In recent years, resistive random access memory (RRAM) has gained significant attention as one of the promising candidates for next generation memory applications. This is due to its anticipated advantages versus Flash technology with respect to high density, low power and fast read and write speed. The main operation mechanism of these devices is a resistance change induced by filament formation through metal-cations or oxygen vacancies.

关键词：电阻；内存；RRAM

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Actual communication systems have only finite channel diversity, and thus the practical implications of interference alignment are uncertain: Just how much channel diversity is required in order to get substantial benefit from interference alignment? The first part of this thesis focuses on this question. Our first result characterizes the degrees of freedom for the three-user interference channel as a function of time or frequency diversity. We next focus on spatial diversity, in the form of multiple antennas at transmitters and receivers.The second part of this thesis studies DNA sequencing from an information theory pointof-view. DNA sequencing is the basic workhorse of modern day biology and medicine.

关键词：无线通信；干扰；自由度

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In this work, we utilize experimental data from a monkey subject performing closed-loop control of a 2D cursor BMI and show that the presence of certain dynamical properties correlate with performance loss. We also show that other dynamical properties represent tradeoffs between naturally competing objectives, such as speed versus accuracy. These empirical findings demonstrate the need to eliminate detrimental dynamics by accounting for the feedback control strategy employed by the user, as well as the need to fine-tune plant dynamics to optimize task-specific performance tradeoffs. To this end, we develop general-purpose tools for designing BMI plant dynamics. Using these tools, we show two different ways to improve accuracy and hold performance at the expense of speed.

关键词：脑机接口；闭环性；动力学；精度；性能；工具

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The CSD describes the probability of sampling an individual with a particular genomic sequence, provided that a collection of individuals from the population, and their corresponding sequences, has already been observed. Critically, the true CSD is generally inaccessible, and it is therefore necessary to use an approximate CSD in its place; such an approximate CSD is ideally both accurate and computationally efficient. In this thesis, we undertake a theoretical and algorithmic investigation of the CSD for coalescent models incorporating mutation, homologous (crossover) recombination, and population structure with migration.

关键词：算法；统计；联合模型；CSD；计算效率

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We focus on an optimization problem on parameterized surfaces of genus one. In particular we trade off the penalty functions for bending a toroidal path and for applying a twist to it and aim to find local minima of this cost function. This analysis forms a key element in demonstrating the different regular homotopy classes of tori. A generalization of this surface optimization, which considers curvature as well as any shearing of its parameter grid, may be used to find the most optimal direct path from an arbitrary closed manifold of genus one into one of the four basic representatives of the four regular homotopy classes of tori.

关键词：参数表面；环形循环；弯曲能量；梯度下降；定期同伦

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As memory accesses increasingly limit the overall performance of reconfigurable accelerators, it is important for high-level synthesis (HLS) flows to adopt a systematic way to discover and exploit memory-level parallelism. This work develops 1) a framework where parallelism between memory accesses can be revealed from runtime profiles of applications and provided to a high level synthesis flow, and 2) a novel multiaccelerator/multi-cache architecture to support parallel memory accesses, taking advantage of the high aggregated memory bandwidth found in modern FPGA devices. Our experimental results have shown that for 10 accelerators generated from 9 benchmark applications, circuits using our proposed memory structure achieve on average 51% improved performance over accelerators using a traditional memory interface. We believe that our study represents a solid advance towards achieving memory-parallel embedded computing on hybrid CPU+FPGA platforms.

关键词：内存；加速器；可重构

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Increasing process variability limits energy reduction in SRAM design by increasing the need for margining and preventing optimal supply voltage scaling. However, tolerating variability with resilient designs can prevent these limitations and enable future energy-efficiency improvements. Understanding resiliency requires understanding how design decisions affect error rates—therefore we propose a unified analytical framework for SRAM design that uses importance sampling of dynamic failure metrics to quantify the effect of different assist techniques, array organization, and timing on failure rates of a 28nm arrays at design-time.

关键词：节能；弹性；SRAM

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This dissertation proposes a solution to the CMOS power crisis via mechanical computing. Specifically, robust electro-mechanical relay technologies are developed for digital circuit application. A 4-Terminal (4T) relay design is firstly developed. Key technology features include tungsten contacts for high endurance; low-thermal-budget p+-poly-Si0.4Ge0.6 structure for post- CMOS process compatibility; Al2O3 as a reliable insulation material; dry release step to mitigate stiction; and folded-flexure design to mitigate the impact of residual stress. Fabricated relays show good conductance (RON < 10 kΩ), abrupt switching behavior (sub-threshold swing below 0.1 mV/dec), and virtually zero leakage (IOFF ~ 10-14 A). Switching delay in the 100 ns range and endurance exceeding 109 on/off cycles is achieved with excellent device yield (> 95%). With relay design and process optimizations, pull-in voltage below 10 V with less than 1 V hysteresis is achieved. Miniaturization reduces the device footprint to 35μm×50μm, ~10% of the first generation device footprint (120μm×150μm). Relays with multiple source/drain electrodes and multiple gate electrodes are proposed for increased circuit functionality and reduced device count.

关键词：集成电路；数字电路；CMOS；继电器

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when can one say that a certain dataflow model faithfully captures a given piece of hardware? The question is investigated in this paper. Finite state machines with synchronous semantics are used to model hardware. Asynchronous processes communicating via queues are employed for dataflow. A conformance relation between these two heterogeneous models of computation is developed that preserves performance properties such as worst-case throughput and latency.

关键词：数据流模型；同步语义模型；吞吐量；硬件

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In the Traditional Chinese Medicine, doctors diagnose patients by reading pulses from their wrists, so as to give out proper receipts of herbs curing patients across generations.In our capstone project, a mobile app with sensor gadget has been developed to detect, gather, convert and process pulse signals, and offer users valuable health suggestions. To get accurate pulse signals from wrists, several sensor prototypes have been developed and prototyped. The best-performing sensor, a piezoelectric sensor, is chosen and implemented in detail. Pulse data was processed to extract a stable pulse signal, in aspects of: amplitude of peak signal, and signal time period. From this information the app makes 'diagnoses' about the stress level and health condition of different organs of users. Finally, our mobile app delivers feedback to users, guiding them to healthier lives. The price of the Dr. Chi hardware, and mobile app is projected to be 30 dollars, and so promises to be orders of magnitudes more affordable than existing products for convenient health diagnoses.

关键词：传统中医；脉冲信号；传感器；移动应用程序

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