The Convolutional Neural Network (CNN) has been used in many fields and has achieved remarkable results, such as image classification, face detection, and speech recognition. Compared to GPU (graphics processing unit) and ASIC, a FPGA (field programmable gate array)-based CNN accelerator has great advantages due to its low power consumption and reconfigurable property. However, FPGA’s extremely limited resources and CNN’s huge amount of parameters and computational complexity pose great challenges to the design. Based on the ZYNQ heterogeneous platform and the coordination of resource and bandwidth issues with the roofline model, the CNN accelerator we designed can accelerate both standard convolution and depthwise separable convolution with a high hardware resource rate. The accelerator can handle network layers of different scales through parameter configuration and maximizes bandwidth and achieves full pipelined by using a data stream interface and ping-pong on-chip cache. The experimental results show that the accelerator designed in this paper can achieve 17.11GOPS for 32bit floating point when it can also accelerate depthwise separable convolution, which has obvious advantages compared with other designs.
Multi-agent reinforcement learning (MARL) has become more and more popular over recent decades, and the need for high-level cooperation is increasing every day because of the complexity of the real-world environment. However, the multi-agent credit assignment problem that serves as the main obstacle to high-level coordination is still not addressed properly. Though lots of methods have been proposed, none of them have thought to perform credit assignments across multi-levels. In this paper, we aim to propose an approach to learning a better credit assignment scheme by credit assignment across multi-levels. First, we propose a hierarchical model that consists of the manager level and the worker level. The manager level incorporates the dilated Gated Recurrent Unit (GRU) to focus on high-level plans and the worker level uses GRU to execute primitive actions conditioned on high-level plans. Then, one centralized critic is designed for each level to learn each level’s credit assignment scheme. To this end, we construct a novel hierarchical MARL algorithm, named MLCA, which can achieve multi-level credit assignment. We also conduct experiments on three classical and challenging tasks to demonstrate the performance of the proposed algorithm against three baseline methods. The results show that our method gains great performance improvement across all maps that require high-level cooperation.
With the development of Internet of Things (IoT) and edge computing technology, gas sensor arrays based on Micro-Electro-Mechanical System (MEMS) fabrication technique have broad application prospects in intelligent integrated systems, portable devices, and other fields. In such complex scenarios, the normal operation of a gas sensing system depends heavily on the accuracy of the sensor output. Therefore, a lightweight Self-Detection and Self-Calibration strategy for MEMS gas sensor arrays is proposed in this paper to monitor the working status of sensor arrays and correct the abnormal data in real time. Evaluations on real-world datasets indicate that the strategy has high performance of fault detection, isolation, and data recovery. Furthermore, our method has low computation complexity and low storage resource occupation. The board-level verification on CC1350 shows that the average calculation time and running power consumption of the algorithm are 0.28 ms and 9.884 mW. The proposed strategy can be deployed on most resource-limited IoT devices to improve the reliability of gas sensing systems.
Convolution neural networks (CNN), support vector machine (SVM) and hybrid CNN-SVM algorithms are widely applied in many fields, including image processing and fault diagnosis. Although many dedicated FPGA accelerators have been proposed for specific networks, such as CNN or SVM, few of them have focused on CNN-SVM. Furthermore, the existing accelerators do not support CNN-SVM, which limits their application scenarios. In this work, we propose a hybrid CNN-SVM accelerator on FPGA. This accelerator utilizes a novel hardware-reuse architecture and unique computation mapping strategy to implement different calculation modes in CNN-SVM so that it can realize resource-efficient acceleration of the hybrid algorithm. In addition, we propose a universal deployment methodology to automatically select accelerator design parameters according to the target platform and algorithm. The experimental results on ZYNQ-7020 show that our implementation can efficiently map CNN-SVM onto FPGA, and the performance is competitive with other state-of-the-art works.
14 March 2019 in International Journal of Online and Biomedical Engineering (iJOE)
Smart Campus is an intelligent and smart environment of teaching, learning and living. It is built on the Internet of Things and application services. Colleges and universities are devoted to the construction and development of the smart campus and have completed some digital campuses of different sizes. However, there are still some problems in the current construction and development process, such as low degree of intelligence, free intelligent functions, energy and resource monitoring is still in the traditional mode of non-intelligent management, the functions of terminal application are still simple, can’t keep up with the intelligent development of the campus. In order to help promote the development of smart campus, we designed a database, smart campus mobile terminal APP. The smart campus APP is based on Android system to monitor and control energy and other nodes in the campus. The monitoring method is real-time, clear and efficient. In addition, smart dormitory, smart classroom and smart map function have also been designed to provide a more convenient and safe living environment for teachers and students in our school. And this APP has laid a solid foundation for establishing a smart, efficient, open, harmonious, humane and safe campus.