Model atmospheres for type Ia supernovae: Basic steps towards realistic synthetic spectra

Type Ia supernovae are an important tool for studying the expansion history of the universe. Advancing our yet incomplete understanding of the explosion scenario requires detailed and realistic numerical models in order to interpret and analyze the growing amount of observational data. Here we present first results of our new NLTE model calculations for the expanding atmospheres of type Ia supernovae that employ a detailed and consistent treatment of all important NLTE effects as well as line blocking and blanketing. The comparison of the synthetic spectra resulting from these models with observed data shows that the employed methods represent an important step towards a more realistic description of the atmospheres of supernovae Ia.Comment: 4 pages, 1 figure, to appear in: Proceedings of the 11th Workshop on Nuclear Astrophysics, Ringberg Castle, Germany, 200

Real-time filtering and detection of dynamics for compression of HDTV

The preprocessing of video sequences for data compressing is discussed. The end goal associated with this is a compression system for HDTV capable of transmitting perceptually lossless sequences at under one bit per pixel. Two subtopics were emphasized to prepare the video signal for more efficient coding: (1) nonlinear filtering to remove noise and shape the signal spectrum to take advantage of insensitivities of human viewers; and (2) segmentation of each frame into temporally dynamic/static regions for conditional frame replenishment. The latter technique operates best under the assumption that the sequence can be modelled as a superposition of active foreground and static background. The considerations were restricted to monochrome data, since it was expected to use the standard luminance/chrominance decomposition, which concentrates most of the bandwidth requirements in the luminance. Similar methods may be applied to the two chrominance signals

Pirate stealth or inattentional blindness?:the effects of target relevance and sustained attention on security monitoring for experienced and naïve operators

Closed Circuit Television (CCTV) operators are responsible for maintaining security in various applied settings. However, research has largely ignored human factors that may contribute to CCTV operator error. One important source of error is inattentional blindness--the failure to detect unexpected but clearly visible stimuli when attending to a scene. We compared inattentional blindness rates for experienced (84 infantry personnel) and naïve (87 civilians) operators in a CCTV monitoring task. The task-relevance of the unexpected stimulus and the length of the monitoring period were manipulated between participants. Inattentional blindness rates were measured using typical post-event questionnaires, and participants' real-time descriptions of the monitored event. Based on the post-event measure, 66% of the participants failed to detect salient, ongoing stimuli appearing in the spatial field of their attentional focus. The unexpected task-irrelevant stimulus was significantly more likely to go undetected (79%) than the unexpected task-relevant stimulus (55%). Prior task experience did not inoculate operators against inattentional blindness effects. Participants' real-time descriptions revealed similar patterns, ruling out inattentional amnesia accounts

Exchange Rate Determination with Systematic and Unsystematic Policy Regime Changes: Evidence From the Yen/Dollar Rate

This paper presents results of estimating an exchange rate equation in light of theoretical considerations regarding changes in sterilization and intervention policy and tax policy which imply that the coefficients in the equation will not behave as fixed parameters in a given sample period,as standard econometric practice assumes. We compare the results of ordinary least squares and a random coefficients model of the Japanese Yen-- U.S. dollar exchange rate during the floating period of July 1973 through June 1982.When systematic end of year policy changes affecting Japanese reserves are explicitly modeled, both OLS and the random coefficients model show increased explanatory power. The random coefficients model appears to be superior to OLS however; by allowing the coefficients to vary over time as required by the economic theory discussed above, estimates of the mean response coefficients for the floating period all have the hypothesized sign, and explanatory power is sharply increased.

Augmented Sparse Reconstruction of Protein Signaling Networks

The problem of reconstructing and identifying intracellular protein signaling and biochemical networks is of critical importance in biology today. We sought to develop a mathematical approach to this problem using, as a test case, one of the most well-studied and clinically important signaling networks in biology today, the epidermal growth factor receptor (EGFR) driven signaling cascade. More specifically, we suggest a method, augmented sparse reconstruction, for the identification of links among nodes of ordinary differential equation (ODE) networks from a small set of trajectories with different initial conditions. Our method builds a system of representation by using a collection of integrals of all given trajectories and by attenuating block of terms in the representation itself. The system of representation is then augmented with random vectors, and minimization of the 1-norm is used to find sparse representations for the dynamical interactions of each node. Augmentation by random vectors is crucial, since sparsity alone is not able to handle the large error-in-variables in the representation. Augmented sparse reconstruction allows to consider potentially very large spaces of models and it is able to detect with high accuracy the few relevant links among nodes, even when moderate noise is added to the measured trajectories. After showing the performance of our method on a model of the EGFR protein network, we sketch briefly the potential future therapeutic applications of this approach.Comment: 24 pages, 6 figure

Adaptive Coordination of Distributed Energy Resources in Lossy Power Distribution Systems

This paper is concerned with the problem of coordinating a set of distributed energy resources (DERs) in a lossy power distribution system to provide frequency regulation services to a bulk power grid with the explicit consideration of system losses. To this end, we formulate the problem as an optimization problem, the objective of which is to minimize some cost function subject to a set of constraints. The formulation requires knowledge of incremental total system losses, which we approximate using the so-called loss factors (LFs) that explicitly capture the impacts of both active and reactive power injections on system losses. The LFs are estimated recursively using power injection measurements; thus, they are adaptive to various phenomena that impact the power system operation. Numerical simulation on a 33-bus distribution test feeder validated the effectiveness of the proposed framework

Subsidies, production structure and technical change – A cross-country comparison

The effect of subsidies on production and technical change of crop farms in France and the United Kingdom (UK) during 1980-2006 is investigated. Subsidies were not neutral on production decisions, in terms of production intensity and type. Crop farms in both countries have experienced technical progress during the period studied, higher in France. Technical progress has favoured labour and chemicals in both countries, land in France, capital in the UK, while it has disfavoured land in the UK and capital in France. Technical change has been slowed down by crop area subsidies but increased by agri-environmental subsidies in both countries.technical change, subsidies, input bias, crop farms, Agricultural and Food Policy, Farm Management, Land Economics/Use,

Regenerable biocide delivery unit

A method and apparatus are disclosed for maintaining continuous, long-term microbial control in the water supply for potable, hygiene, and experimental water for space activities, as well as treatment of water supplies on Earth. The water purification is accomplished by introduction of molecular iodine into the water supply to impart a desired iodine residual. The water is passed through an iodinated anion exchange resin bed. The iodine is bound as I-(sub n) at the anion exchange sites and releases I(sub 2) into the water stream flowing through the bed. The concentration of I(sub 2) in the flowing water gradually decreases and, in the prior art, the ion-exchange bed has had to be replaced. In a preferred embodiment, a bed of iodine crystals is provided with connections for flowing water therethrough to produce a concentrated (substantially saturated) aqueous iodine solution which is passed through the iodinated resin bed to recharge the bed with bound iodine. The bed of iodine crystals is connected in parallel with the iodinated resin bed and is activated periodically (e.g., by timer, by measured flow of water, or by iodine residual level) to recharge the bed. Novelty resides in the capability of inexpensively and repeatedly regenerating the ion-exchange bed in situ