Abstract: This paper presents the work of signal discrimination
specifically for Electrocardiogram (ECG) waveform. ECG signal is
comprised of P, QRS, and T waves in each normal heart beat to
describe the pattern of heart rhythms corresponds to a specific
individual. Further medical diagnosis could be done to determine any
heart related disease using ECG information. The emphasis on QRS
Complex classification is further discussed to illustrate the
importance of it. Pan-Tompkins Algorithm, a widely known
technique has been adapted to realize the QRS Complex
classification process. There are eight steps involved namely
sampling, normalization, low pass filter, high pass filter (build a band
pass filter), derivation, squaring, averaging and lastly is the QRS
detection. The simulation results obtained is represented in a
Graphical User Interface (GUI) developed using MATLAB.
Abstract: In this paper, the application of sliding-mode control to a permanent-magnet synchronous motor (PMSM) is presented. The control design is based on a generic mathematical model of the motor. Some dynamics of the motor and of the power amplification stage remain unmodelled. This model uncertainty is estimated in realtime. The estimation is based on the differentiation of measured signals using the ideas of robust exact differentiator (RED). The control law is implemented on an industrial servo drive. Simulations and experimental results are presented and compared to the same control strategy without uncertainty estimation. It turns out that the proposed concept is superior to the same control strategy without uncertainty estimation especially in the case of non-smooth reference signals.
Abstract: MANEMO is the integration of Network Mobility
(NEMO) and Mobile Ad Hoc Network (MANET). A MANEMO
node has an interface to both a MANET and NEMO network, and
therefore should choose the optimal interface for packet delivery,
however such a handover between interfaces will introduce packet
loss. We define the steps necessary for a MANEMO handover,
using Mobile IP and NEMO to signal the new binding to the
relevant Home Agent(s). The handover steps aim to minimize the
packet loss by avoiding waiting for Duplicate Address Detection
and Neighbour Unreachability Detection. We present expressions for
handover delay and packet loss, and then use numerical examples to
evaluate a MANEMO handover. The analysis shows how the packet
loss depends on level of nesting within NEMO, the delay between
Home Agents and the load on the MANET, and hence can be used
to developing optimal MANEMO handover algorithms.
Abstract: Mostly the real life signals are time varying in nature. For proper characterization of such signals, time-frequency representation is required. The STFT (short-time Fourier transform) is a classical tool used for this purpose. The limitation of the STFT is its fixed time-frequency resolution. Thus, an enhanced version of the STFT, which is based on the cross-level sampling, is devised. It can adapt the sampling frequency and the window function length by following the input signal local variations. Therefore, it provides an adaptive resolution time-frequency representation of the input. The computational complexity of the proposed STFT is deduced and compared to the classical one. The results show a significant gain of the computational efficiency and hence of the processing power. The processing error of the proposed technique is also discussed.
Abstract: Assessment for image quality traditionally needs its
original image as a reference. The conventional method for assessment
like Mean Square Error (MSE) or Peak Signal to Noise Ratio (PSNR)
is invalid when there is no reference. In this paper, we present a new
No-Reference (NR) assessment of image quality using blur and noise.
The recent camera applications provide high quality images by help of
digital Image Signal Processor (ISP). Since the images taken by the
high performance of digital camera have few blocking and ringing
artifacts, we only focus on the blur and noise for predicting the
objective image quality. The experimental results show that the
proposed assessment method gives high correlation with subjective
Difference Mean Opinion Score (DMOS). Furthermore, the proposed
method provides very low computational load in spatial domain and
similar extraction of characteristics to human perceptional assessment.
Abstract: In this work we introduce an efficient method to limit
the impact of the hiding process on the quality of the cover speech.
Vector quantization of the speech spectral information reduces drastically
the number of the secret speech parameters to be embedded
in the cover signal. Compared to scalar hiding, vector quantization
hiding technique provides a stego signal that is indistinguishable from
the cover speech. The objective and subjective performance measures
reveal that the current hiding technique attracts no suspicion about the
presence of the secret message in the stego speech, while being able
to recover an intelligible copy of the secret message at the receiver
side.
Abstract: The important issue considered in the widespread deployment of Wireless Sensor Networks (WSNs) is an efficiency of the energy consumption. In this paper, we present a study of the optimal relay station planning problems using Binary Integer Linear Programming (BILP) model to minimize the energy consumption in WSNs. Our key contribution is that the proposed model not only ensures the required network lifetime but also guarantees the radio connectivity at high level of communication quality. Specially, we take into account effects of noise, signal quality limitation and bit error rate characteristics. Numerical experiments were conducted in various network scenarios. We analyzed the effects of different sensor node densities and distribution on the energy consumption.
Abstract: Since atmosphere pressure field is an actual envoy of
climatic signal the atmospheric Highs and Lows should be attributed
to the key active focal points within the ocean-atmosphere interplay
system. Here we were set a task to determine how the dynamics of
those centres of action relates to the climate change both on regional
and global scales. For this target the near-surface temperature and
atmospheric pressure differences between the Icelandic Low and the
Azores High were considered. The secular term of phase states of the
system under consideration was found divided into three
nonintersecting subsets. Each of that was put in consequence with
one of three climatic scenarios related to the periods of 1905-1935
(relatively warm phase), 1940-1970 (cold phase) and 1980-2000
(warm phase).
Abstract: All climate models agree that the temperature in
Greece will increase in the range of 1° to 2°C by the year 2030 and
mean sea level in Mediterranean is expected to rise at the rate of 5
cm/decade. The aim of the present paper is the estimation of the
coastline displacement driven by the climate change and sea level
rise. In order to achieve that, all known statistical and non-statistical
computational methods are employed on some Greek coastal areas.
Furthermore, Kalman filtering techniques are for the first time
introduced, formulated and tested. Based on all the above, shoreline
change signals and noises are computed and an inter-comparison
between the different methods can be deduced to help evaluating
which method is most promising as far as the retrieve of shoreline
change rate is concerned.
Abstract: Time interleaved sigma-delta (TIΣΔ) architecture is a
potential candidate for high bandwidth analog to digital converters
(ADC) which remains a bottleneck for software and cognitive radio
receivers. However, the performance of the TIΣΔ architecture is
limited by the unavoidable gain and offset mismatches resulting
from the manufacturing process. This paper presents a novel digital
calibration method to compensate the gain and offset mismatch
effect. The proposed method takes advantage of the reconstruction
digital signal processing on each channel and requires only few logic
components for implementation. The run time calibration is estimated
to 10 and 15 clock cycles for offset cancellation and gain mismatch
calibration respectively.
Abstract: Non-stationary trend in R-R interval series is
considered as a main factor that could highly influence the evaluation
of spectral analysis. It is suggested to remove trends in order to obtain
reliable results. In this study, three detrending methods, the
smoothness prior approach, the wavelet and the empirical mode
decomposition, were compared on artificial R-R interval series with
four types of simulated trends. The Lomb-Scargle periodogram was
used for spectral analysis of R-R interval series. Results indicated that
the wavelet method showed a better overall performance than the other
two methods, and more time-saving, too. Therefore it was selected for
spectral analysis of real R-R interval series of thirty-seven healthy
subjects. Significant decreases (19.94±5.87% in the low frequency
band and 18.97±5.78% in the ratio (p
Abstract: In this paper we propose a method for modeling the
correlation between the received signals by two or more antennas
operating in a multipath environment. Considering the maximum
excess delay in the channel being modeled, an elliptical region
surrounding both transmitter and receiver antennas is produced. A
number of scatterers are randomly distributed in this region and
scatter the incoming waves. The amplitude and phase of incoming
waves are computed and used to obtain statistical properties of the
received signals. This model has the distinguishable advantage of
being applicable for any configuration of antennas. Furthermore the
common PDF (Probability Distribution Function) of received wave
amplitudes for any pair of antennas can be calculated and used to
produce statistical parameters of received signals.
Abstract: Mathematical and computational modeling of calcium
signalling in nerve cells has produced considerable insights into how
the cells contracts with other cells under the variation of biophysical
and physiological parameters. The modeling of calcium signaling in
astrocytes has become more sophisticated. The modeling effort has
provided insight to understand the cell contraction. Main objective
of this work is to study the effect of voltage gated (Operated)
calcium channel (VOC) on calcium profile in the form of advection
diffusion equation. A mathematical model is developed in the form
of advection diffusion equation for the calcium profile. The model
incorporates the important physiological parameter like diffusion
coefficient etc. Appropriate boundary conditions have been framed.
Finite volume method is employed to solve the problem. A program
has been developed using in MATLAB 7.5 for the entire problem
and simulated on an AMD-Turion 32-bite machine to compute the
numerical results.
Abstract: Here we report on the utilization of Laser-Induced
Breakdown Spectroscopy (LIBS) for determination of Quantum Dots
(QDs) in liquid solution. The process of optimization of experimental
conditions from choosing the carrier medium to application of colloid
QDs is described. The main goal was to get the best possible signal to
noise ratio.
The results obtained from the measurements confirmed the capability
of LIBS technique for qualitative and afterwards quantitative
determination of QDs in liquid solution.
Abstract: This paper describes a method of signal process applied
on an end effects of Hilbert-Huang transform (HHT) to provide an
improvement in the reality of spectrum. The method is based on
back-propagation network (BPN). To improve the effect, the end
extension of the original signal is obtained by back-propagation
network. A full waveform including origin and its extension is
decomposed by using empirical mode decomposition (EMD) to obtain
intrinsic mode functions (IMFs) of the waveform. Then, the Hilbert
transform (HT) is applied to the IMFs to obtain the Hilbert spectrum of
the waveform. As a result, the method is superiority of the processing
of end effect of HHT to obtain the real frequency spectrum of signals.
Abstract: A mammal-s body can be seen as a blood vessel with
complex tunnels. When heart pumps blood periodically, blood runs
through blood vessels and rebounds from walls of blood vessels.
Blood pressure signals can be measured with complex but periodic
patterns. When an artery is clamped during a surgical operation, the
spectrum of blood pressure signals will be different from that of
normal situation. In this investigation, intestinal artery clamping
operations were conducted to a pig for simulating the situation of
intestinal blocking during a surgical operation. Similarity theory is a
convenient and easy tool to prove that patterns of blood pressure
signals of intestinal artery blocking and unblocking are surely
different. And, the algorithm of Hilbert Huang Transform can be
applied to extract the character parameters of blood pressure pattern.
In conclusion, the patterns of blood pressure signals of two different
situations, intestinal artery blocking and unblocking, can be
distinguished by these character parameters defined in this paper.
Abstract: Signalized intersections on high-volume arterials are
often congested during peak hours, causing a decrease in through
movement efficiency on the arterial. Much of the vehicle delay
incurred at conventional intersections is caused by high left-turn
demand. Unconventional intersection designs attempt to reduce
intersection delay and travel time by rerouting left-turns away from
the main intersection and replacing it with right-turn followed by Uturn.
The proposed new type of U-turn intersection is geometrically
designed with a raised island which provides a protected U-turn
movement. In this study several scenarios based on different
distances between U-turn and main intersection, traffic volume of
major/minor approaches and percentage of left-turn volumes were
simulated by use of AIMSUN, a type of traffic microsimulation
software. Subsequently some models are proposed in order to
compute travel time of each movement. Eventually by correlating
these equations to some in-field collected data of some implemented
U-turn facilities, the reliability of the proposed models are approved.
With these models it would be possible to calculate travel time of
each movement under any kind of geometric and traffic condition. By
comparing travel time of a conventional signalized intersection with
U-turn intersection travel time, it would be possible to decide on
converting signalized intersections into this new kind of U-turn
facility or not. However comparison of travel time is not part of the
scope of this research. In this paper only travel time of this innovative
U-turn facility would be predicted. According to some before and
after study about the traffic performance of some executed U-turn
facilities, it is found that commonly, this new type of U-turn facility
produces lower travel time. Thus, evaluation of using this type of
unconventional intersection should be seriously considered.
Abstract: An integrated vehicle dynamics control system is developed in this paper by a combination of active front steering (AFS) and direct yaw-moment control (DYC) based on fuzzy logic control. The control system has a hierarchical structure consisting of two layers. A fuzzy logic controller is used in the upper layer (yaw rate controller) to keep the yaw rate in its desired value. The yaw rate error and its rate of change are applied to the upper controlling layer as inputs, where the direct yaw moment control signal and the steering angle correction of the front wheels are the outputs. In the lower layer (fuzzy integrator), a fuzzy logic controller is designed based on the working region of the lateral tire forces. Depending on the directions of the lateral forces at the front wheels, a switching function is activated to adjust the scaling factor of the fuzzy logic controller. Using a nonlinear seven degrees of freedom vehicle model, the simulation results illustrate considerable improvements which are achieved in vehicle handling through the integrated AFS/DYC control system in comparison with the individual AFS or DYC controllers.
Abstract: The householder RLS (HRLS) algorithm is an O(N2)
algorithm which recursively updates an arbitrary square-root of the
input data correlation matrix and naturally provides the LS weight
vector. A data dependent householder matrix is applied for such
an update. In this paper a recursive estimate of the eigenvalue
spread and misalignment of the algorithm is presented at a very low
computational cost. Misalignment is found to be highly sensitive to
the eigenvalue spread of input signals, output noise of the system and
exponential window. Simulation results show noticeable degradation
in the misalignment by increase in eigenvalue spread as well as
system-s output noise, while exponential window was kept constant.
Abstract: Ability of accurate and reliable location estimation in
indoor environment is the key issue in developing great number of
context aware applications and Location Based Services (LBS).
Today, the most viable solution for localization is the Received
Signal Strength (RSS) fingerprinting based approach using wireless
local area network (WLAN). This paper presents two RSS
fingerprinting based approaches – first we employ widely used
WLAN based positioning as a reference system and then investigate
the possibility of using GSM signals for positioning. To compare
them, we developed a positioning system in real world environment,
where realistic RSS measurements were collected. Multi-Layer
Perceptron (MLP) neural network was used as the approximation
function that maps RSS fingerprints and locations. Experimental
results indicate advantage of WLAN based approach in the sense of
lower localization error compared to GSM based approach, but GSM
signal coverage by far outreaches WLAN coverage and for some
LBS services requiring less precise accuracy our results indicate that
GSM positioning can also be a viable solution.