A System for the Detection of Adversarial Attacks in Computer Vision via Performance Metrics

Adversarial attacks, or attacks committed by an adversary to hijack a system, are prevalent in the deep learning tasks of computer vision and are one of the greatest threats to these models\u27 safe and accurate use. These attacks force the trained model to misclassify an image, using pixel-level changes undetectable to the human eye. Various defenses against these attacks exist and are detailed in this work. The work of previous researchers has established that when adversarial attacks occur, different node patterns in a Deep Neural Network (DNN) are activated within the model. Additionally, it is known that CPU and GPU metrics look different when different computations are occurring. This work builds upon that knowledge to hypothesize that the system performance metrics, in the form of CPUs, GPUs, and throughput, will reflect the presence of adversarial input in a DNN. This experiment found that external measurements of system performance metrics did not reflect the presence of adversarial input. This work establishes the beginning stages of using system performance metrics to detect and defend against adversarial attacks. Using performance metrics to defend against adversarial attacks can increase the model\u27s safety, improving the robustness and trustworthiness of DNNs

Radiation from Small-Scale Magnetic Field Turbulence: Implications for Gamma-Ray Bursts and Laboratory Astrophysical Plasmas

Relativistic charged particles moving within regions of small-scale magnetic field turbulence radiate as they undergo transverse accelerations reflective of the magnetic field variation along the particle's path. For a particle of Lorentz factor (gamma), relativistic beaming concentrates the bulk of the particle's emission within a small angle 1/(gamma) from the particle's forward direction. Synchrotron radiation is produced when large-scale magnetic fields cause the charged particles to gyrate, with the resulting radiation spectrum being primarily determined by the intermittent sweep of the relativistic beaming cone past the direction to the observer. In small-scale magnetic field turbulence, magnetic fields may be locally strong but varies over sufficiently small scales that the particle's emission is more consistently oriented towards a particular direction. Consequently, deflection effects cease to dominate the observed spectrum and the standard synchrotron model no longer applies. In this dissertation, we focus on the strong jitter radiation regime, in which the field varies over sufficiently short scales that the particle is never substantially deviated from a straight line path and an observer in the particle's forward direction receives consistently strong radiation over many correlation lengths of the magnetic field. We develop the general jitter radiation solutions for such a case and demonstrate that the resulting radiation spectrum differs notably from the synchtrotron spectrum and depends directly on the spectral distribution of the magnetic field encountered by the particle. The Weibel-like filamentation instability generates small-scale magnetic field turbulence through current filamentation in counterstreaming particle populations, such as may be found at or near propagating shock fronts, in outflow from regions of magnetic reconnection, or from a variety of other scenarios producing an anisotropic particle velocity distribution. The current filamentation produces an anisotropy in magnetic field distribution that causes the jitter radiation spectrum to be sensitive to the radiating particle's orientation with respect to the filamentation axis. Because the spectrum observed from any given direction will be dominated by emission from particle's moving along that particular line-of-sight, this results in a natural angular dependence of the jitter radiation spectrum. We explore the implications of jitter radiation's spectral sensitivity to the field anisotropy produced by the Weibel-like filamentation instability to relevant astrophysical and laboratory plasma scenarios. We calculate the jitter radiation spectra that may be produced in a high-energy density laboratory plasma by using quasi-monoenergetic electron beams to generate and then probe a region of current filamentation, and show that the jitter radiation may be used as a radiative diagnostic to determine features of the magnetic field distribution within this region. For gamma-ray bursts, this instability may play a significant role in generating magnetic field strength from relativistic collisionless shocks or other particle acceleration mechanisms. We show that the viewing angle dependence of the jitter radiation spectrum can result in a rapidly time-evolving spectrum whose hard-to-soft evolution, synchrotron-violating low-energy spectral indices, and correlation between low-energy spectral hardness and the flux at peak energy may explain trends noticed in time-resolved GRB spectral evolution. We generate the jitter radiation spectra as would be produced in the co-moving frame by a single, instantantaneously-illuminated shock front, which may then be relativistically transformed with appropriate geometry into a time-evolving spectrum and multiple such signals assembled to produce "synthetic" GRB for comparison with observations

Agile Research Team: The Adaption of Scrum to Academic Research

This project proposes the introduction of agile software development methods into an academic research group, which is one of the first times that agility has been introduced in the research sphere. The agile method Scrum, which has been successful both in industry and the classroom, was adapted to fit the constraints and needs of an academic research group. This new group structure has been coined the Agile Research Team. A traditional, hierarchal research group has limitations in growth and performance, as projects and researchers are all limited in a top-down fashion. This limits the idea generation process, the projects that can be worked on, and the number of students that can participate. By removing the hierarchy and introducing agility, we argue that the knowledge and skill transfer of the group improves, the motivation of individuals is increased, and the group becomes more scalable and more inclusive. This project presents the structure of the Agile Research Team created and discusses initial results and lessons learned after the experimental collection of results, showing that there are potential benefits to forming an agile research team

Hair Care Catered to You

People of color face barriers in healthcare every day, and my goal was to address one of these barriers. Healthcare settings stock products that are tailored for Caucasian hair and skin, so I wanted to add products targeted for Black patients\u27 skin and hair. I added shampoo and lotion to the supply closet of Peyton Manning Children\u27s Hospital as well as bonnets and durags for the patients to wrap their hair in to protect it while they sleep or rest. African American hair and skin requires different care. This is something that often goes unnoticed by healthcare professionals, and I wanted to bring it to their attention. In order to support the Black Lives Matter movement, I chose products from black-owned businesses. I felt that the BLM movement was the heart and inspiration for this project, so choosing products from black-owned businesses felt appropriate

Radiative diagnostics for sub-Larmor scale magnetic turbulence

Radiative diagnostics of high-energy density plasmas is addressed in this paper. We propose that the radiation produced by energetic particles in small-scale magnetic field turbulence, which can occur in laser-plasma experiments, collisionless shocks, and during magnetic reconnection, can be used to deduce some properties of the turbulent magnetic field. Particles propagating through such turbulence encounter locally strong magnetic fields, but over lengths much shorter than a particle gyroradius. Consequently, the particle is accelerated but not deviated substantially from a straight line path. We develop the general jitter radiation solutions for this case and show that the resulting radiation is directly dependent upon the spectral distribution of the magnetic field through which the particle propagates. We demonstrate the power of this approach in considering the radiation produced by particles moving through a region in which a (Weibel-like) filamentation instability grows magnetic fields randomly oriented in a plane transverse to counterstreaming particle populations. We calculate the spectrum as would be seen from the original particle population and as could be seen by using a quasi-monoenergetic electron beam to probe the turbulent region at various angles to the filamentation axis.Comment: 17 pages, 4 figures, submitted to Phys. Plasma

The international experience in domestic mergers – Are purely domestic M&A a myth?

Paralleling the rise of cross-border mergers and acquisitions (M&As) over the last decades, the academic study of the international dimensions and challenges of cross-border M&A has increased. This has led to a conceptual distinction between domestic M&As on the one hand, and cross-border M&As on the other hand. Our two ethnographic case studies on domestic mergers enable us to contradict this well-established assumption. We observe domestic mergers to be impacted by cross-border dimensions. These influences bear particular relevance on the merging organizations’ employees’ experience of the merger. In this light, the employee experience is deemed an international vs. domestic one. This leads us to posit that both academics and practitioners engaged with M&As need to bear caution with respect to the established domestic vs. cross-border divide. Our main contribution claims that in a globalized environment, purely domestic M&As are a myth. This finding bears important implications on the practice and theorizing on M&As and international management at large

Chicks with Sticks: Becoming a Business School Guerilla Knitter

We do not report a tale of research success, but one of struggle. With yarn, space, gender, guerrilla resistance, aesthetics, narrations, and, finally, ethical approvals. The title of this editorial refers to female knitting practice and expresses a bottom up, self-ironic and maladjusted approach towards one’s own business school existence. We seek to encourage readers to try out new, arts-based forms of resistance at work, to bring in the aesthetics and the body when all words in the seemingly rational discourse fail