PORGY: Strategy-Driven Interactive Transformation of Graphs

This paper investigates the use of graph rewriting systems as a modelling tool, and advocates the embedding of such systems in an interactive environment. One important application domain is the modelling of biochemical systems, where states are represented by port graphs and the dynamics is driven by rules and strategies. A graph rewriting tool's capability to interactively explore the features of the rewriting system provides useful insights into possible behaviours of the model and its properties. We describe PORGY, a visual and interactive tool we have developed to model complex systems using port graphs and port graph rewrite rules guided by strategies, and to navigate in the derivation history. We demonstrate via examples some functionalities provided by PORGY.Comment: In Proceedings TERMGRAPH 2011, arXiv:1102.226

Graph Rewriting and Strategies for Modeling Biochemical Networks

International Workshop on Natural Computing and Applications - NCA 2007International audienceIn this paper, we present a rewriting framework for modeling molecular complexes, biochemical reaction rules, and generation of biochemical networks based on the representation of molecular complexes as a particular type of multigraphs with ports called molecular graphs. The advantage of this approach is to obtain for free a rewriting calculus which allows defining at the same level transformation rules and strategies for modeling rule selection and application, in order to prototype network generation

Why not one big database? : principles for data ownership

"This paper supercedes an earlier version, WP#2518-93 published in December 1992 under the title "Ownership principles for distributed database design."Includes bibliographical references (p. 36-39).Supported by the MIT Industrial Performance Center. Supported by the Advanced Research Projects Agency. F30602-93-C-0160Marshall Van Alstyne, Erik Brynjolfsson, Stuart E. Madnick

Dagstuhl Reports : Volume 1, Issue 2, February 2011

Online Privacy: Towards Informational Self-Determination on the Internet (Dagstuhl Perspectives Workshop 11061) : Simone Fischer-Hübner, Chris Hoofnagle, Kai Rannenberg, Michael Waidner, Ioannis Krontiris and Michael Marhöfer Self-Repairing Programs (Dagstuhl Seminar 11062) : Mauro Pezzé, Martin C. Rinard, Westley Weimer and Andreas Zeller Theory and Applications of Graph Searching Problems (Dagstuhl Seminar 11071) : Fedor V. Fomin, Pierre Fraigniaud, Stephan Kreutzer and Dimitrios M. Thilikos Combinatorial and Algorithmic Aspects of Sequence Processing (Dagstuhl Seminar 11081) : Maxime Crochemore, Lila Kari, Mehryar Mohri and Dirk Nowotka Packing and Scheduling Algorithms for Information and Communication Services (Dagstuhl Seminar 11091) Klaus Jansen, Claire Mathieu, Hadas Shachnai and Neal E. Youn

Constitutional Avoidance as Interpretation and as Remedy

In a number of recent landmark decisions, the Supreme Court has used the canon of constitutional avoidance to essentially rewrite laws. Formally, the avoidance canon is understood as a method for resolving interpretive ambiguities: if there are two equally plausible readings of a statute, and one of them raises constitutional concerns, judges are instructed to choose the other one. Yet in challenges to the Affordable Care Act, the Voting Rights Act, the Chemical Weapons Convention, and other major statutes, the Supreme Court has used this canon to adopt interpretations that are not plausible. Jurists, scholars, and legal commentators have criticized these decisions, claiming that they amount to unaccountable judicial lawmaking. These criticisms highlight a basic contradiction in contemporary avoidance doctrine. On the one hand, the avoidance canon is described as an interpretive rule of thumb that guides courts in discerning congressional intent. Yet on the other, the Supreme Court commonly uses the avoidance canon to create statutory meanings that conflict with Congress’s intent, and does so in the name of new constitutional rules that Congress did not foresee. This is not “interpretation” in the conventional sense; it is rewriting in the service of constitutional norm enforcement. This Article mounts a new defense of such rewriting-as-interpretation. It does so by reframing the avoidance canon as two different judicial tools: (1) a canon of interpretation, and (2) a constitutional remedy. The latter of these— avoidance as a constitutional remedy—makes sense of courts’ power to effectively rewrite statutes. A court that finds a statute unconstitutional can creatively reinterpret that statute in a way that changes its meaning in order to fix the constitutional violation, just as it can invalidate statutory language, strike down applications, and impose other kinds of remedies that change the statute’s meaning. This idea is not as unusual as it may seem. Many other countries currently treat avoidance as a constitutional remedy. In the United Kingdom and New Zealand, for example, judges cannot invalidate laws, and so creative reinterpretation of statutes is the only judicial mechanism for remedying violations of constitutional rights. And in Canada, constitutional avoidance doctrine has been divided into an interpretive canon and a remedy, exactly as this Article advocates. Further, the Supreme Court of the United States has effectively treated avoidance as a remedy in two major recent decisions— United States v. Booker and National Federation of Independent Business v. Sebelius—though it did not acknowledge that it was doing so. Bifurcating avoidance into a canon and a remedy resolves the contradiction between avoidance as an interpretive tool and avoidance as a means of changing the law. It does so by separating out these two functions. The interpretive avoidance canon can be used to resolve true ambiguities through the presumption that Congress does not intend to pass statutes that conflict with preexisting constitutional rules. The reinterpretation remedy, in turn, can be used to change a statute’s meaning after it has been held unconstitutional, and to do so even where the court is announcing a new constitutional rule

Twenty years of rewriting logic

AbstractRewriting logic is a simple computational logic that can naturally express both concurrent computation and logical deduction with great generality. This paper provides a gentle, intuitive introduction to its main ideas, as well as a survey of the work that many researchers have carried out over the last twenty years in advancing: (i) its foundations; (ii) its semantic framework and logical framework uses; (iii) its language implementations and its formal tools; and (iv) its many applications to automated deduction, software and hardware specification and verification, security, real-time and cyber-physical systems, probabilistic systems, bioinformatics and chemical systems

The Geography of \u3cem\u3eRevlon\u3c/em\u3e-Land

In Revlon, Inc. v. MacAndrews & Forbes Holdings, Inc., the Delaware Supreme Court explained that, when a target board of directors enters Revlon-land, the board’s role changes from that of “defenders of the corporate bastion to auctioneers charged with getting the best price for the stockholders at a sale of the company.” Unfortunately, the Court’s colorful metaphor obfuscated some serious doctrinal problems. What standards of judicial review applied to director conduct outside the borders of Revlon-land? What standard applied to director conduct falling inside Revlon-land’s borders? And when did one enter that mysterious country? By the mid-1990s, the Delaware Supreme Court had worked out a credible set of answers to those questions. The seemingly settled rules made doctrinal sense and were sound from a policy perspective. Indeed, my thesis herein is that Revlon and its progeny should be praised for having grappled—mostly successfully—with the core problem of corporation law: the tension between authority and accountability. A fully specified account of corporate law must incorporate both values. On the one hand, corporate law must implement the value of authority in developing a set of rules and procedures providing efficient decision making. U.S. corporate law does so by adopting a system of director primacy. In the director primacy (a.k.a. board-centric) form of corporate governance, control is vested not in the hands of the firm’s so-called owners—the shareholders—who exercise virtually no control over either day-to-day operations or long-term policy, but in the hands of the board of directors and their subordinate professional managers. On the other hand, the separation of ownership and control in modern public corporations obviously implicates important accountability concerns, which corporate law must also address. Academic critics of Delaware’s jurisprudence typically err because they are preoccupied with accountability at the expense of authority. In contrast, or so I will argue, Delaware’s takeover jurisprudence correctly recognizes that both authority and accountability have value. Achieving the proper mix between these competing values is a daunting—but necessary—task. Ultimately, authority and accountability cannot be reconciled. At some point, greater accountability necessarily makes the decision-making process less efficient. Making corporate law therefore requires a careful balancing of these competing values. Striking such a balance is the peculiar genius of Unocal and its progeny. In recent years, however, the Delaware Chancery Court has gotten lost in Revlon-land. A number of chancery decisions have drifted away from the doctrinal parameters laid down by the Delaware Supreme Court. In this Article, I argue that they have done so because the Chancellors have misidentified the policy basis on which Revlon rests. Accordingly, I argue that chancery should adopt a conflict of interest–based approach to invoking Revlon, which focuses on where control of the resulting corporate entity rests when the transaction is complete

Designing an Information-Experience Using Creativity Science Theory and Tools

An “information-experience” encapsulated by a technological/digital audio-visual tool presents data and potentially meaningful information to prompt actionable knowledge concerning: “unspoken creative process elements;” their profound impacts on both how well our “physiology of creativity” functions; but also on how well foundational creative thinking and behavioral prerequisites (energy, motivation, imagination, and ownership) are leveraged. The product: 1) introduces the user to one component of the CPS (Creative Problem Solving) Facilitation Process - Exploring the Challenge; 2) features a content specific component which prompts exploration of the many correlations between societal, organizational / community, human physiological / behavioral data, and the direct relationships of these to creative/productive capacities and capabilities; while also 3) establishing an overview and resources to delve further into experiences or information concerning the domain of Creativity Science, Innovation, Change Leadership, or wellness/health-driving productivity factors, behaviors, and tools