68 resultados para Bus terminals


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The localization and distribution of SALMFamide (S1)-like immunoreactivity (IR), was determined at both the cellular and subcellular level in the central nervous system (CNS) of the nematode roundworm Ascaris suum. The techniques of indirect immunofluorescence in conjunction with confocal scanning laser microscopy and post-embedding, IgG-conjugated colloidal gold immunostaining were used, respectively. Immunostaining was widespread in the CNS of adult A. suum, with immunoreactivity (IR) being localized in nerve cells and fibres in the ganglia associated with the anterior nerve ring and in the main nerve cords and their commissures. At the subcellular level, gold labeling of peptide was localized exclusively over dense-cored vesicles within nerve cell bodies, nerve axons and nerve terminals of the neuropile of the anterior nerve ring, main ganglia and nerve cords in the CNS. Double-labeling demonstrated an apparent co-localization of S1- and FMRFamide-IR-together IR-together with S1- and pancreatic polypeptide (PP)-IR in the same dense-cored vesicles. Antigen preabsorption experiments indicated little cross-reactivity, if any, between the three antisera; indeed, neither FMRFamide nor PP antigens abolished S1 immunostaining.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A post-embedding immunogold technique has been used to examine the subcellular distribution of immunoreactivities to vertebrate pancreatic polypeptide (PP) and to the invertebrate peptide, FMRFamide within the central nervous system (CNS) of the nematode, Ascaris suum. Gold labelling of peptide was localized exclusively over dense-cored vesicles within nerve cell bodies, nerve axons and nerve terminals of the main ganglia and nerve cords in the CNS. Double-labelling of peptides demonstrated an apparent co-localization of PP and FMRFamide immunoreactivities in the same dense-cored vesicles, although populations of dense-cored vesicles that labelled solely for FMRFamide were also evident. Antigen preabsorption studies indicated little or no cross-reactivity between the two antisera.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

To enable reliable data transfer in next generation Multiple-Input Multiple-Output (MIMO) communication systems, terminals must be able to react to fluctuating channel conditions by having flexible modulation schemes and antenna configurations. This creates a challenging real-time implementation problem: to provide the high performance required of cutting edge MIMO standards, such as 802.11n, with the flexibility for this behavioural variability. FPGA softcore processors offer a solution to this problem, and in this paper we show how heterogeneous SISD/SIMD/MIMD architectures can enable programmable multicore architectures on FPGA with similar performance and cost as traditional dedicated circuit-based architectures. When applied to a 4×4 16-QAM Fixed-Complexity Sphere Decoder (FSD) detector we present the first soft-processor based solution for real-time 802.11n MIMO.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this paper, the authors have presented one approach to configuring a Wafer-Scale Integration Chip. The approach described is called the 'WINNER', in which bus channels and an external controller for configuring the working processors are not required. In addition, the technique is applicable to high availability systems constructed using conventional methods. The technique can also be extended to arrays of arbitrary size and with any degree of fault tolerance simply by using an appropriate number of cells.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper shows a simple, yet highly effective, tracking phase locked loop circuit which has applications for self steered antenna arrays. The tracking PLL has been demonstrated to accurately phase track signal levels as low as -120 dBm, making it suitable for applications such as SATCOM ground terminals. The implementation is simple requiring a low Q voltage controlled oscillator, a downconverting mixer and a PLL circuit.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The potential for implementation of retrodirective arrays as antenna terminals for future integrated satellite and terrestrial mobile communications is discussed in this paper. Particularly, in the context of the Inmarsat L-band system we address the issues related to array antenna element capacity to produce high-quality circular polarized radiation pattern over large angles of arrival. We also discuss circuitry reduction methodologies and their effect on retrodirected beam characteristics. The possibility of circular polarization modulation of the re-transmit signal is also discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

It is acknowledged that wind power is a stochastic energy source compared to hydroelectric generation which is easily scheduled. In this paper a scheme for coordinating wind power plant and hydroelectric power plant is presented by using PMUs to measure and control the state of wind and hydro power plants. Hydroelectric generation is proposed as a method of energy reserve and compensation in the context of wind power fluctuation in order to avoid full or partial curtailment of wind generation to benefit wind providers. The feasibility of this proposed scheme is investigated by power flow calculation and stability analysis using the IEEE 30-bus power system model.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper proposes a calculation method to determine power system response during small load perturbations or minor disturbances. The method establishes the initial value of active power transient using traditional reduction technique on admittance matrix, which incorporates voltage variations in the determination. The method examines active power distribution among generators when several loads simultaneously change, and verifies that the superposition principle is applicable for this scenario. The theoretical derivation provided in the paper is validated by numerical simulations using a 3-generator 9-bus benchmark model. The results indicate that the inclusion of voltage variation renders an independent and precise measure of active power response during transient conditions.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The rapid growth of wind generation in many European countries is pushing power systems into
uncharted territory. As additional wind generators are installed, the changing generation mix may
impact on power system stability. This paper adopts the New England 39 bus system as a test
system for transient stability analysis. Thermal generator models are based on a likely future plant
mix for existing systems, while varying capacities of fixed-speed induction generators (FSIG) and
doubly-fed induction generators (DFIG) are considered. The main emphasis here has been placed
on the impact of wind technology mix on inter-area oscillations following transient grid
disturbances. In addition, both rotor angle stability and transient voltage stability are examined, and
results are compared with current grid code requirements and standards. Results have shown that
FSIGs can reduce tie-line oscillations and improve damping following a transient disturbance, but
they also cause voltage stability and rotor angle stability problems at high wind penetrations. In
contrast, DFIGs can improve both voltage and rotor angle stability, but their power output
noticeably oscillates during disturbances.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper presents transient stability analysis for a power system with high wind penetration. The transient stability has been evaluated based on two stability criteria: rotor angle stability and voltage stability. A modified IEEE-14 bus system has been used as the main study network and simulations have been conducted at several wind power penetration levels, defined as a fraction of total system generation. A wide range of scenarios have been presented based on the wind farm voltage at the point of connection, i.e. low voltage (LV) distribution level and high voltage (HV) transmission level, and the type of wind generator technology, i.e. fixed speed induction generator (FSIG) and doubly-fed induction generator (DFIG).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper proposes a method to assess the small signal stability of a power system network by selective determination of the modal eigenvalues. This uses an accelerating polynomial transform, designed using approximate eigenvalues
obtained from a wavelet approximation. Application to the IEEE 14 bus network model produced computational savings of 20%,over the QR algorithm.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Scalability and efficiency of on-chip communication of emerging Multiprocessor System-on-Chip (MPSoC) are critical design considerations. Conventional bus based interconnection schemes no longer fit for MPSoC with a large number of cores. Networks-on-Chip (NoC) is widely accepted as the next generation interconnection scheme for large scale MPSoC. The increase of MPSoC complexity requires fast and accurate system-level modeling techniques for rapid modeling and veri-fication of emerging MPSoCs. However, the existing modeling methods are limited in delivering the essentials of timing accuracy and simulation speed. This paper proposes a novel system-level Networks-on-Chip (NoC) modeling method, which is based on SystemC and TLM2.0 and capable of delivering timing accuracy close to cycle accurate modeling techniques at a significantly lower simulation cost. Experimental results are presented to demonstrate the proposed method. ©2010 IEEE.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

For The Map of Watchful Architecture I only concerned myself with defensive architecture along the Border. As the map followed a border it came out as a wavy line of points. This was largely artificial, I only charted architecture within the Border corridor, but was not entirely artificial. That linear landscape has long been staked-out by the regularity of certain kinds of architecture. The 1st/2nd century Black Pig’s Dyke and Dorsey correspond with today’s Border. The concentration of souterrains in north Louth indicate that it may have been a volatile interface zone in later centuries. In 1618 Londonderry and its walls were built. Further north and two centuries later, Martello Towers were constructed to watch over Lough Foyle. During the Second World War pillboxes and observation posts were manned along the Border, close to what was now an international frontier. Then came the Operation Banner installations built during The Troubles. All this adds up to be one of the longest unbroken traditions of defensive architecture anywhere in Western Europe, a tradition some thought finally broken as the last of the Operation Banner towers were de-installed in 2007. But, take a bus south across the Border and you will often be pulled over by the Garda Síochána. They ID check the passengers in an attempt to stop illegal immigration via the UK. What about illegal immigrants who walk through the fields or along quiet lanes? They will have understood the Border is not really how it seems on most maps. It is not a solid line, it is a row of points.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This study presents a new method for determining the transmission network usage by loads and generators, which can then be used for transmission cost/loss allocation in an explainable and justifiable manner. The proposed method is based on solid physical grounds and circuit theory. It relies on dividing the currents through the network into two components; the first one is attributed to power flows from generators to loads, whereas the second one is because of the generators only. Unlike almost all the available methods, the proposed method is assumption free and hence it is more accurate than similar methods even those having some physical basis. The proposed method is validated through a transformer analogy, and theoretical derivations. The method is verified through application to the IEEE 30 bus system and the IEEE 118 test system. The results obtained verified many desirable features of the proposed method. Being more accurate in determining the network usage, in an explainable transparent manner, and in giving accurate cost signals, indicating the best locations to add loads and generation, are among the many desirable features.