• 전자공학회논문지A
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• 제32A권8호
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• pp.119-125
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• 1995

Strained multiple quantum well(SMQW) PBH-DFB-LDs emitting at 1.55$\mu$m wavelength has been fabricated using OMVPE and LPE crystal growth tecnique. Using the SMQW active layer, a linewidty enhancement factor of 2.65 was obtained at lasing wavelength and consequnently, packaged 42 modules showed a very low average chirp of 0.44nm at 2.5Gbps NRZ direct modulation. The 77 devices showed average threshold current of 8.72mA and average slope efficiency of 0.181 mW/mA, and single longitudinal mode operation with SMSR larger than 30dB up to 5mW. Among the 77 devices, standard deviation of lasing wavelength of 3.57nm was obtained owing to a good crystal growth uniformity.

• 한국학교보건학회지
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• 제11권2호
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• pp.203-215
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• 1998

The purpose of this study is to inquire into the degree of health promotion activity in university students, and to find out the relationship between self-efficiency and health promotion behavior, Thus, we can offer basic data for developing an educational method or program for health promotion. For this research, data was collected from university men and women through a questionnaire from February 18 to March 20, 1998. A measuring instrument was based on lating reviews of health promotion behavior in chronic disease protection, perceived self efficiency, demographic factors, biological factors, and circumstatial factors. The content validity of the instrument was authenticated by two professors of nursing, and reliability was confirmed by 'cronbach' (${\alpha}^{\prime}$ after mortifying content through a pre-test on 30 students. 475 persons were analyzed in terms of average, percentage, t-test, ANOVA, Pearson's Correlation Coefficient, and Multiple Stepwise Regression by 'SPSS-PC'. The analyzed data is as follows: 1. Higher self-efficiency, as a cognitive-perceptual factor, has a beneficial effect on health promotion behavior (r=.479, p=.000). The result of analyzing the differences among a low group, a middle group, a high group in terms of self-efficiency reveals that the relationship between self-efficiency and health promoting behavior is meaningful. 2. The degree of health promoting behavior is 3.26 out of 6. Other figuresrelating to health promoting behavior, are as follows. self-actualization area (4.62), interpersonal area (4.60), stress management area (4.01), nutrition area (3.68), responsibility of health area (3.11), liquid and cigaret area (2.85), and exercise area (2.33). 3. The degree of self-efficiency was 6.81 out of 10. Other figures relating to self-efficiency are as follows. interpersonal area (7.89), self-actualization area (7.84), liquid and cigarette area (7.72), exercise area (6.88), stress management area (6.84), responsibility of health area (6.35), and nutrition area (6.34). 4. The different lerels of health promoting behavior according to a subject's general factos are following: age (p=0.003), sex (p=0.000), health concern of parents (p= 0.000), taking health programs (p=0.007), case history of familes (p=0.048). Health promoting behavier is also positirely affeted by the following: higher age, social sciences focus, religion, living the relatives', and the higher health concerns of parents. 5. The difference of self-efficiency according to a subject's general factors is positirely affected by sex (p=.008), the health concerns of parents (p=.004), body indexes (p=.001), and the higher health concerns of parents. 6. As the result of analyzing major factors, the most powerful factor appears to be self-efficiency, 26.6% of health promoting behavior. Suggestions: 1. Results of this study point to self-efficiency as a major factor in the health promoting behavior of university students. It is crucial, therefore, to develop a health program to promote self-efficiency and to study how to promote prerention of certain diseases. 2. That health promoting behavior appears low in this study shows that health education should be taken into the university class, with a focus on the daily life of students as its goal.

• 한국전기전자재료학회논문지
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• 제21권6호
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• pp.569-574
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• 2008

In the device structure of ITO/tris(8-hydroxyquinoline) aluminum ($Alq_3$)/Al device, we investigated the efficiency improvement of organic light-emitting diodes (OLEDs) depending on the hole-size of crucible boat. The device was manufactured using a thermal evaporation under the base pressure of $5{\times}10^{-6}\;Torr$. The $Alq_3$ organics were evaporated to be 100 nm thick at a deposition rate of $1.5\AA/s$, and in order to investigate the optimal surface roughness of $Alq_3$, the $Alq_3$ was thermally evaporated to be 0.8 mm, 1.0 mm, and 1.5 mm as a hole-size of the boat, respectively. We found that luminance and external quantum efficiency are superior when the hole-size of the boat is 1.0 mm. The external quantum efficiency of the device made with the hole-size of 1.0 mm boat were improved by a factor of ten compared to the devices made with the hole-size of non boat.

• The Journal of Asian Finance, Economics and Business
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• 제9권7호
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• pp.261-271
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• 2022

Over the last 20 years, the insurance industry in Vietnam has been rapidly growing with an average annual growth rate of 21%, one of the most active markets in Southeast Asia, raising the question of efficiency to managers, investors, and regulators. This article is one of the first research works using Data Envelopment Analysis combined with the Malmquist index over the period from 2016 to 2020 for 37 insurance firms in Vietnam to investigate the efficiency of this sector. The value-added approach is employed with total equity and operating expenses as inputs, finance income, and gross written premium as outputs. The findings reveal that most of Vietnam's insurance companies are operating quite effectively, and the non-life sector is more efficient than the life sector. There is also a regression in efficiency change, while there is a progression in technological change and total factor productivity change during the period examined. The goal of this research is to give a fundamental understanding of the overall efficiency of insurance firms in Vietnam, and help managers, investors, policyholders, and government agencies make better decisions regarding self-assessment, M&A activities, deregulation... Consequently, the insurance sector could improve in terms of efficiency and develop sustainably over time.

• 지역사회간호학회지
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• 제12권1호
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• pp.278-287
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• 2001

The purpose of this study is to provide with basic information on application of hand acupuncture as a complementary and alternative therapy by giving some recognition of efficiency and effectiveness of hand acupuncture. And so, answers for questionnaires of 290 respondents were used for this research and collected from June 5 through 13, 1999 from adults twenty and over who were participating in the hand acupuncture training program in Seoul and had some direct experiences with hand acupuncture therapy, whatever they had been treated and/or had treated. To secure reliability of measurement tool. Cronbach'a has been calculated and Factor Analysis was done as Validity Analysis of question classification. Demograprucal characteristics of hand acupuncture experienced people and factors related to hand acupuncture experiences are calculated based on the real number and percentage. The degree of recognition of efficiency and effectiveness of hand acupuncture is made as average and standard deviation, while the degree of recognition of efficiency and effectiveness based on general characteristics come from one-way ANOVA. 1. According to socio-demographical analysis. the questioned could be classified firstly as age (40-49 : 32.5%. 30-39 : 24.9%. 50-59 : 21.9%. 60-69 : 14.7%. 20-29 : 6.0%). secondly gender (male 36.6%. female 63.4%). thirdly occupation (housewife: 43.8%. self-employed: 15.5%. company-employee: 14.8%). fourthly education (high school graduate: 41.9%, college graduate: 37.9%), and lastly monthly-income (1 to 2 million: 51.4%. 2 to 3 million: 20,3%) 2, As for the general aspects related to hand acupuncture. 80,0% of the respondents answered almost zero for the monthly average number of visit to hospital and 15.5% responded 1 to 2 visits, 6,2% of the respondents is complaining of a disorder of digestive system. 19,0% circulatory disease, 10.7% bad nervous system. By utilizing hand acupuncture, 84% of the questioned have following experiences in curing diseases: digestive system 47.3%, circulatory system 9.3%, nervous system 8.3%, 54,1% are curing 1 to 2 and 10.3% 3 to 4 patients on a daily basis with hand acupuncture. Research on the demerits of giving medical treatment with hand acupuncture shows 23,8% are feeling economic burden. 16.6% difficulty of learning and 16.2% weak theoretical backgrounds. 3. Among the efficiency recognition, possibility of general application is average 4,29 and simple treatment is 4,19. economic merits 4.36. possibility of establishment with supplementary and alternative medicine 4.17, medical effectiveness 4.09. 4, As a result of demographical analysis on the efficiency and effectiveness of hand acupuncture therapy, it appears that the recognition of efficiency based on occupation and the recognition of effectiveness based on monthly income are most significant to be noticed. In an orderly fashion. government-employee, self-employed, company-employee. and then housewife have perceived hand acupuncture very efficiently, And those who recognize hand acupuncture to be most effective are people earn 1 million to 2 million won a month, 5. The efficiency(p = .003) and effectiveness (p= .049) of hand acupuncture therapy by number of visit to hospital were statiscally significant, and effectiveness of hand acupuncture therapy by disease exist was statiscally significant (p= .033).

• 한국수산과학회지
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• 제42권3호
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• pp.257-261
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• 2009

Two feeding trials were conducted to investigate the effects of several dietary additives on growth and feed utilization of juvenile flounder. In the first experiment, three replicate groups of juveniles (average weight 1.5 g) were fed diets with or without wasabi extract and chitosan for 7 weeks. Survival rate, weight gain, protein efficiency ratio, hepatosomatic index and condition factor were not affected by the different dietary additives (P>0.05). Feed efficiency of fish fed the wasabi extract diet was significantly higher than that of fish fed the control diet (P<0.05). Daily feed intake of fish fed the wasabi extract diet was significantly lower than that of fish fed the other diets (P<0.05). In the second experiment, three replicate groups of juveniles (average weight 1.4 g) were fed diets with or without Pophyra powder for 7 weeks. Survival rate and weight gain were not significantly affected by dietary Pophyra powder (P>0.05). Feed efficiency and protein efficiency ratio of fish fed the Pophyra diet were significantly lower than those of fish fed the control diet (P<0.05). The results of these experiments suggest that feed efficiency of juvenile flounder may be improved by dietary supplementation with wasabi extract.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.87-88
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• 2008

In the structure of ITO/N,N'-diphenyl-N,N' bis (3-methylphenyl)-1,1'-biphenyl-4,4'-diamine(TPD)/tris (8-hydroxyquinoline)aluminum$(Alq_3)$/Al device, we studied the efficiency improvement of organic light-emitting diodes due to variation of deposition rate of TPD materials. The thickness of TPD and $Alq_3$ was manufactured 40 nm, 60 nm, respectively under a base pressure of $5\times10^{-6}$Torr using a thermal evaporation. The $Alq_3$ used for an electron-transport and emissive layer were evaporated to be at a deposition rate of 2.5 $\AA$/s. When the deposition rate of TPD increased from 1.5 to 3.0 $\AA$/s, we found that the average roughness is rather smoother, external quantum efficiency is superior to the others when the deposition rate of TPD is 2.5 $\AA$/s. Compared to the ones from the devices made with the deposition rate of TPD 3.0 $\AA$/s, the external quantum efficiency was improved by a factor of eight.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.265-268
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• 1998

This paper presents a soft-switching average current control PWM high power factor boost converter. Conventional boost ZVT-PWM converter has a disadvantage of hard-switching for auxiliary switch at turn-off. A soft switched auxiliary switch is proposed to achieve a high performance ZVT-PWM boost rectifier. The simulation and experimental results show that soft switching operation can be maintained for wide line and load range, which in turn improves the converter performance in terms of efficiency, switching noise and circuit reliability.

• 신재생에너지
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• 제7권2호
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• pp.28-35
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• 2011

Recently, photovoltaic systems have been devolved into much larger systems up to MW-scale. Photovoltaic industry participants give their focus on power generation capability of photovoltaic modules because their benefits can be decided from the amount of generation. The information on long-term performance change of photovoltaic modules helps to estimate the amount of power generation and evaluate the economic cost-benefits. Long-term performance of a PV system has been analyzed with operation data for 12 years from 1999 to 2010. In the first year, the amount of yearly power generation was 57.7 MWh with 13.2% capacity factor. In 2007, the amount of yearly generation was 44.3 MWh with 10.14% capacity factor, and in 2010, the amount was decreased down to 38.1 MWh with 8.7% capacity factor. The result means that long-term capacity factor has been 4.5% decreased for 12 years and that the amount of generation has been decreased 34.0% for 12 years which is 2.8 % per year. The latter capacity factor has been decreased faster than 0.20%, the average rate for 10 years. The performance decrease of the PV system is meant to be accelerated. The decrease of performance and utilization is due to aged deterioration of photovoltaic modules and lowering conversion efficiency of PCS.

• 자원ㆍ환경경제연구
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• 제20권2호
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• pp.291-308
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• 2011

정부의 '저탄소 녹색성장' 정책기조의 실현가능성 여부는 에너지절약 자본시설에 투자할 경우 과연 산업의 생산성 증가로 이어질 수 있는지 여부에 달려 있다. 본 논문에서는 1차 금속산업을 대상으로 쌍대 비용함수로부터 총 요소생산성을 정의하고 산업생산성 증가의 요인별 분석을 통하여 에너지효율화 투자의 생산성 증가 파급효과를 측정하였다. 1982년~2006년 기간 동안 에너지효율화 투자로 인하여 평균적으로 연간 생산성은 1.16% 포인트 증가한 것으로 추정되었다. 또한 규모경제효과는 에너지효율화 투자의 생산성 증가 기여도를 향상시키는 것으로 나타났다.