• Journal of Korea Water Resources Association
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• v.54 no.3
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• pp.181-190
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• 2021

In this study, a large-scale levee breach experiment from lateral overflow was conducted to verify the effect of the new reinforcement method applied to the levee's surface. The new method could prevent levee failure and minimize damage caused by overflow in rivers. The levee was designed at the height of 2.5 m, a length of 12 m, and a slope of 1:2. A new material mixed with biopolymer powder, water, weathered granite, and loess in an appropriate ratio was sprayed on the levee body's surface at a thickness of about 5 cm, and vegetation recruitment was also monitored. At the Andong River Experiment Center, a flow (4 ㎥/s) was introduced from the upstream of the A3 channel to induce the lateral overflow. The change of lateral overflow was measured using an acoustic doppler current profiler in the upstream and downstream. Additionally, cameras and drones were used to analyze the process of the levee breach. Also, a new method using 3D point cloud for calculating the surface loss rate of the levee over time was suggested to evaluate the performance of the levee reinforcement method. It was compared to existing method based on image analysis and the result was reasonable. The proposed 3D point cloud methodology could be a solution for evaluating the performance of levee reinforcement methods.

• The korean journal of orthodontics
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• v.32 no.6 s.95
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• pp.425-434
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• 2002

The purpose of this investigation was to study the spatial changes of the maxillofacial complex following maxillary protraction transmitted to the center of resistance of a dry juvenile human skull by a modified maxillary protraction appliance. Four dry juvenile human skulls (without mandible) with well aligned upper deciduous dentition and early mixed dentition were used as experimental samples. A modified protraction headgear was fabricated from a Delare's facemask, and following an alginate impression, an orthodontic resin maxillary splint was made for each dry skull. Protraction force level was maintained at approximately 1000gm per side for 6 hours. Cephalometric radiographs were taken pre- and post- protraction, and nine reference markers with 1.5 mm length of $.017\times.025$ TMA wire were placed on the right side of the skull for an accurate superimposition of serial cephalometric radiographs. The present investigation demonstrated that vertical changes associated with an anterior displacement of the maxillary complex was observed, and the most prominent effect of protraction headgear was a counterclockwise rotation of the maxilla, that is, a forward and downward tipping around the palatomaxillary region.

• Journal of Microbiology and Biotechnology
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• v.16 no.8
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• pp.1201-1209
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• 2006

The purpose of this study was to isolate probiotic lactic acid bacteria (LAB) that produce bile salt hydrolase (BSH), and to evaluate its effects on serum cholesterol level. One-hundred-twenty bacterial colonies were initially isolated from human feces, and five strains were selected after screening based on their resistance to acids, tolerance against bile salts, and inhibitory activity on Escherichia coli. The Lactobacillus plantarum strain with the highest level of BSH activity was identified using 16S rRNA sequences, and was named L. plantarum CK 102. L. plantarum CK 102 at a level of 1.36$\times$10$^8$cfu/ml survived in pH 2 buffer for 6 h and exhibited excellent tolerance for bile salt. Coculturing the strain with E. coli in MRS broth resulted in strong inhibition against growth of E. coli at 18 h. Furthermore, the potential effect of CK 102 on serum cholesterol level was evaluated in rats. Thirty-two rats [Sprague-Dawley (SD) male, 129$\pm$l g, 5 weeks old] were divided into four groups of eight each. For six weeks, Group 1 was fed a normal diet (negative control); Group 2 was fed a cholesterol-enriched diet (positive control); Group 3 was fed a cholesterol-enriched diet plus L. plantarum CK 102 at 1.0$\times$10$^7$cfu/ml; and Group 4 was fed a cholesterol-enriched diet plus L. plantarum CK 102 at 5.0$\times$10$^7$cfu/ml. Blood samples were collected, serum lipids were analyzed, and weights of the organs were measured. Total blood cholesterol level, triglyceride, LDL-cholesterol, and free-cholesterol values were lower in rats that were fed 1. plantarum CK 102 than in those not fed L. plantarum CK 102. This cholesterol lowering effect implies that L. plantarum CK 102 could be utilized as an additive for health-assistance foods. In conclusion, these results suggest that the 1. plantarum CK 102 isolated could be used commercially as a probiotic.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.5
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• pp.338-345
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• 2003

Purpose : This study was intended to perform cephalometric comparison between the patients with and without obstructive sleep apnea (OSA). The factors influencing the OSA in the lateral cephalogram was also investigated. Patient and Method : Twenty four patients who visited Sleep Disorder Clinic in Dongsan Medical Center, Keimyung University and evaluated with polysomnograph(PSG) and cephalogram were included in the study. The patients had apnea-hypopnea episode(AHI) over 10 times per hour was diagnosed as OSA after overnight PSG. To evaluate hard and soft tissue profile, cephalometric radiogram were taken at maximal intercuspation(P1) and mandibular protruding position(P2). The diffefence between the OSA and normal group were evaluated statistically and the stepwise regression analysis was applied to analyse the cephalometric influencing factors to OSA. Result : The OSA Group(n=14) had significantly higher Body Mass Index(BMI) than control group(n=10). Lower facial height(ANSGn) was longer in OSA group. However statistically significant difference was not detected in other anteroposterior craniofacial measurements. The soft palate lenth (PNS-P), hyoid position (MP-Hyoid) had positive correlation between AHI (r=0.496, r=0.413, respectively, p<0.05). However, the measurements of oropharyngeal airway was not different between the two groups. The hypothesis, the antero-posteriorly narrow oropharyngeal airway might aggravate the airway resistance and can give rise to higher AHI, was not accepted in the study. This can be attributed by inclusion of the patients performed uvulopalatopharyngoplasty because of the tonsilar or soft palate hypertrophy in the present study. The results of regression analysis revealed that PNS-P, upper airway width(Nph1), upper facial heght(N-ANS), and lower facial height(ANS-Gn) could influence the degree of AHI (F value < 0.0001, $R^2$ = 0.829). Conclusion : We suggest lateral cephalogram may utilized as a useful method to evaluate OSA. The patient with long soft palate, narrow upper airway width, long upper & lower facial height can be expected to have high risk of OSA. However, it should be emphasized the comphrehensive intraoral inspection including soft palate and tonsilar hypertrophy because lateral cepahlogram cannot visualize oropharyngeal status completely.

• Journal of Korean Society of Disaster and Security
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• v.10 no.1
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• pp.85-90
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• 2017

The purpose of this study is to investigate the effect of vertical and horizontal refraction on the lower part of the power supply and control system of various facilities and machinery that use electricity, so that the power distribution system, which is an important electric facility installed in buildings and public facilities, Type earthquake resistant pads to protect the substructure and prevent short-circuiting on the upper part of the system. The GR-63-CORE (Scale 8.3 class) It is earthquake disaster prevention and disaster prevention technology that satisfies seismic performance. As a research result, it is possible to protect the electricity and communication infrastructure, which can contribute to shortening the time for recovering the electric facilities to the normal state in case of an earthquake, and preventing the fire caused by the destruction of the electricity supply facility in case of an earthquake. As a result, it is possible to minimize the spread of fire that occurs when a large-scale earthquake occurs and to minimize the damage of people and damage to property, and it can contribute to the securing of electric infrastructure that enables citizens to quickly recover to daily life even after suffering a major earthquake. In addition, the technology can be applied to ensure the seismic resistance of the equipment in the communication and computer room, and it can be applied to various fields where the facility function can be stopped due to the shaking of the earthquake base.

• Polymer(Korea)
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• v.35 no.5
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• pp.467-471
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• 2011

PET bottle is manufactured by blow molding the preform, which is molded by injection molding. The neck part of the preform of PET bottle for juice or grain-based beverage is crystallized before blowing to improve heat resistance at the entrance of the bottle. However, residual stress, developed during injection molding of preform, prevents the crystallization. In order to release the residual stress in the preform, the preform is annealed after the injection molding. If the residual stress is reduced by optimizing the injection molding conditions of preform the annealing time would be shortened. In this study, the optimum conditions for minimizing the residual stress and increasing dimensional accuracy of the injection molded preform are suggested through CAE analysis. In order to optimize the molding conditions, minimizing residual stress and shrinkage, computer simulations have been carried out with help of design of experiment scheduling. Injection temperature, initial packing pressure and filling time were selected for control parameters. Residual stress was affected by injection temperature and filling time. Shrinkage was affected by injection temperature. It was found that maximum residual stress, distribution of residual stress and shrinkage were decreased by 22%, 40% and 25%, respectively at an optimum molding condition compared with the results of previous molding condition.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.373-383
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• 2019

The objectives of this study were to compare the protein expression patterns and degrees and identify the protein function of disomic addition lines (DAs) in Leymus racemosus, in order to improve the quality of wheat. Upon SDS-PAGE, L. racemosus showed two major protein bands whereas Chinese Spring (CS) had four major protein bands of high molecular weight. The DA(s) generally showed a similar protein expression pattern to that of CS, because 42 chromosomes were from CS and two chromosomes were from L. racemosus. However, only the L.r[J] line showed two protein bands of between 15 and 20 kDa, like L. racemosus. Image analysis based on 2-DE revealed that L.r[F] had the most upregulated protein spots, whereas L.r[N] had the least upregulated protein spots. For L.r[I], the frequency of the downregulated protein spots was higher than that of the upregulated ones. Using MALDI-TOF MS, the protein function was identified for each protein spot on the 2-DE polyacrylamide gel. The protein spots were classified into 11 groups according to protein function. Among the 11 groups, most protein spots of the DA(s) were identified as proteins related to metabolism. Additionally, unique protein spots of the DA(s) were related to abiotic stressors such as cold and heat. Those proteins are useful for improving wheat quality with resistance against abiotic stressors.

• Journal of Animal Environmental Science
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• v.11 no.1
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• pp.11-16
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• 2005

The round bale wrappers are generally used for rice straw after the harvesting of low land rice by combine harvester. In this situation, the bale wrappers should be well adapted under the travelling over raised borders and temporary ditches in soft soil of narrow rice fields. The study was conducted to improve the performance of bale wrapper through the new design for compact size, lowered gravity center and lowered power consumption. The prototype of round bale wrapper had been designed and assembled to tractor with three point hitch mounted. The machine type is one roll driving system with one roll for rotating and one roll for wrapping. The driving torque and work performance of the machines were measured and analysed. The torque requirement of the prototype and conventional type was 6kgf-m and 12kgf-m, respectively. The prototype shaved less friction resistance between bale driving roll and round bale. and the power requirement can also be reduced from 12kgf-m in the conventional to 6kgf-m in the prototype. The work efficiency of the new bale wrapper was $45\%$ higher than the conventional wrapper, and the working cost of the prototype can be reduced $17\%$ than that of the conventional.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.4
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• pp.477-483
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• 2018

Transcranial doppler is a non-invasive method that measures the blood flow velocity and the direction of cerebral blood vessels through the doppler principle. The pulsatility index is an index for measuring the transcranial doppler that reflects the distal vascular resistance and is used as an index for the presence and diffusion of cerebral small vessel diseases. The purpose of this study was to evaluate the risk factors affecting the basilar artery pulsatility index in ischemic stroke patients. From January 2014 to May 2015, 422 patients were selected by measuring the transcranial doppler pulsatility index, considering their basilar artery pulsatility index. Univariate analysis was performed using the basilar artery pulsatility index as a dependent variable. Multiple regression analysis was performed considering the factors affecting the pulsatility index as variables. Univariate analysis revealed age, presence of hypertension, presence of diabetes mellitus, presence of hyperlipidemia, and hematocrit (P<0.1) as factors. Multiple regression analysis showed statistically significant results with age (P<0.001), presence of diabetes (P=0.004), and presence of hyperlipidemia (P=0.041). The risk factors affecting the basilar artery pulsatility index of transcranial doppler were age, diabetes, and hyperlipidemia. Further research will be needed to increase the cerebral pulsatility index as a surrogate marker of the elderly, diabetes, and hyperlipidemia.

• Journal of the Korea Concrete Institute
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• v.25 no.4
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• pp.411-418
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• 2013

Recently, in order to reduce a damage of chloride attack and hydration heat in marine concrete structures, blended cement in mixing the marine concrete is widely used. Long term strength development is distinct in concrete with blended cement and it also has excellent resistance to chloride attack and reduction of hydration heat. However, blended cement has a characteristic of relatively low compressive strength in early age of 28 days. On the other hand, a high level of compressive strength is required in the Standard Specification for marine concrete mix design. Such concrete mix design satisfying Standard Specification is effective to chloride attack but disadvantageous for hydration heat reduction due to large quantity of binder. In this study, the material properties of marine concrete considering water-binder ratio and binder type are experimentally investigated. Through the research results, compressive strength in blended cement at the age of 56 days is similar although it has smaller compressive strength at the age of 28 days compared with result of OPC (ordinary portland cement). Even though blended cement has a large water-binder ratio and small unit of binder content, chloride ion diffusion coefficient is still small and hydration heat is also found to be reduced. For meeting the required compressive strength in Standard Specification for marine concrete at 28 days, the increased unit content of binder is needed but the increased hydration heat is also expected.