• The Korean Journal of Nuclear Medicine
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• v.38 no.5
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• pp.338-343
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• 2004

Purpose: The purpose of this study was to develop a small animal PET using dual layer phoswich detector to minimize parallax error that degrades spatial resolution at the outer part of field-of-view (FOV). Materials and Methods: A simulation tool GATE (Geant4 Application for Tomographic Emission) was used to derive optimal parameters of small PET, and PET was developed employing the parameters. Lutetium Oxyorthosilicate (LSO) and Lutetium-Yttrium Aluminate-Perovskite(LuYAP) was used to construct dual layer phoswitch crystal. $8{\times}8$ arrays of LSO and LuYAP pixels, $2mm{\times}2mm{\times}8mm$ in size, were coupled to a 64-channel position sensitive photomultiplier tube. The system consisted of 16 detector modules arranged to one ring configuration (ring inner diameter 10 cm, FOV of 8 cm). The data from phoswich detector modules were fed into an ADC board in the data acquisition and preprocessing PC via sockets, decoder block, FPGA board, and bus board. These were linked to the master PC that stored the events data on hard disk. Results: In a preliminary test of the system, reconstructed images were obtained by using a pair of detectors and sensitivity and spatial resolution were measured. Spatial resolution was 2.3 mm FWHM and sensitivity was 10.9 $cps/{\mu}Ci$ at the center of FOV. Conclusion: The radioactivity distribution patterns were accurately represented in sinograms and images obtained by PET with a pair of detectors. These preliminary results indicate that it is promising to develop a high performance small animal PET.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.4
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• pp.192-198
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• 2015

Picophytoplankton, a group of tiny microorganisms of less than $3{\mu}m$, play an important role as a major primary producer in tropical open ocean as well as temperate coastal waters. Until now, more than 20 and 10 clades of Synechococcus and Prochlorococcus, respectively, have been identified in various marine environments, and its biogeographical distribution have been well studied as well as ecological niches of its major clades. To understand a distribution of diverse picocyanobacterial clades and environmental factors regulating their distribution, picocyanobacterial abundance and genetic diversity was investigated in adjacent waters of Dokdo showing diverse physical properties not only by seasonal variation but also by diverse physical processes. Synechococcus abundances were low in winter and then exponentially increased as water temperature increased up to $20^{\circ}C$. Above $20^{\circ}C$, the abundances tended to be saturated. On the contrary, Prochlorococcus was undetected or occupied a minor fraction of picocyanobacteria in most seasons. In summer, however, Prochlorococcus belonging to HLII ecotype occupied a significant fraction (up to 7%) of picocyanobacteria. In spring and early summer, the steep increase of Synechococcus abundances were resulted from growth of cold water-adapted Synechococcus belonging to clades I and IV. In summer, diverse Synechococcus clades including warm and pelagic water-favoring clade II tended to replace clades I and IV with maintaining high abundance. The water-column stability as well as temperature were found to be important factors regulating the Synechococcus abundances. Moreover, inflow and mixing of distinct water masses with different origins exerted significant influence on the composition of Synechococcus in the study area. Thus, physical processes as well as natural seasonal variation of environmental factors should be considered to better understand ecology of planktonic organisms around Dokdo.

• Journal of agricultural medicine and community health
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• v.10 no.1
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• pp.42-48
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• 1985

This study was carried out to obtain the basic data for epdemiological survey of hypertension in old population (60 years or more). From May, 1983 to April, 1984, 365 males and 335 females who inhabit in Ko-Chang Gun, Chonbuk Province were investigated for several factors as their socio-econmic status and laboratory examinations with blood pressure, and which factors were analysed by simple correlation and multiple regression analysis. The results are summarized as follows; 1) Sample size of this study is equivalent to 5.2%(male;6.7%, female;4.3%) of population in 60 years or more age group, and the mean age of samples is 70.6${\pm}$5.3 (yr.) in males and 71.4${\pm}$5.3 (yr.) in female (P>0.05). 2) Mean blood pressure of males are 135.9${\pm}$21.3mm Hg in systolic and 85.3${\pm}$13.4mm Hg in diastolic phase and in female, 131.0${\pm}$23.6 mm Hg and 84.1${\pm}$19.9 mm Hg (P < 0.01). Their prevalence rates of hypertension (${\geq}$ 140 mm Hg in systolic, ${\geq}$ 95 mm Hg in diastolic phases) are 33.7% in males, 40.6% in females (P < 0.01). 3) Serum cholesterol levels and other independent variables are revealed in normal ranges, and except to Vervaeck index (89.4${\pm}$5.6 in males, 87.5${\pm}$6.7 in females, p<0.01), other are not significant sexual differences (P>0.05). 4) In the simple correlation analysis, the main factors that affect to blood pressure are serum cholesterol levels (P < 0.05) and Vervaeck index (P < 0.01) in males, age (P <0.05) and Vervaeck index (P <0.01) in females. 5) In multiple regression analysis, prediction equations for blood pressure are calculated as follows; Ysm=-64.55+0.161(X1)+0.124(X2)-0.047(X3)+1.953(X4) Ydm=18.61-0.125(X1)+0.060(X2)+0.032(X3)+0.720(X4) Ysf=-0.22+0.536(X1)+0.134(X2)+0.068(X3+0.788(X4) Yaf=-14.46+0.685(X1)+0.033(X2)+0.176(X3)+0.362(X4) Ysm : Systolic blood pressure in male, Ydm : Diastolic blood pressure in male, Ysf : Systolic blood pressure in female, Ydf : Diastolic blood pressure in female. X1 : Age(year), X2 : Serum cholesterol level (mg%), X3 : Fastin blood sugar (mg% ), X4 : Vervaeck index.

• Journal of agricultural medicine and community health
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• v.27 no.1
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• pp.143-153
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• 2002

This study was performed to examine the want for home-visit health care of health center and health sub-center in rural olders and to provide the basic data to develop strategies for efficient and effective home-visit health care delivery of public health facilities. The questionnaire survey by interview was conducted to 355 olders whose ages were all over 65 years, residing at a rural community, Myun, Gyeongsangbuk- do. Among study population, 64.5% replied that their self-rated health status were 'poor', 14.1% had low ADL and 14.9% had low IADL. Among study population, 73.5% replied that they had health problem which were in need of medical personnel's care. The existence of health problem were significantly different according to sex, age, marital status, health security status, occupation, economic status, circumstances for medical care, self-rated health status, ADL, and IADL(p<0.05). Among olders with health problem which were in need of medical personnel's care, 19.5% wanted to receive the home-visit health care. The degree of want for home-visit health care was higher significantly in olders whose ages were 75-year old or more(p<0.05), jobless olders(p<0.01), the aged persons who were not in harmony with other family members, olders whose self-rated health status were 'poor' and olders with low IADL. The major reasons why they wanted to receive the home-visit health care services were 'they had no helpers when they were sick' (64.7%), 'long distance to the medical facilities from their residence'(23.5%). The medication service was the most need service among home-visit health care services. The reasons why they didn't want to receive the home-visit health care services were 'we could walk and move' (60.0%), 'we wanted to have a direct contact with doctor' (25.7%) in the order of high rate. In multiple logistic regression analysis, the degree of want for home-visit health care were higher significantly in olders who were not in harmony with other family members and olders whose self-rated health status were 'poor'(p<0.05).

• Journal of agricultural medicine and community health
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• v.39 no.1
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• pp.1-13
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• 2014

Objective: The objectives were to estimate the rate of the injury in the elderly over the past year and to identify factors related to injury in the elderly in South Korea. Method: Using data from the 2008 Community Health Survey, 43,049 elderly persons, aged 65 years and older, were selected as study subjects. Their experience of injury during the past year and other variables, including socio-demographic factors, health-related factors, and diagnosed chronic diseases, were used. The chi-squared test and multiple logistic regression analysis with weighted analysis were conducted and statistical significance was set at p<0.05. Result: The rate of injury in the elderly during the past year was 5.1%. The most common types of the injury were falling/slipping down and traffic accidents. Factors related to injury in the elderly were living alone, current drinking, depression, poor self-rated health, stroke, and osteoporosis. Living alone (odds ratio 1.23, 95% CI: 1.05-1.45), current drinkers (OR 1.19, 95% CI: 1.05-1.35), poor self-rated health (OR 1.72, 95% CI: 1.43-2.08), depression (OR 1.23, 95% CI: 1.17-1.68), and history of stroke (OR 1.40, 95% CI: 1.17-1.68), and history of osteoporosis (OR 1.45, 95% CI: 1.26-1.66) were related to an increased risk of injury. Conclusions: Intervention programs that consider the risk factors related to injury should be developed and implemented to decrease and prevent injuries in the elderly.

• The Korean Journal of Zoology
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• v.17 no.2
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• pp.57-68
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• 1974

These experiments were performed in order to study histologically and histochemically on the epithelial cells of gall bladder in Carassius carassius, Bufo bufo gargarizans, Natrix tigrina lateralis, Urloncha striata var. domesticus and Bos taurus var. domesticus. The results of the observation were as follows: 1. There were different cell types in the epithelium of gall bladder in each animal and it could not be supported histochemically that the epithelia cells of gall bladder were divided into two cell types of the rod-shaped and barrel-shaped ones. 2. The epithelium of gall bladder in Carassius carassius, Bufo bufo gargarizans, Natrix tigrina lateralis, Urloncha striata var. domesticus and Bos taurus var. domesticus was simple columnar epithelium. 3. The eosinophilities of cytoplasm in the epithelial cells of gall bladder were in uniform stronger in the upper portion of nucleus in Carassius carassius, Bufo bufo gargarizans and Natrix tigrina lateralis than its other portions, and in Urloncha striata var. domesticus and Lepus cuniculus var. domesticus existed uniformly in all portions, but there were many non-eosinophilic cells in Bufo bufo gargarizans and many cells that weakly eosinophilic around nucleus in Bos taurus var. domesticus. 4. The periodic acid Schiff's reactivities in the epithelial cells of gall bladder were different in each other and the epithelial cells in PAS reaction were divided into two cell types of the dark and light ones. There presented the light cells of 6.4%, 4.3% and 3.7% of epithelial cell of gall bladder in Carassius carassius, Bufo bufo gargarizans and Urloncha striata var. domesticus for each other, but were not presented in Natrix tigrina lateralis and Bos taurus var. domesticus. 5. The ninhydrin-Schiff-active proteins were much in the epithelial cells of gall bladder in Bos taurus var. domesticus, Carassius carassius, Urloncha striata var. domesticus and Natrix tigrina lateralis in order and were much in epithelial cells in the upper portion of mucosal folds in Carassius carassius, Urloncha striata var. domesticus and Natrix tigrina lateralis, and the ninhydrin-Schiff-active protein of the epithelium of gall bladder in Bufo bufo gargarizans was uniformly distributed. 6. The epithelial cells of gall bladder in Carassius carassius, Natrix tigrina lateralis, Urloncha striata var. domesticus and Bos taurus var. domesticus had no stain reactivity or weak stain reactivity to neutral fat and all epithelial cells in Bufo bufo gargarizans had strong stain reactivity, though they were different in quantity of epithelial cell portion. 7. The stain reactivities to RNA and DNA were stronger in the epithelial cells of the upper portion of mucosal fold than in those of other portions.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.764-776
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• 2015

This study aims to identify the structure of the plant community, and the ecological succession sere and the change in the forest ecosystem in Jungdaesa-Birobong area, Odaesan National Park_(i._e., located at high altitudes(over 1,000m)). It seeks to offer the basic data for the planning of vegetation management. In order to verify the status of the forest vegetation between Jungdaesa-Birobong, seventeen plots(size is $20m{\times}20m$) were set up as research sites at high altitudes. Importance value, distribution by diameter at breast height(DBH), the growth volume and age of the sample trees, similarity index and species diversity index of each survey plot were analysed. According to the results of DCA(Detrended Correspondence Analysis), one of the multivariate statistical techniques. It was found that the plant communities were classified into five groups: community I_(Quercus mongolica-Tilia amurensis community), community II_(Q. mongolica-Deciduous broad-leaved community), community III_(Q. mongolica-Pinus koraiensis community), community IV_(Abies holophylla-Q. mongolica community) and community V_(A. holophylla-Deciduous broad-leaved community). Community I which is dominated by Quercus mongolica and Deciduous broad-leaved communities is located at an altitude of over 1,300 meters(ranging from 1,335m to 1,495m), the community IV and V which are dominated by Abies holophylla are located at an altitude of under 1,200 meters(ranging from 1,115m to 1,175m) and the community II and III which include the main species of Quercus mongolica, Pinus koraiensis and Abies holophylla are located at an altitude of between 1,160 meters and 1,300 meters. The results showed that Quercus mongolica tends to have a higher importance value of woody species at a higher altitude while Abies holophylla tends to have higher importance value at a lower altitude. For the importance value woody species and -DBH class distribution, the communites I, II and III are expected to continuously maintain the present status. Whereas, for the influence of communities IV and V, Q. mongolica is predicted to be weakened. The age of sample trees was between 85 and 161; the average age was 123. The index of Shannon's Species diversity (H') showed heterogeneity was found among community I_(i._e., located at high altitude) and communities IV and V_(i._e., located at low altitude). As a results of analysing the index of Shannon's Species diversity (H': unit: $400m^2$), community III showed the highest diversity intex with 1.1109 followed by community II with 1.0475, community I with 1.0125, community IV with 0.9918 and community V with 0.8686. This study verified that the index of Shannon's species was significantly different by plant communities. For instance, when comparing the index of Shannon's species diversity in Quercus mongolica communities of this study and that of past relevant research, the value of index is very similar. However, the diversity index for the community which is dominated by Abies holophylla showed lower value when compared to the results from past relevant research.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.684-693
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• 2016

Daemyung retarding basin located near the confluence floodplain of the Nakdong and Kumho River is a large spawning site for the endangered Kaloula borealis, and needs for protecting the habitat of the endangered species are increasing. However, scientific studies are rarely conducted on the population characteristics and ecological knowledge on the species in the basin. This paper aims to estimate the population size and spatial distribution of the species that inhabited at the Daemyung retarding basin, using the capture-recapture method. Also, pitfall traps were installed in each habitat types classified with micro-topographic features, slope aspects, and vegetation communities to identify the spatial distribution characteristics of the Kaloula borealis of each habitat in the retarding basin. Field survey on the species was conducted from May 2013 to October 2014, showing that the species emerged in May, became more active during July and August and started to hibernate at the end of October. Using capture-recapture method, the first survey was carried out from July to August, 2014. Ninety-eight toads were captured, marked, and released back into the site. In the second survey, 68 toads including 5 marked toads of the previous survey were captured. Based on these two-sample surveys, around 535-2,131 individual toads are estimated to inhabit the Daemyung retarding basin. Fifty-seven pitfall traps were installed in four habitat types: mounded and vegetated flatland, lowland swamps, and slope areas of both the southern and western parts of the basin in order to delineate spatial abundance of the endangered Kaloula borealis during the rainy season when the species is actively spawning. Pitfall traps at the spatially explicit array indicated that the species gradually move to the slope areas near the Daemyung stream, showing high occurrence density of the Kaloula borealis compared to the lowland swamps after the spawning season. The emergence of Kaloula borealis in the lowland swamps appeared to be comparatively higher during the spawning season. However, after the spawning season the toads species rapidly moved into the neighboring land of relatively high elevation such as the slope area towards the Dalsung protected wetlands and Daemyung River. These results are closely related to the migration patterns that toads tend to return to the sheltering sites and/or hibernating grounds after the spawning season. Also, the Kaloula borealis moved to the nearest high-level vegetated areas as the lowland swamps of their spawning grounds deteriorated with the expansion of permanent ponds due to the rise in the groundwater level.

• Korean Journal of Environment and Ecology
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• v.27 no.6
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• pp.676-689
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• 2013

This study is to understand the current situation of Wonju Stream, which flows through Wonju, Kangwon-do, and Seom River, the national river located outside of Wonju, by investigating all river areas using biotope type. Also, this research looked into the relationship between biotope and appearance of wild birds by investigating the location of their appearance. Biotope groups are 'scale', 'shape', and 'landscape'. And, biotope types are 'moisture', 'physical environment', and 'existence of vegetation'. Biotope subtypes are 'river area', 'physical environment', 'vegetation type', and 'usage of land'. Seom River is classified as 21 different sections, and Wonju Stream is classified as 19 different sections. Wild birds are investigated on breeding season, which was January and May of 2008. By marking each bird's location of appearance, it figured out properties of biotope according to the location of bird's appearance. 31 species, 795 birds in spring were founded, and 49 species, 4,348 birds are founded in winter at Seom River area. Also, 34 species, 427 birds in spring, and 33 species, 3,442 birds are founded in winter at Wonju Stream area. In winter, 26 species, 547 birds, and in spring, 12 species, 72 birds at natural river with estuaries in confluence of Seom River area are founded. Also, 34 species, 1412 birds in winter, and 24 species, 341 birds in spring are founded at natural river with estuaries and wetland plants. This means that because agricultural rivers have wide river width, slow flow speed, and many different types of biotope, these rivers can be good habitats for wild birds. The precise investigations and classifications of biotope, which especially are hard for linear rivers, were done to understand the whole and current situation of rivers. Furthermore, the data that shows the locations of wild birds can basically be used for a recovery of biological habitats, a constructing of ecological streams, a river-maintenance, and an enhancement of biodiversity of Wonju. Also, because the types of biotope are altered by rain, a continuous monitoring for maintaining ecosystem of rivers are highly needed.

• Economic and Environmental Geology
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• v.47 no.2
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• pp.147-168
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• 2014

The soil geochemical exploration was carried out targeting around Tri Le area far from about 30 km with northwestern direction from Que Phong within Nghe An province. The interval of sampling are horizontal 200 m interval with 23 line and longitudinal 300 m with 10 line, resulting in 228 soil samples. Based on the result of the soil geochemical exploration, the detailed pitting survey was carried out targeting the grid point with high TREO content, resulting in 75 soil samples within 7 pits. The geology of survey area are consisted of Ban Chieng biotite granite complex and granitic gneiss intruding Ban Khang formation comprising of quartz schist and marble. Main mineralization in the study area have the characteristics of occurrence with tin, ruby and REE-bearing monazite and xenotime to be thought as occurring at the alteration zone of granite complex. In order to elucidate the source rock of monazite and xenotime confirmed from heavy sand, soil geochemical exploration was carried out. As a analysis result with ICP-MS on the soil samples from the soil geochemical exploration, total REE oxide content of background amount to about 2 times of crustal abundance, enriching the heavy rare earth(about 2 times) and light rare earth(about 1.5 times). As a analysis result with ICP-MS on the soil samples from the soil detailed pit survey, we only identified outcrop considering as economic weathered granite body at the grid point 1-10 pit among 7 pits. As a synthetic consideration on the soil geochemical exploration and detailed pit survey, we tentatively designated Tri Le area as no promising target for REE. In 2014, we have the plan to carry out the soil geochemical exploration targeting the extended economic REE ore body in Quy Chau as project area from 2011 to 2012.