Workplace Trauma in a Digital Age: The Impact of Video Evidence of Violent Crime on Criminal Justice Professionals

High-quality video and audio recordings of violent crimes, captured using now ubiquitous digital technologies, play an increasingly important role in the administration of justice. However, the effects of exposure to gruesome material presented in this form on criminal justice professionals who analyze, evaluate, and use this potentially traumatic content in the context of their work, are largely unknown. Using long interviews and constructivist grounded theory, this qualitative study sought to explore experiences of exposure to video evidence of violent crime among Canadian criminal justice professionals. Sixteen individuals including police, lawyers, judges, psychiatrists, law clerks, and court reporters volunteered to participate in qualitative long interviews asking about workplace exposures to violent videos. Themes identified address the ubiquity of video evidence of violent crime; proximity to violence through video; being blindsided through lack of preparedness for violent content; repeated exposures through multiple and protracted viewings; insufficient customary methods for self-protection; and the enduring impact of exposure to videoed violence. We determine that criminal justice professionals are increasingly and repeatedly presented with deeply disturbing imagery that was once imperceptible or unknowable and thus previously held at a greater distance. Elements of what is newly visible and audible in video evidence of violent crime create a new emotional proximity to violence that potentially increases the risks of secondary trauma and underscores the need for improved safety measures

A long-term in vitro silicon-based microelectrode-neuron connection

A novel method for long-term recording and simulation applicable to cultured neurons has been developed. Silicon-based microelectrodes have been fabricated using integrated-circuit technology and micromachining. The chronic connection is made by positioning the tip of the `diving-board electrode' into contact with the top of the cell body. The electrode support structure is then glued to the bottom of the culture dish. Two-way electrical connections to Helisoma B19 neurons have been maintained for up to four days. This capability makes it possible to conduct experiments that are not practical using conventional techniques

Technology facilitated re-victimization: How video evidence of sexual violence contributes to mediated cycles of abuse

With the ubiquity of technological devices producing video and audio recordings, violent crimes are increasingly captured digitally and used as evidence in the criminal justice process. This paper presents the results of a qualitative study involving Canadian criminal justice professionals, and asks questions surrounding the treatment of video evidence and the rights of victims captured within such images. We argue that loss of control over personal images and narratives can re-traumatize survivors of sexual violence, creating technologically-facilitated cycles of abuse that are perpetuated each time images are viewed. We find that the justice system has little to no consistent policy or procedure for handling video evidence, or for ameliorating the impact of these digital records on survivors. Subsequently, we assert that the need for a victim-centred evidence-based understanding of mediated evidence has never been greater

Shot Noise in Gravitational-Wave Detectors with Fabry-Perot Arms

Shot-noise-limited sensitivity is calculated for gravitational-wave interferometers with Fabry–Perot arms, similar to those being installed at the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Italian–French Laser Interferometer Collaboration (VIRGO) facility. This calculation includes the effect of nonstationary shot noise that is due to phase modulation of the light. The resulting formula is experimentally verified by a test interferometer with suspended mirrors in the 40-m arms

Random testing of interrupt-driven software

ManuscriptInterrupt-driven embedded software is hard to thoroughly test since it usually contains a very large number of executable paths. Developers can test more of these paths using random interrupt testing-firing random interrupt handlers at random times. Unfortunately, na¨ıve application of random testing to interrupt-driven software does not work: some randomly generated interrupt schedules violate system semantics, causing spurious failures. The contribution of this paper is the design, implementation, and experimental evaluation of RID, a restricted interrupt discipline that hardens embedded software with respect to unexpected interrupts, making it possible to perform random interrupt testing and also protecting it from spurious interrupts after deployment. We evaluate RID by implementing it in TinyOS and then using random interrupt testing to find bugs and also to drive applications toward their worst-case stack depths

Using hierarchical scheduling to support soft real-time applications in general-purpose operating systems

Journal ArticleThe CPU schedulers in general-purpose operating systems are designed to provide fast response time for interactive applications and high throughput for batch applications. The heuristics used to achieve these goals do not lend themselves to scheduling real-time applications, nor do they meet other scheduling requirements such as coordinating scheduling across several processors or machines, or enforcing isolation between applications, users, and administrative domains. Extending the scheduling subsystems of general-purpose operating systems in an ad hoc manner is time consuming and requires considerable expertise as well as source code to the operating system. Furthermore, once extended, the new scheduler may be as inflexible as the original. The thesis of this dissertation is that extending a general-purpose operating system with a general, heterogeneous scheduling hierarchy is feasible and useful. A hierarchy of schedulers generalizes the role of CPU schedulers by allowing them to schedule other schedulers in addition to scheduling threads. A general, heterogeneous scheduling hierarchy is one that allows arbitrary (or nearly arbitrary) scheduling algorithms throughout the hierarchy. In contrast, most of the previous work on hierarchical scheduling has imposed restrictions on the schedulers used in part or all of the hierarchy. This dissertation describes the Hierarchical Loadable Scheduler (HLS) architecture, which permits schedulers to be dynamically composed in the kernel of a general-purpose operating system. The most important characteristics of HLS, and the ones that distinguish it from previous work, are that it has demonstrated that a hierarchy of nearly arbitrary schedulers can be efficiently implemented in a general-purpose operating system, and that the behavior of a hierarchy of soft real-time schedulers can be reasoned about in order to provide guaranteed scheduling behavior to application threads. The flexibility afforded by HLS permits scheduling behavior to be tailored to meet complex requirements without encumbering users who have modest requirements with the performance and administrative costs of a complex scheduler. Contributions of this dissertation include the following. (1) The design, prototype implementation, and performance evaluation of HLS in Windows 2000. (2) A system of guarantees for scheduler composition that permits reasoning about the scheduling behavior of a hierarchy of soft real-time schedulers. Guarantees assure users that application requirements can be met throughout the lifetime of the application, and also provide application developers with a model of CPU allocation to which they can program. (3) The design, implementation, and evaluation of two augmented CPU reservation schedulers, which provide increase scheduling predictability when low-level operating system activity steals time from applications

Vertically integrated analysis and transformation for embedded software

Journal ArticleProgram analyses and transformations that are more aggressive and more domain-specific than those traditionally performed by compilers are one possible route to achieving the rapid creation of reliable and efficient embedded software. We are creating a new framework for Vertically Integrated Program Analysis (VIPA) that makes use of information gathered at multiple levels of abstraction such as high-level models, source code, and assembly language. This paper describes our approach and shows how and why it will help create better embedded software

Poster abstract: TinyOS 2.1 adding threads and memory protection to tinyOS

ManuscriptThe release of TinyOS 2.0 two years ago was motivated by the need for greater platform flexibility, improved robustness and reliability, and a move towards service oriented application development. Since this time, we have seen the community embrace these efforts and add support for additional hardware platforms (TinyNode, Iris, Shimmer, BtNode, IntelMote2), and new application level services (CTP[4], Deluge 2.0[3], FTSP[9], ICEM[5], printf, TYMO, DIP[8], DRIP[7], ...). These enhancements are important in the progression of TinyOS as a whole, and have resulted in several minor releases (i.e. TinyOS 2.0.1, 2.0.2). TinyOS 2.1 is the next stage in the evolution of TinyOS; it takes a step towards addressing the need for easier and more robust application development. TinyOS 2.1 introduces a number of significant enhancements to core TinyOS components and interfaces. The most notable features include a fully preemptable application-level threads library known as TOSThreads, and a runtime memory protection service called Safe TinyOS. The former aims to ease writing event-driven code while preserving the time-sensitive aspect of TinyOS. The latter aims to make applications more robust through memory safety checks