Achieving Reliable and Sustainable Next-Generation Memories

Conventional memory technology scaling has introduced reliability challenges due to dysfunctional, improperly formed cells and crosstalk from increased cell proximity. Furthermore, as the manufacturing effort becomes increasingly complex due to these deeply scaled technologies, holistic sustainability is negatively impacted. The development of new memory technologies can help overcome the capacitor scaling limitations of DRAM. However, these technologies have their own reliability concerns, such as limited write endurance in the case of Phase Change Memories (PCM). Moreover, emerging system requirements, such as in-memory encryption to protect sensitive or private data and operation in harsh environments create additional challenges that must be addressed in the context of reliability and sustainability. This dissertation provides new multifactor and ultimately unified solutions to address many of these concerns in the same system. In particular, my contributions toward mitigating these issues are as follows. I present GreenChip and GreenAsic, which together provide the first tools to holistically evaluate new computer architecture, chip, and memory design concepts for sustainability. These tools provide detailed estimates of manufacturing and operational-phase metrics for different computing workloads and deployment scenarios. Using GreenChip, I examined existing DRAM reliability techniques in the context of their holistic sustainability impact, including my own technique to mitigate bitline crosstalk. For PCM, I provided a new reliability technique with no additional storage overhead that substantially increases the lifetime of an encrypted memory system. To provide bit-level error correction, I developed compact linked-list and Bloom-filter-based bit-level fault map structures, that provide unprecedented levels of error tabulation, combined with my own novel error correction and lifetime extension approaches based on these maps for less area than traditional ECC. In particular, FaME, can correct N faults using N bits when utilizing a bit-level fault map. For operation in harsh environments, I created a triple modular redundancy (TMR) pointer-based fault map, HOTH, which specifically protects cells shown to be weak to radiation. Finally, to combine the analyses of holistic sustainability and memory lifetime, I created the LARS technique, which adjusts the GreenChip indifference analysis to account for the additional sustainability benefit provided by increased reliability and lifetime

Low Energy Solutions for FIFOs in Networks on Chip

To continue the progress of Moore's law at the end of Dennard Scaling, computer architects turned to multi-core systems, connected by networks-on-chip (NoCs). As this trend persisted, NoCs became a leading energy consumer in modern multi-core processors, with a significant percent originating from the large number of virtual channel (FIFO) buffers. In this work, two orthogonal methods to reduce the use-phase energy of these FIFO buffers are discussed. The first is a reservation based circuit-switching multi-hop routing design, multi-hop segmented circuit switching (MSCS). In a 2D arrangement of an NoC, MSCS performs network control at most once in each dimension for a packet, compared to leading multi-hop approaches which often require multiple arbitration steps. This design resulted in a reduction of FIFO buffer storage by 50% over the leading multi-hop scheme with a nominal latency improvement (1.4%). The second method discussed is the intelligent replacement of SRAM with Domain-Wall Memory (DWM) FIFOs, enabled by novel control schemes which leverage the ''shift-register'' nature of spintronic DWM to create extremely low-energy FIFO queues. The most efficiently designed shift-based buffer used a dual-nanowire approach to more effectively align read and writes to the FIFO with the limited access ports

Communications Biophysics

Contains reports on seven research projects split into three sections, with research objective for the final section.National Institutes of Health (Grant 2 PO1 NS 13126)National Institutes of Health (Grant 5 RO1 NS 18682)National Institutes of Health (Grant 1 RO1 NS 20322)National Institutes of Health (Grant 1 RO1 NS 20269)National Institutes of Health (Grant 5 T32 NS 07047)Symbion, Inc.National Institutes of Health (Grant 5 RO1 NS10916)National Institutes of Health (Grant 1 RO1 NS16917)National Science Foundation (Grant BNS83-19874)National Science Foundation (Grant BNS83-19887)National Institutes of Health (Grant 5 RO1 NS12846)National Institutes of Health (Grant 5 RO1 NS21322)National Institutes of Health (Grant 5 RO1 NS 11080

Communication Biophysics

Contains reports on six research projects.National Institutes of Health (Grant 5 PO1 NS13126)National Institutes of Health (Grant 5 RO1 NS18682)National Institutes of Health (Grant 5 RO1 NS20322)National Institutes of Health (Grant 5 R01 NS20269)National Institutes of Health (Grant 5 T32NS 07047)Symbion, Inc.National Science Foundation (Grant BNS 83-19874)National Science Foundation (Grant BNS 83-19887)National Institutes of Health (Grant 6 RO1 NS 12846)National Institutes of Health (Grant 1 RO1 NS 21322

Petroleum industry in Illinois in 1955.

pt.1. Oil and gas developments, [by] Alfred H. Bell, Virginia Kline -- pt. 2. Waterflood operations, [by] Paul A. Witherspoon, Donald A. Pierre

Deterrence: Selected Articles from the Naval War College Review

The subject of deterrence fell away from the forefront of American strategic thinking during the three decades following the fall of the Soviet Union. Our ability to deter much weaker states by denying them the ability to achieve their aims was long assumed. But today there is a new global security situation that makes it imperative for American military officers and security specialists to begin to relearn the fundamental tenets of this aspect of national security. The purpose of this volume is to contribute to that campaign of learning by drawing on some of the excellent scholarship published in the Naval War College Review during the Cold War and the decades since. Some of the articles included here lay out a few of the fundamentals of the theories of deterrence.https://digital-commons.usnwc.edu/usnwc-newport-papers/1045/thumbnail.jp