• Proceedings of the Korean System Dynamics Society
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• 2000.02a
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• pp.29-37
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• 2000

In this paper an attempt is made to understand contribution factors in the field of electronic commerce(EC). To do that, we adopt and modify an existing commerce model. The following two major conclusions are drawn from our simulation. Most of all, the diminution of information delay introduce monotonous growth rather than fluctuation of EC market. The stable increase of revenue or market scale makes us decide the employment or capacity scale quickly. Second, for favorable and continuous evolution of EC, utilization system of electronic money should be established steadily. The following findings strongly support our claim: We found full oscillation of EC market when electronic money system didn't established well. On the contrary, if electronic money system could provide fast cash flow and fully trustful function, decisions of company or consumer would be executed promptly.

• Korean Journal of Hydrosciences
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• v.8
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• pp.57-68
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• 1997

The daily soil water contents were obtained from the time domain reflectometry(TDR) method and energy balance-water budget approach with eddy correlation at the two small semiarid watersheds of Lucky Hills and Kendall during the summer rainy period. There was a comaprison of daily soil water content measured and estimated from these two different approaches. The comparison is valuable to evaluate the accuracy of current soil water content measuring system using TDR and energy balance-water budget approach using eddy correlation method at a small watershed scale. The degree of simiarity between the regressions of these two methods of measuring soil water content was explained by determining the correlations between these methods. Simple linear regression analyses showed that soil water content measured from TDR method was responsible for 58% and 63% of the variations estimated from energy balance-water budget approach with edy correlation at Lucky Hills and Kendall, respectively. The scatter plots and the regression analyses revealed that two different approaches for soil water content measurement at a small watershed scale have no significant difference.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.440-445
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• 1993

A two dimensional large scale laser digitizer with a cordless cursor was developed. The coordinate detecting scheme of this digitizer is fundamentally based on the triangulation method, in which two laser-rays are scanned by the rotating plane mirros, reflected backward by the cursor, reflected again by the rotating mirrors, and detected by optical sensors. From angles in which the cursor reflections are detected, we can determine the position of the cursor. But this method involves several problems about optical alignment and its calibration especially when it is applied to a large scale digitizer. In this paper, especially we propose simulation for error analysis with connection to angles measured at five control points which are needed to decide an appropriate model for calculating coordinates and optimal simulation for deciding the position of five control points to give the better coordinate accuracy. In this way, we realized the on-site calibration and on-site insurance of measurement accuracy with our appropriate model for calculating coordinates. The time required for on-site calibration is within 5 minutes and the average accuracy of 4m * 3m digitizer is about .+-.0.12mm.

• The Journal of the Acoustical Society of Korea
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• v.19 no.5
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• pp.71-78
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• 2000

Quickness and precision are the two most important requirements for an industrial scale used in production lines. In this paper, a new approach, "Mass-estimation algorithm by vibration-response measurement of dynamic balance", is presented to improve some of drawbacks in conventional scales. The system, consisted of velocity and displacement sensors, spring scale, analog-digital converter and microcomputer, is based on full utilization of dynamic mass measurement of velocity and displacement via microcomputer-assisted real time monitoring. The resulting system, when combined with appropriate mass estimation algorithm software, has shown its effectiveness in terms of two desirable characteristics required.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.10a
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• pp.137-144
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• 1998

This paper proposed a optimal scale factors technique of a fuzzy-neural network for a load frequency control of two areas power system. The optimal scale factors control technique is optimize from an initial fuzzy logic control rule, and then is learned with an error back propagation learning algorithm of the fuzzy-neural network. In application two areas the load frequency control of the power system, it hopes to have response characteristic better than optimal control technique which is the conventional control technique and to show to minimize a frequency deviation and reaching and settling time of a tie line power flow deviation

• Journal of Wellbeing Management and Applied Psychology
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• v.6 no.1
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• pp.23-31
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• 2023

Purpose: The purpose of this study is a preliminary study to develop a comprehensive information avoidance scale that includes various search contexts. Research design, data and methodology: This study is a part of exploratory sequential design of mixed method for the development of information avoidance scale. Based on the themes derived from the analysis of the in-depth interview data collected in the qualitative research of the first stage of the study, 45 preliminary items on information search and avoidance were constructed. The factors related to information searching included information recognition, information seeking purpose, and information search expectations. Individual, information, time, and system factors were related to information avoidance. Pearson's correlation analysis was performed for the correlation between factor items, and Cronbach's alpha analysis was performed for the reliability analysis of the items. Exploratory factor analysis was applied to examine the construct validity of 35 items of information avoidance. Results: Among the information avoidance items, one of the less relevant among information purpose items, two information factor items, and one time factor item were excluded. Conclusions: A secondary survey should be conducted to confirm the validity and reliability of the scale composed of adjusted items (35) based on the results of exploratory factor analysis. The strength of this preliminary scale is that it was developed based on vivid qualitative data of ordinary people who had experiences of search and avoidance in various search contexts.

• The Journal of Pediatrics of Korean Medicine
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• v.20 no.3
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• pp.51-60
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• 2006

Objectives : The purpose of this study was to assess the ability of Extravascular Laser System on pain treatment. Methods : On this study, we carried out with the 9 cases of children who visited in the Department of Pediatrics, OO University Oriental Hospital as pain. 9 children suffering from pain were treated with Extravascular Laser System, and two of these were treated with combined acupuncture. In order to determine the degree of pain relief, a visual analogue scale was used. Results : Extravascular Laser System for pain resulted in a significant decline in the visual analogue scale. For Extravascular Laser System combined with acupuncture, VAS score has fallen by 30% each time compared to 17.5% of Extravascular Laser System only. In 2 cases of chronic pain, VAS score decreased to 0. In 7 cases of acute pain, All of 7 children improved 50% on VAS score, On average VAS score have seen 79.2% reduction. The average treatment times of chronic pain were 5 times, while that of acute pain were 4.1 times. Conclusions : We report the good result of the efficacy of extravascular laser system on children's pain. but, this study's cases were small in number. so more study is need.

• Smart Structures and Systems
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• v.4 no.6
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• pp.759-777
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• 2008

A wireless sensing system is designed for application to structural monitoring and damage detection applications. Embedded in the wireless monitoring module is a two-tier prediction model, the auto-regressive (AR) and the autoregressive model with exogenous inputs (ARX), used to obtain damage sensitive features of a structure. To validate the performance of the proposed wireless monitoring and damage detection system, two near full scale single-story RC-frames, with and without brick wall system, are instrumented with the wireless monitoring system for real time damage detection during shaking table tests. White noise and seismic ground motion records are applied to the base of the structure using a shaking table. Pattern classification methods are then adopted to classify the structure as damaged or undamaged using time series coefficients as entities of a damage-sensitive feature vector. The demonstration of the damage detection methodology is shown to be capable of identifying damage using a wireless structural monitoring system. The accuracy and sensitivity of the MEMS-based wireless sensors employed are also verified through comparison to data recorded using a traditional wired monitoring system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.205-210
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• 2004

The pulse detonation engine (PDE) has recently expected as a new aerospace propulsion system. The PDE system has high thermal efficiency because of its constant-volume combustion and its simple tube structure. We measured thrust of single-tube pulse detonation rocket (PDR) by two methods using the PDR-Engineering Model (full scale model) for ground testing. The first involved measuring the displacement of the PDR-EM by laser displacement meter, and the second involved measuring the time-averaged thrust by combining a load cell and a spring-damper system. From these two measurements, we obtained 130.1 N of time-averaged thrust, which corresponds to 321.2 sec of effective specific impulse (ISP). As well, we measured the heat flux in the wall of PDE tubes. The heat flux was approximately 400 ㎾/$m^2$. We constructed the PDR-Flight Mode] (PDR-FM). In the vertical flight test in a laboratory, the PDR-FM was flying and keeping its altitude almost constant during 0.3 sec.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.1
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• pp.28-37
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• 2001

This paper presents an efficient algorithm for the loss minimization of distribution system by automatic sectionalizing switch operation in large scale distribution systems. Simulated annealing is particularly well suited for large combinational optimization problem, but the use of this algorithm is also responsible for an excessive computation time requirement. Tabu search attempts to determine a better solution in the manner of a greatest-descent algorithm, but it can not give any guarantee for the convergence property. The hybrid algorithm of two methods with two tabu lists and the proposed perturbation mechanism is applied to improve the computation time and convergence property Numerical examples demonstrate the validity and effectiveness of the proposed methodology using a KEPCO's distribution system.