• 한국연초학회지
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• 제5권2호
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• pp.25-32
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• 1983

To obtain basic information on the breeding of burley tobacco, classification of 41 varieties was carried out by using the cluster analysis of correlation coefficients and taxonomic distance based on twenty-one agromonic characters. Eight characters, such as days to flowering, length of flower axis, internode length, leaf length, yield, leaf angle to stem, vein angle to midrib and plant height, were useful in monothetic classification. Forty-one varieties were classified into four groups (I, II, III and IV) with weighted variable group method (WVGM ) and weighted jai. group method(WPGM), whereas the results classification of 33 varieties among them by WVGM were coincident with the results by WPGM. As for the characteristics of each group, group I related to late maturity, tall height and high yield, group II related to intermediate maturity, tall height and low yield, group 19 related to early maturity, intermediate height and low yield, and group W related to early maturity, short height and intermediate yield.

• 대한원격탐사학회지
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• 제26권4호
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• pp.373-385
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• 2010

두 대의 레이더를 이용하여 반사도를 합성할 때 중복영역을 처리하는 새로운 합성 방법을 개발하였다. 이 합성 방법은 인접한 두 레이더의 중복되는 영역의 반사도 차이를 보정한 후 가중치를 주어 합성하는 방법이다. 가중치는 CAPPI(Constant Altitude PPI) 고도와 반사도가 관측된 고도와의 차이의 비를 역으로 계산한 것이다. 이 합성방법의 결과를 분석하기 위하여 두 레이더를 이용하여 관측한 태풍 사례의 반사도장에 대해 다른 합성방법(최댓값, 평균값, 근거리, 거리 가중)과 비교하였다. 두 레이더의 중복영역의 경계지점들에 대해 반사도의 연속성과 치우침을 분석하였고 그 결과 새로운 방법이 다른 합성방법에 비해 더 우수한 결과를 얻었다.

• 대한지하수환경학회지
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• 제6권4호
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• pp.213-217
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• 1999

하천제방은 하천 수리 구조물 중 가장 중요한 구조물중의 하나이다. 하천제방의 붕괴는 재해발생의 직접적인 원인이 되기 때문에 하천제방의 내구성. 안정성은 중요한 요소이다. 제방붕괴의 원인은 홍수범람과 제방 누수를 둘 수 있다. 본 연구는 전기 비저항 탐사를 이용하여 제방누수를 탐사하고. 또 제방의 누수가 발생하였을 경우 weighted residual method를 이용하여 제방 누수량을 평가하였다. 본 연구의 대상유역은 섬진강 상류유역이며. 대상제방의 제원은 길이 300 m. 소단 2.0 m. 제방 폭 4.5 m. 높이 4 m 이다. 본 연구에서는 대상제방에서 전기 비저항 탐사를 이용하여 제방의 누수여부를 평가하였다. 그리고 누수가 발생하는 지점에서 weighted residual method를 이용하여 제방 누수량을 평가하였다. 그 결과 해당제방의 누수는 39~45 m. 80~90 m, 218~222 m. 214~250 m 지점에서 발생하였으며, 누수형상은 직사각형 및 다각형 등의 형상을 보였다. 그리고 이들 누수지점에서 누수량은 2.7$\times$$10^{-3}$ $\textrm{m}^3$/sec로 평가되었다.

• 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.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.267-272
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• 1993

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 ESPI is quite comparable to that of measurement by strain gauge method. This implieds that the method of ESPI is a very effective tool in non-contact two-dimensional in-planc strain analysis. But there is a controversal point,measurment error. This error is discussed to be affected not by ESPI method itseif, 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 occured in the large interval of fringe. so, this paper describes a computer method for drawing when the height is available only for some arbitary collection of points, the method is based on a distance-weighted, least-squares approximation technique, with the weight varying with the distance of the data points.

• 대한전기학회논문지:전력기술부문A
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• 제48권3호
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• pp.294-303
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• 1999

To improve the visual servoing performance, several strategies were proposed in the past such as redundant feature points, using a point with different height and weighted selection of image features. The performance of these visual servoing methods depends on the configuration between the camera and object. And redundant feature points require much computation efforts. This paper proposes the visual servoing method based on the disturbance obsever, which compensates the upper off-diagonal component of image feature jacobian to be the null. The performance indices such as sensitivity for a measure of richness, sensitivity of the control to noise, and comtrollability are shown to be improved when the image feature Jacobian is given as a block diagonal matrix. Computer simulations are carried out for a UUMA560 robot and show some results to verify the effectiveness of the proposed method.

• 한국운동역학회지
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• 제33권4호
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• pp.119-127
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• 2023

Objective: This study aimed to compare the activity of the trunk and leg muscles while performing fente (in fencing) wearing weighted and waterbag vests. Method: The electromyography test was used to measure and analyze the activation of the trunk and leg muscles. Eight active fencers from B University (age: 19.5 ± 0.66 years, height: 179.75 ± 5.93 cm, weight: 72 ± 6.32 kg) were selected for this study. Results: According to the EMG analysis results of the 4 muscles measured in this study, left-right differences were observed for rectus abdominis and external oblique abdominis, but left-right differences between the groups were not significant. The gluteus medius muscle was not significantly different from the adductor muscle, but there were significant differences between the groups. Conclusion: The electromyographic analysis of the four muscles measured in this study revealed no significant difference between the left and right recti abdominis and external obliques depending on the vests. However, significant differences were observed between the left and right gluteus medius and adductor longus. Our results can be interpreted as the effects of the inherent movements involved in the fente. Furthermore, our results indicate that the weight transfer while wearing a waterbag vest, which provides an unstable environment, increased the activity of leg muscles.

• 한국재료학회지
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• 제33권2호
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• pp.54-62
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• 2023

The most comprehensive and particularly reliable method for non-destructively measuring the residual stress of the surface layer of metals is the sin²ψ method. When X-rays were used the relationship of ε_φψ-sin²ψ measured on the surface layer of the processing metal did not show linearity when the sin²ψ method was used. In this case, since the effective penetration depth changes according to the changing direction of the incident X-ray, σ_φ becomes a sin²ψ function. Since σ_φ cannot be used as a constant, the relationship in ε_φψ-sin²ψ cannot be linear. Therefore, in this paper, the orthogonal function method according to Warren's diffraction theory and the basic profile of normal distribution were synthesized, and the X-ray diffraction profile was calculated and reviewed when there was a linear strain (stress) gradient on the surface. When there is a strain gradient, the X-ray diffraction profile becomes asymmetric, and as a result, the peak position, the position of half-maximum, and the centroid position show different values. The difference between the peak position and the centroid position appeared more clearly as the strain (stress) gradient became larger, and the basic profile width was smaller. The weighted average strain enables stress analysis when there is a strain (stress) gradient, based on the strain value corresponding to the centroid position of the diffracted X-rays. At the 1/5 I_max max height of X-ray diffraction, the position where the diffracted X-ray is divided into two by drawing a straight line parallel to the background, corresponds approximately to the centroid position.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2312-2314
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• 1998

To improve the visual servoing performance, several strategies were proposed in the past such as redundant feature points, using a point with different height and weighted selection of image features. The performance of these visual servoing methods depends on the configuration between the camera and object. And redundant feature points require much computation efforts. This paper proposes the visual servoing m based on the disturbance observer, which compe the upper off-diagonal component of image fe Jacobian to be null. The performance indices su sensitivity for a measure of richness, sensitiv the control to noise, and controllability are sho improved when the image feature Jacobian is giv a block diagonal matrix. Computer simulation carried out for a PUMA560 robot and show results to verify the effectiveness of the pro method.

• Journal of Korean Neurosurgical Society
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• 제44권6호
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• pp.370-374
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• 2008

Objective : Aim of study was to find a proper method for assessing subsidence using a radiologic measurement following anterior cervical discectomy and fusion (ACDF) with stand-alone polyetheretherketone (PEEK), $Solis^{TM}$ cage. Methods : Forty-two patients who underwent ACDF with $Solis^{TM}$ cage were selected. With a minimum follow-up of 6 months, the retrospective investigation was conducted for 37 levels in 32 patients. Mean follow-up period was 18.9 months. Total intervertebral height (TIH) of two fused vertebral bodies was measured on digital radiographs with built-in software. Degree of subsidence (${\Delta}TIH$) was reflected by the difference between the immediate postoperative and follow-up TIH. Change of postoperative disc space height (CT-MR ${\Delta}TIH$) was reflected by the difference between TIH of the preoperative mid-sagittal 2D CT and that of the preoperative mid-sagittal T1-weighted MRI. Results : Compared to preoperative findings, postoperative disc height was increased in all cases and subsidence was observed only in 3 cases. For comparison of subsidence and non-subsidence group, TIH and CT-MR ${\Delta}TIH$ of each group were analyzed. There was no statistically significant difference in TIH and CT-MR ${\Delta}TIH$ between each group at 4 and 8 weeks, but a difference was observed at the last follow-up TIH (p=0.0497). Conclusion : ACDF with $Solis^{TM}$ cage was associated with relatively good radiologic long-term results. Fusion was achieved in 94.5% and subsidence occurred in 8.1% by the radiologic assessment. Statistical analysis reveals that the subsidence seen later than 8 weeks after surgery and the development of subsidence does not correlate statistically with the change of the postoperative disc space height.