Comparison of contact resistance between accumulation-mode and inversion-mode multigate FETs

The performances of accumulation-mode and inversion-mode multigate FETs are compared. The influence of gate underlap on the electrical properties is analyzed. Both simulation results and experimental data show that in a device with gate underlap, accumulation-mode devices have a higher current drive, lower source and drain resistance and less process variability than inversion-mode FETs.     

A difference-set cyclic code (1057,813,34)

This paper presents an overview of the implementation of a difference-set cyclic code (1057,813,34). It is easy to achieve coding and decoding circuits. The decoding lays on the analysis of the composite remainder R_c (x) and the use of a decoding matrix of 33 Boolean equations. The error-correcting algorithm has been improved, so the difference-set cyclic code (1057,813,34) can correct up to 26 random errors instead of the 16 previous random errors found by the theory. Moreover, 3 decoding algorithms have been simulated and allow the comparison of their respective efficiency. The hardware achievement is quite easy because the necessary logical elements such as shift delay registers, positive-and gates, positive-or gates, positive-exclusive-or gates exist as a set of libraries.     

Adaptive mesh generation for progressive radiosity: A ray-tracing based algorithm.

The radiosity method is one of the most popular rendering algorithms. It allows to simulate interreflections of light accurately between surfaces as energy transfers are well designed. However, this algorithm and its derivatives need to break scenes into a relatively large number of small elements to approximate the illumination function. Even with a very large number of elements, not all the illumination effects can be simulated. In fact, there are always artefacts when modelling sharp shadows, besides shadows falling between mesh vertices can be missed entirely. To reduce the computational cost of such methods and to increase the accuracy of the radiosity solution, adaptive mesh generation is well suited. In this paper, we present a ray-tracing based algorithm for adaptive mesh generation which resolves all the illumination problems without lengthening computation time too much. This method allows a small number of initial elements and increases element density in critical locations while solving the illumination problem.     

Rubber-modified epoxies. I. Influence of presence of a low level of rubber on the polymerization

Butadiene-acrylonitrile random copolymers with various molecular weights and end-groups were introduced into a system consisting of the diglycidyl ether of bisphenol A (DGEBA) and 3,3′-dimethyl-4,4′-diamino dicyclohexyl methane (3DCM) cured at 50°C. We studied the influence of a low level of soluble additive on the polymerization rate, evolution of viscosity, gelation and vitrification times, and the final network in the cases of different additive molecular weight and end groups of the additive. It was found that the additive influences the final network only by dissolving in the matrix and that the dilution effect plays a minor role, but the catalytic effect of an additive can play a significant role on the polymerization depending on the additive end groups. However, in all the rubber-modified systems, the phase separation has no direct influence on the polymerization rate and the change of viscosity.     

Arbitrarily shaped multiple spatial cluster detection for case event data

An original method is proposed for spatial cluster detection of case event data. A selection order and the distance from the nearest neighbour are attributed to each point, once pre-selected points have been taken into account. This distance is weighted by the expected distance under the uniform distribution hypothesis. Potential clusters are located by modelling the multiple structural change of the distances on the selection order and the best model (containing one or several potential clusters) is selected using the double maximum test. Finally a p-value is obtained for each potential cluster. With this method multiple clusters of any shape can be detected.     

Hemispheric Specialization in the Primary Auditory Area of Awake and Anesthetized Starlings (Sturnus vulgaris).

Although evidence exists for a lateralization of song production, few studies have focused on the perceptual aspect of lateralization in songbirds. In the present study, the authors recorded neuronal responses to a variety of species-specific and artificial, nonspecific stimuli in both hemispheres of awake and anesthetized male starlings (Sturnus vulgaris). Recordings were made in the primary auditory area of the songbird brain, the Field L complex. The right hemisphere exhibited significantly more responsive units than the left hemisphere in awake birds, and this difference was significantly reduced in anesthetized birds. Furthermore, clear hemispheric specialization toward categories of behaviorally relevant stimuli and precise parameters of these stimuli were found. The main auditory area of the starling's brain thus appears to show some degree of lateralization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimisation de ľefficacité de couplage entre un guide ďonde confiné et une fibre optique monomode par ľintermédiaire ďune lentille boule

Theoretical coupling efficiency between a channel waveguide and a single-mode optical fibre using a ball lens is optimized by varying the parameters of the optical system such as the relative position of the components, the refractive index and the size of the lens. A specific software has been used for the optimization. Numerical calculations have been done under the Gaussian approximation of the fields distributions. The losses due to waveguides misalignments with respect to their ideal position have been evaluated. All these theoretical results are compared with those obtained from buttcoupling.     

钻孔测量系统在岩土勘探中的应用(下)

通过灌浆管钻孔可以获得有助于后期隧道建设的辅助性岩土信息。以海上勘探技术为基础发展起来的陆上钻孔测量系统(instrumenteddrillingsystem)已经通过了实地岩土勘探的检验。该系统通过在设备液压回路(hydrauliccircuits)的不同位置安装一组压力传感器,检测其分辨地层的能力。从理论上讲,随着灌浆钻孔的逐层深入,本方法可以应用于几乎所有土壤类型的生成变化的定性解析(qualitativeinterpretation)。鉴于此法的取样间隔较小,约5mm,所以能够分析为传统实地勘测方法所忽略的岩土结构局部变化。本次研究分别在伦敦的坎宁顿公园(KenningtonPark)和朱比利地铁延长线(JubileeLineEx tension)两地对上述系统进行了实地检验,并在之后对从该系统得到的分析结果与获得的岩心样本进行了比对研究。我们对钻机的零部件以及钻孔方法的选择进行了研究和标准化,以便将来获得全球适用的有意义的数据。此外,通过对几组标准化和非标准化的钻孔设备和方法进行交叉相关分析,我们还量化了不一致的钻孔设备和方法对数据质量的影响程度。     

FT-IR studies of polymer blends containing an oligo(isophthalate-co-fumarate of diethylene glycol) and different epoxy prepolymers

Miscibility of one unsaturated polyester (UP) with different epoxy prepolymers have been examined. Thermodynamic interaction parameters have been calculated. Calorimetric and clarity measurements indicate formation of miscible blends. This is in good agreement with the theoretical predictions excepted those with the 3-dimensional solubility parameter. Fourier transform infrared (FT-IR) studies are presented. The ability of acid solvent to associate with ester group have been used to determine the shift of the carbonyl stretching frequency. Similar shift has been found in UP/DGEBA blends and is attributed to specific interactions between these two types of oligomers.