188,645 research outputs found
Scalable depth maps with R-D optimized embedding
No full textRecent work has highlighted the importance of incorporating geometry information into the compression of depth maps. In prior approaches however the geometry information is not resolution scalable nor amenable to embedded coding. In this paper we propose a novel compression strategy for depth maps that incorporates geometry information while achieving the goals of scalability and embedded representation. Our scheme involves two separate image pyramid structures, one for breakpoints and other for sub-band samples produced by a breakpoint-adaptive transform. Breakpoints capture geometric attributes and are amenable to scalable coding. We develop an R-D optimization framework for the breakpoint data. We also use a variation of the EBCOT scheme to produce embedded bit-streams for both the breakpoint and sub-band data, allowing them to be independently and incrementally sequenced based on R-D considerations
Effect of simulated space environments on piezoelectric vinylidene flouride-based polymers
No full textPiezoelectric polymers based on polyvinylidene flouride (PVDF) are of interest as adaptive materials for large aperture space-based telescopes. In this study, two piezoelectric polymers, PVDF and P(VDF-TrFE), were exposed to conditions simulating the thermal, radiative and atomic oxygen conditions of low Earth orbit. The degradation pathways were governed by a combination of chemical and physical degradation processes with the molecular changes primarily induced via radiative damage, and physical damage from temperature and atomic oxygen exposure, as evident from depoling, loss of orientation and surface erosion. The piezoelectric responsiveness of each polymer was strongly dependent on exposure temperature. Radiation and atomic oxygen exposure caused physical and chemical degradation, which would ultimately cause terminal damage of thin films, but did not adversely affect the piezoelectric properties
Degradation of piezoelectric fluropolymers in space environments
No full textThe performance criteria of piezoelectric polymers based on polyvinylidene flouride (PVDF) in complex space environments have been evaluated. Thin films of these materials are being explored as in-situ responsive materials for large aperture space-based telescopes with the shape deformation and optical features dependent on long-term deformation and optical features dependent on long-term degradation effects, mainly due to thermal cycling, vacuum UV exposure and atomic oxygen. A summary of previous studies related to materials testing and performance prediction based on a laboratory environment is presented. The degradation pathways are a combination of molecular chemical changes primarily induced via radiative damage and physical degradation processes due to temperature and atomic oxygen exposure resulting in depoling, loss of orientation and surface erosing. Experimental validation for these materials to be used in space is being conducted as part of MISSE-6 (Materials International Space Station Experiment) with an overview of the experimental strategies discussed here
Mathew R. Martin, ed. Selimus by Robert Greene. Peterborough, ON: Broadview Press, 2022.
No full textThis review considers Mathew R. Martin\u27s edition of Selimus by Robert Greene
Scalable Coding of Depth Maps with R-D Optimized Embedding
No full textRecent work on depth map compression has revealed the importance of incorporating a description of discontinuity boundary geometry into the compression scheme. We propose a novel compression strategy for depth maps that incorporates geometry information while achieving the goals of scalability and embedded representation. Our scheme involves two separate image pyramid structures, one for breakpoints and the other for sub-band samples produced by a breakpoint-adaptive transform. Breakpoints capture geometric attributes, and are amenable to scalable coding. We develop a rate-distortion optimization framework for determining the presence and precision of breakpoints in the pyramid representation. We employ a variation of the EBCOT scheme to produce embedded bit-streams for both the breakpoint and sub-band data. Compared to JPEG 2000, our proposed scheme enables the same the scalability features while achieving substantially improved rate-distortion performance at the higher bit-rate range and comparable performance at the lower rates
Charles R. Buckalew CdV (from House Representatives, 38th Congress Album)
No full textThe photograph features a front-facing bust portrait of Charles R. Buckalew (United States Senator from Pennsylvania). On its verso, it has a Mathew Brady backmark. The CdV is included in an album containing CdVs of Lincoln\u27s cabinet members as well as senators and representatives from the 38th Congress.https://scholarsjunction.msstate.edu/fvw-cdv/1109/thumbnail.jp
John R. McBride CdV (from House Representatives, 38th Congress Album)
No full textThe photograph features a portrait of John R. McBride (United States Representatives from Oregon). On its verso, it has a Mathew Brady backmark. The CdV is included in an album containing CdVs of Lincoln\u27s cabinet members as well as senators and representatives from the 38th Congress.https://scholarsjunction.msstate.edu/fvw-cdv/1158/thumbnail.jp
Christopher Marlowe, The Massacre at Paris, ed. Mathew R. Martin (Manchester: Manchester University Press/The Revels Plays, 2021)
No full textA review of Mathew R. Martin's new edition of Marlowe's Massacre at Paris
James R. Doolittle CdV (from House Representatives, 38th Congress Album)
No full textThe photograph features a right-side profile portrait of James R. Doolittle (United States Senator from Wisconsin). On its verso, it has a Mathew Brady backmark. The CdV is included in an album containing CdVs of Lincoln\u27s cabinet members as well as senators and representatives from the 38th Congress.https://scholarsjunction.msstate.edu/fvw-cdv/1100/thumbnail.jp
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