5,221 research outputs found
Comment on "Chiral Suppression of Scalar Glueball Decay"
Comment on ``Chiral Suppression of Scalar Glueball Decay''Comment: Comment published in Phys. Rev. Lett. 98, 149103(2007
Initialization Methods for FPGA-Based EMT Simulations
FPGA has become a very powerful platform to provide real-time Electromagnetic Transient (EMT) solutions due to the much lower investment costs in comparison to the other existing real-time platform. Existing off-line initialization methods cannot be applied to real-time FPGA directly owing to timing constraints and resource utilization. Without appropriate initialization, it can lead to divergence for FPGA-based EMT simulations and cause inaccurate simulation results. To provide real-time initialization, this paper presents four initialization methods for FPGA-based EMT, namely, physical interface (Method 1), signal declaration (Method 2), signal assignment (Method 3) and Coefficient (COE) file (Method 4). The performance of these four methods are also compared, and Method 4 can initialize instantly with the simplest code. To improve hardware adaptability, optimized strategies are developed for address sequence, interface, update modes and dataflow. To accelerate initialization, software-to-hardware algorithm and structure are developed to automate initialization data sources for different topologies. Case study shows Method 2–4 can both initialize successfully on FPGA platform, while Method 4 achieves the best timing and routing performance. To verify scalability, Method 4 is expanded to initialize 4-machine 11-bus system and eliminate significant error to less than 5%, with a timing constraint of 0.005 ns
Superposition coded modulation with peak-power limitation
We apply clipping to superposition coded modulation (SCM) systems to reduce the peak-to-average power ratio (PAPR) of the transmitted signal. The impact on performance is investigated by evaluating the mutual information driven by the induced peak-power-limited input signals. It is shown that the rate loss is marginal for moderate clipping thresholds if optimal encoding/decoding is used. This fact is confirmed in examples where capacityapproaching component codes are used together with the maximum a posteriori probability (MAP) detection. In order to reduce the detection complexity of SCM with a large number of layers, we develop a suboptimal soft compensation (SC) method that is combined with soft-input soft-output (SISO) decoding algorithms in an iterative manner. A variety of simulation results for additive white Gaussian noise (AWGN) and fading channels are presented. It is shown that with the proposed method, the effect of clipping can be efficiently compensated and a good tradeoff between PAPR and bit-error rate (BER) can be achieved. Comparisons with other coded modulation schemes demonstrate that SCM offers significant advantages for high-rate transmissions over fading channels
ALP explanation to the muon and its test at future Tera- and Higgs factories
Models with an axionlike particle (ALP) can provide an explanation for the discrepancy between experimental measurement of the muon anomalous-magnetic moment and the Standard Model prediction. This explanation relies on the couplings of the ALP to the muon and the photon. We also include more general couplings to the electroweak gauge bosons and incorporate them in the calculations up to the 2-loop order. We investigate the existing experimental constraints and find that they do not rule out the ALP model under consideration as a possible explanation for the anomaly. At the same time, we find the future Tera-Z and Higgs factories, such as the CEPC and FCC-ee, can completely cover the relevant parameter space through searches with final states , , and
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