• The Journal of Korean Academy of Prosthodontics
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• v.39 no.1
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• pp.14-24
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• 2001

The purpose of this study was to compare the fracture strengths and the fracture patterns of several hybrid-ceramic crowns and metal-ceramic crown. Ten crowns were constructed for each group according to the manufacturer's instruction. Removable template of silicone rubber impression material was used for standardization of each crowns. Each crown was cemented on a metal die with hybrid glass ionomer cement. All crowns cemented were stored in distilled water, $36^{\circ}C$ for 24 hours prior to loading in an universal testing machine. The load was directed at 130 degrees the long axis of metal die. The fracture strengths were measured and the fracture patterns were observed. The following results were obtained from this study 1. The mean fracture strengths of $Artglass^{(R)}$, $Sculpture^{(R)}$ and $Targis^{(R)}$ were $57.5{\pm}9.5Kgf,\;62.7{\pm}12.2Kgf$ and $60.2{\pm}10.1Kgf$ respectively. There was no significant difference among each hybrid ceramic crown group. 2. The toad required to fracture hybrid-ceramic crowns was significantly smaller than metal-ceramic crowns($131.7{\pm}22.0Kgf$). 3. In the metal-ceramic crowns, labial porcelain detached partially from porcelain-metal junction of proximal side by load. 4. Hybrid-ceramic crowns showed a simple fracture pattern that fracture line began at the loading area and extended through proximal surface, perpendicular to the margin. The crown was separated into two parts of labial side and lingual side. Above results revealed that three kinds of the hybrid-ceramic crowns used in this study must have careful application in clinical use since the strength of hybrid-ceramic crown was lower(about 1/2) than that of metal-ceramic crown.

• Journal of the Korean Society of Costume
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• v.54 no.5
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• pp.155-166
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• 2004

OP-Art was not appreciated by painters and art critics. and according1y has been forgotten in art history. But recently Op-Art is revitalized in fashion and is in its palmy days. This study intends to re-assess the value of Op-Art, by reviewing its influence on fashion design in the post-modern society To this purpose, conceptual characteristics of Op-Art was analyzed. And then, on the bases of these characteristics, the figural characteristics and the meaning of Op-Art in fashion design of post-modern society was re-explained. Op-Art is characterized as an art of flatness of picture plane which uses repetition of simple forms and colors. It is also based on trick of visual perception. Finally. it creates an impression which is flickering or vibrating by means of optical illusion. These characteristics give birth to some features such as simplicity. anonymity and mobility in the Op-Art fashion. The meanings of Op-Art in fashion design in post-modern society are as follows. First, repetition of simple units employed in Op-Art produces feeling of simplicity. which makes the Op-Art fashion works perceived as polysemy. In other words, the feeling of simplicity can be interpreted In diverse perspectives within the social context of our society. The material civilization and technology civilization, which causes the alienation and standardization of man. can be the backgrounds of the Op-Art fashion. Second, Op-Art is an art based on perspectives of spectators. Anonymity in the Op-Art fashion enhances participation of spectators. which gives Op-Art a sense of affinity. Third, through the feeling of mobility created by optical illusion techniques. the Op-Art fashion expresses the opposition to the ideal body image made by power group. In post-modern society, Op-Art in fashion gives new meaning to art. Op-Art in fashion proposes new roles of artist and spectators, and new concepts of art related with roles of human beings. Through general sensibility of men, Op-art in fashion can express new recognition of the post-modern society.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.3
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• pp.153-168
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• 2003

It is very important to arrange the artificial teeth correctly in bucco-lingual (labio- lingual) relation in reconstrcting dentition. Although many anatomic landmarks and techniques have been reported over the years, they are based on westerns. So this study was performd to examine the horizontal relations of mandibular teeth in Korean dentulous adults. 200 volunteers(mean age 22.9) who had natural dentition were selected. The impressions were taken with irreversible hydrocolloid impression material and mandibular study models were fabricated using class I dental stone. Then they were measured with 3-dimensional measuring device specially designed for this study. The results were as follows ; It is better to consider the lingual cusps of the lower posterior teeth as a guide than the linguoaxial surfaces of the lower posterior teeth, arranging the lower posterior teeth buccally to the line which starts from the mesial aspect of the lower canine and continue backward to the lingual aspect of the retromolar pad. It is better to arrange the fossae of the lower posterior teeth buccally to the line which starts from the cusp tip of the lower canine and continue backward to the top of the retromolar pad. The positions of the lower posterior teeth in the denture-bearing area ; considering the fossa as a guide, the 2nd premolar was positioned in center. considering the buccal cusp as a guide, the 1st molar and the 2nd molar were positioned in center. the distance ratio(d/a) was incresed constantly from the lower canine to the 2nd molar d ; the distance between the buccal vestibule(the lowest point) and the buccal cusp tips of the lower posterior teeth. a ; the distance between the buccal vestibule(the lowest point) and the lingual vestibule(the lowest point). The lower canine was positioned lingually($0.11{\pm}0.13$) than the labial vestibule, and the central incisor and the lateral incisor were positioned almost in the imaginary perpendicular plane of the labial vestibule(the lowest point).

• Journal of Technologic Dentistry
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• v.42 no.1
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• pp.9-16
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• 2020

Purpose: The purpose of this study was to compare the marginal and internal fit of lithium disilicate ceramic inlay produced by heat pressing that inlay pattern made by subtractive manufacturing and additive manufacturing method. Methods: A mandibular lower first molar that mesial occlusal cavity (MO cavity) die was prepared. After fabricating an epoxy resin model using a silicone impression material, epoxy resin die was scanned with a dental model scanner to design an MO cavity inlay. The designed STL pile was used to fabricate wax patterns and resin patterns, and then lithium disilicate ceramic inlays were fabricated using hot-press method. For the measurement of the marginal and internal gap of the lithium disilicate, silicone replica method was applied, and gap was measured through an optical microscope (x 80). Data were tested for significant differences using the Mann-Whitney Utest. Results: The marginal fit was 103.56±9.92㎛ in the MIL-IN group and 81.57±9.33㎛ in the SLA-IN group, with a significant difference found between the two groups (p<0.05). The internal fit was 120.99±17.52㎛ in the MIL-IN group and 99.18±6.65㎛ in the SLA-IN group, with a significant difference found between the two groups (p<0.05). Conclusion: It is clinically more appropriate to apply the additive manufacturing than subtractive manufacturing method in producing lithium disilicate inlay using CAD/CAM system.

• Restorative Dentistry and Endodontics
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• v.40 no.2
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• pp.123-127
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• 2015

Objectives: Glide path preparation is recommended to reduce torsional failure of nickel-titanium (NiTi) rotary instruments and to prevent root canal transportation. This study evaluated whether the repetitive insertions of G-files to the working length maintain the apical size as well as provide sufficient lumen as a glide path for subsequent instrumentation. Materials and Methods: The G-file system (Micro-Mega) composed of G1 and G2 files for glide path preparation was used with the J-shaped, simulated resin canals. After inserting a G1 file twice, a G2 file was inserted to the working length 1, 4, 7, or 10 times for four each experimental group, respectively (n = 10). Then the canals were cleaned by copious irrigation, and lubricated with a separating gel medium. Canal replicas were made using silicone impression material, and the diameter of the replicas was measured at working length (D0) and 1 mm level (D1) under a scanning electron microscope. Data was analysed by one-way ANOVA and post-hoc tests (p = 0.05). Results: The diameter at D0 level did not show any significant difference between the 1, 2, 4, and 10 times of repetitive pecking insertions of G2 files at working length. However, 10 times of pecking motion with G2 file resulted in significantly larger canal diameter at D1 (p < 0.05). Conclusions: Under the limitations of this study, the repetitive insertion of a G2 file up to 10 times at working length created an adequate lumen for subsequent apical shaping with other rotary files bigger than International Organization for Standardization (ISO) size 20, without apical transportation at D0 level.

• Journal of Korean Society for Quality Management
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• v.47 no.3
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• pp.615-630
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• 2019

Purpose: Based on the theory of "Stimulus-Organism-Response" (S-O-R), this thesis takes customer forgiveness as a medium variable to explore the impact of merchant service remedy on customer behavior intention in the context of online shopping service failure. This thesis divides the merchant service remedy into two dimensions: spiritual recovery and material recovery, and reveals the influence difference of different merchant service remedy methods on customer behavior intention and the mediating role of customer forgiveness. Methods : 325 questionnaires were distributed and 307 valid questionnaires were collected for data analysis. The relationship between potential variables is proposed by using Structural Equations Modeling. Results : The two dimensions of service recovery have significant positive impact on customer forgiveness, and physical recovery has greater impact on customer forgiveness. In the influence of physical recovery on customer behavior intention, customer forgiveness is a partial mediating effect. However, in the influence of spiritual recovery on customer behavior intention, customer forgiveness is a complete mediating effect. Conclusion : In case of service faults, merchants should take the initiative to provide appropriate physical recovery and provide spiritual recovery sincerely and patiently. Only in this way can they regain good impression in the hearts of consumers and promote them to improve the quality of service recovery, so as to increase their willingness to repurchase Intention and positive word of mouth.

• Journal of Digital Convergence
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• v.19 no.1
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• pp.355-360
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• 2021

In this study, the factors of confirmation bias that may occur in the initial user experience stage were analyzed using a honeycomb model by deriving user experience factors for each factor. In the initial user experience stage, confirmation bias occurs in the impression stage. At the processing stage of memory, sensory memory, working memory, and long-term memory, which stores and retrieves selective memory, were closely related. Confirmation bias was classified into visibility, correlation, memory, clarity, and universality in the usability part, and satisfaction, joy, and dissatisfaction were derived as emotional factors. As a result of the analysis with the honeycomb model, visuality, clarity, universality in the usability factor, and joy in the emotional factor had little effect on the confirmation bias, and satisfaction and dissatisfaction were analyzed as the main factors of the confirmation bias in the correlation, memory and emotional factors. This study is meaningful in that it can be usefully used as a reference material for companies that customize design patterns for the factor of confirmation bias.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.36 no.5
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• pp.117-124
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• 2020

This study examined ornamental metals used as architectural members among metal artifacts excavated from ancient Buddhist temples and palaces in Korea. Through this, we approached the decorative characteristics of ancient architecture eaves. 1. The decorations used in eaves of Korean ancient architecture include roof-end tiles and ornamental metal. Through excavation examples, the technique of attaching ornamental metal to the rafters and corner rafters of high-ranking architectures in the 7th and 8th centuries (ornamental metal for rafter end, ornamental metal for corner rafter end), and tosu iron in the 10th century It seems to be fashionable. 2. Several buildings were built in ancient Buddhist temples and palaces. At this time, they differentiated ornamental metal according to the hierarchy of the building. The higher the hierarchy, the greater the difference in the number of ornamental metal installations, materials, and decoration techniques. In addition, ornamental metal used in eaves is an important factor in the discrimination of the times as the type, number of members, and patterns change depending on the era. 3. The great feature of the eaves metal decoration excavated in the 7th and 8th centuries is the attachment of ornamental metal to the rafters and horsetails. This seems to create a sense of grandeur by removing the weight of the roof and giving the impression constructed regardless of gravity by supporting it with non-material materials.

• Analytical Science and Technology
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• v.23 no.1
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• pp.89-96
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• 2010

In general, three types of fingerprints could be found at the crime scene: visible, plastic, and latent fingerprints. Examples of visible fingerprint include those made by blood, paint or ink. Plastic fingerprint are made from an impression of the finger on soft material as soap, wax, etc. Latent fingerprint are those of the invisible one to the human eye. Oil-contaminated fingerprints remained in the evidence, that are contaminated with the soybean oil, engine oil, lubricating oil or grease. Oil-contaminated fingerprints are special types of fingerprint evidence but the research for developing method regarding oil-contaminated fingerprints is a few. In this study, ultraviolet light source was employed for untreated oil-contaminated prints and the freeze-dry method with liquid nitrogen for freeze oil residue on the surfaces with sequence of developing oil-contaminated fingerprints with black and magnetic powders, cyanoacrylate (CA) fuming, Basic Yellow 40. The types of oil chosen for the experiment were soybean oil, LSA oil, engine oil and material surfaces selected for the experiment were glass, plastic aluminum plates. The aims of this study were to determine the appropriate developing methods for oil-contaminated fingerprints.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.252-259
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• 2017

Purpose: The purpose of this study was to compare and analyze the wear of a prosthesis for 6 months after restoration with implant-supported fixed dental prosthesis made of either zirconia or gold. Materials and Methods: This study was conducted on patients requiring implant-supported fixed dental prostheses on first or second molar from January, 2015 to January, 2016. A total of 47 prostheses and antagonists were examined. Occlusal surface was recorded by impression of each prosthesis and antagonist 1 week and 6 months after prosthesis delivery. The digital files were created by impression scan. Occlusal shapes of 1 week and 6 months were compared and wear of prostheses and antagonists was analyzed. The Mann-Whitney test was used to analyzed the result data underwent normality test using SPSS (Version 23.0, IBM Corporation) Results: Mann-Whitney test revealed that there was no statistically significant difference in the median amount of mean vertical wear for 6 months in zirconia ($50.84{\mu}m$) and gold ($42.84{\mu}m$) prostheses (P > 0.05). When the opposing teeth were natural, the median amount of mean vertical wear of zirconia and gold prostheses was $47.72{\mu}m$ and $41.97{\mu}m$, respectively, and the median amount of mean vertical wear of enamel was $47.26{\mu}m$ and $44.59{\mu}m$, respectively. Statistical analysis showed no significant difference (P > 0.05). Conclusion: Despite the short study period and the small number of experimental groups, zirconia and gold showed no significant difference in wear during the first 6 months. Opposing natural enamel also showed no significant difference in the wear.