• 한국지구과학회지
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• 제31권5호
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• pp.531-538
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• 2010

This study presents the development of an elevated subsidence inversion over a surface low pressure system, which was formed along the Changma front or Meiu-Baiu front. The results of our analysis strongly suggest that the inversion is dissimilar to those formed in anticyclonic situations but is instead similar to the onion-shaped sounding found in wake low. The present analysis indicates that the observed elevated inversion resulted from the intrusion of stratospheric air associated with tropopause folding.

• 소성∙가공
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• 제30권1호
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• pp.43-48
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• 2021

The success of warm forming of Mg alloy sheet is greatly influenced by friction at elevated temperature, depending on the surface treatment of the tool. The tool coating affected the frictional characteristics of AZ31B Mg alloy sheet at elevated and room temperatures. The frictional behavior of the Mg alloy sheet at room temperature was not significantly affected by surface treatment conditions of the tool, but was significantly affected at elevated temperature. When the contact pressure is high, a few surface-treated tools exhibit a higher coefficient of friction than those without surface treatment. It is important to select the surface treatment conditions of the tool in order to ensure appropriate friction during warm forming of Mg alloy sheet.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.1255-1260
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• 2008

This study is simulation of high elevated liquid line of a modular heat pump system to observe longitudinal subcooling variation. In a high elevated tube, subcooled refrigerant(R410A) through a condenser changes its states by heat transfer with surrounding air and by pressure drop from elevation. In this study, the liquid line was simulated through correlations of heat transfer and pressure drop for the variation from single-phase into two-phase flow. Pressure drop, heat transfer rate and vapor quality were calculated as key parameters. Two-phase turning heights and variations of the key parameters were confirmed from the simulation. As a result, high elevation of liquid line has great influence on upward flow, which requires additional equipment to compensate the variation.

• 동력기계공학회지
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• 제6권1호
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• pp.68-73
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• 2002

An opportunity to use the elevated temperature has been recently increasing in various elements of heat facilities or machines such as heat exchanger tubes, pressure vessels, engines of aircraft, boilers and turbines in power plants, and nuclear reactor components, etc. as machinery industry develops. Thus, the development of such elevated-temperature heat-resisting materials and the studies on their elevated-temperature materials friction welding, creep design and analysis have been considered as an important and needful fact. In this paper, friction welding optimization for 1Cr0.5Mo to STS304 and AE applications for the weld quality evaluation were investigated. The important results of this study are as follows : The techniques for dissimilar friction welding optimization of the elevated temperature materials 1Cr0.5Mo and STS304 and its real-time weld quality evaluation by AE were developed, considering on both strength and toughness. Quantitative relationship was identified among welding condition, weld quality and cumulative AE counts.

• Journal of Computing Science and Engineering
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• 제2권2호
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• pp.180-199
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• 2008

Technology has had a tremendous impact on our daily lives. Recently, technology and its impact on aging has become an expanding field of inquiry. A major reason for this interest is that the use of technology can help older people who experience deteriorating health to live independently. In this paper we give a brief review of the in-home monitoring technologies for the elderly. In the pilot study, we analyze the possibility of employing the data generated by a continuous, unobtrusive nursing home monitoring system for predicting elevated(abnormal)pulse pressure(PP) in elderly(PP=systolic blood pressure-diastolic blood pressure). Our sensor data capture external information(behavioral) about the resident that is subsequently reflected in the predicted PP. By continuously predicting the possibility of elevated pulse pressure we may alert the nursing staff when some predefined threshold is exceeded. This approach may provide additional blood pressure monitoring for the elderly persons susceptible to blood pressure variations during the time between two nursing visits. We conducted a retrospective pilot study on two residents of the TigerPlace aging in place facility with age over 70, that had blood pressure measured between 100 and 300 times during a period of two years. The pilot study suggested that abnormal pulse pressure can be reasonably well estimated (an area under ROC curve of about 0.75) using apartment bed and motion sensors.

• Journal of Preventive Medicine and Public Health
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• 제53권1호
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• pp.45-55
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• 2020

Objectives: This study was conducted to explore recent trends in the prevalence of pediatric elevated blood pressure and hypertension (HTN) in Korea and the United States, applying the new HTN reference values for adolescents. Methods: This study analyzed 17 339 (8755 Korean and 8584 American) adolescents aged 10 to 17 who participated in the Korea National Health and Nutrition Examination Survey and the National Health and Nutrition Examination Survey, respectively, between 2005 and 2016. HTN was defined using percentile-based reference values for non-overweight adolescents from 7 nations, and obesity was defined by body mass index (BMI) based on country-specific growth charts. All analyses were stratified by sex and year-over-year changes were evaluated by calculating the p for trend. Results: Systolic blood pressure showed a statistically meaningful upward trend in Korean boys and girls, while diastolic blood pressure did not show any significant changes. Both systolic and diastolic blood pressure levels declined among United States boys and girls. The prevalence of elevated blood pressure and HTN remained similar in Korean adolescents, but declined in both sexes among United States adolescents. BMI increased in both sexes among Korean adolescents, although the overweight and obesity rates stayed the same. No significant trends were found in any obesity indices among United States adolescents. The prevalence of elevated blood pressure and HTN by obesity level was higher among Korean adolescents than among their United States peers in both sexes, and the gap became higher at more severe levels of obesity. Conclusions: Despite the strong correlation between obesity and HTN, recent trends in the prevalence of HTN and obesity among Korean and United States adolescents were strikingly different. Follow-up studies are necessary to determine why the prevalence of HTN was more than twice as high among Korean adolescents than among their United States counterparts.

• Journal of Chest Surgery
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• 제27권5호
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• pp.345-352
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• 1994

We have performed left lung transplantation followed by ligation of right pulmonary artery in 14 dogs at the Chest Disease Research Institute, Yonsei University College of Medicine from May 1992 to February 1994. Excised left lung was perfused with 1500cc of 4$^{\circ}$C cold Euro-Collin`s[E-C] solution at a pressure of 30cmH2O through main pulmonary artery and preserved in 4$^{\circ}$C cold E-C solution for one hour. Left lung transplantation were proceeded in order of left atrium, left main bronchus, left pulmonary artery and right pulmonary artery ligation as usual method. The femoral artery and pulmonary artery pressures were monitored for more than 5 hours after the transplantations in 14 dogs. Six recipient dogs had elevated mean pulmonary artery pressure to greater than 30mmHg after the left lung transplantation and ligation of right pulmonary artery. The cause of elevated mean pulmonary artery pressure was due to inadequate preservation resulting in ischemic damage to donor lungs in 3 cases, and inadequate surgical techniques in 3 cases. Two recipient dogs without surgical complications died immediate post-operatively due to hemorrhagic shock. The bleeding focuses were LA anastomotic site in one case and femoral artery puncture site in another case. The remaining 6 recipient dogs showed mean pulmonary arterial pressure less than 30mmHg. However, one dog had spontaneous pneumothorax in post-operative 4 days, and another dog had rejection phenomenon in post-operative 5 days which was confirmed by pathologic findings of extracted transplanted lung. One dog succumbed of severe hemoptysis which was due to lung abscess with pin point stenosis of bronchial anastomosis in post-operative 38 days. In conclusion, elevated mean pulmonary arterial pressure greater than 30mmHg in immediate postoperative period can be due to inadequate preservation of extracted lung or poor surgical techniques. And the two dogs succumbed of hemorrhagic shock even though the mean pulmonary arterial pressure was less than 30mmHg. It is thought that careful preservation of the extracted donor lung in 4oC E-C solution and complete surgical techniques are the most important factors early and late complications.

• Journal of Community Nutrition
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• 제8권4호
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• pp.193-199
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• 2006

There have been many studies indicating increased salt intake is related to elevated blood pressure (BP). Hypertension and pre-hypertension are prevalent in Korea. A national survey showed that the Korean average daily salt consumption was 12.5g, which is more than twice the current recommendation in the UK or USA. This study was performed to understand which aspects of the Korean diet contributed to high salt intake and elevated BP in Korea. The subjects consisted of 1,110 Korean adult men aged 30 to 49 years who were selected from the data of 2001 Korean National Health and Nutrition Survey, a nationwide cross sectional survey. The relationship of BP with sodium and high sodium food intakes were analyzed. After categorizing subjects according to their BP, the socio-demographic information and food and nutrients intakes were analyzed. BP increased with a larger amounts of sodium intake and the trend was significant with diastolic BP. However, the trends of BP for sodium densities of the diet were not. People with hypertension significantly tended to be older, larger, and less educated than people with normal BP. And they consumed more foods from the fats, oils & sweets group and larger amounts of discretionary sodium than normal people. The current report advocates that public health intervention, which improves the awareness of the role of salt on elevated blood pressure for the public, should be implemented in Korea.

• Journal of Nutrition and Health
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• 제42권8호
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• pp.732-739
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• 2009

Metabolic syndrome has been strongly associated with elevated alanine aminotransferase (ALT), a surrogate of nonalcoholic fatty liver disease. We investigated the relationship between metabolic syndrome and elevated ALT in the general Korean population. The study sample was comprised of 4,781 Korean adults who had participated in the 2005 Korean National Health and Nutrition Examination Survey. Metabolic syndrome was defined by National Cholesterol Education Program for Adult Treatment Panel III. Elevated ALT was defined as an enzyme activity > 40 IU/L for men, and > 31 IU/L for women. ALT was measured by enzymatic methods. Among participants, 425 (8.9%) subjects displayed elevated ALT. The odds ratios (ORs) for elevated ALT increased in subjects with obesity or one of components of metabolic syndrome such as abdominal obesity, high blood pressure, high fasting glucose, high triglyceride, and low HDL cholesterol after adjusting for age and sex. The unadjusted OR for elevated ALT increased according to the number of components of metabolic syndrome (OR = 1.5, 95% CI: 0.96-2.32 for 1 component; OR = 3.0, 95% CI: 1.98-4.61 for 2 components; OR = 6.3, 95% CI: 4.29-9.35 for ${\geq}3$ components; p for trend < 0.0001). This trend did not differ after adjustments for putative risk factors including age, sex, BMI, smoking status, and alcohol intake. Metabolic syndrome is implicated as a strong risk factor of elevated ALT in Korean adults.

• 한국수소및신에너지학회논문집
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• 제30권1호
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• pp.67-75
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• 2019

An experimental study was conducted to measure laminar burning velocity and Markstein length of SNG fuel with 3% of hydrogen contents from spherical propagating flames at normal and elevated initial pressure. These results were compared with numerical calculations by Premix code with GRI-mech 3.0, USC II and UC San Diego to provide suitable mechanism for SNG fuel. As a result of this work, it was found that the burning velocities and Markstein lengths of SNG fuel decrease with increase of initial pressure regardless of equivalence ratio. In addition, numerical calculations with GRI-mech 3.0 were coincided with experimental results.