• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
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• pp.75-78
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• 2001

Recently, the HFPD measurement testing is widely used in partial discharge measurement of HV machines because HFPD measurement testing receives less influence of external noise and has a merit of good sensitivity. Also HFPD testing is able to offer the judgement standard of degradation level of HV machine and can detect discharge signals in live-line. Therefore it is very useful method compare to previous conventional PD testing method and effective diagnosis method in power transformer that requires live-line diagnosis. But partial discharges have very complex characteristics of discharge pattern so it is required continuous research to development of precise analysis method. In recent, the study of partial discharge is carrying out discover of initial defect of power equipment through condition diagnosis and system development of degradation diagnosis using HFPD(High Frequency Partial Discharge) detection. In this study, simulated transformer is manufactured and HFPD occurred from transformer is measured with broad band antenna in real time, the degradation grade of transformer is analyzed through produced patterns in simulated transformer according to applied voltages.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.601-605
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• 2009

We have proposed a measurement system for measuring a whole shape of an object easily. The proposed system consists of a camera and a cylinder whose inside is coated by a mirror layer. A target object is placed inside the cylinder and an image is captured by the camera from right above. The captured image includes sets of points that are observed from multiple viewpoints: one is observed directly, and others are observed via the mirror. Therefore, the whole shape of the object can be measured using stereo vision in a single shot. This paper shows that a prototype of the proposed system was implemented and an actual object was measured using the prototype. A method based on a pattern matching which uses a value of SSD (Sum of Squared Difference), and a method based on DP (Dynamic Programming) are employed to identify a set of corresponding points in warped captured images.

• 한국정밀공학회지
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• 제12권10호
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• pp.40-49
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• 1995

This paper presents the performance and problems in analysis method and testing system of Electronic Speckle Pattern Interferometry (ESPI) method, in measuring two - dimensional in-plane displacement. The anyalysis result of measurement by ESPE is quite comparable to that tof measurement by strain gauge method. This implies that the method of ESPE is a very effective tool in non-contact two-dimensional in-plane strain analysis. But there is a controversal point, measurment error. This error is discussed to be affected not by ESPE method itself, but by its analysis scheme of the interference fringe, where the first-order interpolation has been applied to the points of strain measured. In this case, it is turned out that the more errors would be occurred in the large interval of fringe. And so this paper describes a computer method for drawing when the height is available only for some arbitrary collection of points. The method is based on a distance-weighted, last- squares approximation technique with the weight varying with the distance of the data points.

• 한국정밀공학회지
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• 제18권5호
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• pp.90-97
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• 2001

An electronic speckle pattern interferometry (ESPI) system for measuring tensile properties under micro-tensile testing has been developed. The system consists of an optical system and an image processing system. In the optical system, optical components for measurement of in-plane deformation are arranged on the path of He-Ne laser. In the image processing system, the window-based program for acquiring speckle pattern interferometric image was developed and deformation in a small specimen is continuously evaluated during the test. Using this system, tensile strain of copper foil was measured during tensile testing. Tensile specimen had the thickness and width of 22 and 500 ${\mu}{\textrm}{m}$, respectively. Tensile properties, including the elastic modulus, yielding strength and tensile strength, of the copper were evaluated and also plastic exponent and coefficient in the Ramberg-Osgood relationship were evaluated from the stress-strain curve.

• 대한전자공학회논문지SD
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• 제48권12호
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• pp.97-102
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• 2011

본 논문에서는 LVDT 구조를 이용한 신호 매핑 기반의 새로운 변위측정 알고리즘을 제안한다. 제안하는 방식은 상대 값을 이용한 신호 매핑방식을 사용하기 때문에 PCB상에 구현되는 코일 패턴이나, 트랜스 소자의 변수들에 독립적으로 동작할 수 있다. 이는 절대 값을 사용하면서 발생하는 다수의 튜닝작업이 필요 없고 단지 상대 값을 추출하기 위해 최종단계에서의 범위를 측정하는 캘리브레이션 공정만 필요하다. TI DSP 칩셋인 TMS320F2812에 코일 패턴이 다른 다수의 보드를 통하여 본 논문에서 제안하는 기법을 구현해 본 결과, PCB 코일 패턴이 조악하더라도 높은 정밀도와 신뢰성을 갖는 출력 신호를 얻음으로써 제안하는 기법의 우수성을 검증하였다.

• Human Ecology Research
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• 제57권4호
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• pp.513-522
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• 2019

This study analyzes the characteristics of somatotype changes of girls from the ages of 13 to 18 that provide basic data on clothing construction for middle and high school girls. We use data obtained from body measurements of 1,590 adolescent girls 13 to 18 years of age provided in the 6th national anthropometric survey report. The differences among the age groups for 56 direct measurements were analyzed by ANOVA, and the structures of the differences by SNK (Students-Newman-Keuls test) were analyzed. The two major growth ages were 'ages 13-14' and 'ages 15-16'. The first major growth ages focused on all measurement items of height, length, circumference, breadth, depth and other items. The second one focused on measurement items of height and length of torso, circumference, and breadth of lower body. The major growth pattern of the age groups was 'ages 13<14&15<16&17&18' which appeared focused on the height and length items of upper body and torso, the width items of lower body and the circumference items of upper body and lower body. The measurement items of front length like waist front length, N.P. to B.P to waistline, N.P. to B.P., and B.P. to B.P. showed the growth pattern for 'ages 13<14<15<16<17&18'.

• Smart Structures and Systems
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• 제18권3호
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• pp.585-599
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• 2016

Steel cables serve as the key structural components in long-span bridges, and the force state of the steel cable is deemed to be one of the most important determinant factors representing the safety condition of bridge structures. The disadvantages of traditional cable force measurement methods have been envisaged and development of an effective alternative is still desired. In the last decade, the vision-based sensing technology has been rapidly developed and broadly applied in the field of structural health monitoring (SHM). With the aid of vision-based multi-point structural displacement measurement method, monitoring of the tensile force of the steel cable can be realized. In this paper, a novel cable force monitoring system integrated with a multi-point pattern matching algorithm is developed. The feasibility and accuracy of the developed vision-based force monitoring system has been validated by conducting the uniaxial tensile tests of steel bars, steel wire ropes, and parallel strand cables on a universal testing machine (UTM) as well as a series of moving loading experiments on a scale arch bridge model. The comparative study of the experimental outcomes indicates that the results obtained by the vision-based system are consistent with those measured by the traditional method for cable force measurement.

• 한국인터넷방송통신학회논문지
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• 제19권4호
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• pp.105-111
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• 2019

본 논문에서는 근접전계 시험을 수행하여 Ka 대역 밀리미터파 탐색기용 도파관 광벽 슬롯 배열 안테나의 성능 검증을 수행하였다. 슬롯 배열 안테나의 측정은 원전계, 근접전계 시험을 모두 수행하고 비교하여 밀리미터파 대역의 근접전계 시험의 유효성을 확인하였다. 검증을 수행한 슬롯 배열 안테나의 빔폭 및 부엽 준위를 포함한 빔 패턴 특성이 동일함을 확인하였다. 방위각, 고각 빔패턴의 부엽준위 차이는 1dB 이내로 검증되었다. 추가로 back-projection 기법을 활용하여 근접전계 데이터를 가공한 후 안테나 개구면의 분포를 새롭게 추출하여 배열 안테나 성능 분석을 수행하는 방법에 대하여 소개하였다.

• 한국의류산업학회지
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• 제6권1호
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• pp.102-108
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• 2004

The anthropometric measurement and the photometric measurement for have been conducted 358 children from 4 years old to 6 years old to design children's clothing. The characteristics of body type were grasped among total 44 measurement items according to the aging, being extracted seven factors from factor analysis. From cluster analysis among the seven factors the three body types were classified. Type 1 shows low fat body with a small figure and short upper body. The body has a round belly and waist. Type 2 shows the fattest body with an average height. The body has been backed with lower shoulders. Type 3 shows common fat body with a high height and a big figure. The body shows crooked round back with a big upper body and rising shoulders.

• Journal of the Korean Data and Information Science Society
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• 제27권6호
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• pp.1645-1651
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• 2016

A lot of data, particularly in the medical field, contain variables that have a measurement error such as blood pressure and body mass index. On the other hand, recently smoothing methods are often used to solve a complex scientific problem. In this paper, we study a Bayesian curve-fitting under functional measurement error model. Especially, we extend our previous model by incorporating covariates free of measurement error. In this paper, we consider penalized splines for non-linear pattern. We employ a hierarchical Bayesian framework based on Markov Chain Monte Carlo methodology for fitting the model and estimating parameters. For application we use the data from the fifth wave (2012) of the Korea National Health and Nutrition Examination Survey data, a national population-based data. To examine the convergence of MCMC sampling, potential scale reduction factors are used and we also confirm a model selection criteria to check the performance.