• Journal of Institute of Control, Robotics and Systems
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• v.6 no.3
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• pp.329-337
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• 2000

This study describes a pressure tracking control of hydroforming process which is used for precision forming of sheet metals. The hydroforming operation is performed in the high-pressure chamber strictly controlled by pressure control valve and by the upward motion of a punch moving at a constant speed, The pressure tracking control is very difficult to design and often does not guarantee satisfactory performances be-cause of the punch motion and the nonlinearities and uncertainties of the hydraulic components. To account for these nonlinearities and uncertainties of the process and iterative learning controller is proposed using Cerebellar Model Arithmetic Computer (CMAC). The experimental results show that the proposed learning control is superior to any fixed gain controller in the sense that it enables the system to do the same work more effectively as the number of operation increases. In addition reardless of the uncertainties and nonlinearities of the form-ing process dynamics it can be effectively applied with little a priori knowledge abuot the process.

• Journal of the Korean Society of Clothing and Textiles
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• v.16 no.3 s.43
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• pp.271-284
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• 1992

The purpose of this study is to clarify the change of important clothing evaluative criteria according to the clothing buying process and to bulid the flow chart of clothing buying process and clothing evaluative criteria. The study is carried out in two ways, they are, literature study and empirical survey. The results are as following; 1. the change of the important clothing evaluative criteria according to the clothing buying process is found out. 2. The clothing buying process is that problem recognition -1 decision of clothing wearing situation $\rightarrow$ search and evaluation of genaral Clothing information $\rightarrow$ decision of price limit $\rightarrow$ (search and evaluation of brand information 1 narrowing of brand range) $\rightarrow$ search and evaluation of store information $\rightarrow$ decision of store $\rightarrow$ search and evaluation of clothings in the store $\rightarrow$ narrowing of determinant clothing range $\rightarrow$ trial, trial evaluation and decision $\rightarrow$ buy-ing (or reject) $\rightarrow$ result evaluation. 3. The flow chart is built by the clothing buying process and the clothing evaluative criteria

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.451-454
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• 1998

This paper proposes a new method of Model Predictive Control (MPC) of nonlinear process by us-ing the measured Volterra kernels as the nonlinear model. A nonlinear dynamical process is usually de-scribed as Volterra kernel representation, In the authors' method, a pseudo-random M-sequence is ar plied to the nonlinear process, and its output is measured. Taking the crosscorrelation between the input and output, we obtain the Volterra kernels up to 3rd order which represent the nonlinear characteristics of the process. By using the measured Volterra kernels, we can construct the nonlinear model for MPC. In applying Model Predictive Control to a nonlinear process, the most important thing is, in general, what kind of nonlinear model should be used. The authors used the measured Volterra kernels of up to 3rd order as the process model. The authors have carried out computer simulations and compared the simulation results for the linear model, the nonlinear model up to 2nd Volterra kernel, and the nonlinear model up to 3rd order Vol-terra kernel. The results of computer simulation show that the use of Valterra kernels of up to 3rd order is most effective for Model Predictive Control of nonlinear dynamical processes.

• Transactions of Materials Processing
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• v.5 no.3
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• pp.239-255
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• 1996

A new forming technology has been developed to fabricate near-net shape products using light metal. A semi-solid forming technology has some advantages compared with the conventional forming processes such as die casting squeeze casting and hot/cold forging. In this study the numerical analysis of semi-solid filling for a straight die shape and orifice die shape in gate pattern is studied on semi-solid materials(SSM) of solid fraction fs =30% in A356 aluminum alloy. The finite difference program of Navier-Stokes equation coupled with heat transfer and solidification has been developed to predict a filling pattern and the temperature distribution of SSM. The programdeveloped in this study gives die filling patterns of SSM and final solidifica-tion region.

• Journal of the Korean Society of Costume
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• v.29
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• pp.39-52
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• 1996

The purpose. of this study were to identify the types of consumer affective responses to investigate the attitude formation process on the apparel advertising and to identify the differences among related variables according to the sensation seeking and the brand famili-arity. The result of this study were as follows: 1. The consumer affective responses on ap-parel dvertising was composed of six dimensions; Upbeat feeling Negative feeling Warm feeling Sensual feeling Emotional feel-ing and Uninvolved feeling. 2. The related variables to consumer responses on apparel advertising were signifi-cant differences according to the sensation seeking and the brand familiarity. 3. The main causal course on the apparel ad-vertising was the consumer affective responselongrightarrowthe advertising attitudelongrightarrowthe brand evalu-ationlongrightarrowthe brand attitudelongrightarrowthe purchase in-tention. Also there were differences in atti-tude formation process according to the con-sumer affective respeonses.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.2
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• pp.115-123
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• 2001

In recent years, compression molding of long fiber-reinforced thermoplastics has been increased in commercial aspects. In the process of compression molding of composites, the flow analysis must be developed in order to accurately predict the finished part properties as a function of the molding process parameters. In this model FRTP is assumed to be nonisothermal fluid, which has different viscosities in extensional and in shear. For verification of the model, the formation of a knit line in the L-shaped parts is compared with that of experiments results. In this paper we will discuss the effects of extensional & shear viscosity ratio and slip parameter $\alpha$ on the other modle fill-ing parameters.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.12
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• pp.994-1000
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• 2001

In this paper, using micro-stereolithography technology, I fabricated a liquid analyzer to measure ion concentration of a solution. Micro-stereolithography is a technology to fabricate 3-dimensional structure by applying laser beam on liquid photo-polymer. This technology makes it possible to do preassemble fabrication without any extra assembling step after the process. So, the liquid analyzer could be fabricated at very low cost with very simple process by micro-stereolithography technology. The liquid analyzer consists of a chamber for containing the solution, a pump using piezoelectric effect of PZT disk, a static mixer and a sensor for measuring ion concentration using Pt electrodes.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2167-2169
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• 2003

The LQG regulator presented in this dissertation is designed to improve system stability with the structure in which Kalman Filters and LQ regulator are inter-connected to avoid disturbances on the system. For the sake of performance evaluation of the LQG regulator in this dissertation, the regulator is put in use for the speed control of DC Servo Motors without speed sensors on them to realize speed control without sensors by estimating uncertain speed with its state signals and to construct an optimal controller using the LQG regulator. Furthermore, state estimation process with white noise entered onto the systems is been experimented through a series of simulation. As a consequence, the process of estimating speed signals out of the signals with white noise inputs is confirmed using Kalman Filter.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.980-983
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• 2005

An agent Is an autonomous process that recognizes external environment, exchanges knowledge with external machines and performs an autonomous decision-making function in order to achieve common goals. The techniques fur tackling complexity in software need to be introduced. That is decomposition, abstraction and organization. Agent-oriented model ing has the merits of decomposition. In decomposition, each autonomous unit may have a control thread. Thread is single sequential flow in program. The use of thread in agent modeling has an important meaning in the performance of CPU and the relation of autonomous units.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.05a
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• pp.18-22
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• 2003

The sapphire wafers for blue light emitting devices were manufactured by the implementation of the surface machining technology based on micro-tribology. This process has been performed by grinding, lapping and polishing. The surfaces of sapphire wafers were mechanically affected by residual stress and surface default. This mechanical stress and strain can be cured by thermal anneal ing process. The sapphire crystalline wafers were annealed at $1100~1400^{\circ}C$ and then characterized by double crystal X-ray diffraction. The sample showed good quality of crystalline wafer surface wi th full width at hal f maximum of 16 arcsec for the 4-hour heat-treatment at $1300^{\circ}C$.