455 research outputs found

    Low Voltage Control for the Liquid Argon Hadronic End-Cap Calorimeter of ATLAS

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    At the ATLAS detector a SCADA system surveys and controls the sub- detectors. The link is realized by PVSS2 software and a CanBus hardware system. The low voltages for the Hadronic Endcaps of the liquid argon calorimeter are produced by DC/DC-converters in the power boxes and split into 320 channels corresponding to the pre- amplifier and summing boards in the cryostat. Six units of a prototype distribution board are currently under test. Each of it contains 2 ELMBs as CanBus interface, a FPGA of type QL3012 for digital control and 30 low voltage regulators for the individual fine adjustments of the outputs

    Personalizable edge services for Web accessibility

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    Web Content Accessibility guidelines by W3C (W3C Recommendation, May 1999. http://www.w3.org/TR/WCAG10/) provide several suggestions for Web designers regarding how to author Web pages in order to make them accessible to everyone. In this context, this paper proposes the use of edge services as an efficient and general solution to promote accessibility and breaking down the digital barriers that inhibit users with disabilities to actively participate to any aspect of society. The idea behind edge services mainly affect the advantages of a personalized navigation in which contents are tailored according to different issues, such as client’s devices capabilities, communication systems and network conditions and, finally, preferences and/or abilities of the growing number of users that access the Web. To meet these requirements, Web designers have to efficiently provide content adaptation and personalization functionalities mechanisms in order to guarantee universal access to the Internet content. The so far dominant paradigm of communication on the WWW, due to its simple request/response model, cannot efficiently address such requirements. Therefore, it must be augmented with new components that attempt to enhance the scalability, the performances and the ubiquity of the Web. Edge servers, acting on the HTTP data flow exchanged between client and server, allow on-the-fly content adaptation as well as other complex functionalities beyond the traditional caching and content replication services. These value-added services are called edge services and include personalization and customization, aggregation from multiple sources, geographical personalization of the navigation of pages (with insertion/emphasis of content that can be related to the user’s geographical location), translation services, group navigation and awareness for social navigation, advanced services for bandwidth optimization such as adaptive compression and format transcoding, mobility, and ubiquitous access to Internet content. This paper presents Personalizable Accessible Navigation (Pan) that is a set of edge services designed to improve Web pages accessibility, developed and deployed on top of a programmable intermediary framework. The characteristics and the location of the services, i.e., provided by intermediaries, as well as the personalization and the opportunities to select multiple profiles make Pan a platform that is especially suitable for accessing the Web seamlessly also from mobile terminals

    Accessibility-based reranking in multimedia search engines

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    Traditional multimedia search engines retrieve results based mostly on the query submitted by the user, or using a log of previous searches to provide personalized results, while not considering the accessibility of the results for users with vision or other types of impairments. In this paper, a novel approach is presented which incorporates the accessibility of images for users with various vision impairments, such as color blindness, cataract and glaucoma, in order to rerank the results of an image search engine. The accessibility of individual images is measured through the use of vision simulation filters. Multi-objective optimization techniques utilizing the image accessibility scores are used to handle users with multiple vision impairments, while the impairment profile of a specific user is used to select one from the Pareto-optimal solutions. The proposed approach has been tested with two image datasets, using both simulated and real impaired users, and the results verify its applicability. Although the proposed method has been used for vision accessibility-based reranking, it can also be extended for other types of personalization context

    SPRWeb: preserving subjective responses to website colour schemes through automatic recolouring

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    Colours are an important part of user experiences on the Web. Colour schemes influence the aesthetics, first impressions and long-term engagement with websites. However, five percent of people perceive a subset of all colours because they have colour vision deficiency (CVD), resulting in an unequal and less-rich user experience on the Web. Traditionally, people with CVD have been supported by recolouring tools that improve colour differentiability, but do not consider the subjective properties of colour schemes while recolouring. To address this, we developed SPRWeb, a tool that recolours websites to preserve subjective responses and improve colour differentiability - thus enabling users with CVD to have similar online experiences. To develop SPRWeb, we extended existing models of non-CVD subjective responses to CVD, then used this extended model to steer the recolouring process. In a lab study, we found that SPRWeb did significantly better than a standard recolouring tool at preserving the temperature and naturalness of websites, while achieving similar weight and differentiability preservation. We also found that recolouring did not preserve activity, and hypothesize that visual complexity influences activity more than colour. SPRWeb is the first tool to automatically preserve the subjective and perceptual properties of website colour schemes thereby equalizing the colour-based web experience for people with CVD.Engineering and Applied Science

    The Liquid Argon Jet Trigger of the H1 Experiment at HERA

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    We report on a novel trigger for the liquid argon calorimeter which was installed in the H1 Experiment at HERA.This trigger, called the “Jet Trigger”, was running at level 1 and implemented a real-time cluster algorithm. Within only 800 ns, the Jet Trigger algorithm found local energy maxima in the calorimeter, summed their immediate neighbors, sorted the resulting jets by energy, and applied topological conditions for the final level 1 trigger decision. The Jet Trigger was in operation from the year 2006 until the end of the HERA running in the summer of 2007. With the Jet Trigger it was possible to substantially reduce the thresholds for triggering on electronsand jets, giving access to a largely extended phase space for physical observables which could not have been reached in H1 before. The concepts of the Jet Trigger may be an interesting upgrade option for the LHC experiments

    Weak temperature dependence of P (+) H A (-) recombination in mutant Rhodobacter sphaeroides reaction centers

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    International audienceIn contrast with findings on the wild-type Rhodobacter sphaeroides reaction center, biexponential P (+) H A (-) → PH A charge recombination is shown to be weakly dependent on temperature between 78 and 298 K in three variants with single amino acids exchanged in the vicinity of primary electron acceptors. These mutated reaction centers have diverse overall kinetics of charge recombination, spanning an average lifetime from ~2 to ~20 ns. Despite these differences a protein relaxation model applied previously to wild-type reaction centers was successfully used to relate the observed kinetics to the temporal evolution of the free energy level of the state P (+) H A (-) relative to P (+) B A (-) . We conclude that the observed variety in the kinetics of charge recombination, together with their weak temperature dependence, is caused by a combination of factors that are each affected to a different extent by the point mutations in a particular mutant complex. These are as follows: (1) the initial free energy gap between the states P (+) B A (-) and P (+) H A (-) , (2) the intrinsic rate of P (+) B A (-) → PB A charge recombination, and (3) the rate of protein relaxation in response to the appearance of the charge separated states. In the case of a mutant which displays rapid P (+) H A (-) recombination (ELL), most of this recombination occurs in an unrelaxed protein in which P (+) B A (-) and P (+) H A (-) are almost isoenergetic. In contrast, in a mutant in which P (+) H A (-) recombination is relatively slow (GML), most of the recombination occurs in a relaxed protein in which P (+) H A (-) is much lower in energy than P (+) H A (-) . The weak temperature dependence in the ELL reaction center and a YLH mutant was modeled in two ways: (1) by assuming that the initial P (+) B A (-) and P (+) H A (-) states in an unrelaxed protein are isoenergetic, whereas the final free energy gap between these states following the protein relaxation is large (~250 meV or more), independent of temperature and (2) by assuming that the initial and final free energy gaps between P (+) B A (-) and P (+) H A (-) are moderate and temperature dependent. In the case of the GML mutant, it was concluded that the free energy gap between P (+) B A (-) and P (+) H A (-) is large at all times

    Industry 4.0 as enabler of sustainability diffusion in supply chain: analysis of influential strength of drivers in emerging economy

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    Industry 4.0 (I4.0) and sustainability are recent buzzwords in manufacturing environments. However, the connection between these two concepts is less explored in the literature. In the current business context, the future generation of manufacturing systems is greatly influenced by the rapid advancement of information technology. Therefore, this study aims to examine the drivers of I4.0 to diffuse sustainability in Supply Chains (SCs). This research identifies the most relevant drivers through the literature and discusses them with area experts. Afterwards, an empirical analysis is conducted to validate the key drivers. Finally, the Grey based DEMATEL method is employed to examine the influential strength of the identified drivers and to build an interrelationship diagram. ‘Government supportive policies’ and ‘Collaboration and transparency among supply chain members’ were reported as highly significant drivers of I4.0. This study is an initial effort that investigates the key drivers of I4.0 to achieve high triple bottom line (ecological-economic-social) gains in SCs by taking an example from an emerging economy, i.e. India. This study may help managers, practitioners and policy makers interested in I4.0 applications to diffuse sustainability in SCs.N/

    Robust Metabolic Responses to Varied Carbon Sources in Natural and Laboratory Strains of Saccharomyces cerevisiae

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    Understanding factors that regulate the metabolism and growth of an organism is of fundamental biologic interest. This study compared the influence of two different carbon substrates, dextrose and galactose, on the metabolic and growth rates of the yeast Saccharomyces cerevisiae. Yeast metabolic and growth rates varied widely depending on the metabolic substrate supplied. The metabolic and growth rates of a yeast strain maintained under long-term laboratory conditions was compared to strain isolated from natural condition when grown on different substrates. Previous studies had determined that there are numerous genetic differences between these two strains. However, the overall metabolic and growth rates of a wild isolate of yeast was very similar to that of a strain that had been maintained under laboratory conditions for many decades. This indicates that, at in least this case, metabolism and growth appear to be well buffered against genetic differences. Metabolic rate and cell number did not co-vary in a simple linear manner. When grown in either dextrose or galactose, both strains showed a growth pattern in which the number of cells continued to increase well after the metabolic rate began a sharp decline. Previous studied have reported that O2 consumption in S. cerevisiae grown in reduced dextrose levels were elevated compared to higher levels. Low dextrose levels have been proposed to induce caloric restriction and increase life span in yeast. However, there was no evidence that reduced levels of dextrose increased metabolic rates, measured by either O2 consumption or CO2 production, in the strains used in this study
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