Abstract: Moulded parts contribute to more than 70% of
components in products. However, common defects particularly in
plastic injection moulding exist such as: warpage, shrinkage, sink
marks, and weld lines. In this paper Taguchi experimental design
methods are applied to reduce the warpage defect of thin plate
Acrylonitrile Butadiene Styrene (ABS) and are demonstrated in two
levels; namely, orthogonal arrays of Taguchi and the Analysis of
Variance (ANOVA). Eight trials have been run in which the optimal
parameters that can minimize the warpage defect in factorial
experiment are obtained. The results obtained from ANOVA
approach analysis with respect to those derived from MINITAB
illustrate the most significant factors which may cause warpage in
injection moulding process. Moreover, ANOVA approach in
comparison with other approaches like S/N ratio is more accurate and
with the interaction of factors it is possible to achieve higher and the
better outcomes.
Abstract: In recent five decades, textured yarns of polyester fiber produced by false twist method are the most
important and mass-produced manmade fibers. There are
many parameters of cross section which affect the physical and mechanical properties of textured yarns. These parameters
are surface area, perimeter, equivalent diameter, large
diameter, small diameter, convexity, stiffness, eccentricity, and hydraulic diameter. These parameters were evaluated by
digital image processing techniques. To find trends between production criteria and evaluated parameters of cross section, three criteria of production line have been adjusted and different types of yarns were produced. These criteria are
temperature, drafting ratio, and D/Y ratio. Finally the relations between production criteria and cross section parameters were
considered. The results showed that the presented technique can recognize and measure the parameters of fiber cross section in acceptable accuracy. Also, the optimum condition
of adjustments has been estimated from results of image analysis evaluation.
Abstract: Scheduling algorithms are used in operating systems
to optimize the usage of processors. One of the most efficient
algorithms for scheduling is Multi-Layer Feedback Queue (MLFQ)
algorithm which uses several queues with different quanta. The most
important weakness of this method is the inability to define the
optimized the number of the queues and quantum of each queue. This
weakness has been improved in IMLFQ scheduling algorithm.
Number of the queues and quantum of each queue affect the response
time directly. In this paper, we review the IMLFQ algorithm for
solving these problems and minimizing the response time. In this
algorithm Recurrent Neural Network has been utilized to find both
the number of queues and the optimized quantum of each queue.
Also in order to prevent any probable faults in processes' response
time computation, a new fault tolerant approach has been presented.
In this approach we use combinational software redundancy to
prevent the any probable faults. The experimental results show that
using the IMLFQ algorithm results in better response time in
comparison with other scheduling algorithms also by using fault
tolerant mechanism we improve IMLFQ performance.
Abstract: This paper deals with the synthesis of fuzzy controller
applied to a permanent magnet synchronous machine (PMSM) with a
guaranteed H∞ performance. To design this fuzzy controller,
nonlinear model of the PMSM is approximated by Takagi-Sugeno
fuzzy model (T-S fuzzy model), then the so-called parallel
distributed compensation (PDC) is employed. Next, we derive the
property of the H∞ norm. The latter is cast in terms of linear matrix
inequalities (LMI-s) while minimizing the H∞ norm of the transfer
function between the disturbance and the error ( ) ev T . The
experimental and simulations results were conducted on a permanent
magnet synchronous machine to illustrate the effects of the fuzzy
modelling and the controller design via the PDC.
Abstract: In this paper a combined feature selection method is
proposed which takes advantages of sample domain filtering,
resampling and feature subset evaluation methods to reduce
dimensions of huge datasets and select reliable features. This method
utilizes both feature space and sample domain to improve the process
of feature selection and uses a combination of Chi squared with
Consistency attribute evaluation methods to seek reliable features.
This method consists of two phases. The first phase filters and
resamples the sample domain and the second phase adopts a hybrid
procedure to find the optimal feature space by applying Chi squared,
Consistency subset evaluation methods and genetic search.
Experiments on various sized datasets from UCI Repository of
Machine Learning databases show that the performance of five
classifiers (Naïve Bayes, Logistic, Multilayer Perceptron, Best First
Decision Tree and JRIP) improves simultaneously and the
classification error for these classifiers decreases considerably. The
experiments also show that this method outperforms other feature
selection methods.
Abstract: Coagulation of water involves the use of coagulating
agents to bring the suspended matter in the raw water together for
settling and the filtration stage. Present study is aimed to examine the
effects of aluminum sulfate as coagulant in conjunction with Moringa
Oleifera Coagulant Protein as coagulant aid on turbidity, hardness,
and bacteria in turbid water. A conventional jar test apparatus was
employed for the tests. The best removal was observed at a pH of 7
to 7.5 for all turbidities. Turbidity removal efficiency was resulted
between % 80 to % 99 by Moringa Oleifera Coagulant Protein as
coagulant aid. Dosage of coagulant and coagulant aid decreased with
increasing turbidity. In addition, Moringa Oleifera Coagulant Protein
significantly has reduced the required dosage of primary coagulant.
Residual Al+3 in treated water were less than 0.2 mg/l and meets the
environmental protection agency guidelines. The results showed that
turbidity reduction of % 85.9- % 98 paralleled by a primary
Escherichia coli reduction of 1-3 log units (99.2 – 99.97%) was
obtained within the first 1 to 2 h of treatment. In conclusions,
Moringa Oleifera Coagulant Protein as coagulant aid can be used for
drinking water treatment without the risk of organic or nutrient
release. We demonstrated that optimal design method is an efficient
approach for optimization of coagulation-flocculation process and
appropriate for raw water treatment.
Abstract: In this paper, we propose an energy efficient cluster
based communication protocol for wireless sensor network. Our
protocol considers both the residual energy of sensor nodes and the
distance of each node from the BS when selecting cluster-head. This
protocol can successfully prolong the network-s lifetime by 1)
reducing the total energy dissipation on the network and 2) evenly
distributing energy consumption over all sensor nodes. In this
protocol, the nodes with more energy and less distance from the BS
are probable to be selected as cluster-head. Simulation results with
MATLAB show that proposed protocol could increase the lifetime of
network more than 94% for first node die (FND), and more than 6%
for the half of the nodes alive (HNA) factor as compared with
conventional protocols.
Abstract: Detection and tracking of the lip contour is an important
issue in speechreading. While there are solutions for lip tracking
once a good contour initialization in the first frame is available,
the problem of finding such a good initialization is not yet solved
automatically, but done manually. We have developed a new tracking
solution for lip contour detection using only few landmarks (15
to 25) and applying the well known Active Shape Models (ASM).
The proposed method is a new LMS-like adaptive scheme based on
an Auto regressive (AR) model that has been fit on the landmark
variations in successive video frames. Moreover, we propose an extra
motion compensation model to address more general cases in lip
tracking. Computer simulations demonstrate a fair match between
the true and the estimated spatial pixels. Significant improvements
related to the well known LMS approach has been obtained via a
defined Frobenius norm index.
Abstract: This paper explores university course timetabling
problem. There are several characteristics that make scheduling and
timetabling problems particularly difficult to solve: they have huge
search spaces, they are often highly constrained, they require
sophisticated solution representation schemes, and they usually
require very time-consuming fitness evaluation routines. Thus
standard evolutionary algorithms lack of efficiency to deal with
them. In this paper we have proposed a memetic algorithm that
incorporates the problem specific knowledge such that most of
chromosomes generated are decoded into feasible solutions.
Generating vast amount of feasible chromosomes makes the progress
of search process possible in a time efficient manner. Experimental
results exhibit the advantages of the developed Hybrid Genetic
Algorithm than the standard Genetic Algorithm.
Abstract: One of the main processes of supply chain
management is supplier selection process which its accurate
implementation can dramatically increase company competitiveness.
In presented article model developed based on the features of
second tiers suppliers and four scenarios are predicted in order to
help the decision maker (DM) in making up his/her mind. In addition
two tiers of suppliers have been considered as a chain of suppliers.
Then the proposed approach is solved by a method combined of
concepts of fuzzy set theory (FST) and linear programming (LP)
which has been nourished by real data extracted from an engineering
design and supplying parts company. At the end results reveal the
high importance of considering second tier suppliers features as
criteria for selecting the best supplier.
Abstract: The Kowsar dam supply water for different usages
such as drinking, industrial, agricultural and aquaculture farms
usages and located next to the city of Dehdashat in Kohgiluye and
Boyerahmad province in southern Iran. There are some towns and
villages on the Kowsar dam watersheds, which Dehdasht and
Choram are the most important and populated cities in this area. The
study was undertaken to assess the status of water quality in the
urban areas of the Kowsar dam. A total of 28 water samples were
collected from 6 stations on surface water and 1 station from
groundwater on the watershed of the Kowsar dam. All the samples
were analyzed for Cd concentration using standard procedures. The
results were compared with other national and international
standards. Among the analyzed samples, as the maximum value of
cadmium (1.131 μg/L) was observed on the station 2 at the winter
2009, all the samples analyzed were within the maximum admissible
limits by the United States Environmental Protection Agency, EU,
WHO, New Zealand , Australian, Iranian, and the Indian standards.
In general results of the present study have shown that Cd mean
values of stations No. 4, 1 and 2 with 0.5135, 0.0.4733 and 0.4573
μg/L respectively are higher than the other stations . Although Cd
level of all samples and stations have had normal values but this is
an indication of pollution potential and hazards because of human
activity and waste water of towns in the areas, which can effect on
human health implications in future. This research, therefore,
recommends the government and other responsible authorities to take
suitable improving measures in the Kowsar dam watershed-s.
Abstract: In this paper, a new reverse converter for the moduli set {2n, 2n–1, 2n–1–1} is presented. We improved a previously introduced conversion algorithm for deriving an efficient hardware design for reverse converter. Hardware architecture of the proposed converter is based on carry-save adders and regular binary adders, without the requirement for modular adders. The presented design is faster than the latest introduced reverse converter for moduli set {2n, 2n–1, 2n–1–1}. Also, it has better performance than the reverse converters for the recently introduced moduli set {2n+1–1, 2n, 2n–1}
Abstract: The Kowsar dam supply water for different usages
such as drinking, industrial, agricultural and aquaculture farms
usages and located next to the city of Dehdashat in Kohgiluye and
Boyerahmad province in southern Iran. There are some towns and
villages on the Kowsar dam watersheds, which Dehdasht and Choram
are the most important and populated cities in this area. The study
was undertaken to assess the status of water quality in the urban areas
of the Kowsar dam. A total of 28 water samples were collected from
6 stations on surface water and 1 station from groundwater on the
watershed of the Kowsar dam. All the samples were analyzed for Ni
concentration using standard procedures. The results were compared
with other national and international standards. Among the analyzed
samples, as the maximum value of Nickel (0.01 mg/L) was observed
on the station 2 at the autumn 2010, all the samples analyzed were
within the maximum admissible limits by the United States
Environmental Protection Agency, EU, WHO and the Iranian. In
general results of the present study have shown that a Ni mean value
of station No. 2 with 0.006 mg/L is higher than the other stations. Ni
level of all samples and stations have had normal values and this is an
indication of pollution potential and hazards because of human
activity and waste water of towns in the areas, which can effect on
human health implications in future. This research, therefore,
recommends the government and other responsible authorities to take
suitable improving measures in the Kowsar dam watersheds.
Abstract: Development, calibration and validation of a threedimensional
model of the Legform impactor for pedestrian crash with
bumper are presented. Lower limb injury is becoming an increasingly
important concern in vehicle safety for both occupants and
pedestrians. In order to prevent lower extremity injuries to a
pedestrian when struck by a car, it is important to elucidate the
loadings from car front structures on the lower extremities and the
injury mechanism caused by these loadings. An impact test
procedure with a legform addressing lower limb injuries in car
pedestrian accidents has been proposed by EEVC/WG17. In this
study a modified legform impactor is introduced and validated
against EEVC/WG17 criteria. The finite element model of this
legform is developed using LS-DYNA software. Total mass of
legform impactor is 13.4 kg.Technical specifications including the
mass and location of the center of gravity and moment of inertia
about a horizontal axis through the respective centre of gravity in
femur and tibia are determined. The obtained results of legform
impactor static and dynamic tests are as specified in the
EEVC/WG17.
Abstract: In spite of all advancement in software testing,
debugging remains a labor-intensive, manual, time consuming, and
error prone process. A candidate solution to enhance debugging
process is to fuse it with testing process. To achieve this integration,
a possible solution may be categorizing common software tests and
errors followed by the effort on fixing the errors through general
solutions for each test/error pair. Our approach to address this issue is
based on Christopher Alexander-s pattern and pattern language
concepts. The patterns in this language are grouped into three major
sections and connect the three concepts of test, error, and debug.
These patterns and their hierarchical relationship shape a pattern
language that introduces a solution to solve software errors in a
known testing context.
Finally, we will introduce our developed framework ADE as a
sample implementation to support a pattern of proposed language,
which aims to automate the whole process of evolving software
design via evolutionary methods.
Abstract: Drought is a phenomenon caused by
environmental and climatic changes. This phenomenon is
affected by shortage of rainfall and temperature. Dust is one
of important environmental problems caused by climate
change and drought. With recent multi-year drought, many
environmental crises caused by dust in Iran and Middle East.
Dust in the vast areas of the provinces occurs with high
frequency. By dust affecting many problems created in terms
of health, social and economic. In this study, we tried to study
the most important factors causing dust. In this way we have
used the satellite images and meteorological data. Finally,
strategies to deal with the dust will be mentioned.
Abstract: The integral form of equations of motion of composite
beams subjected to varying time loads are discretized using a
developed finite element model. The model consists of a straight five
node twenty-two degrees of freedom beam element. The stability
analysis of the beams is studied by solving the matrix form
characteristic equations of the system. The principle of virtual work
and the first order shear deformation theory are employed to analyze
the beams with large deformation and small strains. The regions of
dynamic instability of the beam are determined by solving the
obtained Mathieu form of differential equations. The effects of nonconservative
loads, shear stiffness, and damping parameters on
stability and response of the beams are examined. Several numerical
calculations are presented to compare the results with data reported
by other researchers.
Abstract: Gasoline Octane Number is the standard measure of
the anti-knock properties of a motor in platforming processes, that is
one of the important unit operations for oil refineries and can be
determined with online measurement or use CFR (Cooperative Fuel
Research) engines. Online measurements of the Octane number can
be done using direct octane number analyzers, that it is too
expensive, so we have to find feasible analyzer, like ANFIS
estimators.
ANFIS is the systems that neural network incorporated in fuzzy
systems, using data automatically by learning algorithms of NNs.
ANFIS constructs an input-output mapping based both on human
knowledge and on generated input-output data pairs.
In this research, 31 industrial data sets are used (21 data for training
and the rest of the data used for generalization). Results show that,
according to this simulation, hybrid method training algorithm in
ANFIS has good agreements between industrial data and simulated
results.
Abstract: Recently studies in area of supply chain network
(SCN) have focused on the disruption issues in distribution systems.
Also this paper extends the previous literature by providing a new biobjective
model for cost minimization of designing a three echelon
SCN across normal and failure scenarios with considering multi
capacity option for manufacturers and distribution centers. Moreover,
in order to solve the problem by means of LINGO software, novel
model will be reformulated through a branch of LP-Metric method
called Min-Max approach.
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.