180 research outputs found
Framework Programmable Platform for the Advanced Software Development Workstation: Preliminary system design document
The Framework Programmable Software Development Platform (FPP) is a project aimed at combining effective tool and data integration mechanisms with a model of the software development process in an intelligent integrated software environment. Guided by the model, this system development framework will take advantage of an integrated operating environment to automate effectively the management of the software development process so that costly mistakes during the development phase can be eliminated. The focus here is on the design of components that make up the FPP. These components serve as supporting systems for the Integration Mechanism and the Framework Processor and provide the 'glue' that ties the FPP together. Also discussed are the components that allow the platform to operate in a distributed, heterogeneous environment and to manage the development and evolution of software system artifacts
Radio Astronomy
Contains reports on three research projects.National Aeronautics and Space Administration (Grants No. NsG-250-62 and No. NsG-419)United States Navy, Office of Naval Research (Contract Nonr-3963(02)-Task 2)Lincoln Laboratory (Purchase Order DDL BB-107)United States ArmyUnited States NavyUnited States Air Force (Contract AF19(604)-7400
Radio Astronomy
Contains reports on five research projects.National Aeronautics and Space Administration (Grant NGL 22-009-016)National Aeronautics and Space Administration (Grant NGL 22-009-421)National Science Foundation (Grant GP-13056)California Institute of Technology Contract 95256
Perceptual quality of BRDF approximations: dataset and metrics
International audienceBidirectional Reflectance Distribution Functions (BRDFs) are pivotal to the perceived realism in image synthesis. While measured BRDF datasets are available, reflectance functions are most of the time approximated by analytical formulas for storage efficiency reasons. These approximations are often obtained by minimizing metrics such as L 2 —or weighted quadratic—distances, but these metrics do not usually correlate well with perceptual quality when the BRDF is used in a rendering context, which motivates a perceptual study. The contributions of this paper are threefold. First, we perform a large-scale user study to assess the perceptual quality of 2026 BRDF approximations, resulting in 84138 judgments across 1005 unique participants. We explore this dataset and analyze perceptual scores based on material type and illumination. Second, we assess nine analytical BRDF models in their ability to approximate tabulated BRDFs. Third, we assess several image-based and BRDF-based (Lp, optimal transport and kernel distance) metrics in their ability to approximate perceptual similarity judgments
Appearance Modeling of Living Human Tissues
This is the peer reviewed version of the following article: Nunes, A.L.P., Maciel, A., Meyer, G.W., John, N.W., Baranoski, G.V.G., & Walter, M. (2019). Appearance Modeling of Living Human Tissues, Computer Graphics Forum, which has been published in final form at https://doi.org/10.1111/cgf.13604. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-ArchivingThe visual fidelity of realistic renderings in Computer Graphics depends fundamentally upon how we model the appearance of
objects resulting from the interaction between light and matter reaching the eye. In this paper, we survey the research addressing
appearance modeling of living human tissue. Among the many classes of natural materials already researched in Computer
Graphics, living human tissues such as blood and skin have recently seen an increase in attention from graphics research. There
is already an incipient but substantial body of literature on this topic, but we also lack a structured review as presented here.
We introduce a classification for the approaches using the four types of human tissues as classifiers. We show a growing trend
of solutions that use first principles from Physics and Biology as fundamental knowledge upon which the models are built. The
organic quality of visual results provided by these Biophysical approaches is mainly determined by the optical properties of
biophysical components interacting with light. Beyond just picture making, these models can be used in predictive simulations,
with the potential for impact in many other areas
Photosynthetic characteristics of the benthic diatom species Nitzschia frustulum (KĂĽtzing) Grunow isolated from a soda pan along temperature-, sulfate- and chloride gradients
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