• 제목/요약/키워드: Parameter study

검색결과 9,846건 처리시간 0.043초

Random Parameter를 이용한 4지 신호교차로에서의 교통사고 예측모형 개발 : 부산광역시를 대상으로 (A Development of Traffic Accident Models at 4-legged Signalized Intersections using Random Parameter : A Case of Busan Metropolitan City)

  • 박민호;이동민;윤천주;김영록
    • 한국도로학회논문집
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    • 제17권6호
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    • pp.65-73
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    • 2015
  • PURPOSES : This study tries to develop the accident models of 4-legged signalized intersections in Busan Metropolitan city with random parameter in count model to understanding the factors mainly influencing on accident frequencies. METHODS : To develop the traffic accidents modeling, this study uses RP(random parameter) negative binomial model which enables to take account of heterogeneity in data. By using RP model, each intersection's specific geometry characteristics were considered. RESULTS : By comparing the both FP(fixed parameter) and RP modeling, it was confirmed the RP model has a little higher explanation power than the FP model. Out of 17 statistically significant variables, 4 variables including traffic volumes on minor roads, pedestrian crossing on major roads, and distance of pedestrian crossing on major/minor roads are derived as having random parameters. In addition, the marginal effect and elasticity of variables are analyzed to understand the variables'impact on the likelihood of accident occurrences. CONCLUSIONS : This study shows that the uses of RP is better fitted to the accident data since each observations'specific characteristics could be considered. Thus, the methods which could consider the heterogeneity of data is recommended to analyze the relationship between accidents and affecting factors(for example, traffic safety facilities or geometrics in signalized 4-legged intersections).

쉴드 TBM 터널의 gap parameter와 뒤채움재를 고려한 수치모델링 방법에 대한 연구 (A study on numerical modeling method considering gap parameter and backfill grouting of the shield TBM tunnel)

  • 유광호;김영진
    • 한국터널지하공간학회 논문집
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    • 제19권5호
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    • pp.799-812
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    • 2017
  • 쉴드 TBM 터널에 대한 2차원 수치해석 시 기존 연구에서는 뒤채움재 및 실제적인 내공변위 분포를 적절히 고려하지 않았다. 따라서 본 연구에서는 이를 보완하고자 gap parameter 적용 시 굴착면에서 발생하는 실제적인 내공변위분포를 고려하고, 적정한 뒤채움재 물성치를 적용한 모델링 방법을 제시하였다. 이를 위해 단일층 풍화토 지반을 대상으로 gap parameter와 토피고가 굴착면의 지반손실량과 지표손실량으로 구성되는 체적손실량에 미치는 영향을 분석하였다. 그 결과 대부분의 지표침하가 굴착 직후에 발생하였으며, 토피고 및 gap parameter가 증가할수록 수치해석을 통해 얻은 지표침하곡선의 영향범위가 제안된 이론식보다 넓게 나타났다. 따라서 2차원 수치해석 시 쉴드 TBM 터널의 거동을 정확히 평가하기 위해서는 하중분담률을 이용하여 gap parameter를 적용하고, 뒤채움재의 물성치도 적절히 고려해야 한다고 판단된다.

이항변수방법을 사용한 단일방향 적층복합재의 전단모드 에너지방출률 계산 (Calculation of $G_1$ for unidirectional laminated composites by using the two parameter technique)

  • 이경엽
    • 대한기계학회논문집A
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    • 제21권1호
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    • pp.164-172
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    • 1997
  • Two parameter technique that uses far-field stress and displacement distributions was applied to composite laminates in order to calculate mode II energy release rate, $G_{II}$ . The $G_{II}$ calculated by two parameter technique was compared with that calculated from the crack closure method to inspect the effectiveness of two parameter technique. Sensitivity study of two parameter technique to the crack extension size was also performed. The results showed that both methods produced comparable $G_{II}$ results. In particular, it was found that although the crack closure method was affected by the crack extension size, the two parameter technique was less affected by the crack extension size.

접촉피로 파라미터의 개발 (Development of Fretting Fatigue Parameter)

  • 이혁재
    • 한국군사과학기술학회지
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    • 제14권1호
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    • pp.92-99
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    • 2011
  • In this study, new multi-axial, critical plane based, fretting fatigue crack initiation parameter is developed by the addition of a new term into the Modified Shear Stress Range(MSSR) parameter. The newly developed parameter (MSSR') is then used to evaluate fretting fatigue life of titanium alloy, Ti-6A1-4V with various contact conditions. Finite element analysis is also used in order to obtain stress distribution on the contact surface during fretting fatigue test, which is then used for the calculation of fretting fatigue parameter. The MSSR' parameter shows better performance in predicting fretting fatigue lives from the conventional fatigue data, and less scattering within fretting fatigue data with different contact geometries.

성인의 제2 언어 습득에 있어서 매개변수 재고정 (Parameter resetting in adult second language acquisition)

  • 김학수
    • 영어어문교육
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    • 제5호
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    • pp.219-247
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    • 1999
  • The purpose of this paper is to examine how Korean learners of English reset the "prodrop" parameter of Korean into "non-prodrop" parameter of English in the process of English acquisition. An experiment was conducted to 45 Korean learners of English on the prodrop phenomenon, namely on the null referential or null nonreferential subject, and subject-verb agreement by way of grammatical judgment. The results of the experiment are as follows: First, L2 learners follow the parameter of L1, and then reset the parameter of L2 regardless of the parameter of L1 as their L2 abilities advance. Thus, this study provides further support for the hypothesis that universal grammar is available via L1. Second, the referential subject is, at first, easier to acquire than nonreferential subject, and the triggering fact for the switch from [+prodrop] to [-prodrop] was the use of nonreferential subjects. Third, 3rd person agreement has no connection with the acquisition of the prodrop parameter as a result of subject-verb agreement. Therefore, these results indicate that verb agreement is not a trigger for the recognition of the obligatory subject.

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Design and behavior of two profiles for structural performance of composite structure: A fluid interaction

  • Thobiani, Faisal Al;Hussain, Muzamal;Khadimallah, Mohamed Amine;Ghandourah, Emad;Alhawsawi, Abdulsalam;Alshoaibi, Adil
    • Steel and Composite Structures
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    • 제43권2호
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    • pp.221-228
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    • 2022
  • Two-dimensional stagnation point slip flow of a Casson fluid impinging normally on a flat linearly shrinking surface is considered. The modeled PDEs are changed into nonlinear ODEs through appropriate nonlinear transformations.The flow is assumed to be steady and incompressible, with external magnetic field acting on it. Similarity transformation is utilized to investigate the behavior of many parameters for heat and velocity distributions using truncation approach.The influence of buoyancy parameter, slip parameter, shrinking parameter, Casson fluid parameter on the heat profile. The effect of the magnetic parameter on the streamwise velocity profile is also investigated.

콘크리트 레올로지 정수와 Wet Sieving 모르타르 레올로지 정수의 상관관계 분석 (Correlation Analysis between the Rheology Parameters of Concrete and the Rheological Parameters of Wet Sieving Mortar )

  • 김인태;이유정;한동엽
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2023년도 봄 학술논문 발표대회
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    • pp.103-104
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    • 2023
  • In this study, the correlation between the rheolog y parameter of fresh concrete and the rheology parameter of wet sieving mortar was analyzed for analyzing to possibility predicting the rheology parameter of fresh concrete. Through the experiment, the dynamic yield stress and plastic viscosity of concrete and wet sieving mortar show a direct proportional relationship, and the two data had a correlation. Therefore, it is thought that it is possible to predict the rheology parameter of fresh concrete through the rheology parameter of wet sieving mortar. However, in order to more accurately predict the rheology parameter of fresh concrete, it is need additional relationship analysis by collecting more rheology parameter data of fresh concrete and wet sieving mortar.

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신경회로망을 이용한 대지파라미터와 대지저항률 해석 알고리즘 (An Estimation Algorithm for the Earth Parameter and Resistivity using Artificial Neural Network)

  • 류보혁;김정훈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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    • pp.563-565
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    • 2005
  • In this study, a algorithm to estimate Equivalent earth resistivity and Earth parameter using Artificial Neural Network(ANN) was proposed. Structures of the soil are grouped by using SOM algorithm before estimation. Earth parameter and Equivalent earth resistivity are obtained by using BP algorithm. The effectiveness of the proposed algorithm was verified. In the case study. afterwards, the algorithm proposed in this study will be used in more applications and gained more reliability.

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파라메타 오차에 강인한 독립모달공간 제어기법에 대한 연구 (A Study on the Robust Controller in Independent Modal space for Parameter Errors)

  • 황재혁;김준수;박대성;박명호
    • 소음진동
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    • 제6권5호
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    • pp.595-605
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    • 1996
  • If the control force designed on the basis of the mathematical model with parameter errors is applied to control the actual system, the closed-loop performance of the actual system will be degraded depending on the degree of the errors, In this study, the effect of parameter errors on the robustness of several natural controls has been analyzed and compared. Every asymptoic stability condition for the natural controls has been derived using Lyapunov approach, and the characteristics of the stability conditions has also been compared. The extent of deviation of the closed-loop performance from the designed one for the natural controls is derived using operator techniques, and evaluated by numerical method. It has been found that the optimal control, acceleration feedback control, and acceleration-position feedback control among the considered natural controls would be robust one with respect to the parameter errors.

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지표면의 특성을 고려한 대기경계층내의 열수지 parameter 추정 -열수지 parameter를 이용한 중규모 순환의 수치예측- (Estimation of the Heat Budget Parameter in the Atmospheric Boundary Layer considering the Characteristics of Soil Surface)

  • 이화운;정유근
    • 한국환경과학회지
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    • 제5권6호
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    • pp.727-738
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    • 1996
  • An one dimensional atmosphere-canopy-soil interaction model is developed to estimate of the heat budget parameter in the atmospheric boundary layer. The canopy model is composed of the three balance equations of energy, temperature, moisture at ground surface and canopy layer with three independent variables of Tf(foliage temperature), Tg(ground temperature), and qg(ground specific humidity). The model was verilied by comparative study with OSUID(Oregon State University One Dimensional Model) proved in HAPEX-MOBILHY experiment. Also we applied this model in two dimensional land-sea breeze circulation. According to the results of this study, surface characteristics considering canopy acted importantly upon the simulation of meso-scale circulation. The factors which used in the numerical experiment are as follows ; the change for a sort of soil(sand and peat), the change for shielding factor, and the change for a kind of vegetation.

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