• Journal of Advanced Navigation Technology
• /
• v.21 no.6
• /
• pp.608-613
• /
• 2017

In this paper, we consider the stability bound for uncertainty of delayed state variables in the linear discrete interval time-varying systems with time-varying delay time. The considered system has an interval time-varying system matrix for non-delayed states and is perturbed by the unstructured time-varying uncertainty in delayed states with time-varying delay time within fixed interval. Compared to the previous results which are derived for time-invariant cases and can not be extended to time-varying cases, the new stability bound in this paper is applicable to time-varying systems in which every factors are considered as time-varying variables. The proposed result has no limitation in applicable systems and is very powerful in the aspects of feasibility compared to the previous. Furthermore. the new bound needs no complex numerical algorithms such as LMI(Linear Matrix Inequality) equation or upper solution bound of Lyapunov equation. By numerical examples, it is shown that the proposed bound is able to include the many existing results in the previous literatures and has better performances in the aspects of expandability and effectiveness.

• The Journal of the Korea Contents Association
• /
• v.18 no.5
• /
• pp.386-396
• /
• 2018

The purpose of this study is to examine young Koreans' welfare attitudes towards youth policy and to analyze the determinants on such attitudes. The main results are as follows. Many young people(72.1%) understand that government should be responsible for youth support and spending on youth support policy(49.5%) and job support policy(59.7%) should be expanded than current level. But only 24.1% approved the provision of youth allowance. There was a significant in-group heterogeneity among the young generation in terms of support for expanding fiscal spending for youth policy and youth allowance provision. Results from the regression analysis indicated sex, age, education level, employment status, type of housing affect attitudes towards youth policy and statistical significance of them was different according to each analytic model. Korean young adult generally perceived that our society was unequal and the higher the perception of inequality, the higher support for youth policy. These results implicates that in-group heterogeneity among youth generation in terms of socio-economic needs and subjective perception should be regarded as important factor in the youth policy making process.

• Journal of Labour Economics
• /
• v.40 no.4
• /
• pp.1-31
• /
• 2017

Recent empirical studies highlight the importance of between-firm or between-establishment factors in rising wage inequality. Examining the establishment-level data from the Mining and Manufacturing Survey of 2000-14, this paper finds that overall between-establishment wage dispersion has increased in Korea. However, unlike other OECD countries, the divergence occured in the lower tail of the wage distribution. Dispersion in labor productivity exhibits a similar movement, therefore explains the widening wage dispersion. In contrast, the link between wages and total factor productivity is much weaker, which appears to be associated with inefficient capital reallocation. I also find much heterogeneity in the productivity-wage relationship across productivity distribution. The most productive establishments turn the smallest portion of productivity gains into wage increases.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.5 no.3
• /
• pp.45-55
• /
• 2001

The purpose of this paper is to present the optimal design method of viscoelastic dampers and support brace stiffnesses. The dynamics of visco-elastic dampers and support braces connected in series is modeled by state equation. A constraint on maximum story drifts which are computed using RMS\`s of story drifts and peak factors is added to the optimization problem. The number of variables is reduced by including the constraint associated with the dynamic behavior of the structure in the procedure to compute the gradient of the inequality equation about constraint on the maximum story drifts. In the design example, it is confirmed that the design of dampers considering support brace stiffnesses is necessary when sufficient brace stiffnesses cannot be supplied. It is also found that unnecessary brace stiffnesses can be removed by adding brace stiffnesses to optimal design variables and that the increase of damper volumes to compensate for the variation of maximum story drifts is pretty small.

• Journal of Korean society of Dental Hygiene
• /
• v.17 no.6
• /
• pp.1109-1119
• /
• 2017

Objectives: The purpose of this study is to evaluate the relationship between socioeconomic characteristics and prevalence of periodontal disease in a representative sample of Korean adults older than age 20. Methods: Data of 3,837 adults were collected by the six Korean National Health and Nutrition Examination Survey, which was conducted in 2015. Socioeconomic, demographic, and oral health-related behavior data were collected as independent variables. We determined frequencies, percentage, and determining statistical significance using multiple regression analysis. Results: Prevalence of periodontal diseases showed statistically significant difference in accordance with sex, age, socioeconomic and demographical characteristics and oral health-related behavior. It was confirmed that the prevalence of periodontal diseases was increased in the lower educational level and income (OR, 1.478 and 1.520) after adjusting for conditions such as age, sex, recent dental check-ups, visiting dental clinic, tooth brushing frequency, use of self-care devices. Conclusions: The prevalence of periodontal disease was related with socioeconomic factors in Korean adults. Therefore, differentiated oral health service policies and dental health education among adults with lower education and income is required in order to reduce the prevalence of periodontal disease.

• The Korean Journal of Applied Statistics
• /
• v.16 no.1
• /
• pp.87-100
• /
• 2003

Most of statistical data are generated by a set of dynamic, stochastic, and simultaneous relations. An important question is how to specify statistical models so that they are consistent with the dynamic feature of those data. A general hypothesis is that the lagged effect of a change in an explanatory variable is not felt all at once at a single point in time, but The impact is distributed over a number of future points in time. In other words, current control variables are determined by a function that can be reduced to a distributed lag function of past observations. It is possible to explain the relationship between variables in different points of time and to estimate the long-run impacts of a change in a variable on another if time lag series of explanatory variables are incorporated in the model specification. In this study, distributed lag structure is applied to the domestic stock market model to capture the dynamic response of the market by exogenous shocks. The Domestic market is found more responsive to the changes in foreign market factors both in the short and the long run.

• Health Policy and Management
• /
• v.10 no.4
• /
• pp.1-19
• /
• 2000

We have witnessed several kinds of new discourses and practices in health and medicine since the 1970s, such as popular concerns with alternative or complementary medicine, inordinate attention to the promotion of 'healthy' living, rapid resurrection of traditional medicine and ecological management of health. Four structural and situational factors are discussed to underlie these new trends：(i) as 'crisis' in health care of the 1970s was translated into health care reform of the 1980s backed up by neo-liberal political philosophy, the state responsibility for nation's health is being transferred to the individual ；(ii) it resulted from the limits of biomedical paradigm in dealing with chronic diseases；(iii) medico-scientific knowledge of disease is transformed into the subjective discourses and technologies of health in postmodern society ； and (iv) it is deeply associated with the considerable increase in environmental risk perception of health and disease. There are some inherent countervailing forces in these new discourses and practices. First, while they derive from lifestyle-oriented behavioral change, medicalization of life and death is still consolidated in the new trends. Second, inasmuch as new tides are reliant upon science, they. are likely to be remote from techne that means not the practical application of theoretical knowing but a special form of practical knowing. Third, as new discourses and activities accomplished＇in the name of health＇increasingly occupy important strategies in forming the self-identity, they serve as moral apparatus which involves prescriptions about how we should live our lives and conduct our bodies, both individually and collectively. Therefore, two points are suggested to consider seriously whether these streams will succeed in improving the‘healthy’living of all the people. Instead of limiting tile perspective to medicine, healing and health care, a new matrix that interweave welfare, ecology and labor along with them is timely needed for enhancing the health for all. In addition, as the World Health Report fm strongly shows, inequality in health heavily depends upon socio-economic development of a society, and it is not the richest countries that have the best health status, but those that have the smallest income differences between rich and poor.

• Korean Journal of Health Education and Promotion
• /
• v.24 no.2
• /
• pp.123-134
• /
• 2007

Since 1996, the Health Promotion Programme spearheaded by the Korean Central Government has been actively developing and recently, the Healthy City Project led by the local autonomous entities have also been actively promoted. Healthy City is one in which the health and well-being of the citizens are given the utmost importance in the decision-making of the city. While the Health Promotion Programme focuses on changing the "health behavior" of the people, the Healthy City Project, a policy to improve the existing inequality of public health services, deals with more essential health factors and requires political support as well as a new organization. The Healthy City paradigm based on the New Public Health started in England and ever since the Healthy City Model Project spearheaded by the EURO WHO began in 1986, the Alliance for Healthy Cities centered in the West Pacific region supported by the WHO in Oct 2003 was inaugurated. 19 Korean cities are full members of the Alliance for Healthy Cities and 2 laboratories are associate members. The Ministry of Health and Welfare has held the Healthy City Forum consisting of related officials, experts and representatives of civic bodies on 6 occasions since Dec 2005. The need for adequate administrative and financial support from the Central Government to the local autonomous entities governing the Healthy Cities was raised. It is hoped that this Healthy City Project will bring about the improved health conditions of the people as well as promote the equality of the public health services.

• Informatization Policy
• /
• v.27 no.1
• /
• pp.36-54
• /
• 2020

This study empirically analyzes the impact of digital divide between digital device usage motivation and operational skills on online political participation. The analysis was performed using the National Information Society Agency's 2018 digital divide survey data from September to December 2018 and applying the Heckman selection model to control the sample selection bias that may occur between internet users and non-users. The result shows the gap in motivation and device operational skills of individual citizens using digital devices has significant impact on online political participation. In socio-economic terms, it shows the age, education level and regional factors also have significant impact on online political participation, while gender and income levels do not. This study holds significance in that there are different patterns of digital divide between digital devices, identifying the motivation to use a digital device as an important factor for mobile device users, and the device operational skills, for personal computer users.

• Spatial Information Research
• /
• v.23 no.5
• /
• pp.65-73
• /
• 2015

Newtown Business of Seoul had been performed to reduce deterioration of Gangbuk and economic inequality between Gangnam and Gangbuk. According to this, Eunpyeong-gu was set as test-bed for Newtown business and Newtown business had been completed until 2013. This study aims to analyze the influence of social and economical factors which affect land price using GWR (Geographically Weighted Regression) considered spatial effect. As a result of analysis, GWR model demonstrated a better goodness-of-fit than OLS (Ordinary least square) model typically used in most study. Furthermore, AIC value and Moran's I of residual prove that GWR model is more suitable than OLS model. GWR model enable to explain more detailed than global regression model as coefficient and sign show different value locally. In future, this research will be helpful to develop Eunpyeong-gu considering spatial characters and strength effectiveness of development.