• KNOM Review
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• v.22 no.2
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• pp.22-28
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• 2019

A Science DeMilitarized Zone (DMZ) is an optimized network technology tailored to research data nature. The Science DMZ guarantees end-to-end network performance by forming a closed research network without redundant networking and security devices for the authorized researchers. Data Transfer Node (DTN) is an essential component for the high performance and security of the Science DMZ, since only transfer functions of research data are allowed to the DTN without any security- and performance-threatening functions such as commercial internet service. Current Science DMZ requires per-user DTN server installation which turns out a scalability limitation of the networks in terms of management overhead, entry barrier of the user, and networks-wise CAPEX. In order to relax the aforementioned scalability issues, this paper suggests a centralized DTN design where end users in a group can share the centralized DTN. We evaluate the effectiveness of the suggested sharable DTN design by comparing CAPEX against to that of current design with respect to the diverse network load and the state-of-the-art computing machine.

• Journal of the korean academy of Pediatric Dentistry
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• v.51 no.3
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• pp.290-298
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• 2024

This study aimed to evaluate the antibacterial efficacy of erythrosine-mediated photodynamic therapy (PDT) against Streptococcus mutans (S. mutans) in dentin and its effect on the shear bond strength (SBS) of composite resin to dentin. Eighty extracted human noncarious premolars were used in this study. Forty teeth were used for the antibacterial activity test, while the remaining 40 were used for the SBS test. Both experiments were conducted with 4 experimental groups (n = 10): control (distilled water), sodium hypochlorite (NaOCl, 6%), chlorhexidine (CHX, 0.12%), and erythrosine-mediated PDT. Antibacterial effects were evaluated by counting S. mutans colony-forming units (CFUs). The SBS of composite resins to dentin was measured using a universal testing machine. All treatments (NaOCl, CHX, and PDT) demonstrated statistically significant differences in antibacterial activity compared with the control group (p < 0.05). The antibacterial effects were ranked from strongest to weakest as follows: NaOCl, PDT, and CHX. In the SBS test, the NaOCl group exhibited a statistically significant difference compared with the CHX, PDT, and control groups (p < 0.05), with the lowest bond strength. No statistically significant differences were found among the CHX, PDT, and control groups (p > 0.05). Erythrosine-mediated PDT exhibited significant antibacterial effects against S. mutans, with higher antibacterial activity than CHX but lower than NaOCl. Only NaOCl negatively affected the bond strength of composite resin to dentin. In conclusion, erythrosine-mediated PDT shows potential as a cavity disinfectant due to its significant antibacterial effects against S. mutans and lack of adverse effects on bond strength.

• Membrane and Water Treatment
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• v.15 no.4
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• pp.163-176
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• 2024

Asymmetric flat sheet poly(vinylidene fluoride) (PVDF) membranes were fabricated using the phase inversion technique, employing four distinct solvents with varying solubility power: N, N-dimethylacetamide (DMAc), N, N-dimethylformamide (DMF), Dimethyl sulfoxide (DMSO), and N-Methyl-2-pyrrolidone (NMP). The influence of these solvents on the crystalline properties of the polymers was investigated using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) to elucidate their role in PVDF polymorphism during membrane formation. Our findings revealed significant variations in membrane crystalline phase due to the dissolution of PVDF in different solvents, with α-polymerization predominant in membranes cast with NMP and DMSO, while DMF and DMAc solvents favored β-type polymerization. Further, various additives including PEG-400, TiO2, LiCl, LiBr, acetone, ethanol, propanol, and water were employed to evaluate their impact on membrane morphology and properties. Scanning electron microscopy (SEM) and Ultimate testing machine (UTM) were utilized to analyze membrane morphology, while the tensile strength, contact angle, pore size, and porosity were estimated using the sessile drop method, imageJ, and gravimetric method, respectively. Our results demonstrated that all additives exerted influence on membrane morphology and properties depending on their characteristics and interactions with solvents and polymers. Notably, acetone, being volatile, facilitated the formation of a thin PVDF layer on the membrane surface, resulting in a reduced average pore size (0.18㎛). Conversely, LiCl and LiBr acted as pore-forming additives, yielding membranes with distinct pore characteristics and porosity. Moreover, water as a non-solvent additive induced pregelation during the nonsolvent-induced phase separation (NIPS) process, thereby promoting pore formation (53% porosity) and enhancing membrane hydrophobicity (104° contact angle). To evaluate the quality of synthesized membranes, permeate flux ranging from 16.2 L/m².hr to 27.9 L/m².hr with a salt rejection rate of 98 %, was evaluated using Vacuum Membrane Distillation (VMD).

• Cartoon and Animation Studies
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• s.39
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• pp.261-295
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• 2015

Cyber singer appeared in the late 1990s has disappeared briefly appeared. although a few attempts in the 2000s, it did not show significant successes. cyber singer was born thanks to the technical development of the IT industry and the emergence of an idol training system in the music industry. It was developed by Vocaloid 'Seeyou' starting from 'Adam'. cyber singer that differenatiated typical digital characters in a cartoon or game may be subject to idolize to the music as a medium. They also feature forming a plurality of fandom. therefore, such attempts and repeated failures, this could be considered a fashion, but it flew content creation and ongoing attempts to take advantage of the new media, such as Vocaloid can see that there are expectations for a true Cyber-born singer. Early-Cyber singer is made only resemble human appearance, but 'Sciart' and 'Seeyou' has been evolving to becoming more like the human capabilities. in this paper, stylized cyber singer had disappeared in the past in the process of developing the technology to evolve into own artificial life does not end in failure cases, gradually led to a change in public perceptions of the image look looking machine was an attempt in that sense. With the direction of the evolution of the mechanical function to obtain a human, fun and human exchanges and mutual feelings. And it is equipped with an artificial life form that evolved with it only in appearance and function. in order to support this logic, I refer to the study of the coevolution of man and machine at every Bruce Mazlish. And, I have analyzed the evolution of cyber singer Bruce research from the perspective of the development process since the late 1990s, the planning of the eight singers who have appeared and design of the cyber character and important voices to be evaluated as a singer (vocal). The machine has been evolving coevolution with humans. cyber singer ambivalent development targets are recognized, but strive to become the new artificial creatures of horror idea of human desire and death continues. therefore, the new Cyber-organisms are likely to be the same style as 'Seeyou'. because, cartoon forms and whirring voice may not be in the form of a signifier is the real human desires, but this is because the contemporary public's desire to be desired and the technical development of this type can be created at the point where the cross-signifier.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.2
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• pp.95-103
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• 2024

Purpose. With the advancement of digital technology, 3D printing is being utilized in the fabrication of denture base. Nevertheless, increasing microbial adhesion to the surface of denture base has been reported as the disadvantage of 3D-printed denture base. The purpose of this study is to investigate the antifungal properties and flexural strength of 3D-printed denture base resin according to the different contents of titanium dioxide nanoparticles. Materials and methods. Titanium dioxide nanoparticles were mixed with the 3D printing resin at the ratios of 0.5, 1, 1.5, and 2 wt%. Twenty specimens per each group were printed in the form of cylindrical shape (diameter: 20 mm, height: 3 mm) to evaluate antifungal properties. Ten specimens from each group underwent polishing using autogrinder, while the remaining ten specimens did not. Candida albicans in hyphae form was inoculated onto each specimen, optical density and colony-forming unit were analyzed. The surface of the specimen was observed using scanning electron microscopy. To evaluate the flexural strength, twenty specimens per each group were 3D printed in the form of rectangular prism shape (length: 64 mm, height: 10 mm, width: 3 mm) and three-point bending tests were conducted using universal testing machine according to ISO 20795-1. Results. Colony-forming unit of C.albicans and optical density of culture medium showed no difference between non-polished groups, but decreased in the polished groups at concentration of 1, 1.5, 2 wt% titanium dioxide nanoparticles. Flexural strength increased with titanium dioxide nanoparticle at concentration of 0.5, 1, 1.5 wt%, but decreased at 2 wt% compared to 1.5 wt%. Conclusion. When 1.5 wt% of titanium dioxide nanoparticles were added to the 3D-printed denture base resin with polishing, antifungal properties were increased.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.20-28
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• 2014

The high velocity oxygen fuel spraying (HVOF) is a kind of surface modification process technology to form the sprayed coating layer after spraying the powder to molten or semi-molten state by the ultra-high speed at the high-temperature heat source and conflicting with a substrate. It is desirable to melt completely the thermal spray powder in order to produce the coating layer with an optimal adhesion, however, because a semi-molten powder in a spray process has the low efficiency and become a factor that degrades the mechanical property by the inducement of pore-forming within the coating layer. To improve the wear resistance, corrosion resistance and heat resistance, in this study, the plungers of high-speed and ultra-high pressure reciprocating hydraulic pumps for oil and water used in ironwork are produced with $420J_2$ and the coating layers of plungers are formed by the powders of WC-Co-Cr and WC-Cr-Ni including the high hardness WC. The surface of these plungers is modified by the super-mirror face grinding machine using variable air pressure developed in this laboratory, and then the characteristics of cross-sectional microstructure, and surface roughness and hardness values between no operation and 100 days-operation are examined and made a comparison. The fine tops and bottoms on surface roughness curve of oil-hydraulic pump plunger sprayed by WC-Cr-Ni are molded more and higher than those of water-hydraulic pump sprayed by WC-Co-Cr because the plunger diameter of oil-hydraulic pump is 0.4 times smaller than that of water-hydraulic pump and the pressure of oil-hydraulic pump exerted on the plunger is operated with the 70 bars higher than that of water-hydraulic pump. As a result, it is found that the values of centerline average surface roughness and maximum height for oil-hydraulic pump plunger are bigger than those of water-hydraulic pump plunger.

• Journal of Preventive Medicine and Public Health
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• v.15 no.1
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• pp.17-31
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• 1982

A physician assumes toward his patient the obligation to use such reasonable care and skill as is commonly possessed and exercised by physicians in the same general line of practice in the same or similar localities and to use his best judgment at the times. Medical disputes between physicians and patients are, ever more increased in these days as human body, happens to cause a variety of changes in body unlike the function of machine. Such increased trends of medical disputes became a problem in common across the word under the influence of affluent living standard, high consciousness of life value and right by today's people. The aim of this dissertation is oriented to forming a physician's responsibilities in medicalcare accidents arising between physicians and patients. A general physician, for example, has not been negligent merely because, a specialist might have treated the patient with greater skill and knowledge. However, the fact that a physician may have acted to the best of his ability will not avoid legal problems for damages resulting from substandard treatment, that is the degree of care and skill which is to be expected of the ordinary practitioner in his field of practice. The duty of a physician who is, or holds himself out to be, a specialist is greater in the field of his specialty than one who is a general physician. A patient's consent to routine medical procedures is implied from the fact that patient comes to the physician with a medical problem and voluntarily submits to the procedures. For the more serious medical procedures and for major operations, however, it is preferable for the physician to have the patient's consent in writing, to facilitate proof of the consent in the event of a dispute or litigation. Suppose that mistakes on the part of physicians are likely to be blamed in all cases of malpractice. Then it will create a sort of shrinkage in activities of medical treatment. There should be some limitation on excessive application of 'The thing speaks for itself' on mistakes by physicians and availablity of cause and effect. It is a matter of complicity as well as a matter of importance to draw a definite boundary on responsibilities of physician. A series of further research on this particular aspect is strongly urged.

• Resources Recycling
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• v.15 no.2 s.70
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• pp.18-23
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• 2006

Foaming of slag is a thermodynamically unstable phenomenon and has significant effects in iron and steelmaking processes. For better recycling method of pulp sludge, the application as an defoaming agent during steelmaking process was adopted and tested. The forming machine has been modified in order to produce the briquettes, which are made of pulp sludge and slag with different weight ratio. Influencing factors on the foaming phenomena have been studied and tested for better understanding of foaming phenomena. Experiments were carried out with $CaO-FeO-SiO_2$ based slags with Ar gas injection and addition of coke particles. The slag basicity and (%FeO) contents adapted as major factors to treasure foaming tendency of the slag system. It was found that foam index (${\Sigma}$) gradually decreased as both the basicity and the (FeO) content increase. Four kinds of antifoaming agent such as aluminium dross, cokes, rice bran and pulp sludge with steelmaking slag have been tested in actual process. Aluminium dross was the most effective, and pulp sludge with steelmaking slag also showed the desired results.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.140-149
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• 2014

The purpose of this study was to investigate the influence of etching surface treatment and aging treatment of zirconia on the shear bond strength between zirconia core and veneered ceramic. Four groups of zirconia-ceramic specimens were prepared; 1) NEZ group (no etching zirconia), 2) EZ group (etching zirconia), 3) ANEZ group (aging and no etching zirconia), 4) AEZ group (aging and etching zirconia). The shear bond strength between zirconia and porcelain was measured using Instron Universal Testing Machine. Surface texture with crystalline structure of zirconia surface was examined by the field emission scanning electron microscopy (FE-SEM) with ingredient analysis. The fractured surfaces of specimens were examined to determine the failure pattern by a digital microscope. The mean${\pm}$standard deviation of shear bond strengths were $23.47{\pm}3.47$ Mpa in NEZ, $28.30{\pm}4.34$ Mpa in EZ, $21.85{\pm}4.65$ Mpa in ANEZ, $24.65{\pm}3.65$ Mpa in AEZ group, respectively, and were significantly different (p<0.05). The average shear bond strength was largest in EZ group, followed by AEZ, NEZ, and ANEZ groups. Most specimens in NEZ group showed adhesive failure and most specimens in EZ, AEZ, and ANEZ group showed mixed failure. Surface of etching treatment group (EZ and AEZ) showed complex micro-structure and irregular surface texture which may facilitate mechanical interlocking, while untreated zirconia surface presented simpler micro-structure. In conclusion, an etching treatment improved bonding strength between zirconia and porcelain by forming mechanical interlocking.

• Journal of the Korean Society of Costume
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• v.6
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• pp.7-26
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• 1982

Investigation for industrial revolution has been recognized as an important issue of historical science, since industrial revolution itself was a historical moment in modern economic society and in the forming of modern capitalistic culture. If clothing culture had been developed in close relation to social culture. industrial revolution which gave a base for modern capitalistic culture, would be a birth of modern clothing as well as a moment for modernization of western clothing. As it takes for granted that industrial revolution, historical phenomenon is a developmental base of modern clothing culture. This study tried to enlighten the origin of modern clothing culture phenomenon with investigation of industrial revolution as a historical moment in modern clothing culture through documental study. Historian's point of view and method of studying are important when we investigate the clothing phenomenon. Although culture phenomenon of industrial revolution has been evaluated usually through socialogical aspect, studying for clothing culture phenomenon must be carried out on aethetical as well as well as sociological aspect, on account of dualism of clothing, as it is social and artistic nature. In 19th century, there were technical improvement, changing patterns of production, changing social relation and beginning of mass culture. At the same time clothing culture phenomenon was changed in relation to modern capitalistic society. The findings of the study could be summarized as follows. 1. Technical improvement in textile industry and fitting process brought about mechanization of clothing industry. 2. Appearance of popular clothing culture made it easy to spread to various classes of society. 3. Development of transportation system and communication channel made it internationalization of western clothing. 4. Recognition of importance in functional style of clothing. 5. The pursuit of modern aesthetics made rapid changing mode of clothing. Above distinctive features of modern clothing culture were derived from by-product of machinary culture, mass culture, internationalism, rapidly changing mode of various culture during industrial revolution. Industrial revolution was a change of the material world as well as in industry owing to machine advent, then the culture part that displayed directly these changes was the plastic arts of living that mould the material. The problem of clothing construction caused by industrial revolution was solved by pursuing the functional aesthetics. Clothing phenomenon as a process of value transfer participates mass culture in closs relation to general change of various culture caused by industrial revolution. Therefore western clothing gained the qualities of modern culture, condensed as function, and popularity in the process of modernization.