• 한국CDE학회논문집
• /
• 제11권1호
• /
• pp.49-56
• /
• 2006

In this study, the modeling support system was developed which can make easy and fast FE-modeling and verify the results of static and durability analysis for the lower arm, one of the important parts in automobile suspension module. It took into account of the whole complicated design processes verifying the durability coefficients evaluated by fatigue analysis, which should be used to satisfy a design criteria. To guide the FE-modeling the drive page was constructed by using HTML and XML, which was based on expert's know-hows. It is able to integrate the processes to design the lower arm in practice, so that the standardization of its FE-Modeling is achieved, consequently. The 3 dimensional CAD's geometrical data were changed automatically into pre-defined shell elements under the concept of mesh-offset technique, and then welding elements were treated to connect between target and basic surfaces constructed by the shell elements. This system has also a user interface to control boundary and load ing conditions applied in performing of the static and durability analysis, in which many load cases can be applied simply with the MPCs driven by just few mouse clicks. These were implemented on the platform of MSC.Patran and utilized ANSYS, MSC.Nastran and MSC.Fatigue as the solver of the analysis performed. The developed system brings not only significant decreasing of man-hours required in FE-modeling process, but also obtaining of satisfied qualities in analyzed results. It will be integrated in a part of virtual prototyping module of the developing e-engineering framework.

• 소음진동
• /
• 제8권4호
• /
• pp.609-615
• /
• 1998

In recent years there has been an increasing emphasis on shortening design cycles for bringing products to market. This requires the development of computer aided engineering tools which allow analysts to quickly evaluate the effect of design changes on noise, vibration, and harshness. Statistical Energy Analysis (SEA) modeling is a valuable tool for predicting noise and vibration as SEA models are inherently simpler and more robust than deterministic models. SEA modeling can be combined with design sensitivity analysis(DSA) to identify design changes which give the largest performance benefit. This paper describes SEA modeling of an equipment cab. SEA predictions are compared to test data, showing good agreement. The use of design sensitivity analysis in improving cab design is then demonstrated.

• 산업경영시스템학회지
• /
• 제44권4호
• /
• pp.113-127
• /
• 2021

Topic modeling has been receiving much attention in academic disciplines in recent years. Topic modeling is one of the applications in machine learning and natural language processing. It is a statistical modeling procedure to discover topics in the collection of documents. Recently, there have been many attempts to find out topics in diverse fields of academic research. Although the first Department of Industrial Engineering (I.E.) was established in Hanyang university in 1958, Korean Institute of Industrial Engineers (KIIE) which is truly the most academic society was first founded to contribute to research for I.E. and promote industrial techniques in 1974. Korean Society of Industrial and Systems Engineering (KSIE) was established four years later. However, the research topics for KSIE journal have not been deeply examined up until now. Using topic modeling algorithms, we cautiously aim to detect the research topics of KSIE journal for the first half of the society history, from 1978 to 1999. We made use of titles and abstracts in research papers to find out topics in KSIE journal by conducting four algorithms, LSA, HDP, LDA, and LDA Mallet. Topic analysis results obtained by the algorithms were compared. We tried to show the whole procedure of topic analysis in detail for further practical use in future. We employed visualization techniques by using analysis result obtained from LDA. As a result of thorough analysis of topic modeling, eight major research topics were discovered including Production/Logistics/Inventory, Reliability, Quality, Probability/Statistics, Management Engineering/Industry, Engineering Economy, Human Factor/Safety/Computer/Information Technology, and Heuristics/Optimization.

• 한국항행학회논문지
• /
• 제14권6호
• /
• pp.900-908
• /
• 2010

최근 소프트웨어 개발에 적용하기 시작한 객체지향 방법(OOM:Object-Oriented Method)은 독립적인 소프트웨어의 재사용을 통한 개발 비용과 시간의 단축을 강조하고 있다. 그러나 개발 기술에 대한 지식 부족과 확장성 및 성능을 배제한 설계로 많은 문제점이 나타나고 있다. 따라서 본 논문에서는 소프트웨어 개발 생명주기에서 소프트웨어 생산성 향상을 위한 효율적인 객체지향 모델링 방법을 제안하고자 한다. 제안 방법은 Use Case 모델링, 분석 모델링, 그리고 설계 모델링 방법들을 포함하고 있다.

• Coupled systems mechanics
• /
• 제7권6호
• /
• pp.731-753
• /
• 2018

The recent seismic events have led to concerns on safety and vulnerability of Reinforced Concrete Moment Resisting Frame "RC-MRF" buildings. The seismic design demands are greatly dependent on the computational tools, the inherent assumptions and approximations introduced in the modeling process. Thus, it is essential to assess the relative importance of implementing different modeling approaches and investigate the computed response sensitivity to the corresponding modeling assumptions. Many parameters and assumptions are to be justified for generation effective and accurate structural models of RC-MRF buildings to simulate the lateral response and evaluate seismic design demands. So, the present study aims to develop reliable finite element model through many refinements in modeling the various structural components. The effect of finite element modeling assumptions, analysis methods and code provisions on seismic response demands for the structural design of RC-MRF buildings are investigated. where, a series of three-dimensional finite element models were created to study various approaches to quantitatively improve the accuracy of FE models of symmetric buildings located in active seismic zones. It is shown from results of the comparative analyses that the use of a calibrated frame model which was made up of line elements featuring rigid offsets manages to provide estimates that match best with estimates obtained from a much more rigorous modeling approach involving the use of shell elements.

• Agricultural and Biosystems Engineering
• /
• 제2권2호
• /
• pp.41-49
• /
• 2001

Advanced Life Support Systems(ALSS) are being studied to support human life during long-duration space missions. ALSS can be categorized into four subsystems: Crew, Biomass Production, Food Processing and Nutrition, Waste Processing and Resource Recovery. The System Studies and Modeling (SSM) team of New Jersey-NASA Specialized Center of Research and Training (NJ-NSCORT) has facilitated and conducted analyses of ALSS to address systems level issues. The underlying concept of the SSM work is to enable the effective utilization of information to aid in planning, analysis, design, management, and operation of ALSS and their components. Analytical tools and computer models for ALSS analyses have been developed and implemented for value-added information processing. The results of analyses heave been delivered through the internet for effective communication within the advanced life support (ALS) community. Several modeling paradigms have been explored by developing tools for use in systems analysis. they include objected-oriented approach for top-level models, procedureal approach for process-level models, and application of commercially available modeling tools such as $MATLAB^{R}$/$Simulink^{R}$. Every paradigm has its particular applicability for the purpose of modeling work. an overview is presented of the systems studies and modeling work conducted by the NJ-NSCORT SSM team in its efforts to provide systems analysis capabilities to the ALS community. The experience gained and the analytical tools developed from this work can be extended to solving problems encountered in general agriculture.

• 한국정보처리학회논문지
• /
• 제6권9호
• /
• pp.2373-2383
• /
• 1999

최근에 객체지향 프로그래밍 언어의 광범위한 활용과 더불어 객체지향 개발방법론, 객체지향 모형화 언어가 활발히 보급되어 있다. 객체지향 개발방법론을 채택하여 정보 시스템을 개발할 경우, 사전 작업인 업무 분석 및 재설계 작업을 객체지향 모형화 언어를 활용하여 진행하면 업무 분석 및 재설계 산출물을 정보시스템 개발자들이 쉽게 이해하고 정보시스템 개발에 참조할 수 있다. 본 논문에서는 객체지향 모형화 언어의 표준으로 대두되고 있는 UML(Unified Modeling Language)에 기반한 업무 프로세스 모형화 기법(UML-B, UML extension for Business Modeling)을 제시한다. UML-B에서는 UML의 표기법을 사용하여 업무 시스템의 조직 구조, 행위자, 사용사례, 업무 프로세스, 개체 관점을 표현하도록 한다. 또한 UML이 제공하는 확장 메카니즘을 사용하여 업무에 대한 모형화 작업의 용이성을 증진시키고 경영혁신(BPR, Business Process Reengineering) 기법을 객체지향 모형화와 함께 사용할 수 있도록 지원한다.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
• /
• pp.623-631
• /
• 2000

Advanced Life Support Systems (ALSS) are being studied to support human life during long-duration space missions. ALSS can be categorized into four subsystems: Crew, Biomass Production, Food Processing and Nutrition, Waste Processing and Resource Recovery. The System Studies and Modeling (SSM) team of New Jersey-NASA Specialized Center of Research and Training (NJ-NSCORT) has facilitated and conducted analyses of ALSS to address systems level issues. The underlying concept of the SSM work is to enable the effective utilization of information to aid in planning, analysis, design, management, and operation of ALSS and their components. Analytical tools and computer models for ALSS analyses have been developed and implemented for value-added information processing. The results of analyses have been delivered through the Internet for effective communication within the advanced life support (ALS) community. Several modeling paradigms have been explored by developing tools for use in systems analysis. They include object-oriented approach for top-level models, procedural approach for process-level models, and application of commercially available modeling tools such as MATLAB$\^$(R)//Simulink$\^$(R)/. Every paradigm has its particular applicability for the purpose of modeling work. An overview is presented of the systems studies and modeling work conducted by the NJ-NSCORT SSM team in its efforts to provide systems analysis capabilities to the ALS community. The experience gained and the analytical tools developed from this work can be extended to solving problems encountered in general agriculture.

• Structural Engineering and Mechanics
• /
• 제65권5호
• /
• pp.611-619
• /
• 2018

This paper addresses numerical modeling and nonlinear analysis of unreinforced masonry walls and vaults externally strengthened using fiber reinforced polymers (FRP). The aim of the research is to provide a simple method for design of strengthening interventions for masonry arched structures while considering the nonlinear behavior. Several brick masonry walls and vaults externally strengthened by FRP which have been previously tested experimentally are modeled using finite elements. Numerical modeling and nonlinear analysis are performed using commercial software. Description of the modeling, material characterization and solution parameters are given. The obtained numerical results demonstrate that externally applied FRP strengthening increased the ultimate capacity of the walls and vaults and improved their failure mode. The numerical results are in good agreement with the experimentally obtained ultimate failure load, maximum displacement and crack pattern; which demonstrates the capability of the proposed modeling scheme to simulate efficiently the actual behavior of FRP-strengthened masonry elements. Application is made on a historic masonry dome and the numerical analysis managed to explain its structural behavior before and after strengthening. The modeling approach may thus be regarded a practical and valid tool for design of strengthening interventions for contemporary or historic unreinforced masonry elements using externally bonded FRP.

• Journal of Power Electronics
• /
• 제19권1호
• /
• pp.24-33
• /
• 2019

A new modeling method for AC-AC switched capacitor converters (SCCs) is introduced in this study. The proposed analytical method aims to accurately describe the input-output characteristics of AC-AC SCCs and establish a mathematical model for static voltage conversion ratio and equivalent resistance, which are key performance metrics for SCCs. A quantitative analysis of converter regulation capability is addressed on the basis of the modeling method. In this analysis, the effects of the control parameters and individual components on SCCs are illustrated extensively. Component stresses, such as the peak value and transient variation of the voltage/current of the converter, are also presented. The effectiveness of the proposed method is verified by comparing it with the existing modeling method and applying it to an AC-AC SCC with a conversion ratio of three. Two 1 kW prototypes are built in a laboratory, and their experimental results exhibit good agreement with the theoretical analysis.