• Title/Summary/Keyword: problem analysis

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Modeling and simulation of VERA core physics benchmark using OpenMC code

  • Abdullah O. Albugami;Abdullah S. Alomari;Abdullah I. Almarshad
    • Nuclear Engineering and Technology
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    • v.55 no.9
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    • pp.3388-3400
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    • 2023
  • Detailed analysis of the neutron pathway through matter inside the nuclear reactor core is exceedingly needed for safety and economic considerations. Due to the constant development of high-performance computing technologies, neutronics analysis using computer codes became more effective and efficient to perform sophisticated neutronics calculations. In this work, a commercial pressurized water reactor (PWR) presented by Virtual Environment for Reactor Applications (VERA) Core Physics Benchmark are modeled and simulated using a high-fidelity simulation of OpenMC code in terms of criticality and fuel pin power distribution. Various problems have been selected from VERA benchmark ranging from a simple two-dimension (2D) pin cell problem to a complex three dimension (3D) full core problem. The development of the code capabilities for reactor physics methods has been implemented to investigate the accuracy and performance of the OpenMC code against VERA SCALE codes. The results of OpenMC code exhibit excellent agreement with VERA results with maximum Root Mean Square Error (RMSE) values of less than 0.04% and 1.3% for the criticality eigenvalues and pin power distributions, respectively. This demonstrates the successful utilization of the OpenMC code as a simulation tool for a whole core analysis. Further works are undergoing on the accuracy of OpenMC simulations for the impact of different fuel types and burnup levels and the analysis of the transient behavior and coupled thermal hydraulic feedback.

A Conceptual Study of "Mai (脉)" in Gangpyeong-Shanghanlun Based on Comparative case analysis and Paleography (『강평상한론(康平傷寒論)』 맥(脉)에 관한 고찰: 임상 증례 분석 및 고문자학적 해석을 통하여)

  • Seong-hwan Cho;Hyun-yee Ha;Hyo-joong Yun;Jae-kyung Park;Joo Heo;Sung-jun Lee
    • 대한상한금궤의학회지
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    • v.15 no.1
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    • pp.1-52
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    • 2023
  • Objective : The objective of this study was to explore the meaning of Mai (脉) in the fifteen letters provisions of Gangpyeong-Shanghanlun through the comparative analysis of 10 cases and paleography. Methods : We have collected 10 cases that have been diagnosed and treated by Gangpyeong-Shanghanlun Mai (脉) provision. And then, comparative analysis has been done among those 10 cases. Based on result of case analysis, paleographic meaning of each Mai (脉) have been studied to redefine Gangpyeong-Shanghanlun Mai (脉)'s meaning. Results : After administration of Mai (脉) provision's herbal medicine, all 10 patients recovered their mobility problem and pain. From this result, we could fomulate the hypothesis that Mai (脉) in Gangpyeong-Shanghanlun could mean mobility problems. After through further paleography studies, we could elaborate each Mai (脉)'s clinical meaning and related diseases. Conclusions : Mai (脉) in Gangpyeong-Shanghanlun could mean mobility problems caused by various diseases, which include musculoskeletal pain, neuropathy, syncope, fatigue, developmental disability and major depressive disorder.

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Development and validation of transient analysis module in nodal diffusion code RAST-V with Kalinin-3 coolant transient benchmark

  • Jaerim Jang;Deokjung Lee
    • Nuclear Engineering and Technology
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    • v.56 no.6
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    • pp.2163-2173
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    • 2024
  • This study introduces a transient analysis module developed for RAST-V and validates it using the Kalinin-3 benchmark problem. For the benchmark analysis, RAST-V standalone and STREAM/RAST-V calculations were performed. STREAM supplies the few-group constants and RAST-V conducts a 3D core simulation utilizing few-group cross-sectional data. To improve accuracy, the main solver was developed based on the advanced semi-analytic nodal method. To evaluate the computational capability of the transient analysis module in RAST-V, Kalinin-3 benchmark is employed. Kalinin-3 represents a coolant transient benchmark that offers experimental data during the deactivation of the Main Circulation Pumps. Consequently, the transient calculations reflected the changes in the reactor flow rate. Benchmark comprising steady-state and transient calculations. During the steady state, the STREAM/RAST-V combination demonstrated a 30 ppm root mean square difference from 0 to 128.50 EFPD. For the transient calculations, STREAM/RAST-V showed power differences within ±7 % over a range of 0-300 s. Axial offset differences were within ±3 %, and the RMS difference in radial power ranged within 2.596 % at both 0 and 300 s. Overall, this study effectively demonstrated the newly developed transient solver in RAST-V and validated it using the Kalinin-3 benchmark problem.

Comparison of Spatial Optimization Techniques for Solving Visibility Location Problem (가시권 문제를 위한 공간최적화 기법 비교 연구)

  • Kim, Young-Hoon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.3
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    • pp.156-170
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    • 2006
  • Determining the best visibility positions on terrain surface has been one of the frequently used analytical issues in GIS visibility analysis and the search for a solution has been carried out effectively using spatial search techniques. However, the spatial search process provides operational and methodological challenges for finding computational algorithms suitable for solving the best visibility site problem. For this problem, current GIS visibility analysis has not been successful due to limited algorithmic structure and operational performance. To meet these challenges, this paper suggests four algorithms explored robust search techniques: an extensive iterative search technique; a conventional solution based on the Tornqvist algorithm; genetic algorithm; and simulated annealing technique. The solution performance of these algorithms is compared on a set of visibility location problems and the experiment results demonstrate the useful feasibility. Finally, this paper presents the potential applicability of the new spatial search techniques for GIS visibility analysis by which the new search algorithms are of particular useful for tackling extensive visibility optimization problems as the next GIS analysis tool.

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Analyses of Subject Competencies of the Units Related to Core Concept 'Relation' in Middle School Technology-Home Economics Textbooks based on 2015 Revised Curriculum (2015 개정 교육과정 중학교 기술·가정 교과서의 핵심개념 '관계' 단원에 구현된 교과역량 분석)

  • Kim, Soo Min;Yu, Nan Sook
    • Journal of Korean Home Economics Education Association
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    • v.31 no.2
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    • pp.1-18
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    • 2019
  • The purposes of this study were to develop analysis criteria and analyze the two subject competencies of units dealing with the core concept 'Relation' of the middle school Technology-Home Economics textbook in accordance with the 2015 revised curriculum: 'practical-problem-solving-ability' and 'relationship ability'. The subject of analysis of the current study was the activity assignment of Chapter 1 related to the core concept 'Relation', from the twelve middle school 'Technology-Home Economics II' textbooks. The results of this study were as follows: First, some textbooks showed differences in highlighting or downplaying the components of certain subject competencies. The analysis results for 'practical-problem-solving-ability' in textbook A, E, and G were shown in the high frequency, while in textbook D in the lowest frequency. The analysis results for 'relationship ability' in textbook K and A were shown in the high frequency, while in textbook J in the lowest frequency. Second, Value Judgement was the most frequent component of 'practical-problem-solving-ability' followed by Logical Thinking, Practical Reasoning, and Decision-Making. Family Relation and Sense of Community was the component of 'relationship ability' most frequently dealt with followed by Communication, Conflict Management, and Respecting Others, however Environmental and Ecological Awareness was not shown at all. The two subject competencies were mostly reflected in the Technology-Home Economics textbooks from all the twelve publishers.

Verification of Linear FE Model for Nonlinear SSI Analysis by Boundary Reaction Method (경계반력법에 의한 비선형 SSI 해석을 위한 선형 FE 해석모델 검증)

  • Lee, Gye Hee;Hong, Kwan Young;Lee, Eun Haeng;Kim, Jae Min
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.2
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    • pp.95-102
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    • 2014
  • In this paper, a coupling scheme for applying finite element analysis(FEA) programs, such as, LS-DYNA and MIDAS/Civil, to a nonlinear soil structure interaction analysis by the boundary reaction method(BRM) is presented. With the FEA programs, the structure and soil media are discretized by linear or nonlinear finite elements. To absorb the outgoing elastic waves to unbounded soil region as much as possible, the PML elements and viscous-spring elements are used at the outer FE boundary, in the LS-DYNA model and in MIDAS/Civil model, respectively. It is also assumed that all the nonlinear elements in the problem are limited to structural region. In this study, the boundary reaction forces for the use in the BRM are calculated using the KIESSI-3D program by solving soil-foundation interaction problem subjected to incident seismic waves. The effectiveness of the proposed approach is demonstrated with a linear SSI seismic analysis problem by comparing the BRM solution with the conventional SSI solution. Numerical comparison indicates that the BRM can effectively be applied to a nonlinear soil-structure analysis if motions at the foundation obtained by the BRM for a linear SSI problem excluding the nonlinear structure is conservative.

Brake Juder Analysis for Small Size Bus

  • Kim, Jin-soo;Suh, Eun-Suk
    • International Journal of Precision Engineering and Manufacturing
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    • v.2 no.2
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    • pp.31-37
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    • 2001
  • In this paper, a method to improve judder by changing the front and rear wheel brake force distribution ratio was proposed. ADAMS, a commercial dynamic analysis software was used to model a small size bus and its modeling procedure was explained. By using the ADAMS vehicle model, the judder phenomena of the small bus were analyzed, and based on analysis results, the validity of the improvement method was proposed. Also in order to lessen the problem jubber sensitivity analysis and test results were proposed.

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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.

UNSTEADY FLUID FIELD ANALYSIS OF STAGING SYSTEM (단분리 비정상 유동장의 수치적 해석)

  • Yoon Y. H.;Kwon K. B.;Hong S. K.
    • 한국전산유체공학회:학술대회논문집
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    • 2005.10a
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    • pp.261-267
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    • 2005
  • The unsteady flow analysis of staging system is conducted. This study focuses on comparing the results of two different governing equations between Euler equations and Navier-Stokes equations. The Chimera grid scheme is applied to moving simulations for unsteady flow analysis with dynamic simulation. As a result, it is certified that inviscid simulation have capabilities enough to analyze the present staging problem.

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Analysis for Compressor Motor Core Blanking process (Compressor Motor Core 타발 공정 해석)

  • 최철주;조동협;정완진
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1994.06a
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    • pp.199-230
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    • 1994
  • The blanking sequence of refrigerator and air-conditioner compressor-motor-core has been determined by trial and error. To improve such problem, 2d-analysis using ANSYS to verify the deformation state has been done firstly. And 3d-analysis following up the real process has been done. Additionally, verified the 3-d analysis result using S/W LS-DYNA.