• KSCE Journal of Civil and Environmental Engineering Research
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• v.1 no.1
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• pp.53-68
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• 1981

Most clays under sustained load exhibit time-dependent deformation because of creep movement of soil particles and many investigators have attempted to relate their findings to the creep behavior of natural ground and to the long-term stability of slopes. Since the creep behavior of clays may assume a variety of forms depending on such factors as soil plasticity, activity and water content, it is difficult and complicated to analyse the creep behavior of clays. Rheological models composed of linear springs in combination with linear or nonlinear dashpots and sliders, are generally used for the mathematical description of the time-dependent behavior of soils. Most rheological models, however, have been proposed to simulate the behavior of secondary compression for saturated clays and few definitive data exist that can evaluate the behavior of non-saturated clays under the action of sustained stress. The clays change gradually from a solid state through plastic state to a liquid state with increasing water content, therefore, the rheological models also change. On the other hand, creep is time-dependent, and also the effect of thixotropy is time-function. Consequently, there may be certain correlations between creep behavior and the effects of thixotropy in compacted clays. In addition, the states of clay depend on water content and hence the height of the specimen under drained conditions. Futhermore, based on present and past studies, because immediate elastic deformation occurs instantly after the pressure increment without time-delayed behavior, the factor representing immediate elastic deformations in the rheological model is necessary. The investigation described in this paper, based on rheological model, is designed to identify the immediate elastic deformations and the effects of thixotropy and height of clay specimens with varing water content and stress level on creep deformations. For these purposes, the uniaxial drain-type creep tests were performed. Test results and data for three compacted clays have shown that a linear top spring is needed to account for immediate elastic deformations in the rheological model, and at lower water content below the visco-plastic limit, the effects of thixotropy and height of clay specimens can be represented by the proposed rheological model not considering the effects. Therefore, the rheological model does not necessitate the other factors representing these effects. On the other hand, at water content higher than the visco-plastic limit, although the state behavior of clays is visco-plastic or viscous flow at the beginning of the test, the state behavior, in the case of the lower height sample, does not represent the same behavior during the process of the test, because of rapid drainage. In these cases, the rheological model does not coincide with the model in the case of the higher specimens.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.8-16
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• 2008

Purpose: To assess the effect of extracranial-intracranial (EC-IC) bypass surgery on hemodynamic improvement, we evaluated serial regional cerebral hemodynamic change of the middle cerebral artery (MCA) in symptomatic patients with atherosclerotic occlusion of the internal carotid artery (ICA) or MCA using $^{99m}Tc$-ECD acetazolamide stress brain perfusion SPECT (Acetazolamide SPECT). Materials and Methods: The patients who had suffered a recent stroke with atherosclerotic ICA or MCA occlusion underwent EC-IC bypass surgery and Acetazolamide SPECT at 1 week before and three to six months after surgery. For image analysis, attenuation corrected images were spatially normalized to SPECT templates with SPM2. Anatomical automated labeling was applied to calculate mean counts of each Volume-Of-Interest (VOI). Seven VOIs of bilateral frontal, parietal, temporal regions of the MCA territory and the ipsilateral cerebellum were defined. Using mean counts of 7 VOIs, cerebral perfusion index and perfusion reserve index were calculated. Results: Seventeen patients (M:F =12:5, mean age $53{\pm}2yr$) were finally included in the analysis. The cerebral blood flow of the parietal region increased at 1 week (p = 0.003) and decreased to the preoperative level at 3-6 months (p = 0.003). The cerebrovascular reserve of the frontal and parietal regions increased significantly at 1 week after surgery (p<0.01) and improved further at 3-6 months. Conclusion: Cerebrovascular reserve of the MCA territory was significantly improved at early postoperative period after EC-IC bypass and kept improved state during long-term follow-up, although cerebral blood flow did not significantly improved. Therefore, cerebrovascular reserve may be a good indicator of postoperative hemodynamic improvement resulted from bypass effect.

• Korean Journal of Environmental Agriculture
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• v.27 no.2
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• pp.178-184
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• 2008

This work was carried out to investigate the effect of waterlogging on the growth and nutrient contents of 'Campbell Early' and 'Kyoho' grapevines under the vinyl house condition from June 14 to July 20, 2005. For the trial, seedlings of two-year-old grapevine were transplanted to 40 L pot with a sandy loam soil. Irrigation point of non-waterlogging(control) treatment was controlled at -40 kPa of soil water tension using tensiometer and waterlogging treatments were imposed for 35 days at the water levels of above 10 cm from the soil surface using tap water. The growth of aerial(shoot length, leaf number and stem diameter) and underground(root) parts of 'Campbell Early' and 'Kyoho' grapevines tended to be wholly reduced by waterlogging, while the growth of aerial parts were more severely impaired in 'Kyoho' than in 'Campbell Early' cultivar. The different responses for waterlogging between two grapevines seem to be related with the capacity for absorbing mineral nutrients, because nitrogen content of 'Campbell Early' cultivar leaves was significantly higher than that of 'Kyoho' cultivar although the contents of phosphorus and potassium in leaves of two grapevine cultivars were similarly declined. There was no significant different of fruit quality, such as contents of soluble solid, titratable acidity and weight of berry in 'Campbell Early' between waterlogging and control. In 'Kyoho' cultivar, however, berry weight and titratable acidity were decreased and soluble solid content was increased by waterlogging. It was assumed that waterlogging stress for grapevines promotes maturation and coloring processes of berries by stimulating maturation hormone such as ethylene. In conclusion, 'Campbell Early' cultivar seems to be more tolerable than 'Kyoho' cultivar when comparing the growth responses and nutrient contents between two grapevine cultivars under waterlogging.

• Tuberculosis and Respiratory Diseases
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• v.44 no.1
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• pp.154-161
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• 1997

Background : Although the long term adverse effects of cigarette smoking on health are well known, the acute possible detrimental effects of smoking on pulmonary or cardiovascular function, especially when these systems are stressed by the metabolic demands of exercise, have not been well studied The purpose of this study is to determine the acute action of cigarette smoking on cardiopulmonary function under stress. Method : Twenty -one healthy smoking subjects were studied. Before exrecise testing, history taking, physical examination and baseline studies, including CBC, chest PA, PFT and EKG, were done. The subjects performed an incremental bicycle exercise test to exhaustion on two occasions, one without smoking and the other after smoking 5 cigarettes/h for 2 hours. All indices of P.F.T. and bicycle ergometry were compared between before and after smoking. Results : 1. $VO_2$max and $O_2$ pulse showed significant decrease in smoking day. 2. Although there were no significant differences, anaerobic threshold showed a tendency of decrease and HRmax showed that of increase in smoking day. 3. P.F.T. and respiratory indices showed no significant change io smoking day. Conclusion : Cigarette smoking has immediate adverse effect, especially on the cardiovascular system rather than the respiratory system. These results would be due to the effect of elevated HbCO and/or impaired blood flow in response to the exercise stimulus.

• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.358-371
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• 2020

As climate change is expected to lead to a severe reduction of biodiversity, studies to investigate the reasons for habitat loss, growth decline, and death of Korean fir (Abies koreana Wilson), endangered alpine/subalpine species in Korea, have been conducted for years but found no clear answer yet. This study reviewed previous studies on Korean fir published in the journals in the past 40 years, 1980 through 2020, into 10-year units, examined the study trend by period, region, and subject with a focus on ecological studies, and analyzed the study results. The ecological studies were categorized into evolutionary ecology, physiological ecology, population ecology, and landscape ecology. Based on the results, we suggested the required research fields in the future. We found a total of 73 papers published in the past 40 years and 48 (65.8%) of them published in the past 10 years. In terms of region, Mt. Halla accounted for the most as 41 papers were on it. In terms of ecological subjects, the physiological ecology accounted for the most with 38, and the evolutionary ecology accounted for the least with 10. The review of the study results showed that many studies identified water stress caused by the water resource imbalance due to temperature increase and spring precipitation reduction following climate change as the main reason for the decline and habitat loss of Korean fir. However, recent studies suggested other factors, such as soil environment, disturbing organisms, and climatic events. The cause of the decline and death of the Korean fir not yet being clearly identified is that most of the studies dealt with the basic content, were carried out intermittently, and were concentrated in some regions. Therefore, we need long-term studies with advanced technology in each study subject at a local scale to find the cause of Korean fir decline and present sustainable management and conservation. Moreover, it is necessary to extend our study subjects to ecosystem ecology and systems ecology to integrate the results from various study subjects for a comprehensive understanding of the reason for Korean fir declines. The results of comprehensive studies could provide clearer answers for Korean fir's declines and the alternatives of conservation management and practices.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6D
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• pp.771-778
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• 2011

Preliminary feasibility study on Busan metro line #1 in Yangsan line (Nopo-Bukjeong) depending on active volume of mass transportation between Yangsan city and Busan city was conducted. As the study concluded that it's valid, the necessity to establish the metro railroad network connecting to Busan, Ulsan and Gyeongnam Province is demanded to improve the transportation issues in Ungsang area vulnerable to metro service and to drive the balanced development between metropolitan cities. In addition, the volume of transportation depending on methods in target areas and road traffic assignment are surveyed to put a stress on the necessity to establish the metro railroad network. As the demand of transportation for alternative lines is predicted, the budget and benefits for construction for each alternative line set for the rough economic analysis depending on traffic volume for each method and traffic assignment results. The total project budget necessary for construction of proposal line #1 set as effective one among target three lines in this project is calculated in 794.32 billion won. Construction accounts for the most expensive in expenses for project and contingency allowances, purchases for vehicles and collateral expense are followed in orders. However, compensation for lands is not counted. In particular, according to economic analysis in proposal #1, ratio of benefit/cost (B/C) is 0.584, net present value (NPV) is -217.47 billion won, the internal rate of return (IRR) is analyzed in 0.604 %. At the current stage, it is not economically feasible, but the B/C is 0.737 in long-term upon construction of Yangsan line between Wolpheong and Yongdang which is proposal line #3. Therefore, when Busan metro basic plan is reorganized to aim the benefit of residents in Ungsang area vulnerable to the metro service, we think it must be necessary to establish the metro railroad network connecting to Busan-Yangsan-Ulsan which is proposal line #2 by extending the existing Sinjeong line and including this task line in high-ranked plan related to metro railroad.

• Journal of Life Science
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• v.26 no.5
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• pp.519-530
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• 2016

Vegetative plants in Yakutia are naturally frozen when they are covered with snow in the fall, and they function as green cryo-fodder that is a source of biologically active substances and nutrients for herbivorous animals. We observed a considerable increase in the total fatty acid content in the leaves of Avena sativa, Elytrigia rеpens, Equisetum variegatum and Equisetum scirpoides during the fall period. However, the degree of unsaturation of fatty acids was not higher in the frozen plants covered with snow than in the summer plants, with the exception of E. scirpoides, a dwarf horsetail found in the Pole of Cold in the northern hemisphere. In the internal adipose tissue of the Yakut horse (young horse meat), 18 fatty acids were found, including 10 saturated ones. Monounsaturated oleic С18:1 (n-9) acid and polyunsaturated α-linolenic С18:3 (n-3) acid were equally prevalent among the unsaturated fatty acids, accounting for 70% of the total unsaturated fatty acids. This composition of polyenoic fatty acids in the internal adipose tissue indicates that the Yakut horse actively feeds on the fall vegetation and the wintergreen sedge-grass. We believe that the high plant-specific free fatty acid content in the tissue of Yakut horses may play an important role in the regulation of their resistance to long-term low-temperature stress.

• Journal of Global Scholars of Marketing Science
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• v.8
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• pp.233-267
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• 2001

The management environment in Korea today is undergoing rapid changes; in particular, domestic corporations and businesses are confronting formidable adversity with IMF crisis and WTO. Though cost cutback, higher quality, rapid production, and diversification of products were accepted as important requirements for competitiveness in the past, they have been replaced by brand power. Consumption patterns have changed their focus from function to image orientation. This is why managers in corporations have invested enormous amounts of resources into producing powerful brands, which can attract consumers' attention greatly enough to improve the image of their products. Brands are regarded as a vital vehicle for marketing strategies and thus as a legal asset. Brands with remarkable and favorable image can secure a loyal consumer groups stable revenues. M & A, currently active between corporations, makes brand equity all the more important. The purpose of the present study was to investigate the effect of internal marketing and increased brand diversification on brand equity by combining them as influential factors with marketing mix factor. For this purpose, literature review was make on previous fragmented studies of influential factors on brand equity build-up. Based on the findings of this study, some operational implications were suggested for marketing managers. The findings and implications of the present study are as follows; First, efficient communication among organization members was found to have a significant effect on product quality. Second, job satisfaction and efficient communication among members was shown to significantly influence price policies. Thirdly, efficient communication among organization workers proved to have a significant effect on distribution strategies. Forth, efficient communication among members was demonstrated to significantly influence advertisement and other public-relations activities. Fifth, opacity of market environment appeared to have a significant effect on product quality, prior market entrance as perceived by organization members turned to be of negative influence on product quality. Sixth, opacity of market environment was found to have a significant effect on price policies. Seventh, opacity of market environment was shown to be of significant effect on distribution strategies. Eighth, grater opacity of market environment proved to improve advertisement and other public-relations activities. Ninth, price policies, distribution strategies, advertisement and public-relations activities were found to have a significant effect on brand equity value. To sum up these findings, in order for corporations and businesses to cope with consumers' needs that are increasingly segmented, internal marketing strategies and brand diversification should be implemented so as to generate greater synergy effect. It is also important to stress that differentiated, higher competitiveness should be secured for Korean corporations and businesses to survive in the drastically changing, globalized market environment. In this regard, continuous and long-term management strategies for brand equity build-up should be ensured and is essential in the present unlimited competition. The last but not least important point to notice is that to increase brand equity value, intensive investment and constant emphasis should be made on internal marketing management on intra-organizational members before strengthening external marketing.

• Journal of agricultural medicine and community health
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• v.39 no.4
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• pp.209-221
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• 2014

Objectives: The objective of this study was to identify the effects of area-based health promotion initiatives with community participation and partnerships conducted in Sabong-Myeon, Jinju City for three years. Methods: We used data from the '2008 Sabong-Myeon Health Survey' and the '2011 Health Plus Happiness Plus Community Health Survey'. The study comprised 520 systematically sampled individuals, composed of 300 adults in 2008 and 200 adults in 2011. We compared some health behavior and mental health indicators as well as social capital levels between these two surveys. Results: The prevalences of smoking and walking exercise in 2011 were significantly higher than those in 2008. The prevalences of high risk alcohol consumption in men, stress perception, depressive symptoms experience, and suicide ideation were significantly lower than those in 2008. The proportion of people having a high level of social capital in 2011 was significantly higher than that in 2008, regardless of sex or marital status. However, the difference in the proportion was not statistically significant among people with a high educational background. Conclusions: This study suggested that the 3 years' implementation of area-based health promotion initiatives conducted in Sabong-Myeon might help to improve the mental health and social capital level of this community. The long-term health effects of area-based health promotion initiatives with community participation and partnerships need to be studied further, and lessons from these initiatives can be obtained by adapting proper evaluation methods.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.490-495
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• 2013

Two chrysanthemum varieties, 'ARTI-purple' and 'ARTI-queen', were chronically irradiated with doses of 30, 50, 70, and 100 Gy for four weeks in gamma-phytotron, a long term irradiation facility. We investigated the growth, responses of antioxidant enzymes (ascorbate peroxidase, APX; catalase, CAT; peroxidase, POD; superoxidase dismutase, SOD) and malondialdehyde (MDA) contents under different doses of chronic-irradiation. The five plant growth measurements including plant height, number of leaves, internode length, stalk diameter and leaf thickness were investigated immediately after four week irradiation. The plant height (p<0.001), internode length (p<0.01), the number of leaves (p<0.001) and stalk diameter (p<0.05) were significantly decreased an increasing doses of gamma-ray. Among them, especially, the internode length was remarkably decreased showing the RD50 (Reduction Dose 50) at approximately 65 Gy. The antioxidant response after four weeks of recovery period, ascorbate peroxidase (APX) (p<0.01), superoxide dismutase (SOD) (p<0.01) and peroxidase (POD) (p<0.001) were significantly increased with an increasing dose of gamma-ray. And malondialdehyde (MDA) (p<0.01) contents showed the significant increase at the 70 and 100 Gy which means the oxidative stress was lasting for a considerable period. In this study, the 50 Gy irradiation as optimal dose showed higher growth than the $RD_{50}$, it also showed insignificant differences on the antioxidant responses and MDA contents. However, the 100 Gy dose showed lower growth than $RD_{50}$.