• Nuclear Engineering and Technology
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• v.46 no.2
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• pp.235-246
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• 2014

The automatic seismic trip system (ASTS) continuously monitors PGA (peak ground acceleration) from the seismic wave, and automatically generates a trip signal. This work presents how the system can be designed by using a systems engineering approach under the given regulatory criteria. Overall design stages, from the needs analysis to design verification, have been executed under the defined processes and activities. Moreover, this work contributes two significant design areas for digitalized ASTS. These are firstly, how to categorize the ASTS if the ASTS has a backed up function of the manual reactor trip, and secondly, how to set the requirements using the given design practices either in overseas ASTS design or similar design. In addition, the methodology for determining the setpoint can be applied to the I&C design and development project which needs to justify the error sources correctly. The systematic approach that has been developed and realized in this work can be utilized in designing new I&C (instrument and control system) as well.

• The Journal of Engineering Research
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• v.2 no.1
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• pp.103-111
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• 1997

EDFA (Erbium Doped Fiber Amplifier) is widely used to compensate the loss in fiber optic transmission system. The characteristics of EDFA are investigated by analyzing the mechanism amplifying the optical power of an input with several factors to obtain the criteria for designing EDFA. When it is used in fiber optic transmission system, signal to noise characteristics in the receiver is deteriorated due to the spontaneous emission noise of EDFA. We investigate the operating conditions of EDFA to reduce BER (Bit Error Rate).

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2735-2737
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• 2000

In this paper, we deal with modeling and analysis for mobile manipulator systems. In order to avoid the difficulties occurring due to slippage or unevenness of the terrain, we propose the utilization of minimum actuators. In this case, the resulting systems typically possess kinematic redundancies which can be beneficially employed for correcting the position error. A simple PD control method along with kinematic redundancy is employed to recover position errors for trajectory control in task space. Several primary and secondary criteria utilizing kinematic redundancy of the mobile manipulator system are tested through graphic animation.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2275-2277
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• 1998

This paper presents an algorithmic sensor value validation technique that can systematically explore the embedded sensor redundancies in complex physical systems and maximize their utilization in validating sensor values. The confidency criteria are developed for checking the consistency of sensor relationships called Causal Relations. Development results are applied to a tubular type supercritical pressure type thermal power plant with rated operational data to demonstrate the effectiveness of the proposed technique.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.947-949
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• 1995

In this paper, model reference adaptive fuzzy controller (MRAFC) was proposed in order to overcome the difficulty of extracting rules and defects of the adaptation performance in the FLC. MRAFC comprised inner feedback loop consisting of the FLC and plant, and outer loop consisting of an adaptation mechanism which is designed for tuning a control rule of the FLC. A reference-model was used for design criteria of a fuzzy controller which characterizes and quantizes the control performance required in the overall control system. Tuning control rules of FLC is performed by the adaptation mechanism. For this, the fuzzy model for tuning the contorl rules is designed in accordance with the feature of error information. And DC servo motor was selected for case study of actual industrial plant and tested on various loads.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.03a
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• pp.52-55
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• 1996

Though the increment of using computer vision system in modern industry, there are lots of difficulties to measure precisely because of measurement error distortion phenomenon. Between these reasons, the distortion of edge is dominant reason which is occured by the blurred image. The blurred image is happened when camera can not discriminate its precise focus. To correct and generalize distortion phenomenon is imprrtant. Thus we must fix the discrimination criteria which is collected by image recognition of precise focus. The edge of image means discontinuous point of intensity, and the component of edge is discribed as high frequency component at special domain specturm of image. The good condition of focus means there are much high frequency energy in image. The method of discribing high frequency energy is gradient operater which determines the condition of focus.

• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.67-78
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• 2015

The purpose of the establishment of corporation's Business Continuity Plan(BCP) is to maintain corporations' own business and establish the response plan in order to resume operation in a short time period when crisis situations occur due to natural disaster and human error. This study has presented all types of procedures and criteria which are needed to establish the airport crisis response system in order to maintain the business continuity by utilizing BCP technique. Basically the risk response procedures must be established in the process of (1) preparation stage, (2) plan development stage, (3) documentation stage, (4) test & maintenance stage. The guideline has been suggested that each stage must be carried out in the sequence of Policy & Planning Responsibility, Business Impact Analysis, Recovery Strategy & Plans, Emergency Plan & SOP, Training Awareness and Maintenance & Review

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1195-1198
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• 1993

We investigate a systematic design procedure of automated rule generation of fuzzy logic based controller for uncertain dynamic systems such as an engine dynamic model.“Automated Tuning”means autonomous clustering or collection of such meaningful transitional relations in the state-space. Optimal control strategies are included in the design procedures, such as minimum squared error, minimum time, minimum energy or combined performance criteria. Fuzzy feedback control systems designed by the cell-state transition method have the properties of closed-loop stability, robustness under parameter variabtions, and a certain degree of optimality. Most of all, the main advantage of the proposed approach is that reliability can be potentially increased even if a large grain of uncertainty is involved within the control system under consideration. A numerical example is shown in which we apply our strategic fuzzy controller design to a highly nonlinear model of engine idle speed contr l.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.6
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• pp.686-691
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• 2011

This study is concerned with the identification of fuzzy models. To address the optimization of fuzzy model, we proposed an improved space search evolutionary algorithm (ISSA) which is realized with the combination of space search algorithm and Gaussian mutation. The proposed ISSA is exploited here as the optimization vehicle for the design of fuzzy models. Considering the design of fuzzy models, we developed a hybrid identification method using information granulation and the ISSA. Information granules are treated as collections of objects (e.g. data) brought together by the criteria of proximity, similarity, or functionality. The overall hybrid identification comes in the form of two optimization mechanisms: structure identification and parameter identification. The structure identification is supported by the ISSA and C-Means while the parameter estimation is realized via the ISSA and weighted least square error method. A suite of comparative studies show that the proposed model leads to better performance in comparison with some existing models.

• Industrial Engineering and Management Systems
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• v.3 no.1
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• pp.63-70
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• 2004

In this paper, we consider the adjustment of convergence on Color Display Tube (CDT). Convergence is a measure of how well the red, green and blue beams are physically aligned with each other to strike the same area on the screen. When misconvergence (convergence error) occurs, one way of compensating it is to attach several ferrite sheets on the inner part of Deflection Yoke (DY). We suggest an optimization model of misconvergence compensation process and report test results for 81 DY samples. As a result, more than 90% of the samples could be made to satisfy the required convergence criteria.