• Kyungpook Mathematical Journal
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• v.50 no.4
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• pp.545-556
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• 2010

A good amount of work has been done on degree of approximation of functions belonging to Lip${\alpha}$, Lip($\xi$(t),r) and W($L_r,\xi(t)$) and classes using Ces$\`{a}$ro, N$\"{o}$rlund and generalised N$\"{o}$rlund single summability methods by a number of researchers ([1], [10], [8], [6], [7], [2], [3], [4], [9]). But till now, nothing seems to have been done so far to obtain the degree of approximation of functions using (N,$p_n$)(C, 1) product summability method. Therefore the purpose of present paper is to establish two quite new theorems on degree of approximation of function $f\;\in\;Lip({\alpha},r)$ class and $f\;\in\;W(L_r,\;\xi(t))$ class by (N, $p_n$)(C, 1) product summability means of its Fourier series.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.282-289
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• 2010

A simplified, practical vector network analyzer (VNA) that uses mature radio-over-fiber technology has been designed and demonstrated. The measurement concept allows the full S-parameters of a microwave device (or antenna) to be obtained while minimizing the detrimental effects of electrical cables, which are replaced with a photonic link. A variety of high-frequency light modulation schemes with frequency sweeping capabilities are presented to realize a one-path (single, forward), frequency-multiplied optical link for VNA applications. Using the photonic one-path link, full two-port S-parameters have been extracted based on five-term error modeling, which has half the error terms compared with the standard duplex configuration. The S-parameters of a microwave filter and antenna measured using frequency-multiplied optical links are found to be in good agreement with those obtained using a conventional VNA.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.17 no.4
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• pp.456-465
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• 1988

The performance of the cold latent heat storage is investigated by experiment and by a simplified analytic approach. The heat storage tank has eight horizontal circular tubes and one path of refrigerant evaporating tube. The phase change material in the heat storage tank is water which is frozen by evaporating refrigerant of refrigeration system and melts by the warm air in the heat storage tank. In the experiment, the performance has been studied by the various conditions including the initial water temperature on solidification and flow rate and temperature of air. The rate of recovered heat has been simulated by a simplified model and the results shows a good agreement. In solidification process, initial water temperature causes time delay corresponding to the sensible heat and it is found that the shape of evaporator is important. In melting process, the recovered heat rate from the heat storage tank is proportional to $Re^{0.8}(T_{bi}-T_f)$ of air where $T_{bi}$ and $T_f$ indicate temperatures of inlet air and phase change, respectively. And the deminishing rate of the recovered heat is higher for the higher heat rate.

• Journal of Korean Academy of Nursing
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• v.28 no.3
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• pp.773-785
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• 1998

This study aims at providing more qualitative care in family nursing practice. It is designed to analyze the degree of quality of life(QL) among families of the patients. The subjects consisted of 79 families of hospital hospice patients and 74 families of home-based hospice patients. The ages of the subjects were 17-74 years, at five university hospitals in Seoul, Inchon, and Kyung Gi Province, and one clinic in Chunchon. The data were collected from September, 1996 to August, 1997. The instrument used for the study was the Quality of Life Scale (QLS), which was composed of six factors, developed by Ro, You Ja. The analysis was done using t-test, ANOVA Scheff test, and Stepwise multiple regression. The results were as follows : 1. There were no statistically significant differences between the families of hospital hospice patients and the families of home-based hospice patients ; however, the mean score of the families of hospital hospice patients was higher than that of the families of home-based hospice patients. The scores on QLS ranged from 75 to 224 with a mean score of 140.58 in the families of hospital hospice patients. In the families of home-based hospice patients, the scores ranged from 79 to 214, showing a mean score of 135.25. Among six factors of QLS, family relationships showed the highest score in both groups, but economic life showed the lowest score in the families of hospital hospice patients, and emotional state showed the lowest score in those of home-based hospital patients. Self-esteem and relationship with the neighborhood were significantly higher in the families of hospital hospice patients than the families of home-based hospice patients (t=2.69, P= 0.008 ; 1=2.04, p=0.043). 2. In the families of hospital hospice patients, QL had significant relationship with family member's age(F=2.52, p =0.029), marital status (F=3.57, P=0.018), economic state(F=6.07, P=0.004), and education level(F=3.77, P=0.014). In the families of home-based hospice patients, QL had significant relationship with marital status (F=2.53, P=0.049), education level(F=4.35, P=0.007), occupation(F=3.93, P=0.002), and patient's age(F=2.73, P=0.020) 3. Economic status accounted for 17% of QL, and diagnosis accounted for an additional 7% of QL in the families of hospital hospice patients by means of stepwise multiple regression analysis. In the families of home-based hospice patients, relationships with patient accounted for 12% of QL. The findings showed that self-esteem and relationship with the neighborhood were significantly higher in the families of hospital hospice patients than the families of homed-based hospice patients and family relationships showed the highest value in QL. These findings should be considered in nursing practice.

• Journal of Korean Academy of Nursing
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• v.20 no.3
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• pp.399-413
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• 1990

This descriptive study was under taken to explore relationships among the quality of life, health locus of control and perceived state of health persons with cancer to contribute theoretical understanding about these phenomenon of interest to the quality of nursing care. The subjects of this were 200 persons with cancer (100- in patients and 100- out patients), both male and female, between 30 and 59 years of age. Data were obtained using a convenience sample technique from two university hospitals in seoul from August, 1989, to June, 1990. The instruments used for this study were the Quality of life scale developed by Ro, You - Ja and the Health Locus of Control scale developed by Wallston & Wallston. Data were analyzed using a SAS program for ANOVA, t-test, Schefffe test, Pearson Correlation Coefficients and Stepwise multiple regression. The results were as follows : 1. The scores on the quality of life scale ranged from 95 to 191 with as mean of 147.85(range 47 to 235). The Mean scores(range 1-5) on the different dimensions were family relationships 3.50, relationships with neighbours 3.48, self - esteem 3.17, physical state and function 2.99, economic life 2.93 and emotional life 2.91. 2. Significantly higher scores on the quality of life and demographic characteristics were as follows : the quality of life for women(t＝2.80, p＝ .006), for those without complications(t＝2.54, p＝ .013), and for those who perceived their illness as mild(F＝4.85, p＝ .009). Higher scores on quality of life were correlated with the following : 1) emotional state and the age group 50-59(F＝3.43, p＝ .34). 2) economic life and higher income(F＝6.72, p＝ .002), those without complications(t＝2.68, p＝ .00), and those who perceived their illness as mild(F＝3.11, p＝ .05). 3) self-esteem and marriage(F＝3.64, p＝.028), those without complications(t＝2.18, p＝.03), and those who perceived their illness as mild(F＝7.72, p＝.000). 4) physical state and funciton and the age group 30-39(F＝4.65, p＝.010), those without complications (t＝2.00, p＝.05), and those who perceived their illness as mild(F＝3.38, p＝.04). 5) family relationship and those who live with their spouse(t＝2.82, p＝.005). 3. There was a significant positive correlation between the subjects perceptions of their current state of health and the quality of life score(r＝.4364, p＝.0001). 4. There was no relationship between Locus of control and quality of life in this sample. 5. Stepwise multiple regression analysis showed that: 1) the perception of current health status was the main predictor and accounted for 20.11% of the total variance. 2) sex and educational level accounted for an additional 21.71% of the total variance. 6. The quality of life and the perception of their current health status of these patients with cancer were generally lower than those of healthy adults as noted in previous studies. In conclusion, the quality of life for these cancer patients was generally low especially in regard to their emotional state. The current perceived state of health, sex, complications and perceived degree of illness were important variables relatiog to quality of life.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.05c
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• pp.75-78
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• 2009

It was investigated fire resistance properties and mechanical properties of high strength concrete column using ECC(Engineered Cementitious Composites) permanent form by KS F 2257 Methods of fire resistance test for elements of building construction and compression test for application of precast concrete column method of high rise building in this study. As a test result, it was appeared that ECC permanent form is available as fire resistance method of high strength concrete and new precast concrete construction method for facilitating construction of high rise building.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.339-344
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• 2001

This study is to investigate properties of high strength.high flowing concrete using blast-furnace slag in temperature conditions of 5, 10, 15 and $20^{\circ}C$. The result of this study can be summarized as follows. 1) The use of blast-furnace slag leads to decrease of air content and increase of fluidity in the fresh concrete. 2) The early compressive strength of high strength.high flowing concrete containing blast-furnace slag is lower than the case with portland cement only. 3) The compressive strength development of incorporating in the concrete is poor at low temperature below about $15^{\circ}C$.

• Natural Product Sciences
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• v.14 no.3
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• pp.171-176
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• 2008

Column chromatographic separation of 70% EtOH extract of the roots of Korean cultivated-wild ginseng led to the isolation of ten ginsenosides (1 - 10). The isolated compounds were identified as ginsenoside $Rg_1$ (1), ginsenoside Re (2), ginsenoside Rc (3), ginsenoside $Rb_1$ (4), ginsenoside $Rb_2$ (5), ginsenoside Rd (6), ginsenoside $Rg_3$ (7), ginsenoside $F_2$ (8), ginsenoside $Rb_3$ (9), and ginsenoside $Rd_2$ (10) by physicochemical and spectroscopic methods. The compounds (1 - 10) were for the first time isolated from the roots of Korean cultivated-wild ginseng.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.43-46
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• 2005

[1] There are systematical errors associated with ionospheric influence in retrieving key atmospheric parameters from radio occultation (RO) soundings. In order to obtain better-quality retrievals, we develop a new method, hereafter called National Central University Radio Occultation (NCURO) scheme, to reduce the ionospheric influence. The excess phase is divided into two parts, namely geometric excess length and path excess length (excess length along ray path due to refractivity effect). An excess phase equation is presented and implemented in the NCURO scheme Whose performance is evaluated through comparisons with model simulation and experimental data. The model simulation is based on the use of the ionospheric model 002001 and atmospheric model NRLMSISE-OO. Results show that the NCURO scheme significantly reduces the ionospheric influence at altitudes above 70 km as does the scheme presented in the literature, and provides better corrections for the atmospheric profile. INDEX TERMS: 2400 Ionosphere: Ionosphere; 6964 Radio Science: Radio wave propagation; 6969 Radio Science: Remote sensing.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.15-18
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• 2007

RoF 링크 시스템을 적용한 무선 근거리 통신망(IEEE 802.11b/g)의 중심 주파수 대역인 2.4 GHz에서 저가의 Febry-Perot 레이저 다이오드를 이용한 피드포워드 광송신기를 제작 및 측정 하였다. 제작된 피드포워드 광송신기의 측정 결과는 2.4 GHz에서 주신호의 간격이 10 MHz이고 크기가 -4 dBm인 입력 신호에서 피드포워드 보상기법을 적용하기 전보다 3차 상호 변조 왜곡 신호가 22.9 dB 개선되었다. 제작된 피드포워드 광송신기의 전자소자의 사양을 바탕으로 송신기 집적을 위한 RFIC회로(감쇄기, 증폭기)를 0.18 ${\mu}m$ 공정을 이용하여 설계하였다.