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1. Edge limits of truncated circular beta ensembles

   https://doi.org/10.1214/25-EJP1270  

   Li, Yun; Valkó, Benedek (January 2025, Electronic Journal of Probability)

   We study the scaling limit of the rank-one truncation of various beta ensemble generalizations of classical unitary/orthogonal random matrices: the circular beta ensemble, the real orthogonal beta ensemble, and the circular Jacobi beta ensemble. We derive the scaling limit of the normalized characteristic polynomials and the point process limit of the eigenvalues near the point 1. We also treat multiplicative rank one perturbations of our models. Our approach relies on a representation of truncated beta ensembles given by Killip-Kozhan [24], together with the random operator framework developed in [42, 43, 44] to study scaling limits of beta ensembles. 

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2. Hadronic vacuum polarization of the muon on 2+1+1-flavor HISQ ensembles: an update.

   https://doi.org/10.22323/1.396.0526  

   Lahert, Shaun; DeTar, Carleton; El-Khadra, Aida X; Gámiz, Elvira; Gottlieb, Steven; Kronfeld, Andreas; Neil, Ethan; Peterson, Curtis T.; Van de Water, Ruth (May 2022, The 38th International Symposium on Lattice Field Theory (LATTICE2021))

   We give an update on the status of the Fermilab Lattice-HPQCD-MILC calculation of the con- tribution to the muon’s anomolous magnetic moment from the light-quark, connected hadronic vacuum polarization. We present preliminary, blinded results in the intermediate window for this contribution a^ll_{\mu W}. The calculation is performed on Nf = 2 + 1 + 1 highly-improved staggered quark (HISQ) ensembles from the MILC collaboration with physical pion mass at four lattice spacings between 0.15 fm and 0.06 fm. We also present preliminary results for a study of the two- pion contributions to the vector-current correlation function performed on the 0.15 fm ensemble contribution, 𝑎𝑙𝑙 . The calculation is performed on the 0.15 fm ensemble where we see a factor of four improvement over traditional noise reduction techniques. 

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3. A Smart Chair Sitting Posture Recognition System using Flex Sensors and FPGA Implemented Artificial Neural Network

   https://doi.org/10.1109/JSEN.2020.2980207  

   Hu, Qisong; Tang, Xiaochen; Tang, Wei (January 2020, IEEE sensors journal)

   Sitting is the most common status of modern human beings. Some sitting postures may bring health issues. To prevent the harm from bad sitting postures, a local sitting posture recognition system is desired with low power consumption and low computing overhead. The system should also provide good user experience with accuracy and privacy. This paper reports a novel posture recognition system on an office chair that can categorize seven different health-related sitting postures. The system uses six flex sensors, an Analog to Digital Converter (ADC) board and a Machine Learning algorithm of a two-layer Artificial Neural Network (ANN) implemented on a Spartan-6 Field Programmable Gate Array (FPGA). The system achieves 97.78% accuracy with a floating-point evaluation and 97.43% accuracy with the 9-bit fixed-point implementation. The ADC control logic and the ANN are constructed with a maximum propagation delay of 8.714 ns. The dynamic power consumption is 7.35 mW when the sampling rate is 5 Sample/second with the clock frequency of 5 MHz. 

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4. Code Design Based on Connecting Spatially Coupled Graph Chains

   https://doi.org/10.1109/TIT.2019.2917222  

   Truhachev, Dmitri; Mitchell, David G.; Lentmaier, Michael; Costello, Daniel J.; Karami, Alireza (May 2019, IEEE Transactions on Information Theory)

   A novel code construction based on spatially coupled low-density parity-check (SC-LDPC) codes is presented. The proposed code ensembles are comprised of several protographbased chains characterizing individual SC-LDPC codes. We demonstrate that code ensembles obtained by connecting appropriately chosen individual SC-LDPC code chains at specific points have improved iterative decoding thresholds. In addition, the connected chain ensembles have a smaller decoding complexity required to achieve a specific bit error probability compared to individual code chains. Moreover, we demonstrate that, like the individual component chains, the proposed constructions have a typical minimum distance that grows linearly with block length. Finally, we show that the improved asymptotic properties of the connected chain ensembles also translate into improved finite length performance. 

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5. Finite-Blocklength and Error-Exponent Analyses for LDPC Codes in Point-to-Point and Multiple Access Communication

   https://doi.org/10.1109/ISIT44484.2020.9173963  

   Liu, Yuxin; Effros, Michelle (June 2020, 2020 IEEE International Symposium on Information Theory (ISIT))

   null (Ed.)

   This paper applies error-exponent and dispersionstyle analyses to derive finite-blocklength achievability bounds for low-density parity-check (LDPC) codes over the point-to-point channel (PPC) and multiple access channel (MAC). The error-exponent analysis applies Gallager's error exponent to bound achievable symmetrical and asymmetrical rates in the MAC. The dispersion-style analysis begins with a generalization of the random coding union (RCU) bound from random code ensembles with i.i.d. codewords to random code ensembles in which codewords may be statistically dependent; this generalization is useful since the codewords of random linear codes such as LDPC codes are dependent. Application of the RCU bound yields finite-blocklength error bounds and asymptotic achievability results for both i.i.d. random codes and LDPC codes. For discrete, memoryless channels, these results show that LDPC codes achieve first- and second-order performance that is optimal for the PPC and identical to the best prior results for the MAC. 

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