• 제목/요약/키워드: Improvement of statistics quality

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A Study on the Sound Quality of Passenger Cars (자동차 실내 소음의 음질 연구)

  • 김정우;최종대;허정기;변언섭
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1998.04a
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    • pp.94-101
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    • 1998
  • This paper presents the psychoacoustic analyses on the vehicle interior, noise generated when accelerating. Following the objective quantification for vehicle noises of different classes, the subjective decision process by the jury test is adopted to interrelate these results based on two different approaches. In particular, the paired comparison method is employed in assessing the sound quality in terms of the quietness, the powerfulness, and the pleasantness of the human auditory sensation. Special attention is paid to the physical interpretation of psychoacoutic parameters and their interrelation to the subjective assessment scores. In order to ensure the integrity of statistics of the survey, various tests are performed. The results show that the consistency of the "quiet" sensation is far higher than that of the "powerful" and the "pleasant" sensations. Also, it is found that the most significant parameter determining these feelings turns out to be the inherent loudness of the noise instead of the conventional indicators such as the weighted sound pressure level. It may be concluded that the psychoacoustic analysis offers more realistic evaluation for vehicle noise and assists the improvement of NVH more efficiently.ement of NVH more efficiently.

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Experiences of Implementing TPM in Swedish Industries

  • Liselott Lycke;Akersten, Per-Anders
    • International Journal of Reliability and Applications
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    • v.1 no.1
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    • pp.1-14
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    • 2000
  • The global marketplace is highly competitive and organisations, who want to survive long-term, have to continuously improve, change and adapt in response to market demands. These improvements should focus on cost cutting, increasing productivity levels and quality and guaranteeing deliveries in order to satisfy customers. Total Productive Maintenance (TPM) is one method, which can be used to achieve these goals. TPM is a change management approach that involves employees from both production and maintenance departments. The purpose is to eliminate major production losses by introducing a program of continuous and systematic improvements to production equipment. TPM should be developed and expanded to embrace the whole organisation and all employees should be involved in the process as members of improvement teams. This paper gives a short description of the development of TPM and the TPM implementation process. Findings are reported from a case study in which one of the authors had the possibility of following and guiding a company through their TPM implementation. The implementation process takes several years and the research has focused on the initial three years. The study demonstrates that driving forces, obstacles and difficulties often are dependent on the organisation, its managers and the individual employees.

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The Assessment of Severity Adjustment Measures for AMI Patients in Korea (급성심근경색증 환자를 대상으로 한 중증도 보정 방법의 평가)

  • Park, Hyeung-Keun
    • Quality Improvement in Health Care
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    • v.10 no.2
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    • pp.164-175
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    • 2003
  • Objectives: To evaluate the performance of models to predict AMI patients death using severity adjustment measures in Korea. Methods: Medical records of 861 patients treated by AMI in 7 general hospitals during 1996 and 1997 were reviewed by trained nurses. We measured the severity of patients by APACHE III, MedisGroups, CSI and DS. Using each severity method a predictive mortality for each patient was calculated from a logistic regression model including the severity score. The statistical performance of each severity method model was evaluated by using c-statistics and R2. For each hospital, z scores compared actual and expected mortality rates. Results: The overall in-hospital mortality was 14.5%, ranged from 10.0% to 22.2%. The distributions of severity scores for each method was significantly different by hospitals. The four severity-adjusted models to predict AMI patients death varied in their statistical performance for discrimination power of patients death. Order of Severity-adjusted mortality rates and z scores by four severity measures was different. Conclusion: Severity-adjusted mortality rates of AMI patients might be applied as an indicator for hospital performance evaluation in Korea. Because different severity methods frequently produce different impressions about relative hospital performance, more studies has to be done to use it as quality indicator and more attention should be paid to select appropriate severity measures.

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Gauge Capability Analysis and Designed Experiments (계측기 능력분석과 실험계획법)

  • Baik, Jaiwook;Jo, Jinnam
    • Journal of Korean Society for Quality Management
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    • v.24 no.3
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    • pp.145-159
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    • 1996
  • In today's organization, measurement plays a crucial role in helping improve process or quality. In this paper, we review the measurement error study, classical gauge repeatability and reproducibility study, and designed experiment suited for the determination of the measurement capability. Measurement error study is very simple to use but is rather crude. Hence, it should be used as a preliminary study to determine whether further study is necessary. Classical gauge repeatability and reproducibility (GR&R) study is the most common technique for evaluation of gauge capability. It calculates a percentage that relates the repeatability, reproducibility, and overall R&R to the specification range for the parameter measured. Hence, the individual repeatability and reproducibility statistics will indicate the area on which to concentrate. However, GR&R study only gives a point estimate of each component, which leaves a room for improvement. It is always good to integrate the use of control charts to ascertain the statistical stability of the measurement process. The tools of statistical experimental design are available for a comprehensive design and analysis of the measurement process. Hence, in this paper, we present gauge capability analysis as an experimental design problem and compare it with the classical GR&R study.

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Baby Boom Generation's Burden for Taking Care of Children, Aging Anxiety, Preparations for Old Age and Quality of Life (베이비붐세대의 자녀돌봄부담감, 노화불안, 노후준비 및 삶의 질)

  • Kim, Jeong Sun;Kang, Sook
    • Journal of Korean Public Health Nursing
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    • v.26 no.3
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    • pp.440-452
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    • 2012
  • Purpose: The purpose of this study was to provide basic data for use in development of strategy for healthy aging preparation and successful transfer to old age by identifying factors influencing quality of life of the baby boom generation. Methods: The data were collected from a total of 205 members of the baby boom generation(aged 48 to 56), and analysis was performed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient, and stepwise multiple regression using the SPSS(Version19.0) program. Results: Burden for taking care of children, aging anxiety, preparations for old age, and quality of life according to the general characteristics and health-related characteristics commonly showed a significant difference in education level and presence of stress. The greater the more burden for taking care of children and the deeper the aging anxiety, the lower the quality of life, and the better prepared for aging, the higher the quality of life. Factors affecting quality of life in the baby boom generation included preparations for old age, burden for taking care of children, monthly household income, and quality of sleep. Explanatory power was 32%. Conclusion: For successful transition to old age and for improvement of quality of life in the baby boom generation, a comprehensive approach in micro and macro dimensions will be sought.

Impact of Depression, Optimism and Posttraumatic Growth on Health-related Quality of Life in Female Breast Cancer Survivors Receiving Adjuvant Chemotherapy (항암화학요법을 받은 여성 유방암 생존자의 우울, 낙관성 및 외상 후 성장이 건강관련 삶의 질에 미치는 영향)

  • Kim, Bu Kyung;Sung, Mi-Hae;Choi, Sung In
    • Journal of East-West Nursing Research
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    • v.27 no.1
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    • pp.43-50
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    • 2021
  • Purpose: The purpose of this study was to identify the influence of depression, optimism and posttraumatic growth on health-related quality of life in female breast cancer survivors received adjuvant chemotherapy. Methods: In total, 115 female breast cancer survivors participated in this descriptive correlational study. The participants answered self-report questionnaires. Data were collected from 1 June 2020 to 10 June 2020, and were analyzed using descriptive statistics, the t-test, one-way ANOVA, Pearson correlation coefficients, and stepwise multiple regression with SPSS for Windows ver. 24.0. Results: The mean age of the breast cancer survivors was 45.83 years. The mean score for the degree of health-related quality of life was 81.85 out of 148 points. Participants' scores for health-related quality of life differed significantly based on economic status (F=5.36 p=.006) and hobbies (t=-3.37, p=.001). Health-related quality of life was negatively correlated with depression (r=-.73, p<.001), and positively correlated with optimism (r=.65, p<.001) and posttraumatic growth (r=.28, p=.002). Depression (𝛽=-.55, p<.001) was the most significant factor that affects health-related quality of life, followed by optimism (𝛽=.29, p<.001), and post-traumatic growth (𝛽=.12, p=.048), which together accounted for 62.2% (F=63.61, p<.001) of the variance. Conclusion: It is necessary to develop educational programs for breast cancer survivors to reduce depression, increase optimism and post-traumatic growth, and improve the health-related quality of life. By adapting these programs, positiveness may increase and this may lead to improvement of health-related quality of life for breast cancer survivors.

Factors explaining Quality of Life in Individuals with Coronary Artery Disease (관상동맥질환자의 삶의 질에 영향을 미치는 요소)

  • Park, In-Sook;Song, Rha-Yun;Ahn, Suk-Hee;So, Hee-Young;Kim, Hyun-Li;Joo, Kyung-Ok
    • Journal of Korean Academy of Nursing
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    • v.38 no.6
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    • pp.866-873
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    • 2008
  • Purpose: The study was done to compare quality of life by gender, and to identify factors which explain quality of life in individuals with coronary artery disease. Methods: For the survey, 91 individuals (53 men and 38 women) agreed to participate in the study. Cardiovascular risk factors, systolic blood pressure, body mass index, total cholesterol, triglyceride, high density lipoprotein-cholesterol, and low density lipoprotein-cholesterol, health behavior as well as quality of life, were measured. Descriptive statistics, t-test, correlation and hierarchical multiple regression with SPSS WIN 12.0 were used to analyze the data. Results: Significant gender differences were found for education, smoking status, chronic disease, perceived health status, and quality of life within sub-dimensions. Hierarchical regression analysis showed gender (men), age, perceived health status, cardiovascular risk scores, and health behaviors together explained 40.2% (adjusted $R^2$) of variance in quality of life. Conclusion: As the factors explaining quality of me in individuals with coronary artery disease have been identified as gender (men), age, perceived health status, and health behaviors, health promotion programs designed for this population should focus on these factors for effective behavioral modification, and consequent improvement in quality of life.

An assessment of statistical errors in articles in the Korean journal of veterinary research (수의학회지 논문에 적용된 통계기법의 타당성 평가)

  • Pak, Son-il
    • Korean Journal of Veterinary Research
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    • v.39 no.6
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    • pp.1187-1196
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    • 1999
  • The purpose of this study is to assess the suitability of the statistical techniques employed in papers published in the Korean Journal of Veterinary Research from March 1997 to March 1999 and it is hoped that the critical assessment may be of help to other researchers preparing their works for publication. Of the 246 original papers 94 were included in the analysis. Of 62 papers with the measure of central location and dispersion of data 34 (54.8%) used them correctly : 9 (39.1%) of 23 for t-test ; 1 (33.3%) of 3 for correlation analysis ; 7 (43.8%) of 16 for analysis of variance (ANOVA) ; 5 (62.5%) of 8 for chi-square test ; 44 (71%) of 62 for description of p-value. A number of papers employed ANOVA did not perform subsequent analysis of multiple comparison. Compared to the results of others, relatively higher proportion of papers in the present study was evaluated as appropriate analysis. The reason is that papers described insufficiently on the study design were not included, and evaluation items were restricted to the cases violated seriously inherent assumptions for each statistical technique. Statistical misuse or abuse appeared in the study is due to lack of knowledge on statistics and short of its importance for improvement the quality of paper. Because an inappropriate analysis can lead the readers to misunderstand on findings, observed statistical analyses must be valid, and correctly undertaken. It is suggested that more intensive statistical refereeing are needed, and the communication should be allowed for the controversial points.

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On the Estimation of Satisfaction Distribution for Game Factors (게임요소의 만족도분포 추정에 관한 연구)

  • Yum, Joon-Keun;Ham, Hyung-Bum
    • Journal of Korea Game Society
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    • v.8 no.3
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    • pp.23-30
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    • 2008
  • To strengthen the competitiveness of the game industry, one needs to develope a tool for evaluation of the satisfaction level of the game users, which leads to the improvement of the quality of games and increment of the amount of game trade. In this study, we developed factors to measure the satisfaction level and estimate their distributional properties. For the purpose, using a survey data for RPG games, we discussed several aspects for normalization of score distribution for satisfaction factors and estimated their density function by use of parametric density estimation of SAS/INSIGHT. We believe that the proposed results help us to predict or estimate the satisfaction level of newly developed games as well as the current popular games.

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Factors on the Satisfaction of Korean Medical Tour Convergence Services of Chinese College Students (중국 대학생의 한국 의료관광 융합서비스에 대한 만족 요인)

  • Lee, Won Jae;Song, Yang Min;Oh, Hyun Sook
    • Journal of the Korea Convergence Society
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    • v.8 no.2
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    • pp.53-62
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    • 2017
  • This study was to find the factors influencing satisfaction of Korean medical tour services of Chinese college students. Structured questionnaire was developed to collect data. The data were collected from the 175 students between May 1 and May 15 in 2015 in an international college in China. The expectations and the evaluations on the Korean medical tour services were compare by t-test. To find the factors influencing satisfaction on Korean medical tour services, diverse linear regression models were estimated. According to the best fit regression model, technologies, quality of medical tour services, and health care cost significantly and positively influenced satisfaction on the Korean medical tour services. The results of the study suggested that we need to prepare marketing strategies to improve understandings on Korean medical tour services for the Chinese college students. Improvement of technology, improvement of quality of health service, and setting of reasonable price are important to attract more Chinese patients to Korea.