• Title/Summary/Keyword: reliability factors

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Designing and Realizing the Ground Station Receiver Low Noise Amplifier of the Next-Generation Aeronautical Surveillance System (차세대 항공 감시시스템(ADS-BES) 지상국 수신기 저잡음 증폭기 설계 및 구현)

  • Cho, Ju-Yong;Yoon, Jun-Chul;Park, Chan-Sub;Park, Hyo-Dal;Kang, Suk-Youb
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.10
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    • pp.2273-2280
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    • 2013
  • This article introduces the next-generation air surveillance system and investigates how to design of front-end low noise amplifier of the ground station receiver. In consideration of the international standard documentation and the performance of existing products, the study conducts the link budget on the entire system so that it can be competitive in terms of receive sensitivity or reliability. To obtain a proper low noise amplifier, standards of design are decided so that such factors as gain, gain flatness, and reflective loss can be optimal. In its design, the bias circuit appropriate for the characteristics of low power, low noise, or high gain was built, and according to the results of the simulation conducted after the optimal design, its gain was 16.24dB, noise factor was 0.36dB, input-output reflective loss was -18dB and -28dB each, and frequency stability was 1.11. According to the results measured after the design, its gain was 17dB, noise factor was 0.51dB, gain flatness was 0.23dB, and input-output reflective loss was -18.28dB and -24.50dB each, so the results gained were suitable for building the overall system.

A Study on the Verification of the Profile of Seo구s Elderly Stress Scale (SESS) (노인 스트레스 측정 도구(SESS)의 신뢰도 및 타당도 검증 연구)

  • 서현미;유수정;하양숙
    • Journal of Korean Academy of Nursing
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    • v.31 no.1
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    • pp.94-106
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    • 2001
  • The purpose of this study was to verify the use of Seo's Elderly Stress Scale (SESS), which was developed in 1996. Through the modified tool, it is possible to examine the stress of Korean elders and to contribute to the welfare of them. The subjects were 350 elders over 65 years old who live in Seoul, Kwang-Ju, Yang-Ju Gun Kyung-ki Do, Ui-Jong Bu, and Young-Am Kun, Jeun-Ra Nam Do. the data of 331 elders (94%) were analyzed. Data were collected between January and March in 1996 and analyzed using the SPSS Win 8.0. The result are as follows: 1. Items with low correlation with the total items were removed. So 27 items were removed and 37 items remained. This 37 items were death in the family and/or close friends, family member's behavior not meeting expectations, marriage of daughter, marriage of son, friction with daughter- in-law, argument among children, children refuse to live with parent, children leaving home, sex injury or accident, in frequest visits from children and grandchildren, providing care for your daughter or daughter-in-law post-partum, decrease in decision making and authority in home, Lunar new year and the harvest featival, house sitting, working in the house, performing a sacrificial rite, missed birthday, not living with the eldest son, decreased eyesight, decreased strength, decreased memory, sleep pattern changes, thoughts about death, loneliness, decreased hearing, change of dental condition, change in your diet or eating style, difficulty in self care, moving because of disease or aging, argument with friend or neighbour, travel, dealing with the procedure of heritage, loss of money or property, not enough pocket money, hearing on elderly neglect in television or radio, hope of going home and ignorant from others. 2. Overlapped items were discussed by colleagues and were modified. 'marriage of daughter' and 'marriage of son' were modified in 'marriage of children'. 'self injury or accidents' and 'family accidents' were modified in to self or family accidents. 3. Factor analysis was done in order to identify validity and three factors were obtained from the result. The first factor familial relation area, included 17 items. The second factor, physical area, included 9 items. The third factor, psycho-socio-economic area, included 9 items. Cronbach coefficient alpha for the 35 items was .923. 4. Pearson's correlation was .704 between SESS and SOS (Symptoms of Stress) in order to confirm construct validity. Based on the result, the following is suggested; 1. The modified SESS needs to be reverified with elder. 2. Korean elder's health promotion can be made by development of stress intervention which was accurately measured with SESS.

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A Correlation of the Computer Anxiety and the Variables Affecting the Application of a Hospital Computer System (병원 전산시스템 활용에 영향을 주는 컴퓨터불안과 제변수간의 관계)

  • 김용순;박지원
    • Journal of Korean Academy of Nursing
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    • v.25 no.4
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    • pp.617-632
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    • 1995
  • Nowadays, most big hospitals have a computer system to manage their administration. For maxi mum effectiveness in managing the computer system, an analysis of the variables affecting its implementation is necessary from the beginning. This study was done to analyze the variables influencing the operation of a hospital information system (HIS). The theoretical base for this study considered the combined effects of user expectations of computerization, and computer-anxiety. The relationship between variables in the theoretical base were analyzed and the individual characteristics influencing each variable were also analyzed. This study was done in two steps. First, 344 nurses were given an initial questionnaire developed to evaluate the reliability of the items. Based on the results, a second revised questionnaire was administered to 88 nurses who had been working in the areas where HIS was applied. The results of the first and second steps of the study are as follows 1. The initial study was done with nurses who were trained on the computer system briefly before HIS was implemented. The individual characteristics influencing computer anxiety and expectation regarding computer system usage in that initial study included, length of career, type of degree or certification, previous experiences with a computer, training on a computer, desire for computer training, and level of acceptance of a computerized work environment. But in the second study with nurses working in areas of the hospital where HIS was introduced, the work site was the only influencing characteristics. There-fore, in applying a computer system, overcoming work-environment barriers will be more import-ant than any individual characteristics. 2. The computer anxiety of the nurses in both groups, before and after the computer system ap-plication, was below the average level but the expectation of the effects of computerization was above average. The nurses using the computer program showed an above average level of satis-faction with the computer system itself, and with its effect on their efficiency. Therefore, the ability of nurses operating HIS will be positively. predictive. 3. For the variables included in the theoretical framework of the study, all of the correlational coefficients were statistically significant in the analysis of variation correlation. Therefore, the theoretical base of the study, "expectation in con junction with computer anxiety" can be considered an model which can be evaluated. Accord-ing to our analysis, the higher the level of nurses' motivation to use the computer system and the lower the anxiety about computer usage, the higher the possibility of computer system acceptance by nurses. The results of this study showed that in applying a computer system in the hospital, the main characteristic influencing acceptance was where the individual worked rather than personal characteristics such as length of career, type of degree or certification, and previous experiences with a computer. Therefore, it is suggested that the first step in uncovering and eliminating hindrance factors in ap-plication of a computer system should be an analysis of working conditions in relation to the functional content of the computer system. The suitability of the theoretical model based on the hypothesis ap-plied in this study should be further tested.

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Confirmatory Analysis of Perception and Preference Scales for Work Characteristics among Korean Nurses (중환자실 근무환경 특성에 대한 간호사의 인지도와 선호도 도구 검증)

  • ;;Barbara Daily
    • Journal of Korean Academy of Nursing
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    • v.29 no.2
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    • pp.215-224
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    • 1999
  • The study was conducted to centum the construct of individual perception and preference for work characteristics as personal factors influencing Korean nurses' job satisfaction. The subjects of the study were 231 nurses who are currently working in intensive care units and have been for a minimum of 6 months. The study used the Staff Perception and Preference Scale(Song et al., 1997) to measure the individual's perception and preference on the technical. practice. and management components of the ideal work environment. The Korean version of the Staff Perception and Preference Scale consists of 16 items on perception and 13 on preference with each item related on a scale from 1(not at all) to 4(a great deal). Psychometric testing revealed that the preference and perception scale is internally consistent with Chronbach's alphas of .83 for perception scale arid .80 for preference scale. The subscales of the perception and preference scale also showed acceptable reliability for the early stage of the development of the instruments with Chronbach alphas of .62-.76 and .69-.83 respectively. Criterion-related validity of the scale was tested by examining correlations with individual growth need that is conceptually close to individual preference. but not to individual perception. Individual growth need was significantly related to individual preference(r=.63, p<.05), but the correlation with the perception scale was not significant. A separate factor analysis for the each of perception and preference scales was performed with a three-factor loading solution based on a previous study. The results on the staff perception scale confirmed with varimax rotation that the items were cleanly and strongly loaded on technique. practice and management components, which together explained 50.7% of the variance. The factor analysis on the staff preference scale also yielded a three factor solution that explained 56.7% of the variance. but items on technique and management components were loaded together. This phenomena may due to the current nursing delivery system in Korea where nurses never experience either shared governance nor case management, and as a results they may not be able to consider management roles as their potential extended roles. Therefore, more efforts should be given to enhance nurses' autonomy and decision making in the technique, practice and management components of their work environment. Meanwhile, there is a need for continuously confirming and developing tools for individual perception and preferences to effectively enhance job satisfaction among Korean nurses through innovative work environments.

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Meta-analysis of Association Studies of CYP1A1 Genetic Polymorphisms with Digestive Tract Cancers Susceptibility in Chinese

  • Liu, Chang;Jiang, Zheng;Deng, Qian-xi;Zhao, Ya-nan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.11
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    • pp.4689-4695
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    • 2014
  • Background: A great number of studies have shown that cytochrome P450 1A1 (CYP1A1) genetic polymorphisms, CYP1A1 Msp I and CYP1A1 Ile/Val, might be risk factors for digestive tract cancers, including esophageal cancer (EC), gastric cancer (GC), hepatic carcinoma (HC), as well as colorectal cancer (CC), but the results are controversial. In this study, a meta-analysis of this literature aimed to clarify associations of CYP1A1 genetic polymorphisms with digestive tract cancers susceptibility in Chinese populations. Materials and Methods: Eligible case-control studies published until December 2013 were retrieved by systematic literature searches from PubMed, Embase, CBM, CNKI and other Chinese databases by two investigators independently. The associated literature was acquired through deliberate search and selection based on established inclusion criteria. Fixed-effects or random-effects models were used to estimate odds ratios (ORs and 95%CIs). The meta-analysis was conducted using Review Manager 5.2 and Stata 12.0 softwares with stability evaluated by both stratified and sensitivity analyses. Moreover, sensitivity analysis and publication bias diagnostics confirmed the reliability and stability. Results: Eighteen case-control studies with 1,747 cases and 2,923 controls were selected for CYP1A1 MspI polymorphisms, and twenty case-control studies with 3, 790 cases and 4, 907 controls for the CYP1A1 Ile/Val polymorphisms. Correlation associations between CYP1A1 Ile/Val polymorphisms and digestive tract cancers susceptibility were observed in four genetic models in the meta-analysis (GG vs AA:OR= 2.03, 95%CI =1.52- 2.72; AG vs AA: OR=1.26, 95%CI =1.07-1.48; [GG+AG vs AA] :OR =1.42, 95%CI=1.20-1.68, [GG vs AA+AG]:OR=1.80, 95%CI =1.40-2.31). There was no association between CYP1A1 Msp I polymorphisms and digestive tract cancers risk. Subgroup analysis for tumor type showed a significant association of CYP1A1 Ile/Val genetic polymorphisms with EC in China. However, available data collected by the study failed to reveal remarkable associations of GC or HC with CYP1A1 Ile/Val genetic polymorphisms and EC, GC or CC with CYP1A1 MspI genetic polymorphisms. Conclusions: Our results indicated that CYP1A1 Ile/Val genetic polymorphisms, but not CYP1A1 Msp I polymorphisms, are associated with an increased digestive tract cancers risk in Chinese populations. Additional well-designed studies, with larger sample size, focusing on different ethnicities and cancer types are now warranted to validate this finding.

The Effects of Shopping Value, Ease of Use, and Usefulness on Mobile Purchase Intention (쇼핑가치, 사용용이성, 유용성이 모바일 구매의도에 미치는 영향)

  • Chae, Jin Mie
    • Science of Emotion and Sensibility
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    • v.20 no.2
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    • pp.73-86
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    • 2017
  • The purpose of this study was to investigate the influence of consumers' shopping value(SV), ease of use(EOU), and usefulness(U) on their purchase intention(PI) in mobile shopping mall. Path hypotheses in structural equation model which was constructed for this purpose were verified. In addition, the research model was analyzed according to the groups classified by the level of purchase experience in mobile shopping mall. The survey was limited to the respondents in their 20s and 30s living in Seoul and other metropolitan areas who had purchased fashion products in mobile shopping mall. 411 useful data collected from on-line survey were analyzed by descriptive statistics, exploratory factor analysis, confirmatory factor analysis, reliability analysis, and pearson's correlation analysis using SPSS 21 and AMOS 19. The results of verifying the hypotheses were as follows: First, SV was composed of two factors which included hedonic shopping value(HSV) and utilitarian shopping value(USV). Second, the research model was verified as an acceptable model in explaining the influence of consumers' SV, EOU, and U on PI. Third, seven hypotheses among nine hypotheses were accepted in high purchasers. HSV did not have a significant influence on PI, and EOU did not affect PI significantly. Fourth, five hypotheses were accepted in light purchasers. HSV affected U significantly while USV had a significant impact on EOU and PI. EOU affected U, and U affected PI significantly. In conclusion, USV was proven to be the factor affecting PI directly as well as indirectly. Eou and U also had a significant influnce on PI in mobile fashion shopping. These results will provide mobile marketers with the differentiated strategies to make consumers lead to mobile purchase.

A Study on the Gap between Subjective Age and Real Age, Self-Esteem, Appearance Satisfaction, and Clothing Benefits Pursuit according to Gender and Age of Middle-Aged Consumers (중년소비자의 성별과 연령에 따른 주관적 연령 차이와 자아존중감, 외모만족도 및 의복추구혜택)

  • Kim, Na-Mi;Chung, Sung Ji;Kim, Tae-Eun;Ahn, Si-Hyun;Lee, Min-Ji;Chang, Mi-Soon;Choi, So-Ra
    • Journal of the Korea Fashion and Costume Design Association
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    • v.18 no.2
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    • pp.127-144
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    • 2016
  • The purpose of the study was to investigate the self-esteem, appearance satisfaction, and clothing benefit pursuit the gap between subjective age and real age according to gender and age of middle-aged consumers. For the study, the questionnaire was developed by the authors and distributed to male and female consumers in their forties or fifties on september 1~10, 2014. A total of 470 questionnaires was collected and used for the final analysis. Data were analyzed by frequency analysis, reliability analysis, factor analysis, cluster analysis, ANOVA and Tukey's test, using the SPSS 18.0 Package Program. The findings were summarized as follows. There were significant differences in the subjective age of middle-aged consumers according to gender and age. Female consumers in their fifties perceived their subjective age to be younger than male consumers in forties and fifties. There were no significant differences in self-esteem among the groups according to gender and age. Significant differences were found in appearance satisfaction of male consumers in their fifties having higher appearance satisfaction than female consumers in their forties. There were significant differences in some factors of clothing pursuit benefits including pursuit of fashion, pursuit of youth, pursuit of rationale, pursuit of leisure, and pursuit of loyalty, among the groups according to gender and age with female consumers placing more importance on clothing-related benefits than their male counterparts. Local fashion businesses to consumers who target middle-aged consumers, this study can provide a basic data.

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Influence of the Job Performance upon the Hair beautician's Job Satisfaction (헤어미용인의 직무만족이 직무성과에 미치는 영향)

  • Bang, Hee-Bong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8585-8595
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    • 2015
  • This study was implemented to amass and analyze the data from 500 Seoul district beauty shop workers, which came from the use of the SPSS18.0. The statistical analysis was conducted through frequency for demographic characteristics, validity for factors analysis by using Varimax rotation, and reliability for Cronbach's alpha coefficient.. Also, the analysis was once again analyzed through the Pearson correlation coefficient, where our hypothesis was proven through regression analysis. Our research results have shown that, first, job satisfaction and job performance differed over matters like gender, age, education level, employment conditions, job category, overall work experience, daily work hours, and monthly income. Second, job satisfaction was shown to have a significant influence on job performance, where higher job satisfaction levels led to higher job performance. Thus, job satisfaction was a great factor to increase job performance by fulfilling their needs level. Also, they would act more positive and future-oriented when they have special needs like motivate achievement, wage, promotion, and reward. Therefore, managerial staff should continually develop any programs in order to upgrade beautician's job performance through their job satisfaction.

A Study of Stress and Coping Strategies in School-Age Children (학령기 아동의 스트레스와 대응전략에 관한 연구)

  • 신희선
    • Journal of Korean Academy of Nursing
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    • v.26 no.4
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    • pp.808-819
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    • 1996
  • The purpose of this study was to examine the stressors and coping strategies of school -age children and to explore the relationship between stressful life events and health symptoms and the effects of coping and trait anxiety which is theoretically considered to mediate the relationship between stress and health symptom. The study subjects consisted of 639 elementary school children in the fourth to sixth grade living in Seoul. Of the 639 subjects, 348 were boys and 291 were girls. The mean age was 11.35 (SD=.86). The Feel Bad Scale(FBS), Schoolager's Coping Strategy Inventory(SCSI), Spielberger's Trait Anxiety Scale for Children(STAIC), and Health Symptom Questionnaire (HSQ) were adapted for this study. A pilot study was undertaken to ascertain the reliability and validity of the instruments. The Cronbach alphas of FBS, SCSI, STAIC and HSQ were from .81 to .92. The Researcher and a research assistant visited the school and data were collected in the class using the questionnaire method after an explanation of the purpose and procedures was given to the children. Data collection was done during the period between Nov.25 to Dec.19, 1995. Using the SAS statistical program, percentages, t-test, ANOVA, correlation analysis, and multiple regression were used for data analysis. The result are as follows : 1. The mean score for the FBS was 204.79(range : 48-472) and there was a significant difference according to grade. The most severe stressors perceived by children were parental divorce and death or illness of family members. The most frequently experienced stressful life events were conflict with siblings and being home alone. 2. The mean score for the SCSI was 57.36(range : 9-118) and there was a significant difference according to grade. The most frequently used, and perceived as helpful, coping strategies were distraction and cognitive activities. 3. The mean score for the HSQ were 20.7(range : 0-81) and there were significant differences according to grade and sex. The percentage of the children answering that they perceived their health state as not good was 3.9%. 4. The mean score for the STAIC was 33.76 and there were significant differences according to grade and sex. 5. There was a significant relationship between stressful life events and health symptoms ( r=.53, p<.01). Also, Stressful life events were postively related with coping strategies(r=.39, p<.01). Trait anxiety was highly correlated with health symptoms(r=.72, p<.01). 6. To examine the multivariate effects of the variables to health symptoms, multiple regression was performed. Stressful life events, coping, trait anxiety, and health concerns were identified as significant variables. Explanation of the health symptoms by these variables was 56.78%. The study revealed that stressful life events correlated with health symptoms in school-age children and coping and trait anxiety had mediating effects on this relationship. The implication for nursing is that there is a need to develop supportive interventions for high risk population to decrease health problems due to stress. Also, it is recommended that a study be conducted to explore protective factors for the prevention of health problems in children.

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Risk Assessment of Levee Embankment Integrated Erosion and Seepage Failure Factor (침식과 침투영향을 고려한 하천제방의 위험도 평가)

  • Ahn, Ki-Hong;Han, Kun-Yeun
    • Journal of Korea Water Resources Association
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    • v.42 no.8
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    • pp.591-605
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    • 2009
  • In this study the risk integrated erosion and seepage failure factor and combined risk of the levee embankment were assessed. For the research of the reliability, the risk assessment of erosion, seepage and both of them combined for the levee embankment were conducted using discharge curve and stage hydrograph generated by stochastic rainfall variation method during typhoon and monsoon season. The risk of erosion was evaluated using tractive force and the seepage analysis was performed by selecting representative cross sections for SEEP/W model analysis. And the probability of seepage failure was assessed with MFOSM analysis using critical hydraulic gradient method. Unlike deterministic analysis method, quantitative risk could be obtained and the characteristics of realistic rainfall variation patterns as well as a variety of factors contributing to levee failure could be reflected in this research. The results of this study show significantly enhanced applicability for the combined risk. As this model can be employed to determine dangerous spots for levee failure and to establish flood insurance linked with flood risk map, it will dramatically contribute to the establishment of both efficient and systematic measures for integrated flood management on a watershed.