Abstract: A numerical study on the heat transfer in the thermal
barrier coatings and the substrates of a parallel-plate enclosure is
carried out. Some of the thermal barrier coatings, such as ceramics, are
semitransparent and are of interest for high-temperature applications
where radiation effects are significant. The radiative transfer equations
and the energy equations are solved by using the discrete ordinates
method and the finite difference method. Illustrative results are
presented for temperature distributions in the coatings and the opaque
walls under various heating conditions. The results show that the
temperature distribution is more uniform in the interior portion of each
coating away from its boundary for the case with a larger average of
varying refractive index and a positive gradient of refractive index
enhances radiative transfer to the substrates.
Abstract: The transient hydrodynamics and thermal behaviors of
fluid flow in open-ended vertical parallel-plate porous microchannel are investigated semi-analytically under the effect of the hyperbolic
heat conduction model. The model that combines both the continuum approach and the possibility of slip at the boundary is adopted in the
study. The Effects of Knudsen number , Darcy number , and thermal relaxation time on the microchannel hydrodynamics and thermal behaviors are investigated using the hyperbolic heat
conduction models. It is found that as increases the slip in the hydrodynamic and thermal boundary condition increases. This slip in
the hydrodynamic boundary condition increases as increases. Also, the slip in the thermal boundary condition increases as
decreases especially the early stage of time.
Abstract: The systematic manipulations of shapes and sizes of
inorganic compounds greatly benefit the various application fields
including optics, magnetic, electronics, catalysis and medicine.
However shape control has been much more difficult to achieve.
Hence exploration of novel method for the preparation of differently
shaped nanoparticles is challenging research area. II-VI group of
semiconductor cadmium sulphide (CdS) nanostructure with different
morphologies (such as, acicular like, mesoporous, spherical shapes)
and of crystallite sizes vary from 11 to 16 nm were successfully
synthesized by chemical aqueous precipitation of Cd2+ ions with
homogeneously released S2- ions from decomposition of cadmium
sulphate (CdSO4) and thioacetamide (CH3CSNH2) by annealing at
different radiations (microwave, ultrasonic and sunlight) with matter
and systematic research has been done for various factors affecting
the controlled growth rate of CdS nanoparticles. The obtained
nanomaterials have been characterized by X-ray Diffraction (XRD),
Fourier Transform Infrared Spectroscopy (FTIR),
Thermogravometric (DSC-TGA) analysis and Scanning Electron
Microscopy (SEM). The result indicates that on increasing the
reaction time particle size increases but on increasing the molar ratios
grain size decreases.
Abstract: Machine Translation (MT 3) of English text to its Urdu equivalent is a difficult challenge. Lot of attempts has been made, but a few limited solutions are provided till now. We present a direct approach, using an expert system to translate English text into its equivalent Urdu, using The Unicode Standard, Version 4.0 (ISBN 0-321-18578-1) Range: 0600–06FF. The expert system works with a knowledge base that contains grammatical patterns of English and Urdu, as well as a tense and gender-aware dictionary of Urdu words (with their English equivalents).
Abstract: Ultra-low-power (ULP) circuits have received
widespread attention due to the rapid growth of biomedical
applications and Battery-less Electronics. Subthreshold region of
transistor operation is used in ULP circuits. Major research challenge
in the subthreshold operating region is to extract the ULP benefits
with minimal degradation in speed and robustness. Process, Voltage
and Temperature (PVT) variations significantly affect the
performance of subthreshold circuits. Designed performance
parameters of ULP circuits may vary largely due to temperature
variations. Hence, this paper investigates the effect of temperature
variation on device and circuit performance parameters at different
biasing voltages in the subthreshold region. Simulation results clearly
demonstrate that in deep subthreshold and near threshold voltage
regions, performance parameters are significantly affected whereas in
moderate subthreshold region, subthreshold circuits are more
immune to temperature variations. This establishes that moderate
subthreshold region is ideal for temperature immune circuits.
Abstract: Equilibrium and stability equations of a thin rectangular plate with length a, width b, and thickness h(x)=C1x+C2, made of functionally graded materials under thermal loads are derived based on the first order shear deformation theory. It is assumed that the material properties vary as a power form of thickness coordinate variable z. The derived equilibrium and buckling equations are then solved analytically for a plate with simply supported boundary conditions. One type of thermal loading, uniform temperature rise and gradient through the thickness are considered, and the buckling temperatures are derived. The influences of the plate aspect ratio, the relative thickness, the gradient index and the transverse shear on buckling temperature difference are all discussed.
Abstract: This study presents an exact general solution for
steady-state conductive heat transfer in cylindrical composite
laminates. Appropriate Fourier transformation has been obtained
using Sturm-Liouville theorem. Series coefficients are achieved by
solving a set of equations that related to thermal boundary conditions
at inner and outer of the cylinder, also related to temperature
continuity and heat flux continuity between each layer. The solution
of this set of equations are obtained using Thomas algorithm. In this
paper, the effect of fibers- angle on temperature distribution of
composite laminate is investigated under general boundary
conditions. Here, we show that the temperature distribution for any
composite laminates is between temperature distribution for
laminates with θ = 0° and θ = 90° .
Abstract: Schema matching plays a key role in many different
applications, such as schema integration, data integration, data
warehousing, data transformation, E-commerce, peer-to-peer data
management, ontology matching and integration, semantic Web,
semantic query processing, etc. Manual matching is expensive and
error-prone, so it is therefore important to develop techniques to
automate the schema matching process. In this paper, we present a
solution for XML schema automated matching problem which
produces semantic mappings between corresponding schema
elements of given source and target schemas. This solution
contributed in solving more comprehensively and efficiently XML
schema automated matching problem. Our solution based on
combining linguistic similarity, data type compatibility and structural
similarity of XML schema elements. After describing our solution,
we present experimental results that demonstrate the effectiveness of
this approach.
Abstract: Distance protection of transmission lines including advanced flexible AC transmission system (FACTS) devices has been a very challenging task. FACTS devices of interest in this paper are static synchronous series compensators (SSSC) and unified power flow controller (UPFC). In this paper, a new algorithm is proposed to detect and classify the fault and identify the fault position in a transmission line with respect to a FACTS device placed in the midpoint of the transmission line. Discrete wavelet transformation and wavelet entropy calculations are used to analyze during fault current and voltage signals of the compensated transmission line. The proposed algorithm is very simple and accurate in fault detection and classification. A variety of fault cases and simulation results are introduced to show the effectiveness of such algorithm.
Abstract: Recently, fast neural networks for object/face
detection were presented in [1-3]. The speed up factor of these
networks relies on performing cross correlation in the frequency
domain between the input image and the weights of the hidden
layer. But, these equations given in [1-3] for conventional and fast
neural networks are not valid for many reasons presented here. In
this paper, correct equations for cross correlation in the spatial and
frequency domains are presented. Furthermore, correct formulas for
the number of computation steps required by conventional and fast
neural networks given in [1-3] are introduced. A new formula for
the speed up ratio is established. Also, corrections for the equations
of fast multi scale object/face detection are given. Moreover,
commutative cross correlation is achieved. Simulation results show
that sub-image detection based on cross correlation in the frequency
domain is faster than classical neural networks.
Abstract: The belief decision tree (BDT) approach is a decision
tree in an uncertain environment where the uncertainty is represented
through the Transferable Belief Model (TBM), one interpretation
of the belief function theory. The uncertainty can appear either in
the actual class of training objects or attribute values of objects to
classify. In this paper, we develop a post-pruning method of belief
decision trees in order to reduce size and improve classification
accuracy on unseen cases. The pruning of decision tree has a
considerable intention in the areas of machine learning.
Abstract: The mechanical properties of granular solids are
dependent on the flow of stresses from one particle to another
through inter-particle contact. Although some experimental methods
have been used to study the inter-particle contacts in the past,
preliminary work with these techniques indicated that they do not
have the necessary resolution to distinguish between those contacts
that transmit the load and those that do not, especially for systems
with a wide distribution of particle sizes. In this research, computer
simulations are used to study the nature and distribution of contacts
in a compact with wide particle size distribution, representative of
aggregate size distribution used in asphalt pavement construction.
The packing fraction, the mean number of contacts and the
distribution of contacts were studied for different scenarios. A
methodology to distinguish and compute the fraction of load-bearing
particles and the fraction of space-filling particles (particles that do
not transmit any force) is needed for further investigation.
Abstract: This study was conducted published to investigate
there liability of the equation pressure-impulse (PI) reinforced
concrete column inprevious studies. Equation involves three different
levels of damage criteria known as D =0. 2, D =0. 5 and D =0. 8.The
damage criteria known as a minor when 0-0.2, 0.2-0.5is known as
moderate damage, high damage known as 0.5-0.8, and 0.8-1 of the
structure is considered a failure. In this study, two types of reliability
analyzes conducted. First, using pressure-impulse equation with
different parameters. The parameters involved are the concrete
strength, depth, width, and height column, the ratio of longitudinal
reinforcement and transverse reinforcement ratio. In the first analysis
of the reliability of this new equation is derived to improve the
previous equations. The second reliability analysis involves three
types of columns used to derive the PI curve diagram using the
derived equation to compare with the equation derived from other
researchers and graph minimum standoff versus weapon yield
Federal Emergency Management Agency (FEMA). The results
showed that the derived equation is more accurate with FEMA
standards than previous researchers.
Abstract: It has been established that microRNAs (miRNAs) play
an important role in gene expression by post-transcriptional regulation
of messengerRNAs (mRNAs). However, the precise relationships
between microRNAs and their target genes in sense of numbers,
types and biological relevance remain largely unclear. Dissecting the
miRNA-target relationships will render more insights for miRNA
targets identification and validation therefore promote the understanding
of miRNA function. In miRBase, miRanda is the key
algorithm used for target prediction for Zebrafish. This algorithm
is high-throughput but brings lots of false positives (noise). Since
validation of a large scale of targets through laboratory experiments
is very time consuming, several computational methods for miRNA
targets validation should be developed. In this paper, we present an
integrative method to investigate several aspects of the relationships
between miRNAs and their targets with the final purpose of extracting
high confident targets from miRanda predicted targets pool. This is
achieved by using the techniques ranging from statistical tests to
clustering and association rules. Our research focuses on Zebrafish.
It was found that validated targets do not necessarily associate with
the highest sequence matching. Besides, for some miRNA families,
the frequency of their predicted targets is significantly higher in the
genomic region nearby their own physical location. Finally, in a case
study of dre-miR-10 and dre-miR-196, it was found that the predicted
target genes hoxd13a, hoxd11a, hoxd10a and hoxc4a of dre-miR-
10 while hoxa9a, hoxc8a and hoxa13a of dre-miR-196 have similar
characteristics as validated target genes and therefore represent high
confidence target candidates.
Abstract: With increasing utilization of the wireless devices in
different fields such as medical devices and industrial fields, the
paper presents a method for simplify the Bluetooth packets with
throughput enhancing. The paper studies a vital issue in wireless
communications, which is the throughput of data over wireless
networks. In fact, the Bluetooth and ZigBee are a Wireless Personal
Area Network (WPAN). With taking these two systems competition
consideration, the paper proposes different schemes for improve the
throughput of Bluetooth network over a reliable channel. The
proposition depends on the Channel Quality Driven Data Rate
(CQDDR) rules, which determines the suitable packet in the
transmission process according to the channel conditions. The
proposed packet is studied over additive White Gaussian Noise
(AWGN) and fading channels. The Experimental results reveal the
capability of extension of the PL length by 8, 16, 24 bytes for classic
and EDR packets, respectively. Also, the proposed method is suitable
for the low throughput Bluetooth.
Abstract: The study of the variability of the postural strategies
in low back pain patients, as a criterion in evaluation of the
adaptability of this system to the environmental demands is the
purpose of this study. A cross-sectional case-control study was
performed on 21 recurrent non-specific low back pain patients and 21
healthy volunteers. The electromyography activity of Deltoid,
External Oblique (EO), Transverse Abdominis/Internal Oblique
(TrA/IO) and Erector Spine (ES) muscles of each person was
recorded in 75 rapid arm flexion with maximum acceleration.
Standard deviation of trunk muscles onset relative to deltoid muscle
onset were statistically analyzed by MANOVA . The results show
that chronic low back pain patients exhibit less variability in their
anticipatory postural adjustments (APAs) in comparison with the
control group. There is a decrease in variability of postural control
system of recurrent non-specific low back pain patients that can
result in the persistence of pain and chronicity by decreasing the
adaptability to environmental demands.
Abstract: The objective of this work is to show a procedure for
mesh generation in a fluidized bed using large eddy simulations
(LES) of a filtered two-fluid model. The experimental data were
obtained by [1] in a laboratory fluidized bed. Results show that it is
possible to use mesh with less cells as compared to RANS turbulence
model with granular kinetic theory flow (KTGF). Also, the numerical
results validate the experimental data near wall of the bed, which
cannot be predicted by RANS.model.
Abstract: THEOS is the first earth observation spacecraft of Thailand which was launched on the 1st October 2008 and is currently operated by GISTDA. The transfer phase has been performed by Astrium Flight Dynamics team leading to a hand over to GISTDA teams starting mid-October 2008. The THEOS spacecraft-s orbit is LEO and has the same repetitivity (14+5/26) as the SPOT spacecraft, i.e. the same altitude of 822 km but it has a different mean local solar time (LST). Ground track maintenance manoeuvres are performed to maintain the ground track within a predefined control band around the reference ground track and the band is ±40 km for THEOS spacecraft. This paper presents the first ground track maintenance manoeuvre of THEOS spacecraft and the detailed results. In addition, it also includes one and a half year of operation as seen by GISTDA operators. It finally describes the foreseenable activities for the next orbit control manoeuvre (OCM) preparation.
Abstract: TiO2/MgO composite films were prepared by coating
the magnesium acetate solution in the pores of mesoporous TiO2
films using a dip coating method. Concentrations of magnesium
acetate solution were varied in a range of 1x10-4 – 1x10-1 M. The
TiO2/MgO composite films were characterized by scanning electron
microscopy (SEM), transmission electron microscropy (TEM),
electrochemical impedance spectroscopy(EIS) , transient voltage
decay and I-V test. The TiO2 films and TiO2/MgO composite films
were immersed in a 0.3 mM N719 dye solution. The Dye-sensitized
solar cells with the TiO2/MgO/N719 structure showed an optimal
concentration of magnesium acetate solution of 1x10-3 M resulting in
the MgO film estimated thickness of 0.0963 nm and giving the
maximum efficiency of 4.85%. The improved efficiency of dyesensitized
solar cell was due to the magnesium oxide film as the wide
band gap coating decays the electron back transfer to the triiodide
electrolyte and reduce charge recombination.
Abstract: Perhaps no single issue has been cited as either the root
cause and / or the greatest challenge to the restructured power system then the lack of adequate reliable transmission. Probabilistic transmission planning has become increasingly necessary and important in recent
years. The transmission planning analysis carried out by the authors,
spans a 10-year horizon, taking into consideration a value of 2 % load
increase / year at each consumer. Taking into consideration this increased
load, a probabilistic power flow was carried out, all the system components
being regarded from probabilistic point of view. Several contingencies
have been generated, for assessing the security of the power system. The results have been analyzed and several important conclusions were pointed. The objective is to achieve a network that works without limit violations for all (or most of) scenario realizations. The case study is represented by the IEEE 14 buses test power system.