399 research outputs found
Eigenvector prediction-based precoding for massive MIMO with mobility
Eigenvector decomposition (EVD) is an inevitable operation to obtain the
precoders in practical massive multiple-input multiple-output (MIMO) systems.
Due to the large antenna size and at finite computation resources at the base
station (BS), the overwhelming computation complexity of EVD is one of the key
limiting factors of the system performance. To address this problem, we propose
an eigenvector prediction (EGVP) method by interpolating the precoding matrix
with predicted eigenvectors. The basic idea is to exploit a few historical
precoders to interpolate the rest of them without EVD of the channel state
information (CSI). We transform the nonlinear EVD into a linear prediction
problem and prove that the prediction of the eigenvectors can be achieved with
a complex exponential model. Furthermore, a channel prediction method called
fast matrix pencil prediction (FMPP) is proposed to cope with the CSI delay
when applying the EGVP method in mobility environments. The asymptotic analysis
demonstrates how many samples are needed to achieve asymptotically error-free
eigenvector predictions and channel predictions. Finally, the simulation
results demonstrate the spectral efficiency improvement of our scheme over the
benchmarks and the robustness to different mobility scenarios.Comment: 13pages, 7 figures, 1 table, journa
Synthesis of ionic liquids and their applications in capillary electrophoresis
Ph.DDOCTOR OF PHILOSOPH
HELLaMA: LLaMA-based Table to Text Generation by Highlighting the Important Evidence
Large models have demonstrated significant progress across various domains,
particularly in tasks related to text generation. In the domain of Table to
Text, many Large Language Model (LLM)-based methods currently resort to
modifying prompts to invoke public APIs, incurring potential costs and
information leaks. With the advent of open-source large models, fine-tuning
LLMs has become feasible. In this study, we conducted parameter-efficient
fine-tuning on the LLaMA2 model. Distinguishing itself from previous
fine-tuning-based table-to-text methods, our approach involves injecting
reasoning information into the input by emphasizing table-specific row data.
Our model consists of two modules: 1) a table reasoner that identifies relevant
row evidence, and 2) a table summarizer that generates sentences based on the
highlighted table. To facilitate this, we propose a search strategy to
construct reasoning labels for training the table reasoner. On both the FetaQA
and QTSumm datasets, our approach achieved state-of-the-art results.
Additionally, we observed that highlighting input tables significantly enhances
the model's performance and provides valuable interpretability
A Multi-Dimensional Matrix Pencil-Based Channel Prediction Method for Massive MIMO with Mobility
This paper addresses the mobility problem in massive multiple-input
multiple-output systems, which leads to significant performance losses in the
practical deployment of the fifth generation mobile communication networks. We
propose a novel channel prediction method based on multi-dimensional matrix
pencil (MDMP), which estimates the path parameters by exploiting the
angular-frequency-domain and angular-time-domain structures of the wideband
channel. The MDMP method also entails a novel path pairing scheme to pair the
delay and Doppler, based on the super-resolution property of the angle
estimation. Our method is able to deal with the realistic constraint of
time-varying path delays introduced by user movements, which has not been
considered so far in the literature. We prove theoretically that in the
scenario with time-varying path delays, the prediction error converges to zero
with the increasing number of the base station (BS) antennas, providing that
only two arbitrary channel samples are known. We also derive a lower-bound of
the number of the BS antennas to achieve a satisfactory performance. Simulation
results under the industrial channel model of 3GPP demonstrate that our
proposed MDMP method approaches the performance of the stationary scenario even
when the users' velocity reaches 120 km/h and the latency of the channel state
information is as large as 16 ms
A Self-attention Knowledge Domain Adaptation Network for Commercial Lithium-ion Batteries State-of-health Estimation under Shallow Cycles
Accurate state-of-health (SOH) estimation is critical to guarantee the
safety, efficiency and reliability of battery-powered applications. Most SOH
estimation methods focus on the 0-100\% full state-of-charge (SOC) range that
has similar distributions. However, the batteries in real-world applications
usually work in the partial SOC range under shallow-cycle conditions and follow
different degradation profiles with no labeled data available, thus making SOH
estimation challenging. To estimate shallow-cycle battery SOH, a novel
unsupervised deep transfer learning method is proposed to bridge different
domains using self-attention distillation module and multi-kernel maximum mean
discrepancy technique. The proposed method automatically extracts
domain-variant features from charge curves to transfer knowledge from the
large-scale labeled full cycles to the unlabeled shallow cycles. The CALCE and
SNL battery datasets are employed to verify the effectiveness of the proposed
method to estimate the battery SOH for different SOC ranges, temperatures, and
discharge rates. The proposed method achieves a root-mean-square error within
2\% and outperforms other transfer learning methods for different SOC ranges.
When applied to batteries with different operating conditions and from
different manufacturers, the proposed method still exhibits superior SOH
estimation performance. The proposed method is the first attempt at accurately
estimating battery SOH under shallow-cycle conditions without needing a
full-cycle characteristic test
Traditional Chinese Medicine Improves Activities of Daily Living in Parkinson's Disease
We evaluated the effects of a traditional Chinese medicine (TCM), named Zeng-xiao An-shen Zhi-chan 2 (ZAZ2), on patients with Parkinson's disease (PD). Among 115 patients with idiopathic PD enrolled (mean age, 64.7 ± 10.2 years old), 110 patients (M = 65, F = 45; mean age, 64.9 ± 10.7 years old) completed the study. Patients took either ZAZ2 (n = 59) or placebo granule (n = 56) in a blind manner for 13 weeks while maintaining other anti-Parkinson medications unchanged. All participants wore a motion logger, and we analyzed the power-law temporal autocorrelation of the motion logger records taken on 3 occasions (before, one week, and 13 weeks after the drug administration). Drug efficacy was evaluated with the conventional Unified Parkinson Disease Rating Scale (UPDRS), as well as the power-law exponent α, which corresponds to the level of physical activity of the patients. ZAZ2 but not placebo granule improved the awake-sleep rhythm, the UPDRS Part II, Part II + III, and Part IV scores, and the α values. The results indicate that ZAZ2 improved activities of daily living (ADL) of parkinsonism and, thus, is a potentially suitable drug for long-term use
The mouse and ferret models for studying the novel avian-origin human influenza A (H7N9) virus.
BackgroundThe current study was conducted to establish animal models (including mouse and ferret) for the novel avian-origin H7N9 influenza virus.FindingsA/Anhui/1/2013 (H7N9) virus was administered by intranasal instillation to groups of mice and ferrets, and animals developed typical clinical signs including body weight loss (mice and ferrets), ruffled fur (mice), sneezing (ferrets), and death (mice). Peak virus shedding from respiratory tract was observed on 2 days post inoculation (d.p.i.) for mice and 3-5 d.p.i. for ferrets. Virus could also be detected in brain, liver, spleen, kidney, and intestine from inoculated mice, and in heart, liver, and olfactory bulb from inoculated ferrets. The inoculation of H7N9 could elicit seroconversion titers up to 1280 in ferrets and 160 in mice. Leukopenia, significantly reduced lymphocytes but increased neutrophils were also observed in mouse and ferret models.ConclusionsThe mouse and ferret model enables detailed studies of the pathogenesis of this illness and lay the foundation for drug or vaccine evaluation
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