Computational modeling and elementary process analysis in visual word recognition.

An attempt is made to isolate the assumptions that make a connectionist approach to visual word recognition distinctive. These include the commitment to distributed representations, the claim that there is no distinction between lexical and nonlexical systems in the naming task, and the claim that it is possible to map from orthography to meaning without using localized representations. It is argued that merely demonstrating that a network model can perform these tasks is not sufficient and that a detailed theory of how the network performs its tasks must accompany the simulation, because a simulation is not equivalent to an explanation. It is argued that further progress requires detailed modeling and experimental study of the elementary processes assumed to be involved in networks and that it is premature to dismiss alternative models of lexical access such as serial search models. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

在双镶嵌铜互联中O.13微米器件生成用的基于PVD和ALD阻挡层的先进技术

1. Introduction The requirement of minimal bottom coverageand thick sidewall coverage for PVD-based films forlow via resistance and improved stress migration isnot easy to achieve with traditional depositionmethods. Modern I-PVD techniques give high bot-tom coverage, due to the ionized component of thedeposition flux. Sidewall coverage tends to be low,which is mainly due to off-normal deposition fluxand a less than unity sticking coefficient.     

Operator approach to performance analysis of root-MUSIC androot-min-norm

The authors carry out a performance analysis of two eigenstructure-based direction-of-arrival estimation algorithms, using a series expansion of projection operators (or projectors) on the signal and noise subspaces. In the interest of algebraic simplicity, an operator formalism is utilized. A perturbation analysis is performed on the projectors, the results of which are used to determine the effect on the estimated parameters. The approach makes it possible to carry out the analysis to any chosen order of expansion of the projectors by using an original recurrence formula developed for the higher-order terms in the series expansion of the projectors. This method is used to study the root-MUSIC and root-min-norm algorithms and establish the superiority of root-MUSIC in all cases. The analysis has also resulted in insightful asymptotic expressions that describe the statistical behavior of the estimated angles and radii of the signal zeros     

Maximum Likelihood-Based Direction-of-Arrival Estimator for Discrete Sources

This paper addresses the problem of direction-of-arrival (DOA) parameter estimation in array processing when the signals are inherently discrete, which is the case mainly in the digital communication context. Based on the particular structure of the signal space in the data model, a maximum likelihood-based approach is introduced. The strategy consists in transforming the parameter estimation problem into a decision task. It is shown through numerical simulations that the proposed solution closely follows the performance limit given by the Cramér–Rao bound. Some important features of the technique are as follows: (i) it is capable of handling any number of sources, provided that the number of sensors is greater than or equal to two and the number of snapshots is sufficiently greater than the cardinality of the signal space; (ii) the estimation quality is not affected by the angle and phase separation; and (iii) it offers the possibility to deal with uncalibrated arrays.     

Performance Analysis of Covariance Matrix Estimates in Impulsive Noise

This paper deals with covariance matrix estimates in impulsive noise environments. Physical models based on compound noise modeling [spherically invariant random vectors (SIRV), compound Gaussian processes] allow to correctly describe reality (e.g., range power variations or clutter transitions areas in radar problems). However, these models depend on several unknown parameters (covariance matrix, statistical distribution of the texture, disturbance parameters) that have to be estimated. Based on these noise models, this paper presents a complete analysis of the main covariance matrix estimates used in the literature. Four estimates are studied: the well-known sample covariance matrix M_SCM and a normalized version M_N, the fixed-point (FP) estimate M_FP, and a theoretical benchmark M_TFP. Among these estimates, the only one of practical interest in impulsive noise is the FP. The three others, which could be used in a Gaussian context, are, in this paper, only of academic interest, i.e., for comparison with the FP. A statistical study of these estimates is performed through bias analysis, consistency, and asymptotic distribution. This study allows to compare the performance of the estimates and to establish simple relationships between them. Finally, theoretical results are emphasized by several simulations corresponding to real situations.     

Binary Cellulose Nanocrystal Blends for Bioinspired Damage Tolerant Photonic Films

Most attempts to emulate the mechanical properties of strong and tough natural composites using helicoidal films of wood‐derived cellulose nanocrystals (w‐CNCs) fall short in mechanical performance due to the limited shear transfer ability between the w‐CNCs. This shortcoming is ascribed to the small w‐CNC‐w‐CNC overlap lengths that lower the shear transfer efficiency. Herein, we present a simple strategy to fabricate superior helicoidal CNC films with mechanical properties that rival those of the best natural materials and are some of the best reported for photonic CNC materials thus far. Assembling the short w‐CNCs with a minority fraction of high aspect ratio CNCs derived from tunicates (t‐CNCs), we report remarkable simultaneous enhancement of all in‐plane mechanical properties and out‐of‐plane flexibility. The important role of t‐CNCs is revealed by coarse grained molecular dynamics simulations where the property enhancement are due to increased interaction lengths and the activation of additional toughening mechanisms. At t‐CNC contents greater than 5% by mass the mixed films also display UV reflecting behaviour. These damage tolerant optically active materials hold great promise for application as protective coatings. More broadly, we expect the strategy of using length‐bidispersity to be adaptable to mechanically enhancing other matrix‐free nanoparticle ensembles.     

一种带有片上电荷泵自动调谐结构的非对称带通滤波器的设计

摘要：提出了一种采用片上电荷泵自动调谐结构的MOSFET-C非对称带通滤波器的设计方案,并在UMC（联合电子公司）0.18um标准CMOS工艺线上流片得到验证。带有调谐系统的滤波器采用主从技术进行连续调谐,完成调谐功能后电荷泵输出调谐电压为2.663V,远高于电源电压,提高了滤波器的线性度。非对称带通滤波器带宽为（2.73MHz,5.34MHz）且具有3阶低通和2阶高通特性。以50欧姆作为源阻抗,滤波器带内3阶交调量（IIP3）为16.621dBm。输入参考噪声为47.455uVrms。在1.8V电源电压下,主滤波器功耗为3.528mW,自动调谐电路功耗为2.412mW。带有自动调谐系统的滤波器整个系统占芯片面积0.592mm2,可用于无线局域网,全球定位和蓝牙等系统中。     

Experimental intravitreal gentamicin

Rabbits received intravitreal injections of gentamicin and indirect ophthalmoscopy, electroretinography, and histopathology determined relative toxicity. An intravitreal dose of 0.1 to 0.2 mg of commercially available gentamicin was well tolerated in the rabbit eye. A dosage of 0.4 mg or higher consistently produced significant ocular toxicity as evidenced by extinction of the electroretinogram, gross fundus changes, and histopathologic alterations.     

Antibodies to Candida after operations on the heart

In order to determine the frequency of hypoxaemia and to evaluate the role of increased closing capacity in producing hypoxaemia in patients with cirrhosis of the liver, 13 patients with well-established cirrhosis were studied. Arterial blood gases, spirometry, lung volume, and closing capacity measurements were made with the patients in the seated and recumbent positions after exclusion of cardiopulmonary dysfunction. Four of 13 and six of 12 patients exhibited significant hypoxaemia in the seated and recumbent positions respectively. Five of 13 patients showed a closing capacity greater than predicted. This frequency of increased closing capacity was not higher than in a group of smokers of the same age. Unlike Ruff et al. (1971), we did not find a consistent relationship between hypoxaemia and closing capacity.     

Diamine oxidase supplementation improves symptoms in patients with histamine intolerance

Food Science and Biotechnology - Histamine intolerance (HIT) is thought to be caused by a disproportionate amount of histamine in the body. The enzyme diamine oxidase (DAO) is considered for the...