Abstract: Drilling is the most common machining operation and it forms the highest machining cost in many manufacturing activities including automotive engine production. The outcome of this operation depends upon many factors including utilization of proper cutting tool geometry, cutting tool material and the type of coating used to improve hardness and resistance to wear, and also cutting parameters. With the availability of a large array of tool geometries, materials and coatings, is has become a challenging task to select the best tool and cutting parameters that would result in the lowest machining cost or highest profit rate. This paper describes an algorithm developed to help achieve good performances in drilling operations by automatically determination of proper cutting tools and cutting parameters. It also helps determine machining sequences resulting in minimum tool changes that would eventually reduce machining time and cost where multiple tools are used.
Abstract: This paper describes an effective solution to the task
of a remote monitoring of super-extended objects (oil and gas
pipeline, railways, national frontier). The suggested solution is based
on the principle of simultaneously monitoring of seismoacoustic and
optical/infrared physical fields. The principle of simultaneous
monitoring of those fields is not new but in contrast to the known
solutions the suggested approach allows to control super-extended
objects with very limited operational costs. So-called C-OTDR
(Coherent Optical Time Domain Reflectometer) systems are used to
monitor the seismoacoustic field. Far-CCTV systems are used to
monitor the optical/infrared field. A simultaneous data processing
provided by both systems allows effectively detecting and classifying
target activities, which appear in the monitored objects vicinity. The
results of practical usage had shown high effectiveness of the
suggested approach.
Abstract: Cellular communication is being widely used by all
over the world. The users of handsets are increasing due to the
request from marketing sector. The important aspect that has to be
touch in this paper is about the security system of cellular
communication. It is important to provide users with a secure channel
for communication. A brief description of the new GSM cellular
network architecture will be provided. Limitations of cellular
networks, their security issues and the different types of attacks will
be discussed. The paper will go over some new security mechanisms
that have been proposed by researchers. Overall, this paper clarifies
the security system or services of cellular communication using
GSM. Three Malaysian Communication Companies were taken as
Case study in this paper.
Abstract: In this paper the performance of unified power flow
controller is investigated in controlling the flow of po wer over the
transmission line. Voltage sources model is utilized to study the
behaviour of the UPFC in regulating the active, reactive power and
voltage profile. This model is incorporated in Newton Raphson
algorithm for load flow studies. Simultaneous method is employed
in which equations of UPFC and the power balance equations of
network are combined in to one set of non-linear algebraic equations.
It is solved according to the Newton raphson algorithm. Case studies
are carried on standard 5 bus network. Simulation is done in Matlab.
The result of network with and without using UPFC are compared in
terms of active and reactive power flows in the line and active and
reactive power flows at the bus to analyze the performance of UPFC.
Abstract: Motor imagery classification provides an important basis for designing Brain Machine Interfaces [BMI]. A BMI captures and decodes brain EEG signals and transforms human thought into actions. The ability of an individual to control his EEG through imaginary mental tasks enables him to control devices through the BMI. This paper presents a method to design a four state BMI using EEG signals recorded from the C3 and C4 locations. Principle features extracted through principle component analysis of the segmented EEG are analyzed using two novel classification algorithms using Elman recurrent neural network and functional link neural network. Performance of both classifiers is evaluated using a particle swarm optimization training algorithm; results are also compared with the conventional back propagation training algorithm. EEG motor imagery recorded from two subjects is used in the offline analysis. From overall classification performance it is observed that the BP algorithm has higher average classification of 93.5%, while the PSO algorithm has better training time and maximum classification. The proposed methods promises to provide a useful alternative general procedure for motor imagery classification
Abstract: In this paper, two matrix iterative methods are presented to solve the matrix equation A1X1B1 + A2X2B2 + ... + AlXlBl = C the minimum residual problem l i=1 AiXiBi−CF = minXi∈BRni×ni l i=1 AiXiBi−CF and the matrix nearness problem [X1, X2, ..., Xl] = min[X1,X2,...,Xl]∈SE [X1,X2, ...,Xl] − [X1, X2, ..., Xl]F , where BRni×ni is the set of bisymmetric matrices, and SE is the solution set of above matrix equation or minimum residual problem. These matrix iterative methods have faster convergence rate and higher accuracy than former methods. Paige’s algorithms are used as the frame method for deriving these matrix iterative methods. The numerical example is used to illustrate the efficiency of these new methods.
Abstract: The algorithms of convex hull have been extensively studied in literature, principally because of their wide range of applications in different areas. This article presents an efficient algorithm to construct approximate convex hull from a set of n points in the plane in O(n + k) time, where k is the approximation error control parameter. The proposed algorithm is suitable for applications preferred to reduce the computation time in exchange of accuracy level such as animation and interaction in computer graphics where rapid and real-time graphics rendering is indispensable.
Abstract: We seek exact solutions of the coupled Klein-Gordon-Schrödinger equation with variable coefficients with the aid of Lie classical approach. By using the Lie classical method, we are able to derive symmetries that are used for reducing the coupled system of partial differential equations into ordinary differential equations. From reduced differential equations we have derived some new exact solutions of coupled Klein-Gordon-Schrödinger equations involving some special functions such as Airy wave functions, Bessel functions, Mathieu functions etc.
Abstract: The pressure drag from a cam shaped tube in cross flows have been investigated experimentally using pressure distribution measurement. The range of angle of attack and Reynolds number based on an equivalent circular tube are within 0≤α≤360° and 2×104< Reeq < 3.4 ×104, respectively. It is found that the pressure drag coefficient is at its highest at α=90° and 270° over the whole range of Reynolds number. Results show that the pressure drag coefficient of the cam shaped tube is lower than that of circular tube with the same surface area for more of the angles of attack. Furthermore, effects of the diameter ratio and finite length of the cam shaped tube upon the pressure drag coefficient are discussed.
Abstract: Analytical investigation of the free vibration behavior
of circular functionally graded (FG) plates integrated with two
uniformly distributed actuator layers made of piezoelectric (PZT4)
material on the top and bottom surfaces of the circular FG plate
based on the classical plate theory (CPT) is presented in this paper.
The material properties of the functionally graded substrate plate are
assumed to be graded in the thickness direction according to the
power-law distribution in terms of the volume fractions of the
constituents and the distribution of electric potential field along the
thickness direction of piezoelectric layers is simulated by a quadratic
function. The differential equations of motion are solved analytically
for clamped edge boundary condition of the plate. The detailed
mathematical derivations are presented and Numerical investigations
are performed for FG plates with two surface-bonded piezoelectric
layers. Emphasis is placed on investigating the effect of varying the
gradient index of FG plate on the free vibration characteristics of the
structure. The results are verified by those obtained from threedimensional
finite element analyses.
Abstract: This paper presents a novel CMOS four-transistor
SRAM cell for very high density and low power embedded SRAM
applications as well as for stand-alone SRAM applications. This cell
retains its data with leakage current and positive feedback without
refresh cycle. The new cell size is 20% smaller than a conventional
six-transistor cell using same design rules. Also proposed cell uses
two word-lines and one pair bit-line. Read operation perform from
one side of cell, and write operation perform from another side of
cell, and swing voltage reduced on word-lines thus dynamic power
during read/write operation reduced. The fabrication process is fully
compatible with high-performance CMOS logic technologies,
because there is no need to integrate a poly-Si resistor or a TFT load.
HSPICE simulation in standard 0.25μm CMOS technology confirms
all results obtained from this paper.
Abstract: Attitude Determination (AD) of a spacecraft using the
phase measurements of the Global Navigation Satellite System
(GNSS) is an active area of research. Various attitude determination
algorithms have been developed in yester years for spacecrafts using
different sensors but the last two decades have witnessed a
phenomenal increase in research related with GPS receivers as a
stand-alone sensor for determining the attitude of satellite using the
phase measurements of the signals from GNSS. The GNSS-based
Attitude determination algorithms have been experimented in many
real missions. The problem of AD algorithms using GNSS phase
measurements has two important parts; the ambiguity resolution and
the determining of attitude. Ambiguity resolution is the widely
addressed topic in literature for implementing the AD algorithm
using GNSS phase measurements for achieving the accuracy of
millimeter level. This paper broadly overviews the different
techniques for resolving the integer ambiguities encountered in AD
using GNSS phase measurements.
Abstract: The objective of the present investigation was to
evaluate the morphology of Escherchia coli bacteria in interaction
with SiO2 nanoparticles.
This study was made by atomic force microscopy and quartz
crystal microbalance using SiO2 nanoparticles with 10nm, 50nm and
100nm diameter and bacteria immobilized on polyelectrolyte
multilayer films obtained by spin coating or by “layer by layer”
(LbL) method.
Abstract: System testing is actually done to the entire system
against the Functional Requirement Specification and/or the System
Requirement Specification. Moreover, it is an investigatory testing
phase, where the focus is to have almost a destructive attitude and
test not only the design, but also the behavior and even the believed
expectations of the customer. It is also intended to test up to and
beyond the bounds defined in the software/hardware requirements
specifications. In Motorola®, Automated Testing is one of the testing
methodologies uses by GSG-iSGT (Global Software Group - iDEN
TM
Subcriber Group-Test) to increase the testing volume, productivity
and reduce test cycle-time in iDEN
TM
phones testing. Testing is able
to produce more robust products before release to the market. In this
paper, iHopper is proposed as a tool to perform stress test on iDEN
TM
phonse. We will discuss the value that automation has brought to
iDEN
TM
Phone testing such as improving software quality in the
iDEN
TM
phone together with some metrics. We will also look into
the advantages of the proposed system and some discussion of the
future work as well.
Abstract: Optimal load shedding (LS) design as an emergency plan is one of the main control challenges posed by emerging new uncertainties and numerous distributed generators including renewable energy sources in a modern power system. This paper presents an overview of the key issues and new challenges on optimal LS synthesis concerning the integration of wind turbine units into the power systems. Following a brief survey on the existing LS methods, the impact of power fluctuation produced by wind powers on system frequency and voltage performance is presented. The most LS schemas proposed so far used voltage or frequency parameter via under-frequency or under-voltage LS schemes. Here, the necessity of considering both voltage and frequency indices to achieve a more effective and comprehensive LS strategy is emphasized. Then it is clarified that this problem will be more dominated in the presence of wind turbines.
Abstract: The quality of Ribbed Smoked Sheets
(RSS) primarily based on color, dryness, and the presence or
absence of fungus and bubbles. This quality is strongly
influenced by the drying and fumigation process namely
smoking process. Smoking that is held in high temperature
long time will result scorched dark brown sheets, whereas if
the temperature is too low or slow drying rate would resulted
in less mature sheets and growth of fungus. Therefore need to
find the time and temperature for optimum quality of sheets.
Enhance, unmonitored heat and mass transfer during smoking
process lead to high losses of energy balance. This research
aims to generate simple empirical mathematical model
describing the effect of smoking time and temperature to RSS
quality of color, water content, fungus and bubbles. The
second goal of study was to analyze energy balance during
smoking process. Experimental study was conducted by
measuring temperature, residence time and quality parameters
of 16 sheets sample in smoking rooms. Data for energy
consumption balance such as mass of fuel wood, mass of
sheets being smoked, construction temperature, ambient
temperature and relative humidity were taken directly along
the smoking process. It was found that mathematical model
correlating smoking temperature and time with color is Color
= -169 - 0.184 T4 - 0.193 T3 - 0.160 0.405 T1 + T2 + 0.388 t1
+3.11 t2 + 3.92t3 + 0.215 t4 with R square 50.8% and with
moisture is Moisture = -1.40-0.00123 T4 + 0.00032 T3 +
0.00260 T2 - 0.00292 T1 - 0.0105 t1 + 0.0290 t2 + 0.0452 t3
+ 0.00061 t4 with R square of 49.9%. Smoking room energy
analysis found useful energy was 27.8%. The energy stored in
the material construction 7.3%. Lost of energy in conversion
of wood combustion, ventilation and others were 16.6%. The
energy flowed out through the contact of material construction
with the ambient air was found to be the highest contribution
to energy losses, it reached 48.3%.
Abstract: In this paper, we are concerned with the design and
its simulation studies of a modified extremum seeking control for
nonlinear systems. A standard extremum seeking control has a simple
structure, but it takes a long time to reach an optimal operating point.
We consider a modification of the standard extremum seeking control
which is aimed to reach the optimal operating point more speedily
than the standard one. In the modification, PD acceleration term
is added before an integrator making a principal control, so that it
enables the objects to be regulated to the optimal point smoothly. This
proposed method is applied to Monod and Williams-Otto models to
investigate its effectiveness. Numerical simulation results show that
this modified method can improve the time response to the optimal
operating point more speedily than the standard one.
Abstract: Aurein 1.2 is a 13-residue amphipathic peptide with antibacterial and anticancer activity. Aurein1.2 and its retro analog were synthesized to study the activity of the peptides in relation to their structure. The antibacterial test result showed the retro-analog is inactive. The secondary structural analysis by CD spectra indicated that both of the peptides at TFE/Water adopt alpha-helical conformation. MD simulation was performed on aurein 1.2 and retro-analog in water and TFE in order to analyse the factors that are involved in the activity difference between retro and the native peptide. The simulation results are discussed and validated in the light of experimental data from the CD experiment. Both of the peptides showed a relatively similar pattern for their hydrophobicity, hydrophilicity, solvent accessible surfaces, and solvent accessible hydrophobic surfaces. However, they showed different in directions of dipole moment of peptides. Also, Our results further indicate that the reversion of the amino acid sequence affects flexibility .The data also showed that factors causing structural rigidity may decrease the activity. Consequently, our finding suggests that in the case of sequence-reversed peptide strategy, one has to pay attention to the role of amino acid sequence order in making flexibility and role of dipole moment direction in peptide activity. KeywordsAntimicrobial peptides, retro, molecular dynamic, circular dichroism.
Abstract: The fine structure of supercavitation in the wake of a
symmetrical cylinder is studied with high-speed video cameras. The
flow is observed in a cavitation tunnel at the speed of 8m/sec when the
sidewall and the wake are partially filled with the massive cavitation
bubbles. The present experiment observed that a two-dimensional
ripple wave with a wave length of 0.3mm is propagated in a
downstream direction, and then abruptly increases to a thicker
three-dimensional layer. IR-photography recorded that the wakes
originated from the horseshoe vortexes alongside the cylinder. The
wake was developed to inside the dead water zone, which absorbed the
bubbly wake propelled from the separated vortices at the center of the
cylinder. A remote sensing classification technique (maximum most
likelihood) determined that the surface porosity was 0.2, and the mean
speed in the mixed wake was 7m/sec. To confirm the existence of
two-dimensional wave motions in the interface, the experiments were
conducted at a very low frequency, and showed similar gravity waves
in both the upper and lower interfaces.
Abstract: A new deployment of the multiple criteria decision
making (MCDM) techniques: the Simple Additive Weighting
(SAW), and the Technique for Order Preference by Similarity to
Ideal Solution (TOPSIS) for portfolio allocation, is demonstrated in
this paper. Rather than exclusive reference to mean and variance as in
the traditional mean-variance method, the criteria used in this
demonstration are the first four moments of the portfolio distribution.
Each asset is evaluated based on its marginal impacts to portfolio
higher moments that are characterized by trapezoidal fuzzy numbers.
Then centroid-based defuzzification is applied to convert fuzzy
numbers to the crisp numbers by which SAW and TOPSIS can be
deployed. Experimental results suggest the similar efficiency of these
MCDM approaches to selecting dominant assets for an optimal
portfolio under higher moments. The proposed approaches allow
investors flexibly adjust their risk preferences regarding higher
moments via different schemes adapting to various (from
conservative to risky) kinds of investors. The other significant
advantage is that, compared to the mean-variance analysis, the
portfolio weights obtained by SAW and TOPSIS are consistently
well-diversified.