• Title/Summary/Keyword: Covering models

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The XRCC1 Arg280His Gene Polymorphism and Hepatocellular Carcinoma Risk: A Meta-analysis

  • Li, Lu-Ping;Wu, Wei;Li, Xing-Hai;Song, Shu-Sen
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.3
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    • pp.2033-2036
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    • 2013
  • Many studies have suggested that the XRCC1 Arg280His gene polymorphism might be involved in the development of hepatocellular carcinoma (HCC). However, the results have been inconsistent. In this study, the authors performed a meta-analysis to assess the association between XRCC1 Arg280His and HCC susceptibility. Published literature from PubMed, EMBASE and CNKI Data was searched. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed- or random-effects models when appropriate. Begg's test was used to measure publication bias. A total of 7 case-control studies covering 1,448 HCC cases and 1,544 controls were included. No significant variation in HCC risk was detected in any of the genetic models overall. In the stratified analysis, four studies with sample sizes over 300 produced similar results. The corresponding pooled ORs were not substantially altered after the exclusion of three studies deviating from Hardy-Weinberg equilibrium in the control group, which indicated reliability for our meta-analysis results.

Galaxy Clusters in ELAIS-N1 field

  • Hyun, Minhee;Im, Myungshin;Kim, Jae-Woo;Lee, Seong-Kook;Edge, Alastair C.
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.70.2-70.2
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    • 2014
  • Galaxy clusters, the largest gravitationally bound systems, are an important means to place constraints on cosmological models. Moreover, they are excellent places to test galaxy evolution models in connection to the environments. To this day, massive clusters have been found unexpectedly(Kang & Im 2009, Durret et al. 2011, Tashikawa et al. 2012) and evolution of galaxies in cluster have been still controversial (Elbaz et al. 2007, Cooper et al. 2008, Tran et al. 2009). Finding galaxy cluster candidates in a wide, deep imaging survey data will enable us to solve the such issues of modern extragalactic astronomy. We have used multi-wavelength data from the UKIRT Infrared Deep Sky Survey Deep Extragalactic Survey (UKIDSS DXS/J and K bands), Spitzer Wise-area InfraRed Extragalactic survey (SWIRE/two mid-infrared bands), the Panoramic Survey Telescope and Rapid Response System (PAN-STARRS/ g, r, i, z, y bands) and Infrared Medium-deep Survey(IMS/J band). We report new candidates of galaxy clusters and properties of their member galaxies in one of the wide and deep survey fields ELAIS-N1, European Large Area ISO Survey North1, covering sky area of $8.75deg^2$.

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NEW WALL DRAG AND FORM LOSS MODELS FOR ONE-DIMENSIONAL DISPERSED TWO-PHASE FLOW

  • KIM, BYOUNG JAE;LEE, SEUNG WOOK;KIM, KYUNG DOO
    • Nuclear Engineering and Technology
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    • v.47 no.4
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    • pp.416-423
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    • 2015
  • It had been disputed how to apply wall drag to the dispersed phase in the framework of the conventional two-fluid model for two-phase flows. Recently, Kim et al. [1] introduced the volume-averaged momentum equation based on the equation of a solid/fluid particle motion. They showed theoretically that for dispersed two-phase flows, the overall two-phase pressure drop by wall friction must be apportioned to each phase, in proportion to each phase fraction. In this study, the validity of the proposed wall drag model is demonstrated though one-dimensional (1D) simulations. In addition, it is shown that the existing form loss model incorrectly predicts the motion of the dispersed phase. A new form loss model is proposed to overcome that problem. The newly proposed form loss model is tested in the region covering the lower plenum and the core in a nuclear power plant. As a result, it is shown that the new models can correctly predict the relative velocity of the dispersed phase to the surrounding fluid velocity in the core with spacer grids.

A Study on the Development Model of Life-Type Tourism Destination - Focusing on the Japanese Practical Case - (농촌지역 생활형 (휴양)관광지 발전모델 연구 - 일본의 사례를 중심으로 -)

  • Park, Gu-Won
    • Journal of Korean Society of Rural Planning
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    • v.21 no.4
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    • pp.139-155
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    • 2015
  • This study was conducted to effectively develop rural tourism in Korea. For the purpose, tourism that can develop with local industries and cultures together was designated as life-type tourism and development models of such tourism were reviewed based on an understanding that province-oriented tourism is necessary. An analysis of three actual cases of Japan led to following results. First, life-type tourist destinations can be developed in connection with making local areas based on their special themes, can be developed in relation to their life cultures based on their peculiar life cultures and can be developed in creative forms using characteristic environment and organizational culture of those areas. In pursuing life-type tourist attractions, it will be possible to make practical development using it with those three basic models. Second, it is important to form a flow covering the entire regions based on their own special themes, to build cyclical structure of regions and tourism and tourism and industries and to create overall conditions that can help local residents get benefits and join together, in order to develop such life-type tourist destinations. Development of life-type resort tourist destinations needs roles of practical organizations that can effectively manage them, but such organizations should be dynamic and should be distant from management of money as much as possible.

TOWARDS A MODEL OF THE DIGITAL UNIVERSITY;A GENERALIZED NET MODEL FOR PRODUCING COURSE TIMETABLES

  • Shannon, A.;Orozova, D.;Sotirova, E.;Atanassov, K.;Krawczak, M.;Melo-Pinto, P.;Nikolov, R.;Sotirov, S.;Kim, T.
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2008.04a
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    • pp.299-305
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    • 2008
  • In a series of research papers, the authors have studied some of the most important models of a contemporary universities, such as: the research university, the entrepreneurial university and the digital university and construct their Generalized Net (GN) models. This paper is based on the case-studies of Sofia University, the Technical University of Munich and the University of Edinburgh. The main focus is to put the analysis of the processes of the functioning of a university which effectively integrates Information and Communication Technologies (ICT) in all university activities. A concrete example based on the process of course administration at University of Edinburgh is considered. This university is in a process of developing an integrated information system covering most of the university activities. The opportunity of using GNs as a tool for modeling such processes is analyzed as well.

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High redshift galaxy clusters in ELAIS-N1/N2 fields with a new color selection technique

  • Hyun, Minhee;Im, Myungshin;Kim, Jae-Woo;Lee, Seong-Kook
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.48.1-48.1
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    • 2014
  • Galaxy clusters, the largest gravitationally bound systems, are an important means to place constraints on cosmological models. Moreover, they are excellent places to test galaxy evolution models in connection to the environments. To this day, massive clusters have been found unexpectedly(Kang & Im 2009, Durret et al. 2011, Tashikawa et al. 2012) and evolution of galaxies in cluster have been still controversial (Elbaz et al. 2007, Cooper et al. 2008, Tran et al. 2009). Finding galaxy cluster candidates at z>1 in a wide, deep imaging survey data will enable us to solve the such issues of modern extragalactic astronomy. We report new candidates of galaxy clusters and their physical properties in one of the wide and deep survey fields, European Large Area ISO Survey North1(ELAIS-N1) and North2(ELAIS-N2) fields, covering sky area of and each. We also suggest a new useful color selection technique to separate 1 < z < 2 galaxies from low-z galaxies by combining multi-wavelength data from the UKIRT Infrared Deep Sky Survey Deep Extragalactic Survey (UKIDSS DXS/J and K band), Spitzer Wise-area InfraRed Extragalactic survey (SWIRE/two mid-infrared bands), Canada France Hawaii Telescope (CFHT/z band), Issac Newton Telescope(INT/ u, g, r, i, z band) and Infrared Medium-deep Survey(IMS/J band).

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Finite Element Analysis of Inelastic Behavior of SRC Composite Piers (SRC 합성교각의 비탄성거동에 대한 유한요소해석)

  • Shim, Chang-Su;Han, Jung-Hoon;Park, Chang-Kyu;Chung, Young-Soo
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.269-275
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    • 2006
  • In the design of bridge piers in seismic area, the ductility requirement is one of the most important design criteria. In order to enhance the seismic performance of RC columns, it is necessary to make the ductility of columns larger by covering RC columns with steel tubes or confining RC columns by arranging transverse reinforcement such as hoop ties closely. Concrete encased composite columns can be utilized for bridge piers especially in seismic area. In this paper, finite element analyses are performed to study the nonlinear behavior of concrete encased composite columns with single core steel or multiple steel elements under static and quasi-static loads. The cross-sections of these specimens ate composed of concrete-encased H-shaped structural steel columns and a concrete-encased circular tube with partial in-filled concrete. Test parameters were the amount of the transverse reinforcement, encased steel member, and loading axis. Through the comparison between FE analyses and test results, adequate material models for confined concrete and unconfined concrete ate investigated. After getting the proper analysis models for composite columns, several parameters are considered to suggest design considerations on the details of composite piers.

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Dynamic Interaction between Conditional Stock Market Volatility and Macroeconomic Uncertainty of Bangladesh

  • ALI, Mostafa;CHOWDHURY, Md. Ali Arshad
    • Asian Journal of Business Environment
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    • v.11 no.4
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    • pp.17-29
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    • 2021
  • Purpose: The aim of this study is to explore the dynamic linkage between conditional stock market volatility and macroeconomic uncertainty of Bangladesh. Research design, data, and methodology: This study uses monthly data covering the time period from January 2005 to December 2018. A comprehensive set of macroeconomic variables, namely industrial production index (IP), consumer price index (CPI), broad money supply (M2), 91-day treasury bill rate (TB), treasury bond yield (GB), exchange rate (EX), inflow of foreign remittance (RT) and stock market index of DSEX are used for analysis. Symmetric and asymmetric univariate GARCH family of models and multivariate VAR model, along with block exogeneity and impulse response functions, are implemented on conditional volatility series to discover the possible interactions and causal relations between macroeconomic forces and stock return. Results: The analysis of the study exhibits time-varying volatility and volatility persistence in all the variables of interest. Moreover, the asymmetric effect is found significant in the stock return and most of the growth series of macroeconomic fundamentals. Results from the multivariate VAR model indicate that only short-term interest rate significantly influence the stock market volatility, while conditional stock return volatility is significant in explaining the volatility of industrial production, inflation, and treasury bill rate. Conclusion: The findings suggest an increasing interdependence between the money market and equity market as well as the macroeconomic fundamentals of Bangladesh.

Novel nonlinear stiffness parameters and constitutive curves for concrete

  • Al-Rousan, Rajai Z.;Alhassan, Mohammed A.;Hejazi, Moheldeen A.
    • Computers and Concrete
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    • v.22 no.6
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    • pp.539-550
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    • 2018
  • Concrete is highly non-linear material which is originating from the transition zone in the form of micro-cracks, governs material response under various loadings. In this paper, the constitutive models published by many researchers have been used to generate novel stiffness parameters and constitutive curves for concrete. Following such linear material formulations, where the energy is conservative during the curvature, and a nonlinear contribution to the concrete has been made and investigated. In which, nonlinear concrete elastic modulus modeling has been developed that is capable-of representing concrete elasticity for grades ranging from 10 to 140 MPa. Thus, covering the grades range of concrete up to the ultra-high strength concrete, and replacing many concrete models that are valid for narrow ranges of concrete strength grades. This has been followed by the introduction of the nonlinear Hooke's law for the concrete material through the replacement of the Young constant modulus with the nonlinear modulus. In addition, the concept of concrete elasticity index (${\varphi}$) has been proposed and this factor has been introduced to account for the degradation of concrete stiffness in compression under increased loading as well as the multi-stages micro-cracking behavior of concrete under uniaxial compression. Finally, a sub-routine artificial neural network model has been developed to capture the concrete behavior that has been introduced to facilitate the prediction of concrete properties under increased loading.

Trends of Encrypted Network Traffic Analysis Technologies for Network Anomaly Detection (네트워크 이상행위 탐지를 위한 암호트래픽 분석기술 동향)

  • Y.S. Choi;J.H. Yoo;K.J. Koo;D.S. Moon
    • Electronics and Telecommunications Trends
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    • v.38 no.5
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    • pp.71-80
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    • 2023
  • With the rapid advancement of the Internet, the use of encrypted traffic has surged in order to protect data during transmission. Simultaneously, network attacks have also begun to leverage encrypted traffic, leading to active research in the field of encrypted traffic analysis to overcome the limitations of traditional detection methods. In this paper, we provide an overview of the encrypted traffic analysis field, covering the analysis process, domains, models, evaluation methods, and research trends. Specifically, it focuses on the research trends in the field of anomaly detection in encrypted network traffic analysis. Furthermore, considerations for model development in encrypted traffic analysis are discussed, including traffic dataset composition, selection of traffic representation methods, creation of analysis models, and mitigation of AI model attacks. In the future, the volume of encrypted network traffic will continue to increase, particularly with a higher proportion of attack traffic utilizing encryption. Research on attack detection in such an environment must be consistently conducted to address these challenges.