Constant-Power Bit Loading for Multicarrier Systems: BER-Allocation

Adaptive bit loading algorithms are proposed for multi-channel systems in general, and orthogonal frequency division multiplexing in particular. A discrete coding-modulation adaptation is considered. Constant power allocation is assumed for all subchannels, while the bit error rate on different subchannels is unconstrained. The proposed algorithms are computationally efficient and require limited amount of feedback resources. Their performance compare favorably with other practical schemes known in the art.     

Gradient-based 2-D/3-D rigid registration of fluoroscopic X-ray to CT

We present a gradient-based method for rigid registration of a patient preoperative computed tomography (CT) to its intraoperative situation with a few fluoroscopic X-ray images obtained with a tracked C-arm. The method is noninvasive, anatomy-based, requires simple user interaction, and includes validation. It is generic and easily customizable for a variety of routine clinical uses in orthopaedic surgery. Gradient-based registration consists of three steps: 1) initial pose estimation; 2) coarse geometry-based registration on bone contours, and; 3) fine gradient projection registration (GPR) on edge pixels. It optimizes speed, accuracy, and robustness. Its novelty resides in using volume gradients to eliminate outliers and foreign objects in the fluoroscopic X-ray images, in speeding up computation, and in achieving higher accuracy. It overcomes the drawbacks of intensity-based methods, which are slow and have a limited convergence range, and of geometry-based methods, which depend on the image segmentation quality. Our simulated, in vitro, and cadaver experiments on a human pelvis CT, dry vertebra, dry femur, fresh lamb hip, and human pelvis under realistic conditions show a mean 0.5-1.7 mm (0.5-2.6 mm maximum) target registration accuracy.     

Assessing the scholarly impact of health psychology: A citation analysis of articles published from 1993 to 2003.

Objective: We conducted a citation analysis to explore the impact of articles published in Health Psychology and determine whether the journal is fulfilling its stated mission. Design: Six years of articles (N = 408) representing three editorial tenures from 1993–2003 were selected for analysis. Main Outcome Measures: Articles were coded for several dimensions enabling examination of the relationship of article features to subsequent citations rates. Journals citing articles published in Health Psychology were classified into four categories: (1) psychology, (2) medicine, (3) public health and health policy, and (4) other journals. Results: The majority of citations of Health Psychology articles were in psychology journals, followed closely by medical journals. Studies reporting data collected from college students, and discussing the theoretical implications of findings, were more likely to be cited in psychology journals, whereas studies reporting data from clinical populations, and discussing the practice implications of findings, were more likely to be cited in medical journals. Time since publication and page length were both associated with increased citation counts, and review articles were cited more frequently than observational studies. Conclusion: Articles published in Health Psychology have a wide reach, informing psychology, medicine, public health and health policy. Certain characteristics of articles affect their subsequent pattern of citation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

5. VCNR type characteristic in thin film amorphous TeGeAsSi films

In the hope of further understanding the memory and switching effects of amorphous evaporated semi-conductor films, the current-voltage curve of the quarternary system TeGeAsSi was experimentally examined and our findings are discussed below.     

Compressed Genotyping

Over the past three decades we have steadily increased our knowledge on the genetic basis of many severe disorders. Nevertheless, there are still great challenges in applying this knowledge routinely in the clinic, mainly due to the relatively tedious and expensive process of genotyping. Since the genetic variations that underlie the disorders are relatively rare in the population, they can be thought of as a sparse signal. Using methods and ideas from compressed sensing and group testing, we have developed a cost-effective genotyping protocol to detect carriers for severe genetic disorders. In particular, we have adapted our scheme to a recently developed class of high throughput DNA sequencing technologies. The mathematical framework presented here has some important distinctions from the 'traditional' compressed sensing and group testing frameworks in order to address biological and technical constraints of our setting.     

Stabilization of Ni(I)(1,4,8,11-tetraazacyclotetradecane)+ in a Sol-Gel Matrix: It's Plausible Use in Catalytic Processes

Monovalent nickel is used as a catalyst in a diversity of important chemical systems due to its properties as a strong reducing agent. However, monovalent nickel is unstable in homogeneous systems; its lifetime is very short, and therefore, its efficiency as a catalyst is quite limited. In this article, we demonstrate the catalytic capabilities of Ni(I)(1,4,8,11-tetraazacyclotetradecane)⁺ as a reducing and catalytic agent by its entrapment in the silica sol gel matrix. The EPR results indicate that the sol-gel matrix plays two roles: it inhibits the common mechanism of Ni(I)L⁺ decomposition in aqueous solutions, and it also facilitates its functionality as a heterogeneous catalyst, by stabilizing it for at least several hours. The activity of Ni(I)L⁺ which is entrapped within the matrix, was studied by reducing 2,2-Bis(bromomethyl)-1,3-Propanediol and I₃⁻. The results indicate that Ni(I)L⁺/Ni(III)L−H²⁺ acts as a good reducing agent. These results have important implications for a variety of essential catalytic reactions by shedding light on a new feature of sol-gel matrices and their use as active species stabilizers.