• 한국전자파학회논문지
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• 제7권4호
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• pp.279-287
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• 1996

주파수 점융율 데이터는 개별 주파수 채널의 실제 이용율에 대한 정보를 제공할 수 있다. 또한 스펙트럼의 예비 용량이 추정될 수 있도록 이들 주파수 대역들의 평균 이용율에 대한 정보를 제공한다. 그러한 추정치는 추가 배분 계획 및 스펙트럼 사용에 대한 새로운 기술의 영향을 평가하는 방법으로 사용될 수 있다. 본 논문에서는 국내에서 개발한 주파수 점유율 측정 시스템과 측정 방법을 제시한다. 그리고, 수도권 5개 지역의 전파감시 결과 데이터를 이용하여 주파수의 점유율을 시간대 및 지역별로 제시한다.

• 한국군사과학기술학회지
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• 제11권1호
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• pp.75-84
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• 2008

A new automatic small target detection and tracking algorithm for the real-time IR surveillance system is presented. The automatic target detection and tracking algorithm of the real-time systems, requires low complexity and robust tracking performance in the cluttered environment. Linear-array and parallel-scan IR systems usually suffer from severe scan noise caused by the detector non-uniformity. After the spatial filtering and thresholding, this scan noise still remains as high amplitude clutter which degrades the target detection rate and tracking performance. In this paper, we propose a new feature which consists of area and validity information of a measurement. By adopting this feature to the measurements selection and track confirmation, we can increase the target detection rate and reduce both the track loss rate and false track rate. From the experimental results, we can validate the feasibility of the proposed method in the noisy IR images.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권4호
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• pp.172-177
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• 2005

The testing and evaluating shunting rates of operating substations have become difficult recently due to various factors including increased fault current, limited area of urban substations and construction of substations in mountain location. In this paper, we have analysed the computation and measurement method of shunting currents that be applied grounding system maintenance of power substations. Also, simple and detailed test methods using 70Hz current injection are explained. A computer program is developed for a study on the shunting properties such as grounding impedance and shunting rates of grounding current, and the simulation results are compared with the measurement data to prove validity and effectiveness of the program and measurement method under commercial operation of a GIS type model substation respectively.

• Journal of the Korean Data and Information Science Society
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• 제26권3호
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• pp.749-754
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• 2015

This article presents Bayesian approach to regression splines with knots on a grid of equally spaced sample quantiles of the independent variables under functional measurement error model.We consider small area model by using penalized splines of non-linear pattern. Specifically, in a basis functions of the regression spline, we use radial basis functions. To fit the model and estimate parameters we suggest a hierarchical Bayesian framework using Markov Chain Monte Carlo methodology. Furthermore, we illustrate the method in an application data. We check the convergence by a potential scale reduction factor and we use the posterior predictive p-value and the mean logarithmic conditional predictive ordinate to compar models.

• 한국추진공학회지
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• 제14권1호
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• pp.48-55
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• 2010

본 논문에서는 엔진고공환경 시험설비의 엔진 입구 덕트에서 측정한 전압력과 정압력 및 전온도를 통해 실시간으로 공기유량을 계산하고, 압력프로파일을 이용하여 경계층 레이크를 장착하지 않았을 경우에도 공기유량을 예측할 수 있는 방법을 기술하였다. 또한, 엔진입구배관에 걸친 덕트 연결부를 통한압력손실을 예측하고, 이를 통해 공기유량을 보정함으로써, 고공환경시험설비에서의 공기유량측정의 신뢰도를 향상시키고 설비유지측면에서의 운용성을 보고자 하였다.

• 반도체디스플레이기술학회지
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• 제5권1호
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• pp.1-4
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• 2006

Recently, Ball Grid Arrays(BGAs) are getting used more frequently for a package type. The connectors on a BGA consist of a large number of small solder balls in a grid shape on its bottom side. However, since balls of BGAs mounted on PCBs are not visible, inspection before mounting them is indispensable. High speed non-contact 3D measurement technologies are necessary far real-time measurement of ball height, the most important inspection item. In this paper, an accurate 3D data acquisition system for BGAs is proposed that can acquire 3D profile at high speed using a 3D smart camera and laser slit ray projection. Some clipping and morphological filtering operations are employed to remove spiky error data, which occur due to reflections from some ball area to camera direction.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.269-272
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• 1999

It is still hard to measure the strain distribution over entire surface of a medium or large-size stamped part even by using an automated strain measurement system. Several methods which enable to enlarge the measurement range without losing accuracy and precision are suggested in this study, The superposition of images having different high-lightened or damaged part each other results in an enhanced image. A new method for constructing the element connectivity from a line-thinned image makes it possible to identify up to 1,000 elements. And the geometry assembling algorithm is proved very efficient in which the whole area to be measured is divided into several parts ; the coordinate transformation between every two adjacent parts is obtained from the concept of the least square error ; and the 3-D shape or strain distribution over the whole surface is assembled,

• 전기학회논문지
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• 제61권3호
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• pp.479-484
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• 2012

Geometric effect of landmarks to the navigation error is investigated in the two-dimensional line-of-sight measurement based vision navigation system. DOP is derived between line-of-sight measurement error and navigation solution error. For cases of three landmarks in an area, variations of the DOP were observed through computer simulations. Vision navigation system experiments were performed for the cases. Simulation and experimental results show that navigation solution errors have similar trend to DOP values of the simulation.

• 한국국방경영분석학회지
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• 제22권2호
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• pp.90-112
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• 1996

Research issues in software engineering in recent may be object oriented methodology and software quality. Since Halstead has proposed metric-software science in 1977, software quality area has been studied in steady but inactively until 1980s. As international standards such as ISO 9000-3, 9126 were enacted in 1990s early, interest in software quality is increased but many problems such as how to validate metric, measure quality or apply metric are remained. This paper proposes software quality metric methodology which software developer or project manager can use in measuring quality and validating metric during software development. The methodology is classified by several phases: establishment of quality requirement, identification of quality metric, data collection, metric implementation, metric validation. In order to show its applicability, test program, metrics and data are applied to each phase of the methodology. Consideration of this methodology as a methodology for software quality measurement similar to development methodology for software development is needed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 춘계학술대회 논문집
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• pp.377-382
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• 1995

Conventional measurement methods using ultrasonic wave or x-ray, eddy current for non-destructive testing(NDT) in nuclear power plants and other industrial plants have been performed as the method of contact with objects to be inspected. With this reason these methods have been taken relatively much time and the inspected area is limited by the location of probe or film. But holographic interferometry which is a non-contact optical measurement method using a coherent light source has an advantage that the quantitative measurement can be performed at a time. In this paper a new method using holographic interferometry and image processing for detecting internal flaws of pressure vessels is presented.