• Journal of Korean Society of Environmental Engineers
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• v.38 no.2
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• pp.47-55
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• 2016

In this study, WUA (Weighted Usable Area) based on the Instream Flow Incremental Methodology (IFIM) was calculated to determine ecological flow at JeonJu-Cheon by using River2D model. To calibrate River2D, simulation results for low flow conditions of River2D were compared with calibrated HEC-RAS simulation results and the optimum parameters were determined. The results were RMSE (0.18), NSE (0.71) and coefficient of determination (0.78) for velocity and RMSE (0.02), NSE (0.71), coefficient of determination (0.73) for water depth. The result shows that the model successfully simulates the water flows. A selected target fish species to build the habitat suitability index were composed of Zaccoplatypus and Coreoleuciscus splendidus. These species showed the highest occurrences over the past decade in f ish monitoring. Also, The WUA-Discharge curve was calculated with the suitability index in a medium flow conditions. From the result, WUA is changed according to flowrate. In the flowrate-WUA/A graph, ecological flow can be determined at $1.8{\sim}2.0m^3/s$ for Zaccoplatypus $2.0m^3/s$ and Coreoleuciscus splendidus $1.8m^3/s$ at JeonJu-Cheon upstream. When compared with flow-duration analysis, it is demonstrative that simulation results fitted ecological flow considering quantity of available habitat for each fish species.

• Korean Business Review
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• v.17
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• pp.1-26
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• 2004

After IMF crisis in late 1997, the environment of banking industry has become competitive. To survive in this circumstance, the Local Nong-Hyup is needed to understand the customer's needs and improve the service quality. To achive the purpose, two methods were employed in this study. The first corvered the review of related literature on service. The second adopted field survey approach for data. The study model was developed using Venkatakrishnan & Jagannathan's "An Enhanced Model for Measuring Service Quality" model and details of study as follows. 1. What is the determination factors of service quality for Local Nong-Hyup. 2. Are there differences between "service perception" and "service expectation" for Local Nong-Hyup. 3. Does banking service determination factor of Local Nong-hyup affects customer's satisfaction. 4. Does banking service determination factor of Local Nong-hyup affects customer's repurchase. 5. Does customer's satisfaction for Local Nong-hyup relates repurchase. The samples of this study were extracted at random from the customers of Local Nong-hyup. The results of the questionnaire were analyzed to do frequency analysis, factor analysis, t-test, regression analysis, cross sectional analysis using SPSS Win 10. The results are as follows, First, as determination factors of service quality for Local Nong-Hyup "Reliability, Empathy, Tangibles, Convenience" were extracted by factor analysis. Secondly, using t-test, it was found that there are factor's gap between service anticipation and service perception. Thirdly, using regression analysis, it was found that except Convenience factor, Reliability, Empathy and Tangibles factors affect customer's satisfaction. Forthly, using regression analysis, it was found that all the factors affect repurchase. Finally, using cross sectional analysis, it was found that customer's satisfaction and customer's repurchase correlate.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.6
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• pp.860-868
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• 2009

To provide adequate fit for women over a range of sizes, the grading process should reflect their body dimensions. Current methods of creating sized garments are not addressing the need for a good or even an adequate fit for the easy-order system. This study suggests a grading rule allocating system that can improve the appropriateness of clothing for uniform easy-order system. Also, the study proposes a bi-directional grading method subdivided to horizontal and vertical direction. The grading rule allocating system suggested the size increments which improve the fitness of uniform. Using the 5th Size Korea data, the crosstabulation was conducted with 1305 females in the age group $20{\sim}49$ years, and the size increments including $155\sim165$ of height section and $79\sim94$ of bust section, was selected for easy-order system. Also, the bi-directional grading method subdivided in horizontal and vertical direction was followed by factor analysis based on the circumference and height. And the grading rules were calculated by regression analysis.

• Journal of the Korean earth science society
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• v.36 no.4
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• pp.330-340
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• 2015

For this study, we developed an algorithm to estimate the total amount of clouds using sky image data from the Skyviewer equipped with CCD camera. Total cloud amount is estimated by removing mask areas of RGB (Red Green Blue) images, classifying images according to frequency distribution of GBR (Green Blue Ratio), and extracting cloud pixels from them by deciding RBR (Red Blue Ratio) threshold. Total cloud amount is also estimated by validity checks after removing sunlight area from those classified cloud pixels. In order to verify the accuracy of the algorithm that estimates total cloud amount, the research analyzed Bias, RMSE, and correlation coefficient compared to records of total cloud amount earned by human observation from the Gangwon Regional Meteorological Administration, which is in the closest vicinity of the observation site. The cases are selected four daily data from 0800 LST to 1700 LST for each season. The results of analysis showed that the Bias in total cloud amount estimated by the Skyviewer was an average of -0.8 tenth, and the RMSE was 1.6 tenths, indicating the difference in total cloud amount within 2 tenths. Also, correlation coefficient was very high, marking an average of over 0.91 in all cases, despite the distance between the two observation sites (about 4 km).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.6_1
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• pp.471-481
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• 2013

Recently, the frequency of debris flow disaster has increased, which is one of the natural disasters during extremely heavy rainfall condition. This paper described the analysis method about deposition characteristics of debris flow using topographic characteristics of debris flow path. First, we observed topographic changes by differencing high- resolution LiDAR DEMs acquired before and after the occurrence of debris flow event. We assumed that deposition on outside of debris flow path was generated by movements due to the inertia of debris flows. Then, we analyzed three topographic characteristics of debris flow path: slope in flow direction, transition angle of flow path, and the net efficiency(L/H) of debris flows defined by the ratio of transport length(L) and elevation difference(H). We applied this method to Umyeon Mountain debris flow event in July 2011. The results showed that deposition on outside of debris flow path due to the inertia of debris flows was significantly related to the transition angle of debris flow path. Also, we figured out that there were more frequent such depositions in locations where the ratio of 'transition angle / (L/H)' is over 8.

• Journal of Korean Society of Steel Construction
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• v.14 no.6
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• pp.773-782
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• 2002

In this study, a series of fatigue tests are performed in order to estimate quantitatively the characteristics of fatigue crack growth rate according to the base metal, heat affected zone(HAZ) and weld metal, and the welding method and grade of strength of object steels, and the influence on fatigue crack growth rate according to the direction of welded line for high strength steels of SM570, POSTEN60, and POSTEN80 steels. From the fatigue test results, the retardations of fatigue crack growth rate are remarkable in case that the direction of notch is parallel to welded line than in case that the direction of notch is perpendicular to welded line because of compresive residual stress in weld metal & HAZ. And the characteristics of fatigue crack growth rate according to welding method are that the dispersion of fatigue crack growth rate in case of FCAW method is smaller than that of SAW method. Also, it knows that the fatigue crack growth rate converges in high stress intensity factor range. Meanwhile, fatigue safety is guaranteed sufficiently in the object steels because the fatigue crack growth rate in the range of fatigue crack propagation has a similar tendency to the test results & existing results.

• Journal of Korea Water Resources Association
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• v.51 no.2
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• pp.121-129
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• 2018

Rainfall falling in the impervious area of the cities flows over the surface and into the stormwater pipe networks to be discharged from the catchment. Therefore, it is very important to determine the size of stormwater pipes based on the peak discharge to mitigate urban flood. Climate change causes the severe rainfall in the small area, then the peak rainfall can not be discharged due to the capacity of the stormwater pipes and causes the urban flood for the short time periods. To mitigate these type of flood, the large stormwater pipes have to be constructed. However, the economic factor is also very important to design the stormwater pipe networks. In this study, 4 urban catchments were selected from the frequently flooded cities. Rainfall data from Seoul and Busan weather stations were applied to calculate runoff from the catchments using SWMM model. The characteristics of the peak runoff were analyzed using linear regression model and the 95% confidence interval and the coefficient of variation was calculated. The drainage density was calculated and the runoff characteristics were analyzed. As a result, the drainage density were depended on the structure of stormwater pipe network whether the structures are dendritic or looped. As the drainage density become higher, the runoff could be predicted more accurately. it is because the possibility of flooding caused by the capacity of stormwater pipes is decreased when the drainage density is high. It would be very efficient if the structure of stormwater pipe network is considered when the network is designed.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.1008-1019
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• 2020

The purpose of this study is to investigate the effects of social support of students majoring in physical education on their major satisfaction and intention to continue learning, and to prevent dropout of students majoring in physical education in the credit banking system and to find effective management methods. The research tools were verified by confirmatory factor analysis, concentration validity, discriminant validity, average variance extraction (AVE), concept reliability, and Cronbach's coefficient for validity and reliability verification of the research tools. The data processing method was conducted by using IBM SPSS Statistics 21 and IBM AMOS 21 to verify reliability analysis, correlation analysis, and structural equation model (SEM) through frequency analysis, confirmatory factor analysis, concentration validity, discriminant validity, Cronbach's coefficient calculation. The results are as follows. First, the study model was tested and the criteria were met for verifying the suitability of the relationship between social support, major satisfaction and learning persistence intention of the professors majoring in physical education in credit banking system. Second, as a result of the verification of Hypothesis 1, the social support of the professor of the physical education major in the credit banking system has a significant effect on the major satisfaction. The results of the verification of Hypothesis 2 showed that the social support of the professor of the physical education major in the credit banking system affects on the learning persistence. As a result of the verification of Hypothesis 3, it has been shown that major satisfaction has a significant effect on the learning persistence.

• Journal of Digital Convergence
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• v.16 no.6
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• pp.283-295
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• 2018

This study is to establish the direction of special education curriculum by linking the demands of the health industry and the university curriculum. For this, we conducted a questionnaire survey for 4 months from 18 January to 9 May, 2017. Cronbach alpha coefficient was used for the reliability of the study, frequency analysis was used mainly for the contents of the study, and chi-square test, variance analysis and T test were applied to the study. Cronbach's alpha coefficient was 0.891. Variance analysis, T test and chi-square test show some significant differences. The results of this study are as follows: 35% of practitioners and 22% of convergent intellectuals are desirable in institutions. Practical needs of practitioners are creative practicality, medical policy (58%). It will be necessary to conduct a nationwide survey in the future.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.2
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• pp.217-225
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• 2010

Most of the steel bridges in Korea are being currently designed by the allowable stress design method that uses the conventional deterministic factors of safety. However the limit state design based on the concept of probability, statistics and reliability engineering is becoming very popular as a global standard deign method, leading the rational and economic bridge design. As part of the fundamental research to establish the load and resistance factor design(LRFD) of steel bridges considering domestic environmental conditions and regional characteristics, an experimental design is conducted by applying AASHTO-LRFD specification especially to a steel closed-box girder, which occupies relatively a large portion of steel bridges in Korea. Throughout the experimental design according to various sectional changes, some of the issues to be considered in the LRFD design of a composite steel closed-box girder bridge are examined. In this process, an Excel-based design verification program is developed for easy computation and prevention of errors. Quantitative reliability levels of the bridge sections designed by LRFD are also estimated using a reliability analysis method, and compared with the target reliability indexes applied in the LRFD design to verify the validity of the procedure and methodology used in this study.