• Journal of the Korean Society for Precision Engineering
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• v.21 no.3
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• pp.30-37
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• 2004

This thesis develops a fuzzy-PID control algorithm for control the filament winding tension. It is developed by applying classical PID control technique to a fuzzy logic controller. It is composed of a fuzzy-PI controller and a fuzzy-D controller. The fuzzy-PI controller uses error and integrated error as inputs, and the fuzzy-D controller uses derivative of error as input. The fuzzy-PI controller uses Takagi-Sugeno fuzzy inference system, and the fuzzy-D controller uses Mamdani fuzzy inference system. The fuzzy rule base for the fuzzy-PI controller is designed using 19 rules, and the fuzzy rule base for the fuzzy-D controller is designed using 5 rules. A test-bed is set-up for verifying the effectiveness of the developing control algorithm in control the filament winding tension. It is composed of a mandrel, a carriage, a force sensor, a driving roller, nip rollers, a creel, and a real-time control system. Nip rollers apply a vertical force to a filament, and the driving roller drives it. The real-time control system is developed by using MATLAB/xPC Target. First, experiments for showing the inherent problems of an open-loop control scheme in a filament winding are performed. Then, experiments for showing the robustness of the developing fuzzy-PID control algorithm are performed under various working conditions occurring in a filament winding such as mandrel rotating speed change, carriage traversing, spool radius change, and reference input change.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.2
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• pp.60-68
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• 1992

Fuzzy logic rule based controller has many desirable advantages, whih are simple to implement on the real time and need not the information of structure and dynamic characteristics of the system. Thus, nowadays, the scope of the application of the fuzzy logic controller becomes enlarged. But, if the controlled plant is a time-varying/nonlinear system, it is not easy to construct the fuzzy logic rules which need the knowledge of and expert. In this paper, an approach by which the logic control rules can be auto-generated using the genetic algorithm that is known to be very effective in the optimization problem will be proposed and the effectiveness of the proposed approach will be verified by computer simulation of the 2 d.o.f. planner robot.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.1
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• pp.97-103
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• 2009

The process design of forward Extrusion and Upsetting of Axi-symmetric part has been studied in this paper. During the cold forging product; auto transmission Solenoid Valve part, the defects such as folding and under-fill can be appeared by the improperly controlled metal flow. In this study, to reduce the folding and under-fill the design of experiments has been used to find out the significant design variables in the design of forging process. This paper deals with an Process Planning with which designer can determine operation sequences even after only a little experience in Process Planning of Multi-Former products by multi-stage former working. The approach is based on knowledge-based rules, and a process knowledge-base consisting of design rules is built. Based on the systematic procedure of process sequence design, the forming operation of cold forged auto transmission Solenoid Valve part is analyzed by the commercial Finite Element program, DEFORM/2D.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06c
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• pp.159-162
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• 2007

Semantic Structuralization of data, not Semantic Web base on Ontology but software engineering on many points, can be applied to trace of state or requirements usefully. But it is required much effort that a man converts RDB(Relational DataBase) into Ontology. Hence this study propose rules to convert RDB into Ontology description language OWL automatically.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.699-701
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• 2001

The expert system monitoring and diagnosing 765kV power apparatus was described in this paper. To develop this expert system, we studied the knowledge bases and data bases for 765kV transformer and GIS. In order to make the reliable inference of knowledge base and the good MMI(Man Machine Interface), the data bases were consisted of the tables of power apparatus information, limit level value, measured input data, inference result and diagnosis result. The knowledge base had various rules to infer the conditions of transformer and GIS. We applied both the forward chaining and backward chaining methods to these rules of system for good inferences. This paper describes the applied methods for expert system. Also, this developed system was tested with dissolved gas analyzing result and the result was shown.

• Journal of the Semiconductor & Display Technology
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• v.8 no.4
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• pp.83-88
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• 2009

In this paper TRIZ was used to solve noise and dust reduction related to cable carrier chain system. On modern machines in a clean room, the contradictions arose due to increase noise and dust for the high speed were eliminated with 40 principles and seperation rules. As the results, the sound pressure level of the new carrier chain system was reduced to below 40 dB(A), and cleanroom classifications was satisfied with ISO class 4. In these successful results, TRIZ showed its usefulness in solving the design problems even with severe constraints.

• Journal of Korean Society for Quality Management
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• v.24 no.3
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• pp.77-93
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• 1996

This paper is concerned with the International Standard ISO 2859-1 (1989), Sampling Plans Indexed by Acceptable Quality Level (AQL) for Lot-by-Lot Inspection, his standard is AQL type sampling scheme, and incorporates switching rules to move among normal, tightened, and reduced inspections. Sample size code letters and inspection levels of ISO 2859-1 are the same as those of other attributes standards MIL-STD-105D, ANSI Z1.4, and KS A 3109. But ISO 2859-1 has more simple switching rules than KS A 3109 has. The sampling procedures of the ISO 2859-1 are matched to the variables international standard ISO 3951 to enable us to move between them. Composite OC and ASN curves are given for AQL 2.5% and code letter F.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.126-129
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• 1997

This paper propose a new hybrid genetic algorithm for auto-tunig auzzy controller improving the performance. In general, fuzzy controller used pre-determine d moderate membership functions, fuzzy rules, and scaling factors, by trial and error. The presented algorithm estimates automatically the optimal values of membership functions, fuzzy rules, and scaling factors for fuzzy controller, using hybrid genetic algorithms. The object of the proposed algorithm is to promote search efficiency by overcoming a premature convergence of genetic algorithms. Hybrid genetic algorithm is based on genetic algorithm and modified gradient method. Simulation results verify the validity of the presented method.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.11
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• pp.71-76
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• 1992

In this study, Fuzzy control algorithm to generate a change of rocomotion cordition according to an outer environment is introduced on a motorized wheelchair control. An optimal control rules for conquesting the less of safety and system inefficiency in the past are given to this motorized wheelchair. And dynamic analysis is also adopted to it. Using those rules, a proportional control was possible when the vehicle changed its moving direction. The proposed method which considers the relationship between a moving velocity and the command from the joystick shows better performance in the change of moving direction.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.55-62
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• 1998

This paper presents a method of controlling camera to present virtual space to participating users meaningfully. The users interact with each other by means of dialogue and behavior. Users behave through their avatars. So our problem comes down to controlling the camera to capture the avatars effectively depending on how they interact with each other. The problem is solved by specifying camera control rules based on cinematography developed by film producers. A formal language is designed to encode cinematography rules for virtual environments where people can participate in the story and can influence its flow. The rule has been used in a 3D chatting system we have developed.