• Title/Summary/Keyword: Coefficient analysis

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Estimation model of coefficient of permeability of soil layer using linear regression analysis (단순회귀분석에 의한 토층지반의 투수계수 산정모델)

  • Lee, Moon-Se;Kim, Kyeong-Su
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.1043-1052
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    • 2009
  • To derive easily the coefficient of permeability from several other soil properties, the estimation model of coefficient of permeability was proposed using linear regression analysis. The coefficient of permeability is one of the major factors to evaluate the soil characteristics. The study area is located in Kangwon-do Pyeongchang-gun Jinbu-Myeon. Soil samples of 45 spots were taken from the study area and various soil tests were carried out in laboratory. After selecting the soil factor influenced by the coefficient of permeability through the correlation analysis, the estimation model of coefficient of permeability was developed using the linear regression analysis between the selected soil factor and the coefficient of permeability from permeability test. Also, the estimation model of coefficient of permeability was compared with the results from permeability test and empirical equation, and the suitability of proposed model was proved. As the result of correlation analysis between various soil factors and the coefficient of permeability using SPSS(statistical package for the social sciences), the largest influence factor of coefficient of permeability were the effective grain size, porosity and dry unit weight. The coefficient of permeability calculated from the proposed model was similar to that resulted from permeability test. Therefore, the proposed model can be used in case of estimating the coefficient of permeability at the same soil condition like study area.

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Contact Heat Transfer Coefficient for Finite Element Analysis in Warm Forging Processes (온간단조 공정의 계면열전달계수)

  • Kang J.H.;Ko B.H.;Jae J.S.;Kang S.S.
    • Transactions of Materials Processing
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    • v.15 no.3 s.84
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    • pp.183-188
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    • 2006
  • Heat transfer coefficients have great influence on finite element analysis results in elevated temperature forging processes. Experimentally calculated contact heat transfer coefficient is not suitable for one-time finite element analysis because analyzed temperature will be appeared to be too low. To get contact heat transfer coefficient for one-time finite element analysis, tool temperature in operation was measured with thermocouple and repeated finite element analysis was performed with experimentally calculated contact and cooling heat transfer coefficient. Surface temperature of active tool was obtained comparing measurement and analysis results. Contact heat transfer coefficient for one-time finite element analysis was achieved analyzing surface temperature between repeated finite element analysis and one-time finite element analysis results.

Free Vibration Analysis of Double Cylindrical Shells Using Transfer of Influence Coefficent (영향계수의 전달에 의한 2중 원통형 셸의 자유진동해석)

  • Choi, Myung-Soo;Yeo, Dong-Jun
    • Journal of Power System Engineering
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    • v.21 no.5
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    • pp.48-54
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    • 2017
  • The transfer influence coefficient method which is an vibration analysis algorithm based on the transfer of influence coefficient is applied to the free vibration analysis of double cylindrical shells. After the computational programs for the free vibration analysis of double cylindrical shells were made using the transfer influence coefficient method and the transfer matrix method, we compared the results using the transfer influence coefficient method with those by the transfer matrix method. The transfer influence coefficient method provided the good computational results in the free vibration analysis of double cylindrical shells. In particular, The results of the transfer influence coefficient method are superior to those of the transfer matrix method when the stiffness of internal springs connecting a inside cylindrical shell and a outside cylindrical shell is very large.

Research on heat transfer coefficient of supercritical water based on factorial and correspondence analysis

  • Xiang, Feng;Tao, Zhou;Jialei, Zhang;Boya, Zhang;Dongliang, Ma
    • Nuclear Engineering and Technology
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    • v.52 no.7
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    • pp.1409-1416
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    • 2020
  • The study of heat transfer coefficient of supercritical water plays an important role in improving the heat transfer efficiency of the reactor. Taking the supercritical natural circulation experimental bench as the research object, the effects of power, flow, pipe diameter and mainstream temperature on the heat transfer coefficient of supercritical water were studied. At the same time, the experimental data of Chen Yuzhou's supercritical water heat transfer coefficient was collected. Through the factorial design method, the influence of different factors and their interactions on the heat transfer coefficient of supercritical water is analyzed. Through the corresponding analysis method, the influencing factors of different levels of heat transfer coefficient are analyzed. It can be found: Except for the effects of flow rate, power, power-temperature and temperature, the influence of other factors on the natural circulation heat transfer coefficient of supercritical water is negligible. When the heat transfer coefficient is low, it is mainly affected by the pipe diameter. As the heat transfer coefficient is further increased, it is mainly affected by temperature and power. When the heat transfer coefficient is at a large level, the influence of the flow rate is the largest at this time.

Study on the Coefficient of Consolidation of Marine Clay by Rowecell Consolidation Test (ROWECELL시험에 의한 해성점토의 압밀계수에 대한 연구)

  • 김종국;차영일;김혁기;김영웅
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.725-732
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    • 2003
  • It was achieved that Rowecell test for this undisturbed sample was picked by Block sampler($\phi$:250mm, L:500mm) and hydraulic piston sampler($\phi$:76mm, L:850mm) in the marine clay of YONGYUDO and YEONGJONGDO in this research. Ratio of coefficient of consolidation was analyzed through comparison with C$\_$h/ by CPTu and C$\_$v/ and C$\_$h/ by existent consolidation test. According to analysis, coefficient of consolidation of block sample is fairly greater than coefficient of consolidation of piston sample. And the bigger diameter of undisturbed sample, sample disturbance could know decreasing. Coefficient of consolidation by Rowecell test measured more greatly than coefficient of consolidation by existent consolidation test. Rowecell test could know decreasing consolidation rate because of smear effect by Mandrel injection. Also, C$\_$h/ by CPTu shows deviation by each analysis method, selection of suitable analysis method judged by important leading in the coefficient of consolidation.

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A new consideration for the heat transfer coefficient and an analysis of the thermal stress of the high-interim pressure turbine casing model (열전달계수에 대한 새로운 고찰 및 고-중압 터빈 케이싱 모형의 열응력 해석)

  • Um, Dall-Sun
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.425-429
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    • 2004
  • In real design of the high & interim pressure turbine casing, it is one of the important things to figure out its thermal strain exactly. In this paper, with the establishment of the new concept for the heat transfer coefficient of steam that is one of the factors in analysis of the thermal stress for turbine casing, an analysis was done for one of the high & interim pressure turbine casings in operating domestically. The sensitivity analysis of the heat transfer coefficient of steam to the thermal strain of the turbine casing was done with a 2-D simple model. The analysis was also done with switching of the material properties of the turbine casing and resulted in that the thermal strain of the turbine casing was not so sensitive to the heat transfer coefficient of steam. On the basis of this, 3-D analysis of the thermal strain for the high and interim pressure turbine casing was done.

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Development of the Modified Seismic Coefficient Method to Establish Seismic Design Criteria of Buried Box Structures. (BOX 형 지하구조물의 내진설계 기준 확립을 위한 해석기법개발)

  • 박성우
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.04a
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    • pp.194-201
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    • 2000
  • In this study the modified seismic coefficient method for seismic analysis of buried box structures is developed for practical purpose. The loading coefficient in the modified seismic coefficient method is determined from the results of the response displacement analysis. In the developed method adequate velocity response spectrum in accordance with soil condition is also needed to seismic design of buried box structures, In order to investigate applicability of the modified seismic coefficient method various analyses are performed with different parameters such as depth of base rock height and width of box buried depth and value of standard penetration test. Results from the modified seismic coefficient method are compared with those of the response displacement method in terms of the maximum bending moment and the location of it. From the comparison it is shown that the feasibility of the modified seismic coefficient method for seismic analysis of buried box structures.

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Proposal for the Estimation Model of Coefficient of Permeability of Soil Layer using Linear Regression Analysis (단순회귀분석에 의한 토층의 투수계수산정모델 제안)

  • Lee, Moon-Se;Ryu, Je-Cheon;Lim, Heui-Dae;Park, Joo-Whan;Kim, Kyeong-Su
    • The Journal of Engineering Geology
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    • v.18 no.1
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    • pp.27-36
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    • 2008
  • To derive easily the coefficient of permeability from several other soil properties, the estimation model of coefficient of permeability was proposed using linear regression analysis. The coefficient of permeability is one of the major factors to evaluate the soil characteristics. The study area is located in Kangwon-do Pyeongchang-gun Jinbu-Myeon. Soil samples of 45 spots were taken from the study area and various soil tests were carried out in laboratory. After selecting the soil factor influenced by the coefficient of permeability through the correlation analysis, the estimation model of coefficient of permeability was developed using the linear regression analysis between the selected soil factor and the coefficient of permeability from permeability test. Also, the estimation model of coefficient of permeability was compared with the results from permeability test and empirical equation, and the suitability of proposed model was proved. As the result of correlation analysis between various soil factors and the coefficient of permeability using SPSS(statistical package for the social sciences), the largest influence factor of coefficient of permeability were the effective grain size, porosity and dry unit weight. The coefficient of permeability calculated from the proposed model was similar to that resulted from permeability test. Therefore, the proposed model can be used in case of estimating the coefficient of permeability at the same soil condition like study area.

Numerical Analysis for Buried Box Structures during Earthquake (지중 박스구조물의 지진시 거동 해석)

  • 박성진
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.10a
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    • pp.108-115
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    • 2000
  • Numerical analysis of slop stability is presented using seismic displacement, response seismic coefficient, and earthquake response analysis methods. In seismic displacement and response seismic coefficient methods, horizontal static seismic force is considered as 0.2g while vertical static seismic force is not considered in analysis. For earthquake response analysis Hahinoha-wave is applied, It is found from result that analysis using response seismic coefficient method is much more conservative than that using seismic displacement method Also, analysis result using earthquake response analysis method is somewhat less conservative about 25% when compared with that using seismic displacement method.

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Exploratory data analysis for Chatterjee's ξ coefficient (Chatterjee의 ξ 계수에 대한 탐색적자료분석)

  • Jang, Dae-Heung
    • The Korean Journal of Applied Statistics
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    • v.35 no.3
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    • pp.421-434
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    • 2022
  • Chatterjee (2021) proposed a new correlation coefficient ξ. Focusing on two questions (1. Is ξ coefficient distinguishable for Anscombe's quartet data set?, 2. How does the ξ coefficient value change according to the number of data for various kinds of scatterplots?), an exploratory data analysis is attempted for ξ coefficient. We can compare three measures (ξ coefficient, Pearson's correlation coefficient and mutual information).