41,870 research outputs found

    A Study of Concurrency Bugs and Advanced Development Support for Actor-based Programs

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    The actor model is an attractive foundation for developing concurrent applications because actors are isolated concurrent entities that communicate through asynchronous messages and do not share state. Thereby, they avoid concurrency bugs such as data races, but are not immune to concurrency bugs in general. This study taxonomizes concurrency bugs in actor-based programs reported in literature. Furthermore, it analyzes the bugs to identify the patterns causing them as well as their observable behavior. Based on this taxonomy, we further analyze the literature and find that current approaches to static analysis and testing focus on communication deadlocks and message protocol violations. However, they do not provide solutions to identify livelocks and behavioral deadlocks. The insights obtained in this study can be used to improve debugging support for actor-based programs with new debugging techniques to identify the root cause of complex concurrency bugs.Comment: - Submitted for review - Removed section 6 "Research Roadmap for Debuggers", its content was summarized in the Future Work section - Added references for section 1, section 3, section 4.3 and section 5.1 - Updated citation

    Rule-based relaxation of reference identification failures

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    The inheritance of dynamic and deontic integrity constraints or: Does the boss have more rights?

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    In [18,23], we presented a language for the specification of static, dynamic and deontic integrity constraints (IC's) for conceptual models (CM's). An important problem not discussed in that paper is how IC's are inherited in a taxonomic network of types. For example, if students are permitted to perform certain actions under certain preconditions, must we repeat these preconditions when specializing this action for the subtype of graduate students, or are they inherited, and if so, how? For static constraints, this problem is relatively trivial, but for dynamic and deontic constraints, it will turn out that it contains numerous pitfalls, caused by the fact that common sense supplies presuppositions about the structure of IC inheritance that are not warranted by logic. In this paper, we unravel some of these presuppositions and show how to avoid the pitfalls. We first formulate a number of general theorems about the inheritance of necessary and/or sufficient conditions and show that for upward inheritance, a closure assumption is needed. We apply this to dynamic and deontic IC's, where conditions arepreconditions of actions, and show that our common sense is sometimes mistaken about the logical implications of what we have specified. We also show the connection of necessary and sufficient preconditions of actions with the specification of weakest preconditions in programming logic. Finally, we argue that information analysts usually assume constraint completion in the specification of (pre)conditions analogous to predicate completion in Prolog and circumscription in non-monotonic logic. The results are illustrated with numerous examples and compared with other approaches in the literature

    A new taxonomy for distributed computer systems based upon operating system structure

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    Characteristics of the resource structure found in the operating system are considered as a mechanism for classifying distributed computer systems. Since the operating system resources, themselves, are too diversified to provide a consistent classification, the structure upon which resources are built and shared are examined. The location and control character of this indivisibility provides the taxonomy for separating uniprocessors, computer networks, network computers (fully distributed processing systems or decentralized computers) and algorithm and/or data control multiprocessors. The taxonomy is important because it divides machines into a classification that is relevant or important to the client and not the hardware architect. It also defines the character of the kernel O/S structure needed for future computer systems. What constitutes an operating system for a fully distributed processor is discussed in detail

    A Taxonomy of Views about Time in Buddhist and Western Philosophy

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    We find the claim that time is not real in both western and eastern philosophical traditions. In what follows I will call the view that time does not exist temporal error theory. Temporal error theory was made famous in western analytic philosophy in the early 1900s by John McTaggart (1908) and, in much the same tradition, temporal error theory was subsequently defended by GĂśdel (1949). The idea that time is not real, however, stretches back much further than that. It is common to hear it said that according to Buddhist philosophy (as though that were a monolithic view) time is illusory. While it is not true that, in general, either contemporary or ancient Buddhist scholars have thought time to be illusory, there are certainly some schools of Buddhist thought, such as that of traditional Dzogchen practitioners, according to which there is no time. This paper is an attempt to set out a taxonomy of different views about what it takes for there to be time and, alongside that, a taxonomy of views about whether there is time or not, and if there is time what it is like

    The Topology of Conflict and Co-operation

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    The class of simultaneous 2x2 pure-strategy ordinal games (which include well-known games such as Prisoner’s Dilemma, Chicken and Stag Hunt) have received considerable attention, including complete classification schemes by amongst others Rapoport & Guyer (1978) and Robinson & Goforth (2005). This paper focuses on a particularly pertinent subset of these games, described as the ‘Co-operate-Defect’ (C-D) games, which are characterised by each player having a dominant preference for a particular strategy by the other player. These games are therefore relevant in a number of contexts, including arms race games and collective action problems. The C-D games may be efficiently classified by assigning each player one of six distinct types, a classification that cannot be naturally extended to the full class of 2x2 games. The six types and the resulting game forms are analysed, and the subclass of CD games are identified within a topological structure for the 2x2 games devised by Robinson & Goforth (2005).Conflict; co-operation; game theory; co-operate-defect games

    Public initiatives of settlement transformation. A theoretical-methodological approach to selecting tools of multi-criteria decision analysis

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    In Europe, the operating context in which initiatives of settlement transformation are currently initiated is characterized by a complex, elaborate combination of technical, regulatory and governance-related factors. A similar set of considerations makes it necessary to address the complex decision-making problems to be resolved through multidisciplinary, comparative approaches designed to rationalize the process and treat the elements to be considered in systematic fashion with respect to the range of alternatives available as solutions. Within a context defined in this manner, decision-making processes must often be used to obtain multidisciplinary and multidimensional analyses to support the choices made by the decision-makers. Such analyses are carried out using multi-criteria tools designed to arrive at syntheses of the numerous forms of input data needed to describe decision-making problems of similar complexity, so that one or more outcomes of the synthesis make possible informed, well thought-out, strategic decisions. The technical literature on the topic proposes numerous tools of multi-criteria analysis for application in different decision-making contexts. Still, no specific contributions have been drawn up to date on the approach to take in selecting the tool best suited to providing adequate responses to the queries of evaluation that arise most frequently in the various fields of application, and especially in the settlement sector. The objective of this paper is to propose, by formulating a taxonomy of the endogenous and exogenous variables of tools of multi-criteria analysis, a methodology capable of selecting the tool best suited to the queries of evaluation which arise regarding the chief categories of decision-making problems, and particularly in the settlement sector

    Problems of Religious Luck: Assessing the Limits of Reasonable Religious Disagreement

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    To speak of being religious lucky certainly sounds odd. But then, so does “My faith holds value in God’s plan, while yours does not.” This book argues that these two concerns — with the concept of religious luck and with asymmetric or sharply differential ascriptions of religious value — are inextricably connected. It argues that religious luck attributions can profitably be studied from a number of directions, not just theological, but also social scientific and philosophical. There is a strong tendency among adherents of different faith traditions to invoke asymmetric explanations of the religious value or salvific status of the home religion vis-à-vis all others. Attributions of good/bad religious luck and exclusivist dismissal of the significance of religious disagreement are the central phenomena that the book studies. Part I lays out a taxonomy of kinds of religious luck, a taxonomy that draws upon but extends work on moral and epistemic luck. It asks: What is going on when persons, theologies, or purported revelations ascribe various kinds of religiously-relevant traits to insiders and outsiders of a faith tradition in sharply asymmetric fashion? “I am saved but you are lost”; “My religion is holy but yours is idolatrous”; “My faith tradition is true, and valued by God, but yours is false and valueless.” Part II further develops the theory introduced in Part I, pushing forward both the descriptive/explanatory and normative sides of what the author terms his inductive risk account. Firstly, the concept of inductive risk is shown to contribute to the needed field of comparative fundamentalism by suggesting new psychological markers of fundamentalist orientation. The second side of what is termed an inductive risk account is concerned with the epistemology of religious belief, but more especially with an account of the limits of reasonable religious disagreement. Problems of inductively risky modes of belief-formation problematize claims to religion-specific knowledge. But the inductive risk account does not aim to set religion apart, or to challenge the reasonableness of religious belief tout court. Rather the burden of the argument is to challenge the reasonableness of attitudes of religious exclusivism, and to demotivate the “polemical apologetics” that exclusivists practice and hope to normalize. Lexington Books Pages: 290 978-1-4985-5017-8 • Hardback • December 2018 • 95.00•(£65.00)978−1−4985−5018−5•eBook•December2018•95.00 • (£65.00) 978-1-4985-5018-5 • eBook • December 2018 • 90.00 • (£60.00) ISBN 978-1-4985-5018-5 (pbk: alk. paper) (coming 2020) [Download the 30% personal use Discount Order Form I uploaded for hardcover or e-book, and please ask your library to purchase a copy for their collection.

    SERVICE-PROCESS CONFIGURATIONS IN ELECTRONIC RETAILING: A TAXONOMIC ANALYSIS OF ELECTRONIC FOOD RETAILERS

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    Service-processes of electronic retailers are founded on electronic technologies that provide flexibility to sense and respond online to the dynamic and complex needs of customers. In this paper, we develop a taxonomy of service-processes in electronic retailing and demonstrate their linkage to customer satisfaction and customer loyalty. The taxonomy is grounded in a conceptual classification scheme that differentiates service-process stages on a continuum of flexibility. Using data on electronic service-processes collected from 255 electronic food retailers, we identified eight configurations for the taxonomy. We also collected and analyzed publicly reported customer satisfaction survey data that were available for 52 electronic food retailers in the study sample. The results of this analysis indicate positive and significant correlation of the ordering of the taxonomy configurations with (i) customer satisfaction with product information, product selection, web site aesthetics, web site navigation, customer support, and ease of return, and (ii) customer loyalty. Taken together, the results of our empirical analyses demonstrate that the taxonomy captures information and variety within and across the electronic service-process configurations in ways that can be related to customer satisfaction and customer loyalty.Marketing, Research and Development/Tech Change/Emerging Technologies,
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