• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.610-613
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• 2012

Oyster shell has a high content of $CaCO_3$ to be used as a acidic soil amendment. To enhance productivity of barley and soil microbe in an upland soil, oyster shell and calcium-magnesium carbonate were selected as a soil amendments in this study. A field experiment was treated no treatment (hereafter, control), oyster shell lime $3.09Mg\;ha^{-1}$ and $2.38Mg\;ha^{-1}$, and calcium-magnesium carbonate $2.38Mg\;ha^{-1}$ as amount of lime requirement in silt loam soil. The yield of barley from the oyster shell lime treatment was the highest. The protein content of barley was the highest of 11.1% in the calcium-magnesium carbonate, followed by 10.7% for the control, 10.6% for the oyster shell lime $3.09Mg\;ha^{-1}$, and 10.4% for the oyster shell lime $2.38Mg\;ha^{-1}$. Soil pH value was higher than that of control in harvesting stage. In addition, the population of soil bacteria was highest in oyster shell lime $2.38Mg\;ha^{-1}$, actinomycetes was highest in calcium-magnesium $2.38Mg\;ha^{-1}$. We concluded that the oyster shell lime can be effective to restore soil nutrient and microbe balance in an upland soil.

• The Korean Journal of Ecology
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• v.28 no.6
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• pp.383-387
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• 2005

In order to clarify the causal of free decline, which observed around the industrial complex, we analyzed pH, electrical conductivity (EC), and cation in rainfall and throughfall cations concentration in the air in tree areas, suburban and rural area. pH of both rainfall and throughfall was lower in the industrial area than the suburban and rural areas. Among the abiotic and biotic factors analyzed in this study, relations between decline degree of Pinus thunbergii and ingredients of rainfall, pH and $Ca^{2+}$ showed negative and positive correlations, respectively.

• Bulletin of the Korean Chemical Society
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• v.29 no.4
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• pp.822-826
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• 2008

We report the cathodoluminescence and aging properties of a series of green phosphors of formula $Sr_{1-x}M_xGa_2S_4$:Eu (x = 0.0-1.0, M = Ba or Ca) that have potential applications in field emission displays (FEDs). The series of phosphors was synthesized via NaBr-aided solid-state reactions in a flowing $H_2S$ stream. A low level ($\sim$20%) of Ba or Ca substitution for Sr in $SrGa_2S_4$:Eu maintains the orthorhombic phase of pure $SrGa_2S_4$:Eu phosphors. Further, a low level ($\sim$20%) of Ba or Ca substitution for Sr in $SrGa_2S_4$:Eu provides various green colors and sufficient brightness for FED applications. Substitution of Ba or Ca for Sr in $SrGa_2S_4$:Eu also improved the stability of the phosphor when it was operated under electron-beam irradiation of 5 kV.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.236.2-236.2
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• 2012

We present the interim results of simultaneous time monitoring observations of SiO v=1, 2, J =1-0, $^{29}SiO$ v=0, J =1-0, and $H_2O$ $6_{16}-5_{23}$ maser lines toward about 60 relatively strong SiO and/or H2O maser sources using the single dishes of the Korean VLBI Network from 2009 September to 2012 June. These monitoring sources are composed of representative semiregular variables, Miras, water fountain sources, preplantary nebulae and SiO maser sources of star forming regions etc. The variations of intensity ratios between SiO and $H_2O$ masers and velocity structures are investigated according to stellar optical phases and observational epochs. Several individual sources which show an interesting feature will be presented here.

• Korean Journal of Veterinary Service
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• v.31 no.3
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• pp.397-414
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• 2008

In order to evaluate conception rate of Hanwoo in northwestern region of Gyeongsang-nam-do, we investigated conception rate and reduction of reproductive disorder rate after artificial insemination (AI) in 1,000 heads of breeding cows, This study showed that 80.9% of cows were classified as fertility after 1st and 2nd AI. For a accurate pregnancy diagnosis with practicing ovariectomy and histeotomy, we comparatively investigated each of 80 slaughtered cows, including 30 of non-pregnancy, and used enzyme-linked immunosorbent assay (ELISA) for estimation of plasma progesterone concentration and serum luteal hormone. The mean diameter of non-pregnant corpus luteum is $18.9{\pm}4.2{\times}15.6{\pm}3.6 mm$ and that of pregnant corpus luteum is $22.5{\pm}2.7{\times}18.7{\pm}2.9 mm$. This indicates that corpus luteum is more developed in the ovary of pregnant than non-pregnant cows (P<0.05). The diameter of pregnant corpus luteum according to the stage of pregnancy showed $21.3{\pm}2.4{\pm}18.4{\pm}2.6 mm$ in early stage (1-3 month), $23.4{\pm}2.8{\times}19.1{\pm}2.7 mm$ in middle stage (4-6 month) and $22.8{\pm}3.0{\times}18.8{\pm}2.4mm$, in last stage (7-9 month). This indicates that corpus luteum in middle and last stage is more significantly developed than that of early stage(P<0.05). The mean plasma progesterone concentration of cows showing size of non-pregnant corpus luteum was $4.58{\pm}0.92ng/ml$ and that of pregnant corpus luteum $8.26{\pm}0.98ng/ml$. Thus, it was more significantly increased in pregnant corpus luteum(P<0.02).. However, it was low to $0.58{\pm}0.39ng/ml$. in estrus (corpus albicans). The plasma progesterone concentration according to gestation period was high in proportion to the degree of development in corpus luteum and more significantly increased (P<0.05) and maintained in middle and last state than early state. The concentration was sharply decreased to $0.56{\pm}0.32ng/ml$ at parturition. As a consequence, we can practice the early pregnancy diagnosis by confirming non-pregnancy when the mean plasma progesterone concentration is below 1ng/ml 19 to 22 days after AI and this can be available to diagnose reproductive disorder.

• Journal of Preventive Medicine and Public Health
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• v.45 no.3
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• pp.174-180
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• 2012

Objectives: An ambulance can be a potential source of contagious or droplet infection of a community. We estimated the prevalence of positive carriage of tuberculosis (TB), methicillin-resistant $Staphylococcus$ $aureus$ (MRSA), and vancomycin-resistant $Enterococci$ (VRE) in patients transported by ambulance. Methods: This was a retrospective observational study. We enrolled all patients who visited a tertiary teaching hospital emergency department (ED). Blood, sputum, urine, body fluid, and rectal swab samples were taken from patients when they were suspected of TB, MRSA, or VRE in the ED. The patients were categorized into three groups: pre-hospital ambulance (PA) group; inter-facility ambulance (IA) group; and non-ambulance (NA) group. Adjusted odds ratio (OR) and 95% confidence intervals (CI) were calculated using a multivariable logistic regression model for the prevalence of each infection. Results: The total number of patients was 89206. Of these, 9378 (10.5%) and 4799 (5.4%) were in the PA and IA group, respectively. The prevalence of TB, MRSA, and VRE infection were 0.3%, 1.1%, and 0.3%, respectively. In the PA group, the prevalence of TB, MRSA, and VRE were 0.3%, 1.8%, and 0.4%. In the IA group, the prevalence of TB, MRSA, and VRE were 0.7%, 4.6%, and 1.5%, respectively. The adjusted ORs (95% CI) of the PA and IA compared to the NA group were 1.02 (0.69 to 1.53) and 1.83 (1.24 to 2.71) for TB, 2.24 (1.87 to 2.69) and 5.47 (4.63 to 6.46) for MRSA, 2.59 (1.78 to 3.77) and 8.90 (6.52 to 12.14) for VRE, respectively. Conclusions: A high prevalence of positive carriage of TB, MRSA, and VRE in patients transported by metropolitan ambulances was found.

• Journal of The Korean Society of Clinical Toxicology
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• v.15 no.2
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• pp.140-147
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• 2017

Purpose: This study was conducted to analyze the features of poisoning in individuals aged 0-18 years to understand the characteristics of potential victims and eventually prevent poisoning. Methods: We retrospectively analyzed poisoned children and adolescents (0-18 years) who visited the emergency department of one tertiary hospital from January 2003 through December 2013. We collected data including their age, sex, reason for poisoning, components and dose of poison, results of treatment, and psychiatric diagnosis. Results: During the study period, there were 436 cases of poisoning (male 47.2% (n=206); female 52.8% (n=230)). Subjects were classified into four groups (0-1 years, 2-5 years, 6-12 years, 13-18 years). The most common cause of poisoning in all age groups was accidental poisoning (72.9%), but intentional poisoning increased as age increased (p<0.001). Moreover, females were more often subject to intentional poisoning than males (p<0.001). The most common poisoning material was drugs (41.7%). Among intentional poisoning patients, 62.7% patients had consulted a psychiatrist, and their most common diagnosis was adjustment disorder (44.6%). Conclusion: The most common cause of poisoning in individuals aged 0-18 years was accidental poisoning, while intentional poisoning was most common among adolescents. Guardians should take care to prevent accidental poisoning, while psychiatric consultation and national moderation will be needed to prevent intentional poisoning.

• Journal of Environmental Science International
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• v.30 no.7
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• pp.573-584
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• 2021

To analyze the effects of PM₁₀ and PM_2.5 on daily mortality cases, the relations of death counts from natural causes, respiratory diseases, and cardiovascular diseases with PM₁₀ and PM_2.5 concentrations were applied to the generalized additive model (GAM) in this study. From the coefficients of the GAM model, the excessive mortality risks due to an increase of 10 ㎍/m³ in daily mean PM₁₀ and PM_2.5 for each cause were calculated. The excessive risks of deaths from natural causes, respiratory diseases, and cardiovascular diseases were 0.64%, 1.69%, and 1.16%, respectively, owing to PM₁₀ increase and 0.42%, 2.80%, and 0.91%, respectively, owing to PM_2.5 increase. Our result showed that particulate matter posed a greater risk of death from respiratory diseases and is consistent with the cases in Europe and China. The regional distribution of excessive risk of death is 0.24%-0.81%, 0.34%-2.6%, and 0.62%-1.94% from natural causes, respiratory diseases, and cardiovascular diseases, respectively, owing to PM₁₀ increase, and 0.14%-1.02%, 1.07%-3.92%, and 0.22%-1.73% from natural causes, respiratory diseases, and cardiovascular diseases, respectively, owing to PM_2.5 increase. Our results represented a different aspect from the regional concentration distributions. Thus, we saw that the concentration distributions of air pollutants differ from the affected areas and identified the need for a policy to reduce damage rather than reduce concentrations.

• Journal of Plant Biotechnology
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• v.43 no.2
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• pp.255-260
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• 2016

This research was conducted to improve the cold tolerance of the gerbera cv. Gold Eye by introduction of the Arabidopsis $Ca^{2+}/H^+$ antiporter gene (CAX1) via Agrobacterium-mediated transformation. Prior to genetic transformation, we optimized a combination of plant growth regulators; $1.0mgl^{-1}$ 6-Benzyladenine (BA) and $0.1mgl^{-1}$3-indole-acetic acid (IAA) were found to lead to proper in vitro shoot regeneration from petiole explants. In addition, $50mgl^{-1}$ kanamycin was determined to be the minimal concentration useful for selection of putative transgenic plants. In this study, transgenic gerbera expressing the Arabidopsis $Ca^{2+}/H^+$ antiporter gene (CAX1) were obtained using the optimized concentrations. We expect that introduction of the gene to the cultivar will improve cold tolerance, which will be important in the winter months.

• Journal of Information Technology Applications and Management
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• v.12 no.2
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• pp.15-27
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• 2005

Text categorization systems generally use single words (unigrams) as features. A deceptively simple algorithm for improving text categorization is investigated here, an idea previously shown not to work. It is to identify useful word pairs (bigrams) made up of adjacent unigrams. The bigrams it found, while small in numbers, can substantially raise the quality of feature sets. The algorithm was tested on two pre-classified datasets, Reuters-21578 for English and Korea-web for Korean. The results show that the algorithm was successful in extracting high quality bigrams and increased the quality of overall features. To find out the role of bigrams, we trained the Na$\"{i}$ve Bayes classifiers using both unigrams and bigrams as features. The results show that recall values were higher than those of unigrams alone. Break-even points and F1 values improved in most documents, especially when documents were classified along the large classes. In Reuters-21578 break-even points increased by 2.1%, with the highest at 18.8%, and F1 improved by 1.5%, with the highest at 3.2%. In Korea-web break-even points increased by 1.0%, with the highest at 4.5%, and F1 improved by 0.4%, with the highest at 4.2%. We can conclude that text classification using unigrams and bigrams together is more efficient than using only unigrams.