Abstract: This paper describes a study of geometrically
nonlinear free vibration of thin circular functionally graded (CFGP)
plates resting on Winkler elastic foundations. The material properties
of the functionally graded composites examined here are assumed to
be graded smoothly and continuously through the direction of the
plate thickness according to a power law and are estimated using the
rule of mixture. The theoretical model is based on the classical Plate
theory and the Von-Kármán geometrical nonlinearity assumptions.
An homogenization procedure (HP) is developed to reduce the
problem considered here to that of isotropic homogeneous circular
plates resting on Winkler foundation. Hamilton-s principle is applied
and a multimode approach is derived to calculate the fundamental
nonlinear frequency parameters which are found to be in a good
agreement with the published results. On the other hand, the
influence of the foundation parameters on the nonlinear fundamental
frequency has also been analysed.
Abstract: The purpose of the present study is to analyze the
effect of the target plate-s curvature on the heat transfer in laminar
confined impinging jet flows. Numerical results from two
dimensional compressible finite volume solver are compared
between three different shapes of impinging plates: Flat, Concave
and Convex plates. The remarkable result of this study proves that
the stagnation Nusselt number in laminar range of Reynolds number
based on the slot width is maximum in convex surface and is
minimum in concave plate. These results refuse the previous data in
literature stating the amount of the stagnation Nusselt number is
greater in concave surface related to flat plate configuration.
Abstract: This paper presents the concept and realisation of an
e-learning tool that provides predefined or automatically generated
exercises concerning logistics cost accounting. Students may practise
where and whenever they like to via the Internet. Their solutions are
marked automatically by the tool while considering consecutive
faults and without any intervention of lecturers.
Abstract: Emerging Bio-engineering fields such as Brain
Computer Interfaces, neuroprothesis devices and modeling and
simulation of neural networks have led to increased research activity
in algorithms for the detection, isolation and classification of Action
Potentials (AP) from noisy data trains. Current techniques in the field
of 'unsupervised no-prior knowledge' biosignal processing include
energy operators, wavelet detection and adaptive thresholding. These
tend to bias towards larger AP waveforms, AP may be missed due to
deviations in spike shape and frequency and correlated noise
spectrums can cause false detection. Also, such algorithms tend to
suffer from large computational expense.
A new signal detection technique based upon the ideas of phasespace
diagrams and trajectories is proposed based upon the use of a
delayed copy of the AP to highlight discontinuities relative to
background noise. This idea has been used to create algorithms that
are computationally inexpensive and address the above problems.
Distinct AP have been picked out and manually classified from
real physiological data recorded from a cockroach. To facilitate
testing of the new technique, an Auto Regressive Moving Average
(ARMA) noise model has been constructed bases upon background
noise of the recordings. Along with the AP classification means this
model enables generation of realistic neuronal data sets at arbitrary
signal to noise ratio (SNR).
Abstract: This paper characterizes the effects of artificial short
term aging in the laboratory on the rheological properties of virgin
80/100 penetration grade asphalt binder. After several years in
service, asphalt mixture started to deteriorate due to aging. Aging is a
complex physico-chemical phenomenon that influences asphalt
binder rheological properties causing a deterioration in asphalt
mixture performance. To ascertain asphalt binder aging effects, the
virgin, artificially aged and extracted asphalt binder were tested via
the Rolling Thin film Oven (RTFO), Dynamic Shear Rheometer
(DSR) and Rotational Viscometer (RV). A comparative study
between laboratory and field aging conditions were also carried out.
The results showed that the specimens conditioned for 85 minutes
inside the RTFO was insufficient to simulate the actual short term
aging caused that took place in the field under Malaysian field
conditions
Abstract: In this paper, a fast motion compensation algorithm is
proposed that improves coding efficiency for video sequences with
brightness variations. We also propose a cross entropy measure
between histograms of two frames to detect brightness variations. The
framewise brightness variation parameters, a multiplier and an offset
field for image intensity, are estimated and compensated. Simulation
results show that the proposed method yields a higher peak signal to
noise ratio (PSNR) compared with the conventional method, with a
greatly reduced computational load, when the video scene contains
illumination changes.
Abstract: Earlier studies in kinship networks have primarily
focused on observing the social relationships existing between family
relatives. In this study, we pre-identified hubs in the network to
investigate if they could play a catalyst role in the transfer of physical
information. We conducted a case study of a ceremony performed in
one of the families of a small Hindu community – the Uttar Rarhi
Kayasthas. Individuals (n = 168) who resided in 11 geographically
dispersed regions were contacted through our hub-based
representation. We found that using this representation, over 98% of
the individuals were successfully contacted within the stipulated
period. The network also demonstrated a small-world property, with
an average geodesic distance of 3.56.
Abstract: A two dimensional three segments coupled pendulum system that mathematically models human arm configuration was developed along with constructing and solving the equations of motions for this model using the energy (work) based approach of Lagrange. The equations of motion of the model were solved iteratively both as an initial value problem and as a two point boundary value problem. In the initial value problem solutions, both the initial system configuration (segment angles) and initial system velocity (segment angular velocities) were used as inputs, whereas, in the two point boundary value problem solutions initial and final configurations and time were used as inputs to solve for the trajectory of motion. The results suggest that the model solutions are sensitive to small changes in the dynamic forces applied to the system as well as to the initial and boundary conditions used. To overcome the system sensitivity a new approach is suggested.
Abstract: In the past decade, the development of microstrip
sensor application has evolved tremendously. Although cut and trial
method was adopted to develop microstrip sensing applications in the
past, Computer-Aided-Design (CAD) is a more effective as it ensures
less time is consumed and cost saving is achieved in developing
microstrip sensing applications. Therefore microstrip sensing
applications has gained popularity as an effective tool adopted in
continuous sensing of moisture content particularly in products that is
administered mainly by liquid content. In this research, the Cole-Cole
representation of reactive relaxation is applied to assess the
performance of the microstrip sensor devices. The microstrip sensor
application is an effective tool suitable for sensing the moisture
content of dielectric material. Analogous to dielectric relaxation
consideration of Cole-Cole diagrams as applied to dielectric
materials, a “reactive relaxation concept” concept is introduced to
represent the frequency-dependent and moisture content
characteristics of microstrip sensor devices.
Abstract: This paper presents the applications of computational intelligence techniques to economic load dispatch problems. The fuel cost equation of a thermal plant is generally expressed as continuous quadratic equation. In real situations the fuel cost equations can be discontinuous. In view of the above, both continuous and discontinuous fuel cost equations are considered in the present paper. First, genetic algorithm optimization technique is applied to a 6- generator 26-bus test system having continuous fuel cost equations. Results are compared to conventional quadratic programming method to show the superiority of the proposed computational intelligence technique. Further, a 10-generator system each with three fuel options distributed in three areas is considered and particle swarm optimization algorithm is employed to minimize the cost of generation. To show the superiority of the proposed approach, the results are compared with other published methods.
Abstract: As is known, one of the priority directions of research
works of natural sciences is introduction of applied section of
contemporary mathematics as approximate and numerical methods to
solving integral equation into practice. We fare with the solving of
integral equation while studying many phenomena of nature to whose
numerically solving by the methods of quadrature are mainly applied.
Taking into account some deficiency of methods of quadrature for
finding the solution of integral equation some sciences suggested of
the multistep methods with constant coefficients. Unlike these papers,
here we consider application of hybrid methods to the numerical
solution of Volterra integral equation. The efficiency of the suggested
method is proved and a concrete method with accuracy order p = 4
is constructed. This method in more precise than the corresponding
known methods.
Abstract: In this paper, a recursive algorithm for the
computation of 2-D DCT using Ramanujan Numbers is proposed.
With this algorithm, the floating-point multiplication is completely
eliminated and hence the multiplierless algorithm can be
implemented using shifts and additions only. The orthogonality of
the recursive kernel is well maintained through matrix factorization
to reduce the computational complexity. The inherent parallel
structure yields simpler programming and hardware implementation
and provides
log 1
2
3
2 N N-N+
additions and
N N
2 log
2 shifts which is
very much less complex when compared to other recent multiplierless
algorithms.
Abstract: In this paper we explore the application of a formal proof system to verification problems in cryptography. Cryptographic properties concerning correctness or security of some cryptographic algorithms are of great interest. Beside some basic lemmata, we explore an implementation of a complex function that is used in cryptography. More precisely, we describe formal properties of this implementation that we computer prove. We describe formalized probability distributions (o--algebras, probability spaces and condi¬tional probabilities). These are given in the formal language of the formal proof system Isabelle/HOL. Moreover, we computer prove Bayes' Formula. Besides we describe an application of the presented formalized probability distributions to cryptography. Furthermore, this paper shows that computer proofs of complex cryptographic functions are possible by presenting an implementation of the Miller- Rabin primality test that admits formal verification. Our achievements are a step towards computer verification of cryptographic primitives. They describe a basis for computer verification in cryptography. Computer verification can be applied to further problems in crypto-graphic research, if the corresponding basic mathematical knowledge is available in a database.
Abstract: Grid computing is a high performance computing
environment to solve larger scale computational applications. Grid
computing contains resource management, job scheduling, security
problems, information management and so on. Job scheduling is a
fundamental and important issue in achieving high performance in
grid computing systems. However, it is a big challenge to design an
efficient scheduler and its implementation. In Grid Computing, there
is a need of further improvement in Job Scheduling algorithm to
schedule the light-weight or small jobs into a coarse-grained or
group of jobs, which will reduce the communication time,
processing time and enhance resource utilization. This Grouping
strategy considers the processing power, memory-size and
bandwidth requirements of each job to realize the real grid system.
The experimental results demonstrate that the proposed scheduling
algorithm efficiently reduces the processing time of jobs in
comparison to others.
Abstract: The selective wet-etching of amorphous and
crystalline region of Sb20Se80 thin films was carried out using organic
based solution e.g. amines. We report the development of an in situ
real-time method to study the wet chemical etching process of thin
films. Characterization of the structure and surface of films studied
by X-ray diffraction, SEM and EBSD methods has been done and
potential application suggested.
Abstract: In this paper, delay-dependent stability analysis for
neutral type neural networks with uncertain paramters and
time-varying delay is studied. By constructing new
Lyapunov-Krasovskii functional and dividing the delay interval into
multiple segments, a novel sufficient condition is established to
guarantee the globally asymptotically stability of the considered
system. Finally, a numerical example is provided to illustrate the
usefulness of the proposed main results.
Abstract: The composition, vapour pressure, and heat capacity
of nine biodiesel fuels from different sources were measured. The
vapour pressure of the biodiesel fuels is modeled assuming an ideal
liquid phase of the fatty acid methyl esters constituting the fuel. New
methodologies to calculate the vapour pressure and ideal gas and
liquid heat capacities of the biodiesel fuel constituents are proposed.
Two alternative optimization scenarios are evaluated: 1) vapour
pressure only; 2) vapour pressure constrained with liquid heat
capacity. Without physical constraints, significant errors in liquid
heat capacity predictions were found whereas the constrained
correlation accurately fit both vapour pressure and liquid heat
capacity.
Abstract: Insect pests are the major source of crop
damage, yield and quality reduction in Pakistan and else
where in the world. Cotton crop is the most hit crop in
Pakistan followed by rice and the second most important
foreign exchange earning crop. A wide variety of staple,
horticultural and cash crops grown, reflect serious problems of
many types of insect pests. To overcome the insect pest
problem, pesticide use in Pakistan has increased substantially
which has now been further intensified. Pesticides worth more
than billions of rupees are imported every year. This paper
reviews the over all pesticide use in Pakistan in relation to
pesticide prices, support price of cotton and rice, pesticide use
in different provinces of Pakistan on different crops and their
impact on crop productivity. The environmental pollution
caused by the use of pesticides, contamination of soil and
water resources and the danger associated with the disposal of
their empty containers is also discussed in detail.
Abstract: In the present paper, we obtain a sandwich-type theorem.
As applications of our main result, we discuss the univalence
and starlikeness of analytic functions in terms of certain differential
subordinations and differential inequalities.
Abstract: In switch mode power inverters, small sized inverters
can be obtained by increasing the switching frequency. Switching
frequency increment causes high driver losses. Also, high dt
di
and
dt
dv
produced by the switching action creates high Electromagnetic
Interference (EMI) and Radio Frequency Interference (RFI). In this
paper, a series half bridge series resonant inverter circuit is simulated
and evaluated practically to demonstrate the turn-on and turn-off
conditions during zero or close to zero voltage switching. Also, the
reverse recovery current effects of the body diode of the MOSFETs
were investigated by operating above and below resonant frequency.