587 research outputs found
AWEQ: Post-Training Quantization with Activation-Weight Equalization for Large Language Models
Large language models(LLMs) exhibit excellent performance across a variety of
tasks, but they come with significant computational and storage costs.
Quantizing these models is an effective way to alleviate this issue. However,
existing methods struggle to strike a balance between model accuracy and
hardware efficiency. This is where we introduce AWEQ, a post-training method
that requires no additional training overhead. AWEQ excels in both
ultra-low-bit quantization and 8-bit weight and activation (W8A8) quantization.
There is an observation that weight quantization is less challenging than
activation quantization. AWEQ transfers the difficulty of activation
quantization to weights using channel equalization, achieving a balance between
the quantization difficulties of both, and thereby maximizing performance. We
have further refined the equalization method to mitigate quantization bias
error, ensuring the robustness of the model. Extensive experiments on popular
models such as LLaMA and OPT demonstrate that AWEQ outperforms all existing
post-training quantization methods for large models
The Impact of Microearthquakes Induced by Reservoir Water Level Rise on Stability of Rock Slope
In order to study the impact of frequent microearthquakes induced by water level rise on the stability of rock bedded slopes in the Three Gorges Reservoir (TGR) area, Zhaoshuling Landslide (a representative slope) is selected to study. Safety factors based on probability statistics and FLAC3D are used for numerical simulation (under the operating condition that five earthquakes of Intensity IV are applied to slope in succession after water level rises from 145 m to 175 m). Then the slope’s dynamic stability characteristics and failure mechanism are analyzed. The study shows that slope deformation is evidently the result of thrust load. The deformation starts from the steeply dipping segment in the middle part of slip mass and is controlled by the soft interlayer. Shear failure tends to occur along the soft interlayer and the horizontal slip displacement increases from the rear to the front of the slope. The steeply dipping segment shows a general downslide trend. Although the gentle slope platform on the rear edge is relatively stable, it is vulnerable to tensile fractures which are precursors of landslide. Under the same failure probability, as the number of microearthquake occurrences increases, the safety factor of slope under microearthquake action decreases gradually
IRS-aided UAV for Future Wireless Communications: A Survey and Research Opportunities
Both unmanned aerial vehicles (UAVs) and intelligent reflecting surfaces
(IRS) are gaining traction as transformative technologies for upcoming wireless
networks. The IRS-aided UAV communication, which introduces IRSs into UAV
communications, has emerged in an effort to improve the system performance
while also overcoming UAV communication constraints and issues. The purpose of
this paper is to provide a comprehensive overview of IRSassisted UAV
communications. First, we provide five examples of how IRSs and UAVs can be
combined to achieve unrivaled potential in difficult situations. The
technological features of the most recent relevant researches on IRS-aided UAV
communications from the perspective of the main performance criteria, i.e.,
energy efficiency, security, spectral efficiency, etc. Additionally, previous
research studies on technology adoption as machine learning algorithms. Lastly,
some promising research directions and open challenges for IRS-aided UAV
communication are presented
Double Self-Sustainable Reconfigurable Intelligent Surfaces Aided Wireless Communications
A double self-sustainable reconfigurable intelligent surfaces (RISs) assisted
multi-user multiple input multiple output (MIMO) system is investigated. Two
RISs are equipped with energy harvesting circuit to achieve self-sustainable
transmission. The aim is to minimize the transmission power at the base station
(BS), while guaranteeing the quality of service (QoS) requirements of the users
and meeting the power consumption requirements of the RISs. A block coordinate
descent (BCD) algorithm based on the penalty-based method and successive convex
approximation (SCA) is employed to alternatively optimize the active
beamforming at the BS and the phase shifts, as well as amplitude coefficients
of two RISs. Simulation results show that the required power consumption at the
BS for the proposed double self-sustainable RISs system is significantly
reduced compared to conventional RIS systems
A Deterministic Construction for Jointly Designed Quasicyclic LDPC Coded-Relay Cooperation
This correspondence presents a jointly designed quasicyclic (QC) low-density parity-check (LDPC) coded-relay cooperation with joint-iterative decoding in the destination node. Firstly, a design-theoretic construction of QC-LDPC codes based on a combinatoric design approach known as optical orthogonal codes (OOC) is presented. Proposed OOC-based construction gives three classes of binary QC-LDPC codes with no length-4 cycles by utilizing some known ingredients including binary matrix dispersion of elements of finite field, incidence matrices, and circulant decomposition. Secondly, the proposed OOC-based construction gives an effective method to jointly design length-4 cycles free QC-LDPC codes for coded-relay cooperation, where sum-product algorithm- (SPA-) based joint-iterative decoding is used to decode the corrupted sequences coming from the source or relay nodes in different time frames over constituent Rayleigh fading channels. Based on the theoretical analysis and simulation results, proposed QC-LDPC coded-relay cooperations outperform their competitors under same conditions over the Rayleigh fading channel with additive white Gaussian noise
I/Q Imbalance and Imperfect SIC on Two-way Relay NOMA Systems
Abstract: Non-orthogonal multiple access (NOMA) system can meet the demands of ultra-high data rate, ultra-low latency, ultra-high reliability and massive connectivity of user devices (UE). However, the performance of the NOMA system may be deteriorated by the hardware impairments. In this paper, the joint effects of in-phase and quadrature-phase imbalance (IQI) and imperfect successive interference cancellation (ipSIC) on the performance of two-way relay cooperative NOMA (TWR C-NOMA) networks over the Rician fading channels are studied, where two users exchange information via a decode-and-forward (DF) relay. In order to evaluate the performance of the considered network, analytical expressions for the outage probability of the two users, as well as the overall system throughput are derived. To obtain more insights, the asymptotic outage performance in the high signal-to-noise ratio (SNR) region and the diversity order are analysed and discussed. Throughout the paper, Monte Carlo simulations are provided to verify the accuracy of our analysis. The results show that IQI and ipSIC have significant deleterious effects on the outage performance. It is also demonstrated that the outage behaviours of the conventional OMA approach are worse than those of NOMA. In addition, it is found that residual interference signals (IS) can result in error floors for the outage probability and zero diversity orders. Finally, the system throughput can be limited by IQI and ipSIC, and the system throughput converges to a fixed constant in the high SNR region
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