illumination method
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Buildings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 193
Author(s):  
Marcin Brzezicki

The current study investigates the issue of computer-aided daylight evaluation in a museum room with a dropped translucent ceiling. In this type of room, daylight is admitted through classic windows located in the facade and then distributed in the plenum, which is located above the exhibition space and transmitted through the translucent ceiling into the museum room. This illumination method enables guiding daylight deep into the room, excluding the impact of direct solar radiation. The presented study is based on data obtained through computer-aided daylight simulation by DeLuminæ (DL-Light, ver. 11.0.9) software using the Radiance software for all calculations and real weather data for Wroclaw, Poland. A museum room of 12 × 12 m with three different heights of the plenums was simulated to establish an optimal relation of the width to height plenum ratio. Next, the annual exposure in K lx·h/year was calculated, as sensitive works of art may be subjected to damage caused by light exposure. To further reduce illumination, the simulation of an automatic shading system in the form of horizontal louvers was performed. The system was activated when certain illumination values were detected by the sensor on the building’s roof.


Author(s):  
W. Leontiev ◽  
E. Magni ◽  
C. Dettwiler ◽  
C. Meller ◽  
R. Weiger ◽  
...  

Abstract Objectives The aim of the present study was to compare the accuracy of the conventional illumination method (CONV) and the fluorescence-aided identification technique (FIT) for distinguishing between composite restorations and intact teeth using different fluorescence-inducing devices commonly used for FIT. Materials and methods Six groups of six dentists equipped with one of six different FIT systems each independently attempted to identify composite restorations and intact teeth on a full-mouth model with 22 composite restorations using CONV and, 1 h later, FIT. The entire procedure was repeated 1 week later. Sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values, including 95% confidence intervals (CI), were calculated for CONV and FIT overall and for each device. The influence of examiner age, method, and device on each parameter was assessed by multivariate analysis of variance. Results The sensitivity (84%, CI 81–86%), specificity (94%, CI 93–96%), PPV (92%, CI 90–94%), and NPV (90%, CI 88–91%) of FIT was significantly higher than that of CONV (47%, CI 44–50%; 82%, CI 79–84%; 66%, CI 62–69%, and 69%, CI 68–71%, respectively; p<0.001). The differences between CONV and FIT were significant for all parameters and FIT systems except VistaCam, which achieved no significant difference in specificity. Examiners younger than 40 years attained significantly higher sensitivity and negative predictive values than older examiners. Conclusions FIT is more reliable for detecting composite restorations than the conventional illumination method. Clinical relevance FIT can be considered an additional or alternative tool for improving the detection of composite restorations.


2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Patricia Chajín ◽  
Germán Camacho ◽  
Edwar Herrera

Complex structures like subthrust show high risk during the definition of structural traps in low quality seismic images in depth, so we can use the structural interpretation to simulate the subthrust illumination by wavefield of a prospect area in order to reduce the uncertainty and support the oil exploration process. In general, we performed an exercise of 2D geophysical modeling using a wavefield illumination simulator. At first, we interpreted two geological models from a seismic line in depth. The geological interpretation was adjusted with information about structural styles in this part of Upper Magdalena Basin. Then, we use a velocity scenario and assign these velocities to both geological models. The wavefield illumination method allows us to see all of the wavepaths in the different pair of source-receivers in order to do a fast evaluation of the structure illumination. This could be used to improve the seismic acquisitions in structurally complex media.


2020 ◽  
Vol 2 (4) ◽  
pp. 202-210
Author(s):  
Malti Bansal ◽  
Raaghav Raj Maiya

The research paper prospects the theory of phototransistor ranging from the history of the device to its application in the real world. The research paper deep dives into the characteristics of the phototransistor while discussing its dependence on bias drive, bias voltage, and illumination intensity. The research paper includes a comparative study between the various types of phototransistors based on optical gain, spectral range, and efficiency. It also concludes the best illumination method for the phototransistor based on the optical gain parameter.


2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Jorge Madrid-Wolff ◽  
Manu Forero-Shelton

ABSTRACT Transmitted light imaging is an important tool in biophysics for applications that include sample analysis, recording samples whose viability is compromised by high levels of illumination (e.g., live cell tracking), and finding regions of interest in a sample. Koehler transillumination is a powerful illumination method used in commercial microscopes; yet commercial Koehler condensers are expensive, are difficult to integrate into tabletop systems, and make learning the concepts of Koehler illumination difficult because of their closed-box nature. Here, we show a protocol to build a simple 4f Koehler illumination system that offers advantages with respect to commercial condensers in terms of simplicity, cost, and compatibility with tabletop systems, such as open-source light sheet fluorescence microscopes. We include step-by-step instructions that can be followed by advanced undergraduate or graduate students without experience in optics on how to align and assemble the illuminator, along with a list of the necessary parts for assembly. We also include supplemental material that describes 4 supporting educational activities students can conduct with the apparatus and helps in the understanding of key concepts relevant to Koehler illumination and optics. The performance of the system is comparable to that of commercial condensers and significantly better, in terms of illumination homogeneity and depth of field (optical sections are possible), than that of LED flashlights, such as those found in low-cost diagnostic devices and tabletop systems.


2020 ◽  
Vol 59 (11) ◽  
pp. 3518 ◽  
Author(s):  
Huai-liang Zhang ◽  
Ling Peng ◽  
Yong-kang Luo ◽  
Sheng Yu

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4953
Author(s):  
Wei Shao ◽  
Kaibin Liu ◽  
Yunqiu Shao ◽  
Awei Zhou

At present, visual imaging is widely applied for surface defects such as bumps and scratches in the manufacture of precise parts with a highly reflective surface. However, the high light reflection and halo disturbance as a result of the illumination in visual imaging exert a direct influence on the accuracy of defect detection. In this regard, the present paper develops an adaptive illumination method based on space–time modulation for a visual imaging system. Furthermore, a digital micro-mirror device (DMD) is employed to realize the pixel-level spatiotemporal modulation of illumination. Then, in combination with the illumination intensity feedback of charge coupled device (CCD), the time-space ratio is adjusted automatically to achieve adaptive uniform illumination and effectively suppress the high light reflection and halo disturbance of highly reflective surfaces. The experimental results show that, in terms of restraining high light disturbance, the visibility and accuracy of visual imaging are improved.


2019 ◽  
Vol 86 (s1) ◽  
pp. 32-36 ◽  
Author(s):  
Chia-Wei Chen ◽  
Matthias Hartrumpf ◽  
Thomas Längle ◽  
Jürgen Beyerer

AbstractEllipsometry is a widely used optical method for the characterization of materials and thin films. However, only flat or nearly flat surfaces can be measured since small deviations of the angle of incidence might lead to significant experimental errors. In order to overcome the geometrical limitations of ellipsometry, the retroreflex ellipsometry developed at Fraunhofer IOSB is used. Based on this configuration, a new illumination method is proposed. When the sample is illuminated by modulated circular polarized light (LCP and RCP), the ellipsometric parameters (Ψ, Δ) and the tilted angle (Φ) can be determined directly. Combined with reflectance measurement or prior knowledge of optical properties of samples, the surface orientation can be obtained.


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