Synthetic aperture radar/LANDSAT MSS image registration

Algorithms and procedures necessary to merge aircraft synthetic aperture radar (SAR) and LANDSAT multispectral scanner (MSS) imagery were determined. The design of a SAR/LANDSAT data merging system was developed. Aircraft SAR images were registered to the corresponding LANDSAT MSS scenes and were the subject of experimental investigations. Results indicate that the registration of SAR imagery with LANDSAT MSS imagery is feasible from a technical viewpoint, and useful from an information-content viewpoint

Assessing the costs of adapting to sea-level rise: a case study of San Francisco Bay

Atmospheric concentrations of carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), tropospheric ozone (O3), chlorofluorocarbons (CFCs), and other trace gases are growing due to human activities. These trace gases are transparent to incoming solar radiation and trap outgoing infrared (heat) radiation, acting like a blanket to warm the Earth. Without any of these gases in the atmosphere, the surface of the Earth would be about 35 C (70 F) colder than at present, and life, if any could exist, would be quite different. This natural greenhouse effect is being intensified by human activities that accelerate the emission of these trace gases, such as the combustion of fossil fuels and deforestation. One of the direct consequences of climatic changes will be a rise in sea level due to the melting of land ice and the expansion of the upper layers of the ocean as they warm. This study presents a method for assessing the costs to society of protecting against an increase in sea level, and applies this method to the San Francisco Bay area -- a region of great ecological diversity, economic importance, and vulnerability. Hydrodynamic effects around the margin of San Francisco Bay are evaluated, structural options for protecting property are identified and chosen for threatened areas, and estimates of costs of protection are determined. For the purposes of this study, a one-meter sea-level rise was assumed, and all development below the future 100-year high tide elevation in San Francisco Bay was considered to be at risk. The types of shoreline protection proposed include constructing new levees and seawalls, raising existing levees and bulkheads, raising buildings, freeways and railroads where necessary, and replenishing beaches. The costs described here are not the total costs of protection -- for example, no estimates are available for evaluating costs of protecting natural ecosystems. Other 3 costs left out are described in detail in the text

Linking Classical and Quantum Key Agreement: Is There "Bound Information"?

After carrying out a protocol for quantum key agreement over a noisy quantum channel, the parties Alice and Bob must process the raw key in order to end up with identical keys about which the adversary has virtually no information. In principle, both classical and quantum protocols can be used for this processing. It is a natural question which type of protocols is more powerful. We prove for general states but under the assumption of incoherent eavesdropping that Alice and Bob share some so-called intrinsic information in their classical random variables, resulting from optimal measurements, if and only if the parties' quantum systems are entangled. In addition, we provide evidence that the potentials of classical and of quantum protocols are equal in every situation. Consequently, many techniques and results from quantum information theory directly apply to problems in classical information theory, and vice versa. For instance, it was previously believed that two parties can carry out unconditionally secure key agreement as long as they share some intrinsic information in the adversary's view. The analysis of this purely classical problem from the quantum information-theoretic viewpoint shows that this is true in the binary case, but false in general. More explicitly, bound entanglement, i.e., entanglement that cannot be purified by any quantum protocol, has a classical counterpart. This "bound intrinsic information" cannot be distilled to a secret key by any classical protocol. As another application we propose a measure for entanglement based on classical information-theoretic quantities.Comment: Accepted for Crypto 2000. 17 page

Close to Uniform Prime Number Generation With Fewer Random Bits

In this paper, we analyze several variants of a simple method for generating prime numbers with fewer random bits. To generate a prime $p$ less than $x$, the basic idea is to fix a constant $q\propto x^{1-\varepsilon}$, pick a uniformly random $a<q$ coprime to $q$, and choose $p$ of the form $a+t\cdot q$, where only $t$ is updated if the primality test fails. We prove that variants of this approach provide prime generation algorithms requiring few random bits and whose output distribution is close to uniform, under less and less expensive assumptions: first a relatively strong conjecture by H.L. Montgomery, made precise by Friedlander and Granville; then the Extended Riemann Hypothesis; and finally fully unconditionally using the Barban-Davenport-Halberstam theorem. We argue that this approach has a number of desirable properties compared to previous algorithms.Comment: Full version of ICALP 2014 paper. Alternate version of IACR ePrint Report 2011/48

Nesting behaviour influences species-specific gas exchange across avian eggshells

Carefully controlled gas exchange across the eggshell is essential for the development of the avian embryo. Water vapour conductance (GH2O) across the shell, typically measured as mass loss during incubation, has been demonstrated to optimally ensure the healthy development of the embryo while avoiding desiccation. Accordingly, eggs exposed to sub-optimal gas exchange have reduced hatching success. We tested the association between eggshell GH2O and putative life-history correlates of adult birds, ecological nest parameters and physical characteristics of the egg itself to investigate how variation in GH2O has evolved to maintain optimal water loss across a diverse set of nest environments. We measured gas exchange through eggshell fragments in 151 British breeding bird species and fitted phylogenetically controlled, general linear models to test the relationship between GH2O and potential predictor parameters of each species. Of our 17 life-history traits, only two were retained in the final model: wet-incubating parent and nest type. Eggs of species where the parent habitually returned to the nest with wet plumage had significantly higher GH2O than those of parents that returned to the nest with dry plumage. Eggs of species nesting in ground burrows, cliffs and arboreal cups had significantly higher GH2O than those of species nesting on the ground in open nests or cups, in tree cavities and in shallow arboreal nests. Phylogenetic signal (measured as Pagel's λ) was intermediate in magnitude, suggesting that differences observed in the GH2O are dependent upon a combination of shared ancestry and species-specific life history and ecological traits. Although these data are correlational by nature, they are consistent with the hypothesis that parents constrained to return to the nest with wet plumage will increase the humidity of the nest environment, and the eggs of these species have evolved a higher GH2O to overcome this constraint and still achieve optimal water loss during incubation. We also suggest that eggs laid in cup nests and burrows may require a higher GH2O to overcome the increased humidity as a result from the confined nest microclimate lacking air movements through the nest. Taken together, these comparative data imply that species-specific levels of gas exchange across avian eggshells are variable and evolve in response to ecological and physical variation resulting from parental and nesting behaviours

Effects of paddock management on vegetation, nutrient accumulation, and internal parasites in laying hens

Management of paddocks for free-range layers requires an effort from farmers to minimize the adverse effects of these systems on animal health (e.g., parasites) and environment (e.g., nutrient accumulation and leaching). In this study, we report results from 2 on-farm experiments conducted to investigate (1) the effects of rotational versus continuous use of the paddocks and (2) the effects of wood chips in the area close to the pop holes (openings to the paddock) with regard to turf quality, nutrient load in the soil, and parasite infections. Rotational use of the hen paddocks led to a lower proportion of bare soil close to the house, but not in more distant regions. Covering the area in front of the house with wood chips did not reduce bare areas. Nitrogen and phosphorous contents in soil were similar in permanently and rotationally used paddocks; they were usually higher close to the house than in distant regions. Neither nutrient accumulated over the observation period. There was no significant effect of the 2 management regimens on worm burdens (Ascaridia galli, Heterakis gallinarum, Capillaria spp.) at the end of the laying period. Fecal egg counts were significantly reduced on rotationally used paddocks and (in 3 of 4 cases) on paddocks with wood chips in the area close to the pop holes compared with unmanaged paddocks. Based on the positive effects on turf quality, manageability, and helminth egg excretion, we recommend rotational paddock management and a permanently used, small all-weather run covered with wood chips or gravel for free-range layer flock

Conjugacy and Equivalence of Weighted Automata and Functional Transducers

International audienceWe show that two equivalent K-automata are conjugate to a third one, when K is equal to B, N, Z, or any (skew) ¯eld and that the same holds true for functional tranducers as well

Evaporation of a packet of quantized vorticity

A recent experiment has confirmed the existence of quantized turbulence in superfluid He3-B and suggested that turbulence is inhomogenous and spreads away from the region around the vibrating wire where it is created. To interpret the experiment we study numerically the diffusion of a packet of quantized vortex lines which is initially confined inside a small region of space. We find that reconnections fragment the packet into a gas of small vortex loops which fly away. We determine the time scale of the process and find that it is in order of magnitude agreement with the experiment.Comment: figure 1a,b,c and d, figure2, figure