Abstract: This paper presents a new circuit arrangement for a
current-mode Wheatstone bridge that is suitable for low-voltage
integrated circuits implementation. Compared to the other proposed
circuits, this circuit features severe reduction of the elements number,
low supply voltage (1V) and low power consumption (
Abstract: Bagging and boosting are among the most popular resampling ensemble methods that generate and combine a diversity of classifiers using the same learning algorithm for the base-classifiers. Boosting algorithms are considered stronger than bagging on noisefree data. However, there are strong empirical indications that bagging is much more robust than boosting in noisy settings. For this reason, in this work we built an ensemble using a voting methodology of bagging and boosting ensembles with 10 subclassifiers in each one. We performed a comparison with simple bagging and boosting ensembles with 25 sub-classifiers, as well as other well known combining methods, on standard benchmark datasets and the proposed technique was the most accurate.
Abstract: An experimental campaign of measurements for a
Darrieus vertical-axis wind turbine (VAWT) is presented for open
field conditions. The turbine is characterized by a twisted bladed
design, each blade being placed at a fixed distance from the rotational
shaft. The experimental setup to perform the acquisitions is described.
The results are lower than expected, due to the high influence of the
wind shear.
Abstract: In the present work, we propose a new technique to
enhance the learning capabilities and reduce the computation
intensity of a competitive learning multi-layered neural network
using the K-means clustering algorithm. The proposed model use
multi-layered network architecture with a back propagation learning
mechanism. The K-means algorithm is first applied to the training
dataset to reduce the amount of samples to be presented to the neural
network, by automatically selecting an optimal set of samples. The
obtained results demonstrate that the proposed technique performs
exceptionally in terms of both accuracy and computation time when
applied to the KDD99 dataset compared to a standard learning
schema that use the full dataset.
Abstract: Decrease in hardware costs and advances in computer
networking technologies have led to increased interest in the use of
large-scale parallel and distributed computing systems. One of the
biggest issues in such systems is the development of effective
techniques/algorithms for the distribution of the processes/load of a
parallel program on multiple hosts to achieve goal(s) such as
minimizing execution time, minimizing communication delays,
maximizing resource utilization and maximizing throughput.
Substantive research using queuing analysis and assuming job
arrivals following a Poisson pattern, have shown that in a multi-host
system the probability of one of the hosts being idle while other host
has multiple jobs queued up can be very high. Such imbalances in
system load suggest that performance can be improved by either
transferring jobs from the currently heavily loaded hosts to the lightly
loaded ones or distributing load evenly/fairly among the hosts .The
algorithms known as load balancing algorithms, helps to achieve the
above said goal(s). These algorithms come into two basic categories -
static and dynamic. Whereas static load balancing algorithms (SLB)
take decisions regarding assignment of tasks to processors based on
the average estimated values of process execution times and
communication delays at compile time, Dynamic load balancing
algorithms (DLB) are adaptive to changing situations and take
decisions at run time.
The objective of this paper work is to identify qualitative
parameters for the comparison of above said algorithms. In future this
work can be extended to develop an experimental environment to
study these Load balancing algorithms based on comparative
parameters quantitatively.
Abstract: The element of justice or al-‘adl in the context of
Islamic critical thinking deals with the notion of justice in a thinking
process which critically rationalizes the truth in a fair and objective
manner with no irrelevant interference that can jeopardize a sound
judgment. This Islamic axiological element is vital in technological
decision making as it addresses the issues of religious values and
ethics that are primarily set to fulfill the purpose of human life on
earth. The main objective of this study was to examine and analyze
the perception of Muslim engineering students in Malaysian higher
education institutions towards the concept of al-‘adl as an essential
element of Islamic critical thinking. The study employed mixed
methods approach that comprises data collection from the
questionnaire survey and the interview responses. A total of 557
Muslim engineering undergraduates from six Malaysian universities
participated in the study. The study generally indicated that Muslim
engineering undergraduates in the higher institutions have rather
good comprehension and consciousness for al-‘adl with a slight
awareness on the importance of objective thinking. Nonetheless there
were a few items on the concept that have implied a comparatively
low perception on the rational justice in Islam as the means to grasp
the ultimate truth.
Abstract: Support Vector Domain Description (SVDD) is one of the best-known one-class support vector learning methods, in which one tries the strategy of using balls defined on the feature space in order to distinguish a set of normal data from all other possible abnormal objects. As all kernel-based learning algorithms its performance depends heavily on the proper choice of the kernel parameter. This paper proposes a new approach to select kernel's parameter based on maximizing the distance between both gravity centers of normal and abnormal classes, and at the same time minimizing the variance within each class. The performance of the proposed algorithm is evaluated on several benchmarks. The experimental results demonstrate the feasibility and the effectiveness of the presented method.
Abstract: In this paper, by exploiting a single semiconductor
optical amplifier-Mach Zehnder Interferometer (SOA-MZI), an
integratable all-optical flip-flop (AOFF) is proposed. It is composed
of a SOA-MZI with a bidirectional coupler at the output. Output
signals of both bar and crossbar of the SOA-MZI is fed back to SOAs
located in the arms of the Mach-Zehnder Interferometer (MZI). The
injected photon-rates to the SOAs are modulated by feedback signals
in order to form optical flip-flop. According to numerical analysis,
Gaussian optical pulses with the energy of 15.2 fJ and 20 ps duration
with the full width at half-maximum criterion, can switch the states of
the SR-AOFF. Also simulation results show that the SR-AOFF has
the contrast ratio of 8.5 dB between two states with the transition
time of nearly 20 ps.
Abstract: This work deals with unsupervised image deblurring.
We present a new deblurring procedure on images provided by lowresolution
synthetic aperture radar (SAR) or simply by multimedia in
presence of multiplicative (speckle) or additive noise, respectively.
The method we propose is defined as a two-step process. First, we
use an original technique for noise reduction in wavelet domain.
Then, the learning of a Kohonen self-organizing map (SOM) is
performed directly on the denoised image to take out it the blur. This
technique has been successfully applied to real SAR images, and the
simulation results are presented to demonstrate the effectiveness of
the proposed algorithms.
Abstract: In our modern world, more physical transactions are being substituted by electronic transactions (i.e. banking, shopping, and payments), many businesses and companies are performing most of their operations through the internet. Instead of having a physical commerce, internet visitors are now adapting to electronic commerce (e-Commerce). The ability of web users to reach products worldwide can be greatly benefited by creating friendly and personalized online business portals. Internet visitors will return to a particular website when they can find the information they need or want easily. Dealing with this human conceptualization brings the incorporation of Artificial/Computational Intelligence techniques in the creation of customized portals. From these techniques, Fuzzy-Set technologies can make many useful contributions to the development of such a human-centered endeavor as e-Commerce. The main objective of this paper is the implementation of a Paradigm for the Intelligent Design and Operation of Human-Computer interfaces. In particular, the paradigm is quite appropriate for the intelligent design and operation of software modules that display information (such Web Pages, graphic user interfaces GUIs, Multimedia modules) on a computer screen. The human conceptualization of the user personal information is analyzed throughout a Cascaded Fuzzy Inference (decision-making) System to generate the User Ascribe Qualities, which identify the user and that can be used to customize portals with proper Web links.
Abstract: The need in cognitive radio system for a simple, fast, and independent technique to sense the spectrum occupancy has led to the energy detection approach. Energy detector is known by its dependency on noise variation in the system which is one of its major drawbacks. In this paper, we are aiming to improve its performance by utilizing a weighted collaborative spectrum sensing, it is similar to the collaborative spectrum sensing methods introduced previously in the literature. These weighting methods give more improvement for collaborative spectrum sensing as compared to no weighting case. There is two method proposed in this paper: the first one depends on the channel status between each sensor and the primary user while the second depends on the value of the energy measured in each sensor.
Abstract: The atmospheric pressure plasma torch with a direct
current arc discharge stabilized by water vapor vortex was
experimentally investigated. Overheated up to 450K water vapor was
used as plasma forming gas. Plasma torch design is one of the most
important factors leading to a stable operation of the device. The
electrical and thermal characteristics of the plasma torch were
determined during the experimental investigations. The design and
the basic characteristics of the water vapor plasma torch are presented
in the paper.
Plasma torches with the electric arc stabilized by water vapor
vortex provide special performance characteristics in some plasma
processing applications such as thermal plasma neutralization and
destruction of organic wastes enabling to extract high caloric value
synthesis gas as by-product of the process. Syngas could be used as a
surrogate fuel partly replacing the dependence on the fossil fuels or
used as a feedstock for hydrogen, methanol production.
Abstract: Over the past decade, mobile has experienced a
revolution that will ultimately change the way we communicate.All
these technologies have a common denominator exploitation of
computer information systems, but their operation can be tedious
because of problems with heterogeneous data sources.To overcome
the problems of heterogeneous data sources, we propose to use a
technique of adding an extra layer interfacing applications of
management or supervision at the different data sources.This layer
will be materialized by the implementation of a mediator between
different host applications and information systems frequently used
hierarchical and relational manner such that the heterogeneity is
completely transparent to the VoIP platform.
Abstract: Cooktop burners are widely used nowadays. In
cooktop burner design, nozzle efficiency and greenhouse
gas(GHG) emissions mainly depend on heat transfer from the
premixed flame to the impinging surface. This is a complicated
issue depending on the individual and combined effects of various
input combustion variables. Optimal operating conditions for
sustainable burner design were rarely addressed, especially in the
case of multiple slot-jet burners. Through evaluating the optimal
combination of combustion conditions for a premixed slot-jet
array, this paper develops a practical approach for the sustainable
design of gas cooktop burners. Efficiency, CO and NOx emissions
in respect of an array of slot jets using premixed flames were
analysed. Response surface experimental design were applied to
three controllable factors of the combustion process, viz.
Reynolds number, equivalence ratio and jet-to-vessel distance.
Desirability Function Approach(DFA) is the analytic technique
used for the simultaneous optimization of the efficiency and
emission responses.
Abstract: This paper presents the results of a comprehensive
investigation of five blackouts that occurred on 28 August to 8
September 2011 due to bushing failures of the 132/33 kV, 125 MVA
transformers at JBB Ali Grid station. The investigation aims to
explore the root causes of the bushing failures and come up with
recommendations that help in rectifying the problem and avoiding the
reoccurrence of similar type of incidents. The incident reports about
the failed bushings and the SCADA reports at this grid station were
examined and analyzed. Moreover, comprehensive power quality
field measurements at ten 33/11 kV substations (S/Ss) in JBB Ali
area were conducted, and frequency scans were performed to verify
any harmonic resonance frequencies due to power factor correction
capacitors. Furthermore, the daily operations of the on-load tap
changers (OLTCs) of both the 125 MVA and 20 MVA transformers
at JBB Ali Grid station have been analyzed. The investigation
showed that the five bushing failures were due to a local problem, i.e.
internal degradation of the bushing insulation. This has been
confirmed by analyzing the time interval between successive OLTC
operations of the faulty grid transformers. It was also found that
monitoring the number of OLTC operations can help in predicting
bushing failure.
Abstract: The present work is concerned with the effect of turning process parameters (cutting speed, feed rate, and depth of cut) and distance from the center of work piece as input variables on the chip micro-hardness as response or output. Three experiments were conducted; they were used to investigate the chip micro-hardness behavior at diameter of work piece for 30[mm], 40[mm], and 50[mm]. Response surface methodology (R.S.M) is used to determine and present the cause and effect of the relationship between true mean response and input control variables influencing the response as a two or three dimensional hyper surface. R.S.M has been used for designing a three factor with five level central composite rotatable factors design in order to construct statistical models capable of accurate prediction of responses. The results obtained showed that the application of R.S.M can predict the effect of machining parameters on chip micro-hardness. The five level factorial designs can be employed easily for developing statistical models to predict chip micro-hardness by controllable machining parameters. Results obtained showed that the combined effect of cutting speed at it?s lower level, feed rate and depth of cut at their higher values, and larger work piece diameter can result increasing chi micro-hardness.
Abstract: In this paper, a new efficient method for load balancing in low voltage distribution systems is presented. The proposed method introduces an improved Leap-frog method for optimization. The proposed objective function includes the difference between three phase currents, as well as two other terms to provide the integer property of the variables; where the latter are the status of the connection of loads to different phases. Afterwards, a new algorithm is supplemented to undertake the integer values for the load connection status. Finally, the method is applied to different parts of Tabriz low voltage network, where the results have shown the good performance of the proposed method.
Abstract: This paper considers the problem of Null-Steering beamforming using Neural Network (NN) approach for antenna array system. Two cases are presented. First, unlike the other authors, the estimated Direction Of Arrivals (DOAs) are used for antenna array weights NN-based determination and the imprecise DOAs estimations are taken into account. Second, the blind null-steering beamforming is presented. In this case the antenna array outputs are presented at the input of the NN without DOAs estimation. The results of computer simulations will show much better relative mean error performances of the first NN approach compared to the NNbased blind beamforming.
Abstract: In this study the behavior of interlaminar fracture of
carbon-epoxy thermoplastic laminated composite is investigated
numerically and experimentally. Tests are performed with Arcan
specimens. Testing with Arcan specimen gives the opportunity of
utilizing just one kind of specimen for extracting fracture properties
for mode I, mode II and different mixed mode ratios of materials with
exerting load via different loading angles. Variation of loading angles
in range of 0-90° made possible to achieve different mixed mode
ratios. Correction factors for various conditions are obtained from
ABAQUS 2D finite element models which demonstrate the finite
shape of Arcan specimens used in this study. Finally, applying the
correction factors to critical loads obtained experimentally, critical
interlaminar fracture toughness of this type of carbon- epoxy
composite has been attained.
Abstract: Many IT projects come to failure because of having
technical approach, focusing on the final product and lack of proper
attention to strategic alignment. Project management models quite
often have technical management view [4], [8], [13], [14]. These
models focus greatly on the finalization of the project product and the
delivery of the product to the customer. However, many project
problems are due to lack of attention to the needs and capabilities of
the organizations or disregarding how to deploy and use the product
in the organization. In this regard, in the current research we are
trying to present a solution with the purpose of raising the value of
the project in an organization. This way, the project outputs will be
properly deployed in the organization. Therefore, a comprehensive
model is presented which takes into account the whole processes
from initial step of project definition to the deployment of the final
outputs in the organization and then the definition of all roles and
responsibilities to put the model into practice. Taking into account
the opinions of experts and project managers, to prove the
performance of the model, the project problems were recognized and
based on the model, categorized and analyzed. And at the end it is
made clear that ignoring the proper definition of the project and not
having a proper understanding of the expected value on the one hand
and not supervising the emerged value in the process of production
and installment are among the most important factors that bring a
project to failure.