• Title/Summary/Keyword: curve section

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The Test of Stochastic Convergence of Environment Emission and Environmental Kuznets Curve Hypothesis in Asian Developing Countries (아시아 국가들 환경오염배출량의 확률수렴성과 환경쿠즈네츠곡선가설 검정)

  • Kim, Ji Uk
    • Environmental and Resource Economics Review
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    • v.19 no.3
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    • pp.571-595
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    • 2010
  • This research applies an panel data stationarity and stochastic convergence test developed by Carrion-i-Silvestre et al. (2005), which has the advantage of considering multiple structural breaks and the presence of cross-section dependence in order to investigate the hypothesis that relative emission $CO_2$ per capita stochastically converge for 11 Asian countries from 1971~2007. We find that relative emission $CO_2$ per capita is stationary after the structural breaks and cross-section dependence are introduced into the model. We also investigate whether Environmental Kuznets Curve (EKC) hypothesis exists in 11 Asian countries. For EKC test, using the panel cointegration tests of Banerjee and Carrion-i-Silvestre (2006) and Westerlund and Edgerton(2007), we find that relative emission $CO_2$ per capita and relative GDP per capita are cointegrated. However EKC hypothesis in 11 Asian countries is not supported.

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Development of a Fuel-Efficient Driving Strategy in Horizontal Curve Section (평면곡선부 구간에서의 연료효율적 주행전략 개발)

  • Jeong, Yangrok;Bae, Sanghoon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.15 no.3
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    • pp.77-84
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    • 2016
  • In 2012, total GHG emissions in transport sector reached 88 Million ton CO2eq. The emissions generated in the road accounted for 94% of the transport sector. Currently, there are many efforts to operate an education and campaign for eco-driving. However study for eco-friendly vehicle control considering road alignment is limited. Therefore, the purpose of this study is to address fuel-efficient driving strategy in horizontal curve section. To fulfill the goal, designed ideal freeway horizontal curve road follows regulations about road structure. And safety speed is calculated for considering vehicle's safety on horizontal curve road. Authors composed the acceleration and deceleration scenario for each horizontal curve section and generated the speed profiles that are limited by the safety speed. Speed profiles are converted into force that horizontal curve affect to fuel consumption. Then, we calculated fuel consumption using Comprehensive Modal Emission Model. Then, we developed eco-driving strategy by selecting most fuel-efficient scenario. To validate this strategy, we selected study site and compared fuel consumption for eco and manual driving. As the result, fuel consumption when driver used eco-driving was lessened by 20.73% than that of manual driving.

A Study on Development of Assessment Model for Spatio-Temporal Changes in River Bed Using Numerical Models (수치모형을 이용한 하상변동 시공간 평가 기법 개발 연구)

  • Kim, Chul-Moon;Lee, Jeong-Ju;Choi, Su-Won;Ahn, Won-Sik
    • Journal of Korea Water Resources Association
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    • v.44 no.12
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    • pp.975-990
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    • 2011
  • In this study, to develop an assessment method for spatio-temporal riverbed changes, a 1-dimensional model (HEC-RAS) and a 2-dimensional model (CCHE2D) were built and applied. As for the analysis of a riverbed's long-term change in a real stream, three new assessment methods were developed, which are called the "Sediment section cumulative curve", "Sediment section moment", and "Sediment probability distribution function." These methods were used to assess the characteristics of riverbed changes using a consistent valuation standard and to understand changes in quantities intuitively. From the results of this study, sediment characteristics of cross sections can be detected effectively by applying the "Sediment section cumulative curve" method to determine whether there is any sedimentation or erosion in total emission. The amount of sedimentation or erosion occurring in the right or left banks, which divided by center column, could be presented as one criterion by applying the "Sediment section moment" method. This approach could be utilized as an indicator for sediment predictions. Spatio-temporal sediment variables can be presented quantitatively by determining the mean and uncertain boundaries through the "Sediment probability distribution function", and finally, the results can be illustrated for each cross section to provide intuitive recognition.

A Study on the Shape Design of Cylindrical Cam in a Folder Hinge Mechanism for Mobile Phones (휴대폰 폴더힌지기구를 위한 원통캠 형상 설계에 관한 연구)

  • Lee S.J.;Park J.K.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1613-1616
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    • 2005
  • In this paper, we developed an algorithm of generating cam contour curve for hinge mechanism of folder-type mobile phone. The main feature of this hinge mechanism is that we can operate uniform torque to open or close the mobile phone. We divided the opening or closing intervals of the cam into finite sub-intervals, and then we determined the cam contour curve of each sub-interval as a parabolic curve. Finally, these finite parabolic curves form the total cam contour. We can design single cam, which composed moving cam with contour curve and fixed cam that plays only roller, and twin cam with contour curve that is made up the pair of two cams symmetrically.

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Center of Gravity and a Characterization of Parabolas

  • KIM, DONG-SOO;PARK, SOOKHEE;KIM, YOUNG HO
    • Kyungpook Mathematical Journal
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    • v.55 no.2
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    • pp.473-484
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    • 2015
  • Archimedes determined the center of gravity of a parabolic section as follows. For a parabolic section between a parabola and any chord AB on the parabola, let us denote by P the point on the parabola where the tangent is parallel to AB and by V the point where the line through P parallel to the axis of the parabola meets the chord AB. Then the center G of gravity of the section lies on PV called the axis of the parabolic section with $PG=\frac{3}{5}PV$. In this paper, we study strictly locally convex plane curves satisfying the above center of gravity properties. As a result, we prove that among strictly locally convex plane curves, those properties characterize parabolas.

Estimate for Ensuring sight Distance of Curve Section from Consideration of the Environmental Impact Assessment based on the 3D GIS (환경영향을 고려한 곡선부 시거 안정성 분석을 위한 3차원 GIS 적용)

  • Choi Hyun;Han Sung-Dae;Lee Yong-Hee;Kang In-Joon
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.431-436
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    • 2006
  • The latest system of GIS has been changing from 2 dimension to 3 dimension. According to the rapid growth of the fields linked to 3D GIS, 3D GIS has variously affected the public field, the national defense field, and the industrial field. This study estimated sight distance safety of curve section considering the environmental impact based on 3D GIS. Sight distance is calculated from the relation between road which keeps the three-dimension character and driver gaze, so it needs to consider both plane and vertical ior the accurate measuring. This study made analysis of the sight distance through considering the environmental impact with driving simulation of design speed 80km/h and running speed 60-120km/h.

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Local Buckling Characteristics of a column with I section (I형강기둥의 국부좌굴 특성)

  • 임종완;임장근
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.4
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    • pp.18-26
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    • 1994
  • The buckling characteristics of I - shaped columns which are composed of thin web and equal upper/lower flange plates are generally classified into the local and global modes. In this paper, its local buckling problem has been formulated on the basis of the assumed buckling modes using the finite element method for beams and plates. The effects of local bucklings are studied for various size rations and end conditions of I-shaped columns. The calculated results are comparatively well consistent with values obtained from the existing studies. The global buckling characteristics calculated by the present method are in good agreement with the classical rigid web solution

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A curvature method for beam-column with different materials and arbitrary cross-section shapes

  • Song, Xiaobin
    • Structural Engineering and Mechanics
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    • v.43 no.2
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    • pp.147-161
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    • 2012
  • This paper presents a curvature method for analysis of beam-columns with different materials and arbitrary cross-section shapes and subjected to combined biaxial moments and axial load. Both material and geometric nonlinearities (the p-delta effect in this case) were incorporated. The proposed method considers biaxial curvatures and uniform normal strains of discrete cross-sections of beam-columns as basic unknowns, and seeks for a solution of the column deflection curve that satisfies force equilibrium conditions. A piecewise representation of the beam-column deflection curve is constructed based on the curvatures and angles of rotation of the segmented cross-sections. The resulting bending moments were evaluated based on the deformed column shape and the axial load. The moment curvature relationship and the beam-column deflection calculation are presented in matrix form and the Newton-Raphson method is employed to ensure fast and stable convergence. Comparison with results of analytic solutions and eccentric compression tests of wood beam-columns implies that this method is reliable and effective for beam-columns subjected to eccentric compression load, lateral bracings and complex boundary conditions.

Nonlinear Stability Analysis of Slender Concrete Columns (세장한 콘크리트 기둥의 비선형 안정 해석)

  • 김진근;양주경;김원근
    • Proceedings of the Korea Concrete Institute Conference
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    • 1992.04a
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    • pp.80-85
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    • 1992
  • A nonlinear second-order analysis program that properly describes the nonlinear behavior of concrete was developed by using the layering technique. As the slenderness ratio of column is increased, the peaks of P-M curve lie remote from the section interaction diagram for the same eccentricities. But the peaks of P-M curve lie rather close to the section interaction diagram for very large eccentricities. In this study , the effects of compressive strength of concrete, longitudinal steel ratio, and yield strength of steel on second-order moment of concrete columns were analyzed. As the compressive strength of concrete and the yield strength of steel are increased, the ratio of peak axial force to maximum axial strength for concentrically loaded short column( Pu/Po) is decreased. But as the longitudinal steel ratio is increased, the ratio , Pu/Po increases.

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