• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.520-523
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• 1997

This paper presents FPGA implementation of fuzzy controller using Product-Sum inference method. Product-Sum inference method has much better performance than other inference methods. This fuzzy controller is composed of several digital modules, e.g. fuzzifier, rule base, adder, multiplier, select center and divider, and is operated by error and error variation. We synthesized the fuzzy controller and performed wave simulation using Xilinx VHDL tool(ViewLogic, ViewSim).

• Journal of Family Resource Management and Policy Review
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• v.1 no.1
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• pp.89-100
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• 1997

The purpose of this study is to investigate the sages’ philosophic view of home economic management in Chosun dynasty. The research method is to review literatures such as Jangbosanrimkongje, Songhosasal, Sasojul, Nehun, Geneusa, Mocminsimsa and Dasanmusun. The major points of this study were as, 1) Sages mastered that the primary principle of home economic management is to control the material desires. 2) Sages believed that home life management is required the lowest materials, and those materials enough are able to obtained through diligence, frugality, thift and savings. Therefore Sages advised us that each of us lives a diligent, frugal, thrifty and saving life.

• Journal of Power System Engineering
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• v.13 no.6
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• pp.43-50
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• 2009

If an internal combustion engine is operated by consolidated control, the minimum fuel consumption is achieved satisfying the demanded objectives. For this, it is necessary that the engine is operated on the ideal operating line which satisfies minimum fuel consumption. In this context of view, there are many tries to achieve given object. However, the parameter in the internal combustion engines are variable and depend on the operating points. Therefore, it is necessary to cope with the uncertainties such that the optimal operating may be possible. From this point of view, this paper gives a controller design method and a robust stability condition for engine torque control which satisfies the given control performance and robust stability in the presence of physical parameter perturbation. Exactly, the present paper considers a robust stability of this 2DOF servosystem with nonlinear type uncertainty in the engine system, and a robust stability condition for the servosystem is introduced. This result guarantees that if the plant uncertainty is in the permissible set defined by the given condition then a gain tuning can be carried out to suppress the influence of the plant uncertainties.

• Journal of Power System Engineering
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• v.2 no.2
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• pp.55-59
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• 1998

In practice, the property of nonlinearity is contained in all physical systems. In other word, all physical systems are nonlinear to some degree. Therefore it is important that we acquires a facility for analyzing feedback control systems with varying degrees of nonlinearity. To operate the system linearly over wide range of variation of signal amplitude and frequency, the system requires components of an extremely high quality. Such a system would probably be impractical in the view points of cost, space and weight. In this context of view, it is worth noting that the nonlinearities may be intentionally introduced into a system in order to compensate for the effects of other undesirable nonlinearities or to obtain better performance than what could be achieved using linear element only. A simple example of an intentional nonlinearity is the use of a nonlinear damped system to optimize response in accordance with the magnitude of error. In this paper, an on-off type nonlinear controller is introduced and the applicability and validity of a simple on-off controller are presented by the experimental result.

• Journal of Korean Society for Quality Management
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• v.7 no.1
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• pp.15-25
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• 1979

Recently ('70~'76) the average annual export expansion rate was 31.7% (the foremost rate in the world). In '77 the export amounted to 10 billion dollars, and 12.7 billion dollars in '78. The tendeney has been to increase yearly. In view of the structure of export goods, the major export products have been changed from primary industrial materials (86% of the total export in '76) to industrial products (82% in '75). These trends are due to the remarkable progress in the technology advancement. Only 33.6% of the total export items can compete with those of advanced industrial countries in both of price and non-price competitiveness, therefore ours stand in weak position to that of advanced industrial countries. In order to promote good will and strengthen international competitiveness, the major stress of this paper is first of all on the problems of Quality Control, which covers the present states and derived problems of Quality control. These are investigated and analyzed to insure the rational application of Quality Control to the major export goods with a view of the establishment of the direction and systematic improving means of Quality Control.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1528-1532
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• 2000

The conventional optics and near field optics are compared numerically in the view points of the spot size and propagation characteristics. The decaying characteristics of near field light require the optics to access the object within several tens of nanometers. Therefore the gap control is one of the main issues in the near field optics area. In this paper the gap control is done by using the shear force of the NF(Near Field) probe and the characteristics are examined. The probe is modeled as a 2'nd order mass-spring-damper system driven by a harmonic force. The primary cause of the decrease in vibration amplitude is due to the damping force - shear force - between the surface and the probe. Using the model, damping constant and resonance frequency of the probe is calculated as a function of probe-sample distance. Detecting the amplitude and phase shift of the NF probe attached to the high Q-factor piezoelectric tuning fork, we can control the position of the NF probe about 0 to 50nm above the sample. The feedback signal to regulate the probe-sample distance can be used independently for surface topography imaging. 3-D view of the shear force image of a testing sample with the period of $1{\mu}m$ will be shown.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1655-1658
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• 2004

In this paper, we design and implement remote servo motor control system with real-time micro embedded operating system. The system, where controller and camera image grabber are mounted, handles control commands transmitted from a remote PC web browser. A hard real-time servo motor driver running on the real-time micro embedded OS and then a digital control application which confirms precise sampling time intervals is constructed. Frame grabber images transmitted from camera are saved in a image data format to view on remote PC web browser.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.934-938
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• 1989

This paper considers the model predictive control (MPC) problems in nonlinear processes or systems. The MPC method determines the control law such that the predicted output based on the identified process model is equal to the reference output which consists of both the process output at current time and the setting value called as the command generator. In this paper, the nonlinear MPC software for a chemical reactor is developed and analized from the point of view of practical applications.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.36-40
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• 1986

This paper describes a design of the dynamic robot arm controller with two points of view, robustness and minimum tracking error. A new approach to the robust control of robot arm is developed and an explicit solution for minimum tracking error control is obtained from the regulator problem in the error space given by modifying the tracking problem. This control law is applied to the SCARA robot and the computer simulation is presented.

• Journal of Korean Society for Quality Management
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• v.25 no.1
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• pp.116-134
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• 1997

The present automated manufacturing environment is very different when the classical statistical process control method based on batch processing were used. Therefore these must be replaced by automated statistical process control method. In this point of view, this paper intends to develop the automated statistical process control method which can be implemented in the present automated manufacturing environment. Specially this study developed the rules to identify the special causes of the manufacturing process in the aspect of the 100 PPM management, and a numerical example is demonstrated to verify the usefulness of these rules.