• Journal of the Korean Statistical Society
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• v.19 no.1
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• pp.1-14
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• 1990

This paper proposes an approach to the identification of trnasfer function models. A strategy for the identification of the model structure is based on R and S arrays constructed by the impulse response function of the model. Theoretical patterns of the arrays associated with the model are investigated, and the practical implementation method of the suggested approach is also discussed. Finally two published samples are employed to demonstrate the practicability of the approach.

• Journal of the Korea Society for Simulation
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• v.25 no.4
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• pp.77-84
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• 2016

This paper proposes a methodology for creating a function based reliability prediction model. Although, there are various works for reliability prediction, one of the features of their research is that the research is based on hardware-centered reliability prediction. Reliability is often defined as the probability that a device will perform its intended function, under operating condition, for a specified period of time, there is a profound irony about reliability prediction problem. In this paper, we proposed four-phase modeling procedure for function-centered reliability prediction. The proposed modeling procedure consists of four models; 1) structure block model, 2) function block model, 3) device model, and 4) reliability prediction model. We performed function-centered reliability prediction for electronic ballast using the proposed modeling procedure and MIL-HDBK-217F which is the military handbook for reliability prediction of electronic equipment.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.9
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• pp.416-423
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• 2014

To verify different boundary conditions on the borehole wall, which are commonly used for generating g-function, the well-known TRNSYS simulation model, DST (Duct STorage), is employed. By letting the fluid circulation determine the borehole wall conditions, a DST-based g-function is induced with numerical processes proposed in this work. A new TRNSYS module is also developed to accommodate g-function data and predict dynamic outlet fluid temperatures. Results showed that the modified g-function, which is different from Eskilson's original g-function, is closer to the DST-based g-function. This implies that the uniform heat transfer rates over the height can be used for good approximation. In fact, simulations with the modified g-function showed similar results as the DST model, while Eskilson g-function case deviated from the DST model as time progressed.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.3
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• pp.166-171
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• 2008

In this paper, the optimization design module for the brake system of a vehicle is developed. As using this module, design variables, that minimize an object function and satisfy nonlinear constraint conditions, can be found easily. Before an optimization is operated, Plackett-Burman design, one of the factorial design methods, is used to choose the design variables which affect a response function significantly. Using the response surface analysis, second order recursive model function, which informs a relation between design variables and response function, is estimated. In order to verify the reliability of the model function, analysis of variances(ANOVA) table is used. The value of design variables which minimize the model function and satisfy the constraint conditions is predicted through Sequential Quadratic-Programming (SQP) method. As applying the above procedure to a real vehicle simulation model and comparing the values of object functions of a current and optimized system, the optimization results are verified.

• Journal of the Korea Society of Computer and Information
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• v.14 no.12
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• pp.225-232
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• 2009

Function Point Method have been applied to measure software size estimation in industry because it supports to estimate the software's size by user's view not developer's. However, the current function point method has some problems for example complexity's upper limit etc. So, In this paper, an enhanced function point model. Micro FP model, was suggested. Using this model, software effort estimation can be more efficiently because this model has some regression equation. This model specially can be applied to estimate in detail the large application system's size Analysis results show that measured software size by this Micro FP model has the advantage with more correlative between the one of LOC, as of 10 applications operated in an large organization.

• The Transactions of the Korea Information Processing Society
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• v.4 no.4
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• pp.993-1003
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• 1997

In this paper an improvement is made on the function point moedl,one of sortware size dstimation model,for better fesibility with increased accuracy as my proposed moedl.For better feasibility seven function typcs are proposed in this model and technical complexity factors are used to assecss the diffculties of considering technical and distributed enviroment attributes.To assess the creditability of the proposed model,24-software develop-ment cases were cinsidered in the regression model with the actual require efforts as the total function points. As seen in the statistical results,the proposed model is at least as superior to the known function point models.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.2
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• pp.88-103
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• 1996

The objective of this study is to develop stochastic and deterministic models which could be used to synthesize water application time series. Adaptive models using mulitivariate ARIMA(Transfer Function Model) are developed for daily urban water use forecasting. The model considers several variables on which water demands is dependent. The dynamic response of water demands to several factors(e.g. weekday, average temperature, minimum temperature, maximum temperature, humidity, cloudiness, rainfall) are characterized in the model by transfer functions. Daily water use data of Kumi city in 1992 are employed for model parameter estimation. Meteorological data of Seonsan station are utilized to input variables because Kumi has no records about the meteorological factor data.To determine the main factors influencing water use, autocorrelogram and cross correlogram analysis are performed. Through the identification, parameter estimation, and diagnostic checking of tentative model, final transfer function models by each month are established. The simulation output by transfer function models are compared to a historical data and shows the good agreement.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.2B no.4
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• pp.168-173
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• 2002

A new identification algorithm for the Preisach model is presented. The algorithm treats the identification procedure of the Preisach model as an inverse problem where the independent variables are parameters of the distribution function and the objective function is constructed using only the initial magnetization curve or only tile major loop of the hysteresis curve as well as the whole reversal curves. To parameterize the distribution function, the Bezier spline and Gaussian function are used for the coercive and interaction fields axes, respectively. The presented algorithm is applied to the ferrite permanent magnets, and the distribution functions are correctly found from the major loop of the hysteresis curve or the initial magnetization curve.

• Korean Journal of Biological Psychiatry
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• v.14 no.1
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• pp.61-67
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• 2007

Objectives : The purpose of this study was to test stage model in Traumatic Brain Injury(TBI) patients. According to the stage model, attention deficits which is basic stage in information processing lead to memory disturbance and subsequently affect higher-order cognitive function such as memory, decision-making, abstract thinking, and judgement related to executive function. Therefore, it was hypothesized that attention affect recall(retrieval efficacy) related to executive function mostly relative to other cognitive function, in TBI patients with low executive function. Methods : Participants were referred to a TBI clinic and then was rated on K-WAIS and Executive Intelligence Test(EXIT). Participants were divided into two groups according to Executive IQ(EIQ) score, which of high function group(N=67) was more than 80(above low average) and of low function group(N=52) was under 80 (under borderline). To test the stage model, using hierarchical regression analysis, recall(retrieval efficacy) was regressed on 3 subscales(attention, verbal, visuospatial scale) after controlling for IQ according to each group. Furthermore, the mediation effect of attention between retrieval efficacy and verbal, visuospatial score was analyzed. Results : In the low function group, only attention area predicted significantly recall(retrieval efficacy), indicating that lower attention were related to lower EIQ after controlling for IQ. In the high function group, no area predicted significantly retrieval efficacy. In the low function group, verbal and visuospatial scale did not predicted significantly retrieval efficacy, indicating that there was no evidences supporting the mediation model. Conclusion : Only attention affect retrieval efficacy in TBI patients with low executive function. But, the mediation effect of attention between retrieval efficacy and verbal and visuospatial scale was not tested in the low function group. These results implied that stage model was tested partially. In treating cognitive deficit in TBI patients, it is necessary to develop cognitive rehabilitation program based on stage model. Furthermore, it is necessary to necessary to test mediation model in the future study.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11a
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• pp.98-98
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• 2002

In higher dicotyledonous plants, the floral organs are arranged in four different whorls, containing sepals, stamens and carpels. petals, stamens and carpels. The specification of floral organ identity is explained by the ABC model (Weigel and Meyerowitz 1994). expression of an A-function gene specifies sepal formation in whorl 1. the combination of A-and B-function genes specifies the formation of petals in whorl 2, B-and C-function genes spesify stamen formation in whorl 3, and expression of the C-function alone determines the formation of carpels in whorl 1. A-, B-, C-function genes have been isolated from many plant species and most of them belong to the family of MADS-box genes encoding transcription factor. In contrast to the flower of higher dicots, the perianths of genseng plants have three whorls of almost identical petaloid organs. van Tunen et al. (1993) proposed a modified ABC model, exemplified with tulip. In this model, B-function genes are expressed in whorl 1 as well as whorl 2 and 3, theefore the organs of whorl 1 and whorl 2 have the same petaloid structure. They proposed this model with the molphological data of wild type and mutant flowers of tulip, however, there are no molecular data. To date, B-function genes were isolated several grass plants, rice, wheat and maize. However, grass plants have highly derived flowers, without well-developed perianths. To find out how the ABC model has to be modified for the Genseng plants, we have cloned and characterized orthologs of A-, B-, C-function genes from genseng.