• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권8호
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• pp.2675-2690
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• 2014

We study the problem of optimal opportunistic spectrum access with unknown and heterogeneous channel dynamics in cognitive radio networks. There is neither statistic information about the licensed channels nor information exchange among secondary users in the respective systems. We formulate the problem of maximizing network throughput. To achieve the desired optimization, we propose a win-shift lose-stay algorithm based only on rewards. The key point of the algorithm is to make secondary users tend to shift to another channel after receiving rewards from the current channel. The optimality and the convergence of the proposed algorithm are proved. The simulation results show that for both heterogeneous and homogenous systems the proposed win-shift lose-stay algorithm has better performance in terms of throughput and fairness than an existing algorithm.

• 산업융합연구
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• 제19권5호
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• pp.119-128
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• 2021

본 연구는 여성 간호사가 선호하는 근무형태에 따른 조직몰입도와 이직의도를 비교하여 여성 간호사의 근무 환경을 개선하고자 수행되었다. 본 연구는 서술적 조사연구로서 7개 의료기관에서 3교대 근무중인 여성 간호사 465명에게 온라인 설문조사를 통해 자료수집을 하였다. 수집된 자료는 SPSS WIN 24.0를 이용하여 χ² test, two sample independent t-test, pearson correlation, MANCOVA로 분석한 결과 고정근무 선호집단의 연령이 많을수록 조직몰입도가 높았으며, 이직경험이 있는 경우 이직의도가 높았다. 그리고 고정근무 선호집단이 교대근무 선호집단 보다 조직몰입도가 낮았으며 이직의도가 높았다. 고정근무를 희망하는 여성 간호사들의 조직몰입도를 높이고, 이직을 줄이기 위해서는 다양한 근무형태를 개발하여 여성 간호사의 근무환경을 개선하기 위한 노력이 필요하다.

• 대한산업공학회지
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• 제25권4호
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• pp.476-489
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• 1999

This paper is concerned with the deployment of core technologies for automotive steel sheets, based on the structural change of global market. The main tasks of automotive industry are to ensure the energy consumption, environmental regulations, and driving safety. With social and legal requirements, this study analyzes the market creation processes with technological innovations for hot rolled, cold rolled and galvanized steel sheets during the 20th century. It has been proven that the leading country in the steel industry was also that in the automotive. The purchaser-supplier relations of sheet materials are then patternized in the regional markets of the United States and Japan, who share nearly 50% of market in the world. According to the paradigm shift of globalization, the balance of power in Porter's 5 forces has been moved to the buyers', and both industries pursue Win-Win strategies such as the PNGV(Partnership for a New Generation of Vehicles ) and design-in system with the competition.

• Asian-Australasian Journal of Animal Sciences
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• 제8권2호
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• pp.145-149
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• 1995

Validity of use of a Y-maze for determining a foraging strategy of cattle was investigated with the object of establishing a procedure of testing foraging strategies of large herbivores. Cattle were placed in a start box of a Y-maze, forced into either goal arm and allowed to consume half of the feed at the end of the arm. Then, cattle were returned to the start box and allowed to choose either arm in the second half of a trial. This time animals were allowed to deplete the feed in the goal arm they chose. A return to the previous arm was recorded a "stay" Choice of the other arm was recorded as a "shift". Shift strategy was not observed. Rather, their behavior appeared either random or stay. However, it might have been caused by inappropriateness of the application of the apparatus and/or the procedure used in the study of foraging behavior of rats. Although the existence of lateral preference was suggested, further study with an elaborated procedure will be necessary to investigate foraging strategies of cattle.

• Journal of Korean Biological Nursing Science
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• 제22권4호
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• pp.308-316
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• 2020

Purpose: This study aimed to explore the knowledge and performance of sleep hygiene among nurses with shift work schedules and examine the influence on sleep disturbance. Methods: A total of 199 shift-work nurses from a tertiary hospital were included in the study. To examine the knowledge and performance of sleep hygiene, the participants were asked to respond to a self-reported survey. To assess sleep disturbance, the General Sleep Disturbance Scale was used. Descriptive statistics and multiple linear regression were applied using the SPSS/WIN 21.0 program to analyze the data. Results: Both the knowledge and performance of sleep hygiene among nurses with shift work schedules were measured at a moderate level. Nurses' knowledge and the performance of sleep hygiene was not significantly associated with sleep disturbance, whereas age, experience with shift-working, and perceived health status were significantly associated. Conclusion: Strategies for providing more accurate information and motivating better sleep hygiene would help to enhance sleep hygiene in nurses with shift work schedules. Further studies examining the association of knowledge and the performance of sleep hygiene with sleep disturbances in nurses with shift work schedules are needed.

• 간호행정학회지
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• 제13권1호
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• pp.32-39
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• 2007

Purpose: This study is conducted to compare and analyse the health status and job satisfaction of nurses. Method: The subjects were a group of 90 nurses on fixed day nurse and the other group of 100nurses on night nurse. The collected data were analysed by using the SPSS WIN(10.0) program for descriptive statistics, t-test, ${\chi}^2-test$, ANOVA, and Pearson correlation coefficient. Result: There was a significant difference according to years in services. In nurses on day shift, there was a inverse correlation between the health status and job satisfaction. And in nurses on day shift, job satisfaction levels differed significantly depending on personality, satisfaction to pay, and current health status. In nurses on night shift, nurses' job satisfaction levels differed significantly depending satisfaction to pay. Conclusion: It was confirmed that health of nurses is greatly affected by shift work. so, it is very important to maintain and promote their health status in nurses on night shift. We must find out the factors that greatly affect health of nurses, and continuously make an effort to improve the working environment.

• 대한간호학회지
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• 제48권5호
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• pp.622-635
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• 2018

Purpose: This study aimed to develop and test a structural model for sleep quality in female shift work nurses. The hypothetical model was constructed on the basis of Spielman's 3P model of insomnia and previous research related to the sleep quality of shift nurses. Methods: This cross-sectional study used structural equation modeling and recruited 285 female shift work nurses from four general and university hospitals with over 300 beds located in C and J cities in Gyeongsangnamdo. Data were collected from September 27 to October 20, 2016, and then analyzed using descriptive statistics, Pearson's correlation, and structural equation modeling. The study used SPSS/Win 18.0 and AMOS 18.0 in processing the data. Results: The final model showed good fit to the empirical data: ${\chi}^2/df=2.19$, SRMR=.07, RMSEA=.07, AGFI=.85, TLI=.91, GFI=.93, GFI=.89, NFI=.87. The factors that influenced sleep quality were sleep hygiene (${\beta}=.32$), perceived shift work status (${\beta}=-.16$), stress response (${\beta}=.16$), shift work experience (${\beta}=.15$), perceived health status (${\beta}=-.14)$, and circadian rhythm (${\beta}=-.13$) explaining 36.0% of the variance. Conclusion: The model of sleep quality of the shift work nurses constructed in this study is recommended as a model to understand and predict the sleep quality of shift work nurses. The results suggest that strategies for improving the sleep quality of shift work nurses should focus on sleep hygiene, perceived health status, stress response, circadian rhythm, perceived shift work status, and shift work experience.

• 한국직업건강간호학회지
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• 제20권1호
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• pp.74-82
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• 2011

Purpose: This study investigated how shift work nurses' fatigue influences job stress and turnover intention, and how job stress mediates the relationship between fatigue and turnover intention. Methods: As a descriptive research design, the data were collected from 203 shift work nurses in a city. It was analyzed using the SPSS/WIN 14.0 and AMOS 5.0. Results: fatigue and job stress in shift work nurses influenced turnover intention. Job stress worked as a partial mediation between fatigue and turnover intention. Conclusion: It is necessary to reduce fatigue and job stress for reducing turnover intention in strategies of hospital manpower.

• 성인간호학회지
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• 제24권1호
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• pp.11-19
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• 2012

Purpose: The purpose of this study was to explore the effect of an environmental intervention on sleep, reported emotions and job satisfaction of rotating shift nurses in intensive care unit. Methods: The study was a non-equivalent design with a comparison group. The participants in the study were 34 shift workers randomly assigned to one of two groups. The intervention for one group was the use of an eye shield for two weeks with the other group not receiving the treatment. Data on quality of sleep, stress, depression and job satisfaction were collected from both groups at the beginning and the end of the two week period. See note at bottom page. Data were analyzed by ANCOVA using the SPSS/WIN 18.0. Results: Quality of sleep and job satisfaction were more positively reported along with reports of less depression and stress by those nurses receiving the eyeshild intervention. Conclusion: These results suggest that the eyeshield intervention may be an effective intervention.

• 한국산학기술학회논문지
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• 제17권6호
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• pp.546-559
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• 2016

본 연구의 목적은 교대근무 간호사를 대상으로 스트레스 반응, 신체활동, 수면위생과 수면의 질의 관계를 분석하고, 수면의 질에 미치는 영향요인을 파악하기 위함이다. 연구대상은 경남 C시에 소재한 대학병원과 종합병원에서 교대근무 하는 간호사 168명이었고, 자료수집기간은 2016년 3월 25일부터 2016년 3월 31일까지 였다. 연구도구는 Pittsburgh Sleep Quaility Index, Stress Response Inventory, Korean version International Physical Activity Questionnaire Short Form 및 Sleep Hygiene Practice Scale을 사용하였다. SPSS WIN 18.0을 이용하여 빈도, 백분율, 평균, 표준편차, t-test, ANOVA 및 사후검증, Pearson correlation coefficient, Hierarchical mutiple regression으로 분석하였다. 연구결과, 교대근무 간호사의 수면의 질은 7.35점(범위 0-21점), 스트레스 반응은 2.20점(범위 1-5점), 신체활동량은 3986MET-min/week, 수면위생은 2.73점(범위 1-6점)이었다. 수면의 질은 교대근무 간호사의 특성 중 교대근무 경력, 건강상태, 일주기 리듬에서 유의한 차이를 보였다. 수면의 질에 영향을 미친 변수는 교대근무경력, 수면위생, 스트레스 반응, 신체활동으로 나타났으며 설명력은 40%(F=8.16, p<.001)였다. 따라서, 교대근무 간호사의 수면의 질을 향상시키기 위하여 수면위생 증진 교육을 실시하고, 스트레스 반응을 줄이기 위한 전략을 사용하도록 하며, 중간정도의 신체활동을 권장하는 것이 필요하다.