• Journal of Korea Water Resources Association
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• v.43 no.8
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• pp.733-745
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• 2010

Seasonality of hydrologic extreme variable is a significant element from a water resources managemental point of view. It is closely related with various fields such as dam operation, flood control, irrigation water management, and so on. Hydrological frequency analysis conjunction with partial duration series rather than block maxima, offers benefits that include data expansion, analysis of seasonality and occurrence. In this study, nonstationary frequency analysis based on the Bayesian model has been suggested which effectively linked with advantage of POT (peaks over threshold) analysis that contains seasonality information. A selected threshold that the value of upper 98% among the 24 hours duration rainfall was applied to extract POT series at Seoul station, and goodness-fit-test of selected GEV distribution has been examined through graphical representation. Seasonal variation of location and scale parameter ($\mu$ and $\sigma$) of GEV distribution were represented by Fourier series, and the posterior distributions were estimated by Bayesian Markov Chain Monte Carlo simulation. The design rainfall estimated by GEV quantile function and derived posterior distribution for the Fourier coefficients, were illustrated with a wide range of return periods. The nonstationary frequency analysis considering seasonality can reasonably reproduce underlying extreme distribution and simultaneously provide a full annual cycle of the design rainfall as well.

• Journal of Korean Society of Transportation
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• v.15 no.4
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• pp.73-90
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• 1997

The warrants to install traffic signals used in U.S.A. are well specified comparing to those in other countries. Among the eleven warrants of the U.S.A., the Warrant 9, 10, and 11 are especially fit in practice. The warrant relaxed to traffic volumes used presently in Korea have been adopted from the U.S.A. Those may not have been reliable in the traffic situation of Korea. The rules required passing through intersections are not kept well at intersections controlled without signals. The purposes of this study are to test and evaluate the reliability of the Warrant 9 and 11 adopted form U.S.A.n Korean traffic situation and to propose new traffic signal warrants related to traffic volumes fitted in here. The traffic volume warrants are proposed considering the situation of rules not being kept well(current situation) and that of vice versa(ideal situation). The results of this study are following; 1) The total volumes warranted to traffic signals are 1600vph, 1700vph, and 1800vph at 4-legs intersection having 1 by 1 lane, 1 by 2 lanes, and 2 by 2 lanes respectively. The total volumes warranted are 1400vph and 1600vph at 3-legs intersection haying 1 by 2 1anes, and 2 by 2 lanes respectively. 2) Another traffic warrants proposed are transformed from the currant warrants 9 and 11. These warrants are composed of the total volumes and the ratio of the volume of the minor street to that of the major street.

• Journal of Distribution Science
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• v.12 no.8
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• pp.71-82
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• 2014

Purpose - This study is to examine the effect of environmental orientation on innovation, environmental and market performance in Korean franchise firms' context. This study also investigates how environmental orientation, innovation and environmental performance play mediating roles between environmental orientation and market performance. For these purposes, the authors developed a structural model which consists of several constructs. In the model, environmental orientation was proposed to affect innovation and environmental performance, while innovation and environmental performance influence market performance. Specifically, innovation and environmental performance were proposed as core mediators between franchise firms' environmental orientation and market performance. Research design, data, and methodology - The data were collected from 155 franchise firms in Korea during January 2012. The results of factor analysis with reliability test with Cronbach's α warranted unidimensionality of the measures for each construct. In addition, nomological validity of the measures of each construct was warranted from the result of correlation analysis. The data were analyzed with reliability analysis, and structural equation modeling with SPSS Win/PC 18.0 and AMOS 18.0. Results - The results of the overall model analysis appeared as follow: χ²=52.388(df=21), p=.000. GFI=.932, AGFI=.854, NFI=.964, CFI=.978, RMSEA=.099, RMR=.059. Since the result of the overall model analysis demonstrated a good fit, we further analyzed our data. The findings can be summarized as follows: Firstly, the environmental orientation had a positive effect on innovation and environmental performance, but had not a direct effect on market performance. Secondly, innovation had a positive effect on environmental performance, but had not a direct effect on market performance. Thirdly, environmental performance had a positive effect on market performance. Conclusions - The results of this study show that, in order to achieve competitive advantages and environmental and market performance in turbulent market situation, franchise firms should emphasize internal and external environmental orientation, and put through improvements in perspective of technology, organization, and product. Consequently, this research suggests that environmental orientation is a motive for franchise companies' innovation, environmental performance, and market performance. It also suggests theoretical and managerial implications, limitations, and further research directions.

• The Journal of the Korea Contents Association
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• v.19 no.10
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• pp.593-606
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• 2019

This study examines effective message strategies that fit with the characteristics of retargeting advertisements, based on the Construal Level Theory. First, we investigate whether the social distance that applies between interpersonal interactions can also be observable in an online environment and test the effects of social distance, depending on the type of online sites. We then examine consumers' construal level when social and temporal distances interplay, and how the effects of the messages change accordingly. As a result, social distance and message construal levels by website type were consistent with existing CLT studies. However, the hypothesis that advertising effects will be higher only when all, multidimensions' distances and construal levels of messages match, was partially supported. Also the current view, that the consumers' evaluations will show no difference to when either or both dimensions are distal, was rejected. Instead, when a discrepancy between temporal and social distance was present, the construal level of the message was more effective when congruent with the social distance out the two dimensions. Hence, it is possible to infer that the influence of psychological distance may vary depending on the dimension of distance.

• Journal of Conservation Science
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• v.37 no.5
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• pp.536-544
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• 2021

In the present study, safe management and value improvement of bamboo sunblind, which is an item of cultural heritage, were performed by adopting stable conservation treatment methods. The bamboo sunblind used in the present study was excavated from No. 1 catchment site in Baesanseongji, Busan. It was determined that the main material used to make the sunblind was bamboo, and herbal plants were used to weave the bamboo using lacquer as an adhesive agent. All contaminants and soil adhered to the sunblind was removed. Thereafter, the sunblind, which was recovered in the form of blocks, was washed separately after fixing it to a temporary plaster frame and to avoid the blocks from breaking during washing. Then, polyethylene glycol (PEG) impregnation was utilized for the reinforcement treatment. Based on the preliminary test results, the shape of the sunblind was fixed using a stainless-steel frame to prevent physical damage that may occur during the drying process. Thereafter, the bamboo sunblind was vacuum freeze-dried. PEG 20% (in ethyl alcohol) was applied as a surface treatment agent for stabilization the sunblind. After the surface treatment, the bamboo sunblind were joined together to fit the maximum width, and the rectangular shape of the sunblind was restored-as best as possible-while filling in the missing parts by maximizing the use of unknown members such as in the disturbed layers below bamboo sunblind surface. The conservation treatment was completed by fixing the bamboo sunblind into the fabricated frame.

• Journal of Internet Computing and Services
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• v.22 no.2
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• pp.59-68
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• 2021

As artificial intelligence(AI) technologies, which have made rapid growth recently, began to be applied to the marine environment such as ships, there have been active researches on the application of CNN-based models specialized for digital videos. In E-Navigation service, which is combined with various technologies to detect floating objects of clash risk to reduce human errors and prevent fires inside ships, real-time processing is of huge importance. More functions added, however, mean a need for high-performance processes, which raises prices and poses a cost burden on shipowners. This study thus set out to propose a method capable of processing information at a high rate while maintaining the accuracy by applying Quantization techniques of a deep learning model. First, videos were pre-processed fit for the detection of floating matters in the sea to ensure the efficient transmission of video data to the deep learning entry. Secondly, the quantization technique, one of lightweight techniques for a deep learning model, was applied to reduce the usage rate of memory and increase the processing speed. Finally, the proposed deep learning model to which video pre-processing and quantization were applied was applied to various embedded boards to measure its accuracy and processing speed and test its performance. The proposed method was able to reduce the usage of memory capacity four times and improve the processing speed about four to five times while maintaining the old accuracy of recognition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.52-63
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• 2019

Biased performance implications are common in conducting empirical analysis on leading firms in strategic management field. Venture businesses in which successful and failing firms in the future are mixed in the present could provide a better discriminative result for examining the determinants of performance. We suggest hypotheses on how competitive strategy, CEO characteristics, and their interactions affect firm performance. We examine these hypotheses through empirical analyses on the basis of a survey collected from 387 venture businesses in order to assure the validity of strategic management theories by using more deviated data. Empirical results show that innovative differentiation from competitive strategies affects firm performance and innovativeness and long-term orientation from CEO characteristics affect firm performance. According to the results of the interaction analyses between competitive strategies and CEO characteristics, cost-leadership and marketing differentiation strategies have combination effects with risk taking, innovativeness, and long-term orientation, while innovative differentiation strategy has no combination effects with risk taking, innovativeness, and long-term orientation. We conclude that cost-leadership and marketing differentiation strategies have no direct effect on firm performance but have combination effects with CEO characteristics, while innovative differentiation strategy has direct effect on firm performance but has no combination effect. Our primary contribution is that we test and confirm that the fit between competitive strategies and CEO characteristics are an important consideration to increase firm performance in venture businesses.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.130-143
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• 2019

The purpose of this study is to identify factors of 25~36 months old infant's happiness and to develop a scale to measure infant happiness. The subjects were 250 infants aged 25~36 months. The results of this study are as follows: First, the components and items of infant's happiness scale selected through the literature, the previous measurement tool, and the focus group interview were 8 components and 29 items. The items were composed of 4 items of problem behavior, 4 items of achievement through immersion, 4 items of relationship with friends, 4 items of relationship with teacher, 3 items of physical environment, 4 items of positive emotion, 3 items of negative emotion, and 3 items of health. Second, as a result of validation of validity for infant's happiness scale, the item fit was confirmed with CFI=0.89, TLI=0.88, and RMR=0.05. Also, the construct validity was confirmed with convergent validity and discriminant validity. The concurrent validity was significantly correlated with the components of the previously developed measurement tools, and the reliability was appeared with 0.71-0.89. The infant's happiness scale developed in this study ensured reliability and validity as a measurement to measure infant happiness. Therefore, this scale is expected to be used as a major test tool to develope and verify a program for promoting infant happiness.

• Journal of Ocean Engineering and Technology
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• v.33 no.2
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• pp.168-177
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• 2019

KRISO (Korea Research Institute of Ship & Ocean Engineering) started a project to develop the core algorithms for autonomous intervention using an underwater robot in 2017. This paper introduces the development of the robot platform for the core algorithms, which is an ROV (Remotely Operated Vehicle) type with one 7-function manipulator. Before the detailed design of the robot platform, the 7E-MINI arm of the ECA Group was selected as the manipulator. It is an electrical type, with a weight of 51 kg in air (30 kg in water) and a full reach of 1.4 m. To design a platform with a small size and light weight to fit in a water tank, the medium-size manipulator was placed on the center of platform, and the structural analysis of the body frame was conducted by ABAQUS. The robot had an IMU (Inertial Measurement Unit), a DVL (Doppler Velocity Log), and a depth sensor for measuring the underwater position and attitude. To control the robot motion, eight thrusters were installed, four for vertical and the rest for horizontal motion. The operation system was composed of an on-board control station and operation S/W. The former included devices such as a 300 VDC power supplier, Fiber-Optic (F/O) to Ethernet communication converter, and main control PC. The latter was developed using an ROS (Robot Operation System) based on Linux. The basic performance of the manufactured robot platform was verified through a water tank test, where the robot was manually operated using a joystick, and the robot motion and attitude variation that resulted from the manipulator movement were closely observed.

• Journal of Convergence for Information Technology
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• v.9 no.9
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• pp.219-228
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• 2019

The purpose of this study was to develop a tool to assess the job satisfaction of dental hygienists and to evaluate the validity and reliability of the dental hygienist. A total of 54 items were translated into 24 items through content validity and content analysis. The results of this study are as follows: overall satisfaction, income, patient relations, professional time, personal time, Practice Management, Delivery of Care and co-worker relations were classified by exploratory factor analysis. The fit of the model through confirmatory factor analysis generally met the criteria. As a result of the internal consistency test, Cronbach's ${\alpha}$ was found to be a reliable measure of measurement, with an overall satisfaction of 0.918, an income of 0.833, a patient relationship of 0.804, an occupational time of 0.675, a personal time of 0.939, a work practice of 0.739, The validity and reliability of the dental hygienist 's job satisfaction measurement tool were verified to be appropriate. It can be used to study the job satisfaction of dental hygienist in the future.