• Proceedings of the KIEE Conference
• /
• 2000.07b
• /
• pp.1330-1332
• /
• 2000

In general, the expected life of power semiconductor elements is known for semi-permanent, but actual characteristics are changed according to the such environment conditions obviously because of using time or operating condition. Specially, in case of using at the power plant it is very important to sustain reliability for power semiconductor which it affect to stop operating condition as deterioration or break. Therefore, we need to apply maintenance technics to got the reliability which is a prediction method of life cycle. This paper shows the result of the analyzed data for element characteristic and effects used practically and we had developed the effective equipment which for diagnostic the semiconductor performance.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.11a
• /
• pp.233-236
• /
• 2004

The purpose of this paper is to evaluate performance on reducing the chloride diffusion of surface treatment systems with elapsed time, treatment thickness, treatment frequency, and the types of surface treatment - coating, penetrator, and both all. Based on this paper, the guideline to applicate surface treatment systems will be established and comprehended how effective the resistance of chloride diffusion is. The selection of surface treatment materials and thickness to acquire service life of target will be possible. It is also expected to select optimum surface treatment system groups to resist chloride diffusion effectively and to estimate increased service life as the effect of durability enhancement.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.06a
• /
• pp.218-219
• /
• 2020

The risk of a fire in a building is closely related to the usage of the building. In particular, all fires that occur in a building are not risky to safety of human life, and it is associated with the combustion area and the increase of total floor area of the building. Therefore, this study focused on safety of human life in terms of the statistics of fire with considering the aspect of growing fires and analyzed the statistical data of fire for 10 years. As for the analysis on fire, the time of occurrence by usages of buildings, frequency of occurrence and the ratio of casualties etc. were analyzed. It is expected that results of this study could be used for evaluations on a variety of parts in terms of design, construction and maintenance of buildings.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.24
• /
• pp.10871-10874
• /
• 2015

Background: Gestational trophoblastic neoplasia (GTN) is a malignant disease which occurs in women of reproductive age. Treatment of GTN has an excellent outcome and further pregnancies can be expected. However, data concerning quality of life in these cancer survivor patients are limited. This study aimed to assess quality of life in women who were diagnosed with GTN and remission after treatment, and to determine factors that may affect quality of life status. Materials and Methods: This cross sectional study was conducted from July 2013 to May 2014 in the Gestational Trophoblastic Disease Clinic, King Chulalongkorn Memorial Hospital, Bangkok, Thailand. Patients who were diagnosed GTN and complete remission were recruited. Data collection was accomplished by interview with two sets of questionnaires, one general covering demographic data and the other focusing on quality of life, the fourth version of Functional Assessment of Cancer Therapy (FACT-G). Descriptive statistics were used to determine general data and quality of life scores. Students t-test and one way ANOVA were used to compare between categorical and continuous data. Results: Forty four patients were enrolled in this study. The overall mean quality of life score (FACT-G) was 98.2. The overall FACT-G score was not significantly correlated with age, education level, stage of disease, treatment modalities, and time interval from remission to enrollment. However, patients who needed further fertility showed significant lower FACT-G scores in the emotional well-being domain (p=0.02). Conclusions: Overall quality of life scores in post-treatment gestational trophoblastic neoplasia patients are in the mild impairment range. Patients who desire fertility suffer lower quality of life in the emotional well-being domain.

• Journal of Biosystems Engineering
• /
• v.38 no.3
• /
• pp.180-184
• /
• 2013

Purpose: This study explored the factors influencing heating value in the process of torrefaction of water hyacinth. Methods: Torrefaction was applied with three temperature settings (200, 300, $400^{\circ}C$) and three time settings (1, 2, 3 h) using small electric heaters (11.3L of holding volume). This study investigated the heating values with the washing process and process factors influenced the torrefaction. In addition, this study compared the heating values in washed and unwashed samples and suggested the optimal conditions for increasing heating value. Results: Torrefaction increased the heating value by 8.18 ~ 30.04%. Comparing heating values of each condition, the optimal temperature for torrefaction was $300^{\circ}C$ and holding time was 1 hour. The washing process increased the heating value by 19 ~ 27%. The heating value of the sample treated at $300^{\circ}C$ for three hours was 4310.80 kcal/kg, which was greater than the first class wood pellet of 4300 kcal/kg. Conclusions: This study proved that the torrefaction and washing process increased the heating value of water hyacinth. Therefore, water hyacinth is expected to be an eco-friendly biomass which substitutes for wood pellet.

• Journal of Families and Better Life
• /
• v.21 no.3
• /
• pp.47-60
• /
• 2003

The purpose of this study was to analyze the housewives' needs for educational program. In this study the needs lot housewives educational program are consisted on 3 areas ; 1. program contents, 2. program management and 3. program activization plan. For the survey and statistical analysis the questionares from 445 full-time housewives who participate in educational program at present are used. The results of this study are following； 1, in the area of program contents the needs for housing/health, nutrition, family life planning for elderly stage and enhancement of parents-children relationship are very high. This contents are very related with research topics of human ecology. So the researcher of our science are expected to be involved more in the related program development and actualization in the field. 2. in the area of program management the needs for the concret management process such as human resource management and education period are much higher than the educational provision. 3. in the area of program activization the systematization of the program incording with program level is most needed. 4. the housewive who are keeping the social characteristics such as social orientation, the motivation of social integration, the participation in the social-oriented educational program have higher needs for the most entire program contents, management and activization plan.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.3 no.1
• /
• pp.42-48
• /
• 2008

The architecture of WSN based Vehicle Speed Measurement System is presented in this paper from Telematics Sensor Network(TSN) to Management System. To verify the feasibility of the system, we implemented the vehicle speed measurement system and evaluated the accuracy of velocity measured by the system in our testbed, an old highway located near Kyungbu highway. The system performed over 95% of accuracy at 80kmph from the measurement. In addition, the battery life time of the sensor node was evaluated by simulation analysis with real measured current consumption profiles. Assuming the maximum average daily traffic in 2005, the battery life time is expected to be over 1.6 year from the simulation result.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.07a
• /
• pp.119-122
• /
• 2000

Recently polymer insulators are being used for outdoor high voltage applications. Polymer insulators for transmission line have significant advantages over porcelain and glass insulators, especially for ultra-high voltage transmission lines. Their advantages are light weight, vandalism resistance and hydrophobicity. Polymer insulators are a relatively new technology, but their expected life is still unknown. Therefore these estimating technique are very important. Their life time is related to weathering and operating condition. Multi-aging test is requested because aging factor is occurred by multi-aging than unique aging. The aging test about polymer insulators have mainly carried out by IEC 61109. This paper presents multi-stress chamber experiments and tracking wheel test to examine the tracking and erosion performance of polymer insulator for transmission. Multi-stress testing is able to demonstrate deficiencies of polymer insulator materials and designs, including the nature of interfaces in insulation design. We have investigated IEC 61109 Annex C (5000h aging test) and CEA tracking wheel test as test methods of artificial accelerated aging. The aging degree of polymer insulator is estimated by leakage current, measurement of hydrophobicity degree, damage conditions of insulator surface, withstand voltage test etc.

• Journal of the Korean Electrochemical Society
• /
• v.19 no.1
• /
• pp.14-20
• /
• 2016

Vanadium redox flow battery (VRFB) is an energy conversion device in which charging and discharging are alternatively carried out by oxidation and reduction reactions of vanadium ions with different oxidation states. VRFB consists of electrolyte, electrode, ion-exchange membrane, etc. The role of ion-exchange membranes in VRFB separates anolyte and catholyte and provides a high conductivity to hydrogen ions. Recently much attention has been devoted to develop ideal ion-exchange membranes for VRFB. A number of developed ion-exchange membranes should be evaluated to find out ideal ion-exchange membranes for VRFB. Long-term durability test is a crucial characterization of ion-exchange membranes for commercialization, but is very time-consuming. In this study, the life time prediction protocol of ion-exchange membranes in VRFB cell tests was developed through short-term single cell performance evaluation (real total operation time, 87.5 hrs) at three different current densities. We confirmed a decrease in test time up to 96.2% of real durability tests (expected total operation time, 2,296 hrs) and 5~6% of relative error discrepancy between the predicted and the real life time in a unit cell.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.12
• /
• pp.802-807
• /
• 2008

A Study on Typical Rates of Water-use for School Facilities has been carried out in this work. Water supply system is given much weight in school facilities. Therefore, it set up a basis efficiency using of water sources to calculate typical rates of water use. The results are summarized as follows; 1) On the whole, typical rates of water-use was founded out 15 L/stu. d in pirmary school, 10 L/stu. d in middle school and 30 L/stu. d in high school smaller than the existing it. It was rate of water-use change as season and Max. Rates of water-use was July. 2) I deem that school hours are 5 hour's in primary school, 7 hour's in middle school and 8 hour's in high school. It the concept of 1 hour that is lesson time 40 minutes and resting time 10 minutes in primary school, lesson time 45 minutes and resting time 10 minutes in middle school and lesson time 50 minutes and resting time 10 minutes in high school. 3) It is desired that we calculate the volume of pump and water tank throughout this concept and the size of water tank should be 1.5 times with taking peak load into consideration by this study on typical rate of water-use. 4) The amount of using water increases in gradually and I consider the life cycle of facilities is more than 10 years. As a result, I can forecast that the size will be insufficiency but I deem that if we devise a plan about parallel pumping on water tank space, we can cope with it. Also, it is expected that we can cut back the transport energy by controlling pump volume.