Field-programmable gate array (FPGA)-based sensor nodes are popular for their flexible design approach and field reconfigurability. RISC32 is one of the recent Internet of Things (IoT) processors proposed for the development of FPGA-based sensor nodes, and it includes the ability to reconfigure the microarchitecture on the fly in order to reduce dynamic energy consumption. However, such a method does not minimize static energy consumption, which is important in FPGA-based systems. In this work, clock gating (CG) and dynamic voltage and frequency scaling (DVFS) are applied to further reduce the energy consumption in RISC32. In the research presented here, we implemented a new software called the energy reduction program analyzer to estimate the parameters that configure a sensor node to achieve minimum energy consumption, targeting the typical IoT application scenario. Experimental results show that the low-power techniques applied in this work (RISC32-LP) can reduce energy consumption by 47%, compared to the standard RISC32 processor.
High route loss and line-of-sight requirements are two of the fundamental challenges of millimeter-wave (mm-wave) communications that are mitigated by incorporating sensor technology. Sensing gives the deep reinforcement learning (DRL) agent comprehensive environmental feedback, which helps it better predict channel fluctuations and modify beam patterns accordingly. For multi-user massive multiple-input multiple-output (mMIMO) systems, hybrid precoding requires sophisticated real-time low-complexity power allocation (PA) approaches to achieve near-optimal capacity. This study presents a unique angular-based hybrid precoding (AB-HP) framework that minimizes radio frequency (RF) chain and channel estimation while optimizing energy efficiency (EE) and spectral efficiency (SE). DRL is essential for mm-wave technology to make adaptive and intelligent decision-making possible, which effectively transforms wireless communication systems. DRL optimizes RF chain usage to maintain excellent SE while drastically lowering hardware complexity and energy consumption in an AB-HP architecture by dynamically learning optimal precoding methods using environmental angular information. This article proposes enabling dual optimization of EE and SE while drastically lowering beam training overhead by incorporating maximum reward beam training driven (RBT) in the DRL. The proposed RBT-DRL improves system performance and flexibility by dynamically modifying the number of active RF chains in dynamic network situations. The simulation results show that RBT-DRL-driven beam training guarantees good EE performance for mobile users while increasing SE in mm-wave structures. Even though total power consumption rises by 45%, the SE improves by 39%, increasing from 14 dB to 20 dB, suggesting that this strategy could successfully achieve a balance between performance and EE in upcoming B5G networks.
18 July 2023 in IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Practical deployment of convolutional neural network (CNN) and cryptography algorithm on constrained devices are challenging due to the huge computation and memory requirement. Developing separate hardware accelerator for AI and cryptography incur large area consumption, which is not desirable in many applications. This article proposes a viable solution to this issue by expressing the CNN and cryptography as generic-matrix-multiplication (GEMM) operations and map them to the same accelerator for reduced hardware consumption. A novel systolic tensor array (STA) design was proposed to reduce the data movement, effectively reducing the operand registers by $2\times $ . Two novel techniques, input layer extension and polynomial factorization, are proposed to mitigate the under-utilization issue found in existing STA architecture. Additionally, the tensor processing element (TPE) is fused using DSP unit to reduce the look-up table (LUT) and flip-flops (FFs) consumption for implementing multipliers. On top of that, a novel memory efficient factorization technique is proposed to allow computation of polynomial convolution on the same STA. Experimental results show that Cryptensor achieved 21.6% better throughput for VGG-16 implementation on XC7Z020 FPGA; up to $8.40\times $ better-energy efficiency compared to existing ResNet-18 implementation on XC7Z045 FPGA. Cryptensor can also flexibly support multiple security levels in NTRU scheme, with no additional hardware. The proposed hardware unifies the computation of two different domains that are critical for IoT applications, which greatly reduces the hardware consumption on edge nodes.
To fulfil the tight area and memory constraints in IoT applications, the design of efficient Convolutional Neural Network (CNN) hardware becomes crucial. Quantization of CNN is one of the promising approach that allows the compression of large CNN into a much smaller one, which is very suitable for IoT applications. Among various proposed quantization schemes, Power-of-two (PoT) quantization enables efficient hardware implementation and small memory consumption for CNN accelerators, but requires retraining of CNN to retain its accuracy. This paper proposes a two-level post-training static quantization technique (DoubleQ) that combines the 8-bit and PoT weight quantization. The CNN weight is first quantized to 8-bit (level one), then further quantized to PoT (level two). This allows multiplication to be carried out using shifters, by expressing the weights in their PoT exponent form. DoubleQ also reduces the memory storage requirement for CNN, as only the exponent of the weights is needed for storage. However, DoubleQ trades the accuracy of the network for reduced memory storage. To recover the accuracy, a selection process (DoubleQExt) was proposed to strategically select some of the less informative layers in the network to be quantized with PoT at the second level. On ResNet-20, the proposed DoubleQ can reduce the memory consumption by 37.50% with 7.28% accuracy degradation compared to 8-bit quantization. By applying DoubleQExt, the accuracy is only degraded by 1.19% compared to 8-bit version while achieving a memory reduction of 23.05%. This result is also 1% more accurate than the state-of-the-art work (SegLog). The proposed DoubleQExt also allows flexible configuration to trade off the memory consumption with better accuracy, which is not found in the other state-of-the-art works. With the proposed two-level weight quantization, one can achieve a more efficient hardware architecture for CNN with minimal impact to the accuracy, which is crucial for IoT applications.
24 August 2020 in Journal of Clinical Monitoring and Computing
Specialized medical care is crucial for addressing the increasing prevalence of chronic and non-communicable diseases in Malaysia. However, there is still a shortage of medical specialists, which remains a challenge to be solved if medical officers lack the motivation to pursue a specialization. This lack of motivation is influenced by various contextual factors. This study applies the London’s Career Motivation Theory to investigate the interplay between perceived benefits, perceived barriers, facilitating conditions, and career motivation for specialization among medical officers. Partial Least Squares Structural Equation Modelling was used within a quantitative approach to examine the proposed hypotheses. Data were collected from medical officers in healthcare clinics and hospitals across various states, and 309 valid responses were obtained. The findings reveal a positive association between perceived benefits and career motivation, while perceived barriers correlate negatively with career motivation. Additionally, facilitative conditions moderate the relationship between perceived barriers and career motivation for specialization. These results hold significant implications for healthcare organizations and policymakers.