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 $p+\bar p$ experimental data and the PHOBOS and PHENIX $Au+Au$ data at RHIC energy could be fairly reproduced within the framework of JPCIAE model and without retuning the model parameters. The predictions for $Pb+Pb$ 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