1,148 research outputs found

    A stochastic analysis of goods allocation by queuing and the prevention of violence

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    When demand for a good exceeds its supply, queuing mechanisms are commonly used to allocate the good in question to citizens. However, very long queues result in excessive wait times and this can lead to violence. As such, the purpose of this paper is to analyze two stochastic models of goods allocation with queuing and the possibility of violence. In the first model, there is no capacity constraint. Using this model, we compute the long run delay per citizen in allocating the pertinent good. Next, we discuss the computation of the equilibrium probabilities for our discrete-time Markov chain theoretic model. In the second model, we capture the violence aspect of the underlying story explicitly with a capacity constraint. Then, we compute the long run fraction of citizens who are not provided the relevant good and the long run fraction of time the good allocating public official is busy.Capacity Constraint, Goods Allocation, Queuing Mechanism, Scarcity, Violence

    High spectral resolution ground-based observations of Venus in the 450-1250 cm sup-1 region

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    The thermal emission of Venus was recorded during the winter of 1970-1971, and in 1973 using the 2.7m telescope at McDonald Observatory. The double beam Michelson interferometer installed at the Coude focus was used. The spectrum was recorded between 400/cm and 1,400/cm. For the 1970 observations, the spectral resolution was 0.25/cm and the linear spatial resolution was 3/4 of the disk of Venus. In 1973 the spectral resolution was 0.20/cm with a spatial resolution 1/3 of the planetary disk. In addition to Venus, the moon, the sky adjacent to each object, and the zenith sky were recorded to help eliminate the absorption and emission effects of the earth's atmosphere

    Reprogrammable field programmable gate array with integrated system for mitigating effects of single event upsets

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    An integrated system mitigates the effects of a single event upset (SEU) on a reprogrammable field programmable gate array (RFPGA). The system includes (i) a RFPGA having an internal configuration memory, and (ii) a memory for storing a configuration associated with the RFPGA. Logic circuitry programmed into the RFPGA and coupled to the memory reloads a portion of the configuration from the memory into the RFPGA's internal configuration memory at predetermined times. Additional SEU mitigation can be provided by logic circuitry on the RFPGA that monitors and maintains synchronized operation of the RFPGA's digital clock managers

    Systems and methods for detecting a failure event in a field programmable gate array

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    An embodiment generally relates to a method of self-detecting an error in a field programmable gate array (FPGA). The method includes writing a signature value into a signature memory in the FPGA and determining a conclusion of a configuration refresh operation in the FPGA. The method also includes reading an outcome value from the signature memory

    Estimating rainfall distributions at high temporal resolutions using a multifractal model

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    International audienceRainfall data from 18 stations in the vicinity of Tokyo city, measured to a precision of 1 mm, were analysed for multifractal properties. A multifractal model based on the scaling properties of temporal distribution of rainfall intensities was formulated to investigate the intensity distribution relationships in the available scaling regime. Although conventional analysis did not provide encouraging results with these measurements, an alternative approach that could be applied to rainfall data of widely variable quality and duration was used to establish a scaling relationship between daily and hourly rainfall intensities. Using a discrete cascade algorithm based on the log-Lèvy generator, synthetic hourly rainfall series were generated from the multifractal statistics of daily-accumulated rainfall. Several properties of rainfall time series that are relevant to the use of rainfall data in surface hydrological studies were used to determine, statistically, the degree of agreement between the synthetic hourly series and observed hourly rainfall. Keywords: rainfall modelling, cascades, multifractal, downscalin

    Valuing Avoided Soil Erosion by Considering Private and Public Net Benefits

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    The population in New Zealand is expected to increase to over five million by the mid 2020’s from the current level of 4.3 million (Statistics New Zealand, 2009). An increasing demand for primary produce as a result may put pressure on marginal land to be farmed. Understanding the economic value of avoided erosion in New Zealand is therefore an important factor in policy making to optimise the soil related activities in the economy. Establishing a methodology for estimating the economic value of avoided soil erosion is the first step in assessing the problem. This study uses the future forest scenarios developed by Scion to identify potential afforestation areas and thereby compare the current erosion/sedimentation status under current land-use (non woody vegetation) with potential future afforestation. The study aims to quantify the incremental public and private net benefits from the change in scenario. The notion has come under different headings in the literature, such as on-site and off-site erosion effects or sediment and soil erosion effects, all of which recognize the importance of separation of effects to avoid double-counting. The separation into public and private benefits and costs in this case, while avoiding double-counting, will also help identify appropriate policy instruments to avoid soil erosion damage using the private and public net benefit framework (Pannell, 2008).Environmental Economics and Policy, Land Economics/Use,

    Investigation of the agricultural resources in Sri Lanka

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    The author has identified the following significant results. Several in-house capabilities were developed. The facilities to prepare color composites of excellent quality were developed, using bulk B/W 70 mm transparencies or 1:1,000,000 positive transparencies. These color composites were studied through optical devices on light tables. A zoom transfer scope was also added, enabling direct transfer of LANDSAT composite data on to base maps

    Radiation-Tolerant Intelligent Memory Stack - RTIMS

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    This innovation provides reconfigurable circuitry and 2-Gb of error-corrected or 1-Gb of triple-redundant digital memory in a small package. RTIMS uses circuit stacking of heterogeneous components and radiation shielding technologies. A reprogrammable field-programmable gate array (FPGA), six synchronous dynamic random access memories, linear regulator, and the radiation mitigation circuits are stacked into a module of 42.7 42.7 13 mm. Triple module redundancy, current limiting, configuration scrubbing, and single- event function interrupt detection are employed to mitigate radiation effects. The novel self-scrubbing and single event functional interrupt (SEFI) detection allows a relatively soft FPGA to become radiation tolerant without external scrubbing and monitoring hardwar

    Radiation Tolerant Intelligent Memory Stack (RTIMS)

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    The Radiation Tolerant Intelligent Memory Stack (RTIMS), suitable for both geostationary and low earth orbit missions, has been developed. The memory module is fully functional and undergoing environmental and radiation characterization. A self-contained flight-like module is expected to be completed in 2006. RTIMS provides reconfigurable circuitry and 2 gigabits of error corrected or 1 gigabit of triple redundant digital memory in a small package. RTIMS utilizes circuit stacking of heterogeneous components and radiation shielding technologies. A reprogrammable field programmable gate array (FPGA), six synchronous dynamic random access memories, linear regulator, and the radiation mitigation circuitries are stacked into a module of 42.7mm x 42.7mm x 13.00mm. Triple module redundancy, current limiting, configuration scrubbing, and single event function interrupt detection are employed to mitigate radiation effects. The mitigation techniques significantly simplify system design. RTIMS is well suited for deployment in real-time data processing, reconfigurable computing, and memory intensive applications

    From rituals to magic: Interactive art and HCI of the past, present, and future

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    The connection between art and technology is much tighter than is commonly recognized. The emergence of aesthetic computing in the early 2000s has brought renewed focus on this relationship. In this article, we articulate how art and Human–Computer Interaction (HCI) are compatible with each other and actually essential to advance each other in this era, by briefly addressing interconnected components in both areas—interaction, creativity, embodiment, affect, and presence. After briefly introducing the history of interactive art, we discuss how art and HCI can contribute to one another by illustrating contemporary examples of art in immersive environments, robotic art, and machine intelligence in art. Then, we identify challenges and opportunities for collaborative efforts between art and HCI. Finally, we reiterate important implications and pose future directions. This article is intended as a catalyst to facilitate discussions on the mutual benefits of working together in the art and HCI communities. It also aims to provide artists and researchers in this domain with suggestions about where to go next
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