65,590 research outputs found
Anomalous physical properties of underdoped weak-ferromagnetic superconductor RuSrEuCuO
Similar to the optimal-doped, weak-ferromagnetic (WFM induced by canted
antiferromagnetism, T = 131 K) and superconducting (T = 56 K)
RuSrGdCuO, the underdoped RuSrEuCuO
(T = 133 K, T = 36 K) also exhibited a spontaneous vortex state
(SVS) between 16 K and 36 K. The low field (20 G) superconducting
hysteresis loop indicates a weak and narrow Meissner state region of average
lower critical field B(T) = B(0)[1 -
(T/T)], with B(0) = 7 G and T = 16 K. The
vortex melting transition (T = 21 K) below T obtained from
the broad resistivity drop and the onset of diamagnetic signal indicates a
vortex liquid region due to the coexistence and interplay between
superconductivity and WFM order. No visible jump in specific heat was observed
near T for Eu- and Gd-compound. This is not surprising, since the
electronic specific heat is easily overshadowed by the large phonon and
weak-ferromagnetic contributions. Furthermore, a broad resistivity transition
due to low vortex melting temperature would also lead to a correspondingly
reduced height of any specific heat jump. Finally, with the baseline from the
nonmagnetic Eu-compound, specific heat data analysis confirms the magnetic
entropy associated with antiferromagnetic ordering of Gd (J = S = 7/2)
at 2.5 K to be close to ln8 as expected.Comment: 7 figure
Anti-Fall: A Non-intrusive and Real-time Fall Detector Leveraging CSI from Commodity WiFi Devices
Fall is one of the major health threats and obstacles to independent living
for elders, timely and reliable fall detection is crucial for mitigating the
effects of falls. In this paper, leveraging the fine-grained Channel State
Information (CSI) and multi-antenna setting in commodity WiFi devices, we
design and implement a real-time, non-intrusive, and low-cost indoor fall
detector, called Anti-Fall. For the first time, the CSI phase difference over
two antennas is identified as the salient feature to reliably segment the fall
and fall-like activities, both phase and amplitude information of CSI is then
exploited to accurately separate the fall from other fall-like activities.
Experimental results in two indoor scenarios demonstrate that Anti-Fall
consistently outperforms the state-of-the-art approach WiFall, with 10% higher
detection rate and 10% less false alarm rate on average.Comment: 13 pages,8 figures,corrected version, ICOST conferenc
Gait Verification using Knee Acceleration Signals
A novel gait recognition method for biometric applications is proposed. The approach has the following distinct features. First, gait patterns are determined via knee acceleration signals, circumventing difficulties associated with conventional vision-based gait recognition methods. Second, an automatic procedure to extract gait features from acceleration signals is developed that employs a multiple-template classification method. Consequently, the proposed approach can adjust the sensitivity and specificity of the gait recognition system with great flexibility. Experimental results from 35 subjects demonstrate the potential of the approach for successful recognition. By setting sensitivity to be 0.95 and 0.90, the resulting specificity ranges from 1 to 0.783 and 1.00 to 0.945, respectively
Parallel Computing on a PC Cluster
The tremendous advance in computer technology in the past decade has made it
possible to achieve the performance of a supercomputer on a very small budget.
We have built a multi-CPU cluster of Pentium PC capable of parallel
computations using the Message Passing Interface (MPI). We will discuss the
configuration, performance, and application of the cluster to our work in
physics.Comment: 3 pages, uses Latex and aipproc.cl
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