• Title/Summary/Keyword: performance objective

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A Study of TOEIC Results and College Recruiting Policy

  • Lee, Eun-Pyo
    • English Language & Literature Teaching
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    • v.11 no.3
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    • pp.57-69
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    • 2005
  • There have been changes throughout the past 100 years of English education in Korea. The Ministry of Education revised the English curriculum numerous times. From the 6th national curriculum, communicative competence became an essential objective in English learning. The study is to see if E University students' TOEIC results show any significant difference between the two groups under the 5th and 6th national curriculum. Another objective of this research is to see if recruiting medical students with high scores of the standardized English tests is suitable to select the best candidates who can fulfill medical studies. For these two purposes, sophomore students' TOEIC results in 2000 & 2004 and non-resident-status students' cumulative GPA were analyzed. The study shows that there is no significant difference in the two groups. Moreover, the current recruiting policy to select the best fit medical candidates based on their high TOEIC or TOEFL scores does not seem to be an appropriate measure since such students' GPA reveals poor academic performance amid their high scores in English.

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Performance Analysis of OTEC Power Plant (해양온도차 발전 플랜트 성능해석)

  • Uhm, Ji-Hong;Lee, Jae-Yong;Kim, Nam-Jin;Kim, Chong-Bo
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.234-240
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    • 2000
  • The Energy is the basis for almost all industrial activities and domestic needs. But recently there are increasing concerns internationally over environmental problems and consequent climate changes caused by the excessive use of fossil fuels. Furthermore the price of crude oil is increasing steadily with unstable supplies. In order to solve these national energy problems, the utilization of Ocean Energy is introduced as one of the best alternative technologies for the future. OTEC Power Plant has been installed at the West Inchon Power Plant Site. Temperature differences of $20{\sim}25^{\circ}C$ have been utilized for plant operations, where R22 is used as a working fluid. The system is composed of low pressure turbine, plate type heat exchanger, and pumps. In the present investigation the experimental results, such as gross power, net power and objective function, are analysed when temperature differences change from the reference design point.

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A dynamic game approach to robust stabilization of time-varying discrete linear systems via receding horizon control strategy

  • Lee, Jae-Won;Kwon, Wook-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.424-427
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    • 1995
  • In this paper, a control law based on the receding horizon concept which robustly stabilizes time-varying discrete linear systems, is proposed. A dynamic game problem minimizing the worst case performance, is adopted as an optimization problem which should be resolved at every current time. The objective of the proposed control law is to guarantee the closed loop stability and the infinite horizon $H^{\infty}$ norm bound. It is shown that the objective can be achieved by selecting the proper terminal weighting matrices which satisfy the inequality conditions proposed in this paper. An example is included to illustrate the results..

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Fuzzy Gain Scheduling of Velocity PI Controller with Intelligent Learning Algorithm for Reactor Control

  • Kim, Dong-Yun;Seong, Poong-Hyun
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.11a
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    • pp.73-78
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    • 1996
  • In this study, we proposed a fuzzy gain scheduler with intelligent learning algorithm for a reactor control. In the proposed algorithm, we used the gradient descent method to learn the rule bases of a fuzzy algorithm. These rule bases are learned toward minimizing an objective function, which is called a performance cost function. The objective of fuzzy gain scheduler with intelligent learning algorithm is the generation of adequate gains, which minimize the error of system. The condition of every plant is generally changed as time gose. That is, the initial gains obtained through the analysis of system are no longer suitable for the changed plant. And we need to set new gains, which minimize the error stemmed from changing the condition of a plant. In this paper, we applied this strategy for reactor control of nuclear power plant (NPP), and the results were compared with those of a simple PI controller, which has fixed gains. As a result, it was shown that the proposed algorithm was superior to the simple PI controller.

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Propositions of the Ductility Reduction Factor for Estimating Inelastic Displacement Responses of Bridge Structures (교량구조물의 비탄성변위응답 평가를 위한 연성도감소계수 산정식 제안)

  • Song, Jong-Keol;Kim, Hak-Soo
    • Journal of Industrial Technology
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    • v.26 no.A
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    • pp.153-161
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    • 2006
  • The main objective of this study was to derive a formula of ductility reduction factor, expressed as $R_{\mu}$. To attain this objective, a study comprised reduction factors computed for stiffness degrading systems undergoing different levels of ductility and to investigate an accuracy of the formula. Based on this study, the main conclusions can be summarized :(1) The ductility reduction factor is primarily affected by the period of the system and the displacement ductility ratio. (2) The proposed formula is simpler and the inelastic deformations of bridge structures are better than those by the others formulas we used before.

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Design Optimization of an Impingement Jet on Concave Surface for Enhancement of Heat Transfer Performance (곡면에서의 열전달성능 향상을 위한 충돌제트의 최적설계)

  • Heo, M.W.;Lee, K.D.;Kim, K.Y.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.100-103
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    • 2011
  • In the present work, a numerical study of fluid flow and heat transfer on the concave surface with impinging jet has been performed by solving three-dimensional Reynods-averaged Naver-Stokes(RANS) equations. The constant temperature condition was applied to the concave impingement surface. The inclination angle of jet nozzle and the distance between jet nozzles are chosen as design variables under equivalent mass flow rate of working fluid into cooling channel, and area averaged Nusselt number on concave impingement surface is set as the objective function. Thirteen training points are obtained by Latin Hypercube sampling method, and the PEA model is constructed by using the objective function values at the trainging points. And, the sequential quadratic programming is used to search for the optimal paint from the PBA model. Through the optimization, the optimal shape shows improved heat transfer rate as compared to the reference geometry.

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Development of Core Technology for Object Detection in Excavation Work Using Laser Sensor (레이저 센서를 이용한 굴삭기 작업의 장애물 탐지 요소기술 개발)

  • Soh, Ji-Yune;Kim, Min-Woong;Lee, Jun-Bok;Han, Choong-Hee
    • Journal of the Korea Institute of Building Construction
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    • v.8 no.4
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    • pp.71-77
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    • 2008
  • Earthwork is very equipment-intensive task and researches related to automated excavation have been conducted. There is an issue to secure the safety for an automated excavating system. Therefore, this paper focuses on how to improve safety for semi- or fully-automated backhoe excavation. The primary objective of this research is to develop the core technology for automated object detection in excavation work. In order to satisfy the research objective, a diverse sensing technologies are investigated and analysed in terms of functions, durability, and reliability. The authors developed detecting algorithm for the objects using laser sensor and verified its performance by several tests. The results of this study would be the basis for developing the automated object detection system.

The Multi-objective Optimization of Switched Reluctance Motor (스위치드 릴럭턴스 전동기의 다중목적함수의 최적화 방법 연구)

  • Choi, Jae-Hak;Shin, Hyun-Hun;Lim, Jin-Jae;Lee, Ju;Lee, Jung-Ho;Baek, Soo-Hyun
    • Proceedings of the KIEE Conference
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    • 2002.11d
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    • pp.118-120
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    • 2002
  • In this paper, a multi-object optimization based on a progressive quadratic response surface method (PQRSM) and a time stepping finite element method (FEM) is proposed. The new PQRSM and FEM are able to decide optimal geometric and electric variables of the switched reluctance motor (SRM) with two objective functions: torque ripple minimization and average torque maximization. The result of the optimum design for SRM show an improved performance of motor and a relationship between torque ripple and average torque.

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Evaluation of Clinical Competence in Plastic Surgery using OSCE(Objective Structured Clinical Examination): 3-Year Experience (객관구조화진료시험을 이용한 성형외과학 진료능력평가: 3년간의 경험)

  • Hwang, Kun;Lee, Se Il
    • Archives of Plastic Surgery
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    • v.32 no.6
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    • pp.675-682
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    • 2005
  • This is the evaluation report of clinical competence of undergraduate medical students in Plastic Surgery field using OSCE(Objective Structured Clinical Examination) executed in three years. OSCE comprises of assessment of subject, choice of clinical stations sampling, identification of components of clinical competence to be evaluated, the level of performance required, development of specification table, editing of OSCE presentation page and assessment of practicability and results exploitation. About fifty students were examined annually. Seven station stimuli with simulated patient participation were carried out. The mean OSCE score was $82.3{\pm}6.19$. The reliability of the total station was 0.72. The examination shows a positive response to the OSCE. Our experience shows OSCE's feasibility for Plastic Surgery during the initial course of education. Referring to our experiences, the Korean Society of Plastic and Reconstructive Surgeons (KPRS) applied the OSCE test for Korean Plastic Surgery Board Certification

An Investigation of the Mount Design of Engine Power System in Vehicles (차량 엔진동력계의 마운트 설계에 관한 연구)

  • 박노길
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.1
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    • pp.36-54
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    • 1996
  • This paper presents a design procedure of engine power system for vehicle. The implementation and operation environment of engine plant is somewhat diversed through the various kind of vehicles. Regarding this point, we adopt a multi-purposed design objective function which can be easily modified to reflect diverse mount design rules which have been recommended and used generally by relating fields. To search the mount parameters which provide the optimal performance, a direct search method based on an orthogonal array is developed and applied. Through several simulated results, the effectiveness of the developed disign tool is investigated and discussed.

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