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摘要： The article explains how the production of aesthetic theory, informed by the burgeoning field of sociology, created a space for Black women. Topics discussed include information on black clubwomen, which worked to address the myriad challenges the black race faced for civil rights; social and political awareness of black clubwomen; and information on black clubwomen's public writing and print culture.

关键词： Robotics   Computer science  

摘要： Autonomous mobile robots today still lack the necessary understanding of indoor environments for making informed decisions about the state of the world beyond their immediate field of view. As a result, they are forced to make conservative and often inaccurate assumptions about unexplored space, inhibiting the degree of performance being increasingly expected of them in the areas of high-speed navigation and mission planning. In order to address this limitation, this thesis explores the use of Building Information Models (BIMs) for providing the existing ecosystem of local and global planning algorithms with informative compact higher-level representations of indoor environments. Although BIMs have long been used in architecture, engineering, and construction for a number of different purposes, to our knowledge, this is the first instance of them being used in robotics. Given the technical constraints accompanying this domain, including a limited and incomplete set of observations which grows over time, the systems we present are designed such that together they produce BIMs capable of providing explanations of both the explored and unexplored space in an online fashion. The first is a SLAM system that uses the structural regularity of buildings in order to mitigate drift and provide the simplest explanation of architectural features such as floors, walls, and ceilings. The planar model generated is then passed to a secondary system that then reasons about their mutual relationships in order to provide a water-tight model of the observed and inferred freespace. Our experimental results demonstrate this to be an accurate and efficient approach towards this end.

关键词： Computer science  

关键词： Electrical engineering   Computer science  

摘要： Power has become a critical constraint for the evolution of large scale High Performance Computing (HPC) systems and commercial data centers. This constraint spans almost every level of computing technologies, from IC chips all the way up to data centers due to physical, technical, and economic reasons. To cope with this reality, it is necessary to understand how available or permissible power impacts the design and performance of emergent computer systems. For this reason, we propose power bounded computing and corresponding technologies to optimize performance on HPC systems with limited power budgets. We have multiple research objectives in this dissertation. They center on the understanding of the interaction between performance, power bounds, and a hierarchical power management strategy. First, we develop heuristics and application aware power allocation methods to improve application performance on a single node. Second, we develop algorithms to coordinate power across nodes and components based on application characteristic and power budget on a cluster. Third, we investigate performance interference induced by hardware and power contentions, and propose a contention aware job scheduling to maximize system throughput under given power budgets for node sharing system. Fourth, we extend to GPU-accelerated systems and workloads and develop an online dynamic performance & power approach to meet both performance requirement and power efficiency. Power bounded computing improves performance scalability and power efficiency and decreases operation costs of HPC systems and data centers. This dissertation opens up several new ways for research in power bounded computing to address the power challenges in HPC systems. The proposed power and resource management techniques provide new directions and guidelines to green exscale computing and other computing systems.

摘要： For nearly three decades, researchers have studied the persistent underrepresentation of women in computer science and computing-related fields. Findings indicate that recruitment and retention strategies result in short-term gains in interest and diversity in computer science. One recruitment strategy that shows promise to increase student interest in computer science is after-school programs. To increase the number of students exposed to and interested in computer science and Science, Technology, Engineering, and Math (STEM) fields, a suburban school district in southeastern Pennsylvania started an after-school program. This fee-based program offers seven-week long robotics, programming, and science experiment courses for elementary and middle school students. This study used a quantitative approach with the expectancy-value model as the theoretical framework to examine whether there are lasting effects from this after-school program on course and career selection. The results show a higher likelihood of study participants, each of whom participated in an after-school program, to select computer science in high school than the general high school population. The results also show that the rate of computer science choice for this group is also significant when accounting for the gender of the participants. Family dynamics may have been the influencing factor. The results are not supportive of the after-school program influencing participants to study computer science at the collegiate level, but there is some support for study participants interest in a computing career.

关键词： Applied mathematics   Mechanical engineering   Computer science  

摘要： Simulating physical materials with dynamic movements to photo-realistic resolution has always been one of the most crucial and challenging topics in Computer Graphics. This dissertation considers large-strain elastoplasticity theory applied to the low-to-medium stiffness regime, with topological changes and codimensional objects incorporated. We introduce improvements to the Material Point Method (MPM) for two particular objectives, simulating fracturing ductile materials and incorporation of MPM and Lagrangian Finite Element Method (FEM). Our first contribution, simulating ductile fracture, utilizes traditional particle-based MPM [SSC13, SCS94] as well as the Lagrangian energy formulation of [JSS15] which uses a tetrahedron mesh, rather than particle-based estimation of the deformation gradient and potential energy. We model failure and fracture via elastoplasticity with damage. The material is elastic until its deformation exceeds a Rankine or von Mises yield condition. At that point, we use a softening model that shrinks the yield surface until it reaches the damage thresh- old. Once damaged, the material Lam ́e coefficients are modified to represent failed material. This approach to simulating ductile fracture with MPM is successful, as MPM naturally captures the topological changes coming from the fracture. However, rendering the crack surfaces can be challenging. We design a novel visualization technique dedicated to rendering the material’s boundary and its intersection with the evolving crack surfaces. Our approach uses a simple and efficient element splitting strategy for tetrahedron meshes to create crack surfaces. It employs an extrapolation technique based on the MPM simulation. For traditional particle-based MPM, we use an initial Delaunay tetrahedralization to connect randomly sampled MPM particles. Our visualization technique is a post-process and can run after the MPM simulation for efficiency. We demonstrate our method with several challenging simul

关键词： Information technology   Artificial intelligence   Computer science  

摘要： Protecting computer networks from intrusions is more important than ever for our privacy, economy, and national security. Seemingly a month does not pass without news of a major data breach involving sensitive personal identity, financial, medical, trade secret, or national security data. Democratic processes can now be potentially compromised through breaches of electronic voting systems. As ever more devices, including medical machines, automobiles, and control systems for critical infrastructure are increasingly networked, human life is also more at risk from cyber-attacks. Research into Intrusion Detection Systems (IDSs) began several decades ago and IDSs are still a mainstay of computer and network protection and continue to evolve. However, detecting previously unseen, or zero-day, threats is still an elusive goal. Many commercial IDS deployments still use misuse detection based on known threat signatures. Systems utilizing anomaly detection have shown great promise to detect previously unseen threats in academic research. But their success has been limited in large part due to the excessive number of false positives that they produce. This research demonstrates that false positives can be better minimized, while maintaining detection accuracy, by combining Extreme Learning Machine (ELM) and Hidden Markov Models (HMM) as classifiers within the context of a situation awareness framework. This research was performed using the University of New South Wales–Network Based 2015 (UNSW-NB15) data set which is more representative of contemporary cyber-attack and normal network traffic than older data sets typically used in IDS research. It is shown that this approach provides better results than either HMM or ELM alone and with a lower False Positive Rate (FPR) than other comparable approaches that also used the UNSW-NB15 data set.

摘要： Phebe Gibbes, an 18th century novelist, antedates the OED’s first citation of the word “orientalised” by more than twenty years (Franklin xxxvi). The phrase comes from Hartly House, Calcutta, an epistolary novel published anonymously in 1789 about a young woman named Sophia Goldborne to travels to India with her father, an employee of the East India Company. Gibbes’ apparent coinage of the term signifies a particular transition in Sophia’s understanding of the subcontinent when she says, “I have been orientalised at all points” (Gibbes 8). This declaration registers a change in the way Sophia experiences the implications of colonialism, which is her susceptibility to the spread of disease in British India. I argue that Gibbes uses the epidemiological realities of British India to represent the effects of economic and political corruption. Moreover, the novel’s representation of disease operates as an act of resistance as it complicates the perception of Britain’s imperial control and the stability of western information systems.

关键词： Computer engineering   Electrical engineering   Computer science  

摘要： Formal verification methods have been shown to be very effective in finding corner-case bugs and ensuring the safety of embedded software systems. The use of formal verification requires a specification, which is typically a high-level mathematical model that defines the correct behavior of the system to be verified. However, embedded software requirements are typically described in natural language. Transforming these requirements into formal specifications is currently a big gap. While there is some work in this area, we proposed solutions to address this gap in the context of refinement-based verification, a class of formal methods that have shown to be effective for embedded object code verification. The proposed approach also addresses both functional and timing requirements and has been demonstrated in the context of safety requirements for software control of infusion pumps. The next step in the verification process is to develop the refinement map, which is a mapping function that can relate an implementation state (in this context, the state of the object code program to be verified) with the specification state. Actually, constructing refinement maps often requires deep understanding and intuitions about the specification and implementation, it is shown very difficult to construct refinement maps manually. To go over this obstacle, the construction of refinement maps should be automated. As a first step toward the automation process, we manually developed refinement maps for various safety properties concerning the software control operation of infusion pumps. In addition, we identified possible generic templates for the construction of refinement maps. Recently, synthesizing procedures of refinement maps for functional and timing specifications are proposed. The proposed work develops a process that significantly increases the automation in the generation of these refinement maps. The refinement maps can then be used for refinement-based verification. Thi

关键词： Electrical engineering   Computer science  

摘要： There has been a significant amount of recent work towards fooling deep-learning-based classifiers, particularly for images, via adversarial inputs that are perceptually similar to benign examples. However, researchers typically use minimization of the Lp-norm as a proxy for imperceptibility, an approach that oversimplifies the complexity of real-world images and human visual perception. We exploit the relationship between image features and human perception to propose a Perceptual Loss (PL) metric to better capture human imperceptibly during the generation of adversarial images. By focusing on human perceptible distortion of image features, the metric yields better visual quality adversarial images as our experiments validate. Our results also demonstrate the effectiveness and efficiency of our algorithm.