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Homogeneous codes for energy-efficient illumination and imaging

Matthew O'Toole, Supreeth Achar, Srinivasa G. Narasimhan, Kiriakos N. Kutulakos
2015 ACM Transactions on Graphics  
The homogeneous factorization equation maximizes energy efficiency subject to all imaging constraints, by maximizing the scalar γ or, equivalently, minimizing its reciprocal γ −1 : min γ,t,M,L  ...  Substituting the mask and illumination variables with a k l k and a −1 k m k satisfies the equality constraint for all scalars a k > 0.  ...  Instead, we reformulate and then relax this problem into a simpler form. Reformulation There is a bilinear relation between the masks m k and illumination patterns l k .  ... 
doi:10.1145/2766897 fatcat:2odc2wskjzcafg72ttxpxxmjpm

Assessment of Photosynthesis Tolerance to Herbicides, Heat and High Illumination by Fluorescence Imaging

Pedro Saura, Maria Jose Quiles
2009 The Open Plant Science Journal  
Fluorescence imaging represents a non-invasive tool for revealing and understanding spatial heterogeneity in leaf performance caused by external factors, such as abiotic stress.  ...  The control plants of all species showed homogeneous images of the fluorescence parameters throughout the leaf.  ...  The control images present a homogeneous colour throughout the leaf; the mean Y(II), F and NPQ values were 0.746, 0.071, and 0.254 respectively, indicating that the photochemical efficiency was high and  ... 
doi:10.2174/1874294700903010007 fatcat:gnddtxnqt5hrbfhedjumdswj6e

Calibration of the Spectrometer aboard the INTEGRAL satellite [article]

Stéphane Schanne, B. Cordier, M. Gros, D. Attié, P. v. Ballmoos, L. Bouchet, R. Carli, P. Connell, R. Diehl, P. Jean, J. Kiener, A. v. Kienlin, J. Knödlseder (+17 others)
2003 arXiv   pre-print
and high intensity radioactive sources for imaging performance measurements.  ...  A coded mask imaging technique provides a 2 deg angular resolution. The 16 deg field of view is defined by an active BGO veto shield, furthermore used for background rejection.  ...  (Italy), for their help and hospitality during the successive SPI calibration activities, as well as the staff from CNES in Toulouse (France) for their generous support during installation and operation  ... 
arXiv:astro-ph/0310792v1 fatcat:lyf6kshfabb35f7246vpjjv7ie

Local efficiency analysis of solar cells based on lock-in thermography

Otwin Breitenstein
2012 Solar Energy Materials and Solar Cells  
Assuming the local validity of the two-diode model, this information enables the construction of local and global dark and illuminated characteristics and of realistic images of local solar cell parameters  ...  like efficiency, fill factor, and open circuit voltage with a good spatial resolution.  ...  Iwig (MSC-Technik Halle) for writing the ''Local I-V 2'' code.  ... 
doi:10.1016/j.solmat.2012.07.019 fatcat:rgbnaxxro5dztkbgsprcoay4q4

Approximate Bias Compensation for Rendering Scenes with Heterogeneous Participating Media

Thomas Engelhardt, Jan Novák, Thorsten-W. Schmidt, Carsten Dachsbacher
2012 Computer graphics forum (Print)  
We investigate VPL-based methods for rendering scenes with participating media, and propose a novel and efficient approximate bias compensation technique.  ...  In the Crytek Sponza the clamped volumetric and surface illumination was rendered in 39 minutes (using 118k VPLs), while the missing energy was recovered using a two-bounce ABC in only 13 minutes.  ...  Acknowledgements We thank Christoph Weber for proof-reading drafts of the paper and the reviewers for helpful comments.  ... 
doi:10.1111/j.1467-8659.2012.03207.x fatcat:ksyvradwpnfgvn4kaaaxxtxm6e

Design of zoom homogenizer to control size of illumination field

Taeshin Kim
2018 Optical Engineering: The Journal of SPIE  
An equivalent lens system was used to derive the imaging condition and size of the illumination field.  ...  We proposed a zoom homogenizer that can control the size of the illumination field by adding one lens array to the conventional imaging-type beam homogenizer.  ...  The development of the 125 J·Hz laser system for laser peening was funded by the Ministry of Trade, Industry, and Energy (MI, Korea).  ... 
doi:10.1117/1.oe.57.3.035102 fatcat:6fs7yp47fjcrpetpklvpojry64

Demonstration of a simplified optical mouse lighting module by integrating the non-Lambertian LED chip and the free-form surface

Jui-Wen Pan, Sheng-Han Tu
2012 Applied Optics  
A cost-effective, high-throughput, and high-yield method for the efficiency enhancement of an optical mouse lighting module is proposed.  ...  We integrated imprinting technology and free-form surface design to obtain a lighting module with high illumination efficiency and uniform intensity distribution.  ...  This study was supported in part by the National Science Council, project number NSC100-2220-E-009-023 and NSC101-2314-B-384-001, and in part by the "Aim for the Top University Plan" of the National Chiao  ... 
doi:10.1364/ao.51.002834 pmid:22614583 fatcat:ainjbzbmnrcnvhemg4fotr57s4


Chandra Sekhar Reddy P, Eswara Reddy B, Vijaya Kumar V
2013 ICTACT Journal on Image and Video Processing  
The present paper proposed an Image Dimensionality Reduction using shape Primitives (IDRSP) model for efficient face recognition.  ...  One of the problems with the recent image classification and recognition approaches are they have to extract features on the entire image and on the large grey level range of the image.  ...  Janardhana Raju, Dean, Nalla Narasimha Reddy Education Society"s Group of Institutions for encouraging towards research and for providing advanced research lab facilities.  ... 
doi:10.21917/ijivp.2013.0101 fatcat:hodhgiqyhnharpi7zeoq6z34xq

Experimental study of local and integral efficiency behavior of a concave holographic diffraction grating

E. G. Loewen, E. K. Popov, J. Hoose, L. V. Tsonev
1990 Optical Society of America. Journal A: Optics, Image Science, and Vision  
In particular, peak values are less, and anomalies are usually absent or at least greatly attenuated.  ...  It has long been observed that the efficiency behavior of concave gratings differs from that of the well-studied plane gratings.  ...  In the region .0BA0G > 0.5 absolute efficiency gain amounts to 5%, which is almost the same as that for homogeneous illumination.  ... 
doi:10.1364/josaa.7.001764 fatcat:ix56zugtjfem7dttpstscy6saq

Using Chlorophyll Fluorescence Imaging for Early Assessment of Photosynthesis Tolerance to Drought, Heat and High Illumination [chapter]

Mara Jos, Helena Ibez, Romualdo Muoz
2012 Artificial Photosynthesis  
The results are shown as colour-coded images according to the pattern shown below the images. All the leaves provided similar images with a homogeneous colour throughout the leaf.  ...  Images are colour coded according to the pattern (0 to 1 x 100 range) shown below the images.  ...  Using Chlorophyll Fluorescence Imaging for Early Assessment of Photosynthesis Tolerance to Drought, Heat and High Illumination, Artificial Photosynthesis, Dr Mohammad Najafpour (Ed.), ISBN: 978-953-307  ... 
doi:10.5772/26136 fatcat:yrxuqnrhavh4zdq7oaqzaw6zk4

Metropolis Monte Carlo simulation scheme for fast scattered X-ray photon calculation in CT

Yuan Xu, Yusi Chen, Zhen Tian, Xun Jia, Linghong Zhou
2019 Optics Express  
Monte Carlo (MC) method is commonly considered as the most accurate approach for particle transport simulation because of its capability to precisely model physics interactions and simulation geometry.  ...  The path-by-path simulation scheme ensures contribution of every sampled event to the signal of interest, improving overall efficiency.  ...  Acknowledgments We thank the members of the MCSimulation group from Department of Radiation Oncology at University of Texas Southwestern Medical Center for their assistance with comments and suggestions  ... 
doi:10.1364/oe.27.001262 pmid:30696195 pmcid:PMC6410917 fatcat:qlernvpsebfwpg7mycoi6ygptu

Comparison of DLIT- and PL-based Local Solar Cell Efficiency Analysis

Otwin Breitenstein, Chao Shen, Henner Kampwerth, Martin A. Green
2013 Energy Procedia  
The physical reasons for the differences between DLIT and PL based local efficiency analysis are discussed.  ...  Special methods have been proposed for evaluating DLIT or PL images taken under various conditions with the goal to extract the local two-diode parameters.  ...  Acknowledgements This work was financially supported by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety and by industry partners within the research cluster "SolarWinS  ... 
doi:10.1016/j.egypro.2013.07.243 fatcat:ddqmq2biozampl72taahmobb7i

Analysis of the Square Beam Energy Efficiency of a Homogenizer Near the Target for Laser Shock Peening

Taeshin Kim, Seungjin Hwang, Kyung Hee Hong, Tae Jun Yu
2016 Journal of the Optical Society of Korea  
Then, we found the relationship between the depth of focus for the laser shock peening and four main parameters of the square beam homogenizer: the plasma threshold of the metal, the number of lenslets  ...  We analyzed through numerical simulations the properties of a square beam homogenizer near the target for laser shock peening.  ...  The beam homogenizer was configured in CODE V, a lens design program.  ... 
doi:10.3807/josk.2016.20.3.407 fatcat:cldnjt7cfjfnhmav7aaswn66vi

A New Energy Function for Segmentation and Compression

Michael King, Zinovi Tauber, Ze-Nian Li
2007 Multimedia and Expo, 2007 IEEE International Conference on  
We propose a new DCT-based energy function E DCT for objectoriented segmentation and compression.  ...  Tests on images and videos show promising results, where still image compression achieves over 15% improvement over JPEG and video compression achieves similar improvement over MPEG-2.  ...  We propose a DCT-based energy function that groups pixels into regions of similar textures. These regions facilitate a more efficient image and video compression than global methods.  ... 
doi:10.1109/icme.2007.4284983 dblp:conf/icmcs/KingTL07 fatcat:vtoqsxg7jrdfpcp7evwleyclwq

Optical Modeling of Laser Ablation for Microstructure Fabrication

M C Gower
2013 Journal of Laser Micro/Nanoengineering  
properties of the laser beam and delivery system.  ...  The model includes secondary illumination effects produced by the microstructure created by successive pulses (wall reflections, refraction, wave guiding, shadowing, etc.) as well as the complete optical  ...  homogenizers and the imaging objective NA.  ... 
doi:10.2961/jlmn.2013.01.0012 fatcat:zwciz4jw6jcopmweatgntnacjm
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