Safety Verification of Fault Tolerant Goal-based Control Programs with Estimation Uncertainty

Fault tolerance and safety verification of control systems that have state variable estimation uncertainty are essential for the success of autonomous robotic systems. A software control architecture called mission data system, developed at the Jet Propulsion Laboratory, uses goal networks as the control program for autonomous systems. Certain types of goal networks can be converted into linear hybrid systems and verified for safety using existing symbolic model checking software. A process for calculating the probability of failure of certain classes of verifiable goal networks due to state estimation uncertainty is presented. A verifiable example task is presented and the failure probability of the control program based on estimation uncertainty is found

Safety verification of a fault tolerant reconfigurable autonomous goal-based robotic control system

Fault tolerance and safety verification of control systems are essential for the success of autonomous robotic systems. A control architecture called Mission Data System (MDS), developed at the Jet Propulsion Laboratory, takes a goal-based control approach. In this paper, a method for converting goal network control programs into linear hybrid systems is developed. The linear hybrid system can then be verified for safety in the presence of failures using existing symbolic model checkers. An example task is simulated in MDS and successfully verified using HyTech, a symbolic model checking software for linear hybrid systems

Differential regulation of innate and adaptive immune responses in viral encephalitis.

Viral encephalitis is a global health concern. The ability of a virus to modulate the immune response can have a pivotal effect on the course of disease and the fate of the infected host. In this study, we sought to understand the immunological basis for the fatal encephalitis following infection with the murine coronavirus, mouse hepatitis virus (MHV)-JHM, in contrast with the more attenuated MHV-A59. Distinct glial cell cytokine and chemokine response patterns were observed within 3 days after infection, became progressively more polarized during the course of infection and with the infiltration of leukocytes. In the brain, MHV-JHM infection induced strong accumulation of IFNbeta mRNA relative to IFNgamma mRNA. This trend was reversed in MHV-A59 infection and was accompanied by increased CD8 T cell infiltration into brain compared to MHV-JHM infection. Increased apoptosis appeared to contribute to the diminished presence of CD8 T cells in MHV-JHM-infected brain with the consequence of a lower potential for IFNgamma production and antiviral activity. MHV-JHM infection also induced sustained mRNA accumulation of the innate immune response products interleukin (IL)-6 and IL-1. Furthermore, high levels of macrophage-inflammatory protein (MIP)-1alpha, MIP-1beta, and MIP-2 mRNA were observed at the onset of MHV-JHM infection and correlated with a marked elevation in the number of macrophages in the brain on day 7 compared to MHV-A59 infection. These observations indicate that differences in the severity of viral encephalitis may reflect the differential ability of viruses to stimulate innate immune responses within the CNS and subsequently the character of infiltrating leukocyte populations

The Conferences

This article surveys the breadth of conferences and scholarly events devoted to comics across the globe. We will use our contacts worldwide to be as inclusive as possible in our coverage of these events. The first half of the piece will give a historical introduction to the emergence of scholarly comics-related events, and changing attitudes towards them, and proceed to an inclusive survey that offers brief summaries of the size, scope and focus of each event, organised by country. There will be a focus on place of scholarship within the fan driven early events and the move towards the professionalisation of many of events, and the rise of a convention industry, and the place of scholarship within events that blend aspects of a convention and a conference. The second half of the article is comprised of a series of case studies of contemporary events, in which we focus on some key examples to reflect on the variance and implications of their different aims and approaches. We will draw on interviews with organisers and participants to consider: the place and impact of comics strands in larger international academic conferences (e.g. the PCA); large-scale events (e.g. Angouleme; San Diego Comic-Con); 'aca-fan' events (e.g. the Comic Arts Conference; Leeds Thought Bubble); and creator-organised events (e.g. the Lake Festival; Kapow Comic-Con). The article will conclude with reflections on the current position of comics events and their impact in shaping and sustaining the discipline's scholarly community and its field of study, for example regarding participants' identities, locations, research and so fort

Regulating AI and machine learning: setting the regulatory agenda

Disruptive technologies arrive with regularity. Whether it is the first industrial revolution with steam powered factories and transportation, or subsequent revolutions which brought about chemical engineering, communications revolutions, aviation and eventually biotechnology and digitisation. We stand at the edge of the next revolution the AI revolution where methods of artificial intelligence and machine learning offer possibilities hitherto unimagined. How this revolution develops and how our society absorbs the potential of this new technology will be largely determined by the models of regulation and governance applied to the nascent technology. In this paper the authors examine lessons from history and propose a framework for identifying and analysing the key elements of regulatory regimes and their interactions which can form the basis for developing a new model for for AI regulatory systems. Furthermore, it argues that the goals of such systems should be to manage the risks different models and uses of AI pose, not just the ethical issues they create

The state of primate enrichment in Australasian zoos

Eleven Australasian zoos housing primates were included in a large international ‘captive mammal enrichment survey’. Individuals who directly work with, research and manage captive mammals were invited to participate in the survey which was comprised of three sections. The first section was designed to identify current enrichment practices and the factors that limit the quality and quantity of enrichment provided to captive mammals. The aim of the second section was to ascertain current methods used in the evaluation of enrichment and establish the factors that limit the frequency and quality of this evaluation. A third section was incorporated in the survey to determine respondents’ interest in potential applications of an automated enrichment system which is currently being designed to reduce many of the current limitations involved with implementing and evaluating enrichment. As expected, animals from the Primate order were most often provided with enrichment. However, the survey identified that lack of available staff time was the greatest factor limiting both the provision and evaluation of enrichment. Accordingly, the majority of survey respondents agreed that more enrichment would be provided if this was manageable. Overall, there was a very high level of interest from Australasian respondents in the applications of an automated enrichment system as a tool to provide and evaluate a greater quantity, variety and frequency of enrichment for captive mammals without requiring additional staff time

Narrow-line Laser Cooling by Adiabatic Transfer

We propose and demonstrate a novel laser cooling mechanism applicable to particles with narrow-linewidth optical transitions. By sweeping the frequency of counter-propagating laser beams in a sawtooth manner, we cause adiabatic transfer back and forth between the ground state and a long-lived optically excited state. The time-ordering of these adiabatic transfers is determined by Doppler shifts, which ensures that the associated photon recoils are in the opposite direction to the particle's motion. This ultimately leads to a robust cooling mechanism capable of exerting large forces via a weak transition and with reduced reliance on spontaneous emission. We present a simple intuitive model for the resulting frictional force, and directly demonstrate its efficacy for increasing the total phase-space density of an atomic ensemble. We rely on both simulation and experimental studies using the 7.5~kHz linewidth $^1$S$_0$ to $^3$P$_1$ transition in $^{88}$Sr. The reduced reliance on spontaneous emission may allow this adiabatic sweep method to be a useful tool for cooling particles that lack closed cycling transitions, such as molecules.Comment: 5 pages, 4 figure

Post-cancer treatment support program : an evaluation

Funding: This work was supported by the University of Aberdeen via research funds provided to CM and LB as part of their postgraduate studies. Acknowledgements: We thank Bethany Mills who collected study data and the staff and service users at Maggie’s who participated in this study.Peer reviewedPostprin

Strategic Opportunities in Rental Companies and Ridesharing

Given the future of mobility, the increase in online shopping, and the ease of ridesharing, companies need to adapt their network to one that uniquely utilizes their resources to cater to these dramatic changes. The task in this case was to re-image Goodyear’s dealer network and find possible ways to use their excess space to help establish themselves in the future of mobility. The team conducted secondary research on three main topics: retail versus online shopping, Goodyear’s services compared to services needed by Uber and Lyft drivers, and information regarding the current and future status of ridesharing