• Proceedings of the KACD Conference
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• 2001.05a
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• pp.235-237
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• 2001

;Dentistry has benefited from tremendous advances in technology with the introduction of new techniques and materials, and patients are aware that esthetic approaches in dentistry can change one's appearance. Increasingly. tooth-colored restorative materials have been used for restoration of posterior teeth. Tooth-colored restoration for posterior teeth can be divided into three categories: 1) the direct techniques that can be made in a single appointment and are an intraoral procedure utilizing composites: 2) the semidirect techniques that require both an intraoral and an extraoral procedure and are luted chairside utilizing composites: and 3) the indirect techniques that require several appointments and the expertise of a dental technician working with either composites or ceramics. But, resin restoration has inherent drawbacks of microleakage. polymerization shrinkage, thermal cycling problems. and wear in stress-bearing areas. On the other hand, Ceramic restorations have many advantages over resin restorations. Ceramic inlays are reported to have less leakage than resin restoration and to fit better. although marginal fidelity depends on technique and is laboratory dependent. Adhesion of luting resin is more reliable and durable to etched ceramic material than to treated resin composite. In view of color matching, periodontal health. resistance to abrasion, ceramic restoration is superior to resin restorationl. Materials which have been used for the fabrication of ceramic restorations are various. Conventional powder slurry ceramics are also available. Castable ceramics are produced by centrifugal casting of heat-treated glass ceramics. and machinable ceramics are feldspathic porcelains or cast glass ceramics which are milled using a CAD/CAM apparatus to produce inlays (for example, Cered. They may also be copy milled using the Celay apparatus. Pressable ceramics are produced from feldspathic porcelain which is supplied in ingot form and heated and moulded under pressure to produce a restoration. Infiltrated ceramics are another class of material which are available for use as ceramic inlays. An example is $In-Ceram^{\circledR}$(Vident. California, USA) which consists of a porous aluminum oxide or spinell core infiltrated with glass and subsequently veneered with feldspathic porcelain. In the 1980s. the development of compatible refractory materials made fabrication easier. and the development of adhesive resin cements greatly improved clinical success rates. This case report presents esthetic ceramic inlays for posterior teeth.teeth.

• Journal of Biomedical Engineering Research
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• v.42 no.4
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• pp.150-158
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• 2021

Intracranial hemorrhage (ICH) refers to acute bleeding inside the intracranial vault. Not only does this devastating disease record a very high mortality rate, but it can also cause serious chronic impairment of sensory, motor, and cognitive functions. Therefore, a prompt and professional diagnosis of the disease is highly critical. Noninvasive brain imaging data are essential for clinicians to efficiently diagnose the locus of brain lesion, volume of bleeding, and subsequent cortical damage, and to take clinical interventions. In particular, computed tomography (CT) images are used most often for the diagnosis of ICH. In order to diagnose ICH through CT images, not only medical specialists with a sufficient number of diagnosis experiences are required, but even when this condition is met, there are many cases where bleeding cannot be successfully detected due to factors such as low signal ratio and artifacts of the image itself. In addition, discrepancies between interpretations or even misinterpretations might exist causing critical clinical consequences. To resolve these clinical problems, we developed a diagnostic model predicting intracranial bleeding and its subtypes (intraparenchymal, intraventricular, subarachnoid, subdural, and epidural) by applying deep learning algorithms to CT images. We also constructed a visualization tool highlighting important regions in a CT image for predicting ICH. Specifically, 1) 27,758 CT brain images from RSNA were pre-processed to minimize the computational load. 2) Three different CNN-based models (ResNet, EfficientNet-B2, and EfficientNet-B7) were trained based on a training image data set. 3) Diagnosis performance of each of the three models was evaluated based on an independent test image data set: As a result of the model comparison, EfficientNet-B7's performance (classification accuracy = 91%) was a way greater than the other models. 4) Finally, based on the result of EfficientNet-B7, we visualized the lesions of internal bleeding using the Grad-CAM. Our research suggests that artificial intelligence-based diagnostic systems can help diagnose and treat brain diseases resolving various problems in clinical situations.

• Korean Journal of Optics and Photonics
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• v.14 no.3
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• pp.312-320
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• 2003

The basic mechanistic aspects of the interaction and practical considerations related to polymer ablation were briefly reviewed. Photochemical and photothermal effects, which highly depend on laser wavelength have close correlation with each other. In this study, multi-scanning laser ablation processing of polymer with a DPSS (Diode Pumped Solid State) 3rd harmonic Nd:YVO$_4$ laser (355 nm) was developed to fabricate a three-dimensional micro shape. Polymer fabrication using DPSSL has some advantages compared with the conventional polymer ablation process using KrF and ArF laser with 248 nm and 193 nm wavelength. These advantages include pumping efficiency and low maintenance cost. And this method also makes it possible to fabricate 2D patterns or 3D shapes rapidly and cheaply because CAD/CAM software and precision stages are used without complex projection mask techniques. Photomachinability of polymer is highly influenced by laser wavelength and by the polymer's own chemical structure. So the optical characteristics of polymers for a 355 nm laser source is investigated experimentally and theoretically. The photophysical and photochemical parameters such as laser fluence, focusing position, and ambient gas were considered to reduce the plume effect which re-deposits debris on the surface of substrate. These phenomena affect the surface roughness and even induce delamination around the ablation site. Thus, the process parameters were tuned to optimize for gaining precision surface shape and quality. This maskless direct photomachining technology using DPSSL could be expected to manufacture tile prototype of micro devices and molds for the laser-LIGA process.

• Korean Journal of Construction Engineering and Management
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• v.14 no.5
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• pp.35-43
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• 2013

Nowadays the widely used media in architecture include visualizations, animations and three-dimensional models. 3D digital methods using active CAM(Computer Aided Manufacturing) and CNC(Computerized Numerical Control) imaging have been developed for accurate shape and 3D measurements in freeform buildings. In contrast to a conventional building using auto CAD system and others, the proposed digital optimization method is based on a combination of 3D numerical data and parametric 3D model for design and construction. The objective of this paper is therefore to present digital optimization process for constructability of freeform building. The method can be useful in the effective implementation of an error-proofing process of freeform building during design and construction phase. 3D digital coordinate data can be used effectively to identify correct size of structural and finish members and installation location of each members in construction field. In addition, architects, engineers and contractors can evaluate design, materials, constructability and identify error-proofing opportunities. Other project participants can also include representatives from all levels of management, departments as well as workers and key subcontractors' personnel, if necessary. The 3D digital optimization process is therefore appropriate to serious variations in freeform shape. For future study, the developed digital optimization method is necessary to be carried out to verify the robustness and accuracy for constructability in construction field.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.3
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• pp.177-184
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• 2020

Purpose: The purpose of this study was to compare and evaluate the tensile bond strength of chairside reline resin to denture base resin fabricated by different methods (subtractive manufacturing, additive manufacturing, and conventional heat-curing). Materials and methods: Denture base specimens were fabricated as cuboid specimens with a width of 25 mm × length 25 mm × height 3 mm by subtractive manufacturing (VITA VIONIC BASE), additive manufacturing (NextDent Base) and conventional heat-curing (Lucitone 199). After storing the specimens in distilled water at 37℃ for 30 days and drying them, they were relined with polyethyl methacrylate (PEMA) chairside reline resin (REBASE II Normal). The subtractive and additive manufacturing groups were set as the experimental group, and the heat-curing group was set as the control group. Ten specimens were prepared for each group. After storing all bound specimens in distilled water at 37℃ for 24 hours, the tensile bond strength between denture bases and chairside reline resin was measured by a universal testing machine at a crosshead speed of 10 mm/min. The fracture pattern of each specimen was analyzed and classified into adhesive failure, cohesive failure, and mixed failure. Tensile bond strength, according to the fabrication method, was analyzed by 1-way ANOVA and Bonferroni's method (α=.05). Results: Mean tensile bond strength of the heat-curing group (2.45 ± 0.39 MPa) and subtractive manufacturing group (2.33 ± 0.39 MPa) had no significant difference (P>.999). The additive manufacturing group showed significantly lower tensile bond strength (1.23 ± 0.36 MPa) compared to the other groups (P<.001). Most specimens of heat-curing and subtractive manufacturing groups had mixed failure, but mixed failure and adhesive failure showed the same frequency in additive manufacturing group. Conclusion: The mean tensile bond strength of the subtractive manufacturing group was not significantly different from the heat-curing group. The additive manufacturing group showed significantly lower mean tensile bond strength than the other two groups.

• Journal of the Korean Society of Costume
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• v.31
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• pp.165-188
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• 1997

This study aims at 1) examining the perceived importance of clothing norms 2) examining relationship between perceptions of clothing norms clothing behavior and psycho-logical variables-ego identity(uniqueness and self acceptance) and sex role identity and 3) ascertaining any significant differences in the level of the perceived importance of clothing norms among variables-sex role identity and the uniqueness in psychological variables-and which variables are influencingon perception of clothing norms. The perception of cloth in norms inventory clothing norms inventory clothin behavior inventory ego identity in-ventory and the Bem Sex Role Inventory were administered to 620 college students. Sex role identity was classified into androgynous mas-culine feminine and undifferentiated type. Subjects were asked to rate each statement on the clothing norms under two kinds of instructions: their attitudes(TATT) and their beliefs about the expectations of others toward clothing norms(TBEO). 1) The scores of 3 TBEO of the students were higher than the scores of TATT. But the scores of TBEO concerning modesty of students were lower than the scores of TATT. Discrepancy scores of TATT and TBEO of the students were revealed significances differently according to clothing norms. males lower and higher class students had more free attitudes to the norms concerning genaral clothing attitudes. Females and higher class students had less free attitudes to the clothing norms concerning modesty. Females and lower and higher class students had more free attitudes to the norms concening sex-role related clothing attitudes but male students had less free to the sex-role related clothing norms. 2) Significant negative correlations between each variable of clothing norms and conform-ity-individuality were found. But negative correlations between those variables of the males and lower class students were higher than the correlations of the female and higher class students and the former had more posi-tive relationships with clothing norms and con-formity as compared with the latter. And sig-nificant positive correlations between each variable of clothing norms and modesty were found. But positive correlations between those variables of the males females and higher class students were higher than the correlations of the lower class students and the latter had less positive relationship with clothing norms and modesty as compared with the former. 3) Significant negative correlations between clothing norms and uniqueness were found in the subjects groups. The females and lower class students had more negative relationships with clothing norms and uniqueness as compared with the male and higher class students. Significant positive correlations be-tween uniqueness and conformity-individuality were found in all subjects groups, Therefore the higher uniqueness the student have the less they perceive theimportance of clothing norms and the more they have individuality. Significant positive correlations between sex-role related(higher class) general(female) clothing norms and self acceptance were found. but significant negative correlations be-tween campus style(higher class) general(female) clothing norms and self acceptance were found. But significant negative correlations be-tween campus style(males lower class, higher class) clothing norms and self acceptance were found. Clothing norms therfore related posi-tively or negatively with self acceptance ac-cording to the subjects groups. And significant negative correlations between conformity in-dividuality and self acceptance was found in higher class students. 4) The female masculine groups and the masculine groups of lower class revealed high scores than the scores of andrgynous group and undifferentiated group in clothing norms concerning modesty. And the feminine group revealed high scores in conformity-individu-ality than the scores of the masculine group. Male masculine and feminine group revealed high scores in clothing norms concerning cam-pus style than the scores of the androgynous group. The masculine group and feminine group of the lower classes revealed high scores in general clothing norms than the scores of the androgynous group. 5) The most influencing variables on the clothing norms were sex conformity-individu-altiy and masculine-feminine variables in the right order. The general clothing norms and clothing norms concerning modesty were influened by the sex role identity but the sex role related clothing norms and clothing norms concerning campus style were influenced by the ego identity. 6) Based on the sum scores of the uniqueness each group of the subjects was separately segmened into "high medium and low" groups. By the analysis of variances sig-nificant differences in discrepancy scores of TBEO and TATT among 3 uniqueness level groups were found on all clothing norms variables in all students three clothing norms variables in male and female students and one clothing norms variable in lower and higher students and in each clothing norms variable the mean discrepancy scores of the high uniqueness group were higher than those of the other groups. The findings indicated that the differences in the discrepancy score mainly contributed to the results of correla-tions described above.bed above.