• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.12 no.4
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• pp.239-247
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• 2008

Let $I{\in}C^{1,1}$ be a strongly indefinite functional defined on a Hilbert space H. We investigate the number of the critical points of I when I satisfies two pairs of Torus-Sphere variational linking inequalities and when I satisfies m ($m{\geq}2$) pairs of Torus-Sphere variational linking inequalities. We show that I has at least four critical points when I satisfies two pairs of Torus-Sphere variational linking inequality with $(P.S.)^*_c$ condition. Moreover we show that I has at least 2m critical points when I satisfies m ($m{\geq}2$) pairs of Torus-Sphere variational linking inequalities with $(P.S.)^*_c$ condition. We prove these results by Theorem 2.2 (Theorem 1.1 in [1]) and the critical point theory on the manifold with boundary.

• Journal of the Korean Home Economics Association
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• v.32 no.3
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• pp.27-44
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• 1994

Despite the rapid economic growth since the 1960s the economic inequality has been exacerbated in Korea. This study analyzed the variables influencing the level of objective deprivation. For empirical analysis this study used the data on 602 households in the city of Inchon collected by the researcher through interviews. The major method used in this study was the four stepwise multiple regression. The findings were as follows : the residential class was the most critical variable in determining the level of deprivation. For the entire sample assets had stronger effect on the deprivation than nonasset income but two variables had different effects depending on residential class. For the poor residential class two variables had the effect These results imply that the household consumption in Korea shows remarkable difference according to residential class and that the inequality of wealth compared to that of nonasset income had much more serious effects.

• The Journal of Industrial Distribution & Business
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• v.6 no.1
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• pp.5-15
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• 2015

Purpose - This study reviews Cameroon's economic growth, crisis, and recovery, aiming to: review the principal factors of Cameroon's real economic growth; explore the causes of its economic crisis analyze the determinants of its economic recovery; and suggest appropriate policies to ameliorate economic growth. Research design, data, and methodology - By reviewing the relevant literature and economic indicators, we observed that from the 1980s to the present, Cameroon experienced all the possible business cycle phases: economic prosperity (until 1985), economic and social crisis (1986-1994), and renewed economic growth (after 1995). Results - As a result of the economic changes in Cameroon, its macroeconomic indicators have evolved. Poverty and inequality have changed in both quantitative and qualitative terms. Throughout the examined period, rural poverty has become more widespread, deeper, and more severe than urban poverty, while inequality has experienced greater increases in urban areas relative to rural zones. Conclusions -To reap maximum benefits and reduce poverty from these economic changes, Cameroon needs to liberalize trade and foreign exchange transactions to attract foreign investment, especially during the current globalization.

• Bulletin of the Korean Mathematical Society
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• v.46 no.2
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• pp.311-319
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• 2009

Let H be a Hilbert space which is the direct sum of five closed subspaces $X_0,\;X_1,\;X_2,\;X_3$ and $X_4$ with $X_1,\;X_2,\;X_3$ of finite dimension. Let J be a $C^{1,1}$ functional defined on H with J(0) = 0. We show the existence of at least four nontrivial critical points when the sublevels of J (the torus with three holes and sphere) link and the functional J satisfies sup-inf variational inequality on the linking subspaces, and the functional J satisfies $(P.S.)^*_c$ condition and $f|X_0{\otimes}X_4$ has no critical point with level c. For the proof of main theorem we use the nonsmooth version of the classical deformation lemma and the limit relative category theory.

• Journal of the Chungcheong Mathematical Society
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• v.21 no.4
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• pp.437-445
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• 2008

We show the existence of at least four nontrivial critical points of the $C^{1,1}$ functional f on the Hilbert space $H=X_0{\oplus}X_1{\oplus}X_2{\oplus}X_3{\oplus}X_4$, $X_i$, i = 0, 1, 2, 3 are finite dimensional, with f(0) = 0 when two sublevel subsets, torus with three holes and sphere, of f link, the functional f satisfies sup-inf variatinal linking inequality on the linking subspaces, the functional f satisfies $(P.S.)_c$ condition, and $f{\mid}_{X_0{\oplus}X_4}$ has no critical point with level c. We use the deformation lemma, the relative category theory and the critical point theory for the proof of main result.

• Health Policy and Management
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• v.6 no.1
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• pp.110-143
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• 1996

The purpose of this study is to assess the extent of inequality in health outcomes and the distribution of health services according to health need under National Health Insurance System in Korea. For the empirical analysis, data were collected through an interview survey during one month of October, 1994. Interview were conducted with a total of 10, 875 of the employees and the self-employed selected through cluster, systematic sampling. The major findings of this research are as follows: 1. The analysis of the differentials in morbidity rates by socio-economic group showed that health inequality in the pro-higher groups existed in all self-reported morbidity indicators. 2. The findings of the conventional use measures showed that the lower socio-economic groups had more ambulatory and inpatient services than the higher groups. In contrast to the level of the medical care utilization, however, the higher socio-economic groups were more likely to use the high-quality source of care in terms of their treatment place compared to the lower groups. 3. By using the need-based use measures, the results were different from each use-disability ration indicator. Using the use-disability ration measured by physician visits per 100 restricted-activity days in the population, it was found that there was no evidence favoring the higher socio-economic groups. In contrast, the use-disability ration based on physician visits per a chronic patient in one year displayed that there was remarkable relative difference by income group as well as the evidence of the pro-higher income groups. 4. The results of logistic regression analysis and two-stage estimation method indicated that although the utilization is significantly affected by type and duration of insurance coverage, the use or nonuse of service and the volume of physician care consumed is determined by health need and demographic characteristics rater than economic status. In sum, these findings suggest that physician service is equitably distributed according to health need under national health insurance system in Korea. As there were some evidences of inequality including the differential in physician visits of chronic patients by income group, however, the government should strengthen the activities to guarantee the equity of health services utilization.

• Nuclear Engineering and Technology
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• v.16 no.4
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• pp.181-194
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• 1984

The in-core fuel management problem was studied by use of the calculus of variations. Two functions of interest to a public power utility, the profit function and the cost function, were subjected to the constraints of criticality, the reactor turnup equations and an inequality constraint on the maximum allowable power density. The variational solution of the initial profit rate demonstrated that there are two distinct regions of the reactor, a constant power region and a minimum inventory or flat thermal flux region. The transition point between these regions is dependent on the relative importance of the profit for generating power and the interest charges for the fuel. The fuel cycle cost function was then used to optimize a three equal volume region reactor with a constant fuel enrichment. The inequality constraint on the maximum allowable power density requires that the inequality become an equality constraint at some points in the reactor. and at all times throughout the core cycle. The finite difference equations for reactor criticality and fuel burnup in conjunction with the equality constraint on power density were solved, and the method of gradients was used to locate an optimum enrichment. The results of this calculation showed that standard non-linear optimization techniques can be used to optimize a reactor when the inequality constraints are properly applied.

• Journal of Preventive Medicine and Public Health
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• v.38 no.3
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• pp.359-365
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• 2005

Objectives : An abrupt economic decline may widen the socioeconomic differences in health between the advantaged and disadvantaged in a society. The aim of this study was to examine whether the South Korean economic crisis of 1997-98 affected the socioeconomic inequality from all-causes and from cause-specific mortality between 1995 and 2001. Methods : Population denominators were obtained from the registration population data, with the number of death (numerators) calculated from raw death certificate data. The indicator used to assess the geographic socioeconomic position was the per capita regional tax revenue. Administrative districts (Si-Gun-Gu) were ranked according to this socioeconomic measure, and divided into equal population size quintiles on the basis of this ranking. The sex- and 5-year age-specific numbers of the population and deaths were used to compute the sex- and age-adjusted mortality rates (via direct standardization method), standardized mortality ratios (via indirect standardization methods) and relative indices of inequality (RII) (via Poisson regression). Results : Geographic inequalities from all-causes of mortality, as measured by RII, did not increase as a result of the economic crisis (from 1998-2001). This was true for both sexes and all age groups. However, the cause-specific analyses showed that socioeconomic inequalities in mortalities from external causes were affected by South Korean economic crisis. For males, the RIIs for mortalities from transport accidents and intentional self-harm increased between 1995 and 2001. For females, the RII for mortality from intentional self-harm increased during the same period. Conclusions : The South Korean economic crisis widened the geographic inequality in mortalities from major external causes. This increased inequality requires social discourse and counter policies with respect to the rising health inequalities in the South Korean society.

• Communications for Statistical Applications and Methods
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• v.11 no.3
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• pp.513-518
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• 2004

The well-known mode-mean-median inequality for the unimodal population distribution does not always hold for the frequency distribution. But many elementary statistics text books just mention that the relative location of the mean and median can be used to determine whether a distribution is positively or negatively skewed. In this paper we introduce the method generating data that is positively skewed but mean

• The Journal of the Korea Contents Association
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• v.13 no.6
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• pp.236-245
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• 2013

This study analyzed the relationship between elderly suicide rates and socio-economic factors from the macroscopic perspectives. As certain theoretical background of elderly suicide, sociological and economic perspectives are applied. The economic factors of elderly suicide rates consisted of economic growth and unemployment rate, economic activity rate of the aged, and relative poverty rate (income inequality rate). The sociological factors included social welfare spending, divorce rate, growth rate of population aging, and elderly dependency ratio. According to research findings, first, the more economic activity of the aged is low, the more elderly suicide rate is high. Second, the more social welfare spending rate goes flat, the more elderly suicide rate is growing. Third, the more relative poverty rate (income inequality), increasing population aging rate, and elderly dependency ratio are high, elderly suicide rate goes high at the same time. Finally, this study proposed several socio-economic policy alternatives for preventing continuous growth of Korean elderly suicide rate.