• Korean Journal of Ecology and Environment
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• 제37권1호통권106호
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• pp.112-121
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• 2004

A study was performed to examine the effects of UV-disinfected reclaimed water on microorganism concentration during rice culture. Four treatments were used and each one was triplicated to evaluate the changes of microorganism concentrations: stream water irrigation (STR), biofilter effluent irrigation (BE), UV-disinfected water irrigation with dose of 6 mW ${\cdot}$ s $cm{-2}$ (UV-6), and UV-disinfected water irrigation with dose of 16 mW ${\cdot}$ s $cm{-2}$ (UV-16). The indicator microorganisms of interest were total coliform (TC), fecal coliform (FC), and E. coli. The biofilter effluent from 16-unit apartment sewage treatment plant was used as reclaimed water and flowthrough type UV-disinfection system was used. Concentrations of indicator microorganisms in the treatment plots ranged from $10^2$ to $10^5$ MPN/100 mL during 24 hours after irrigation in May and June, where initial irrigation water for transplanting reparation was biofilter-effluent without UV-disinfection. It implies that initial irrigation using only non-disinfected reclaimed water for puddling in paddy field can be health-concerned because of more chance of farmer's physical contact with elevated concentration of microorganisms. The concentrations of microorganisms varied widely with rainfall, and treatments using UV-disinfected water irrigation showed significantly lower concentrations than others and their levels were within the range of paddy rice field with normal surface water irrigation. The mean concentrations of STR and BE during growing season were in the range of 4 ${\times}\;10^3$ MPN/100 mL for TC, and 2${\times}\;10^3$ MPN/100 mL for FC and E, Coli, While mean concentrations of UV-S and UV-lS were less than 1${\times}\;10^3$ MPN/100 mL for all the indicator microorganisms. Overall, UV-disinfection was thought to be feasible and practical alternative for agricultural reuse of secondary level effluent in Korea.

• Korean Journal of Psychosomatic Medicine
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• 제20권1호
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• pp.59-65
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• 2012

Objectives : The present study takes part of the agricultural district cohort study of a certain county located in Gyeonggido and aims to investigate the difference of the heart rate variability(HRV) according to the social support level. Methods : We used data from 1727 participants of a health promotion program who are older than 40 years old. A physical examination, as well as a one-to-one interview to obtain sociodemographic characteristics, was performed with each participant. In addition, the participants completed the Medical Outcomes Study-Social Support Survey(MOS-SSS) for their the social support level to be assessed, and their HRV were measured to evaluate their autonomic function. The entire group was divided in two groups according to its MOS-SSS points to facilitate the research. Those who were evaluated as the high 25%(432 persons) were denominated as high social support (HSS) group and those who were evaluated as the low 25%(425 persons) were denominated as poor social support(PSS) group. Results : The two groups showed significant differences on the sociodemographic factor such as mean age and gender composition(p<0.05). Comparing the indices related to the HRV, the HSS group had the following values higher than the PSS group : SDNN(F=4.938, p=0.027), TP(F=8.088, p=0.005), VLF(F=6.220, p=0.013) LF (F=3.873, p=0.049). Conclusion : According to the research, the PSS group showed dysfunction on their autonomic nervous system comparing to the HSS group. The social support helps an individual overcome difficulties, helps the adaptation during the changes of circumstances and in stressful situations it serves like a buffer. Based on that, it's possible to define that a low social support level gave an impact on the autonomic function. Also, using the fact that the HRV can evaluate the autonomic function in an objective view, it was possible to visualize that it has a potential to be used as an assistant factor to evaluate the social support.

• Progress in Medical Physics
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• 제25권3호
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• pp.167-175
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• 2014

The purpose of this study is to evaluate the variation of the dose which is delivered to the patients with glottis cancer under IMRT (intensity modulated radiation therapy) by using the 3D registration with CBCT (cone beam CT) images and the DIR (deformable image registration) techniques. The CBCT images which were obtained at a one-week interval were reconstructed by using B-spline algorithm in DIR system, and doses were recalculated based on the newly obtained CBCT images. The dose distributions to the tumor and the critical organs were compared with reference. For the change of volume depending on weight at 3 to 5 weeks, there was increased of 1.38~2.04 kg on average. For the body surface depending on weight, there was decreased of 2.1 mm. The dose with transmitted to the carotid since three weeks was increased compared be more than 8.76% planned, and the thyroid gland was decreased to 26.4%. For the physical evaluation factors of the tumor, PITV, TCI, rDHI, mDHI, and CN were decreased to 4.32%, 5.78%, 44.54%, 12.32%, and 7.11%, respectively. Moreover, $D_{max}$, $D_{mean}$, $V_{67.50}$, and $D_{95}$ for PTV were increased or decreased to 2.99%, 1.52%, 5.78%, and 11.94%, respectively. Although there was no change of volume depending on weight, the change of body types occurred, and IMRT with the narrow composure margin sensitively responded to such a changing. For the glottis IMRT, the patient's weight changes should be observed and recorded to evaluate the actual dose distribution by using the DIR techniques, and more the adaptive treatment planning during the treatment course is needed to deliver the accurate dose to the patients.

• Journal of Korea Water Resources Association
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• 제45권3호
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• pp.301-316
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• 2012

Two models, TANK and SWAT (Soil and Water Assessment Tool) were compared for simulating natural flows in the Paldang Dam upstream areas of the Han River basin in order to understand the limitations of TANK and to review the applicability and capability of SWAT. For comparison, simulation results from the previous research work were used. In the results for the calibrated watersheds (Chungju Dam and Soyanggang Dam), two models provided promising results for forecasting of daily flows with the Nash-Sutcliffe model efficiency of around 0.8. TANK simulated observations during some peak flood seasons better than SWAT, while it showed poor results during dry seasons, especially its simulations did not fall down under a certain value. It can be explained that TANK was calibrated for relatively larger flows than smaller ones. SWAT results showed a relatively good agreement with observed flows except some flood flows, and simulated inflows at the Paldang Dam considering discharges from upper dams coincided with observations with the model efficiency of around 0.9. This accounts for SWAT applicability with higher accuracy in predicting natural flows without dam operation or artificial water uses, and in assessing flow variations before and after dam development. Also, two model results were compared for other watersheds such as Pyeongchang-A, Dalcheon-B, Seomgang-B, Inbuk-A, Hangang-D, and Hongcheon-A to which calibrated TANK parameters were applied. The results were similar to the case of calibrated watersheds, that TANK simulated poor smaller flows except some flood flows and had same problem of keeping on over a certain value in dry seasons. This indicates that TANK application may have fatal uncertainties in estimating low flows used as an important index in water resources planning and management. Therefore, in order to reflect actually complex and complicated physical characteristics of Korean watersheds, and to manage efficiently water resources according to the land use and water use changes with urbanization or climate change in the future, it is necessary to utilize a physically based watershed model like SWAT rather than an existing conceptual lumped model like TANK.

• Asian-Australasian Journal of Animal Sciences
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• 제29권6호
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• pp.823-829
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• 2016

Eight Holstein steers ($216{\pm}48kg$ body weight) fitted with ruminal and duodenal cannulas were used to evaluate effects of wheat straw processing (ground vs pelleted) at two straw inclusion rates (7% and 14%; dry matter basis) in dry rolled or steam-flaked corn-based finishing diets on characteristics of digestion. The experimental design was a split plot consisting of two simultaneous $4{\times}4$ Latin squares. Increasing straw level reduced ruminal (p<0.01) and total tract (p = 0.03) organic matter (OM) digestion. As expected, increasing wheat straw level from 7% to 14% decreased (p<0.05) ruminal and total tract digestion of OM. Digestion of neutral detergent fiber (NDF) and starch, per se, were not affected (p>0.10) by wheat straw level. Likewise, straw level did not influence ruminal acetate and propionate molar proportions or estimated methane production (p>0.10). Pelleting straw did not affect ($p{\geq}0.48$) ruminal digestion of OM, NDF, and starch, or microbial efficiency. Ruminal feed N digestion was greater (7.4%; p = 0.02) for ground than for pelleted wheat straw diets. Although ruminal starch digestion was not affected by straw processing, post-ruminal (p<0.01), and total-tract starch (p = 0.05) digestion were greater for ground than for pelleted wheat straw diets, resulting in a tendency for increased post-ruminal (p = 0.06) and total tract (p = 0.07) OM digestion. Pelleting wheat straw decreased (p<0.01) ruminal pH, although ruminal volatile fatty acids (VFA) concentration and estimated methane were not affected ($p{\geq}0.27$). Ruminal digestion of OM and starch, and post-ruminal and total tract digestion of OM, starch and N were greater (p<0.01) for steam-flaked than for dry rolled corn-based diets. Ruminal NDF digestion was greater (p = 0.02) for dry rolled than for steam-flaked corn, although total tract NDF digestion was unaffected (p = 0.94). Ruminal microbial efficiency and ruminal degradation of feed N were not affected (p>0.14) by corn processing. However, microbial N flow to the small intestine and ruminal N efficiency (non-ammonia N flow to the small intestine/N intake) were greater (p<0.01) for steam-flaked than for dry rolled corn-based diets. Ruminal pH and total VFA concentration were not affected ($p{\geq}0.16$) by corn processing method. Compared with dry rolled corn, steam-flaked corn-based diets resulted in decreased acetate:propionate molar ratio (p = 0.02). It is concluded that at 7% or 14% straw inclusion rate, changes in physical characteristics of wheat straw brought about by pelleting negatively impact OM digestion of both steam-flaked and dry-rolled corn-based finishing diets. This effect is due to decreased post-ruminal starch digestion. Replacement of ground straw with pelleted straw also may decrease ruminal pH.

• Journal of the Korean Association of Geographic Information Studies
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• 제2권2호
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• pp.27-44
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• 1999

Digital maps produced in Korea are various in scale and include a lot of geographic and attribute data. In this study, it is argued that, to reduce the production cost and the difficulties for renewal, it is necessary to establish the already nationally drawn 1:5,000 scale digital maps as the base maps and simplify them as much as the TIGER files in the U.S. The comprehensive data included in the digital maps in Korea are mostly land use information, which are supposed to be established separately from the digital maps. The land use information system could be maintained and updated cheaply and frequently at the local government level. In response to common needs, the land use information could be imported to GIS and used for analyses. As technologies and societies changes, the Census questions and methodologies should be changed for better uses. Along with GIS, the Census would be developed and processed more reliably and efficiently. Also, it is recommended for Korean government to develop the Census Tract and Block Group system. Current Eup, Myon, Dong as basic units for Census information may not be useful or effective for micro level urban analyses and public service planning activities because of their large population and land areas. It is recommended that optimum population of a Census Tract be 5,000 and a Block Groups 1,500, and one Census Tract includes 1~9 Block Groups. It is recommend that Census Tract and Block Group boundary lines be decided flexibly in light of population, physical features, socio-economic attributes, and tradition. For urban analyses using GIS, socio-economic census data, city government's information such as parcel data and building permit data, survey data, and satellite image data could also be used. The existence of Census Tracts and Block Groups as well as GIS could help for the data and methods to be useful for urban analyses and public service provisions.

• Korean Journal of Environment and Ecology
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• 제30권1호
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• pp.130-134
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• 2016

How does $CO_2$ affect on the stomatal mechanism? The mechanism of stomatal opening by $CO_2$ is not clear as it is difficult to see $CO_2$ effect on light-induced stomatal opening. Furthermore, stomata may react differently according to the concentration of $CO_2$. The significance of the possible endogenous rhythms must consider to understand on $CO_2$-related response. It is clear that $CO_2$ has an effect on the accumulation of osmotic materials which determines the degree of stomatal apertures because it is known that stomata open in the condition of the reduced $CO_2$ concentration. However, it is not fully understood how $CO_2$ leads to the stomatal opening. It has been thought that $CO_2$ can not affect on the ion fluxes which determines the increase of osmotic potential in guard cells. However, in this study, the changes of guard cell membrane permeability by $CO_2$ have been focused on. There are many reports that $CO_2$ related reactions are dominant when the leaf is exposed to certain a mount of $CO_2$. The hypothesis of the stomatal opening by light is based on the increase of osmotic materials in guard cells including $K^+$, $Cl^-$, sucrose and $malate^{2-}$. It was reported that $CO_2$ induced a big hyperpolarization indicating that $H^+$ was extruded to the cell outside. It was also found that $CO_2$ caused guard cell membrane hyperpolarization in the intact leaf up to 3 or 4 times higher than that of light induced membrane hyperpolarization. These results represent that $CO_2$ can affect on the change of physical characteristics which affects on the change of the membrane permeability.

• Journal of the Korean Arthroscopy Society
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• 제10권1호
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• pp.77-82
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• 2006

Purpose: The purpose of this study was to analyze the clinical results of symptomatic lateral discoid meniscus found in adults over 40 years old. Materials & Methods: From March 1994 to March 2004, 53 cases treated for lateral discoid meniscus in 48 patients aged over 40 years with the mean age $48.4(40{\sim}62)$ who were followed up more than 1 year, were analyzed by physical findings, simple X-ray, MRI and arthroscopic exam. Results: Most of the cases (42 cases, 79.2%) had symptoms for less than 1 year duration. 26 cases(49.1 %) out of 53 had trauma history. Simple radiologic evaluation showed that lateral condylar abnormality such as the flattening of lateral femoral condyle, marginal osteophytes, and subchondral sclerosis was seen in 37cases(69.8%). Also medial condyle showed degenerative changes in 16 cases (30.2%). Tear of discoid meniscus in 45 cases(84.9%) were examined by arthroscope and tear was not detected in 8 cases(15.1%). Type of tear was complex(18 cases), longitudinal(12 cases), horizontal(11 cases) and transverse(4 cases). Concomitant medial meniscal rupture was found in 7 cases(13.2%). The simple procedure done was reshaping(46 cases), subtotal resection(5 cases), total resection(1 case) and meniscal repair after reshaping in 6 cases, and arthroplasty was performed after arthroscopic examination in 1 case. Conclusion: Onset of symptom in adult lateral discoid meniscus is usually traumatic in origin. Most cases showed radiologic abnormality such as degenerative change in lateral condyles as well as medial condyles and the results of preservative surgical treatment was the most preferred option in most patients.

• Journal of Environmental Impact Assessment
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• 제26권4호
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• pp.272-289
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• 2017

This study analyzed the status of the naturalized plants in islands in Jeollanamdo from an island biogeographic perspective. As a result of a floristic analysis at 47 inhabited islands and 194 uninhabited islands, 30 families and 134 species naturalized plants are reported. The most commonly occurring naturalized plant from 141 islands was Rumex crispus. The average number of naturalized plants by islands is 20.6 species (${\pm}14.22$) at the inhabited islands and 3.7 species (${\pm}3.89$) at the uninhabited islands. Presence of fifty nine naturalized species at Geumodo in Yeosu-si is the largest in number. The naturalization ratio, which is the ratio of naturalized plants to native plants, is 7.66% (${\pm}3.96$) in the inhabitable islands and 4.97% (${\pm}3.70$) in the uninhabitable islands. The naturalization ratio among islands of the West Sea in Jeollanam-do is 5.92% (${\pm}4.49$), and it is higher than 4.96% (${\pm}2.15$) in islands in the South Sea. Especially, the naturalization ratio at the inhabitable islands, i.e., 8.39% (${\pm}4.37$) at the islands of the West Sea is higher than 5.80% (${\pm}1.41$) at islands in the South Sea. The naturalization ratio of naturalized plants at the islands shows positive correlation with the size of the island (r=0.412, p<0.01), but the correlations with distance from the mainland and altitude above sea level are not significant. Eight ecosystem disturbing species designated by law are reported, and each species shows distinct distributional ranges. The regional differences in the number of naturalized plant species seem to be a result of the complex reflection of natural and human environmental factors, such as the degree of traffic between mainland and islands, degree of cultivation activities, along with the physical environmental differences. Since islands have limited habitats and resources, islands could be more vulnerable to the incoming species from outside, and environmental changes than mainland. Therefore, continuous monitoring and management against the naturalized plants in islands are needed.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• 제22권4호
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• pp.172-186
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• 2017

Current study is a part of the efforts to assess the estuarine barrage effects on the coastal ecosystem induced by the Si flux changes. Surface sediments from Seomjin and Nakdong estuary and sediment cores from Nakdong estuary was analysed to investigate the effect of estuarine barrage on the distribution of grain size, organic matter (loss on ignition: LOI) and biogenic silica (BSi). The samples of Seomjin estuary were collected in March, 2015 and those of Nakdong estuary were collected in November, 2014. Generally, the longitudinal distribution of grain size, LOI and BSi in Seomjin estuary, natural estuary, was gradually changed. However mud (silt and clay), LOI and BSi increased from station mid-estuary where tide reaches year-round. The distribution of grain size, LOI and BSi in Nakdong estuary, however, were entirely different between inside and outside of estuarine barrage. The mud percentage and LOI were low and consistent in inside of the barrage except R05, inside of right gate, yet those of outside of the barrage were higher and varied by adjacent sluices. Mud, LOI and BSi of ND1 and ND2 decreased immediately after the construction of Nakdong estuarine barrage due to disturbance of sediment and decrease of sediment supply. To exclude the physical effects by the barrage, BSi excess ($BSi_{exc}$) was calculated using regression equation of BSi-LOI and BSi-mud of Seomjin estuary. $BSi_{exc}$ of Seomjin estuary decreased gradually from upper estuary to lower estuary. $BSi_{exc}$ of Nakdong estuary were positive in inside of the barrage and negative in outside of the barrage. BSi retention and shift of species composition of diatom by the barrage would affect $BSi_{exc}$ distribution. Before the construction of Nakdong estuarine barrage, $BSi_{exc}$ of ND2 was negative and consistent owing to high mud sedimentation. After the construction, $BSi_{exc}$ of ND2, however, fluctuated due to continuous disturbance of sediment due to construction of Eulsuk bridge and East gate.