• 한국국방경영분석학회지
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• 제3권1호
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• pp.97-107
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• 1977

This report examines several models, such as random or area bombardment, salvo fire and pattern fire, for the computation of target coverage when multiple rounds are fired at a target. Fractional kill of a fragment sensitive target by a fragmenting projectile as a function of the number of rounds fired is compared for two salvo fire models. The first is a standard salvo fire model in which N rounds are fired at the same aim point, in the second model single kill probability is computed for a fragment sensitive target and then fractional kill from the firing of N rounds is computed according to the assumption that the effects of each round are independent. Because the method of solution becomes very laborious for large patterns, this report gives a method only for the case of evaluating the effectiveness of stick and trianglar pattern fire. The need for the sophisticated and complicated target coverage models is demonstrated by the results of computations performed in this report.

• 한국정밀공학회지
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• 제16권10호
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• pp.203-208
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• 1999

By tilting the reference mirror of Twynman-Green interferometer having a reference mirror and a moving mirror, firinge pattern composed of bright and dark parallel lines can be obtained and the fringe pattern is shifted according to the displacement of the mowing mirror. Several studies are executed for displacement measurement by detecting the intensity of the fringe with photo-diodes having small detecting area. In this study, to improve the sensitivity and robustness, the intensity of fringe is detected by using a large-area quadratic photo-diode masked with a grating panel having four kinds of binary grating having phase-difference of 0, {\pi}$/4, {\pi}$/2, 3 {\pi}$/4. The phase of the fringe is calculated with a simple 4-buckets algorithm. A experimental result shows that standard deviation of 5.653 nm is obtained comparing with a capacitive type gap sensor having nearly 1 nm accuracy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권12호
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• pp.3055-3070
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• 2013

This paper proposes an improved carrier frequency offset (CFO) and sampling frequency offset (SFO) estimation scheme for orthogonal frequency division multiplexing (OFDM) based broadcasting system with cyclic delay diversity (CDD) antenna. By exploiting a periodic nature of channel transfer function, cyclic delay and pilot pattern with a maximum channel power are carefully chosen, which helps to enable a robust estimation of CFO and SFO against the frequency selectivity of the channel. As a performance measure, a closed-form expression for the achievable mean square error of the proposed scheme is derived and is verified through simulations using the parameters of the digital radio mondiale standard. The comparison results show that the proposed frequency estimator is shown to benefit from properly selected delay parameter and pilot pattern, with a performance better than the existing estimator.

• 한국광학회지
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• 제9권6호
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• pp.396-402
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• 1998

광학계의 결상성능평가는 optical transfer function(OTF)을 측정하는 것이 표준적인 방법으로 사용되고 있다. 그러나, 대량 생산되는 광학계의 경우에서는 측정의 편리함 때문에 test pattern을 투영하여 contrast를 검사하는 방법도 많이 사용되고 있다. 본 연구에서는 회절결상이론을 사용하여 주기적 line-space pattern에 대한 contrast transfer function(CTF)을 계산하는 프로그램을 개발하고, C­계수와 Zernike 다항식으로 표현되는 3차 파면수차에 의한 광학계의 modulation transfer function (MTF)과 CTF 변화를 비교, 분석하였다.

• 복식문화연구
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• 제11권5호
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• pp.647-656
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• 2003

Mass customization utilizes the new computer technologies, supply chain management, product information management, and some level of customization of the product for the individual customer. This study aimed at grasping the actual conditions of mass customization of domestic men's suit industry and the use of MTM CAD program. The MTM apparel production programs that are used by five leading men's suit manufacturers in Korea were compared. The results of the study showed that most of the manufacturers produced mass customized men's suits to supply extraordinarily large or small size suit based on the individual order. The information listed on an order sheet used at shops was not necessarily corresponding to the information in the MTM CAD program that is use for production of suit ordered from the shop. The pattern data base on the MTM CAD program are constructed based on the sizing system of individual manufacturer. The most manufacturers translated the customer's body dimensions into difference between the standard pattern and the customer's needed adjustment.

• 한국시뮬레이션학회논문지
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• 제14권3호
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• pp.1-12
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• 2005

Designing a production and equipment investment plan for semiconductors, many variables must be taken into account. However, depending on these variables could bring many changes to the plans, and the end result is hard to predict. Because it's hard to predict the end result, it's never easy to make a standard production plan. So, the goal of this project is to design a production plan based on past marketing patterns to satisfyall the variables and come up with a reasonable thesis on a standardized process.

• 대한조선학회논문집
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• 제45권6호
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• pp.637-645
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• 2008

It is very hard to control the quality of coating work in shipbuilding process, because it is highly affected by several parameters such as space between object and nozzle tip, spray velocity, pressure, tip size, etc.. Even so a coating work in shipbuilding is done by workers' experience and skill as yet. It causes not only an excessive use of paints but also a decrease of productivity. In order to solve this problem, we developed a formula that predicts the film thickness and determined the proper coating pattern. Also we had done a series of experiments to verify the results of this study.

• 대한전자공학회논문지
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• 제24권5호
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• pp.880-886
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• 1987

This paper proposes a new pattern recognition system using Radon transform and analyzes the performances of the system for given input patterns. The proposed system uses many optical parts in order to utilize the high speed characteristics of light and processes a signal easily by transforming 2-D image into a 1-D signal to increase flexibility. The squared Mahalanobis distance obtained from means and standard deviations of the features for the given input patterns is used for discrimination. As a result, this system represents a better recognition rate than any other systems using the same input patterns.

• 한국산업정보학회논문지
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• 제6권2호
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• pp.1-6
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• 2001

본 논문에서는 구간 데이터 식별을 위한 구간 신경망의 학습 알고리즘을 제안한다. 제안된 기법은 각 데이터의 속성치가 구간으로 주어져 있는 경우의 패턴 식별 문제에 적용된다. 먼저, 구간 입력 벡터를 다루기 위한 구간 신경망의 구조를 제안하고, 평가 함수를 이용하여 학습 알고리즘을 도출한다. 평가 함수는 구간 신경 망으로부터의 구간 출력과 대응하는 목표 출력을 이용하여 정의된다. 마지막으로 컴퓨터 시뮬레이션에 의해 제안 기법의 구간 데이터 식별 능력을 나타내고, 통상의 역전파 신경망을 이용 기법과 비교한다.

• 한국정밀공학회지
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• 제24권6호
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• pp.131-137
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• 2007

In metal casting process, it is very difficult to predict the form accuracy of cast part and reduce repeatability error. In this study, the variations of form accuracy were measured in the process of metal cast prototyping, where RP part is manufactured from CAD model in the first, and then, wax part is cast in the vacuum environment using the RP part as master model, and finally metal prototype is cast using ceramic mold and the wax part as pattern. To investigate the variations of form accuracy, the averages and standard deviations of error distribution of the parts measured by 3D scanner were compared. It was observed that the biggest shrinkage is generated during the extraction of wax part in the second step and the biggest deterioration of form accuracy is generated during the metal part casting in the last step.