• The Journal of Advanced Prosthodontics
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• v.12 no.3
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• pp.140-149
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• 2020

PURPOSE. This study evaluated the color stabilities of two computer-aided design and computer-aided manufacturing (CAD/CAM) blocks and a nanofill composite resin and the microtensile bond strength (µTBS) between the materials. MATERIALS AND METHODS. Twelve specimens of 4 mm height were prepared for both Lava Ultimate (L) and Vita Enamic (E) CAD/CAM blocks. Half of the specimens were thermocycled (10,000 cycle, 5° to 55℃) for each material. Both thermocycled and non-thermocycled specimens were surface treated with one of the three different methods (Er,Cr:YSGG laser, bur, or control). For each surface treatment group, one of the thermocycled and one of non-thermocycled specimens were restored using silane (Ceramic Primer II), universal adhesive (Single Bond Universal), and nanofill composite resin of 4-mm height (Filtek Ultimate). The other specimens were restored with the same procedure without using silane. For each group, 1 × 1 × 8 mm bar specimens were prepared using a microcutting device. Bar specimens were thermocycled (10,000 cycle, 5° to 55℃) and microtensile tests were performed. Staining of the materials in coffee solution was also compared using a spectrophotometer. Data were analyzed using one-way ANOVA, t-test and post-hoc Scheffe tests. RESULTS. µTBS were found similar between the thermocycled and non-thermocycled groups (P>.05). The highest µTBS (20.818 MPa) was found in the non-thermocycled, bur-ground, silane-applied E group. Silane increased µTBS at some E groups (P<.05). Composite resin specimens showed more staining than CAD/CAM blocks (P<.05). CONCLUSION. CAD/CAM blocks can be repaired with composite resins after proper surface treatments. Using silane is recommended in repair process. Color differences may be shown between CAD/CAM blocks and the nanofill composite after a certain time period.

• Journal of the Korean Society of Costume
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• v.65 no.6
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• pp.15-24
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• 2015

Dahoe is a traditional Korean term for cords and Dongdahoe for round cords. The main purpose of this study is to analyze the structure of a semi-automatic loom depicted in the paintings of Jun Geun Kim, and verify whether it actually worked or not. Jun Geun Kim is a genre painter of the late Joseon Dynasty. His nom de plume is Gisan and he drew genre paintings for foreigners who visited Korea in the late 19th century. These paintings are important in understanding the lifestyle and custom of the times. His paintings at the Staatliche Museen zu Berlin in Germany and the British Museum in England both depict a semi automatic loom that operates two looms at the same time. This is a unique loom that is not found in any other country and currently no artifacts of such loom exist in Korea. The study went through the following steps: We first analyzed the structure and the operating mechanism of the loom in the painting. The structure of each parts and their roles were also analyzed. Then a loom that was similar in structure and size was made to check if it was operational. The loom depicted in the paintings had some problems, and adjustments to fix the said problems were made accordingly. Wood was primarily used to make the $80{\times}90cm$ loom. The loom was used to make Dahoe and the study confirmed that there were no differences between the handmade Dongdahoe and the Dongdahoe made with the semi automatic loom.

• Journal of the Korea Fashion and Costume Design Association
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• v.11 no.2
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• pp.23-32
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• 2009

The purpose of this study is to research fabrics, colors, and arrangement of color in Jogak-bo which were developed during the late Chosun dynasty. It is expected that from the analysis of the number, distribution and arrangement of colors of Jogak-bo in the late Chosun we can suggest various color arrangements thoset can be applied to modern fashion are summarized as follows. First, as for the number of colors of Jogak-bo according to material, silk fabrics Jogak-bo used a variety of colors whereas hemp fabrics Jogak-bo mostly used one color showing contrast between silk fabrics Jogak-bo and hemp fabrics ones. Second, as for the distribution of colors of silk Jogak-bo and hemp fabrics ones, warm colors were used most frequently. On the other hand, fewer achromatic colors were used to silk fabrics Jogak-bo, and they were more applied to hemp fabrics Jogak-bo. As for the use of cold colors, fewer cold colors were applied to hemp fabrics Jogak-bo compared to silk fabrics Jogak-bo. Third, as for the arrangement of colors, various colors were used in silk fabrics Jogak-bo, but a single color or not more than 1 color was applied to hemp fabrics Jogak-bo. It well demonstrates brilliance and glamour of silk Jogak-bo and stability and unity of hemp fabrics Jogak-bo. As for the arrangement of colors of Jogak-bo, most of Jogak-bo showed contrasting colors and shades, and similar colors and shades were hardly found in silk fabrics Jogak-bo whereas they were frequently found in hemp fabrics Jogak-bo.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1121-1124
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• 2004

Carbon Nitride exhibits high electrical resistivity and thermal conductivity that are similar to the properties shown by diamond-like carbon (DLC) films. These diamond-like transport properties in Carbon Nitride come in a material consisting of $sp^2$-bonded carbon versus the $sp^3$-carbon of DLC. The diamond-like properties and nondiamond-like bonding make NDLC an attractive candidate for applications. Liquid crystal (LC) alignment capabilities with ion beam exposure on carbon nitride thin films and Electro-Optical (EO) performances of the ion-beam aligned twisted nematic liquid crystal display (TN-LCD) with oblique ion beam exposure on the Carbon Nitride thin film surface were studied. An excellent uniform alignment of the nematic liquid crystal (NLC) alignment with the ion beam exposure on the Carbon Nitride thin films was observed. In addition, the good EO properties of the ion-beam-aligned TN-LCD were achieved. Finally, we achieved the residual DC property of the ion-beam- aligned TN-LCD on the Carbon Nitride thin film.

• The Journal of the Korean dental association
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• v.47 no.8
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• pp.522-533
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• 2009

Purpose: Infection with HIV-1 virus has become a critical worldwide public health problem. The oral complications of HIV infection with its progression of impairment of the host response to combat infection present unique challenges to the periodontists. Material and Methods : Medline research was carried out to find relationship of the progression of HIV infection to the occurrence of oral lesions including the HIV-related periodontal diseases. Results: The linear gingival erythema, necrotizing ulcerative periodontitis, necrotizing ulcerative gingivitis and oral candidiasis are common lesions in HIV-infected individuals. The linear gingival erythema and necrotizing ulcerative periodontitis lesions in HIV-infected subjects were found to have a similar microbiological profile. There are several general considerations in the periodontal management of the HIV-infected patient with or without periodontal disease. The altered immunity and host response in patients with HIV infection may also affect the incidence and severity of other common forms of periodontal disease not associated with HIV infection. Conclusion: Periodontal diseases in HIV-infected individuals present unique challenges in diagnosis, monitoring, treatment and maintenance. Therefore exact HIV staging, geographic location, antiviral and antimicrobial therapies and oral habits should be taken into consideration when treating HIV-infected patients.

• Korean Journal of Materials Research
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• v.20 no.6
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• pp.331-337
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• 2010

A highly porous Biphasic Calcium Phosphate (BCP) scaffold was fabricated by the sponge replica method with a microwave sintering technique. The BCP scaffold had interconnected pores ranging from $80\;{\mu}m$ to $1000\;{\mu}m$, which were similar to natural cancellous bone. To enhance the mechanical properties of the porous scaffold, infiltration of polycaprolactone (PCL) was employed. The microstructure of the BCP scaffold was optimized using various volume percentages of polymethylmethacrylate (PMMA) for the infiltration process. PCL successfully infiltrated into the hollow space of the strut formed after the removal of the polymer sponge throughout the degassing and high pressure steps. The microstructure and material properties of the BCP scaffold (i.e., pore size, morphology of infiltrated and coated PCL, compressive strength, and porosity) were evaluated. When a 30 vol% of PMMA was used, the PCL-BCP scaffold showed the highest compressive strength. The compressive strength values of the BCP and PCL-BCP scaffolds were approximately 1.3 and 2MPa, respectively. After the PCL infiltration process, the porosity of the PCL-BCP scaffold decreased slightly to 86%, whereas that of the BCP scaffold was 86%. The number of pores in the $10\;{\mu}m$ to $20\;{\mu}m$ rage, which represent the pore channel inside of the strut, significantly decreased. The in-vitro study confirmed that the PCL-infiltrated BCP scaffold showed comparable cell viability without any cytotoxic behavior.

• Journal of Periodontal and Implant Science
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• v.40 no.1
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• pp.11-18
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• 2010

Purpose: Significant interest has emerged in the design of cell scaffolds that incorporate peptide sequences that correspond to known signaling domains in extracellular matrix and bone morphogenetic protein. The purpose of this study was to evaluate the bone regenerative effects of the synthetic peptide in a critical-size rat calvarial defect model. Methods: Eight millimeter diameter standardized, circular, transosseus defects created on the cranium of forty rats were implanted with synthetic peptide, collagen, or both synthetic peptide and collagen. No material was was implanted the control group. The healing of each group was evaluated histologically and histomorphometrically after 2- and 8-week healing intervals. Results: Surgical implantation of the synthetic peptide and collagen resulted in enhanced local bone formation at both 2 and 8 weeks compared to the control group. When the experimental groups were compared to each other, they showed a similar pattern of bone formation. The defect closure and new bone area were significantly different in synthetic peptide and collagen group at 8 weeks. Conclusions: Concerning the advantages of biomaterials, synthetic peptide can be an effective biomaterial for damaged periodontal regeneration.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.55 no.3
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• pp.146-152
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• 2006

In order to analyze the characteristics of series arcs that could happen in poor connections of electrical facilities, we made an apparatus which is similar to actual situation. series arcs are generated between copper and copper, copper and bronze, copper and brass, bronze and bronze, and then oxidation growth and voltage waveform were measured. A very small vibration with constant movement is needed to grow oxidation initially, whereas oxidation growth proceeded without a vibration after a certain amount of time. At first, blue white flame was generated initially between copper and copper, and then yellow flame was generated. In case of contact between copper and copper, the length of oxidation growth was about 7.1[mm] in 90[min]. In case of contact between copper and brass, the length of oxidation growth was about 4.3[mm] in 90[min], When bronze is contacted with copper, the lengths of oxidation growth were about 1.4[mm] in 20[min] and 2.7[mm] in 40[min] respectively, and no more oxidation growth was shown after that. In case of contact between brass and brass, the length of oxidation growth was about 1.2[mm] in 90[min], so it was the smallest compared to other cases. When copper is contacted with copper, the current through the load was about 1.6[A] and the power dissipation increased from 19[W] to 31[W]. In case of oxidation growth between copper and brass, the voltage changed from 8.4[V] to 11[V]. However, the voltage drop and the power dissipation between copper and brass were small compared to oxidation growth between copper and copper. When series arcs were generated between bronze and copper, a peak was shown at the beginning of voltage increase, and 40[min] later, oxidation material was not grown any longer. When oxidation growth occurred, voltage waveform showed irregular waveforms with tiny ripples.

• Journal of the Korean Society for Library and Information Science
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• v.38 no.1
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• pp.173-197
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• 2004

It is searched that 56 out of 185 university libraries(30.2%) has adopted 'subject specialization' organization. This 'subject specialization' emerged when university libraries began to care about their users and services for them more than other factors in planning and structuring their organization. The number of university libraries which try to adopt that organization has been continuously increasing. To settle 'subject specialization' in the university libraries under Korea's proper condition and to maximize its effect, each library should consider one's own conditions and step the reasonable procedure in adopting that system. Considering the similar condition which the university libraries in Korea face such as shortage of material support, 'Mixed Model of subject specialization" is reasonable, which means in whole structure of library function-oriented organization is adopted and in Reference Service, subject specialization is adopted. However, the ideal and final destination of Korea's university libraries is the adoption of 'Full subject specialized model": it can be reached when they are supported by sufficient human resources and good conditions.

• Journal of the Korean Society of Costume
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• v.30
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• pp.295-306
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• 1996

A large quantity of exhumed clothing found for recent 20 years has becom-e the material for making a concrete clarification of the structure of clothing in the Chosun dynasty. Exhumed clothing means the clothing found in the coffin when the grave of the ancestor buried several hundred several hundred years ago is removed to another pla-ce and it is almost comprised of ordinary clothes of the grave-owner not mourning clothes as well as clothing and ornaments in the period between the 15th cen-tury and th 19th century. This research is intended to inquire into the kind of chimas in the 16th century before the Imjin Japancese Invasion of Korea during 1592-1598. The after effect of the Imjin Japanese In-vasion was generally reflected in clothing them and the structure of clothing in the Chosun dynasty began to overshadew its di-chotomy with the Imjin Japanese I vasion of Korea as the point. Accordingly this research is concerned with the study of the chima system of the early Chosun dynasty which shows that there is a common point of the identical form though clothing was exhumed in different graves. Therefore it was possible to grasp women's clothing that was fashionable at that time The object for research is the women in the upper class of the 16th century whose representative characteristics are depicted as follows: 1. Women in the upper class wore the splendid clothing similar to the ordinary clothing of court ladies. 2. The division of ordinary chima and ceremonial chima appeared in the concrete. 3. Ceremonial chima had its extra width and length and exhibited its exaggerated silhouette. in particular it had a various forms of over-pleats made at its center front which play a role in supplementing discomfort in walking. This associate bustle and crinolin styles through which the modern design of clothing can be glimpsed. 4. The opposite phenomenon was shown that has been perceived up to now such as folding at the right plain seam the treatment of the edge-and the like. 5. The elaboration of manual needlework shows the culmination of women's workmanship.