• Journal of Korean Neurosurgical Society
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• v.62 no.1
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• pp.96-105
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• 2019

Objective : The aims in the management of thoracolumbar spinal fractures are not only to restore vertebral column stability, but also to obtain acceptable alignment of the thoracolumbar junction (T-L junction) to prevent complications. However, insufficient surgical correction of the thoracolumbar spine would be likely to cause late progression of abnormal kyphosis. Therefore, we identified the surgical factors that affected unfavorable radiologic outcomes of the thoracolumbar spine after surgery. Methods : This study was conducted in a single institution from January 2007 to December 2013. A total of 98 patients with unstable thoracolumbar spine fracture were included. In these patients, fixation was done through transpedicular screws with rods by three surgical patterns. We reviewed digital radiographs and analyzed the images preoperatively and postoperatively during follow-up visits to compare the change of the thoracolumbar Cobb angle with radiologic parameters and clinical outcomes. The unfavorable radiologic group was defined as the patients who were measured as having greater than 20 degrees of thoracolumbar Cobb angle on the last follow-up, or who underwent kyphotic progression of thoracolumbar Cobb angle greater than 10 degrees from the immediate postoperative state to final follow-up, or who had overt instrument failure with/without additional surgery. We assessed the risk factors that affected the unfavorable radiologic outcomes. Results : We had 43 patients with unfavorable radiologic outcomes, including 35 abnormal thoracolumbar alignments and 14 instrumental failures with/without additional surgery. The multivariate logistic regression test showed that immediate postoperative T-L junction Cobb angle less than 10.5 degrees was a statistically significant risk factor, as well as the presence of osteoporosis (p=0.017 and 0.049, respectively). Conclusion : Insufficient correction of thoracolumbar kyphosis was considered to be a major factor of an unfavorable radiological outcome. The spinal surgeon should consider that having a T-L junction Cobb angle larger than 10.5 degrees immediately after surgery could result in an unfavorable radiological outcome, which is related to a poor clinical outcome.

• Journal of the Korean Geotechnical Society
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• v.35 no.5
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• pp.21-30
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• 2019

While the study of the shallow tunnel has been mainly on the longitudinal load transfer and horizontal surface conditions, the study of the ground behavior of shallow tunnel under the slope is not sufficient. Therefore, in this study on the ground behavior around a tunnel due to the sidewall deformation of shallow tunnel under the slope that is excavated in longitudinal direction, a scale-down model test has been performed. The model tunnel has the dimension of 320 mm wide, 210 mm high and 55 mm long with enough material strength in aluminum and the model ground has the uniform ground conditions by 3 types of carbon rods. The model test has been performed with the variables of slopes and the cover depths by controlling the tunnel sidewall deformation, and the change of sidewall-load, load transfer, ground subsidence was monitored and analyzed. According to the increase of the slope, the maximum ground subsidence increased by 20~39% compared to the horizontal surface. The load ratio increased by maximum 20% in the tunnel crown and decreased in sidewall according to the surface slope. The load transfer shows maximum 128% of increase at the cover depth of 1.0D, while at the 1.5D cover depth it shows non-critical difference from horizontal surface. The slope has major effects on load transfer at the cover depth of 1.0D.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.101-110
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• 2019

The aim of this study was to evaluate and compare the microstructural properties and mineralization quality of mesiodens with permanent and primary central incisors. Fifteen mesiodens, permanent and primary central incisors were collected. The enamel rod diameter and enamel thickness were observed and measured using field emission scanning electron microscope (FE-SEM). Chemical composition of the enamel was analyzed using energy dispersive X-ray spectrometer (EDS). The measurements were then assessed using the one-way ANOVA and Tukey test. There was no statistically significant difference in the enamel rod diameter between mesiodens and permanent central incisors. However, enamel rods of primary central incisors were smaller than remaining two groups. The thickness of enamel was thick in order of permanent central incisors, mesiodens, primary central incisors. In the composition analysis using EDS, there was no difference in the Ca/P ratio and Ca/C ratio between mesiodens and permanent central incisors, but small in primary central incisors. In conclusion, the microstructural properties of mesiodens were more similar to those of permanent central incisors compared to primary central incisors. Futher, the mineralization quality of mesiodens did not differ significantly from that of permanent central incisors.

• Journal of the Korean Applied Science and Technology
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• v.39 no.5
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• pp.605-613
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• 2022

The genus Flavobacterium, type genus of the family Flavobacteriaceae and a member of the phylum Bacteriodetes includes gram-negative and yellow-pigmented rods. Those bacteria have been isolated from various environments of the earth. A yellow-pigmented, gram-negative rod was isolated from a pond in the campus of the Changwon University, Changwon, Kyeongnam and designated as strain B1. Strain B1 was further analyzed physiologically, biochemically and phylogenetically, and concluded to be a member of genus Flavobacterium. BLAST search of the 16S rRNA gene sequence of strain B1 shows homology no higher than 99.0% with those sequences of other bacteria. The major fatty acids of strain B1 are iso-C_15:0 (19.6%), summed feature 3(C_16:1 ω7c and/or C_16:1 ω6c, 16.1%), iso-C_17:0 3OH(10.2%), iso-C_15:0 3OH(8.4%) and iso-C_15:1 G(6.6%) showing significant differences in fatty acid compositions between strain B1 and the other known Flavobacterium species. DNA sequence of 16S rRNA gene of strain B1 was deposited in genbank under accession number OP060681.

• Journal of Space Technology and Applications
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• v.2 no.1
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• pp.41-51
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• 2022

CubeSat is a satellite platform that is widely used not only for earth observation but also for space exploration. CubeSat is also used in magnetic field investigation missions to observe space physics phenomena with various shape configurations of magnetometer instrument unit. In case of magnetic field measurement, the magnetometer instrument should be far away from the satellite body to minimize the magnetic disturbances from satellites. But the accommodation setting of the magnetometer instrument is limited due to the volume constraint of small satellites like a CubeSat. In this paper, we investigated that the magnetic field interference generated by the cube satellite was analyzed how much it can affect the reliability of magnetic field measurement. For this analysis, we used a reaction wheel and Torque rods which have relatively high-power consumption as major noise sources. The magnetic dipole moment of these parts was derived by the data sheet of the manufacturer. We have been confirmed that the effect of the residual moment of the magnetic torque located in the middle of the 3U cube satellite can reach 36,000 nT from the outermost end of the body of the CubeSat in a space without an external magnetic field. In the case of accurate magnetic field measurements of less than 1 nT, we found that the magnetometer should be at least 0.6 m away from the CubeSat body. We expect that this analysis method will be an important role of a magnetic cleanliness analysis when designing a CubeSat to carry out a magnetic field measurement.

• Science of Emotion and Sensibility
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• v.25 no.1
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• pp.115-128
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• 2022

This study investigates the effect of wrist guards equipped with electronic muscle stimulation on reducing wrist pain and improving wrist function of actual lure fishing participants. This study combined conductive fabrics by selecting two products of wrist guards that can be used in lure fishing, which requires holding fishing rods with hands for a long time. It was conducted on ten healthy men aged 35 to 45, and the selection conditions were selected for those who did not have a history of surgery on the wrist and are currently enjoying lure fishing as a hobby. The experimental movement was performed 100 times before each experiment to cause delayed muscle pain to cause wrist fatigue when lure fishing was performed with the operation of grip strength and range of motion. As a result of this study, it was found that pain reduction, range of motion, and grip strength were improved when electrical stimulation was applied after wearing a wrist band in the form of a wrist wrap and semi-gloves. The conclusion of this study was that when electrical stimulation was applied to the wrist guards, the effect of improving the fatigue and function of the wrist could be confirmed through experiments. Through this study, it is expected that wearing electronic muscle stimulation wrist guards will have a significant effect on preventing wrist injuries and improving functional recovery for lure fishing participants.

• Journal of Microbiology and Biotechnology
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• v.33 no.7
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• pp.909-914
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• 2023

While searching for the bacteria which are responsible for degradation of pesticide in soybean field soil, a novel bacterial strain, designated 5-5^T, was isolated. The cells of the strain were Gram-staining-positive, aerobic and non-motile rods. Growth occurred at 10-42℃ (optimum, 30℃), pH 5.5-9.0 (optimum, pH 7.0-7.5), and 0-2% (w/v) NaCl (optimum, 1%). The predominant fatty acids were C_15:0 anteiso, C_17:0 anteiso, and summed feature 8 (C_18:1 ω7c and/or C_18:1 ω6c). The predominant menaquinone was MK-9 (H₂). Diphosphatidylglycerol, glycolipids, phosphatidylinositol, and phosphatidylglycerol were the major polar lipids. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain 5-5^T is a member of the genus Sinomonas and its closest relative is Sinomonas humi MUSC 117^T, sharing a genetic similarity of 98.4%. The draft genome of strain 5-5^T was 4,727,205 bp long with an N50 contig of 4,464,284 bp. Genomic DNA G+C content of strain 5-5^T was68.0 mol%. The average nucleotide identity (ANI) values between strain 5-5^T and its closest strains S. humi MUSC 117^T and S. susongensis A31^T were 87.0, and 84.3 % respectively. In silico DNA-DNA hybridization values between strain 5-5^T and its closest strains S. humi MUSC 117^T and S. susongensis A31^T were 32.5% and 27.9% respectively. Based on the ANI and in silico DNA-DNA hybridization analyses, the 5-5^T strain was considered as novel species belonging to the genus Sinomonas. On the basis of the results from phenotypic, genotypic and chemotaxonomic analyses, strain 5-5^T represents a novel speciesof the genus Sinomonas, for which the name Sinomonas terrae sp. nov. is proposed. The type strain is 5-5^T (=KCTC 49650^T =NBRC 115790^T).

• Nuclear Engineering and Technology
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• v.23 no.1
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• pp.66-80
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• 1991

The LOFT intermediate break experiment L5-1, which simulates 12 inch diameter ECC line break in a typical PWR, has been analyzed using the reactor thermal/hydraulic analysis code RELAP5/MOD2, Cycle 36.04. The base calculation, which modeled the core with single flow channel and two heat structures without using the options of reflood and gap conductance model, has been successfully completed and compared with experimental data. Sensitivity studies were carried out to investigate the effects of nodalization at reactor vessel and core modeling on major thermal hydraulic parameters, especially on peak cladding temperature(PCT). These sensitivity items are : single flow channel and single heat structure (Case A), two flow channel and two heat structures (Case B), reflood option added (Case C) and both reflood and gap conductance options added (Case D). The code, RELAP5/MOD2 Cycle 36.04 with the base modeling, predicted the key parameters of LOFT IBLOCA Test L5-1 better than Cases A,B,C and D. Thus, it is concluded that the single flow channel modeling for core is better than the two flow channel modeling and two heat structure is also better than single heat structure modeling to predict PCT at the central fuel rods. It is, therefore, recommended to use the reflood option and not to use gap conductance option for this L5-1 type IBLOCA.

• Nuclear Engineering and Technology
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• v.25 no.1
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• pp.91-101
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• 1993

To predict accurately the thermal hydraulic behavior of light water reactors during normal or abnormal operation, the accurate estimation of the void distribution is required. Up to date, many techniques for predicting void fraction of two-phase flow systems have been suggested. Among these techniques, the drift-flux model is widely used because of its exact calculation ability and simplicity. However, to get more accurate prediction of void fraction using drift-flux model, slip and flow regime effects must be considered more properly In the drift-flux method, these two effects are accounted for by two drift-flux parameters ; $C_{o}$ and (equation omitted). At earlier stage, $C_{o}$ is measured in a circular tube. In this study, $C_{o}$ is experimentally determined by measuring local void fraction and vapor velocity distribution in a rectangular subchannel having 4 heating rods which simulates nuclear subchannels. The measurements are peformed with two-electrical conductivity probes which are known to be adequate for measuring local parameters. The experiments are performed at low flow rate and the system pressure less than 3 atmo spheric pressure. In this experiment, (equation omitted), is not measured, but quoted from well-known empirical correlation to formulate $C_{o}$. Finally, $C_{o}$ is expressed as a function of channel averaged void fraction. fraction.

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.2
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• pp.193-200
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• 2010

Due to the characteristic of culvert structure, the standard section of the culvert has been established and applied in field. However, this becomes a limitation in selecting a section design corresponding to various field conditions although it can improve the design and applicability of culvert structure. In order to overcome this limitation, we have developed the design and application technology of culvert structure corresponding to the field conditions that various shapes of culvert structure can be covered by assembly of precast segments. Because the structural characteristics of assembling-type waterway culvert structure, the thickness of structure and amount of reinforcing rods can vary according to the fixation or internal hinge status in the connection part of precast segments. This has a strong influence on the applicability and economic efficiency of culvert structure. Accordingly, in order to suggest a reasonable modeling technique of segment connection parts, this study has conducted the field experiment and numerical analysis. According to the results of field experiment and numerical analysis, the slab, wall and base slab with mortar splice sleeves have shown that the assembling-type of waterway culvert structure behaves like an integrated structure.