147,907 research outputs found

    Exploring potential of crowdsourced geographic information in studies of active travel and health: Strava data and cycling behaviour

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    In development of sustainable transportation and green city, policymakers encourage people to commute by cycling and walking instead of motor vehicles in cities. One the one hand, cycling and walking enables decrease in air pollution emissions. On the other hand, cycling and walking offer health benefits by increasing people’s physical activity. Earlier studies on investigating spatial patterns of active travel (cycling and walking) are limited by lacks of spatially fine-grained data. In recent years, with the development of information and communications technology, GPS-enabled devices are popular and portable. With smart phones or smart watches, people are able to record their cycling or walking GPS traces when they are moving. A large number of cyclists and pedestrians upload their GPS traces to sport social media to share their historical traces with other people. Those sport social media thus become a potential source for spatially fine-grained cycling and walking data. Very recently, Strava Metro offer aggregated cycling and walking data with high spatial granularity. Strava Metro aggregated a large amount of cycling and walking GPS traces of Strava users to streets or intersections across a city. Accordingly, as a kind of crowdsourced geographic information, the aggregated data is useful for investigating spatial patterns of cycling and walking activities, and thus is of high potential in understanding cycling or walking behavior at a large spatial scale. This study is a start of demonstrating usefulness of Strava Metro data for exploring cycling or walking patterns at a large scal

    Microscopic Description of Band Structure at Very Extended Shapes in the A ~ 110 Mass Region

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    Recent experiments have confirmed the existence of rotational bands in the A \~ 110 mass region with very extended shapes lying between super- and hyper-deformation. Using the projected shell model, we make a first attempt to describe quantitatively such a band structure in 108Cd. Excellent agreement is achieved in the dynamic moment of inertia J(2) calculation. This allows us to suggest the spin values for the energy levels, which are experimentally unknown. It is found that at this large deformation, the sharply down-sloping orbitals in the proton i_{13/2} subshell are responsible for the irregularity in the experimental J(2), and the wave functions of the observed states have a dominant component of two-quasiparticles from these orbitals. Measurement of transition quadrupole moments and g-factors will test these findings, and thus can provide a deeper understanding of the band structure at very extended shapes.Comment: 4 pages, 3 eps figures, final version accepted by Phys. Rev. C as a Rapid Communicatio

    Oscillation-Based Test Structure and Method for OTA-C Filters

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    “This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." “Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.”This paper describes a design for testability technique for operational transconductance amplifier and capacitor filters using an oscillation-based test topology. The oscillation-based test structure is a vectorless output test strategy easily extendable to built-in self-test. The proposed methodology converts filter under test into a quadrature oscillator using very simple techniques and measures the output frequency. The oscillation frequency may be considered as a digital signal and it can be evaluated using digital circuitry therefore the test time is very small. These characteristics imply that the proposed method is very suitable for catastrophic and parametric faults testing and also effective in detecting single and multiple faults. The validity of the proposed method has been verified using comparison between faulty and fault-free simulation results of two integrator loop and Tow-Thomas filters. Simulation results in 0.25 mum CMOS technology show that the proposed oscillation-based test strategy for OTA-C filters has 87% fault coverage and with a minimum number of extra components, requires a negligible area overhead

    A CMOS 100 MHz continuous-time seventh order 0.05° equiripple linear phase leapfrog multiple loop feedback Gm-C filter

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    “This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." “Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.”A novel 100 MHz CMOS Gm-C seventh-order 0.05° equiripple linear phase low-pass multiple loop feedback (MLF) filter based on leapfrog (LF) topology is presented. The filter is implemented using a fully-differential linear, high performance operational transconductance amplifier (OTA) based on cross-coupled pairs. PSpice simulations in a standard TSMC 0.25 μm CMOS process and with a single 5 V power supply have shown that the cut-off frequency of the filter without and with gain boost ranges from 8-32 MHz and 15-100 MHz, respectively. With gain boost, total harmonic distortion (THD) for a differential input voltage Vid of 315 mVpp at 1 MHz is less than -40 dB, dynamic range at 1% THD is over 55 dB, output noise with bandwidth 500 MHz is only 300 μVRMS, and power consumption is 322 mW

    Oscillation-based Test Method for Continuous-time OTA-C Filters

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    “This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." “Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.”Design for testability technique using oscillation-based test topology for KHN OTA-C filters is proposed. The oscillation-based test structure is a vectorless output test strategy easily extendable to built-in self-test. During test mode, the filter under test is converted into an oscillator by establishing the oscillation condition in its transfer function. The oscillator frequency can be measured using digital circuitry and deviations from the cut-off frequency indicate the faulty behaviour of the filter. The proposed method is suitable for both catastrophic and parametric fault diagnosis as well as effective in detecting single and multiple faults. The validity of the proposed method has been verified using comparison between faulty and fault-free simulation results of KHN OTA-C filter. Simulation results in 0.25mum CMOS technology show that the proposed oscillation-based test strategy has 84% fault coverage and with a minimum number of extra components, requires a negligible area overhead.Final Published versio
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