• International Journal of Aeronautical and Space Sciences
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• v.1 no.2
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• pp.30-42
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• 2000

On-orbit thermal environment test of KOMPSAT was performed in early 1999. An analysis of the test data are addressed in this paper. For the thermal-environmental simulation of spacecraft bus, an artificial heating through the radiator zones and onto some critical heat-dissipating electronic boxes was made by Absorbed-heat Flux Method. Test data obtained in terms of temperature history were reduced into flight heater duty cycles and converted into the total electrical power required for spacecraft thermal control. Verification result of flight heaters dedicated to the bus thermal control is presented. Additionally, an exhaustive heating-control process for maintaining the spacecraft thermally safe and for realistic simulation of the orbital-thermal environment during the test are graphically shown. Qualitative suggestions to post-test model correlation are given in consequency of the analysis.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1358-1364
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• 2019

The mechanical properties of Heavy duty resin of synthetic polyurethane-epoxy resin for stainless steel were measured by SEM, FT-IR, tensile properties, and specific mass loss by EIS analysis, etc. As interest in eco-friendly medium coatings increased, the Heavy duty coatings were synthesized for various metals such as stainless steel composed of Polyol, MDI, water bored Epoxy resin, filling agent, silicon surfactant, catalyst etc. The coatings of synthetic Heavy duty resin were increased tensile strength due to various temperature change, and the low-Specific Mass Loss was measured in a highly electrolytic solution. In conclusion, the Heavy Duty coatings composed of polyurethane and waterbored Epoxy resin were synthetic microstructure with cross linkage can be good material for coating of anticorrosion of metal substrates such as stainless steel.

• Journal of Hydrogen and New Energy
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• v.23 no.6
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• pp.634-639
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• 2012

The contribution levels of emissions from the heavy-duty vehicles have been continuously increased. Among the exhaust emissions, NOx (nitric oxides) have a ratio of 73.2% and particle matters have a proportion of 61.8% in the heavy-duty vehicles. Also, natural gas vehicles have the 78.9% of total registered local buses in Korea. Therefore, the investigation on emission characteristics of heavy-duty vehicles using CNG and diesel fuel according to the various driving cycles was carried out in this study. In order to analyze the emission characteristics, the five kinds of buses by using CNG and diesel fuels with a after-treatment devices (DPF, p-DPF) was used and five test driving schedules were applied for analysis of emission characteristics in a chassis dynamometer. To analyze the exhaust emission, the exhaust emission and PM analyzers were used. From this study, it is revealed that diesel buses with after-treatment had reduced emission of CO, HC, PM but NOx. Also, NMHC emission of CNG bus have a higher level and NOx level was similar with diesel buses. In addition, emissions in NIER06 with slow average speed shows lowest levels compared to other test modes.

• Journal of Korean society of Dental Hygiene
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• v.14 no.4
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• pp.453-462
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• 2014

Objectives : The purpose of the study is to investigate the education, certification system, and extent of duty of dental hygienist between Korea and five developed countries including United States, Canada, England, Australia, and Japan. Methods : Internet based access to five developed countries was made and the analysis was done for the definition of occupation, main duties, similar occupations, education policy, job descriptions, license certification system, standards of duty, Q & A management, current status of obtaining certification, and scope of work. Results : United States has a two-year associate degree(AS) and a four-year bachelor degree(BS). Canada has two to three years degree and a two-year course is accepted in england and Australia. In the meanwhile, Korea and Japan have two-year and four-year educational courses. The duty of dental hygienists includes the prevention education for dental health and continuing dental health care. Most of the dental hygienists in Korea and Japan play the assistant roles for the dental surgeons. United States has national board examinations including written examinations, practical examinations, and computer assisted examination. Written and practical examinations are also conducted in Korea. England and Australia have the recognized educational organizations for qualification. Conclusions : Problem based and problem solving skills are the most important in dental hygienist education in Korea. The training of highly competent dental hygienists must be done for the improvement of dental hygiene in Korea in the near future.

• International Commerce and Information Review
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• v.13 no.1
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• pp.217-241
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• 2011

The basic purpose of Customs Drawback System of the material for export goods is export support as cut a price down the export goods' price. Especially the trade volume between South Korea and China is the greatest in comparison with other countries in 2010. Therefore companies involved China is necessary to understand exactly for China's tariff system(duty drawback system). Due to inconsistent policies, it is difficult to understand VAT-related provisions on exports goods of China compared with South Korea Tax System. Accordingly, the results of this study is significant in China-related companies. In South Korea and China, amount of customs duty drawback is very large 4.017606 billion won 732.8 billion yuan respectively. Thus, the amount of customs duty drawback is greater, a comparison of customs duty drawback in South Korea and China is very necessary on Customs Drawback System.

• Culinary science and hospitality research
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• v.22 no.4
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• pp.222-239
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• 2016

This study is composed of both a research of research literature and empirical analysis. With regard to literature based, consideration was given to present conditions of domestic coffee shops, thhe definition of barista, the duty characteristics baristas, and intention to change job. Empirical analysis established hypotheses and verified the effect of duty characteristics on job satisfaction and turnover intention. A survey to verifying the hypothesis of study was performed for 400 baristas who were working at their coffee shops with selecting coffee shops randomly in Seoul and Kyeonggi-do. 2012.08.15~2012.08.30, for 15 days, I performed survey, without faithless answers and questionnaires which weren't written, I used total 331 papers for actual analysis. Collected basic data were analyzed through SPSS 18.0 program by frequency analysis, correlation analysis, factorial analysis, reliability analysis, regression analysis, and so on. I suggested like this for managing effective human resources. For increasing satisfaction of duty of barista, manager should give opportunity for attending important duty to barista, and because of this, barista can feel sense of responsibility and self-esteem.

• Journal of Korean Academy of Nursing Administration
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• v.5 no.3
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• pp.513-524
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• 1999

The shortage of nursing personnel was become one of the most serious problems in operating pediatric oncology nursing unit which was the first pediatric oncology nursing unit in Korea. The purpose of this study was to estimate the optimal number of nursing personnel by calculating nursing care hours. The subjects were 13 staff nurses and inpatients of pediatric oncology nursing unit at Seoul National University Hospital during the period of May 20, 1996, to June 2, 1996. The number of nurses' duty was 132, the number of patients treated was 1288 for these 2 weeks. The tools used for this study were pediatric patient classification indexes and direct & indirect care indexes. Each nurse measured the time that they spent for their activities by self record under the supervision of their nurse manager. The method used to calculate the number of nursing personnel was multiplication of the average number of nursing care hours per patient per day with the number of patients. Percentage, average, t-test, F-test were used for data analysis. The results of this study were as follows : 1) The distribution of patient class : Class I & II none, Class III 86.8%. Class IV 12.9% 2) Direct nursing care hours for a patient per shift according to patient classification: Class III : 27.64 minutes, Class IV : 54.64 minutes The average direct nursing service hours for a patient per shift(3 shift) was 31.54 minutes(94.62 m/day). The average indirect nursing service hours for each patient per duty(3 shift) is 21.3 minutes (63. 91 m/day). 3) The average nursing hours for a patient per duty was 52.80 minutes(2.64h/day). 4) The group of administering medications in direct care activities showed the highest percentage (38.9%). Checking vital signs among observation took the most time am.ong each direct care activity (6.88 minutes for a patient per duty). 5) Charting took the most time of each indirect care activity(52.53 minutes/ duty/nurse). 6) The average personal time per duty is 29.40 minutes, which 'was below 30 minutes of this hospital regulations. 7) The average nursing hours that a nurse provided for a duty was 8.60 hours, which meant that a nurse worked 1.10 hours overtime. 8) Standardizing to a 33 bed to a unit, 17 nurses were needed at the present nursing level.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12A
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• pp.1246-1252
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• 2006

In this paper, a collision probability, processing time and traffic capacity analysis algorithm for RFID system using random FHSS and synchronous FHSS is proposed. Service time, duty cycle, traffic intensity and additional delay time required for re-transmission due to collision are considered and the processing delay and frequency channel capacity are analyzed for the steady state operation of the system. The simulation results which show maximum capacity of the system and explain the accuracy of the algorithm are provided.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.242-247
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• 2009

In this paper, we investigate interference between short-range radiocommunication devices (SRDs) with frequency hopping spread spectrum (FHSS) and direct sequence spread spectrum (DSSS) methods when they are in the same frequency bands. In order to analyze interference from unwanted emission of SRD with DSSS to that of FHSS, Monte-Carlo (MC) simulation method is employed and interference probabilities are calculated. We simulate interference scenarios in accordance with several duty cycles and bandwidths. It is also assumed that the propagation model is free space The effect of distance between interfering transmitter and victim receiver is analyzed and bit error rate (BER) is simulated. From the interference analysis results, it is shown that duty cycle affects compatibility more than bandwidth does. Also, we can make sure of the separation distance which satisfies BER criterion when there are only one interfering transmitter and multiple interfering transmitters.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.74-78
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• 2003

This paper shows the dosimetric uncertainties of electromagnetic field at in-vivo and in-vitro experiments. For more accurate consequences of these researches, we have tried to find out any correlations among output power, power density and specific absorption rate(SAR) with the results of in-vivo, in-vitro tests and SAR reports of cellular phone and PDA. In the case of in-vivo tests, the power density has close statistical correlations with SAR value and in the event of in-vitro tests, the output power has considerable statistical correlations with SAR containing duty factor. On the other hand, we found that both power density and output power don't have any close correlations with SAR. And, we obtained fitted regression form among frequency, power density and SAR containing duty factor through multiple linear regression analysis.