• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.4
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• pp.401-412
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• 2003

In this paper, a broadband phase shifter structure using a new switched network was proposed. A new reference network is composed of coupled lines and 45$^{\circ}$open and short stubs, which are shunted at the edge points of a main line, respectively, A delay network is composed of only a standard transmission line. It is possible to design a broadband 180$^{\circ}$phase shifter that phase dispersive characteristics by an impedance ratio R of coupled lines and greater phase dispersive characteristics by characteristic impedances Zm, Zs of a main line and stubs are used together. By considering a structure symmetry, the even and odd mode analysis was performed to obtain theoretical S-parameters of the proposed phase shifter. Also, through computer simulation on the basis of derived equations, design graphs were presented to optimally design a 180$^{\circ}$broadband phase shifter. Design graphs provide the values of characteristic impedances Zm, Zs, and I/O match and phase bandwidths. To verify electrical performances of the broadband phase shifter proposed in this paper, low different 180$^{\circ}$phase shifters, operated at the center frequency 3 GHz were designed and fabricated using design graphs, and were experimented. One of them was designed as a standard Schiffman structure to compare with electrical performances. Measured results of each phase shifter to satisfy simultaneously design conditions of I/O match （VSWR=1.15:1) and maximum phase deviation $({\varepsilon}_{{\Delta}{\phi}}＝{\pm}2^{\circ})$ were well in agreement with corresponding simulation results over impedance match and phase error bandwidths, and showed broadband characteristics.

• Korean Journal of Medicinal Crop Science
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• v.16 no.6
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• pp.446-454
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• 2008

An advanced extraction method by ultrasonic extraction with applied solid phase extraction (SPE) has been developed for the determination of simultaneous eight major ginsenosides, namely ginsenosides Rg1, Re, Rf, Rb1, Rg2, Rc, Rb2, and Rd in the root of Panax ginseng. Four extraction methods including n-BuOH reflux extraction (Method A), 70% EtOH reflux extraction (Method B), 50% MeOH reflux extraction with SPE (Method C), and 50% MeOH ultrasonication with SPE clean-up process (Method D) were investigated for the determination of eight major ginsenosides. Total contents of ginsenosides were highest by extraction of Method C as $2.408{\pm}0.011%$. However, Method D was evaluated as relatively simpler and more efficient method due to short extraction time, small solvent consumption and less expensive, compared to conservative reflux method. Ginsenosides were also satisfactorily separated with good resolution and the accuracy range was between 1.05 and 4.06% as relative standard deviation (RSD) by Method D. SPE condition and HPLC condition were further optimized for determination of eight major ginsenosides by the ultrasonic extraction method. Conclusively, ultrasonic extraction of 2 g sample of ginseng using ultrasonic bath and 1 loading for SPE was evaluated as proper condition for extraction of ginseng.

• The International Journal of Costume Culture
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• v.2 no.2
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• pp.97-118
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• 1999

Ever since China adopted a free market economy, it has been basking in unprecedented economic growth. It has now emerged as one of the most promising markets in the world for the near future. The purpose of this study was to investigate of Chinese and Korea college female students's cognitive body type and to suggest basic informations for high quality clothing merchandising for china export. The subjects in this study were 430 college female students, aged from 18 to 24 living in Beijing(215) and Seoul(215). The survey were taken from June to July, 1999. SAS(Statistical Analysis System) is used for frequency, percentage, average, standard deviation, χ²-test. The results of this study are as follows. The 90% of Chinese collge female students has under 4000 yuan for monthly income, and they consume less than 1000 yuan for clothing purchasing for one year. About 42% chinese students are interested in controlling of physical body shape. The Korean college female students has from 1,000,000 won to 10,000,000 won for monthly income, and the 84% of them consume less than 1,000,000 for clothing purchasing for one year. It represents of economical difference between China and Korea. Examination on the Korean and Chinese self-perception on obesity of the body as a whole showed that both groups perceived themselves as normal or slightly overweight. More Korean respondents regarded their weight as normal than the Chinese did. The Chinese female college students perceived themselves rather overweight, and held a lower satisfaction level about their physical construction. While the Korean female college students showed low satisfaction level about specific bodily parts, they held a normal level of satisfaction about their physical construction as a whole. It is noteworthy that more Chinese respondents generally held lower satisfaction impressions about their physical construction than their Korean counterparts. It is needed to different merchandising project for export clothing in China.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.541-550
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• 2012

The purpose of this study was to investigate the effect of aerobic exercise training and half bath on blood component, cardiorespiratory function, and vascular compliance of middle-aged obese men. The subjects were 3 groups; aerobic exercise(n=10), half bath(n=10), and controlled group(n=10). They were tested on their blood component, cardiorespiratory function, and vascular compliance at the beginning and at the end of the 12-week study(pre-post test). For data analysis, mean and standard deviation scores were calculated, and repeated measure two-way ANOVA and Scheffe were used. The results of this study are as follows. First, aerobic exercise group was significantly improved on all blood component after the 12-weeks, and showed significant difference among groups. Half bath group was better than control groups on Triglyceride, LDL-C, and HDL-C levels. Second, aerobic exercise group was significantly improved on maximum oxygen uptake, maximum heart rate, and maximum ventilation after the 12-weeks. Third, in vascular compliance measured in both hands and both feet, the half bath group and aerobic exercise training group were significantly increases the control group. Therefore, these results imply that aerobic exercise and half bath can be helpful for better blood component, cardiorespiratory function, and vascular compliance in middle-aged obese men.

• Journal of muscle and joint health
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• v.7 no.2
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• pp.281-293
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• 2000

This study was conducted to identify the relationships among self-care agency, family support, qualify of life in patients with rheumatoid arthritis. The subjects were 120 rheumatoid arthritis patients who attended RA O.P.D. at a university hospital, located in Daegu city, from 10th of May in 1998 to 30th of July in 1998. Three structure questionnaires were administered for explore three main research variables; 소향숙's self-care agency scale, 강현숙's family support scale, and 김종임's quality of life scale of RA patien. Data analysis was conducted with SPSS program including percentage, mean, standard deviation, mean score, Pearson Correlation Coefficient, multiple regression, and Cronbach's Alpha. Results are summarized as follows; 1. The mean of RA patient's self-care agency was 136.62, the mean of family support 37.38, and the mean of qualify of life 134.41. 2. Subject's self-care agency was positively correlated with family support(r=.2446) and with quality of life(r=.4341). Subject's family support was positively correlated with quality of life(r=.2630). 3. Stepwise multiple regression was used to determine the predictors of subject's quality of life. Significant predictors for subject's quality of life were self-care agency(t=4.873 p=0.0000), family support(t=4.480 p=0.0000) and the severity of arthralgia(t=-3.838, p=0.0002). The number of joints involved and the periods of illness did not show significant contribution to subject's quality of life. Self-care agency, family support, and family support explained 40. 39% of the variance in RA patient's quality of life. Given this results, it is suggested that a repeated study to measure RA patient's self-care practice in their own life may be needed to develope and validate an optimum level of nursing intervention for RA patient with which family support will be encouraged and patient's self-care agency will be facilitated.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.663-670
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• 1997

Four kinds of commercial vinegars were investigated to compare physicochemical properties (pH, acidity, color, tannin and metal content), minor components (free sugar, free amino and organic acid), and their organoleptic tastes. The ratio of nonvolatile organic acid to the total organic acid was decreased in the order of brewed, cider, brown rice, and persimmon vinegar. Especially malic acid content was appeared to be highly remarkable in cider vinegar. Glucose and fructose were the predominant components among free sugars regardless of the kinds of vinegar. Free amino acid contents in cider, brown rice and persimmon vinegars have shown a little deviation among the same kind of vinegar samples, but were obviously more abundant than those in brewed vinegars. Color preference, sourness and sweetness of the vinegars were not statistically different (p>0.05) among four kinds of vinegars, whereas overall taste preference, background taste preference and intensity showed significant differences (p<0.05) with respect to the type of vinegar. Brewed and cider vinegars have revealed higher sensory scores in overall and background taste preference than the persimmon and brown rice vinegars. Even though there were no high relationships between minor components and organoleptic taste in commercial vinegars the ratio of acetic acid to the total organic acid was significantly correlated (p<0.01) with the overall taste preference.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.1
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• pp.55-64
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• 2018

The purpose of this study is to provide a design and operation technical guideline for meeting the appropriate design criteria to biogas utilization treating organic wastes. In accordance with the government's mid-to long-term policies on bio-gasification and energization of organic wastes, the expansion of the waste-to-energy (WTE) facilities is being remarkably promoted. However, because of the limitation of livestock manure containing low-concentration of volatile solids, there has been increased in combined bio-gasification without installing new anaerobic digestion facilities. The characteristics and common problems of each treatment processes were investigated for on-going 11 bio-gasification facilities. The seasonal precision monitoring of chemicophysics analysis on anaerobic digestor samples was conducted to provide guidelines for design and operation according to the progress of biogas utilization. Consequently, Major problems were investigated such as large deviation of organic materials depending on seasons, proper dehumidification of biogas, pretreatment of hydrogen sulfide, operation of power generation and steam. This study was conducted to optimize biogas utilization of type of organic waste(containing sewage sludge and food waste, animal manure), research the facilities problem through field investigation.

• The Journal of the Korea Contents Association
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• v.16 no.12
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• pp.124-131
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• 2016

This study was conducted to serve as a basis for education by identifying the correlation of college admission type, college-life satisfaction and academic achievement of radiologic science students. Data were collected from 2 universities and 2 colleges located in Gyeonggi Provice, North Chungcheong Province, North Gyeongsang Province. A total of 371 questionnaires were collected, 363 of which were included in this study. The results showed that there were no differences in academic achievement according to the type of college admission. It could be able to interpret that since department of radiologic science is popular, students with high academic records applies the department of radiologic science and there are less deviation of academic records among students. A correlation analysis of academic achievement showed learning attitude is a statistically valid factor. Learning attitudes can be changed by exposure to the environment. This will require a variety of program development for improving learning attitudes. In addition, academic achievement of radiologic science students is associated with license acquisition. It need to be made together research on determinants and development of learning method to improve the learning attitude.

• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.516-525
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• 2020

The densities of aqueous solutions of the amphiphile 2-(2-hexyloxyethoxy)ethanol (C₆E₂) were measured at 279.15 K and 282.15 K by vibrating-tube densitometry. Then using the density data of the binary C₆E₂ (1)/water(2) system, the excess volumes and partial molar volumes were determined at various compositions. Excess volume V^E exhibits negative deviation for the whole region of composition, which implies relatively stronger attraction between molecules. At the C₆E₂ mole fraction of around 0.45, V^E was at its minimum. Partial molar volume ${\bar{V}}_1$ increases monotonously with the mole fraction x₁(=x) and ${\bar{V}}_2$ decreases with x. Any particular point in ${\bar{V}}_1$ and ${\bar{V}}_2$, which may point to molecular association, was unobserved.

• Korean Journal of Childcare and Education
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• v.9 no.5
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• pp.277-297
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• 2013

The present study was designed to examine fathers' awareness and practice of picture book reading with toddlers. The subjects were 221 fathers who have toddlers, and the data collected by questionnaires were analysed by mean and standard deviation, and frequency analysis. As a result, approximately 59% of fathers stated that it is essential to read to their children who are 12 month old or less, and 36% of fathers answered that they read books as much as their children wanted. The majority considered the emotional aspect of picture book reading as being significant. Also, nearly half (46%) of the fathers read books to their children 1-2 times per week, and 37% of them spent 6-10 minutes at a time reading books. While reading books, 60% of the fathers explained text and pictures to their children and a fourth of the fathers answered their children's questions. Also, while reading books, fathers tried to accept their toddlers' responses positively. However, they did not have much time to read books to their children and had little knowledge on how to read books to infants. Further research and education programs on picture book reading for fathers are needed.