Molecular Gas Around Young Stellar Clusters

We have begun a survey of the molecular gas surrounding 31 young clusters in order to investigate the link between environment and the resulting cluster. We present here a preliminary comparison of two clusters in our sample: GGD12-15 and Mon R2. Since both clusters are located in the MonR2 molecular cloud at a distance of 830 pc, observational biases due to differing sensitivities and angular resolutions are avoided.Comment: 2 pages, 2 figures, uses newpasp.sty. To appear in "Hot Star Workshop III: The Earliest Phases of Massive Star Birth" (ed. P.A. Crowther

A Verified Packrat Parser Interpreter for Parsing Expression Grammars

Parsing expression grammars (PEGs) offer a natural opportunity for building verified parser interpreters based on higher-order parsing combinators. PEGs are expressive, unambiguous, and efficient to parse in a top-down recursive descent style. We use the rich type system of the PVS specification language and verification system to formalize the metatheory of PEGs and define a reference implementation of a recursive parser interpreter for PEGs. In order to ensure termination of parsing, we define a notion of a well-formed grammar. Rather than relying on an inductive definition of parsing, we use abstract syntax trees that represent the computational trace of the parser to provide an effective proof certificate for correct parsing and ensure that parsing properties including soundness and completeness are maintained. The correctness properties are embedded in the types of the operations so that the proofs can be easily constructed from local proof obligations. Building on the reference parser interpreter, we define a packrat parser interpreter as well as an extension that is capable of semantic interpretation. Both these parser interpreters are proved equivalent to the reference one. All of the parsers are executable. The proofs are formalized in mathematical terms so that similar parser interpreters can be defined in any specification language with a type system similar to PVS.Comment: 15 pages, 15 figures, Certified Proofs and Program

Strokes of serendipity: community co-curation and engagement with digital heritage

This article explores the potential that community–led digital engagement with heritage holds for stimulating active citizenship through taking responsibility for shared cultural heritage and for fostering long-lasting relationships between local community heritage groups and national museums. Through the lens of a pilot project titled Science Museum: Community-in- Residence, we discovered that — despite working with community groups that were already loyal to and enjoyed existing working ties with the Science Museum in London, U.K — this undertaking proved challenging owing to a range of structural and logistical issues even before the application of digital devices and tools had been considered. These challenges notwithstanding, the pilot found that the creation of time and space for face-to-face dialogue and interactions between the Science Museum and the participating community heritage groups helped to establish the parameters within which digital co-curation can effectively occur. This, in turn, informed the development of a digital prototype with huge potential to enable remote, virtual connectivity to, and interactivity with, conversations about shared heritage. The ultimate goal was two-fold: (a) to help facilitate collaborative sense-making of our shared past, and (b) to aid the building of sustainable institutional and community/public working ties around emerging affinities, agendas and research questions in relation to public history and heritage

The 1st Verified Software Competition, Extended Experience Report

We, the organizers and participants, report our experiences from the 1st Veried Software Competition, held in August 2010 in Edinburgh at the VSTTE 2010 conferenc

The 1st Verified Software Competition, Extended Experience Report

We, the organizers and participants, report our experiences from the 1st Veried Software Competition, held in August 2010 in Edinburgh at the VSTTE 2010 conferenc

The Great Lakes Charter: Principles for the Management of Great Lakes Water Resources

The water resources of the Great Lakes Basin are precious public natural resources, shared and held in trust by the Great Lakes States and Provinces. The Great Lakes are valuable regional, national and international resources for which the federal governments of the United States and Canada and the International Joint Commission have, in partnership with the States and Provinces, and important, continuing an abiding role and responsibility. The waters of the Great Lakes Basin are interconnected and part of a single hydrologic system. The multiple uses of these resources for municipal, industrial and agricultural water supply; mining; navigation; hydroelectric power and energy production; recreation; and the maintenance of fish and wildlife habitat and a balanced ecosystem are interdependent. Studies conducted by the International Joint Commission, the Great Lakes States and Provinces, and other agencies have found that without careful and prudent management, the future development of diversions and consumptive uses of the water resources of the Great Lakes Basin may have significant adverse impacts on the environment, economy, and welfare of the Great Lakes region. As trustees of the Basin\u27s natural resources, the Great Lakes States and Provinces have a shared duty to protect, conserve, and manage the renewable but finite waters of the Great Lakes Basin for the use, benefit, and enjoyment of all their citizens, including generations yet to come. The most effective means of protecting, conserving, and managing the water resources of the Great Lakes is through the joint pursuit of unified and cooperative principles, policies and programs mutually agreed upon, enacted and adhered to by each and every Great Lakes State and Province. Management of the water resources of the Basin is subject to the jurisdiction, rights and responsibilities of the signatory States and Provinces. Effective management of the water resources of the Great Lakes requires the exercise of such jurisdiction, rights, and responsibilities in the interest of all the people of the Great Lakes Region, acting in a continuing spirit of comity and mutual cooperation. The Great Lakes States and Provinces reaffirm the mutual rights and obligations of all Basin jurisdictions to use, conserve, and protect Basin water resources, as expressed in the Boundary Waters Treaty of 1909, the Great Lakes Water Quality Agreement of 1978, and the principles of other applicable international agreements. Les ressources en eau du bassin des Grands Lacs constituent des ressources naturelles publiques de grande valeur partagées et tenues en fiducie par les États et provinces du bassin des Grands Lacs. Les Grands Lacs constituent de précieuses ressources régionales, nationales et internationales à l\u27égard desquelles les gouvernements fédéraux respectifs des États-Unis et du Canada et la Commission mixte internationale assument, de façon constante et en association avec les États et les provinces, un rôle et une responsabilité essentiels et constants. Les eaux du bassin des Grands Lacs sont reliées entre elles et font partie d\u27un même système hydrologique. Les multiples utilisations auxquelles se prêtent ces ressources sont interdépendantes et comprennent: l\u27alimentation en eau à des fins municipales, industrielles et agricoles; l\u27exploitation minière; la navigation; la production hydro-électrique et énergétique; les loisirs et le maintien de l\u27habitat du poisson et de la faune et de l\u27équilibre de l\u27écosystème. Des études menées par la Commission mixte internationale, par les États et les provinces du bassin des Grands Lacs et par d\u27autres organismes ont montré qu\u27à défaut d\u27une gestion sage et prévoyante, une éventuelle augmentation des dérivations et consommations des eaux du bassin des Grands Lacs pourrait avoir des effets défavorables appréciables sur l\u27environnement, l\u27économie et la prospérité de la région des Grands Lacs. À titre de fiduciaires des ressources naturelles du Bassin, les États et les provinces du bassin des Grands Lacs partagent collectivement le devoir de protéger, conserver et gérer les ressources renouvelables mais limitées que sont les eaux du bassin des Grands Lacs, pour l\u27usage, le bénéfice et la jouissance de tous leurs citoyens, y compris les générations à venir. Pour s\u27acquitter de ce devoir, le moyen le plus efficace consiste à élaborer collectivement des principes, des politiques et des programmes unifiés et coopératifs qui auront tous été convenus et adoptés et auront reçu l\u27adhésion de tous et chacun des États et provinces du bassin des Grands Lacs. La gestion des ressources en eau du Bassin est soumise à la juridiction, aux droits et aux responsabilités des États et provinces signataires. Une gestion efficace des ressources en eau des Grands Lacs requiert, dans l\u27intérêt des populations de la région des Grands Lacs, que cette juridiction, ces droits et ces responsabilités s\u27exercent dans un esprit constant de bonne entente et de coopération mutuelle. Les États et provinces du bassin des Grands Lacs réaffirment les droits et obligations réciproques de tous les gouvernements du Bassin d\u27utiliser, de conserver et de protéger les ressources en eau du Bassin, tel qu\u27il est énoncé dans le Traité des eaux limitrophes internationales de 1909, dans l\u27Accord relatif à la qualité de l\u27eau dans les Grands Lacs de 1978 et dans les principes de tous les autres accords internationaux pertinents

Never Any Doubt: A Resilient America

This article appeared in Homeland Security Affairs (September 2011), v.7 no.2"Former DHS Secretary Tom Ridge reminds us of the dangers of complacency and that 'ten years is enough time to know that in the next ten years, the fight will still be with us.' He also reminds us that as new threats surface our tools, policies and security strategies must continue to evolve. 'Because after taking fifty years to win the Cold War, while we emerged as the lone superpower, we were also left with a stockpile of weapons, tactics, and diplomatic relationships that were of little utility in the new security environment.'"Approved for public release; distribution is unlimited

Lem: reusable engineering of real-world semantics

Recent years have seen remarkable successes in rigorous engineering: using mathematically rigorous semantic models (not just idealised calculi) of real-world processors, programming languages, protocols, and security mechanisms, for testing, proof, analysis, and design. Building these models is challenging, requiring experimentation, dialogue with vendors or standards bodies, and validation; their scale adds engineering issues akin to those of programming to the task of writing clear and usable mathematics. But language and tool support for specification is lacking. Proof assistants can be used but bring their own difficulties, and a model produced in one, perhaps requiring many person-years effort and maintained over an extended period, cannot be used by those familiar with another. We introduce Lem, a language for engineering reusable largescale semantic models. The Lem design takes inspiration both from functional programming languages and from proof assistants, and Lem definitions are translatable into OCaml for testing, Coq, HOL4, and Isabelle/HOL for proof, and LaTeX and HTML for presentation. This requires a delicate balance of expressiveness, careful library design, and implementation of transformations – akin to compilation, but subject to the constraint of producing usable and human-readable code for each target. Lem’s effectiveness is demonstrated by its use in practice