• 한국지반공학회논문집
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• 제29권11호
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• pp.99-106
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• 2013

본 연구에서는 일반국도 상에 존재하는 2종 비탈면 104개소에 대해 상태평가 항목과 상태평가 등급의 연관성을 분석하고, 평가항목을 고려한 다중회귀분석을 통해 안전등급을 예측할 수 있는 회귀모형을 제시하였다. 분석결과, 사면경사와 강우 및 지하수의 평가항목은 상태평가 등급과의 연관성이 낮은 것으로 분석되었다. 또한, 다중회귀분석을 통해 제시된 회귀모형은 절취상태, 강우 및 지하수의 항목을 판단하기 어려운 조건에서 활용이 가능한 것으로 판단된다.

• 전기학회논문지P
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• 제53권2호
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• pp.43-50
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• 2004

Percentage differential characteristic relaying(PDR) has been recognized as the principal basis for power transformer protection. Second harmonic restraint PDR has been widely used for magnetizing inrush in practice. Nowadays, relaying signals can contain 2nd harmonic component to a large extent even in a normal state, and 2nd harmonic ratio indicates a tendency of relative reduction because of the advancement of material. Further, as the power system voltage becomes higher and more underground cables are used, larger 2nd harmonic component in the differential current under internal fault is observed. And then, conventional 2nd harmonic restraint PDR exposes some doubt in reliability. It is, therefore, necessary to develop a new algorithm for performance improvement of conventional protective relaying. This paper proposes an advanced protective relaying algorithm by using voltage-current trend and flux-differential current slope characteristic. To evaluate the performance of the proposed algorithm, we have made comparative studies of PDR, fuzzy relaying and DWT relaying. The paper is constructed power system model including power transformer, utilizing the WatATP, and data collection is made through simulation of various internal faults and inrush. As the results of test, the new proposed algorithm was proven to be faster and more reliable.

• 한국의류학회지
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• 제48권4호
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• pp.756-773
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• 2024

This study proposes a prototype design method for pants suited to adult women with a difference of 27cm or more between the circumference of their waist and hip. The first pattern was modified around the hem, in the number of darts at the waist and in the slope of the front center. The second pattern was modified in the position of the waist darts and the length of the front and back darts. The third pattern showed side-line wrinkling, so the slope of the side-line and the number of darts were adjusted. Pants patterns for women with large hips can be calculated by inserting the difference between hip and waist circumference in the settings for the center front angle, center back angle, front side line angle, back side line angle, dart length, etc. This enables designers to draft pants patterns suited to the body shape of women with a difference in hip and waist circumference of 27cm or more.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 정보화시공 학술발표회
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• pp.19-27
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• 2001

Early detection of premonitory symptom of slope movement ensures tremendous saving of lives and repair costs from catastrophic disaster. Therefore, it is essential to constantly monitor the performance and integrity of both reinforced and un-reinforced cut slopes. We developed a novel monitoring system by using tension wire sensors. It's advantages are highly sensitivity, simple installation, large displacement measurement, durability of system, capability of remote sensing. Real-time measurement of slope surface movement is shown graphically and it gives a warning when the monitored value exceeds a given threshold level so that any sign of abnormal slope movement can be easily perceived.

• 한국안전학회지
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• 제9권4호
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• pp.103-111
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• 1994

Recently, rock slope in large scale is often accompanied with the construction of mountain roads and power plants. Rock in nature has a number of discontinuities such as bedding plane, joints, fracture zones and others. In order to improve rock slope stability, it is necessary to research shear properties of rock joint. In this paper shear properties of rock joint were studied by tilting test. Relations between properties of roughness and shear behavior of rock joint are investigated experimentally. The roughness are examined by compared with shear strength. Consequently, it becomes clear that the engineering properties and failure state modes of slope is different by JRC, and the peak friction angle is different by percent of filling.

• 한국환경복원기술학회지
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• 제11권2호
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• pp.1-9
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• 2008

The objective of the study is 10 know the relation of landslide occurrence with using TPI (Topographic Position Index) in the Pyungchang County. Total 659 landslide scars were detected from aerial photographs. To analyze TPI, 100m SN (Small-Neighborhood) TPI map, 500m LN (Large-Neighborhood) TPI map, and slope map were generated from the DEM (Digital Elevation Model) data which are made from 1 : 5,000 digital topographic map. 10 classes clustered by regular condition after overlapping each TPI maps and slope map. Through this process, we could make landform classification map. Because it is only to classify landform, 7 classes were finally regrouped by the slope angle information of landslide occurrence detected from aerial photography analysis. The accuracy of reclassified map is about 46%.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.152-155
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• 2001

The study investigates characteristic variations of firsthand execution concrete in the slope form a part of technical development on banking slope stabilization, Concrete constructions variations of water-cement ration provide the regular hour-for following verify changes of test piece volume, variations of compressive strength etc. A result, a knowledge of changes of test piece volume large, augering rather than driving, increase in compressive strength of concrete by water-cement ration of small quantity, raise in compressive strength of concrete by increase in water content.

• 한국해양공학회지
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• 제20권6호
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• pp.61-66
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• 2006

Two iterative solvers are applied to solve the modified mild slope equation. The elliptic formulation of the governing equation is selected for numerical treatment because it is partly suited for complex wave fields, like those encountered inside harbors. The requirement that the computational model should be capable of dealing with a large problem domain is addressed by implementing and testing two iterative solvers, which are based on the Stabilized Bi-Conjugate Gradient Method (BiCGSTAB) and Generalized Conjugate Gradient Method (GCGM). The characteristics of the solvers are compared, using the results for Berkhoff's shoal test, used widely as a benchmark in coastal modeling. It is shown that the GCGM algorithm has a better convergence rate than BiCGSTAB, and preconditioning of these algorithms gives more than half a reduction of computational cost.

• 대한전자공학회논문지
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• 제25권7호
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• pp.819-825
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• 1988

An 1-bit DPCM image coding method is presented. Our method is specially designed to reduce the slope overload which seems to be the major performance degradation factor in 1-bit DPCM. In the present algorithm, based on the classification of neighborhoods by its flatness, slope strength and direction, predictor and quantizer operate adaptively through switching action. Compared with some other methods by computer simulation, proposed method shows improved performance in image quality as well as in signal to noise ratio. This gain mainly comes from the reduced slope overload and seems large to compensate the increased complexity in prediction. As a post processing, Lee filter is used to reduce the granular noise subjectively annoying in flat region.

• 지구물리
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• 제8권3호
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• pp.137-143
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• 2005

Early detection of premonitory symptom of slope movement ensures tremendous saving of lives and repair costs from catastrophic disaster. Therefore, it is essential to constantly monitor the performance and integrity of both reinforced and un-reinforced cut slopes. We developed a novel monitoring system by using tension wire sensors. It's advantages are highly sensitivity, simple installation, large displacement measurement, durability of system, capability of remote sensing. Real-time measurement of slope surface movement is shown graphically and it gives a warning when the monitored value exceeds a given threshold level so that any sign of abnormal slope movement can be easily perceived.