• 전기학회논문지
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• 제63권4호
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• pp.559-564
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• 2014

A microgrid as a small scale power system is operated by the grid-connected mode and islanded mode. It is anticipated that the battery energy storage system (BESS) is able to be applied to the microgrid for stable power control, such as tie-line and smoothing control in the grid-connected mode and voltage and frequency control in the islanded mode. In this paper, a digital signal processor (DSP), Two BESS controllers based on TMS320F28335 of a microgrid are implemented and are tested to show control performance in the hardware-in-the loop simulation (HILS) system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.911-914
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• 2005

Soft tissue characterization and modeling based on living tissues has been investigated in order to provide a more realistic behavior in a virtual reality based surgical simulation. In this paper, we characterize the nonlinear viscoelastic properties of intra-abdominal organs using the data from in vivo animal experiments and inverse FE parameter estimation algorithm. In the assumptions of quasi-linear-viscoelastic theory, we estimated the nonlinear material parameters to provide a physically based simulation of tissue deformations. To calibrate the parameters to the experimental results, we developed a three dimensional FE model to simulate the forces at the indenter and an optimization program that updates new parameters and runs the simulation iteratively. The comparison between simulation and experimental behavior of pig intra abdominal soft tissue are presented to provide a validness of the tissue model using our approach.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.422-425
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• 2004

This paper develops an octree-based algorithm for machining simulation. Most commercial machining simulators are based on the Z map model, which has several limitations in terms of achieving a high level of precision in five-axis machining simulation. Octree representation being a three-dimensional (3D) decomposition method, an octree-based algorithm is expected to be able to overcome such limitations. With the octree model, storage requirement is reduced. Moreover, recursive subdivision is processed in the boundaries, which reduces useless computations. The supersampling method is the most common form of antialiasing and is typically used with polygon mesh rendering in computer graphics. The supersampling technique is being used to advance the efficiency of the octree algorithm..

• 한국CDE학회논문집
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• 제13권1호
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• pp.18-26
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• 2008

Shipbuilding industries have been struggling to reduce production time and cost of their products in many aspects. Manufacturing systems have been changed, new production lines and robots have been installed, and new planning and scheduling systems have been adopted in order to achieve shorter time-to-market and higher productivity. Simulation based manufacturing, digital manufacturing, or virtual manufacturing simulation, whatever the name means, is an approach to achieve such a goal. In order to improve productivity in a shipbuilding process at a shipyard, a digital shipyard development has been driven. This paper proposed how to implement the digital shipyard, what to do with it, and what to obtain from it. This digital shipyard will help simulate and optimize the entire shipbuilding life cycle with its virtual environment through shipbuilding process from the initial development stage to the launch.

• International Journal of Ocean System Engineering
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• 제2권3호
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• pp.170-175
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• 2012

Currently, most logistics use containers. The construction of new port and high speed medium size container ship for the transportation of merchandise have become very important. The problem of ship stability is also important because of its direct influence on the loss of human life, ships, and merchandise. The stability of a container ship during its operation is not a large problem because it is well considered in the design process. However, the assessment of ship stability during container loading/unloading in port still depends on the expertise of experienced personnel. In this paper, a model based simulation system is introduced, which is able to assess ship stability during container loading/unloading, using ENVISION, a general purpose simulation system.

• 전기학회논문지
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• 제63권3호
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• pp.343-348
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• 2014

Recently, applications of VSC-HVDC systems to power systems are growing because of their control ability of reactive power. Meanwhile, the hardware-in-the-loop simulation (HILS) based on the real-time digital simulator has been applying to develop and test imbedded controllers and systems in the power industry to decrease costs and to save time. In this paper, a 3-level neutral point clamped (NPC) VSC-HVDC system is modeled and the embedded controllers of the NPC VSC-HVDC system are designed. The designed controllers are implemented by TMS320F28335. The TMS320F28335-based controllers of the NPC VSC-HVDC system are tested using the HILS.

• 한국정밀공학회지
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• 제20권5호
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• pp.47-56
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• 2003

Geometric cutting-simulation and verification play an important role in detecting NC machining errors in mold & die manufacturing and thereby reducing correcting time & cost on the shop floor. Current researches in the area may be categorized into view-based, solid-based, and discrete vector-based methods mainly depending on workpiece models. Each methodology has its own strengths and weaknesses in terms of computing speed, representation accuracy, and its ability of numerical inspection. The paper proposes a hybrid modeling scheme for workpiece representation with z-map model and discrete vector model, which performs 3-axis and 5-axis cutting-simulation via tool swept surface construction by connecting a sequence of silhouette curves.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.638-642
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• 1994

The objectives of this work are to present the dynamic simulation strategy based on cluster-modular approach and to develop a prototype simulator. In addition, methods for the improvement of computational efficiency and applicability are studied. A process can be decomposed into several clusters which consist of strongly coupled units depending upon the process dynamics or topology. The combined approach of simultaneous and sequential simulation based on the cluster structure is implemented within the developed dynamic process simulator, MOSA(Multi Objective Simulation Architecture). Dynamic simulation for a utility plant is presented as a case study in order to prove the efficiency and flexibility of MOSA.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1729-1734
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• 2005

The use of gantry crane systems for transporting payload is very common in industrial application. However, moving the payload using the crane is not an easy task especially when strict specifications on the swing angle and on the transfer time need to be satisfied. To overcome this problem, this paper describes development of an intelligent gantry crane system based on the mechatronic design. A lab-scale gantry crane is designed and then its intelligent controllers are developed. Fuzzy logic controllers are adopted, designed and implemented for controlling payload position as well as the swing angle of the gantry crane. The performance of the intelligent gantry crane system is evaluated on a hardware-in-the-loop simulation (HILS) environment. Moreover robustness of the proposed system is also evaluated. The result shows that the intelligent gantry crane system designed based on the mechatronic design approach has better performance compared with the automatic gantry crane system controlled by classical PID controllers. Moreover simulation result shows that the intelligent gantry crane system is more robust to parameter variation than the automatic gantry crane system.

• 한국환경과학회지
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• 제13권6호
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• pp.489-495
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• 2004

The purpose of this research is to apply GIS(Geographic Information System) for the road simulation and find some benefits analysis for the design processes. The northern Jeju island was selected as a case study. The 1/5,000 digital map and GIS technique were used for optimum road design of the island based on Arc View software. Using this software we can get an overlay map by combination of hill shade map, slope map, aspect map, and building buffer map. Based on the overlay map, we designed the optimum road line and performed three dimensional simulation. From the results, we found that the developed three dimensional road simulation technique using GIS technique that was very useful tool to estimate the reasonable road design before the real road construction works.