• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.2
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• pp.21-26
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• 2016

Purpose Because of many advantages, PET-CT Scanners generally use CT Data for attenuation correction. By using CT based attenuation correction, we can get anatomical information, reduce scan time and make more accurate correction of attenuation. However in case metal artifact occurred during CT scan, CT-based attenuation correction can induce artifacts and quantitative errors that can affect the PET images. Therefore this study infers true SUV of metal artifact region from attenuation corrected image count -to- non attenuation corrected image count ratio. Materials and Methods Micro phantom inserted $^{18}F-FDG$ 4mCi was used for phantom test and Biograph mCT S(40) is used for medical test equipment. We generated metal artifact in micro phantom by using metal. Then we acquired both metal artifact region of correction factor and non metal artifact region of correction factor by using attenuation correction image count -to- non attenuation correction image count ratio. In case of clinical image, we reconstructed both attenuation corrected images and non attenuation corrected images of 10 normal patient($66{\pm}15age$) who examined PET-CT scan in SNUH. After that, we standardize several organs of correction factor by using attenuation corrected image count -to- non attenuation corrected count ratio. Then we figured out metal artifact region of correction factor by using metal artifact region of attenuation corrected image count -to- non attenuation corrected count ratio And we compared standard organs correction factor with metal artifact region correction factor. Results according to phantom test results, metal artifact induce overestimation of correction factor so metal artifact region of correction factors are 12% bigger than the non metal artifact region of correction factors. in case of clinical test, correction factor of organs with high CT number(>1000) is $8{\pm}0.5%$, correction factor of organs with CT number similar to soft tissue is $6{\pm}2%$ and correction factor of organs with low CT number(-100>) is $3{\pm}1%$. Also metal artifact correction factors are 20% bigger than soft tissue correction factors which didn't happened metal artifact. Conclusion metal artifact lead to overestimation of attenuation coefficient. because of that, SUV of metal artifact region is overestimated. Thus for more accurate quantitative evaluation, using attenuation correction image count -to-non attenuation correction image count ratio is one of the methods to reduce metal artifact affect.

• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.149-155
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• 2009

The present study was conducted to compare the carcass yields and meat characteristics of three types of commercial male chicks White mini broilers, Ross broilers and Hy-Line brown chicks under the identical feeding condition. One-hundred 1-d chicks of each type were randomly placed into four pens per group (25 chicks per pen) and fed corn-soybean meal based commercial diets for 35d, 18d or 49d, respectively. At the end of the feeding trial, the birds were sacrificed and subjected to carcass measurements. The dressing percentages of White mini broilers and Ross broilers were significantly higher (P<0.05) than that of Hy-Line brown cockerels. The rate of breast meat of Hy-Line brown cockerels was significantly lower (P<0.05) than those of White mini broilers and Ross broilers. However, Hy-Line brown cockerels showed higher (P<0.05) leg meats than the others. There were no significant differences in serum total cholesterol and the activities of glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase among the groups. The breast meats of White mini broilers presented highest lightness value. The yellowness of breast and redness of leg meats of White mini broilers and Ross broilers were significantly higher (P<0.05) than those of Hy-Line brown cockerels. There were no significant differences in the SOD-like activity and change of pH in edible meats among the groups. The meat color in White mini broilers was significantly higher than that of Hy-Line brown cockerels. No significant differences were observed in term of flavor, tenderness and overall acceptability. In conclusion, the physico-chemical properties and sensory characteristics of edible meats were not greatly affected by genotype if they were similar body weights and kept under the identical feeding condition. But the Hy-Line brown cockerels were less desirable as a meat-type strain due to lower carcass yields and inferior growth and feed conversion ratio.

• Pediatric Infection and Vaccine
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• v.14 no.2
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• pp.162-170
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• 2007

Purpose : While cases of vancomycin-resistant enterococci (VRE) have increasingly been reported worldwide since it was first reported in the late 1980s, there have been few systemic studies on the pediatric population. The purpose of this study is to contribute to the planning of VRE prevention by investigating the prevalence, risk factors and transmission of VRE infection. Methods : We studied 230 patients under age 15 years who were isolated VRE between January 2001 and December 2006 retrospectively. The patients were classified into the intensive care unit (ICU) and the non-ICU groups. We reviewed the procedures before VRE detection as well as antibiotic sensitivity of detected organisms. Results : The number of VRE-isolation cases was higher in the ICU group than the non-ICU group. Instances of VRE-isolation were also more prevalent in patients who underwent operations or active procedures while taking 3rd-generation cephalosporins or glycopeptides. Almost all antibiotics except tetracycline were resistant to VRE. The proportion of 3rd-generation cephalosporin use was higher than those of any other antibiotics before VRE detection. Additionally, the use of 3rd-generation cephalosporins has increased annually, but that of glycopeptides had decreased in 2006. Also, the rates of VRE isolation have been increasing since 1998. Conclusion : VRE infection is increasing in pediatric population. Strict adherence to appropriate infection control guidelines for the prevention of VRE transmission in hospitals, and tracking of VRE colonization through active surveillance in high risk units are recommended.

• Journal of the Mineralogical Society of Korea
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• v.16 no.1
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• pp.33-47
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• 2003

Various applied-mineralogical characterization including measurements of surface area, size distribution, swelling index, and viscosity were done for some domestic bentonites in order to decipher the rheological properties and their controlling factors. The bentonites, which are Ca-type and relatively low-grade (rnontmorillonite contents: 30 ∼ 75 wt%), occur mostly as subhedral lamellas with the size range of 2 ∼ 4 $\mu\textrm{m}$. The size distribution of mineral fractions in bentonite suspension is dominant in the range of 10 ∼ 100 $\mu\textrm{m}$, and though rather complicated, exhibits roughly bimodal patterns. The feature is more conspicuous in the case of zeolitic bentonite. The bentonites have surface areas ranging 269 ∼ 735 $\m^2$/g, which are measured by EGME adsorption method. The EGME surface areas are nearly proportional to the rnontmorillonite contents, moisture contents, or total CEC. In the surface area measurements, zeolitic bentonites have slightly higher values than those zeolite- free types. The measured swelling index and viscosity of domestic bentonites are comparatively low in values. The swelling values of bentonites were measured to be 250∼500% at maximum by progressively mixing amounts of 2 ∼ 5 wt% Na$_2$CO$_3$, which varies depending on the contents of rnontmorillonite and other impurities, especially zeolite. Much amount of sodium carbonate is required for optimum swelling property of zeolitic bentonited which has usually strong Na- exchanged capacity. The bentonites, which are comparatively feldspar-rich and low in size and crystallinity, tend to be higher in viscosity values. Tn addition, the viscosity is largely higher in case of the bentonites with higher pH in suspension. However, the rheological properties of bentonites such as swelling index and viscosity do not show any obvious relationships with rnontmorillonite contents and mean particle size in suspension. In contrast, roughly speaking, the swelling index of bentonites is reversely proportional to the values of surface area which can be regarded as a collective physico-chemical parameter encompassing all the effects caused by mineral composition, surface charge, particle size, morphological farm, and etc. in bentonites. Thus, the rheological properties in bentonite suspension appear to be rather complicated characteristics which mainly depend on the flocculation of clay particles and the mode of particle association, i.e. quasicrystals, controlled by surface charge, morphology, size, and texture of rnon-tmorillonite, and which partly affected by the finer impurities such as zeolite.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.3
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• pp.229-235
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• 2011

Purpose: The aim of this study was to evaluate the current status of dental geriatric education in Korea. Materials and methods: One of the faculty members related in geriatric education was selected in each Korean dental school and the questionnaire on geriatric dental education was sent to them by e-mail. The questionnaire consists of the topics about undergraduate geriatric education and administration of the geriatric education. The information obtained from the questionnaire was compared with that of other countries in the aspects of curriculum, teaching methods, subjects, and existence of specific clinics, etc. Results: Seven schools have geriatric dentistry in undergraduate education curriculum. Among those, only two schools had it taught by theoretical lecture as well as clinical lecture. Two dental schools had specific geriatric clinic among seven dental schools. Compared with the USA and western European countries, the geriatric dental education in Korea is at a developing stage and was perfunctory without diverse clinical experience. Conclusion: In Korean dental schools, geriatric education was mostly conducted by lectures, and clinical teaching programs were not well organized compared with developed countries. It seems that the status of geriatric dental education in Korea has not been well established academically or administratively yet.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.5
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• pp.523-530
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• 2010

This study was conducted to analyze and determine formation potentials for chlorination disinfection by-products (DBPs) from 14 synthetic nitrogen compounds with or without $Br^-$. 5 of 14 compounds were 3-aminobenzoic acid, 2-aminophenol, aniline, anthranilic acid and 4-nitroaniline that were relatively shown high for formation of THMs/DOC whether or not $Br^-$ presented. 6 compounds that were p-nitrophenol, 3-aminobenzoic acid, 2-aminophenol, aniline, anthranilic acid and 4-nitroaniline were shown high for formation of haloacetic acids (HAAs)/DOC whether or not $Br^-$ presented. Trichloroacetic acid (TCAA) was dominated in 6 compounds. The formation of haloacetonitriles (HANs)/DOC whether or not $Br^-$ presented was high in 3-aminobenzoic acid, 2-aminophenol, aniline and anthranilic acid. Specially, aniline was detected 14.6∼16.1 ${\mu}g/mg$. The formation of chloral hydrate (CH)/DOC and chloropicrin (CP)/DOC were shown high in 3-aminobenzoic acid and 2-aminophenol in 14 compounds. 6 compounds (3-aminobenzoic acid, 2-aminophenol, aniline, anthranilic acid, 4-nitroaniline, p-nitrophenol) and a commercial humic acid were tested for the formation of DBPs/DOC whether or not $Br^-$ presented. When $Br^-$ was added, the DBPs/DOC was higher for the order of aniline> anthranilic acid> 3-aminobenzoic acid> 4-nitroaniline> humic acid> p-nitrophenol> 2-aminophenol. And when $Br^-$ was not added, the DBPs/DOC was higher for the order of anthranilic acid> aniline> p-nitrophenol> humic acid> 4-nitroaniline> 3-aminobenzoic acid> 2-aminophenol.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.4
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• pp.355-362
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• 1999

This experiment was conducted to evaluated the effect of maturity at harvest and wrap colors on the quality of round baled rye(Secal cereale L.) silage at the forage experimental field, Grassland and Forage Crops Division, National Livestock Research Institute, Suwon in 1998. The experiment was consist of split-plot design with three repications. The main plots were three different harvesting stages : boot, heading, and flowering stages, the subplots were wrap colors : white, black, and light green color. Acid detergent fiber(ADF) and neutral detergent fiber(NDF) of rye silage were increased with delayed harvesting date, but there were no significant differdence among wrap colors. However, average in vitro dry matter digestibility (IVDMD) of rye silage with white color wrap tended to have higher than those of other colors. The silage pH of heading stage was highest (5.12), and that of flowering stage was lowest (4.57) in different harvest stages. Among tested wrap colors, white color wrap resulted on lowest pH than others (p<0.05), but there were no significant difference between black and light green color. Dry matter (DM) content of rye silage were increased as harvest stage progressed (p<0.05). However, DM content of white color was highest among warp colors, but there was signifiant difference (p<0.05). Ammonia-N content of silage harvested at boot stage was the highest in harvest stage, but there was no difference between heading and flowering stages. Among wrap colors tested, ammonia-N content of black color was highest, but there was no significant difference. The number of lactic acid bacteria of white colors was highest in different colors, and that of flowering stage was highest among harvest stage. Acetic and butyric acid contents were decreased as harvest stage progressed, and lactic acid was increased from 6.33 to 7.98%. However, wrap colors did not influence lactic acid concentration. Among different wrap colors, outside temperature of rye silage was affected by air temperature, but effect of inside temperature was minimal. Black color wrap increased inside temperature by $3{\sim}5^{\circ}C$. The results of this study indicate that rye should be harvested for round bale silage after heading stage. The quality of rye silage wrapped white and light green color will increase slightly.

• Journal of Distribution Science
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• v.10 no.1
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• pp.33-42
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• 2012

This study is focused on traditional market's competitiveness in Korea. Ever since the Korean retail industry had been opened to the big conglomerates, the traditional markets have faced very serious competition from various types of distribution channels. In particular, this study has been conducted to find another way to help the Korean traditional market from the perspective of college students who are consumers of the future. This study examines the relationships among store choice attributions, consumption emotion, consumer's value, and relationship quality from the perspective of college students. In order to verify the relationship, and moderating and mediating effects, data were collected from 126 college students in Whasung, Gyeonggi Province to test the theoretical model and its hypotheses. The results of this study are as follows: First, service (= .263, p < .01) and advertising (= .188, p < .05) are significantly positively related to relationship quality. However, store atmosphere (= .176, p = .052) is not statistically significantly related to relationship quality. The result that students have stereotypes about the atmosphere of traditional markets and are therefore excluded from their store choice attributions can be expected. Second, college students selected service division (= .230, p < .05) as the most important factor among the traditional market's store choice attributions. This result reflected that enhancing service strategy would strengthen the traditional market against discount stores. The process of product selection by customers in discount stores is based on the concept of self-service. However, traditional market traders can make various contacts with their customers. If traditional market traders can enhance various service factors just like in the process of product selection, it will effect strong competitive advantages. Third, it is also revealed that consumer's value exhibit complete mediation effect in the relationships between service and advertising. These results showed that traditional markets must be considered for consumer value. Because previous studies showed that values refer to "enduring belief that … specific mode of conduct or end-stat of existence … personally or socially preferable to an opposite of converse mode of conduct or end-state of existence" (Rokeach, 1973; George and Jones, 1996). Furthermore, Schwartz (1994) defined values as desirable trans-situational goals, varying in importance, that serve as guiding principles in the life of a person or other social entity. As conceptions of desirable end-states of existence or modes of conduct, values help people choose, evaluate, and give meaning to their experiences (Rokeach, 1973). Efforts (e.g. promote the consumers value) of the traditional market traders will improve the preferences for the traditional market of consumers and college students. Implications and future research directions are also discussed.

• Clinical and Experimental Pediatrics
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• v.52 no.10
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• pp.1109-1118
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• 2009

Purpose : Metabolic syndrome (MS), characterized by obesity and insulin resistance, elicits risk factors such as hyperlipidemia, hypertension, and glucose intolerance with additive effects on atherosclerosis, leading to cardiovascular diseases. The purposes of this study were to evaluate the prevalence of MS among overweight and obese adolescents and to investigate the impact of obesity on the cardiovascular system. Methods : In all, 684 adolescents were included in the study. Blood pressure, body mass index (BMI), fasting blood glucose, total cholesterol, triglyceride, low-density-lipoprotein (LDL)-cholesterol, high-density-lipoprotein (HDL)-cholesterol, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and high-sensitive C-reactive protein (hs-CRP) were measured in the patients with a BMI of >85 percentile. Brachial-ankle pulse wave velocity (BaPWV) and ankle brachial index were measured using Vascular Profiler (VP)-1000. Results : MS was confirmed in 19.5% of the overweight and obese adolescents and 50.8% of the obese adolescents. The systolic and diastolic blood pressure, height, weight, fat mass, %fat, BMI, obesity index, and waist circumference were higher in the overweight and obese adolescents with MS. Moreover, the triglyceride, AST, ALT, and hs-CRP levels were higher, whereas HDL-cholesterol level was significantly lower in this group. The overweight and obese adolescents with MS showed shorter diastolic and systolic times, higher heart rate and BaPWV, and longer E-wave deceleration time by echocardiography. Conclusion : Overweight and obese adolescents showed characteristic MS features such as hypertension and hyperlipidemia. Thus, obese adolescents predisposed to MS should be provided early treatment for obesity.

• Korean Journal of Weed Science
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• v.12 no.1
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• pp.61-69
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• 1992

Weed control in mid season of rice fields was systemized earlier in Korea than in Western Europe or China. The most representative method was pull out the weeds by hand followed by 'Seojibeob'(鋤地法 : method of hoeing) after draining. It was practiced 3 to 4 times to do extensively. Also, the purposes of transplanting arid direct seeding in rows were to manage weed problems effectively, which means that the development of cultural techniques is closely related to 'Seojibeob'(鋤地法). From the 17th century, techniques of deep plowing(because of principal : 'Simkyonginu'(深耨易耕 : Deep plowing make easy to hoe) and 'Hwanubeob'(火耨法 : derived from 'Hwakyong soonubeob) for effective weed management of waste lands were newly adopted and spreaded due to the situations ant that time. Thus, the practice of large-scale farming resulted from the adaptation of the techniques and methods described above. In the 18th to 19th century, the cultural methods, not much different from 'Seojibeob', were changed and the number of weeding was decreased. Especially, the techniques of dry seeding of rice were practiced by originating the ideal 'Seojibeob', in which water availability was improved in northern drought areas and also weed problems were easily managed. In addition, intensively large-scale farming showed weed management problems, so that 'Cheonilrok'(千一錄) by Woo Ha-young described the techniques of 'Banjongbeob'(反種法) or 'Hwanubeob' and in the end of the Chosun dynasty extensively large-scale farming was practiced by putting intensive and extensive techniques together. As the results, agricuitural productivity of Korea was increased 5 times by that time.