• Title/Summary/Keyword: dummy variables

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Optimization of extrusion process for long-length multi-filaments of BSCCO 2223 superconductor tape (고온초전도 BSCC02223 장선재 제조를 위한 압출공정의 최적화)

  • Cho, Ki-Hyun;Choi, Jong-Ung;Yoo, Jim-Moo;Ko, Jae-Woong;Kim, Hai-Doo
    • 한국초전도학회:학술대회논문집
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    • v.10
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    • pp.230-235
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    • 2000
  • The extrusion process for long-length multi-filaments of BSCCO 2223 superconductor tape has been investigated with aids of Finite Element Method and experimental inspection. Since the arrangement of filaments in matrix material has characteristic of rotational symmetry, a 2-dimensional commercial FEM package, DEFORM-2D, was adopted to simulate extrusion process with different variables such as hardness of sheath material, lengths of each filament and arrangement. From the FEM analysis, since the inner filaments move faster than the outer one, distribution of filaments is needed to be optimized. In the case of pure Ag matrix, undesirable non-uniform distribution of filament was obtained due to low hardness of sheath material. Dummy sample(brass (sheath) and talc powder(filament)), however, which has relatively high hardness of sheath material, had been produced with desirable results. Therefore, it is necessary to optimize hardness of sheath material, extrusion temperature and billet design.

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Relationships between Short Sleep, Obesity, and Screen Time in High School Students (고등학생의 수면 부족, 비만, 스크린 타임 사이의 관련성 연구)

  • Ha, Yeongmi;Park, Hyunju
    • Journal of Korean Biological Nursing Science
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    • v.16 no.2
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    • pp.80-89
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    • 2014
  • Purpose: The purpose of this study was to investigate relationships between short sleep, obesity, and screen time. Methods: Data were obtained from a survey using a sample of 1,166 academic, and 597 vocational high school students. A structured questionnaire was used to assess demographics, hours spent in sleep, TV viewing, internet usage, and game playing. Obesity was determined using the body mass index. Descriptive statistics, Cochran Mantel Haenszel Chi-square test, and multiple logistic regression with dummy variables were performed. Results: Short sleep (<8 hours/day) was significantly related to obesity, not in academic school students, but in vocational school students. Academic high school students who had enough sleep (${\geq}8$ hours/day), had more time spent on TV viewing, internet usage, and game playing. Similar results were found in vocational high school students except for internet use. Interestingly, students with better school performance spent significantly less time in TV viewing, internet usage, and game playing, and therefore had a lower risk of obesity in academic school students. Conclusion: There is a significant relationship between short sleep and obesity that was found only in vocational high school students. The relationship between short sleep and screen time was not significant in Korean high school students.

A Study on Shape Design of the Passenger Airbag for Efficiency Improvement (조수석 에어백 성능 개선을 위한 형상 설계연구)

  • Yang, Sunghoon;Yim, Jonghyun;Kim, Seungki;Chae, Soo-Won
    • Transactions of the Korean Society of Automotive Engineers
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    • v.25 no.2
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    • pp.242-249
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    • 2017
  • In this study, the relationship between the shape of a passenger airbag and the possibility of injury is analyzed using the Taguchi method. The optimal shape combination is proposed for a design guideline that can reduce the possibility of injury to the dummy. The airbag FE model for analysis is obtained using a CAD system that can change the shape through several independent variables. The widths of the left / right, top / bottom, and back / forth direction of the airbag shape are set as the design factors, and the effect of the combination injury probability according to the shape is analyzed. The minimum geometric combinations are obtained using the orthogonal array method. The signal to noise ratio is calculated and the optimal shape combination is obtained through sensitivity analysis. The obtained optimal shape combination is compared with the possibility of injury of the initial airbag shape to confirm improved airbag performance.

Migration and Economic Inequality in Indonesia: Longitudinal Data Analysis

  • YULIADI, Imamudin;RAHARJA, Sigit Satria
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.541-548
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    • 2020
  • This study aimed to explain the factors that influenced an individual's decision to migrate. The method of analysis in this study was the estimation of the probit regression model with data from the Indonesian Family Life Survey (IFLS-5), which covered 30,000 individuals from 13 provinces in Indonesia. Data from IFLS-5 were longitudinal data, meaning that the study was looking for data consistently to get reliable data from respondents. The research variables to determine the individual's decision to migrate were education level, income level, employment status, marital status, land ownership status, health quality, gender, residence status, and poverty status. Individual decision to migrate as a dependent variable was placed as a dummy variable. The results showed that the level of education, income level, employment status, marital status, land ownership status, health quality, and poverty status significantly influenced an individual's decision to migrate. Meanwhile, gender and residence status did not significantly affect an individual's decision to migrate. This research recommends that it is necessary to pursue a policy of economic equality between regions because economic factors are the main trigger for an individual's decision to migrate. Policies to overcome economic disparities among regions will reduce the individual's decision to migrate.

Is Real Appreciation or More Government Debt Contractionary? The Case of the Philippines

  • Hsing, Yu;Morgan, Yun-Chen
    • East Asian Journal of Business Economics (EAJBE)
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    • v.4 no.4
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    • pp.1-7
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    • 2016
  • This paper has studied the impacts of the exchange rate, government debt as a percent of GDP and other relevant macroeconomic variables on aggregate output in the Philippines. A simultaneous-equation model consisting of aggregate demand and short-run aggregate supply is applied. The dummy variable technique is employed to detect whether the slope and intercept of the real effective exchange rate may have changed. Real depreciation during 1998.Q1 - 2006.Q3, real appreciation during 2006.Q4 - 2016.Q1, a lower domestic debt as a percent of GDP, a lower real interest rate, a higher stock price or a higher lagged real oil price would raise aggregate output. Recent trends of real peso appreciation, declining domestic debt as a percent of GDP, lower real interest rates, and rising stock prices are in line with the empirical results and would promote economic growth. The authorities may need to continue to pursue fiscal prudence and maintain a stronger peso as the positive effect of real appreciation dominates its negative effect in recent years.

Empirical Analysis on the Factors Affecting the Net Income of Regional and Industrial Fisheries Cooperatives Using Panel Data (패널자료를 이용한 지구별·업종별 수산업협동조합의 수익에 영향을 미치는 요인 분석)

  • Kim, Cheol-Hyun;Nam, Jong-Oh
    • The Journal of Fisheries Business Administration
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    • v.51 no.1
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    • pp.81-96
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    • 2020
  • The purpose of this paper is to analyze factors affecting the net income of regional and industrial fisheries cooperatives in South Korea using panel data. This paper utilizes linear or GLS regression models such as pooled OLS model, fixed effects model, and random effects model to estimate affecting factors of the net income of regional and industrial fisheries cooperatives. After reviewing various tests, we eventually select random effects model. The results, based on panel data between 2013 and 2018 year and 64 fisheries cooperatives, indicate that capital and area dummy variables have positive effects and employment has negative effect on the net income of regional and industrial fisheries cooperatives as predicted. However, debt are opposite with our predictions. Specifically, it turns out that debt has positive effect on the net income of regional and industrial fisheries cooperatives although it has been increased. Additionally, this paper shows that the member of confreres does not show any significant effect on the net income of regional and industrial fisheries cooperatives in South Korea. This study is significant in that it analyzes the major factors influencing changes in the net income that have not been conducted recently for the fisheries cooperatives by region and industry.

Investigation on the Health Inequality in China (중국 건강불평등 현상에 대한 고찰)

  • Xue, Mi;Lim, Jae Young
    • International Area Studies Review
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    • v.20 no.2
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    • pp.175-194
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    • 2016
  • In this study, we aimed to identify the impact of socioeconomic characteristics on the health status of Chinese, which suggests that there might be the phenomena of health inequality in China. We used the year 2000, 2004 and 2009 pooled cross-sectional data of China Health and Nutrition Survey (CHNS), and utilized the Ordinary Least Square model (OLS) and Ordered Logit Estimation Method for this purpose. Empirical results showed that socioeconomic status and year dummy variables have a meaningful impact on Chinese health status. Therefore, we conclude that the phenomenon of health inequality has existed in China since 2000.

Effects of the Real Estate Transaction Tax on Saudi Arabia's Economic Cycles

  • HARIRI, Mohammad Majdi
    • Asian Journal of Business Environment
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    • v.12 no.1
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    • pp.25-33
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    • 2022
  • Purpose: The purpose of this paper is to determine the effects of the Real Estate Transactions Tax (RETT) on the economic cycles of Saudi Arabia. A secondary purpose is to determine the effects of RETT on the construction and real estate sectors of Saudi Arabia. Research design, data and methodology: The data used is retrieved from the General Authority of Statistics, Saudi Central Bank and the World Bank Open Data. Econometric models of multiple linear regression with dummy variables have been conducted to achieve the objectives and to quantitatively verify the hypotheses. Results: With the VAT exemption in real estate transactions and its substitution with RETT, a positive effect on the economy and the real estate sector has been observed. However, this tax reform has not produced any significant effects in the construction sector. Conclusions: The main conclusion of the present research is that the real estate market has a major influence on economic cycles. After the tax reform, a reduction in the contribution of taxes on real estate transactions to GDP was detected. For the construction sector, after the tax reform, it is estimated that there will be an insignificant reduction in the contribution of the real estate price index, and of the taxes on real estate transactions, to GDP.

A Study on the Characteristics of Companies Using Technologies of the 4th Industrial Revolution in Response to Global Competition (글로벌 경쟁에 대응한 4차 산업혁명 기술 활용의 기업 특성 연구)

  • Jung-Hwan Cho;Tae-Hwang Kim
    • Korea Trade Review
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    • v.46 no.2
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    • pp.355-368
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    • 2021
  • The purpose of this study is to analyze the factors affecting innovation activities related to the introduction of the 4th Industrial Revolution technology for Korean firms faced to the severe global trade and competition environments. This paper conducted an empirical analysis using the 'The Survey of Business Activities' distributed by the Statistics Korea in 2019. According to the results of the analysis, it was found that the firm size, labor cost, R&D, and intellectual property rights had a significant influence on the firms' adoption of the 4th industrial revolution technology. It was also found that the dummy variables such as strategic alliance between companies, review of entry into a new business, transfer of main business operations, and holding of subsidiaries had statistically significant effects on innovation activities. In addition, this paper showed that the firm characteristics had impacts on innovation activities of firms by the 4th industrial revolution technology type. In order for Korean firms to adapt to the challenges by the 4th Industrial Revolution, it is important to provide policy support and an environment in line with the characteristics of the firms.

An Empirical Study on the Relationship of Justice, Pay Level Satisfaction and Pay System (공정성 요인, 임금수준 만족 그리고 임금제도에 관한 실증연구)

  • Lee, Jung-Gil;lee, Kwang-Hee
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.39 no.3
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    • pp.118-128
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    • 2016
  • The purpose of this study is to verify the role of moderating effect of pay system on the relation between organizational justice and employee's pay level satisfaction. By default, it would be a justice find out a positive impact on pay levels satisfaction members feel. It will examine the mediating effect of the wage system the main purpose of this study is to prove their relationship. A survey was conducted to examine the role of moderating effect of pay system on the responses of 218 employees. sex, education, status, and service type were chosen as control variable, and the regression model which treated the distributive justice and procedural justice as independent variable was set. A pay system was supposed as moderating variable of the relation between organizational justice and pay level satisfaction, In addition the pay system have a dummy variable (if pay system is lower than the average, pay system is 0, else pay system is 1). The result showed that the relation of organizational justice and pay level satisfaction are significantly unique. This means that pay system moderates the relation of organizational justice and pay level satisfaction. These results are different from the prior researches which had treated pay system as mediative variable of organizational justice and pay level satisfaction. This difference may be from the property of attitude variable. For example, pay satisfaction is individual-based attitude. Moreover, organizational committment has the instrumentality for future reward, while pay satisfaction does not. The future study should consider the properties of these variables and other employee's attitude variables.