• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1998년도 The Korea Society for Simulation 98 춘계학술대회 논문집
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• pp.106-110
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• 1998

Some successful scheduling systems are based on simulation technique. However, they are relatively expensive. A cost-effective solution is to apply general-purpose simulation software to the scheduling system. This paper is concerned with developing a simulation model for MPS(Master Production Schedule) evaluation system. The target system of the model is PC production system. AIM (Analyzer for Improving Manufacturing system), a well-known manufacturing oriented simulation software, is used for modeling tool. Eventually, the model can be included into an MPS evaluation system as simulation module and a scheduler can use the system to verify the MPS in advance.

• Structural Engineering and Mechanics
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• 제33권5호
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• pp.605-619
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• 2009

This paper presents the details of finite element (FE) modeling and analysis of an external prestressing technique to strengthen a prestressed concrete (PSC) end block. Various methods of external prestressing techniques have been discussed. In the proposed technique, transfer of external force is in shear mode on the end block creating a complex stress distribution. The proposed technique is useful when the ends of the PSC girders are not accessible. Finite element modeling issues have been outlined. Brief description about material nonlinearity including key aspects in modeling inelastic behaviour has been provided. Finite element (FE) modeling including material, loading has been explained in depth. FE analysis for linear and nonlinear static analysis has been conducted for varying external loadings. Various responses such as out-of-plane deformation and slip have been computed and compared with the corresponding experimental observations. From the study, it has been observed that the computed slope and slip of the steel bracket under external loading is in good agreement with the corresponding experimental observations.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.9-10
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• 2001

Simulation has been evolved with the advance of computer and technique of modeling application systems. Early simulations were numerical analysis of engineering models known as continuous simulation, analysis of random events using various random number generators thus named as Monte Carlo simulation, iud analysis o(\\\\`queues which are prevalent in many real world systems including manufacturing, transportation, telecommunication. Discrete-event simulation has been used far modeling and analyzing the systems with waiting lines and inefficient delays. These simulations, either discrete-event, continuous, or hybrid, have played a key role in industrial age by helping to design and implement the efficient real world systems. In the information age which has been brought up by the advent of Internet, e-business has emerged. E-business, any business using Internet, can be characterized by the network of extended enterprises---extended supply and demand chains. The extension of value chains spans far reaching scope in business functions and space globally. It also extends to the individual customer, customer preferences and behaviors, to find the best service and product fit for each individual---mass customization. Simulation should also play a key role in analyzing and evaluating the various phenomena of e-business where the phenomena can be characterized by dynamics, uncertainty, and complexity. In this tutorial, applications of simulation to e-business phenomena will be explained and illustrated. Examples are the dynamics of new economy, analysis of e-business processes, virtual manufacturing system, digital divide phenomena, etc. Partly influenced by e-business, a new trend of simulation has emerged called agent-based simulation, Agent-based simulation is a technique of simulation using software agent that have autonomy and proactivity which are useful in analyzing and integrating numerous individual customer's behavior. One particular form of agent-based simulation is swarm. This tutorial concludes with the illustration of swarm or swarm Intelligence applied to various e-business applications, and future directions and implications of this new trend of simulation.

• 한국안전학회지
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• 제23권2호
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• pp.51-56
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• 2008

In these days, work-related musculoskeletal disorders(WMSDs) is one of the issues in the shipbuilding industry. As the number of injured workers and demands for worker's compensation have rapidly increased, improvement of work conditions and environments to prevent WMSDs has been more demanded. To reduce WMSDs' hazards in the shipbuilding industry, simulation technique which showed it's ability of increasing the manufacturing productivity was applied, because simulation technique has the evaluation ability for a worker's danger level of production process by RULA(Rapid Upper Limb Assesment). In this research, worker's altitude had modeled and worker's action has simulated. After the caution level was evaluated, we pointed out clues which had high workload. To reduce work-load, we applied ergonomic principles for improving working conditions and environments. Improved working conditions and environments were simulated using human modelling and simulation and their workload were evaluated again.

• 화약ㆍ발파
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• 제22권4호
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• pp.7-15
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• 2004

본 연구에서는 PFC3D를 사용한 폭원모델링 기법을 제안하고, 제안된 기법을 시멘트 모르타르와 같은 연약재료의 발파에 적용하여 그 적용성을 시험해 보았다. PFC3D는 개별요소법(DEM)을 기반으로 하고 있어 응력파의 전파와 재료의 동적 파괴현상을 모사하는데 적합한 코드로 분류된다. 폭원모델링 과정에서는 공내입자들의 반경을 팽창/수축시키는 기법을 통해 공벽입자들에 접촉력의 형태로 폭발압력을 부여하는 방법을 사용하였으며, 입력하중에 따라 공벽에서 유발되는 접촉력을 계산단계마다 측정 및 보정함으로써 폭발압력의 크기를 제어할 수 있도록 하였다. 시멘트 모르타르 블록의 발파모델링 과정에서는 기존의 외력을 이용하는 방법과 본 연구에서 제안하고 있는 접촉력을 이용하는 기법을 각기 적용함으로써 연약재료의 파괴과정을 정성적으로 비교하여 보았다. 해석결과, 제안된 폭원모델링 기법을 적용한다면 암석이나 콘크리트와 같은 공학재료들이 발파과정에서 보이는 파괴거동을 수치적으로 보다 유사하게 모사 할 수 있을 것으로 판단된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1053-1056
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• 2008

An application of CSG (Constructive Solid Geometry) modeling technique in Machining Simulation is introduced in this paper. The current CSG model is based on z-buffer CSG Rendering Algorithm. In order to build a CSG model, frame buffers of VGA (Video Graphic Accelerator) should be used in term of color buffer, depth buffer, and stencil buffer. In addition to using CSG model in machine simulation Stock and Cutter Swept Surface (CSS) should be solid. Method to create a solid Cuboid stock and Ball-end mill CSS are included in the present paper. Boolean operations are used to produce the after-cut part, especially the Difference operation between Stock and CSS as the cutter remove materials form stock. Finally, a small program called MaSim which simulates one simple cut using this method was created.

• 산업공학
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• 제1권1호
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• pp.27-37
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• 1988

In the multi-stage and multi-process plant, it is not an easy task to describe the interrelationships among each process and facility. The purpose of this simulation study is to analyze the effect of additional facilities on productivity in a steel mill. The simulation was performed using SLAM Simulation Language for Alternative Modeling. The results of this study was used by the plant engineers in making decisions on the expansion of the plate mill. The prediction of which process would cause bottle-necks enabled the plant engineers to invest most effectively.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.773-776
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• 2003

This paper presents modeling and analysis of a PWM buck AC-AC converter The converter is modelled by using DQ transformation whereby both the static and dynamic characteristics are analyzed completely. The feedforward-feedback control technique is also proposed to obtain instantaneous duty level change whereby very fast dynamic response is achieved. The simulation results show the validity of the modeling and analysis.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.297-300
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• 2001

Physical modeling technique is applied to investigate foam generation in molten aluminum. By using room temperature water with specially designed equipment, the effects of stirrer type, fluid viscosity(glycerine added to water) and stirring velocity on foam generation behaviors are intensively analysed The distribution and size of bubbles varied with each process parameters but the most important parameters are stirring velocity and fluid viscosity. The results obtained from physical simulation have been confirmed by actual aluminum foam generation experiment at various process variables.

• 지질공학
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• 제5권2호
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• pp.155-165
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• 1995

열극암반내의 지하수유동 및 용질이동 해석을 위해서는 추계론적인(Simulation Techique) 3차원 불연속체 모형(Discrete Fracture Model)이 요구된다. Monte Carlo 모의기법(Simulation Techique)에 의해 구성된 추계론적 불연속체모형을 지하 유류저장공동의 기밀성평가를 위한 지하수유동 및 용질이동 모의에 적용하였다. 불연속체모형구성에 영향을 미치는 열극 특성요소는 방향서 및 크기로 분석되었으며, 구성도니 모형(Model)에서의 지하수유동에 영향을 미치는 요소는 투수성 열극밀도로 분석되었다. Particle Tracking 기법을 사용한 불연속체모형의 용질이동 모의에서는 열극의 투수성에 의해 이동경로 및 이동속도에 많은 차이가 관찰되었다. 검증된 추계론적 불연속체모형은 지하 유류저장공동 기밀성평가에 적용이 가능함이 부분적으로 인정되었다.