Transducer interconnection with a standard fieldbus

This paper discusses fieldbus systems and introduces MIL-STD-1553B, IEC International Fieldbus, Arcnet, Bitbus and The Local Operating Network as examples of the world-wide fieldbus activity. The main features of fieldbus instrumentation are introduced and communication protocols, safety and condition monitoring applications, and smart instrumentation are discussed.     

Elements of a theory of coordinate measurements of the kinematic error of involute gears

Elements of a theory of measurement of the kinematic error of involute gears are examined along with an algorithm for calculating that error. Translated from Izmeritel'naya Tekhnika, No. 10, pp. 34–36, October, 1999.     

12路并行光互连子系统研究

针对高速芯片间光互连的应用,利用垂直腔面发射激光器(VCSEL)列阵作为光源、PIN列阵作为探测器,采用并行光传输的方式,设计了高密度的12路高速信号的光互连子系统,并利用12芯标准多模光纤带进行了1m距离内的光传输试验测试.测试结果表明,在零误码率的条件下系统单路速率大于6Gb/s,接收端信号的上升时间(F1)为91...     

An advanced theory of the strength of hybrid composites

This paper proposes a statistical approach to the strength of a unidirectionally-arrayed hybrid sheet. This paper proposes of modification of the theory proposed by Zweben. The concept of the hybrid effect has been clarified and the present theory has been compared with experimental data. Quantitative evaluation of the hybrid effect and stress-strain behaviour of hybrids is possible, although there remain some discrepancies between experimental data and theoretical prediction. Stress (or strain) concentration factors and ineffective length around a discontinuous fibre are calculated in a more precise manner, which are used for a statistical approach.     

Topologies for optical interconnection networks based on the optical transpose interconnection system

Many results exist in the literature describing technological and theoretical advances in optical network topologies and design. However, an essential effort has yet to be made in linking those results together. We propose a step in this direction by giving optical layouts for several graph-theoretical topologies studied in the literature, using the optical transpose interconnection system (OTIS) architecture. These topologies include the family of partitioned optical passive star (POPS) and stack-Kautz networks as well as a generalization of the Kautz and the de Bruijn digraphs.     

A unified theory for formulation of hybrid stress membrane elements

A theory is proposed in this paper to explain, in a unified manner, the three rational approaches using the incompatible displacements u _λ in the hybrid element formulation. Limited to the plane stress case, the theory suggests that the introduction of u _λ is to constrain the total value of the invariant I₂(= σ_xσ_y – τ) of the assumed stresses over the element to zero. In the plane stress case, this is the well-known condition for the stress distributions to be independent of the elastic constants of the material. The theory proposed is also used to explain the closeness of the performances of the four 4-node hybrid stress membrane elements, 5β-I, 5β-II, 5β-A and 5β-C, that have been developed previously. The differences among them are shown to be of the second degree in the distortion measures of the element shape, when they are compared on the basis of the non-vanishing total value of I₂ of their respectively adopted assumed stress field. Several numerical examples are used to verify and to illustrate the proposed theory.     

On hybrid stress,hybrid strain and enhanced strain finite element formulations for a geometrically exact shell theory with drilling degrees of freedom

The paper is concerned with the finite element formulation of a recently proposed geometrically exact shell theory with natural inclusion of drilling degrees of freedom. Stress hybrid finite elements are contrasted by strain hybrid elements as well as enhanced strain elements. Numerical investigations and comparison is carried out for a four-node element as well as a nine-node one. As far as the four-node element is concerned it is shown that the stress hybrid element and the enhanced strain one are equivalent. The hybrid strain formulation corresponds to the hybrid stress formulation only in shear dominated problems, that is the case of the plate. © 1998 John Wiley & Sons, Ltd.     

Optical interconnection for neural networks by use of a self-imaging function

A grating-lens combination unit is developed to form a scalingself-transform function that can self-image on scale. Then an arrayof many such grating-lens units is used for the optical interconnectionof a two-dimensional neural network, and experiments are carriedout. We find that our idea is feasible, the optical interconnectionsystem is simple, and optical adjustment is easy.     

Free-space parallel multichip interconnection system

A parallel data-communication scheme is described for interchip communication with free-space optics. We present a proof-of-concept and feasibility demonstration of a practical modular packaging approach in which free-space optical interconnect modules can be simply integrated on top of an electronic multichip module (MCM). Our packaging architecture is based on a modified folded 4-f imaging system that is implemented with off-the-shelf optics, conventional electronic packaging techniques, and passive assembly techniques to yield a potentially low-cost packaging solution. The prototype system, as built, supports 48 independent free-space channels with eight separate laser and detector chips, in which each chip consists of a one-dimensional array of 12 devices. All chips are assembled on a single ceramic carrier together with three silicon complementary metal-oxide semiconductor chips. Parallel optoelectronic (OE) free-space interconnections are demonstrated at a speed of 200 MHz. The system is compact at only 10 in.(3) (~164 cm(3)) and is scalable because it can easily accommodate additional chips as well as two-dimensional OE device arrays for increased interconnection density.     

24-DOF quadrilateral hybrid stress element for couple stress theory

A 24-DOF quadrilateral hybrid stress element for couple stress theory is proposed in this study. In order to satisfy the equilibrium equation in the domain of the element, the $21\beta $ Airy stress functions are chosen a assumed stress interpolation functions, and beam functions are adopted as the displacement interpolation functions on the boundary. This element can satisfy weak C $^{0}$ continuity with second-order accuracy and weak $\hbox {C}^1$ continuity simultaneously. So the element can pass the enhanced patch test of a convergence condition. Moreover, the reduced integration and a stresses smooth technique are introduced to improve the element accuracy. Numerical examples presented show that the proposed model can pass the $\hbox {C}^{0-1}$ enhanced patch test and indeed possesses higher accuracy. Besides, it does not exhibit extra zero energy modes and can capture the scale effects of microstructure.     

Diffractive interconnection between a high-power Nd:YAG laser and a fiber bundle

Beam splitters are used to couple the light of high-power Nd:YAG lasers into a fiber bundle. By the fibers the light is delivered to the workstations in the factory. This technique is used to reduce the costs of the light and to simplify the logistics within the fabrication process. Typically, dielectric beam splitters are used. However, they suffer from a polarization-sensitive splitting ratio. Because the polarization content of a high-power Nd:YAG-laser is not constant in time, polarization-independent beam splitters are of concern. The feasibility of diffractive beam splitters is investigated.     

Hierarchical optical ring interconnection (HORN): scalable interconnection network for multiprocessors and multicomputers

A new interconnection network for massively parallel computing is introduced. This network is called a hierarchal optical ring interconnection (HORN). The HORN consists of a single-hop, scalable, constant-degree, strictly nonblocking, fault-tolerant interconnection topology that uses wavelength-division multiple access to provide better utilization of the terahertz bandwidth offered by optics. The proposed optical network integrates the attractive features of hierarchical ring interconnections, e.g., a simple node interface, a constant node degree, better support for the locality of reference, and fault tolerance, with the advantages of optics. The HORN topology is presented, its architectural properties are analyzed, and an optical design methodology for it is described. Furthermore, a brief feasibility study of the HORN is conducted. The study shows that the topology is highly amenable to optical implementation with commercially available optical elements.     

A random critical-core theory of microdamage in interply hybrid composites: I—First failure and hybrid effect

This paper presents a statistical analysis for the tensile first failure and hybrid effect (which is part of the synergistic effect) of unidirectional interply hybrid composites. A shear-lag model is applied to solve the stress redistributions after the breakage of low-elongation fibers. By applying the random critical core model, the probabilistic first failure strain of hybrids is evaluated first, and the hybrid effect for strains is consequently evaluated. Reduction of the stress concentration factor and ineffective length of the low-elongation fibers in hybrids and differences between microdamage mechanisms in hybrids and single fiber composites provide a theoretical explanation of the hybrid effect. The present theoretical results show reasonable agreement with the existing experimental results.     

Self-assembled interconnection by bamboo-like carbon nanotubes

Carbon nanotubes (CNTs) could be formed on Si substrate using nickel catalyst under microwave plasma-enhanced chemical vapor deposition system. Under the high, negative-bias voltage (−400 V) condition, we found the formation of the carbon nanotube islands and the bamboo-like carbon nanotube interconnection lines. Most of the bamboo-like carbon nanotubes connected with the carbon nanotubes themselves, which indicates the self-assembled characteristics of the carbon nanotube interconnection lines. The self-assembled characteristics of the bamboo-like carbon nanotube interconnection lines were evaluated using computer-aided image analysis.     

Folded free-space polarization-controlled multistage interconnection network

We present a folded free-space polarization-controlled optical multistage interconnection network (MIN) based on a dilated bypass-exchange switch (DBS) design that uses compact polarization-selective diffractive optical elements (PDOE's). The folded MIN design has several advantages over that of the traditional transparent MIN, including compactness, spatial filtering of unwanted higher-order diffraction terms leading to an improved signal-to-noise ratio (SNR), and ease of alignment. We experimentally characterize a folded 2 x 2 switch, as well as a 4 x 4 and an 8 x 8 folded MIN that we have designed and fabricated. We fabricated an array of off-axis Fresnel lenslet PDOE's with a 30:1 SNR and used it to construct a 2 x 2 DBS with a measured SNR of 60:1. Using this PDOE array in a 4 x 4 MIN resulted in an increased SNR of 120:1, highlighting the filtering effect of the folded design.     

Reconfigurable array interconnection by photorefractive correlation

Electronic parallel processors might communicate more effectively by photons sent through glass or air than by electrons sent through wires, but quickly routing thousands of optical signals remains a problem. Previous photorefractive interconnection networks have dedicated one hologram to each input channel. Instead, we compute a control image from the entire network configuration and store it as a single color-keyedvolume hologram. This lets us use hologram superposition for fast switchingbetween multiple prestored patterns. During operation, data signals from the input modulator array, powered by a shared wavelength-tunable laser, are correlated optically with one color-matched connection hologram to produce the output array. This decouples both data rate and interconnect switching speeds from the slow photorefractive response. We can display arbitrary connection weights using simple binary-phase spatial light modulators and gracefully accommodate modulator limitations by trading off control-image bandwidth for output signal-to-noise ratio. Experimental results with color-multiplexed reflection holograms in z-cut LiNbO(3) confirmed our theoretical predictions that this approach works best for densely connected networks with high fan-in to each output. We obtained an average aggregate signal-to-noise ratio of more than 200:1 for 1024 inputs and outputs.