• 제목/요약/키워드: Empirical power

검색결과 947건 처리시간 0.021초

Identification of the associations between genes and quantitative traits using entropy-based kernel density estimation

  • Yee, Jaeyong;Park, Taesung;Park, Mira
    • Genomics & Informatics
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    • 제20권2호
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    • pp.17.1-17.11
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    • 2022
  • Genetic associations have been quantified using a number of statistical measures. Entropy-based mutual information may be one of the more direct ways of estimating the association, in the sense that it does not depend on the parametrization. For this purpose, both the entropy and conditional entropy of the phenotype distribution should be obtained. Quantitative traits, however, do not usually allow an exact evaluation of entropy. The estimation of entropy needs a probability density function, which can be approximated by kernel density estimation. We have investigated the proper sequence of procedures for combining the kernel density estimation and entropy estimation with a probability density function in order to calculate mutual information. Genotypes and their interactions were constructed to set the conditions for conditional entropy. Extensive simulation data created using three types of generating functions were analyzed using two different kernels as well as two types of multifactor dimensionality reduction and another probability density approximation method called m-spacing. The statistical power in terms of correct detection rates was compared. Using kernels was found to be most useful when the trait distributions were more complex than simple normal or gamma distributions. A full-scale genomic dataset was explored to identify associations using the 2-h oral glucose tolerance test results and γ-glutamyl transpeptidase levels as phenotypes. Clearly distinguishable single-nucleotide polymorphisms (SNPs) and interacting SNP pairs associated with these phenotypes were found and listed with empirical p-values.

창의적 융복합 『미래융합IT인문학』 교과목 개발 및 운영 효과성 검증 (Creative Convergence Course 『Future Confluence IT Humanities』 Development and Operational Effectiveness Verification)

  • 최은선;고전;최근배;김희필;이호수;박남제
    • 한국멀티미디어학회논문지
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    • 제24권4호
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    • pp.569-582
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    • 2021
  • Education emphasizes problem-solving skills based on convergent thinking power in an era of rising uncertainty and rapid progress. This paper proactively designed e-Learning team teaching convergence liberal arts courses for prospective teachers by these social needs. It analyzed the empirical effects on the operation of the subjects to foster future talent who can converge and apply knowledge in various fields. The curriculum consisted of professors of mathematics, practical Arts, computer, and education, and was operated to convey convergent knowledge of information technology and humanities, and consisted of 15 liberal arts courses at J University. Besides, textbooks and teaching materials were also developed by the faculty. As a result of the primary research, prospective teachers who took the course generally showed high satisfaction with the class, especially for the faculty. The students' overall convergent thinking ability has increased to a statistically significant level (p<.01), and the students' major has been found to be irrelevant. On the other hand, it can be seen that communication, content convergence, and caring factors, excluding creativity factor, have all risen to a significant level.

Improved prediction model for H2/CO combustion risk using a calculated non-adiabatic flame temperature model

  • Kim, Yeon Soo;Jeon, Joongoo;Song, Chang Hyun;Kim, Sung Joong
    • Nuclear Engineering and Technology
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    • 제52권12호
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    • pp.2836-2846
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    • 2020
  • During severe nuclear power plant (NPP) accidents, a H2/CO mixture can be generated in the reactor pressure vessel by core degradation and in the containment as well by molten corium-concrete interaction. In spite of its importance, a state-of-the-art methodology predicting H2/CO combustion risk relies predominantly on empirical correlations. It is therefore necessary to develop a proper methodology for flammability evaluation of H2/CO mixtures at ex-vessel phases characterized by three factors: CO concentration, high temperature, and diluents. The developed methodology adopted Le Chatelier's law and a calculated non-adiabatic flame temperature model. The methodology allows the consideration of the individual effect of the heat transfer characteristics of hydrogen and carbon monoxide on low flammability limit prediction. The accuracy of the developed model was verified using experimental data relevant to ex-vessel phase conditions. With the developed model, the prediction accuracy was improved substantially such that the maximum relative prediction error was approximately 25% while the existing methodology showed a 76% error. The developed methodology is expected to be applicable for flammability evaluation in chemical as well as NPP industries.

Comparison of Machine Learning Analysis on Predictive Factors of Children's Planning-Organizing Executive Function by Income Level: Through Home Environment Quality and Wealth Factors

  • Lim, Hye-Kyung;Kim, Hyun-Ok;Park, Hae-Seon
    • 인간식물환경학회지
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    • 제24권6호
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    • pp.651-662
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    • 2021
  • Background and objective: This study identifies whether children's planning-organizing executive function can be significantly classified and predicted by home environment quality and wealth factors. Methods: For empirical analysis, we used the data collected from the 10th Panel Study on Korean Children in 2017. Using machine learning tools such as support vector machine (SVM) and random forest (RF), we evaluated the accuracy of the model in which home environment factors classify and predict children's planning-organizing executive functions, and extract the relative importance of variables that determine these executive functions by income group. Results: First, SVM analysis shows that home environment quality and wealth factors show high accuracy in classification and prediction in all three groups. Second, RF analysis shows that estate had the highest predictive power in the high-income group, followed by income, asset, learning, reinforcement, and emotional environment. In the middle-income group, emotional environment showed the highest score, followed by estate, asset, reinforcement, and income. In the low-income group, estate showed the highest score, followed by income, asset, learning, reinforcement, and emotional environment. Conclusion: This study confirmed that home environment quality and wealth factors are significant factors in predicting children's planning-organizing executive functions.

천수 효과가 대형 컨테이너선의 저항 성능에 미치는 영향에 관한 전산유체역학 해석 연구 (Shallow Water Effect on Resistance Performance of Large Container Ship Based on CFD Analysis)

  • 이선규;유영준;김진해
    • 대한조선학회논문집
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    • 제59권6호
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    • pp.345-354
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    • 2022
  • It is easy for a ship passing through confined waters to be exposed in dangers of collisions and grounding due to different hydrodynamic responses. Since marine accidents can cause significant impacts on environments, global economy, and human lives, it is necessary to study the effect of shallow water on hydrodynamic performance of a ship. In this paper, the effect of water depth on resistance performance was investigated using CFD analysis as an initial study for improving navigational safety of a large container ship under confined waters. After a CFD set-up for deep water condition was validated and verified by comparing CFD analysis with model test results, CFD calculations according to ship speed and water depth were conducted. The features were investigated in terms of tendency and physical knowledge related to resistance performance. The increase of resistance due to shallow water effect was reviewed with empirical formula suggested from SWABE JIP. Speed loss due to shallow water effect was additionally reviewed from estimated delivered power according to ship speed and water depth.

Application of data driven modeling and sensitivity analysis of constitutive equations for improving nuclear power plant safety analysis code

  • ChoHwan Oh;Doh Hyeon Kim;Jeong Ik Lee
    • Nuclear Engineering and Technology
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    • 제55권1호
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    • pp.131-143
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    • 2023
  • Constitutive equations in a nuclear reactor safety analysis code are mostly empirical correlations developed from experiments, which always accompany uncertainties. The accuracy of the code can be improved by modifying the constitutive equations fitting wider range of data with less uncertainty. Thus, the sensitivity of the code with respect to the constitutive equations is evaluated quantitatively in the paper to understand the room for improvement of the code. A new methodology is proposed which first starts by dividing the thermal hydraulic conditions into multiple sub-regimes using self-organizing map (SOM) clustering method. The sensitivity analysis is then conducted by multiplying an arbitrary set of coefficients to the constitutive equations for each sub-divided thermal-hydraulic regime with SOM to observe how the code accuracy varies. The randomly chosen multiplier coefficient represents the uncertainty of the constitutive equations. Furthermore, the set with the smallest error with the selected experimental data can be obtained and can provide insight which direction should the constitutive equations be modified to improve the code accuracy. The newly proposed method is applied to a steady-state experiment and a transient experiment to illustrate how the method can provide insight to the code developer.

Revisiting the Nexus of Foreign Direct Investment, Financial Development, and Economic Growth: The Case of Emerging Economies

  • KUMAR, Jai;SOOMRO, Ahmed Nawaz;KUMARI, Joti
    • The Journal of Asian Finance, Economics and Business
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    • 제9권1호
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    • pp.203-211
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    • 2022
  • Foreign direct investment (FDI) has increased at an exponential rate during the last two decades. It is now a feature of emerging market economies as well. Foreign direct investment and financial development are important factors in an economy's growth. Various studies have examined the impact of foreign direct investment and financial development on economic growth in different countries and areas. However, the findings are currently inconclusive. Using updated data from 1970 to 2020, this study will examine the relationships between FDI, financial development, and economic growth in 30 rising economies.GDP is the dependent variable, while FDI, financial development, trade openness, infrastructure, exchange rate, and GDP growth are the independent factors. To estimate the panel data, we used the most recent econometric models. The study's major findings suggest that FDI and financial development are critical determinants in emerging economies' economic progress. Furthermore, multiple robustness checks supported the study's empirical findings. The results of this study include various practical recommendations for investors, governments, and policymakers, given the increased interest in global economic integration and member states' reliance on FDI as a critical aspect of sustaining prosperity.

The Effect of Institutional Capability on Entrepreneurship Education: An Empirical Study of Vietnamese Universities

  • NGUYEN, Trong Luan;NGUYEN, Trung Hau;THACH, Thao Vy;TRAN, Doan Vy;HOANG, Nguyen Huong Giang;PHAM, Ngoc Phuong Trang
    • The Journal of Asian Finance, Economics and Business
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    • 제9권1호
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    • pp.363-372
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    • 2022
  • Entrepreneurs are valuable assets for any country. Rather than being confronted with new obstacles, they should be fostered and nurtured. Entrepreneurial firms have the power to influence how we live and work, in addition to producing jobs and contributing to economic progress. Entrepreneurs have the ability to change the world by creating diversified skill sets and profitable businesses that are vital to the advancement of our economies. How does one go about being a successful business, though? More resources are believed to be needed to create entrepreneurial environments in higher education that foster progressive ideas and innovation while also providing students with the practical knowledge and skills they need to navigate the troublesome, difficult, and uncertain situations that come with owning a business. This article will outline the scales of components from which to measure variables impacting universities' ability to encourage entrepreneurial behavior among students, based on the aforementioned significance of universities. This article is based on a survey of 507 students from different universities and backgrounds in Vietnam. The research methods used are Cronbach's alpha test and Structural Equation Modeling. From the research results, it can be seen that the university's environment plays a significant role in fostering entrepreneurial behavior among students.

확률론적 안전성평가를 위한 일반 기기 신뢰도 데이타 베이스 구축 절차와 적용 (Development Procedure of Generic Component Reliability Data Base in PSA and Its Application)

  • 황미정;김길유;임태진;정원대;김태운
    • 한국안전학회지
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    • 제12권4호
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    • pp.241-248
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    • 1997
  • 건설중이거나 기기 이력이 부족한 원자력 발전소에 대한 확률론적 안전성평가에 사용되는 일반 기기 신뢰도 데이타를 기 개발된 일반 데이타 및 발전소 데이타를 취합하여 구한다. 이를 위해 본 논문에서 사용한 계산 Code는 모수적 선험적 베이지안 방법에 근거하여 3단계 베이지안 방법으로 한국 원자력연구소에서 개발한 MPRDP Code이다. 일반 자료원에서 주로 자료를 취합하였으므로 각 문헌들 사이에 존재할 수 있는 종속성을 고려하여 Code에서 처리하였다. 본 논문에서는 결과로 얻어진 기기 신뢰도 자료표의 일부분을 보여준다.

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Electronic Theses and Dissertations' Development in University Libraries in Nigeria

  • Jerry Eyerinmene Friday;Constance Timi-pere Afamukoro
    • International Journal of Knowledge Content Development & Technology
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    • 제14권1호
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    • pp.75-110
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    • 2024
  • The study was meant to examine electronic theses and dissertations' development in Nigerian federal university libraries. The study adopted descriptive survey research design. The study population comprised forty-eight institutional repository librarians in eighteen Nigerian federal university libraries. The sample consisted of forty three librarians. A questionnaire was used for data collection. The data collected were analyzed with mean and standard deviation. Findings reveal that the policies available for developing electronic theses and dissertations (ETDs) in the libraries require submission of electronic copies of theses and dissertations by students, participation of digital/IR librarians in ETD development and provision of free access to ETDs; the libraries comply with standards of Open Archives Initiative Protocol for Metadata Harvesting and Search/Retrieval via URL using DSpace for building ETDs and taking advantage of such available ICT facilities as computers, scanners, CD-ROM, LAN, internet connectivity and printer. The libraries achieve ETD through digitisation, mandating submission of electronic versions of TDs by students and creation of IR. However, the process is hindered by technological obsolescence, financial problems, absence of clearly-defined ETD development policy, required ICT facilities and trained staff, copyright, irregular power supply and unstable internet connectivity. This study represents a fresh empirical investigation into electronic theses and dissertations' development in federal university libraries in Nigeria.