• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 제7회 단조 심포지엄
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• pp.105-112
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• 2002

A new grid-based approach is presented for automatic generation of hexahedral meshes for simulation of plastic deformation in metal forming. In this approach, special enveloping schemes are applied, to eradicate the sources of the degenerate elements that may appear in a generated mesh. The schemes are described in detail, along with a complete procedure for mesh generation. The capability of the approach to deal with an arbitrary, 3-D process geometry is demonstrated through application to a selected forming problem.

• 전기학회논문지
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• 제59권10호
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• pp.1823-1831
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• 2010

This paper proposes an automatic tracking control algorithm for efficiency improvement of photovoltaic generation. Increasing the power of PV systems should improve the efficiency of solar cells or the power condition system. The normal alignment of the PV module always have to run perpendicular to the sun's rays. The solar tracking system, able to improve the efficiency of the PV system, was initiated by applying that to the PV power plant. The tracking system of conventional PV power plant has been studied with regard to the tracking accuracy of the solar cells. Power generation efficiency were increased by aligning the cells for maximum exposure to the sun's rays. Using a perpendicular position facilitated optimum condition. However, there is a problem about the reliability of tracking systems unable to not track the sun correctly during environmental variations. Therefore, a novel control algorithm needs to improve the generation efficiency of the PV systems and reduce the loss of generation. This control algorithm is the proposed automatic tracking algorithm in this paper. Automatic tracking control is combined the sensor and program method for robust control in environment changing condition. This tracking system includes the insolation, rain sensor and anemometer for climate environment changing. Proposed algorithm in this paper, is compared to performance of conventional tracking control algorithm in variative insolation condition. And prove the validity of proposed algorithm through the experimental data.

• Journal of Advanced Marine Engineering and Technology
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• 제25권1호
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• pp.199-208
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• 2001

In this paper, an automatic route tracking algorithm using the position variables and the yaw angle of a ship is suggested, Since most autopilot systems paly only a role of course-keeping by integrating the gyrocompass output, they cannot cope with position errors between the desired route and real route of the ship resulted from a drifting and disturbances such as wave, wind and currents during navigation. In order for autopilot systems to track the desired route, a method which can reduce such position errors is required and some algorithms have been proposed[1,2]While such were turned out effective methods, they have a shortage that the rudder control actions for reducing the position errors are occurred very frequently. In order to improve this problem it is necessary to convert that error into the corresponding yaw angle and necessary to treat only yaw angle control problem. To do this a command generation algorithm which converts the rudder angle command reducing the current position error into they yaw angle command is suggested. To control the ship under disturbances and nonlinearities of the ship dynamics, the adaptive fuzzy controller is developed. Finally, through computer simulations for two ship models, the effectiveness of the suggested method and the possibility of the automatic route tracking are assured.

• 한국정밀공학회지
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• 제9권2호
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• pp.44-51
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• 1992

This paper is concerned with the propram of the automatic mesh generation for 2-dimensional domain which contains the curved boundaries and holes. This program treats a new vertical-line drawing method. This method starts with 4-subdivisions of problem domain and the classification of the cross points of grid lines and boundaries. The new node is generated by the vertical line to the line connecting the two intersections of a boundary and two grid lines in gereral. And the node very close to the boundary is moved to the boundary. The automatic mesh generation composed of only rectangular elements is achieved by this procedure. The boundaries are piecewise-curves composed of lines, circles, arcs, and free curves. The free curves are generated by B-Spline form. Although there were some bad elements for the complex boundary, it was possible to obtain the acceptible rectangular elements for the given boundaries.

• 한국CDE학회논문집
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• 제11권3호
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• pp.157-163
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• 2006

Surfaces of many engineering structures, especially, those of ships are commonly made out of either single- or double-curved surfaces to meet functional requirements. The first step in the fabrication process of a three-dimensional design surface is unfolding or flattening the surface, otherwise known as planar development, so that manufacturers can determine the initial flat plate which is required to form the design shape. In this paper, an algorithm for optimal approximated development of a general curved surface, including both single- and double-curved surfaces, is established by minimizing the strain energy of deformation from its planar development to the design surface. The unfolding process is formulated into a constrained nonlinear programming problem, based on the deformation theory and finite element. Constraints are subjected to the characteristics of the fabrication method. And the design surface, or the curved shell plate is subdivided by automatic mesh generation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.720-725
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• 1991

This paper is concerned with the program of the automatic mesh generation for 2-dimensional domain which contains the curved boundaries and holes. This program treats a new vertical - line drawing method. This method starts with 4-subdivisions of problem domain and the classification of the cross points of grid lines and boundaries. And the new node is generated by the vertical line to the line connecting the two intersections of a boundary and two grid lines in general. The boundaries are piecewise-curves composed of lines, circles, arcs, and free curves. The free curves are generated by B-Spline form. Although there were some bad elements for the complex boundary, it was possible to obtain the acceptable elements for the given boundaries. The results of automatic mesh generation can be verified directly by drawing on the computer monitor in executing the program. And it is possible to add the processes - that is, editing, hard copying, etc - using the script file in Auto-CAD.

• International Journal of Internet, Broadcasting and Communication
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• 제12권2호
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• pp.45-50
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• 2020

A Language model with neural networks commonly trained with likelihood loss. Such that the model can learn the sequence of human text. State-of-the-art results achieved in various language generation tasks, e.g., text summarization, dialogue response generation, and text generation, by utilizing the language model's next token output probabilities. Monotonous and boring outputs are a well-known problem of this model, yet only a few solutions proposed to address this problem. Several decoding techniques proposed to suppress repetitive tokens. Unlikelihood training approached this problem by penalizing candidate tokens probabilities if the tokens already seen in previous steps. While the method successfully showed a less repetitive generated token, the method has a large memory consumption because of the training need a big vocabulary size. We effectively reduced memory footprint by encoding words as sequences of subword units. Finally, we report competitive results with token level unlikelihood training in several automatic evaluations compared to the previous work.

• Journal of information and communication convergence engineering
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• 제6권2호
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• pp.222-227
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• 2008

The important problem in designing a Fuzzy Logic Controller(FLC) is generation of fuzzy control rules and it is usually the case that they are given by human experts of the problem domain. However, it is difficult to find an well-trained expert to any given problem. In this paper, I describes an application of genetic algorithm, a well-known global search algorithm to automatic generation of fuzzy control rules for FLC design. Fuzzy rules are automatically generated by evolving initially given fuzzy rules and membership functions associated fuzzy linguistic terms. Using genetic algorithm efficient fuzzy rules can be generated without any prior knowledge about the domain problem. In addition expert knowledge can be easily incorporated into rule generation for performance enhancement. We experimented genetic algorithm with a non-trivial vehicle controling problem. Our experimental results showed that genetic algorithm is efficient for designing any complex control system and the resulting system is robust.

• 한국CDE학회논문집
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• 제14권5호
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• pp.297-305
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• 2009

Automatic generation of the mid-surfaces of a CAD model is becoming a useful function in that it can help increase the efficiency of engineering analysis as far as it does not affect the result seriously. Several methods had been proposed previously to automatically generate the mid-surfaces, but they often failed to generate the mid-surfaces of complex CAD models. Due to the inherent difficulty of this mid-surface generation problem, it may not be possible to come up with a complete and general method to solve this problem. Since a method that can handle a specific case may not work for different cases, it seems that developing case-specific methods ends up with solving only a fraction of the problem. In this paper, therefore, we propose a method to generate mid-surfaces based on a divide-and-conquer paradigm. This method first decomposes a complex CAD model into simple volumes. The mid-surfaces of the simple volumes are automatically generated by the existing methods, and then they are converted into the mid-surfaces of the original CAD model.

• 한국생산제조학회지
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• 제6권4호
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• pp.65-71
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• 1997

The automation of mesh generation in BEM is very important in numerical analysis field for the time and efficiency. In order to this problem, program and algorithm to achive the purpose of making input data and automation of mesh generation based in Expert System are developed in this study. This program has the function of rotating and zooming. The stress intensity factor which is a criteria of fracture mechanics is calculated and compared with other results to prove efficiency and availability of the program in result.