• Title, Summary, Keyword: Objective analysis

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Multi-objective Optimization of a Laidback Fan Shaped Film-Cooling Hole Using Evolutionary Algorithm

  • Lee, Ki-Don;Husain, Afzal;Kim, Kwang-Yong
    • International Journal of Fluid Machinery and Systems
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    • v.3 no.2
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    • pp.150-159
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    • 2010
  • Laidback fan shaped film-cooling hole is formulated numerically and optimized with the help of three-dimensional numerical analysis, surrogate methods, and the multi-objective evolutionary algorithm. As Pareto optimal front produces a set of optimal solutions, the trends of objective functions with design variables are predicted by hybrid multi-objective evolutionary algorithm. The problem is defined by four geometric design variables, the injection angle of the hole, the lateral expansion angle of the diffuser, the forward expansion angle of the hole, and the ratio of the length to the diameter of the hole, to maximize the film-cooling effectiveness compromising with the aerodynamic loss. The objective function values are numerically evaluated through Reynolds- averaged Navier-Stokes analysis at the designs that are selected through the Latin hypercube sampling method. Using these numerical simulation results, the Response Surface Approximation model are constructed for each objective function and a hybrid multi-objective evolutionary algorithm is applied to obtain the Pareto optimal front. The clustered points from Pareto optimal front were evaluated by flow analysis. These designs give enhanced objective function values in comparison with the experimental designs.

The Effect of Atmospheric Flow Field According to the Radius Influence and Nudging Coefficient of the Objective Analysis on Complex Area (자료동화의 영향반경과 동화강도가 복잡지형 기상장 수치모의에 미치는 영향)

  • Choi, Hyun-Jung;Lee, Hwa-Woon;Sung, Kyoung-Hee;Kim, Min-Jung
    • Journal of Environmental Science International
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    • v.18 no.3
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    • pp.271-281
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    • 2009
  • In order to reduce the uncertainties and improve the air flow field, objective analysis using observational data is chosen as a method that enhances the reality of meteorology. To improve the meteorological components, the radius influence and nudging coefficient of the objective analysis should perform a adequate value on complex area for the objective analysis technique which related to data reliability and error suppression. Several numerical experiments have been undertaken in order to clarify the impacts of the radius influence and nudging coefficient of the objective analysis on meteorological environments. By analyzing practical urban ground conditions, we revealed that there were large differences in the meteorological differences in each case. In order to understand the quantitative impact of each run, the Statistical analysis by estimated by MM5 revealed the differences by the synoptic conditions. The strengthening of the synoptic wind condition tends to be well estimated when using quite a wide radius influence and a small nudging coefficient. On the other hand, the weakening of the synoptic wind is opposite.

Design and Analysis of an Objective Lens for a Scanning Electron Microscope by Coupling FE Analysis and Ray Tracing (유한요소해석과 광선추적을 연계한 주사전자 현미경 대물렌즈의 설계 및 해석)

  • Park, Keun;Lee, Jae-Jin;Park, Man-Jin;Kim, Dong-Hwan;Jang, Dong-Young
    • Journal of the Korean Society for Precision Engineering
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    • v.26 no.11
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    • pp.92-98
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    • 2009
  • The scanning electron microscope (SEM) contains an electron optical system in which electrons are emitted and moved to form a focused beam, and generates secondary electrons from the specimen surfaces, eventually making an image. The electron optical system usually contains two condenser lenses and an objective lens. The condenser lenses generate a magnetic field that forces the electron beams to form crossovers at desired locations. The objective lens then focuses the electron beams on the specimen. The present study covers the design and analysis of an objective lens for a thermionic SEM. A finite element (FE) analysis for the objective lens is performed to analyze its magnetic characteristics for various lens designs. Relevant beam trajectories are also investigated by tracing the ray path of the electron beams under the magnetic fields inside the objective lens.

A Study on the Subjective Textures, Sensibilities and the Objective Handle of Knit Fabrics (니트 소재의 주관적 질감 및 감성과 객관적 태에 관한 연구)

  • Ju, Jeong-Ah;Ryu, Hyo-Seon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.1
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    • pp.83-93
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    • 2006
  • The purpose of this study is to analyze the relationship among subjective textures, sensibilities and objective handle of knit fabrics and to provide useful information in planning and designing knit fabrics. We made 20 plain knit fabrics, as specimens, with a combination of 5 kinds of wool/rayon fiber contents and 4 kinds of stitch loop length. For the subjective evaluation, we used 29 questions of subjective textures and sensibilities and employed statistical analysis tools such as factor, Pearson's correlation analysis. An objective handle was measured by Kawabata evaluation system and HV and THV was calculated by KN-402-KT and KN-301-winter. The analysis of a Pearson's correlation with objective properties and handles and structural properties of knit fabrics demonstrated a highly linear relationship. Especially, wool/rayon contents and WT of tensile properties and loop stitch length and G of shear properties showed a correlation coefficient over 0.9. But a relationship of objective properties and subjective textures and sensibilities was non-linear and a linear multi-regression analysis showed that a objective handle had a lower prediction power in the area of subjective textures and sensibilities.

Objective Bayesian inference based on upper record values from Rayleigh distribution

  • Seo, Jung In;Kim, Yongku
    • Communications for Statistical Applications and Methods
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    • v.25 no.4
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    • pp.411-430
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    • 2018
  • The Bayesian approach is a suitable alternative in constructing appropriate models for observed record values because the number of these values is small. This paper provides an objective Bayesian analysis method for upper record values arising from the Rayleigh distribution. For the objective Bayesian analysis, the Fisher information matrix for unknown parameters is derived in terms of the second derivative of the log-likelihood function by using Leibniz's rule; subsequently, objective priors are provided, resulting in proper posterior distributions. We examine if these priors are the PMPs. In a simulation study, inference results under the provided priors are compared through Monte Carlo simulations. Through real data analysis, we reveal a limitation of the appropriate confidence interval based on the maximum likelihood estimator for the scale parameter and evaluate the models under the provided priors.

The effect of child, adolescent period's father-child relationship on interpersonal problems among married women : The mediating role of impaired objective self and emotional regulation difficulties (어린 시절 부-자녀관계가 대인관계문제에 미치는 영향 : 대상적 자기손상과 정서조절곤란의 매개효과)

  • Lee, MunHee
    • 한국가족관계학회지
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    • v.23 no.1
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    • pp.97-120
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    • 2018
  • Objectives: The purpose of this study is to examine the process of how a parent-child relationship affects an impaired objective self, emotional regulation difficulties, and, consequently, interpersonal problems. Methods: To carry out this study, a total of 467 married women were surveyed on their parent-child relationship, impaired objective self, and emotional regulation difficulties. The resulting data was interpreted using descriptive statistics analysis, correlation analysis, and structural equation models analysis. Results: First, the parent-child relationship shows negative correlations with an impaired objective self, emotional regulation difficulties, and interpersonal problems. In addition, an impaired objective self, emotional regulation difficulties, and interpersonal problems show positive correlations with one another. Second, an impaired objective self and emotional regulation difficulties mediate the parent-child relationship and intrapersonal problems consecutively. Conclusions: This indicates that efforts to mitigate an impaired objective self and to intervene in difficulties in emotional regulation can help address intrapersonal difficulties. Finally, this paper examines how this study affects the ongoing discussion on this matter and its implications for future studies.

Multi-objective Optimization of Butterfly Valve using the Coupled-Field Analysis and the Statistical Method (연성해석과 통계적 방법을 이용한 Butterfly Valve의 다목적 최적설계)

  • 배인환;이동화;박영철
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.9
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    • pp.127-134
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    • 2004
  • It is difficult to have the existing structural optimization using coupled field analysis from CFD to structure analysis when the structure is influenced of fluid. Therefore in an initial model of this study after doing parameter design from the background of shape using topology optimization. and it is making a approximation formula using by the CFD-structure coupled-field analysis and design of experiment. By using this result, we conducted multi-objective optimization. We could confirm efficiency of stochastic method applicable in the scene of structure reliability design to be needed multi-objective optimization. And we presented a way of design that could overcome the time and space restriction in structural design such as the butterfly valve with the less experiment.

A Development of Inequality Constrained Algorithm and Applying to Power System Analysis (부등호 제약조건 처리 알고리즘 개발 및 전력계통 해석 적용)

  • Yang, Minuk;Kim, Kern-Joong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.10
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    • pp.1349-1353
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    • 2013
  • The optimal analysis has objective functions, equality constraint functions and inequality functions. Objective functions may be used with inequality function, because occasionally variables are moved to non-analytic condition with calculating objective functions. But inequality constraint functions are very complicated problem in a optimal analysis. this paper suggest a method to solve inequality constraint functions.

The Design & Effect Analysis of Project Objective Management Information System for National R&D cooperated by Industries, Universities and Government-supported research institutes (국가 산.학.연 협력 연구개발을 위한 과제목표관리 정보시스템의 설계 및 효과 분석)

  • Sohn, Kwon-Joong;Yoo, Wang-Jin;Lee, Cheol-Gyu
    • Journal of Technology Innovation
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    • v.16 no.1
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    • pp.107-139
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    • 2008
  • We studied how to achieve successful implementation of massive research and development projects requiring collaboration among industries, universities and government-supported research institute. We have set up an engineering process innovation model to be deemed most adequately for all practical purposes, relying on the theoretical studies on the merits and analysis of the effect of the information system based on Milestone Management, Work Breakdown Structures and Web, which is known to be effective for research project (schedule) management and the objective management, and implemented a real-world web-based project objective management system. After a review of various R & D Project Schedule Management methods, we found that this information system was very compatible with project objective management. This project objective management information system carries out research and development projects effectively and efficiently, getting together in cyber-space and sharing information, and has been equipped with an Early Warning Subsystem to allow for pre-analysis and timely response to potential problems arising from the course of the project. The system also contains an Executive Information System that in real time, automatically provides the management information required by managers with the rate of project progress (achievement, fulfillment and delay). Lastly, actual progress can be cross-checked through both on-line objective management on the web-based information system and design review meeting held on site, to improve the efficiency and validity of the information system. Moreover, overall effect was analyzed through questionnaires on how well the system and generated information meet requirements and on the ultimate impact of the system upon objective management and communication. The questionnaire on the system effect revealed that the information system was useful to objective management and communication, and that the quality of the system was more than acceptable as well.

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Application of multi-objective genetic algorithm for waste load allocation in a river basin (오염부하량 할당에 있어서 다목적 유전알고리즘의 적용 방법에 관한 연구)

  • Cho, Jae-Heon
    • Journal of Environmental Impact Assessment
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    • v.22 no.6
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    • pp.713-724
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    • 2013
  • In terms of waste load allocation, inequality of waste load discharge must be considered as well as economic aspects such as minimization of waste load abatement. The inequality of waste load discharge between areas was calculated with Gini coefficient and was included as one of the objective functions of the multi-objective waste load allocation. In the past, multi-objective functions were usually weighted and then transformed into a single objective optimization problem. Recently, however, due to the difficulties of applying weighting factors, multi-objective genetic algorithms (GA) that require only one execution for optimization is being developed. This study analyzes multi-objective waste load allocation using NSGA-II-aJG that applies Pareto-dominance theory and it's adaptation of jumping gene. A sensitivity analysis was conducted for the parameters that have significant influence on the solution of multi-objective GA such as population size, crossover probability, mutation probability, length of chromosome, jumping gene probability. Among the five aforementioned parameters, mutation probability turned out to be the most sensitive parameter towards the objective function of minimization of waste load abatement. Spacing and maximum spread are indexes that show the distribution and range of optimum solution, and these two values were the optimum or near optimal values for the selected parameter values to minimize waste load abatement.