1,970 research outputs found
An improved chaos method for monitoring the depth of anaesthesia
This paper proposed a new method to monitor the depth of anaesthesia (DoA) by modifying the Hurst parameters in Chaos method. Two new indices (CDoA and CsDoA) are proposed to estimate the anaesthesia states of patients. In order to reduce the fluctuation of CDoA and CsDoA trends, the Chaos and Modified Detrended Average methods (C-MDMA) are combined together. Compared with Bispectrum (BIS) index, CDoA, the CsDoA and C-MDMA trends are close to the BIS trend in the whole scale from 100 to 0 with a full recording time
Q-enhanced fold-and-bond MEMS inductors
This work presents a novel coil fabrication technology
to enhance quality factor (Q factor) of microfabricated inductors
for implanted medical wireless sensing and data/power transfer
applications. Using parylene as a flexible thin-film device
substrate, a post-microfabrication substrate folding-and-bonding
method is developed to effectively increase the metal thickness of
the surface-micromachined inductors, resulting in their lower
self-resistance so their higher quality factor. One-fold-and-bond
coils are successfully demonstrated as an example to verify the
feasibility of the fabrication technology with measurement results
in good agreements with device simulation. Depending on target
specifications, multiple substrate folding-and-bonding can be
extensively implemented to facilitate further improved electrical
characteristics of the coils from single fabrication batch. Such Q-enhanced
inductors can be broadly utilized with great potentials
in flexible integrated wireless devices/systems for intraocular
prostheses and other biomedical implants
Local Cyber-physical Attack with Leveraging Detection in Smart Grid
A well-designed attack in the power system can cause an initial failure and
then results in large-scale cascade failure. Several works have discussed power
system attack through false data injection, line-maintaining attack, and
line-removing attack. However, the existing methods need to continuously attack
the system for a long time, and, unfortunately, the performance cannot be
guaranteed if the system states vary. To overcome this issue, we consider a new
type of attack strategy called combinational attack which masks a line-outage
at one position but misleads the control center on line outage at another
position. Therefore, the topology information in the control center is
interfered by our attack. We also offer a procedure of selecting the vulnerable
lines of its kind. The proposed method can effectively and continuously deceive
the control center in identifying the actual position of line-outage. The
system under attack will be exposed to increasing risks as the attack
continuously. Simulation results validate the efficiency of the proposed attack
strategy.Comment: Accepted by IEEE SmartGridComm 201
The local relaxation and correlation production in the quantum Ising model
Isolated quantum systems follow the unitary evolution, which guarantees the
full many body state always keeps a constant entropy as its initial one. Here
we consider the local dynamics of a quantum Ising model with a finite size. It
turns out, for both strong and weak coupling situations, the dynamics of local
observables exhibits similar relaxation behavior as the macroscopic
thermodynamics, which is called the local relaxation; after a certain typical
time, the relaxation behavior suddenly changes and appears random, which is
referred as a recurrence. Besides, we find that the total correlation entropy
of this system approximately exhibit a monotonic increasing envelope in both
strong and weak coupling cases, which is quite similar as the irreversible
entropy production in the standard macroscopic thermodynamics.Comment: 6 pages, 2 figure
Local Cyber-Physical Attack for Masking Line Outage and Topology Attack in Smart Grid
Malicious attacks in the power system can eventually result in a large-scale
cascade failure if not attended on time. These attacks, which are traditionally
classified into \emph{physical} and \emph{cyber attacks}, can be avoided by
using the latest and advanced detection mechanisms. However, a new threat
called \emph{cyber-physical attacks} which jointly target both the physical and
cyber layers of the system to interfere the operations of the power grid is
more malicious as compared with the traditional attacks. In this paper, we
propose a new cyber-physical attack strategy where the transmission line is
first physically disconnected, and then the line-outage event is masked, such
that the control center is misled into detecting as an obvious line outage at a
different position in the local area of the power system. Therefore, the
topology information in the control center is interfered by our attack. We also
propose a novel procedure for selecting vulnerable lines, and analyze the
observability of our proposed framework. Our proposed method can effectively
and continuously deceive the control center into detecting fake line-outage
positions, and thereby increase the chance of cascade failure because the
attention is given to the fake outage. The simulation results validate the
efficiency of our proposed attack strategy.Comment: accepted by IEEE Transactions on Smart Grid. arXiv admin note: text
overlap with arXiv:1708.0320
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