1,324 research outputs found

    A computer simulation of digital recording Final development progress report, 29 Dec. 1966 - 29 Dec. 1967

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    Fourier series digital computer simulation of tape recording process - signal detection in prescence of white Gaussian nois

    Addendum no. 1 to final development report

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    Pseudo-linearity concept impact on linear filters designed to ease pulse crowding effects at high bit densitie

    Why it will be difficult for Jeff Sessions to put the genie back into the bottle on marijuana policy

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    Last week, the US Attorney General, Jeff Sessions, announced that he would be revoking Obama-era Department of Justice guidance which left the enforcement of marijuana policy to the states by giving prosecutors more discretion to pursue marijuana cases. A. Lee Hannah and Daniel J. Mallinson write that Sessions' policy about-face draws opposition from many of those in his own party, state US attorneys, interest groups, and state legislatures. Given that the federal government is dependent on state and local law enforcement for implementing drug prohibition, this opposition could well push Congress to change federal marijuana law

    Uncooperative federal government has led to innovation on marijuana policy in more liberal, less religious states.

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    In the past two decades, 29 states and Washington DC have liberalized their laws on the use of medical marijuana - in defiance of federal regulations. A. Lee Hannah and Daniel J. Mallinson look at why some states have become 'defiant innovators' in this area. They find that if a state is more liberal and less religious, if the state ..

    The practical feasibility of using RFID in a metal environment

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    Passive Radio Frequency Identification (RFID) has revolutionized the way in which products are identified. This paper considers the effect of metals on the performance of RFID at ultra high frequency (UHF). The paper establishes read patterns in space, highlighting the interference of RF waves due to three different metals, one ferrous and the other two non ferrous, when placed behind a transponder. The effect of thickness of the metal plate is also examined. Different metals have been found to have different interference effects although there are some similarities in their read patterns related to their material properties. Also experiments have been carried out to identify and establish various methods of improving this performance. Finally, differences between performance-measuring parameters, namely attenuating transmitted power and calculating read rate at a fixed attenuation are established and possible reasons of these observations are presented

    Outnumb3r3d : intrinsically motivating mathematics for the PlayStation 4

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    This paper and accompanying poster describes the design of an intrinsically integrated educational game to improve children’s competencies in mental mathematics. A number of researchers have suggested that educational games are more effective when they are closely integrated with their learning content. Specifically work by the lead author has showed that a closer integration between an educational game's core-mechanics and its learning content can be both more appealing (in terms of time spent on-task) and more educationally effective (in terms of learning outcomes) than a less integrated "edutainment" approach. However, cursory approaches to integrating learning content remain common in contemporary educational software, and the literature lacks an exemplar of what can be achieved using an integrated approach. The Outnumb3r3d game was conceived to provide a commercial and theoretical exemplar of intrinsic integration for the Nintendo Wii, but was never completed. This project is now porting the original Wii prototype onto the PlayStation 4 in order to revive Outnumb3r3d as a research project. This paper details the design of Outnumb3r3d with reference to the key theoretical constructs that underlie its pedagogical design. In doing so it provides an example of a game design created to integrate mathematical learning content seamlessly into the game's core mechanics, ensuring that the mathematics is what makes the game intrinsically motivating to play rather than trying to hide or "sugar coat" its learning content. At the time of writing the game’s implementation is still a “work in progress”, but is expected to be the subject of future empirical evaluations into its effectiveness as a teaching tool

    Geologic framework of the northern North Carolina, USA inner continental shelf and its influence on coastal evolution

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    © The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marine Geology 348 (2014): 113-130, doi:10.1016/j.margeo.2013.11.011.The inner continental shelf off the northern Outer Banks of North Carolina was mapped using sidescan sonar, interferometric swath bathymetry, and high-resolution chirp and boomer subbottom profiling systems. We use this information to describe the shallow stratigraphy, reinterpret formation mechanisms of some shoal features, evaluate local relative sea-levels during the Late Pleistocene, and provide new constraints, via recent bedform evolution, on regional sediment transport patterns. The study area is approximately 290 km long by 11 km wide, extending from False Cape, Virginia to Cape Lookout, North Carolina, in water depths ranging from 6 to 34 m. Late Pleistocene sedimentary units comprise the shallow geologic framework of this region and determine both the morphology of the inner shelf and the distribution of sediment sources and sinks. We identify Pleistocene sedimentary units beneath Diamond Shoals that may have provided a geologic template for the location of modern Cape Hatteras and earlier paleo-capes during the Late Pleistocene. These units indicate shallow marine deposition 15–25 m below present sea-level. The uppermost Pleistocene unit may have been deposited as recently as Marine Isotope Stage 3, although some apparent ages for this timing may be suspect. Paleofluvial valleys incised during the Last Glacial Maximum traverse the inner shelf throughout the study area and dissect the Late Pleistocene units. Sediments deposited in the valleys record the Holocene transgression and provide insight into the evolutionary history of the barrier-estuary system in this region. The relationship between these valleys and adjacent shoal complexes suggests that the paleo-Roanoke River did not form the Albemarle Shelf Valley complex as previously proposed; a major fluvial system is absent and thus makes the formation of this feature enigmatic. Major shoal features in the study area show mobility at decadal to centennial timescales, including nearly a kilometer of shoal migration over the past 134 yr. Sorted bedforms occupy ~ 1000 km2 of seafloor in Raleigh Bay, and indicate regional sediment transport patterns between Capes Hatteras and Lookout that help explain long-term sediment accumulation and morphologic development. Portions of the inner continental shelf with relatively high sediment abundance are characterized by shoals and shoreface-attached ridges, and where sediment is less abundant, the seafloor is dominated by sorted bedforms. These relationships are also observed in other passive margin settings, suggesting a continuum of shelf morphology that may have broad application for interpreting inner shelf sedimentation patterns.Funding for this research was provided by the USGS Coastal and Marine Geology Program

    Development of a very light rail vehicle

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    The collaborative very light rail project involves the development of a novel railcar designed to revolutionise the rail industry: a self-powered, Very Light Rail (VLR) vehicle. Each of the two bogies contains a complete diesel-electric series-hybrid drive system, whilst the whole vehicle has undergone significant lightweighting activity to realise a target weight of less than 18 tonnes, or 1 tonne per linear meter. The target cost is £500,000, which is to be achieved through the use of standardised, modular components, and appropriate materials and structural design methodologies. The research covers several aspects of the GB Rail Technical Strategy (RTS) chapter relating to Rolling Stock. Lightweighting leads to a reduction in the propulsion requirements and reduces the infrastructure installation and maintenance costs. The use of higher efficiency drive systems achieved through on-board energy systems enables a reduction in carbon emissions. These hybridisation activities improve the passenger experience through quieter operation, decreased vibration and the possible elimination of exhaust emissions in stations. Combining new drive systems with modular lightweight structures will lead to lower life-cycle costs and thus could enable the economical reopening of lines
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