• Korean Journal of Weed Science
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• v.4 no.2
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• pp.211-218
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• 1984

In order to establish the chemical weed control systems in orchard, field experiments were conducted to evaluate the effects of spray methods and mixing of herbicides. The mixtured dosage of glyphosate 100cc/10a and 2,4-D 75㏄/10a showed higher control effects than mono-treatment of glyphosate and paraquat on Artemisia vulgaris var. indica and Polygonum hydropiper L. And oxyfluorfen was more effective in reducing the cover rate and dry weight of weeds than simazine and alachlor on 75th day after treatment. In the mixing experiment of land and foliar appling herbicides. The effect of glyphosate on May 17 followed by oxyfluorfen on June 12 showed the best control effect.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1006-1011
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• 1998

Volatile flavor components in three varieties (shingo(niitaka), mansamgil (okusankichi) and chuwhang pears) of Pear (Pyrus pyrifolia N.) were extracted for 24 hours with pentane-diethylether (1 : 1, v/v) using the LLEP (liquid-liquid extraction & perforation). Neutral fraction was separated from the extract and then analyzed by GC-FID and GC/MS equipped with a fused silica capillary column (Carbowax 20M, HP). Individual components were identified by mass spectrometry and their retention indices. The totals of 52, 47 and 22 volatiles were identified in shingo, mansamgil and chuwhang pears, respectively. Ethyl acetate, propyl acetate, hexanal, 1-hexanol, ethyl butanoate, ethyl-3-hydroxy butanoate, ethyl-2-hydroxy propanoate were the main components in each samples, though there were several differeces in composition of volatile compounds. Total contents of volatile components isolated in shingo, mansamgil and chuwhang pears were 6.972, 2.776 and 2.653 mg/kg of pears.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.154-154
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• 2011

화석연료의 가격 및 공급의 불안정과 온실가스감축 국제 규제 강화 등에 대한 대안으로 여기는 신 재생에너지는 높은 초기 투자 부담으로 인하여 관련기술의 연구개발과 보급정책 등 전과정에 걸친 정책 지원체계가 필요하다. 본 연구에서는 지열에너지를 이용하는 지열냉난방기술에 중점을 두고 이에 대한 중장기 정책 포트폴리오 작성을 위한 기술 및 정책적 접근방안을 제시하고자한다. 지열에너지의 가장 큰 특징은 기후 등에 영향을 크게 부하가 변하는 태양광, 풍력 등과 달리 일정한 부하를 유지함으로써 안정적인 에너지공급이 가능하다는 것이다. 또, 품질 측면에서도 화석연료를 이용한 기존의 연료보다 쾌적한 환경을 조성하여 고급에너지로 평가받고 있다. 반면, 설비를 갖추기 위한 천공, 히트펌프 설치 등에 큰 비용이 든다는 단점을 가지고 있다. 현재 히트펌프 제작기술은 국산화를 완료한 상태로 사실상 기술개발에 의한 큰 폭의 원가절감은 기대하기 힘든 상황이다. 하지만, 유사분야인 시스템 에어컨이 표준화 및 대량생산을 통한 시장 보급 확대로 보급단가가 하락한 것을 고려해 볼 때 이를 통한 가격하락은 어느 정도 기대해 볼 수 있을 것으로 생각된다. 에너지 외적인 측면에서 볼 때도 지열에너지의 공급은 상당한 의미를 갖는다. 건물 냉 난방용 이외에 다양한 용도의 개발을 통해 비닐하우스나 온실 등에 지열에너지를 이용할 경우 정부차원에서 농어촌에 대한 지원이 가능하다. 또, 기존의 에너지원을 조달하는데 어려움이 있는 산간, 도서지방에서는 도시지역보다 투자대비 큰 효과를 볼 수 있어 지역간 에너지 불균형 해도에도 도움이 될 수 있다. 이와같은 지열에너지의 특성에 따라 향후 발전방향을 정리해 보았다. 핵심기술인 지열 히트펌프의 산업구조와 시장 보급 확대를 통한 가격하락을 기대한다. 지역개발 및 고립지역에서 타 신 재생에너지와 함께 독립적인 전력, 냉난방 등의 완전 에너지 공급시스템을 갖출 수 있다. 또한 특수 작물 등의 고급 농수산물 생산등의 용도개발을 통해 지열에너지 공급역량을 성장시킬 수 있을 것이다. 이와 함께 중장기 비젼을 제시하기 위해 추진되어야 할 연구과제로는 시장 보급 확대에 따른 가격경쟁력 도달 가능성에 대한 연구를 통해 산업육성 방안 마련, 타 신 재생에너지기술과 복합 설치에 의한 시너지 효과 및 이에따른 초기 투자비 증가에 대한 대책, 보급 잠재량 조사, 지열시스템의 자금 조달 및 관련 정책 검토 등이 있을 수 있다.

• The Journal of Korean Physical Therapy
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• v.12 no.1
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• pp.87-99
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• 2000

A study was conducted in order to determine back pain experience status of elementary. junior and senior high school teachers and the factors affecting their knowledge of back pain and physical therapy from April 2 through June 30, 1999 in major big cities and small and medium towns. Questionnaires were sent to 924 teachers and the collected daa were analyzed. The results summarized are as follows ; 1. $46.3\%$ of the respondents had experienced back pain, and $47.0\%$ of females, $62.0\%$ of the people over 50years old, $57.4\%$ of junior high school teachers, $47.5%$ of teachers of art and physical education, $46.9\%$ of married persons, $47.8\%$ of the people living in medium or small towns, and $58.6\%$ of the persons whose economic status was low han experienced back pains, $58.9\%$ of respondents who were not healthy, and $49.3\%$ of those who did not drink alcohol, $47.9\%$ of nonsmokers, and $49.1\%$ of those who slept on ondol had experienced back pains. $76.7\%$ of the respondents got health information on back pains from health professionals. 2. An average level of the respondents en physical therapy was $14.95\pm8.32$ points out of 44 and it was 34 points when converted to 100. The knowledge levels of males,. elementary teachers, married persons, those teaching students far more than 20 hours a week, smokers, those who did not drink, those who exercised regularly, and those who had experienced back pains were higher than those in other groups. The knowledge level of those who had experienced back pain prevention education was $18.88\pm8.88$ points and the difference between those with experience and those without experience was statistically significant. The depression level of those who got 40 pome on back pains, and physical therapy was higher than other group(p<0.001). 3, Depression levels of teachers on back pains and physical therapy related knowledge was higher in those with back pains than those without back pains(p<0.01). 4. The factors affecting experience of back pains were back pain related age, economic status, health status, smoking, style of kitchen, sown of information on back pain, and back pain prevention education. (p<0.001), 5. The factors affecting the knowledge on physical therapy were general knowledge levels on back pains, position when tilling, and moving heavy stuffs, driving position, sources of information on back pain prevention, type of bed, age, and health status, and the explanation power of those factors was $45.2\%$.

• The Journal of Dong Guk Oriental Medicine
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• v.8 no.1
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• pp.93-106
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• 1999

For the purpose of investigate the inhibition effects of Injinchunggantang on Hepatitis and C Virus. The inhibition experiments were as follows : 1. The inhibition effects of Hepatitis B surface antigen production was remarkably increased in the pretreated group of Injinchunggantang compared with control group. 2. Amplified PCR products of HBV-DNA in culture media was considerably decreased in the pretreated group of Injinchunggantang compared with control group. 3. Results of ATP quantitation and ATPase inhibition percent was increased pretreated group of Injinchunggantang. Also ATPase activity of HCV helicase inhibition assay was increased with a dose dependent manner. These results may suggest that Injinchunggantang will have the inhibition effects of Hepatitis B and C Virus.

• Journal of Society of Preventive Korean Medicine
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• v.8 no.1
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• pp.89-107
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• 2004

This study was conducted to analyze community residents' behavior of Oriental medicine utilization and its related factors in order to provide basic data for formulation of policies on Oriental medicine. The subjects of this study was 500 residents who lived in big or medium sized cities and towns or villages Data were collected from March, 2002 to June, 2002. The results of this study can be summarized as follows. 1) According to socio-demographic characteristics of the respondents, female was 50.3%; 'over 50 years old' 29.9%, 'over college graduate' 39.7%, 'housewife' 23.0%, 'having spouse' 62.1%, 'Buddhist' 50.8%, 'living in big cities' 59.0%, 'middle economic class' 88.1%. 2) The highest proportion of frequency of Oriental medicine utilization was over 10 times(32.5%). The respondents visited Oriental medicine institutions for taking invigorant(51.1%), treatment of diseases in muscle or bone system(30.8%), treatment of diseases in digestive system(6.3%), etc. 3) According to the reasons of utilizing Oriental medicine, the proportion of good effect was highest(36.3%). 66.8% of the respondents replied that Oriental medical fee was expensive, while 0.8% of them replied that it was not expensive. 33.3% of them thought it was proper. 4) 35.5% of the respondents replied that treatment by Oriental medicine could cause side effect and 40.3% of them replied that the side effect could be caused by taking herb medicine. 5) 62.8% of the respondents replied that they would continuously receive opinions on Oriental medicine. The score of knowledge level of treatment by Oriental medicine $6.25{\pm}2.82$ points on the basis of 14 points. 6) The variables significantly influencing utilization of Oriental medicine includes taking diseases, living in big cities, male, upper (economic class, having religion, and effect of Oriental medicine. 7) The factors affecting effect of herb medicine were effect of treatment by Oriental medicine, marital status, knowledge level of Oriental medicine, having diseases, and frequency of receiving the treatment.

• Journal of Radiation Industry
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• v.10 no.4
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• pp.219-225
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• 2016

The apron is one of the essential protectors to reduce the exposure dose of radiological technologists. This study is to provide a guideline for purchasing the aprons with excellent performance and to help reducing the exposure dose by measuring the shielding ration and uniformity of aprons according to lead equivalent and form types. The shielding ratio of aprons were measured by using radiation generator and dosimeter. Exposure conditions were 81 kVp, 25 mAs, source to image receptor distance (SID) 100 cm and field of view (FOV) $17^{{\prime}{\prime}}{\times}17^{{\prime}{\prime}}$. Exposure areas for front type and around type aprons were divided into 9 areas and for 2 pieces type aprons were divided into 3 areas of top and 4 areas of skirt. The uniformity of aprons were measured by using fluoroscopy and Image J. The 4 regions of interest (ROI) were set into acquired images and measured uniformity by measuring the standard deviation of pixel intensity in ROIs. In continuous shielding ration measurement of aprons according to exposure area, there was not statistical significance (P>0.05). In ANOVA test of aprons, there was statistical significance (P<0.01). In the results of sheilding ratio, although the aprons had equal lead equivalent, there were difference in shielding ratio from 83.59% to 98.15%. In the results of uniformity, the front type aprons with equal lead equivalent indicated the similar uniformity. However, the around type and 2 pieces type apron with equal lead equivalent indicated the different uniformity each other, from 1.8 to 22.2. If the performance evaluation in this study were conducted regularly before and after purchase the aprons, the exposure does to patients and radiological technologists could be reduced.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.1
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• pp.116-123
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• 2019

Thermal batteries are also called molten-salt batteries as the electrolyte is mainly composed of molten salt. The molten-salt electrolyte is a solid that does not conduct electricity at room temperature, but when it is melted by a pyrotechnic heat source, it becomes an excellent ionic conductor. Thermal batteries are a kind of pyrotechnic battery because they operate only when the solid electrolyte is melted by the heat energy provided by pyrotechnic materials. Pyrotechnic components used in a thermal battery include heat sources, fuse strips, and an igniter. The reliability of these pyrotechnic components critically affects the reliability and performance of the battery that must supply electricity stably to guided munitions even under extreme environmental conditions. Different igniter types offer different advantages: notch-type igniters offer improved ignition probability, whereas film-type igniters offer improved safety. The addition of metal oxides to the heat paper could improve the burn rate, and the ignition reliability could be greatly improved by using it with a flame igniter at the same time. Using a two-step reduction process, high-purity Fe particles in coral form can be safely obtained.

• 대한공업교육학회지
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• v.41 no.2
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• pp.119-133
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• 2016

This study is aimed at verifying the effect of scratch programming education for middle school students on their information science creative personality and technological problem solving tendency. The results of such study can be used as basic data for raising 'future creative talents' armed with problem-solving capability they honed in software education. The results of this research are as follows. First, a statistically significant difference was confirmed between ex ante and ex post samples in a t-test which was performed to verify information science creative personality of the middle school students (t(37)=4.305, p<.01). Their information science creative personality was high in the average score as it dropped from 3.00 in the ex-ante test to 2.51 in the ex post test. It was confirmed that the education of scratch programming influences information science creative personality for middle school students positively, suggesting that middle school students are interested in new problematic situations they found in information science and discover new problem-solving methods in the programming education, thereby showing positive feedback in the education performance. However, it was revealed that the middle school students were unable to immerse themselves in the scratch programming course completely and change their psychological states. Second, a statistically significant difference was confirmed between ex ante and ex post samples in a t-test which was performed to verify their technological problem solving tendency (t(37)=3.074, p<.01). Their technological problem solving tendency was high in the average score as it dropped from 4.06 in the ex-ante test to 3.55 in the ex post test. It was confirmed that the education of scratch programming influences technological problem solving tendency for middle school students positively: they understood problems associated with technology, explored diverse breakthroughs for the identified problems and assessed and improved resolutions. Third, a moderate correlation was confirmed between their information science creative personality and technological problem solving tendency (r=.343, p<.05). Therefore, it is judged that the middle school students who took scratch programming education demonstrated its influence in the correlation between the imagination for problem solving, positivity in the information science creative personality and the confidence for problem solving in the technological problem solving tendency.

• Restorative Dentistry and Endodontics
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• v.33 no.4
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• pp.332-340
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• 2008

The purpose of this study was to evaluate the viability of periodontal ligament cell in rat teeth using slow cryopreservation method with magnetic field through MTT assay and TUNEL test. For each group, 12 teeth of 4 weeks old white female Sprague-Dawley rat were used for MTT assay, and 6 teeth in TUNEL test. The Maxillary left and right, first and second molars were extracted as atraumatically as possible under tiletamine anesthesia. The experimental groups were group1 (immediately extraction), group 2 (cold preservation at 4$^{\circ}C$ for 1 week), group 3 (rapid cryopreservation in liquid nitrogen), group 4 (slow cryopreservation with magnetic field of 1 G), and group 5 (slow cryopreservation). F medium was used as preservation medium and 10% DMSO as cryoprotectant. After preservation and thawing, the MTT assay and TUNEL test were processed. One way ANOVA and Scheffe method were performed at the 95% level of confidence. The value of optical density obtained after MTT analysis was divided by the value of eosin staining for tissue volume standardization. In both MTT assay and TUNEL test, it had showed no significant difference among group 3, 4, and 5. And group 3 had showed higher viability of periodontal ligament cell than group 2. From this study, slow cryopreservation method with magnetic field can be used as one of cryopreservation methods.