• Title/Summary/Keyword: Linear program

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Contact Pressure around the Buried Rigid pipe under Embankment (성토하에 매설된 강성관의 접촉응륜력)

  • 안중선;강병희
    • Geotechnical Engineering
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    • v.1 no.2
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    • pp.7-16
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    • 1985
  • The behaviour of buried rigid pipe under embankment is analysed by a linear finite element program to study the influence of variation of the geometry of soil-conduit pipe system and elastic modulus of soil on the pipe response. The geometry of the system considered includes the thickness of pipe, the height of embankment, and the width arid the depth of trench. The normal contact pressure distribution around the pipe and the vertical load on the pipe are modelled by a multiple linear regression. And the vertical load on the pipe computed by Marston-Spangles Theory Is generally larger than that by finite element analysis. The settiement ratio in Marston-Spangler Theory is found to be variable for various for various of all factors mentioned above.

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On the Sealing Force of Perfluoroelastomer O-rings Including Temperature Effects (온도를 고려한 FFKM O-링의 밀봉력에 관한 연구)

  • 김청균;조승현
    • Tribology and Lubricants
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    • v.20 no.5
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    • pp.278-283
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    • 2004
  • O-ring seal is widely used for sealing pressure vessels and oil containers in various applications of mechanical equipments. The doughnut shape of the O-ring is very important components in most of the system assembly of mechanical apparatus. This paper presents the sealing force of a pressurized perfluoroelastomer O-ring, which is very important contact seal in sealing the semiconductor equipment. The sealing pressure is measured by experimental method and analyzed numerically by using the non-linear MARC finite element program. The seal tester is made to measure the contact force and displacement of the O-ring with an automatic control system of the working temperature. The results show the reasonable agreements between the computed FEM results and measured ones when the operating temperature is moderate temperature. But the compared values between the computed and tested results show a difference because of the increased temperature, which is related to the non-linear parameter of the O-ring material.

The Study on the Wave Interaction Due to Offshore Structures (파랑과 해안구조물과의 상호작용에 관한 연구)

  • Kim, Sung-Duk;Lee, Ho-Jin;Dho, Hyon-Seung
    • Journal of the Korea Safety Management & Science
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    • v.11 no.4
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    • pp.139-145
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    • 2009
  • The present study is to investigate the effect of wave-structure interaction such as wave oscillation. The theoretical method is based upon the linear diffraction theory obtained by the boundary element method. The water depth and incident wave period in fluid region are assumed to be constant. To investigate the wave interaction due to offshore structures, the numerical program has been developed and the simulation has been carried out by varying the conditions of distance and width of offshore structures. This study can effectively be utilized for safety assessment to various breakwater systems and layout of offshore breakwater in the ocean and coastal field. It can give information for the safety to construct offshore structure and revetment in coastal region.

Analysis of Quasi-Likelihood Models using SAS/IML

  • Ha, Il-Do
    • Journal of the Korean Data and Information Science Society
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    • v.8 no.2
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    • pp.247-260
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    • 1997
  • The quasi-likelihood models which greatly widened the scope of generalized linear models are widely used in data analysis where a likelihood is not available. Since a quasi-likelihood may not appear to be an ordinary likelihood for any known distribution in the natural exponential family, to fit the quasi-likelihood models the standard statistical packages such as GLIM, GENSTAT, S-PLUS and so on may not directly applied. SAS/IML is very useful for fitting of such models. In this paper, we present simple SAS/IML(version 6.11) program which helps to fit and analyze the quasi-likelihood models applied to the leaf-blotch data introduced by Wedderburn(1974), and the problem with deviance useful generally to model checking is pointed out, and then its solution method is mention through the data analysis based on this quasi-likelihood models checking.

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Research and Development of a Geological Remote Sensing Information Extraction System

  • Zhengmin, He
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1275-1277
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    • 2003
  • This paper presents a geological remote sensing information extraction system, the aim of which is to provide practical models and powerful tools to extract geological information from remote sensing images for geological exploration applications. After reviewing and analyzing the existing methods for geological information extraction, we developed more than ten models to enhance and extract geological information, such as alteration information, linear features and special lithological characters. The system is developed based on Erdas Imagine using its programming language. It has been successfully used in the 'reat Investigation of Land and Natural Resources of China' program.

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Non-Linear FEM Analysis Study of the Flexural Behavior of the RC Beams Strengthened by CFRP plate (CFRP 플레이트로 휨보강한 보의 거동에 대한 비선형 FEM 해석)

  • Koh, Byung-Soon;Yang, Dong-Suk;Park, Sun-Kyu;You, Young-Chan;Park, Young-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.536-539
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    • 2004
  • This paper focues on the flexural behavior of RC beams externally reinforced using Carbon Fiber Reinforced Plastics plates. (CFRP) A non-linear finite element (FE) analysis is proposed in order to complete the experimental analysis of the flexural behaviour of the beams. This paper is a part of a complete program aiming to set up design formulate to predict the strength of CFRP strengthende beams, particularly when premature failure through plates-end shear or concrete cover delamination occurs. An elasto-plastic behaviour is assumed for reinforced concrete and interface elements are used to model the bond and slip.

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Analysis of Flow Characteristics and Experiment of Conductive Liquid Metal Coupling Lorentz Force with Fluid Equation (전자력과 유동방정식을 결합한 전도성 용융금속의 유동특성 해석 및 실험)

  • Jeon, Mun-Ho;Lee, Suk-Won;Kim, Chang-Eob
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.7
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    • pp.1329-1335
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    • 2009
  • This paper presents the flow characteristics in the fluid circulation loop using the tubular type linear induction motor(TLIM) electromagnetic pump. A TLIM pump was designed using the equivalent and genetic algorithm for the flow system of 40[1/min]. The flow characteristics are analyzed by coupling the Maxwell equations with the Navier-Stokes equation. The analysis algorithm also takes account of the effects of the thrust. The flow characteristics are analysed with the proposed method and compared with the commercial program and experiment and discussed.

The Development of a Programmable Single-Phase AC Power Source with a Linear Power Amplifier

  • Jeon, Jeong-Chay;Jeon, Hyun-Jae;Yoo, Jae-Geun;Son, Jae-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.9
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    • pp.39-46
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    • 2007
  • This paper presents a programmable single-phase ac power source that provides a sinusoidal output voltage with an adjustable output amplitude and frequency over a wide range as well as an arbitrary waveform. The ac power source under consideration have a linear power amplifier. The desired output values can be programmed with a personal computer. The power source operates at 220[V]/60[Hz] mains and the output voltage is isolated from the input circuit. The system consists mainly of a power converter to generate and amplify the waveform signal, a controller to control the desired output signal and measure the output parameters, and a control program to set the desired output and display the values. The prototype ac power source was constructed and tested with the results demonstrating a good performance.

A Lagrangian Relaxation Approach to Capacity Planning for a Manufacturing System with Flexible and Dedicated Machines

  • Lim, Seung-Kil;Kim, Yeong-Dae
    • Journal of the Korean Operations Research and Management Science Society
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    • v.23 no.2
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    • pp.47-65
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    • 1998
  • We consider a multiperiod capacity planning problem for determining a mix of flexible and dedicated capacities under budget restriction. These capacities are controlled by purchasing flexible machines and/or new dedicated machines and disposing old dedicated machines. Acquisition and replacement schedules are determined and operations are assigned to the flexible or dedicated machines for the objective of minimizing the sum of discounted costs of acquisition and operation of flexible machines, new dedicated machines, and old dedicated machines. In this research, the Problem is formulated as a mixed integer linear Program and solved by a Lagrangian relaxation approach. A subgradient optimization method is employed to obtain lower bounds and a multiplier adjustment method is devised to improve the bounds. We develop a linear programming based Lagrangian heuristic algorithm to find a good feasible solution of the original problem. Results of tests on randomly generated test problems show that the algorithm gives relatively good solutions in a reasonable amount of computation time.

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Performance of Vocal Tract Area Estimation from Deaf and Normal Children's Speech (청각장애아동과 건청아동의 성도면적 추정 성능)

  • Kim Se-Hwan;Kim Nam;Kwon Oh-Wook
    • MALSORI
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    • no.56
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    • pp.159-172
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    • 2005
  • This paper analyzes the vocal tract area estimation algorithm used as a part of a speech analysis program to help deaf children correct their pronunciations by comparing their vocal tract shape with normal children's. Assuming that a vocal tract is a concatenation of cylinder tubes with a different cross section, we compute the relative vocal tract area of each tube using the reflection coefficients obtained from linear predictive coding. Then, we obtain the absolute vocal tract area by computing the height of lip opening with a formula modified for children's speech. Using the speech data for five Korean vowels (/a/, /e/, /i/, /o/, and /u/), we investigate the effects of the sampling frequency, frame size, and model order on the estimated vocal tract shape. We compare the vocal tract shapes obtained from deaf and normal children's speech.

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