• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.11
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• pp.625-631
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• 2000

In designing fuzzy model, we encounter a major difficulty in the identification of an optimized fuzzy rule base, which is traditionally achieved by a tedious-and-error process. This paper presents an approach to automatic design of optimal fuzzy rule bases for modeling using evolutionary programming. Evolutionary programming evolves simultaneously the structure and the parameter of fuzzy rule base a given task. To check the effectiveness of the suggested approach, 3 examples for modeling are examined, and the performance of the identified models are demonstrated.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.1
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• pp.112-119
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• 2009

An automatic transmission of construction equipment is controlled by hydraulic and electronic system for doing in various functions like as shifting and operation. The shifting is operated by the engaged and disengaged clutch motion from hydraulic power. On the shifting process, suitable pressure control to the clutch is required for smooth shifting. Hydraulic control system in the automatic transmission is divided by the pilot control type and the direct control type greatly. The direct control type has an advantage than the pilot control type. Because the structure is simple, the design and the manufacture are having less troubles and the system can be maximized precision pressure control. However, the excellent performance proportional control valve should be used to achieve proper control-ability. In this study, the dynamic analysis model composing the automatic transmission and hydraulic system for forklift truck is presented to simulate the characteristics of hydraulic system about the direct control type. That model is verified the validity compared the results of the testing examination. Parameters of input signal are analyzed to reduce the output torque according to input control signal is affected in shifting characteristic.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.744-746
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• 2003

A 3D modeling of urban area can be composed the terrain modeling that can express specific and shape of the terrain and the object modeling such as buildings, trees and facilities which are found in urban areas. Especially in a 3D modeling of building, it is very important to make a unit model by simplifying 3D structure and to take a texture mapping, which can help visualize surface information. In this study, the texture mapping technique, based on library for 3D urban modeling, was used for building modeling. This technique applies the texture map in the form of library which is constructed as building types, and then take mapping to the 3D building frame. For effectively apply, this technique, we classified buildings automatically using LiDAR data and made 3D frame using LiDAR and digital map. To express the realistic building texture, we made the texture library using real building photograph.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.891-895
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• 1995

This paper describes a solid modeling system based on a systematic description of techniques for analyzing and understanding on engineering drawings. Main stress is placed on clarifying the difference between the drawing understanding and the drawing recognition. The former, in which we feel major interest, is intrinsically a difficult problem because it inherent contains combinatorial search to require more than polynomial time. Actually, understanding drawings is regarded as a process to recover the information lost in projection 3-D objects to 2-D drawings. But, solid modeling by automatic understanding of the given drawings is one of the promising approach, which is described precisely in the text. Reviewing the studies performed so far, we summarize the future direction of the project and inevitable open problems left.

• Journal of Positioning, Navigation, and Timing
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• v.8 no.4
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• pp.193-200
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• 2019

The auto-encoder network which is a good candidate to handle the modeling of the signal strength attenuation is designed for denoising and compensating the distortion of the received data. It provides a non-linear mapping function by iteratively learning the encoder and the decoder. The encoder is the non-linear mapping function, and the decoder demands accurate data reconstruction from the representation generated by the encoder. In addition, the adaptive network width which supports the automatic generation of new hidden nodes and pruning of inconsequential nodes is also implemented in the proposed algorithm for increasing the efficiency of the algorithm. Simulation results show that the proposed method can improve the neural network training surface to achieve the highest possible accuracy of the signal modeling compared with the conventional modeling method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.141-144
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• 1997

This paper presents design automation system using API and parametric modeling of solid modeler, which is applied on axial fans for cooling towers. The design data including chord length and twist angle according to the fan length are given by design program, and API functions are applied to automate the modeling and assembly process of fan blade. The boss to connect fan and motor is designed with parametric design function provided by UG so as to be flexibly changed by the value of design parameters. The process of generating 2-D drafting for parts and an assembly is also automated. With developed system, the modeling time is reduced to 5 minutes even with unskilled operators.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.202-210
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• 2019

The obstacles modeling is a fundamental and significant issue for path planning and automatic navigation of Unmanned Surface Vehicle (USV). In this study, we propose a novel obstacles modeling method based on high resolution satellite images. It involves two main steps: extraction of obstacle features and construction of convex hulls. To extract the obstacle features, a series of operations such as sea-land segmentation, obstacles details enhancement, and morphological transformations are applied. Furthermore, an efficient algorithm is proposed to mask the obstacles into convex hulls, which mainly includes the cluster analysis of obstacles area and the determination rules of edge points. Experimental results demonstrate that the models achieved by the proposed method and the manual have high similarity. As an application, the model is used to find the optimal path for USV. The study shows that the obstacles modeling method is feasible, and it can be applied to USV path planning.

• Journal of the Korean Society of Mechanical Technology
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• v.20 no.6
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• pp.803-808
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• 2018

Combining digital automation solutions throughout recent manufacturing process is essential. Advanced robot and mechanical techniques are required for design, manufacture, and distribution process. Manual design of repetitive similar mechanical components during the development phase of these advanced machines and robots can occur wasting time and money. Developed gear design module, which is the power transfer system mechanical component, was programmed in the Visual Basic language in CATIA V5 environment. Automation Process is Based on Parametric Modeling Method. and it was found to be effective in reducing design time compared to designers manual modeling.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.486-490
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• 2002

When the fuzzy controller apply to a real plant, We have not excepted result of a satisfactory control by modeling error and lacking information about an plant. In this case, we have to adjust the scale factors for improvement of the control performance and this method need a lot of time and cost for perform a trial and error. In this paper, we proposed the fuzzy controller with the automatic adjustment of scaling factors. It was improve upon the control performance using a adequate scale factor by fuzzy logic and normalizer. As the results of simulation through the second order plant, we confirmed that the proposed the fuzzy controller within the function of automatic scale get a good response compare with the fuzzy controller within the fixed scale factor.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.28-31
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• 2002

In this study, we develop automatic design program, which create 3D model of spur gear and helical gear used VisuaILISP and create helical gear in the CATIA using 2D profile of gear. This model become the standard model, which give not only in itself mold information but also computer processed product with measuring date. Spur gear require mathematical examination of involute curve and trocoidal fillet curve. Automatic design program, which have a mathematical development create the profile of spur gear.