• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.5
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• pp.448-454
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• 2009

Hydrogen was produced from water plasma excited in high frequency (HF) inductively coupled tubular reactor. Mass spectrometry was used to monitor gas phase species at various process conditions, Water dissociation rate depend on the process parameters such as ICP power, $H_{2}O$ flow-rate and process pressure, Water dissociation percent in ICP reactor decrease with increase of chamber pressure, while increase with increase of ICP power and $H_{2}O$ flow rate. The effect of $CH_4$ gas addition to a water plasma on the hydrogen production has been studied in a HF ICP tubular reactor. The main roles of $CH_4$ additive gas in $H_{2}O$ plasma are to react with 0 radical for forming $CO_x$ and CHO and resulting additional $H_2$ production. Furthermore, $CH_4$ additives in $H_{2}O$ plasma is to suppress reverse-reaction by scavenging 0 radical. But, process optimization is needed because $CH_4$ addition has some negative effects such as cost increase and $CO_x$ emission.

• Women's Health Nursing
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• v.23 no.4
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• pp.233-242
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• 2017

Purpose: This study investigated the relationships among parenting stress, husband's support, and breastfeeding adaptation in mothers. Methods: A correlational survey design was utilized in this study. Data were collected from 181 breastfeeding mothers with infants under 12 months of age. Participants were recruited from the outpatient clinic, a child photo studio, or from the kid's cafe from July 22 to September 13, 2016. Instruments for collecting data included Childcare Stress Inventory (CSI), Husband's Support scale, and the Breastfeeding Adaptation scale. Data were analyzed using SPSS 21.0 by frequency, descriptive statistics, t-test, one-way ANOVA, Pearson's correlation coefficient and multiple regression. Results: Of the 181 subjects, 54.7% responded they only breastfed with 75.7% who received breastfeeding education. Seventy-two percent of mothers made a decision to breastfeed by themselves. The mean score was $2.39{\pm}0.53$ for parenting stress, $3.07{\pm}0.43$ for husband's support, and $3.85{\pm}0.49$ for breastfeeding adaptation. Factors influencing breastfeeding adaptation were identified as lower parenting stress (${\beta}=-.54$), greater husband's support (${\beta}=.31$), breastfeeding (${\beta}=.31$), and older age of baby (${\beta}=.14$), with 56.0% that explained variance. Conclusion: This study reports that parenting stress has negative effect on breastfeeding adaptation, while husband's support has positive effect. Results may be useful in developing new strategies for enhancing breastfeeding adaptation.

• Journal of Acupuncture Research
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• v.25 no.4
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• pp.95-103
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• 2008

Objectives : This study was to investigate the regulatory effect of electro-acupuncture on Jogsamni ($ST_{36}$) in bradygastric condition or gastroparesis which is a neuropathic complication of type 2 diabetes mellitus(T2DM), assessed using 4-channel electrogastrography (EGG). Methods : It was a case series study. Each patient was given electro-acupuncture(EA) one point, Jogsamni($ST_{36}$) or Gyeonu($LI_{15}$) bilaterally for thirty minutes with 2Hz bipolar square wave frequency and moderate intensity of stimulation. With attaching electrodes around stomach region throughout pre-acupuncture, acupuncture, and post-acupuncture session, these parameters were produced; percent rate of bradygastria power compared to sum of power in all kind of gastric rhythm(% bradygastria), dominant frequency(DF) and dominant power(DP). Parameter was analysed per each channel's variable change from pre-acupuncture session by paired t-test. Results : There was statistically significant decrease in % bradygastria parameters on one of the $ST_{36}$ treated patients from pre-acupuncture session and to post-acupuncture session(P=0.015, P=0.008 respectively). A marginal significant decrease of DP was shown in the other $ST_{36}$ treated patient from pre-acupuncture session through post-acupuncture session(P=0.049). Combined data of two $ST_{36}$ Treated patients showed that there was significant decrease of %bradygastria from pre-acupuncture session to acupuncture session(P=0.020), and was decrease of DP from pre-acupuncture session to post- acupuncture session(P=0.020). Conclusions : EA at $ST_{36}$ resulted in statistically significant decrease in %bradygastria and DP for dysrhythmic condition in T2DM gastroparesis patients. Considering this limited results, further study will be needed to elucidate the effect of multiple-acupuncture on gastric myoelectrical activities.

• Korean Journal of Community Nutrition
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• v.25 no.1
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• pp.48-60
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• 2020

Objectives: Most cohort studies used food frequency questionnaires (FFQ) to evaluate coffee consumption as it assesses habitual dietary patterns, whereas some studies have used the 24-hour recalls (24HR) as it elicits in-depth description of foods and the amount eaten. The aim of this study was to compare FFQs and 24HR to assess the consumption of various types of coffee. Methods: We included 25,904 participants aged 40 years or older from the Health Examinees (HEXA) Study of the Korean Genome and Epidemiologic Study (KoGES). Each participant completed one FFQ and one-day (n=11,280) or two-day 24HR (n=14,624). We classified coffee types into: black coffee, coffee with sugar and cream, and coffee with sugar alone or cream alone. We compared the proportions of nondrinkers, black coffee, and coffee with sugar and cream through FFQ and 24HR. Results: Among those who completed one FFQ and one-day 24HR, 39.4% of "nondrinkers" on one-day 24HR reported that they did not drink coffee on their FFQs. Whereas among those who complete two-day 24HR, 71.2% of "nondrinkers" on two-day 24HR said that they did not drink coffee on their FFQs. Among those who completed one FFQ and oneday 24HR, 58.3% marked "black coffee" on one-day 24HR said that they drank black coffee on their FFQs. Among those who complete two-day 24HR, 58.8% marked "black coffee" on two-day 24HR said that they drank black coffee on their FFQs. The kappa coefficients and percent agreements were 0.4 and 59.6%, respectively, for the comparison of coffee intake between FFQ and one-day 24HR, and 0.6 and 72.8%, respectively, for the comparison of coffee intake between FFQ and two-day 24HR. Conclusions: We found discrepancies between FFQs and 24HR in the types of coffee consumed. Such limitations should be considered when using the 24HR data to examine the effect of coffee consumption on disease development.

• Journal of Nutrition and Health
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• v.40 no.1
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• pp.31-40
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• 2007

The purpose of this study was to investigate the association between insulin resistance and cardiovascular disease risk factors in Korean type 2 diabetes patients. The subjects were 429 (male: 218, female: 211) type 2 DM patients visited DM clinic, and they were classified into quartiles based on $K_{ITT}$ index (%/min, Insulin Tolerance Test). Anthropometric and biochemical characteristics, and dietary intakes by Food Frequency Questionnaire were assessed. The means of waist circumference, fat mass, percent body fat and abdominal fat thickness were significantly higher in the lowest quartile (the most insulin resistant group) than in the highest quartile (the least insulin resistant group) of $K_{ITT}$ index (%/min)(p<0.05), For hematological values, the lowest quartile showed significantly higher fasting blood glucose, HbA1c, C-peptide, insulin, triglyceride, ApoB/apoA-1 ratio and C-reactive protein compared to the highest quartile (p < 0.05). Moreover, $K_{ITT}$ index (%/min) was negatively correlated with waist circumference, fat mass, percent body fat, abdominal fat thickness and fasting blood concentrations of glucose, HbA1c, C-peptide, insulin, cholesterol, triglyceride, ApoB/apoA-1 ratio and C-reactive protein (p < 0.05). Nutrient intakes were not significantly different among the quartile groups of $K_{ITT}$ index (%/min) and also not correlated with insulin resistance, however, they showed correlation with obesity parameters (BMI, waist circumference, waist-hip ratio, vat mass, abdominal fat thickness), which were strongly associated with insulin resistance. In conclusion, cardiovascular disease risk would be higher as the insulin resistance grows in Korean type 2 DM patients, and nutrient intakes would affect to the insulin resistance through the effect on anthropometric parameters.

• Journal of Ocean Engineering and Technology
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• v.23 no.1
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• pp.74-80
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• 2009

In this study, the static and modal analyses to find the characteristic of eigenvalues for a towed cable were with a free boundary condition at the bottom end carried out with numerical study. The resulting numerical code with finite element method was used to study sample problems for a cable with towing speeds. After tracing the equilibrium state with a towing speed through the static analysis, modal analysis on the basis of static results was performed. The static top tension for a critical towing speed is nearly 50 percent of what it was for a free hanging pipe. From static analyses, it is found that towing speed has a noticeable effect on top tension of a towed pipe. At a high towing speed, differences between the first and second periods become larger. Compared to the fundamental period for a free hanging pipe, that for a towed pipe with a critical towing speed is approximately 1.4 times larger. This result is very important point in that the lock in condition and tension of the towed cable system with top excitation can be predicted. The corrected close form solution to solve natural periods for a towed cable was presented in this study. The code is validated by comparison of the results of theoretical and numerical studies. Two results were in very good agreement. This study can contribute to predicting the lock-in condition and tension for a towed cable or pipe with top excitation.

• Proceedings of the Ginseng society Conference
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• 1984.09a
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• pp.49-55
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• 1984

Dormant one-year-old ginseng roots were subjected to a range of stratification temperatures and time to define effective limits to these parameters and to quantify their effect on terminating dormancy. Effective storage temperatures tested ranged from $0^{\circ}C\;to\;9^{\circ}C.$ A low percentage of roots produced tops with as few as 30 days in stratification; however, 75 to 90 days were required for 100 percent emergence. Days to emergence, after planting, decreased with increased days in storage thru the maximum storage time of 120 days. The number of days of dormancy was relatively constant, near 126.5 days, over the range of effective temperatures and acceptable storage times. The minimum period of dormancy was associated with 75 days in storage at $3^{\circ}C.$ Root growth rate, after emergence, was greatest following 105 days of stratification. The frequency distribution of emergence with days in stratification suggests the potential of selecting for strains of ginseng with low chilling needs for satisfying dormancy requirements.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.6
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• pp.924-932
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• 2014

This study investigated intake of energy drinks, side effects and willingness to stop intake of 255 high school students in Gyeoungbuk region. The data were collected by the self-administered questionnaire. Frequency, t test, one-way ANOVA, Duncan's multiple range test, and ${\chi}^2$ test were conducted by SPSS Window V.21.0. About 78% of the respondents had experience of intake of energy drinks. The respondents were aware of energy drinks from 'advertisements on mass media (44.3%)', 'friends (32.2%)', and 'looking in stores (16.9%)'. The mean of the amount of energy drink intake per day was 30.62 mg. Forty-four percent of the respondents had energy drinks during an examination period, and 37% took it at home. The main reasons for intake of energy drinks were 'to fight off sleepiness', 'to recover from fatigue', and 'good taste' in order. Many respondents answered that energy drinks did not much help to increase concentration or learning ability. About 72% of the respondents experienced 'not feel sleepy' after having energy drinks. Half of the respondents experienced side effects such as palpitation, insomnia, and increase of urination. Most respondents had willingness to stop having energy drinks if it had bad effect on health.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.12
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• pp.502-508
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• 2016

An optimized PI controller design method is presented to promote the control performance of an oil cooler system for high precision machine tools. First, a transfer function model of the oil cooler system with a variable rotating speed compressor was obtained by the perturbation method as the first order system with a negligible dead time. Then, the closed-loop control system was described as the second order system with a zero. Its dynamic behaviors are mostly governed by characteristic parameters, the damping ratio, and the natural frequency which is incorporated in PI gains. Next, an optimum integral of the time-weighted absolute error (ITAE) criterion was applied to the second order system. The characteristic parameters can be determined by the given design specifications, percent overshoots and settling times and comparisons with the ITAE criterion. Hence, the PI gains were plainly identified in a deterministic way. Finally, the PI gains were fine-tuned to obtain desirable dynamics in real systems, considering the zero effect and parameter variations. The validity of the proposed method was proven by computer simulations and real experiments for selected cases.

• Biomolecules & Therapeutics
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• v.10 no.4
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• pp.274-280
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• 2002

The fluoroquinolones have been reported to cause, although at low frequency, severe phototoxicity which is due to singlet oxygen produced by ultraviolet-A (UVA; 320-400 nm) exposure. The objective of this study was to evaluate the phototoxicity based on plasma and tissue concentrations of commonly prescribed fluoroquinolones; lomefloxacin (LFLX), enoxacin (ENX), ofloxacin (OFLX), and ciprofloxacin (CPFX). The phototoxic potentials were investigated by measuring increments in ear thickness, 24 hrs after these fluoroquinolones were orally administered to Balb/c mice, which they were exposed to UVA 17.5 J/$\textrm{cm}^2$ for 2 hrs following drug administration. The fifty percent ear thickness increment-inducing doses ($ETID_{50}$), determined by single ascending dosing of each fluoroquinolone to mice, were calculated to be 50(LMFX), 250(ENX), 770(OFLX), 1100(CPFX) mg/kg. Post the administration of ETID$_{50}$, drug concentrations in plasma and ear tissue were measured at specified times and phototoxicities were quantified. Both peak plasma ($\mu\textrm{g}$/ml) and ear tissue ($\mu\textrm{g}$/g) concentrations were summarized as follows; 7.3/1.4 for LMFX, 15.0/1.6 for ENX, 90.1/18.4 for OFLX and 87.2/3.7 for CPFX. The degree of photo toxicity was more relevant to plasma concentrations than tissue concentrations. In order to assess the effect of irradiation time after drug administration on phototoxicity, the 2 hr UVA irradiation was given at 0, 1, 2, 3, and 5 hr after administering $ETID_{50}$, respectively and photo toxicities were evaluated. The shorter inteval between dosing and UVA exposure was, the higher risk of phototoxicity was produced.d.