Detection of an unknown rank-one component in white noise

We consider the detection of an unknown and arbitrary rank-one signal in a spatial sector scanned by a small number of beams. We address the problem of finding the maximal invariant for the problem at hand and show that it consists of the ratio of the eigenvalues of a Wishart matrix to its trace. Next, we derive the generalized-likelihood ratio test (GLRT) along with expressions for its probability density function (pdf) under both hypotheses. Special attention is paid to the case m= 2, where the GLRT is shown to be a uniformly most powerful invariant (UMPI). Numerical simulations attest to the validity of the theoretical analysis and illustrate the detection performance of the GLRT

Contingent Fee: Champerty or Champion

In 1952, an article appeared in Reader\u27s Digest magazine castigating both the contingent fee system of financing litigation and the trial lawyers of the United States. Since that article appeared, the client public has been barraged with a stream of propaganda aimed at barring the use of the contingent fee as a means of retaining a lawyer

A Feasibility Study on Miniaturizing an Automatic Amino Acid Analyzer for Use on Apollo Mission and Mars Voyager Mission Progress Report, Jun. - Dec. 1966

Miniaturizing automatic amino acid analyzer for Apollo and Voyager mission

A Feasibility Study on Miniaturizing an Automatic Amino Acid Analyzer for Use on Apollo Mission and Mars Voyager Mission Progress Report, Jan. - Jun. 1967

Miniaturizing n automatic amino acid analyzer for use on Apollo mission and Mars Voyager missio

Escaping from nonhyperbolic chaotic attractors

We study the noise-induced escape process from chaotic attractors in nonhyperbolic systems. We provide a general mechanism of escape in the low noise limit, employing the theory of large fluctuations. Specifically, this is achieved by solving the variational equations of the auxiliary Hamiltonian system and by incorporating the initial conditions on the chaotic attractor unambiguously. Our results are exemplified with the H{\'e}non and the Ikeda map and can be implemented straightforwardly to experimental data.Comment: replaced with published versio

Adaptive subspace detectors

Includes bibliographical references.In this paper, we use the theory of generalized likelihood ratio tests (GLRTs) to adapt the matched subspace detectors (MSDs) of [1] and [2] to unknown noise covariance matrices. In so doing, we produce adaptive MSDs that may be applied to signal detection for radar, sonar, and data communication. We call the resulting detectors adaptive subspace detectors (ASDs). These include Kelly's GLRT and the adaptive cosine estimator (ACE) of [6] and [19] for scenarios in which the scaling of the test data may deviate from that of the training data. We then present a unified analysis of the statistical behavior of the entire class of ASDs, obtaining statistically identical decompositions in which each ASD is simply decomposed into the nonadaptive matched filter, the nonadaptive cosine or t-statistic, and three other statistically independent random variables that account for the performance-degrading effects of limited training data.This work was supported by the Office of Naval Research under Contracts N00014-89-J-1070 and N00014-00-1-0033, and by the National Science Foundation under Contracts MIP-9529050 and ECS 9979400

An atlas of gene regulatory networks reveals multiple three-gene mechanisms for interpreting morphogen gradients

Although >450 different topologies can achieve the same multicellular patterning function, they can be grouped into six main classes, which operate using different underlying dynamics.Alternative designs for the same functions can therefore split into two types: (a) topology alterations that retain the same underlying dynamics and (b) alterations that utilize a completely different underlying dynamical mechanism.This segregation of networks into distinct dynamical mechanisms can be revealed by the shape of the topology atlas itself.Cell–cell communication is not usually part of the causal mechanism underlying a band-pass response during morphogen interpretation, but it can tune the result or increase robustness

Géométries, invariances et interprétations par le rapport signal à bruit de détecteurs en sous-espaces adaptés ou adaptatifs

Matched subspace detectors generalize the matched filter by accommodating signals that are only constrained to lie in a multidimensional subspace. There are four of these detectors, depending upon knowledge of signal phase and noise power. The adaptive subspace detectors generalize the matched subspace detectors by accommodating problems where the noise covariance matrix is unknow, and must be estimated from training data. In this paper we review the geometries and invariances of the matched and adaptive subspace detectors. We also establish that every version of a matched or adaptative subspace detectors can be interpreted as an estimator of output signal-to-noise ratio (SNR), in disquise

Simulation of Fluid Flow During Direct Synthesis of H2_{2}O2_{2} in a Microstructured Membrane Reactor

A microstructured membrane reactor has been developed to overcome the safety and productivity challenge of the direct synthesis of hydrogen peroxide. A single membrane is employed for separate, continuous dosage of the gaseous reactants hydrogen and oxygen to the solid catalyst present in the aqueous solvent. Using a custom OpenFOAM® model, the impact of catalyst‐coated static mixers with different mixer geometries is studied. It is demonstrated that the custom fluid guiding elements outperform the investigated commercial static mixer under the flow conditions relevant to this application

An analytic model of the Gruneisen parameter at all densities

We model the density dependence of the Gruneisen parameter as gamma(rho) = 1/2 + gamma_1/rho^{1/3} + gamma_2/rho^{q}, where gamma_1, gamma_2, and q>1 are constants. This form is based on the assumption that gamma is an analytic function of V^{1/3}, and was designed to accurately represent the experimentally determined low-pressure behavior of gamma. The numerical values of the constants are obtained for 20 elemental solids. Using the Lindemann criterion with our model for gamma, we calculate the melting curves for Al, Ar, Ni, Pd, and Pt and compare them to available experimental melt data. We also determine the Z (atomic number) dependence of gamma_1. The high-compression limit of the model is shown to follow from a generalization of the Slater, Dugdale-MacDonald, and Vashchenko-Zubarev forms for the dependence of the Gruneisen parameter.Comment: 14 Pages, LaTeX, 5 eps figues; changes in the tex