• Journal of Korean Society of Disaster and Security
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• v.12 no.4
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• pp.1-13
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• 2019

Recently, as the occurrence frequency of sudden floods due to climate change increased, it is necessary to install the facilities that can cope with the initial stormwater. Most researches have been conducted on the design of facilities applying the Low Impact Development (LID) and the reduction effect on rainfall runoff to examine with 1D or 2D numerical models. However, the studies on the examination about flow characteristics and stability of pipe network systems were relatively insufficient in the literature. In this study, the stability of the pipe network system in rainwater storage tank was examined by using 3D numerical model, FLOW-3D. The changes of velocity and dynamic pressure were examined according to the number of rainwater storage tank and compared with the design criteria to derive the optimal design plan for a rainwater storage tank. As a results of numerical simulation with the design values in the previous study, it was confirmed that the velocity became increased as the number of rainwater storage tank increased. And magnitude of the velocity in pipes was formed within the design criteria. However, the velocity in the additional rainwater storage pipe was about 3.44 m/s exceeding the allowable range of the design criteria, when three or more additional rainwater storage tanks were installed. In the case of turbulence intensity and bottom shear stress, the bottom shear stress was larger than the critical shear stress as the additional rainwater storage was increased. So, the deposition of sediment was unlikely to occur, but it should be considered that the floc was formed by the reduction of the turbulence intensity. In addition, the dynamic pressure was also satisfied with the design criteria when the results were compared with the allowable internal pressure of the pipes generally used in the design of rainwater storage tank. Based on these results, it was suitable to install up to two additional rainwater storage tanks because the drainage becomes well when increasing of the number of storage tank and the velocity in the pipe becomes faster to be vulnerable to damage the pipe. However, this study has a assumption about the specifications of the rainwater storage tanks and the inflow of stormwater and has a limitation such that deriving the suitable rainwater storage tank design by simply adding the storage tank. Therefore, the various storage tank types and stormwater inflow scenarios will be asked to derive more efficient design plans in the future.

• Radiation Oncology Journal
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• v.12 no.1
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• pp.27-31
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• 1994

There are a number of reports suggesting that there may be a correlation between the clinical response to radiotherapy in various tumors and the clonogenic survival of cell lines derived from these tumors following exposure to 2 Gy(SF2). Authors conducted this study to determine SF2 for cells in primary culture from surgical specimens. The tumor tissues with squamous cell carcinoma of uterine cervix and head and neck were obtained. The tumor tissues were disaggregated to single cells by incubating with collagenase type w for 2 hours with constant stirring. Single cell suspensions were inoculated in four 24-well plates precoated with cell adhesive matrix. After 24 hours of incubation at 37$ ^{\circ}C $, rows of four wells were then irradiated, consisting of control set and five other sets each receiving doses of 1,2,3,4, and 6 Gy. After incubation for a total of 13 days, the cultures were stained with crystal violet and survival at each dose was determined by quantitative image analysis system, To determine whether cell growth was of epithelial origin, immunocytochemical staining with a mixture of cytokeratin and epithelial monoclonal antibodies were performed on cell cultures. During the period of this study, we received 5 squamous cell carcinoma specimens of head and neck and 20 of uterine cervical carcinoma. Of these, 15 yielded enough cells for radiosensitivity testing. This resulted an overall success rate of 60$ \% $. The mean SF2 value for 15 tumours was 0.55$\pm$0.17 ranging from 0.20 to 0.79. These results indicate that there is a broad range of sensitivities to radiation in same histologic type. So with a large patient population, we plan to determine whether a different SF2 value is associated with tumours that are controlled with radiotherapy than those that are not.

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.382-393
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• 2009

The objectives of this study were to characterize long-term annual and seasonal trophic state of Topjeong Reservoir using conventional variables of Trophic State Index (TSI) and to determine the empirical relations between the trophic parameters. For the analysis, we used water quality dataset of 1995$\sim$2007, which is obtained from the Ministry of Environment, Korea and the number of parameters was 9. Annual ambient mean values of TN and TP were 1.78 mg $L^{-1}$ and 0.03 mg $L^{-1}$, respectively and TN : TP ratios averaged 76, indicating that this system was nitrogen-rich hypertrophic, and was probably phosphorus-limitation for algal growth. Therefore, nitrogen varied little with seasons and years, and total phosphorus (TP) varied depending on season and year. Monsoon dilutions of TP occurred in August and monthly fluctuations of suspended solid (SS) was similar to those of chlorophyll-$\alpha$ (CHL). Annual mean values of BOD and $COD_{Mn}$ were 1.61 mg $L^{-1}$ and 4.23 mg $L^{-1}$, respectively and the interannual values were directly influenced by the intensity of annual rainfall. There were no significant differences in the trophic variables between the two sampling sites. Mean values of Trophic State Index (TSI, Carlson, 1977), based on TN, TP, CHL, and SD (Secchi depth), turned out as eutrophic state, except for the TN (hypertrophic). Regression analyses of log-transformed seasonal CHL against TP and TN showed that variation of the CHL was explained 37% by the variation of TP ($R^2$=0.37, p<0.001, r=0.616), but not by TN ($R^2$=0.03, p>0.05). Regression coefficient of $Log_{10}$CHL vs $Log_{10}SD$ was 0.330 (p<0.003, r=0.580), indicating that transparency is regulated by the organic matter in the system. Results, data suggest that one of the ways controlling the eutrophication would be a reduction of phosphorus from the watershed.

• Journal of Preventive Medicine and Public Health
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• v.40 no.5
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• pp.363-370
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• 2007

Objectives: The principal objective of this study was to determine the relationship between maternal exposure to air pollution and low birth weight and to propose a possible environmental health surveillance system for low birth weight. Methods: We acquired air monitoring data for Seoul from the Ministry of Environment, the meteorological data from the Korean Meteorological Administration, the exposure assessments from the National Institute of Environmental Research, and the birth data from the Korean National Statistical Office between January 1, 2002 and December 31, 2003. The final birth data were limited to singletons within $37{\sim}44$ weeks of gestational age. We defined the Low Birth Weight (LBW) group as infants with birth weights of less than 2500g and calculated the annual LBW rate by district. The air monitoring data were measured for $CO,\;SO_2,\;NO_2,\;and\;PM_{10}$ concentrations at 27 monitoring stations in Seoul. We utilized two models to evaluate the effects of air pollution on low birth weight: the first was the relationship between the annual concentration of air pollution and low birth weight (LBW) by individual and district, and the second involved a GIS exposure model constructed by Arc View 3.1. Results: LBW risk (by Gu, or district) was significantly increased to $1.113(95%\;CI=1.111{\sim}1.116)\;for\;CO,\;1.004(95%\;CI=1.003{\sim}1.005)\;for\;NO_2,\;1.202(95%\;CI=1.199{\sim}1.206\;for\;SO_2,\;and\;1.077(95%\;CI=1.075{\sim}1.078)\;\;for\;PM_{10}$ with each interquartile range change. Personal LBW risk was significantly increased to $1.081(95%\;CI=1.002{\sim}1.166)\;for\;CO,\;1.145(95%\;CI=1.036{\sim}1.267)\;for\;SO_2,\;and\;1.053(95%\;CI=1.002{\sim}1.108)\;for\;PM_{10}$ with each interquartile range change. Personal LBW risk was increased to $1.003(95%\;CI=0.954{\sim}1.055)\;for\;NO_2$, but this was not statistically significant. The air pollution concentrations predicted by GIS positively correlated with the numbers of low birth weights, particularly in highly polluted regions. Conclusions: Environmental health surveillance is a systemic, ongoing collection effort including the analysis of data correlated with environmentally-associated diseases and exposures. In addition. environmental health surveillance allows for a timely dissemination of information to those who require that information in order to take effective action. GIS modeling is crucially important for this purpose, and thus we attempted to develop a GIS-based environmental surveillance system for low birth weight.

• Journal of Home Health Care Nursing
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• v.7 no.1
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• pp.58-72
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• 2000

This study was an attempt to encourage the development of a rehabilitation delivery system and programs as a substitute service for hospitalization on the case of car accident patients, such as hospital based home health care nursing services. Various substitute services for hospitalization are required to curtail the length of stay for inpatients who were hospitalized with car accident compensation insurance. It focused on developing an estimation an early discharge day for car accident inpatients based on detailed statements of treatment for 111 inpatients who were hospitalized at the General Hospital in 1997. This study had four specific purposes as follows. First. to find out the utilization of medical services. Second, to estimate the time of early discharge and income increasing effect based on early discharge for those patients. Third, to identify the factors affecting total medical expenditure and the length of stay for those inpatients. Forth, to figure out the need of utilizing home health care nursing service for accident patients. In order to analyze the length of stay and medical expenditure for inpatients who were hospitalized due to car accidents, the authors conducted micro- and macro-analysis of medical and medical expenditure records. Micro-analysis was done by nominal group discussion of 4 expertise with the critical criteria, such as a decrease in the amount of treatment after surgery, treatments, tests, drugs and changes in the test consistency, drug methods, vital signs, start of ROM exercise, doctor's order, patient's outside visiting ability, and stable conditions. In addition to identifying variables affecting medical expenditure, and the length of stay and income effect due to early discharge day, the data was analyzed with a multiple regression analysis and linear regression analysis model by SPSS-PC for windows and Excell program. Results of this study were as follows. First. the mean length of stay was 50.3 days. whereas the mean length of stay due to early discharge was 34.3 days at the hospital. The estimation of time of early discharge depended on the length of stay. The longer the length of stay, the longer the length of time of early discharge : for instance a length of stay under 10 days was estimated as correlating to a mean length of stay of 6.6 days and early discharge of 6.5. The mean length of stay was 217.4 days and the time of early discharge was 110.1 respectively. The mean medical expenditure per day was found to be 169.085 Won and the mean medical expenditure per day showed negative linear trends according to the length of stay at the hospital. The estimation results of the income effect due to being discharged 16 days early was around 2,244,000 won per bed. However. this sum does not represent the real benefits resulting from early discharge, but rather the income increasing amount without considering medical prime cost in the general hospital. Therefore, further analysis is required on the cost containments and benefits as turn over rate per bed as the medical prime costs. The length of stay was most significant and was positive to the total medical expenditure, as expected. Surgery and patient's residential area was also an important variable in explaining medical expenditure. The level of complications was the most significant variable in explaining the length of stay. There was a high level for need a home health care nursing service which further supports early discharge for accident patients. In addition, when the patient was discharged. they needed follow up care for complications suffered during the car accident. $86.8\%$ of discharged patients responded that they needed home health services after early discharge. From these research findings, the following suggestions have been drawn. Strategies on a health care delivery system must be developed in order to focus on the consumer's needs and being planned for 21 century health policy in Korea. Community based intermediate facilities or home health care should be developed for rehabilitation services as a substitute for hospitalization in order to shorten the length of stay would be. A hospital based home health care nursing service. it would be available immediately to utilize by patients who want rehabilitation services as a substitute for hospitalization with the cooperation of car insurance companies.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.3
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• pp.217-226
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• 2015

To investigate the distributions of BVOCs (Biogenic Volatile Organic Compounds) from mountain near mega city and their role in forest atmospheric, BVOCs and their oxidized species were measured at a 41 m tower in Mt. Taehwa during May, June and August 2013. A proton transfer reaction-mass spectrometer (PTR-MS) was used to quantify isoprene and monoterpenes. In conjunction with BVOCs, $O_3$, meteorological parameters, PAR (Photosynthetically Active Radiation) and LAI (Leaf Area Index) were measured. The average concentrations of isoprene and monoterpenes were 0.71 ppbv and 0.17 ppbv, respectively. BVOCs showed higher concentrations in the early summer (June) compared to the late summer (August). Isoprene started increasing at 2 PM and reached the maximum concentration around 5 PM. In contrast, monoterpenes concentrations began to increase 4 PM and stayed high at night. The $O_3$ maximum was generally found at 3 PM and remained high until 5 PM or later, which was concurrent with the enhancement of $O_3$. The concentrations of BVOCs were higher below canopy (18 m) than above canopy, which indicated these species were produced by trees. At night, monoterpenes concentrations were negatively correlated with these of $O_3$ below canopy. Using MEGAN (Model of Emissions of Gases and Aerosols from Nature), the emissions of isoprene and monoterpenes were estimated at 1.1 ton/year and 0.9 ton/year, respectively at Mt. Taehwa.

• Korean Journal of Food Science and Technology
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• v.49 no.5
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• pp.550-558
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• 2017

The effect of Artemisia argyi H. under liquid-state fermentation by Monascus purpureus (AAFM) on cognitive impairments has been studied in a mice model of diabetes-associated cognitive decline induced by streptozotocin (STZ). C57BL/6 mice (9 weeks of age, male) were separated into four groups: a normal control, STZ-induced diabetic mouse group (STZ group), Artemisia argyi H. (AA) 10 group (diabetic mouse+AA 10 mg/kg/day), AAFM 10 group (diabetic mouse+AAFM 10 mg/kg/day). Administration of AA and AAFM significantly improved glucose tolerance, as shown by the intraperitoneal glucose tolerance test (IPGTT), and ameliorated cognitive deficit, as shown by the behavioral tests including passive avoidance, Morris water maze, and Y-maze tests. After behavioral tests, the cholinergic system was examined by assessment of the acetylcholine (ACh) level and acetylcholinesterase (AChE) inhibitory activity, and the antioxidant system was also assessed by measuring malondialdehyde (MDA) and superoxide dismutase (SOD) levels in the brain and liver.

• KDI Journal of Economic Policy
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• v.32 no.2
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• pp.144-170
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• 2010

This paper considers the effect of various types of procurement auction system on competition focusing on the rate of successful bidding. We analyze the number of bidders and the rate of successful bids using online procurement data of the Public Procurement Service. The average number of bidders is 301 and the average rate of successful bids is 87.42% while the weighted average rate is 75.13%. These numbers show that there is quite strong competition among bidders and the rate is lower as the expected price is higher. When we analyze the data of price procurement auction, the rate is also shown to be lower as the expected price is higher. Furthermore, the rate decreases as the number of bidders increases which naturally makes the competition stronger. Meanwhile, the analysis finds that the inclusion of the onsite bidding, the PQ(Pre-Qualification) result, or major-10 winning companies cannot explain the rate much in our data. In case of turnkey-alternative, the average rate of successful bidding for 484 cases record 90.20%. The average is 84.89% with 120 alternatives and 91.97% with 364 cases of turnkey. The reason why the rate of turnkey-alternative is lower than that of price procurement auction is the lack of competition as well as the systematic difference. By setting up a model, we are able to explain the difference in rate caused by the respective reason. When we suppose there are 3 bidders in case of price procurement auction for a project that exceeds 100 billion won, the rate is expected to be around 64%. This implies that difference of 26% is caused by the systemic difference and 3% by the lack of competition. Therefore, we conclude that the difference in rate between turnkey-alternative and price procurement auction is caused mainly by the systemic difference. In case of PPP(Public Private Partnership) projects, among 154 projects in total, only 40% has more than 2 bidders that compete. The average number of bidders is 1.88 which is less than 2, and the average rate of successful bids is 90%. In sum, under the price procurement auction, there is strong competition which is reflected by the rate of successful bids. However, there is room to decrease the rate by strengthening the competition under the turnkey-alternative. Also with PPP projects, we expect the rate can be steadily reduced with revived competition among bidders.

• Restorative Dentistry and Endodontics
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• v.31 no.6
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• pp.452-459
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• 2006

Competition will usually develop between the opposing walls as the restorative resin shrinks during polymerization. Magnitude of this phenomenon may be depended upon cavity configuration and volume. The purpose of this sturdy was to evaluate the effect of cavity configuration and volume on microleakage of composite resin restoration that has margins on the enamel site only. The labial enamel of forty bovine teeth was ground using a model trimmer to expose a flat enamel surface. Four groups with cylindrical cavities were defined, according to volume and configuration factor(Depth x Diameter / C-factor) - Group I : 1.5 mm ${\times}$ 2.0 mm / 4.0, Group II : 1.5 mm ${\times}$ 6.0 mm / 2.0, Group III : 2.Omm ${\times}$ 1.72 mm / 5.62, Group IV : 2.0 mm ${\times}$ 5.23 mm / 2.54. After treating with fifth-generation one-bottle adhesive - BC Plus$^{TM}$ (Vericom, AnYang, Korea), cavities were bulk flted with microhybrid composite resin - Denfill$^{TM}$ (Vericom). Teeth were stored in distilled water for one day at room temperature and were finished and polished with Sof-Lex system. Specimens were thermocycled 500 times between 5$^{\circ}$C and 55$^{\circ}$C for 30 second at each temperature. Teeth were isolated with two layers of nail varnish except the restoration surface and 1 mm surrounding margins. Electrical conductivity (${\mu}$A) was recorded in distilled water by electrochemical method. Microleakage scores were compared and analyzed using two-way ANOVA at 95% level. The results were as follows: 1. Small cavity volume showed lower microleakage score than large one, however, there was no statistically significant difference. 2. There was no relationship between cavity configuration and microleakage. Factors of cavity configuration and volume did not affect on microleakage of resin restorations with enamel margins only.

• Sleep Medicine and Psychophysiology
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• v.8 no.1
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• pp.52-58
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• 2001

Objectives: An Increased level of psychophysiologic arousal and diminished physiologic flexibility would be observed in patients with panic disorder compared with a normal control group. We investigated the differences of psychophysiologic response between patients with panic disorder and normal control to examine this hypothesis. Methods: Ten Korean patients with panic disorder who met the diagnostic criteria of DSM-IV were compared with 10 normal healthy subjects. In psychological assessment, levels of anxiety and depression were evaluated by State-Trait Anxiety Inventory, Beck's Depression Inventory and Hamilton Rating Scale For Anxiety and Depression. Heart rate, respiration rate, electrodermal response, and electromyographic activity were measured by biofeedback system (J & J I-330 model) to determine psychophysiologic responses on autonomic nervous system. Stressful tasks included mental arithmetic, video game, hyperventilation, and talking about a stressful event. Psychophysiologic responses were measured according to the following procedures : baseline(3 min)-mental arithmetic (3 min)-rest (3 min)-video game (3 min)-rest (3 min)-hyperventilation (3 min)-rest (3 min)-talking about a stressful event (3 min). Results: The baseline level of anxiety and depression, electrodermal response (p=.017), electromyographic activity (p=.047) and heart rate (p=.049) of patients with panic disorder were significantly higher than those of the normal subject group. In electrodermal response, patient group had significantly higher startle response than the control group during hyperventilation (p=.001). Startle and recovery responses of heart rate in the patient group were significantly lower than responses in the control group during mental arithmetic (p=.007, p=.002). In electrodermal response of the patient group, startle response was significantly higher than recovery response during mental arithmetic (p=.000) and video game task (p=.021). Recovery response was significantly higher than startle response in respiratory response during hyperventilation. Conclusion: The results showed that patients with panic disorder had higher autonomic arousal than the control group, but the physiologic flexibility was variable. We suggest that it is helpful for treatment of panic disorder to decrease the level of autonomic arousal and to recover the physiologic flexibility in certain stressful event.