• Title/Summary/Keyword: Engineering subject

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Analysis of Research Trend by Technical Field of Construction Management Using Subject Classification Code (주제분류코드에 의한 국내외 건설사업관리(CM) 기술 분야별 연구 현황분석)

  • Kang, Leen-Seok;Park, Ho-Byung;Kim, Min-Ji;Moon, Hyoun-Seok
    • Korean Journal of Construction Engineering and Management
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    • v.11 no.1
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    • pp.48-58
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    • 2010
  • Recently, the application of construction management system is being increased and various research activities by each specific field are going on many universities and research institutes. It is necessary to understand the latest research trends by each subject for keeping up excellent products in CM field. This study suggests a subject breakdown structure for classifying detailed technologies of CM field. And over 2,000 domestic and international papers in the last five years are analyzed for analogizing research trends by each subject. The analyzed results include research trends by year and strong and weak fields by each research subject of CM technology. Finally, this study suggests an improved countermeasure for guaranteeing sustainable research activation in CM field.

A Study on the Selection of Candidates for Substances Subject to Permission Using Chemicals Ranking and Scoring (CRS) (화학물질 우선순위 선정기법(CRS)을 활용한 허가대상 후보물질 선정 연구)

  • Kim, Hyo-dong;Park, Kyo-shik
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.32 no.3
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    • pp.253-267
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    • 2022
  • Objectives: This study was performed to check whether the CRS (Chemical Ranking and Scoring) system is appropriate as a method to determine substances as candidates for substances subject to permission and to apply this system to the selection of candidates for substances subject to permission. Methods: A risk score was obtained by multiplying the hazard score and the exposure score and then ranking them. The hazard sub-indicators are carcinogenicity, germ cell mutagenicity, reproductive toxicity, specific target organ toxicity-repeated exposure, respiratory sensitization and endocrine disrupting chemicals. Exposure sub-indicators are persistence, bioaccumulation and emission volume. Sensitivity analysis was performed for missing values. Correlation analysis and multivariable linear regression analysis were performed among hazard, exposure and risk in order to confirm that CRS was an appropriate method. Results: As a result of the sensitivity analysis on missing values, it was confirmed that the effect on the risk ranking was not sensitive. Correlation and regression analysis confirmed that exposure had a greater effect on risk than hazard. Conclusions: The CRS system, which derives a risk score using a hazard and exposure score, is judged to be appropriate as a method for the selection of preliminary of candidates for substances subject to permission. Benzene, cadmium, nickel, and cobalt were selected as priority candidates for substances subject to permission.

Generalized Control Procedure for a Process Subject to Linear Shift

  • Kim, Hang Rae;Jang, Joong Soon
    • Journal of Korean Society for Quality Management
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    • v.12 no.2
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    • pp.6-10
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    • 1984
  • A model for obtaining optimal resetting period and optimal target value of the process quality level is proposed when the quality characteristic is subject to a linear shift in mean. Different sales conditions are considered where good items can he sold at a regular price and bad items at a discounted one. Some numerical examples are also given.

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Predictive Control of Structural Vibration Subject to Wind Loads (풍하중에 대한 구조진동의 예측제어)

  • 최창근;권대건;이은진
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1996.10a
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    • pp.29-36
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    • 1996
  • A procedure for the predictive control for structural vibration control in building subject to wind loads is presented. The building motions are modeled by the first mode of the response. Wind velocities are generated by the simulation using power spectral density function. Predictive control algorithm is the discrete-time formulation and that is developed as a control strategy that computes the control signal which makes the predicted process output equal to a desired process output. Results on the reduction of the dynamic response and control effectiveness of the algorithm are presented and discussed.

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Base Acceleration Feedforward Control For An Active Magnetic Bearing System Subject To Base Motion (베이스 가진을 받는 전자기 베어링계의 베이스 가속도 피드포워드 제어)

  • Kang, Min-Sig
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.399.2-399
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    • 2002
  • This paper concerns on a non-rotating single-DOF beam-active magnetic bearing(AMB) system subject to arbitrary shaped base motion. In such a system, it is desirable to retain the beam within the predetermined air-gap under foundation excitation. Motivated form this, an adaptive acceleration feedforward control is proposed to reduce the base motion response without deteriorating other feedback control performances. Experimental results demonstrate the effectiveness of the acceleration feedforward control.

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Large-sample comparisons of calibration procedures when both measurements are subject to error

  • Lee, Seung-Hoon;Yum, Bong-Jin
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1990.04a
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    • pp.254-262
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    • 1990
  • A predictive functional relationship model is presented for the calibration problem in which the standard as well as the nonstandard measurements are subject to error. For the estimation of the relationship between the two measurements, the ordinary least squares and maximum likelihood estimation methods are considered, while for the prediction of unknown standard measurementswe consider direct and inverse approaches. Relative performances of those calibration procedures are compared in terms of the asymptotic mean square error of prediction.

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Optimal Replacement Policy for a System Subject to Shocks

  • Park, Byung Chun;Jang, Joong Soon
    • Journal of Korean Society for Quality Management
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    • v.13 no.1
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    • pp.51-55
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    • 1985
  • A replacement policy for a system subject to shocks where each shock increases the running cost is considered. The shocks arrive to the system according to a nonhomogeneous Poisson process. Optimal replacement policy to minimize the long-run expected cost rate is obtained and some numerical examples are given.

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An analytical Study on the Elasto-Plastic Behaviour of Steel Structure Member & Frame under Cyclic Load (반복 하중을 받는 강 구조 부재 및 골조의 탄소성 성상에 관한 해석적 연구)

  • 김화중;권영환;박정민
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1992.10a
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    • pp.52-57
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    • 1992
  • The purpose of this study is that to develop computer program, which is about to analy size nonlinear behaviour of elastic framed structures include to geometric & material nonlineality, and to formulate between stress-strain relationship. In order to examplity the efficiency of this program, a few analytical results have been obtained on : (1) nonlinear behaviour of beam which is subject to vertical force (2) nonlinear behaviour of portal frame which is subject to vertical & horizontal force.

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A Study of Variables and Subject to the Restrictions using the Program of Simplex Method (단체법중 프로그램을 이용한 변수와 제약조건에 관한 연구)

  • 고용해
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.3 no.3
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    • pp.49-53
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    • 1980
  • Computer program about the simplex method -one of the most popularity used linear programming- has been studied. Variable and subject to the restriction are growing according to the growing of all of the problem. In this paper, the problem that can be solved by simplex method may be processed with enormous block unit ( $50\;{\times};\50$ ). Because of using computer all of the problem can be solved more accurately and quickly. In appendix, computer program and running example are recorded.

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Analysis of the Muscular Force on the Swing Using Soft Golf Club (소프트 골프 클럽을 이용한 스윙 시 근력 분석)

  • Kim K.;Choi H.Y.;Eun H.I.;Lee S.C.;No B.H.;Kwon T.K.;Hong C.U.;Kim N.G.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.903-906
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    • 2005
  • The purpose of this study was to analyze the muscular force of swing using the soft golf club in comparison with the muscular force of swing using normal golf club. The subject was normal adult (twenties) and performed swing motion using normal and soft golf club. And then we compared muscular power soft golf club with normal golf club of the subject. The muscular power of the subject was measured by MP 100(BIOPAC Systems, Inc.). For the analysis of muscular power of swing using soft golf club, we measured EMG(Electromyography) of the subject. The position of muscle was deltoid, latissimus dorsi, external oblique and rectus abdominis of the upper limbs and rectus femoris, biceps femoris, gastrocnemius and soleus of the lower limbs. The result of experiment, muscle pattern of swing using soft golf club was similar to pattern of swing using normal golf club and muscular power of subjects using the soft golf was smaller than normal golf.

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