• The Journal of Korean Association of Computer Education
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• v.5 no.1
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• pp.57-66
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• 2002

Real time multimedia data services have been made possible by the rapid development of the computer and internet technology. Based on the technology, Many multimedia system developer try to use VOD(Video on Demand) and GVA technologies for distance education. However the system has mainly been developed to provide the video screen of good quality in real time and to compose contents efficiently. Not many researches and developments have been made for providing the users that is taking distance education with various types of service using VOD and GVA. Therefore In this paper we have designed and implemented an active on-demand multimedia service system to improve user-side service quality in distance education using VOD and GVA service. The on-demand multimedia service system can prominently help users to save the time and effort to search and select the studying data by this paper enables off-line search functions through E-mail and periodical current awareness service supported by PUSH technology, user oriented information booking supported by SDI service and feedback service.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.249-254
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• 2019

The concept of 'Edu-Tech', which is rapidly reorganized around e-Learning, has been spreading along with the development of intelligent information technology according to the fourth industrial revolution such as Artificial Intelligence (AI), Internet of Things (IoT), BigData. Currently, leading companies are conducting online education services, but real-time two-way communication is difficult. In addition, in the case of off-line class, there are many students, and not only the time is limited, but also they often miss the opportunities to ask questions. In order to solve these problems, this paper develops a real - time interactive question and answer management system that can freely questions both on - line and off - line by combining the benefits of offline instant answers and the advantages of online openness. The developed system is a real-time personalized education system that enables the respondent to check the situation of the questioner in real time and provide a customized answer according to the inquirer's request. In addition, by measuring and managing the system usage time in seconds, the questioner and the respondent can efficiently utilize the system.

• The Journal of Korean Institute for Practical Engineering Education
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• v.4 no.2
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• pp.158-161
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• 2012

Wee developed the automatic operation system for the laboratories equipment based on MATLAB GUI. By using Instrument Control Tool Box and standard protcol, PC and equipments are well connected each other. Wee developed the software to control the display of input and output between PC and equipments by using MATLAB GUI, This system will be effectively used in laboratories and experimental facilities and more in on-line education system for experiments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.487-495
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• 2021

The voltages mainly used in ships are 450 [V], 6.6 [kV], and 11 [kV], and an earthed system is applied to ensure the stability of the power distribution system. In general, low-voltage ships using 450 [V] apply an unearthed system, while high-voltage ships using 6.6 [kV] or 11 [kV] use a high-resistance earthed system. When an earth fault occurs in a ship's power distribution system, the voltage of the healthy phase increases to the line-to-line voltage or higher, which causes an excessive impact on the insulation of the cable. Thus, analyzing this behavior is very important. In this paper, we investigate the characteristics of the line-to-earth voltage variation according to earth faults and a recognition procedure of a faulty phase using the symmetrical coordinate method for a high-resistance earthed system and unearthed system. A mathematical model of the line-to-earth voltage was derived through the symmetric coordinate method, and the ship voltage for simulations was selected as 6.6 [kV] and 450 [V]. A MATLAB simulation proved that this method can determine the highest increase of the line-to-earth voltage, which leads by 120° on the faulty phase, and it accurately judges the faulty phase in both earthed systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.689-696
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• 2018

System grounding is applied to the neutral point of a power source to secure the from any abnormal voltage and/or grounding fault. System grounding, which is applied mainly in ships is an ungrounded and resistance grounded system. Vessels using the MV power system with 3.3kV, 6.6kV, and 11kV mainly adopt a high resistance grounding system among the resistance grounding systems. The ground fault accounts for 95% of all faults occurring in the electrical system and when a fault occurs, the line-to-ground voltage of the power system is increased excessively, which adversely affects the onboard insulation system. This study analyzed the variation characteristics of the line-to-ground voltage neutral point according to the degree of ground fault in a resistance ground system applied in vessels. For this purpose, the characteristics of the grounding system were first explained, and the modeling of the neutral point potential of the line-to-ground voltage of the resistance grounding system in the vessels was derived. Finally, this study examined how the line-to-ground voltage, line voltage, and neutral point change according to various variable environments through MATLAB simulations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.529-534
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• 2008

This study grasped the problem by examining the consciousness of professors about the e-learning and reached a conclusion as follows. The teaching-learning model of e-learning should be developed. Universities should develop study system modules that can select assortatively by learners according to the e-Learning course and present a new education model of university for the liberal arts course, areas needing an industry-academic cooperation and an lifelong education in university and so on. Also, the one step e-Learning course of four weeks quantities should be administered through developing combination courses that appropriately combine advantages both face-to-face courses and on-line courses to activate the e-Learning.

• Journal of Practical Engineering Education
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• v.11 no.2
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• pp.251-258
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• 2019

In order to establish the NIVTPD which is only one qualification training institute for vocational training teachers in Cameroon, the research team taught such as curriculum development methods, course materials development, and lecturing methodology for master teachers of NIVTPD. Also we prepared actual operation of NIVTPD by conducting actual lecture through Pilot training. This paper also includes two different surveys (Base-line and End-line surveys) results and two different tests (pre and post-test) results to assess the impact of training gained in NIVTPD on classroom performance. The results of the survey will be used for the improvement of NIVTPD's educational program through identifying the current state of the vocational training interface and integration, modification and improvement of the curriculum. Examination results can also be used as indicators for vocational training teachers' pedagogical knowledge and for future certification.

• Journal of Navigation and Port Research
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• v.33 no.2
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• pp.105-110
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• 2009

Shipwaves am have harmful effects on ships working on the sea, in a harbour or navigational channel and caused beach erosion, seawall destruction. This study aims to investigate describe the characteristics of the wave pattern generated by an individual model ship tested at different velocities and hull forms for a given water depth and to investigate the variations at a given distance from the sailing line under the same conditions. As a result, the angles a's by model ship tests are smaller than those by real ship ones. Wave heights decreases with an increasing the mid-ship cross sectional area $A_s$. The maximum wave height and period increase rapidly in the subcritical speed, and beyond the critical speed the height and period decrease with increasing depth Froude number. And the period keeps constant with the distance from the sailing line.

• Proceedings of the Korean Society of Computer Information Conference
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• 2009.01a
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• pp.147-152
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• 2009

정보 컴퓨터 분야의 실무현장에서 요구하는 인재는 바로 문제해결력과 프로젝트 수행능력을 갖춘 현장적 합성 연재라 하겠다. 본 논문에서는 정보 컴퓨터 분야의 전문계 고교에서 문제해결력과 프로젝트 수행능력을 갖춘 인력을 양성하기 위한 프로젝트식 모둠별 협력 학습 교육과정을 제안하고, 학습을 직접적으로 지원할 수 있는 온라인 평가 시스템을 설계 및 구현한다. 제안하는 시스템을 통해 진행되는 모둠별 학습을 체계적으로 관리할 수 있으며, 향후 같은 교육과정을 이수하는 학습자에게 사례 데이터베이스로서의 역할을 수행할 수 있을 것이다. 또한, 실무능력을 향상시키기 위한 외부전문가의 교과과정 참여를 이끌고 시간 공간적인 제약을 제안하는 시스템을 통해 극복할 수 있을 것이며, 각 진행 단계마다 평가되는 결과를 즉각적이고 다양한 형태로 피드백 해줌으로 해서 학습자는 동기부여와 학습강화 효과를 얻을 수 있다.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.2
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• pp.269-277
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• 2009

Ventilation equipment performs a central role to maintain comfort subway environment. So ventilation equipment of Busan subway line No.1 is required to improve thermal environment. In this study, conditions of thermal environment are presented to improve ventilation equipment at existing subway station platforms by measuring thermal environment of platforms operated ventilation equipment at 14 stations of Busan subway line No.1. AWS of data in comparison with the neighbouring platforms and thermal environment analysis. Thermal environment status of subway platform analysis results are as follows. 1)Daytime platform temperature was higher than outdoor temperature, but night time platform temperature was lower than outdoor temperature. 2)Train wind had effect on improving thermal comfort in platform. 3)When outdoor temperature is below $24^{\circ}C$, inlet air is able to lower than platform temperature. 4)Considering existing ventilation system, night purge systems is useful to improving platform thermal environment.