• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.546-559
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• 2016

This study was conducted to analyze the relationship between sleep quality, stress response, physical activity and sleep hygiene in shift work nurses and identify factors influencing sleep quality. The participants were 168 shift nurses from university hospitals and general hospitals located in C city, Gyeongnam. Data were collected from March 25 to 31, 2016. The study instrument use to the Pittsburgh Sleep Quality Index, Stress Response Inventory, Korean version of the International Physical Activity Questionnaire Short Form and Sleep Hygiene Scale. Date were analyzed by frequency, t-test, ANOVA, Pearson's correlation and hierarchical multiple regression using SPSS/win18.0. The sleep quality index was 7.35 (range 0-21), stress response was 2.20 (range 1-5), physical activity was 3986MET-min/week, and sleep hygiene was 2.73 (range 1-6 points). There were significant differences in sleep quality according to shift work experience, health status and circadian rhythm type. Factors influencing sleep quality included shift work experience, sleep hygiene, stress response and physical activity, which together explained 40% of the total variance of sleep quality. Therefore, it is recommended that sleep hygiene education be implemented as a strategy to reduce stress response, and that shift work nurses engage in a moderate level of physical activity to improve their sleep quality.

• Journal of Korean Academy of Nursing
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• v.2 no.1
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• pp.63-72
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• 1971

The conclusions were obtained from the detailed survey of 1,285 students experiencing menstruation, who were chosen among 1,717 students in middle & high school girls in Seoul. The survey was conducted during July 20-July 24, 1971. 1. Age of Menarche An average age of menarche was 13.3$\pm$1.07. The earliest age of menarche was 9 and the latest age 18. Ages of menarche were between 12 and 14 in 84.3 percent of the students surveyed. a. By present age distribution, the aged students were lower, than younger students in the average age of menarche. b. By father′s educational levels, among the students whose fathers were graduated from high schools, college & ever the earliest average age of menarche was found with 13.2, and among the students whose fathers were graduated from primary schools that wag latest with 13.6. c. By father′s occupations, among the students whose fathom engaged in "workers not classifiable"the earliest age of menarche was found with 12.5$\pm$0.27, among the students whose fathers were in "service business"the second was 12.9$\pm$1.07, and among the students whose fathers were in "miners, quarrymen and related workers"that was latest with 13.8$\pm$1.14. d. By economic status, among the students of "wealthy"families the age of menarche was 13.1$\pm$0.25, the among the students of "ordinary"families the lags of menarche 13.3$\pm$1.06. and the among the students of "poor" families that was 13.8$\pm$0.31. e. By home discipline, among the students being treated "rigid" the age of menarche was 13.5$\pm$1.13, among the students being treated "moderate"the age of menarche was 13.3$\pm$0.22, and those being treated "indifferent" that was 13.0$\pm$0.26. f. By students physical condition, among the students of "good" condition the average of menarche was 13.3$\pm$0.16, and among the students "poor" that was 13.5$\pm$0.31. 2. Menstruation a. For the six months after the average of menarche 39.0 percent of the students had normal menstruations, and 61.3 percent of them had abnormal ones. Of the students with abnormal menstruation 21.7 percent had abnormal menstruation from time to time, 25.4 percent had no menstruation for one month to three months, 7.2 percent had menstruation for four to six months and 6.7 per cent had no menstruation for more than sin months. Most students became to have normal menstruations a few months later the age of menarche. b. At the time interviewed, the percentile of cycle of menstruation as following: 23 days types: 46.8 percent 30 days types: 40.6 percent others : 12.6 percent The average cycle of menstruation was every 28.9 days. c. The average duration of menstruation is 4.69 days. d. The subjective symptoms during menstruation period: Out of the total 89.7 per cent had some pains, while 10.3 percent had no symptom. Among the symptoms, abdominal pain occupied 29.9 percent, neurotic symptoms 19.0 percent and lumbago 15.1 percent. e. By attitude or Action at first physical change, "Treated it by own experience" : 30.0 percent "Don′t know what to do because of ignorance" : 20.1 percent "Asked others about it" : 43.0 percent

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.162-162
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• 1999

초고주파 집적회로의 핵심소자로 각광을 받고 있는 GaAs MESFET(MEtal-emiconductor)은 게이트 형성 공정이 가장 중요하며, WNx 내화금속을 이용한 planar 게이트 구조의 경우 임계전압(Vth:threshold voltage)의 균일도가 우수할 뿐만 아니라 특히 Side-wall을 이용한 self-align 게이트는 소오스 저항을 줄일 수 있어 고성능의 소자 제작을 가능하게 한다.(1) 본 연구의 핵심이 되는 Side-wall을 형성하기 위하여 PECVD법에 의한 SiOx 박막을 증착하고, 건식식각법을 이용하여 SiOx side-wall을 형성하였다. 이 공정을 이용하여 소오스 저항이 낮고 임계전압의 균일도가 우수한 고성능의 self-aligned gate MESFET을 제작하였다. 3inch GaAs 기판상에 이온주입법에 의한 채널 형성, d.c. 스퍼터링법에 의한 WNx 증착, PECVD법에 의한 SiOx 증착, MERIE(Magnetic Enhanced Reactive Ion Etcing)에 의한 Side-wall 형성, LDD(Lightly Doped Drain)와 N+ 이온주입, 그리고 RTA(Rapid Thermal Annealing)를 사용하여 활성화 공정을 수행하였다. 채널은 40keV, 4312/cm2로, LDD는 50keV, 8e12/cm2로 이온주입하였고, 4000A의 SiOx를 증착한 후 2500A의 Side-wall을 형성하였다. 옴익 접촉은 AuGe/Ni/Au 합금을 이용하였고, 소자의 최종 Passivation은 SiNx 박막을 이용하였다. 제작된 소자의 전기적 특성은 hp4145B parameter analyzer를 이용한 전압-전류 측정을 통하여 평가하였다. Side-wall 형성은 0.3$\mu\textrm{m}$ 이상의 패턴크기에서 수직으로 잘 형성되었고, 본 연궁에서는 게이트 길이가 0.5$\mu\textrm{m}$인 MESFET을 제작하였다. d.c. 특성 측정 결과 Vds=2.0V에서 임계전압은 -0.78V, 트랜스컨덕턴스는 354mS/mm, 그리고 포화전류는 171mA/mm로 평가되었다. 특히 본 연구에서 개발된 트랜지스터의 게이트 전압 변화에 따른 균일한 트랜스 컨덕턴스의 특성은 RF 소자로 사용할 때 마이크로 웨이브의 왜곡특성을 없애주기 때문에 균일한 신호의 전달을 가능하게 한다. 0.5$\mu\textrm{m}$$\times$100$\mu\textrm{m}$ 게이트 MESFET을 이용한 S-parameter 측정과 Curve fitting 으로부터 차단주파수 fT는 40GHz 이상으로 평가되었고, 특히 균일한 트랜스컨덕턴스의 경향과 함께 차단주파수 역시 게이트 바이어스, 즉 소오스-드레스인 전류의 변화에 따라 균일한 값을 보였다. 본 연구에서 개발된 Side-wall 공정은 게이트 길이가 0.3$\mu\textrm{m}$까지 작은 경우에도 사용가능하며, WNx self-align gate MEESFET은 낮은 소오스저항, 균일한 임계전압 특성, 그리고 높고 균일한 트랜스 컨덕턴스 특성으로 HHP(Hend-Held Phone) 및 PCS(Personal communication System)와 같은 이동 통신용 단말기의 MMICs(Monolithic Microwave Integrates Circuits)의 제작에 활용될 것으로 기대된다.

• Journal of Forest and Environmental Science
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• v.11 no.1
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• pp.81-101
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• 1995

Random amplified polymorphic DNA (RAPD) technology, a recent approach in molecular genetics, is much usable to select the elite trees and to maximize the genetic gain in forest tree breeding program, providing a clue to determine the genetic marker-trait correlation. This review intorduces research on bark thickness and breeding strategy in Pinus elliottii, Pinus caribaea and their hybrid by Queensland Forest Service and ForBio Research Pty Ltd, University of Queensland, which employ RAPD technology. Genetic linkage map of $F_1$ hybrids includes 186 RAPD markers and 16 linkage groups (1641 cM long in total) and 6 quantitative trait loci are located putatively for bark thickness. Following recent research results and experiences in pine breeding programs, the forseeable stages in the application and development are proposed for marker assisted selectin; stage 1-determination of species specific markers for genes controlling traits of commercial interest, and stage 2-determination of marker-allele association for specific allelic variants within pure species. As pines inherit their megagametophytes from the seed parent and zygotic embryos from both male and female parents, the determination of marker-trait correlation is possible even in embryo stage, eventually making ways for the early selection of elite individuals.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.1
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• pp.38-43
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• 2013

In this study we aims to examine the effects of $Co_3O_4$ and NiO doping on the defects and electrical properties in ZnO-$Bi_2O_3-Sb_2O_3$ (Sb/Bi=0.5) varistors. It seemed to form ${Zn_i}^{{\cdot}{\cdot}}$(0.20 eV) and ${V_o}^{\cdot}$(0.33 eV) as dominant defects in Co and Ni co-doped ZBS system, however only ${V_o}^{\cdot}$ appeared in Co- or Ni-doped ZBS. Even though the same defects it was different in capacitance (1.5~4.5 nF) and resistance ($0.3{\sim}9.5k{\Omega}$). The varistor characteristics were improved with Co and Co+Ni doping (non-linear coefficient, ${\alpha}$= 36 and 29, relatively) in ZBS. The various parameters ($N_d=1.43{\sim}2.33{\times}10^{17}cm^{-3}$, $N_t=1.40{\sim}2.28{\times}10^{12}cm^{-2}$, ${\Phi}b$=1.76~2.37 V, W= 98~118 nm) calculated from the C-V characteristics in our systems did not depend greatly on the type of dopant, which were in the range of a typical ZnO varistors. It should be derived a improved C-V equation carefully for more reliable parameters because the variation of the varistor capacitance as a function of the applied dc voltage is depend on the defect, frequency, and temperature.

• Membrane Journal
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• v.13 no.2
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• pp.65-72
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• 2003

This study was focused on the investigation of filtration characteristics of membrane-coupled fermentor system for dissolved organics recovery from liquid organic sludge. On the filterability of MF over the range of $0.1{\sim}5 {\mu}m,$ the magnitude of total membrane resistance ($R_t$) is ranged as follows in the order; $0.1 {\mu}m>0.2{\mu}m>0.5 >1{\mu}m>2{\mu}m>5{\mu}m$. The cake layer resistance ($R_c$) occupied about 68~88% of total resistance with fermented sludge. Permeation flux decline was mainly attributed to the $R_c$, which was formed by a strong deposition from physico-chemical interactions of solids on membrane surface. Higher suspended solids (SS) concentration of suspension caused lower permeation flux. However, there was not a proportion relation beyond a certain SS concentration. The cross-flow velocity on the membrane surface was faster, which resulted in the higher permeation flux and also more efficient with low trans membrane pressure (TMP) in viewpoint of energy efficiency. The appropriate pH of suspension was over the range of 5.0~6.0 for dissolved organics recovery as well as the permeation flux. It is possible f3r bacteria to be separated perfectly with $0.1{\mu}m\; and \;0.2{\mu}m$ membrane pore size. Based on experimental results, most appropriate membrane pore size for the recovery is believed to around $1{\mu}m$.

• Journal of Korean Society of Forest Science
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• v.96 no.4
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• pp.438-447
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• 2007

The purpose of this study was to understand the ecosystem structure and function and soil water changes in Tricholoma matsutake producing pine stands. The investigated stands were pine forest in Sogrisan National Park in Chungbuk-do of Korea. For the purpose we investigated main vegetation, leaf area index(LAI) as ecosystem structural factors and measured photosynthesis, transpiration, xylem water potential, and soil water changes as ecosystem functional factors. Vertical vegetation structure of the site was composed of Pinus densiflora as a overstory species, Quercus mongolica as midstory, Rhododendron mucronulatum, R. schlippenbachii and Fraxinus sieboldiana as understory ones. In the stands LAI was 3.8 during June to September, 2.6 in October and 2.1 during November to April. Photosyntheses of the trees were 6.0 to $7.0{\mu}mol\;CO_2/m^2/s$ in August, and for P. densiflora about $4.0{\mu}mol\;CO_2/m^2/s$ and for Q. mongolica $2.0{\mu}mol\;CO_2/m^2/s$ in mid October. However, R. mucronulatum stopped fixing $CO_2$ and F. sieboldiana shed off the leaves already in mid October. Transpirations were 2.5 to $3.5mmol\;H_2O/m^2/s$ in late August and about $1.0mmol/H_2O/m^2/s$ in mid October. Plant water potentials were -10 to -22 bars for P. densiflora and -5 to -12 bars for the other woody species. The lowest potentials was in late August and highest in late October. Soil water in the stand was closely related to topography. Soil water contents were 7 to 11% at the ridge, 8 to 15% at the hillside and 11 to 19% at the base. Soil temperatures were 0.2 to $0.4^{\circ}C$ higher in T. matustuake colony than noncolony. Mid September soil temperature decreased to $19^{\circ}C$ at which T. matsutake forms primordia. In T. matsutake colony soil moisture was 0.5 to 2.0% lower due to metabolism for consuming water. We suggest that the complicate relationships between ecosystem structure and function in Tricholoma matsutake producing pine stand need to be further investigated.

• Asia Marketing Journal
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• v.14 no.1
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• pp.1-24
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• 2012

Nowadays, customer satisfaction has been one of company's major objectives, and the index to measure and communicate customer satisfaction has been generally accepted among business practices. The major issues of CSI(customer satisfaction index) are three questions, as follows: (a)what level of customer satisfaction is tolerable, (b)whether customer satisfaction and company performance has positive causality, and (c)what to do to improve customer satisfaction. Among these, the second issue is recently attracting academic research in several perspectives. On this study, the second issue will be addressed. Many researchers including Anderson have regarded customer satisfaction as core competencies, such as brand equity, customer equity. They want to verify following causality "customer satisfaction → market performance(market share, sales growth rate) → financial performance(operating margin, profitability) → corporate value performance(stock price, credit ratings)" based on the process model of marketing performance. On the other hand, Insoo Jeon and Aeju Jeong(2009) verified sequential causality based on the process model by the domestic data. According to the rejection of several hypotheses, they suggested the balance model of marketing performance as an alternative. The objective of this study, based on the existing process model, is to examine the causal relationship between customer satisfaction and corporate value performance. Anderson and Mansi(2009) proved the relationship between ACSI(American Customer Satisfaction Index) and credit ratings using 2,574 samples from 1994 to 2004 on the assumption that credit rating could be an indicator of a corporate value performance. The similar study(Sangwoon Yoon, 2010) was processed in Korean data, but it didn't confirm the relationship between KCSI(Korean CSI) and credit ratings, unlike the results of Anderson and Mansi(2009). The summary of these studies is in the Table 1. Two studies analyzing the relationship between customer satisfaction and credit ratings weren't consistent results. So, in this study we are to test the conflicting results of the relationship between customer satisfaction and credit ratings based on the research model considering Korean credit ratings. To prove the hypothesis, we suggest the research model as follows. Two important features of this model are the inclusion of important variables in the existing Korean credit rating system and government support. To control their influences on credit ratings, we included three important variables of Korean credit rating system and government support, in case of financial institutions including banks. ROA, ER, TA, these three variables are chosen among various kinds of financial indicators since they are the most frequent variables in many previous studies. The results of the research model are relatively favorable : R², F-value and p-value is .631, 233.15 and .000 respectively. Thus, the explanatory power of the research model as a whole is good and the model is statistically significant. The research model has good explanatory power, the regression coefficients of the KCSI is .096 as positive(+) and t-value and p-value is 2.220 and .0135 respectively. As a results, we can say the hypothesis is supported. Meanwhile, all other explanatory variables including ROA, ER, log(TA), GS_DV are identified as significant and each variables has a positive(+) relationship with CRS. In particular, the t-value of log(TA) is 23.557 and log(TA) as an explanatory variables of the corporate credit ratings shows very high level of statistical significance. Considering interrelationship between financial indicators such as ROA, ER which include total asset in their formula, we can expect multicollinearity problem. But indicators like VIF and tolerance limits that shows whether multicollinearity exists or not, say that there is no statistically significant multicollinearity in all the explanatory variables. KCSI, the main subject of this study, is a statistically significant level even though the standardized regression coefficients and t-value of KCSI is .055 and 2.220 respectively and a relatively low level among explanatory variables. Considering that we chose other explanatory variables based on the level of explanatory power out of many indicators in the previous studies, KCSI is validated as one of the most significant explanatory variables for credit rating score. And this result can provide new insights on the determinants of credit ratings. However, KCSI has relatively lower impact than main financial indicators like log(TA), ER. Therefore, KCSI is one of the determinants of credit ratings, but don't have an exceedingly significant influence. In addition, this study found that customer satisfaction had more meaningful impact on corporations of small asset size than those of big asset size, and on service companies than manufacturers. The findings of this study is consistent with Anderson and Mansi(2009), but different from Sangwoon Yoon(2010). Although research model of this study is a bit different from Anderson and Mansi(2009), we can conclude that customer satisfaction has a significant influence on company's credit ratings either Korea or the United State. In addition, this paper found that customer satisfaction had more meaningful impact on corporations of small asset size than those of big asset size and on service companies than manufacturers. Until now there are a few of researches about the relationship between customer satisfaction and various business performance, some of which were supported, some weren't. The contribution of this study is that credit rating is applied as a corporate value performance in addition to stock price. It is somewhat important, because credit ratings determine the cost of debt. But so far it doesn't get attention of marketing researches. Based on this study, we can say that customer satisfaction is partially related to all indicators of corporate business performances. Practical meanings for customer satisfaction department are that it needs to actively invest in the customer satisfaction, because active investment also contributes to higher credit ratings and other business performances. A suggestion for credit evaluators is that they need to design new credit rating model which reflect qualitative customer satisfaction as well as existing variables like ROA, ER, TA.

• Journal of the Korean Applied Science and Technology
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• v.39 no.1
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• pp.42-51
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• 2022

This study was conducted to identify the factors affecting the problem solving ability in nursing students. Method: The subjects of this study were 226 nursing students from two universities located in G and C provinces. The collected data were analyzed by t-test, ANOVA, Correlation Coefficient, and Multiple Regression Analysis. Results: As a result of multiple regression analysis, the significant predictors of problem solving ability of nursing students were critical thinking disposition(β=.490, p<.001) and self-directed learning ability(β=.355, p=<.014). Problem solving ability was explained 61.9% of variance in critical thinking disposition and self-directed learning ability. Conclusion: The results of this study showed that self-directed learning ability and critical thinking disposition in nursing students were the influential factor on problem solving ability. Therefore, the results of this study suggest that it is necessary to find ways to improve critical thinking disposition and self-directed learning ability in order to improve problem solving ability of nursing students, and it is considered to be useful as basic data for developing education programs to improve problem solving ability.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.7
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• pp.928-935
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• 2008

The myostatin gene of seven important meat (Beltex (Australia), Beltex$\times$Huyang (F1), Meat and Multi-Prolific Chinese Merino Fine Wool, Meat Chinese Merino Fine Wool and Dorper (South Africa)) and non-meat (Huyang and Kazak) sheep breeds was analyzed to study the genetic basis of muscular hypertrophy (double muscling) phenotype in sheep. SNPs, four in regulatory regions and several in the introns in the myostatin gene, were identified, and the former four SNPs were used for further studies. Twelve haplotypes were predicted by PHASE program, of which four main haplotypes (1, 3, 7, 9) were present in 90% of the 364 sheep in the study. Haplotypes 1-4 were mainly present in meat breeds while haplotypes 7 and 9 dominated the non-meat breeds. The association between haplotypes and average daily gain (ADG) was analyzed among 116 sheep with production data, Haplo2 (CGAA) and Haplo8 (TGAA) were identified to have significant (p<0.05) effect on ADG by the model (JMP5.1 software) taking into account the effects of breed, family background, haplotype, birth weight and sex. ADG of these haplotype groups also correlated well (r = 0.82) with hypertrophic phenotype scores. In conclusion, the mutations -956 (T$\rightarrow$C), -41 (C$\rightarrow$A) and 6223 (G$\rightarrow$A) involved in Haplo2 and 8 may be associated with the double-muscling trait by influencing myostatin function and be suitable markers in selecting meat sheep.