• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.491-496
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• 2000

This paper presents the evaluation of behavior and the prediction of tensile capacity of anchors that fail concrete, as the design basis for anchorage. Tests of cast-in-place headed anchors, domestically manufactured and installed in uncracked, unreinforced concrete are performed to investigate the behavior of single anchors and multiple anchors with the consideration of various embedment lengths and edge distances. The failure mode and the load-deformation response of these anchors are discussed and the concrete failure dta are then compared with capacity predictions by the two existing methods : the 45 degree cone method of ACI 349, 318 and the concrete capacity design (CCD) method. Discrepancies between the test results and these two prediction methods, FEM analysis are assessed.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.763-768
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• 2000

The purpose of this paper is to predict the flexural strengthening of reinforced concrete beams by the external bonding of carbon fiber reinforced plate(CFRP) to the tension face of the beam. Used computational equation is derived by relation of stress an strain. This equation is applied to four-nondamage beam and tow-preloading beam. Six scale beams were tested to evaluate the strength enhancement provided by the CFRP. And describes the strength enhancement provided to the flexural capacity of reinforced concrete beam by the external bonding of CFRP. An inelastic section analysis procedure was developed that accurately predicts the load displacement response of the retrofitted beams.

• KCI Concrete Journal
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• v.12 no.2
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• pp.3-10
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• 2000

A computer program, named NEO-PCBRG, for the analysis and design of prestressed con-crete(PSC) bridges was developed using the finite element method. NEO-PCBRG can predict the response of PSC bridges throughout the various stages of construction and service. NEO-PCBRG has both pre- and post-processing capabilities. Pre-processing refers to all the neces- sary steps required to prepare a virtual prototype, more commonly termed a varied model for analysis. Post-processing here stands for the step in which the results from the analysis are reviewed and interpreted. In order to allow for the easy and convenient execution of the entire procedure, NEO-PCBRG was developed using computer graphics in the Visual Basic pro- gramming language. In conclusion, this study presents a new software architecture for analy-sis using the user-oriented design technique.

• Transactions on Control, Automation and Systems Engineering
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• v.2 no.2
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• pp.121-129
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• 2000

In this paper, an optimal group control for elevator systems is proposed with timed Petri net based approach. Elevator system is modeled by time Petri nets and hall call response times are estimated with moment generating functions (MGFs) methos, which is applicable to real traffic patterns. Two assignment policies are proposed to satisfy the demands of passengers(i.e. hall/car calls) and to handle exceptional situations. In addition, optimal algorithms are implementated to minimize cost functions. THe performances of the elevator system employing the proposed algorithms are compared with each others in ways of several performance measures by a computer simulation.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1997-2000
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• 1996

A strip-type bending actuator using perfluoro sulfonic acid film ($Nafion^{(R)}$ 117, Du Pont), which is a kind of conducting polymer, fabricated and characterized. Conducting polymer is a useful material as an actuator due to the simple structure, fabrication method and low driving voltage. Experimental results show that the fabricated bending actuator has about ${\pm}10^{\circ}$ of bending angle at 4 V and fast response, which means that the conducting polymer can be used practically as actuator material.

• Culinary science and hospitality research
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• v.10 no.3
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• pp.18-31
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• 2004

Korean food industry has been developed while it receives footlights as the most encouraging industry and composing one axis of food industry under various marketing activities and severe competitions. The purpose of this study was to understand customer's reason to use bakery, extract important factor, systematically analyze and suggest the direction of bakery industry through study on the character of bakery-user. The researcher Modified the Questionnaire developed by Yoon, YH(2000) & Kim, SE(2002). The major findings obtained from this study were as follows. First, on factors of confidence and propriety, price and communication with consumers, product and service, and service response, there was a high difference between male and female. Second, on factors of accessibility & product and service, there was a high difference among disparity of age. Third, on item of confidence and propriety, there was a high difference among customers' residing styles. Fourth, in relation to income level, there was statistically no difference.

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.2
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• pp.136-145
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• 2000

The objective of this study is to evaluate the human performance relating to the layouts of the two different hand switch types with two and three buttons in the nuclear power plants. Using a computer simulation, the cognitive performance for the hand switch layouts was measured on the basis of response and task completion times. Comparative analyses were performed with three different layouts representing the current switch arrangements in the Yonggwang nuclear plants 5 and 6 and Ulchin 3 and 4, respectively. Statistical analyses revealed that the performance of the two-buttoned switch layouts was found to be better than those of the three-buttoned switch. Furthermore, the superiority of the two-buttoned switch type is consistent regardless of various layout types. These results imply that the difference of the cognitive performance can be attributable to the switch types rather than to the switch layouts. Therefore, from the cognitive perspective, the two-buttoned switch type is recommended for future power nuclear plants.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.11a
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• pp.135-142
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• 2000

The adjusting parameter set which enable control systems to locate on stability limit can be derived from theoretical or trial methods for an existing real system. The data from the results are much available to keep a system in the Proper stability condition even to site engineers who are inexperienced in the control system. In this paper, a general one loop control system was adopted for a model system the process of which was assumed to consist of a time-delay element and a first order-lag element in series. After obtaining the corresponding parameter set for the model system by mathematical procedures, their loci on the parameter space was taken according to frequency change. The parameter set loci of stability limit showed unique pattern, and particularity , the curves on the Kg-Ti parameter space were able to be generalized in the form of, an unique exponential formula. These properties were also compared with the results taken from experimental procedures by Nyquist response method and Ziegler & Nichols method on the time domain, and both results were confirmed to be nearly same.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.452-457
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• 2000

This paper presents control response of a semi-active electro-rheological(ER) suspension. After showing dynamic characteristics of the ER damper, 1/4 car model is formulated by incorporating with the time constant of the damping force. $H_{\infty}$ controller compensating mass and time constant uncertainties is then designed in order to suppress vibration level of the suspension. The control responses such as vertical acceleration are presented.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.399-404
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• 2000

Functionally graded materials(FGMs) involve dual-phase graded layers in which two different constituents are mixed continuously and functionally according to a given volume fraction. For the analysis of their thermo-mechanical response, conventional homogenized methods have been widely employed in order to estimate equivalent material properties of the graded layer. However, such overall estimations are insufficient to accurately predict the local behavior. In this paper, we compare the thermo-elastic behaviors predicted by several overall material-property estimation techniques with those obtained by discrete analysis models utilizing the finite element method, for various volume fractions and loading conditions.