• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.315-322
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• 2019

In this study, the contents of ${\beta}$-carotene and cholesterol were evaluated in various types of agricultural and processed foods (vegetables, legume products, dairy products, and eggs). Certified reference material (CRM) with an assigned value was used for the validation of the ${\beta}$-carotene and cholesterol analytical methods. High recoveries (accuracy) of ${\beta}$-carotene (96%) and cholesterol (97%) were obtained from the quantitative analysis of the CRM, with a relative standard deviation (%) of 1.86 and 3.35% for the ${\beta}$-carotene and cholesterol, respectively. Vegetables contained relatively high concentrations of ${\beta}$-carotene (raw Toona sinensis, $1650.97{\mu}g/100g$, a raw small onion, $879.09{\mu}g/100g$, and a raw lettuce stem, $591.89{\mu}g/100g$). The ${\beta}$-carotene values in dried chickpeas ($22.94{\mu}g/100g$) and dried brown lentils ($21.98{\mu}g/100g$) were similar. The highest ${\beta}$-carotene value among the analyzed dairy products was found in banana milk ($234.21{\mu}g/100g$) while other flavored products (strawberry milk and chocolate milk) did not contain any ${\beta}$-carotene. Furthermore, ${\beta}$-carotene was not detected in goat milk and high calcium milk in this study. With regard to cholesterol among the analyzed samples, the highest cholesterol value was found in egg yolk (629.30 mg/100 g), and cooking methods (boiling and frying) had little effect on the cholesterol levels of eggs. In addition, the cholesterol content in vanilla ice cream was 28.77 mg/100 g which was the highest value among the analyzed dairy products.

• Journal of the Semiconductor & Display Technology
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• v.18 no.1
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• pp.10-14
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• 2019

In this study, we synthesized two $Y_3Al_5O_{12}:Ce^{3+}$ phosphors ($7{\mu}m$-sized and $2{\mu}m$-sized YAG) with different sizes by controlling particles sizes of starting materials of the phosphors for white LED. In the smaller one ($2{\mu}m$-sized YAG), its photoluminescence intensity in the reflective mode was 63 % that of the bigger one ($7{\mu}m$-sized YAG); the quantum efficiencies were 93 % and 70 % for the smaller and the bigger ones. Two kinds of white LED packages with the same color coordinates were fabricated with a blue package (chip size $53{\times}30$) and two phosphors. The luminous flux of the white LED package with the smaller YAG phosphor was 92 % of that with the bigger one, indicating that the quantum efficiency of phosphor dispersed inside LED package was higher than that of the pure powder. It was consistently confirmed by the optical simulation (LightTools 6.3). It is notable according to the optical simulation that the white LED with the smaller phosphor showed 24 % higher luminous efficiency. If the smaller one had the same quantum efficiency as the bigger one (~93 %). Therefore, it can be suggested that the higher luminous efficiency of white LED can be possible by reducing the particle size of the phosphor along with maintaining its similar quantum efficiency.

• Kosin Medical Journal
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• v.33 no.3
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• pp.318-327
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• 2018

Objectives: To investigate the effect of absorbable suture on surgically-induced corneal astigmatism in 3.0-mm sclera tunnel cataract surgeries. Methods: Medical records of patients who underwent phacoemulsification cataract surgery using a 3.0-mm sclera tunnel incision made by a single surgeon were reviewed. Uncorrected distant visual acuity, corneal astigmatism and surgically-induced astigmatism were measured in 56 patients' eyes that underwent sclera tunnel cataract surgery with absorbable sutures (sutured group) and in 23 patients' eyes without sutures (unsutured group). Uncorrected visual acuity, intraocular pressure, slit lamp examination, and automated keratometry were evaluated preoperatively and at 3 days, 2 weeks, 4 weeks, and 8 weeks after cataract operation. Results: There were no significant differences in preoperative average uncorrected distant visual acuity of the two groups (sutured group: $0.79{\pm}0.64$, unsutured group: $0.68{\pm}0.72$, P = 0.145). Corneal astigmatism measured using keratometry in the sutured and unsutured group at postoperative day 3 were $2.27{\pm}2.12D$ versus $0.83{\pm}0.55D$ at (P < 0.001), a difference which had disappeared after 4 weeks. Surgically induced astigmatism using the Holladay and Vector methods showed similar outcomes, suggesting that the sutured group exhibited higher astigmatism compared with the unsutured group until 2 weeks post-surgery. Conclusions: TPatients undergoing scleral tunnel cataract surgery with absorbable sutures have greater surgically induced astigmatism, especially in the early postoperative period, compared with those without sutures. However, this surgically induced astigmatism due to absorbable sutures in scleral tunnel cataract surgery is temporary and disappears at 4 weeks post-surgery.

• ETRI Journal
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• v.43 no.5
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• pp.909-915
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• 2021

GaAs on Si grown via metalorganic chemical vapor deposition is demonstrated using various Si substrate thicknesses and three types of dislocation filter layers (DFLs). The bowing was used to measure wafer-scale characteristics. The surface morphology and electron channeling contrast imaging (ECCI) were used to analyze the material quality of GaAs films. Only 3-㎛ bowing was observed using the 725-㎛-thick Si substrate. The bowing shows similar levels among the samples with DFLs, indicating that the Si substrate thickness mostly determines the bowing. According to the surface morphology and ECCI results, the compressive strained indium gallium arsenide/GaAs DFLs show an atomically flat surface with a root mean square value of 1.288 nm and minimum threading dislocation density (TDD) value of 2.4×10⁷ cm^-2. For lattice-matched DFLs, the indium gallium phosphide/GaAs DFLs are more effective in reducing the TDD than aluminum gallium arsenide/GaAs DFLs. Finally, we found that the strained DFLs can block propagate TDD effectively. The strained DFLs on the 725-㎛-thick Si substrate can be used for the large-scale integration of GaAs on Si with less bowing and low TDD.

• Journal of Digital Convergence
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• v.19 no.8
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• pp.43-48
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• 2021

There are prior studies that describe in detail the classification and shape of 26 species of Korean flounder, but it is difficult to make them out and they are used interchangeably or misused. It is intended to present the taxonomic standards of Pleuronichthys cornutus and Pleuronichthys japonicus and use them as tourism education materials using aquatic resources. Morphological comparison was made through counting and measurement. The two fish species were generally flattened in an oval shape with a low body height and a wide body width, and the anal fin developed and sized similar to the dorsal fin, and the caudal fin was widely spread out. Among the hyoid bones, in three parts of the coccyx, the main part, the ischial part, and the cardinal process, there were differences in the degree of curvature, the open angle, and the shape of the ischial part and the lateral process, which corresponded to the representative classification characteristics. In addition, it will be expected that it will serve as a basis as a fishery and marine education material for marine tourism that classifies and categorizes the characteristics as a genus of flounder and categorizes the characteristics, and reduces misuse of scientific names and names in the future.

• The Journal of the Korea Contents Association
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• v.21 no.10
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• pp.476-493
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• 2021

This study is on the simulation conditions of the tentative 'mobilization simulation mode'(MOBSM) and the setting option of major simulation elements. The MOBSM is a training module that practices mobilization of various institutions through a simulation computer similar to actual situations. So far, mobilization exercise(Mob-Ex) is a message simulation method, so it is necessary to convert into a MOBSM because many problems such as fragmentary and practice only by some institutions are raised. Therefore, the theoretical background and previous studies on Mob-Ex and simulation were reviewed to derive the requirements and simulated elements of the MOBSM to meet the purpose of government level exercise and to suggest the critical concepts and the direction of application. The basic requirement is to simulate the main mobilization practices by institution and provide information on the mobilization execution in a nationwide scope. The simulation elements are simulated events and flow charts by mobilization type, simulated range and level by object, simulated contents of material mobilization by institution, key simulated items, DB application, and simulated period, etc. This study will be useful for policy establishment and follow-up research for technology development of MOBSM in the future, and will accelerate the transition to practical mobilization exercise by MOBSM.

• The Journal of Advanced Prosthodontics
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• v.12 no.6
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• pp.369-375
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• 2020

PURPOSE. This study evaluated the availability of multi-directionally forged (MDF) titanium (Ti) as a component of removable partial dentures (RPDs). MDF-Ti remarkably improved the mechanical properties of RPDs due to its ultrafine-grained structure. MATERIALS AND METHODS. The wear resistance, plaque adhesion, and machinability of MDF-Ti were tested. As controls, commercially pure (CP) titanium was used for wear, plaque adhesion, and machinability tests. For wear resistance, the volume losses of the titanium teeth before and after wear tests were evaluated. Plaque adhesion was evaluated by the assay of Streptococcus mutans. In the machinability test, samples were cut and ground by a steel fissure bur and carborundum (SiC) point. An unpaired t-test was employed for the analysis of the significant differences between MDF-Ti and the control in the results for each test. RESULTS. Wear resistance and plaque adherence of MDF-Ti similar to those of CP-Ti (P>.05) were indicated. MDF-Ti exhibited significantly larger volume loss than CP-Ti in all conditions except 100/30,000 g/rpm in machinability tests (P<.05). CONCLUSION. Although the wear resistance and plaque adherence of MDF-Ti were comparable to those of controls, MDF-Ti showed better machinability than did CP-Ti. MDF-Ti could be used as a framework material for RPDs.

• The Journal of Advanced Prosthodontics
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• v.12 no.6
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• pp.329-337
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• 2020

PURPOSE. To verify the influence of computer-aided design/computer-aided manufacturing (CAD/CAM) implant-supported prostheses manufactured with cobalt-chromium (Co-Cr) and zirconia (Zr), and whether ceramic application, spark erosion, and simulation of masticatory cycles modify biomechanical parameters (marginal fit, screw-loosening torque, and strain) on the implant-supported system. MATERIALS AND METHODS. Ten full-arch fixed frameworks were manufactured by a CAD/CAM milling system with Co-Cr and Zr (n=5/group). The marginal fit between the abutment and frameworks was measured as stated by single-screw test. Screw-loosening torque evaluated screw stability, and strain analysis was explored on the implant-supported system. All analyses were performed at 3 distinct times: after framework manufacturing; after ceramic application in both materials' frameworks; and after the spark erosion in Co-Cr frameworks. Afterward, stability analysis was re-evaluated after 106 mechanical cycles (2 Hz/150-N) for both materials. Statistical analyses were performed by Kruskal-Wallis and Dunn tests (α=.05). RESULTS. No difference between the two materials was found for marginal fit, screwloosening torque, and strain after framework manufacturing (P>.05). Ceramic application did not affect the variables (P>.05). Spark erosion optimized marginal fit and strain medians for Co-Cr frameworks (P<.05). Screw-loosening torque was significantly reduced by masticatory simulation (P<.05) regardless of the framework materials. CONCLUSION. Co-Cr and Zr frameworks presented similar biomechanical behavior. Ceramic application had no effect on the biomechanical behavior of either material. Spark erosion was an effective technique to improve Co-Cr biomechanical behavior on the implant-supported system. Screw-loosening torque was reduced for both materials after masticatory simulation.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.7
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• pp.81-88
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• 2019

The purpose of this study is to investigate the relations between brick and stone brick pagodas in all classes of pagoda with their construction and shape. Research objects of this study are brick and stone brick pagodas of National Treasure and Treasure and masonry pagodas that are similar to brick and stone brick pagoda. This study includes checking preceding researches, drawing questions from these preceding researches, and finding answers from these questions. The results of this study are as follows. First, pagoda of Bunhwangsa Temple, the first pagoda in the Silla Dynasty, was built as a masonry pagoda, not a stone brick pagoda. Second, roofs of stone brick pagoda barrows from brick pagoda's techniques for performance of material and ease construction. Third, brick or stone brick pagodas' base have Type II that has low and extensive foundation with soil and stones usually. Forth, Korean pagodas are categorized by their materials, construction methods, and shapes. Wooden pagodas, stone pagodas, and brick pagodas are categorized by materials, post-and lintel pagodas and masonry stone pagodas are categorized by construction methods, and pitched roof pagodas and terraced roof pagodas are categorized by shapes. Fifth, masonry pagodas of Buddhism that have shape of multi-story building were developed from Doltap, traditional stone stack, and they advanced with brick pagodas and stone pagodas to terraced roof stone pagodas and post-and lintel base brick pagodas.

• Journal of Technologic Dentistry
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• v.43 no.2
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• pp.42-47
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• 2021

Purpose: The purpose of this study was to evaluate the stability of abutment screws used with the zirconia fixture-based implant system and compare them with those used with the existing titanium fixture system via the finite element method. Methods: A single implant-supported restoration was designed for the finite element analysis. A universal analysis program was used to set 8 occlusal points along the direction to the long axis of the implant, and an occlusal load of 700 N was applied. Results: In all models (Zir and Ti-fixture model), the screw threads presented with the highest von Mises stress (VMS) values, whereas the head and end presented with the lowest VMS values. The VMS of the screw used in the zirconia-fixture model was 5.97% lower than that used in the titanium-fixture model (261.258 vs. 276.911 MPa, respectively) despite statistical significance. Furthermore, the zirconia fixture (352.912 MPa) had a higher stress value (8.42%) than the titanium fixture (332.331 MPa). In a completely tightened titanium fixture implant system, the stress was concentrated in the implant-abutment connection interface, the zirconia fixture presented with a stable stress distribution. Conclusion: Although the zirconia fixture demonstrated a high VMS value, owing to the stiffness and elasticity coefficients of the material, the stress generated in the abutment screws was similar in all models. In conclusion, the zirconia fixture-based implant system presented with a more stable stress distribution in the abutment screws than the titanium fixture-based implant system.