Optimal high-order Yule-Walker estimation of sinusoidal frequencies

The asymptotic properties of sinusoidal frequency estimators based on the high-order Yule-Walker (HOYW) equations were analyzed recently. The results of that analysis are used to propose two classes of frequency estimators; one class uses singular value decomposition, and the other uses a sparse matrix solution. Both classes entail two estimation steps: the first step generates initial estimates which are used to obtain an optimal weighting matrix, and the second step generates an optimally weighted estimate. Each two-step method produces asymptotically minimum variance estimates over all estimators of their class. The implementation of the proposed estimators is described in detail, and numerical examples are presented to evaluate their performance     

Review of Advances in clinical rehabilitation (Vol. 3).

Reviews the book, Advances in clinical rehabilitation (Vol. 3), edited by M. G. Eisenberg and R. C. Grzesiak (no year provided). The editors introduce this volume, the third in their ongoing series of multidisciplinary overviews of team treatment principles in rehabilitation, as a contribution to the continuing education literature for rehabilitation professionals in variety of distinct but interrelated fields. The goal of the volume, and of the series as a whole, is to provide in-depth, clinically practical updates on important issues in rehabilitation for all members of the treatment team. This is a difficult task since multidisciplinary specialization typically encourages deep, but narrow mastery of knowledge regarding management of health care problems that affect a specific organ system. The aim of the current volume and others in this series is to provide in-depth topical updates for selected rehabilitation professionals by leading specialists in those review areas. The series as a whole is meant to serve as a periodic topical update resource for multidisciplinary rehabilitative professionals, but it is not intended to be an encyclopedia or a textbook of rehabilitation practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis of pyramidal,cubical and truncated octahedral magnetite nanocrystals by controlling reaction heating rate

Pyramidal, cubical and truncated octahedral magnetite nanocrystals have been synthesized by thermal de-composition of iron (III) acetylacetone (Fe(acac)₃) in the presence of oleic acid under various reaction rate controlled by heating rate. The magnetite nanocrystals were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). High-resolution transmission electron microscopy (HRTEM) was applied to reveal the structural information of single magnetite (Fe₃O₄) nanocrystals. Magnetization curves of the three types of magnetite nanocrystals show that the pyramidal crystals exhibit a slight hysteresis compared to the other two despite of the similar size range. The results suggest that in addition to the surfactant selective capping and varying reaction temperature, the reaction rate variation is also an effective means for controlling the morphology and functions of the magnetite nanocrystals.     

Dynamic excitations in membranes induced by optical tweezers

We present the phenomenology of transformations in lipid bilayers that are excited by laser tweezers. A variety of dynamic instabilities and shape transformations are observed, including the pearling instability, expulsion of vesicles, and more exotic ones, such as the formation of passages. Our physical picture of the laser-membrane interaction is based on the generation of tension in the bilayer and loss of surface area. Although tension is the origin of the pearling instability, it does not suffice to explain expulsion of vesicles, where we observe opening of giant pores and creeping motion of bilayers. We present a quantitative theoretical framework to understand most of the observed phenomenology. The main hypothesis is that lipid is pulled into the optical trap by the familiar dielectric effect, is disrupted, and finally is repackaged into an optically unresolvable suspension of colloidal particles. This suspension, in turn, can produce osmotic pressure and depletion forces, driving the observed transformations.     

GaInNAs-based distributed feedback laser diodes emitting at 1.5 /spl mu/m

For the first time, GaAs-based 1.5 /spl mu/m singlemode emission has been realised utilising GaInNAs active-layer material and lateral distributed feedback. The double quantum well separate confinement laser structure was grown by plasma-assisted molecular beam epitaxy. A threshold current of 240 mA and an external efficiency of 0.11 W/A could be demonstrated with a sidemode suppression ratio of better than 26 dB in pulsed operation. Singlemode emission up to 1506.5 nm has been realised.     

Stenting after optimal lesion debulking (sold) registry. Angiographic and clinical outcome

BACKGROUND: Coronary stenting has reduced restenosis in focal de novo lesions, but its impact has been less pronounced in complex lesion subsets. Preliminary data suggest a role for plaque burden in promoting intimal hyperplasia after stent implantation. The aim of this study was to test the hypothesis that plaque removal with directional atherectomy before stent implantation may lower the intensity of late neointimal hyperplasia, reducing the incidence of in-stent restenosis. METHODS AND RESULTS: Seventy-one patients with 90 lesions underwent directional atherectomy before coronary stenting. Intravascular ultrasound-guided stenting was performed in 73 lesions (81%). Clinical success was achieved in 96% of patients. Procedural complications were as follows: emergency bypass surgery in 1 patient (1.4%), who died 2 weeks later; Q-wave myocardial infarction in 2 patients (2.8%); and non-Q-wave myocardial infarction in 8 patients (11.3%). None of the patients had stent thrombosis at follow-up. Angiographic follow-up was performed in 89% of eligible patients at 5.7+/-1.7 months. Loss index was 0.33 (95% CI, 0.26 to 0.40), and angiographic restenosis was 11% (95% CI, 5% to 20%). Clinical follow-up was performed in all patients at 18+/-3 months. Target lesion revascularization was 7% (95% CI, 3% to 14%). CONCLUSIONS: Directional atherectomy followed by coronary stenting could be performed with good clinical success rate. Also, these data point to a possible reduction in angiographic restenosis and a significant reduction in the need for repeated coronary interventions. Therefore, a randomized clinical trial seems appropriate to test the validity of this approach.     

On-line hardness assessment of cold-rolled motor lamination steels

It is important to be aware of variations in the mechanical hardness of strip emerging from the strand anneal lines, which are used to anneal continuous steel strip during production. Lamination stamping, punching, and handling characteristics can depend on the hardness of the materials. A novel technique for the nondestructive determination of the hardness of nonoriented electrical steels has been developed. This technique exploits the measurements of structure-sensitive magnetic parameters, which are measured continuously on-line in real time. The magnetic data being produced are then processed through appropriate algorithms to provide an evaluation of material mechanical hardness. Variation of hardness along the length of coils then can be readily examined.