Doctor of Philosophy

dissertationAdvancements in process technology and circuit techniques have enabled the creation of small chemical microsystems for use in a wide variety of biomedical and sensing applications. For applications requiring a small microsystem, many components can be integrated onto a single chip. This dissertation presents many low-power circuits, digital and analog, integrated onto a single chip called the Utah Microcontroller. To guide the design decisions for each of these components, two specific microsystems have been selected as target applications: a Smart Intravaginal Ring (S-IVR) and an NO releasing catheter. Both of these applications share the challenging requirements of integrating a large variety of low-power mixed-signal circuitry onto a single chip. These applications represent the requirements of a broad variety of small low-power sensing systems. In the course of the development of the Utah Microcontroller, several unique and significant contributions were made. A central component of the Utah Microcontroller is the WIMS Microprocessor, which incorporates a low-power feature called a scratchpad memory. For the first time, an analysis of scaling trends projected that scratchpad memories will continue to save power for the foreseeable future. This conclusion was bolstered by measured data from a fabricated microcontroller. In a 32 nm version of the WIMS Microprocessor, the scratchpad memory is projected to save ~10-30% of memory access energy depending upon the characteristics of the embedded program. Close examination of application requirements informed the design of an analog-to-digital converter, and a unique single-opamp buffered charge scaling DAC was developed to minimize power consumption. The opamp was designed to simultaneously meet the varied demands of many chip components to maximize circuit reuse. Each of these components are functional, have been integrated, fabricated, and tested. This dissertation successfully demonstrates that the needs of emerging small low-power microsystems can be met in advanced process nodes with the incorporation of low-power circuit techniques and design choices driven by application requirements

Time-Space Constrained Codes for Phase-Change Memories

Phase-change memory (PCM) is a promising non-volatile solid-state memory technology. A PCM cell stores data by using its amorphous and crystalline states. The cell changes between these two states using high temperature. However, since the cells are sensitive to high temperature, it is important, when programming cells, to balance the heat both in time and space. In this paper, we study the time-space constraint for PCM, which was originally proposed by Jiang et al. A code is called an \emph{$(\alpha,\beta,p)$-constrained code} if for any $\alpha$ consecutive rewrites and for any segment of $\beta$ contiguous cells, the total rewrite cost of the $\beta$ cells over those $\alpha$ rewrites is at most $p$. Here, the cells are binary and the rewrite cost is defined to be the Hamming distance between the current and next memory states. First, we show a general upper bound on the achievable rate of these codes which extends the results of Jiang et al. Then, we generalize their construction for $(\alpha\geq 1, \beta=1,p=1)$-constrained codes and show another construction for $(\alpha = 1, \beta\geq 1,p\geq1)$-constrained codes. Finally, we show that these two constructions can be used to construct codes for all values of $\alpha$, $\beta$, and $p$

A Low-Power DSP Architecture for a Fully Implantable Cochlear Implant System-on-a-Chip.

The National Science Foundation Wireless Integrated Microsystems (WIMS) Engineering Research Center at the University of Michigan developed Systems-on-a-Chip to achieve biomedical implant and environmental monitoring functionality in low-milliwatt power consumption and 1-2 cm3 volume. The focus of this work is implantable electronics for cochlear implants (CIs), surgically implanted devices that utilize existing nerve connections between the brain and inner-ear in cases where degradation of the sensory hair cells in the cochlea has occurred. In the absence of functioning hair cells, a CI processes sound information and stimulates the nderlying nerve cells with currents from implanted electrodes, enabling the patient to understand speech. As the brain of the WIMS CI, the WIMS microcontroller unit (MCU) delivers the communication, signal processing, and storage capabilities required to satisfy the aggressive goals set forth. The 16-bit MCU implements a custom instruction set architecture focusing on power-efficient execution by providing separate data and address register windows, multi-word arithmetic, eight addressing modes, and interrupt and subroutine support. Along with 32KB of on-chip SRAM, a low-power 512-byte scratchpad memory is utilized by the WIMS custom compiler to obtain an average of 18% energy savings across benchmarks. A synthesizable dynamic frequency scaling circuit allows the chip to select a precision on-chip LC or ring oscillator, and perform clock scaling to minimize power dissipation; it provides glitch-free, software-controlled frequency shifting in 100ns, and dissipates only 480μW. A highly flexible and expandable 16-channel Continuous Interleaved Sampling Digital Signal Processor (DSP) is included as an MCU peripheral component. Modes are included to process data, stimulate through electrodes, and allow experimental stimulation or processing. The entire WIMS MCU occupies 9.18mm2 and consumes only 1.79mW from 1.2V in DSP mode. This is the lowest reported consumption for a cochlear DSP. Design methodologies were analyzed and a new top-down design flow is presented that encourages hardware and software co-design as well as cross-domain verification early in the design process. An O(n) technique for energy-per-instruction estimations both pre- and post-silicon is presented that achieves less than 4% error across benchmarks. This dissertation advances low-power system design while providing an improvement in hearing recovery devices.Ph.D.Electrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/91488/1/emarsman_1.pd

The Wooster Voice (Wooster, OH), 1985-03-08

This edition of the College of Wooster student run newspaper was published on March 8 of 1985 and it is sixteen pages long. Open Floodgates, American Association of State Colleges and Universities discuss the rules to fire teachers. Music Building Planned, construction for a new music building is underway. Kwame Ture Visits Campus, Stokely Carmichael known as Kwame Ture speaks on at the college. Athletic updates for the past week are highlighted on pages fourteen and fifteen. A list of students that signed a petition is featured on the final page.https://openworks.wooster.edu/voice1981-1990/1350/thumbnail.jp

Print- Aug. 11, 1978

https://neiudc.neiu.edu/print/1322/thumbnail.jp

Control Plane in Software Defined Networks and Stateful Data Planes

L'abstract è presente nell'allegato / the abstract is in the attachmen

The Wooster Voice (Wooster, OH), 1997-01-24

In this edition of the Voice, Associate Professor of Art History at Yale University, Jonathan Weinberg, presents We Are Here: Lesbian and Gay Presence in Modern Art to the College community. Edwin Sanders, from the Metropolitan Interdenominational Church, delivers the final presentation in a series of Martin Luther King Jr. Day lectures. A fire breaks out in Kitterage Dining Hall however, little damage is caused. The Ohio band, “Oroboros,” plays a show at the College. Additionally, an article discusses the benefits of being in a Wooster Greek life group.https://openworks.wooster.edu/voice1991-2000/1160/thumbnail.jp

The Beacon, April 19, 2007

Vol. 19, Issue 64, 16 pageshttps://digitalcommons.fiu.edu/student_newspaper/1152/thumbnail.jp

“How to Lose the Hounds”: Tracing the Relevance of Marronage for Contemporary Anti-Police Struggles

This dissertation analyzes the interconnected practices of flight from slavery and flight from policing. Focusing on Black communities within Montgomery County, Maryland, I provide evidence for how local legacies of enslavement and flight from slavery have empowered later generations of residents, including people still living there today, to practice safety and security on their own terms, beyond policing. I draw on archival and ethnographic research in seven Black communities in Montgomery County to document historical and ongoing local Black life practices and organizing against and outside of policing. I center these communities’ past and present placemaking and collective strategies of valuing their own humanity as a model for police abolition—the end of policing and the building of something new. As a guiding theory, I developed the concept “maroon geographies” to emphasize connections between slavery-era and more contemporary Black flight and placemaking beyond racial police violence. Marronage—which is the practice of flight from slavery—allowed slaves to assert their freedom and, at times, to create communities that were physically removed from the dominant slave society. Black people who escaped or were freed from slavery established several rural, urban, and suburban towns sustained as multi-generational Black communities in the present-day United States. Like maroon communities during slavery, these Black enclaves, across later generations, developed various levels of autonomy from the operations of dominant society. Together, Black communities and their slavery-era predecessors form “maroon geographies” defined by Black-led, place-based communal struggles against state and extralegal racial and economic violence. My findings show how generations of residents in Montgomery County’s Black communities have lived and continue to live out abolitionist praxes in their daily lives—from fleeing slave catchers, some of the earliest policing efforts in this country, to not relying on police to resolve issues nor to ensure safety in their communities. I discuss the local history and folklore around marronage in Montgomery County and connect it to continued anti-police practices and organizing. I examine local acts of refusal of and flight from policing, and I outline a model of maroon restorative justice based in examples from local Black communities. Further, I highlight Black epistemologies and practices of community beyond policing, rooted in marronage and characterized by radical visions of places that fulfill human needs. These Black geographic visions, I contend, show that community safety and security are already operating outside of policing