• Title/Summary/Keyword: Difference-In-Difference

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감마카메라의 공간분해능 변화와 화질과의 관계 (Relationship Between Image Quality and Changes in Spation Resolution for the Gamma Camera)

  • 이만구;박성옥
    • 대한방사선기술학회지:방사선기술과학
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    • 제25권1호
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    • pp.77-81
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    • 2002
  • The purpose of this study is to examine quantitatively the relationship between visual image quality and degradation In spatial resolution for a gamma camera by the increase in distance from collimator. The relationship between the portion(p) of images identified the difference of image quality and the difference(${\Delta}FWHM$) in FWHM between paired images was showed in a sigmoid curve. Using Dendy's method, minimum level to be correctly identified the difference of Image duality on three out of four occasion(p=0.75) was corresponded to 0.4 mm in ${\Delta}FWHM$. Using fuzzy theory, the level to be identified the difference of image quality was examined under various conditions. The truth-value of fuzzy sets-degraded or slightly degraded and not-degraded in image quality between palled Images-was gained the peak at 0.5 mm of ${\Delta}FWHM$. It was founded that changes of $0.4{\sim}0.5\;mm$ in FWHM-corresponding about 2 cm distance from collimator could be sufficiently identified in the difference of image quality.

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청소년의 성차에 따른 자아존중감, 신체적 및 정신적 건강 (Gender Difference in Self-esteem, Physical and Mental Health in Adolescents)

  • 이은영;탁영란
    • Child Health Nursing Research
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    • 제7권4호
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    • pp.474-482
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    • 2001
  • The purpose of this study was to investigate the gender difference of relationships between the self-esteem and physical and mental health of adolescents. The sample were consisted of 410 adolescents, 202 boys and 208 girls in two urban city of Korea and the mean age was 17.4 years old. The instruments used in this study were Hare Self-Esteem Scale(Hare, 1985) and School Health Efficacy Questionnaire(Froman & Owen, 1991) which is consisted of both physical and mental health. The results showed that there was no gender difference in self-esteem of adolescents. However, the school domain of self-esteem was related to physical health of boys, and both the family domain and the school domain of self-esteem were related to physical health of girls. And both the school domain and the peer domain of self-esteem were positively related to mental health of boys, and all domains of self-esteem(peer, school, and family) were positively related to mental health of girls. In conclusion, there was not gender difference in degree of self-esteem, but there were gender difference in specific domains of self-esteem related with physical and mental health in adolescents.

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동자개(Pseudobagrus fulvidraco)의 생식소 발달에 수온과 광주기가 미치는 영향에 관한 연구 (Effect of Water Temperatures and Photoperiods on Gondal Development in Banded Catfish Pseudobagrus fulvidraco)

  • 임상구;한창희
    • 수산해양교육연구
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    • 제24권6호
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    • pp.854-861
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    • 2012
  • To investigate the role of water temperatures and photoperidos as environmental cues regulating reproductive rhythm in banded catfish Pseudobagrus fulvidraco, rearing experiments were conducted using sveral rearing regimes conbined with changes in photoperiods and water temperatures during growing and spawning periods. GSI of $23^{\circ}C$ was significantly higher than $18^{\circ}C$ in female, but 9 light of 18 and $23^{\circ}C$ were no difference in male. In case of estradiol, $18^{\circ}C$ and 15 L was higher than other experintal precinct after 20 days. But, end of the experiment, all of experimental precinct were no difference. Testosteron of female was no difference in $18^{\circ}C$-9 and 15 L after 20 days. Testosteron of male was no difference in $18^{\circ}C$-9 L. In case of 11-KT, control level was $0.39{\pm}0.03$ ng/mL and $18^{\circ}C$-9 L was no significantly difference after 20 days. But, 15 L was higher than other experimental precinct.

한국인 구개파열 아동의 치아발육에 관한 연구 (A STUDY ON THE TOOTH DEVELOPMENT OF THE KOREAN CHILDREN WITH CLEFT)

  • 유재형;손동수
    • 대한소아치과학회지
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    • 제11권1호
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    • pp.113-120
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    • 1984
  • The author surveyed the tooth development of 50 cleft affected children(M: 34, F:16). The following results were obtained. 1. The difference between the chronologic age and dental age was 0.61 years in the cleft group and 0.15 years in the control group. The delay in tooth development was observed in the cleft group. 2, In the cleft group, there was no difference in the delay of tooth development between the boys and the girls. 3. In the cleft group, there was no difference in the delay of tooth development between the maxilla and the mandible. 4. The delay of tooth development was more severe in the bilateral cleft group than in the unilateral cleft group. 5. In the unilateral cleft, there was no difference in tooth formation between the cleft side and corresponding side.

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중학생의 학교 스트레스 요인과 대처방식 (Factors and Countermeasures for Middle School Students' School Related Stress)

  • 장인열;박영수
    • 한국학교ㆍ지역보건교육학회지
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    • 제4권
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    • pp.61-78
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    • 2003
  • This research was conducted to identify the factors that cause school related stress among middle school students, and to develop countermeasures in order to prevent the rebellious acts of middle school students that are on the rise and to pursue after effective guidance measures. To achieve these research objectives, 856 questionnaires were distributed to the two middle schools, situated in Goyang-si, Gyeonggi Province, and these questionnaires were analyzed, using the SPSS statistical package program. The conclusions were as follows; 1. Perceived factors for School Related Stress Overall average of the perceived degree school related stress factors was a level that goes beyond the normalcy. Stress on the grade was the highest Among these, the average of question items that addressed decrease in grade was the highest of all items followed by class factors, teacher-related factors, friend-related factors, and environmental factors. Accordingly, this research demonstrated that the students feel pressured by the university entrace examination and a school life that is focused on grades. The teacher-related factors and class factors were higher than the average, and others were relatively low. 2. School Related Stress according by Individual All the factors for school related stress were statistically significant difference according to the gender, and teacher-related factors, class factors, and environmental factors were statistically significant difference according to their school years. Their grade made their grade factors statistically significant difference, and the number of friends produced a statistically significant difference result on the teacher-related factors. Wheather they had extra classes or not made a statistically significant difference result on the class factors and environmental factors, and especially the time of doing physical exercises produced statistically significant difference on the environmental factors. 3. Countermeasures for School Related Stress according by Individual As for the countermeasures for school related stress according to the individuality, the active reacting was statistically significant difference according to the gender index, and the student's degree to react passively was statistically significant difference according to their grade. The students in different school years showed statistically significant difference reactions in both passive ways and active ways. students tended to react differently in an unreality index. Lastly, Wheather they had extra classes and physical exercises made then to react passively or actively. When the results are compiled, students are most affected by the stress related to grades, which reflected the university entrance examination oriented school life. An alternative is that the development of educational program that factors in the students' talents and aptitude is needed urgently. Moreover, character and career path related guidance and education are just as important as the academics. Given that the stress factors exert some degree of influence on the countermeasures, it is necessary to block the factors in advance and for all the teachers and parents to make an effort to react actively.

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유가수온($CH_{3}$ HgCl) 투여시 흰쥐의 각 장기별 중금속 (유기수온, 총수은, 아연, 구리) 분포 (Organ Distribution of Total mercury, Organicmercury, Zinc and Copper in Methylmercury-Administered Rats)

  • 이진헌;김영규;정문호
    • 한국환경보건학회지
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    • 제17권2호
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    • pp.127-139
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    • 1991
  • Four group(Control I II, Treatment I II ) of Rats, each consisting of 10 rats, were studied Methylmercury Chloride MMc was orally given to Sprague-Dawley male at does of 10mg/kg (5 mg/kg $\cdot$ day), 10mg/kg after two weeks. This study was designed to investigate the distribution, the difference and the ratio of organic mercury, total mercury, zinc and copper in tissue, in each others group. The result were as follows: 1. There was no significantly difference in the body weight between two groups( p > 0.05). 2. There was significantly difference in the distribution of zinc concentration in liver, kidndey, blood, spleen between control I and treatment I, and in blood, spleen between control II and treatment II (P < 0.05). 3. There was significantly difference in the distribution of copper concentration in kidney, blood between control I and treatment I, and in spleen brain between control II and treatment II. 4. The ratio of zinc concentration in treatment/control was high at spleen. 5. The ratio of methylmercury/totalmercury was high at spleen.

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A Numerical Analysis on Thermal Stratification Phenomenon by In-Leakage in a Branch Piping

  • Park Jong-Il
    • Journal of Mechanical Science and Technology
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    • 제19권12호
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    • pp.2245-2252
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    • 2005
  • Thermal stratification in the branch piping of power plants can be generated by turbulent penetration or by valve leakage. In this study, a numerical analysis was performed to estimate the thermal stratification phenomenon by in-leakage in the SIS branch piping of nuclear power plant. Leakage rate, leakage area and leakage location were selected as evaluation factors to investigate the thermal stratification effect. As a result of the thermal stratification effect according to leakage rate, the maximum temperature difference between top and bottom of the horizontal piping was evaluated to be about 185K when the valve leakage rate was about 10 times as much as the allowed leakage rate. For leakage rate more than 10 times the allowed leakage rate, the temperature difference was rapidly decreased due to the increased mixing effect. In the result according to leakage area, the magnitude of temperature difference was shown in order of $3\%,\;1\%\;and\;5\%$ leakage area of the total disk area. In the thermal stratification effect, according to the leakage location, temperature difference when leakage occurred in the lower disk was considerably higher than that of when leakage occurred in the upper disk.

축구선수의 킥 동작시 키네시오 테이핑 적용에 따른 하지근활성화 및 동작분석 (Analysis of Low-leg Activation and Movement of Soccer Players during Kicking Action by Applying Kinesiotaping)

  • 김용재;모안나
    • 한국운동역학회지
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    • 제17권2호
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    • pp.131-143
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    • 2007
  • In this study, we are concluded like this : 5 men who are soccer player of P university in B city measure the Electromyography with an angle of motion according to kinesiotaping's application when practicing in-step kick. When exercising in-step kick, the change of realization of muscle load of lower limbs enhence Gastrocnemius Lateralis and Vastus Medialis in the section of backswing, and improve Tibialis Anterior, Vastus Medialis, Rectus Femoris prior to impact after back-swing. Before impact, it mainly impoved Tibialis Anterior, Vastus Medialis, Rectus Femoris. After impact, it generally improved Gastrocnemius Lateralis, Vastus Medialis. Average integral electromyography value, it was such a small difference(; the difference of the value in Tibialis Anterior, Rectus Femoris, Vastus Medialis) that we can't compare case of after taping than before. In Electromyography, in case of after taping was considerably decreased at Gastrocnemius Lateralis, there was statistically significant difference between before and after. It was a little increased, after taping than before at Knee angle. And degree was a little decreased at Ankle angle. But, It's so delicate difference, there was not statistically significant difference between before and after.

백화점 독점 수입브랜드 자산에 대한 소비자와 유통업자 간 평가 차이와 성과와의 관계 (The Relationship between Difference of Evaluation of the Brand Equity from Consumers and Retailers toward Exclusive Imported Brands at Department Stores and the Performance)

  • 류문상
    • 한국의류산업학회지
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    • 제13권2호
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    • pp.173-185
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    • 2011
  • This study aimed to clarify the difference between consumers and hands-on staff in evaluation of the attributes importance of asset evaluation attributes and the relationship between difference from consumers and hands-on staff in evaluation of the attributes and the performance. Subjects for the quantitative research, quota sampling was adopted in the areas where the subject brands were in place, and 452 questionnaires (141 of hands-on staff, 311 of consumers) were analyzed. The results were as follows; 1. The factors that hands-on staff and consumers regarded as most important as to asset evaluation attributes of department store-exclusive importation brands included preference and product quality in the order, and then image, recognition, reliability, and country of origin in the case of hands-on staff, and reliability, image, recognition, and country of origin in the case of consumers in the order. 2. As a result of examining the effect of the difference between hands-on staff and consumers regarding exclusive importation brands(GAP, ZARA) of certain department stores on business achievement and consumer attitude, it turned out that the smaller the difference between the two groups with regard to evaluation, the higher the business achievement and consumer attitude.

Comparison of the Characteristics of Precipitable Water Vapor Measured by Global Positioning System and Microwave Radiometer

  • Sohn, Dong-Hyo;Park, Kwan-Dong;Won, Ji-Hye;Cho, Jung-Ho;Roh, Kyoung-Min
    • Journal of Astronomy and Space Sciences
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    • 제29권1호
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    • pp.1-10
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    • 2012
  • In this study, global positioning system (GPS)-derived precipitable water vapor (PWV) and microwave radiometer (MWR)-measured integrated water vapor (IWV) were compared and their characteristics were analyzed. Comparing those two quantities for two years from August 2009, we found that GPS PWV estimates were larger than MWR IWV. The average difference over the entire test period was 1.1 mm and the standard deviation was 1.2 mm. When the discrepancies between GPS PWV and MWR IWV were analyzed depending on season, the average difference was 0.7 mm and 1.9 mm in the winter and summer months, respectively. Thus, the average difference was about 2.5 times larger in summer than that in winter. However, MWR IWV measurements in the winter months were over-estimated than those in the summer months as the water vapor content got larger. The results of the diurnal analysis showed that MWR IWV was underestimated in the daytime, showing a difference of 0.8 mm. In the early morning hours, MWR IWV has a tendency to be over-estimated, with a difference of 1.3 mm with respect to GPS PWV.