• 한국재료학회지
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• 제5권7호
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• pp.786-793
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• 1995

Ag를 $Y_1$Ba$_2$Cu$_3$O$_{7-y}$에 첨가하여 고상반응법으로 시료를 제작, Ag가 $Y_1$Ba$_2$Cu$_3$O$_{7-y}$의 고온초전도성과 그의 미세구조에 미치는 영향을 조사하였고 그에 따른 기계적 특성을 연구하였다. Ag의양이 증가함에 따라 결정립의 크기가 증가하였고 연결성이 향상되어 시료의 결정구조가 치밀해지고 단단해졌으며 결정립간의 weak link와 weak coupling을 줄이고 균일한 초전도 상을 형성시킨다는 것을 알 수 있었다. 또한 $Y_1$Ba$_2$Cu$_3$O$_{7-y}$결정구조의 이방성을 줄였고 $Y_1$Ba$_2$Cu$_3$O$_{7-y}$의 열적 안정성을 향상 시켰음을 알 수 있었다. 그리고 Ag의 첨가에 따라 시료의 기계적 강도가 증가함을 보였다.가함을 보였다.

• 지능정보연구
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• 제7권2호
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• pp.19-33
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• 2001

본 연구에서는 부도예측용 인공신경망의 입력노드 선정을 위한 휴리스틱으로 연결강도분석접근법을 제안한다. 연결강도분석은 학습이 끝난 인공신경망에서 입력노드와 은닉노드를 연결하는 연결가중치의 절대값 즉, 연결강도를 분석하여 입력변수를 선정하는 접근법으로, 선정기준에 따라 약체연결뉴론제거법과 강체연결뉴론선택법을 들 수 있다. 본 연구에서는 약체연결뉴론제거법, 강체연결뉴론선택법 그리고 이 두 기법을 통합한 통합 연결강도 모형을 제안하여 각각 의사결정트리 및 다변량판별분석에 의해 선정된 입력변수를 이용한 인공신경망 모형과 예측율을 비교한다. 실험 결과 본 연구에서 제안하고 있는 방법론이 의사결정트리나 다변량판별분석 기법보다 높은 예측율을 보여주었다. 특히 두 기법의 통합연결강도 모형의 경우에는 다른 단일 기법보다 높은 예측율을 보이고 있다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.921-926
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• 2001

The link for the Superconducting Flux Flow Transistor (SFFT) which is based on the flux flow has been fabricated by the ICP etching methods. The channel width and the thickness of the SFFT were a 3 ${\mu}$m and about 300 nm, respectively. The superconducting characteristic of the link was measured by the x-ray diffraction and the E.D.S.. The SFFT etched by ICP showed an I-V characteristic like the three terminal transistor.

• 한국인터넷방송통신학회논문지
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• 제8권2호
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• pp.49-55
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• 2008

To address the convergence issue of power control algorithms, a number of algorithms have been developed hat shape the dynamics of up-link power control for cellular network. Power algorithms based on fixed point iterations can be accelerated by the use of various methods, one of the simplest being the use of Newton iterations, however, this method has the disadvantage which not only needs derivatives of the cost function but also may be weak to noisy environment. we showed performance of the power control schemes to solve the fixed point problem under static or stationary channel. They proved goof performance to solve the fixed point problem due to their predictor based optimal control and quadratic convergence rate. Here, we apply the proposed power control schemes to the problem of the dynamic channel or to dynamic time varying link gains. The rigorous simulation results demonstrated the validity of our approach.

• 한국언어정보학회지:언어와정보
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• 제12권2호
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• pp.77-93
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• 2008

This paper examines a condition that licenses distributivity. Choe (1987) and Link (1998) have proposed an indefiniteness condition on distributivity. However, detecting counter-examples, Zimmermann (2002) has argued for a non-specificity condition. This paper primarily revises the indefiniteness/non-specificity condition. Observing that the systematic class of the exceptions belongs to weak definites proposed by Poesio (1994), I claim that the property that constrains distributivity is non-strong-definiteness. Based on Landman (2000), I further explain the non-strong-definiteness condition and argue that the condition does not need to be imposed on the grammar independently. The new condition naturally accounts for Spector's (2003) scopal asymmetry. Even more, defining donkey pronouns as weak definites, I cope with various properties of donkey sentences.

• 디지털산업정보학회논문지
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• 제12권4호
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• pp.89-96
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• 2016

Before an IT product is used, there is a sequence of the process such as the components supply-demand of the product, their assembly and production, their logistics and delivery, and then finally, the product can be used by a user. During this sequence of the process, there can be many security exposures and risks. In this paper, we show, by examining security cases of various IT products, that there are many security exposures in the process of IT products from their production to their delivery to end users and in their use, and also show how critical the security exposures are. Even though there are various security theories, technologies and security controls, there is still weak link from the production of an IT product to its use, and this weak link can lead to security vulnerabilities and risks. This paper tries to call attention to the importance of the execution of the security control and the control components. We examine the practical cases to find out how the security control is paralyzed, and to show how it is compromised by asymmetric security resources. Lastly, from the cases, we examine and review the possible domestic security issues and their countermeasures.

• 한국정밀공학회지
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• 제22권7호
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• pp.146-154
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• 2005

Recently, the high-speed and intelligence technology of machine tools are developed for the high efficiency of productivity Under the operating condition from the high-speed of machine tools, the various failure modes can occur in core units of manufacturing system. Therefore it is for the reliability concept of machine tool to be required in a design level. And the above-stated technology must be accommodated in the feeding and spindle subsystem, etc those are the core units of machine tools. In this study, we are developed the test-bed of sliding cover (C-plate) in order to evaluating reliability and estimating failure modes of feeding subsystem under operating conditions. The reliability experiment using the developed test-bed and the additional structural analysis executed on single and double structure. We found out the weak parts of sliding cover and were able to predict a life cycle from the experiment results. In this study, we propose the new C-plate model with double link structure to apply the high-speed machine tool in the fundamental guideline.

• 한국군사과학기술학회지
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• 제18권1호
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• pp.37-45
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• 2015

These days many systems use the gps signal to get their own position. Because it's cheap and accurate and convenient. But, the strength of gps signal is very weak and can be easily interrupted by GPS jamming and GPS spoofing. Normally, fighter can use DME, TACAN, etc to correct their position error when GPS is not working. But, many aircraft which does not have those kinds of hardware need to pay additional cost to get it. In this paper, we propose how to overcome GPS jamming and GPS spoofing by only using data link system. The main purpose of this paper is to make the data link protocol to get an exact position information of own unit at gps error environment.

• 한국컴퓨터정보학회논문지
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• 제17권5호
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• pp.49-57
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• 2012

본 논문에서는 P2P스트리밍에서 peer간 연결 정보를 이용하는 방법을 기반으로 topology 최적화를 연구한다. 제안하는 방법은 mesh-network에서 사용된 link와 사용되지 않은 link의 수로 peer의 업로드 용량을 추정하는 방법을 기반으로 한다. 연결된 link의 정보를 사용하는 기존 방법은 peer의 자원 관리 측면에서 메시지 과부하를 줄이는데 효과적이다. 하지만 업로드 대역폭이 고려되지 않는 topology를 구성할 우려가 있다. 또한 서버에 가까운 peer에서 네트워크 오류 발생시 네트워크 전송성능이 저하될 수 있다. 본 논문에서는 기존 방법의 단점을 보완하는 방법을 제안한다. 기존 방법과 제안하는 방법을 시뮬레이션 하고 결과를 비교 분석한다.

• 한국군사과학기술학회지
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• 제13권5호
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• pp.861-868
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• 2010

As CAS, X-ATK, and INT models considered as the most typical Air-to-Ground operation models in ROKAF are mainly designed as the voice-centered system between aircraft and ground control facilities, it is critical to newly develop the Link-16 based model for the ROK-US combined operation between F-15K, AWACS, M-SAM, and KDX-III equipped with Link-16. Former studies had been limited to the CAS operation, and they had mainly focused on reducing the voice transmission time to exchange the information between each mission step with maintaining existing operation steps. Therefore, this paper makes up the weak point in former studies, thereby designing new Air-to-Ground operation model for CAS, X-ATK, INT mission using Enterprise Architecture OV6c, which enables both aircraft and ground control facilities or between aircraft to obtain the real-time information on the location, identification, armament and the real-time image data through the broadcasting function. Based on the analysis of new operation model, we come to a conclusion that by simultaneously exchanging the information on mission between nodes concerned through the broadcasting function of Link-16. It is possible to cut down superfluous steps among the mission steps, and to reduce the mission time. It is clear that it gives rise to improve the battle efficiency and the decision-making tempo as well as the battlefield situational awareness.