5,302 research outputs found
Mutual Information-Maximizing Quantized Belief Propagation Decoding of Regular LDPC Codes
In mutual information-maximizing lookup table (MIM-LUT) decoding of
low-density parity-check (LDPC) codes, table lookup operations are used to
replace arithmetic operations. In practice, large tables need to be decomposed
into small tables to save the memory consumption, at the cost of degraded error
performance. In this paper, we propose a method, called mutual
information-maximizing quantized belief propagation (MIM-QBP) decoding, to
remove the lookup tables used for MIM-LUT decoding. Our method leads to a very
efficient decoder, namely the MIM-QBP decoder, which can be implemented based
only on simple mappings and fixed-point additions. Simulation results show that
the MIM-QBP decoder can always considerably outperform the state-of-the-art
MIM-LUT decoder, mainly because it can avoid the performance loss due to table
decomposition. Furthermore, the MIM-QBP decoder with only 3 bits per message
can outperform the floating-point belief propagation (BP) decoder at high
signal-to-noise ratio (SNR) regions when testing on high-rate codes with a
maximum of 10-30 iterations
The Construction of MTI Translation Evaluation Index System
Translation evaluation was essential to MTI training. In order to standardize, guide, diagnose, and regulate the process, the study firstly examined researches regarding translation competency both at home and abroad from 1970s till now; Then, based on the latest understanding of translation competency, with Analytic Hierarchy Process (AHP), a MTI Translation Evaluation Index System (MTI TEIS) was developed, aiming to digitally represent and assess the gradual progress of translator’s comprehensive translation abilities on an objective basis. The MTI TEIS was translator-oriented and  it emphasized individual difference. It may not only apply to MTI teachers who were in charge of evaluating and controlling the whole translation training process, but also to MTI candidates who expected to conduct self-evaluation regularly
Charged multiplicity density and number of participant nucleons in relativistic nuclear collisions
The energy and centrality dependences of charged particle pseudorapidity
density in relativistic nuclear collisions were studied using a hadron and
string cascade model, JPCIAE. Both the relativistic experimental
data and the PHOBOS and PHENIX data at RHIC energy could be fairly
reproduced within the framework of JPCIAE model and without retuning the model
parameters. The predictions for collisions at the LHC energy were also
given. We computed the participant nucleon distributions using different
methods. It was found that the number of participant nucleons is not a well
defined variable both experimentally and theoretically. Thus it may be
inappropriate to use the charged particle pseudorapidity density per
participant pair as a function of the number of participant nucleons for
distinguishing various theoretical models. A discussion for the effect of
different definitions in nuclear radius (diffused or sharp) was given.Comment: 15 pages, 7 figure
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