• 제목/요약/키워드: COEFFICIENT OF VARIATION

검색결과 2,637건 처리시간 0.03초

Reliability analysis of soil slope reinforced by micro-pile considering spatial variability of soil strength parameters

  • Yuke Wang;Haiwei Shang;Yukuai Wan;Xiang Yu
    • Geomechanics and Engineering
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    • 제36권6호
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    • pp.631-640
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    • 2024
  • In the traditional slope stability analysis, ignoring the spatial variability of slope soil will lead to inaccurate analysis. In this paper, the K-L series expansion method is adopted to simulate random field of soil strength parameters. Based on Random Limit Equilibrium Method (RLEM), the influence of variation coefficient and fluctuation range on reliability of soil slope supported by micro-pile is investigated. The results show that the fluctuation ranges and the variation coefficients significantly influence the failure probability of soil slope supported by micro-pile. With the increase of fluctuation range of soil strength parameters, the mean safety factor of the slope increases slightly. The failure probability of the soil slope increases with the increase of fluctuation range when the mean safety factor of the slope is greater than 1. The failure probability of the slope increases by nearly 8.5% when the fluctuation range is increased from δv=2 m to δv =8 m. With the increase of the variation coefficient of soil strength parameters, the mean safety factor of the slope decreases slightly, and the probability of failure of soil slope increases accordingly. The failure probability of the slope increases by nearly 31% when the variation coefficient increases from COVc=0.2, COVφ=0.05 to COVc=0.5, COVφ=0.2.

Reliability based partial safety factor of concrete containing nano silica and silica fume

  • Nanda, Anil Kumar;Bansal, Prem Pal;Kumar, Maneek
    • Computers and Concrete
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    • 제26권5호
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    • pp.385-395
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    • 2020
  • The influence of combination of nano silica and silica fume, as partial cement replacement materials, on the properties of concrete has been studied through the measurement of compressive strength. The compressive strength of concrete in terms of mean, standard deviation and with-in-test coefficient of variation related to the variation in the nominated parameters have also been developed. The compressive strength data developed experimentally has been analyzed using normal-probability distribution and partial safety factors of composite concretes have been evaluated by using first order second moment approach with Hasofer Lind's method. The use of Nano silica and silica fume in concrete decreases the partial safety factor of concrete i.e., increase the reliability of concrete. The experimental results show that the properties of concrete having nano silica and silica fume in combination were better than that of a plain concrete. The SEM test results showing the level of Ca(OH)2 in plain concrete and consumption level Ca(OH)2 of concrete containing nano silica & silica fume have also been presented.

감정 변화에 강인한 음성 인식 파라메터 (Robust Speech Recognition Parameters for Emotional Variation)

  • 김원구
    • 한국지능시스템학회논문지
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    • 제15권6호
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    • pp.655-660
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    • 2005
  • 본 논문에서는 인간의 감정 변화에 강인한 음성 인식 기술 개발을 목표로 하여 감정 변화의 영향을 적게 받는 음성 인식시스템의 특징 파라메터에 관한 연구를 수행하였다. 이를 위하여 우선 다양한 감정이 포함된 음성 데이터베이스를 사용하여 감정 변화가 음성 인식 시스템의 성능에 미치는 영향에 관한 연구와 감정 변화의 영향을 적게 받는 음성 인식 시스템의 특징 파라메터에 관한 연구를 수행하였다. 본 연구에서는 LPC 켑스트럼 계수, 멜 켑스트럼 계수, 루트 켑스트럼 계수, PLP 계수와 RASTA 처리를 한 멜 켑스트럼 계수와 음성의 에너지를 사용하였다 또한 음성에 포함된 편의(bias)를 제거하는 방법으로 CMS와 SBR 방법을 사용하여 그 성능을 비교하였다. 실험 결과에서 RASTA 멜 켑스트럼과 델타 켑스트럼을 사용하고 신초편의 제거 방법으로 CMS를 사용한 경우에 HMM 기반의 화자독립 단어 인식기의 오차가 $7.05\%$로 가장 우수한 성능을 나타내었다. 이러한 것은 멜 켑스트럼을 사용한 기준시스템과 비교하여 $59\%$정도 오차가 감소된 것이다.

pH 변화에 따른 점토의 투수특성변화에 관한 연구 (A study on the Permeability Characteristics of Clay Contaminated with Various Degree of pH)

  • 장병욱;우철웅;김성필;김재형
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2001년도 학술발표회 발표논문집
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    • pp.375-378
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    • 2001
  • This study was peformed to understand permeability characteristic of clays with various pH values. A serious of physical properties and permeability tests, consolidation tests was performed on a clay and a marine clay. Results of the study are as follows. As pH values were decreased, coefficient of permeability was increased because of increase in effective void caused by decrease in thickness of diffuse double layer besides change in soil structures and effective grain size. As pH values were increased, coefficient of permeability of marine clay was increased. Variation of coefficient of permeability of marine clay was increased. Variation of coefficient of permeability of marine clay was largely related because of higher clay contents.

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의료급여 1종 노인 수급권자의 입원이용 (Hospital Services Utilization in Type-I Medicaid Elderly Beneficiaries)

  • 임승주
    • 동서간호학연구지
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    • 제15권2호
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    • pp.63-70
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    • 2009
  • Purpose: The purpose of this study was to evaluate hospital service utilization by the types of hospitals in Type I Medicaid claims frequently cited by elderly beneficiaries. Methods: Three frequently claimed inpatient diseases were selected: cerebral infarction, hypertension and diabetes mellitus. Relevant data were collected for the year 2008 from the computer database of the National Health Insurance Corporation. The data was analyzed using SPSS by descriptive statistics, ANOVA and coefficient of variation. Results: The coefficient of variance of hospitalization per episode was higher than daily hospital expenditure among hospitals for all three diseases. The coefficient of variance of hospitalization per episode was highest for cerebral infarction. The coefficient of variation of hospital expenditure per hospital day was highest for hypertension. Conclusions: Evaluating of the volume and pattern of hospital service utilization and the appropriateness for hospital admission for Type-I Medicaid elderly beneficiaries is important for Medicaid-based case management.

디지털구내방사선사진의 구리당량화상에 대한 평가 (An Assessment on Cu-Equivalent Image of Digital Intraoral Radiography)

  • 김재덕
    • 치과방사선
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    • 제29권1호
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    • pp.33-42
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    • 1999
  • Geometrically standardized dental radiographs were taken. We prepared Digital Cu-Equivalent Image Analyzing System for quantitative assessment of mandible bone. Images of radiographs were digitized by means of Quick scanner and personal Mcquintosh computer. NIH image as software was used for analyzing images. A stepwedge composed of 10 steps of 0.1mm copper foil in thickness was used for reference material. This study evaluated the effects of step numbers of copper wedge adopted for calculating equation. kVp and exposure time on the coefficient of determination(r²)of the equation for conversion to Cu-equivalent image and the coefficient of variation and Cu-Eq value(mm) measured at each copper step and alveolar bone of the mandible. The results were as follows: 1. The coefficients of determination(r²) of 10 conversion equations ranged from 0.9996 to 0.9973(mean=0.9988) under 70kVp and 0.16 sec. exposure. The equation showed the highest r was Y=4.75614612-0.06300524x +0.00032367x² -0.00000060x³. 2. The value of r² became lower when the equation was calculated from the copper stepwedge including 1.0mm step. In case of including 0mm step for calculation. the value of r showed variability. 3. The coefficient of variation showed 0.11, 0.20 respectively at each copper step of 0.2, 0.1mm in thickness. Those of the other steps to 0.9 mm ranged from 0.06 to 0.09 in mean value. 4. The mean Cu-Eq value of alveolar bone was 0.14±0.02mm under optimal exposure. The values were lower than the mean under the exposures over 0.20sec. in 60kVp and over 0.16sec. in 70kVp. 5. Under the exposure condition of 60kVp 0.16sec.. the coefficient of variation showed 0.03. 0.05 respectively at each copper-step of 0.3, 0.2mm in thickness. The value of r² showed over 0.9991 from both 9 and 10 steps of copper. The Cu-Eq value and the coefficient of variation was 0.14±0.01mm and 0.07 at alveolar bone respectively. In summary. A clinical application of this system seemed to be useful for assessment of quantitative assessment of alveolar provided high coefficient of determination is obtained by the modified adoption of copper step numbers and the low coefficient of variation for the range of Cu-Equivalent value of alveolar bone from optimal kVp and exposure time for each x-ray machine.

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실린더 벽면 치수변화에 따른 변형이 충격흡수장치 감쇠계수에 미치는 영향 (The Effect of Impact Absorbing System Deformation According to the Variation of Cylinder Wall Dimensions on Damping Coefficient)

  • 한근조;안찬우;안성찬;심재준;김성윤
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 추계학술대회 논문집
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    • pp.765-768
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    • 1997
  • Many malfunctions take place in container crane spreader due to impact. So we designed a hydraulic impact absorbing equipment to absorb the impact and we studied the change of damping coefficient with respect to the variation of dimensions of oil-cylinder wall. When we design the dimension of hydraulic cylinder wall considering the displacement on the wall, the value of it over 20mm didn't affect the damping coefficient.

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이종 접합부재의 두께 변화에 따른 계면균열의 초음파 산란 보정 (Ultrasonic Scatter and Compensation of Interfacial Crack due to Thickness Variation of Dissimilar Bonded Components)

  • 박성일;정남용;진윤호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.25-30
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    • 2004
  • In this paper, the compensation of interfacial scatter due to adhesive layer and adherend thickness ratio variation was applied to improve measuring precision by calculating ultrasonic attenuation coefficient in the Al/Epoxy dissimilar bonded components. The optimum condition of theoretical value and experimental measuring accuracy by the ultrasonic method in the Al/Epoxy dissimilar bonded components have been investigated. From the experimental results, we proposed a measurement method of the interfacial crack lengths by the ultrasonic attenuation coefficient and discussed it.

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Cycle-to-Cycle Variations Under Cylinder- Pressure- Based Combustion Analysis in Spark Ignition Engines

  • Han, Sung-Bin
    • Journal of Mechanical Science and Technology
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    • 제14권10호
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    • pp.1151-1158
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    • 2000
  • Combustion analysis based on cylinder-pressure provides a mechanism through which a combustion researcher can understand the combustion process. The objective of this paper was to identify the most significant sources of cycle-to-cycle combustion variability in a spark ignition engine at idle. To analyse the cyclic variation in a test engine, the burn parameters are determined on a cycle-to-cycle basis through the analysis of the engine pressure data. The burn rate analysis program was used here and the burn parameters were used to determine the variations in the input parameter-i. e., fuel, air, and residual mass. In this study, we investigated the relationship of indicated mean effective pressure (IMEP), coefficient of variation (COV) of IMEP, burn angles, and lowest normalized value (LNV) in a spark ignition engine in a view of cyclic variations.

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담배 약에서 유기된 반수체 배가계통의 변이, 상관 및 경로분석 (Correlation Coefficients and Path - Analysis of Various Characteristics of Dihaploids derived from Tobacco (Nicotiana tabacco L.)Anther Culture in vitro)

  • 금완수;제상율
    • 한국연초학회지
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    • 제3권1호
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    • pp.41-48
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    • 1981
  • Dihaploid lines were derived from the anthers of the F, of single cross, "Va 115" x"SC 72" (Nicotiana tabacum L.). The path-analysis, correlation coefficient, and variation of characteristics among dihaploid families were evaluated. Dihaploid lines displayed much greater variation than their parents. The genetic correlation coefficient between yield and total alkaloids of dihaploids was significantly lower than that of conventional varieties and lines. In path-analysis which relates yield components to yield, number of leaves harvested and leaf width had a direct effect on yield. a direct effect on yield.

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