• Journal of Korean Neurosurgical Society
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• v.59 no.2
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• pp.129-136
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• 2016

Objective : The purpose of this study was to figure out the radiologic findings and risk factors related to adjacent segment degeneration (ASD) after anterior cervical discectomy and fusion (ACDF) using 3-year follow-up radiography, computed tomography (CT), and magnetic resonance image (MRI). Methods : A retrospective matched comparative study was performed for 64 patients who underwent single-level ACDF with a cage and plate. Radiologic parameters, including upper segment range of motion (USROM), lower segment range of motion (LSROM), upper segment disc height (UDH), and lower segment disc height (LDH), clinical outcomes assessed with neck and arm visual analogue scale (VAS), and risk factors were analyzed. Results : Patients were categorized into the ASD (32 patients) and non-ASD (32 patients) group. The decrease of UDH was significantly greater in the ASD group at each follow-up visit. At 36 months postoperatively, the difference for USROM value from the preoperative one significantly increased in the ASD group than non-ASD group. Preoperative other segment degeneration was significantly associated with the increased incidence of ASD at 36 months. However, pain intensity for the neck and arm was not significantly different between groups at any post-operative follow-up visit. Conclusion : The main factor affecting ASD is preoperative other segment degeneration out of the adjacent segment. In addition, patients over the age of 50 are at higher risk of developing ASD. Although there was definite radiologic degeneration in the ASD group, no significant difference was observed between the ASD and non-ASD groups in terms of the incidence of symptomatic disease.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.1
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• pp.69-76
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• 2020

Bridges which are components of road network consume large amounts of resources such as concrete and steel materials, which have large environmental impacts during construction. This causes a great environmental burden. In order to reduce the environmental impact caused by the construction of the bridge, the environmental impact should be reviewed based on reasonable data in the early design stage. The purpose of this study is to provide basic data for LCA-based environmental impact assessment in the process of selecting bridge type in the early design stage. For this purpose, design data for four types of PSC bridges (general PSC girder, IPC girder, e-Beam, DR girder) were collected and LCA was performed to analyze the basic unit value and impact factors of environmental load. The results of the analysis showed that the environmental impact of IPC girder was the smallest, and the environmental impact of e-Beam was 133.7% higher than that of IPC girder. In addition, concrete, reinforcement, PC strand, square timber, sheath pipe, and steel plate were derived as the main factors that generate 98.5% of the overall environmental impact of PSC girder.

• Journal of Convergence for Information Technology
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• v.7 no.1
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• pp.67-73
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• 2017

Paper sludge ash, blast furnace slag, fine powder quicklime, anhydrous gypsum, and fly ash as the main ingredients were prepared to suit the salty soils of marine soils. The solidification component is a kind of recycled ceramic, and CaO plays an important role in solidification. The neutralization time after solidification was about 2 weeks, and the compressive strength was about 12N/mm2 in the mortar test after one week incubation with standard yarn. This is about 14 times stronger than the solidifying agent used in the metropolitan area. As a result of applying plate load test to saltous marine soils, we obtained the yield load that can pass the large scale even after 5 days. In the uniaxial compressive strength test, shear strength of about 300 kPa was obtained after 5 days. It will be useful for supplementing the soft ground in the area where marine reclamation is much like the Incheon area.

• Journal of Food Hygiene and Safety
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• v.5 no.4
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• pp.229-236
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• 1990

The effects of ethanol (ET) on the teratogenicity of the fat soluble drug, Vita. min A (VA) were examined in SPF Wistar rats. VA and ET were orally administered with sonde. The drugs were administered for 3 days of day 9-11 of gestation. Four groups were made; G-I control (sesame oil + saline), G-II VA $40{\times}10^{4}$ (I.Ulkg/day), G-III ET 2 (g/kg/day), G-IV $40{\times}10^{4}$ + ET 2. Congenital malformations were found G-II, G-III and G-IV. All fetuses in G-IV combination had malforamtions. Main malformation in G-IV combi. nation were microstomia, disposition of ear, open eyelids brachygnathia and cleft plate. Accordingly it might be demonstrated that the teratogenicity of hypervitaminosis A was pontentiated by concurrent ethanol in rats.

• Journal of the Korean Dietetic Association
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• v.14 no.1
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• pp.87-96
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• 2008

The purposes of this research were to investigate in-patients' perception on foodservice quality and to examine factors influencing their meal consumption at hospitals. Three general hospitals with over 400 beds in Seoul and Chon-An agreed to participate in the research. A total of 516 in-patients of the hospitals were surveyed on their meal consumptions, reasons of plate wastes, perceptions of foodservice quality, and demographic information. A response rate was 76% after excluding responses with significant missing data. On average the regular diet patients consumed 72%, 69%, and 68% of rice, soups, and side dishes served, respectively; the therapeutic diet patients consumed less than 70% of the meals they were served. The consumption rates did not differ significantly by diet type, gender, age, and hospitalization period. Among the therapeutic diet patients, those who had nutrition education consumed significantly more rice than the others (p<0.05). The main reasons why the patients did not eat all food served were 'lack of energy' and 'not tasty'. The patients' perception on foodservice quality was low; the therapeutic diet patients perceived more negatively than the regular diet patients in 'keeping hot food hot, cold food cold(p<0.05)', 'maintaining consistency of taste(p<0.01)', and 'providing nutrition information(p<0.01)'. To achieve the goal of the foodservice at hospitals, the dietitians can use the findings of the research in developing and implementing strategies to improve the patients' meal consumption. Recipe standardization, employee training, and production management will be useful for improving food quality and nutrition education on therapeutic diets for the patients will improve their meal consumption at hospitals.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.10
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• pp.102-111
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• 2004

The procedure of design and manufacture of sub-scale combustor using bipropellant swirl injector with external mixing for a liquid rocket engine are described. The results of cold flow test, ignition test and combustion test of the sub-scale combustor are also given in this paper. The sub-scale combustor uses liquid oxygen(LOx) and kerosene as propellants and has a injector head, an ablative material combustor wall and a water cooled nozzle. The injector head has LOx manifold, fuel manifold, fire face plate, one center swirl injector and 18 main swirl injectors. The cold flow, ignition and combustion tests were successfully performed without damage of combustor. Results of hot firing tests show that combustion efficiency meets the target of design and operations of start and stop cyclogram are stable and high frequency combustion instability does not occur.

• Journal of Environmental Health Sciences
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• v.29 no.1
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• pp.51-61
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• 2003

Pollution purification using titanium dioxide (TiO$_2$) photocatalyst has attracted a great deal of attention with increasing number of relent environmental problems. Currently, the application of TiO$_2$ photocatalyst has been focused on purification and treatment of waste water. However. the use of conventional TiO$_2$ powder photocatalyst results in disadvantage of stirring during the reaction and of separation after the reaction. And the usage of artificial UV lamp has made the cost of photocatalyst treatment system high. Consequently, we herein studied the pilot-scale design to aid in optimization of the energy-saving process for more through development and reactor design by solar light/UV lamp/ TiO$_2$system. In this study, we manufactured the TiO$_2$sol by sol-gel method. According to analysis by XRD, SEM and TEM, characterization of TiO$_2$ sol were nano-size (5-6 nm) and anatase type. Inorganic binder (SiO$_2$) was added to TiO$_2$ lot to be coated for support strongly, and support of ceramic bead was used to lower separation rate that of glass bead The influences were studied of various experimental parameters such as TiO$_2$ quantity, pH, flow rate. additives, pollutants concentration, climate condition and reflection plate by means of reaction time of the main chararteristics of the obtained materials. In water treatment system, variable realtor as solar light/ or UV lamp according to climate condition such as sunny and cloudy days treated the phenol and E-coli(Escherichia coli) effectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.6
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• pp.612-619
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• 2010

In this paper, an elastomeric bearing for a helicopter rotor hub is designed using nonlinear finite element method. The elastomeric bearing is the main component of the helicopter rotor hub that acts as a hinge to three motions(flapping, lagging and pitching) of rotor blade. The elastomeric bearing consists of rubber and metal plates. The stiffness design of the elastomeric bearing is important because elastic deformation of rubber is served to hinge. Accordingly, the elastomeric bearing is designed to satisfy the stiffness requirements for rotor hub bearing. In this study, a FE model generation algorithm is developed and stiffness characteristic of a rubber plate is analyzed for an efficient design of the spherical elastomeric bearing. It is proven that the elastomeric bearing satisfies stiffness requirements of the spherical bearing for a helicopter rotor hub.

• Journal of Food Hygiene and Safety
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• v.20 no.3
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• pp.175-178
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• 2005

Clean Natural is a new disinfectant of which main components are propolis and wood vinegar from Quercus mongolica. To evauate the bacterial reverse mutation of Clean Watural, the in vitro Ames test using Salmonella typhimurium TA98, TA100, TA102, TA1535 and TA1537 were performed with clean natural at the concentrations 0, 5, 2.5, and 1.25 mg/ml/plate. Clean Natural was negative in Ames test with Salmonella typhymuyium with and without rat liver microsomal enzyme (S-9 fraction). These results indicate that Clean Watural does not cause bacterial reverse mutation.

• Korean journal of food and cookery science
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• v.25 no.2
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• pp.189-198
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• 2009

This study was conducted to analyse middle school students' perceptions of seafood as well as their eating experiences and favorite cooking methods for seafood. It also examined the frequency and use of seafood on school lunch menus. Questionnaires were distributed to 739 students in 5 middle schools in the Busan area. On a scale of 5.00, the average scores for perceptions toward seafood were as follows: 3.67 for health & nutrition, 3.53 for taste, 2.53 for smell, 2.77 for convenience. The male students had significantly_(p<0.05) higher perception scores for health & nutrition, taste, and smell than the female students. Among 38 types of seafoods, the highest percentages for eating experiences included seaweed_(99.2%), anchovies_(99.1%), fried fish paste_(98.6%), shrimp_(98.4%), crab_(98.2%), squid_(97.9%), sea mustard_(97.8%), mackerel_(97.7%), dried squid_(97.3%), and hair tail_(96.9%). However, the majority of students had eaten a limited amount of seafood. The degree of seafood intake at home was significantly_(p<0.01) higher than at school. The students' favorite cooking methods for seafood were in the order of grilling, stir-frying, steaming, deep-fat frying, and soup. However, the middle school lunch programs primarily served as soup, seasoning, stir-fried, braised, deep-fat fried, and grilled, respectively. The main reasons for leaving seafood on a plate were inconvenience due to the fishbones_(62.7%), tasteless_(45.4%), and disliking the smell_(35.7%). Improvements that students wanted for seafood on school lunch menus included removal of fishbone for convenience_(67.0%), taste_(52.0), and increased variety of seafood types_(38.2%).