• The Journal of Advanced Prosthodontics
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• 제10권3호
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• pp.252-258
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• 2018

PURPOSE. The purpose of this study was to evaluate the repeatability and matching accuracy between two identical intraoral spectrophotometers. MATERIALS AND METHODS. The maxillary right central incisor, canine, and mandibular left central incisor of each of 30 patients were measured using 2 identical intraoral spectrophotometers with different serial numbers (EasyShade V). The color of each shade tab from 3 shade guides (VITA 3D-Master) was also determined with both devices. All measurements were performed by a single operator. Statistical analyses were performed to verify the repeatability, accuracy, and the differences between the devices with paired t-tests, one-way ANOVA, and intra-class correlation coefficients (ICCs) (${\alpha}=.05$). RESULTS. A high level of measurement repeatability (ICC>0.90) among $L^*$, $a^*$, and $b^*$ color components was observed within and between devices (P<.001). Intra-device matching agreement rates were 80.00% and 81.11%, respectively, while inter-device matching agreement rate was 51.85%. ANOVA revealed no significant different color values within each device, while paired t-test provided significant different color values between both devices. The CIEDE2000 color differences between both devices were $2.28{\pm}1.61$ ${\Delta}E_{00}$ for in-vivo readings. Regarding the clinical matching accuracy of both devices, ${\Delta}E_{00}$ values between teeth and matching shade tabs were $3.05{\pm}1.19$ and $2.86{\pm}1.02$, respectively. CONCLUSION. Although two EasyShade V devices with different serial numbers show high repeatability of CIE $L^*$, $a^*$, and $b^*$ measurements, they could provide different color values and shade for the same tooth.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 추계학술대회 논문집
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• pp.153-156
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• 2008

According to the conversion of building into skyscraper, most buildings have curtain wall structures, so the shading device of building is required. The types of shading systems are a roller shade, venetian bind, and vatical blind and so on. A miler shade is mostly used among the shading systems. An experimental evaluation was verified whether there was an effect of shading materials(Perforated panel, Fabric) in each condition by an experiment with artificial lighting and daylight.

• 대한건축학회논문집:구조계
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• 제34권12호
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• pp.65-72
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• 2018

The purpose of this study is to predict vertical illuminance accurately at the design stage of a building without the help of simulation tools. Comparing two well-known vertical illuminance prediction algorithms with measured values, it is verified that the Igawa model is more consistent with the measured values than the Perez model. Using the DIVA program, we simulated the vertical illuminance at 30-degree intervals from south to north, compared with the vertical illuminance calculated with the Igawa model. The result of calculation values were verified from 120 degrees east to 120 degrees west. The vertical illuminance values with each of three shade devices were calculated using the Igawa model, and compared with the vertical illuminance simulated by DIVA program. As a result, all the errors when installing horizontal / vertical / grid shade divices were included in the error standard specified by ASHRAE.

• Restorative Dentistry and Endodontics
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• 제49권1호
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• pp.7.1-7.11
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• 2024

Objectives: This study aimed to evaluate the impact of substrate color and interface distance on the color adjustment of 2 single-shade composites, Vittra APS Unique and Charisma Diamond One. Materials and Methods: Dual disc-shaped specimens were created using Vittra APS Unique or Charisma Diamond One as the center composite, surrounded by shaded composites (A1 or A3). Color measurements were taken with a spectrophotometer against a gray background, recording the color coordinates in the CIELAB color space. Illumination with a light-correcting device and image acquisition using a polarizing filter-equipped cell phone were performed on specimens over the same background. Image processing software was used to measure the color coordinates in the center and periphery of the inner composite and in the outer composite. The color data were then converted to CIELAB coordinates and adjusted using data from the spectrophotometer. Color differences (ΔE₀₀) between the center/periphery of single-shade and outer composites were calculated, along with color changes in single-shade composites caused by different outer composites. Color differences for the inner composites surrounded by A1 and A3 were also calculated. Data were analyzed using repeated-measures analysis of variance (α = 0.05). Results: The results showed that color discrepancies were lowest near the interface and when the outer composite was whiter (A1). Additionally, Charisma Diamond One exhibited better color adjustment ability than Vittra APS Unique. Conclusions: Color discrepancies between the investigated single-shade composites diminished towards the interface with the surrounding composite, particularly when the latter exhibited a lighter shade.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.571-576
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• 2006

A Color Discerning Device(CDD) is the equipment to use in Rice Processing Complex(RPC). By use a high-speed charge-coupled device camera, CDD can sorting discolored grain according to light and shade. The existing CDD's driving performance is not so good as overseas machine. Besides, transportation process causes a defect in the mechanism from impact or harmonic excitation or etc. This study is represented the problem of CDD through modal analysis and static analysis by using ANSYS workbench. To analysis the problem of driving condition, devide each part of CDD for performed modal analysis. The problem of driving condition and transportation process solved by carry out modal analysis and static analysis.

• 한국산학기술학회논문지
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• 제19권10호
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• pp.590-597
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• 2018

최근 전 세계적으로 에너지 고갈과 기후변화 문제로 인하여, 재생 가능하고 친환경적인 태양광전원에 대한 관심이 증가되고 있다. 그러나, 이러한 태양광전원은 주변 환경에 따라 출력이 크게 변동되는데, 일부 모듈에만 음영이 발생하여도 태양광전원의 전체적인 운용 효율이 상당히 저하되는 문제점을 가지고 있다. 즉, 기존의 제어방식에서는 모듈을 직렬로 연결된 스트링들이 인버터에 연계되어 있으므로, 일부 모듈에 부분 음영이 발생하면 해당 스트링의 전압이 인버터의 동작전압범위를 벗어나게 되어, 해당 스트링이 인버터에서 탈락되는 문제점이 발생할 수 있다. 따라서, 본 논문에서는 음영에 의하여 태양광 스트링이 인버터에서 탈락되는 것을 방지하기 위하여, 태양광스트링에 리튬이온전지를 연결한 태양광전원 운용효율 향상장치의 제어알고리즘을 제안한다. 또한, 전력전자 회로해석 상용 프로그램인 PSIM S/W를 이용하여 태양광스트링, 리튬이온전지, 계통연계형 인버터로 구성된 태양광전원의 운용효율향상장치의 모델링을 수행하여 운용 특성을 분석한 결과, 직렬로 연결된 리튬이온전지가 부분 음영에 의하여 전압 저하를 발생한 해당 스트링의 전압을 보상함으로서, 해당 스트링이 인버터에서 탈락되는 현상을 개선하여 태양광전원의 운용효율을 향상시킬 수 있음을 알 수 있었다.

• 한국태양에너지학회 논문집
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• 제38권6호
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• pp.1-14
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• 2018

The shading device on the window of the building can be an passive solution to reduce the cooling load and lighting energy, as well as improving the indoor comfort. It is also an architectural element that must be considered for building energy-efficient buildings such as eco-buildings and zero-energy buildings. However, due to various building environments and various shading devices, the installation of excessive shade may lead to the risk of losing the effectiveness of windows. In this study, we propose a method for optimal automatic control of shading device and evaluate its effectiveness by energy analysis of several shading devices.

• 대한치과기공학회지
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• 제35권3호
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• pp.193-200
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• 2013

Purpose: In this study, in order to provide objective standard of the mixed concentration of the zirconia coloring-liquids, compare the shade differences after colored zirconia blocks from different concentrations. Methods: After immersion for 2 minutes zirconia specimen ($1.5{\times}1.5{\times}0.6{\pm}0.01mm$) in coloring-liquids that produced different concentrations, were sintered in furnace dedicated. Then, it was measured in spectrophotometer and Shadepilot. It has been determined mean and standard deviation of the color difference for each group, and verified by one-way ANOVA using the (version12.0) SPSS WIN Program the difference in shade according to the concentration at the significance level of 95% confidence, it conducted a Tukey's multiple range test to post-test. Results: The mean of $L^*$ was decreased toward LN35 group, however the mean of $a^*$ and $b^*$ was increased(p<.05). There is a statistically significant difference in the results of $L^*$ post hoc test of each group was LN15-LN30/LN35, LN20-LN30/LN35, LN25-LN30/LN35, and LN30-LN35 group. The $a^*$ group, it was found that there is a statistically significant difference in all groups for each(p<.05). The $b^*$ group, it was found that there is a statistically significant difference in all groups except the LN25-LN30(p<.05). Conclusion: In order to make effective use of the coloring-liquids of zirconia, the device objective, accurate concentration measurement is required, from the present study, we presented evidence basic to this.

• 치과방사선
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• 제21권2호
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• pp.415-423
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• 1991

This study was performed to evaluate the geometric standardization of periapical intraoral radiography. Image distortion was measured by analysing serial radiography obtained from dry skull using 5 types of bite registration device. After 16 weeks, the angular distortion of Pattern resin was 0.26±0.14 degree(Horizontal angle 0.17±0.14, Vertical angle 0.16±0.11) which was the lowest among the 5 registration device, and that of putty type Exaflex was 0.49±0.35 degree(Horizontal angle 0.42±0.35, Vertical angle 0.17±0.13) which was the highest. The mean amount of distortion variance of Tooth shade acrylic at each experimental period was 0.06±0.08 which was the lowest among the 5 registration device, and that of XCP alone was 0.ll±0.13 which was the highest.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.702-707
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• 2007

A Color Discerning Device(CDD) is the equipment to use in a Rice Processing Complex(RPC). A CDD can sorting discolored grain according to light and shade. The existing a CDD's driving performance is not so good as overseas machine. Besides, transportation process causes a defect in the mechanism from impact or harmonic excitation or etc. This study is represented the problem of CDD through experiment and simulation on a CDD. To analysis the problem of driving condition, devide each part of CDD for performed modal analysis. The problem of driving of driving condition and transportation process solved by carry out modal analysis and static analysis.