503 research outputs found

    A large scale system for searching and browsing images from the World Wide Web

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    This paper outlines the technical details of a prototype system for searching and browsing over a million images from the World Wide Web using their visual contents. The system relies on two modalities for accessing images — automated image annotation and NNk image network browsing. The user supplies the initial query in the form of one or more keywords and is then able to locate the desired images more precisely using a browsing interface

    Using segmented objects in ostensive video shot retrieval

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    This paper presents a system for video shot retrieval in which shots are retrieved based on matching video objects using a combination of colour, shape and texture. Rather than matching on individual objects, our system supports sets of query objects which in total reflect the user’s object-based information need. Our work also adapts to a shifting user information need by initiating the partitioning of a user’s search into two or more distinct search threads, which can be followed by the user in sequence. This is an automatic process which maps neatly to the ostensive model for information retrieval in that it allows a user to place a virtual checkpoint on their search, explore one thread or aspect of their information need and then return to that checkpoint to then explore an alternative thread. Our system is fully functional and operational and in this paper we illustrate several design decisions we have made in building it

    Motion blur reduction for high frame rate LCD-TVs

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    Today's LCD-TVs reduce their hold time to prevent motion blur. This is best implemented using frame rate up-conversion with motion compensated interpolation. The registration process of the TV-signal, by film or video camera, has been identified as a second motion blur source, which becomes dominant for TV displays with a frame rate of 100 Hz or higher. In order to justify any further hold time reduction of LCDs, this second type of motion blur, referred to as camera blur, needs to be addressed. This paper presents a real-time camera blur estimation and reduction method, suitable for TV-applications

    Cross-lingual searching and visualization for greek and latin and old norse texts

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    We explore approaches to multi--lingual information retrieval for Greek, Latin, and Old Norse texts and an innovative visualization facility for the results

    Numerical and experimental investigation of dielectric recovery in super-critical nitrogen

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    A supercritical (SC) nitrogen (N2) switch is designed and tested. The dielectric strength and recovery rate of the SC switch are investigated by experiments. In order to theoretically study the discharge and recovery process of the SC N2 switch under high repetition rate operation, a numerical model is developed. For SC N2 with initial parameters of p = 80.9 bar and T = 300 K, the simulation results show that within several nanoseconds after the streamer bridges the switch gap, the spark is fully developed and this time depends on the applied electric field between electrodes. During the whole discharge process, the maximum temperature in the channel is about 20 000 K. About 10μs after the spark excitation of 200 ns duration, the temperature on the axis decays to Taxis 1500 K, mainly contributed by the gas expansion and heat transfer mechanisms. After 100μs, the dielectric strength of the gap recovers to above half of the cold breakdown voltage due to the temperature decay in the channel. Both experimental and numerical investigations indicate that supercritical fluid is a good insulating medium that has a proved high breakdown voltage and fast recovery speed

    Beneficial Inner-City Quay Walls?

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    Inner-city quay walls in public urban areas: expense or added value? These civil structures approach, reach or exceed the end of their life span. This threatens the quality of the public urban area. Many municipalities are still willing to invest in the management of inner-city quay walls, despite the costs. Apparently, the quay walls generate more benefits than that are initially expected based on their original functions. Until now, municipalities have failed to determine the added value of inner-city quay walls. Theoretical and practical research suggests that adequate asset management is indispensable. Nevertheless, no research focuses on valuable management of inner-city quays, in terms of performance, costs, benefits and risks. How to decide on a management strategy that adds the most value to the public area? A new framework should identify and incorporate the value of inner-city quay walls in the management process

    Differential effects of familial Alzheimer’s disease-causing mutations on amyloid precursor protein (APP) trafficking, proteolytic conversion, and synaptogenic activity

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    The amyloid precursor protein (APP) is a key player in Alzheimer`s disease (AD) and the precursor of the Aβ peptide, which is generated by consecutive cleavages of β- and γ-secretases. Familial Alzheimer’s disease (FAD) describes a hereditary subgroup of AD that represents a low percentage of AD cases with an early onset of the disease. Different APP FAD mutations are thought to have qualitatively different effects on its proteolytic conversion. However, few studies have explored the pathogenic and putative physiological differences in more detail. Here, we compared different FAD mutations, located at the β- (Swedish), α- (Flemish, Arctic, Iowa) or γ-secretase (Iberian) cleavage sites. We examined heterologous expression of APP WT and FAD mutants in non-neuronal cells and their impact on presynaptic differentiation in contacting axons of co-cultured neurons. To decipher the underlying molecular mechanism, we tested the subcellular localization, the endocytosis rate and the proteolytic processing in detail by immunoprecipitation–mass spectrometry. Interestingly, we found that only the Iberian mutation showed altered synaptogenic function. Furthermore, the APP Iowa mutant shows significantly decreased α-secretase processing which is in line with our results that APP carrying the Iowa mutation was significantly increased in early endosomes. However, most interestingly, immunoprecipitation–mass spectrometry analysis revealed that the amino acid substitutions of APP FAD mutants have a decisive impact on their processing reflected in altered Aβ profiles. Importantly, N-terminally truncated Aβ peptides starting at position 5 were detected preferentially for APP Flemish, Arctic, and Iowa mutants containing amino acid substitutions around the α-secretase cleavage site. The strongest change in the ratio of Aβ40/Aβ42 was observed for the Iberian mutation while APP Swedish showed a substantial increase in Aβ1–17 peptides. Together, our data indicate that familial AD mutations located at the α-, β-, and γ-secretase cleavage sites show considerable differences in the underlying pathogenic mechanisms

    Factors influencing noncompliance with bicycle passing distance laws

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    Many jurisdictions around the world have implemented laws to require a minimum distance when motor vehicles pass cyclists, but research into the factors influencing passing distances has produced inconsistent results, indicating the need for future research. This study examined the factors influencing motorists’compliance with a legislated bicycle passing distance rule in Queensland, Australia. Unlike the earlier studies, which used volunteer riders to record passing events, this study used a naturalistic study design to record passing events where none of the motorists or the cyclists were aware of being studied. As a result, this study captured the ‘true’driving and riding behaviours during passing events. The likelihood of non-compliance was greater on higher (70–80 km/h speed limits) and lower (40 km/h) speed roads than 60 km/h roads, at curved road sections, and on roads with narrower traffic lanes. Rider characteristics (age, gender, helmet status, type of clothing, type of bicycle, and individual or group riding) had no statistically significant association with compliance status. The findings indicate that efforts to improve cyclist safety during overtaking events should focus on non-rider related factors, such as roadway infrastructure characteristics
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