Linear mixing model applied to coarse resolution satellite data

A linear mixing model typically applied to high resolution data such as Airborne Visible/Infrared Imaging Spectrometer, Thematic Mapper, and Multispectral Scanner System is applied to the NOAA Advanced Very High Resolution Radiometer coarse resolution satellite data. The reflective portion extracted from the middle IR channel 3 (3.55 - 3.93 microns) is used with channels 1 (0.58 - 0.68 microns) and 2 (0.725 - 1.1 microns) to run the Constrained Least Squares model to generate fraction images for an area in the west central region of Brazil. The derived fraction images are compared with an unsupervised classification and the fraction images derived from Landsat TM data acquired in the same day. In addition, the relationship betweeen these fraction images and the well known NDVI images are presented. The results show the great potential of the unmixing techniques for applying to coarse resolution data for global studies

Aerosol Remote Sensing from AERONET, the Ground-Based Satellite

Atmospheric particles including mineral dust, biomass burning smoke, pollution from carbonaceous aerosols and sulfates, sea salt, impact air quality and climate. The Aerosol Robotic Network (AERONET) program, established in the early 1990s, is a federation of ground-based remote sensing aerosol networks of Sun/sky radiometers distributed around the world, which provides a long-term, continuous and readily accessible public domain database of aerosol optical (e.g., aerosol optical depth) and microphysical (e.g., aerosol volume size distribution) properties for aerosol characterization, validation of satellite retrievals, and synergism with Earth science databases. Climatological aerosol properties will be presented at key worldwide locations exhibiting discrete dominant aerosol types. Further, AERONET's temporary mesoscale network campaign (e.g., UAE2, TIGERZ, DRAGON-USA.) results that attempt to quantify spatial and temporal variability of aerosol properties, establish validation of ground-based aerosol retrievals using aircraft profile measurements, and measure aerosol properties on compatible spatial scales with satellite retrievals and aerosol transport models allowing for more robust validation will be discussed

Relationships Between Habitat and Snag Characteristics and the Reproductive Success of the Brown-headed Nuthatch (Sitta pusilla) in Eastern Texas.

Habitat use and reproductive success of the Brown-headed Nuthatch (Sitta pusilla Latham) were studied in East Texas during the 2001-2002 breeding seasons. We compared nest cavity selection at used and randomly selected non-used areas. Height of nest trees, midstory density, and percent leaf litter were negatively correlated with nest site selection. Brown-headed Nuthatches showed a strong preference for short snags; yet placed their nest cavity entrances near the top ofthe snags. While nuthatches may be selecting for habitats with little or no midstory density, percent of leaf litter in the nest sites is most likely the consequence of frequent burning. No significant differences among habitat variables and snag characteristics were found between successful and failed nest cavities. Additionally, no habitat variables were correlated with the number of chicks fledged per nest. Predation was the major cause of nest failure in this study

Improving Deaf Accessibility to Web-based Multimedia

Internet technologies have expanded rapidly over the past two decades, making information of all sorts more readily available. Not only are they more cost-effective than traditional media, these new media have contributed to quality and convenience. However, proliferation of video and audio media on the internet creates an inadvertent disadvantage for deaf Internet users. Despite technological and legislative milestones in recent decades in making television and movies more accessible, there has been little progress with online access. A major obstacle to providing captions for internet media is the high cost of captioning and transcribing services. To respond to this problem, a possible solution lies in automatic speech recognition (ASR). This research investigates possible solutions to Web accessibility through utilization of ASR technologies. It surveys previous studies that employ visualization and ASR to determine their effectiveness in the context of deaf accessibility. Since there was no existing literature indicating the area of greatest need, a preliminary study identified an application that would serve as a case study for applying and evaluating speech visualization technology. A total of 20 deaf and hard-of-hearing participants were interviewed via video phone and their responses in American Sign Language were transcribed to English. The most common theme was concern over a lack of accessibility for online news. The second study evaluated different presentation strategies for making online news videos more accessible. A total of 95 participants viewed four different caption styles. Each style was presented on different news stories with control for content level and delivery. In addition to pre-test and post-test questionnaires, both performance and preference measures were conducted. Results from the study offer emphatic support for the hypothesis that captioning the online videos makes the Internet more accessible to the deaf users. Furthermore, the findings lend strong evidence to the idea of utilizing automatic captions to make videos comprehensible to the deaf viewers at a fraction of the cost. The color-coded captions that used highlighting to reflect the accuracy ratings were found neither to be beneficial nor detrimental; however, when asked directly about the benefit of color-coding there was support for the concept. Further development and research will be necessary to find the appropriate solution

Stratigraphy and chronology of the Stent tephra, a c. 4000 year old distal silicic tephra from Taupo Volcanic Centre, New Zealand.

Tephrostratigraphic and chronologic studies in two areas of the North Island have identified a previously unrecorded, thin, distal silicic tephra derived from the Taupo Volcanic Centre. In Taranaki, three radiocarbon ages of the uncorrelated tephra are consistent with the independent radiocarbon chronology obtained from enveloping Egmontsourced tephras. In western Bay of Plenty, where the uncorrelated tephra is also directly dated, it is overlain by Whakaipo Tephra (c. 2.7 ka) and underlain by Hinemaiaia Tephra (c. 4.5 ka). From these sites in Taranaki and western Bay of Plenty, seven radiocarbon dates obtained on the uncorrelated silicic tephra yield an error-weighted mean age of 3970 ±31 conventional radiocarbon years B.P. The ages on the uncorrelated tephra (informally referred to as Stent tephra) from both areas are statistically identical but significantly different from those on both Waimihia and Hinemaiaia Tephras. occurrence of Stent tephra in Taranaki, c. 160 km upwind from the postulated source area, and in western Bay of Plenty, suggests that it represents the product of a moderately large plinian eruption. Until recently, its validity as a discrete eruptive event had been problematical, because a near-source equivalent deposit between Waimihia and Hinemaiaia Tephras was not recognised in the Taupo area. However, a revised stratigraphy proposed by C. J. N. Wilson in 1993 for eastern sectors of the Taupo area shows that multiple tephra layers were erupted from Taupo volcano between c. 3.9 and 5.2 ka. Of these newly recognised layers, unit-g--the product of a moderately large eruption (>0.15 km3) at c. 4.0 ka--is tentatively correlated with Stent tephra. Other eruptive units recognised by Wilson are either too old or too small in volume to be considered as likely correlatives

The Regulation of Biological Pollution: Preventing Exotic Species Invasions from Ballast Water Discharged into California Coastal Waters

In Part I of this article, we describe ballast water\u27s use, its contribution to biological invasions, and the technical approaches that could be used to combat the problem. In Part II, we describe opportunities for employing existing laws and regulations to manage ballast discharges in California. We first discuss the limitations of international, federal and state laws that have tried to address ballast discharges of exotic organisms as a shipping issue. We then consider the potential for regulating ballast discharges under federal and state laws aimed at controlling water pollution, protecting wildlife, ensuring the assessment, disclosure and mitigation of environmental impacts, and providing for the planning and management of coastal zone development. While we evaluate these laws in terms of their potential application in California, the federal laws and, in many cases, corresponding state laws could be applied in other coastal regions. We conclude by summarizing how existing regulations may provide a comprehensive overall framework for achieving effective regulation of ballast water discharges

Trap-assisted tunnelling and Shockley-Read-Hall lifetime of extended defects in In.53Ga.47As p+n junction

Several In.53Ga.47As p+n junctions with various extended defect densities (EDDs) have been grown by metalorganic vapor phase epitaxy (MOVPE), by carefully controlling the growth conditions. After fabrication, T-dependent J-V, C-V and double DLTS (DDLTS) are performed to extract the electrical field dependence of the extended defect levels. From this characterization, it is derived that the extended defects dominate the electrical field enhancement factor Gamma regardless of the value of the EDD and significantly increases the leakage current under reverse bias (i.e., decrease the Shockley-Read-Hall lifetime). These impacts are strongly connected to a "band-like" density of states of extended defects E2 at E-C-0.32 eV by comparing the DDLTS and T-dependent J-V characteristics. On the other hand, the reference sample (without EDs) surprisingly exhibits an even stronger field dependence with lower leakage current. Nevertheless, no straightforward candidate point defects can be found in this sample and the possible explanation are discussed

The RANLUX generator: resonances in a random walk test

Using a recently proposed directed random walk test, we systematically investigate the popular random number generator RANLUX developed by Luescher and implemented by James. We confirm the good quality of this generator with the recommended luxury level. At a smaller luxury level (for instance equal to 1) resonances are observed in the random walk test. We also find that the lagged Fibonacci and Subtract-with-Carry recipes exhibit similar failures in the random walk test. A revised analysis of the corresponding dynamical systems leads to the observation of resonances in the eigenvalues of Jacobi matrix.Comment: 18 pages with 14 figures, Essential addings in the Abstract onl

Optimality Theory as a Framework for Lexical Acquisition

This paper re-investigates a lexical acquisition system initially developed for French.We show that, interestingly, the architecture of the system reproduces and implements the main components of Optimality Theory. However, we formulate the hypothesis that some of its limitations are mainly due to a poor representation of the constraints used. Finally, we show how a better representation of the constraints used would yield better results