• 한국군사과학기술학회지
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• 제3권1호
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• pp.66-75
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• 2000

The purpose of this study is to develop and illustrate methods of applying trade-off techniques to landing craft air cushion design evaluation. The problem areas of concern are the application of quantitative analytical methods to conceptual design. The interrelationships between composite system measures and selected performance requirements(speed, cruising range, cargo etc.) are analyzed and the expressions for gross weight are developed as functions of performance parameters. Trade-offs of performance parameters in terms of weight are then calculated. The application of these results to evaluation of Require Operational Capabilities are illustrated.

• 대한심미치과학회지
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• 제12권2호
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• pp.31-38
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• 2003

Amelogenesis imperfecta patients suffered common clinical problems of poor esthetics, teeth sensitivity, and loss of occlusal vertical dimension. Amelogenesis imperfecta is a group of inherited disorders primarily affecting dental enamel. Variants of amelogenesis imperfecta generally classified hypoplastic, hypocalcified, or hypomaturation types based on the primary enamel defects. The mildest problems were found in the pitted hypoplastic type whereas the most severe problems were encountered in the hypocalcified type amelogenesis imperfecta. Management stragies include composite resin veneer and jacket crowns for anterior teeth as well as steel crowns for posterior teeth. Knowledge of the clinical features and dental complications of each variants if amelogenesis impecta helps in the diagnosis of the condition and allows institution of early preventive measures. The objective of this paper is to provide a review of the current concepts of the wide spectrum of etiological factors involved in the pathogenesis of this significance clinical entity in the primary dentition.

• 반도체디스플레이기술학회지
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• 제2권2호
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• pp.1-4
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• 2003

We have developed a rotating compensator spectroscopic ellipsometer (RCSE). As the ellipsometry measures a change in the polarization state of a light wave upon non-normal reflection from surface, the degree of sensitivity is enhanced greatly through the detection of relative phase change. RCSE acquires additional information from the non-ideal surface of sample and operates over the photon energy range from 1.5 to 4.5 eV. We applied RCSE to measure the optical properties of films and the line-width of patterned PR films on crystalline silicon.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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• pp.1-6
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• 1996

Cellulose fiber reinforced cement composites manufactured by the slurry-dewatering process have found broad applications in thin cement products as replacement for asbestos cement. This paper focuses on the durability characteristics of these composites under different aging conditions. The effects of wetting-drying and freezing-thaw cycles, carbonation, and exposure to hot and humid environments on the structure and properties of cellulose fiber-cement composites were investigated. The predominant mechanisms of aging in the composites were identified through investigation of structure-property relationships. Measures to control these aging mechanisms were diversed and evaluated. Refined cellulose fiber-cement composites are shown to possess excellent durability characteristics under the effects of various aging processes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 D
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• pp.1112-1114
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• 1997

When reliability is estimated to be insufficient, a planner must take action to improve them. So, the measures for improving reliability are mainly considered in the planning process. In order to provide quantitative information concerning reliability evaluation, this paper-describes an algorithm to find reserve margin in power system planning. The IEEE Reliability Test System(RTS) is used to demonstrate the effectiveness of the proposed algorithm.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.141-142
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• 2013

The modular construction method have improved quality, reduction of defects, such as the reduction of air, a number of advantages. It is utilized composite, larger, in skyscraper building already abroad. The domestic, various studies have been conducted on technical matters taller, automation of production, such as process control, but is still inadequate circumstances. Therefore, in this study, is the purpose that you have presented activation measures to investigate and analyze the case of co-housing with a modular construction system of outside, and to make the co-housing of modular construction system of domestic.

• 비파괴검사학회지
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• 제30권3호
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• pp.212-224
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• 2010

The usefulness of the magnetic camera for non-destructive testing of aging aircraft is discussed in this paper. The magnetic camera can be used f magnetic particle testing(MT), magnetic flux leakage testing(MFLT), eddy current testing(ECT) and penetration testing(PT). It measures the distribution of a magnetic field and visualizes the magnetic pattern. Near and far side cracks, fatigue, thickness degradation, and cracks under rivets have been detected. The possibility of quantitative evaluation was also examined. Using indirect experiments, we verified the detection ability of the sensor for cracks in titanium and advanced composite materials.

• 한국문헌정보학회지
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• 제16권
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• pp.177-205
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• 1989

Retrieval effectiveness is the principal criteria for measuring the performance of an information retrieval system. This paper deals with the characteristics of 'relevance' of information and various measuring techniques of retrieval effectivess. The outlines of this study are as follows: 1) Relevance decision for evaluation should be devided into the user-oriented and the system-oriented decisions. 2) The recall-precision measure seems to be user-oriented, and the recall-fallout measure to be system-oriented. 3) Many of composite measures can not be justified III any rational manner unfortunately. 4) The Swets model has demonstrated that it yields, in general, a straight line instead of a curve of varying curvature and emphasized the fundamentally probabilistic nature of information retrieval. 5) The Cooper model seems to be a good substitute for precision and a useful measure for systems which ranked documents. 6) The Rocchio model were proposed for the evaluation of retreval systems which ranked documents, and were designed to be independent of cut-off. 7) The Cawkell model suggested that the Shannon's equation for entropy can be applied to measuring of retrieval effectiveness.

• 대한의생명과학회지
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• 제28권3호
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• pp.178-185
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• 2022

The purpose of this study was to analyze the effect of chewing difficulty on osteoarthritis in Korean adults. Data from the National Health and Nutrition Examination Survey for two years from 2019 to 2020. The collected data were analyzed using the SPSS (21.0) program using composite samples, and the mean crossover analysis and logistic return analysis were performed. An analysis of the effects of chewing difficulty on osteoarthritis in korean adults showed that those with chewing difficulty had a 2.02 fold higher risk of osteoarthritis (95%CI=1.56~2.42) and a statistically significant difference (P<0.05). The association between the chewing difficulty on osteoarthritis could be confirmed, and measures improve of the oral health and preventing osteoarthritis should be prepared.

• 비파괴검사학회지
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• 제29권5호
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• pp.436-441
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• 2009

광섬유 센서는 구조 건전성 감시 분야에 적용되는 유망한 센서 시스템이다. 특히 광섬유 브래그 격자(FBG) 센서는 본 분야에 있어 가장 각광받는 센서들 중에 하나이다. 이러한 FBG 센서는 브래그 파장의 이 동량을 알아내는 방법에 따라 다양한 시스템 구성이 가능하다. 또한 센서 시스템의 동특성은 이러한 시스템에 의해 결정된다. 본 논문에서는 FBG 센서의 브래그 파장 스팩트럼 최대 경사부에 단일 파장 레이저의 중심 파장을 맞춰 놓을 경우, 센서의 경사도가 센서 감도로 작용할 수 있다는 측정 원리를 이용하였다. 이러한 원리는 전체 측정 범위의 한계는 있지만 높은 민감도를 보장한다. 본 측정 원리의 적용 예로서, FBG 센서를 삽입한 복합재 평판을 오토클래이브를 이용해 제작하고 앞서 설명한 측정 원리를 적용하였다. 첫째로 삽입된 FBG 센서를 이용해 충격 망치로 가격된 복합재 평판의 고유 진동수를 성공적으로 측정하였다. 둘째로 고출력 스피커를 이용해 앞서 측정된 고유진동수 중 하나의 특정 주파수로 복합재 평판을 강제 가진 시켰다. 이때 발생하는 구조 진동을 FBG 센서로 측정하였고 동시에 ESPI 측정 시스템을 이용해 진동 모드 형상 역시 성공적으로 측정하여 복합재 구조물의 동특성을 파악하였다. 따라서, 이러한 두 실험을 통해 FBG 센서 시스템과 ESPI 측정 시스템이 복합재 구조물의 동특성 측정에 매우 유용한 기술임을 증명하였다.