• Journal of Korean Society on Water Environment
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• v.26 no.5
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• pp.841-849
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• 2010

Soil erosion is an natural phenomenon. However accelerated soil erosion has caused many environmental problems. To reduce soil loss from a watershed, many management practices have been proposed worldwide. To develop proper and efficient soil erosion best management practices, soil erosion rates should be estimated spatially and temporarily. The Universal Soil Loss Equation (USLE) and USLE-based soil erosion and sediment modelling systems have been developed and tested in many countries. The Sediment Assessment Tool for Effective Erosion Control (SATEEC) system has been developed and enhanced to provide ease-of-use interface to the USLE users. However many researchers and decision makers have requested to enhance the SATEEC system for simulation of soil erosion and sediment reflecting effects of single storm event. Thus, the SATEEC R factors were estimated based on 5 day antecedent rainfall data. The SATEEC 2.1 daily R factor was applied to the study watershed and it was found that the R2 and EI values (0.776 and 0.776 for calibration and 0.927 and 0.911 for validation) with the daily R were greater than those (0.721 and 0.720 for calibration and 0.906 and 0.881 for validation) with monthly R, which was available in the SATEEC 2.0 system. As shown in this study, the SATEEC with daily R can be used to estimate soil erosion and sediment yield at a watershed scale with higher accuracy. Thus the SATEEC with daily R can be efficiently used to develop site-specific soil erosion best management practices based on spatial and temporal analysis of soil erosion and sediment yield at a daily-time step, which was not possible with USLE-based soil erosion modeling system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.9
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• pp.681-688
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• 2013

Several problems caused by inevitable increment of airplane have been issued. The most effective solution to solve the issues is considered as establishing appropriate Air Traffic Management (ATM) that reduces aircraft's delay at an airport and intensify the airport's capacity. The purpose of this paper is to produce the optimum aircraft schedules that maximize the aircraft throughput by smooth air traffic flow near terminal area of an airport In this paper, mathematical formulations of the scheduling problem are firstly specified. Based on the mathematical modelling, an Optimization-Based Flight Scheduler that provides the optimum flight schedules for arriving aircraft is developed by introducing the Mixed Integer Linear Programming(MILP) and the Genetic Algorithms(GA). With this scheduler, we calculated the optimum schedules to compare to real schedule data from an Incheon Airport. As a result, it is validated that aircraft throughput produced by the optimum schedule is much better than that of the schedule from the Incheon airport. The optimization-based flight scheduler is expected to deal with problems due to the aircraft saturation in near future.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.4
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• pp.246-257
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• 2015

The progressive degradation paths of structures have quantitatively been tracked by using stochastic processes, such as Wiener process, gamma process and compound Poisson process, in order to consider both the sampling uncertainty due to the usual lack of damage data and the temporal uncertainty associated with the deterioration evolution. Several important features of stochastic processes which should carefully be considered in application of the stochastic processes to practical problems have been figured out through assessing cumulative damage and lifetime distribution as a function of time. Especially, the Wiener process and the gamma process have straightforwardly been applied to armors of rubble-mound breakwaters by the aid of a sample path method based on Melby's formula which can estimate cumulative damage levels of armors over time. The sample path method have been developed to calibrate the related-parameters required in the stochastic modelling of armors of rubble-mound breakwaters. From the analyses, it is found that cumulative damage levels of armors have surely been saturated with time. Also, the exponent of power law in time, that plays a significant role in predicting the cumulative damage levels over time, can easily be determined, which makes the stochastic models possible to track the cumulative damage levels of armors of rubble-mound breakwaters over time. Finally, failure probabilities with respect to various critical limits have been analyzed throughout its anticipated service life.

• Archives of design research
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• v.19 no.5 s.67
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• pp.313-322
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• 2006

Among many modelling factors which consist of a screen, a form brings a child's psychological response, according to its being drawn and expressed shape, and would be defined as a visual descriptive method which transmits the relation between the subject and background by a story content and the circumstance and emotion of characters in the story. In this study, to analyze how an expressed form on a screen works to a child visually and psychologically, I, first have examined how differently a child's perception development and its experience to the form is come out by the age of a child, and have found that it influences on a child's originality and creativity development, visual and psychological thinking development, and the stimulation on dream and imagination. And I have examined each characteristic by discriminating the expressive style of the form into a reproductive, a simplified, an exaggerated and a distorted form expression, and by utilizing it as substantiative data through the 1st and 2nd stage, have analyzed responses and preferences according to a style of a child's expression form. In conclusion, I have considered that the analysis result through the substantiative study would be a help not only to the form expression which is based on an illustrator's personality and creativity, and also would be utilized in the effective expression method study and experiment of students who learns the illustration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.618-627
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• 2017

Recently, the number of cases of child abuse has been increasing and, consequently, the social interest in this issue is increasing. The purpose of this study is to examine the relationship between child abuse, rejection sensitivity and emotional regulation and to identify the mediating effects of rejection sensitivity in the relationship between child abuse and emotional regulation. For this purpose, a survey on child abuse, rejection sensitivity and emotional regulation was administered to 217 elementary school students in the fourth, fifth and sixth grades, who had been reported as victims of child abuse or managed as suspected child abuse victims in the Seoul, Gyeonggi, Gangwon, Chungcheong, and Gyeongsang regions. The data was analyzed using structural equation modelling and bootstrapping. The findings showed that child abuse was significantly negatively correlated with emotional regulation, but positively correlated with rejection sensitivity. Emotional regulation was significantly negatively correlated with rejection sensitivity. Second, the structural equation analysis also revealed that rejection sensitivity fully mediated the relationship between child abuse and emotional regulation. This means that child abuse has an indirect effect on emotional regulation through rejection sensitivity. Therefore, when counseling abused children with emotional regulation problems, it is important for the counselors to include interventions designed to lower their rejection sensitivity.

• Journal of KIISE:Software and Applications
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• v.37 no.2
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• pp.110-119
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• 2010

In this paper, we propose an automatic segmentation of the prostate using intensity distribution and gradient information in MR images. First, active shape model using adaptive intensity profile and multi-resolution technique is used to extract the prostate surface. Second, hole elimination using geometric information is performed to prevent the hole from occurring by converging the surface shape to the local optima. Third, the surface shape with large anatomical variation is corrected by using 2D gradient information. In this case, the corrected surface shape is often represented as rugged shape which is generated by the limited number of vertices. Thus, it is reconstructed by using surface modelling and smoothing. To evaluate our method, we performed the visual inspection, accuracy measures and processing time. For accuracy evaluation, the average distance difference and the overlapping volume ratio between automatic segmentation and manual segmentation by two radiologists are calculated. Experimental results show that the average distance difference was 0.3${\pm}$0.21mm and the overlapping volume ratio was 96.31${\pm}$2.71%. The total processing time of twenty patient data was 16 seconds on average.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.2926-2934
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• 2010

The purpose of this study was to examine the satisfaction level and behavioral intention of visitors in a health care and medical equipment fair in consideration of their benefits sought. The purpose is basically meant to identify the relationship of variables related to the satisfaction level of the visitors, their satisfaction level with benefits sought and behavioral intention to provide useful information to hosts of health care and medical equipment fairs and related people. The subjects in this study were 250 people who were selected from among the visitors in a health care and medical equipment fair in Wonju. After a survey was conducted, the collected data were analyzed by SPSS 14.0 and AMOS 16.0 programs, and descriptive statistics, factor analysis, reliability analysis and structural equation modelling were utilized. The findings of the study were as follows: Benefits sought had a significant impact on satisfaction level and behavioral intention, and satisfaction level affected behavioral intention in a significant manner as well. So all the hypotheses formulated in the study were accepted, and those who hosted a health care and medical equipment fair should try to address the needs of participants in the light of their characteristics and provide appropriate event products and services to stir up their satisfaction level and behavioral intention.

• Journal of the Korean Institute of Navigation
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• v.23 no.1
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• pp.75-84
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• 1999

Although many studies on modelling of port competitive situation have been conducted, both theoretical frame and methodology are still very weak. In this study, therefore, a new algorithm called ESD (Extensional System Dynamics) for the evaluation of port competition was presented, and applied to simulate port systems in northeast asia. The detailed objectives of this paper are to develop Unit fort Model by using SD(System Dynamics) method; to develop Competitive Port Model by ESD method; to perform sensitivity analysis by altering parameters, and to propose port development strategies. For these the algorithm for the evaluation of part's competition was developed in two steps. Firstly, SD method was adopted to develop the Unit Port models, and secondly HFP(Hierarchical Fuzzy Process) method was introduced to expand previous SD method. The proposed models were then developed and applied to the five ports - Pusan, Kobe, Yokohama, Kaoshiung, Keelung - with real data on each ports, and several findings were derived. Firstly, the extraction of factors for Unit Port was accomplished by consultation of experts such as research worker, professor, research fellows related to harbor, and expert group, and finally, five factor groups - location, facility, service, cargo volumes, and port charge - were obtained. Secondly, system's structure consisting of feedback loop was found easily by location of representative and detailed factors on keyword network of STGB map. Using these keyword network, feedback loop was found. Thirdly, for the target year of 2003, the simulation for Pusan port revealed that liner's number would be increased from 829 ships to 1,450 ships and container cargo volumes increased from 4.56 million TEU to 7.74 million TEU. It also revealed that because of increased liners and container cargo volumes, length of berth should be expanded from 2,162m to 4,729m. This berth expansion was resulted in the decrease of congested ship's number from 97 to 11. It was also found that port's charge had a fluctuation. Results of simulation for Kobe, Yokohama, Kaoshiung, Keelung in northeast asia were also acquired. Finally, the inter port competition models developed by ESB method were used to simulate container cargo volumes for Pusan port. The results revealed that under competitive situation container cargo volume was smaller than non-competitive situation, which means Pusan port is lack of competitive power to other ports. Developed models in this study were then applied to estimate change of container cargo volumes in competitive relation by altering several parameters. And, the results were found to be very helpful for port mangers who are in charge of planning of port development.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.12
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• pp.821-827
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• 2014

The 4major river project has caused changes in flow and water quality patterns in major rivers in Korea including the Nakdong River where several toxicant release accidents have had occurred. Three dimensional hydrodynamic model, the Environmental Fluid Dynamics Code (EFDC), was applied to evaluate the effect of geomorphological change of the river on the advection and dispersion patterns of a conservative toxic pollutant. A hypothetical scenario was developed using historical data by assuming a toxic release from an upstream location. If there is a toxic release at the Gumi Industrial Complex, the toxic material would be detected after 2.22 and 9.83 days at Chilgok and Gangjung weir, respectively, in the new river system. It was estimated that they took at least 12 times longer than those with the river conditions before the project. Effect of relocation of intake towers for Daegu Metro City to upstream of Gumi City was also evaluated using the developed modeling system. It was observed that hydraulic residence time would be increased due to decreased flow rate and thus due to lowered water level. However, peak concentration differences were found to be about 2% lower in both places due to increased dispersion effect after the relocation.

• Journal of the Korea Society of Computer and Information
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• v.25 no.7
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• pp.203-211
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• 2020

This purpose of this study is to verity the impact of new logistics factors on the Intention of use and consumer happiness, the mediating effect of perceived benefits, and provide suggestions on how to improve the level of new distribution. Based on the previous theories of online experience, off-line experience, logistics experience, perceived benefits, Intention of use and consumer happiness, the study puts forward 6 key research hypotheses. Reliability and validity tests were carried out by using data collected on new logistics factors on the Intention of use and consumer happiness. The hypotheses are verified through structural equation modelling. The study on the impact of new logistics factors on the Intention of use and consumer happiness and the mediating effect of perceived benefits, indicates that online experience, off-line experience, logistics experience have positive effects on perceived benefits, the perceived benefits has positive effects on Intention of use and consumer happiness, and the Intention of use has positive effects on consumer happiness. Moreover, perceived benefits as the mediating variable have effects on the relationship between online experience, off-line experience, logistics experience and the Intention of use and consumer happiness. The study extended the existing previous studies to provide theoretical and practical implications by verifying the relationship between new logistics factors and the Intention of use and consumer happiness.