• Title/Summary/Keyword: Meta model

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The Methylenetetrahydrofolate Reductase C677T Polymorphism and Breast Cancer Risk in Asian Populations

  • Rai, Vandana
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.14
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    • pp.5853-5860
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    • 2014
  • Background: Methylenetetrahydrofolate (MTHFR) is the key enzyme of the folate metabolic pathway and several studies have pointed to association between the MTHFR C677T polymorphism and breast cancer risk. Although significant association was observed in some studies, in others no clear link could be established. Objective: A meta-analysis of published Asian case control studies was therefor carried out to shed further light on any C677T breast cancer association. Materials and Methods: PubMed, Springer Link, Google Scholar and Elsevier databases were searched for case control studies of associations between MTHFR C677T polymorphism and breast cancer risk. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association. A total of 36 studies including 8,040 cases and 10,008 controls were included in the present meta-analysis. Results: Overall, a significantly elevated breast cancer risk was associated with the T allele and TT genotype in homozygote comparison and dominant genetic models when all studies were pooled into the meta-analysis (T vs C (allele contrast model): OR=1,23, 95%CI=1.13-1.37, p=0.000 ; TT vs CC(homozygote model): OR=1.38, 95%CI=1.16-1.63, p=0.0003; TT+CT vs CC (dominant model): OR=1.12, 95%CI=1.01-1.23, p=0.02). Conclusions: The present meta-analysis strongly suggested a significant association between the MTHFR C677T polymorphism and risk of breast cancer in Asian populations.

Development of Meta Problem Types to Improve Problem-solving Power (문제 해결력 신장을 위한 베타 문제 유형 개발)

  • 현종익
    • Education of Primary School Mathematics
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    • v.2 no.1
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    • pp.3-13
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    • 1998
  • In mathematics education we have focused on how to improve the problem-solving ability, which makes its way to the new direction with the introduction of meta-cognition. As meta-cognition is based on cognitive activity of learners and concerned about internal properties, we may find a more effective way to generate learners problem-solving power. Its means that learners can regulate cognitive process according to their gorls of learning by themselves. Moreover, they are expected to make active participation through this process. If specific meta problems designed to develop meta-cognition are offered, learners are able to work alone by means of their own cognition and regulation while solving problems. They can transfer meta-cognition to the other subjects as well as mathematics. The studies on meta-cognition conducted so far may be divided into these three types. First in Flavell([3]) meta-cognition is defined as the matter of being conscious of one's own cognition, that is, recognizing cognition. He conducted an experiment with presschoolers and children who just entered primary school and concluded that their cognition may be described as general stage that can not link to specific situation in line with Piaget. Second, Brown([1], [2]) and others argued that meta-cognition means control and regulation of one's own cognition and tried to apply such concept to classrooms. He tried to fined out the strategies used by intelligent students and teach such types of activity to other students. Third, Merleary-Ponty (1962) claimed that meta-cognition is children's way of understanding phenomena or objects. They worked on what would come out in children's cognition responding to their surrounding world. In this paper following the model of meta-cognition produced by Lester ([7]) based on such ideas, we develop types of meta-cognition. In the process of meta-cognition, the meta-cognition working for it is to be intentionally developed and to help unskilled students conduct meta-cognition. When meta-cognition is disciplined through meta problems, their problem-solving power will provide more refined methods for the given problems through autonomous meta-cognitive activity without any further meta problems.

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The Impact of Aircraft Spare Engine and Module Inventory Level on Wartime Operational Availability (항공기 예비엔진 및 모듈 재고수준이 전시 운용가용도에 미치는 영향)

  • Kim, Jinho;Lee, Sangjin;Jung, Sungtae
    • Korean Management Science Review
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    • v.31 no.2
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    • pp.33-48
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    • 2014
  • It is important to maintain on operational availability of aircraft during wartime. The KF-16 fighter, the backbone of the ROKAF (Republic Of Korea Air Force), has a single engine. Therefore, the engine has a critical influence on operational availability. The purpose of this study is to estimate optimal levels of spare part inventories concerning both engines and modules. That is provided by linear programming methods utilizing a developed meta-model. For drawing out the meta-model, we develop a simulation model which can consider wartime demands. In the previous study, $2^k$ factorial design method is used to check the influence of each independent variable. That method requires relatively many scenarios because every extreme value combination of independent variables should be checked. However, this study adopts NOLH (Nearly Orthogonal Latin Hypercube) as an experimental design. By adopting NOLH, this study increases not only efficiency but also accuracy. That is proven by comparing the validity of the developed meta-model on both experimental designs. This study also utilizes the OptQuest simulation tool in ARENA to derive the optimal level of spare stocks. By comparing the result of OptQuest to that of the developed meta-model, the validity of this study is secured.

Design MetaModel for MCF (Mobile Cross Framework) Based MDA (MDA기반 모바일 크로스 프레임워크를 위한 메타모델 설계)

  • Song, Yujin;Han, Deoksoo;Lee, Eunjoo
    • Journal of Korea Multimedia Society
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    • v.22 no.2
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    • pp.292-298
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    • 2019
  • Mobile-based software development methodology has been vigorously researched from using object-oriented development methodology and component-based development methodology previous structural developing methodology. There are two types of OS in mobile platform which are android and iOS. There is a problem that the application to be developed is developed depending on the device type. To resolve this problem, first, the system structure and design method should be managed effectively. Second, a basic design guide that can be commonly adapted to the each project is required. In this paper, we define a mobile cross platform meta model based on MDA-development methodology, focusing on reusability, portability and interoperability about non - dependent part of the mobile platform. If the proposed meta-model is applied to manage the related information and all the types of Mobile-Apps become available through independent mobile app development process, henceforward, it will be much of help establishing formulaic mobile-app developmental methodology.

A Study on Innovation Types of Cloud Companies based on a Meta Model (메타모델 기반의 클라우드 기업의 혁신유형 연구)

  • Seo, Kwang-Kyu
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.3
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    • pp.87-92
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    • 2021
  • Cloud is emerging as a key factor in digital transformation. In particular, the industry is paying attention to cloud as a key factor in economic revitalization after COVID-19. In this economic environment, cloud companies can survive only through continuous innovation. In this study, we propose the innovation types of cloud companies using the meta model, which is a high-level conceptual model that generalizes various corporate activities. The proposed cloud company innovation type applies a conceptual model divided into two axes such as the corporate value chain and the business management layer. The contribution of this study is to provide a basis for research in a new academic field called corporate innovation in the cloud domain, and to provide decision-making tools for diagnosing innovation levels or exploring innovation directions for cloud companies.

Four Polymorphisms in the Cytochrome P450 1A2 (CYP1A2) Gene and Lung Cancer Risk: a Meta-analysis

  • Bu, Zhi-Bin;Ye, Meng;Cheng, Yun;Wu, Wan-Zhen
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.14
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    • pp.5673-5679
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    • 2014
  • Background: Previous published data on the association between CYP1A2 rs762551, rs2069514, rs2069526, and rs2470890 polymorphisms and lung cancer risk have not allowed a definite conclusion. The present meta-analysis of the literature was performed to derive a more precise estimation of the relationship. Materials and Methods: 8 publications covering 23 studies were selected for this meta-analysis, including 1,665 cases and 2,383 controls for CYP1A2 rs762551 (from 8 studies), 1,456 cases and 1,792 controls for CYP1A2 rs2069514 (from 7 studies), 657 cases and 984 controls for CYP1A2 rs2069526 (from 5 studies) and 691 cases and 968 controls for CYP1A2 rs2470890 (from 3 studies). Results: When all the eligible studies were pooled into the meta-analysis for the CYP1A2 rs762551 polymorphism, significantly increased lung cancer risk was observed in the dominant model (OR=1.21, 95 % CI=1.00-1.46). In the subgroup analysis by ethnicity, significantly increased risk of lung cancer was observed in Caucasians (dominant model: OR=1.29, 95%CI=1.11-1.51; recessive model: OR=1.33, 95%CI=1.01-1.75; additive model: OR=1.49, 95%CI=1.12-1.98). There was no evidence of significant association between lung cancer risk and CYP1A2 rs2069514, s2470890, and rs2069526 polymorphisms. Conclusions: In summary, this meta-analysis indicates that the CYP1A2 rs762551 polymorphism is linked to an increased lung cancer risk in Caucasians. Moreover, our work also points out the importance of new studies for rs2069514 associations in lung cancer, where at least some of the covariates responsible for heterogeneity could be controlled, to obtain a more conclusive understanding about the function of the rs2069514 polymorphism in lung cancer development.

Approximate Design Optimization of Active Type Desk Support Frame for Float-over Installation Using Meta-model (메타모델을 이용한 플로트오버 설치 작업용 능동형 갑판지지프레임의 근사설계최적화)

  • Lee, Dong Jun;Song, Chang Yong;Lee, Kangsu
    • Journal of the Korean Society of Industry Convergence
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    • v.24 no.1
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    • pp.31-43
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    • 2021
  • In this study, approximate design optimization using various meta-models was performed for the structural design of active type deck support frame. The active type deck support frame was newly developed to facilitate both transportation and installation of 20,000 ton class offshore plant topside. Structural analysis was carried out using the finite element method to evaluate the strength performance of the active type deck support frame in its initial design stage. In the structural analysis, the strength performances were evaluated for various design load conditions that were regulated in ship classification organization. The approximate optimum design problem based on meta-model was formulated such that thickness sizing variables of main structure members were determined by achieving the minimum weight of the active type deck support frame subject to the strength performance constraints. The meta-models used in the approximate design optimization were response surface method, Kriging model, and Chebyshev orthogonal polynomials. The results from approximate design optimization were compared to actual non-approximate design optimization. The Chebyshev orthogonal polynomials among the meta-models used in the approximate design optimization represented the most pertinent optimum design results for the structure design of the active type deck support frame.

Pairwise pseudolikelihood approach for adjusting selection bias in meta-analysis (메타분석의 선택 편향 보정을 위한 쌍별 유사가능도 접근법)

  • Kuk, Sunghee;Lee, Woojoo
    • The Korean Journal of Applied Statistics
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    • v.33 no.4
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    • pp.439-449
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    • 2020
  • Meta-analysis provides a way of integrating several independent studies of interest. Since small studies with statistically significant results are more likely to be published, publication bias, which is a special case of selection bias, often occurs in meta analysis. Conditional likelihood and weighted estimating equation have been proposed to deal with publication bias, but they require to specify a correct selection probability model. In contrast, the pairwise pseudolikelihood approach can correct publication bias without fully specifying the correct selection probability model, but its performance in meta-analysis was not investigated. In this paper, we perform a numerical study about whether the pairwise pseudolikelihood approach is effective for solving publication bias arising from typical meta-analysis settings.

Effects of the Variables related to the Health Action Process Approach Model on Physical Activity: A Systematic Literature Review and Meta-analysis (신체활동에 대한 건강행동과정접근모델(Health Action Process Approach Model) 관련 변인의 효과: 체계적 문헌고찰 및 메타분석)

  • Choi, Yun;Yang, Sook Ja;Song, Hye Young
    • Research in Community and Public Health Nursing
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    • v.29 no.3
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    • pp.359-370
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    • 2018
  • Purpose: The purpose of this study is to identify effects of the variables of Health Action Process Approach (HAPA) Model on physical activity. Methods: This study has conducted a systematic literature review and meta-analysis. Sixteen articles were searched through electronic databases (PsycINFO, PubMed, CINAHL, Web of science, Science Direct, RISS, KMBASE, KoreaMed, KISS, DBpia) and additional journals from 2000 to July, 2017. To estimate the effect size (ES), the meta-analysis of the studies was performed by using Comprehensive Meta-Analysis programs. Results: The overall effect size of the variables of HAPA on physical activity was median (ES=.28). Of the core variables of HAPA model, action control (ES=.43) showed the largest effect size, followed by coping self-efficacy (ES=.31) and planning (ES=.31).Additional variables were identified as preparatory behavior (ES=.39) and past physical activity (ES=.24). Through the moderator effect analysis, the effect size was higher in the volitional phase than in the motivational phase, and higher in the healthy group than in the patient group. The higher the proportion of males and the lower the age, the larger the effect size. Conclusion: This finding shows empirical evidence that all core variables of the HAPA model are useful for predicting physical activity. We propose the use of the HAPA model to develop physical activity promotion intervention.

A Study on ROK Military PBL Using Simulation and Meta Model (시뮬레이션과 메타 모델을 이용한 한국군 성과기반군수 연구)

  • Won, Bong Yeon;Lee, Sang Jin
    • Journal of the Korea Society for Simulation
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    • v.28 no.1
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    • pp.81-91
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    • 2019
  • The ROK military uses Performance Based Logistics(PBL) as one of the ways to utilize civilian resources and advanced techniques. However, the Korean PBL is mainly focused on purchasing and repairing parts, which is not contributing to the improvement of the availability of overall system. The objective of this study is to suggest the methodology to evaluate the PBL metrics using the simulation and meta model. A meta model is a regression model to analyze the effect of the PBL through simulating various scenarios with performance metrics. As a result, if the PBL is limited to the part level, the performance has little influence on the availability of overall system. In addition, analysis using the meta model shows that it cannot achieve the performance targets when the same metrics are applied to various items without considering the characteristics of the applied items. Therefore, in order to improve availability, PBL coverage should be extended to a system level that includes key components that have a large impact on availability. If multiple items are included in the PBL coverage, the metrics should be applied differently, taking into account the characteristics of each item.