• 한국전기전자재료학회논문지
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• 제14권9호
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• pp.773-778
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• 2001

In this dissertation the results of the combined experimental and theoretical studies designed to understand and predict the spatial growth and transport coefficients for electrons in SF$_{6}$ and SF$_{6}$-Ar mixtures have described. The ionization and attachment coefficients in pure SF$_{6}$ and SF$_{6}$-Ar mixtures have been calculated over the range of 10$_{6}$ molecule and for Ar atom proposed by other authors. The transport coefficients for electrons in (0.2%)SF$_{6}$-Ar and (0.5%)SF$_{6}$-Ar mixtures were measured by time-of-flight method, and the electron energy distribution function and the parameters of the velocity and the diffusion were determined by the variation of the collision cross-sections with energy. The results obtained in this work will provide valuable information on the fundamental haviors of electrons in weakly ionized gases and the role of electron attachment in the choice of better gases and unitary gas dielectrics or electro negative components in dielectric gas mixtures. gas mixtures.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.298-301
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• 2006

This paper describes the electron energy distribution function characteristics in $SF_6-Ar$ gas calculated for range of E/N values from $50\sim700[Td]$ by the Monte Carlo simulation(MCS) and Boltzmann equation(BE) method using a set of electron collision cross sections determined by the authors and the values of electron swarm parameters are obtained by time of flight(TOF) method. In this dissertation the results of the combined experimental and theoretical studies designed to understand and predict the spatial growth and transport coefficients for electrons in $SF_6$ and $SF_6-Ar$ mixtures have described. The ionization and attachment coefficients in pure $SF_6$ and $SF_6-Ar$ mixtures have been calculated over the range of 10$SF_6$ molecule and for Ar atom proposed by other authors. The results obtained in this work will provide valuable information on the fundamental behaviors of electrons in weakly ionized gases and the role of electron attachment in the choice of better gases and unitary gas dielectrics or electro negative components in dielectric gas mixtures.

• 한국지진공학회논문집
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• 제26권6호
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• pp.255-265
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• 2022

In order to determine fragility curves, the limit state of piers for each damage level is suggested in this paper based on the previous test results in Korea, including our test results. In previous studies, the quantitative measures for damage levels of piers have been represented by curvature ductility, lateral drift ratio, or displacement ductility. These measures are transformed to lateral drift ratios of piers for consistency, and the transformed values are compared and verified with our push-over test results for flexural RC piers with a circular cross-section. The test specimens are categorized concerning the number of lap-splices in the plastic hinge region and whether seismic design codes are satisfied or not. Based on the collected test results in Korea, including ours, the lateral drift ratio for each pier damage level is suggested.

• 한국지형학회지
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• 제26권2호
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• pp.1-14
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• 2019

This study analyzed the relativity between block stream and talus distributions by employing a likelihood ratio approach. Possible distribution sites for each debris slope landform were extracted by applying a spatial integration model, in which we combined fuzzy set model, Bayesian predictive model, and logistic regression model. Moreover, to verify model performance, a success rate curve was prepared by cross-validation. The results showed that elevation, slope, curvature, topographic wetness index, geology, soil drainage, and soil depth were closely related to the debris slope landform sites. In addition, all spatial integration models displayed an accuracy of over 90%. The accuracy of the distribution potential area map of the block stream was highest in the logistic regression model (93.79%). Eventually, the accuracy of the distribution potential area map of the talus was also highest in the logistic regression model (97.02%). We expect that the present results will provide essential data and propose methodologies to improve the performance of efficient and systematic micro-landform studies. Moreover, our research will potentially help to enhance field research and topographic resource management.

• Physical Therapy Rehabilitation Science
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• 제8권4호
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• pp.175-186
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• 2019

Objective: Non-specific chronic low back pain (NS-CLBP) has been related to abnormal trunk muscle activations, but literature reported considerable variability in muscle amplitudes of NS-CLBP patients during prolonged sitting periods. Therefore, the purpose of this study was to examine the differences among homogenous NS-CLBP subgroups in muscle activity, using muscle co-contraction indices as a more objective approach, and their roles on pain development during a 1-hour period of prolonged sitting. Design: Cross-sectional study. Methods: Twenty NS-CLBP subjects with motor control impairment (MCI) [10 classified as having flexion pattern disorder, and 10 with active extension pattern disorder], and 10 healthy controls participated in the study. Subjects followed a 1-hour sitting protocol on a standard office chair. Four trunk muscle activities including amplitudes and co-contraction indices were recorded using electromyography over the 1-hour period. Perceived back pain intensity was recorded using a numeric pain rating scale every 10 minutes throughout the sitting period. Results: All study groups presented with no significantly distinctive trunk muscle activities at the beginning of sitting, nor did they change over time when pain increased to a significant level. Both MCI subgroups reported a similarly significant increase in pain behavior through mid-sitting (p<0.001). However, after mid-sitting, they significantly differed from each other in pain (p<0.01) but did not differ in the levels of muscle activation. Conclusions: This study was the first to highlight the similarities in trunk muscle activities among homogenous NS-CLBP patients related to MCI and compared them to healthy controls while sitting for an extended period of time, and the significant increase in pain over the 1-hour sitting might not be attributed to trunk muscle activation.

• 치위생과학회지
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• 제19권4호
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• pp.213-219
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• 2019

Background: Smoking exerts an adverse effect on the periodontal tissue by reorganizing the ecosystem of oral microorganisms and is considered to be an important factor in the development of periodontal disease. Although cross-sectional studies on smokers and non-smokers have been attempted to investigate the microbial differences in periodontal oral cavity, only few studies have been conducted to investigate the changes in oral microorganisms during smoking cessation. The purpose of this study was to investigate the changes of bacteria in saliva and gingival crevicular fluid (GCF) over a period of one year among 11 smokers trying to quit smoking. Methods: Eleven smokers trying to quit smoking visited the clinic at baseline, two weeks, two months, four months, six months, and 12 months to give saliva and GCF samples. The amounts of 16S rRNA, Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia, Fusobacterium nucleatum subsp. nucleatum, Streptococcus mutans, and Streptococcus sobrinus in saliva and GCF were quantified using real-time polymerase chain reaction TaqMan probe assay. The results were analyzed by nonparametric statistical analysis using Friedman test and Spearman correlation coefficient. Results: After cessation of smoking, the amounts of 16S rRNA corresponding to P. gingivalis, F. nucleatum, P. intermedia, and T. denticola in saliva decreased and then again increased significantly. The amount of F. nucleatum 16S rRNA in GCF decreased significantly after smoking cessation. Positive correlations were observed between 16S rRNA and F. nucleatum and between F. nucleatum and T. denticola in saliva and GCF. Conclusion: Even if the number of subjects in this study was small, we suggest that smoking cessation may reduce the total bacterial amount and F. nucleatum in GCF. However, the results regarding changes in the microbial ecosystem due to smoking or smoking cessation were inconsistent. Therefore, further in-depth studies need to be carried out.

• Journal of Acupuncture Research
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• 제27권4호
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• pp.115-125
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• 2010

Objectives : The purpose of this study is to determine the effect of Bee-venom Acupuncture on upper limb spasticity control in stroke patients. Methods : Ten stroke patients with upper limb spasticity were randomly divided into two groups, a Bee-Venom Acupuncture group(group I) and a normal saline group(group II). After 1 week resting phase, this trial was used a cross-over trial. The numbers of Pharmacopuncture treatment were 3 times a week for 3 weeks. Modified Ashworth Scale(MAS), WMFT(Wolf Motor Function Test), The 10-second Test were used for evaluation of spasticity control before experiment, after 1 week, 2 weeks, 3 weeks. Results : Group I showed significant improvement(p<.05) in MAS, WMFT, The 10-second Test. But Group II showed no significant improvement(p<.05) in MAS, WMFT, The 10-second Test. The results showed significant difference in WMFT, The 10-second Test, but no significant difference in MAS between two groups. Conclusions : These results showed that Bee-venom Acupuncture might decrease upper limb spasticity and increase arm motor function in stroke patients. Further studies will be required to examine more cases in the long period for the effect on upper limb in spasticity by Bee-Venom Acupuncture.

• 대한한의진단학회지
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• 제19권2호
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• pp.91-100
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• 2015

Objectives The aim of this study is to develop a structured clinical protocol related with acquisition of radial pulse wave in the randomized, $2{\times}2$ cross-over design, and cold-heat intervention trial for a pilot and preliminary study. Methods The protocol was contrived based on wide ranging literature searches for cold-heat intervention experiments and radial pulse diagnoses. Results Sample size of 60 subjects was calculated based on an effect size derived from the previous study designed to detect the pre-post cold-heat differences in the radial pulse. Each subjects will be randomly assigned to the cold (first) to heat (last) group (n=30) or heat (first) to cold (last) group (n=30). All subjects will fill out a case report form and questionnaires related with pattern identification, dietary patterns, sleep quality, and physical activity will be surveyed and used as a secondary outcomes. Safety assessment will be reported at the final stage. Conclusions This protocol will provide an additional reference to future studies related with observation of radial pulse during any interventions and also expect to be used as a guideline for acquisition of reliable radial pulse wave data.

• Nutrition Research and Practice
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• 제9권3호
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• pp.328-335
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• 2015

BACKGROUND/OBJECTIVES: Studies conducted in Western populations have suggested that dietary calcium may protect against metabolic abnormalities, but there is little evidence of this effect in Asians, who have relatively low calcium intake. We evaluated the cross-sectional relationship between dietary calcium and metabolic syndrome among Korean men and women aged 40 years and over. SUBJECTS/METHODS: A total of 6,375 subjects aged 40 years and over and were recruited between January 2005 and February 2010 from the baseline study of the Multi-Rural Communities Cohort Study in Rural Communities (MRCohort). A food frequency questionnaire was used to collect dietary information. Metabolic syndrome was defined using the modified criteria published in the Third Report of the National Cholesterol Education Program Adult Treatment Panel. RESULTS: Calcium intake was related inversely to metabolic syndrome in women (P-value = 0.0091), but not in men (P = 0.1842). Among metabolic components, high waist circumference (WC) (P = 0.0426) and high blood glucose (P = 0.0027) in women and hypertriglyceridemia (P = 0.0017) in men were inversely correlated with calcium intake. Excluding those who used calcium or multinutrient supplements did not attenuate the relationship between dietary calcium and metabolic abnormalities. CONCLUSION: Dietary calcium intake from foods may be inversely related to metabolic syndrome, WC, and blood glucose among women in rural areas of Korea.

• Acta Via Serica
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• 제4권1호
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• pp.87-109
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• 2019

In the Iranian epic $K{\bar{u}}shn{\bar{a}}ma$, there is a rather interesting story that recounts how the inhabitants of $B.s{\bar{i}}l\bar{a}$ cross-breed their domesticated horses with a magical horse living in the sea in order to obtain fine-bred ones. What is even more interesting is that similar accounts are also seen in many of other classical Perso-Arabic works and Chinese sources. The regions that such events took place in mainly spread over Central Asia and western China while in $K{\bar{u}}shn{\bar{a}}ma$, the story happens in $B.s{\bar{i}}l\bar{a}$, a legendary kingdom with its historical prototype being Silla. By sorting out certain records of how ancient people sought fine horses by cross-breeding domesticated horses with wild horses that inhabited mountains and waters within Chinese sources and classical Muslim works, and comparing these accounts with similar plot lines as depicted in $K{\bar{u}}shn{\bar{a}}ma$, this paper attempts to elucidate that the story in $K{\bar{u}}shn{\bar{a}}ma$ is a result of flourishing land and maritime exchanges between East Asia and West Asia during ancient and medieval times, rather than a purely literary fiction. It was not only influenced by the horse culture that thrived over the Eurasian Steppe, but the story is also coincidentally in accordance with the fact that the nomadic zone which lies within the central Eurasian continent extends as far as the Korean Peninsula in northeast Asia.