VictorJuiz/thesis huggingface dataset:
Architectural Introspection and Applications

Widespread adoption of virtualization has resulted in an increased interest in Virtual Machine (VM) introspection. To perform useful analysis of the introspected VMs, hypervisors must deal with the semantic gap between the low-level information available to them and the high-level OS abstractions they need. To bridge this gap, systems have proposed making assumptions derived from the operating system source code or symbol information. As a consequence, the resulting systems create a tight coupling between the hypervisor and the operating systems run by the introspected VMs. This coupling is undesirable because any change to the internals of the operating system can render the output of the introspection system meaningless. In particular, malicious software can evade detection by making modifications to the introspected OS that break these assumptions. Instead, in this thesis, we introduce Architectural Introspection, a new introspection approach that does not require information about the internals of the introspected VMs. Our approach restricts itself to leveraging constraints placed on the VM by the hardware and the external environment. To interact with both of these, the VM must use externally specified interfaces that are both stable and not linked with a specific version of an operating system. Therefore, systems that rely on architectural introspection are more versatile and more robust than previous approaches to VM introspection. To illustrate the increased versatility and robustness of architectural introspection, we describe two systems, Patagonix and P2, that can be used to detect rootkits and unpatched software, respectively. We also detail Attestation Contracts, a new approach to attestation that relies on architectural introspection to improve on existing attestation approaches. We show that because these systems do not make assumptions about the operating systems used by the introspected VMs, they can be used to monitor both Windows and Linux based VMs. We emphasize that this ability to decouple the hypervisor from the introspected VMs is particularly useful in the emerging cloud computing paradigm, where the virtualization infrastructure and the VMs are managed by different entities. Finally, we show that these approaches can be implemented with low overhead, making them practical for real world deployment.

Keywords: Computer Science
Computer Engineering
Security
Computer Security
Virtualization
Virtual Machine
Hypervisor
Introspection
Attestation
Semantic Gap
Rootkit
Patch Management
Advisor: Lie, David
Decentralized Coding in Unreliable Communication Networks

Many modern communication networks suffer significantly from the unreliable characteristic of their nodes and links. To deal with failures, traditionally, centralized erasure codes have been extensively used to improve reliability by introducing data redundancy. In this thesis, we address several issues in implementing erasure codes in a decentralized way such that coding operations are spread to multiple nodes. Our solutions are based on fountain codes and randomized network coding, because of their capability of being amenable to decentralized implementation originated from their simplicity and randomization properties. Our contributions consist of four parts. First, we propose a novel decentralized implementation of fountain codes utilizing random walks. Our solution does not require node location information and enjoys a small local routing table with a size in proportion to the number of neighbors. Second, we introduce priority random linear codes to achieve partial data recovery by partition and encoding data into non-overlapping or overlapping subsets. Third, we present geometric random linear codes to decrease communication costs in decoding significantly, by introducing modest data redundancy in a hierarchical fashion. Finally, we study the application of network coding in disruption tolerant networks. We show that network coding achieves shorter data transmission time than replication, especially when data buffers are limited. We also propose an efficient variant of network coding based protocol, which attains similar transmission delay, but with much lower transmission costs, as compared to a protocol based on epidemic routing.

Keywords: error-correcting codes
wireless networking
Advisor: Li, Baochun
Liang, Ben
Cognitive Interference Management in 4G Autonomous Femtocells

We present a vision for 4G cellular networks based on the concept of autonomous infrastructure deployment. Cellular base stations, or femtocell access points, are deployed by network users without being constrained by the conventional cell planning process from the network operator. Autonomous deployment allows the network to grow in an organic manner which requires new methods for spectrum management. We study a framework for autonomous network optimization based on the method of cognitive interference management. In our model, a number of femtocells are co-channel deployed in an underlay macrocellular network. Instead of fully reusing 100% of the macrocellular resource, partial reuse is cognitively determined in femtocells based on their individual network environment. According to an interference signature perceived from the environment, a femtocell autonomously determines the appropriate channel allocation and minimizes the network interference. Upon the cognitive acquisition of the random infrastructure topology, base station pilot power is autonomously configured in order to maximize the cellular coverage. A series of network self-configuration procedures are discussed for automatic cell size adaptation and resource management. Our results show that the new approaches based on cognitive radio configuration facilitate the network optimization in terms of interference management, mobile handoff, pilot power control and network resource allocation. The proposed framework offers a 4G vision for spectrum management in an autonomous self-managed cellular architecture.

Keywords: Wireless Communication
Interference Management
4th Generation
Autonomous Cellular Network
Advisor: Sousa, Elvino Silveira
Integrated Droplet-based Microfluidics for Chemical Reactions and Processes

This thesis describes a study of various aspects of chemical reactions conducted in microfluidic reactors. (i) In the first project, we proposed the application of the 'internal trigger' approach to multi-step microfluidic polymerization reactions conducted in droplets, namely, polyaddition and polycondensation. We hypothesized and experimentally established that heat generated in the exothermic free radical polymerization of an acrylate monomer triggers the polycondensation of the urethane oligomer. As a result, we synthesized monodispersed poly(acrylate/urethane) microparticles with an interpenetrating polymer network structure. (ii) In the second project, we developed a multiple modular microfluidic reactor with the purpose of increasing productivity in microfluidic synthesis. Compared to the productivity of the single microfluidic reactor < 1g/hr, we synthesized poly(N-isopropylacrylamide) particles at a productivity of approximately 50g/hr with a CV < 5%. We analyzed and addressed several challenges of this process, such as the fidelity in the fabrication of microfluidic reactors, crosstalk between individual reactors sharing a common liquid supply, and coalescence of droplets. (iii) We developed an integrated microfluidic reactor comprising four parallel individual reactors to study the effect of geometry and surface energy of the microchannels on the emulsification process. We spontaneously generated droplets with different volumes by integrating individual droplet generators in parallel with varying geometry. This approach is important in studies of the effect of droplet surface and volume on chemical reactions, and in the studies of diffusion-controlled processes. (iv) We conducted a microfluidic study of the reversible binding of CO2 to secondary amines in the process that mediates solvent polarity switch. We studied reaction rates and CO2 uptake by generating plugs of gaseous a CO2 and monitoring the change in their dimensions. We also demonstrated fast screening of reaction conditions, as well as the ability to reverse the reaction in situ.

Keywords: microfluidics
microreactor
Advisor: Kumacheva, Eugenia
Administrative Law and Curial Deference

This thesis examines three interrelated issues. The first concerns a question about the status of administrative law, namely whether administrative officials have authority to determine what the law requires under a democratic constitution. Historically, this question has not been adequately addressed in public law scholarship because neither Diceyan constitutional theory nor common law doctrine has been traditionally receptive to administrative law. In this thesis, I argue that there are good reasons for people to respect the legal authority of administrative officials and their decisions. Those reasons are rooted in respect for the democratic process by which administrative officials are empowered, and respect for the various forms of expertise that administrative officials possess. The second issue concerns the doctrinal aspect of administrative law. If there are good reasons for believing that administrative officials have legitimate legal authority, then those same reasons suggest that judges should respect administrative legal decisions. In order to better understand how the relevant reasons for respecting administrative decisions alter the practice of judicial review, I compare and contrast the traditional doctrine of jurisdictional review with the doctrine of curial deference. This comparison shows that the doctrine of curial deference provides a superior account of the legitimate legal authority of administrative officials, and that this account makes a practical difference for the practice of judicial review. The third issue concerns whether the doctrine of curial deference can be reconciled with the rule of law. Assuming that there are good reasons for respecting administrative decisions, how can judges both respect an administrative decision while ensuring that it is consistent with the rule of law? I argue that judges can both respect administrative decisions and maintain the rule of law by requiring administrative officials to justify their decisions adequately in light of public reasons which are both patent and latent in existing legal materials.

Keywords: administrative law
judicial review
Advisor: Dyzenhaus, David
The Effects of a Teacher-child Play Intervention on Classroom Compliance in Young Children in Child Care Settings

The current study evaluated the effect of a teacher conducted play intervention on pre-school aged children’s compliance in child care settings. Study participants included 11 children ranging in age from 2 to 5 years old and seven early childhood education teachers within seven classrooms across five child care centres. Teachers were trained to conduct daily 5 minute play sessions consisting of contingent praise, mirroring, and warm responsiveness. A combination ABAB and multiple baseline design was used to demonstrate the effect of the play intervention. Pre-treatment observations revealed varying degrees of recurring child compliance difficulties. The play intervention was associated with improved rates of compliance for each participant child regardless of differences in age, gender, and level of compliance difficulties. The intervention is discussed with regard to its potential as a pro-active, non-intrusive strategy for improving young children’s classroom compliance.

Keywords: compliance
child care
pre-school
play
children
Advisor: Ducharme, Joseph
A Newton-Krylov Approach to Aerodynamic Shape Optimization in Three Dimensions

A Newton-Krylov algorithm is presented for aerodynamic shape optimization in three dimensions using the Euler equations. An inexact-Newton method is used in the flow solver, a discrete-adjoint method to compute the gradient, and the quasi-Newton optimizer to find the optimum. A Krylov subspace method with approximate-Schur preconditioning is used to solve both the flow equation and the adjoint equation. Basis spline surfaces are used to parameterize the geometry, and a fast algebraic algorithm is used for grid movement. Accurate discrete-adjoint gradients can be obtained in approximately one-fourth the time required for a converged flow solution. Single- and multi-point lift-constrained drag minimization optimization cases are presented for wing design at transonic speeds. In all cases, the optimizer is able to efficiently decrease the objective function and gradient for problems with hundreds of design variables.

Keywords: Aerodynamic
Shape
Optimization
Newton-Krylov
Advisor: Zingg, David W.
Symphonic Engagement: A Case Study of Extra-curricular Engagement in String Orchestras

Symphonic Engagement is a longitudinal study spanning six years, investigating the reasons and benefits for, and the impact on twelve urban public school students who decided to use their free time to participate and be engaged in extra-curricular activities in string orchestras. Literature and research inform us that the arts can play a significant role in the curriculum, inside and outside school, and this study discusses: the connection of the music curriculum to students’ future lives after secondary school graduation; the place of music education in the curriculum; music in our society; music and the brain; the effect of after-school programs on student engagement; and the pedagogy of arts education. Case study is the qualitative methodology used in this research. Data comes from interviews, field notes, and questionnaires that explore and interrogate the issues surrounding music education. Twelve young participants, from different gender, ethnic, and socio-economic backgrounds, were interviewed about their lived experiences and involvement with string orchestras, and on the ways in which these experiences have affected them as students and as members of society. The analysis of the data reveals connections between the author’s arts experiences in the public school system, and those of the twelve students interviewed. The teacher-student relationship, equity, family influence, and technology are discussed as factors that can strengthen programs for youth, by deepening engagement in school experiences. This study explores why some teachers and students choose to participate or become engaged in extra-curricular activities and examines the impact on educational communities, on the future direction of string education, and on the relationship of the teaching/learning experience.

Keywords: Music
Education
String Education
Engagement
Advisor: Booth, David
Does Conforming Make Us More Liked? Perceptions of Conformist and Non-conformist Behaviour

Although social psychologists have long argued that conformity is motivated by a concern for social approval, very few studies have tested whether conformity actually results in increased approval of the conformist. The present research examined participants’ evaluations of confederates who displayed either conformist or non-conformist behaviour. Studies 1 and 2 used a music task, in which remote confederates either conformed or did not conform to participants’ choices for favourite music clips. Participants evaluated confederates by rating them on a series of both positive and negative descriptors. Relative to non-conformists, conformists were rated more favourably on items that referred to ‘liking’ (e.g., likeableness, willingness to befriend) (Studies 1 & 2), and less favourably on items that referred to “independence” (e.g., independence, originality, strength) (Study 2). Interestingly, although conforming confederates were judged as less independent than were confederates who simply agreed with (rather than conformed to) participants’ choices, conformity did not have a positive effect on liking over and above mere agreement (Study 2). Conformity, rather than being a means of gaining approval, might be better construed as a means of avoiding disapproval. Study 2 further examined evaluations made by observers who were exposed to the same confederate behaviours as were targets; however, no observer-target difference in ratings was found. Study 3 assessed the degree to which participants valued the traits that they ascribed to people who demonstrated either conformist or non-conformist behaviour. Positive traits associated with conformist behaviour (e.g., agreeableness, cooperativeness) were reported as having a more positive effect on participants’ liking of a person than were positive traits associated with non-conformist behaviour (e.g., independence, originality). Furthermore, in determining their liking for a conformist, participants reported placing more importance on the conformist’s possessing the positive traits associated with conforming than on their possessing the negative traits associated with conforming (e.g., dependence, passivity). In spite of their lack of independence, therefore, conformists in Study 2 were liked because participants placed more value on the virtuous aspects of conformity (e.g., agreeableness, cooperativeness). Implications for our culture’s ambivalent attitudes toward both conformity and independence are discussed.

Keywords: Conformity
Non-Conformity
Perceptions
Advisor: Pliner, Patricia
Herman, C. Peter
Novel Manufacturing Processes for Polymer Bead Foams

Polymer bead foams are manufactured through a sintering process using foamed polymer beads. It is worth emphasis that the bead foam technology is the only process that can produce 3-dimensionally shaped foam products with ultra-low densities. This unique feature of bead foam process has been attracting enormous attentions from various foam industries. However the conventional bead foam processes still have some limitations associated with manufacturing productivity and safety during the treatment. This thesis deals with novel approaches to innovative and cost-effective manufacturing processes for polystyrene (PS) and polypropylene (PP) bead foam materials, based on thorough understanding of the scientific issues in bead foam technologies. This study also demonstrates the feasibility of new processes by conducting a series of foaming experiments such as batch foaming and continuous extrusion foaming as well as steam chest molding which is a critical common process for all bead foam products. In addition, this study aimed at developing new bead foam processes based on the relationship between the cellular structure and processing/material parameters. When it comes to expandable PS (EPS) bead process, research efforts have been made to eliminate n-pentane which has some disadvantages related to its flammability and low boiling temperature. In addition, the bi-celullar PS foams that feature the superior thermal-insulation property was manufactured through continuous extrusion foaming process. With regard to expanded PP (EPP) bead process, research efforts were focused on the development of cost-effective continuous foaming process in order to resolve the high cost issue of conventional EPP beads. These research strategies were designed on the basis of the comprehension of thermoplastic foaming, steam chest molding process and gas dissolution/diffusion phenomena. The results in the thesis provided considerable introductory and advanced knowledge about the bead foam technologies so that further promising researches can be performed to invent entirely new bead foam materials such as ultrahigh–temperature-durable bead foam products, biodegradable bead foams, other highly functional bead foam products aside from EPS and EPP bead foams.

Keywords: Polymer
Bead
Foam
Advisor: Naguib, Hani E.
Park, Chul B.
Mesodermal Differentiation of Skin-derived Precursor cells

Neural crest stem cells (NCSCs) are embryonic multipotent cells that give rise to a wide range of cell types that include those forming the peripheral neural cells and the mesodermal cells of the face including the facial bones. In neonatal and adult skin, skin-derived precursor cells (SKPs) are multipotent dermal precursors that share similarities with NCSCs and can differentiate into peripheral neural and mesodermal cells, such as adipocytes. Based on the similarities between SKPs and NCSCs, I asked, in this thesis, whether rodent or human SKPs can differentiate into skeletal mesodermal cell types by determining their ability to differentiate into osteoblasts and chondrocytes. In culture, rodent and human SKPs differentiated into alkaline phosphatase-, osteopontin- and type-I collagen-positive osteoblasts that produced mineral deposits and into type-II collagen expressing chondrocytes. Clonal analysis showed that SKPs are multipotent for the osteogenic and chondrogenic lineages. To ask whether SKPs can generate these cells in vivo, genetically-tagged naïve rat SKPs were transplanted into a tibia bone fracture model. Six weeks post-transplantation, SKP-derived osteoblasts and osteocytes were present in the newly formed bone, showing their osteogenic differentiation in vivo. At three weeks post-transplantation, some of the injected cells differentiated into hypertrophic chondrocytes in the callus and others into perivascular cells in areas just outside the callus. To test whether it is the local environment that dictates the phenotype of transplanted SKPs, GFP-tagged undifferentiated rat SKPs were injected into the hypodermis of the skin, an adipogenic environment. Four weeks post-transplantation, SKPs differentiated into adipocytes, but not in inappropriate cell types. These results further the known differentiation potential of SKPs, show that local environment of a bone fracture or the hypodermis of the skin is sufficient to induce the differentiation of undifferentiated SKPs into appropriate cell types and suggest the use of SKPs as source of mesodermal precursor cells for cell therapy.

Keywords: SKP
osteoblasts
bone
Cartillage
transplantation
perivascular cells
Advisor: Kaplan, David R.