Forward Analysis and Model Checking for Trace Bounded WSTS

We investigate a subclass of well-structured transition systems (WSTS), the bounded---in the sense of Ginsburg and Spanier (Trans. AMS 1964)---complete deterministic ones, which we claim provide an adequate basis for the study of forward analyses as developed by Finkel and Goubault-Larrecq (Logic. Meth. Comput. Sci. 2012). Indeed, we prove that, unlike other conditions considered previously for the termination of forward analysis, boundedness is decidable. Boundedness turns out to be a valuable restriction for WSTS verification, as we show that it further allows to decide all $\omega$-regular properties on the set of infinite traces of the system

Journalistic interventions: The structural factors affecting the global emergence of fact-checking

Since the emergence of FactCheck.org in the United States in 2003, fact-checking interventions have expanded both domestically and globally. The Duke Reporter’s Lab identified nearly 100 active initiatives around the world in 2016. Building off of previous exploratory work by Amazeen, this research utilizes the framework of critical juncture theory to examine why fact-checking interventions are spreading globally at this point in time. Seen as a professional reform movement in the journalistic community, historical research on reform movements suggests several possible factors influencing the emergence of fact-checking such as a decline in journalism, easy access to technology for the masses, and socio-political strife. This study offers empirical support that fact-checking may be understood as a democracy-building tool that emerges where democratic institutions are perceived to be weak or are under threat and examines similarities between the growth of fact-checking interventions and previous consumer reform movements. As politics increasingly adopts strategies orchestrated by marketing and advertising consultants and agencies – exemplified in the Brexit referendum – political fact-checking may benefit from examining the path of consumer reform movements. For, before fact-checking can be effective at informing individuals, it must first establish itself within a structural environment

Practitioner perceptions: critical junctures and the global emergence and challenges of fact-checking

Since 2003 and the emergence of FactCheck.org in the United States, fact-checking has expanded both domestically and internationally. As of February, 2016, the Duke Reporter’s Lab identified nearly 100 active initiatives around the world. This research explores why fact-checking is spreading globally at this point in time. Seen as a professional reform movement in the journalistic community (Graves, 2016), historical research on reform movements suggest several possible factors influencing the emergence of fact-checking including a decline in journalism, easy access to technology for the masses, and socio-political strife (McChesney, 2007; Pickard, 2015; Stole, 2006). Using a phenomenological approach, two focus groups were conducted among fact-checkers during the 2015 Global Fact-checking Summit in London, England. Participants shared rich experiences about conditions and contexts surrounding the emergence and challenges facing their organizations. Ultimately, as the purpose of this research is to help future fact-checkers around the world become aware of the circumstances under which fact-checking is most likely to emerge and thrive (or fail), recommendations from current global practitioners are offered.Accepted manuscrip

GSTE is partitioned model checking

Verifying whether an ω-regular property is satisfied by a finite-state system is a core problem in model checking. Standard techniques build an automaton with the complementary language, compute its product with the system, and then check for emptiness. Generalized symbolic trajectory evaluation (GSTE) has been recently proposed as an alternative approach, extending the computationally efficient symbolic trajectory evaluation (STE) to general ω-regular properties. In this paper, we show that the GSTE algorithms are essentially a partitioned version of standard symbolic model-checking (SMC) algorithms, where the partitioning is driven by the property under verification. We export this technique of property-driven partitioning to SMC and show that it typically does speed up SMC algorithm

Improving Saturation-based Bounded Model Checking

Formal verification is becoming a fundamental step in assuring the correctness of safety-critical systems. Since these systems are often asynchronous and even distributed, their verification requires methods that can deal with huge or even infinite state spaces. Model checking is one of the current techniques to analyse the behaviour of systems, as part of the verification process. In this paper a symbolic bounded model checking algorithm is presented that relies on efficient saturation-based methods. The previous approaches are extended with new bounded state space exploration strategies. In addition, constrained saturation is also introduced to improve the efficiency of bounded model checking. Our measurements confirm that these approaches do not only offer a solution to deal with infinite state spaces, but in many cases they even outperform the original methods

The Changing Narratives of Death, Dying, and HIV in the United Kingdom

Death and infection were closely linked from the start of the HIV epidemic, until successful treatments became available. The initial impact of mostly young, gay men dying from HIV was powerful in shaping UK responses. Neoliberal discourses developed at the same time, particularly focusing on how citizens (rather than the state) should take responsibility to improve health. Subsequently “successful ageing” became an allied discourse, further marginalising death discussions. Our study reflected on a broad range of meanings around death within the historical UK epidemic, to examine how dying narratives shape contemporary HIV experiences. Fifty-one participants including people living with HIV, professionals, and activists were recruited for semistructured interviews. Assuming a symbolic interactionist framework, analysis highlighted how HIV deaths were initially experienced as not only traumatic but also energizing, leading to creativity. With effective antiretrovirals, dying changed shape (e.g., loss of death literacy), and better integration of palliative care was recommended

Presenting a retro appearance through sewing for oneself: Motivations and methods

Retro sewers, defined for the purposes of this study as women who sew vintage-inspired or vintage-reproduction clothing for themselves for everyday use, are a group that has not previously been studied. Retro sewers represent a unique subset of the home sewing market that overlaps with the vintage clothing market. The purpose of this study was to understand the motivations and the methods for retro sewers and how their motivations and methods intersect. This study utilized a qualitative, grounded-theory approach with interviews as the primary data source. Eighteen retro sewers from English-speaking countries were recruited from the researcher’s personal network, Facebook groups dedicated to retro sewing, and snowball sampling. The participants were purposively sampled to ensure maximum possible diversity in age, race/ethnicity, geographic location, decades preferred, and types of sewing patterns used; these sewers participated in in-depth, semi-structured interviews. Participants were asked questions about why they value a vintage appearance and why they use sewing for themselves to create their desired vintage appearance, how they use sewing for themselves to create their desired vintage appearance, and how their motivations and methods intersect. Questions were also asked about their views on feminism and how those views impact their retro sewing. The core theme emerging from the analysis of the interview data was that retro sewing is an expression of identity. The expression of identity through retro sewing is a postmodern fashion phenomenon, motivated primarily by nostalgia combined with a desire for uniqueness and mediated by symbolic interactionism. Retro sewing provides identity continuity through connection with family, one’s personal past, and a collective past; the aesthetics of historic clothing are a major reason that clothing, specifically, is chosen as an avenue for the expression of nostalgic identity. This study provides information about this segment of the home sewing industry, which can be used by sewing pattern companies, fabric producers, retro clothing companies, and purveyors of nostalgic goods to produce products that will appeal to retro sewers. This study also provides a new context for the application of several theories, including nostalgia, symbolic interactionism, and expression of identity through clothing