• Title/Summary/Keyword: high effectiveness

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Measurement of Film Cooling Effectiveness and Heat Transfer of Rectangular-Shaped Film Cooling Holes (사각홀에서 막냉각 효율 및 열전달계수의 측정)

  • 이윤석;이동호
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.5
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    • pp.365-376
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    • 2002
  • An experimental study has been conducted to measure the local film-cooling effectiveness and the heat transfer coefficient for a single row of rectangular-shaped holes. four different cooling hole shapes such ai a straight rectangular hole, a rectangular hole with laterally expanded exit, a circular hole and a two-dimensional slot are tested. A technique using thermochromic liquid crystals determine adiabatic film cooling effectiveness values and heat transfer coefficients on the test surface. Both film cooling effectiveness and heat transfer coefficient are measured for various blowing rates and compared with the results of the cylindrical ho1es and the two-dimensional slot. The flow patterns downstream of holes are calculated numerically using a cummercial package. The results show that the rectangular hopes provide better peformance than the cylindrical holes. For the rectangular holes with expanded exit, the penetration is reduced significantly, and the higher and more uniform cooling Peformance is obtained even at relatively high blowing rates.

An Experimental Study on the Development of Electromagnetic Shielding Concrete Wall System Using Conductive Materials for Shielding High-altitude Electromagnetic Pulse(HEMP) (HEMP를 대상으로 한 도전성 재료 혼입 콘크리트 전자파 차폐 벽체 시스템 개발에 관한 실험적 연구)

  • Choi, Hyun-Jun;Choi, Hyun-Kuk;Kim, Jae-Young;Min, Tae-Beom;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.10a
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    • pp.20-21
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    • 2016
  • In this study, the shielding properties of concrete with conductive materials as shielding material for electromagne- tic pulse(EMP) within 10kHz~18GHz were investigated. The shielding effectiveness of specimens were compared with different entrained materials. The shielding effectiveness were determined according to MIL-STD-188-125-1, IEEE-STD-299 at 28 days of concrete curing. The results of shielding effectiveness did not meet the criteria(80dB) severely.

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Basic Study on the Regenerator of Stirling Engine (I) -The influence of the heat exchange effectiveness of the regenerator on the engine power- (스털링기관용 재생기에 관한 기초연구(I) -재생기의 열교환 유효도가 기관 출력에 미치는 영향-)

  • 김태한;이정택;이시민
    • Journal of Biosystems Engineering
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    • v.27 no.1
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    • pp.33-38
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    • 2002
  • The indicated power of Stirling engine was affected by the heat exchange effectiveness of the regenerator. The temperature difference of working fluid between the expansion and the compression space of Stilting engine depends on the heat exchange effectiveness of the regenerator. The influence of the temperature ratio of expansion space to compression space of Stirling engine on the indicated power was analyzed by using Schmidt analysis in this study. In the Stirring engine, as the temperature ratio increased, the indicated power generally decreased. Therefor, it is necessary to develope the regenerator of high effectiveness. The actual indicated power was shown 64.9 percent of the predicted indicated power in maximum and 47.2 percent of that in minimum due to increased dead volume of engine, the loss of flow friction and heat transfer in the regenerator.

The Influence of Work-Family Conflict and Organizational Support on Organizational Effectiveness among Married Working Women of Health Services Organizations (의료서비스조직 기혼 여성근로자의 직장-가정 갈등, 조직 지원이 조직유효성에 미치는 영향)

  • Ha, Eun Jeong;Kwon, Su Jin
    • The Korean Journal of Health Service Management
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    • v.1 no.1
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    • pp.31-44
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    • 2007
  • The purpose of this study is to shed light on the effect of work-family conflict on organizational effectiveness, focusing on the moderating effect of organizational support among married working women of health services organizations. Data were collected from 149 married working women of health services organizations located in Busan Metropolitan areas by structured self-administered questionnaire. Main results of this study is as the following: First, based on the type of work-household conflicts, namely time-based conflict(2.82 points), strain-based conflict(2.81 points) and behavior-based conflict(2.69 points), working women mainly experienced time and strain-based conflicts. The level of work-household conflicts was significantly higher among younger groups, highly educated, nurses, and regular workers. Second, the perceived organizational effectiveness found to be an above-average. Especially scores were high in the subcategories of customer orientation(3.84), followed by organizational commitment (3.42) and job satisfaction(3.19). The level of organizational effectiveness was significantly higher among older groups, medical technician and administrative job holders, day-time workers, and higher income groups. Third, the results of the regression analysis on the effects of work-household conflicts on organizational effectiveness showed that strain-based conflicts have a significant negative effect on organizational effectiveness such as job satisfaction and organizational commitment. Fourth, organizational support found to have a strong controlling effect for strain-based conflicts on organizational effectiveness. Above results imply that practical family-supportive policies for lessening the work-household conflicts is crucial for enhancing organizational effectiveness in health services organization.

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Cost-utility Analysis of Home Physical Therapy to Improve Daily Activities of Stroke Patient Living at Home (재가 뇌졸중 환자의 일상생활동작 향상을 위한 방문물리치료의 비용-효용 분석)

  • Heo, Jae-Won
    • Journal of The Korean Society of Integrative Medicine
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    • v.10 no.2
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    • pp.13-25
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    • 2022
  • Purpose : This study compared the cost-effectiveness ratio of physical therapy in health centers and home physical therapy, two physical therapy methods for home-bound stroke patients, and clarified the economic validity regarding the effect of home physical therapy. Methods : To measure and compare the cost and effectiveness of the two physical therapy methods for stroke patients, subjects were recruited based on in-hospital and home physical therapy. Among the entire data collected, 82 and 90 participants were selected for in-hospital and home physical therapy, respectively. To measure costs, regarding both in-hospital and home physical therapy, direct cost and indirect cost for patients, family, medical institutes, and the government were measured. In addition, activities of daily living were measured in both methods to measure their effectiveness. Through collected data, the cost-effectiveness and incremental cost-effectiveness ratios were analyzed. Results : Based on the analysis of cost-effectiveness, home physical therapy showed lower cost-effectiveness than in-hospital physical therapy. Furthermore, the incremental cost-effectiveness ratio also showed a difference, which implied home physical therapy could have high effectiveness compared to cost. Conclusion : Based on these results, home physical therapy could be considered as an alternativeto other methods of physical therapy, for home-bound stroke patients. In addition, the result of thisstudy contribute by providing evidence that home physical therapy offers economic benefits and canbe more effective in treating home-bound patients when policy decisions are made to establish a home physical therapy system.

Evaluation of Teacher Training Program effectiveness and Exploration of improvement for Specialized high-school Teacher in Invention and Patent field (특성화고 교사를 위한 발명.특허 교원 직무연수 프로그램의 효과성 평가와 개선 방안 탐색)

  • Lim, Yun-Jin;Choi, Yu-Hyun
    • 대한공업교육학회지
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    • v.40 no.1
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    • pp.23-39
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    • 2015
  • The purposes of this study were to evaluate the effectiveness of teacher training program for specialized school teacher in invention patent field and to explore the program improvement ideas. The study was carried out through on survey method and using program evaluating model developed for this study. The study subjects are 39 specialized high school teacher participated in training program about invention patent field at CNU-IECT(Invention education center for teacher). The data collection was done on August 2, 2014. The 37 questionnaies were analyzed. The educational needs of the training program were calculated by using the Borich(1980)'s needs assessment formula. The evaluating model was developed by the team. Major findings of this study were as follows; First, the training needs of specialized high-school teachers was high. Second, the satisfaction of the training program was high. Third, the overall effectiveness of training programs was high. Fourth, the improvement ideas were divided into four area - 1)The status quo area, 2) the alternatives exploration area, 3) the strategy modifications area, 4) the expected expansion area.

Evaluation of Measles Vaccine Effectiveness in a Community Outbreak (지역사회 유행을 통하여 평가한 홍역 예방접종의 효과)

  • Park, Byung-Chan;Park, Sue-Kyung;Cheong, Hae-Kwan
    • Journal of Preventive Medicine and Public Health
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    • v.35 no.1
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    • pp.33-40
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    • 2002
  • Objective : From an analysis of a community outbreak of measles in Youngju, Gyeongbuk, in March 2000, the authors evaluated the effectiveness of the measles vaccination and its determinants to Provide an epidemiologic basis for the establishment of a vaccination policy. Methods : Information was collected regarding the vaccinations from the health records of four primary schools and through a questionnaire surrey of the parents of students in two middle and two high schools (N=4638). Measles cases were surveyed from the patient list of each school and from case reports in the public health center. The attack rate and vaccine effectiveness of measles was evaluated by school; grade; frequency, region, and institution of vaccination. Results : The attack rate cf measles, 6.3% among the total subjects, was higher in middle school students (15.8%) than in primary (2.0%, p<0.05) and high school students (8.9%, p<0.05). The attack rate of the unvaccinated group was 4.6-fold higher than the vaccinated group in primary schools (p<0.05). Vaccine effectiveness was 83.2% among lower graders of primary schools, 34.0% among higher graders of primary schools,26.1% in middle schools, and -7.0% in high schools. In multiple logistic regression analysis, grade in school (odds ratio, 0.77; 95% CI=0.67-0.87) and frequency of vaccination (odds ratio, 0.57: 95% CI=0.37-0.58) were significant predictors of the outcome. Conclusions : We concluded that the explosive outbreak of measles in this area resulted from both inadequate vaccination coverage and secondary failure of vaccination. There was no evidence of any effect of the cold chain system on the vaccine failure.

Cost-Effectiveness of Voluntary HIV Testing Strategies in a Very Low-Prevalence Country, the Republic of Korea

  • Lee, Young Hwa;Bang, Ji Hwan;Park, Sang Min;Kang, Cho Ryok;Cho, Sung-Il;Oh, Myoung-don;Lee, Jong-Koo
    • Journal of Korean Medical Science
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    • v.33 no.46
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    • pp.304.1-304.7
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    • 2018
  • Background: The Republic of Korea has a very low prevalence of human immunodeficiency virus (HIV) infection, but the number of new HIV diagnoses has steadily risen, strongly indicating a large number of undetected HIV infections. Thus, it is important for Korean public health authorities to adopt and encourage cost-effective HIV detection tools, such as rapid HIV screening tests. In this study, we aimed to evaluate the cost-effectiveness of enzyme-linked immunosorbent assays (ELISA) and rapid tests in a public health center (PHC) setting. Methods: We developed a decision analytic model to assess the per-examinee cost and the cost-effectiveness of identifying HIV patients in a PHC setting using two HIV testing strategies: conventional HIV screening by ELISA versus rapid HIV testing. Analysis was performed in two scenarios: HIV testing in an average-risk population and in a high-risk population. Results: Compared to the ELISA, the rapid test was cost-saving and cost-effective. The per-examinee cost was USD 1.61 with rapid testing versus USD 3.38 with ELISA in an average-risk population, and USD 4.77 with rapid testing versus USD 7.62 with ELISA in a high-risk population. The cost of identifying a previously undiagnosed HIV case was USD 26,974 with rapid testing versus USD 42,237 with ELISA in an average-risk population, and USD 153 with rapid testing versus USD 183 with ELISA in a high-risk population. Conclusion: Rapid testing would be more cost-effective than using conventional ELISA testing for identifying previously undiagnosed HIV-infected cases in Korea, a country with extremely low HIV prevalence.

Vibration control in high-rise buildings with tuned liquid dampers - Numerical simulation and engineering applications

  • Zijie Zhou;Zhuangning Xie;Lele Zhang
    • Wind and Structures
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    • v.36 no.2
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    • pp.91-103
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    • 2023
  • Tuned liquid dampers (TLDs) are increasingly being used as efficient dynamic vibration absorbers to mitigate wind-induced vibration in super high-rise buildings. However, the damping characteristics of screens and the control effectiveness of actual structures must be investigated to improve the reliability of TLDs in engineering applications. In this study, a numerical TLD model is developed using computational fluid dynamics (CFD) and a simulation method for achieving the coupled vibration of the structure and TLD is proposed. The numerical results are verified using shaking table tests, and the effects of the solidity ratio and screen position on the TLD damping ratios are investigated. The TLD control effectiveness is obtained by simulating the wind-induced vibration response of a full-scale structure-TLD system to determine the optimal screen solidity ratio. The effects of the structural frequency, damping ratio, and wind load amplitude on the TLD performance are further analyzed. The TLD damping ratio increases nonlinearly with the solidity ratio, and it increases with the screens towards the tank center and then decreases slightly owing to the hydrodynamic interaction between screens. Full-scale coupled simulations demonstrated that the optimal TLD control effectiveness was achieved when the solidity ratio was 0.46. In addition, structural frequency shifts can significantly weaken the TLD performance. The control effectiveness decreases with an increase in the structural damping ratio, and is insensitive to the wind load amplitude within a certain range, implying that the TLD has a stable damping performance over a range of wind speed variations.

A Study on the Effectiveness Evaluation of Youth Life Respect Education "Life Talk Talk" (청소년 생명존중교육 「생명톡톡」의 효과성 검증 연구)

  • Jong-Hun Lee;Kwang-Za Yu;Tae-Hee Park;Mi-Na Lee;Eun-Jin Kim
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.4
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    • pp.17-25
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    • 2023
  • Purpose: This study aimed to examine the effectiveness of a suicide prevention education program called "Life Talk Talk" among middle and high school students in D City. Methods: The educational content of the "Life Talk Talk" program was compiled through nine rounds of consultations and meetings with suicide prevention experts. Prior to the implementation of the program, consent was obtained from all research participants and their guardians. First , a pilot study was conducted with 100 middle and high school students located in D city, following which the present study was conducted from May to July 2023 with 1,400 middle and high school students in D city. The effects of the program were evaluated by assessing the changes in suicidal ideation, help-providing abilities, and suicide prevention knowledge in the data collected both before and after the education. Statistical analysis included frequency analysis and a paired-sample t-test. Results: The final analysis included 1,380 participants. In the general characteristics,, 1,079 people (78 %) answered "yes" to the question about suicide prevention education experience . The study found a significant decrease in suicidal attitudes (t=-8.92, p<.001) and significant improvements in emotional and cognitive attitudes of participants after the "Life Talk Talk" program . Additionally, all five items related to help-providing abilities (t=-23.83, p<.001) and suicide prevention knowledge (p<.001) showed significant improvement from before the program. Conclusion: The significance of this study lies in demonstrating the effectiveness of the "Life Talk Talk" suicide prevention education program in reducing suicidal attitudes as well as improving help-providing abilities and suicide prevention knowledge. Therefore, to enhance the effectiveness of suicide prevention education, it is essential to regularly implement concise and engaging educational programs that capture the attention of adolescents.