Real-time Analog Pixel-to-pixel Dynamic Frame Differencing with Memristive Sensing Circuits

In this paper, we propose an analog pixel differencing circuit for differentiating pixels between frames directly from CMOS pixels. The analog information processing at sensor is a topic of growing appeal to develop edge AI devices. The proposed circuit is integrated into a pixel-parallel and pixel-column architectures. The proposed system is design using TSMC $180nm$ CMOS technology. The power dissipation of the proposed circuit is $96.64mW$, and on-chip ares is $531.66 \mu m^2$. The architectures are tested for moving object detection application.Comment: IEEE SENSORS 201

Low Power Memory/Memristor Devices and Systems

This reprint focusses on achieving low-power computation using memristive devices. The topic was designed as a convenient reference point: it contains a mix of techniques starting from the fundamental manufacturing of memristive devices all the way to applications such as physically unclonable functions, and also covers perspectives on, e.g., in-memory computing, which is inextricably linked with emerging memory devices such as memristors. Finally, the reprint contains a few articles representing how other communities (from typical CMOS design to photonics) are fighting on their own fronts in the quest towards low-power computation, as a comparison with the memristor literature. We hope that readers will enjoy discovering the articles within

Temporal Data Analysis Using Reservoir Computing and Dynamic Memristors

Temporal data analysis including classification and forecasting is essential in a range of fields from finance to engineering. While static data are largely independent of each other, temporal data have a considerable correlation between the samples, which is important for temporal data analysis. Neural networks thus offer a more general and flexible approach since they do not depend on parameters of specific tasks but are driven only by the data. In particular, recurrent neural networks have gathered much attention since the temporal information captured by the recurrent connections improves the prediction performance. Recently, reservoir computing (RC), which evolves from recurrent neural networks, has been extensively studied for temporal data analysis as it can offer efficient temporal processing of recurrent neural networks with a low training cost. This dissertation presents a hardware implementation of the RC system using an emerging device - memristor, followed by a theoretical study on hierarchical architectures of the RC system. A RC hardware system based on dynamic tungsten oxide (WOx) memristors is first demonstrated. The internal short-term memory effects of the WOx memristors allow the memristor-based reservoir to nonlinearly map temporal inputs into reservoir states, where the projected features can be readily processed by a simple linear readout function. We use the system to experimentally demonstrate two standard benchmarking tasks: isolated spoken digit recognition with partial inputs and chaotic system forecasting. High classification accuracy of 99.2% is obtained for spoken digit recognition and autonomous chaotic time series forecasting has been demonstrated over the long term. We then investigate the influence of the hierarchical reservoir structure on the properties of the reservoir and the performance of the RC system. Analogous to deep neural networks, stacking sub-reservoirs in series is an efficient way to enhance the nonlinearity of data transformation to high-dimensional space and expand the diversity of temporal information captured by the reservoir. These deep reservoir systems offer better performance when compared to simply increasing the size of the reservoir or the number of sub-reservoirs. Low-frequency components are mainly captured by the sub-reservoirs in the later stages of the deep reservoir structure, similar to observations that more abstract information can be extracted by layers in the late stage of deep neural networks. When the total size of the reservoir is fixed, the tradeoff between the number of sub-reservoirs and the size of each sub-reservoir needs to be carefully considered, due to the degraded ability of the individual sub-reservoirs at small sizes. Improved performance of the deep reservoir structure alleviates the difficulty of implementing the RC system on hardware systems. Beyond temporal data classification and prediction, one of the interesting applications of temporal data analysis is inferring the neural connectivity patterns from the high-dimensional neural activity recording data. By computing the temporal correlation between the neural spikes, connections between the neurons can be inferred using statistics-based techniques, but it becomes increasingly computationally expensive for large scale neural systems. We propose a second-order memristor-based hardware system using the natively implemented spike-timing-dependent plasticity learning rule for neural connectivity inference. By incorporating biological features such as transmission delay to the neural networks, the proposed concept not only correctly infers the direct connections but also distinguishes direct connections from indirect connections. Effects of additional biophysical properties not considered in the simulation and challenges of experimental memristor implementation will be also discussed.PHDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/167995/1/moonjohn_1.pd

Entropy in Image Analysis II

Image analysis is a fundamental task for any application where extracting information from images is required. The analysis requires highly sophisticated numerical and analytical methods, particularly for those applications in medicine, security, and other fields where the results of the processing consist of data of vital importance. This fact is evident from all the articles composing the Special Issue "Entropy in Image Analysis II", in which the authors used widely tested methods to verify their results. In the process of reading the present volume, the reader will appreciate the richness of their methods and applications, in particular for medical imaging and image security, and a remarkable cross-fertilization among the proposed research areas

Air Force Institute of Technology Research Report 2011

This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, Mathematics, Statistics and Engineering Physics