• 치위생과학회지
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• 제20권4호
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• pp.252-260
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• 2020

Background: In this study, the bleaching effect and surface damage of two types of over-the-counter home tooth bleaching agents were explored using an in vitro study of bleaching agents applied to bovine teeth specimens for 14 days. Methods: Domestic over-the-counter home tooth bleaching agents of gel and patch form that shared common active ingredients and manufacturers were selected and tested. The experiment specimens were made using composite resin with bovine tooth samples and then measured the initial microhardness. Specimens were then divided into a Gel group and a Patch group and underwent bleaching treatment once a day for two weeks for 30 to 60 minutes (recommended) or 7 hours. All specimens were coffee-stained prior to bleaching. The bleaching effect was measured using a spectrophotometer and surface damage was measured using a microhardness meter. Results: The difference in color following the bleaching procedure was positive in both the Gel and Patch group, although there were no statistically significant differences in bleaching effect between groups. There was no significant difference in bleaching effect based on duration. The microhardness test revealed that both the Gel group and the Patch group had surface damage after bleaching. The greatest surface damage was found in the Patch group that had undergone a 7-hour bleaching treatment, although the differences were not statistically significant. Conclusion: The bleaching effect of the home tooth bleaching agent was visible to the naked eye. However, longer applications than recommended did not result in greater bleaching, unlike consumers' expectations, and instead increased the chance of enamel damage. As such, there is a need for consumers to be alert and adhere to recommendations provided by each company.

• 전자공학회논문지D
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• 제34D권12호
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• pp.8-13
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• 1997

In this paper, the input impedance and efficiency of rectangulr microstip patch antenna located inside a rectangular wavegudie is calculated by using the cavity model and the mode excited by te patch antenna which is modeled as an equivanlent surface magnetic current on the conducting plate. Measured return losses of a rectangular microstrip patch antenna tuned at 5.93 GHz in the free space and inside the retangular waveguide are compared and found to be in good agreement with calculated results.

• 한국멀티미디어학회:학술대회논문집
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• 한국멀티미디어학회 2003년도 춘계학술발표대회논문집
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• pp.492-498
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• 2003

본 논문에서는 실사와 같은 사실적인 3차원 Facial Model 제작을 위해 해부학 접근을 통한 근육기반의 자연스러운 Facial Modeling 제작을 연구하였다 한국인 기본형 얼굴을 연구 대상으로 선정하여 안면근육 비례를 분석한 후 Multi-patch Surface Modeling 방법을 적용하며 제작하였다. 이 방법에는 통계적 분석기법 중 L/sub 27/(3/sup 13/) 3수준계 직교배열표를 이용하여 검증하였다. 본 연구를 통하여 Facial Model 제작 시 최소의 UV spans 수로 최대 시각화 즉, 원본의 형상을 최대한 유지하면서 작업시간과 Rendering 시간 단축 및 Data 용량을 줄일 수 있는 Modeling 방법을 제안하였고, 향후 자연스런 Facial Animation 제작 및 연구에도 많은 도움이 될 것으로 기대된다.

• 한국CDE학회논문집
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• 제2권2호
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• pp.122-129
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• 1997

Ball rolling blending is a popular technique for blending between parametric surfaces. The ball rolling blend surface is conceptually a trajectory of a ball rolling between two base sufaces. It is constructed by sweeping a circular arc along a ball contact curve pair. Since a ball rolling blend surfaces does not have a polynomial form like a Bezier surface patch, it is impossible to apply this method directly to a commercial CAD/CAM system. In this paper an algorithm is developed to approximate a ball rolling blend surface into Bezier surface patches. Least square method is applied to obtain proper Bezier surface patches under a given tolerance. The Bezier surface patches have degree three or more and guarantee VC1-continuity.

• 한국지능시스템학회논문지
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• 제20권6호
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• pp.748-754
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• 2010

깨어진 항아리 조각들을 가상 공간에서 조립하기 위하여 조각 표면을 이용한 빠른 3차원 회전축 추정 방법을 제안한다. 물체의 원형성과 표면의 국지적 평면성을 이용하여 대칭축을 찾는 방법을 사용한다. 항아리 조각 같은 회전축 대칭 물체는 반지름이 다른 여러 원통의 중첩으로 생각될 수 있다. 각 원통의 원형성을 회전축 계산에 이용한다. 먼저, 표면 위 임의의한 점을 지정하고 그 점을 통과하는 여러 개의 원통상의 궤도를 각각의 곡률의 변화를 측정 검사하여 조사한다. 올바른 원의 궤도는 곡률의 변화가 없을 것이므로 가장 작은 곡률의 변화가 원의 궤도로 선택된다. 또한 원의 중심점으로 축이 통과하는 경로가 되므로 원의 중심점이 축의 위치가 된다. 표면의 국지적 평면성과 프로파일 곡선 근사를 통한 축 위치 추정 방법 또한 연구 되었다. 제안된 방법은 기존의 방법에 비해 계산 속도가 향상되었고 조각의 부위에 영향을 받지 않는 강건성을 가짐을 실험적으로 입증하였다.

• Journal of Electrical Engineering and Technology
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• 제4권2호
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• pp.277-281
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• 2009

The complex resonant frequency problem of a superconductor patch is formulated in terms of an integral equation which is the kernel of a dyadic Green's function. To include the effect of the superconductivity of the microstrip patch, the surface complex impedance of the superconductor film is introduced using the two fluids model of Gorter and Casimir. The Galerkin procedure is used in the resolution of the electric field integral equation. Numerical results concerning the effect of the operating temperature of a superconductor patch on the characteristics of the antenna are presented.

• 소성∙가공
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• 제6권5호
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• pp.416-424
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• 1997

In the present study, a contact search and check algorithm for general tool surface described by triangular FE patch is proposed. To improve numerical stability, SEAM element using the linear Coons interpolation has been used. To check the proposed algorithm, both clover cup and L-shape cup deep drawing processes are calculated. The computed results shows that the proposed contact algorithm can be successfully applied for sheet metal forming processes with general shaped tools.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2001년도 종합학술발표회 논문집 Vol.11 No.1
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• pp.91-95
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• 2001

This paper presents that photonic bandgap structures suppressing the propagation of surface waves can improve the performance of the patch antennas on thick high dielectric constant substrate. The forbidden propagation of surface wave due to the photonic bandgap enhances the radiation efficiency and reduce the back radiation drastically with maintaining the small size and wide bandwidth of the antennas.

• KSTLE International Journal
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• 제2권1호
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• pp.29-34
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• 2001

The stress field in a body caused by the tangential loading of a rectangular patch on a semi-infinite solid has been solved analytically using a potential function. The validity of the results of this study was preyed by Saint-Venant's principle in the remote region and by the superposition of point loads in the vicinity of the surface.

• 대한의용생체공학회:의공학회지
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• 제35권6호
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• pp.203-210
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• 2014

Wearable medical device has been a resurgence of interest thanks to the development of technology and propagation of smart phone in recent years. Various types of wearable devices have been introduced and available in market. Capacitive coupled electrode which measures electrocardiogram over cloth is able to be applied wearable device. In previous approaches of capacitive electrode, they need proper pressure for stable contact of the electrode to body surface. However, wearable device that gives pressure on body surface is not suitable for long-term monitoring. In this study, we proposed adhesive polyurethane-based capacitive electrode for patch-type wearable electrocardiogram (ECG) monitoring device. Self-adhesive polyurethane make the electrode and whole system be adhered to the surface of skin without any pressure. The patch-type system is consisted of analog filter, analog-to-digital converter and wireless transmission module and designed to be attached on the body as a patch. To validate the feasibility of the developed system, we measured ECG signal in stable and active state and extracted heart rate. Therefore, we observed skin response after long-term attachment for biocompatibility of the adhesive polyurethane and adhesive strength of it. The result shows the possibility of applying the developed system for ECG monitoring in real-life.