• International Journal of Fluid Machinery and Systems
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• 제10권3호
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• pp.307-317
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• 2017

In liquid-propellant rockets, POGO instability can occur, in which a fluctuation of propellant supply to the engine, a thrust fluctuation, and a structural vibration are coupled. For the prediction of this instability, it is required to provide dynamic characteristics of the pump represented as the transfer matrix correlating the upstream and downstream pressure and flow rate fluctuations. In the present study, the flow rate fluctuation is evaluated from the fluctuation of pressure difference at the different locations assuming that the fluctuation is caused by the inertia of the flow rate fluctuation. The experiments were performed in some flow conditions, and it was shown that the tendencies of dynamic characteristics are related to excitation frequencies, cavitation numbers and flow rate coefficients.

• 보건행정학회지
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• 제30권4호
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• pp.451-459
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• 2020

Background: Although Korean government have been adopting several policies to expand coverage of National Health Insurance (NHI) program, the coverage rate is still below average across Organization for Economic Cooperation and Development countries. This study was to identify public perception on appropriateness of coinsurance rate and factors associated with coinsurance rate in National Health Insurance. Methods: For this cross-sectional study, 507 participants over aged 20 years were recruited from telephone surveys. Respondents experienced at least one and more visiting medical facilities due to medical problems in last 12 months. Demographic factors, socioeconomic positions, and experiences on medical utilization were measured in order to identify factors associated with perception appropriateness of coinsurance rate. Results: The 49.9% (n=209) of the public responded that the coinsurance rate of NHI program was appropriate. There were no differences in positive perception according to socio-demographic factors and experiences on medical utilization except for gender, residential area, and felt expensive when using medical services. People who felt burden of medical expenditure were more likely to perceive coinsurance rate inappropriate (odds ratio, 2.33; 95% confidence interval, 1.52-3.58) Conclusion: In spite of the relatively low coverage rate of NHI, this study identified that 49.9% of the public perceived the current coinsurance rate was adequate. However, people who felt the burden of medical expenditure were still had a negative perception of the coinsurance rate needed to decrease the coinsurance rate.

• JSTS:Journal of Semiconductor Technology and Science
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• 제12권3호
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• pp.266-269
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• 2012

High-efficiency built-in redundancy analysis (BIRA) is presented. The proposed BIRA uses three techniques to achieve a high repair rate using spare mapping registers with adjustable fault tags to reduce area overhead. Simulation results show that the proposed BIRA is a reasonable solution for embedded memories.

• Journal of Acupuncture Research
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• 제21권5호
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• pp.13-25
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• 2004

Objective : Herniation of Nucleus Pulpous(HNP) of Lumbar is the most important reason that causes low back pain. The aim of this study is to investigate the effectiveness of Bee-venom acua-acupuncture therapy for protrusion disc patients. Methods : To evaluate the effectiveness of Bee-Venom Acupuncture Therapy, 20 patients were treated by bee-venom acua-acupuncture therapy. To estimate the efficacy of treatment, we used Quardruple Visual Analog Scale(QVAS). Results : 1. As a objectivity treatment record, they test treatment record good 60%, fair 25%, excellent 15%. 2. After bee-venom therapy, pain rate changed from 8.25 to 2.15. 3. By the results which puts out the statistics in sex, a pain rate of male changed from 8.75 to 2.50, a pain rate of female 7.92 to 1.92. Intentional difference is none as a therapy. By the results which puts out the statistics in age, after forties changed from 7.78 to 2.22 and before forties changed from 7.90 to 1.92. By the results which puts out the statistics in disc herniation, pain rate of central type changed from 8.29 to 2.29, pain rate of left type changed from 8.20 to 1.40, pain rate of Right type changed from 8.00 to 4.00.

• Annals of Occupational and Environmental Medicine
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• 제34권
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• pp.30.1-30.13
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• 2022

Background: Although working hours have decreased in Korea, they are still high compared to that of other countries. In Korea, cardiovascular and cerebrovascular diseases (CCVDs) related to overwork in Korea continually occur, and the social burden from overwork is estimated to be high. This study investigated the amendment of regulations affecting the approval rate of occupational CCVDs. Methods: The change in approval rate of occupational CCVDs and related regulations were investigated using the Act and public notice on the standards for recognition of occupational CCVDs and the yearbooks of the Ministry of Employment and Labor. The CCVD mortality was estimated using data on the number of deaths according to the cause of death, the number of employed people, and resident registration population aged 15-64 years. The cumulative mortality of CCVDs was estimated using the Kaplan-Meier method. Results: Since the establishment of the standards for recognition in Korea in 1982, the scope of occupational diseases has been expanded to include intracerebral hemorrhage, subarachnoid hemorrhage, cerebral infarction, myocardial infarction, and aortic dissection. In 2013, the concept of working hours was introduced in chronic overwork. The approval rate of occupational CCVDs was 44.7% in 2006, which decreased to 12.9% in 2011. After the improvement of related regulations, the approval rate increased to 41.3% in 2018. From 2000 to 2017, the CCVD mortality of both the unemployed and employed tended to decrease, and their cumulative CCVD mortalities were 549.3 and 319.7 per 100,000 people, respectively. Conclusions: CCVDs are recognized as occupational diseases in Korea. The amendments to the standards for recognition, the introduction of the Occupational Disease Adjudication Committee, the principle of presumption, and the reduction of working hours have changed the approval rate of occupational CCVDs. A strategic approach is needed to further reduce the incidence of CCVDs.

• Journal of Photoscience
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• 제9권2호
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• pp.130-133
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• 2002

The last step in the photocycle of photoactive yellow protein (PYP) is a spontaneous recovery of the dark state from the active state in which the p-coumaric acid chromophore is thermally isomerized, concomitantly with the deprotona- tion of the chtomophore and the refolding of the protein moicty. For the purpose of understanding the mechanism of the thermal back-isomerization, we have investigated the rate-determining step by analyzing mutant PYPs of Met100, which was previously shown to play a major role in facilitating the reaction (1). The mutation to Lys, Leu, Ala, or Glu decelerated the dark state recovery by 1 to 3 three orders of magnitude. By evaluating temperature-dependence and pH-dependence of the kinetics of the dark state recovery, it was found that the retardation by mutations resulted from elevation of the activation enthalpy ( H$\^$┿/) and that the pKa of the chromophore, which was affected by the mutation, is in a linier correlation with the amplitude of the rate constants. It was, therefore, deduced from the correlation that the free energy for crossing the activated state in the dark recovery process is proportional to the free energy for the deprotonation of the chromophore, identifying the rate-determining step as the deprotonation of the chromophore. (1) Devanathan, S. Genick, U. K. Canestrelli, I. L. Meyer, T. E. Cusanovich, M. A. Getzoff, E. D. Tollin, G., Biochemistry 1998, 37, 11563 - 11568

• International Journal of Fluid Machinery and Systems
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• 제2권4호
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• pp.431-438
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• 2009

A Large Eddy Simulation (LES) of the flow in an inducer is carried out under flow rate oscillations. The present study focuses on the dynamic response of the backflow and the unsteady pressure performance to the flow rate fluctuations under non-cavitation conditions. The amplitude of angular momentum fluctuation evaluated by LES is larger than that evaluated by RANS. However, the phase delay of backflow is nearly the same as RANS calculation. The pressure performance curve exhibits a closed curve caused by the inertia effect associated with the flow rate fluctuations. Compared with simplified one dimensional evaluation of the inertia component, the component obtained by LES is smaller. The negative slope of averaged performance curve becomes larger under unsteady conditions. From the conservations of angular momentum and energy, an expression useful for the evaluation of unsteady pressure rise was obtained. The examination of each term of this expression show that the apparent decrease of inertia effects is caused by the response delay of Euler's head and that the increase of negative slope is caused by the delay of inertial term associated with the delay of backflow response. These results are qualitatively confirmed by experiments.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.947-952
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• 1996

The effect of fluctuating temperature on the respiration of vegetables has been investigated. Spinach was selected as the experimental material because of its high respiratory activity and kept under the condition that temperature changed alternately at low and high levels every 4 hours. The low-high level temperature combination was set in $1-10^{\circ}C,{\;}1-20^{\circ}C{\;}and{\;}1-30^{\circ}C$. Respiration was evaluated in terms of quantity of $CO_2$ evolved from spinach. The evolution rate of $CO_2$ was determined by a change in its concentration. The evaluation rate of $CO_2$ followed closely the temperature change. In the temperature combinations at $1-10^{\circ}C{\;}and{\;}1-20^{\circ}C$, the relationship between $CO_2$ evolution rate and temperature was found to be able to express by Arrhenius law, while at $1-30^{\circ}C$, it did not obey the law.

• 전기전자학회논문지
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• 제12권2호
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• pp.81-86
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• 2008

In wireless communication system using 2.4GHz radio link, data rate varies with time due to interferences, which causes the performance degradation. Therefore, effective transmission methods are required to obtain better performance according to varying data rate. This paper proposes a novel method that increases the data rate, as well as the influence of different loop-filter bandwidths on the performance of the PLL. Experimental results show that the proposed method is effective because it can achieve higher throughput in various data rate.

• 한국컴퓨터정보학회논문지
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• 제22권8호
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• pp.107-112
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• 2017

In this paper, I studied several universities which are especially famous for video and media fields in the United States to develop our international competitiveness. I selected the outstanding US universities and researched the various indexes of corresponding department, internship program and other activities related with company. Then, analyzed the research results and compared with the department of Video Broadcasting at the K women's university in our country. As a result, the retention rate and the graduate rate of the 4-years universities(bachelor's degree) are very higher than the 2-years associated degree among the US universities. On the other hand, although the department of Video Broadcasting at the K women's university is the associated degree course, it shows up the highest the retention rate and the graduate rate than the US universities. Therefore, we are able to recognize that K Women's University has managed its students well. However, the employment rate of the K Women's University was poor than the US universities due to the lack of the internship programs, other activities supported by companies and the career service center.