1,292 research outputs found

    Measuring interactions and involvement in a cultural context

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    This paper stems from a prior longitudinal case study in which the authors analyzed the experience of Palazzo Strozzi, an Italian Cultural Institution experimenting an open approach to the process of sense-making that takes place during the visit. Through a significant re-design of the language, Palazzo Strozzi provides visitors with a two-way pattern of communication instead of a more traditional one-way flow of information .Both in cultural and in non-cultural contexts, innovation has taken place upstream and the role of the user can be mainly considered as a receiver. In terms of sense-making process, users hold a personal set of codes, which is used to give sense to the objects. We describe an experiment in which three different types of verbal content are used to describe different exhibits and the time of frontal interaction between people and exhibits is measured, thus highlighting the effect of the supporting content

    Decision Procedure for Entailment of Symbolic Heaps with Arrays

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    This paper gives a decision procedure for the validity of en- tailment of symbolic heaps in separation logic with Presburger arithmetic and arrays. The correctness of the decision procedure is proved under the condition that sizes of arrays in the succedent are not existentially bound. This condition is independent of the condition proposed by the CADE-2017 paper by Brotherston et al, namely, one of them does not imply the other. For improving efficiency of the decision procedure, some techniques are also presented. The main idea of the decision procedure is a novel translation of an entailment of symbolic heaps into a formula in Presburger arithmetic, and to combine it with an external SMT solver. This paper also gives experimental results by an implementation, which shows that the decision procedure works efficiently enough to use

    A formal soundness proof of region-based memory management for object-oriented paradigm.

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    Region-based memory management has been proposed as a viable alternative to garbage collection for real-time applications and embedded software. In our previous work we have developed a region type inference algorithm that provides an automatic compile-time region-based memory management for object-oriented paradigm. In this work we present a formal soundness proof of the region type system that is the target of our region inference. More precisely, we prove that the object-oriented programs accepted by our region type system achieve region-based memory management in a safe way. That means, the regions follow a stack-of-regions discipline and regions deallocation never create dangling references in the store and on the program stack. Our contribution is to provide a simple syntactic proof that is based on induction and follows the standard steps of a type safety proof. In contrast the previous safety proofs provided for other region type systems employ quite elaborate techniques

    Tracheocutaneous fistula in patients undergoing supracricoid partial laryngectomy: the role of chronic aspiration

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    The aim of the present retrospective controlled study was to analyse and compare risk factors for tracheocutaneous fistula in patients who received tracheostomy after supracricoid partial laryngectomy with those who received tracheostomy for other causes. We enrolled 39 patients with tracheocutaneous fistulas who were divided into two groups. The first received temporary tracheostomy for supracricoid partial laryngectomies (n = 21), while the control group consisted of patients who received temporary tracheostomy for other causes (n = 18). Risk factors believed to play a role in the pathogenesis of tracheocutaneous fistula were examined including advanced age, cardiopathy, local infections, radiotherapy, elevated body mass index, malnutrition, decannulation time and aspiration grade. The Leipzig and Pearson scale score was significantly higher in the supracricoid partial laryngectomy group (p = 0.006 and 0.031 for univariate and multivariate analyses, respectively). The penetration/aspiration scale score was significantly higher in the supracricoid partial laryngectomy group as determined by univariate analysis (p = 0.014). The decannulation time was significantly lower in the supracricoid partial laryngectomy group (p = 0.004 and 0.0004 for univariate and multivariate analyses, respectively). The number of surgical closures for tracheocutaneous fistula was significantly higher in the supracricoid partial laryngectomy group by univariate analysis (p = 0.027). These results suggest that chronic aspiration and related cough may be important pathogenic factors for tracheocutaneous fistula and could be responsible for the significantly higher rates of closure failure in patients after supracricoid partial laryngectomy

    Prenex Separation Logic with One Selector Field

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    International audienceWe show that infinite satisfiability can be reduced to finite satisfiabil-ity for all prenex formulas of Separation Logic with k ≥ 1 selector fields (SL k). This fact entails the decidability of the finite and infinite satisfiability problems for the class of prenex formulas of SL 1 , by reduction to the first-order theory of a single unary function symbol and an arbitrary number of unary predicate symbols. We also prove that the complexity of this fragment is not elementary recursive, by reduction from the first-order theory of one unary function symbol. Finally, we prove that the Bernays-Schönfinkel-Ramsey fragment of prenex SL 1 formulas with quantifier prefix in the language ∃ * ∀ * is PSPACE-complete

    What Developers Want and Need from Program Analysis: An Empirical Study

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    Program Analysis has been a rich and fruitful field of research for many decades, and countless high quality program analysis tools have been produced by academia. Though there are some well-known examples of tools that have found their way into routine use by practitioners, a common challenge faced by researchers is knowing how to achieve broad and lasting adoption of their tools. In an effort to understand what makes a program analyzer most attractive to developers, we mounted a multi-method investigation at Microsoft. Through interviews and surveys of developers as well as analysis of defect data, we provide insight and answers to four high level research questions that can help researchers design program analyzers meeting the needs of software developers. First, we explore what barriers hinder the adoption of program analyzers, like poorly expressed warning messages. Second, we shed light on what functionality developers want from analyzers, including the types of code issues that developers care about. Next, we answer what non-functional characteristics an analyzer should have to be widely used, how the analyzer should fit into the development process, and how its results should be reported. Finally, we investigate defects in one of Microsoft's flagship software services, to understand what types of code issues are most important to minimize, potentially through program analysis

    Graph-Based Shape Analysis Beyond Context-Freeness

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    We develop a shape analysis for reasoning about relational properties of data structures. Both the concrete and the abstract domain are represented by hypergraphs. The analysis is parameterized by user-supplied indexed graph grammars to guide concretization and abstraction. This novel extension of context-free graph grammars is powerful enough to model complex data structures such as balanced binary trees with parent pointers, while preserving most desirable properties of context-free graph grammars. One strength of our analysis is that no artifacts apart from grammars are required from the user; it thus offers a high degree of automation. We implemented our analysis and successfully applied it to various programs manipulating AVL trees, (doubly-linked) lists, and combinations of both
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