• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.7
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• pp.784-795
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• 2007

In this thesis, the Multi element antenna with wideband and enhanced gain characteristic is proposed to operate at both frequency range from 824 MHz to 896 11Hz for the CDMA and frequency range from 908.5 MHz to 914 MHz for the RFID band. The proposed antenna has tile size of $35{\times}15{\times}5mm^3$ in order to put it in the A model of S company and each element of the proposed antenna is folded to obtain the minimum size. To obtain the antenna with wideband and high gain characteristic, the radiator of the antenna is divided into 4 elements. As a result, bandwidth of the proposed antenna become broader and lower center frequency is appeared due to increased and lengthened current path. Moreover, the enhanced gain characteristic is verified because divided element structure that induct uniform current distribution can get increased antenna efficiency. To attain more uniform current distribution, modified structure of the feeding point that can deliver currents directly is designed. The antenna that alters the feeding structure has higher gain value. Each element is folded to increase the current paths considering the current directions to attain the miniaturization of the antenna. To measure the handset antenna, the handset case must be considered. Even though antenna is designed for predicted characteristic, the resonance frequency is shifted and antenna gain is deteriorated at predicted frequency while antenna is set in the handset case. 1.08 GHz of the resonant frequency is determined after frequency shift from 150 MHz to 200 MHz is confirmed and the maximum gain is measured as 3.1 dBi while antenna is not set in the handset. In case handset case is considered, the experimental results show that the impedance bandwidth for VSWR<2 is from 0.824 GHz to 0.936 GHz(110 MHz). This result appears that the proposed antenna can cover both CDMA and RFID band at once. The measured gain is from -3.4 dBi to -0.5 dBi and it has omni-directional pattern practically.

• Korean Journal of Environmental Biology
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• v.36 no.1
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• pp.11-20
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• 2018

In planktonic ecosystems, the microplastics are considered as a potential food source for the zooplankton. To study a relationship between the zooplankton and the neustonic microplastics, a research experiment was carried out during May in the surface layers of the Yeosu coastal areas including Yeoja Bay, Gamak Bay, Yeosuhae Bay, and Botdol Sea. A neustonic zooplankton net (mesh size $300{\mu}m$; mouth area $30cm{\times}18cm$) was towed from the side of the ship in the event that it would not be affected by waves crashing by the ship at a speed of ca. 2.5 knots. All of the microplastic particles were separated from the zooplankton. The zooplankton and microplastics were appearing in a range of 61 to $763indiv.m^{-3}$ and 0.0047 to $0.3471particle\;m^{-2}$, respectively. It was noted that the Acartia omorii, Paracalanus parvus s. l., Labidocera euchaeta, A. hongi, decapod larvae, and cirriped larvae were predominantly seen in the experiment. For verifying relationships between zooplankton and environmental factors in addition to microplastics, a model redundancy analysis (RDA) was performed. The zooplankton were divided into two groups on the basis of feeding types (i.e. particle feeders, and carnivores), and the associated zooplankton larvae were also separately considered. A review of the additional environmental factors such as water temperature, salinity, turbidity, chlorophyll-${\alpha}$ concentration, diatom density, and dinoflagellate density were also contained in the analysis. The results showed that a noted zooplankton abundance had no close relation with the occurring number of microplastic particles, but rather was significantly related with other noted environmental factors such as temperature, salinity, turbidity, and chlorophyll-${\alpha}$ concentration. This fact implies that most zooplankton can feed themselves as a unit, by selecting the most likely available nutritious foods, rather than microplastics under the circumstance of food-richness areas, such what food resources are available as in the location of coastal waters.

• KSBB Journal
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• v.17 no.1
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• pp.73-79
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• 2002

The method to optimize the microbial production of ethanol from CO using Clostridium ljungdahlii was developed. The kinetic parameter study on CO conversion with Clostridium ljungdahlii was carried out and maximum CO conversion rate of 37.14 mmol/L-hr-O.D. and $K_{m}$ / of 0.9516 atm were obtained. It was observed that method of two stage fermentation, which consists of cell growth stage and ethanol production stage, was effective to produce ethanol. When pH was shifted from 5.5 to 4.5 and ammonium solution was supplied to culture media as nitrogen source at ethanol production stage, the concentration of ethanol produced was increased 20 times higher than that without shift. Ethanol production from CO in a fermenter with Clostridium ljungdahlii was optimized and the concentration of ethanol produced was 45 g/L and maximun ethanol productivity was 0.75 g ethanol/L-hr.

• Journal of Animal Environmental Science
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• v.2 no.1
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• pp.27-39
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• 1996

A survey was conducted for dairy farmer to estimate the optimum number of machine and equipment in 1994. Labor hours, operation costs and operation methods for each dairy processing were investigated and analyzed for the farmers to find the expected numbers of machine and equipment on the basis of the desired farm scale. And also, the estimated models were compared and analyzed with the conventional models which more than half dairy farmers used bucket milker in tie stall barn. Some of the results are as follows : 1. Analysis results of conventional model showed that a dairy farm could raise to 15 heads of dairy cow with family labor of 1.5 men, labor hours of 2, 700 in you and total operation costs of 734 thousand won per head. 2. The result, used in conjunction with minimum operation costs in tie stall barn, showed that 28 dairy cows could be raised by using concentrates feeding by hoppers, water supply by water cups, milking by pipeline milker, and manure cleaning by barn cleaner with total operation costs of 520 thousands won per head. 3. The total operation costs of a loose barn system is higher than those of tie stall barn system to raise about 30 heads. For the loose barn system, the herringbone parlour was used for milking, concentrate feeding by automatic concentrate feeder, water supply by thermal insulation feeder, and manure cleaning by scraper with total operation costs of 582 thousands won per head every year.

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.711-723
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• 2013

The objectives of this study were to access climate change by global warming in Korea, and to investigate its effects on production efficiency of lactating dairy cows. Two regions, Daegu and Daekwanryung, were selected to represent a warm and a cold area, respectively. Time-series analyses on meteorological records for 25 years (from January 1, 1988 to December 31, 2012) revealed significant and different climate changes in two regions. In the warm area there has been a significant (P<0.05) increase in low temperature during the summer, which can cause heat stress to the animal. On the other hand, a decrease in low temperature during the winter was observed in the cold region (P<0.01), and cold stress in winter can thus be an issue in this region. Simulations using a model integrated the Korean feeding standard for dairy cattle and the environmental effect module of Cornell Net Carbohydrate and Protein System, indicated that a reduction in feed efficiency can be a problem during the winter in the cold region while during the summer in the warm area. We conclude that the effect of climate change by global warming varies in different areas in Korea and a region-specific management strategy should be developed in order to maintain productivity, health and welfare of lactating dairy cows.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5238-5246
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• 2012

This study was done to identify the evaluation of CPSCS for neurocritical patients and provide effective nursing interventions for these patients. Data were collected from medical records of 203 neurocritical patients over 18 years of age who were admitted to the ICU of C University Hospital during the period from January 2008 to May 2009 and from October 2011 to December 2011. Collected data were analyzed through t-test, ANOVA test, Person's correlation analysis, trend analysis, stepwise multiple regression. The average CPSCS score was $112.09{\pm}18.91$ and there was a significant trendency for higher severity to lead to higher CPSCS's scores(survival: J-T:9.795, die: J-T:5.415, p=<.001). The scores of the respective areas follows measurement of vital sign($3.74{\pm}2.15$), monitoring($28.97{\pm}4.31$), activity daily living ($34.99{\pm}3.66$), feeding($.19{\pm}.98$), intravenous infusion ($18.20{\pm}8.27$), treatment/procedure ($16.93{\pm}4.90$), respiratory therapy($8.61{\pm}7.07$). By means of stepwise multiple regression analysis, the intravenous therapy & medication, respiratory therapy, activities of daily living, and monitoring area that contains the model showed a significant (F=2073.963, p<.001), and they explained 98.1% of CPSCS. These findings provide information that is relevant in designing interventions to enhance CPSCS among neurocritical patients in hospital.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.508-514
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• 2010

This study was conducted to evaluate the effects of dietary arachidonic acid (AA, 20:4n-6) levels on growth performance and body composition in juvenile eel, Anguilla japonica. Six semi-purified experimental diets were formulated to be isonitrogenous and iso-caloric containing 55.0% crude protein and 15% crude lipid (18.3 kJ of available energy $g^{-1}$). Six different levels of AA were added to the basal diet, with 0, 0.2, 0.4, 0.6, 0.8 or 1.2% on a dry matter (DM) basis, respectively ($AA_{0.07},\;AA_{0.22},\;AA_{0.43},\;AA_{0.57},\;AA_{0.78}\;or\;AA_{1.23}$). After a conditioning period, fish initially averaging 27${\pm}$0.5 g (mean${\pm}$SD) were randomly distributed into each aquarium as triplicate groups of 20 fish each. One of six experimental diets was fed on a DM basis to fish in three randomly selected aquaria at a rate of 2-3% of total body weight twice a day. At the end of the 12-week feeding trial, weight gain (WG) and feed efficiency (FE) of fish fed $AA_{0.78}$ and $AA_{1.23}$ diets were significantly higher than of fish fed $AA_{0.07},\;AA_{0.22},\;AA_{0.43}$ diets (p<0.05). Specific growth rate (SGR) of fish fed the $AA_{0.78}$ diet was significantly higher than of fish fed $AA_{0.07},\;AA_{0.22},\;AA_{0.43}$ diets (p<0.05). However, there were no significant differences in WG, SGR and FE among fish fed $AA_{0.57},\;AA_{0.78}\;or\;AA_{1.23}$ diets (p>0.05). Whole body AA deposition of fish fed the $AA_{1.23}$ diet was significantly higher than for the other diets (p<0.05). Broken-line model analysis on the basis of WG and SGR indicated that the dietary AA requirement could be greater than 0.69% but less than 0.71% of the diet in juvenile eel. The growth-promoting activity of AA observed in the present study provides strong support for the contention that dietary AA is essential for juvenile eel.

• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.231-239
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• 2013

BACKGROUND: The disease resistant (OsCK1) rice was generated by inserting choline kinase (CK1) and phosphinothricin acetyltransferase (PAT) genes isolated from Oriza sativa and Streptomyces hygroscopicus into the genome of rice (Nakdongbyeo). With the potential problems of safety, the non-target organism evaluation is required as an essential element for the environmental risk assessment of genetically modified (GM) crops. In present study, we studied the effects on survival of Misgurnus anguillicaudatus and Cyprinus carpio, commonly used as a model organism in ecotoxicological studies. METHODS AND RESULTS: The M. anguillicaudatus and C. carpio were fed on disease resistant (OsCK1) rice and non-genetically modified (non-GM) rice (Nakdongbyeo) to 0, 10, 100, 1,000 and 5,000 mg/L, as treatment concentration respectively. The OsCK1 rice used for the test was confirmed to have the OsCK1/PAT gene expression by the PCR and ELISA analysis. Feeding test showed that no significant differences in cumulative immobility and abnormal response of M. anguillicaudatus and C. carpio fed on between OsCK1 rice and non-GM rice. The 96hr-$LC_{50}$ values showed no difference between OsCK1 rice (>5,000 mg/L) and non-GM rice (>5,000 mg/L). CONCLUSION(S): The results of this study suggested that there was no significant difference in toxicity for M. anguillicaudatus and C. carpio between OsCK1 rice and non-GM counterparts.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1762-1768
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• 2004

The Korean formula medicine, Gami-Yukmi-Jihwang-Tang (GYJT) has been used for growing slowly, short of stature, incomplete development, fatigue, weak child, growing pain of child. However, it is still unclear how GYJT has an effect on experimental models. In the present study, the author investigated the immune-enhancing effect of GYJT. Forced swimming test (FST) was performed as a model of activity test in mice and measured blood urea nitrogen (BUN), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactic dehydrogenase (LDH), glucose (Glc) and total protein (TP) in the serum. GYJT (1, 0.1 and 0.01 g/㎏) were orally administered to mice, once per day for 7 days using a feeding atraumatic needle. After 3 days, on FST, the immobility time was significantly decreased in the GYJT (0.01g/㎏/day)-fed group (120.75±5.71s) in comparison with the saline-fed group (153.80±10.74s). After 7 days, the immobility time was significantly decreased in the GYJT (0.1 and 0.01g/㎏/day)-fed group (125.67±5.36s and 107.67±3.71s) in comparison with the saline-fed group (167.67±12.99s). In addition, the contents of BUN and Glc in the blood serum were significantly decreased and the contents of AST, ALT and LDH were also decreased in the GYJT (1g/㎏/day)-fed group. However, the content of TP was not changed. The present results suggest that GYJT may be useful for the anti-fatigue and immune-enhancing agent. Also, the author investigated the effect of GYJT on the production of cytokines in human T-cell line, MOLT-4 cells. However, GYJT has not affected the production of IFN­γ, IL-2, IL-4. These results suggest that GYJT has immune-enhancing effect but does not affect T cell-mediated production of cytokines in the immune function improvement.

• Journal of Preventive Medicine and Public Health
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• v.36 no.3
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• pp.279-288
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• 2003

Objectives : Evidence for an effect of rerroductive factors on colorectal carcinogenesis is not yet consistent. Little research has been conducted to investigate whether reproductive factors were associated with colorectal adenomas that are the precursors of colorecta1 cancer, We evaluated the relationships between reproductive factors and the degree of dysplasia of the colorectal adenoma and cancer as colorectal adenoma-carcinoma sequence. Methods : For this study, 241 adenoma cases with histopathologically confirmed incident colorectal adenoma, 76 cancer cases with colorectal cancer and 1677 controls were collected from Our Lady of Mercy Hospital, The Catholic University of Korea, during 1994-1999. Before colonoscopy, information on demographic characteristics, reproductive factors, life style habits and dietary intake were obtained by interviewed questionnaire. Adjusted OR and 95% CI were estimated by using polytomous logistic regression model, Potential confounders that were selected based on the goodness of fit Statistics and interaction between risk factors were considered in this adjustment. The Wald statistic was calculated to test the heterogeneity of the odds ratios for each case. Results .: Postmenopausal women with natural menopause were found to be positively associated with the risk of mild dysplasia adenoma (multivariate-adjusted OR : 2.59, 95% CI=1.1-0.2). Parity was found to be negatively associated with the risk of colorectal lancer (age-adjusted OR : 0.40, 95% CI=0.2-0.9), but did not significantly decrease the risk of colorectal cancer (multivariate-adjusted OR : 0.95, 95% CI=0.3-2.9). Me associations were seen between a9e at menarche, breast feeding, induced abortion, oral contraceptive use, menopausal types, menopausal age or hormone replacement therapy (HRT and the degree of dysplasia of the colorectal adenoma and cancer. However, none of these associations differed' significantly between the degree of dysplasia of the colorectal adenoma and cancer. Conclusions : These findings suggest that postmenopausal women with natural menopause may experience increased risk of mild dysplasia adenorna among colorectal adenoma-carcinoma sequence.