A Novel Network Coded Parallel Transmission Framework for High-Speed Ethernet

Parallel transmission, as defined in high-speed Ethernet standards, enables to use less expensive optoelectronics and offers backwards compatibility with legacy Optical Transport Network (OTN) infrastructure. However, optimal parallel transmission does not scale to large networks, as it requires computationally expensive multipath routing algorithms to minimize differential delay, and thus the required buffer size, optimize traffic splitting ratio, and ensure frame synchronization. In this paper, we propose a novel framework for high-speed Ethernet, which we refer to as network coded parallel transmission, capable of effective buffer management and frame synchronization without the need for complex multipath algorithms in the OTN layer. We show that using network coding can reduce the delay caused by packet reordering at the receiver, thus requiring a smaller overall buffer size, while improving the network throughput. We design the framework in full compliance with high-speed Ethernet standards specified in IEEE802.3ba and present solutions for network encoding, data structure of coded parallel transmission, buffer management and decoding at the receiver side. The proposed network coded parallel transmission framework is simple to implement and represents a potential major breakthrough in the system design of future high-speed Ethernet.Comment: 6 pages, 8 figures, Submitted to Globecom201

EQUIPARTITION OF FORCES: REVIEW OF A NEW PRINCIPLE FOR PROCESS DESIGN AND OPTIMIZATION

We present a general proof for a design principle developed during the last two years: The principle of equipartition of forces. The principle is derived for parallel, coupled transport processes without restrictions on the phenomenological coefficients. Minimum entropy production is obtained for the total system, when the thermodynamic forces of transport are the same over all parallel paths in the system. We review some of the results obtained so far by application of the principle to distillation columns

Web based evaluation of material handling alternatives for automated manufacturing : a parallel replications approach.

This research project describes the application of a master/slave configuration of processors to study a comparison of alternative material handling configurations for automated manufacturing. Such a study usually requires a large number of simulation replications, and carrying out those replications on a multi-processor platform can yield a significant savings in elapsed time. The objective of this study is to develop such a platform. In the present application, a parallel replication simulation system is developed to foster simultaneous processing. This system utilizes two separate applications to facilitate communication between master and slave computers. Additionally, the master and slave or client applications work in conjunction with a specialized set of Arena(tm) simulation models. The simulation models considered in this research effort represent two types of transport mechanisms in a closed cell work environment. Transport type, transport velocity, and an associated efficiency factor of a machine in cell 3. These models have been modified for use within the parallel replications environment. This system uses 2^3 = 8 design points (simulation models) for an experimental design. The models are transferred to remote PCUs via Transmission Control Protocol (TCP) file transfer. Following receipt, the models are executed, and results sent back to the master application where factor significance is determined. The resulting Metamodel (Kleijnen, 1979) describes a linear relationship between model variables, and system output

Interface of the transport systems research vehicle monochrome display system to the digital autonomous terminal access communication data bus

An upgrade of the transport systems research vehicle (TSRV) experimental flight system retained the original monochrome display system. The original host computer was replaced with a Norden 11/70, a new digital autonomous terminal access communication (DATAC) data bus was installed for data transfer between display system and host, while a new data interface method was required. The new display data interface uses four split phase bipolar (SPBP) serial busses. The DATAC bus uses a shared interface ram (SIR) for intermediate storage of its data transfer. A display interface unit (DIU) was designed and configured to read from and write to the SIR to properly convert the data from parallel to SPBP serial and vice versa. It is found that separation of data for use by each SPBP bus and synchronization of data tranfer throughout the entire experimental flight system are major problems which require solution in DIU design. The techniques used to accomplish these new data interface requirements are described

Dynamics of coherence, localization and excitation transfer in disordered nanorings

Self-assembled supramolecular aggregates are excellent candidates for the design of efficient excitation transport devices. Both artificially prepared and natural photosynthetic aggregates in plants and bacteria present an important degree of disorder that is supposed to hinder excitation transport. Besides, molecular excitations couple to nuclear motion affecting excitation transport in a variety of ways. We present an exhaustive study of exciton dynamics in disordered nanorings with long-range interactions under the influence of a phonon bath and take the LH2 system of purple bacteria as a model. Nuclear motion is explicitly taken into account by employing the Davydov ansatz description of the polaron and quantum dynamics are obtained using a time-dependent variational method. We reveal an optimal exciton-phonon coupling that suppresses disorder-induced localization and facilitate excitation de-trapping. This excitation transfer enhancement, mediated by environmental phonons, is attributed to energy relaxation toward extended, low-energy excitons provided by the precise LH2 geometry with anti-parallel dipoles and long-range interactions. An analysis of localization and spectral statistics is followed by dynamical measures of coherence and localization, transfer efficiency and superradiance. Linear absorption, 2D photon-echo spectra and diffusion measures of the exciton are examined to monitor the diffusive behavior as a function of the strengths of disorder and exciton-phonon coupling.Comment: 18 pages, 13 figure

High performance architecture for robot control

Practical aspects of the design and implementation of a modular, high performance, parallel computer control system for telerobots are discussed. Topics of consideration include system architecture, operator interface, and control execution. In a laboratory environment, a telerobotics test control configuration is used to obtain measurements on communications and control loop timing for use in an effective full scale operational system design. The feasibility of the selected architectural approach has been successfully demonstrated. The modularity of the software and hardware enables ease of transport for use in the operational system. The distributed partioning of the control algorithms and the performance measurements acquired during control system implementation are discussed

P and W/GE propulsion systems studies introduction

The topics covered include the following: Pratt and Whitney (P&W)/ General Electric (GE) High Speed Civil Transport (HSCT) collaboration - joint propulsion studies and parallel technical organization; HSCT engine concepts; engine cycle/design ground rules - 2005 entry into service; engine evaluation criteria; 1991 HSCT system studies plan; P&W NASA study tasks; and GE NASA study tasks