GEMNET: a generalized, shuffle-exchange-based, regular, scalable,modular, multihop, WDM lightwave network

GEMNET is a generalization of shuffle-exchange networks and it can represent a family of network structures (including ShuffleNet and de Bruijn graph) for an arbitrary number of nodes. GEMNET employs a regular interconnection graph with highly desirable properties such as small nodal degree, simple routing, small diameter, and growth capability (viz. scalability). GEMNET can serve as a logical (virtual), packet-switched, multihop topology which can be employed for constructing the next generation of lightwave networks using wavelength-division multiplexing (WDM). Various properties of GEMNET are studied     

Thermodynamics of copper matte converting: Part III. Steady-state volatilization of Au,Ag, Pb,Zn, Ni,Se, Te,Bi, Sb,and As from slag,matte, and metallic copper

A comprehensive compilation of various thermodynamic data required for a complete analysis of copper matte converting reactions is presented. The data comprise estimated free energies of formation for such gases as SeO, SeS, TeO, TeS, BiO, BiS, SbO, SbS, AsO, and AsS, as well as activity coefficients in dilute copper alloys and vapor pressures of various elements and compounds. The volatilization of minor elements in steady-state reactors comprising gas and several condensed phases is mathematically formulated, and a parameter which governs the volatilization in such reactors is defined and named volatilization constant. The vapor pressures of various volatile species are calculated thermodynamically for the Noranda Process reactor by assuming equilibrium conditions. The volatilization constants of various minor elements are expressed explicitly as functions of oxygen and sulfur activities. Formerly Associate Professor, Department of Metallurgical Engineering, University of Utah, Salt Lake City, UT     

Bits, symbols, bauds, and bandwidth

The use of clear, concise, and unambiguous language in telecommunications engineering is vital to communicate a desired meaning and understanding. Terminology should be based on rigorous engineering principles and traceable to well known and dependable sources. This article deals with four everyday terms commonly encountered in the popular semi-technical press as well as in serious engineering periodicals. The misuse of these and other terms can lead to low-balled cost proposals, court litigation, and patent infringement cases. Imagine how an engineering student can be confused when she/he typically encounters bandwidth measured in bits per second     

Novel planar, square-shaped, dielectric-waveguide, single-, and dual-mode filters

This paper presents a novel concept of a square-shaped dielectric-waveguide resonator, which can easily realize a dielectric-waveguide cross-coupled filter or a dielectric-waveguide dual-mode filter, using the conventional printed circuit board (PCB) process. This planar dielectric-waveguide resonator has a higher Q value than a microstrip resonator. The physical mechanisms of both single- and dual-mode filters are elucidated. Some new coupling structures are developed for undergoing the PCB process. Filter design procedures are detailed. Design curves for the coupling coefficients of internal- and external-coupling structures are determined by full-wave finite-element-method electromagnetic calculations. Measurement results are highly consistent with theory for all trial filters. This study offers an effective means of producing low-cost high-performance planar circuit filters.     

Dilemmas,uncertainty, risks,and board performance

This paper traces the origins of the words risk, uncertainty, governance and development and argues that a deeper understanding of each allows more effective decision taking in the boardroom. It argues that the role of the board of directors is to balance and rebalance continuously their irresolvable dilemma — ‘how do we drive our enterprise forward while keeping it under prudent control?’ It argues that it is the board’s role to focus on uncertainty, rather than risk, and this requires a different set of intellectual skills from board members to be able to cope with monitoring a range of diverse scenarios. This is crucial for a board to develop stronger ways of both leading their organisation and of ensuring the connectedness of the learning within and between the board and the operational unit’s risk taking. It advocates that to achieve this a board must develop new ways of learning — especially of thinking strategically and becoming more sensitised to the dynamics of their changing external environments. This will take them well beyond the comforts of their specialist managerial disciplines and into the true world of directing. The paper demonstrates the importance of continuous learning in reducing organisational uncertainty and risk. It uses the ‘Learning Board’ process and model as the central processor of both strategic and operational learning to create an annual rhythm for the board’s year.     

PBX技术.市态.营销.选购

本文介绍了ＰＢＸ交换机的技术及市场需求态势。并提出ＰＢＸ产品的营销要素及其用户在选购时应遵循的原则。     

Uncertainty, Value, Communication, and Problematic Integration

This essay discusses problematic integration (PI) theory, a general perspective on the nature of the dynamic relationship between communication and tensions among expectations and desires and considers the relevance and potential value of PI theory to questions foundational to the field of communication research. The paper begins with a discussion of the main propositions of PI theory, then considers the relationship between the theory and emerging analyses of uncertainty, attending in particular to the meanings of uncertainty and the tensions among uncertainties, wants, and wishes.     

Evolution, neural networks, games, and intelligence

Mathematical games provide a framework for studying intelligent behavior in models of real-world settings or restricted domains. The obstacle comes in choosing the appropriate representation and learning algorithm. Neural networks and evolutionary algorithms provide useful means for addressing these issues. This paper describes efforts to hybridize neural and evolutionary computation to learn appropriate strategies in zero- and nonzero-sum games, including the iterated prisoner's dilemma, tic-tac-toe, and checkers. With respect to checkers, the evolutionary algorithm was able to discover a neural network that can be used to play at a near-expert level without injecting expert knowledge about how to play the game. The implications of evolutionary learning with respect to machine intelligence are also discussed. It is argued that evolution provides the framework for explaining naturally occurring intelligent entities and can be used to design machines that are also capable of intelligent behavior     

Electronic Band-Structure Calculations of Ba8Me x Si46-x Clathrates with Me = Mg,Pd, Ni,Au, Ag,Cu, Zn,Al, Sn

Clathrate materials of AlSi, CuSi or NiSi type consisting of abundant elements have a realistic chance of becoming useful thermoelectrics in the near future, because the rattling effect due to their crystal cage structure provides a large figure of merit ZT even in experiments measured under large temperature gradients. In the search for better thermoelectrics, new element combinations in the clathrate type I structure with cubic space group Pm3n were calculated using VASP ab initio software. Predictions of the Seebeck coefficient were made by checking the electronic band structure and density of states for a large variety of input data. For x values around 4 to 6 in the structural formula Ba₈Me _x Si_46?x the substituents Cu, Au, and Ag are best for good thermoelectric behavior, which is discussed in this paper as a result of the low electron–phonon interaction parameter.     

Pulsed-ion laser performance in nitrogen, oxygen, krypton, xenon, and argon

Operational parameters for pulsed-ion laser operation in nitrogen, oxygen, krypton, xenon, and argon in the wavelength range from 350 to 460 nm are presented.     

Introduction, September, 1968

When I was invited by the regular editor, S. Okwit, to be Guest Editor of the special issue of this TRANSACTIONS on the subject of noise, I had no idea how many man-hours of effort would be involved. My management may or may not have known either, but, nevertheless, they encouraged me to accept the invitation, which I did. I am happy to report that I have had their whole-hearted support not only in providing me with special secretarial assistance, communication conveniences, and incidental expenses, but also in granting me the time to complete the assignment.     

Electrorefraction and electroabsorption in InP, GaAs, GaSb, InAs, and InSb

Effective-mass theory is used to calculate electric-field-induced changes in optical refraction and absorption (the Franz-Keldysh effect) in five direct-gap III-V semiconductors: InP, GaAs, GaSb, InAs, and InSb, covering the 0.88 to 10 μm wavelength range. The magnitude of the effect is determined by fitting experimental absorption data. Results are given for photon energies from the band gap to 100 meV below the gap for applied electric fields from3 times 10^{3}to3 times 10^{5}V/cm. Values ofDelta nandDelta kas large as 10^-3to 10^-2are found. The results are applicable to integrated-optic devices including switches and modulators.     

Fly, Robot, Fly

There is no more rewarding moment for roboticists than when they first see their creations begin to twitch with a glimmer of life. For me, that moment of paternal pride came a year ago this month, when my artificial fly first flexed its wings and flew. It began when I took a stick-thin winged robot, not much larger than a fingertip, and anchored it between two taut wires, rather like a miniature space shuttle tethered to a launchpad. Next I switched on the external power supply. Within milliseconds the carbon-fiber wings, 15 millimeters long, began to whip forward and back 120 times per second, flapping and twisting just like an actual insect's wings. The fly shot straight upward on the track laid out by the wires. As far as I know, this was the first flight of an insect-size robot.     

Symmetric-gain, zero-offset, self-aligned, and refractory-contact double HBT's

We report double-heterostructure bipolar transistors using refractory emitter and base contacts (WSix/InAs for n-type, and W with rapid diffusion of Zn for p-type) and self-aligned implantation. These devices have near-symmetric gain (∼ 100) across a fairly large current range (∼ four decades), negligible offset voltage, and a weak current gain dependence on device size. This results from suppression of surface recombination obtained using a P-GaAlAs electron barrier at the extrinsic-base surface. We also demonstrate use of a technique for deconvolving various recombination mechanisms. The major gain-limiting mechanisms in these devices are shown to be (a) residual damage from ion implantation and its effects on base transport factor, and (b) Shockley-Read-Hall recombination in the depletion regions and its effect on injection efficiency. Devices similar to the above showed gains approaching theoretical values of ∼ 1000 at high currents, and greater than 10 at picoampere currents when the processing was designed to obtain high lifetime in the implanted region.     

Introduction, August, 1969

As Guest Editor of this computer-oriented special issue of the IEEE Transactions on Microwave Theory and Techniques, I've had a wide view of computer-oriented microwave engineering of 1968-69. In a very general way, here's how it looks to me now. Within microwaves, electromagnetic field analysts seem to be the group most fully converted to the computer. They have been reevaluating classical techniques and developing new techniques to solve boundary value problems by numerical methods. Problems which formerly could be solved only conceptually, or by excessive commitment of hand calculation, are now done in a few minutes or even seconds of machine time.