3,463 research outputs found

    “Canada’s Roll of Honour”: Controversy over Casualty Notification and Publication During the Second World War

    Get PDF
    During the Second World War, the Canadian Army’s announcement of casualties to next–of–kin and the press often caused controversy. Even though the army tried to notify the family and public as quickly as possible, it could not always do so. Unofficial communications with the family, procedural failures, and more frequently press and censorship errors, cause occasional mistakes in casualty reporting. Moreover, the interests of Canada’s allies often prevented the timely publication of casualty names and figures, as in the aftermath of the Dieppe Raid, Sicily campaign and Normandy landings. These delays were often for alleged security reasons, sometimes with questionable justification. This led to widespread, albeit inaccurate, suspicion of political manipulation of this process by the Canadian Army and federal government

    A Social Process in Science and its Content in a Simulation Program

    Get PDF
    We lay open a position concerning the difference between scientific processes and processes in science. Not all processes in science are scientific. This leads into the center of social simulation. More scientific theories should be incorporated in social simulations, and this should lead to more united structural approaches.Social Simulation, Process, Science, Theory, Social Science, Philosophy of Science

    Smaller = denser, and the brain knows it: natural statistics of object density shape weight expectations.

    Get PDF
    If one nondescript object's volume is twice that of another, is it necessarily twice as heavy? As larger objects are typically heavier than smaller ones, one might assume humans use such heuristics in preparing to lift novel objects if other informative cues (e.g., material, previous lifts) are unavailable. However, it is also known that humans are sensitive to statistical properties of our environments, and that such sensitivity can bias perception. Here we asked whether statistical regularities in properties of liftable, everyday objects would bias human observers' predictions about objects' weight relationships. We developed state-of-the-art computer vision techniques to precisely measure the volume of everyday objects, and also measured their weight. We discovered that for liftable man-made objects, "twice as large" doesn't mean "twice as heavy": Smaller objects are typically denser, following a power function of volume. Interestingly, this "smaller is denser" relationship does not hold for natural or unliftable objects, suggesting some ideal density range for objects designed to be lifted. We then asked human observers to predict weight relationships between novel objects without lifting them; crucially, these weight predictions quantitatively match typical weight relationships shown by similarly-sized objects in everyday environments. These results indicate that the human brain represents the statistics of everyday objects and that this representation can be quantitatively abstracted and applied to novel objects. Finally, that the brain possesses and can use precise knowledge of the nonlinear association between size and weight carries important implications for implementation of forward models of motor control in artificial systems

    Electronic double-excitations in quantum wells: solving the two-time Kadanoff-Baym equations

    Full text link
    For a quantum many-body system, the direct population of states of double-excitation character is a clear indication that correlations importantly contribute to its nonequilibrium properties. We analyze such correlation-induced transitions by propagating the nonequilibrium Green's functions in real-time within the second Born approximation. As crucial benchmarks, we compute the absorption spectrum of few electrons confined in quantum wells of different width. Our results include the full two-time solution of the Kadanoff-Baym equations as well as of their time-diagonal limit and are compared to Hartree-Fock and exact diagonalization data