• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.1
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• pp.34-45
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• 2006

In this study comparison estimates travel times with observed travel time. In generally, peak flood discharges decrease become travel times longer. It is closely related to storage constant for the watershed routing of a flood. There are so many empirical formulas available for the estimation of travel time, storage coefficients and lag time but results computed generally show great different depending on individual formulas. When calculated flood discharge depend on the travel times varying the discharge. In this study the Wichun travel time shorter optimization travel time than observed travel time for the rusa and memi. There are showed good results for flood discharges, water level and velocity of the memi at the Younggok.

• Applied Chemistry for Engineering
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• v.4 no.3
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• pp.530-536
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• 1993

Acidic degreasing agent(ADA) was prepared by blending n-octanoic acid, MJU-100A, Tetronix T-701, POE(6)-2-ethylhexyl ether, Newpol PE-68, sorbitol, and phosphoric acid. The physical properties of ADA tested with aluminum specimen showed the following results; when 3wt% ADA-5 was performed at $70^{\circ}C$, the degreasing rate was 98% which is comparitively good, and the percentage of etching was 0.277% which was found to be less than that of commercialized product. When 20wt% of ADA-5 was added at $65^{\circ}C$, the percentage of derusting was 93% and the good defoaming effect proved by following low foaming power tests respectively : Ross and Miles, and Ross and Clark methods.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.10
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• pp.846-852
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• 2012

The present paper is the preliminary study of the development of a morphing aircraft wing and investigates experimently the aerodynamic characteristics of a base airfoil and a morphing airfoil. The wind tunnel tests are conducted for a base Clark-Y airfoil, an airfoil with a mechanical flap, and a morphing airfoil. Lifts, drags, and pitching moments are measured by using a three-axis load cell and they are calibrated by considering solid blockage and wake blockage. The wind tunnel tests are conducted for various air speeds, Reynolds' numbers, and angles of attack. The experimental results show that the aerodynamic characteristics of the morphing airfoil in lift-drag and lift-pitching moment are better than those of the airfoil with a mechanical flap.

• Journal of Korea Water Resources Association
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• v.34 no.1
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• pp.67-80
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• 2001

This study is to propose temporal pattern of design rainfall which causes maximum peak discharge and to analyze the variation in peak discharge according to design rainfall durations. In this study, the Mononobe, the Yen and Chow triangular, the Huff's 4th quartiles and the Keifer and Chu methods are applied to estimate the proper temporal pattern of design rainfall and three rainfall-runoff models such as SCS, Nakayasu, and Clark methods are used to estimate the runoff hydrograph. And to examine the variability of peak discharge, the hydrologic characteristics from the rainfall-runoff models to which uniform rainfall intensity is applied are used as the standard values. The type of temporal pattern of design rainfall which causes maximum peak discharge in both of the watersheds and the rainfall-runoff models has resulted in Yen and Chow distribution method with the dimensionless vague of 0.75. On the basis of determined temporal pattern, the examination of the variability of peak discharge according to design rainfall durations shows that design rainfall duration varies greatly with the types of probable intensity formula, and the variation of peak discharge is more affected by the types of probable intensity formula and I-D-F currie than rainfall-runoff models.

• Journal of the Korea Convergence Society
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• v.11 no.8
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• pp.247-256
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• 2020

This study aimed to verify the mediating effect of locus of control on the relationship between materialism and well-being of middle-aged woman. For the study, the survey of 239 middle-aged women in B, C, D city was used. As a scale, a Richins & Dawson(1992)'s widely-used materialism scale, the Levenson(1981)'s locus of scale, Watson, Clark & Tellegen(1988)'s positive and negative affect scale (PANAS) and Ryff(1989)'s psychological well-being scale(PWBS) were used. The survey data was analyzed by descriptive statistics, reliability, correlation and the mediating effect was verified by Baron & Kenny (1986)'s 3 step using SPSS 23 and sobel test. Mediating analysis indicated that the significant relationships between materialism and affective well-being and psychological well-being were reduced significantly when the external locus of control was statistically controlled. Results are meaningful with respect to overcome materialism of middle-aged woman and in the relation to other research that has explored reasons why materialism is related to lower level of affective well-being & psychological well-being.

• Journal of Korean Critical Care Nursing
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• v.5 no.2
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• pp.15-27
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• 2012

Purpose: To evaluate the applicability of Lasater Clinical Judgment Rubric (LCJR) as an evaluation tool for hypoglycemia simulation practicum on Korean nursing students. Methods: The methodological study was done to evaluate the reliability and validity of the LCJR. Based on Benner's 4 levels of nursing grading rubric, ten items of the LCJR was evaluated for interrater reliability and internal consistency. The content validity was tested by eight experts and concurrent validity was done by Clark (2006)'s clinical simulation grading rubric. Fifty five video-taped cases of senior nursing students in Y University were used for the reliability and concurrent validity of the LCJR. Results: The interrater reliability was r=.90 (p<.001); Kendall tau b=.87 (p <.001), and Cronbach's alpha was .90. A value of item content validity index of the LCJR was .97 and correlation coefficient between the LCJR and Clark's instrument was .90 (p<.001). The mean (${\pm}SD$) of the nursing students' clinical judgment was 2.04 (${\pm}50$). Conclusion: The LCJR is a useful tool to examine the simulation performance evaluation for improving competency among nursing students. The results indicated that the LCJR may provide valuable information regarding clinical judgment of nursing students and thus, suggested to use to develop a simulation-based education program.

• Journal of Korea Water Resources Association
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• v.30 no.3
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• pp.279-291
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• 1997

This study is to evaluate the accuracy and practicality of the existing four conceptual models, two linear models of Clark and Nash model and two nonlinear models of Laruenson and WBN model, and to select an appropriate model to simulate the rainfall-runoff process in a given catchment. The variability of parameters for linear models is generally larger than that of nonlinear models. The errors in peak discharge are similar among the four conceptual models buy the errors in time to peak are quite different. Nonlinear models produce better results for time distribution than linear models. A comparison of the conceptual models to predict overall hydrograph using Friedman two-way analysis of variance by rank test indicates that nonlinear models are slightly better than linear models.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.3
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• pp.17-27
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• 2008

In this study, three different unit hydrograph methods (Snyder, SCS, Clark) in the HEC-HMS were compared to find better fit with the observed data in the small agricultural watershed. Baran watershed, having $3.85km^2$ in size, was selected as a study watershed. The watershed input data for HEC-HMS were retrieved using HEC-GeoHMS which was developed to assist making GIS input data for HEC-HMS. Rainfall and water flow data were monitored since 1996 for the study watershed. Fifty five storms from 1996 to 2003 were selected for model calibration and verification. Three unit hydrograph methods were compared with the observed data in terms of simulated peak runoff, peak time and total direct runoff for the selected storms. The results showed that the coefficient of determination ($R^2$) for the observed peak runoff was $0.8666{\sim}0.8736$ and root mean square error, RMSE, was $5.25{\sim}6.37\;m^3/s$ for calibration stages. In the model verification, $R^2$ for the observed peak runoff was $0.8588{\sim}0.8638$ and RMSE was $9.57{\sim}11.80\;m^3/s$, which were slightly less accurate than the calibrated data. The simulated flood hydrographs were well agreed with the observed data. SCS unit hydrograph method showed best fit, but there was no significant difference among the three unit hydrograph methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.4
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• pp.489-498
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• 2016

Despite the extant quantum communication technology that does not allow copying, wiretapping, and/or monitoring, cyber-terror-attempts from hackers with unconscientious purposes and motives are prospected to persist. Hence, it is imperative and necessary to invest in studies geared toward understanding the psychology of hackers. The current study referred to Beebe & Clark (2006) and sought out the psychological variables in hackers involved in deviant hacking activities, measured the purpose of hacking and actual hacking experiences, and constructed a predictive model that can categorize hacker types based on their intentions.

• Water for future
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• v.29 no.6
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• pp.189-201
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• 1996

The main objective of this study is to determine the time distribution models of rainfall in Korea for estimating design floods and to suggest new runoff model(Geomorphologic Instantaneous Unit Hydrograph; GIUH) in order to be easily use the rainfall-runoff model put rainfall models practice to be suitable for the regional characteristics of hydrologic situation by practicing engineers. As a result, the reappearance of triangular hyetograph and GIUH runoff model showed promising. The historical data from about 13,000 event-rainfalls and 73 rainfall-runoff measuring data during 12 years in International Hydrological Program (IHP) basins have been used to determine the statistical factors of the time distribution for rainfalls by the Yen-Chow, Huff, Pilgrim-Cordery and Mononobe models. The Rational, Kajiyama, Nakayasu and Clark model and GIUH model that this study runoff model were used for the purpose of application limit for basin area against design concept by the estimation of flood runoff and the derivation of empirical equations to estimate the parameters for ungaged basins.