• 제목/요약/키워드: Parametric Study

검색결과 3,721건 처리시간 0.032초

AHP & 모수추정법을 이용한 차기 다련장로켓의 비용대 효과분석 (A Study on the Analysis of the Cost-Effectiveness for the New Generation Multiple Launcher Rocket System Using AHP & Parametric Estimating)

  • 조기홍
    • 한국군사과학기술학회지
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    • 제13권1호
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    • pp.84-90
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    • 2010
  • Korean army currently considers the development of the new generation MLRS(Multiple Launcher Rocket System) as a new alternative, which responses on the renovation of the artillery and future battlefield environment. This study suggests that it presents cost-effectiveness of MLRS based on the Analytic Hierarchy Process and Parametric Estimating(PRICE H). According to this study, the cost-effectiveness of new generation MLRS presented that alternative A is 2.30 times and alternative B is 1.70 times, which are better than currently operating M270A1. Therefore, The best acquisition is alternative A that launcher is carried on currently operating 10ton standard truck but final acquisition alternative should be politically decided to consider viability of operator, performance and the latest of equipment.

섬유강화 복합재료, 고분자 포움 및 레진 콘크리트로 구성된 샌드위치 구조 설계를 위한 파라메트릭 연구 (Parametric study on design of sandwich structures composing of fibre reinfoced composites, polymer foam and resin concrete)

  • 김대일;장승환
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2005년도 춘계학술대회 논문집
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    • pp.429-434
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    • 2005
  • In this paper sandwich structures like beams and plates are optimised by using parametric study. The structures are composed of fibre reinforced composites for facial material and resin concrete and PVC foam for core materials. The stacking sequences and thickness of the composites are controlled as major parameters to find out the optimal condition for machine tool components. For the plate structure for machine tool bed composites-skined sandwich structure which has several ribs are proposed to enhance both directional bending stiffnesses at the same time. From the results optimal configuration and materials for high precesion machine tools are proposed.

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접속부의 강성완화를 위한 Approach zone의 매개분석 (Approach zone of parametric analysis for hardness mitigation of connection)

  • 손지현;최진유;오지택;황원섭
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2006년도 추계학술대회 논문집
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    • pp.558-564
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    • 2006
  • When vehicles pass the connection between the bridge and earthwork, the difference of both sections' stiffness produces an increasing wheelload. As a consequence, it results in the excessive vibration of vehicles and the damage of bearing system. In general, steel plate girder railway bridges without ballast track have larger stiffness than the bridge with ballast, and produces larger impulse on the bridge superstructure. Thus, it is necessary to reduce the differences of both stiffness. This study presents parametric studies on the behavior of plate girder bridges and their tracks by means of various stiffnesses and the length of approach zone. The results of numerical study showed that the smaller the stiffness of both sides and the longer the length of approach zone, the variation of wheelload becomes smaller. Hence, it gives less burden into the plate girder bridges and their tracks. It is expected that the results of parametric study can be used as a preliminary data for the determination of economical length on the approach zone and the stiffness of both sides.

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결합된 파라메트릭 활성함수를 이용한 완전연결신경망의 성능 향상 (Performance Improvement Method of Fully Connected Neural Network Using Combined Parametric Activation Functions)

  • 고영민;이붕항;고선우
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제11권1호
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    • pp.1-10
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    • 2022
  • 완전연결신경망은 다양한 문제를 해결하는데 널리 사용되고 있다. 완전연결신경망에서 비선형활성함수는 선형변환 값을 비선형 변환하여 출력하는 함수로써 비선형 문제를 해결하는데 중요한 역할을 하며 다양한 비선형활성함수들이 연구되었다. 본 연구에서는 완전연결신경망의 성능을 향상시킬 수 있는 결합된 파라메트릭 활성함수를 제안한다. 결합된 파라메트릭 활성함수는 간단히 파라메트릭 활성함수들을 더함으로써 만들어낼 수 있다. 파라메트릭 활성함수는 입력데이터에 따라 활성함수의 크기와 위치를 변환시키는 파라미터를 도입하여 손실함수를 최소화하는 방향으로 최적화할 수 있는 함수이다. 파라메트릭 활성함수들을 결합함으로써 더욱 다양한 비선형간격을 만들어낼 수 있으며 손실함수를 최소화하는 방향으로 파라메트릭 활성함수들의 파라미터를 최적화할 수 있다. MNIST 분류문제와 Fashion MNIST 분류문제를 통하여 결합된 파라메트릭 활성함수의 성능을 실험하였고 그 결과 기존에 사용되는 비선형활성함수, 파라메트릭 활성함수보다 우수한 성능을 가짐을 확인하였다.

피스톤 타입 조파기의 형상 매개변수에 대한 조파성능 연구 (A Parametric Study of the Wave-Generation Performance of a Piston-Type Wave Maker)

  • 권도수;김성재;구원철
    • 한국해양공학회지
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    • 제33권6호
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    • pp.504-509
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    • 2019
  • The wave-generation performance of a piston-type wave maker was analyzed using the numerical wave tank technique, and the numerical results were compared with theoretical solutions. A two-dimensional frequency domain analysis was conducted based on the Rankine panel method. Various parameters were used to examine the wave-generation performance, such as the width and gap of the wave board. The effects of the thickness of the wave board and of the gap from the bottom of the tank were evaluated. The difference in the amplitude of the generated wave between the analytical solution and the numerical result was examined, and its causes were addressed due to the gap flow between the bottom of the tank and the wave board. This parametric analysis can be utilized to design an optimum wave make parametric analysis to design an optimum wave maker that can generate waves with amplitudes that can be predicted accurately.

매개변수 종속 최적화에서 최대치형 목적함수 처리에 관한 연구 (A study on the treatment of a max-value cost function in parametric optimization)

  • 김민수;최동훈
    • 대한기계학회논문집A
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    • 제21권10호
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    • pp.1561-1570
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    • 1997
  • This study explores the treatment of the max-value cost function over a parameter interval in parametric optimization. To avoid the computational burden of the transformation treatment using an artificial variable, a direct treatment of the original max-value cost function is proposed. It is theoretically shown that the transformation treatment results in demanding an additional equality constraint of dual variables as a part of the Kuhn-Tucker necessary conditions. Also, it is demonstrated that the usability and feasibility conditions on the search direction of the transformation treatment retard convergence rate. To investigate numerical performances of both treatments, typical optimization algorithms in ADS are employed to solve a min-max steady-state response optimization. All the algorithm tested reveal that the suggested direct treatment is more efficient and stable than the transformation treatment. Also, the better performing of the direct treatment over the transformation treatment is clearly shown by constrasting the convergence paths in the design space of the sample problem. Six min-max transient response optimization problems are also solved by using both treatments, and the comparisons of the results confirm that the performances of the direct treatment is better than those of the tranformation treatment.

상용 CFD 코드에서 사용되는 촤 반응속도 모델에 대한 이해 (Understanding the Use of Coal Char Kinetic Models in commercial CFD Codes)

  • 김대희;최상민
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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    • pp.91-94
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    • 2013
  • Commercial computational fluid dynamics (CFD) codes traditionally rely on the computational efficiency of the simplified single-film apparent char kinetic model to predict char particle temperatures and char conversion rates in pulverized coal boilers. The aim of this study is to evaluate the reliability of the single-film apparent kinetic model and to suggest the importance of proper use of this model. For this, a parametric study was conducted with a consideration of main parameters such as Stefan flow, product species, particle evolution, and kinetic parameters.

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수질자료의 추세분석을 위한 비모수적 통계검정에 관한 연구 (A Study of Non-parametric Statistical Tests to Analyze Trend in Water Quality Data)

  • 이상훈
    • 환경영향평가
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    • 제4권2호
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    • pp.93-103
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    • 1995
  • This study was carried out to suggest the best statistical test to analyze the trend in monthly water quality data. Traditional parametric tests such as t-test and regression analysis are based on the assumption that the underlying population has a normal distribution and regression analysis additionally assumes that residual errors are independent. Analyzing 9-years monthly COD data collected at Paldang in Han River, the underlying population was found to be neither normal nor independent. Therefore parametric tests are invalid for trend detection. Four Kinds of nonparametric statistical tests, such as Run Test, Daniel test, Mann-Kendall test, and Time Series Residual Analysis were applied to analyze the trend in the COD data, Daniel test and Mann-Kendall test indicated upward trend in COD data. The best nonparametric test was suggested to be Daniel test, which is simple in computation and easy to understand the intuitive meaning.

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