• Title/Summary/Keyword: Linear hypothesis

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The Effects of Ownership Concentration on Savings Bank Diversification by using Panel Data (패널데이터를 이용한 저축은행 소유집중도와 다각화)

  • Bae, Soo Hyun
    • The Journal of the Convergence on Culture Technology
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    • v.5 no.2
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    • pp.77-82
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    • 2019
  • The purpose of this study is to analyze the relationship between the controlling shareholding ratio and the business diversification of savings banks The difference in this study is the analysis of the relationship between the controlling shareholding ratio of the savings bank and the business diversification using panel data. In this study, the semi-annual financial statements for the period 2014-2018 were used on the basis of a sample of 79 saving banks. The research model is analyzed using random effects generalized linear square (GLS) model considering the autocorrelation problem. As a result of the empirical analysis, it is estimated that the relationship between the controlling shareholding ratio of the savings bank and the business diversification is significant (+). This is the result of supporting the hedging hypothesis.

The Evaluation of Axial Stress in Continuous Welded Rails via Three-Dimensional Bridge-Track Interaction

  • Manovachirasan, Anaphat;Suthasupradit, Songsak;Choi, Jun-Hyeok;Kim, Bum-Joon;Kim, Ki-Du
    • International journal of steel structures
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    • v.18 no.5
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    • pp.1617-1630
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    • 2018
  • The crucial differences between conventional rail with split-type connectors and continuous welded rails are axial stress in the longitudinal direction and stability, as well as other issues generated under the influence of loading effects. Longitudinal stresses generated in continuously welded rails on railway bridges are strongly influenced by the nonlinear behavior of the supporting system comprising sleepers and ballasts. Thus, the track structure interaction cannot be neglected. The rail-support system mentioned above has properties of non-uniform material distribution and uncertainty of construction quality. The linear elastic hypothesis therefore cannot correctly evaluate the stress distribution within the rails. The aim of this study is to apply the nonlinear finite element method using the nonlinear coupling interface between the track and structural model and to illustrate the welded rail behavior under the loading effect and uncertain factors of the ballast. Numerical results of nonlinear finite analysis with a three-dimensional solid and frame element model are presented for a typical track-bridge system. A composite plate girder, modeled by solid and shell elements, is also analyzed to consider the behavior of the welded rail. The analysis result showed buckling under the independent calculations of load cases, including 'temperature change', 'bending of the supporting structure', and 'braking' of the railway vehicle. A parametric study of the load combination method and the loading sequence is also included in this analysis.

Effect of cryotherapy duration on experimentally induced connective tissue inflammation in vivo

  • Jorge Vera;Mayra Alejandra Castro-Nunez;Maria Fernanda Troncoso-Cibrian;Ana Gabriela Carrillo-Varguez;Edgar Ramiro Mendez Sanchez;Viviana Sarmiento;Lourdes Lanzagorta-Rebollo;Prasanna Neelakantan;Monica Romero;Ana Arias
    • Restorative Dentistry and Endodontics
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    • v.48 no.3
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    • pp.29.1-29.8
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    • 2023
  • Objectives: This study tested the hypothesis that cryotherapy duration influences lipopolysaccharide (LPS)-induced inflammation in a rat model. Materials and Methods: Six Wistar rats (Rattus norvegicus albinus) were used. Five sites were selected per animal and divided into 5 groups: a negative control group (NC), 2 positive control groups (PC1 and PC2), and 2 experimental groups (E1 and E2). Cryotherapy was applied for 1 minute (E1) or 5 minutes (E2). An acute inflammatory response was induced in the PC and E groups via subcutaneous administration of 0.5 mL/kg. In the PC2 group, a catheter was inserted without additional treatment. For the E1 and E2 groups, 2.5℃ saline solution was administered through the implanted catheters for 1 and 5 minutes, respectively. The rats were sacrificed, and samples were obtained and processed for histological analysis, specifically examining the presence of polymorphonuclear neutrophils and hemorrhage. The χ2 test was used to compare the presence of acute inflammation across groups. Dependent variables were compared using the linear-by-linear association test. Results: Inflammation and hemorrhage varied significantly among the groups (p = 0.001). A significantly higher degree of acute inflammation was detected (p = 0.0002) in the PC and E1 samples than in the E2 group, in which cryotherapy was administered for 5 minutes. The PC and E1 groups also exhibited significantly greater numbers of neutrophils (p = 0.007), which were essentially absent in both the NC and E2 groups. Conclusions: Cryotherapy administration for 5 minutes reduced the acute inflammation associated with LPS and catheter implantation.

Replicative Senescence in Cellular Aging and Oxidative Stress (세포 노화에 있어서 복제 세네센스 현상과 산화적 스트레스의 영향)

  • 박영철
    • Toxicological Research
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    • v.19 no.3
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    • pp.161-172
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    • 2003
  • Explanted mammalian cells perform a limited number of cell division in vitro and than are arrested in a state known as replicative senescence. Such cells are irreversibly blocked, mostly in the G1 phase of cell cycle, and are no longer sensitive to growth factor stimulation. Thus replicative senescence is defined as a permanent and irreversible loss of replicative potential of cells. For this characteristic, replicative senescence seems to evolve to protect mammalian organism from cancer. However, senescence also contributes to aging. It seems to decrease with age of the cell donor and, as a form of cell senescence, is thought to underlie the aging process. Extensive evidence supports the idea that progressive telomere loss contributes to the phenomenon of cell senescence. Telomeres are repetitive structures of the sequence (TTAGGG)n at the ends of linear chromosomes. It has been shown that the average length of telomere repeats in human somatic cells decreases by 30∼200 bp with each cell division. It is generally believed that when telomeres reach a critical length, a signal is activated to initiate the senescent program. This has given rise to the hypothesis that telomeres act as mitotic clocks to regulate lifespan. One proposes that cumulative oxidative stress, mainly reactive oxygen species generated from mitochondria, may mainly cause telomere shortening, accelerating aging. Here, the biological importance and mechanism of replicative senescence were briefly reviewed. Also it was summarized that how oxidative stress affects replicative senescence and telomere shortening.

Assessment of casting parts fatigue life for 3MW offshore wind turbine (3MW 해상풍력발전기 주물품의 내구수명 평가)

  • Roh, Gitae;Kang, Wonhyoung;Lee, Seongchan
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.189.2-189.2
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    • 2010
  • The purpose of this study is fatigue damage assessment for large sized casting parts (hub and mainframe) of the 3MW offshore wind turbine by computer simulation. Hub and mainframe durability assessment is necessary because wind turbine have to guarantee for 20 years. Fatigue life evaluation must be considered all of fatigue load conditions as the components are wind load transmission path. Palmgren-Miner linear damage accumulation hypothesis is applied for fatigue life estimation with stress-life approach. S-N curve for the spheroid graphite cast iron EN-GJS-400-18-LT is derived according to durability guidelines. Reduction factors were applied for survival probability, surface roughness, material quality and partial safety factor according to Germanischer Lloyd rules. To calculate fatigue damage, stress tensors, extracted from the unity load calculation from ANSYS is multiplied with time track of fatigue loads extracted from GH bladed. Damage accumulation is performed with all of fatigue load conditions at each finite element nodes. In this study maximum nodal damage value is under 1.0. casted parts are safe. This research was financially supported by the Ministry of Knowledge Economy(MKE), Korea Institute for Advancement of Technology(KIAT) and Honam Leading Industry Office through the Leading Industry Development for Economic Region.

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Moderating Effects of Peer Competence on the Relationship Between Children's Perception of Parenting Attitudes and Depression by Gender (성별에 따라 아동이 지각한 부와 모의 양육태도와 우울의 관계에서 또래 유능성의 조절 효과)

  • Seo, Yu Jin;Kim, Sarah Hyoung Sun
    • Korean Journal of Child Studies
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    • v.38 no.3
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    • pp.65-73
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    • 2017
  • Objective: This study aimed to investigate the moderating effects of peer competence between children's perception of parenting attitudes and depression among $5^{th}$ grade elementary students. The differences are examined based by gender. Methods: 'The Children's Perception of the Parenting Attitudes Inventory', 'Children's Depression Inventory', and 'Peer Competence Inventory' were used to collect data from 200 elementary school students from Seoul, Korea. The research hypothesis were analyzed using t-tests, Pearson's correlation analysis, standard linear regression analysis and hierarchical multiple regression analysis via SPSS 21.0. Results: The results are as follows: First, only peer competence showed a difference between the boys and girls, where the boys scored higher than the girls. Second, there was a significant correlation between all the factors. Third, the moderating effect of peer competence on the father's parenting attitude was supported only in the boys. Conclusion: The results denote the need of a gendered approach to understanding problems and developing counseling programs to address depression among children. They also demonstrate that high peer competence can be used to treat depression in boys dissatisfied with their father' parenting attitude.

Effect of CAR and NPL on ROA: Empirical Study in Indonesia Banks

  • TANGNGISALU, Jannati;HASANUDDIN, Rusdiah;HALA, Yusriadi;NURLINA, Nurlina;SYAHRUL, Syahruni
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.6
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    • pp.9-18
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    • 2020
  • This study seeks to analyze the effect of Non-Performing Loans and Capital Adequacy Ratio on Return on Assets on ten conventional banks listed on the Indonesia Stock Exchange (BEI-IDX). This study uses secondary panel data for 2015-2019 in the form of CAR and NPL values from ten conventional banks listed on the BEI-IDX during the 2020 observation period. The research approach is quantitative descriptive with data analysis methods, namely, linear regression. The testing phase of this study includes: transform value, F-test, T-test and hypothesis test with significancy level sig < 0.05. The results of this study reveal that Non-Performing Loans had a significant negative effect (t = -2,637) (0.011 <0.0) on Return on Assets, while Capital Adequacy Ratio has no significant effect on ROA (0.760 > 0.05). R2 value is 0.128 or 12.8%. It has a significant effect on variables, calling efforts by banks, governments, and authorities monetary of related institutions to maintain the stability of finance. The reduction of Non-Performing Loan impacts on assets and capital adequacy ratio, besides, the normal NPL will control the stability of finance. If a balance is created either in the form of values or amounts of the variables, the reduction in Non-Performing Loans will be controlled.

A Study on the Evaluation of Linear Cumulative Damage Factor of Membrane Type LNG Tank by use of Probability Density Function (확률밀도함수를 이용한 멤브레인방식 LNG탱크의 선형누적손상도 평가에 관한 연구)

  • 김종호
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.6
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    • pp.993-999
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    • 2004
  • The estimation of fatigue life at the design stage of membrane type LNG tank is very important in order to arrive at feasible and cost effective solutions considering the total lifetime of the tank. In this study, the practical procedure of fatigue life prediction by use of cumulative damage factors based on Miner-Palmgren hypothesis and probability density function has been shown with the corner region of Gaz Transport Membrane type LNG tank being used as an example. In particular the parameters of Weibull distribution that determine the stress spectrum are discussed. The main results obtained from this study are as follows: 1. The recommended value for the shape parameter of Weibull distribution for the LNG tank is 1.1 in case of using the direct calculation method proposed in this study. 2. The calculated fatigue life is influenced by the shape parameter of Weibull distribution and stress block. The safe fatigue design can be achieved by using higher value of shape parameter and the stress blocks divided into more stress blocks.

Comparison of methods for the proportion of true null hypotheses in microarray studies

  • Kang, Joonsung
    • Communications for Statistical Applications and Methods
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    • v.27 no.1
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    • pp.141-148
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    • 2020
  • We consider estimating the proportion of true null hypotheses in multiple testing problems. A traditional multiple testing rate, family-wise error rate is too conservative and old to control type I error in multiple testing setups; however, false discovery rate (FDR) has received significant attention in many research areas such as GWAS data, FMRI data, and signal processing. Identify differentially expressed genes in microarray studies involves estimating the proportion of true null hypotheses in FDR procedures. However, we need to account for unknown dependence structures among genes in microarray data in order to estimate the proportion of true null hypothesis since the genuine dependence structure of microarray data is unknown. We compare various procedures in simulation data and real microarray data. We consider a hidden Markov model for simulated data with dependency. Cai procedure (2007) and a sliding linear model procedure (2011) have a relatively smaller bias and standard errors, being more proper for estimating the proportion of true null hypotheses in simulated data under various setups. Real data analysis shows that 5 estimation procedures among 9 procedures have almost similar values of the estimated proportion of true null hypotheses in microarray data.

Impact of Work stopped on Site Productivity and Productivity Achievement Ratio (작업중단이 현장 생산성과 생산성달성율에 미치는 영향)

  • Kim Tae-Wan;Yu Jung-Ho;Lee Hyun-Soo
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.311-314
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    • 2003
  • This study takes a statistical approach to quantify tile impact of wort stopped on the following day's site productivity. Therefore, this study is aimed to verify this null hypothesis: 'A work stopped in a construction field does not impact on the following day's productivity and productivity achievement ratio'. For the purpose, work, stopped is presumed as a dummy variable impacting site productivity in multiple linear regression analysis. Moreover, the quantified impact of work slopped on productivity achievement ratio is identified based on this study. This study shows that construction managers should persevere in their efforts to secure the work continuity in order to improve site productivity and productivity achievement ratio.

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