Generating Property-Directed Potential Invariants By Backward Analysis

This paper addresses the issue of lemma generation in a k-induction-based formal analysis of transition systems, in the linear real/integer arithmetic fragment. A backward analysis, powered by quantifier elimination, is used to output preimages of the negation of the proof objective, viewed as unauthorized states, or gray states. Two heuristics are proposed to take advantage of this source of information. First, a thorough exploration of the possible partitionings of the gray state space discovers new relations between state variables, representing potential invariants. Second, an inexact exploration regroups and over-approximates disjoint areas of the gray state space, also to discover new relations between state variables. k-induction is used to isolate the invariants and check if they strengthen the proof objective. These heuristics can be used on the first preimage of the backward exploration, and each time a new one is output, refining the information on the gray states. In our context of critical avionics embedded systems, we show that our approach is able to outperform other academic or commercial tools on examples of interest in our application field. The method is introduced and motivated through two main examples, one of which was provided by Rockwell Collins, in a collaborative formal verification framework.Comment: In Proceedings FTSCS 2012, arXiv:1212.657

Aeneas of Gaza on the Soul

Aeneas of Gaza’s late fifth-century dialogue the Theophrastus investigates philosophical theories about the pre-existence and immortality of the soul in the course of making a Christian case against the Neoplatonic doctrine of the eternity of the world. I explore Aeneas’ knowledge of theories about the soul in the Greek philosophical tradition and his rebuttals of them. Aeneas’ arguments are indebted to earlier philosophers and touch on Origenist ideas most likely arising in local monasteries. His arguments about the pre-existence of the soul thus illumine creative interactions between Christians and philosophers, monks and school-men in late antique Gaza

Genetic algorithm and tabu search approaches to quantization for DCT-based image compression

Today there are several formal and experimental methods for image compression, some of which have grown to be incorporated into the Joint Photographers Experts Group (JPEG) standard. Of course, many compression algorithms are still used only for experimentation mainly due to various performance issues. Lack of speed while compressing or expanding an image, poor compression rate, and poor image quality after expansion are a few of the most popular reasons for skepticism about a particular compression algorithm. This paper discusses current methods used for image compression. It also gives a detailed explanation of the discrete cosine transform (DCT), used by JPEG, and the efforts that have recently been made to optimize related algorithms. Some interesting articles regarding possible compression enhancements will be noted, and in association with these methods a new implementation of a JPEG-like image coding algorithm will be outlined. This new technique involves adapting between one and sixteen quantization tables for a specific image using either a genetic algorithm (GA) or tabu search (TS) approach. First, a few schemes including pixel neighborhood and Kohonen self-organizing map (SOM) algorithms will be examined to find their effectiveness at classifying blocks of edge-detected image data. Next, the GA and TS algorithms will be tested to determine their effectiveness at finding the optimum quantization table(s) for a whole image. A comparison of the techniques utilized will be thoroughly explored

Relationship Between Oral Health and Clinical Osteoporosis Among Hospitalized Patients with and Without Diabetes

Objective: Diabetes mellitus (DM) is associated with poor oral health and osteoporosis (OP). The aim of this study was to assess the relationship between OP, periodontal disease (PD), and other dental and health outcomes in a cohort of hospitalized patients with and without DM. Method: Using a cross-sectional study design, we enrolled consecutive hospitalized patients. We administered a questionnaire to gather demographic information, oral health history, smoking history, and history of OP. We inspected their dentition and reviewed their charts. Data were analyzed using t-tests, chi-square tests, and logistic regression models. Result: Out of 301 patients enrolled, 275 had PD, 102 had DM, and 30 had OP. In univariate analyses, factors associated with OP included older age... (See full abstract in article)

But were they talking about emotions? Affectus, affectio, and the history of emotions

This study investigates how Latinate writers from the classical world to the early modern might have referenced the concept of 'emotion'. It focuses on the polyvalent terms 'affectus' and 'affectio', as these not only appear to have been heavily implicated in premodern discourses about emotional states and dispositions, but are also the cognates of modern terms, such as 'affect' and 'affection', that are undeniably emotions-centred. The study provides a preliminary survey of what the terms 'affectus' and 'affectio' could denote in terms of emotions, considers whether they were synonyms or signified discretely, and explores the expansion of their meaning when used in compounds with terms denoting the mind or body. It uncovers no teleology, but rather the likelihood that usage was modulated according to genre and authority. In conclusion it suggests points of departure for further research that will be able to nuance and complicate this important word history

Beyond the bottom line:redefining the value of design in SME formation

For SMEs to operate in the complex and globalised economic landscape of today engaging with innovation can sustain competitive advantage. Within Design Management, design is being increasingly posited as a strategic resource to facilitate the absorption of new design resources and leverage design knowledge in ways that support SMEs through such economic pressures. Evidencing the relationship between design and economic performance is complex, leading to extensive current research and industry efforts to show how design adds economic value. Despite the value of such efforts, it is important to recognise that innovation means different things to different organizations, especially for start-ups and SMEs. Within the rising tide of design-led innovation, there is a gap being explored in how design can effectively capture and evaluate its contribution within the complex and diverse situations of business development it engages. In seeking to address this gap, this paper presents findings from research undertaken within Design in Action (DiA), an AHRC-funded knowledge exchange hub. Presenting DiA as a single case study, the paper offers methodical reflection on five case example start-up businesses funded by DiA in order to explore the value that design-led innovation approaches offered in their formation

Constraining the dense matter equation-of-state with radio pulsars

Radio pulsars provide some of the most important constraints for our understanding of matter at supranuclear densities. So far, these constraints are mostly given by precision mass measurements of neutron stars (NS). By combining single measurements of the two most massive pulsars, J0348$+$0432 and J0740$+$6620, the resulting lower limit of 1.98 $M_\odot$ (99% confidence) of the maximum NS mass, excludes a large number of equations of state (EOSs). Further EOS constraints, complementary to other methods, are likely to come from the measurement of the moment of inertia (MOI) of binary pulsars in relativistic orbits. The Double Pulsar, PSR J0737$-$3039A/B, is the most promising system for the first measurement of the MOI via pulsar timing. Reviewing this method, based in particular on the first MeerKAT observations of the Double Pulsar, we provide well-founded projections into the future by simulating timing observations with MeerKAT and the SKA. For the first time, we account for the spin-down mass loss in the analysis. Our results suggest that an MOI measurement with 11% accuracy (68% confidence) is possible by 2030. If by 2030 the EOS is sufficiently well known, however, we find that the Double Pulsar will allow for a 7% test of Lense-Thirring precession, or alternatively provide a $\sim3\sigma$-measurement of the next-to-leading order gravitational wave damping in GR. Finally, we demonstrate that potential new discoveries of double NS systems with orbital periods shorter than that of the Double Pulsar promise significant improvements in these measurements and the constraints on NS matter.Comment: 13 pages, 8 figures. Accepted by MNRA

Identification of subgroups with differential treatment effects for longitudinal and multiresponse variables

We describe and evaluate a regression tree algorithm for finding subgroups with differential treatments effects in randomized trials with multivariate outcomes. The data may contain missing values in the outcomes and covariates, and the treatment variable is not limited to two levels. Simulation results show that the regression tree models have unbiased variable selection and the estimates of subgroup treatment effects are approximately unbiased. A bootstrap calibration technique is proposed for constructing confidence intervals for the treatment effects. The method is illustrated with data from a longitudinal study comparing two diabetes drugs and a mammography screening trial comparing two treatments and a control

Some dilemmas for an account of neural representation: A reply to Poldrack

“The physics of representation” (Poldrack 2020) aims to (1) define the word “representation” as used in the neurosciences, (2) argue that such representations as described in neuroscience are related to and usefully illuminated by the representations generated by modern neural networks, and (3) establish that these entities are “representations in good standing”. We suggest that Poldrack succeeds in (1), exposes some tensions between the broad use of the term in neuroscience and the narrower class of entities that he identifies in the end, and between the meaning of “representation” in neuroscience and in psychology in (2), and fails in (3). This results in some hard choices: give up on the broad scope of the term in neuroscience (and thereby potentially opening a gap between psychology and neuroscience) or continue to embrace the broad, psychologically inflected sense of the term, and deny the entities generated by neural nets (and the brain) are representations in the relevant sense

Perspectivas cognitivas da depressão: Critica teórica

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