Noisy image restoration by cost function minimization

Implementation of a new approach to the nonlinear noisy image restoration problem, which is feasible for large images, is described. The approach is based on a vector space representation of images and on using the conjugate gradient algorithm to solve a least squares minimization problem. Computer simulations yield good results with relatively little computational cost.     

Principles of psychotherapeutic strategy.

Argues that strategy fills a real need in psychotherapeutic thinking. An attempt is made to define strategic rules for (1) choosing and defining goals, (2) locating strategic points, (3) actively searching for the client's responses, (4) dealing with resistance, (5) exploiting or creating propitious timings, (6) mobilizing allies, (7) concentrating the therapeutic influence, (8) stabilizing partial achievements, (9) dealing with competing demands, (10) retreating after failure, and (11) changing the therapeutic framework when needed. Each principle is illustrated by interventions from different therapeutic orientations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bounds on maximum likelihood ratio-part I: application to antenna array detection-estimation with perfect wavefront coherence

The multiple hypothesis testing problem of the detection-estimation of an unknown number of independent Gaussian point sources is adequately addressed by likelihood ratio (LR) maximization over the set of admissible covariance matrix models. We introduce nonasymptotic lower and upper bounds for the maximum LR. Since LR optimization is generally a nonconvex multiextremal problem, any practical solution could now be tested against these bounds, enabling a high probability of recognizing nonoptimal solutions. We demonstrate that in many applications, the lower bound is quite tight, with approximate maximum likelihood (ML) techniques often unable to approach this bound. The introduced lower bound analysis is shown to be very efficient in determining whether or not performance breakdown has occurred for subspace-based direction-of-arrival (DOA) estimation techniques. We also demonstrate that by proper LR maximization, we can extend the range of signal-to-noise ratio (SNR) values and/or number of data samples wherein accurate parameter estimates are produced. Yet, when the SNR and/or sample size falls below a certain limit for a given scenario, we show that ML estimation suffers from a discontinuity in the parameter estimates: a phenomenon that cannot be eliminated within the ML paradigm.     

Temporal segregation in coexisting spiny mice (genus Acomys): role of photoperiod and heterospecific odor

The distal long arm of chromosome 10 harbors genes of biomedical interest such as MXI1, a putative tumor suppressor gene, and those encoding the adrenergic receptors alpha2A (ADRA2A) and beta1 (ADRB1). As part of a physical and genetic study of this genomic region, we constructed a 1.5-Mb YAC contig mapping to 10q25 that contains MXI1 and ADRA2A as well as a number of STSs. Rare cutting restriction site analysis of overlapping YACs allowed fine mapping of these genes and markers along the contig and revealed the presence of four CpG islands. MXI1 and ADRA2A appear to be about 600 kb apart, whereas ADRB1 is separated from ADRA2A by a distance larger than previously reported.     

Ultrasonic flow rate measurement of low speed non-isothermal flows

In this study, a performance evaluation of a non-intrusive ultrasonic flowmeter is carried out for slow, non-isothermal flows. The purpose of the study is to investigate the adequacy of the above meter for flow rate measurements in thermal convection loops. The flowmeter is found to be useful only for part of the range of interest.     

Context-free attentional operators: The generalized symmetry transform

Active vision systems, and especially foveated vision systems, depend on efficient attentional mechanisms. We propose that machine visual attention should consist of both high-level, context-dependent components, and low-level, context free components. As a basis for the context-free component, we present an attention operator based on the intuitive notion of symmetry, which generalized many of the existing methods of detecting regions of interest. It is a low-level operator that can be applied successfully without a priori knowledge of the world. The resultingsymmetry edge map can be applied in various low, intermediate-and high- level tasks, such as extraction of interest points, grouping, and object recognition. In particular, we have implemented an algorithm that locates interest points in real time, and can be incorporated in active and purposive vision systems. The results agree with some psychophysical findings concerning symmetry as well as evidence concerning selection of fixation points. We demonstrate the performance of the transform on natural, cluttered images.     

Setting safety lead-times for purchased components in assembly systems: a general solution procedure

In a recent paper, Hopp and Spearman (1993) presented a model to determine optimal lead-times for purchasing components where the only manufacturing operation is the final assembly. It is assumed that delivery times of the different components are normal variates. An approximate iterative solution procedure is presented that facilitates derivation of the optimal lead-times.

Based on an approximation for the delivery-time distribution, an alternative solution procedure is proposed that results in closed-form expressions for the decision variables of the problem. Both simplicity and ease of calculation are achieved. Furthermore, the new procedure is extended to non-normal delivery-time distributions.

For Hopp and Spearman's numerical examples, the new procedure is shown to yield better accuracy.     

Thermoregulatory responses of mesic and xeric rodent species to photoperiod manipulations

PURPOSE: To evaluate hypertrophied bronchial arteries on thin-section computed tomographic (CT) scans in patients with bronchiectasis by using CT angiographic correlation. MATERIALS AND METHODS: Spiral CT angiography was performed prospectively in 14 patients (eight men, six women; age range, 34-71 years) with bronchiectasis who were suspected of having bronchial arterial hypertrophy at thin-section CT (performed without contrast medium). The inclusion criteria were tubular (in six patients) or nodular (in 14 patients) areas of soft-tissue attenuation that had an appearance unlike that of lymph nodes at thin-section CT and that were within the mediastinum and around the central airway. These findings were subsequently correlated with the spiral CT angiographic findings. RESULTS: At comparative analysis of thin-section CT scans and CT angiograms, seven of the eight (88%) tubular lesions and 19 of the 36 (53%) nodular lesions in the mediastinal soft tissue were proved to be hypertrophied bronchial arteries. All of the six (100%) tubular and 19 of the 21 (90%) nodular lesions around the walls of the main (primary) and lobar bronchi were hypertrophied bronchial arteries. In eight (57%) patients, CT angiograms showed 11 intraluminal protrusions caused by hypertrophied bronchial arteries in the main bronchi, lobar bronchi, or both. CONCLUSION: Nodular and tubular structures in the mediastinum and around the central airway on thin-section CT scans in the patients with bronchiectasis are suggestive of hypertrophied bronchial arteries. Recognition of the hypertrophied bronchial artery can be critical for the bronchoscopist.