• Title/Summary/Keyword: multilevel analysis

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Understanding of the Overview of Quality 4.0 Using Text Mining (텍스트마이닝을 활용한 품질 4.0 연구동향 분석)

  • Kim, Minjun
    • Journal of Korean Society for Quality Management
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    • v.51 no.3
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    • pp.403-418
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    • 2023
  • Purpose: The acceleration of technological innovation, specifically Industry 4.0, has triggered the emergence of a quality management paradigm known as Quality 4.0. This study aims to provide a systematic overview of dispersed studies on Quality 4.0 across various disciplines and to stimulate further academic discussions and industrial transformations. Methods: Text mining and machine learning approaches are applied to learn and identify key research topics, and the suggested key references are manually reviewed to develop a state-of-the-art overview of Quality 4.0. Results: 1) A total of 27 key research topics were identified based on the analysis of 1234 research papers related to Quality 4.0. 2) A relationship among the 27 key research topics was identified. 3) A multilevel framework consisting of technological enablers, business methods and strategies, goals, application industries of Quality 4.0 was developed. 4) The trends of key research topics was analyzed. Conclusion: The identification of 27 key research topics and the development of the Quality 4.0 framework contribute to a better understanding of Quality 4.0. This research lays the groundwork for future academic and industrial advancements in the field and encourages further discussions and transformations within the industry.

Related Factors of Depression according to Individual Attributes and Regional Environment: Using Multi-Level Analysis (다수준분석을 활용한 개인특성 및 지역환경에 따른 우울증 관련 영향요인 분석)

  • Moon, Seok-Jun;Lee, Ga Ram;Nam, Eun-Woo
    • Health Policy and Management
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    • v.30 no.3
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    • pp.355-365
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    • 2020
  • Background: This study is aimed to verify individual and regional-level factors affecting the depression of Koreans and to develop social programs for improving the depressive status. Methods: This study used individual-level variables from the Korean Community Health Survey (2018) and used the e-regional index of the Korean Statistical Information Service as the regional-level variable. A multi-level logistic regression was executed to identify individual and regional-level variables that were expected to affect the extent of depressive symptoms and to draw the receiver operating characteristic curve to compare the volume of impact between variables from both levels. Results: The results of the multi-level logistic regression analysis in regards to individual-level factors showed that older age, female gender, a lower income level, a lower education level, not having a spouse, the practice of walking, the consumption of breakfast higher levels of stress, and having high blood pressure or diabetes were associated with a greater increase in depressive symptoms. In terms of regional factors, areas with fewer cultural facilities and fewer car registration had higher levels of depressive symptoms. The comparison of area under the curve showed that individual factors had a greater influence than regional factors. Conclusion: This study showed that while both, individual and regional-level factors affect depression, the influence of the latter was relatively weaker as compared to the first. In this sense, it is necessary to develop programs focused on the individual, such as social prescribing at the local or community-level, rather than the city and nation-level approach that are currently prevalent.

Life-cycle estimation of HVDC full-bridge sub-module considering operational condition and redundancy (HVDC 풀-브리지 서브모듈의 동작 조건과 여유율을 고려한 수명예측)

  • Kang, Feel-soon;Song, Sung-Geun
    • Journal of IKEEE
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    • v.23 no.4
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    • pp.1208-1217
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    • 2019
  • The life-cycle prediction of the sub-module which is the unit system of MMC is very important from the viewpoint of maintenance and economic feasibility of HVDC system. However, the life-cycle prediction that considers only the type, number and combination of parts is a generalized result that does not take into account the operating condition of the sub-module, and may significantly differ from the life-cycle of the actual one. Therefore, we design a fault tree for the purpose of reflecting the operation characteristics of the full-bridge sub-module and apply the MIL-HDBK-217F to the failure rate of the basic event to predict the life-cycle of the full-bridge sub-module. It compares the life-cycle expectancy of the conventional failure rate analysis with the proposed fault-tree analysis and compares the lifetime according to whether the redundancy of the full-bridge sub-module is considered.

Effects of the Community Environmental Characteristics on Drinking Problems of Adults: A Multilevel Analysis (지역사회의 환경적 특성이 개인의 음주문제에 미치는 영향에 관한 다수준분석)

  • Kim, Kwang Kee;JeKarl, Jung;Kwon, Yong Mi;Park, Min Soo
    • Korean Journal of Health Education and Promotion
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    • v.29 no.5
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    • pp.103-113
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    • 2012
  • Objectives: This study aims to identify the effects of environmental characteristics of the community on adults' drinking problems with held constant effects of characteristics of drinkers themselves. Methods: A multi-level regression analysis was employed to differentiate the variances accounted for by measurements both at individual and group levels. Data on individual demographic, behavioral, and mental health status were obtained from the Community Health Survey conducted in 2009 in the province of Kyunggido, which include 41,376 respondents aged 19 and over. This study included 28,335 adults who were classified as drinkers. They were from 45 communities(si, gun, or gu) for which data on contextual characteristics were collected by secondary data available on local government websites and KOSIS(Korea Statistical Information System). Results: Multi-level analyses showed that the variance of the dependent variable, harmful use of alcohol measured by alcohol use disorder identification test was independently accounted for by variance of independent variables at group level, including number of on-premises alcohol outlet per inhabitant and divorce rate, with held other independent variables of the model controlled. Conclusions: This study confirms that in order to prevent and reduce harms caused by harmful use of alcohol requires restricting physical availability of alcohol in the community where the drinker lives.

Ecological Factors Affecting School Adjustment of Low-Income Adolescents Attending Community Child Care Center (저소득가정 청소년의 학교적응과 생태학적 영향요인: 지역아동센터 이용 청소년을 중심으로)

  • Park, Jiyoung;Park, Youngsook;Lee, Jeongeun;Kim, Soobin
    • Child Health Nursing Research
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    • v.23 no.2
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    • pp.158-167
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    • 2017
  • Purpose: The purpose of this study was to investigate the ecological factors influencing school adjustment of adolescents from low-income families. Methods: Secondary data analysis was performed using data of 1,321 low-income adolescents in 123 regions found on the Survey on Service Satisfaction with Community Child Care Center. Results: The results of multi-level analysis identified the factors influencing school adjustment of low-income adolescents as follows: individual-level factors were gender, grade in school, and emotional problem; an interpersonal-level factor was family structure; organizational-level factors were length of time attending center and satisfaction with the service of the center; community-level factors were region and perception of community. Conclusion: The results suggest that low-income adolescents' adjustment to school is influenced not only by individual factors but also by diverse environmental factors. Community factors suggest that more education support systems and leisure facilities for adolescents need to be built in small and medium cities. Strategies to enhance positive perception of community are also needed for this population. Further, it is necessary to develop multi-level interventions to improve the school adjustment of adolescents from vulnerable social groups.

The Effects of Individual Characteristics, School Factors, and Community Factors on Adolescents School Violence Behavior -A multilevel analysis- (청소년의 학교폭력 가해행동에 영향을 미치는 요인 -다층모형 분석-)

  • Lee, Ji Hyeon
    • Journal of the Korean Society of Child Welfare
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    • no.55
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    • pp.143-171
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    • 2016
  • This study investigated the effects of individual characteristics, school factors, and community factors on adolescent school violence behaviors. Data from a total of 1,777 middle school students from 50 schools in the Seoul and Gyeonggi regions were used for analysis. A hierarchical generalized linear modeling was employed to conduct a two-level analysis. Results showed that adolescents' individual factors, including attitudes toward violence, parental attachment, child abuse experiences, and affiliation with delinquent peers, as well as school factors including teacher's abusive classroom discipline, affected adolescent school violence behaviors. In addition, neighborhood disorder was found to be significantly positively correlated with adolescents' school violence. The results of this study suggest that for an understanding of school violence and to prepare countermeasures accordingly, integrated consideration of various environmental contexts in adolescents' daily lives, such as family, school, and community environments, is necessary. A multidimensional, integrated intervention plan to effectively resolve school violence based on these research results is discussed.

Analysis and Improvement of Power Quality for A Fuel Cell System Based on Multi-level Converters (멀티 레벨 컨버터를 이용한 연료 전지 시스템의 전력품질 분석과 개선)

  • Kim Yoon-Ho;Moon Hyun-Wook;Kim Soo-Hong;Jeong Eun-Jin
    • Journal of Energy Engineering
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    • v.14 no.1
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    • pp.37-45
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    • 2005
  • The fuel cell system is one of very useful energy sources. The system has advantages as renew-able and environmental sources. To obtain AC electricity from fuel cells, inverters are necessary. A multilevel converter is used as an inverter for a high power fuel cell system. Through harmonic analysis, it is shown that the harmonic components and THD increase while fundamental component decreases as voltage sag increases. To solve the voltage sag problems, three different approaches are investigated in this paper; installation of a boost converter at the fuel cell output, control of pulse widths, and use of ultracapacitors. The proposed three approaches are analyzed and compared using simulation and experimental results.

Associations between Quality of Life and Marital Status in Cancer Patients and Survivors

  • Han, Kyu-Tae;Kim, Sun Jung;Song, Haiyan;Chun, Sung-Youn;Kim, Chan Ok;Kim, Jung-Soo;Park, Eun-Cheol
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.13
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    • pp.5287-5291
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    • 2014
  • Background: The cancer survival rate in Korea has substantially increased, necessitating the management of not only patients with cancer but also longer term survivors. Although the divorce rate has drastically increased in Korea, there is not sufficient research regarding the relationship between changes in marital status and quality of life (QOL) in cancer patients and survivors. Thus, we aimed to examine the relationship between marital status and QOL in such cases. Materials and Methods: This study was performed using the Community Health Survey of 2008 administered by the Korea Centers for Disease Control and Prevention (N=169,328). We used t-tests and Chi-square tests to compare demographic variables between men and women, and analysis of variance (ANOVA) to compare QOL scores among comparison groups. We also performed a multilevel analysis on the relationship between QOL and marital status while accounting for provincial differences. Results: Decline of EuroQOL five dimensions (EQ-5D) in single patients with cancer was greater than in any other marital status group, but there was no statistically significant decline in survivors of cancer with regard to marital status. In the general population, the decline of EQ-5D was higher among single people than married people. Using the EuroQOL visual analog scale (EQ-VAS), single people had higher values than those of other marital status among both patients with cancer and survivors of cancer. In the general population, EQ-VAS values were higher for single people compared to married people. Conclusions: There may be a significant relationship between marital status and QOL in cancer patients and survivors. Policy interventions to manage patients with cancer who experience a decline in QOL as well as marital problems should be conducted.

Student feedback to improve the United States Department of Agriculture Fresh Fruit and Vegetable Program

  • Lin, Yi-Chun;Fly, Alyce D.
    • Nutrition Research and Practice
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    • v.10 no.3
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    • pp.321-327
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    • 2016
  • BACKGROUND/OBJECTIVES: Fruit and vegetable consumption of children in the United States falls below recommendations. The U.S. Department of Agriculture Fresh Fruit and Vegetable Program (FFVP) is a national free-fruit and vegetable school distribution program designed to address this problem. This permanent, legislated program provides funding to qualified elementary schools for provision of additional fruit and vegetables outside of school meals. The objective of this study was to understand children's perceptions of FFVP after the intervention and formulate recommendations that may improve success of the intervention. SUBJECTS/METHODS: Secondary data were obtained from 5,265 $4^{th}-6^{th}$ graders at 51 randomly-selected FFVP intervention schools in Indiana. Anonymous questionnaires were completed late in the 2011-2012 academic year. Multilevel logistic regressions were used to determine associations between students' perceptions of program effects (4 close-ended items) and their preference toward the program. Content analysis was applied to a single open-ended item for program comments. RESULTS: Over 47% of students reported greater intake of fruit and vegetables due to FFVP, and over 66% reported liking the program. Student-reported program effects were positively associated with preference for the program (P < 0.01). Themes that emerged during analysis of 3,811 comments, included, students liked: the opportunity to try different kinds of fruit and vegetables, types and flavors of fruits served, and benefits of eating fruit. Fewer students liked the types of vegetables and their benefits. A small group disliked the program citing poor flavor of vegetables and quality of fruits. Important suggestions for the program include serving more dipping sauces for vegetables, cooking vegetables, and providing a greater variety of produce. CONCLUSIONS: The degree that students liked FFVP may predict the program's effects on fruit and vegetable intake. FFVP may become more acceptable to students by incorporating their suggestions. Program planners should consider these options for achieving program goals.

Implementation of TTS Engine for Natural Voice (자연음 TTS(Text-To-Speech) 엔진 구현)

  • Cho Jung-Ho;Kim Tae-Eun;Lim Jae-Hwan
    • Journal of Digital Contents Society
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    • v.4 no.2
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    • pp.233-242
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    • 2003
  • A TTS(Text-To-Speech) System is a computer-based system that should be able to read any text aloud. To output a natural voice, we need a general knowledge of language, a lot of time, and effort. Furthermore, the sound pattern of english has a variable pattern, which consists of phonemic and morphological analysis. It is very difficult to maintain consistency of pattern. To handle these problems, we present a system based on phonemic analysis for vowel and consonant. By analyzing phonological variations frequently found in spoken english, we have derived about phonemic contexts that would trigger the multilevel application of the corresponding phonological process, which consists of phonemic and allophonic rules. In conclusion, we have a rule data which consists of phoneme, and a engine which economize in system. The proposed system can use not only communication system, but also utilize office automation and so on.

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