• 제목/요약/키워드: definition of variables

검색결과 223건 처리시간 0.028초

사면안정 2차원해석과 토질정수에 관한 연구 (Study on Soil Parameters and Two Dimensional Analysis in Slope Stability)

  • 김경진;김규문;박일철
    • 기술사
    • /
    • 제18권3호
    • /
    • pp.21-27
    • /
    • 1985
  • Earthen mass located beneth a sloping group surface, whether natural or manmade, have a tendency to move downward and outward under the influence of gravity. Unless this tendency is suitably counteracted by the Shearing resistances within the mass, a landslide occurs. Avoiding such instabilities is a major concern of the geotechnical engineer. The shearing behavior of a soil is determined empirically, i.e., by field tests or laboratory tests. This results are applied to the slope stability analysis. The factor of safety for slope stability analysis is much more sensitive to the choice of strength parameters as interpreted from soil tests than to the choice of the computational method of analysis. This paper was investigated the influence of the change in the factor of safety due to a change in one of the parameters, relative to the total change in the factor of safety due to change in all parameters. A conclusion may be reached with respect to the required precision definition of the different variables to limit uncertainties in the factor of safety to tolerable levels.

  • PDF

반응 경로의 일의적 함수 (제 1 보). 정의 및 근사 (A Unique Function of Reaction Path (I). Definition and Approximation)

  • 김호징;장효원
    • 대한화학회지
    • /
    • 제32권2호
    • /
    • pp.94-102
    • /
    • 1988
  • principle of least motion의 정량적 표현을 제시하였다. potential energy surface상의 주어진 반응 경로에 대하여 전자 위치 변수의 함수, 그 함수의 norm과 반응 경로 평균 에너지를 일의적으로 정의하였고, 그들의 성질을 검토하였다. 함수의 norm과 평균 에너지를, 일분자 이성질체화 반응의 허용된 경로를 판별하는 척도로 사용할 수 있음을 제안하였다. 대칭성을 가진 분자에 대해서 계산하지 않고 허용된 경로를 판별하였으며 Woodward-Hoffmann 규칙의 적용과 같은 결과를 얻었다

  • PDF

성능이 서서히 저하되는 시스템의 신뢰도 척도 (Performance-Based Reliability Measures for Gracely Degrading Systems: the Concept)

  • Kim, Yon-Soo;Park, Sang-Min
    • 산업경영시스템학회지
    • /
    • 제17권32호
    • /
    • pp.227-232
    • /
    • 1994
  • In the performance domain, physical performance is a measure that represents some degree of system, subsystem, component or device success in a continuous sense, as opposed to a classical binomial sense (success or failure). If applicable sensing and monitoring means exist, physical performance can be observed over time, along with explanatory variables or covariables. Performance-based reliability represents the probability that performance will remain satisfactory over a finite period of time or usage cycles in the future when a performance critical limit (which represents an appropriate definition of failure in terms of performance) is set at a fixed level, based on application requirements. In the case of inadequate knowledge of the failure mechanics, this physical based empirical modeling concept along with performance degradation knowledge can serve as an important analysis tool in reliability work in product and process improvement.

  • PDF

등기하해석법을 이용한 자유진동 평면구조물의 위상최적화 (Topology Optimization of Plane Structures under Free Vibration with Isogeometric Analysis)

  • 이상진;배정은
    • 대한건축학회논문집:구조계
    • /
    • 제34권6호
    • /
    • pp.11-18
    • /
    • 2018
  • Isogeometric concept is introduced to find out the optimum layout of plane structure under free vibration. Eigenvalue problem is formulated and numerically solved in order to obtain natural frequencies and mode shapes of plane structures. For the exact geometric expression of the structure, the Non-Uniform Rational B-spline Surface (NURBS) basis functions is employed and it is also used to define the material density functions. A node-wise design variables is adopted to deal with the updating of material density in topology optimization (TO). The definition of modal strain energy is employed to achieve the maximization of fundamental frequency through its minimization. The verification of the proposed TO technique is performed by a series of benchmark test for plane structures.

RELATIONS OF DAGUM DISTRIBUTION BASED ON DUAL GENERALIZED ORDER STATISTICS

  • KUMAR, DEVENDRA
    • Journal of applied mathematics & informatics
    • /
    • 제35권5_6호
    • /
    • pp.477-493
    • /
    • 2017
  • The dual generalized order statistics is a unified model which contains the well known decreasingly ordered random variables like order statistics and lower record values. With this definition we give simple expressions for single and product moments of dual generalized order statistics from Dagum distribution. The results for order statistics and lower records are deduced from the relations derived and some computational works are also carried out. Further, a characterizing result of this distribution on using the conditional moment of the dual generalized order statistics is discussed. These recurrence relations enable computation of the means, variances and covariances of all order statistics for all sample sizes in a simple and efficient manner. By using these relations, we tabulate the means, variances, skewness and kurtosis of order statistics and record values of the Dagum distribution.

확률론적 기법을 이용한 시변 ATC 용량 결정 (Probabilistic approach to time varying Available Transfer Capability calculation)

  • 신동준;이준경;이효상;김진오;정현수
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2004년도 하계학술대회 논문집 A
    • /
    • pp.645-647
    • /
    • 2004
  • According to NERC definition, Available Transfer Capability (ATC) is a measure of the transfer capability remaining in the physical transmission network for the future commercial activity To calculate ATC, accurate and defensible TTC, CBM and TRM should be calculated in advance. This paper proposes a method to quantify time varying ATC based on probabilistic approach. The uncertainties of power system and market are considered as complex random variables. TRM with the desired probabilistic margin is calculated based on PLF analysis, and CBM is evaluated using LOLE of the system. Suggested ATC quantification method is verified using IEEE RTS with 72 bus. The proposed method shows efficiency and flexibility for the quantification of ATC.

  • PDF

다목적 최적화 방법을 이용한 구조설계 대안의 생성과 평가 (Generation and Evaluation of Structural Design Alternatives Using Multicriteria Optimization)

  • 양영순;유원선;김기화
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 1998년도 봄 학술발표회 논문집
    • /
    • pp.199-209
    • /
    • 1998
  • Since most engineering problems have had open-ended and ill-defined characteristics, design process is in advance attended with determination of alternatives based on realistic constraints after definition of appropriate problem. And it is completed with selection of best alternative through their comparison and investigation, and with performance of selected-alternative's detail design. As the process of structural design compared with that of general design, this paper presents a paradigm which can generate structural design alternatives, select optimum structure among them and simultaneously set its optimum design variables in reference of several objective as a result in more extended design region. For this purpose, specialized genetic algorithms which can handle design alternatives and multicriteria problems is used.

  • PDF

확률론적 조류계산을 이용한 송전 신뢰도 여유 계산 (Calculate Transmission Reliability Margin using Probabilistic Load Flow)

  • 신동준;김진오;김규호
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2003년도 하계학술대회 논문집 A
    • /
    • pp.569-571
    • /
    • 2003
  • As a definition of NERC, Available Transfer Capability(ATC) is a measure of the transfer capability remaining in the physical transmission network for the future commercial activity. To calculate ATC, accurate and defensible TTC, CBM and TRM should be calculated in advance. In this paper, we propose a method to quantify TRM using probabilistic load flow based on the method of moment. Generation output, bus voltages, loads, and line outages are considered as complex random variables (CRV) to take into account for uncertainties related to the transmission network conditions. Probability Density Function (PDF) of line flow at the most limiting line is used to quantify TRM with the desired probabilistic margin. Suggested method is compared with the results from conventional CPF method and verified using 24 bus MRTS, and the suggested method based on PLF shows efficiency and flexibility for the quantification of TRM compared with the conventional method.

  • PDF

박슬라브 주형에 따른 용강내의 상변화현상에 대한 수치적 해석 (Numerical Prediction of Phase Change within the Molten Steel with Thin Slab Casting)

  • 최원록;유홍선;최영기
    • 한국안전학회지
    • /
    • 제15권3호
    • /
    • pp.14-22
    • /
    • 2000
  • A numerical analysis has been performed on the two-dimensional rectangular gallium melting problem using the enthalpy method. The major advantage of this method is that the physical domain is discretized with fixed grids without transforming variables and the interface conditions of phase change are accounted for the definition of suitable source terms in the governing equations. But in the fixed method, there is some ambiguity in defining the porosity constant which has no physical interpretation. If the velocity correction is included in the momentum equation, for the appropriate range of porosity constant, the realistic predictions are obtained. The object of the present work is to predict the phase change within the molten steel with thin riser slab using the modified enthalpy-porosity method. The computational procedures for predicting velocity and temperature are based on the finite volume method and the non-staggered grid system. The influence of natural convection on the melting process is considered. A comparison with the experimental results shows that the modified method is better than the previous one.

  • PDF

중국관광객의 면세점 바오마이 결정요인에 대한 실증연구 (Determinants of BAOMAI of Chinese Customer in Duty-Free Shop: Analytical Framework and Empirical Analysis)

  • 임성훈;고숭;진가영
    • 무역학회지
    • /
    • 제45권5호
    • /
    • pp.201-222
    • /
    • 2020
  • This paper examines that determinants of BAOMAI, (i.e., behavior of Chinese tourist bulk purchase in duty free shop) with analytical framework and empirical tests. The results of applying the structural equation modeling to 196 samples suggest that Chinese tourist consumption orientations (conspicuous/compulsive/unplanned consumption) have a positive effect on BAOMAI decision value chain (perceived value and loyalty). The marketing mix of duty free shop as control variables in research framework also have a positive effect on BAOMAI perceived values (functional/social/emotional value). This paper has a contribution to prior literatures: the first empirical analysis on BAOMAI determinants with exploring scholarly definition.