• Korean Journal of Social Welfare
• /
• v.59 no.1
• /
• pp.199-221
• /
• 2007

This study examines the conditions and causes of income inequality and seeks assignments for mitigating income inequality. An analysis of the conditions and causes of income inequality is summarized as follows. First, income inequality, which rapidly increased after the economic crisis, increased and reduced repeatedly during 1999-2004, and remained a level in 2005 as high as that of the year directly after the economic crisis. Second, an analysis of the causes of income inequality by utilizing the long-term data(1985-2004) shows that unemployment rate, nonstandard employment rate, and the rising rate of land prices positively affect income inequality. Third, an analysis of the causes of income inequality by utilizing the data before and after the economic crisis(1995-2004) demonstrates that unemployment rate, nonstandard employment rate, and the workers' income ratio between large enterprises and small enterprises positively affect income inequality. Fourth, the rising rate of land prices which significantly affects income inequality in the data of 1985-2004 does not affect income equality in the data of 1995-2004, and the workers' income ratio between large enterprises and small enterprises which does not affect income inequality in the data of 1985-2004 significantly affect income equality in the data of 1995-2004. These results suggest several implications for mitigating income inequality. First, alternative plans to reduce unemployment rate must be prepared. Second, policies to reduce nonstandard employment rate should be established. Third, programs to stabilize or lower the land prices must be deliberated. Fourth, a master-plan to support small to medium enterprises must be carried out in order to reduce the wage differentials between large enterprises and small to medium enterprises.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.27 no.2
• /
• pp.259-264
• /
• 2003

One Clausius inequality based on an apparatus with a single thermal reservoir is reviewed. Some intricate issues regarding the apparatus are brought up and therefore a preferred way to interpret the Kelvin-Planck statement is suggested. Then it is shown that another Clausius inequality can be established from a direct application of the proposition regarding the efficiency of a Carnot cycle. The establishment is based on an apparatus with two reservoirs, and the resultant inequality involves the temperature of external reservoir. Finally, a different apparatus which also has two thermal reservoirs is utilized to compare the cyclic integral of the former inequality with the one of the latter resulting in the proof of the former inequality which involves the temperature at the system boundary. The applications and limitations of these two Clausius inequalities are discussed.

• 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.

• STI Policy Review
• /
• v.7 no.2
• /
• pp.1-15
• /
• 2016

This study provides empirical evidences for the relationship between income inequality and economic growth, and relationship of income inequality with some of explanatory variables such as technological innovation, trade globalization, financial globalization and fiscal policy. We find out that income inequality has an adverse effect on economic growth, showing its dynamic features, for which we employed the polynomial distributed lags (PDL) model. The effect of income inequality on economic growth lasts over 9 years, and its dynamic effect peaks after 4 years. In addition, we also attempted to find out empirical evidences of sources of income inequality. The results show that income inequality is positively related to technological innovation, financial globalization, and fiscal policy; negatively related to the trade globalization. Many studies employ cross-country data, but it could have serious problems in collecting statistical data. Korean data is used over the time period of 1990-2015 in this study.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.3 no.1
• /
• pp.127-135
• /
• 1999

An inequality of Ostrowski's type for monotonous nondecreasing mappings is given. Applications for quadrature formulas are pointed out.

• Journal of applied mathematics & informatics
• /
• v.8 no.3
• /
• pp.1021-1026
• /
• 2001

In this paper, we give an improvement of Carleman’s inequality by using the strict monotonicity of the power mean of n distinct positive numbers.

• East Asian mathematical journal
• /
• v.18 no.2
• /
• pp.163-173
• /
• 2002

In this paper an inequality of Ostrowski type in terms of the lower and upper bounds of the first derivative is found.

• Journal of the Chungcheong Mathematical Society
• /
• v.22 no.2
• /
• pp.287-291
• /
• 2009

A comparison of constants is given to show that a better constant for the Sobolev trace inequality can be obtained from the conjectured extremal function.

• Journal of applied mathematics & informatics
• /
• v.16 no.1_2
• /
• pp.151-163
• /
• 2004

In this paper, we improve several inequalities involving Tay-lor's remainder by using some variants of Gruss inequality.

• Journal of the Chungcheong Mathematical Society
• /
• v.21 no.4
• /
• pp.493-499
• /
• 2008

We construct a minimizing sequence for the Sobolev trace inequality which satises compactness in the concentration compactness property.