251 research outputs found

    Kleene Algebras, Regular Languages and Substructural Logics

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    We introduce the two substructural propositional logics KL, KL+, which use disjunction, fusion and a unary, (quasi-)exponential connective. For both we prove strong completeness with respect to the interpretation in Kleene algebras and a variant thereof. We also prove strong completeness for language models, where each logic comes with a different interpretation. We show that for both logics the cut rule is admissible and both have a decidable consequence relation.Comment: In Proceedings GandALF 2014, arXiv:1408.556

    Synchronous Subsequentiality and Approximations to Undecidable Problems

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    We introduce the class of synchronous subsequential relations, a subclass of the synchronous relations which embodies some properties of subsequential relations. If we take relations of this class as forming the possible transitions of an infinite automaton, then most decision problems (apart from membership) still remain undecidable (as they are for synchronous and subsequential rational relations), but on the positive side, they can be approximated in a meaningful way we make precise in this paper. This might make the class useful for some applications, and might serve to establish an intermediate position in the trade-off between issues of expressivity and (un)decidability.Comment: In Proceedings GandALF 2015, arXiv:1509.0685

    On the metatheory of linguistics

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    Wurm C. On the metatheory of linguistics. Bielefeld: UB Bielefeld; 2013

    What's exposed? Mapping elements at risk from space

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    The world has suffered from severe natural disasters over the last decennium. The earthquake in Haiti in 2010 or the typhoon “Haiyan” hitting the Philippines in 2013 are among the most prominent examples in recent years. Especially in developing countries, knowledge on amount, location or type of the exposed elements or people is often not given. (Geo)-data are mostly inaccurate, generalized, not up-to-date or even not available at all. Thus, fast and effective disaster management is often delayed until necessary geo-data allow an assessment of effected people, buildings, infrastructure and their respective locations. In the last decade, Earth observation data and methods have developed a product portfolio from low resolution land cover datasets to high resolution spatially accurate building inventories to classify elements at risk or even assess indirectly population densities. This presentation will give an overview on the current available products and EO-based capabilities from global to local scale. On global to regional scale, remote sensing derived geo-products help to approximate the inventory of elements at risk in their spatial extent and abundance by mapping and modelling approaches of land cover or related spatial attributes such as night-time illumination or fractions of impervious surfaces. The capabilities and limitations for mapping physical exposure will be discussed in detail using the example of DLR’s ‘Global Urban Footprint’ initiative. On local scale, the potential of remote sensing particularly lies in the generation of spatially and thematically accurate building inventories for the detailed analysis of the building stock’s physical exposure. Even vulnerability-related indicators can be derived. Indicators such as building footprint, height, shape characteristics, roof materials, location, and construction age and structure type have already been combined with civil engineering approaches to assess building stability for large areas. Especially last generation optical sensors – often in combination with digital surface models – featuring very high geometric resolutions are perceived as advantageous for operational applications, especially for small to medium scale urban areas. With regard to user-oriented product generation in the FP-7project SENSUM, a multi-scale and multi-source reference database has been set up to systematically screen available products – global to local ones – with regard to data availability in data-rich and data-poor countries. Thus, the higher ranking goal in this presentation is to provide a systematic overview on EO-based data sets and their individual capabilities and limitations with respect to spatial, temporal and thematic details to support decision-making in before, during and after natural disasters

    DEVELOPMENT OF A MEASUREMENT SCALE FOR BUSINESS PROCESS STANDARDIZATION

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    Process-oriented companies face the dichotomy of process standardization versus process diversity. On the one hand, multinational companies try to realize returns of scale by standardization. On the other hand, markets require businesses to adapt to local needs and government regulations. As of to-day, there is no framework available to measure the degree of process standardization. This is both a problem for companies that want to assess their degree of standardization as well as for research that aims to investigate standardization and its connection with other concepts. In this paper, we address this research gap from the perspective of scale development. We utilize a well-acknowledged method for devising a measurement instrument to specifically and directly measure the degree of standardiza-tion in business processes. Various application scenarios and future research areas are pointed out

    Exploring Indoor Thermal environment and cognitive performance in a short-term occupancy setting

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    It is general knowledge that the thermal comfort strongly influences people's wellbeing, health, and productivity. Many studies point to a significant relationship between working performance and indoor thermal conditions. This contribution presents the results of a related large scale experiment with a group of architectural students. Participants were separated in two groups, placed in two identical rooms (seated at tables), and shown a brief video lecture. One of the test rooms was heated, the other one was cool. After watching the video, participants were asked to work on a test involving a few multiple choice and open questions. The test cells were monitored with regard to temperature, relative humidity and CO2 concentration. We discuss the test performance of the two groups of participants in the context of the corresponding indoor climate conditions

    The fate of the distal aorta after repair of acute type A aortic dissection

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    ObjectivesThe residual aorta’s behavior after repair of acute type A dissection is incompletely understood. We analyzed segmental growth rates, distal reoperation, and factors influencing long-term survival.MethodsOne hundred seventy-nine consecutive patients (70% male; mean age, 60 years) with acute type A dissection underwent aggressive resection of the intimal tear and open distal anastomosis (1986-2003). Hospital mortality was 13.4%. Survivors had serial computed tomographic scans: digitization yielded distal segmental dimensions. Segment-specific average rates of enlargement and factors influencing faster growth were analyzed. Distal reoperations and patient survival were examined.ResultsEighty-nine (57%) patients had imaging data sufficient for growth rate calculations. The median diameters after repair were as follows: aortic arch, 3.6 cm; descending aorta, 3.7 cm; and abdominal aorta, 3.2 cm. Subsequent growth rates were 0.8, 1.0, and 0.8 mm/y, respectively. Initial size of greater than 4 cm (P = .005) and initial diameter of less than 4 cm with a patent false lumen (P = .004) predicted greater growth in the descending aorta, and male sex (P = .05) significantly affected growth in the abdominal aorta. No significant factors were found for the aortic arch. There were 25 distal aortic reoperations (16 patients), and risk of reoperation was 16% at 10 years. Risk factors reducing long-term survival after repair of acute type A dissection included age (P < .0001), new neurological deficit at presentation (P = .04), absence of preoperative thrombus in the false lumen of the ascending aorta (P = .03), and a patent distal false lumen postoperatively (P = .06) but not distal reoperation.ConclusionsGrowth of the distal aorta after repair of acute type A dissection is typically slow and linear. Distal reoperation is uncommon, and late risk of death is approximately twice that of a healthy population

    Desarrollo de instrumental de laboratorio controlado por Arduino

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    El proyecto se desarrolla en el marco de la cåtedra de Electrónica del Profesorado en Física de la Facultad de Ciencias Exactas, Químicas y Naturales de la Universidad Nacional de Misiones, en el que participan docentes y alumnos. Los dispositivos diseñados pueden ser implementados para la enseñanza de la física tanto en nivel medio como universitario. Las propuestas surgen como requerimientos o necesidades dentro del Profesorado en Física o por iniciativa de los estudiantes.Demostraciones educativas.Red de Universidades con Carreras en Informåtica (RedUNCI

    Desarrollo de instrumental de laboratorio controlado por Arduino

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    El proyecto se desarrolla en el marco de la cåtedra de Electrónica del Profesorado en Física de la Facultad de Ciencias Exactas, Químicas y Naturales de la Universidad Nacional de Misiones, en el que participan docentes y alumnos. Los dispositivos diseñados pueden ser implementados para la enseñanza de la física tanto en nivel medio como universitario. Las propuestas surgen como requerimientos o necesidades dentro del Profesorado en Física o por iniciativa de los estudiantes.Demostraciones educativas.Red de Universidades con Carreras en Informåtica (RedUNCI
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