• 대한전자공학회논문지TC
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• 제46권11호
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• pp.25-31
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• 2009

기존 GPSR(Greedy Perimeter Stateless Routing) 프로토콜의 Greedy Forwarding에서는 항상 목적지에 가까운 노드만을 Next-Hop으로 설정하는 방식으로, 어느 특정 노드의 에너지 소모가 커지는 경향이 있는데, 이를 해결하기 위하여 기존의 Greedy Forwarding 방식에 목적지에 가까운 노드를 선택하면서 각 노드의 에너지 잔량을 고려하여 전체 네트워크의 수명(Network lifetime)을 연장시킬 수 있는 방법을 제안한다. 무선 ad hoc 네트워크를 구성하는 노드들의 한정된 에너지를 효율적으로 사용하기 위하여 네트워크의 수명에 초점을 맞추어 각 노드들의 에너지 잔량을 고려하면서 최단 거리 역시 고려할 수 있는 라우팅 기법인 개선된 EAGPSR(Energy Aware Greedy Perimeter Stateless Routing)을 제안한다. 제한된 프로토콜의 성능 평가를 위하여 ns-2를 사용하였으며, 성능 평가를 통하여 GPSR과 기존의 EAGPSR와 비교하여 네트워크 수명이 향상된 것을 확인할 수 있다.

• 대한원격탐사학회지
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• 제32권6호
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• pp.657-672
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• 2016

빈번하게 다양한 유형으로 발생하는 해안 침식 현상에 대하여 지속적인 모니터링을 통하여 변화 자료를 축적함으로써 효과적으로 침식 지역을 관리하고 대응 방안을 수립할 수 있다. 경제적으로 정밀한 해안지역 모니터링을 수행하기 위한 수단으로써 저고도 자율 비행이 가능한 드론사진측량 시스템이 제안되고 있다. 본 연구에서는 해안 지역에서 드론 시스템으로부터 취득된 데이터를 처리하여 생성된 정사영상과 수치표고모델(Digital Elevation Model: DEM)을 다양한 기준 데이터와 비교함으로써 정확도를 분석하고자 한다. 비교 검증 방법을 수립하고, 이에 따라 분석된 정확도를 확인함으로써 해안 침식 모니터링에 드론 사진측량의 활용 가능성을 검증하였다. 기준 데이터와 다양한 조건에서 취득된 드론 영상으로부터 생성된 공간정보를 비교한 결과, 수평 및 수직 정확도(RMSE)는 각각 약 2.9 cm와 4.8 cm이었으며, 이는 해안 침식 모니터링의 요구정확도인 5 cm를 거의 만족시키는 수준으로 판단된다.

• 전기전자학회논문지
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• 제15권1호
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• pp.104-112
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• 2011

지상군은 감시정찰, 지휘통제 및 정밀타격과 관련된 정보를 교환하기 위한 수단으로 음성위주로 사용하고 있다. 하지만 지상군 작전에 참가하는 전력들간에 전장 가시화를 위해서는 자동화된 상황인식과 지휘통제를 제공할 수 있는 지상전술데이터링크가 필요하다. 이런 필요한 핵심기술 확보를 위해 응용연구를 통하여 메지지 표준과 메시지처리기가 완성되었다. 또한 각 무기체계의 장착을 위한 지상용 데이터링크가 시험개발이 진행 중이다. 본 논문에서는 합동작전, 지상작전 및 연합작전을 수행으로 통합 전장관리체계의 연동성 확보가 가능하여 근실시간으로 상황인식과 타격체계가 자동화된 한국형 지상전술데이터링크의 구축 연구를 제시한다. 메시지 처리기의 M&S 실험결과, 단일 소대망의 노드수와 메시지 길이 및 메시지 발생주기에 따라 지연 시간이 변화하는 것을 확인할 수 있었다. 따라서 각 상황에 네트워크 프로토콜을 변경하여 성능을 최적화 할 수 있음을 확인하였다.

• Steel and Composite Structures
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• 제3권4호
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• pp.261-275
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• 2003

Truss members built-up with double angles back-to-back have monosymmetric cross-section and twisting always accompanies flexion upon the onset of buckling about the axis of symmetry. Approximate formulae for calculating the buckling capacity are presented in this paper for routine design purpose. For a member susceptible only to flexural buckling, its optimal cross-section should consist of slender plate elements so as to get larger radius of gyration. But, occurrence of twisting changes the situation owing to the weakness of thin plates in resisting torsion. Criteria for limiting the leg slenderness are discussed herein. Truss web members in compression are usually considered as hinged at both ends for out-of-plane buckling. In case one (or both) end of member is not supported laterally by bracing member, its adjoining members have to provide an elastic support of adequate stiffness in order not to underdesign the member. The stiffness provided by either compression or tension chords in different cases is analyzed, and the effect of initial crookedness of compression chord is taken into account. Formulae are presented to compute the required stiffness of chord member and to determine the effective length factor for inadequately constrained compressive diagonals.

• 근관절건강학회지
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• 제25권1호
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• pp.1-11
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• 2018

Purpose: The purpose of this study was to understand and describe the experiences of exercise maintenance in elderly with osteoarthritis (OA). Methods: Three focus group interviews were conducted with a total of 19 older adults with OA who have been exercising for more than six months. Results: Two main themes emerged from the analysis: the changing exercise in life's journey (exercise maintained by self and family affection, exercise maintained by social networking expansion, exercise changing for function and body-image and exercise changing for economic efficiency) and the exercise pervaded into the life (Exercise used as a side effect-free treatment, exercise internalized by will and a sense of accomplishment and exercise become daily routine habits). Conclusion: Despite the various problems associated with aging and OA, participants made exercise a part of their lives by changing it to fit their own functions, abilities and circumstances. It is necessary to emphasize the positive aspects of the overall situation and to provide appropriate education and exercise based on the theory as well as the individual's overall fitness and limitations.

• 대한지역사회영양학회지
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• 제6권3호
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• pp.371-379
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• 2001

The present study was conducted to determine whether the food shortage situation in North Korea has affected its people differentially according to social class. We performed a literature search on North Korean books and documents on food and nutrition. We also conducted a mail survey on North Korean defectors to estimate the energy and nutrient intake and the practice of foraging for wild foods at the time of food crisis in North Korea. The subjects were 150 adults, 104 men and 46 women, aged 20 years and older, who resettled in the South Korea after the food crisis. The mean energy intakes for men and women were estimated to be 1,260 kcal and 980.6 kcal, respectively, which were far less than 2,900 kcal and 2,600 kcal, the intake levels recommended for North Korean men and women, respectively. Thirty seven percent of the subjects reported a lack of foods adequate enough for work and other daily activities, and fifty seven percent reported a routine use of wild foods such as roots, grass, stalks, and tree bark with an average of 4 items per day. Food consumption patterns on a typical day were different by social classes with the high class people consuming an affluent diet in the midst of a severe food shortage.

• 복식
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• 제51권4호
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• pp.141-163
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• 2001

This study was to analyse the meanings of the appropriation inherited in the modern costumes from the latter of the 20th century to the present. According to the dictionary, the meanings of a word. "appropriation" is to steal something, used in order to avoid saying this directly. The sorts of the appropriation represented in the works of Art was as follow : First. the reconstruction by the imitation of the works of a great master or partly induction of the works of a great master Second, the introduction by the history, modern art, the image of popular culture Third, the imitation by the works of photograph, etc The appropriation in the modern costumes could be distinguished as two facts : First, the appropriation of the image of popular culture, 1) the way by the induction of popular factors of the extremely routine, commonplace character 2) the way by the citation of critical sentence of society, complaint message of the situation of times. Second, the reinterpretation of the past works : 1) the way by the reinterpretation of a great artist′s works, or popular works. In accordance with its change of a standard of value of the beauty, the products of modern culture, called the artificial second image, that is, popular factor, ready made factor, a signboard, a trademark etc, was appropriated in modern costumes and was reinterpreted by the works of fashion designer′s empathy. We can say that the modern costumes is not only the products of creative, original action of fashion designers but also the mirror of times, having relationship with society.

• 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.

• 공학교육연구
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• 제15권1호
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• pp.53-60
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• 2012

On the grounds of Diane Vaughan's pioneering study into the Challenger Disaster, STS(Science and Technology Studies) scholars have recently argued that most engineers seldom face an ethical situation, in which the boundary between the ethical and the unethical is absolutely clear, and for which a serious moral decision such as "whistle blowing" is urgently needed. They have instead suggested that engineering ethics needs to address engineers' everyday routine practices, which, if accumulated, may have some impact upon the overall performance of the technological system. However, such studies have not completely resolved the tension between STS that emphasizes contextual elements in which the everyday practice of engineers are done, on the one hand, and engineering ethics that stresses individual engineer's moral decision of an existential kind, on the other. By discussing various works on the Challenger Disaster and related issues over technological risks, this paper attempts to establish an interface between STS and engineering ethics, and proposes some practical implications for the effective education of engineering ethics to engineering students.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1641-1646
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• 2007

Subway station is installed with equipment of deficient ventilation and air purification in need of routine activity for users because projectors didn't have recognition of the importance of prevention equipment on disasters in subway stations. So if the accident in Deagu is occurred again, we can't prevent it. And it is urgently necessary to improve antique subway station for the safety and service to citizens because users were increased far more. Improvement of subway station has to be modernized the backward and antique subway station and maintained and developed by the center of traffic to give the social contribution with management of social facilities. And subway station has to be made conveniently so that everyone may use the station with one-stop system including sales, business, service equipment. This study will show the improvement plan of problem in underground space and situation of metropolitan-train history to improve metropolitan-train station .we will study a traffic line and equipment relocation of underground space considering safety by choosing the improved station and problems of the underground station in seoul. And then we will study the improvement plan of air purification and sound isolation to upgrade service in citizens.