• Title/Summary/Keyword: influence coefficient

Search Result 2,182, Processing Time 0.03 seconds

A Study on the Slope Stability of Embankment in Consideration of Seismic Coefficient (지진계수를 고려한 제방의 사면안정에 관한 연구)

  • 강우묵;지인택;이달원
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.33 no.4
    • /
    • pp.105-120
    • /
    • 1991
  • This study was performed to investigate the minimum safety factor of embankment in consideration of seismic coefficient by the psuedo-static analysis The variables were cohesion, the internal friction angle, angle of slope, height of seepage, height of embankment, depth of replacement The results obtained were compared with those by Fellenius method, simplified Bishop method and Janbu method. The results were summarized as follows: 1.The increasing rate of the minimum safety factor with the increasing of cohesion appeared larger in Fellenius method and Bishop method than in Janbu method. And that with the increasing of the internal friction angle appeared the lowest value in Janbu method. The minimum safety factor was influenced larger on the internal friction angle than on cohesion. 2.The variation of the minimum safety factor with the height of seepage at 0m and 5 m was nearly similar to Fellenius method, Bishop method and Janbu method. On the other hand, it was decreased suddenly at 25 m. 3.The minimum safety factor with the height of embankment was decreased remarkably under 10 m with the increasing of seismic coefficient. But, it was decreased slowly more than 10 m. As the height of embankment was low, the influence of cohesion appeared larger. 4.In heigher case of the depth of replacement, the phenomenon of reduction of the minimum safety factor appeared remarkably with seismic coefficient increased. And in lower case of the depth of replacement, the minimum safety factor was similar in Fellenius method and Bishop mehtod. But it appeared larger in Bishop method and Janbu method than in Fellenius method with the depth of replacement increased. 5.As the cohesion and the internal friction angle were large, the phenomenon of reduction of the minimum safety factor with the increasing of seismic coefficient appeared remarkably. Also, the influence of seismic coefficient in minimum safety factor appeared larger with the soil parameter increased. 6.When the seismic coefficient was considerated, investigation of the structural body on the slope stability appeared profitably in Fellenius method and Janbu method than in Bishop method.

  • PDF

An Analysis of Economic Effects of Korean Fisheries using Input, Output Analysis (산업연관분석을 이용한 수산업의 경제적 파급효과 추이 분석)

  • Park, Kyoung-Il;Park, Joon-Soon;Seo, Ju-Nam
    • The Journal of Fisheries Business Administration
    • /
    • v.43 no.3
    • /
    • pp.75-87
    • /
    • 2012
  • Today, the Korean fisheries is undergoing significant hardships, both domestically and internationally. While declining amount of catch, ascending international oil prices and others pose a compelling challenge to the fishing sector, the ever strengthening influence of international institutions related to fisheries and international trade organizations also compel to bring about myriad of changes in the realm of fishery products. Against the backdrop, this study attempted to examine the fisheries catch, aquaculture, service, processing fields in terms of its rippling effect and of how the industry has been changed by analyzing the past and present through an input-output analysis. As for research methods, 168 items of the input-output tables in 2000, 2005, 2009, and 2010 were integrated to form and classify 32 sectors (28 basic sectors + catch, aquaculture, fishery service, processed fishery products) so as to generate production inducement coefficient, sensitivity coefficient, and impact coefficient. The analysis results revealed that : though the linkage effect of fishery industry was not very sizable, the impact coefficient of the processed fishery products was high; the consumption and investment coefficient sector among production inducement coefficient was on an upturn trend ; the export coefficient was tended to decline. In the future research, it is necessary to carry out a study based on the integration of detailed classification (404 sector) and a study and analysis of fishery industry by different regions through the inter-regional input-output tables. The fishery industry is one of the crucial industries in Korea. The fishery industry is not only important in its own right but also significant as it exerts influence over other industries. Therefore, it is required that there should be more investment and supports for the development of the fishery industry, and pay efforts to ensure that the investment and development could lead to mutual growth for both the fishery and other various industries.

Collapse mechanism of tunnel roof considering joined influences of nonlinearity and non-associated flow rule

  • Yang, X.L.;Xu, J.S.;Li, Y.X.;Yan, R.M.
    • Geomechanics and Engineering
    • /
    • v.10 no.1
    • /
    • pp.21-35
    • /
    • 2016
  • Employing non-associated flow rule and Power-Law failure criterion, the failure mechanisms of tunnel roof in homogeneous and layered soils are studied in present analysis. From the viewpoint of energy, limit analysis upper bound theorem and variation principle are introduced to study the influence of dilatancy on the collapse mechanism of rectangular tunnel considering effects of supporting force and seepage force. Through calculation, the collapsing curve expressions of rectangular tunnel which are excavated in homogeneous soil and layered soils respectively are derived. The accuracy of this work is verified by comparing with the existing research results. The collapsing surface shapes with different dilatancy coefficients are draw out and the influence of dilatancy coefficient on possible collapsing range is analyzed. The results show that, in homogeneous soil, the potential collapsing range decreases with the decrease of the dilatancy coefficient. In layered soils, the total height and the width on the layered position of possible collapsing block increase and the width of the falling block on tunnel roof decrease when only the upper soil's dilatancy coefficient decrease. When only the lower soil's dilatancy coefficient decrease or both layers' dilatancy coefficients decrease, the range of the potential collapsing block reduces.

Forced vibration analysis of beam-like structures by the combination and transfer of dynamic stiffness coefficient (동강성계수의 조합 및 전달에 의한 보형 구조물의 강제진동 해석)

  • 문덕홍;최명수
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.22 no.1
    • /
    • pp.21-27
    • /
    • 1998
  • The authors have developed the transfer dynamic stiffness coefficient method(TDSCM) which is based on the concepts of the substructure synthesis method and transfer influence coefficient method. As a result, we suggested the algorithm for free vibration analysis of beam-like structures which are mainly found in mechanical design by applying the TDSCM in the previous reports. In this paper, we extend this algorithm to the forced vibration analysis for them. And we also confirmed the merits of this method.

  • PDF

An Analysis of the Economic Effects of Unmanned Aerial Vehicle(UAV) Industry (무인항공기 산업의 경제적 파급효과 분석)

  • Kim, Kwang-Hoon;Won, Dong-Kyu;Yeo, Woon-Dong
    • The Journal of the Korea Contents Association
    • /
    • v.18 no.2
    • /
    • pp.216-230
    • /
    • 2018
  • In this paper, we analyze the economic ripple effects of technology related to the unmanned aerial vehicle industry by applying industry association analysis. Specifically, the effects of employment creation, value added inducement, sensitivity coefficient, and influence coefficient can be calculated, and implications for the analysis result are presented. As a result, the employment inducement effect was confirmed to be 10.017 persons per 1 billion won of investment. The value added inducement effect was much higher than the other manufacturing industry average (employment inducement coefficient: 2.285, value added inducement coefficient: 0.581) when the 1 won budget was added, resulting in 0.9771 won added value. In the unmanned aerial vehicle industry, the coefficient of sensitivity, which means the front chain effect, is 0.7870, which is lower than the manufacturing average (sensitivity coefficient 1.125), and the coefficient of influence, which means the backward chain effect, is 1.161, which is higher than the manufacturing average (influence coefficient: 1.116). Therefore, it is classified as the final demand manufacturing industry. This means that the unmanned aerial vehicle industry is an industry that is less affected by economic fluctuations and can be interpreted as an industry with a greater economic impact than other sectors. Based on these data, it can be used to establish the R&D investment direction policy of the unmanned aerospace industry.

Comparison Study on Electric Acceleration Test Method for Estimation of Chloride Diffusion Coefficient (염화물 확산 평가를 위한 전기적 실험법의 비교 연구)

  • Choi, Yoon-Suk;Choi, Sung-Ha;Kim, Myung-Yu;Yang, Eun-Ik;Yi, Seong-Tae
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2005.05b
    • /
    • pp.257-260
    • /
    • 2005
  • A general electric acceleration testing method for estimation of chloride diffusion coefficient is RCPT and CTH. Also, this testing methods have merit that reduce the testing time. In this paper, an experimental study is executed to investigate the effect of testing method on coefficient of chloride diffusion and it is compared with RCPT and CTH. According to this experiment results, W/C ratio and testing method influence chloride diffusion coefficient of concrete. As W/C ratio is increased, diffusion coefficient in concrete is also increased. Diffusion coefficient obtained by each testing method show the different values. However, there is no remarkable difference between the two testing method.

  • PDF

Measurement of the Ionization Coefficient in Gases by the Luminous-flux Method (광속법을 이용한 기체의 전이계수 측정)

  • 백용현;하성철;이복희;김희택;김정섭
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.34 no.7
    • /
    • pp.289-296
    • /
    • 1985
  • The Townsend primary ionization coefficient a was measured by the luminous-flux method using the fact that the intensity of radiant light is proportional to electron density in the townsend discharge domain. The ranges of measurements were 15for He gas and 10

  • PDF

Variable Selection Criteria in Regression

  • Kim, Choong-Rak
    • Journal of the Korean Statistical Society
    • /
    • v.23 no.2
    • /
    • pp.293-301
    • /
    • 1994
  • In this paper we propose a variable selection criterion minimizing influence curve in regression, and compare it with other criteria such as $C_p$(Mallows 1973) and adjusted coefficient of determination. Examples and extension to the generalized linear models are given.

  • PDF

The Effect of Rotation of Discharge Hole on the Discharge Coefficient and Pressure Coefficient (송출공의 회전이 송출계수와 압력계수에 미치는 영향)

  • Ha, Kyoung-Pyo;Ku, Nam-Hee;Kauh, S.Ken
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.27 no.7
    • /
    • pp.948-955
    • /
    • 2003
  • Pressure coefficient in rotating discharge hole was measured to gain insight into the influence of rotation to the discharge characteristics of rotating discharge hole. Pressure measurements were done by the telemetry system that had been developed by the authors. The telemetry system measures static pressure using piezoresistive pressure sensors. Pressure coefficients in rotating discharge hole were measured in longitudinal direction and circumferential direction with various rotating speed and 3 pressure ratios. From the results, the pressure coefficient, and therefore the discharge coefficient, is known to decrease with the increase of Ro number owing to the increase of flow approaching angle to the discharge hole inlet. However, there exists critical Ro number where the decrease rate of discharge coefficient with the increase of Ro number changes abruptly; flow separation occurs from the discharge hole exit at this critical Ro number. Critical Ro number increases with the increase of length-to-diameter ratio, but the increase is small where the length-to-diameter ratio is higher than 3. The decrease rate of discharge coefficient with the increase of Ro number depends on the pressure recovery at the discharge hole, and the rate is different from each length-to-diameter ratio; it has tendency that the short discharge hole shows higher decrease rate of discharge coefficient.

An Analysis of Factors Influencing Insulation Performance of Inorganic Autoclaved Lightweight Concrete Sandwich Wall Panels Using Shear Connectors (전단연결재를 적용한 무기계 경량기포콘크리트(ALC) 샌드위치 외벽 패널의 단열성능에 미치는 영향요인 분석)

  • Kang, Dong Howa;Kang, Dong Hwa;Shin, Dong Hyeon;Kim, Hyung Joon
    • Journal of the Architectural Institute of Korea Structure & Construction
    • /
    • v.34 no.1
    • /
    • pp.79-87
    • /
    • 2018
  • The purpose of this study was to analyze factors influencing insulation performance of inorganic Autoclaved Lightweight Concrete(ALC) sandwich wall panels with the application of shear connectors. To analyze the effect of shear connectors on the thermal performance of sandwich wall panels, heat transfer analysis was conducted by using the three-dimensional heat transfer simulation software. Four types of shear connector such as Pin, Clip, Grid, and Truss were selected for insulation performance analysis. Thermal bridge coefficient was calculated by varying typical panel thickness and shear connector thickness and materials such as steel, aluminum, and stainless steel. The results showed that Grid and Truss type widely distributed along the section of sandwich wall panel had a great influence on the thermal bridge coefficient by changing the influence factors. Based on the results of thermal and structural performance analysis, effective heat transmission coefficient of the sandwich wall panel satisfying the passive house insulation criteria was calculated. As a result, it was found that heat transmission coefficient was increased from $0.132W/m^2{\cdot}K$ to $0.141{\sim}0.306W/m^2{\cdot}K$ depending on the shear connector types and materials. In the majority of cases, the passive house insulation criteria was not satisfied after using shear connectors. The results of this study were likely to vary according to how influence factors were set, but it is important to apply the methods that reduce the thermal bridge when there would be a possibility of greatly affecting the insulation performance.