28,920 research outputs found

    Before the Morning After

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    Making War: The President and Congress

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    Versatile Data Acquisition and Controls for Epics Using Vme-Based Fpgas

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    Field-Programmable Gate Arrays (FPGAs) have provided Thomas Jefferson National Accelerator Facility (Jefferson Lab) with versatile VME-based data acquisition and control interfaces with minimal development times. FPGA designs have been used to interface to VME and provide control logic for numerous systems. The building blocks of these logic designs can be tailored to the individual needs of each system and provide system operators with read-backs and controls via a VME interface to an EPICS based computer. This versatility allows the system developer to choose components and define operating parameters and options that are not readily available commercially. Jefferson Lab has begun developing standard FPGA libraries that result in quick turn around times and inexpensive designs.Comment: 3 pages, ICALEPCS 2001, T. Allison and R. Foold, Jefferson La

    Making War: The President and Congress

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    The main aim of this dissertation was to investigate the difference in neural language patternsrelated to language ability in healthy adults. The focus lies on unraveling the contributions of theright‐hemispheric homologues to Broca’s area in the inferior frontal gyrus (IFG) and Wernicke’s areain the posterior temporal and inferior parietal lobes. The functions of these regions are far from fullyunderstood at present. Two study populations consisting of healthy adults and a small group ofpeople with generalized epilepsy were investigated. Individual performance scores in tests oflanguage ability were correlated with brain activation obtained with functional magnetic resonanceimaging during semantic and word fluency tasks. Performance‐dependent differences were expectedin the left‐hemispheric Broca’s and Wernicke’s area and in their right‐hemispheric counterparts. PAPER I revealed a shift in laterality towards right‐hemispheric IFG and posterior temporal lobeactivation, related to high semantic performance. The whole‐brain analysis results of PAPER IIrevealed numerous candidate regions for language ability modulation. PAPER II also confirmed thefinding of PAPER I, by showing several performance‐dependent regions in the right‐hemispheric IFGand the posterior temporal lobe. In PAPER III, a new study population of healthy adults was tested.Again, the right posterior temporal lobe was related to high semantic performance. A decrease in lefthemisphericIFG activation could be linked to high word fluency ability. In addition, task difficultywas modulated. Increased task complexity showed to correlate positively with bilateral IFGactivation. Lastly, PAPER IV investigated anti‐correlated regions. These regions are commonly knownas the default mode network (DMN) and are normally suppressed during cognitive tasks. It wasfound that people with generalized epilepsy had an inadequate suppression of regions in the DMN,and showed poorer performance in a complex language test. The results point to neural adaptabilityin the IFG and temporal lobe. Decreased left‐lateralization of the IFG and increased rightlateralizationof the posterior temporal lobe are proposed as characteristics of individuals with highlanguage ability

    Parrondo's games with chaotic switching

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    This paper investigates the different effects of chaotic switching on Parrondo's games, as compared to random and periodic switching. The rate of winning of Parrondo's games with chaotic switching depends on coefficient(s) defining the chaotic generator, initial conditions of the chaotic sequence and the proportion of Game A played. Maximum rate of winning can be obtained with all the above mentioned factors properly set, and this occurs when chaotic switching approaches periodic behavior.Comment: 11 pages, 9 figure

    A multisensor analysis of Nimbus-5 data recorded on 22 January 1973

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    The Nimbus 5 meteorological satellite has a full complement of radiation sensors. Data from these sensors were analyzed and intercompared for orbits 569 and 570. The electrically-scanning microwave radiometer (19.35-GHz region) delineated rain areas over the ocean off the U.S. east coast, in good agreement with radar imagery, and permitted the estimation of rainfall rates in this region. Residual ground water, from abnormal rainfall in the lower Mississippi Valley, was indicated under clear sky conditions by soil brightness temperature values in the Nimbus 5 electrically scanning microwave radiometer and U.S. Air Force Data Acquisition and Processing Program infrared data. The temperature-humidity infrared radiometer (6.7 micron and 11 micron) showed the height and spatial configuration of frontal clouds along the east coast and outlined the confluence of a polar jet stream with a broad subtropical jet stream along the U.S. Gulf Coast. Temperature profiles from three vertical temperature sounders are found to be in good agreement with related radiosonde ascents along orbit 569 from the subtropics to the Arctic Circle

    A multi-sensor analysis of Nimbus 5 data on 22 January 1973

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    The Nimbus 5 meteorological satellite carried aloft a full complement of radiation sensors, the data from which were analyzed and intercompared during orbits 569-570 on 22 January 1973. The electrically scanning microwave radiometer (ESMR) which sensed passive microwave radiation in the 19.35 GHz region, delineated rain areas over the ocean off the U.S. east coast, in good agreement with WSR-57 and FPS-77 radar imagery and permitted the estimation of rainfall rates in this region. Residual ground water in the lower Mississippi Valley, which resulted from abnormal rainfall in previous months, was indicated under clear sky conditions by soil brightness temperature values in the Nimbus 5 ESMR and U.S. Air Force Data Acquisition and Processing Program (DAPP) IR data. The temperature-humidity infrared radiometer showed the height and spatial configuration of frontal clouds along the east coast and outlined the confluence of a polar jet stream with a broad sub-tropical jet stream along the U.S. Gulf Coast. Temperature profiles from three vertical temperature sounders, the infrared temperature profile radiometer (ITPR), the Nimbus E microwave spectrometer (NEMS) and the selective chopper radiometer (SCR) were found to be in good agreement with related radiosonde ascents along orbit 569 from the sub-tropics to the Arctic Circle

    What Happened to the Soviet Superpower’s Nuclear Arsenal? Clues for the Nuclear Security Summit

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    Twenty years ago Russia and fourteen other newly-independent states emerged from the ruins of the Soviet empire, many as nations for the first time in history. As is typical in the aftermath of the collapse of an empire, this was followed by a period of chaos, confusion, and corruption. As the saying went at the time, “everything is for sale.” At that same moment, as the Soviet state imploded, 35,000 nuclear weapons remained at thousands of sites across a vast Eurasian landmass that stretched across eleven time zones. Today, fourteen of the fifteen successor states to the Soviet Union are nuclear weapons-free. When the U.S.S.R. disappeared, 3,200 strategic nuclear warheads remained in Ukraine, Kazakhstan, and Belarus, most of them atop intercontinental ballistic missiles (ICBMs) that stood on alert, ready to be fired at targets in the U.S. Today, every one of the nuclear weapons in Ukraine, Kazakhstan, and Belarus has been deactivated and returned to Russia, where they were dismantled and the nuclear material in the warheads blended down to produce fuel for civilian reactors. Strategic nuclear weapons are nuclear warheads aimed at an adversary’s nuclear weapons, cities and military infrastructure. Typically, they are large in yield and heavy. Of greater interest to terrorists, however, were the former U.S.S.R’s 22,000 tactical nuclear weapons with smaller yields and shorter ranges. These were designed primarily for battlefield use, with some small enough to fit into a duffel bag. Today, all of these have also been returned to Russia, leaving zero nuclear weapons in any other state of the former Soviet Union. Former Czech president Vaclav Havel observed about the rush of events in the 1990s: “things have changed so fast we have not yet taken time to be astonished.” Perhaps the most astonishing fact about the past twenty years is something that did not happen. Despite the risk realistically estimated by former Secretary of Defense Dick Cheney in 3 What Happened to the Soviet Superpower's Nuclear Arsenal? Clues for the Nuclear Security Summit December 1991, two decades have passed without the discovery of a single nuclear weapon outside Russia. This paper will address the question: how did this happen? Looking ahead, it will consider what clues we can extract from the success in denuclearizing fourteen post-Soviet states that can inform our non-proliferation and nuclear security efforts in the future. These clues may inform leaders of the U.S., Russia, and other responsible nations attending the Seoul Nuclear Security Summit on March 26-27, 2012. The paper will conclude with specific recommendations, some exceedingly ambitious that world leaders could follow to build on the Seoul summit’s achievements against nuclear terrorism in the period before the next summit in 2014. One of these would be to establish a Global Alliance Against Nuclear Terrorism
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