• 제목/요약/키워드: Panel Data Models

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A Comparison of Models for Predicting Discretionary Accruals: A Cross-Country Analysis

  • ACAR, Goksel;COSKUN, Ali
    • The Journal of Asian Finance, Economics and Business
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    • 제7권9호
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    • pp.315-328
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    • 2020
  • In this study, we examined various aspects of discretionary accruals. We compared the power of Jones Model (JM), Modified Jones Model (MJM) and Performance Matched Model (PMM). Furthermore, we tested whether accruals derived from cash flow approach or balance sheet approach provide better results and we investigated the significance of country and industry control variables in models. In order to perform these tests, we constructed thirty equations. The data consists of 319 non-financial companies over five years in the GCC region. We used panel data regression models, and testing suggests us to use random effect model as the most suitable one. The results show that PMM has the highest explanatory power among models and it is followed by JM and MJM, consecutively. Secondly, results reveal that accruals derived from cash flow approach provide more accurate results. Moreover, country dummies are significant in models with cash flow approach and they lose significance in balance sheet approach. We differentiated industries due to two different classifications: the first group with higher number of industries is more precise compared to the second group with a narrower scope and lower number of industries. The model including both industrial and country-wise dummies scores highest in significance.

성인의 체질량지수(BMI)와 자살생각의 관계 -2009~2013년 한국의료패널자료를 활용한 연구- (Style for the Journal of Korean Contents Relation between BMI and Suicide Ideation in Adult : Using Data from the Korea Health Panel 2009~2013)

  • 이종익
    • 한국콘텐츠학회논문지
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    • 제18권2호
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    • pp.616-625
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    • 2018
  • 본 연구는 2009~2013년 한국의료패널 데이터를 이용하여 체질량지수(BMI)와 자살생각의 관계를 분석하여 자살에 대한 위험요인을 확인하고자 하는 목적으로 진행되었다. 본 연구에서는 BMI와 자살생각의 관계를 분석하기 위해 R통계패키지를 활용하여 로지스틱 회귀분석을 실시하고 그래프로 나타냈다. 본 연구의 결과로는 BMI를 투입한 모델에서 모두 유의미한 변수로 자살생각에 정적인 영향을 미치는 것으로 나타났다. 즉, 비만인 집단이 다른 집단에 비해 자살생각을 더 하는 것으로 나타났다. 이러한 결과를 기초로 자살예방과 개입을 위한 사회적 함의를 모색하고자 한다.

단파장 영역에서의 부가저항 해석 (Analysis of Added Resistance in Short Waves)

  • 양경규;서민국;김용환
    • 대한조선학회논문집
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    • 제52권4호
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    • pp.338-348
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    • 2015
  • In this study, the added resistance of ships in short waves is systematically studied by using two different numerical methods - Rankine panel method and Cartesian grid method – and existing asymptotic and empirical formulae. Analysis of added resistance in short waves has been preconceived as a shortcoming of numerical computation. This study aims to observe such preconception by comparing the computational results, particularly based on two representative three-dimensional methods, and with the existing formulae and experimental data. In the Rankine panel method, a near-field method based on direct pressure integration is adopted. In the Cartesian grid method, the wave-body interaction problem is considered as a multiphase problem, and volume fraction functions are defined in order to identify each phase in a Cartesian grid. The computational results of added resistance in short waves using the two methods are systematically compared with experimental data for several ship models, including S175 containership, KVLCC2 and Series 60 hulls (CB = 0.7, 0.8). The present study includes the comparison with the established asymptotic and empirical formulae in short waves.

Does Paid Sick Leave Induce Welfare Burden?

  • Namhoon KIM
    • Asian Journal of Business Environment
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    • 제14권2호
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    • pp.11-18
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    • 2024
  • Purpose: The purpose of this study is to empirically evaluate the unintended welfare losses induced by paid sick leave, examine the severity of the unintended moral hazard loss caused by paid sick leave, and evaluate how much moral hazard cost society can accept to obtain paid sick leave benefits. Research Design, Data and Methodology: We examine the Medical Expenditure Panel Survey data collected in 2013 and 2014 by employing a panel probit analysis to control for individual heterogeneity. Results: The estimation result shows that the probability of absence due to paid sick leave increases from 4.91% to 7.84%. Among them, excluding the probability of increasing absence from 1.29% to 2.69% due to the actual disease, the probability of absence due to the moral hazard was estimated to be 2.41% to 6.49% in the proposed models. Based on the result, if we evaluate the increase in absence caused by moral hazard as a social cost, the estimated cost is approximately $174 to $297 per worker per year. Conclusion: Considering these expected costs, our society can obtain the access benefit from paid sick leave if we are willing to accept the moral hazard cost.

동태적 패널모형을 통한 무역보험의 거시경제효과 연구 (A Study on the Macroeconomic Effects of Trade Insurance Using Dynamic Panel Models)

  • 남상욱
    • 무역상무연구
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    • 제61권
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    • pp.165-190
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    • 2014
  • The purpose of this study is to measure the trade insurance's macroeconomic effects by analyzing the causality between major economic variables(GDP per capita, market interest rate, inflation, unemployment rate, exchange rate) and trade insurance variable. I conducted empirical analyses using First-difference GMM(Generalized Method of Moments), System GMM and Panel-VAR Model, with panel data from 11 countries(Korea, United States, Japan, BRICs, Indonesia, Singapore, Hong Kong, Vietnam) between 1992 and 2011. There are several important findings. Above all, Trade insurance is positively and significantly related to GDP. This results show that trade insurance serves to increase economic growth. In other words, trade insurance leads to economic growth by helping increase GDP per capita. Especially, trade insurance negatively related to unemployment rate, it is for sure that trade insurance contribute to decrease unemployment rate. And trade insurance helps control of inflation. It is also confirmed that trade insurance contributes to price stability, which in turn serves to stabilize the overall economy. And this research finds as uncertainty in the market increases, seen it as increase of exchange rate, increasing trade insurance supply is stabilize the exchange rate.

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Using a feed forward ANN to model the inelastic behaviour of confined sandwich panels

  • Marante, Maria E.;Barreto, Wilmer J.;Picon, Ricardo A.
    • Structural Engineering and Mechanics
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    • 제71권5호
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    • pp.545-552
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    • 2019
  • The analysis and design of complex structures like sandwich-panel elements are difficult; the use of finite element method for the analysis is complicated and time consuming when non-linear effects are considered. On the other hand, artificial neural network (ANN) models can capture the non-linear effects and its application requires lesser computational demand. Two ANN models were trained, tested and validated to compute the force for a given displacement of a sandwich-type roof element; 2555 force and element deformation pairs were used for training the ANN models. For the models trained without considering the damping effect, there were two values in the input layer: maximum displacement and current displacement, and for the model considering damping, displacement from the previous step was used as an additional input. Totally, 400 ANN models were trained. Results show that there is a good agreement between the experimental and simulated data, and the models showed a good performance with a mean square error value of 4548.85. Both the ANN models could simulate the inelastic behaviour, loss of rigidity, and evolution of permanent displacements. The models could also interpolate and extrapolate, which enables them to be used as an analysis and design tool for such complex elements.

등록금 및 장학금이 대학생 휴학률에 미치는 영향: 패널회귀모형을 이용한 실증분석 (Influence of tuition and scholarship on the stop-out rate: An empirical analysis using panel regression model)

  • 양호석;최재석;한준태;정진아
    • Journal of the Korean Data and Information Science Society
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    • 제26권3호
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    • pp.631-638
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    • 2015
  • 본 연구는 대학정보공시 자료를 활용하여 2010~2013년까지 4년간의 패널자료를 구성하고 패널분석을 통해서 우리나라 4년제 대학의 등록금 및 장학금이 대학 휴학률에 미치는 영향을 국공립 대학과 사립 대학으로 나누어 파악했다. 전임교원 1인당 학생수, 취업률, 학생 1인당 교육비, 평균 등록금, 1인당 장학금 등을 고려해 3가지 모델로 연구하였다. 이 연구의 결과는 국공립 대학에서 등록금 및 순 등록금 (net tuition)이 낮을수록 대학 휴학률이 낮아지며, 1인당 교외 장학금이 높을수록 대학휴학률이 낮아졌으며, 사립 대학에서는 등록금이 낮을수록 대학 휴학률이 낮아졌으며, 1인당 장학금(교내+교외), 1 인당 교내장학금 및 교외장학금이 높을수록 대학 휴학률이 낮아지는 결과를 보였다.

자동차 프레스 금형 설계를 위한 3차원 CAD 시스템의 개발 (Development of Three-dimensional CAD System for Die Design for Automotive Body Panels)

  • 이상화;유승우;이상헌
    • 한국CDE학회논문집
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    • 제12권1호
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    • pp.39-49
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    • 2007
  • Recently three-dimensional (3-D) die design and production process has been widely introduced into the tooling shops of automotive manufacturers to reduce time-to-production of brand-new automobiles. 3-D solid models created in CAD systems are used not only for various simulations for design verification, but also for NC tool path generation to machine dies and their Styrofoam patterns. However, a lot of time and cost will be required to build solid models for dies if designers use only the generalized modeling capabilities of commercial 3-D CAD systems. To solve this problem, it is necessary to customize 3-D CAD system for the specific die design and manufacturing process. This paper describes a dedicated 3-D CAD system based on Unigraphics for die design for automotive body panels. The system provides not only 3-D design capabilities, but also standard part libraries, to enhance design productivity. The design process modeling technology has been introduced to facilitate redesign of the die for the modified panel. By introducing this system, dies can be designed more rapidly in the 3-D space, and their solid data can be directly transferred to CAM tools for NC tool path generation and simulation tools for virtual manufacturing.

Flexural bearing capacity of diaphragm-through joints of concrete-filled square steel tubular columns

  • Rong, Bin;Liu, Rui;Zhang, Ruoyu;Chen, Zhihua;Apostolos, Fafitis
    • Steel and Composite Structures
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    • 제20권3호
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    • pp.487-500
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    • 2016
  • In order to investigate the flexural bearing capacity of panel zone of diaphragm-through joint between concrete filled square steel tubular column and steel beam, four specimens were tested under static tension loads to study the mechanical properties and bearing capacity of diaphragm-through joints with a failure mode of panel zone. Finite element models of these specimens were developed to simulate the test and compare the predicted failure modes, load-displacement curves and bearing capacities with the experimentally observed. It was found that the tensile load from the steel beam flange is mainly shared by the square steel tube and the diaphragm. The diaphragm plastic zone appears along the cross-section lines enclosed by the square steel tube and the influence of steel beam web on the plastic zone of the steel tube is significant and cannot be neglected. Computational models of yield lines on square steel tube and diaphragm are established based on the distribution pattern of the plastic zone, and an analytical method for the evaluation of the bearing capacity of the joint is proposed. The theoretical results and the experimental data are compared and found in good agreement.

Impacts of Financial Constraints on Firm Value for KONEX Listed Firms

  • Zhang, Xue Dong;Kang, Shinae
    • 융합경영연구
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    • 제9권4호
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    • pp.1-8
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    • 2021
  • Purpose: This study empirically investigates what factors contribute to corporate value in the Korea New Exchange (KONEX) market and determines whether financial constraints contribute any effect on it. Research design, data and methodology: A fixed-effect panel regression model was utilized to analyze financial constraints on firm value for KONEX listed firms through the fiscal period from 2013 to 2020. Results: we find that firms' research and development, volatility, size, and sales growth give significant impacts to firm value, but the significance and direction are different. In addition, no significant relationship exists between the largest shareholder's equity ratio and firm value in all models. The debt-to-equity ratio did not show a significant relationship with corporate value. A significant negative relationship was found between R&D and corporate value in the entire sample. Volitility exhibited a positive relationship with corporate value in the entire sample and financially unconstrained companies. Firm size presented a significant negative relationship with company value in all models. Sales growth showed a significant negative relationship with corporate value in financially constrained companies. Conclusions: No difference is found between financially constrained and unconstrained companies in the KONEX market. We can infer that KONEX companies have a large difference with KOSPI or KOSDAQ. Further analysis is needed on the differences among these markets.