• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.268-274
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• 2023

In this case, a CAD-CAM complete denture that can be easily remanufactured and reduced the number of visits was decided in consideration of the fact that it was difficult to visit the dental hospital and many existing dentures were lost because the patient was inpatient in a nursing hospital. In order to reflect the shape, vertical dimension, and maxillomandibular relationship of the existing provisional dentures adapted by the patient to the fabrication of the final denture, the existing provisional dentures were scanned and closed mouth impression was taken with the printed individual tray. After digital facebow transfer using UTS CAD and arranging artificial teeth in CAD software, the maxillary and mandibular complete dentures were fabricated by milling the denture base and artificial teeth at once with the monolithic disc.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.3
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• pp.374-381
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• 2013

The purpose of this study was to analyze the antioxidant effects and antimicrobial activity of extracts from yacon powder. The total polyphenol contents of yacon powder extracted with methanol was 38.5 mg/g, while extracted with water was 24.0 mg/g. Extractions with methanol were therefore more effective than with water. The total flavonoid contents of yacon powder extracted with methanol was 9.2 mg/g, while that with water was 7.8 mg/g. The electron donating ability of yacon powder extracts, natural antioxidant, and artificial antioxidant at 1.0 mg/mL arranged in order of decreasing concentration were ascorbic acid (98.7%) > BHT (44.7%) > methanol extract (12.1%) > water extract (7.8%). Nitrite-scavenging ability of yacon powder extracted with methanol at pH 1.2 was 13.1%, while that of powder extracted with water at pH 1.2 was 6.8%. And, the hydroxyl radical scavenging activities of yacon powder with methanol at 5 mg/mL was 40.2%. The antimicrobial activity of yacon powder extracted with methanol could be detected on Bacillus cereus ($10,000{\mu}g/disc$) and Staphylococcus aureus ($10,000{\mu}g/disc$).

• Journal of the East Asian Society of Dietary Life
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• v.22 no.3
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• pp.392-400
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• 2012

The purpose of this study was to analyze the physiological activity and antibiosis of mulberry powder by extract method. The total phenol content of mulberry powder extracted with methanol was 82.9 mg/g, while that of powder extracted with water was 46.9 mg/g. Extractions with methanol were therefore more effective than with water. The total flavonoid contents of mulberry powder extracted with methanol was 13.0 mg/g, while that of powder extracted with water was 9.4 mg/g. Also, the nitrite-scavenging ability of mulberry powder was lower than ascorbic acid and BHT. The SOD-like activity of mulberry powder extracts, natural antioxidant, and artificial antioxidant at 5 mg/mL arranged in order of decreasing concentration were ascorbic acid (98.3%) > BHT (88.1%) > water extract (9.8%) > methanol extract (3.0%). And, the OH radical scavenging activities of mulberry powder extracts and natural antioxidant at 5 mg/mL in order of decreasing concentration was ascorbic acid (97.0%) > methanol extract (46.2%) > water extract (35.8%). The antimicrobial effects of mulberry powder extracted with methanol could be detected on Bacillus cereus ($10,000{\mu}g/disc$) and Staphylococcus aureus ($10,000{\mu}g/disc$).

• Journal of Korean Neurosurgical Society
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• v.60 no.6
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• pp.676-683
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• 2017

Objective : The purpose of this study is to evaluate the efficacy and safety of 3-level hybrid surgery (HS), which combines fusion and cervical disc replacement (CDR), compared to 3-level fusionin patient with cervical spondylosis involving 3 levels. Methods : Patients in the anterior cervical discectomy and fusion (ACDF) group (n=30) underwent 3-level fusion and the HS group (n=19) underwent combined surgery with fusion and CDR. Clinical outcomes were evaluated using the visual analogue scale for the arm, the neck disability index (NDI), Odom criteria and postoperative complications. The cervical range of motion (ROM), fusion rate and adjacent segments degeneration were assessed with radiographs. Results : Significant improvements in arm pain relief and functional outcome were observed in ACDF and HS group. The NDI in the HS group showed better improvement 6 months after surgery than that of the ACDF group. The ACDF group had a lower fusion rate, higher incidence of device related complications and radiological changes in adjacent segments compared with the HS group. The better recovery of cervical ROM was observed in HS group. However, that of the ACDF group was significantly decreased and did not recover. Conclusion : The HS group was better than the ACDF group in terms of NDI, cervical ROM, fusion rate, incidence of postoperative complications and adjacent segment degeneration.

• Journal of Korean Neurosurgical Society
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• v.46 no.2
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• pp.144-151
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• 2009

Objective: To compare two testing protocols for evaluating range of motion (ROM) changes in the preloaded cadaveric spines implanted with a mobile core type Charite$^{TM}$ lumbar artificial disc. Methods: Using five human cadaveric lumbosacral spines (L2-S2), baseline ROMs were measured with a bending moment of 8 Nm for all motion modes (flexion/extension, lateral bending, and axial rotation) in intact spine. The ROM was tracked using a video-based motion-capturing system. After the Charite$^{TM}$ disc was implanted at the L4-L5 level, the measurement was repeated using two different methods: 1) loading up to 8 Nm with the compressive follower preload as in testing the intact spine (Load control protocol), 2) loading in displacement control until the total ROM of L2-S2 matches that when the intact spine was loaded under load control (Hybrid protocol). The comparison between the data of each protocol was performed. Results: The ROMs of the L4-L5 arthroplasty level were increased in all test modalities (p < 0.05 in bending and rotation) under both load and hybrid protocols. At the adjacent segments, the ROMs were increased in all modes except flexion under load control protocol. Under hybrid protocol, the adjacent segments demonstrated decreased ROMs in all modalities except extension at the inferior segment. Statistical significance between load and hybrid protocols was observed during bending and rotation at the operative and adjacent levels (p< 0.05). Conclusion: In hybrid protocol, the Charite$^{TM}$ disc provided a relatively better restoration of ROM, than in the load control protocol, reproducing clinical observations in terms of motion following surgery.

• Journal of the Korean Ceramic Society
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• v.40 no.9
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• pp.881-885
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• 2003

Wear and friction properties of the alumina-glass dental ceramics were evaluated in exact in vitro environment (artificial saliva at 37$^{\circ}C$), using a ball-on-disc apparatus, at contact loads from 49 N to 196 N and with the disc rotating at 120 rpm up to 10$^{6}$ cycles to investigate the wear behavior. As the load increased from 49 N to 196 N, the friction coefficient of 0.025 was maintained, however, the volumetric wear rate rose from 2.18 ${\times}$10$^{-9}$TEX>$mm^{3}$/Nㆍm to 2.35 ${\times}$10$^{-6}$TEX>$mm^{3}$/Nㆍm. Experimental results indicated that the wear behavior of the alumina-glass composites with a sliding distance of 4.4 km was a typical adhesive wear, which was applicable for orthodontia ceramic brackets.

• Korean Journal of Agricultural Science
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• v.5 no.2
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• pp.149-157
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• 1978

This study was carried out to obtain basic data for the type selection of furrow openers for the no-tillage soybean planter trailed by the two-wheel tractor from the standpoint of minimum draft and good performance of furrowing. For this study, two models of furrow opener, hoe and disc type, were tested on the artificial soil stuffed in the moving soil bin. The results obtained were as follows. In the case of disc furrow opener, the drafts were measured according to various diameters of discs under the condition of disc angle $8^{\circ}$ and $16^{\circ}$, working depth 3cm and 6cm, working speed 2.75cm/sec. Minimum draft appeared when the diameter of disc was about 28cm and the drafts increased as the diameter of discs became larger or smaller than this diameter. Specific draft showed almost same tendencies as above but showed the minimum when the diameter was about 30cm. For the purpose of controlling the seeding depth, the relationships between draft and working depths, 3cm and 6cm, were tested. The variations of draft concerning the various working depths showed linear changes and were affected in higher degree by depths than other factors. There were general tendencies at both working depths, 3cm and 6cm, that total draft showed the minimum with the disc diameter of about 28cm and specific draft showed it with the disc diameter of about 30cm regardless of disc angle and working speed. For the purpose of controlling the working width and speed, the relationships among drafts, disc angle and working speed were investigated and there were general tendencies that the draft increased as the angle and speed were increased and the draft was affected more by speed than by angle. To compare the hoe-type with disc-type opener, the specific drafts of hoe openers were compared with those of disc opener of $16^{\circ}$ angle and 30cm diameter. The specific draft of disc-type opener with the diameter of 30cm was $0.35{\sim}0.5kg/cm^2$, while $0.71{\sim}1.02kg/cm^2$ in the case of hoe type with the lift angle of $20^{\circ}$ which is 2 times as much as that of disc type in average value. And the furrows opened by disc openers were cleaner than those opened by hoe openers.

• Development and Reproduction
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• v.17 no.3
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• pp.247-255
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• 2013

The gonadsomatic index (GSI) of mottled skate was the highest in April, GSI and HSI showed a reverse phase for its reproductive cycle. The fish had one pair of egg capsules, having 1 to 7 fertilized eggs, and spawned all the year round. When surveying the reproductive characteristics of females over 63 cm in disc width, we found the spawning peak was between April to June, and the appearance ratio of egg capsules was the highest in May (32.1%). The eggs were hatched at $8^{\circ}C$, $13^{\circ}C$, $18^{\circ}C$, water temperature (12.8 to $24.2^{\circ}C$), and the best hatching temperature was $18^{\circ}C$. The number of fish hatched was 4 to 5 fish/egg capsules, and the hatching rate was 100%. The sex ratios of hatching larvae were 45.5% female and 54.5% male. Therefore this study will provide fundamental data and information for artificial reproduction of the mottled skate.

• Steel and Composite Structures
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• v.47 no.2
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• pp.167-184
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• 2023

In this study, a new recentering friction device (RFD) to retrofit steel moment frame structures is introduced. The device provides both self-centering and energy dissipation capabilities for the retrofitted structure. A hybrid performance-based seismic design procedure considering multiple limit states is proposed for designing the device and the retrofitted structure. The design of the RFD is achieved by modifying the conventional performance-based seismic design (PBSD) procedure using computational intelligence techniques, namely, genetic algorithm (GA) and artificial neural network (ANN). Numerous nonlinear time-history response analyses (NLTHAs) are conducted on multi-degree of freedom (MDOF) and single-degree of freedom (SDOF) systems to train and validate the ANN to achieve high prediction accuracy. The proposed procedure and the new RFD are assessed using 2D and 3D models globally and locally. Globally, the effectiveness of the proposed device is assessed by conducting NLTHAs to check the maximum inter-story drift ratio (MIDR). Seismic fragilities of the retrofitted models are investigated by constructing fragility curves of the models for different limit states. After that, seismic life cycle cost (LCC) is estimated for the models with and without the retrofit. Locally, the stress concentration at the contact point of the RFD and the existing steel frame is checked being within acceptable limits using finite element modeling (FEM). The RFD showed its effectiveness in minimizing MIDR and eliminating residual drift for low to mid-rise steel frames models tested. GA and ANN proved to be crucial integrated parts in the modified PBSD to achieve the required seismic performance at different limit states with reasonable computational cost. ANN showed a very high prediction accuracy for transformation between MDOF and SDOF systems. Also, the proposed retrofit showed its efficiency in enhancing the seismic fragility and reducing the LCC significantly compared to the un-retrofitted models.

• Journal of the Korean Society for Nondestructive Testing
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• v.8 no.1
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• pp.6-11
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• 1988

The comparison and analysis of flaw detectability, flaw sizing methods and allowable criteria in accordance with the applicable codes, ASME and RCC-M Code, in ultrasonic examination of pressure vessel in nuclear power plants were studied. Accordding to the codes, calibration blocks were made. The artificial flaws such as disc and band types in test specimens were machined. They were detected and evaluated with etch code requirements and measured values were compared with the actual flaws.