• Journal of Life Science
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• v.28 no.5
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• pp.577-586
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• 2018

We recently reported the potential probiotic properties of Lactobacillus brevis SBB07 isolated from blueberries. The present study investigates the effect of culture conditions such as temperature, initial pH, culture time, and medium constituent for industrial application. The ingredients of the medium to improve cell growth were selected by Plackett-Burman design (PBD) and central composite design (CCD) within a desirable range. The PBD was applied with 19 factors: seven carbon sources, six nitrogen sources, and six microelements. Protease peptone, corn steep powder (CSP), and yeast extract were found to be significant factors for the growth of SBB07. The CCD was then applied with three variables found from the PBD at five levels, and the optimum values were decided for the three variables: protease peptone, CSP, and yeast extract. In the case of the growth of SBB07, the proposed optimal media contained 2.0% protease peptone, 2.5% CSP, and 2.0% yeast extract, and the maximum dried-cell weight was predicted to be 2.93963 g/l. By the model verification, it was confirmed that the predicted and actual results are similar. Finally, the study investigated the effects of incubation temperature and initial pH at the optimized medium. It was confirmed that the dried-cell weight increased from $2.2933{\pm}0.0601g/l$ to $3.85{\pm}0.0265g/l$ when compared to the basal medium at $37^{\circ}C$ and initial pH 8.0. Establishing the optimal culture condition for SBB07 provides good potential for applications in probiotics and can serve as the foundation for the industrialization of materials.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.4
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• pp.677-687
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• 1999

This study was performed to evaluate the effect of aging and thermal cycling on the tensile strength of six commercially available glass-ionomer materials: two chemically set glass-ionomer materials(Fuji II, Fuji IX), two resin-modified glass-ionomer materials(Fuji II LC, Vitremer), and two polyacid-modified composite resins(Compoglass, Dyract). Rectangular tension test specimens were fabricated in a teflon mold giving 5mm in gauge length and 2mm in thickness. All samples were divided into 3 groups. Group 1 was immersed in a $37^{\circ}C$ distilled water for 1 hour. Group 2 was immersed in a $37^{\circ}C$ distilled water for 30 days. Group 3 was subjected to 10,000 thermal cycles between $5^{\circ}C$ and $55^{\circ}C$, and the immersion time in each bath was 15 seconds per cycle. Tensile testing was carried out at a cross-head speed of 0.5mm/min and fracture surfaces were examined with scanning electron microscope. The results obtained were summarized as follows; 1. The polyacid-modified composite resins were stronger than the resin-modified glass-ionomer materials, which were much stronger than the conventional glass-ionomer materials. 2. Tensile strengths were slightly increased after aging treatments for 30days. 3. Tensile strengths of conventional glass ionomers were significantly increased after thermal cycling treatment(p<0.01). 4. The highest tensile strength value of 45.4MPa was observed in the Dyract group and the lowest value of 13.3MPa was observed in the Fuji II LC group after the thermal cycling test, and the strengths of polyacid-modified composite groups were significantly higher than those of other groups. 5. The highest characteristic strength value of 48.6MPa was obtained in the Dyract group, however the highest Weibull modulus value of 8.9MPa was obtained in the Compoglass group after thermal cycling test.

• Journal of dental hygiene science
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• v.13 no.3
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• pp.254-263
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• 2013

This study is to develop an evaluation index for infection control and to verify its validity by examining each set of weighted data collected from 121 infection control personnel at dental hospitals who agreed to the preliminary survey and advisory. The study was conducted from 14th December, 2010 to 31st January, 2011, and PASW Statistics 18.0 and AMOS 5.0 had been used for the statistical data analysis. As a result of the study, five evaluation factors with 21 sub-indicators have been identified at structural level, eight evaluation factors with 32 sub-indicators at processing level, and one evaluation fact with five sub-indicators at resulting level, total 14 evaluation factors with 58 sub-indicators throughout all levels. The path analysis added on the result that 'standard precautions ($x_1$)', 'infection control support system ($x_2$)', 'internal and external characteristics ($x_3$)' are exogenous variables that affect on other variables, and 'standard infection control ($y_1$)','Organization equipment management handwashing ($y_2$)', 'environmental infection control ($y_3$), 'personal protective equipment ($y_4$)', 'waste and laundry management ($y_5$)' are endogenous variables that are infulenced by others. The standardized metrics are more needed than anything else when examining on infection control. This study attempts to develop proper dental infection control metrics adequately adjusted for domestic circumstances, and therefore to contribute to effective systematic management and decision-making in infection control.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.119-128
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• 2015

The purpose of this study is to understand the effects of obesity and stress on oral disease in Korean adults by using the data of the Fifth Korea National Health and Nutrition Examination Survey. The subjects of this study are 4,627 adults at the age of 19 to 64, and the data were analyzed by using SPSS Windows ver.18.0. The results are as follows: Obesity was higher in men and the age of 40 to 64 than the other. And the group with lower education or lower income level tended to show significantly higher obesity (p<0.05). As for stress, women, the age of 19 to 39 and the subjects with higher academic career tended to indicate significantly higher stress (p<0.05). As for the effects of obesity on oral disease, there were no significant difference between body mass index (BMI) or waist-hip ratio (WHR) and oral disease but there was statistically significant difference between stress and temporomandibular joint disorder (TMD) (p<0.05). Even when the subjects with stress were obese or abdominally obese, there was no significant difference in oral disease (p>0.05). As to correlation among variables, there were correlations between BMI and WHR, stress and TMD, masticatory problems and periodontal disease or TMD (p<0.05). About the effects of general characteristics, obesity, and stress on oral disease, age was the variable influencing TMD, and age and abdominal obesity were the variables influencing masticatory problems (p<0.05). In this society, the environment surrounding individuals is fairly complex, and the concept of health including quality of life has more complex meaning than in the past. Various factors are influencing obesity and stress, and they are also influencing oral health and behaviors. Accordingly, it will be needed not only to make efforts to reduce obesity and stress but also to employ approaches from different perspectives to improve oral health.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.20-25
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• 2005

This study was conducted to evaluate the effects of Zizyphus vulgaris supplementation on growth performance, blood cortisol and meat quality characteristics in finishing pigs. The total of thirty-six [Duroc${\times}$Yorkshir${\times}$Landrace] pigs ($91{\pm}2.11$ kg average initial body weight) were used in a 30-days assay. Dietary treatments included 1) CON (basal diet), 2) T1 (basal diet for 15 days and 0.1 % Zizyphus vulgaris for 15 days) and 3) T2 (0.1 % Zizyphus vulgaris for 30 days). The ADG (Average daily gain), ADFI (Average daily feed intake) and ADG/ADFI during the feeding period were not significantly differences among the treatments (p>0.05). Backfat thickness of pigs fed CON was higher than those of T1 and T2 (p<0.05). The appearance rate of A or B carcass grade was in T1 (74%) and T2 (84%) was significantly higher than that in CON (58%) (p<0.05). Pigs fed Zizyphus vulgaris 0.1 % for 30 days tended to decrease on blood cortisol compared with pigs fed CON and T1. But, there was not significantly difference among the treatments (p>0.05). The Hunter's L/sup */ (lightness) value of loin in the pork fed CON was higher than that of loin in the pork fed T1 and T2 (p<0.05). After 7 days, the L/sup */ value of loin in the pigs fed T2 was higher increased than that of pigs fed T1 and CON (p<0.05). However, a/sup */ and b/sup */ values were not affected by dietary Zizyphus vulgaris (p>0.05). There were not found remarkable differences in sensory properties (marbling, firmness and color) among the treatments. The results from the present study suggest that Zizyphus vulgaris could be a effective feed additive to improve meat quality of pigs. However, further research is needed to investigate effects of carcass characteristics.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.4
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• pp.15-24
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• 2007

The recognition of postal address images is indispensable for the automatic sorting of postal envelopes. The process of the address image recognition is composed of three steps-address image preprocessing, character recognition, address interpretation. The extracted character images from the preprocessing step are forwarded to the character recognition step, in which multiple candidate characters with reliability scores are obtained for each character image extracted. aracters with reliability scores are obtained for each character image extracted. Utilizing those character candidates with scores, we obtain the final valid address for the input envelope image through the address interpretation step. The envelope sorting rate depends on the performance of all three steps, among which character recognition step could be said to be very important. The good character recognizer would be the one which could produce valid candidates with very reliable scores to help the address interpretation step go easy. In this paper, we propose the method of generating character candidates with reliable recognition scores. We utilize the existing MLP(multilayered perceptrons) neural network of the address recognition system in the current automatic postal envelope sorters, as the classifier for the each image from the preprocessing step. The MLP is well known to be one of the best classifiers in terms of processing speed and recognition rate. The false alarm problem, however, might be occurred in recognition results, which made the address interpretation hard. To make address interpretation easy and improve the envelope sorting rate, we propose promising methods to reestimate the recognition score (confidence) of the existing MLP classifier: the generation method of the statistical recognition properties of the classifier and the method of the combination of the MLP and the subspace classifier which roles as a reestimator of the confidence. To confirm the superiority of the proposed method, we have used the character images of the real postal envelopes from the sorters in the post office. The experimental results show that the proposed method produces high reliability in terms of error and rejection for individual characters and non-characters.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.549-557
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• 2006

The characteristics of supercritical water oxidation have been studied to decompose the waste anionic exchange resins which were produced from a power plant. The waste resins from a power plant were mixture of anionic and cationic exchange resins. The waste anionic exchange resins had been separated from the waste resins using a solid-liquid fluidized bed. It was confirmed that the cationic exchange resins were not included in the separated anionic exchange resins by the elemental and thermogravimetric analysis. A slurry of anionic exchange resins which could be fed continuously to a supercritical water oxidation apparatus by a high pressure pump was prepared using a wet ball mill. Although the COD of liquid effluent had been reduced more than 99.9% at 25.0 MPa and $500^{\circ}C$ within 2 min, the total nitrogen content was reduced only 41%. The addition of nitric acid to the slurry could reduce the total nitrogen content in treated water. The central composite design as a statistical desist of experiments had been applied to optimize the conditions of decomposing anionic resin slurry by means of the COD and total nitrogen contents in treated waters as the key process output variables. The COD values of treated waters had been reduced sufficiently to $99.9{\sim}100%$ af the reaction conditions of $500{\sim}540^{\circ}C$, 25.0 MPa within 2 min. The effects of temperature and nitric acid concentration on COD were not significant. However, the effect of nitric acid concentration on the total nitrogen was found to be significant. The regression equation for the total nitrogen had been obtained with nitric acid concentration and the coefficient of determination($r^2$) was 95.8%.

• Korean Journal of Environment and Ecology
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• v.23 no.5
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• pp.411-417
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• 2009

This research is intended to discover physiological and biochemical defense mechanisms against herbivores of 8 species of the genus Acerby examining the morphological characteristics of the leaf, the structure and number of leaf domatia, herbivores insects and mites feeding on leaves, which were collected from the trees growing in Mt. Chiak, Mt. Cheongtae, Mt. Jungwang, Mt. Bangtae, Mt. Taebaek and Wonju City. This research was conducted from May through July, 2009, and the results are as follows. The domatia of A. pseudosieboldianum, A. pictum subsp. mono and A. mandshuricum belongs to tuft type; that of A. palmatum, A. triflorum and A. tschonoskii pocket+tuft type; and that of A. tegmentosum pocket type. The number of domatia per leaf turned out to be the highest in the case of A. tegmentosum(20.2), and the lowest in the case of A. ginnala (4.2). Leaf surface trichomes of A. palmatum, A. pseudosiebotdianum, A. ginnala and A. mandshuricum are covered with villi; those of A. pictum subsp. mono and A. triflorum with soft, pilose type of hair, and those of A. tschonoskii with stiff, strigose hair. The trichome density of lower leaf surface is found to be higher than that of the upper leaf surface. Only in the case of A. palmatum, A. pseudosieboldianum, A. tegmentosum and A. tschonoskii, a small amount of nectar is found to be secreted from the distal vein parts of the leaf margin. The number of mites on each leaf are found to be significantly different among tree species, and average mites number per leaf was the highest in the case of A. tschonoskii (9.2/leaf), and A. mandshuricum, A. pseudosieboldianum, and A. triflorum follow it in decreasing order. Minute insects attacking the leaf of Acer spp. include Periphyllus californiensis, P. viridis, Psylla spp, and gall mites, and the number of these insects are found in Periphyllus californiensis, Psylla spp, P. viridis, and Cicadellidae sp. in decreasing order. The natural enemies of these herbivores insects are predatory mites, such as Chilocorus rubidus, Coccinella septempunctata and the nymph, Aphidius ervi, Poecilocoris lewisi and its larva, and Poecilocoris lewisi. Lasius japonicus and Formica japonica are symbiotic with aphids, and supports herbivores. Finally, our research confirmed that predatory mites attack Periphyllus californiensis and suck the body fluid of their victim. This proves that mites form a symbiotic relationship with plants through the mediation of leaf domatia. This also indicates that a protective mutualism may be more conspicuous in temperate broad-leaved trees.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.469-483
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• 2019

North Korea has experienced floods and sediment-related disasters annually since the 1970s due to deforestation. It is of paramount importance that technologies and trends related to forest restoration and soil erosion control engineering be properly understood in a bid to reduce damage from sediment-related disasters in North Korea, and to effect national territorial management following unification. This paper presents a literature review and bibliometric analysis including 146 related articles published in North Korea. First, we analyzed the textual characteristics of the articles. We then employed the VOSviewer software package to classify the research topic and analyzed this topic based on the time change. The results showed that articles on the topic have consistently increased since the 1990s. In addition, research related to soil erosion control engineering has been classified into four subjects in North Korea: (i) assessment of hazard area on soil erosion and soil loss, sediment related-disasters; (ii) hydraulic and hydrologic understanding of forests; (iii) reasonable construction of soil erosion control structures; and (iv) effects and management plan of soil erosion control works. The proportion of research related to the (ii) hydraulic and hydrologic understanding of forests had been significant during the reign of Kim Ilsung. However, the proportion of research related to the (i) assessment of hazard area on soil erosion and soil loss, sediment-related disasters, increased during the reign of Kim Jongil and Kim Jongun. Using these results, our analysis indicated that an interest in and need for soil erosion control engineering in North Korea has continually increased. The results of this study are expected to serve as a basis for preparing forestry cooperation between North and South Korea, and to serve as essential data for better understanding soil erosion control engineering in North Korea.

• Tuberculosis and Respiratory Diseases
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• v.64 no.5
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• pp.362-368
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• 2008

Background: LKB1(STK11) is a serine/threonine kinase that functions as a tumor growth suppressor. The functions of LKB1 in lung cancer are not completely understood. This study evaluated the relationship between LKB1 protein expression and the clinicopathological features in lung cancer tissues. Methods: The expression of LKB1 was studied in paraffin-embedded tumor blocks, which were obtained from 77 patients who had undergone surgery at Wonkwang University Hospital. The expression of the LKB1 protein was considered positive if the staining intensity in the tumor tissue adjacent to the normal airway epithelium was >30%. Results: The LKB1 expression was positive in 31 (40%) of samples. Loss of LKB1 expression was significantly associated with being male, smoking history, and squamous cell carcinoma. In the peripheral sites, the loss of LKB1 expression was strongly associated with a smoking history. A loss of LKB1 expression was more frequently associated with progression according to TNM staging, particularly more than T2, N progression. Conclusion: There was a significant relationship between the loss of the LKB1 protein and gender, smoking history, and histological type in primary lung cancer. Although LKB1 expression was not found to be a significant prognostic factor, further studies with a larger cohort of patient's lung cancer tissue samples will be needed to confirm this.