• Title/Summary/Keyword: dummy variable

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Estimating Utility Function of In-Vehicle Traffic Safety Information Incorporating Driver's Short-Term Memory (운전자 단기기억 특성을 고려한 차내 교통안전정보의 효용함수 추정)

  • Kim, Won-Cheol;Fujiwara, Akimasa;Lee, Su-Beom
    • Journal of Korean Society of Transportation
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    • v.27 no.4
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    • pp.127-135
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    • 2009
  • Most traffic information that drivers receive while driving are stored in their short-term memory and disappear within a few seconds. Contemporary modeling approaches using a dummy variable can't fully explain this phenomenon. As such, this study proposes to use utility functions of real-time in-vehicle traffic safety information (IVTSI), analyzing its safety impacts based on empirical data from an on-site driving experiment at signalized intersection approach with a limited visibility. For this, a driving stability evaluation model is developed based on driver's driving speed choice, applying an ordered probit model. To estimate the specified utility functions, the model simultaneously accounts for various factors, such as traffic operation, geometry, road environment, and driver's characteristics. The results show three significant facts. First, a normal density function (exponential function) is appropriate to explain the utility of IVTSI proposed under study over time. Second, the IVTSI remains in driver's short-term memory for up to nearly 22 second after provision, decreasing over time. Three, IVTSI provision appears more important than the geometry factor but less than the traffic operation factor.

Empirical Analysis on the Factors Affecting the Consumption of Aquatic Products in China Using Panel Data (패널자료를 이용한 중국 수산물소비지출에 영향을 미치는 요인에 관한 연구)

  • Lin, Xuemei;Kim, Ki-Soo
    • The Journal of Fisheries Business Administration
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    • v.44 no.2
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    • pp.19-33
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    • 2013
  • China is the world's largest producer of aquatic products and its fishery sector is comprised primarily of aquaculture facilities, both fresh and seawater, and a much smaller wild catch component. The expansion of the aquaculture sector continues to boost China's aquatic output. The increase is attributable to several factors. Among them rapidly growing domestic demand is no doubt one of the most important reasons. Rapid economic growth and rising disposable income are influencing domestic consumption and the economic recovery of major import markets is further stimulating consumption of China's aquatic products. This paper tries to examine the status, trend and reasons of consumption of aquatic products in China. Based on the analysis on the consumption of aquatic products and its change, this paper utilizes panel regression model to estimate the affecting factors of aquatic products consumption in China. By using panel data between 1997 and 2010, the results indicate that income, urbanization, aging and dummy variable have positive effects and fish price index has negative effect on China's aquatic products consumption as predicted. However, effects of meat consumption and education on fishery consumption are totally opposite with our predictions. In other words, it turns out that meat consumption has positive effect on fish consumption while education turns out to have negative effect. Finally the member of household does not show any significant effect on consumption of aquatic products in China.

A Study on the Influence of System Quality and Synchronization Factors for Learning Performance in e-Learning: The Mediating Effect of Learning Flow (e-러닝의 시스템품질과 동기화요인이 학업성과에 미치는 영향에 관한 연구 : 학습몰입의 매개효과를 중심으로)

  • Kim, Youn-Ae;Shin, Ho-Kyun;Kim, Joon-Woo
    • The Journal of Information Systems
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    • v.20 no.4
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    • pp.181-204
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    • 2011
  • Recently, the development of ICT(information & communications technology) with the advent of new media paradigm shift in learning has brought a dramatic impact on the competitiveness of universities. The previous studies on the academic performance of e-learning mainly targeted on e-learning users, studying additional synchronization and system quality factors to measure academic performance. This study empirically analyzed the learning flow and academic performance considering both DeLone & McLean model system quality and synchronizing factors based on ARCS model. Relating to quality and synchronization factors, the academic performance of e-learning system was tested, and the difference between learning flow and academic performance was also analyzed based on time-series data, by the test difference(in the beginning, during, and final of the semester). The results of the study are as follows. First, the study shows that both system quality and synchronization directly affected the learning performance. Thus, when designing e-learning system, it is necessary to consider these two factors at the same time. Second, the indirectly mediating effect on the system quality and synchronization factors turned out to be significant in learning flow. Third, the result of regression analysis on the contents of utilizing dummy variable presents that the teacher's explanation has greater influence than multimedia has to the academic performance, and furthermore, the test difference showed no significance. Further research should be undertaken to consider the learner's degree of acceptance which reflects various aspects for building m-learning or u-learning.

The Effects of NIE Program on Environmental Perception and Practice of Teenagers (NIE 프로그램이 청소년의 환경 인식과 실천에 미치는 영향)

  • Gam, Ye-Seul;Yang, Jung-Hwan;Ahn, Gyoung-Sook
    • Hwankyungkyoyuk
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    • v.21 no.2
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    • pp.80-88
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    • 2008
  • As the gravity of the issue of the global warming surfaced, environmental protection and energy conservation have become one of the most serious issues that global society faces. At the status quo, there are criticisms for not effectively educating the students although the problem is very severe. In middle school, for instance, only 10% of the school offer environmental education while only $20{\sim}30%$ of the high school offer it. As witnessed by these examples, we can infer that there are not well-structured, effective environmental education for teenagers. Recently, NIE(Newspaper-In-Education) has been used as effective means for some fields of middle and/ or high school education. If so, it also could be used for environmental education. The researches, however, on the topic of NIE on environmental education are very rare. In this study, the effect of NIE on environmental education was empirically tested. Our basic assumption is that NIE will cause differences in environmental perception; the cognition and concern. And environment education through NIE will cause the high level of cognition, concern, and practice regarding environment issue. Using simple experimental design and regression analysis, we tested the effect of NIE on cognition, and, concern of environment issue, and then, on the practice of environment-improving action. The "cognition level" did not show significant difference between the experimental group(which was exposed to NIE) and control group(which was not exposed to NIE). The "concern level" for environment showed significant difference. Finally, the "practice level" showed highly significant difference between the experimental and the control group. According to regression analysis, "concern" and "NIE"(dummy variable) was turned out to be statistically significant variables for practice of environment improving action. Therefore, we came up with the conclusion that NIE, which provides the most up-to-date information regarding the environmental status, can serve as the good supplementary mechanism for the effective environment education in the present Korean middle school curriculum system. The statistical result also suggests that each individual school needs to employ and extend NIE method in its environment education curriculum.

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An Analysis on the Coupling of Korea's Economy and U.S. Economy through the Asset Market (자산시장을 통한 한국경제와 미국경제의 동조화 분석)

  • Kim, Jongseon
    • International Area Studies Review
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    • v.15 no.3
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    • pp.393-405
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    • 2011
  • Three different models have been consecutively employed with the U.S. yield curve and the Korean composite stock price index, firstly to see the coupling between the economies of the U.S. and Korea, secondly to find out the time consumed completing the coupling, and lastly to figure out the impact of the recent U.S. financial crisis on this coupling. This study has, first of all, produced an empirical research outcome which proved the existence of coupling between two countries' economies. The direction of this coupling was consistent with the general expectation that when the yield spread between the U.S. 10-year Treasury Note and the U.S. 3-month Treasury Bill increased which often occurred with better prospects of U.S. economy, the asset price of emerging economies including Korea also rose reflecting the accompanying change in investment atmosphere in favor of risk. It has also found out that the degree of the coupling was maximized with a lag of one week. And finally the recent US financial crisis has been revealed to reduce the degree of the coupling by as much as half in a regression model with a dummy variable.

Empirical Analysis on the Effects of FTAs and FTA Spillover on the Bilateral Trade using GMM, Fixed and Random Panel Model, and PPML Estimation (GMM, 패널, PPML 비교분석을 통한 FTA와 FTA파급효과 분석)

  • Lee, Soon-Cheul
    • International Area Studies Review
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    • v.22 no.2
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    • pp.3-18
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    • 2018
  • This paper analyzes both the FTA effects and FTA spillover effects on bilateral trade using 62 countries' panel data during the period of 2003 ~ 2013. To this end, we construct a FTA dummy variable for the effect of FTA in the model and the weighted FTA matrix interacted with export and import for the spillover effect of FTA. Gravity model is applied to the empirical analysis with GMM, fixed and random effects, and PPML estimation. As a result of the analysis, FTA variables have positive relationships with bilateral export and import. The weighted FTA matrix interacted with export and import also have positive signs on the bilateral export and import in all estimations. Thus, we conclude that various FTAs of neighbor or 3rd countries increase the bilateral export and import. We provide some implications that a country to increase the amount of trade has a trade relationship with the countries having various FTAs and for the FTA effect analysis, the three-country model is better than to the two-country model.

Contribution analysis of carcass traits and seasonal effect on auction price for Hanwoo steers

  • Kang, Tae Hun;Cho, Seong-Keun;Seo, Jakyeom;Kim, Myunghoo;Kim, Byeong-Woo
    • Korean Journal of Agricultural Science
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    • v.46 no.3
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    • pp.461-469
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    • 2019
  • The aim of this study was to analyze the contribution of carcass traits (backfat thickness, eye muscle area, carcass weight and marbling score) and the season at slaughter to the price (auction and market) using squared semi-partial correlation. The season at slaughter (summer expressed as season_2, autumn as season_3, and winter as season_4) were added into the estimation as dummy variables, and spring was set as a default variable. In this study, the carcass grades of 22,298 Hanwoo steers slaughtered from 2012 to 2017 were used to performmultiple regression analysis. The rankings of the contribution of the carcass traits and the seasons at slaughter to the auction prices were in the order of marbling score (68.63%), season_4 (11.88%), backfat thickness (10.45%), eye muscle area (6.11%), season_3 (2.19%), season_2 (0.45%) and carcass weight (0.28%). (R-square of the regression = 0.4101). The rankings of the contribution to the total prices were in the order of carcass weight (51.74%), marbling score (32.12%), season_4 (6.04%), backfat thickness (5.54%), eye muscle area (3.22%), season_3 (1.14%), and season_2 (0.19%). (R-Square of the regression = 0.6486). As a result, season_3 and season_4 had a negative effect on the auction price and total price. Because of seasonal event such as Korean Thanksgiving Day and Korean New Year's Day on season_3 and season_4, much supply was needed to meet the high demand. Thus, the seasonal effect at slaughter could be another factor to be cosideredin when considering of slaughter or breeding.

Differences in Needs of Continuing Education by Academic Background for Physical Therapists

  • Kim, Ki-Jong;Yu, Seong-Hun
    • Journal of The Korean Society of Integrative Medicine
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    • v.8 no.4
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    • pp.13-18
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    • 2020
  • Purpose : The purpose of this paper is to look at educational needs based on the academic background to improve continuing education (CE) for physical therapists in the Republic of Korea. Methods : 350 people who attended the CE were selected for analysis of the need of the education in Gwangju Metropolitan city of the Korean Physical Therapy Association. Final education was classified as college, university, and master of science course (MSc) or higher. The authors selected 11 subjects such as basic education, musculoskeletal system, nervous system, pediatric, cardiopulmonary, sports, senior citizens, physical therapy, women, oriental medicine, and others. Simple linear regression analysis was performed using dummy variable to identify the needs of the CE according to the academic background. Results : The need for CE in the MSc or higher was greater than college graduation in the nervous system (R2=.019, B=.347), pediatric (R2=.028, B=.491), cardiopulmonary system (R2=.038, B=.600), sports (R2=.037, B=.584), geriatric (R2=.030, B=.261), oriental (R2=.033, B=.597), and others (R2=.028, B=.531). University graduation was lower than college graduation in the need of physical agents (R2=.037, B=-.277). Conclusion : Authors infer that CE was not fully satisfied with physical therapists especially according to academic background that's why present study showed no meaningful statistical results were found. Therefore, we still think that a wider survey of CE will be needed, and the efforts are constantly required for both the Korean physical therapy association and people who working as physiotherapists to strengthen their awareness of the education.

The Ratio of Outside Directors according to their Tenure and Firm Value (재임기간에 따른 사외이사 비율과 기업가치)

  • Lim, Sae-Hun;Park, Young-Seog
    • Asia-Pacific Journal of Business
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    • v.11 no.4
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    • pp.225-241
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    • 2020
  • Purpose - The purpose of this study was to examine the effect of the ratio of outside directors, especially the ratio of outside directors according to their tenure, on firm value. Design/methodology/approach - This study collected total 3,861 firm-year data about companies listed KRX KOSPI market in Korea. The Pooled Ordinary Least Square Model and Panel Fixed Effects Model were hired in order to analyze the data. Findings - First, it was found that the ratio of outside directors for total sample had no significant effect on firm value, and the estimation coefficient of dummy variable for the average tenure less than 3 years had a significant positive(+) effect on firm value. Second, the ratio of outside directors corresponding to the tenure of less than 3 years had a significant positive(+) effect on the firm value. On the contrary, the ratio of outside directors corresponding to the tenure of 3 years or more had a significant negative(-) effect on firm value. Third, the ratio of outside directors corresponding to the tenure for more than 6 years did not show any significant influence on firm value. Research implications or Originality - First, if other matters are not additionally considered, keeping the tenure of outside directors shortly on average could help to increase firm value. Second, in the case of firms facing the decision to reappoint outside directors for the first time, it is highly likely that the firm value would decrease on average, so careful decisionmaking considering various aspects is required. However, this study does not take into account the legal standards for the appointment of outside directors, diversity of outside directors, and the actual independence of outside directors according to other criteria in the analysis. Therefore, if these factors are considered, there is a possibility that the empirical analysis results of this study may show different patterns.

The Analysis of the Effects of Physical Activity on Impaired Fasting Glucose in Adults Over 20 Years of Age

  • Joo-Won Yoon
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.2
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    • pp.181-196
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    • 2023
  • Purpose : The purpose of this study was to investigate the effects of physical activity on impaired fasting glucose in adults aged 20 years or older. Methods : This study utilized raw data from the 8th National Health and Nutrition Examination survey (2019~2021). The subjects of this study were 5,344 adults aged 20 years or older who were confirmed to be free of diabetes. The control variables in this study model are health behavior characteristics (subjective health status, smoking, drinking), anthropometric characteristics (body mass index), and personal background characteristics (gender, age, income level, education level, marital status). As for the analysis method, the degree of physical activity was made into a dummy variable, and a probit model was used. Results : As a result of this study, compared to quartile 1 of the relative grip strength value obtained by dividing the grip strength by the body mass index (body mass index, kg, m2), fasting blood glucose levels were significantly higher in quartile 2 (.05, p<.01), quartile 3 (.04, p<.01), and quartile 4 (.04, p<.01). It was found that the probability of belonging to the normal category was higher than that of impaired fasting glucose. In addition, in the group of adults aged 20 or older who had a lot of aerobic and anaerobic physical activity, fasting blood sugar was more likely to be in the normal category. Conclusion : Based on the results of this study, it was suggested that diabetes should be managed through physical activity in the pre-diabetic stage, as prevention is important as well as treatment. From a practical point of view, muscle strength, such as grip strength, can be identified as a reliable indicator for identifying impaired fasting glucose.