A new ADMM algorithm for the Euclidean median and its application to robust patch regression

The Euclidean Median (EM) of a set of points $\Omega$ in an Euclidean space is the point x minimizing the (weighted) sum of the Euclidean distances of x to the points in $\Omega$. While there exits no closed-form expression for the EM, it can nevertheless be computed using iterative methods such as the Wieszfeld algorithm. The EM has classically been used as a robust estimator of centrality for multivariate data. It was recently demonstrated that the EM can be used to perform robust patch-based denoising of images by generalizing the popular Non-Local Means algorithm. In this paper, we propose a novel algorithm for computing the EM (and its box-constrained counterpart) using variable splitting and the method of augmented Lagrangian. The attractive feature of this approach is that the subproblems involved in the ADMM-based optimization of the augmented Lagrangian can be resolved using simple closed-form projections. The proposed ADMM solver is used for robust patch-based image denoising and is shown to exhibit faster convergence compared to an existing solver.Comment: 5 pages, 3 figures, 1 table. To appear in Proc. IEEE International Conference on Acoustics, Speech, and Signal Processing, April 19-24, 201

Competition between Superconductivity and Charge Density Wave Ordering in the Lu5_5Ir4_4(Si1−x_{1-x}Gex_x)10_{10} Alloy System

We have performed bulk measurements such as dc magnetic susceptibility, electrical resistivity and heat capacity on the pseudo-ternary alloys Lu$_5$Ir$_4$(Si$_{1-x}$Ge$_x$)$_{10}$ to study the interplay and competition between superconductivity and the charge density wave (CDW) ordering transition. We track the evolution of the superconducting transition temperature T$_{SC}$ and the CDW ordering temperature T$_{CDW}$ as a function of x (concentration of Ge) ($0.0 \leq x\leq~1.0$). We find that increasing x (increasing disorder) suppresses the T$_{CDW}$ rapidly with the concomitant increase in T$_{SC}$. We present a temperature-concentration (or volume) phase diagram for this system and compare our results with earlier work on substitution at the Lu or Ir site to show how dilution at the Si site presents a different situation from these other works. The heat capacity data in the vicinity of the CDW transition has been analyzed using a model of critical fluctuations in addition to a mean-field contribution and a smooth lattice background. We find that the critical exponents change appreciably with increasing disorder. This analysis suggests that the strong-coupling and non mean-field like CDW transition in the parent compound Lu$_5$Ir$_4$Si$_{10}$ changes to a mean-field like transition with increasing Ge concentration.Comment: 14 pages and 8 figures. Accepted for publication in Phys. Rev.

Refinement and application of acoustic impulse technique to study nozzle transmission characteristics

An improved acoustic impulse technique was developed and was used to study the transmission characteristics of duct/nozzle systems. To accomplish the above objective, various problems associated with the existing spark-discharge impulse technique were first studied. These included (1) the nonlinear behavior of high intensity pulses, (2) the contamination of the signal with flow noise, (3) low signal-to-noise ratio at high exhaust velocities, and (4) the inability to control or shape the signal generated by the source, specially when multiple spark points were used as the source. The first step to resolve these problems was the replacement of the spark-discharge source with electroacoustic driver(s). These included (1) synthesizing on acoustic impulse with acoustic driver(s) to control and shape the output signal, (2) time domain signal averaging to remove flow noise from the contaminated signal, (3) signal editing to remove unwanted portions of the time history, (4) spectral averaging, and (5) numerical smoothing. The acoustic power measurement technique was improved by taking multiple induct measurements and by a modal decomposition process to account for the contribution of higher order modes in the power computation. The improved acoustic impulse technique was then validated by comparing the results derived by an impedance tube method. The mechanism of acoustic power loss, that occurs when sound is transmitted through nozzle terminations, was investigated. Finally, the refined impulse technique was applied to obtain more accurate results for the acoustic transmission characteristics of a conical nozzle and a multi-lobe multi-tube supressor nozzle

Role of Social Institutions In a Multicultural Society

With the rapid change in the demographic structure of the American society, the United States is becoming a mosaic of multiculturalism. Such changes have dramatic implications for social institutions. To understand such changes an overview of the evolution of multiculturalism from a historical perspective is provided. The concept of cultural pluralism is discussed for delineating the role of social institutions. Also examined is the issue of affirmative action, and the role of social welfare institution

Retroperitoneal Ganglioneuroma: A case report and review of literature

Ganglioneuroma, a tumor of neural crest origin, is a rare neoplasm; to encounter it in an adult over 50 years of age is very rare. This report describes the case of a 56-year-old man who was seen at Henry Ford Hospital with an abdominal mass confirmed as ganglioneuroma on histopathology. Experience at Henry Ford Hospital and the available literature on the subject are reviewed

Enzyme changes during seed storage in groundnut (Arachis hypogaea L.)

A change in enzyme activity in seeds due to ageing is a topic of scientific importance. Vigour is essentially a physiological phenomenon influenced by the reserved metabolites, enzyme activities and growth regulators. The exact cause of loss of seed vigour and viability is still unknown as deterioration of seed is a complex process. In the presence of oxygen, ageing of seed can lead to peroxidative changes in polyunsaturated fatty acids. The free radical -induced non-enzymatic peroxidation, which has the potential to damage membrane, is likely to be a primary cause of deterioration of stored seeds. Certain anabolic enzymes help in maintaining viability while some catabolic enzymes decrease viability. The seed catalase and peroxidase activity seem to be decreased during storage. The results revealed that the peroxidase enzyme activity decreased from 0.236 to 0.444 OD 10 min-1 when storage period increased. A decrease in catalase activity from 0.454 to 0.444 ?g H2O2 mg-1 min-1 followed by a small increase from 0.434 to 0.452 ?g H2O2 mg-1 min-1 was observed during storage. But the activity of lipase enzyme increased from 0.236 to 0.231 meq min-1g-1 of sample when the storage period was increased. The study would help to know the deterioration pattern of stored groundnut seeds