Do-Young Jung

A new buck-boost dc/dc converter of high efficiency by soft switching technique

In this paper, we study on a new buck-boost dc/dc converter of high efficiency by soft switching technique. The switching devices in the proposed converter are operated by soft switching with a new partial resonant circuit. The partial resonant circuit is designed to replacement of an energy storage inductor and a snubber circuit used in a conventional buck-boost converter, and then the configuration of the proposed converter is simplified. The switching control technique of the converter is also simplified for the switches to drive in a constant switching frequency. The results are that the switching power loss is very low and system efficiency is high. In addition, the output voltage of the converter is regulated by PWM control technique, and the discontinuous current flowing into the resonant inductor of the converter makes to simplify control method and control components. In comparison with the conventional buck-boost dc/dc converter, some simulation results on computer and experimental results are confirmed the validity of analytical results of the proposed converter.

Influences of Safety-Practice and Cognitive Failure on Safety Accident among Middle Students

This study was investigate to impact on safety accidents occurrence for the safety practices of middle school students learn the extent of the failure. A total of 292 patients and it survey data were collected from 5 November 2012 to 11 May 25 of research subjects. Research tools were used SPSS win17.0, the mean and standard deviation, Paired t-test, Pearsons correlation coefficient was used. Safey practice and cognitive failure of subjects was related to negative correlation and according as safety practices was higher, cognitive failure was low. According as safety practices and cognitive failure was low, Safety incidents experienced was high. Therefore, by applying safety practices and cognitive failu re degree, it need to for research to come up with ways for the prevention of safety accidents. Besides, A variety of safety and accident prevention training programs by expanding the scope of the study in school, it should be done generalization of safety awareness, cultivate and Safety practice.

A Study on Design and Operation Performance of Automatic Fire Detection Equipment (P-type One-class Receiver) by Bidirectional Communication

In this paper, authors will develop the quick and precise remote controller of automatic fire detection equipment (P-type one-class receiver) based on information communication technology (IT). The remote controller detects the fire and disaster in the building automatically and quickly and then activates the facilities to extinguish the fire and disaster, monitoring such situation in a real time through wire-wireless communication network. The proposed remote controller is applied a programmable logic device (PLD) micom. of one-chip type which is small size and lightweight and also has highly sensitive-precise reliabilities. The one-chip type PLD micom. analyzes digital signals from sensors, then activates fire extinguishing facilities for alarm and rapid suppression in a case of fire and disaster. The detected data is also transferred to a remote situation room through wire-wireless network of RS232c and bluetooth communication, and then the situation room sends an emergency alarm signal. The automatic fire detection equipment (AFDE) based on IT will minimize the life and wealth loss while prevents fire and disaster.

A Study on the Improvement Plan of Industrial Safety and Health Education for Industrial Disaster Prevention

This study is aimed to provide the basic data for improve plan of industrial safety and health education for industrial disaster prevention. The self-administered questionnaire were given to 167 manufacturing industry workers of 5 manufactural workplace in Kangwon province during the period from March 15th to April 15th, 2010. As a results, The rate of 76.6% in manufacturing industry workers have educational place for industrial safety and health education, but their industrial safety and health education was established in the workplace office, about 44.3%. Industrial safety and health education almost was done by means of lecture. Industrial safety and health education for manufacturing industry worker was done without thinking about general characteristics and kinds of work of manufacturing industry workers. The results of this study indicate that industrial safety and health education are needed to improve the problems. To improve the industrial safety and health education, it is necessary to be established industrial safety and health education thinking about general characteristics and kinds of work of workers.

Relationship among safety accident, impulsiveness and maternal child-rearing attitude of elementary students

This aim of the study intended to investigate the relationship among safety accident, impulsiveness and maternal child-rearing attitude of elementary students. The study was also done to acquire basic information on safety education program to help students be more aware of safety. A research was conducted from November 15 to 24, 2010 by means of self-report questionnaires distributed to 558 elementary students. Safety accident occurrence of subject is 51.3%, and the most frequent place was on school and home around. The safety accident occurrence was statistically significant difference according to students` gender, grade and the level of school life attitude. The safety accident occurrence correlated positively with authoritarian control, overprotection, and achievement, as defined maternal child-rearing attitude, and not with impulsiveness. The results of this study indicate that safety education program are needed to prevent the safety accidents, and to change the maternal child-rearing attitude of elementary students.

A study on the Prevention of industrial Disaster of the Coal Mining Industry through Safety Education

This study aims to examine the current situation of safety education of coal mining industry in Gangwon province, and suggest its problems and improvement directions. And the theoretical background was established through the literature, a survey study for general workers were conducted and its data were analyzed.

The Development of Landslide Predictive System using Measurement Information based on u-IT

Abstract This paper has studied about the development and application of landslide collapse prediction real-time monitoring system based on USN to detect and measure the collapse of landslide. The rainfall measuring sensor, gap water pressure sensor, indicator displacement measuring sensor, index inclination sensor, water content sensor and image analysis sensor are selected and these are applied on the test bed. Each sensors operation and performance for reliability verification is tested by the instrument which is installed in the field. As the result, u-IT based real-time landslide monitoring system which is developed by this research for landslide collapse detection could minimize life and property damages because it makes advance evacuation with collapse risk pre-estimate through real-time monitoring on roadside cut and bedrock slopes. This system is based on the results of this study demonstrate the effect escarpment plan are spread throughout. Key Words : Landslide Collapse, Real-Time Monitoring, Sensor, u-IT

Development of the Monitoring System Model Based on USN for Landslide Detection Using Tilting Sensor

This paper proposes a model of the real time monitoring system based on Ubiquitous Sensor Network (USN) for the detection and prediction of landslides. For this purpose, the real time monitoring system with tilting sensor and USN was set up and the performance was conducted. The performance was accomplished by conducting both field examinations and the experimental evaluation of the monitoring system. The results of this study show that the angle , , and of sensor position detected by the sensor module coincide with the data measured from USN monitoring system by giving a sampling time 100[msec]. Consequently, the proposed model of the real time monitoring system with tilting sensor based on USN will be widely used as a monitoring system in the exposure to dangerous landslide regions.