726 research outputs found

    Weighted Modal Transition Systems

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    Specification theories as a tool in model-driven development processes of component-based software systems have recently attracted a considerable attention. Current specification theories are however qualitative in nature, and therefore fragile in the sense that the inevitable approximation of systems by models, combined with the fundamental unpredictability of hardware platforms, makes it difficult to transfer conclusions about the behavior, based on models, to the actual system. Hence this approach is arguably unsuited for modern software systems. We propose here the first specification theory which allows to capture quantitative aspects during the refinement and implementation process, thus leveraging the problems of the qualitative setting. Our proposed quantitative specification framework uses weighted modal transition systems as a formal model of specifications. These are labeled transition systems with the additional feature that they can model optional behavior which may or may not be implemented by the system. Satisfaction and refinement is lifted from the well-known qualitative to our quantitative setting, by introducing a notion of distances between weighted modal transition systems. We show that quantitative versions of parallel composition as well as quotient (the dual to parallel composition) inherit the properties from the Boolean setting.Comment: Submitted to Formal Methods in System Desig

    MANUFACTURER AND RETAILER BRANDS IN FOOD RETAIL ASSORTMENTS Notes from a shopping trip across Europe

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    Food retailers present consumers with a complex market offering. They offer consumers an assortment of products sourced from numerous suppliers, along with various services within a retailer-controlled environment (Burt & Sparks 2002). Food retailers aim to offer an assortment of products and perform a variety of activities and services, which provide added value in the eyes of consumers (Burt 2000). In this connection, branding is becoming increasingly important, as food retailers develop their own brands within and across product categories. Many retailers are attempting to cultivate an overall brand identity in order to protect and identify their market offering (Burt & Sparks 2002). The assortment of products food retailers offer typically includes manufacturer brands, re-tailer brands and generic or unbranded products. In recent years, increasing competition in food retailing has made food retailers focus on whether they offer the "right" assort-ment to consumers. Under headings such as efficient consumer response (ECR) and cate-gory management (CM), retailers have been readjusting their assortments, delisting many brands that were deemed to be under-performing and including retailer branded products in an attempt to differentiate themselves by offering goods only available in their stores. Despite the importance of branding to retailers, the branding literature has focused on how manufacturers develop and maintain strong brands. Relatively little work has been done in the area of retail brands and even less about the interaction between retailer brands and manufacturer brands. In contrast, this paper develops a concept of retailer brand architecture, which captures that retailers typically offer an assortment of manu-facturer brands, retailer brands and generic products. In doing so we adapt the concept of brand architecture to a retail context. The concept of 'brand architecture', as originally developed by (Aaker & Joachimsthaler 2002), describes how the different brands used to market a range of products from the same manufacturer are related. The concept of brand architecture is based on the assumption that brands are not evaluated in isolation, but are placed in and evaluated within a broader context. This assumption is also important in a retail context. Consumers do not look at an isolated product or brand on the shelf. Their evaluation of the individual brand depends on the context; for instance, what other products are offered in the product category and in the retail outlet, previous experiences with the product or other products from the same manufacturer, as well as previous experiences with the retailer in question. In this paper, we take the concept of brand architecture and apply it to food retailers, con-ceptualising the brand architectures of food retailers as the portfolio of brands (gene-ric, retailer and manufacturer brands), which are included in the assortment of a retail concept (ie, a retail chain). In addition to developing a concept of 'retailer brand archi-tecture', we use this concept to investigate the brand architecture of a number of European food retailers in order to determine similarities and differences in brand architecture strategies. The paper is structured as follows: firstly, the concept of brand archi-tecture is presented. Secondly, the concept of brand architecture is applied to a retail setting and a number of other concepts important for understanding the brand architecture strategies of food retailers are introduced and discussed. Thirdly, the methodology used to investigate the brand architectures of European food retailers is discussed. Then, the findings from a shopping trip across Europe are presented. Finally, a discussion of the findings is provided and it is briefly considered how the findings of this study were used as input for a study of consumer perceptions of the brand architectures of food retailers. This subsequent study investigated whether consumers notice differences between the brand architectures of food retailers and how these are evaluatedNo keywords;

    Synchronizing Words for Weighted and Timed Automata

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    The problem of synchronizing automata is concerned with the existence of a word that sends all states of the automaton to one and the same state. This problem has classically been studied for complete deterministic finite automata, with the existence problem being NLOGSPACE-complete. In this paper we consider synchronizing-word problems for weighted and timed automata. We consider the synchronization problem in several variants and combinations of these, including deterministic and non-deterministic timed and weighted automata, synchronization to unique location with possibly different clock valuations or accumulated weights, as well as synchronization with a safety condition forbidding the automaton to visit states outside a safety-set during synchronization (e.g. energy constraints). For deterministic weighted automata, the synchronization problem is proven PSPACE-complete under energy constraints, and in 3-EXPSPACE under general safety constraints. For timed automata the synchronization problems are shown to be PSPACE-complete in the deterministic case, and undecidable in the non-deterministic case

    Dynamic stereo microscopy for studying particle sedimentation

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    We demonstrate a new method for measuring the sedimentation of a single colloidal bead by using a combination of optical tweezers and a stereo microscope based on a spatial light modulator. We use optical tweezers to raise a micron-sized silica bead to a fixed height and then release it to observe its 3D motion while it sediments under gravity. This experimental procedure provides two independent measurements of bead diameter and a measure of Faxén’s correction, where the motion changes due to presence of the boundary

    Moderate physical activity may prevent cartilage loss in women with knee osteoarthritis : data from the Osteoarthritis Initiative

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    All authors have completed the ICMJE uniform disclosure form at http://www.icmje.org/coi_disclosure.pdf and declare: data acquisition in this study was funded by the Osteoarthritis Initiative, a public–private partnership comprised of five contracts (N01-AR-2-2258; N01-AR-2-2259;N01-AR-2-2260; N01-AR-2-2261; N01-AR-2-2262) funded by the National Institutes of Health, a branch of the Department of Health and Human Services, and conducted by the Osteoarthritis Initiative study Investigators. Private funding partners of the OAI include Merck Research Laboratories, Novartis Pharmaceuticals Corporation, GlaxoSmithKline, and Pfizer, Inc. Private sector funding for the Osteoarthritis Initiative is managed by the Foundation for the National Institutes of Health. The image analysis in this study was partly funded by the FNIH OA Biomarkers Consortium, with grants, direct and in -kind contributions, provided by: AbbVie; Amgen Inc.; Arthritis Foundation; Bioiberica S.A.; DePuy Mitek, Inc.; Flexion Therapeutics, Inc.; GlaxoSmithKline; Merck KGaA; Rottapharm | Madaus; Sanofi; and Stryker. Other parts of funding were provided by a direct grant from Merck KGaA, by a contract with the University of Pittsburgh (Pivotal OAI MRI Analyses [POMA]: NIH/NHLBI Contract No. HHSN2682010000 21C), by a vendor contract from the OAI coordinating center at University of California, San Francisco (N01-AR-2-2258), and by an ancillary study to the OAI held by the Division of Rheumatology, Feinberg School of Medicine, Northwestern University (R01 AR52918). This research has also received funding from the European Union Seventh Framework Programme (FP7-PEOPLE-2013-ITN; KNEEMO) under grant agreement number 607510. AGC is supported by a National Health and Medical Research Council (NHMRC) of Australia Early Career Fellowship (Neil Hamilton Fairley Clinical Fellowship No.1121173). The sponsors were not involved in the design and conduct of this particular study, in the analysis and interpretation of the data, and in the preparation, review, or approval of the manuscript.Peer reviewedPostprin

    The Mannheim Corona study: Life in Germany in a state of emergency : Report for March 20 to July 09, 2020

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    We are all affected by the corona pandemic and the measures taken by the federal government to decelerate the spread of the virus. At the University of Mannheim, we have developed a survey instrument over the past eight years which we can use to quickly examine the social implications of the pandemic in Germany. To the best of our knowledge, our study is the only one in Germany which can assess how the corona crisis is affecting people’s lives in Germany on a daily basis. That is why we consider it as our social duty to contribute to a better understanding of how the corona crisis is affecting the population and to inform the public as well as decision-makers in politics and business about current developments. The Mannheim Corona Study started on Friday, March 20. The study is carried out daily and reports on life in Germany during the corona crisis. We examine social and economic aspects (such as childcare, employment situations, and disposable income), the influence of political measures on social interactions, anxiety as well as public acceptance of the measures taken to contain the pandemic. Between 411 und 643 (on average 489) respondents take part in the study every day

    The Mannheim Corona study: life in Germany in a state of emergency : report for March 20 to May 28, 2020, English translation of the original report (in German)

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    We are all affected by the corona pandemic and the measures taken by the federal government to decelerate the spread of the virus. At the University of Mannheim, we have developed a survey instrument over the past eight years which we can use to quickly examine the social implications of the pandemic in Germany. To the best of our knowledge, our study is the only one in Germany which can assess how the corona crisis is affecting people’s lives in Germany on a daily basis. That is why we consider it as our social duty to contribute to a better understanding of how the corona crisis is affecting the population and to inform the public as well as decision-makers in politics and business about current developments. The Mannheim Corona Study started on Friday, March 20. The study is carried out daily and reports on life in Germany during the corona crisis. We examine social and economic aspects (such as childcare, employment situations, and disposable income), the influence of political measures on social interactions, anxiety as well as public acceptance of the measures taken to contain the pan

    The Mannheim Corona Study: Life in Germany in a state of emergency : Report for March 20 to June 30, 2020 ; English translation of the original report (in German)

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    We are all affected by the corona pandemic and the measures taken by the federal government to decelerate the spread of the virus. At the University of Mannheim, we have developed a survey instrument over the past eight years which we can use to quickly examine the social implications of the pandemic in Germany. To the best of our knowledge, our study is the only one in Germany which can assess how the corona crisis is affecting people’s lives in Germany on a daily basis. That is why we consider it as our social duty to contribute to a better understanding of how the corona crisis is affecting the population and to inform the public as well as decision-makers in politics and business about current developments
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