• Restorative Dentistry and Endodontics
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• v.38 no.3
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• pp.134-140
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• 2013

Objectives: There has been a growing interest in glass ceramic systems with good esthetics, high fracture resistance and bonding durability, and simplified fabrication techniques using CAD/CAM. The aim of this study is to compare flexural strength before and after heat treatment of two lithium disilicate CAD/CAM blocks, IPS e.max CAD (Ivoclar Vivadent) and Rosetta SM (Hass), and to observe their crystalline structures. Materials and Methods: Biaxial flexural strength was tested according to ISO 6872 with 20 disc form specimens sliced from each block before and after heat treatment. Also, the crystalline structures were observed using field-emission scanning microscopy (FE-SEM, Hitachi) and x-ray diffraction (XRD, Rigaku) analysis. The mean values of the biaxial flexural strength were analyzed by the Mann-Whitney U test at a significance level of p = 0.05. Results: There were no statistically significant differences in flexural strength between IPS e.max CAD and Rosetta SM either before heat treatment or after heat treatment. For both ceramics, the initial flexural strength greatly increased after heat treatment, with significant differences (p < 0.05). The FE-SEM images presented similar patterns of crystalline structure in the two ceramics. In the XRD analysis, they also had similar patterns, presenting high peak positions corresponding to the standard lithium metasilicate and lithium disilicate at each stage of heat treatment. Conclusions: IPS e.max CAD and Rosetta SM showed no significant differences in flexural strength. They had a similar crystalline pattern and molecular composition.

• Fashion & Textile Research Journal
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• v.23 no.5
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• pp.667-673
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• 2021

The purpose of this study was to obtain drape information and objective texture of fabrics easily and quickly by using a constructed fabric database. For the construction of the fabric database, 287 woven fabrics were examined by using the CLO fabric kit, KES-FB system, and drape test system. The k-means cluster analysis method was used to classify the fabrics into 7 grades. After correlation analysis of the fabric properties for each experiment, similar properties of the CLO fabric kit and KES-FB system were chosen, which were then designed to extract similar fabrics from the database. It was confirmed that inferring the drape information and objective hand feeling of fabrics was to some extent possible by extracting similar fabrics from the database. In this study, the primary hand and total hand value(THV) of KES-FB system, which was constructed by Kawabata and other experiments, were used to quantify the objective hand feeling, because they are the most widely used. However, these standards can be changed over time; in order to be applied within the clothing industry, these standards may have to be changed to some extent. Moreover, it is notable that although objective hand feeling cannot be expressed in the 3D virtual costume program, it can be easily derived from the constructed database. Additionally, it is expected that the existing 3D virtual costume program will express the costumes more realistically by improving these results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.9
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• pp.1104-1109
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• 2019

Business utilization of holograms is widely used as a similar hologram. The use of holograms has been proposed in many cases. In this paper, we present an outline of similar holograms using up to 3 or 4 facets, and express the similar holograms using the results produced by 3D modeling for a building from dealing with the representation of buildings from hololens to pseudo-hologram by using 3D modeling results. In addition, to reflect the real image of the disadvantage of modeling, we propose a method to enhance the 3D expression of the object by reflecting the actual building surface on the 3D model through photographing. Virtual building seen by the human eye can be virtually shown in space through a hologram among various methods shown in a virtual space such as AR / VR / MR. Through this study, it will be possible to express holograms of various materials such as buildings or cultural properties with enhanced realism.

• Food Science and Industry
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• v.49 no.4
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• pp.40-63
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• 2016

John Glenn, America's first man to eat anything in the near-weightless environment of Earth orbit, found the task of eating fairly easy. With improved packaging came improved food quality and menus. By the time of the Apollo Program, the quality and variety of food increased even further. Apollo astronauts were the first to have hot water, which made rehydrating foods easier and improved the food's taste. Thermostabilized pouches were also introduced on Apollo. The task of eating in space got a big boost in Skylab. It also had a food freezer and refrigerator a convenience offered by no other vehicle before or since. Two different food systems will be used for future long-duration missions to other planets, one for traveling to and from the distant body and one for use on the surface of the moon or Mars. The transit food system will be similar to the space station food system with the exception that products with three-to five-year shelf lives will be needed. Thus, this part of the trip will be similar to what occurs aboard space missions now. The surface food system, be it lunar or planetary, will be quite different. It will be similar to a vegetarian diet that someone could cook on Earth. Once crew members arrive on the surface and establish living quarters, they can start growing crops. Once the crops are processed into edible ingredients, cooking will be done in the spacecraft's galley to make the food items. Disposal of used food packaging will be an issue since there will be no Progress vehicles to send off and incinerate into the Earth's atmosphere. Packaging materials will be used that have less mass but sufficient barrier properties for oxygen and water to maintain shelf life as those now in use.

• The Korea Journal of Herbology
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• v.33 no.6
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• pp.1-8
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• 2018

Objectives : Herbal medicinal mixture (JMB) are consisted of Caryophylli Flos, Aucklandiae Radix and Angelicae Dahuricae Radix. Each of herbal medicines has studied on anti-oxidant effect. So this study was conducted to investigate efficacy and potency of JMB on anti-oxidation. Methods : The JMB was extracted at room temperature by 80% ethanol. And total polyphenol contents, total flavonoid contents in JMB ethanol extract were determined by colorimetric method. Also, DPPH, ABTS free radical scavenging capacity and reducing power of JMB ethanol extract were measured at 100, 500, 1000, $5000{\mu}g/m{\ell}$ concentrations by spectrometric assay. Positive control was used BHA (butylated hydroxyanisole). Results : The total polyphenol contents and total flavonoid contents of the extract were 55.38 mg/TAEg, 513.72 mg/RUEg, respectively. Also, DPPH free radical scavenging capacity and reducing power of JMB ethanol extract in treated concentrations (100, 500, 1000, $5000{\mu}g/m{\ell}$) increased dose dependently. In particular, DPPH free radical scavenging capacity of JMB ethanol extract at 500, 1000, $5000{\mu}g/m{\ell}$ was similar to positive control (BHA) at high concentration (50, $100{\mu}g/m{\ell}$). ABTS free radical scavenging capacity of JMB ethanol extract at 500, 1000, 5000 ug/ml was similar to BHA at high concentration (50, $100{\mu}g/m{\ell}$). Also, reducing power was showed that JMB ethanol extract at $5000{\mu}g/m{\ell}$ was similar to BHA at high concentration (50, $100{\mu}g/m{\ell}$). Conclusions : These results suggest that JMB ethanol extract has effects to scavenge free radicals. Therefore, JMB has potential and applicable benefits for development of materials and products to have anti-oxidation functions.

• Hip & pelvis
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• v.34 no.2
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• pp.96-105
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• 2022

Purpose: Use of dual mobility (DM) articulations can reduce the risk of instability in both primary and revision total hip arthroplasty (THA). Knowledge regarding the impact of this design on patient-reported outcome measures (PROMs) is limited. This study aims to compare clinical outcomes between DM and fixed bearing (FB) prostheses following primary THA. Materials and Methods: All patients who underwent primary THA between 2011-2021 were reviewed retrospectively. Patients were separated into three cohorts: FB vs monoblock-D vs modular-DM. An evaluation of PROMs including HOOS, JR, and FJS-12, as well as discharge-disposition, 90-day readmissions, and revisions rates was performed. Propensity-score matching was performed to limit significant demographic differences, while ANOVA and chi-squared test were used for comparison of outcomes. Results: Of the 15,184 patients identified, 14,652 patients (96.5%) had a FB, 185 patients (1.2%) had a monoblock-DM, and 347 patients (2.3%) had a modular-DM prosthesis. After propensity-score matching, a total of 447 patients were matched comparison. There was no statistical difference in the 90-day readmission (P=0.584), revision rate (P=0.265), and 90-day readmission (P=0.365) and revision rate due to dislocation (P=0.365) between the cohorts. Discharge disposition was also non-significant (P=0.124). There was no statistical difference in FJS-12 scores at 3-months (P=0.820), 1-year (P=0.982), and 2-years (P=0.608) between the groups. Conclusion: DM bearings yield PROMs similar to those of FB implants in patients undergoing primary THA. Although DM implants are utilized more often in patients at higher-risk for instability, we suggest that similar patient satisfaction may be attained while achieving similar dislocation rates.

• Journal of Gastric Cancer
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• v.24 no.4
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• pp.451-463
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• 2024

Purpose: Although laparoscopic distal gastrectomy has rapidly replaced open distal gastrectomy, laparoscopic total gastrectomy (LTG) is less frequently performed owing to technical difficulties. Robotic surgery could be an appropriate minimally invasive alternative to LTG because it alleviates the technical challenges posed by laparoscopic procedures. However, few studies have compared the oncological safety of robotic total gastrectomy (RTG) with that of LTG, especially for advanced gastric cancer (AGC). Herein, we aimed to assess the oncological outcomes of RTG for AGC and compare them with those of LTG. Materials and Methods: We retrospectively reviewed 147 and 204 patients who underwent RTG and LTG for AGC, respectively, between 2007 and 2020. Long-term outcomes were compared using inverse probability of treatment weighting (IPTW). Results: After IPTW, the 2 groups exhibited similar clinicopathological features. The 5-year overall survival was comparable between the 2 groups (88.5% [95% confidence interval {CI}, 79.4%-93.7%] after RTG and 87.3% [95% CI, 80.1%-92.0%]) after LTG; log-rank P=0.544). The hazard ratio (HR) for death after RTG compared with that after LTG was 0.73 (95% CI, 0.40-1.33; P=0.304). The 5-year relapse-free survival was also similar between the 2 groups (75.7% [95% CI, 65.2%-83.4%] after RTG and 76.4% [95% CI, 67.9%-83.0%] after LTG; log-rank P=0.850). The HR for recurrence after RTG compared with that after LTG was 0.93 (95% CI, 0.60-1.46; P=0.753). Conclusions: Our findings revealed that RTG and LTG for AGC had similar long-term outcomes. RTG is an oncologically safe alternative to LTG and has technical advantages.

• Journal of Periodontal and Implant Science
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• v.36 no.4
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• pp.797-808
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• 2006

Objective : The purpose of this study was to evaluate the physicochemical properties and cytocompatibility of microporous, spherical biphasic calcium phosphate(BCP) ceramics with a 60/40 $hydroxyapatite/{\beta}$ -tricalcium phosphate weight ratio for application as a bone graft substitute. Materials and Methods : Microporous, spherical BCP granules(MGSB) were prepared and their basic characteristics were compared with commercially available BCP(MBCP; Biomatlante, France) and deproteinized bovine bone mineral(Bio-Oss; GBistlich-Pharma, Switzerland, BBP; Oscotec. Korea), Their physicochemical properties were evaluated by scanning electron microscopy, X-ray diffractometry, Fourier-transform infrared spectroscopy, inductively coupled plasma atomic emission spectrometer, and Brunauer-Emmett-Teller method. Cell viability and proliferation of MC3T3-El cells on different graft materials were evaluated. Results : MGSB granules showed a chemical composition and crystallinity similar with those in MBCP, they showed surface structure characteristic of three dimensionally, well-interconnected micropores. The results of MTT assay showed increases in cell viablity with increasing incubation times. At 4d of incubation, MGSB, MBCP and BBP showed similar values in optical density, but Bio-Oss exhibited significantly lower optical density compared to other bone substitutes(p <0,05). MGSB showed significantly greater cell number compared to other bone substitutes at 3, 5, and 7d of incubation(p <0,05), which were similar with those in polystyrene culture plates. Conclusion: These results indicated the suitable physicochemical properties of MGSB granules for application as an effective bone graft substitute. which provided compatible environment for osteoblast cell growth. However, further detailed studies are needed to confirm its biological effects on bone formation in vivo.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.21-26
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• 2017

In this study, performance tests were conducted to investigate the applicability of a double-tube heat recovery ventilation system. Paper, aluminum, polymer, were investigated as materials for the inner tube using the same exhaust-air volume. In all cases, the temperature exchange efficiency of the aluminum tube was the highest, while the paper tube showed similar results to those of the polymer tube. This probably resulted from the differences in thermal conductivity and thicknesses of the materials. The humidity exchange efficiency was the highest for the paper tubes in all cases, while the aluminum tubes and polymer tubes showed similar results. The total heat exchange efficiency, which includes the values of humidity exchange and temperature exchange, was highest in the case of the paper tube, and the aluminum tube and the polymer tube showed similar results. In the case of the paper tube, sensible heat and latent heat exchange occur at the same time, and the coefficient of energy of the aluminum tube and polymer tube are large values, when to be compared with only applicably sensible heat exchange coefficient of the aluminum tube and the polymer tube of total heat exchange efficiency value. The results of this study could be applied to the design of a ventilation system.

• Journal of Powder Materials
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• v.24 no.3
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• pp.195-201
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• 2017

In this study, H13 tool steel sculptures are built by a metal 3D printing process at various laser scan speeds. The properties of commercial H13 tool steel powders are confirmed for the metal 3D printing process used: powder bed fusion (PBF), which is a selective laser melting (SLM) process. Commercial H13 powder has an excellent flowability of 16.68 s/50 g with a Hausner ratio of 1.25 and a density of $7.68g/cm^3$. The sculptures are built with dimensions of $10{\times}10{\times}10mm^3$ in size using commercial H13 tool steel powder. The density measured by the Archimedes method is $7.64g/cm^3$, similar to the powder density of $7.68g/cm^3$. The hardness is measured by Rockwell hardness equipment 5 times to obtain a mean value of 54.28 HRC. The optimum process conditions in order to build the sculptures are a laser power of 90 W, a layer thickness of $25{\mu}m$, an overlap of 30%, and a laser scan speed of 200 mm/s.