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Let $PU_n$ denote the projective unitary group of rank $n$ and $BPU_n$ be its classifying space, for $n>1$. By using the Serre spectral sequence induced by the fibration $BU_n\to BPU_n\to K(\mathbb{Z},3)$, we compute the integral cohomology of $BPU_n$ in dimensions less than $15$ except for $4\mid n$ in dimension $14$., Comment: arXiv admin note: text overlap with arXiv:2402.09103

In [6], the authors construct a cochain complex $C\!H^*(\mathcal{Z}_{\mathcal{K}})$ on the cohomology of a moment-angle complex $\mathcal{Z}_{\mathcal{K}}$ and call the resulting cohomology the double cohomology, $H\!H^*(\mathcal{Z}_{\mathcal{K}})$. In this paper, we study the change of rank in double cohomology after gluing an $n$-simplex to a simplicial complex $\mathcal{K}$ in certain conditions. As an application, we give a positive answer to an open problem in [6]: For any even integer $r$, there always exists a simlicial complex $\mathcal{K}$ such that $\operatorname{rank} H\!H^*(\mathcal{Z}_{\mathcal{K}})=r$., Comment: 12 pages

Let $PU_n$ denote the projective unitary group of rank $n$, and let $BPU_n$ be its classifying space. We extend our previous results to a description of $H^s(BPU_n;\mathbb{Z})_{(p)}$ for $s<2p+9$ by showing that $p$-primary subgroups of $H^s(BPU_n;\mathbb{Z})$ is $\mathbb{Z}/p$ for $s=2p+5$ and are trivial for $s = 2p+7$ and $s = 2p+8$, where $p$ is an odd prime.

Hierarchical beam search in mmWave communications incurs substantial training overhead, necessitating deep learning-enabled beam predictions to effectively leverage channel priors and mitigate this overhead. In this study, we introduce a comprehensive probabilistic model of power distribution in beamspace, and formulate the joint optimization problem of probing beam selection and probabilistic beam prediction as an entropy minimization problem. Then, we propose a greedy scheme to iteratively and alternately solve this problem, where a transformer-based beam predictor is trained to estimate the conditional power distribution based on the probing beams and user location within each iteration, and the trained predictor selects an unmeasured beam that minimizes the entropy of remaining beams. To further reduce the number of interactions and the computational complexity of the iterative scheme, we propose a two-stage probing beam selection scheme. Firstly, probing beams are selected from a location-specific codebook designed by an entropy-based criterion, and predictions are made with corresponding feedback. Secondly, the optimal beam is identified using additional probing beams with the highest predicted power values. Simulation results demonstrate the superiority of the proposed schemes compared to hierarchical beam search and beam prediction with uniform probing beams.

Let $PU_n$ the projective unitary group of rank $n$ and $BPU_n$ its classifying space. For an odd prime $p$, we extend previous results to a compete description of $H^s(BPU_n;\mathbb{Z})_{(p)}$ for $s<2p+5$ by showing that the $p$-primary subgroups of $H^s(BPU_n;\mathbb{Z})$ are trivial for $s = 2p+3$ and $s = 2p+4$., Comment: 13 pages. Minor Changes.To appear in the Proceedings of the AMS

Submersible Buoy (SB) is an important apparatus capable of long-term, fixed-point, continuous and multi-directional measurement of acoustic signals and hydrological environment monitoring in the harsh marine environment, providing important information for hydrological environment research, marine organism research and protection. We will describe a real-time data acquisition (DAQ) system with multiple designs to meet low-power consumption and high-speed data transmission.

A completely New Small Wheel (NSW) will be constructed for ATLAS Phase-1 upgrade. Small-Strip Thin-Gap-Chamber (sTGC) will devote to the trigger function of NSW. A full-size sTGC quadruplet consists of 4 layers, and will need 4 pad Front-End-Boards and 4 strip Front-End-Boards for sTGC signals readout. The 8 boards should be readout simultaneously at a time. This paper presents the study of multi-layer sTGC test system, a FEB Driver Card (FEBDC) is designed for pFEB and sFEB boards handling. The design and test of FEBDC are described in details., Comment: 3 pages, 7 figures, conference record for RealTime Conference

This paper presents a readout system designed for testing the prototype of Small-Strip Thin Gap Chamber (sTGC), which is one of the main detector technologies used for ATLAS New-Small-Wheel Upgrade. This readout system aims at testing one full-size sTGC quadruplet with cosmic muon triggers.

Micromegas detector is a gas detector with parallel plate structure, and it consists of a conversion gap in which radiations liberate ionization electrons and a thin amplification gap. The signal of the micromegas detector consists of two parts: the electron peak and the ion tail. The electronic signal just keeps few nanoseconds, which is used for precise time measurement. The ion signal carries most of the signal energy, and it is used to reconstruct particle energy. The micromegas detector has the advantages of high counting rate, high gain, good time resolution and position resolution, excellent radiation-hardened performance, large sensitive area and readout convenience. This paper introduces a signals readout electronics system for micromegas detector based on VMM chips. The VMM is the front end ASIC to be used in the front end electronics readout system of both the micromegas and sTGC detectors of the New Small Wheels Upgrade project. The VMM is designed by Brookhaven National Laboratory, and each chip is composed of 64 linear front-end channels. Each channel integrates a low-noise charge amplifier (CA) with adaptive feedback, test capacitor, and adjustable polarity (to process either positive or negative charge). Based on those characteristics, the VMM is applicable for the signals readout system of multichannel detectors. The readout system consists of three parts: the front-end board, the data acquisition board, and the host computer with the control software., Comment: 3 pages

The FEB(front end board) configuration test board is developed aiming at meeting the requirement of testing the new generation ASIC(application-specific integrated circuit) chips and its configuration system for ATLAS NSW(New Small Wheel) upgrade, In this paper, some functions are developed in terms of the configurations of the key chips on the FEB, VMM3 and TDS2 using GBT-SCA. Additionally, a flexible communication protocol is designed, verifying the whole data link. It provides technical reference for prototype FEB key chip configuration and data readout, as well as the final system configuration.

The Pad Front End Board (pFEB) and the Strip Front End Board (sFEB) are developed for the ATLAS Phase-I sTGC Trigger Upgrade. The pFEB is used to to gather and analyze pads trigger, and the sFEB is developed to accept the pad trigger to define the regions-of-interest for strips readout. The performance of p/sFEBs must be confirmed before they are mounted on the sTGC detector. We will present the scanning test system prototype which is designed according to the test requirements of the p/sFEB. In this test system prototype, a simulation signal board is developed to generate different types of signal to the p/sFEB. PC software and FPGA XADC cooperate to achieve the scan test of analog parameter.