• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.70-75
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• 1998

A model of pond system is developed for treatment and recycling of excreta from twenty-five adult dairy cattle. It is composed of wastewater treatment ponds and small fish ponds. Those are three facultative ponds in series; primary-secondary-tertiary pond and these are designed to rear carps without feeding. A pit is constructed at the bottom of primary pond for efficient sludge sedimentation and effective methane fermentation. It is contrived to block into it the penetration of oxygen dissolved in the upper layer of pond water. The excreta from the cattle housed in stalls are diluted by water used for clearing them. The washed excreta flow into the pit. The average yearly $BOD_5$ concentration of influent is 398.7mg/l. That of the effluent from primary, secondary and tertiary pond of the system is 49.18, 27.9, and 19.8.mg/l respectively. Approximate 88, 93, and 95 % of BOD5 are removed in each pond. The mean yearly SS concentration of influent is 360.5 mg/l That of the effluent from each pond is 53.4, 45.7, and32.7mg/l respectively. Approximate 86, 88, and 91% of SS are removed in each pond. The $BOD_5$ concentration of secondary and tertiary pond can satisfy 30mg/l secondary treatment standard. The SS concentration of effluent from tertiary pond, however, is slightly greater than the standard, which results from activities of carps growing in the pond. The average yearly total nitrogen concentration of influent is 206.8mg/l and that of the effluent from each pond is 48.6, 30.8, and 21.0mg/l respectively. Approximate 74, 88, and 90% of total nitrogen are removed in each pond. The mean yearly total phosphorous concentration of influent is 20.7mg/l and that of the effluent from each pond is 5.3, 3.2, and 2.1mg/l respectively. Approximate 97, 98, and 99% of total phosphorous are removed in each pond. The high removal of nitrogen and phosphorous results from active growth of algae in the upper layer of pond water. Important pond design parameters for southern part of Korea -- areal loading of BOD5, liquid depth, hydraulic detention time, free board, and pond arrangement -- are taken up.

• Journal of KIISE:Information Networking
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• v.29 no.6
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• pp.595-612
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• 2002

One of the most important issues in guaranteeing the high degree of QoS on mobile computing is how to reduce hand-off drops caused by lack of available bandwidth in a new cell. Each cell can request bandwidth reservation to its adjacent cells for hand-off calls. This reserved bandwidth can be used only for hand-offs, not for new calls. It is also important to determine how much of bandwidth should be reserved for hand-off calls because reserving too much would increase the probability of a new call being blocked. Therefore, it is essential to develop a new mechanism to provide QoS guarantee on a mobile computing environment by reserving an appropriate amount of bandwidth and call admission control. In this paper. bandwidth reservation and call admission control mechanisms are proposed to guarantee a consistent QoS for multimedia traffics on a mobile computing environment. For an appropriate bandwidth reservation, we propose an adaptive bandwidth reservation mechanism based on an MPP and a 2-tier cell structure. The former is used to predict a next move of the client while the latter to apply our mechanism only to the client with a high hand-off probability. We also propose a call admission control that performs call admission test only on PNC(Predicted Next Cell) of a client and its current cell. In order to minimize a waste of bandwidth caused by an erroneous prediction of client's location, we utilize a common pool and QoS adaptation scheme. In order evaluate the performance of our call admission control mechanism, we measure the metrics such as the blocking probability of new calls, dropping probability of hand-off calls, and bandwidth utilization. The simulation results show that the performance of our mechanism is superior to that of the existing mechanisms such as NR-CAT2, FR-CAT2, and AR-CAT2.

• Journal of Korean Home Economics Education Association
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• v.18 no.4 s.42
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• pp.67-84
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• 2006

This study was carried out to investigate nutrient intake, dietary self-efficacy, and physical activity self-efficacy of elementary school students by obesity index in Gyeongbuk area. The survey was conducted from June 7 to June 18 in 2005. The study was peformed by analyzing a questionnaire answered by 523 elementary school student in 5th and 6th grade. The obesity index was gained by height and weight data. Nutrient intakes was evaluated by 24hr-dietary record. Statistical data analysis were completed using the SPSS 12.0 program. The results were summarized as follows; The result of the body measurement was that 31.7% of underweight group, 45.1% of normal group, 12.8% of overweight group, 10.3% of obese group. 13.9% of underweight group experienced weight control, and 17.5% of the subject respond they will try the weight control in the future. Male students showed significantly higher exercise frequency than female students(p<0.001). Male underweight group and female obese group show the highest exercise frequency. Daily energy intake of the subject showed 80.1% in male students and 87.5% in female students revealed under the recommended dietary allowance(RDA) for Korean. The intake ratio of energy nutrients was identical in male and female of underweight group and obese group, so this showed that intake style was similar in two groups. By investigating through MAR(mean adequacy ratio), underweight group of male students and both normal and overweight group of female students were lowest, while overweight group of male students and underweight group of female students were the highest. Physical activity self-efficacy of male students was higher than female students, and physical activity self-efficacy by obesity index was higher in underweight group of male students and obese group in female.

• Korean Journal of Ecology and Environment
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• v.39 no.4 s.118
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• pp.462-470
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• 2006

The zooplankton community dynamics and grazing experiments was evaluated along a 40 km section of the lower Seomjin river system. Zooplankton was sampled twice a month from January 2005 to June 2006 at three sites (River mouth; RKO, Seomjin bridge: RK12 and Gurae bridge: RK36) in the main river channel. During the study period, the values of most limnological parameters in the three sites were fairly similar, except for conductivity. Annual variation of conductivity in River mouth and Seomjin bridge was more dramatic than which of the other site. There were statistically significant spatial and seasonal differences in zooplankton abundance (ANOVA, P<0.01). Total abundance of major zooplankton groups at both stations was much higher than in Gurae bridge. Among the macrozooplankton, cladocerans abundance was negligible in study sites during study periods. Community filtering rates (CFRs) for phytoplankton and bacteria varied from 0 to 50 mL $L^{-1}\;D^{-1}$ and from 0 to 45 mL $L^{-1}\;D^{-1}$, respectively. The spatial variation of CFRs for phytoplankton was significant (ANOVA, P<0.05). The CFRs of copepods for phytoplankton and bacteria was much higher than that of cladocerans at study sites. Total zooplankton filtering rates on bacteria were slightly lower than filtering rates on phytoplankton. The CFRs of microzooplankton (MICZ) for bacteria were much higher than for macrozooplankton (MACZ) at all sites. Considering the total zooplankton community, MICZ generally were more important than MACZ as grazers of bacteria and phytoplankton in freshwater zone, while MACZ were more important than MICZ as grazers of phytoplankton in brackish zone.

• Journal of Life Science
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• v.26 no.1
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• pp.83-90
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• 2016

This study was investigated the improvement effects of Ledebouriella seseloides (LS) ethanol extracts on lipid parameters in an ovariectomized animal model. Sixty, nine-week old female Sprague Dawley rats were randomly assigned to four groups as follows: sham-operated rats (SHAM), ovariectomized rats (OVX-CON) and ovariectomized rats that were treated with LS ethanol extracts (50 mg/kg/day and 200 mg/kg/day, respectively). The diets were fed to the rats for six weeks after their operation. The total-cholesterol and triglyceride contents on serum increased in the OVX-CON group compared to the SHAM group, but supplementation with the LS extract caused these factors to decrease. Notably, the serum LDL-cholesterol concentration in the supplemented 200 mg/kg/day LS ethanol extract group was significantly more reduced than the OVX-CON group. In addition, the platelet aggregation ability was lower in groups treated with LS than in the OVX-CON group. The alkaline phosphatase (ALP) activity was lower in the LS extract group compared to the OVX-CON group. Collagen content, in bone and cartilage, were reduced by ovariectomy, but the supplemented LS extract groups exhibited higher concentrations in their bones. According to these results, the improvement effects of LS extract on serum lipid parameters and osteogenesis in ovariectomized rats were illuminated.

• KSBB Journal
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• v.18 no.3
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• pp.211-216
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• 2003

The removal yield of dissolved organic matter in drinking water by biological activated carbon (BAC) process was investigated. The tested processes wer raw water-AC process (BAC1), raw water-ozonation-BAC process (BAC2), and raw water-ozonation-coagulation/sedimentation-BAC process (BAC3). The amounts of organic matter was measured as dissolved organic carbon (DOC), ulta-violet radiation at 254 nm wavelength ($UV_{254}$), total nitrogen (T-N), ammonia nitrogen (NH_3$-N), and total phosphate (T-P). As a results, 30.7% DOC was removed by BAC2 process, which showed higher removal efficiency than BAC1 or BAC3 processes. The removal yield of $UV_{254}$ in BAC1, BAC2, and BAC3 processes were observed as 45.3%, 44.6%, 58.4%, respectively. And the removal yield of ammonia nitrogen were 66%, 81%, 29% in each BAC processes. The optimal empty bed contact time (EBCT) of BAC processes was estimated as 10 minute. This study has shown that BAC process combined with ozone treatment was efficient for removing dissolved organic matter in water.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.3
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• pp.288-297
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• 2010

The purpose of this study was to evaluate the effect of light cured fluoride-releasing materials on the inhibition of demineralization. In addition, the pattern of fluoride uptake of adjacent tooth structure was analyzed with EPMA. Eighty intact premolars were restored with $Filtek^{TM}$ Z250(control group, composite), Fuji Filling $LC^{TM}$(RMGI), Dyract $AP^{(R)}$ (compomer) and Beautifil II(giomer). Restored teeth were stored in distilled water for 30 days. Then sixty teeth(n=15) were exposed to demineralizing solution(pH 4.3). Demineralized teeth were bisected and polished. The specimens were observed with confocal laser scanning microscope. The depth of outer lesion and the thickness of inhibition zone were measured. Remained twenty teeth(n=5) were bisected for fluoride uptake analysis. The fluoride analysis were taken at enamel-restoration interface and dentin-restoration interface by electron probe micro-analyzer. The results are as follows: 1. The depth of outer lesion of Fuji Filling $LC^{TM}$ Dyract AP, Beautifil II was shallower than that of $Filtek^{TM}$ Z250 at the margin of restoration(p<0.05). 2. The thickness of caries inhibition zone of Fuji Filling $LC^{TM}$, Dyract AP, Beautifil II was greater than that of $Filtek^{TM}$ Z250 at the margin of restoration(p<0.05). 3. Fuji Filling $LC^{TM}$, Dyract AP, Beautifil II groups showed the greater fluoride uptake into enamel and dentine around restoration than $Filtek^{TM}$ Z250 group. 4. In dentin the difference of fluoride concentration were greater than in enamel, and Dyract AP showed the greatest fluoride concentration in dentin.

• Journal of The Korean Association For Science Education
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• v.20 no.4
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• pp.582-598
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• 2000

There are many bioethical issues in line with the rapid advance of biology. In this situation, it is important for students to make a rational decision on value problem. In this study 'value inquiry in biology education' is defined as 'the process of rational value judgement and wise decision-making in the biology-related value problem' and the model was developed. To develop the model, value inquiry models were reviewed. Value clarification model is helpful for the formation of the personal value as the process of individual value inquiry, but it isn't helpful for clarifying the value conflicts. Value analysis model focuses on the rational solution of value problem through the logical procedure. But it has the limitations that overemphasizing the logical and systematic aspects results in devaluating students' affective aspects. So it is necessary to coordinate psychological and logical aspects of value inquiry. In this regard, the model was developed, including identifying and clarifying value problem, understanding biological knowledge related to conflict situation, considering on the related persons, searching for alternatives, predicting the consequences of each alternative, selecting the alternative, evaluating the alternative, and final value judgement and affirming it. The educational objectives of value inquiry were selected in consideration of the ability to carry out the steps of the developed model. And the selected contents were animal duplication, test-tube baby, genetic engineering, growth hormone injection problem, brain death, organ transplant, animal to be experimented and were organized on the basis of the 6th and the 7th science curriculum. And the suitable instructional models for the value inquiry education were selected: bioethical value clarification decision-making model, group presentation according to the value analysis model, role play and debate, and discussion through web forum. And the interview was considered to be suitable to evaluate the students' value inquiry ability and the rubric was made to evaluate the attainment of the educational objectives for value inquiry.

• Tuberculosis and Respiratory Diseases
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• v.48 no.4
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• pp.500-512
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• 2000

Background : To evaluate the efficacy of two methods of obtaining lung recruitment to reduce ventilator-induced lung injury(VILI). Methods : Fifteen New-Zealand white rabbits were ventilated in the pressure-controlled mode while maintaining constant tidal volume(10 ml/kg) and fixed respiration rate. Lung injury was induced by repeated saline lavage (PaO2<100 mmHg), and the pressure-volume curve was drawn to obtain Pflex. The animals were then randomly assigned to three groups and ventilated for 4 hours. In the control group(n=5), positive end-expiratory pressure(PEEP) less than that of Pflex by 3 mmHg was applied throughout the study. In the recruitment maneuver(RM) group(n=5), RM(CPAP of 22.5 mmHg, for 45 seconds) was performed every 15 minutes in addition to PEEP level less than Pflex by 3 mmHg This phrase is unclear. In the Pflex group, PEEP of Pflex was given without RM. Gas exchange, lung mechanics, and hemodynamics parameters as well as pathology were examined. Results : 1) Both the control and RM groups showed decreasing tendency in PaO2 with time. There was significantly decreased PaO2 at 4 hr compared to Ihr(p<0.05). But in the Pflex group, PaO2 did not decrease with time(p<0.05 vs other groups at 3, 4 hr). PaCO2 did not show significant difference among the three groups. 2) There was no significant difference in static compliance and plateau pressure. Mean blood pressure and heart rate also did not show any significant difference among the three groups. 3) The pathologic exam showed significantly less neutrophil infiltration in the Pflex group than in the control group(p<0.05). There was borderline significant difference in hyaline membrane score among the groups (p= 0.0532). Conclusion : Although recruitment maneuver of the injured lung may be important in decreasing VILI, it alone may not be sufficient to minimize VILI.

• Tuberculosis and Respiratory Diseases
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• v.55 no.6
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• pp.579-588
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• 2003

Background : The hospital-acquired pneumonia is the most common nosocomial infection. Recently, the Acinetobacter baummannii infections are rapidly increasing, especially the frequency of Multi-drug resistant A. baumannii. Therefore we assessed clinical features and prognosis of patients in the ICU with Multi-drug resistant A. baumannii from the sputum culture using the Clinical Pulmonary Infection Score(CPIS). Method : The medical records of 43 patients with Multi-drug resistant A. baumannii from sputum culture who were suspected had clinically pneumonia and admitted to the ICU from January 2000 to July 2002 were retrospectively analyzed. Results : 19 patients were CPIS greater than 6 and 24 patients were CPIS less than or equal to 6. Mean age for the former was $71{\pm}11$ years old, and the latter was $61{\pm}19$ years old. The mean APACHE II score on admission and on sputum study was not different between two groups($17.4{\pm}5.7$ vs $18.5{\pm}6.1$, p=0.553, $20{\pm}6$ vs $17{\pm}8$, p=0.078). But the mortality rate was 73.7% for the former, and 16.7% for the latter(p<0.001). Conclusion : In ICU patients who had clinically suspected pneumonia with sputum culture positive for Multi-drug resistant A. baumannii, the mortality was significantly higher if CPIS was greater than 6.