• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.260-260
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• 2011

SWAT is semi-distributed and continuous-time distributed simulation watershed model, which can simulate point and nonpoint source pollutants as well as hydrology and water quality. It was developed to predict the effects of alternative management decisions on water, sediment, and chemical yields with reasonable accuracy. It is able to predict and manage hydrology, sediments, nutrients, and pesticides with Best Management Practices (BMPs) in a watershed. SWAT model also has potential for use in ungauged basins to predict streamflow and baseflow from saturated source area in watersheds. According to various cultivation practices and climate change, SWAT model is available to analyze relative change in hydrology and water quality. In order to establish optimum management of water quality, both monitering and modeling have been conducted actively using SWAT model. As SWAT model is computer program to simulate a lot of natural phenomena, it has limitation to predict and reflect them with on hundred percent accuracy. Thus, it is possible to analyze the effect of BMPs in the watershed where users want to simulate hydrology and water quality only if model accuracy and applicability are assessed first of all and the result of it is well for the study watershed. For assessment of SWAT applicability, most researchers have used $R^2$ and Nash and Sutcliffe Efficiency (NSE). $R^2$ and NSE are likely to show different results according to a warm up period and sometimes its results are very different. There have been hardly any studies of whether warm up period can affect simulation results in SWAT model. In this study, how warm up period has a effect on SWAT results was analyzed and a appropriate warm up period was suggested. Lots of SWAT results were compared after using measured data of Soyanggang-dam watershed and applying various warm up period (0 ~ 10 year(s)). As a result of this study, when there was no warm up period, $R^2$ and NSE were 0.645, 0.602 respectively, when warm up period was 2 years, $R^2$ and NSE were 0.648, 0.632, and when warm up period was 4 years, $R^2$ and NSE were 0.663, 0.652 separately. Through this study, sensitive analysis of warm up period in SWAT model was conducted, and this study could give a guideline able to simulate hydrology and water quality for more accuracy than before as users change a lot of warm up periods as well as any simulation parameters.

• 한국데이터정보과학회:학술대회논문집
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• 2005.04a
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• pp.145-154
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• 2005

There have been some controversies on the use of the coefficient of determination for linear no-intercept model. One definition of the coefficient of determination, $R^2=\sum\;{y}{^{\hat{2}}/\sum\;{y^2}$, is being widely accepted only for linear no-intercept models though Kvalseth(1985) demonstrated some possible pitfalls in using such $R^2$. Main objective of this article is to provide a cautionary notice for use of the $R^2$ by pointing out its tricky aspects by means of empirical simulations.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.4
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• pp.329-335
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• 2013

Three-dimensional quantitative structure-activity relationships (3D-QSARs) models between the substituents with changing groups ($R_1$ & $R_2$) of 4-hydroxybenzyl alcohol (4-HBA) derivatives as substrate molecule and their inhibitory activities against tyrosinase were derived and discussed quantitatively. The optimized CoMSIA FF model showed the best predictability and fitness ($r^2$ = 0.858 & $q^2$ = 0.951). The contour maps of the optimized CoMSIA FF model showed that, the inhibitory activities of the analogues against tyrosinase were expected to increase when hydrophobic (Hy) favor, negative charge (E) favor, steric (S) disfavor and hydrogen bond donor (HD) disfavor groups were substituted at the $R_2$ position. When the hydrogen bond donor (HD) favor groups were substituted at the $R_1$ position, it is predicted that the substituents will be able to increase the inhibitory activity.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.307-310
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• 2018

우리 사회는 데이터를 기반으로 진화 하고 있어 데이터분석을 할 수 있는 통계패키지가 오늘날 상용화 되고 있다. 상용화되고 있는 통계패키지를 이용해 본 논문에서는 통계패키지 R을 Model1구조가 아닌 Model2 MVC구조로 적용하여, 웹사이트의 유지보수와 코드 효율성을 증진시키고자 한다. 이를 이용하여 웹 스크래핑을 통한 데이터를 수집 후 데이터 분석을 토대로 사용자가 분석내용을 쉽게 이해할 수 있도록, 편의성을 증진시키고 검색 할 수 있는 웹사이트를 설계 및 구현 하고자 한다.

• International Journal of Advanced Culture Technology
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• v.9 no.4
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• pp.61-70
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• 2021

At a time when children of multicultural families have begun to enter adolescence in Korea, this study examined the effects of parental support and bicultural acceptance on the career attitude maturity of multicultural adolescents. This study tried to derive the implications related to the career path of multicultural adolescents by verifying the effects of self-esteem on the relationship between parental support, bicultural acceptance, and career attitude maturity. Using the 8th Multicultural Adolescent Panel Survey data (MAPS), the relative influence of antecedent variables on career attitude maturity was confirmed by hierarchical regression analysis of the data from 1,197 respondents. Model 1 included gender and parental support, Model 2 added bicultural acceptance to Model 1, and Model 3 added self-esteem to Model 2. As a result of the study, in Model 1, women had higher career attitude maturity than men, and the more supportive their parents were, the more positive the level of career attitude maturity. The adjusted R2 of Model 1 was .058, which did not have much influence. In Model 2, gender, parental support, and bicultural acceptance had statistically significant effects on career attitude maturity, and the amount of change in F was also significant. The adjusted R2 of Model 2 was .132. In Model 3, parental support was not statistically significant, and gender, bicultural acceptance, and self-esteem had statistically significant effects on career attitude maturity. The amount of change in F was statistically significant and the adjusted R2 was .185. That is, it was confirmed that the more the women, the more the bicultural acceptance, and the higher the self-esteem, the more prepared and determined the career path. Based on the research results, the implications related to career preparation of multicultural adolescents were presented.

• Journal of Biosystems Engineering
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• v.22 no.3
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• pp.333-342
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• 1997

The objective of this research was to develop model equations for measuring rice milling ratio by using visible / HIR spectroscopy. Twelve kinds of brown rice(n = 149) were milled to obtain various milling ratio ranged from 86% to 94%. Visible/NIR spectra were collected with a spectrophotometer with sample transport module. The reflectance and transmission spectra were measured in the range of 400~2, 500nm and 600~1, 400nm, respectively, with 2 nm intervals. Multiple linear regression(MLR), Partial least square (PLS), and Artificial neural network(ANN) were used to develop models. Model developed with reflectance spectra showed better prediction results then those with transmission spectra. The MLR model with six-wavelength obtained from first derivative spectra gave to the best results for measuring the rice milling ratio(SEP = 0.535, , $r^2$ = 0.980). The PLS model(SEP = 0.604, $r^2$= 0.976) and ANN model(SEP = 0.566, $r^2$= 0.978) also can be used to determine the rice milling ratio effectively.

• Journal of Korea Technology Innovation Society
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• v.2 no.2
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• pp.201-218
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• 1999

The article contains an introduction of possibility of applying Multi-Attribute Utility Theory(MAUT) for priority setting of R&D projects. MAUT is compared with AHP, which is widely used recently. These two techuiques are applied to set priorities of R&D projects In a Government-funded Research Institute. Six criteria are chosen from consultation with decision makers. They are composed of 1) validity as representative projects, 2) possibility of resource mobilization, 3) spillover effect of developed technologies, 4) possibility of success, 5) scope of participation and 6) clarity of research goal. To set priorities of R&D projects, SMART(Simple MultiAttribute Rating Technique) and DVM(Difference Value Measurement) out of many MAUT methods are used to design the utility function and to determine the weights among criteria. The aggregation model is additive on the assumption the criteria are independent. AHP executes pairwise comparisons for criteria and alternatives. From the results of the case study, the results and theoretical characteristics are compared.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1469-1473
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• 2010

Influences of alrylamino (R) substituents on the herbicidal activity ($pI_{50}$) of 1-(4-chloro-2-fluoro-5-propargyloxypheny)-3-(R)-thiourea analogues (1 ~ 35) against the barnyard grass (Echinochloa crusgalli) in the pre-emergence step were discussed quantitatively using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) as the three dimensional quantitative structure-activity relationship (3D-QSAR) method. The statistically most satisfactory CoMFA models for the herbicidal activity against the barnyard grass had the better predictability ($r^2{_{cv.}}$) and correlativity ($r^2{_{ncv.}}$) than those of CoMSIA models. The optimized CoMFA model 1($r^2{_{cv.}}$ = 0.531 & $r^2{_{ncv.}}$ = 0.931) with the sensitivity to the perturbation (${d_q}^{2'}{dr^2}_{yy'}$ = 1.081) and the prediction ($q^2$ = 0.475) produced by a progressive scrambling analyses were not dependent on chance correlation. And statistical qualities with the atom based fit alignment (AF) were slightly higher than those of the field fit alignment (FF). According to the optimized CoMFA model 1, the contribution ratio (%) of the steric field (76.9%) on the herbicidal activity of the Thioureas was three-fold higher than that of the electrostatic field (20.1%) and the hydrophobic field (3.0%) had the least influence. A steric favor group is on the vicinity of the nitrogen atom in alrylamino (R) substituent, and a steric disfavor group is on the outer side of alrylamino (R) substituent. Thus, as the size of alrylamino (R) substituent increases, so does the herbicidal activity of the substituent.

• Journal of Information Technology Applications and Management
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• v.12 no.4
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• pp.133-155
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• 2005

This Paper makes an attempt to suggest a process of automatically generating application software based on the Entity-Relationship model 1. The designer develops an E-R model of an real-world system. 2. The designer inputs the entity and relationship types, and attributes shown in the E-R model, and also the basic operations of the application system to the software generator. 3. The application generator produces database schema and link information between application programs, and then automatically generates a stereo-type application system. In order for the automated application generator to build the application system in a systematic way, four basic program generation rules have been suggested. A set of computer programs have been developed in order to show the applicability of the automated software generation process suggested in this paper. By following each rule with the generator, the designer can build an application in an efficient manner compared with traditional (manual programming) approaches. It has been demonstrated from the case study that the idea of applying an automated generator in systems development based upon the E-R model is feasible.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.1
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• pp.104-111
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• 2000

A fuzzy logic Run-by-Run(RbR) controller and an in -line wafer characteristics prediction scheme for the rapid thermal processing system have been developed for the study of process repeatability. The fuzzy logic RbR controller provides a framework for controlling a process which is subject to disturbances such as shifts and drifts as a normal part of its operation. The fuzzy logic RbR controller combines the advantages of both fuzzy logic and feedback control. It has two components : fuzzy logic diagnostic system and model modification system. At first, a neural network model is constructed with the I/O data collected during the designed experiments. The wafer state after each run is assessed by the fuzzy logic diagnostic system with featuring step. The model modification system updates the existing neural network process model in case of process shift or drift, and then select a new recipe based on the updated model using genetic algorithm. After this procedure, wafer characteristics are predicted from the in-line wafer characteristics prediction model with principal component analysis. The fuzzy logic RbR controller has been applied to the control of Titanium SALICIDE process. After completing all of the above, it follows that: 1) the fuzzy logic RbR controller can compensate the process draft, and 2) the in-line wafer characteristics prediction scheme can reduce the measurement cost and time.