• Title/Summary/Keyword: Meta-model

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Lack of Associations of the COMT Val158Met Polymorphism with Risk of Endometrial and Ovarian Cancer: a Pooled Analysis of Case-control Studies

  • Liu, Jin-Xin;Luo, Rong-Cheng;Li, Rong;Li, Xia;Guo, Yu-Wu;Ding, Da-Peng;Chen, Yi-Zhi
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6181-6186
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    • 2014
  • This meta-analysis was conducted to examine whether the genotype status of Val158Met polymorphism in catechol-O-methyltransferase (COMT) is associated with endometrial and ovarian cancer risk. Eligible studies were identified by searching several databases for relevant reports published before January 1, 2014. Pooled odds ratios (ORs) were appropriately derived from fixed-effects or random-effects models. In total, 15 studies (1,293 cases and 2,647 controls for ovarian cancer and 2,174 cases and 2,699 controls for endometrial cancer) were included in the present meta-analysis. When all studies were pooled into the meta-analysis, there was no evidence for significant association between COMT Val158Met polymorphism and ovarian cancer risk (Val/Met versus Val/Val: OR=0.91, 95% CI=0.76-1.08; Met/Met versus Val/Val: OR=0.90, 95% CI=0.73-1.10; dominant model: OR=0.90, 95% CI=0.77-1.06; recessive model: OR=0.95, 95% CI=0.80-1.13). Similarly, no associations were found in all comparisons for endometrial cancer (Val/Met versus Val/Val: OR 0.97, 95% CI=0.77-1.21; Met/Met versus Val/Val: OR=1.02, 95% CI=0.73-1.42; dominant model: OR=0.98, 95% CI=0.77-1.25; recessive model: OR=1.02, 95% CI=0.87-1.20). In the subgroup analyses by source of control and ethnicity, no significant associations were found in any subgroup of population. This meta-analysis strongly suggests that COMT Val158Met polymorphism is not associated with increased endometrial and ovarian cancer risk.

MTHFR Polymorphisms and Pancreatic Cancer Risk:Lack of Evidence from a Meta-analysis

  • Li, Lei;Wu, Sheng-Di;Wang, Ji-Yao;Shen, Xi-Zhong;Jiang, Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.2249-2252
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    • 2012
  • Objective: Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms have been reported to be associated with pancreatic cancer, but the published studies had yielded inconsistent results.We therefore performed the present meta-analysis. Methods: A search of Google scholar, PubMed, Cochrane Library and CNKI databases before April 2012 was conducted to summarize associations of MTHFR polymorphisms with pancreatic cancer risk. Assessment was with odds ratios (ORs) and 95% confidence intervals (CIs). Publication bias were also calculated. Results: Four relative studies on MTHFR gene polymorphisms (C667T and A1298C) were involved in this meta-analysis. Overall, C667T(TT vs. CC : OR = 1.61, 95%CI = 0.78 - 3.34; TT vs. CT : OR = 1.41, 95%CI = 0.88-2.25; dominant model: OR = 0.68, 95%CI = 0.40-1.17; recessive model: OR = 0.82, 95%CI = 0.52-1.30) and A1298C(CC vs. AA:OR=1.01, 95%CI=0.47-2.17; CC vs. AC: OR=0.99,95%CI=0.46-2.14; dominant model: OR=1.01, 95%CI = 0.47-2.20; recessive model: OR = 1.01, 95%CI = 0.80-1.26) did not increase pancreatic cancer risk. Conclusion: This meta-analysis indicated that MTHFR polymorphisms (C667T and A1298C) were not associated with pancreatic cancer risk.

A Meta-analysis and Review of External Factors based on the Technology Acceptance Model : Focusing on the Journals Related to Smartphone in Korea (기술수용모델 선행요인에 관한 문헌적 고찰 및 메타분석)

  • Nam, Soo-Tai;Shin, Seong-Yoon;Jin, Chan-Yong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.4
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    • pp.848-854
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    • 2014
  • A Meta-analysis refers to a statistical literature synthesis method from the quantitative results of many known empirical studies. We conducted a meta-analysis and review of external factors based on the technology acceptance model for Smartphone-related researches. This study surveyed 106 research papers that established causal relationships in the technology acceptance model published in Korean academic journals during 2008 and 2013. The result of the meta-analysis might be summarized that the playfulness has the highest effect size in the path from external factors to the perceived usefulness, with the effect size(0.536). Also the self efficacy showed the highest effect size(0.626) in the path from external factors to the perceived ease of use. Based on these findings, several theoretical and practical implications were suggested and discussed with the difference from previous researches.

Approximate Optimization Based on Meta-model for Weight Minimization Design of Ocean Automatic Salt Collector (해양자동채염기의 최소중량설계를 위한 메타모델 기반 근사최적화)

  • Song, Chang Yong
    • Journal of Convergence for Information Technology
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    • v.11 no.1
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    • pp.109-117
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    • 2021
  • In this paper, the meta-model based approximate optimization was carried out for the structure design of an ocean automatic salt collector in order to minimize the structure weight. The structural analysis was performed by using the finite element method to evaluate the strength performance of the ocean automatic salt collector in its initial design. In the structural analysis, it was evaluated the strength performance of the design load conditions. The optimum design problem was formulated so that design variables of main structure thickness would be determined by minimizing the structure weight subject to strength performance constraints. The meta-models used in the approximate optimization were the response surface method, Kriging model, and Chebyshev orthogonal polynomials. Regarding to the numerical characteristics, the solution results from approximate optimization techniques were compared to the results of non-approximate optimization. The Chebyshev orthogonal polynomials among the meta-models used in the approximate optimization showed the most appropriate optimum design results for the structure design of the ocean automatic salt collector.

A Comparison of Meta-learning and Transfer-learning for Few-shot Jamming Signal Classification

  • Jin, Mi-Hyun;Koo, Ddeo-Ol-Ra;Kim, Kang-Suk
    • Journal of Positioning, Navigation, and Timing
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    • v.11 no.3
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    • pp.163-172
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    • 2022
  • Typical anti-jamming technologies based on array antennas, Space Time Adaptive Process (STAP) & Space Frequency Adaptive Process (SFAP), are very effective algorithms to perform nulling and beamforming. However, it does not perform equally well for all types of jamming signals. If the anti-jamming algorithm is not optimized for each signal type, anti-jamming performance deteriorates and the operation stability of the system become worse by unnecessary computation. Therefore, jamming classification technique is required to obtain optimal anti-jamming performance. Machine learning, which has recently been in the spotlight, can be considered to classify jamming signal. In general, performing supervised learning for classification requires a huge amount of data and new learning for unfamiliar signal. In the case of jamming signal classification, it is difficult to obtain large amount of data because outdoor jamming signal reception environment is difficult to configure and the signal type of attacker is unknown. Therefore, this paper proposes few-shot jamming signal classification technique using meta-learning and transfer-learning to train the model using a small amount of data. A training dataset is constructed by anti-jamming algorithm input data within the GNSS receiver when jamming signals are applied. For meta-learning, Model-Agnostic Meta-Learning (MAML) algorithm with a general Convolution Neural Networks (CNN) model is used, and the same CNN model is used for transfer-learning. They are trained through episodic training using training datasets on developed our Python-based simulator. The results show both algorithms can be trained with less data and immediately respond to new signal types. Also, the performances of two algorithms are compared to determine which algorithm is more suitable for classifying jamming signals.

Common Variants in the PALB2 Gene Confer Susceptibility to Breast Cancer: a Meta-analysis

  • Zhang, Yi-Xia;Wang, Xue-Mei;Kang, Shu;Li, Xiang;Geng, Jing
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7149-7154
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    • 2013
  • Objective: Increasing scientific evidence suggests that common variants in the PALB2 gene may confer susceptibility to breast cancer, but many studies have yielded inconclusive results. This meta-analysis aimed to derive a more precise estimation of the relationship between PALB2 genetic variants and breast cancer risk. Methods: An extensive literary search for relevant studies was conducted in PubMed, Embase, Web of Science, Cochrane Library, CISCOM, CINAHL, Google Scholar, CNKI and CBM databases from their inception through September 1st, 2013. A meta-analysis was performed using the STATA 12.0 software and crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Results: Six case-control studies were included with a total of 4,499 breast cancer cases and 6,369 healthy controls. Our meta-analysis reveals that PALB2 genetic variants may increase the risk of breast cancer (allele model: OR>1.36, 95%CI: 1.20~1.52, P < 0.001; dominant model: OR>1.64, 95%CI: 1.42~1.91, P < 0.001; respectively). Subgroup analyses by ethnicity indicated PALB2 genetic variants were associated with an increased risk of breast cancer among both Caucasian and Asian populations (all P < 0.05). No publication bias was detected in this meta-analysis (all P > 0.05). Conclusion: The current meta-analysis indicates that PALB2 genetic variants may increase the risk of breast cancer. Thus, detection of PALB2 genetic variants may be a promising biomarker approach.

A Study on the Meta Evaluation for Defense R&D Programs (국방Bt&D사업 자체평가시스템 메타평가)

  • Kim, Soon-Yeong;Ha, Kyu-Soo
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.32 no.3
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    • pp.59-70
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    • 2009
  • This study is the result of meta evaluation for the self evaluation of defense R&D programs in Korea by using meta evaluating indicators. The overall meta evaluation result of defense R&D programs gained 74.3 points out of 100, so it was evaluated as 'Good'. But it demonstrated that further improvement for overall system of defense R&D programs evaluation is required. And especially, it demonstrated that more alternatives are necessary in order to improve the utilizations and the feedbacks of evaluation results. The evaluation context component gained 80.2 points out of 100, so it was evaluated as 'Very Good'. The evaluation input component gained 73.1 points out of 100, so it was evaluated as 'Good'. The evaluation process component gained 74.8 points out of 100, so it was evaluated as 'Good'. And the evaluation outcome component gained 69.0 points out of 100, so it was evaluated as 'Good'. Basic model of meta evaluation was derived from the literature review and brain storming. And this meta evaluation model was determined by adopting the result of experts who performed evaluations for defense R&D programs in recent years. The reliability of components and items was verified by Cronbach's a coefficient. It was over 0.6 in evaluation components and items. And the reliability of evaluation context was 0.877, that of evaluation input was 0.755, that of evaluation process was 0.755, that of evaluation output was 0.755 respectively. From the analysis, it is attempted to identify possible problems and to find out the ways of improvements related to the self evaluation system of defense R&D programs. The ultimate objective of this study is to manage the programs effectively and improve the reliability and the objectiveness of the defense R&D programs.

Development and application of prediction model of hyperlipidemia using SVM and meta-learning algorithm (SVM과 meta-learning algorithm을 이용한 고지혈증 유병 예측모형 개발과 활용)

  • Lee, Seulki;Shin, Taeksoo
    • Journal of Intelligence and Information Systems
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    • v.24 no.2
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    • pp.111-124
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    • 2018
  • This study aims to develop a classification model for predicting the occurrence of hyperlipidemia, one of the chronic diseases. Prior studies applying data mining techniques for predicting disease can be classified into a model design study for predicting cardiovascular disease and a study comparing disease prediction research results. In the case of foreign literatures, studies predicting cardiovascular disease were predominant in predicting disease using data mining techniques. Although domestic studies were not much different from those of foreign countries, studies focusing on hypertension and diabetes were mainly conducted. Since hypertension and diabetes as well as chronic diseases, hyperlipidemia, are also of high importance, this study selected hyperlipidemia as the disease to be analyzed. We also developed a model for predicting hyperlipidemia using SVM and meta learning algorithms, which are already known to have excellent predictive power. In order to achieve the purpose of this study, we used data set from Korea Health Panel 2012. The Korean Health Panel produces basic data on the level of health expenditure, health level and health behavior, and has conducted an annual survey since 2008. In this study, 1,088 patients with hyperlipidemia were randomly selected from the hospitalized, outpatient, emergency, and chronic disease data of the Korean Health Panel in 2012, and 1,088 nonpatients were also randomly extracted. A total of 2,176 people were selected for the study. Three methods were used to select input variables for predicting hyperlipidemia. First, stepwise method was performed using logistic regression. Among the 17 variables, the categorical variables(except for length of smoking) are expressed as dummy variables, which are assumed to be separate variables on the basis of the reference group, and these variables were analyzed. Six variables (age, BMI, education level, marital status, smoking status, gender) excluding income level and smoking period were selected based on significance level 0.1. Second, C4.5 as a decision tree algorithm is used. The significant input variables were age, smoking status, and education level. Finally, C4.5 as a decision tree algorithm is used. In SVM, the input variables selected by genetic algorithms consisted of 6 variables such as age, marital status, education level, economic activity, smoking period, and physical activity status, and the input variables selected by genetic algorithms in artificial neural network consist of 3 variables such as age, marital status, and education level. Based on the selected parameters, we compared SVM, meta learning algorithm and other prediction models for hyperlipidemia patients, and compared the classification performances using TP rate and precision. The main results of the analysis are as follows. First, the accuracy of the SVM was 88.4% and the accuracy of the artificial neural network was 86.7%. Second, the accuracy of classification models using the selected input variables through stepwise method was slightly higher than that of classification models using the whole variables. Third, the precision of artificial neural network was higher than that of SVM when only three variables as input variables were selected by decision trees. As a result of classification models based on the input variables selected through the genetic algorithm, classification accuracy of SVM was 88.5% and that of artificial neural network was 87.9%. Finally, this study indicated that stacking as the meta learning algorithm proposed in this study, has the best performance when it uses the predicted outputs of SVM and MLP as input variables of SVM, which is a meta classifier. The purpose of this study was to predict hyperlipidemia, one of the representative chronic diseases. To do this, we used SVM and meta-learning algorithms, which is known to have high accuracy. As a result, the accuracy of classification of hyperlipidemia in the stacking as a meta learner was higher than other meta-learning algorithms. However, the predictive performance of the meta-learning algorithm proposed in this study is the same as that of SVM with the best performance (88.6%) among the single models. The limitations of this study are as follows. First, various variable selection methods were tried, but most variables used in the study were categorical dummy variables. In the case with a large number of categorical variables, the results may be different if continuous variables are used because the model can be better suited to categorical variables such as decision trees than general models such as neural networks. Despite these limitations, this study has significance in predicting hyperlipidemia with hybrid models such as met learning algorithms which have not been studied previously. It can be said that the result of improving the model accuracy by applying various variable selection techniques is meaningful. In addition, it is expected that our proposed model will be effective for the prevention and management of hyperlipidemia.

Efficacy of probiotics for managing infantile colic due to their anti-inflammatory properties: a meta-analysis and systematic review

  • Shirazinia, Reza;Golabchifar, Ali Akbar;Fazeli, Mohammad Reza
    • Clinical and Experimental Pediatrics
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    • v.64 no.12
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    • pp.642-651
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    • 2021
  • Background: Infantile colic (IC) is excessive crying in otherwise healthy children. Despite vast research efforts, its etiology remains unknown. Purpose: Most treatments for IC carry various side effects. The collection of evidence may inform researchers of new strategies for the management and treatment of IC as well as new clues for understanding its pathogenesis. This review and meta-analysis aimed to evaluate the efficacy and possible mechanisms of probiotics for mananaging IC. Methods: Ten papers met the study inclusion and exclusion criteria, and the meta-analysis was conducted using Review Manager (RevMan) software and a random-effects model. Results: This meta-analysis revealed that probiotics are effective for treating infantile colic, while the review showed that this efficacy may be due to their anti-inflammatory effects. Conclusion: Probiotics may be an important treatment option for managing infantile colic due to their anti-inflammatory properties.

Effects of Hormone Replacement Therapy on Motor Functions in Postmenopausal Women: A Systematic Reviews and Meta-Analysis (호르몬 대체 요법 제공이 폐경기 이후 여성들의 운동기능에 미치는 영향: 체계적 문헌고찰 및 메타분석 연구)

  • Lee, Hanall;Park, Young-Min;Kang, Nyeonju
    • Korean Journal of Applied Biomechanics
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    • v.32 no.2
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    • pp.56-68
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    • 2022
  • Objective: The purpose of this systematic review and meta-analysis was to investigate potential effects of HRT (hormone replacement therapy) on motor functions in postmenopausal women. Method: In this meta-analysis, 19 studies that examined changes in motor functions between postmenopausal women with and without HRT intervention were qualified. We additionally conducted moderator variable analyses including: (1) motor function type, (2) hormone type, and (3) duration of HRT intervention. Results: The random effects model showed no significant overall effects (SMD = 0.199; SE = 0.115; 95% CI = -0.026~0.425; Z = 1.730; p = 0.084; I2 = 93.258%). Additional three moderator variable analyses revealed no significant effect sizes indicating that specific HRT protocols did not improve different motor functions in postmenopausal women. Conclusion: These meta-analytic findings suggest that HRT had no positive effects on motor functions in postmenopausal women.