• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.3
• /
• pp.289-297
• /
• 2014

This article surveys the control theoretic study on time delay systems. Since time delay systems are infinite dimensional, there are not analytic but numerical solutions on almost analysis and synthesis problems, which implies that there are a tremendous number of approximated solutions. To show how to find such solutions, several results are summarized in terms of two different axes: 1) theoretic tools like integral inequality associated with the derivative of delay terms, Jensen inequality, lower bound lemma for reciprocal convexity, and Wirtinger-based inequality and 2) various candidates for Laypunov-Krasovskii functionals.

• Journal of Preventive Medicine and Public Health
• /
• v.51 no.6
• /
• pp.310-319
• /
• 2018

Objectives: This study examined trends in inequality in cigarette smoking prevalence by income according to recent anti-smoking policies in Korea. Methods: The data used in this study were drawn from three nationally representative surveys, the Korea National Health and Nutrition Examination Survey, the Korea Community Health Survey, and the Social Survey of Statistics Korea. We calculated the age-standardized smoking prevalence, the slope index of inequality, and the relative index of inequality by income level as a socioeconomic position indicator. Results: Smoking prevalence among men decreased during the study period, but the downward trend became especially pronounced in 2015, when the tobacco price was substantially increased. Inequalities in cigarette smoking by income were evident in both genders over the study period in all three national surveys examined. Absolute inequality tended to decrease between 2014 and 2015 among men. Absolute and relative inequality by income decreased between 2008 and 2016 in women aged 30-59, except between 2014 and 2015. Conclusions: The recent anti-smoking policies in Korea resulted in a downward trend in smoking prevalence among men, but not in relative inequality, throughout the study period. Absolute inequality decreased over the study period among men aged 30-59. A more aggressive tax policy is warranted to further reduce socioeconomic inequalities in smoking in young adults in Korea.

• Journal of Preventive Medicine and Public Health
• /
• v.40 no.6
• /
• pp.422-430
• /
• 2007

The socioeconomic inequalities in health have recently become an important public health concern in South Korea, and the issue has gained increasing attention from many South Korean researchers due to the increasing income inequality and Widening social polarization following its economic crisis in the late 1990s. However, despite the mounting literature on health inequalities published in recent years, the history of research on health inequality in South Korea is premature in comparison to the long histories in several Western countries. Understanding the historical background underlying the issue of health inequality research may aid in establishing and accumulating scientifically solid evidence in South Korea. It may also direct the South Korean research community to develop research agendas that are. more politically and academically appropriate for South Korean society. This paper describes the historical development of health inequality research in the West and introduces several important issues contributing to the advancement of health inequality research. Specifically, the major studies conducted before and after the UK Black Report are presented. In addition, the history and current status of health inequality research in South Korea are documented and evaluated. Finally, several research agendas for the quantitative and qualitative improvement of health inequality research in South Korea are proposed.

• Korea Trade Review
• /
• v.44 no.2
• /
• pp.269-282
• /
• 2019

This study analyzes the effects of participation in the global production network on the income inequality using panel data from 2005 to 2016 for 63 countries. In this study were used fixed effects model with autocorrelation, random effect model with autocorrelation and the GLS method. Results are as follows: First, the economic development level supports the Kuznets hypothesis. And then, the forward participation in global value chains increased income inequality, and the backward participation decreased income inequality. In order to derive more detailed estimation results, we analyzed OECD countries and non-OECD countries. First, OECD countries featured decreased, but increased beyond a certain level as a U-shaped curve, that did not support the Kuznets hypothesis. In contrast, non-OECD countries followed the Kuznets U-curve. Second, participation in the global production network showed that both OECD and non-OECD countries featured increased income inequality. In contrast, backward participation appears to mitigate income inequality both in OECD and non-OECD countries. Finally, the ratio of labor and capital is significant in mitigating income inequality in non-OECD countries in which they feature backward participation in production networks. This can be interpreted as developing economies participate in the global production network due to increased capital accumulation and increased the labor productivity.

• Bulletin of the Korean Mathematical Society
• /
• v.38 no.4
• /
• pp.701-708
• /
• 2001

In this article, using the properties of power mean, some new generalizations of the strengthened Hardy's inequalities are given.

• Communications of the Korean Mathematical Society
• /
• v.13 no.1
• /
• pp.159-170
• /
• 1998

In this paper, we extend Burkholder's exponential inequality for a strong subordinate of a nonnegative bounded submartingale.

• Journal of the Chungcheong Mathematical Society
• /
• v.35 no.2
• /
• pp.161-170
• /
• 2022

It is presented a Banach space of functions of bounded mean oscillation BMO type.

• Health Policy and Management
• /
• v.20 no.3
• /
• pp.36-57
• /
• 2010

The degree of income inequality deepened by health care expenditure was useful in assessing the health security level. This exploratory study was conducted to provide a basic evidence to prove the necessity of reinforcement the benefit coverage of South Korea's health security systems. Data from the Household Income and Expenditure Survey of Korea and Luxembourg Income Study were used. Income inequality indices before and after deduction of health care expenditure were computed, and the degree of the increase in the indices was compared among 13 countries. The degree of decrease against the effect of income inequality reduction policies by health care expenditure was determined. The relationships between the national characteristics and the increase in income inequality were examined. In South Korea, all income inequality indices increased after deducting health care expenditure, but the difference was not high compared to the mean of 13 countries. However, the degree of decrease against the effect of income inequality reduction policies by health care expenditure was high, compared to the mean of 13 countries. The proportion of public sector spending on health care proved to be statistically significant with the increase of income inequality indices (p<0.05). In the context of the continuous increase in health care expenditure, if benefit coverage of health security systems is not reinforced, income inequality will all the more increase due to health care expenditure. In the establishment of the policies for reinforcement of the benefit coverage, income inequality after deduction of health care expenditure should be continuously monitored.

• Journal of muscle and joint health
• /
• v.19 no.1
• /
• pp.27-36
• /
• 2012

Purpose: The purpose of this study was to investigate the leg length Inequality, habitual posture, and pain in women's college students. Methods: The subjects were 281 students, in 8 women's college in Korea. The tapelines were used for measuring leg length Inequality and questionnaires were used for measuring habitual posture, and pain. The data were collected between August and October 2010 and analyzed using SPSSWIN 11.5. length Inequality(<1 cm). The subjects of 2.8% were the length differences of above 2cm. The worst habitual posture were leaning habits. Especially, the habits of crossing her legs were significantly different to leg length Inequality(F=3.342, $p$=.037). The subjects of 84% were felt a severe pain on the upper body such as waist, back, scapula, neck or shoulder. But there is no difference between pain and leg length Inequality. Habitual posture are related to pain(r=.212, $p$=.001). Conclusion: To protect the severe health problem of musculoskeletal system, this study results will be give aid to health education in women's college students.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10b
• /
• pp.486-490
• /
• 1993

In addtion to a basic motion task, redundant manipulators can achieve some additional tasks by optimizing proper performance criteria. Some of performance criteria can be transformed to inequality constraints. So the redundancy resolving problem can be reformulated as a local optimization problem with equality constraints for the end effector and inequality constraints for some performance criteria. In this article, we propose a method for solving the inverse kinematics of a manipulator with redundancy using the Kuhn-Tucker theorem to incorporate inequality constraints. With proper choice of inequality constraints, the proposed method gives a way of optimizing multiple criteria in redundant manipulators.