Abstract: Multi-level voltage source inverters offer several
advantages such as; derivation of a refined output voltage with
reduced total harmonic distortion (THD), reduction of voltage ratings
of the power semiconductor switching devices and also the reduced
electro-magnetic-interference problems etc. In this paper, new
carrier-overlapped phase-disposition or sub-harmonic sinusoidal
pulse width modulation (CO-PD-SPWM) and also the carrieroverlapped
phase-disposition space vector modulation (CO-PDSVPWM)
schemes for a six-level diode-clamped inverter topology
are proposed. The principle of the proposed PWM schemes is similar
to the conventional PD-PWM with a little deviation from it in the
sense that the triangular carriers are all overlapped. The overlapping
of the triangular carriers on one hand results in an increased number
of switchings, on the other hand this facilitates an improved spectral
performance of the output voltage. It is demonstrated through
simulation studies that the six-level diode-clamped inverter with the
use of CO-PD-SPWM and CO-PD-SVPWM proposed in this paper is
capable of generating multiple levels in its output voltage. The
advantages of the proposed PWM schemes can be derived to benefit,
especially at lower modulation indices of the inverter and hence this
aspect of the proposed PWM schemes can be well exploited in high
power applications requiring low speeds of operation of the drive.
Abstract: The study investigates the mixing performance of
electrokinetically-driven power-law fluids in a microchannel
containing patterned trapezoid blocks. The effects of the geometry
parameters of the patterned trapezoid blocks and the flow behavior
index in the power-law model on the mixing efficiency within the
microchannel are explored. The results show that the mixing efficiency
can be improved by increasing the width of the blocks and extending
the length of upper surface of the blocks. In addition, the results show
that the mixing efficiency increases with an increasing flow behavior
index. Furthermore, it is shown that a heterogeneous patterning of the
zeta potential on the upper surfaces of the trapezoid blocks prompts
the formation of local flow recirculations, and therefore improves the
mixing efficiency. Consequently, it is shown that the mixing
performance improves with an increasing magnitude of the
heterogeneous surface zeta potential.
Abstract: This research aims at development of the Multiple
Intelligences Measurement of Elementary Students. The structural
accuracy test and normality establishment are based on the Multiple
Intelligences Theory of Gardner. This theory consists of eight aspects
namely linguistics, logic and mathematics, visual-spatial relations,
body and movement, music, human relations, self-realization/selfunderstanding
and nature. The sample used in this research consists
of elementary school students (aged between 5-11 years). The size of
the sample group was determined by Yamane Table. The group has
2,504 students. Multistage Sampling was used. Basic statistical
analysis and construct validity testing were done using confirmatory
factor analysis. The research can be summarized as follows; 1.
Multiple Intelligences Measurement consisting of 120 items is
content-accurate. Internal consistent reliability according to the
method of Kuder-Richardson of the whole Multiple Intelligences
Measurement equals .91. The difficulty of the measurement test is
between .39-.83. Discrimination is between .21-.85. 2). The Multiple
Intelligences Measurement has construct validity in a good range,
that is 8 components and all 120 test items have statistical
significance level at .01. Chi-square value equals 4357.7; p=.00 at the
degree of freedom of 244 and Goodness of Fit Index equals 1.00.
Adjusted Goodness of Fit Index equals .92. Comparative Fit Index
(CFI) equals .68. Root Mean Squared Residual (RMR) equals 0.064
and Root Mean Square Error of Approximation equals 0.82. 3). The
normality of the Multiple Intelligences Measurement is categorized
into 3 levels. Those with high intelligence are those with percentiles
of more than 78. Those with moderate/medium intelligence are those
with percentiles between 24 and 77.9. Those with low intelligence
are those with percentiles from 23.9 downwards.
Abstract: This paper describes the architecture for a collaborative Car Pooling System based on a credits mechanism to motivate the cooperation among users. Users can spend the accumulated credits on parking facilities. For this, we propose a business model to support the collaboration between a car pooling system and parking facilities. The Portuguese Lisbon-s Metropolitan area is used as application scenario.
Abstract: In recent years Malaysia has included renewable
energy as an alternative fuel to help in diversifying the country-s
energy reliance on oil, natural gas, coal and hydropower with
biomass and solar energy gaining priority. The scope of this paper is
to look at the designing procedures and analysis of a solar thermal
parabolic trough concentrator by simulation utilizing meteorological
data in several parts of Malaysia. Parameters which include the
aperture area, the diameter of the receiver and the working fluid may
be varied to optimize the design. Aperture area is determined by
considering the width and the length of the concentrator whereas the
geometric concentration ratio (CR) is obtained by considering the
width and diameter of the receiver. Three types of working fluid are
investigated. Theoretically, concentration ratios can be very high in
the range of 10 to 40 000 depending on the optical elements used and
continuous tracking of the sun. However, a thorough analysis is
essential as discussed in this paper where optical precision and
thermal analysis must be carried out to evaluate the performance of
the parabolic trough concentrator as the theoretical CR is not the only
factor that should be considered.
Abstract: Induction motors are being used in greater numbers
throughout a wide variety of industrial and commercial applications
because it provides many benefits and reliable device to convert the
electrical energy into mechanical motion. In some application it-s
desired to control the speed of the induction motor. Because of the
physics of the induction motor the preferred method of controlling its
speed is to vary the frequency of the AC voltage driving the motor. In
recent years, with the microcontroller incorporated into an appliance
it becomes possible to use it to generate the variable frequency AC
voltage to control the speed of the induction motor.
This study investigates the microcontroller based variable
frequency power inverter. the microcontroller is provide the variable
frequency pulse width modulation (PWM) signal that control the
applied voltage on the gate drive, which is provides the required
PWM frequency with less harmonics at the output of the power
inverter.
The fully controlled bridge voltage source inverter has been
implemented with semiconductors power devices isolated gate
bipolar transistor (IGBT), and the PWM technique has been
employed in this inverter to supply the motor with AC voltage.
The proposed drive system for three & single phase power inverter
is simulated using Matlab/Simulink. The Matlab Simulation Results
for the proposed system were achieved with different SPWM. From
the result a stable variable frequency inverter over wide range has
been obtained and a good agreement has been found between the
simulation and hardware of a microcontroller based single phase
inverter.
Abstract: The main objectif of this paper is to present a tool that
we have developed subject to characterize and modelling indoor radio
channel propagation at millimetric wave. The tool is based on the
ray tracing technique (RTT). As, in realistic environment we cannot
neglect the significant impact of Human Body Shadowing and other
objects in motion on indoor 60 GHz propagation channel. Hence,
our proposed model allows a simulation of propagation in a dynamic
indoor environment. First, we describe a model of human body.
Second, RTT with this model is used to simulate the propagation
of millimeter waves in the presence of persons in motion. Results
of the simulation show that this tool gives results in agreement with
those reported in the literature. Specially, the effects of people motion
on temporal channel properties.
Abstract: An original Direct Numerical Simulation (DNS) method to tackle the problem of particulate flows at moderate to high concentration and finite Reynolds number is presented. Our method is built on the framework established by Glowinski and his coworkers [1] in the sense that we use their Distributed Lagrange Multiplier/Fictitious Domain (DLM/FD) formulation and their operator-splitting idea but differs in the treatment of particle collisions. The novelty of our contribution relies on replacing the simple artificial repulsive force based collision model usually employed in the literature by an efficient Discrete Element Method (DEM) granular solver. The use of our DEM solver enables us to consider particles of arbitrary shape (at least convex) and to account for actual contacts, in the sense that particles actually touch each other, in contrast with the simple repulsive force based collision model. We recently upgraded our serial code, GRIFF 1 [2], to full MPI capabilities. Our new code, PeliGRIFF 2, is developed under the framework of the full MPI open source platform PELICANS [3]. The new MPI capabilities of PeliGRIFF open new perspectives in the study of particulate flows and significantly increase the number of particles that can be considered in a full DNS approach: O(100000) in 2D and O(10000) in 3D. Results on the 2D/3D sedimentation/fluidization of isometric polygonal/polyedral particles with collisions are presented.
Abstract: The parametrical study of Shrouded Contra-rotating
Rotor was done in this paper based on 2D axisymmetric simulations.
The calculations were made with an actuator disk as double rotor
model. It objects to explore and quantify the effects of different shroud
geometry parameters mainly using the performance of power loading
(PL), which could evaluate the whole propulsion system capability as
5 Newtontotal thrust generationfor hover demand. The numerical
results show that:The increase of nozzle radius is desired but limited
by the flow separation, its optimal design is around 1.15 times rotor
radius, the viscosity effects greatly constraint the influence of nozzle
shape, the divergent angle around 10.5° performs best for chosen
nozzle length;The parameters of inlet such as leading edge curvature,
radius and internal shape do not affect thrust great but play an
important role in pressure distribution which could produce most part
of shroud thrust, they should be chosen according to the reduction of
adverse pressure gradients to reduce the risk of boundary separation.
Abstract: The development of One Tambon One Product
(OTOP) became the policy of the government in 1997 after the
former Prime Minister had been in power. The strategy of sections is
currently set for the policy. OTOP has become the part of the way of
community lives around the country. OTOP may be developed under
changing into ASEAN economic community in 2015 because of the
flow of capitals, productions, and many workers in the region. All
sectors are improved for the change. The purposes of study were to
study the strength and weakness of the OTOP-creating process via its
policy and to lead to the strategy to be able to apply before changing.
The methodology is qualitative to study its policy including
document and to interview experienced persons. The findings showed
that the effort of improvement of all sectors obviously involves with
OTOP development. Particularly, the strategic administration of
OTOP is in every level of the state, central sector, region, and
community.
Abstract: One of the main challenges for one phase anaerobic digestion processes is the high concentration of NH4+ and PO4 3- ions
in the digested sludge supernatant. This project focuses on enhancing the removal of nutrients during the anaerobic digestion process through fixing both NH4+ and PO4 3- ions in the form of struvite (magnesium ammonium phosphate, MAP, MgNH4PO4.6H2O) within the anaerobic sludge. Batch anaerobic digestion tests showed that Mg2+ concentration in the range 279 – 812 mg/L had insignificant effect on CGP but incurred a slight increase in COD removal. The reactor that had soluble Mg2+:NH4+:PO43- at a molar ratio of 1.28:1:00:1:00 achieved the best performance enhancement of 8% increase in COD removal and 32% reduction in NH4+ in the reactor supernatant. Overall, the results show that there is a potential to optimise conventional anaerobic digestion such that supernatant lean in P and N, and sludge rich in nutrients are obtained.
Abstract: This paper describes a steady state model of a multiple
effect evaporator system for simulation and control purposes. The
model includes overall as well as component mass balance equations,
energy balance equations and heat transfer rate equations for area
calculations for all the effects. Each effect in the process is
represented by a number of variables which are related by the energy
and material balance equations for the feed, product and vapor flow
for backward, mixed and split feed. For simulation 'fsolve' solver in
MATLAB source code is used. The optimality of three sequences i.e.
backward, mixed and splitting feed is studied by varying the various
input parameters.
Abstract: The mixture formation prior to the ignition process
plays as a key element in the diesel combustion. Parametric studies of
mixture formation and ignition process in various injection parameter
has received considerable attention in potential for reducing
emissions. Purpose of this study is to clarify the effects of injection
pressure on mixture formation and ignition especially during ignition
delay period, which have to be significantly influences throughout the
combustion process and exhaust emissions. This study investigated
the effects of injection pressure on diesel combustion fundamentally
using rapid compression machine. The detail behavior of mixture
formation during ignition delay period was investigated using the
schlieren photography system with a high speed camera. This method
can capture spray evaporation, spray interference, mixture formation
and flame development clearly with real images. Ignition process and
flame development were investigated by direct photography method
using a light sensitive high-speed color digital video camera. The
injection pressure and air motion are important variable that strongly
affect to the fuel evaporation, endothermic and prolysis process
during ignition delay. An increased injection pressure makes spray tip
penetration longer and promotes a greater amount of fuel-air mixing
occurs during ignition delay. A greater quantity of fuel prepared
during ignition delay period thus predominantly promotes more rapid
heat release.
Abstract: The evaluation and measurement of human body
dimensions are achieved by physical anthropometry. This research
was conducted in view of the importance of anthropometric indices
of the face in forensic medicine, surgery, and medical imaging. The
main goal of this research is to optimization of facial feature point by
establishing a mathematical relationship among facial features and
used optimize feature points for age classification. Since selected
facial feature points are located to the area of mouth, nose, eyes and
eyebrow on facial images, all desire facial feature points are extracted
accurately. According this proposes method; sixteen Euclidean
distances are calculated from the eighteen selected facial feature
points vertically as well as horizontally. The mathematical
relationships among horizontal and vertical distances are established.
Moreover, it is also discovered that distances of the facial feature
follows a constant ratio due to age progression. The distances
between the specified features points increase with respect the age
progression of a human from his or her childhood but the ratio of the
distances does not change (d = 1 .618 ) . Finally, according to the
proposed mathematical relationship four independent feature
distances related to eight feature points are selected from sixteen
distances and eighteen feature point-s respectively. These four feature
distances are used for classification of age using Support Vector
Machine (SVM)-Sequential Minimal Optimization (SMO) algorithm
and shown around 96 % accuracy. Experiment result shows the
proposed system is effective and accurate for age classification.
Abstract: Human immunodeficiency virus infection and
acquired immunodeficiency syndrome is a global pandemic with
cases reporting from virtually every country and continues to be a
common infection in developing country like India.
Microalbuminuria is a manifestation of human immunodeficiency
virus associated nephropathy. Therefore, microalbuminuria may be
an early marker of human immunodeficiency virus associated
nephropathy, and screening for its presence may be beneficial. A
strikingly high prevalence of microalbuminuria among human
immunodeficiency virus infected patients has been described in
various studies. Risk factors for clinically significant proteinuria
include African - American race, higher human immunodeficiency
virus ribonucleic acid level and lower CD4 lymphocyte count. The
cardiovascular risk factors of increased systolic blood pressure and
increase fasting blood sugar level are strongly associated with
microalbuminuria in human immunodeficiency virus patient. These
results suggest that microalbuminuria may be a sign of current
endothelial dysfunction and micro-vascular disease and there is
substantial risk of future cardiovascular disease events. Positive
contributing factors include early kidney disease such as human
immunodeficiency virus associated nephropathy, a marker of end
organ damage related to co morbidities of diabetes or hypertension,
or more diffuse endothelial cells dysfunction. Nevertheless after
adjustment for non human immunodeficiency virus factors, human
immunodeficiency virus itself is a major risk factor. The presence of
human immunodeficiency virus infection is independent risk to
develop microalbuminuria in human immunodeficiency virus patient.
Cardiovascular risk factors appeared to be stronger predictors of
microalbuminuria than markers of human immunodeficiency virus
severity person with human immunodeficiency virus infection and
microalbuminuria therefore appear to potentially bear the burden of
two separate damage related to known vascular end organ damage
related to know vascular risk factors, and human immunodeficiency
virus specific processes such as the direct viral infection of kidney
cells.The higher prevalence of microalbuminuria among the human
immunodeficiency virus infected could be harbinger of future
increased risks of both kidney and cardiovascular disease. Further
study defining the prognostic significance of microalbuminuria
among human immunodeficiency virus infected persons will be
essential. Microalbuminuria seems to be a predictor of cardiovascular
disease in diabetic and non diabetic subjects, hence it can also be
used for early detection of micro vascular disease in human
immunodeficiency virus positive patients, thus can help to diagnose
the disease at the earliest.
Abstract: The nickel and gold nanoclusters as supported
catalysts were analyzed by XAS, XRD and XPS in order to
determine their local, global and electronic structure. The present
study has pointed out a strong deformation of the local structure of
the metal, due to its interaction with oxide supports. The average
particle size, the mean squares of the microstrain, the particle size
distribution and microstrain functions of the supported Ni and Au
catalysts were determined by XRD method using Generalized Fermi
Function for the X-ray line profiles approximation. Based on EXAFS
analysis we consider that the local structure of the investigated
systems is strongly distorted concerning the atomic number pairs.
Metal-support interaction is confirmed by the shape changes of the
probability densities of electron transitions: Ni K edge (1s →
continuum and 2p), Au LIII-edge (2p3/2 → continuum, 6s, 6d5/2 and
6d3/2). XPS investigations confirm the metal-support interaction at
their interface.
Abstract: Effective evaluation of software development effort is an important issue during project plan. This study provides a model to predict development effort based on the software size estimated with function points. We generalize the average amount of effort spent on each phase of the development, and give the estimates for the effort used in software building, testing, and implementation. Finally, this paper finds a strong correlation between software defects and software size. As the size of software constantly increases, the quality remains to be a matter which requires major concern.
Abstract: The Influence Diagrams (IDs) is a kind of Probabilistic Belief Networks for graphic modeling. The usage of IDs can improve the communication among field experts, modelers, and decision makers, by showing the issue frame discussed from a high-level point of view. This paper enhances the Time-Sliced Influence Diagrams (TSIDs, or called Dynamic IDs) based formalism from a Discrete Event Systems Modeling and Simulation (DES M&S) perspective, for Exploring Analysis (EA) modeling. The enhancements enable a modeler to specify times occurred of endogenous events dynamically with stochastic sampling as model running and to describe the inter- influences among them with variable nodes in a dynamic situation that the existing TSIDs fails to capture. The new class of model is named Dynamic-Stochastic Influence Diagrams (DSIDs). The paper includes a description of the modeling formalism and the hiberarchy simulators implementing its simulation algorithm, and shows a case study to illustrate its enhancements.
Abstract: Some of the students' problems in writing skill stem
from inadequate preparation for the writing assignment. Students
should be taught how to write well when they arrive in language
classes. Having selected a topic, the students examine and explore the
theme from as large a variety of viewpoints as their background and
imagination make possible. Another strategy is that the students
prepare an Outline before writing the paper. The comparison between
the two mentioned thought provoking techniques was carried out
between the two class groups –students of Islamic Azad University of
Dezful who were studying “Writing 2" as their main course. Each
class group was assigned to write five compositions separately in
different periods of time. Then a t-test for each pair of exams between
the two class groups showed that the t-observed in each pair was
more than the t-critical. Consequently, the first hypothesis which
states those who utilize Brainstorming as a thought provoking
technique in prewriting phase are more successful than those who
outline the papers before writing was verified.
Abstract: Bythe development of the Internet, e-commerce has
got very popular between organizations. E-commerce means buying
and selling products and services over the Internet. One of the
challenging issues in e-commerce is how to attract the customers and
how to satisfy them. Therefore, it is important to keep good
relationship with the customers. This paper proposes a new model to
increase the customer satisfaction by introducing live-operator.
Live-operator is a system which is involved both with the customers
and the organization.In this system the customers feelthatthey receive
the service directly from the organization. This model decreases the
response time and the customer loss. Moreover, it increases customer
trust and the ability of organizations.