Browsing by Subject "Power"

Electronic design automation (EDA) technology has achieved remarkable progress over the past decades. However, modern chip design is not completely automatic yet in general and the gap is not easily surmountable. For example, the chip design flow is still largely restricted to individual point tools with limited interplay across tools and design steps. Tools applied at early steps cannot well judge if their solutions may eventually lead to satisfactory designs, inevitably leading to over-pessimistic design or significantly longer turnaround time. While existing challenges have long been unsolved, the ever-increasing complexity of integrated circuits (ICs) leads to even more stringent design requirements. Therefore, there is a compelling need for essential improvement in existing EDA techniques.

The stagnation of EDA technologies roots from insufficient knowledge reuse. In practice, very similar simulation or optimization results may need to be repeatedly constructed from scratch. This motivates my research on introducing more ``intelligence'' to EDA with machine learning (ML), which explores complex correlations in design flows based on prior data. Besides design time, I also propose ML solutions to boost IC performance by assisting the circuit management at runtime.

In this dissertation, I present multiple fast yet accurate ML models covering a wide range of chip design stages from the register-transfer level (RTL) to sign-off, solving primary chip-design problems about power, timing, interconnect, IR drop, routability, and design flow tuning. Targeting the RTL stage, I present APOLLO, a fully automated power modeling framework. It constructs an accurate per-cycle power model by extracting the most power-correlated signals. The model can be further implemented on chip for runtime power management with unprecedented low hardware costs. Targeting gate-level netlist, I present Net2 for early estimations on post-placement wirelength. It further enables more accurate timing analysis without actual physical design information. Targeting circuit layout, I present RouteNet for early routability prediction. As the first deep learning-based routability estimator, some feature-extraction and model-design principles proposed in it are widely adopted by later works. I also present PowerNet for fast IR drop estimation. It captures spatial and temporal information about power distribution with a customized CNN architecture. Last, besides targeting a single design step, I present FIST to efficiently tune design flow parameters during both logic synthesis and physical design.

Background: Haiti has the highest maternal mortality rate in the Latin American and Caribbean region. Despite the fact that Haiti has received twice as much family planning assistance as any other country in the western hemisphere, the unmet need for contraception remains particularly high. Our hypothesis is that unsuccessful efforts of family planning programs may be related to a misconstrued understanding of the complex role of gender in relationships and community in Haiti. This manuscript is one of four parts of a study that intends to examine some of these issues with a particular focus on the influence of uptake and adherence to long acting contraceptive (LAC) methods.

Methods: We conducted a three-month community-based qualitative assessment through 20 in-depth interviews in Fondwa, Haiti. Participants were divided into 4 groups of five: female users, female non-users, men and key community stakeholders.

Results: Based on the qualitative interviews, we found that main barriers included lack of access to family planning education and services and concerns regarding side effects and health risks, especially related to menstrual disruption and fears of infertility. Women have a constant pressure to remain fertile and bear children, due not only to social but also economic needs. As relationships are conceived as means for economic provision, the likelihood of uptake of irreversible methods (vasectomy and tubal ligation) was restricted by loss of fertility. Consequently, the discourse of family planning, though self-recognized in their favor, assumes women can afford not to bear children. This assumption should be questioned given the complexities of the other social determinants at play, all which affect the reproductive decisions made by Haitians.

Conclusions: Overall, our study indicated awareness surrounding contraception in the Haitian Fondwa community. Combining the substantial impact of birth spacing with the elevated yet unmet need for contraceptives in the area, it is necessary to address the intricacies of gender issues in order to implement successful programing. In Haiti not being able to bear a child poses a threat to economic and social survival, possibly explaining a dimension of the low uptake of LACs in the region, even when made available. For this reason, we believe IUDs (Intrauterine Devices) provide a suitable alternative, allowing the couple to comprehend all of the factors involved in decision making, thus decreasing the imbalances of power and knowledge prior to considering an irreversible alternative.

My dissertation investigates twin financial interventions—urban development and emergency management—in a single small town. Once a thriving city drawing blacks as blue-collar workers during the Great Migration, Benton Harbor, Michigan has suffered from waves of out-migration, debt, and alleged poor management. Benton Harbor’s emphasis on high-end economic development to attract white-collar workers and tourism, amidst the poverty, unemployment, and disenfranchisement of black residents, highlights an extreme case of American urban inequality. At the same time, many bystanders and representative observers argue that this urban redevelopment scheme and the city’s takeover by the state represent Benton Harbor residents’ only hope for a better life. I interviewed 44 key players and observers in local politics and development, attended 20 public meetings, conducted three months of observations, and collected extensive archival data. Examining Benton Harbor’s time under emergency management and its luxury golf course development as two exemplars of a larger relationship, I find that the top-down processes allegedly intended to alleviate Benton Harbor’s inequality actually reproduce and deepen the city’s problems. I propose that the beneficiaries of both plans constitute a white urban regime active in Benton Harbor. I show how the white urban regime serves its interests by operating an extraction machine in the city, which serves to reproduce local poverty and wealth by directing resources toward the white urban regime and away from the city.

Mobile devices have been the driving force behind the electronics industry for over a decade. Compared more traditional computing systems such as desktop or laptop computers, these devices prioritize ease-of-use and portability over raw compute power or extensible input methodologies. This change in focus results in devices which are generally small in size, regularly transported (and forgotten), using greatly simplified user interfaces. The main challenges with such devices become 1) securing the data produced by and stored on them, and 2) minimizing power consumption during operation in order to prolong limited battery life.

W.r.t. the first of these two challenges, the first research goal of this dissertation is to identify and develop robust and transparent methodologies for both authenticating a user to a device, as well as securing data stored on or generated by these devices. For securing data produced by and stored on mobile devices, consideration must be given to both user authentication and data integrity. For this dissertation, a novel means of user authentication based on device interaction will be examined. The detailed gesture-based authentication scheme is shown to have high accuracy, while requiring no additional input from the user beyond utilizing the device. Additionally, for securing data stored on the device post-authentication, this dissertation will explore alternate methodologies for detection of adversarial noise added to user images. The discussed methodology is shown to have high attack-detection accuracy while remaining computationally efficient.

W.r.t. the second challenge, the second research goal of this dissertation is to examine alternative, more computationally- and power-efficient methodologies for accomplishing existing tasks, tailored around the unique capabilities and limitations of mobile devices. For this dissertation, a general-case power-saving technique of dynamic framerate and resolution scaling will be investigated. It is shown that significant power savings can be achieved with little- to no-impact on user experience. For saving power in a more specialized task, this dissertation will investigate the use of the GPS in route reconstruction apps for wearable devices. The demonstrated scheduler greatly reduces power consumption while still allowing route reconstruction.

This dissertation identifies a logic of “equal agency” at the heart of a great deal of contemporary thinking about politics. Scholars and citizens alike, I claim, often use some version of this logic in trying to understand what is valuable about liberal and democratic institutions. As a way of thinking democratically at the highest level, however—as a comprehensive principle for organizing our various practical and theoretical commitments, understanding the nature and value of democracy, and orienting ourselves towards a democratic future—I believe that it is deeply flawed. This dissertation demonstrates why such an alternative is needed, and proceeds to articulate one: the dispersion of power.

The introduction lays out the scope and methods before giving a chapter outline and a summary of the dissertation’s contributions. Chapter one gives an account of the logic of equal agency, demonstrating its pervasiveness in political theory and its reliance on an ideal of individual subjectivity. Chapter two employs contemporary biology and cognitive science to support Foucault’s critique of subjectivity, and chapter three demonstrates that this should lead us to abandon the logic of equal agency more generally. Chapter four articulates conceptions of agency and power that are compatible with Foucault’s critique, and chapter five demonstrates how we might “think democratically” using these concepts within a logic of dispersing power. Chapter six links a crisis in contemporary democratic theory to the logic of equal agency and suggests that the dispersion of power can help to resolve it; a promise that is followed up in chapter seven. Chapter eight concludes by employing the logic of dispersing power to advocate for a universal basic income.

Three distinct chapters explore the individual-level dynamics of legitimacy judgments and support for leaders and their initiatives. Chapter 1 develops a theoretical framework for understanding the content of legitimacy judgments and the process by which those judgments develop and change over time. Chapter 2 explores the role of group orientation in moderating the impact of instrumental, relational, and moral concerns in determining support for leaders. Chapter 3 explores the role of power in moderating leaders' assumptions about the types of behaviors that will elicit support for followers.

In Chapter 1, I build on institutional, social psychological, and sociological theory to develop a theoretical framework that specifies both the content underlying judgments of the legitimacy of social entities and a model of the process by which these judgments develop and change over time. With respect to the content of legitimacy judgments, I argue that individual-level judgments of the legitimacy of social entities are based on perceptions and beliefs about the entity that fall along three key dimensions: instrumental, relational, and moral. With respect to the process by which legitimacy judgments develop and change over time, I specify three modes of the legitimacy judgment process (evaluative, passive, and socialization), and I explain which of these modes is likely to predominate as individuals move through the stages of the legitimacy judgment process. The model specifies the circumstances under which the legitimacy of existing institutions is likely to be either challenged or bolstered. I conclude by discussing the implications of this framework for advancing a more detailed understanding of the micro-level dynamics of critical areas of inquiry in organizational studies.

In Chapter 2, I present a series of three studies demonstrating that individuals' intrinsic or extrinsic orientation toward their group moderates their responsiveness to different types of behaviors and appeals, such that individuals who have an intrinsic orientation (such as high identifiers and individuals who feel a high level of group belongingness) are more responsive to moral behaviors and appeals, while individuals with an extrinsic orientation (such as low identifiers and individuals who feel a low level of group belongingness) are more responsive to instrumental behaviors and appeals.

In Chapter 3, four studies demonstrate that subjective feelings of social power impact leaders' assumptions about the bases of their legitimacy with followers, which in turn impacts leaders' decisions about what types of leadership behaviors and tactics to engage. Study 1 demonstrates that leaders who feel a high level of power within their group or organization perceive support from followers as stemming primarily from their instrumental rather than relational behaviors, while leaders who feel a low level of power perceive that the support they receive from followers stems primarily from their relational rather than instrumental behaviors. Study 2 is a vignette study in which individuals primed with high power report greater expectations of support in response to decisions made on instrumental rather than relational bases, while individuals primed with low power report greater expectations of support in response to decisions made on relational rather than on instrumental bases. Study 3 replicates this interaction and shows that the effect is mediated by leaders' assumptions about the types of behaviors that followers prefer. Study 4 demonstrates that leaders primed with power are more likely to engage in instrumental behaviors in their attempts to persuade followers, while individuals primed with low power are more likely to engage in relational behaviors in their attempts to persuade followers. Theoretical and practical implications are discussed.

Chapter 4 describes a final study that integrates the findings from Chapters 2 and 3. Specifically, Chapter 4 demonstrates that there is a positive effect of leader power on support for the leader among low, but not high, identifying groups. The findings further indicate that this effect is mediated by followers' perceptions of the leader's instrumental behaviors. Implications, limitations, and future directions of the research are discussed.