• Title/Summary/Keyword: Correlated data

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Job Stressors, Job Stress Symptoms and Job Performance of Workers in Fashion Industry (섬유패션산업 종사자의 직무스트레스 요인, 직무스트레스 징후 및 직무성과)

  • 유화숙;박광희
    • Journal of the Korean Home Economics Association
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    • v.41 no.2
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    • pp.93-106
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    • 2003
  • The purpose of this study was to investigate job stressors, job stress symptoms, and job performance of workers in fashion industry. The data were obtained from questionnaire completed by 529 workers who were employed in textile or clothing manufactures located in Seoul, Daegu, Busan, and Masan area. The SPSS package was used for data analysis which included frequency, mean, correlation, and factor analysis. Job stressors consisted of environmental related stressors, job related stressors(task characteristics and role characteristics) and organization related stressors(organization climate and career development). Most of job stressors were significantly correlated with job stress symptoms but their correlation coefficients were low. Among job stressors, quantitative work overload was found to be a major stressor. Workers in fashion industry appeared to evaluate their job performance relatively good. Also, it was found that behavioral and psychological symptoms were negatively correlated with job performance.

Multivariate CUSUM control charts for monitoring the covariance matrix

  • Choi, Hwa Young;Cho, Gyo-Young
    • Journal of the Korean Data and Information Science Society
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    • v.27 no.2
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    • pp.539-548
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    • 2016
  • This paper is a study on the multivariate CUSUM control charts using three different control statistics for monitoring covariance matrix. We get control limits and ARLs of the proposed multivariate CUSUM control charts using three different control statistics by using computer simulations. The performances of these proposed multivariate CUSUM control charts have been investigated by comparing ARLs. The purpose of control charts is to detect assignable causes of variation so that these causes can be found and eliminated from process, variability will be reduced and the process will be improved. We show that the charts based on three different control statistics are very effective in detecting shifts, especially shifts in covariances when the variables are highly correlated. When variables are highly correlated, our overall recommendation is to use the multivariate CUSUM control charts using trace for detecting changes in covariance matrix.

Factors Affecting Adaptation in Parents of Newborn with Congenital Heart Disease (선천성 심질환 환아 부모의 적응 영향요인)

  • Kim, Kyoung-Nam
    • The Korean Journal of Health Service Management
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    • v.7 no.3
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    • pp.111-123
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    • 2013
  • The purpose of this study was to identify factors affecting stress and adaptation in newborn congenital heart disease patients of parents. Data were obtained through questionnaires from 181 newborn congenital heart disease inpatients of parents from P university in Y city. The data were analyzed SPSS 18.0, using descriptive statistics, Pearson correlation coefficients and stepwise multiple regression. Stress was negative correlated with level of patents adaptation. Social support, marital communication and family cohesion were positive correlated with level of patents adaptation. The explained variances for patents adaptation were 45.2% and factors affecting patients adaptation were congenital heart disease, family cohesion, stress, social support and marital communication. Educational intervention program for parents of newborn with congenital heart disease, reduce stress, and to increase the adaptation will be developed.

On the Performance of Turbo Codes-Based Hybrid ARQ with Segment Selective Repeat in WCDMA

  • Shi Tao;Cao Lei
    • Journal of Communications and Networks
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    • v.8 no.2
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    • pp.212-219
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    • 2006
  • In this paper, a new turbo codes-based hybrid automatic repeat request (TC-HARQ) scheme with segment selective repeat (SSR) is proposed. The main strategy is, upon retransmission, to repeat the data that are most important for the next round of decoding based on the distribution of residual errors after current decoding. The performance in terms of reliability and throughput is analyzed. To adapt to correlated fading channels where an inter-leaver is always employed before transmission, we further modify the SSR strategy so that data having experienced correlated deep fading are selected for retransmission. Finally, this proposed scheme is applied to the wideband code division multiple access (WCDMA) system under frequency selective fading channels. Simulation results demonstrate that in all single and multiple user cases, SSR-based TC-HARQ leads to significant throughput improvement with similar bit error rate (BER) performance as compared to type-I TC-HARQ.

Performance of Multicarrier-CDMA Uplink with Antenna Arrays and Multiuser Detection

  • Sigdel, Shreeram;Ahmed, Kazi M.;Fernando, Anil
    • Journal of Communications and Networks
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    • v.5 no.2
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    • pp.150-156
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    • 2003
  • In this paper, an uplink MC-CDMA system incorporating multiuser detection and smart antennas has been considered. The performance of asynchronous as well as synchronous system is studied over a correlated Rayleigh multipath slow fading channel. A simplified array-processing algorithm suitable for slow fading situation is investigated to overcome the heavy computational complexity associated with Eigen solutions. The effect of variable data rate in the system performance is considered and effectiveness of antenna array to handle high data rate is discussed. A brief investigation on the system performance degradation due to correlated channel is also carried out. Based on the extensive simulation carried out, the performance of the asynchronous uplink system is found dramatically improved with antenna array and multiuser detection. Asynchronicity and channel correlation are found to affect the system performance significantly. The investigated simpli- fied algorithm produces similar results as Eigen solutions in slow fading situation with much reduced complexity.

Uncertainty and Anxiety in Families of Hospitalized Children (입원 아동 가족의 불확실성과 불안)

  • Koo Hyun-Young
    • Child Health Nursing Research
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    • v.8 no.1
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    • pp.67-76
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    • 2002
  • The purpose of this study was to investigate the level of uncertainty and anxiety in families of hospitalized children. Data were collected through self-report questionnaires which were constructed to include parent's perception of uncertainty and state anxiety. The subjects consisted of 126 families of hospitalized children in one university-affiliated hospital in Daegu. The data were analyzed by the SPSS program. The results were as follows; 1. The mean score of uncertainty was 64.70 (Range=31-95). The mean scores of subsets of the uncertainty were followed as: lack of clarity (2.59), unpredictability (2.46), lack of information (2.22) and ambiguity (2.14). 2. The mean score of state anxiety was 47.93 (Range=20-67). 3.The level of uncertainty was positively correlated to the level of state anxiety. 4. The level of anxiety was different depending on their religion and monthly income. The above findings indicated that the level of uncertainty and the state anxiety in families of hospitalized children were positively correlated. Therefore, nursing intervention for reducing uncertainty and anxiety and improving coping method should be provided for families of hospitalized children.

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Markovian EWMA Control Chart for Several Correlated Quality Characteristics

  • Chang, Duk-Joon;Kwon, Yong-Man;Hong, Yeon-Woong
    • Journal of the Korean Data and Information Science Society
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    • v.14 no.4
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    • pp.1045-1053
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    • 2003
  • Markovian EWMA control chart for simultaneously monitoring mean vector of the several correlated quality characteristics is investigated. Properties of multivariate Shewhart chart and EWMA chart are evaluated for matched FSI (fixed sampling interval) and VSI(variable sampling interval) scheme. We obtained VSI EWMA chart is more efficient than Shewhart chart for small or moderate shifts. And, we obtained stablized numerical results with Markov chain method when the number of transient state is greater than 100.

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Statistically Proper Multiple Range Tests for a Within Subject Factor in a Repeated Measures Design

  • Park, Cheol-Yong;Park, Sang-Bum
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.2
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    • pp.525-534
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    • 2007
  • It is a common practice in many research areas that multiple range tests for a between subject factor such as Tukey are applied to a within subject factor in a repeated measures design. Tukey procedure, however, sometimes detects no pairs with different means even when the hypothesis of all equal level means is rejected. This study attempts to provide a rationale for the proposition that Tukey is inappropriate post hoc procedure for a within subject factor in which the observations are correlated. We introduce two multiple range tests, Bonferroni and Scheffe, for a within subject factor and show that Bonferroni is more appropriate than Scheffe for pairwise multiple comparisons. Subsequent simulation study indicates that Tukey has significantly less power than Bonferroni in detecting actual difference between means of some pairs when the observations of a within subject factor are highly correlated.

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Correlation of Berg Balance Scale and Functional Reach Test

  • Park, Eun-Young;Kim, Won-Ho
    • Physical Therapy Korea
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    • v.14 no.4
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    • pp.28-34
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    • 2007
  • The purposes of this study were to provide the basic data and investigate the reliability of functional reach test and identify correlation of Berg balance scale (BBS) and functional reach test (FRT). The subjects were twenty healthy young adults and forty-five over 65 years old in order to compare balance ability. These data were analyzed by independent t-test and Pearson's correlation test using SPSS WIN 10.0. The results were as follows. Intrarater reliability coefficients of FRT was .976 and interrater was .942. FRT was significantly correlated with age, height, and BBS (p<.05). There were no significant differences in FRT and BBS by sex. There was significant difference in reach distance between below 74 elderly and above in FRT. FRT is very reliable test for balance and significantly correlated with BBS. Therefore, it is suggested that FRT is a clinically useful tool to substitute for BBS measuring balance ability in the elderly.

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Correlation between High-Caffeine Energy Drink Intake and Mental Health in High School Students (고등학생의 고카페인 에너지 음료섭취와 정신건강의 상관성)

  • Park, Woong-Sub;Park, Sunu;Kim, Sang-A
    • Journal of the Korean Society of School Health
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    • v.29 no.3
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    • pp.132-139
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    • 2016
  • Purpose: In this study, we analyzed the correlation between high-caffeine energy drink intake and mental health in high school students. Methods: Analyses were conducted using the data of 27,097 responses from the 2015 Korea Youth Risk Behavior Web-based Survey of general high school students. Data were analyzed by logistic regression based on a complex sample design. Results: High-caffeine energy drink intake was positively correlated with the rates of smoking, alcohol consumption, violence, depression, and suicidal thoughts and negatively correlated with the sense of happiness. Conclusion: High-caffeine energy drink intake has a significant impact on the mental health of high school students. Therefore, in-depth research and policies on high-caffeine energy drink intake and the mental health of young individuals are required.