176 research outputs found
Measurement of Absorption Cross Section of a Lossy Object in Reverberation Chamber Without the Need for Calibration
A reliable and simple procedure is proposed to measure the averaged absorption cross section (ACS) of a lossy object in a reverberation chamber (RC). This procedure is based on the time-domain measurement of the ACS in an RC. In the time-domain, to obtain the ACS, the chamber decay time needs to be known. Conventionally, the ACS is normally measured in the frequency domain, and a full two-port calibration must be carried out before collecting the S-parameters, which is tedious and time-consuming. In reality, the chamber decay time depends on the diffused loss of the RC, not the insertion loss of the cables. In this paper, by making use of this fact, the ACS can be measured accurately without calibration, which will simplify the measurement process and shorten the measurement time at the same time
A Distributed Computation Model Based on Federated Learning Integrates Heterogeneous models and Consortium Blockchain for Solving Time-Varying Problems
The recurrent neural network has been greatly developed for effectively
solving time-varying problems corresponding to complex environments. However,
limited by the way of centralized processing, the model performance is greatly
affected by factors like the silos problems of the models and data in reality.
Therefore, the emergence of distributed artificial intelligence such as
federated learning (FL) makes it possible for the dynamic aggregation among
models. However, the integration process of FL is still server-dependent, which
may cause a great risk to the overall model. Also, it only allows collaboration
between homogeneous models, and does not have a good solution for the
interaction between heterogeneous models. Therefore, we propose a Distributed
Computation Model (DCM) based on the consortium blockchain network to improve
the credibility of the overall model and effective coordination among
heterogeneous models. In addition, a Distributed Hierarchical Integration (DHI)
algorithm is also designed for the global solution process. Within a group,
permissioned nodes collect the local models' results from different
permissionless nodes and then sends the aggregated results back to all the
permissionless nodes to regularize the processing of the local models. After
the iteration is completed, the secondary integration of the local results will
be performed between permission nodes to obtain the global results. In the
experiments, we verify the efficiency of DCM, where the results show that the
proposed model outperforms many state-of-the-art models based on a federated
learning framework
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