• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.341-346
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• 2015

This study was conducted to investigate the awareness tendency of the government employees who manage forest roads about problems of forest road use and how to improve them in the future using surveys. The results show there are more silvicultural operations than harvesting operations using forest roads. The main purpose of using forest roads is to transport workers; however, the road will be used more for harvesting operations in the future. The respondents wanted to be accessibility for forest operations within 200 m from road in both present and future. For silvicultural operations 1-ton vehicle is used at present, and 5-ton vehicles are expected to be used in the future. For harvesting operations 5-ton vehicle is used at present, and 10-ton vehicles are will be used in the future. The roadway width is 3 - 4 m at present, but should be 4 - 4.5 m in the future. The longitudinal gradient of roads is 7 - 10% at present, and will be below 10% in the future. The minimum curve radius of roads is 12 - 15 m at present, and will be 15 - 20 m in the future. The results provide basic data for making future forest road policies.

• Journal of Periodontal and Implant Science
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• v.43 no.6
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• pp.269-275
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• 2013

Purpose: In this study, the effect of calcium sodium phosphosilicate (NovaMin) desensitizing agent, which is a powder-based system, and hydroxyethyl methacrylate and glutaraldehyde (Gluma desensitizer), which is liquid-based system, on dentinal tubule occlusion was analyzed by scanning electron microscope. The effects of the above two along with one control group were compared to determine the more effective method of sealing the dentinal tubules after initial application. Methods: Twenty specimens were allocated to each of 3 groups: Control, Gluma desensitizer, and NovaMin. Two additional samples were also prepared and treated with Gluma and NovaMin; these samples were longitudinally fractured. The specimens were prepared from extracted sound human premolars and were stored in 10% formalin at room temperature. The teeth were cleaned of gross debris and then sectioned to provide one to two dentin specimens. The dentin specimens were etched with 6% citric acid for 2 minutes and rinsed in distilled water. Control discs were dried, and the test discs were treated with the desensitizing agents as per the manufacturer's instructions. The discs as well as longitudinal sections were later analyzed under the scanning electron microscope. The proportions of completely occluded, partially occluded, and open tubules within each group were calculated. The ratios of completely and partially occluded tubules to the total tubules for all the groups was determined, and the data was statistically analyzed using nonparametric tests and statistical significance was calculated. Results: NovaMin showed more completely occluded tubules ($0.545{\pm}0.051$) while Gluma desensitizer showed more partially occluded tubules ($0.532{\pm}0.075$). The differences among all the groups were statistically significant ($P{\leq}0.05$). Conclusion: Both materials were effective in occluding dentinal tubules but NovaMin appeared more promising in occluding tubules completely after initial application.

• Korean Journal of Social Welfare
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• v.67 no.2
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• pp.183-202
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• 2015

This study examined the relationships among fear of falling, ADL/IADL disability, and depressive symptoms among Korean community-dwelling middleaged and older adults based on the disablement process model. The panel data from the Korean Longitudinal Study of Aging(KLoSa) were used to test whether fear of falling affects disablement process as a risk factor and an exacerbator. The results of path analysis showed that middle-aged and older adults who reported fear of falling were more likely to experience ADL/IADL disability and depressive symptoms, and fear of falling influenced depressive symptoms through increasing the risk of ADL/IADL disability. In addition, fear of falling exacerbate the risk of ADL/IADL disability among middle-aged and older adults who had chronic illnesses. The results indicated that fear of falling is not only risk factor but also excerbator in predicting ADL/IADL disability and depressive symptoms prospectively.

• KDI Journal of Economic Policy
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• v.29 no.3
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• pp.75-109
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• 2007

This paper empirically investigates the effects of import tariff on within-plant productivity growth in Korean manufacturing, using the detailed plant-level longitudinal data of the Korea Census of Manufacturers for the period of 1993-2003. Our main findings are as follows: First, the productivity changes of Korean manufacturing for the period under analysis were mostly induced by within-plant productivity gains, rather than within-industry and/or between-industry resource reallocations. Second, after controlling for firm-specific heterogeneity, the estimation results indicate that lowering tariff-barriers has a positive impact on within-plant TFP growth. We interpret the results in a way that trade liberalization through the removal of tariff and non-tariff barriers heightens the competitive pressure, which in turn creates incentives to reduce production and managerial inefficiency and to invest more on innovative activities. Third, we also find that plant productivity growth from reducing tariff barriers is particularly conspicuous within a year after tariff changes, which implies that plants are quickly adjusting to heightened import competition. On the other hand, our results show that the trade effect on employment creation proceeds relatively slow.

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.4
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• pp.101-112
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• 1985

It is important to extract the mechanical informations from the image sequences of the moving object. We have studied the computer algorithms for analysis of the moving heart using X-ray image sequence. A new mathematical method was developed to estimate the local epicardial deformation, wall thickness, and the regional circumferential and longitudinal wall stress using biplane coronary cineangiograms. In this method, the motion images of the coronary artery bifurca-tion points were used as natural landmarks for the kinematic analysis of the ventricular deformation. In four dogs and a normal patient's coronary cineangiograms, the estimation results show the validity of the present analysis, compared with the experimental results based upon the implanted markers. Thus, the present method provides a new method of evaluating the regional wall deformation and wall stress together with the blood vessel conditions using the coronary cineangiography procedure.

• Korean Journal of Social Welfare
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• v.67 no.3
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• pp.281-303
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• 2015

This study examined the interdependent retirement decision between husbands and wives. Since most of retirees in Korea retired by involuntary reasons such as health problems, it purposes to test whether the involuntary retirement of husbands(wives) influences the retirement decision of wives(husbands). Using data from 4th Korean Longitudinal Study of Ageing Panel, it conducted probit and multivariate probit analysis on 1,038 dual-earner couples aged 51~76 to test interdependence of couples' retirement. The results showed that husbands who have retired wife were more likely to retire. It also proved that involuntary retirement of spouse is a significant predictor of early retirement decision, though the direction of the effect is reversed by gender. Wives were more likely to retire when husband were retired involuntarily, while husbands were more likely to stay in labor market. These findings helped to understand the retirement decision of aged couples in Korea and brought suggestion on labor market and care policies for aged couples.

• Korean Journal of Biological Psychiatry
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• v.22 no.1
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• pp.1-6
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• 2015

Suicide, the fourth leading cause of death in Korea, is a serious national problem. The Korea National Suicide Survey (KNSS) is the result of the first legislation to address this issue, "Article 11 of THE ACT FOR THE PREVENTION OF SUICIDE AND THE CREATION OF A CULTURE OF RESPECT FOR LIFE" (the "Act for the Prevention of Suicide"). To overcome the limitations of previous studies, the KNSS was designed by collaborators from a variety of fields : psychology, epidemiology, social welfare, and psychiatry. The KNSS was composed of four substudies that addressed the multifaceted process involved in suicide-related behavior over time, exploring general attitudes toward suicide and suicidal ideation, suicide planning, suicide attempts, and completed suicides. Study 1 examined the risk factors for suicide based on data regarding completed suicides ; Study 2 adopted the approach of a psychological autopsy ; Study 3 focused on suicide attempters ; and Study 4 explored attitudes toward suicide in the general population. The KNSS was designed to provide a comprehensive understanding of suicide from a longitudinal, multifaceted perspective to serve as a basis for policies aimed at suicide prevention.

• Journal of Preventive Medicine and Public Health
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• v.29 no.2 s.53
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• pp.279-294
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• 1996

This study was to evaluate hospital characteristics as composition of manpower and facilities to the death rate of patient; and to earmark the factors affecting the overall hospital mortality rates. The data utilized were derived from survey material conducted by the Korean Hospital Association on 32 tertiary referral hospitals in Korea between 1986 and 1994. The findings are : 1. Those hospitals having the most capacity per bed had little difference to the mortality rates than the others. 2. Those hospitals having the most daily patients per specialist had significantly higher mortality rates than the others, but the number of daily patients per nurse had little effect on the mortality rates. 3. Those hospitals which had a relatively sufficient number of quality assurance activities revealed a lower mortality, and particularly in case where such effort was directed to the clinicians, the outcome was remarkable. We concluded that the major factor affecting the hospital mortality rates seems to be the number of specialists per number of beds, the degree of quality assurance assessment of the clinicians, the quality assurance activities of each hospital as a whole, and the number of daily patient per specialist. According to the findings of this study, the composition and quality of specialist and adequate quality assurance activities seemed to be the essential for the improvement of hospital care. Therefore, in this regard e proper implementation of policy and support is highly recommended. Due to lack of available research material, the personal characteristics of specialists haven't been considered in this study. However, this longitudinal observation of 32 tertiary referral hospitals over a nine year period has significant merit alone.

• Journal of Preventive Medicine and Public Health
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• v.42 no.5
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• pp.275-282
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• 2009

Objectives : This study aimed to verify the association between wealth or income level and health status after adjusting for other socio-economic position (SEP) indicators among Korean adults aged 45 and over. Methods : Data were obtained from the 1st wave of Korean Longitudinal Study of Ageing (households: 6,171, persons: 10,254). We used self-rated health status and activities of daily living (ADLs) as dependent variables. Explanatory variables included both net wealth measured by savings, immovables, the other valuated assets and total income including pay, transfer, property and so on. Binary logistic regression was conducted to examine the relationships. Also, in order to determine the relative health inequality across economic groups, we estimated the relative index of inequality (RII). Results : The inequality of health status was evident among various wealth and income groups. The wealthiest group (5th quintile) was much healthier than the poorest group, and this differential increased with age. Likewise, higher income was associated with better health status among the elderly. However, these effects, as measured by the odds ratio and RII, showed that wealth was more important in determining health status of elderly people. Conclusions : This study suggests that economic capability plays a significant role in determining the health status and other health-related problems among the elderly. Particularly, our results show that health status of the aged is related more closely to the individual s wealth than income.

• Korean Journal of Ecology and Environment
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• v.40 no.4
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• pp.527-536
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• 2007

In this study, we applied 10-metric health assessment model, based on the Index of Biological Integrity (IBI) during 2006 in the Changwon Stream, which is located in the Changwon city, Gyeongnam province, S. Korea, and then compared with water quality data. The Index of Biological Integrity (IBI) in the Changwon Stream varied from 18 to 38 in the watershed depending on the sampling location and averaged 30.3 (n=6) during the study. Analysis of tolerance guilds showed that the proportion of sensitive species was 13%, but tolerant and intermediate species were 34% and 53%, respectively. Qualitative Habitat Evaluation Index (QHEI) averaged 43.3 (range: 65-104, n=6) indicating non-supporting condition, based on the criteria of U.S. EPA (1993). Values of QHEI showed a typical longitudinal decreases from the headwater reach to the downstream location, except for Site 1 with a low QHEI value by artificial habitat by concrete construction. Minimum QHEI was found in Site 4 where fish diversity was minimal. Conductivity increased continuously along the gradients and especially showed abrupt increases in the downstream sites along with turbidity. Stream ecosystem health of IBI matched to the values of QHEI except for S6. Low IBI values in the sites 4 and 5 was considered to be a result of combined effects of chemical pollutions and habitat degradations. Our results support the hypotheses of Plafkin et ai. (1989) that physical habitat quality directly influences the trophic structure and species richness, and is closely associated with IBI values.