Finite sample size effect on minimum variance beamformers: optimum diagonal loading factor for large arrays

Minimum variance beamformers are usually complemented with diagonal loading techniques in order to provide robustness against several impairments such as imprecise knowledge of the steering vector or finite sample size effects. This paper concentrates on this last application of diagonal loading techniques, i.e., it is assumed that the steering vector is perfectly known and that diagonal loading is used to alleviate the finite sample size impairments. The analysis herein is asymptotic in the sense that it is assumed that both the number of antennas and the number of samples are high but have the same order of magnitude. Borrowing some results of random matrix theory, the authors first derive a deterministic expression that describes the asymptotic signal-to-noise-plus-interference ratio (SINR) at the output of the diagonally loaded beamformer. Then, making use of the statistical theory of large observations (also known as general statistical analysis or G-analysis), the authors derive an estimator of the optimum loading factor that is consistent when both the number of antennas and the sample size increase without bound at the same rate. Because of that, the estimator has an excellent performance even in situations where the quotient between the number of observations is low relative to the number of elements of the array.     

True Density and Apparent Density During the Drying Process for Vegetables and Fruits: A Review

Abstract: This review presents the concepts involved in determining the density of foodstuffs, and summarizes the volumetric determination techniques used to calculate true density and apparent density in foodstuffs exposed to the drying process. The behavior of density with respect to moisture content (X) and drying temperature (T) is presented and explained with a basis in changes in structure, conformation, chemical composition, and second‐order phase changes that occur in the processes of mass and heat transport, as reported to date in the literature. A review of the empirical and theoretical equations that represent density is presented, and their application in foodstuffs is discussed. This review also addresses cases with nonideal density behavior, including variations in ρ_s and ρ_w as a function of the inside temperature of the material, depending on drying conditions (X, T). A compilation of studies regarding the density of dehydrated foodstuffs is also presented.     

Cross-coupled DOA trackers

A new robust, low complexity algorithm for multiuser tracking is proposed, modifying the two-stage parallel architecture of the estimate-maximize (EM) algorithm. The algorithm copes with spatially colored noise, large differences in source powers, multipath, and crossing trajectories. Following a discussion on stability, the simulations demonstrate an asymptotic and tracking behavior that neither the EM nor a nonparallelized tracker can emulate     

Effect of temperature cycling on allinase activity in garlic

Allinase, which catalyzes the conversion of alliin to allicin, the principal component of potential medicinal value in garlic, is a thermo-labile enzyme. The potential for allicin formation is determined by the quantity of allinase that remains active after the process of preserving garlic by drying. The kinetics of enzymatic activity loss during drying by temperature cycling or by constant temperature were evaluated and compared. Allicin-forming potential was 91% preserved by temperature cycling from 40 to 60 °C. It was found that sugars present in the garlic and the high molecular mass of the enzyme were responsible for protection against degradation at high drying temperatures. Preservation of the enzymatic activity under cyclical conditions occurred mainly with exposure to low temperatures for drying periods longer than those of constant drying conditions.     

Evaluation of emu oil extraction methods and their effects on physical and rheological behavior

In this study we evaluated the efficiency of six extraction methods for emu fat based on the quantification of yield, color, density, refraction index, and rheological behavior. Both physical methods (Bain Marie, rotary evaporator, fusion, ultrasound, and microwave) and chemical methods (solvents) were evaluated. Oil properties were compared with commercial emu oil as a reference. Solvent‐based extraction produced the greatest yield (72.8%). Among the physical methods, the greatest yield was produced by the ultrasound method (42.8%). In general, properties were similar to those reported for vegetable oils. The rotary evaporator method showed the greatest difference in total color (ΔE) in comparison with a commercially‐produced reference, while the fusion method showed the smallest ΔE. No statistically significant differences were found between the density and refraction index of the treated samples and those of the reference. Kinematic viscosity increased significantly in samples extracted via microwave method. All samples displayed pseudoplastic behavior. The data showed a good fit to the power law model (R² > 0.90). The consistency coefficient and flow behavior index were determined for all methods. Practical applications: Therapeutic applications for oil have been posited for emu oil. In pharmaceutical products, oils are used as emollients and as carriers for medicinal substances. The practical importance of an oil depends on its physical properties, thus a thorough understanding of those physical properties is very important for identifying potential applications. These properties are affected by the extraction method employed; the present paper evaluates the effects of a range of extraction methods on yield efficiency, as well as physical and rheological properties. Novel extraction methods such as ultrasound and microwave are also evaluated in this study.     

Spatial processing for frequency diversity schemes

A novel technique to obtain optimum blind spatial processing for frequency diversity spread spectrum (FDSS) communication systems is introduced. The sufficient statistics for a linear combiner, which prove ineffective due to the interferers frequency characteristics, are modified to yield improved detection under partial jamming in the spectral domain. Robustness to partial time jamming is achieved by extending the notion of replicas over the frequency axis to a repetition over the time variable. Analysis and simulations are provided, showing the advantages of using FDSS with spatial diversity to combat the interference when it is confined to a narrow frequency band or short time interval relative to the desired signal extent in either domain     

Catabolite inactivation of the yeast maltose transporter requires ubiquitin-ligase npi1/rsp5 and ubiquitin-hydrolase npi2/doa4

Peripheral benzodiazepine receptors have been shown in some endocrine tissues, namely the testis, the adrenal gland, and the pituitary gland. In this work we evaluated whether peripheral benzodiazepine receptors can be found in the purified human pancreatic islets and whether they may have a role in insulin release. Binding of the isoquinoline compound [3H]1-(2-chlorophenyl-N-methyl-1-methyl-propyl)-3- isoquinolinecarboxamide (13H]PK-11195) a specific ligand of peripheral benzodiazepine receptors, to cellular membranes was saturable and Scatchard's analysis of the saturation curve demonstrated the presence of a single population of binding sites, with an affinity constant value of 9.20 +/- 0.80 nM and a maximum number of binding sites value of 8913 +/- 750 fmol/mg of proteins. PK-11195 and 7-chloro-1,3-dihydro-1-methyl-5-(p-chlorophenyl)-2H-1,4- benzodiazepine-2-on (Ro 5-4864) significantly potentiated insulin secretion from freshly isolated human islets at 3.3 mM glucose. These results show the presence of peripheral benzodiazepine receptors in purified human pancreatic islets and suggest their role in the mechanisms of insulin release.     

In-the-wild Material Appearance Editing using Perceptual Attributes

Intuitively editing the appearance of materials from a single image is a challenging task given the complexity of the interactions between light and matter, and the ambivalence of human perception. This problem has been traditionally addressed by estimating additional factors of the scene like geometry or illumination, thus solving an inverse rendering problem and subduing the final quality of the results to the quality of these estimations. We present a single-image appearance editing framework that allows us to intuitively modify the material appearance of an object by increasing or decreasing high-level perceptual attributes describing such appearance (e.g., glossy or metallic). Our framework takes as input an in-the-wild image of a single object, where geometry, material, and illumination are not controlled, and inverse rendering is not required. We rely on generative models and devise a novel architecture with Selective Transfer Unit (STU) cells that allow to preserve the high-frequency details from the input image in the edited one. To train our framework we leverage a dataset with pairs of synthetic images rendered with physically-based algorithms, and the corresponding crowd-sourced ratings of high-level perceptual attributes. We show that our material editing framework outperforms the state of the art, and showcase its applicability on synthetic images, in-the-wild real-world photographs, and video sequences.     

Robust Design of Spatial Tomlinson-Harashima Precoding in the Presence of Errors in the CSI

In this letter, we study spatial Tomlinson-Harashima precoding (STHP) from an information theoretic point of view encompassing both the single and the multiuser scenarios. Since the performance of any communications preceding scheme relies on the quality of the channel state information (CSI) that is made available at the transmitter side, in this work we focus our attention on the analysis of the robustness of STHP in terms of rate loss when the CSI is imperfect. Precisely, we present a robust design of the set of moduli used in STHP and, consequently, of the corresponding power allocation, that maximizes the achievable rates for the worst-case errors in the CSI in the small errors regime.