Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Environmental Sciences (1245)
- Earth Sciences (617)
- Physics (567)
- Computer Sciences (529)
- Chemistry (477)
-
- Geology (415)
- Sustainability (385)
- Engineering (377)
- Life Sciences (353)
- Social and Behavioral Sciences (304)
- Mathematics (287)
- Water Resource Management (209)
- Oceanography and Atmospheric Sciences and Meteorology (196)
- Environmental Monitoring (171)
- Environmental Indicators and Impact Assessment (157)
- Natural Resources Management and Policy (138)
- Hydrology (129)
- Civil and Environmental Engineering (120)
- Computer Engineering (117)
- Applied Mathematics (116)
- Geography (93)
- Forest Sciences (76)
- Fresh Water Studies (76)
- Education (71)
- Systems Architecture (68)
- Medicine and Health Sciences (66)
- Glaciology (60)
- Natural Resources and Conservation (57)
- Public Affairs, Public Policy and Public Administration (57)
- Keyword
-
- Climatic changes (76)
- Sustainability (51)
- Sustainable agriculture (43)
- Hydrologic models (41)
- Finite element method (38)
-
- Machine learning (38)
- Data mining (35)
- Hydrodynamics -- Mathematical models (34)
- Image processing -- Digital techniques (34)
- City planning -- Environmental aspects (33)
- Reconstructability Analysis (33)
- Magnetic resonance imaging (31)
- Sustainable urban development (30)
- Neural networks (Computer science) (29)
- Cities and towns (28)
- Cooperation (28)
- Information Theory (28)
- Multivariate analysis discrete multivariate modeling (28)
- Numerical analysis (28)
- Partnership (28)
- Probabilistic graphical modeling (28)
- Universities and colleges (28)
- Contrast media (Diagnostic imaging) (27)
- Ecosystem services (27)
- Nanostructured materials (27)
- Fluid dynamics (26)
- Computer vision (25)
- Galerkin methods (25)
- System theory (25)
- Computer software -- Development (24)
- Publication Year
- Publication
-
- Dissertations and Theses (1027)
- Physics Faculty Publications and Presentations (336)
- Chemistry Faculty Publications and Presentations (285)
- Environmental Science and Management Faculty Publications and Presentations (278)
- Mathematics and Statistics Faculty Publications and Presentations (276)
-
- Computer Science Faculty Publications and Presentations (219)
- Geology Faculty Publications and Presentations (188)
- All Sustainability History Project Oral Histories (119)
- Institute for Sustainable Solutions Publications and Presentations (100)
- Civil and Environmental Engineering Faculty Publications and Presentations (93)
- University Honors Theses (92)
- Student Research Symposium (86)
- Systems Science Faculty Publications and Presentations (85)
- Environmental Science and Management Professional Master's Project Reports (82)
- Geography Faculty Publications and Presentations (68)
- Center for Lakes and Reservoirs Publications and Presentations (56)
- Institute for Natural Resources Publications (35)
- Systems Science Friday Noon Seminar Series (30)
- Mechanical and Materials Engineering Faculty Publications and Presentations (29)
- Campus Sustainability Office Publications, Reports and Presentations (26)
- Economics Faculty Publications and Presentations (21)
- Civil and Environmental Engineering Master's Project Reports (20)
- Special Collections: Oregon Public Speakers (20)
- Portland Institute for Computational Science Publications (17)
- Urban Studies and Planning Faculty Publications and Presentations (17)
- Biology Faculty Publications and Presentations (14)
- REU Final Reports (10)
- Anthropology Faculty Publications and Presentations (9)
- Gin McCollum (9)
- ESM Colloquium (8)
- Publication Type
- File Type
Articles 3271 - 3300 of 3797
Full-Text Articles in Physical Sciences and Mathematics
Symmetry, Symmetry Breaking, And The Current View Of The Dirac Monopole, Erik Kristian Leder
Symmetry, Symmetry Breaking, And The Current View Of The Dirac Monopole, Erik Kristian Leder
Dissertations and Theses
The ideas of symmetry and symmetry breaking are considered in the context of classical gauge theory. Local U(l) symmetry is developed for a complex scalar field and electromagnetism is identified as the associated gauge field. Local S0(3) theory for a triplet of real scalar fields is derived and the incorporation of additional gauge fields is demonstrated. Symmetry breaking for the S0(3) gauge theory is performed and the gauge fields are shown to acquire mass by the Higgs mechanism. The equations of the t'Hooft-Polyakov monopole are derived and compared to those of the magnetic monopole of Dirac.
Cheetahs Are Fast, But Nearly Irrelevant, Calton Pu, Jonathan Walpole, Charles Consel
Cheetahs Are Fast, But Nearly Irrelevant, Calton Pu, Jonathan Walpole, Charles Consel
Computer Science Faculty Publications and Presentations
A brief paper submitted to the NSF Workshop on New Challenges and Directions for Systems Research, held in St. Louis, Mo., July 31-August 1, 1997. Outlines the case for more cooperation among software system architects, and a less reductionistic approach to software development.
Researchers Pool Knowledge About Antarctic Dry Valleys, Andrew G. Fountain, Sarah Spaulding
Researchers Pool Knowledge About Antarctic Dry Valleys, Andrew G. Fountain, Sarah Spaulding
Geology Faculty Publications and Presentations
Most of us think of ice when we think of the Antarctic, and rightly so, considering that only 5% of it is ice-free. Dry valleys--the ice-free areas--have sandy, rocky valley floors, ice-covered lakes, and streams that flow only two months of the year. The McMurdo Dry Valleys (78øS 163øE) are the largest of these regions.
Dynamic Load Distribution In Mist, K. Al-Saqabi, R. M. Prouty, Dylan Mcnamee, Steve Otto, Jonathan Walpole
Dynamic Load Distribution In Mist, K. Al-Saqabi, R. M. Prouty, Dylan Mcnamee, Steve Otto, Jonathan Walpole
Computer Science Faculty Publications and Presentations
This paper presents an algorithm for scheduling parallel applications in large-scale, multiuser, heterogeneous distributed systems. The approach is primarily targeted at systems that harvest idle cycles in general-purpose workstation networks, but is also applicable to clustered computer systems and massively parallel processors. The algorithm handles unequal processor capacities, multiple architecture types and dynamic variations in the number of processes and available processors. Scheduling decisions are driven by the desire to minimize turnaround time while maintaining fairness among competing applications. For efficiency, the virtual processors (VPs) of each application are gang scheduled on some subset of the available physical processors.
A Toolkit For Specializing Production Operating System Code, Crispin Cowan, Dylan Mcnamee, Andrew P. Black, Calton Pu, Jonathan Walpole, Charles Krasic, Perry Wagle, Qian Zhang
A Toolkit For Specializing Production Operating System Code, Crispin Cowan, Dylan Mcnamee, Andrew P. Black, Calton Pu, Jonathan Walpole, Charles Krasic, Perry Wagle, Qian Zhang
Computer Science Faculty Publications and Presentations
Specialization has been recognized as a powerful technique for optimizing operating systems. However, specialization has not been broadly applied beyond the research community because the current techniques, based on manual specialization, are time-consuming and error-prone. This paper describes a specialization toolkit that should help broaden the applicability of specializing operating systems by assisting in the automatic generation of specialized code, and {\em guarding} the specialized code to ensure the specialized system continues to be correct. We demonstrate the effectiveness of the toolkit by describing experiences we have had applying it in real, production environments. We report on our experiences with …
Review Of The United States Environmental Protection Agency Superfund Technical Assistance Grant Program, Robert Leslie Annear, Scott A. Wells, Shuguang Li, Marvin Beeson, Michael L. Cummings, Richard Pratt
Review Of The United States Environmental Protection Agency Superfund Technical Assistance Grant Program, Robert Leslie Annear, Scott A. Wells, Shuguang Li, Marvin Beeson, Michael L. Cummings, Richard Pratt
Civil and Environmental Engineering Faculty Publications and Presentations
The EPA Technical Assistance Grant Program has been around for several years, but there are not many examples of its use in the Pacific Northwest from which citizens can learn from when considering applying for a Technical Assistance Grant. The EPA program is designed to provide citizens with technical assistance in understanding the issues related to a Superfund site (or proposed Superfund site) in their community. This report provides an overview of the Technical Assistance Grant Program with information on applying for the grant, selecting a Technical Advisor and managing the grant. Additionally two case studies are reviewed in order …
Syntheses And Characterizations Of Unsymmetrical Porphyrins As Photosensitizers For A Solid-State Solar Cell, Yinping Zhao
Syntheses And Characterizations Of Unsymmetrical Porphyrins As Photosensitizers For A Solid-State Solar Cell, Yinping Zhao
Dissertations and Theses
Solar light is the most important source of regenerative energy and represents mankind's only inexhaustible energy source. One of today's most promising tools to make use of solar energy is its direct conversion into electrical energy in a photovoltaic cell. The practical use of these solar cells depends on the price of the devices and therefore of the obtained energy. The conventional silicon cells, although efficient, are expensive for common consumer applications. The Grätzel cell is a photovoltaic system for harvesting the sun's energy that operates at about 10-15% overall efficiency, like a conventional solar cell, but does it at …
Geochemistry, Stratigraphy And Provenance Of The Portland Hills Silt In The Tualatin Mountains, Portland, Oregon, John L. Lawes Iii
Geochemistry, Stratigraphy And Provenance Of The Portland Hills Silt In The Tualatin Mountains, Portland, Oregon, John L. Lawes Iii
Dissertations and Theses
Soil morphology and geochemistry of loess were investigated at nine sites in the Tualatin Mountains west of Portland and at additional sites in The Dalles, eastern Washington and Puget Sound. A total of forty samples were examined using Instrumental Neutron Activation Analysis (INAA).
Stratigraphic relationships and soil development suggest that the PHS ages of Lentz (1977) be revised. The age of the Portland Hills Silt (PHS) ranges from 12,000 to at least 960,000 years before present.
The geochemistry of the PHS supports the Lentz (1977) hypothesis of the PHS as a loess of continental origin. Thorium/scandium ratios in the PHS …
Molecular Fluorescence At A Rough Surface: The Orientation Effects, William Lee Blacke
Molecular Fluorescence At A Rough Surface: The Orientation Effects, William Lee Blacke
Dissertations and Theses
The interaction between an emitting molecular dipole and a conducting substrate with a periodic surface roughness is looked at with particular interest in the different orientations of the dipole with respect to the substrate surface. A previous dynamical, perturbative theory for the effects of perpendicular dipole is extended to treat a dipole oriented parallel to the surface of the substrate. The results are then applied to study the modified fluorescence characteristics of the emitting dipoles. Numerical results demonstrate that some fluorescence characteristics are extremely sensitive to the molecular orientation with the dipole oriented along the grating (x direction) exhibiting unique …
Early To Middle Pleistocene Catastrophic Flood Deposits, The Dalles, Oregon, David Irving Cordero
Early To Middle Pleistocene Catastrophic Flood Deposits, The Dalles, Oregon, David Irving Cordero
Dissertations and Theses
A roadcut on Highway 197, three kilometers southeast of The Dalles, Oregon, exposes a sequence of Quaternary sediments and five buried paleosols. The sediments, paleosols, and associated tephras at this site provide evidence of a Quaternary history of catastrophic flooding in the Columbia Basin extending back at least 700 ka and of an early eruption (ca. 600 ka) of Mount Adams. Four sedimentary units are exposed in this cut: Holocene loess, late Wisconsin Missoula Flood slackwater deposits, five pre-late Wisconsin catastrophic flood slackwater deposits bearing well developed paleosols, and late Tertiary Dalles Formation volcaniclastics. All but the oldest are predominantly …
Predictable File Access Latency For Multimedia, Dan Revel, Crispin Cowan, Dylan Mcnamee, Calton Pu, Jonathan Walpole
Predictable File Access Latency For Multimedia, Dan Revel, Crispin Cowan, Dylan Mcnamee, Calton Pu, Jonathan Walpole
Computer Science Faculty Publications and Presentations
Multimedia applications are sensitive to I/O latency and jitter when accessing data in secondary storage. Transparent adaptive prefetching (TAP) uses software feedback to provide multimedia applications with file system quality of service (QoS) guarantees. We are investigating how QoS requirements can be communicated and how they can be met by adaptive resource management. A preliminary test of adaptive prefetching is presented.
Post-Middle Miocene Geologic History Of The Tualatin Basin, Oregon With Hydrogeologic Implications, Doyle Coley Wilson
Post-Middle Miocene Geologic History Of The Tualatin Basin, Oregon With Hydrogeologic Implications, Doyle Coley Wilson
Dissertations and Theses
The geologic history and sedimentary till of the Tualatin Basin after Columbia River Basalt Group (CRBG) emplacement is assessed and related to groundwater characteristics. The 334 m deep HBD-1 core from the Hillsboro Airport, provides the primary information for sediment characterization and is supported by over 2400 well logs and cores, and four seismic lines. The sedimentary section above the 26 m thick paleosol on the CRBG in HBD-I is divided into two main groups: a 25 m thick section of Missoula flood sediments called the Willamette Silt overlies a 263 m thick finegrained sequence of fluvial Neogene sediments.
Pollen, …
Geochemical Characteristics And Correlations Within The Triassic-Jurassic Age Gabbs And Sunrise Formations Of West Central Nevada, Karen Elizabeth Boelling
Geochemical Characteristics And Correlations Within The Triassic-Jurassic Age Gabbs And Sunrise Formations Of West Central Nevada, Karen Elizabeth Boelling
Dissertations and Theses
Trace and minor element geochemistry was determined using Instrumental Neutron Activation Analysis for ninety-six (96) limestone and calcareous siltstone samples from four stratigraphic sections in the Triassic-Jurassic age Gabbs and Sunrise formations of west central Nevada. Geochemical data support lithologic and faunal interpretations of relative basin positions of the Sunrise Formation stratigraphic sections, as well as basin development (including transgressive-regressive sequences) during deposition of the Gabbs and Sunrise formations at New York Canyon (Gabbs Valley Range). All sections show characteristics of both oceanic and continental island arc sources. Rare positive Eu anomalies relative to chondrites suggest that the Gabbs Formation …
Distribution Of Heavy Metals And Trace Elements In Soils Of Southwest Oregon, Rafiqul Alam Khandoker
Distribution Of Heavy Metals And Trace Elements In Soils Of Southwest Oregon, Rafiqul Alam Khandoker
Dissertations and Theses
Soil samples from 118 sites on 71 geologic units in southwest Oregon were collected and analyzed to determine the background concentrations of metals in soils of the region. Sites were chosen in areas that were relatively undisturbed by human activities. The U.S. Environmental Protection Agency approved total-recoverable method was used to recover metals from samples for analysis. The twenty six metals analyzed were: Ag, AI, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Tl, V and Zn.
The Klamath Mountains followed by the Coast Range contain the …
The Columbia Slough, Scott A. Wells
The Columbia Slough, Scott A. Wells
Civil and Environmental Engineering Faculty Publications and Presentations
This report was written in an attempt to provide the public and Bureau of Environmental Services Staff with a summary of work accomplished on the Columbia Slough system by Portland State University and other consultants working on the Slough over the last 6 years. An attempt was made to create an easy-to-read report with important overviews of the "big picture", glossary of definitions, index, and further details to assist in technology transfer.
General Remarks On Spectral Entropy Vs. Statistical Entropy, John D. Ramshaw
General Remarks On Spectral Entropy Vs. Statistical Entropy, John D. Ramshaw
Physics Faculty Publications and Presentations
Crepeau and Herzel [1] (CH) have recently compared the spectral entropy of Powell and Percival [2] with the standard statistical (Boltzmann-Gibbs-Shannon) entropy in three simple physical systems. Here we compare and contrast these two entropies in a more general way by considering their values for an arbitrary stationary process X(t).
Optical Imaging Of Carrier Dynamics In Silicon With Subwavelength Resolution, Andres H. La Rosa, B. I. Yakobson, H. D. Hallen
Optical Imaging Of Carrier Dynamics In Silicon With Subwavelength Resolution, Andres H. La Rosa, B. I. Yakobson, H. D. Hallen
Physics Faculty Publications and Presentations
Characteristic rate variations of carrier processes are imaged using near-field scanning optical microscopy. We couple both a visible pump and an infrared probe light through a subwavelength aperture to investigate the interband recombination and intraband diffusion of excess carriers in oxidized silicon. Typical values of the locally measured life time constants agree well with those obtained by conventional space-averaged techniques. Moreover, the images locate defects, reveal variations, and can map the regions in which a recombination process is active.
A Strategy For Monitoring Glaciers, Andrew G. Fountain, Robert M. Krimmel, Dennis C. Trabant
A Strategy For Monitoring Glaciers, Andrew G. Fountain, Robert M. Krimmel, Dennis C. Trabant
Geography Faculty Publications and Presentations
Glaciers are important features in the hydrologic cycle and affect the volume, variability, and water quality of runoff. Assessing and predicting the effect of glaciers on water resources require a monitoring program to provide basic data for this understanding. The monitoring program of the U.S. Geological Survey employs a nested approach whereby an intensively studied glacier is surrounded by less intensively studied glaciers and those monitored solely by remote sensing. Ideally, each glacierized region of the United States would have such a network of glaciers. The intensively studied glacier provides a detailed understanding of the physical processes and their temporal …
Hausdorff Dimension Of Boundaries Of Self-Affine Tiles In R N, J. J. P. Veerman
Hausdorff Dimension Of Boundaries Of Self-Affine Tiles In R N, J. J. P. Veerman
Mathematics and Statistics Faculty Publications and Presentations
We present a new method to calculate the Hausdorff dimension of a certain class of fractals: boundaries of self-affine tiles. Among the interesting aspects are that even if the affine contraction underlying the iterated function system is not conjugated to a similarity we obtain an upper- and and lower-bound for its Hausdorff dimension. In fact, we obtain the exact value for the dimension if the moduli of the eigenvalues of the underlying affine contraction are all equal (this includes Jordan blocks). The tiles we discuss play an important role in the theory of wavelets. We calculate the dimension for a …
Microlanguages For Operating System Specialization, Calton Pu, Andrew P. Black, Crispin Cowan, Jonathan Walpole, Charles Consel
Microlanguages For Operating System Specialization, Calton Pu, Andrew P. Black, Crispin Cowan, Jonathan Walpole, Charles Consel
Computer Science Faculty Publications and Presentations
Specialization is a technique that has the potential to provide operating system clients with the performance and functionality that they need, while still retaining the advantages of a simple generic code base for the operating system maintainer. However, at present the specialization process is labor-intensive and requires the knowledge of an expert in the domain of application behavior. In order to realize the full advantages of specialization, we believe that the process must be automated. This means building tools for specialization, and also making the domain knowledge explicit in some form or other. A specialization toolkit has been developed jointly …
Resolution Of Local Inconsistency In Identification, Douglas Ray Anderson, Martin Zwick
Resolution Of Local Inconsistency In Identification, Douglas Ray Anderson, Martin Zwick
Systems Science Faculty Publications and Presentations
This paper reports an algorithm for the resolution of local inconsistency in information-theoretic identification. This problem was first pointed out by Klir as an important research area in reconstructability analysis. Local inconsistency commonly arises when an attempt is made to integrate multiple data sources, i.e., contingency tables, which have differing common margins. For example, if one ha)s an AB table and a BC table, the B margins obtained from the two tables may disagree. If the disagreement can be assigned to sampling error, then one can arrive at a compromise B margin, adjust the original AB and BC tables to …
Physical Media Independence: System Support For Dynamically Available Network Interfaces, Jon Inouye, Jim Binkley, Jonathan Walpole
Physical Media Independence: System Support For Dynamically Available Network Interfaces, Jon Inouye, Jim Binkley, Jonathan Walpole
Computer Science Faculty Publications and Presentations
Advances in hardware technology has fueled the proliferation of dynamically configurable network interface cards. This empowers mobile laptop users to select the most appropriate interface for their current environment. Unfortunately, the majority of system software remains "customized" for a particular network configuration, and assumes many network characteristics remain invariant over the runtime of the software. Physical Media Independence (PMI) is the concept of making assumptions about a particular device explicit, detecting events which invalidate these assumptions, and recovering once events are detected. This paper presents a model supporting PMI. Based on device availablilty, the model identifies implicit device-related assumptions made …
A Migratable User-Level Process Package For Pvm, Ravi Kunuru, Steve Otto, Jonathan Walpole
A Migratable User-Level Process Package For Pvm, Ravi Kunuru, Steve Otto, Jonathan Walpole
Computer Science Faculty Publications and Presentations
Shared, multi-user, workstation networks are characterized by unpredictable variability in system load. Further, the concept of workstation ownership is typically present. For efficient and unobtrusive computing in such environments, applications must not only overlap their computation with communication but also redistribute their computations adaptively based on changes in workstation availability and load. Managing these issues at application level leads to programs that are difficult to write and debug. In this paper, we present a system that manages this dynamic multi-processor environment while exporting a simple message-based programming model of a dedicated, distributed memory multiprocessor to applications. Programmers are thus insulated …
Weak Bands Within Ice Stream B, West Antarctica, Christina L. Hulbe, I. M. Whillans
Weak Bands Within Ice Stream B, West Antarctica, Christina L. Hulbe, I. M. Whillans
Geology Faculty Publications and Presentations
Kilometer-scale variations in ice velocity and surface topography are used to investigate the style of glacier deformation in the main body of Ice Stream B, West Antarctica. The pattern is very different from that reported for other glaciers. For the 250 km2 area studied on Ice Stream B, most of the observed deformation occurs within two narrow bands, in which there is large across-flow compression and slow lateral shearing. The bands underlie valleys in the ice-surface topography. Measured upward displacement of ice adjacent to the rapidly compressing bands appears to be linked to the creation of the ice stream's topography. …
Potential For Coastal Flooding Due To Coseismic Subsidence In The Central Cascadia Margin, Elson T. Barnett
Potential For Coastal Flooding Due To Coseismic Subsidence In The Central Cascadia Margin, Elson T. Barnett
Dissertations and Theses
Interpretations made from compilation of existing core and cutbank data for Oregon and Washington are used to evaluate the potential flooding impact from regional coseismic subsidence. Estimates of regional subsidence are based on tidal level indicators including plant macrofossils, peat development, and diatoms. A compilation of existing late Holocene stratigraphic records shows multiple burial events in all bays of Oregon, however some coastal sites in central Oregon show continuous submergence. Tests of tidal level indicators using modern Cascadia wetlands indicate that paleosubsidence can be estimated to 0.0 ± 0.5m, 1.0 ±0.5m, and 2 m ± 0.5m. An AMS date from …
Measurement Of The Focal Properties Of A Magnetic Electron Lens Using The Shadowgraph Method, Luis Thomas Almaraz
Measurement Of The Focal Properties Of A Magnetic Electron Lens Using The Shadowgraph Method, Luis Thomas Almaraz
Dissertations and Theses
A method of experimentally determining the properties of a magnetic electron lens is presented. The method uses the shadows cast by two meshes, one placed in front of the lens and one behind the lens, to study the properties of the image of a point source. The lens properties are then calculated from the image properties. The paraxial values of focal length and focal distance as well as their spherical aberrations, are determined. The relationship between image and lens properties are discussed. The method is used here for the first time in determining the focal properties of a magnetic lens.
The Interaction Of Naphthoquinones With The Calcium Release Channel Of Skeletal Muscle Sarcoplasmic Reticulum, Ruohong Xia
The Interaction Of Naphthoquinones With The Calcium Release Channel Of Skeletal Muscle Sarcoplasmic Reticulum, Ruohong Xia
Dissertations and Theses
The sarcoplasmic reticulum (SR) is an intracellular membrane system which regulates cytoplasmic calcium concentration in muscle and controls the contractile state of muscle. In this thesis, the interaction between naphthoquinone and the Ca2+ release mechanism of SR is described. 1,4-naphthoquinone (1,4NQ) is shown to stimulate Ca2+ release and to modify high-affinity ryanodine binding to skeletal muscle sarcoplasmic reticulum. The interaction between 1,4NQ and the SR involves the oxidation ofcritical sulfhydryl groups associated with the Ca2+ release mechanism. The modulation of ryanodine binding by 1,4NQ is biphasic. At low concentrations of 1,4NQ (<10 >μM) ryanodine binding is stimulated, …10>
Efficient Implementation Of Image Compression-Postprocessing Algorithm Using A Digital Signal Processor, Nadir Sinaceur
Efficient Implementation Of Image Compression-Postprocessing Algorithm Using A Digital Signal Processor, Nadir Sinaceur
Dissertations and Theses
In this thesis, an attempt has been made to develop a fast way to implement a post-processing algorithm for image compression. All the previous tests for this postprocessing algorithm, which we will present, have been only software based and did not consider the time parameter.
For this purpose a new algorithm is used to compute the 2-D DCT transform. This change made the process a lot faster on a Spare 5 workstation. We have then decided to further increase the speed of the post-processing scheme by implementing it on the ADSP21020 chip.
The results show that such a chip can …
A Specialization Toolkit To Increase The Diversity Of Operating Systems, Calton Pu, Andrew P. Black, Crispin Cowan, Jonathan Walpole, Charles Consel
A Specialization Toolkit To Increase The Diversity Of Operating Systems, Calton Pu, Andrew P. Black, Crispin Cowan, Jonathan Walpole, Charles Consel
Computer Science Faculty Publications and Presentations
Virus and worm attacks that exploit system implementation details can be countered with a diversified set of implementations. Furthermore, immune systems show that attacks from previously unknown organisms require effective dynamic response. In the Synthetix project, we have been developing a specialization toolkit to improve the performance of operating system kernels. The toolkit helps programmers generate and manage diverse specialized implementations of software modules. The Tempo-C specializer tool generates different versions for both compile-time and run-time specialization. We are now adapting the toolkit to improve operating system survivability against implementations attacks.
Synthesis And Characterization Of Novel Sf5 Containing Fluoroalkyl Iodides And Derivatives, Julia Anne Renn
Synthesis And Characterization Of Novel Sf5 Containing Fluoroalkyl Iodides And Derivatives, Julia Anne Renn
Dissertations and Theses
Preparation of four SF5-containing fluoroalkyl iodides and derivatives thereof was accomplished beginning with a simplified synthesis of ICF2CF2I. Characterization of the products followed using a variety of spectroscopic and physical methods. The simplified method for preparing ICF2CF2I from iodine and tetrafluoroethylene (TFE) involved a reaction temperature of approximately 54°C and pressures of less than two atmospheres for the TFE. The synthesized ICF2CF2I was reacted with S2F1o and tetrafluoroethylene to give SF5CF2CF2I. The subsequent synthesis of the SFs containing fluoroalkyl iodides and derivatives were carried out using SFsCF2CF2I as the starting material in a Carius tube reaction vessel. The synthesized SFs …