하고, 인터넷을 통해 태그에 대한 정보 획득, 태그 메모리에 데이터를 읽기/쓰기 기능을 가지고 있다. 마지막으로 태그 메모리에 기록된 데이터를 리더를 통해 PC에 전송하고 읽기 명령으로 수신된 데이터와 태그로 전송하고 읽기 명령으로 수신된 데이터와 태그로 전송한 데이터를 비교한다. 이러한 기능을 가진 900MHz 대역의 EPC global Network RFID 교육용 시스템을 구현하였다.

• 복식문화연구
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• 제18권3호
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• pp.499-512
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• 2010

The purposes of this study were to identify awareness of pollution and attitudes toward eco-friendly clothing according to women's LOHAS lifestyle. Over 60% of women were not aware of severity of environment pollution by clothing wastes and 37.2% kept their not-wearing clothing in dead storage. 26.7% of women disposed not-wearing clothing into clothing collecting box separately and 20.9% sent them to neighbors or friends. 39.4% of women were willing to pay 10% more for eco-friendly clothing and 84.6% were not willing to buy clothing produced by unethical companies. Factors of LOHAS lifestyle were healthy food, environmental protection, family life, healthy clothing, healthy housing, and community service, and were segmented into using leisure group, family centered group, LOHAS group, and LOHAS stagnated group. Using leisure group were university women with low incomes, well aware of environmental pollution by clothing wastes and eco-friendly clothing, kept their not-wearing clothing into dead storage, and low intention to buy clothing produced by unethical companies. Family centered group were women of 30’s with average income and higher educationl, unaware of environmental pollution by clothing wastes and eco-friendly clothing, but low intention to buying them, disposed not-wearing clothing into clothing collecting box. LOHAS group were the over forties home makers with higher income and education, well aware of severity of environmental pollution, sent not-wearing clothing to others or remodeled, intended to buy eco-friendly clothing, and not to buy clothing produced by unethical companies. LOHAS stagnated group were university students, unaware of severity of environmental pollution by clothing wastes and threw not-wearing clothing into trash box, no experience of eco-friendly clothing, could buy clothing produced by unethical companies if needed.

• 한국통신학회논문지
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• 제29권1C호
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• pp.25-34
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• 2004

이동 에이전트 환경에서는 에이전트의 이동성으로 인하여 플레이스간에 연속된 위임(cascaded delegation)이 빈번하게 발생한다. 이동 에이전트 환경에서의 연속된 위임은 에이전트가 셋 이상의 플레이스를 이주하면서 플레이스간에 권한을 위임하는 과정으로서 정의된다. 이동 에이전트 환경에서 위임에 대한 대표적인 연구로는 Berkovits의 연구가 있다. 이 연구에서는 에이전트의 안전한 이주를 위하여 에이전트를 실행하고 있는 플레이스와 에이전트가 이주하게 될 플레이스간에 주고받아야 할 메시지만을 정의하고 있다. 그러나 이 연구는 에이전트의 이주와 관련된 두 플레이스만을 위임의 대상으로 고려하기 때문에, 셋 이상의 플레이스를 대상으로 하는 연속된 위임을 위한 연구로는 부적절하다. 즉, 연속된 위임을 안전하게 수행하기 위해서는 연속된 위임에 참여하는 모든 플레이스들이 주고받는 메시지간의 관계 형성이 필수적이나, 이러한 관계 형성 과정이 존재하지 않는다. 본 논문에서는 이동에이전트 환경에서 연속된 위임을 안전하게 수행하는 위임 기법을 제안한다. 제안 기법은 각 위임토큰(delegation token)을 다음에 생성되는 위임토큰에 내포시킨 후 서명하는 방법을 사용한다. 또한, 제안 기법이 재연(replay)에 의한 공격 및 위임토큰의 치환에 의한 공격으로부터 안전함을 증명한다.

• Journal of Communications and Networks
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• 제11권6호
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• pp.589-598
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• 2009

In wireless sensor networks, a node that reports information gathered from adjacent assets should relay packets appropriately so that its location context is kept private, and thereby helping ensure the security of the assets that are being monitored. Unfortunately, existing routing methods that counter the local eavesdropping-based tracing deal with a single asset, and most of them suffer from the packet-delivery latency as they prefer to take a separate path of many hops for each packet being sent. In this paper, we propose a routing method, greedy perimeter stateless routing-based source-location privacy with crew size w (GSLP-w), that enhances location privacy of the packet-originating node (i.e., active source) in the presence of multiple assets. GSLP-w is a hybrid method, in which the next-hop node is chosen in one of four modes, namely greedy, random, perimeter, and retreat modes. Random forwarding brings the path diversity, while greedy forwarding refrains from taking an excessively long path and leads to convergence to the destination. Perimeter routing makes detours that avoid the nodes near assets so that they cannot be located by an adversary tracing up the route path. We study the performance of GSLP-w with respect to crew size w (the number of packets being sent per path) and the number of sources. GSLP-w is compared with phantom routing-single path (PR-SP), which is a notable routing method for source-location privacy and our simulation results show that improvements from the point of the ratio of safety period and delivery latency become significant as the number of source nodes increases.

• 대한치과의사협회지
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• 제53권11호
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• pp.817-843
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• 2015

Korean dentist's new mission was extended in dental practice field since the National Liberation Day of Korea. Modern dentistry development were due to the introduction of american dentistry, the development of Military dentistry, the unified academic activities koreans dental Association and improvement of korean dentist system. Modern dentistry development factors were as follows, First, Seoul National University's professors have been sent for studying abroad since May 1954. Thanks to this advanced system, each dental department established branch academy. Researchers and academic activities were increased in Seoul National University, Second, from January 1954, the military started training program to the korean dentists in the United States, and also the korean dentists were sent to the US Army hospital in korea for practical training courses (On the Job Training) so they could get chances to learn the advanced dentistry. During the korean war, the oral surgery dentists enlarged treatments to the maxillofacial field. Third, korean Dental academy meeting, special lectures and tables clinic from 1947 were contributing to the development of modern dentistry in the transmission of knowledge and skills. Since 1955 "Dentistry(齒學)" with a focus on the translation of foreign literature also developed modern dentistry. Since 1958 the International dental conference could broaden dental knowledge, it also provided opportunities to communicate with the world dentistry. On Oct 11, 1962, revised the Articles of association in Korean Dental academy and korean dental association unified meeting and enhanced the conferences. Improvement of korean dentist system in 1964 unified the dentists as new dentist education. Articles, case reports, review articles and academic meetings of korean dental association from 1946 to 1969 analyzed to demonstrate the development of korean modern dentistry, The titles and lectures were classified according to department and they were organized by topic.