• Journal of Korean Society of Environmental Engineers
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• v.33 no.11
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• pp.790-796
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• 2011

In this study, we measured the concentrations of volatile organic compounds (VOCs) in Shiwha area by using active and passive sampler. We did a comparative analysis of the characteristics of the active sampler and passive sampler. In the case of the passive sampler, the average TVOC concentration of the industrial area was 1.86 times higher than that of the residential area. In the case of the active sampler, the average TVOC concentration of the industrial area was 1.07 times higher than that of the residential area. When using the passive sampler, the concentration of VOCs in the industrial area was noted to be higher than the concentration found in the residential area. However, when we used the thermal desorption tube, the concentration of residential area was higher rather than that of industrial area in some substances such as trichloroethylene, toluene, ethylbenzene, and xylene. Toluene was a larger percentage of the overall BTEX ratio. In case of the passive sampler, the relative ratio of toluene, ethylbenzene, and xylene was higher in the industrial area than in the residential area. In contrast in case of the thermal desorption tube, the ratio of these substances was higher in the residential area rather than in the industrial area. The passive sampling in this study showed an appropriate method to analyze the temporal and spatial concentrations of air contaminants. This assessment would prove to be useful for its observance of standards or epidemical study.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.1
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• pp.40-47
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• 2006

Purpose: The aim of this study was to examine the effects of attenuation correction (AC) and scatter correction (SC) on the quantification of PET count rates. Materials and Methods: To assess the effects of AC and SC $^{18}F$-FDG PET images of phantom and cat brain were acquired using microPET R4 scanner. Thirty-minute transmission images using $^{68}Ge$ source and emission images after injection of FDG were acquired. PET images were reconstructed using 2D OSEM. AC and SC were applied. Regional count rates were measured using ROIs drawn on cerebral cortex including frontal, parietal, and latral temporal lobes and deep gray matter including head of caudate nucleus, putamen and thalamus for pre- and post-AC and SC images. The count rates were then normalized with the injected dose per body weight. To assess the effects of AC, count ratio of "deep gray matter/cerebral cortex" was calculated. To assess the effects of SC, ROIs were also drawn on the gray matter (GM) and white matter (WM), and contrast between them ((GM-WM)/GM was measured. Results: After the AC, count ratio of "deep gray matter/cerebral cortex" was increased by $17{\pm}7%$. After the SC, contrast was also increased by $12{\pm}3%$. Conclusion: Relative count of deep gray matter and contrast between gray and white matters were increased after AC and SC, suggesting that the AC would be critical for the quantitative analysis of cat brain PET data.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.2
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• pp.165-172
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• 2014

Experiments were conducted to identify basic characteristics of $CO_2$ capture using a spray tower with a single nozzle. Results were evaluated in terms of $CO_2$ saturation which is the main determining factor of regeneration energy, and capture efficiency under various operating conditions. Changes in the capture efficiency under various conditions are well expressed as a monotone increasing function of the relative solvent $(NH_3):CO_2$ flow rate. Although changes in $CO_2$ saturation are also well described as a function of the $NH_3/CO_2$ flow rate ratio, these are expressed as a monotone decreasing function, in contrast with the increasing function of $CO_2$ efficiency. In recent research on the relationship between $CO_2$ saturation and capture efficiency, $CO_2$ saturation was found to decrease when capture efficiency increased. In conclusion, the results show that the amount of solvent used for achieving high capture efficiencies is excessive, as is the amount of regeneration energy needed.

• Journal of Yeungnam Medical Science
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• v.25 no.2
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• pp.102-107
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• 2008

Background : Malignant pulmonary nodules account for 30 to 40 percent of all solitary pulmonary nodules (SPNs). Therefore, characterization of SPNs is very important for treatment. Recently, dynamic CT has been widely used for tissue characterization and formation of differential diagnoses. The purpose of this study was to evaluate the ability of dynamic CT to formulate the differential diagnosis of SPNs. Materials and Methods : Nineteen patients with SPNs underwent dynamic CT (unenhanced scans, followed by a series of images at 20, 40, 60, 80, 100, 120, 140, 160, and 180 sec after intravenous injection of contrast medium). Diagnosis of SPN was performed based on pathologic findings in needle biopsy samples. Peak enhancement, net enhancement, slope of enhancement, and maximum relative enhancement ratio of the SPN were measured on dynamic CT, and Levene's test was performed to assess benignancy and malignancy. Results : Twelve SPNs were confirmed to have malignant pathology. There were no significant differences between benign and malignant nodules with respect to peak enhancement (p=0.787), net enhancement (p=0.135), or slope of enhancement (p=0.698). The maximal enhancement ratio was increased in malignancy compared to benignancy, but the difference was not statistically significant (p=0.094). Conclusion : In our study, the hemodynamic characteristics of dynamic CT were not significantly different between benign and malignant nodules. Therefore, long-term studies of larger patient samples are required to confirm our findings.

• Journal of Nutrition and Health
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• v.49 no.6
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• pp.411-419
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• 2016

Purpose: Dysregulation of adipokines caused by excess adipose tissue has been implicated in the development of obesity-related metabolic diseases. This study evaluated the effects of mugwort (Artemisia princeps Pampanini) ethanol extract on lipid metabolic changes, insulin resistance, adipokine balance, and body fat reduction in obese rats. Methods: Male Sprague-Dawley rats were fed either a control diet (NC), high-fat diet (HF, 40% kcal from fat), or high-fat diet with 1% mugwort extract (HFM) for 6 weeks. Results: Epididymal and retroperitoneal fat mass increased in the HF group compared with the NC group, and epididymal fat mass was reduced in the HFM group (p < 0.05). No difference was observed in serum levels of total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) among the groups. However, triglyceride (TG), TG/HDL-C ratio, and TC/HDL-C ratio increased in the HF group and significantly decreased in the HFM group. TG and TC levels in the liver were significantly higher in the HF group, whereas these levels were significantly reduced in the HFM group. HF rats had lower insulin sensitivity as indicated by increased homeostasis model assessment of the insulin resistance (HOMA-IR) value. HOMA-IR values significantly decreased in the HFM group. Adiponectin levels were higher in NC rats, and their leptin and PAI-1 levels were lower. Relative balance of adipokines was reversed in the HF group, with lower adiponectin levels but higher leptin and PAI-1 levels. In contrast, the HFM group maintained balance of adiponectin/leptin and adiponectin/PAI-1 levels similar to NC by reducing leptin and PAI-1 levels. Conclusion: Overall data indicated that mugwort extract can be effective in alleviating metabolic dislipidemia, insulin resistance, and adipokine dysregulation induced by a high-fat diet.

• Progress in Medical Physics
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• v.19 no.4
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• pp.269-275
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• 2008

Although MR imaging is generally applicable to depict knee joint deterioration it, is sometimes occurred to mis-read and mis-diagnose the common knee joint diseases. In this study, we employed magnetization transfer ratio (MTR) method to improve the diagnosis of the various knee joint diseases. Spin-echo (SE) T2-weighted images (TR/TE 3,400-3,500/90-100 ms) were obtained in seven cases of knee joint deterioration, FSE T2-weighted images (TR/TE 4,500-5,000/100-108 ms) were obtained in seven cases of knee joint deterioration, gradient-echo (GRE) T2-weighted images (TR/TE 9/4.56/$50^{\circ}$ flip angle, NEX 1) were obtained in 3 cases of knee joint deterioration, In six cases of knee joint deterioration, fat suppression was performed using a T2-weighted short T1/tau inverse recovery (STIR) sequence (TR/TE =2,894-3,215 ms/70 ms, NEX 3, ETL 9). Calculation of MTR for individual pixels was performed on registration of unsaturated and saturated images. After processing to make MTR images, the images were displayed in gray color. For improving diagnosis, three-dimensional isotropic volume images, the MR tristimulus color mapping and the MTR map was employed. MTR images showed diagnostic images quality to assess the patients' pathologies. The intensity difference between MTR images and conventional MRI was seen on the color bar. The profile graph on MTR imaging effect showed a quantitative measure of the relative decrease in signal intensity due to the MT pulse. To diagnose the pathologies of the knee joint, the profile graph data was shown on the image as a small cross. The present study indicated that MTR images in the knee joint were feasible. Investigation of physical change on MTR imaging enables to provide us more insight in the physical and technical basis of MTR imaging. MTR images could be useful for rapid assessment of diseases that we examine unambiguous contrast in MT images of knee disorder patients.

• Journal of the Korean earth science society
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• v.29 no.6
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• pp.454-465
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• 2008

Benthic foraminiferal assemblage and AMS radiocarbon dating of core sediments from the northern shelf of the East China Sea were analyzed in order to understand the paleoenvironment and sedimentary environmental changes around the Korean marginal seas since the last glacial maximum (LGM). The core sediments, containing continuous records of the last 16,000 years, reveal a series of well-defined vertical changes in number of species (S), P/T ratio and species diversity (H) as well as foraminiferal assemblage. Such down-core variations display a sharp change at a core depth of approximately 240 cm, which corresponds to ca. 10,000 year B.P. The sediments of the lower part of the core (240${\sim}$560 cm, Zone I), including the well-developed tide-influenced sedimentary structures, are characterized by high abundances of Ammonia beccarii and Elphidium clavatum (s.l.) and low values in number of species, P/T ratio and diversity. These tide-influenced signatures and foraminiferal assemblage characters suggest that the sediments of Zone I were deposited in a coastal environment (water depths of 20${\sim}$30 m) such as tidal estuary with an influence of the paleo-rivers (e.g., old-Huanghe and Yangtze rivers) during the early phase of the sea-level rise (ca. 16,000 to 10,000 years) since the LGM. In contrast, the upper core sediments (0${\sim}$240 cm, Zone II) are characterized by abundant Eilohedra nipponica and Bolivina robusta with a minor contribution of A. ketienziensis angulata and B. marginata. and high values in number of species, P/T ratio and diversity. Based on relative abundance of these assemblage, Zone II can be divided into two subzones (IIa and IIb). Zone IIa is interpreted to be deposited under the inner-to-middle shelf environment during the marine transgression in the early Holocene (after ca. 9,000 yr B.P.) when sea level rapidly increased. The sediments of zone IIb most likely deposited after 6,000 yr B.P. under the outer shelf environment (80${\sim}$100 m water depth), which is similar to modem depositional environments. The muddy sediments of zone IIb were probably transported from the old-Huanghe and Yangtze Rivers during the late Holocene. We suggest that the present-day oceanographic conditions over the Yellow and the East China Seas have been established after ca. 7,000${\sim}$6,000 yr B.P. when the Kuroshio Current began to influence this area.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.878-886
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• 2011

The soybean is one of the oldest cultivated crops in the world. Microwave remote sensing is an important tool because it can penetrate into cloud independent of weather and it can acquire day or night time data. Especially a ground-based polarimetric scatterometer has advantages of monitoring crop conditions continuously with full polarization and different frequencies. In this study, soybean growth parameters and soil moisture were estimated using polarimetric discrimination ratio (PDR) by radar scatterometer. A ground-based polarimetric scatterometer operating at multiple frequencies was used to continuously monitor the soybean growth condition and soil moisture change. It was set up to obtain data automatically every 10 minutes. The temporal trend of the PDR for all bands agreed with the soybean growth data such as fresh weight, Leaf Area Index, Vegetation Water Content, plant height; i.e., increased until about DOY 271 and decreased afterward. Soil moisture lowly related with PDR in all bands during whole growth stage. In contrast, PDR is relative correlated with soil moisture during below LAI 2. We also analyzed the relationship between the PDR of each band and growth data. It was found that L-band PDR is the most correlated with fresh weight (r=0.96), LAI (r=0.91), vegetation water content (r=0.94) and soil moisture (r=0.86). In addition, the relationship between C-, X-band PDR and growth data were moderately correlated ($r{\geq}0.83$) with the exception of the soil moisture. Based on the analysis of the relation between the PDR at L, C, X-band and soybean growth parameters, we predicted the growth parameters and soil moisture using L-band PDR. Overall good agreement has been observed between retrieved growth data and observed growth data. Results from this study show that PDR appear effective to estimate soybean growth parameters and soil moisture.

• Korean Journal of Social Welfare
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• v.55
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• pp.205-230
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• 2003

This article examines the continuity and change of Korean welfare regime during 1990s. Democracy, globalization and the financial crisis changed the landscape of Korean society as a whole and provided a catalyst for the change of the Korean welfare regime. In order to show how and what changed in Korean welfare regime, this study concentrates on the transformations of income maintenance programmes and social welfare services. The changed aspects are as follow: (1) The ratio of social expenditure to GDP has increased during 1990s and now stood at ten percent level. (2)Rather than backing up the company welfare, government strove to build and expand income maintenance devices for all citizens. (3) The poverty and inequality reduction effects of income maintenance programs are very weak in early 1990s, but they are gradually getting stronger impact on poverty and inequality. But, there are also continuance. (1) In spite of the relative development of income maintenance programs, social welfare services are still poorly designed as before. (2) The expenditure level of social welfare services shows sharp contrast to income maintenance programs and lagged behind the other OECD countries. (3) The expansion of social service sector employment are also not so salient. In 2002, social service employment is only at close to 2.5 per cent of the total employment. Accordingly, korean welfare regime is now characterized by a model which is to curb poverty and inequality by engaging in direct government provision of income maintenance programs, but refrain from expanding social service by relying on net welfare which encourage the provision of services within the family. A implication of our analysis is that the expansion of social welfare Korea saw after 1997 was not really an regime shift. According to the arguments of Peter Hall, first and second order changes in policy do not automatically lead to third order changes which imply regime shift. Policy changes which occurred during 1990s was not accompanied by a shift in policy paradigms. Family dependency in welfare is not yet changed.

• Korean Journal of Ecology and Environment
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• v.36 no.3 s.104
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• pp.257-268
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• 2003

Daily monitoring was conducted to elucidate the changes in turbidity and distribution of particles in the turbid water of a river-type reservoir (Paltang Reservoir) from 1999 to 2001. Water turbidity and the particle distribution of turbid water were principally affected by meteorological factors particularly rainfall patterns and hydrological factors such as inflow and outflow. The mean concentration of turbidity was constant each year, with the concentration of less than 10 NTU accounting for 85%. Seasonal characteristics were remarkable, with winter and spring having < 5 NTU, autumn 5 ${\sim}$ 10 NTU, and summer > 20 NTU. Unlike hydrological changes, maximum turbidity was observed from late July to early August and continuously increased from 1999 to 2001. In particular, the maximum turbidity of reservoirs remarkably increased toward the lower part of reservoir in 2001. Discharge and turbidity increased or decreased slowly in 1999; in contrast, turbidity rapidly increased in the early rainfall period of 2000 and 2001 but later decreased as discharge increased. In the particles of turbid water, clay ingredients were more densely distributed and more dominant in all stations. Of the total particles in turbid water, clay constituted 63.9${\sim}$66.6% and silt 33.4${\sim}$36.1% to account for a combined total of 98.9 ${\sim}$ 100%. Sand made up less than 1.1%. The turbidity of river-type reservoir was also found to be mainly affected by the biomass of plankton in a non-rainfall period. During a rainfall period, however, the quantity and relative ratio of inorganic particles depending on the soil components affected turbidity.