• Journal of Advanced Navigation Technology
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• v.2 no.1
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• pp.61-67
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• 1998

In this paper, we have described the Ramp Activity Coordination Expert System (RACES) which can solve aircraft parking problems. RACES includes a knowledge-based scheduling problem which assigns every daily arriving and departing flight to the gates and remote spots with the domain specific knowledge and heuristics acquired from human experts. RACES processes complex scheduling problem such as dynamic inter-relations among the characteristics of remote spots/gates and aircraft with various other constraints, for example, custome and ground handling factors at an airport. By user-driven modeling for end users and knowledge-driven near optimal scheduling acquired from human experts, RACES can produce parking schedules of aircraft in about 20 seconds for about 400 daily flights, whereas it normally takes about 4 to 5 hours by human experts. Scheduling results in the form of Gantt charts produced by the RACES are also accepted by the domain experts. RACES is also designed to deal with the partial adjustment of the schedule when unexpected events occur. After daily scheduling is completed, the messages for aircraft changes and delay messages are reflected and updated into the schedule according to the knowledge of the domain experts. By analyzing the knowledge model of the domain expert, the reactive scheduling steps are effectively represented as rules and the scenarios of the Graphic User Interfaces (GUI) are designed. Since the modification of the aircraft dispositions such as aircraft changes and cancellations of flights are reflected to the current schedule, the modification should be notified to RACES from the mainframe for the reactive scheduling. The adjustments of the schedule are made semi-automatically by RACES since there are many irregularities in dealing with the partial rescheduling.

• International Journal of Computer Science & Network Security
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• v.22 no.8
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• pp.97-104
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• 2022

European integration processes have acted as a catalyst for the emergence of a new type of educational environment, which is characterized by competent flexibility of specialists. Therefore, the article focuses on professional training of teachers in the context of European integration processes using information technology and the search for innovative methods of training specialists. One of the educational priorities in Europe is to create a new model of a teacher who has an academic education, knows innovative methods, is able to perform functions and tasks efficiently and professionally, adequately, quickly and correctly respond to changes and innovations. The tasks facing education in the European dimension are formulated. The main trends in the education of teachers in modern Europe are described: the need to deepen and expand subject training programs in pedagogical institutions of Higher Education, which will allow autonomy of activity, awareness of responsibility for independent creative decisions, create favorable conditions for the development of professionalism through the use of Information Technology and the search for innovative methods of training specialists. At the present stage, various models of teacher training are being developed based on the University and practical concept using information technology and searching for innovative methods of training specialists. On this basis, two different theories of perception of teacher education were formed: as preparation of teachers for work throughout their professional career; as preparation for the first years of professional work, which is periodically repeated in the process of continuous professional training and improvement. Among the advantages that the use of Information Technology and the search for innovative methods of training specialists to implement the learning process, it is worth mentioning the following: simultaneous use of several channels of perception of the student or student in the learning process, thanks to which the integration of information processed by different sensory organs is achieved; the ability to simulate complex real experiments; visualization of abstract information by dynamic representation of processes, etc.

• The Journal of the Korea Contents Association
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• v.17 no.6
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• pp.504-513
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• 2017

This study investigated one of the controversial issues on debate or even controversial between policy makers at the government and corporate levels: To examine any financial determinants on the cash holdings of the firms in the advanced and emerging capital markets. Futhermore, it focused on the large representative firms headquartered in the U.S. and the Republic of Korea, taking into account scarcity of the previous literature concentrated on the comparative studies on this particular subject. Several legitimate, but robust econometric estimations such as static and dynamic panel data models and Tobit regression, were applied to investigate possible financial factors ono the cash liquidity. Given the continued debates or arguments on the excess cash reserves between interest partied at the government and corporate levels in the advanced and/or emerging capital markets, and more accelerated capital transfers among associated nations by engaging in the arrangements of the FTAs, the results of the study may provide a vision to search for the optimal level of corporate cash holdings for firms in the two nations.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.6
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• pp.689-695
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• 2015

The offshore plant crews that were commissioned in the commercial startup phase boarded the offshore plant in two shifts until the end of the project. The crews who were hired by the owner side stayed in the original offshore plant during the project. However, most of the offshore plant commissioned members who were dispatched from the shipyard were accommodated in the offshore accommodation barge. For this reason, they were exposed to many accidents since there are a lot of people staying in a small space. This study suggested a method for improving survival rate at offshore accommodation barge in terms of life safety. It is assumed that the fire accident among unfortunate events which take place in the offshore accommodation barge mainly occurred. So, this study analyzed the safety evacuation for offshore plant employees using fire simulation model based on both domestic and international law criteria. In particular, When fire occurs in the offshore accommodation barge, the periodically well trained crews are followed safety evacuation procedure. whereas many employees who have different background such as various occupations, cultural differences, races and nationality can be commissioned with improper evacuation behaviors. As a result, the risk will be greater than normal situation due to these inappropriate behaviors. Therefore, This study analyzed the Required Safe Escape Time (RSET) and Available Safe Escape Time (ASET). Also it was suggested the improvement of structure design and additional arrangement of safety equipment to improve the survival rate of the residents in offshore accommodation barge.

• Journal of Families and Better Life
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• v.21 no.2
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• pp.1-18
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• 2003

In recent years, Korean society has witnessed an increased interest in the observance of everyday life proprieties, building healthy families, and psychological well-being of family members. The main purpose of this research was to examine the relationships among the practice of everyday life proprieties, dynamics of family systems, and psychological well-being of Korean married couples. A self-report Questionnaire was used to collect data from married couples with a child over four-years-old who are currently residing in Seoul. 513 couples(1026 individuals) were used for the final data analysis. Statistical analyses were conducted using frequencies, percentages, means, standard deviations, Cronbach'α, Pearson correlation, paired t-test, factor analysis, and multiple regression. The findings of this study are as follows: First, the level of the practice of everyday life propriety was relatively high in both husbands and wives, and no significant gender difference was found in the level. Yet, there were some statistically significant differences in certain sub-dimensions. Wives showed a higher degree of performance in public decorum and social etiquette, whereas husbands exhibited a higher degree of performance in family decorum and communication manners. The family systems were highly dynamic, according to both husbands and wives, and there was no difference between husbands and wives. As for the sub-dimensions, the extent of communication was found to be higher among husbands than among wives. Psychological well-being was again relatively high for both husbands and wives, with husbands significantly higher than wives. Second, the findings indicate that the causal model did fit the data well, and that a myriad of background variables had direct and indirect impacts on psychological well-being, and these relationships were mediated by several variables in the sub-dimension of proprieties observance, family adaptability, and the degree of communication. The implication is that the practice of life propriety, an intervening variable, is crucial in improving psychological well-being of married couples. The findings of this research demonstrate that there are significant causal relationships among the practice of everyday life propriety, family systems dynamics, and psychological well-being. In addition, the observance of proprieties is shown to be a concept that can be used as an important predictor in the area of family resource management. Further research is needed to expand its focus on the practice of proprieties in the family resource management. More concrete and specialized family life education programs should be developed to help build healthy families. Lastly, the results indicate that proprieties education needs to be incorporated in family policies in order to promote the quality of family life.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.4
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• pp.231-241
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• 2021

Although the deterioration of bridges may occur due to various causes, one of the representative causes is that the chloride used for deicing in the winter penetrates bridge members and results in corrosion. This study aims to quantify the ageing degree resulting from the corrosion of a bridge, apply it to the inelastic dynamic analysis model of the bridge, perform a seismic fragility analysis, and evaluate the relationship between the ageing degree and the seismic fragility curve. It is important to appropriately define the threshold values for each damage state in seismic fragility analyses considering the ageing degree. The damage state was defined using the results of existing experimental studies on the characteristics of the deterioration in the displacement ductility capacity of the pier, according to the ageing degree. Based on the seismic fragility analyses of six types of bridges divided by three types of bearing devices and two pier heights, it was found that the seismic vulnerability tends to increase with the ageing degree. The difference in seismic vulnerability with respect to the ageing degree exhibits a tendency to increase as the damage state progresses from slight to moderate, severe, and collapse.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.53-60
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• 2002

Motion of lung tumors from respiration has been reported in the literature to be as large as of 1-2 cm. This motion requires an additional margin between the Clinical Target Volume (CTV) and the Planning Target Volume (PTV). While such a margin is necessary, it may not be sufficient to ensure proper delivery of Intensity Modulated Radiotherapy (IMRT) to the CTV during the simultaneous movement of the DMLC. Gated treatment has been proposed to improve normal tissues sparing as well as to ensure accurate dose coverage of the tumor volume. The following questions have not been addressed in the literature: a) what is the dose error to a target volume without gated IMRT treatment\ulcorner b) what is an acceptable gating window for such treatment. In this study, we address these questions by proposing a novel technique for calculating the 3D dose error that would result if a lung IMRT plan were delivered without gating. The method is also generalized for gated treatment with an arbitrary triggering window. IMRT plans for three patients with lung tumor were studied. The treatment plans were generated with HELIOS for delivery with 6 MV on a CL2100 Varian linear accelerator with a 26 pair MLC. A CTV to PTV margin of 1 cm was used. An IMRT planning system searches for an optimized fluence map ${\Phi}$ (x,y) for each port, which is then converted into a dynamic MLC file (DMLC). The DMLC file contains information about MLC subfield shapes and the fractional Monitor Units (MUs) to be delivered for each subfield. With a lung tumor, a CTV that executes a quasi periodic motion z(t) does not receive ${\Phi}$ (x,y), but rather an Effective Incident Fluence EIF(x,y). We numerically evaluate the EIF(x,y) from a given DMLC file by a coordinate transformation to the Target's Eye View (TEV). In the TEV coordinate system, the CTV itself is stationary, and the MLC is seen to execute a motion -z(t) that is superimposed on the DMLC motion. The resulting EIF(x,y)is inputted back into the dose calculation engine to estimate the 3D dose to a moving CTV. In this study, we model respiratory motion as a sinusoidal function with an amplitude of 10 mm in the superior-inferior direction, a period of 5 seconds, and an initial phase of zero.

• The Journal of the Korea Contents Association
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• v.18 no.2
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• pp.178-187
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• 2018

This study aimed to develop a model of the program for automation measuring the preference of the portraits based on the relationship between the image quality factors and the preferences in the portraits for manufacturers aiming at high utilization of the users. in order to proceed with the evaluation, the image quality measurement was divided into objective and subjective items, and the evaluation was done through image processing and statistical methods. the image quality measurement items can be divided into objective evaluation items and subjective evaluation items. RSC Contrast, Dynamic Range and Noise were selected for the objective evaluation items, and the numerical values were statistically analyzed and evaluated through the program. Exposure, Color Tone, composition of person, position of person, and out of focus were selected for subjective evaluation items and evaluated by image processing method. By applying objective and subjective assessment items, the results were very accurate, with the results obtained by the developed program and the results of the actual visual inspection. but since the currently developed program can be evalua ted only after facial recognition of the person, future research will need to develop a program that can evaluate all kinds of portraits.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.4
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• pp.337-346
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• 2020

Traffic jam and congestion in urban areas has caused the need to improve the utility of underground space. In response, research on underground structures is increasingly being conducted. Notably, a double-deck tunnel is one of the most widely used of all those underground structures. This double-deck tunnel is separated by the middle slab into the upper and lower roadways. Both vehicle load and earthquake load cause the middle slab to exhibit dynamic behavior. Earthquake-related response characteristics, in particular, are highly complex and difficult to interpret in a theoretical context, and thus experimental research is required. The aim of the present study is to assess the stability of a double-deck tunnel's middle slab of the Collapse Prevention Level and Seismic Category 1 with regard to the presence of vibration-damping Rubber Bearings. In vibration table tests, the ratio of similitude was set to 1/4. Linings and vibrating platforms were fixed during scaled model tests to represent the integrated behavior of the ground and the applied models. In doing so, it was possible to minimize relative behavior. The standard TBM cross-section for the virtual double-deck tunnel was selected as a test subject. The level of ground motion exerted on the bedrock was set to 0.154 g (artificial seismic wave, Collapse Prevention Level and Seismic Category 1). A seismic wave with the maximum acceleration of 0.154 g was applied to the vibration table input (bedrock) to analyze resultant amplification in the models. As a result, the seismic stability of the middle slab was evaluated and analyzed with respect to the presence of vibration-damping rubber bearings. It was confirmed that the presence of vibration-damping rubber bearings improved its earthquake acceleration damping performance by up to 40%.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.6
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• pp.17-24
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• 2002

Dynamic behaviors of a bridge system with several simple spans are evaluated to examine the effects of nonlinear abutment motions upon the seismic responses of the bridge. The idealized mechanical model for the whole bridge system is developed by adopting the multi-degree-of-freedom system, which can consider various influential components. To compare the results, both linear and nonlinear abutment-backfill models are prepared. The linear system has the constant abutment stiffness, and the nonlinear system has the nonlinear stiffness considering the abutment stiffness degradation due to the abutment-soil interaction. From simulation results, the nonlinear abutment motion is found to have an important influence upon the global bridge motions. Maximum relative distances between adjacent vibration units are found to be larger than those found from the linear system. In particular, maximum relative distances at the location with the highest possibility of unseating failure are increased up to about 30% in the nonlinear system. The effects of nonlinear behavior of an abutment on the bridge seismic behaviors are also increased as the number of span increase. Therefore, it can be concluded that the abutment-soil interaction should be considered in the seismic analysis of the bridge system.