160,463 research outputs found
Tor: modular search with hookable disjunction
Horn Clause Programs have a natural exhaustive depth-first procedural semantics. However, for many programs this semantics is ineffective. In order to compute useful solutions, one needs the ability to modify the search method that explores the alternative execution branches.
Tor, a well-defined hook into Prolog disjunction, provides this ability. It is light-weight thanks to its library approach. Tor supports modular composition of search methods and other hooks. The Tor library is already provided and used as an add-on to SWI-Prolog
Development of multiple media documents
Development of documents in multiple media involves activities in three different
fields, the technical, the discoursive and the procedural. The major development problems of
artifact complexity, cognitive processes, design basis and working context are located where these
fields overlap. Pending the emergence of a unified approach to design, any method must allow for
development at the three levels of discourse structure, media disposition and composition, and
presentation. Related work concerned with generalised discourse structures, structured
documents, production methods for existing multiple media artifacts, and hypertext design offer
some partial forms of assistance at different levels. Desirable characteristics of a multimedia
design method will include three phases of production, a variety of possible actions with media
elements, an underlying discoursive structure, and explicit comparates for review
On Composing Separated Concerns, Composability and Composition Anomalies
It is generally acknowledged that separation of concerns is a key requirement for effective software engineering: it helps in managing the complexity of software and supports the maintainability of a software system. Separation of concerns makes only sense if the realizations in software of these concerns can be composed together effectively into a working program. The ability to compose systems from independently developed components that can be adapted and extended easily is a long-standing goal in the software engineering discipline. However, both research and practice have shown that composability of software is far from trivial and fails repeatedly. Typically this occurs when components exhibit complex behavior, in particular when multiple concerns are involved in a single component. We believe that, to address the composability problems, we need a better understanding of the requirements involved in successful composition, and in addition define the situations where composition fails. To this aim, in this paper we introduce a number of requirements for designlevel composability and define a category of composition problems that are inherent for given composition models, which we term as composition anomalies
The Antecedents of a ‘Chilly Climate’ for Women Faculty in Higher Education
The literature on women’s under-representation in academia asserts that faculty women face a ‘chilly climate’, but there are few theoretically based studies examining this proposition. Relational demography, organizational justice, and social network theories all identify possible antecedents of ‘chilly climate’. Using survey data of faculty at a private Midwestern US university, we test whether the perception of exclusion (chilly climate) is influenced by demographic dissimilarity, and perceptions of fairness and gender equity. We find that faculty women perceive more exclusion from academic departments with a low representation of women, consistent with relational demography. Perceptions of procedural fairness and gender equity are powerful factors that foster inclusion and warm the climate for both men and women. The ‘chilly climate’ for women faculty is a complex phenomenon with multiple causes. Policies that fail to address these multiple causes are unlikely to be effective
Creating Space: Building Digital Games
Studies of games, rhetoric, and pedagogy are increasingly common in our field, and indeed seem to grow each year. Nonetheless, composing and designing digital games, either as a mode of scholarship or as a classroom assignment, has not seen an equal groundswell. This selection first provides a brief overview of the existing scholarship in gaming and pedagogy, much of which currently focuses either on games as texts to analyze or as pedagogical models. While these approaches are certainly valuable, I advocate for an increased focus on game design and creation as valuable act of composition. Such a focus engages students and scholars in a deeply multimodal practice that incorporates critical design and computational thinking. I close with suggestions on tools for new and intrepid designers
TOR: modular search with hookable disjunction
Horn Clause Programs have a natural exhaustive depth-first procedural
semantics. However, for many programs this semantics is
ineffective. In order to compute useful solutions, one needs the
ability to modify the search method that explores the alternative
execution branches.
Tor, a well-defined hook into Prolog disjunction, provides this ability.
It is light-weight thanks to its library approach and efficient
because it is based on program transformation.
Tor is general enough to mimic search-modifying
predicates like ECLiPSe's search/6. Moreover, Tor supports
modular composition of search methods and other hooks.
The Tor library is already
provided and used as an add-on to SWI-Prolog.publisher: Elsevier
articletitle: Tor: Modular search with hookable disjunction
journaltitle: Science of Computer Programming
articlelink: http://dx.doi.org/10.1016/j.scico.2013.05.008
content_type: article
copyright: Copyright © 2013 Elsevier B.V. All rights reserved.status: publishe
Ultra-trace Cu isotope ratio measurements via multi-collector ICP-mass spectrometry using Ga as internal standard : an approach applicable to micro-samples
The capabilities of Cu isotope ratio measurements are often restricted by the small volumes of sample available and/or their low Cu concentration. In this work, an analytical approach was developed for performing Cu isotopic analysis via multi-collector ICP-mass spectrometry (MC-ICP-MS) at ultra-trace level using Ga as an internal standard for mass bias correction. The minimum concentration of Cu required for accurate and precise isotope ratio measurements was established to be 20 mu g L-1 with wet plasma conditions and 5 mu g L-1 with dry plasma conditions. The use of Ga as an internal standard for mass bias correction provided several advantages compared to Ni, i.e. improved internal precision on delta Cu-65 values and lower blank levels. Ga can also be used at a 4- fold lower concentration level than Ni. However, in wet plasma conditions, the signals of (ArO2H+)-Ar-36-O-16-H-1 and (ArNO+)-Ar-40-N-15-O-16 interfered with the signals of Ga-69(+) and Ga-71(+), respectively, while in dry plasma conditions, realized by the use of a desolvation unit, Ga-69(+) suffered from spectral interference from (ArN2H+)-Ar-40-N-14-H-1. These interferences were resolved by using medium mass resolution. For validation purposes, the approach was applied to commercially available blood and serum samples. The delta Cu-65 values for the samples measured at a concentration level of 5 mu g L-1 Cu and 5 mu g L-1 Ga using dry plasma conditions were in good agreement with those obtained for isotope ratio measurements at the "standard" concentration level of 200 mu g L-1 Cu and 200 mu g L-1 Ni using wet plasma conditions. In addition, the delta Cu-65 values obtained for micro-samples of serum/blood (volume of 100 mu L) were in good agreement with the corresponding ones obtained using the "standard" volume for isotopic analysis (500 mu L)
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