Abstract: Mixed convection in two-dimensional shallow rectangular enclosure is considered. The top hot wall moves with constant velocity while the cold bottom wall has no motion. Simulations are performed for Richardson number ranging from Ri = 0.001 to 100 and for Reynolds number keeping fixed at Re = 408.21. Under these conditions cavity encompasses three regimes: dominating forced, mixed and free convection flow. The Prandtl number is set to 6 and the effects of cavity inclination on the flow and heat transfer are studied for different Richardson number. With increasing the inclination angle, interesting behavior of the flow and thermal fields are observed. The streamlines and isotherm plots and the variation of the Nusselt numbers on the hot wall are presented. The average Nusselt number is found to increase with cavity inclination for Ri ³ 1 . Also it is shown that the average Nusselt number changes mildly with the cavity inclination in the dominant forced convection regime but it increases considerably in the regime with dominant natural convection.
Abstract: In this paper, an automatic detecting algorithm for
QRS complex detecting was applied for analyzing ECG recordings
and five criteria for dangerous arrhythmia diagnosing are applied for a
protocol type of automatic arrhythmia diagnosing system. The
automatic detecting algorithm applied in this paper detected the
distribution of QRS complexes in ECG recordings and related
information, such as heart rate and RR interval. In this investigation,
twenty sampled ECG recordings of patients with different pathologic
conditions were collected for off-line analysis. A combinative
application of four digital filters for bettering ECG signals and
promoting detecting rate for QRS complex was proposed as
pre-processing. Both of hardware filters and digital filters were
applied to eliminate different types of noises mixed with ECG
recordings. Then, an automatic detecting algorithm of QRS complex
was applied for verifying the distribution of QRS complex. Finally,
the quantitative clinic criteria for diagnosing arrhythmia were
programmed in a practical application for automatic arrhythmia
diagnosing as a post-processor. The results of diagnoses by automatic
dangerous arrhythmia diagnosing were compared with the results of
off-line diagnoses by experienced clinic physicians. The results of
comparison showed the application of automatic dangerous
arrhythmia diagnosis performed a matching rate of 95% compared
with an experienced physician-s diagnoses.
Abstract: Mobile ad hoc network is a collection of mobile
nodes communicating through wireless channels without any existing
network infrastructure or centralized administration. Because of the
limited transmission range of wireless network interfaces, multiple
"hops" may be needed to exchange data across the network. In order
to facilitate communication within the network, a routing protocol is
used to discover routes between nodes. The primary goal of such an
ad hoc network routing protocol is correct and efficient route
establishment between a pair of nodes so that messages may be
delivered in a timely manner. Route construction should be done
with a minimum of overhead and bandwidth consumption. This paper
examines two routing protocols for mobile ad hoc networks– the
Destination Sequenced Distance Vector (DSDV), the table- driven
protocol and the Ad hoc On- Demand Distance Vector routing
(AODV), an On –Demand protocol and evaluates both protocols
based on packet delivery fraction, normalized routing load, average
delay and throughput while varying number of nodes, speed and
pause time.
Abstract: This paper deals with the design of a periodic output
feedback controller for a flexible beam structure modeled with
Timoshenko beam theory, Finite Element Method, State space
methods and embedded piezoelectrics concept. The first 3 modes are
considered in modeling the beam. The main objective of this work is
to control the vibrations of the beam when subjected to an external
force. Shear piezoelectric sensors and actuators are embedded into
the top and bottom layers of a flexible aluminum beam structure, thus
making it intelligent and self-adaptive. The composite beam is
divided into 5 finite elements and the control actuator is placed at
finite element position 1, whereas the sensor is varied from position 2
to 5, i.e., from the nearby fixed end to the free end. 4 state space
SISO models are thus developed. Periodic Output Feedback (POF)
Controllers are designed for the 4 SISO models of the same plant to
control the flexural vibrations. The effect of placing the sensor at
different locations on the beam is observed and the performance of
the controller is evaluated for vibration control. Conclusions are
finally drawn.
Abstract: This paper presents three-phase evolution search methodology to automatically design fuzzy logic controllers (FLCs) that can work in a wide range of operating conditions. These include varying load, parameter variations, and unknown external disturbances. The three-phase scheme consists of an exploration phase, an exploitation phase and a robustness phase. The first two phases search for FLC with high accuracy performances while the last phase aims at obtaining FLC providing the best compromise between the accuracy and robustness performances. Simulations were performed for direct-drive two-axis robot arm. The evolved FLC with the proposed design technique found to provide a very satisfactory performance under the wide range of operation conditions and to overcome problem associated with coupling and nonlinearities characteristics inherent to robot arms.
Abstract: Feature selection plays an important role in applications with high dimensional data. The assessment of the stability of feature selection/ranking algorithms becomes an important issue when the dataset is small and the aim is to gain insight into the underlying process by analyzing the most relevant features. In this work, we propose a graphical approach that enables to analyze the similarity between feature ranking techniques as well as their individual stability. Moreover, it works with whatever stability metric (Canberra distance, Spearman's rank correlation coefficient, Kuncheva's stability index,...). We illustrate this visualization technique evaluating the stability of several feature selection techniques on a spectral binary dataset. Experimental results with a neural-based classifier show that stability and ranking quality may not be linked together and both issues have to be studied jointly in order to offer answers to the domain experts.
Abstract: A mathematical model for the transmission of SARS is developed. In addition to dividing the population into susceptible (high and low risk), exposed, infected, quarantined, diagnosed and recovered classes, we have included a class called untraced. The model simulates the Gompertz curves which are the best representation of the cumulative numbers of probable SARS cases in Hong Kong and Singapore. The values of the parameters in the model which produces the best fit of the observed data for each city are obtained by using a differential evolution algorithm. It is seen that the values for the parameters needed to simulate the observed daily behaviors of the two epidemics are different.
Abstract: BRI-STARS (BRIdge Stream Tube model for Alluvial
River Simulation) program was used to investigate the scour depth around bridge piers in some of the major river systems in Iran. Model
calibration was performed by collecting different field data. Field data are cataloged on three categories, first group of bridges that
their rivers bed are formed by fine material, second group of bridges
that their rivers bed are formed by sand material, and finally bridges that their rivers bed are formed by gravel or cobble materials.
Verification was performed with some field data in Fars Province. Results show that for wide piers, computed scour depth is more than
measured one. In gravel bed streams, computed scour depth is greater
than measured scour depth, the reason is due to formation of armor layer on bed of channel. Once this layer is eroded, the computed
scour depth is close to the measured one.
Abstract: The design of Class A and Class AB 2-stage X band
Power Amplifier is described in this report. This power amplifier is
part of a transceiver used in radar for monitoring iron characteristics
in a blast furnace. The circuit was designed using foundry WIN
Semiconductors. The specification requires 15dB gain in the linear
region, VSWR nearly 1 at input as well as at the output, an output
power of 10 dBm and good stable performance in the band 10.9-12.2
GHz. The design was implemented by using inter-stage
configuration, the Class A amplifier was chosen for driver stage i.e.
the first amplifier focusing on the gain and the output amplifier
conducted at Class AB with more emphasis on output power.
Abstract: Laser Doppler flowmetry is a modern method of noninvasive
microcirculation investigation. The aim of our study was to
use this method in the examination of patients with secondary
lymphedema of the lower extremities and obliterating atherosclerosis
of lower extremities. In the analysis of the amplitude-frequency
spectrum of secondary lymphedema patients we have identified
remarkable changes. To describe the changes we used a special
amplitude rate. In both of patients groups this rate was significally
(p
Abstract: The hydrothermal behavior of a bed consisting of
magnetic and shale oil particle admixtures under the effect of a
transverse magnetic field is investigated. The phase diagram, bed
void fraction are studied under wide range of the operating
conditions i.e., gas velocity, magnetic field intensity and fraction of
the magnetic particles. It is found that the range of the stabilized
regime is reduced as the magnetic fraction decreases. In addition, the
bed voidage at the onset of fluidization decreases as the magnetic
fraction decreases. On the other hand, Nusselt number and
consequently the heat transfer coefficient is found to increase as the
magnetic fraction decreases. An empirical equation is investigated to
relate the effect of the gas velocity, magnetic field intensity and
fraction of the magnetic particles on the heat transfer behavior in the
bed.
Abstract: In this paper, we carry over some of the results which
are valid on a certain class of Moufang-Klingenberg planes M(A)
coordinatized by an local alternative ring A := A(ε) = A+Aε of
dual numbers to finite projective Klingenberg plane M(A) obtained
by taking local ring Zq (where prime power q = pk) instead of A.
So, we show that the collineation group of M(A) acts transitively
on 4-gons, and that any 6-figure corresponds to only one inversible
m ∈ A.
Abstract: In this paper we propose a novel method for human
face segmentation using the elliptical structure of the human head. It
makes use of the information present in the edge map of the image.
In this approach we use the fact that the eigenvalues of covariance
matrix represent the elliptical structure. The large and small
eigenvalues of covariance matrix are associated with major and
minor axial lengths of an ellipse. The other elliptical parameters are
used to identify the centre and orientation of the face. Since an
Elliptical Hough Transform requires 5D Hough Space, the Circular
Hough Transform (CHT) is used to evaluate the elliptical parameters.
Sparse matrix technique is used to perform CHT, as it squeeze zero
elements, and have only a small number of non-zero elements,
thereby having an advantage of less storage space and computational
time. Neighborhood suppression scheme is used to identify the valid
Hough peaks. The accurate position of the circumference pixels for
occluded and distorted ellipses is identified using Bresenham-s
Raster Scan Algorithm which uses the geometrical symmetry
properties. This method does not require the evaluation of tangents
for curvature contours, which are very sensitive to noise. The method
has been evaluated on several images with different face orientations.
Abstract: Use of a sliding joint is an effective method to
decrease the stress in foundation structure where there is a horizontal
deformation of subsoil (areas afflicted with underground mining) or
horizontal deformation of a foundation structure (pre-stressed
foundations, creep, shrinkage, temperature deformation). A
convenient material for a sliding joint is a bitumen asphalt belt.
Experiments for different types of bitumen belts were undertaken at
the Faculty of Civil Engineering - VSB Technical University of
Ostrava in 2008. This year an extension of the 2008 experiments is in
progress and the shear resistance of a slide joint is being tested as a
function of temperature in a temperature controlled room. In this
paper experimental results of temperature dependant shear resistance
are presented. The result of the experiments should be the sliding
joint shear resistance as a function of deformation velocity and
temperature. This relationship is used for numerical analysis of
stress/strain relation between foundation structure and subsoil. Using
a rheological slide joint could lead to a decrease of the reinforcement
amount, and contribute to higher reliability of foundation structure
and thus enable design of more durable and sustainable building
structures.
Abstract: In this paper a simple terrain evaluation method for
hexapod robot is introduced. This method is based on feet coordinate
evaluation when all are on the ground. Depending on the feet
coordinate differences the local terrain evaluation is possible. Terrain
evaluation is necessary for right gait selection and/or body position
correction. For terrain roughness evaluation three planes are plotted:
two of them as definition points use opposite feet coordinates, third
coincides with the robot body plane. The leaning angle of body plane
is evaluated measuring gravity force using three-axis accelerometer.
Terrain roughness evaluation method is based on angle estimation
between normal vectors of these planes. Aim of this work is to
present a simple method for embedded robot controller, allowing to
find the best further movement settings.
Abstract: This project aims to investigate the potential of
torrefaction to improve the properties of Malaysian palm kernel shell
(PKS) as a solid fuel. A study towards torrefaction of PKS was
performed under various temperature and residence time of 240, 260,
and 280oC and 30, 60, and 90 minutes respectively. The torrefied
PKS was characterized in terms of the mass yield, energy yield,
elemental composition analysis, calorific value analysis, moisture and
volatile matter contents, and ash and fixed carbon contents. The mass
and energy yield changes in the torrefied PKS were observed to
prove that the temperature has more effect compare to residence time
in the torrefaction process. The C content of PKS increases while H
and O contents decrease after torrefaction, which resulted in higher
heating value between 5 to 16%. Meanwhile, torrefaction caused the
ash and fixed carbon content of PKS to increase, and the moisture
and volatile matter to decrease.
Abstract: Due to the rise of aging population, effective utilization
of healthcare resources has become an important issue. With the
advance of ICT technology, the application of tele-healthcare service
has received more attention than ever. The main purpose of this
research is to investigate how to conduct innovative design for
tele-healthcare service based on user-s perspectives. First, the
healthcare service blueprint was used to describe the processes
of tele-healthcare service delivery, and then construct PZB service
quality gap model based on the literature and practitioners-
interviews. Next, TRIZ theory is applied to implement service
innovation. We found the proposed service innovation procedures can
effectively improve the quality of service design.
Abstract: Decision feedback equalizers are commonly employed to reduce the error caused by intersymbol interference. Here, an adaptive decision feedback equalizer is presented with a new adaptation algorithm. The algorithm follows a block-based approach of normalized least mean square (NLMS) algorithm with set-membership filtering and achieves a significantly less computational complexity over its conventional NLMS counterpart with set-membership filtering. It is shown in the results that the proposed algorithm yields similar type of bit error rate performance over a reasonable signal to noise ratio in comparison with the latter one.
Abstract: The paper examines the theories of media, dominant
effects and critical and cultural theories that are used to examine
media and society issues, and then apply the theories to explore the
current situation of news media in Arab societies. The research is
meant to explore the nature of media in the Arab world and the way
that modern technologies have changed the nature of the Arab public
sphere. It considers the role of an open press in promoting a more
democratic society, while recognizing the unique qualities of an Arab
culture.
Abstract: This research explores visitor-s expectations of service
quality in intelligent living space showroom – Living 3.0 in Taiwan.
Based on the five dimensions of PZB service quality, a specialist
questionnaire is utilized to establish a complete service quality
evaluation framework for Living 3.0. In this research, analysis
hierarchy process (AHP) is applied to find the relative weights among
the criteria. Finally, the service quality evaluation framework and
evaluation results can be used as a guide for Living 3.0 proprietors to
review, improve, and enhance service planning and service qualities in
the future.