Abstract: High Peak to Average Power Ratio (PAPR) of the
transmitted signal is a serious problem in multicarrier systems (MC),
such as Orthogonal Frequency Division Multiplexing (OFDM), or in
Multi-Carrier Code Division Multiple Access (MC-CDMA) systems,
due to large number of subcarriers. This effect is possible reduce with
some PAPR reduction techniques. Spreading sequences at the
presence of Saleh and Rapp models of high power amplifier (HPA)
have big influence on the behavior of system. In this paper we
investigate the bit-error-rate (BER) performance of MC-CDMA
systems. Basically we can see from simulations that the MC-CDMA
system with Iterative algorithm can be providing significantly better
results than the MC-CDMA system. The results of our analyses are
verified via simulation.
Abstract: Many organizations bring e-Learning to use as a tool
in their training and human development department. It is getting
more popular because it is easy to access to get knowledge all the
time and also it provides a rich content, which can develop the
employees’ skill efficiently. This study is focused on the factors that
affect using e-Learning efficiently, so it will make job satisfaction
increasing. The questionnaires were sent to employees in large
commercial banks, which use e-Learning located in Bangkok, the
results from multiple linear regression analysis showed that
employee’s characteristics, characteristics of e-Learning, learning and
growth have influence on job satisfaction.
Abstract: Bacterial strains capable of degradation of malathion
from the domestic sewage were isolated by an enrichment culture
technique. Three bacterial strains were screened and identified as
Acinetobacter baumannii (AFA), Pseudomonas aeruginosa (PS1),
and Pseudomonas mendocina (PS2) based on morphological,
biochemical identification and 16S rRNA sequence analysis.
Acinetobacter baumannii AFA was the most efficient malathion
degrading bacterium, so used for further biodegradation study. AFA
was able to grow in mineral salt medium (MSM) supplemented with
malathion (100 mg/l) as a sole carbon source, and within 14 days,
84% of the initial dose was degraded by the isolate measured by high
performance liquid chromatography. Strain AFA could also degrade
other organophosphorus compounds including diazinon, chlorpyrifos
and fenitrothion. The effect of different culture conditions on the
degradation of malathion like inoculum density, other carbon or
nitrogen sources, temperature and shaking were examined.
Degradation of malathion and bacterial cell growth were accelerated
when culture media were supplemented with yeast extract, glucose
and citrate. The optimum conditions for malathion degradation by
strain AFA were; an inoculum density of 1.5x 10^12CFU/ml at 30°C
with shaking. A specific polymerase chain reaction primers were
designed manually using multiple sequence alignment of the
corresponding carboxylesterase enzymes of Acinetobacter species.
Sequencing result of amplified PCR product and phylogenetic
analysis showed low degree of homology with the other
carboxylesterase enzymes of Acinetobacter strains, so we suggested
that this enzyme is a novel esterase enzyme. Isolated bacterial strains
may have potential role for use in bioremediation of malathion
contaminated.
Abstract: The research was conducted to empirically validate
the proposed maturity model of e-Government implementation,
composed of four dimensions, further specified by 54 success factors
as attributes. To do so, there are two steps were performed. First,
expert’s judgment was conducted to test its content validity. The
second, reliability study was performed to evaluate inter-rater
agreement by using Fleiss Kappa approach. The kappa statistic
(kappa coefficient) is the most commonly used method for testing the
consistency among raters. Fleiss Kappa was a generalization of
Kappa in extensions to the case of more than two raters (multiple
raters) with multi-categorical ratings. Our findings show that most
attributes of the proposed model were related to their corresponding
dimensions. According to our results, The percentage of agree
answers given by the experts was 73.69% in dimension A, 89.76% in
B, 81.5% in C and 60.37% in D. This means that more than half of
the attributes of each dimensions were appropriate or relevant to the
dimensions they were supposed to measure, while 85% of attributes
were relevant enough to their corresponding dimensions. Inter-rater
reliability coefficient also showed satisfactory result and interpreted
as substantial agreement among raters. Therefore, the proposed
model in this paper was valid and reliable to measure the maturity of
e-Government implementation.
Abstract: The idea of the asynchronous transmission in
wavelength division multiplexing (WDM) ring MANs is studied in
this paper. Especially, we present an efficient access technique to
coordinate the collisions-free transmission of the variable sizes of IP
traffic in WDM ring core networks. Each node is equipped with a
tunable transmitter and a tunable receiver. In this way, all the
wavelengths are exploited for both transmission and reception. In
order to evaluate the performance measures of average throughput,
queuing delay and packet dropping probability at the buffers, a
simulation model that assumes symmetric access rights among the
nodes is developed based on Poisson statistics. Extensive numerical
results show that the proposed protocol achieves apart from high
bandwidth exploitation for a wide range of offered load, fairness of
queuing delay and dropping events among the different packets size
categories.
Abstract: Wireless mesh networking is rapidly gaining in
popularity with a variety of users: from municipalities to enterprises,
from telecom service providers to public safety and military
organizations. This increasing popularity is based on two basic facts:
ease of deployment and increase in network capacity expressed in
bandwidth per footage; WMNs do not rely on any fixed
infrastructure. Many efforts have been used to maximizing
throughput of the network in a multi-channel multi-radio wireless
mesh network. Current approaches are purely based on either static or
dynamic channel allocation approaches. In this paper, we use a
hybrid multichannel multi radio wireless mesh networking
architecture, where static and dynamic interfaces are built in the
nodes. Dynamic Adaptive Channel Allocation protocol (DACA), it
considers optimization for both throughput and delay in the channel
allocation. The assignment of the channel has been allocated to be codependent
with the routing problem in the wireless mesh network and
that should be based on passage flow on every link. Temporal and
spatial relationship rises to re compute the channel assignment every
time when the pattern changes in mesh network, channel assignment
algorithms assign channels in network. In this paper a computing
path which captures the available path bandwidth is the proposed
information and the proficient routing protocol based on the new path
which provides both static and dynamic links. The consistency
property guarantees that each node makes an appropriate packet
forwarding decision and balancing the control usage of the network,
so that a data packet will traverse through the right path.
Abstract: This paper impart the design and testing of
Nanotechnology based sequential circuits using multiplexer
conservative QCA (MX-CQCA) logic gates, which is easily testable
using only two vectors. This method has great prospective in the
design of sequential circuits based on reversible conservative logic
gates and also smashes the sequential circuits implemented in
traditional gates in terms of testability. Reversible circuits are similar
to usual logic circuits except that they are built from reversible gates.
Designs of multiplexer conservative QCA logic based two vectors
testable double edge triggered (DET) sequential circuits in VHDL
language are also accessible here; it will also diminish intricacy in
testing side. Also other types of sequential circuits such as D, SR, JK
latches are designed using this MX-CQCA logic gate. The objective
behind the proposed design methodologies is to amalgamate
arithmetic and logic functional units optimizing key metrics such as
garbage outputs, delay, area and power. The projected MX-CQCA
gate outshines other reversible gates in terms of the intricacy, delay.
Abstract: Environmental impacts of six 3D printers using
various materials were compared to determine if material choice
drove sustainability, or if other factors such as machine type, machine
size, or machine utilization dominate. Cradle-to-grave life-cycle
assessments were performed, comparing a commercial-scale FDM
machine printing in ABS plastic, a desktop FDM machine printing in
ABS, a desktop FDM machine printing in PET and PLA plastics, a
polyjet machine printing in its proprietary polymer, an SLA machine
printing in its polymer, and an inkjet machine hacked to print in salt
and dextrose. All scenarios were scored using ReCiPe Endpoint H
methodology to combine multiple impact categories, comparing
environmental impacts per part made for several scenarios per
machine. Results showed that most printers’ ecological impacts were
dominated by electricity use, not materials, and the changes in
electricity use due to different plastics was not significant compared
to variation from one machine to another. Variation in machine idle
time determined impacts per part most strongly. However, material
impacts were quite important for the inkjet printer hacked to print in
salt: In its optimal scenario, it had up to 1/38th the impacts coreper
part as the worst-performing machine in the same scenario. If salt
parts were infused with epoxy to make them more physically robust,
then much of this advantage disappeared, and material impacts
actually dominated or equaled electricity use. Future studies should
also measure DMLS and SLS processes / materials.
Abstract: Over the last few decades, oilfield service rolling
equipment has significantly increased in weight, primarily because of
emissions regulations, which require larger/heavier engines, larger
cooling systems, and emissions after-treatment systems, in some
cases, etc. Larger engines cause more vibration and shock loads,
leading to failure of electronics and control systems.
If the vibrating frequency of the engine matches the system
frequency, high resonance is observed on structural parts and mounts.
One such existing automated control equipment system comprising
wire rope mounts used for mounting computers was designed
approximately 12 years ago. This includes the use of an industrialgrade
computer to control the system operation. The original
computer had a smaller, lighter enclosure. After a few years, a newer
computer version was introduced, which was 10 lbm heavier. Some
failures of internal computer parts have been documented for cases in
which the old mounts were used. Because of the added weight, there
is a possibility of having the two brackets impact each other under
off-road conditions, which causes a high shock input to the computer
parts. This added failure mode requires validating the existing mount
design to suit the new heavy-weight computer.
This paper discusses the modal finite element method (FEM)
analysis and experimental modal analysis conducted to study the
effects of vibration on the wire rope mounts and the computer. The
existing mount was modelled in ANSYS software, and resultant
mode shapes and frequencies were obtained. The experimental modal
analysis was conducted, and actual frequency responses were
observed and recorded.
Results clearly revealed that at resonance frequency, the brackets
were colliding and potentially causing damage to computer parts. To
solve this issue, spring mounts of different stiffness were modeled in
ANSYS software, and the resonant frequency was determined.
Increasing the stiffness of the system increased the resonant
frequency zone away from the frequency window at which the engine
showed heavy vibrations or resonance. After multiple iterations in
ANSYS software, the stiffness of the spring mount was finalized,
which was again experimentally validated.
Abstract: The IEEE 802.22 working group aims to drive the
Digital Video Broadcasting-Terrestrial (DVB-T) bands for data
communication to the rural area without interfering the TV broadcast.
In this paper, we arrive at a closed-form expression for average
detection probability of Fusion center (FC) with multiple antenna
over the κ − μ fading channel model. We consider a centralized
cooperative multiple antenna network for reporting. The DVB-T
samples forwarded by the secondary user (SU) were combined using
Maximum ratio combiner at FC, an energy detection is performed
to make the decision. The fading effects of the channel degrades
the detection probability of the FC, a generalized independent and
identically distributed (IID) κ − μ and an additive white Gaussian
noise (AWGN) channel is considered for reporting and sensing
respectively. The proposed system performance is verified through
simulation results.
Abstract: The focal aspire of e-Government (eGovt) is to offer
citizen-centered service delivery. Accordingly, the citizenry
consumes services from multiple government agencies through
national portal. Thus, eGovt is an enterprise with the primary
business motive of transparent, efficient and effective public services
to its citizenry and its logical structure is the eGovernment Enterprise
Architecture (eGEA). Since eGovt is IT oriented multifaceted
service-centric system, EA doesn’t do much on an automated
enterprise other than the business artifacts. Service-Oriented
Architecture (SOA) manifestation led some governments to pertain
this in their eGovts, but it limits the source of business artifacts. The
concurrent use of EA and SOA in eGovt executes interoperability and
integration and leads to Service-Oriented e-Government Enterprise
(SOeGE). Consequently, agile eGovt system becomes a reality. As an
IT perspective eGovt comprises of centralized public service artifacts
with the existing application logics belong to various departments at
central, state and local level. The eGovt is renovating to SOeGE by
apply the Service-Orientation (SO) principles in the entire system.
This paper explores IT perspective of SOeGE in India which
encompasses the public service models and illustrated with a case
study the Passport service of India.
Abstract: The computational fluid dynamics (CFD) study of
stirred tank with the air-water interface are carried out in the presence
of different types of the impeller and with or without baffles. A
multiple reference frame (MRF) approach with the volume of fluid
(VOF) method is used to capture the air-water interface. The RANS
(Reynolds Averaged Navier-Stokes) equations with k-ε turbulence
model are solved to predict the flow behavior of water and air phase
which are treated as a different phases. The predicted results have
shown that the VOF method is able to capture the interface in the
unbaffled tank. While, the VOF method is showing an unfeasible
results in the baffled tank with high rotational impeller speed. For
continuous stirred tank, the air-water interface is disturbed by the
inflow and the level of water is also increased with time.
Abstract: The classroom of the 21st century is an ever changing
forum for new and innovative thoughts and ideas. With increasing
technology and opportunity, students have rapid access to
information that only decades ago would have taken weeks to obtain.
Unfortunately, new techniques and technology are not the cure for
the fundamental problems that have plagued the classroom ever since
education was established. Class size has been an issue long debated
in academia. While it is difficult to pin point an exact number, it is
clear that in this case more does not mean better. By looking into the
success and pitfalls of classroom size the true advantages of smaller
classes will become clear. Previously, one class was comprised of 50
students. Being seventeen and eighteen- year- old students,
sometimes it was quite difficult for them to stay focused. To help
them understand and gain much knowledge, a researcher introduced
“The Theory of Multiple Intelligence” and this, in fact, enabled
students to learn according to their own learning preferences no
matter how they were being taught. In this lesson, the researcher
designed a cycle of learning activities involving all intelligences so
that everyone had equal opportunities to learn.
Abstract: Solar air heater is a type of heat exchanger which
transforms solar radiation into heat energy. The thermal performance
of conventional solar air heater has been found to be poor because of
the low convective heat transfer coefficient from the absorber plate to
the air. It is attributed to the formation of a very thin boundary layer
at the absorber plate surface commonly known as viscous sub-layer.
Thermal efficiency of solar air heater can be improved by providing
the artificial roughness on absorber plate is the most efficient
technique. In this paper an attempt is made to provide artificial
roughness by incorporating inclined multiple V-ribs in the underside
of the absorber plate. 60˚V – ribs are arranged inclined to the
direction of air flow. Performance of collector estimated theoretically
and experimentally. Results of the investigation reveal that thermal
efficiency of collector with multiple V-ribs increased by 14%.
Abstract: Communicating and managing customers’
requirements in software development projects play a vital role in the
software development process. While it is difficult to do so locally, it
is even more difficult to communicate these requirements over
distributed boundaries and to convey them to multiple distribution
customers. This paper discusses the communication of multiple
distribution customers’ requirements in the context of customised
software products. The main purpose is to understand the challenges
of communicating and managing customisation requirements across
distributed boundaries. We propose a model for Communicating
Customisation Requirements of Multi-Clients in a Distributed
Domain (CCRD). Thereafter, we evaluate that model by presenting
the findings of a case study conducted with a company with
customisation projects for 18 distributed customers. Then, we
compare the outputs of the real case process and the outputs of the
CCRD model using simulation methods. Our conjecture is that the
CCRD model can reduce the challenge of communication
requirements over distributed organisational boundaries, and the
delay in decision making and in the entire customisation process
time.
Abstract: We report on the use of strong external optical
feedback to enhance the modulation response of semiconductor lasers
over a frequency passband around modulation frequencies higher
than 60 GHz. We show that this modulation enhancement is a type of
photon-photon resonance (PPR) of oscillating modes in the external
cavity formed between the laser and the external reflector. The study
is based on a time-delay rate equation model that takes into account
both the strong feedback and multiple reflections in the external
cavity. We examine the harmonic and intermodulation distortions
associated with single and two-tone modulations in the mm-wave
band of the resonant modulation. We show that compared with
solitary lasers modulated around the carrier-photon resonance
frequency, the present mm-wave modulated signal has lower
distortions.
Abstract: Learner motivation is considered to be an important
component for the Blended e-Learning (BL) Method. BL is an
effective learning method in multiple domains, which opens several
opportunities for its participants to engage in the learning
environment. This research explores the learners’ perspective of BL
according to the Self-Determination Theory (SDT). It identifies the
opportunities and challenges for using the BL in Logistics Education
(LE) in Egyptian Higher Education (HE). SDT is approached from
different perspectives within the relationship between Intrinsic
Motivation (IM), Extrinsic Motivation (EM) and Amotivation (AM).
A self-administered face-to-face questionnaire was used to collect
data from learners who were geographically widely spread around
three colleges of International Transport and Logistics (CILTs) at the
Arab Academy for Science, Technology and Maritime Transport
(AAST&MT) in Egypt. Six hundred and sixteen undergraduates
responded to a questionnaire survey. Respondents were drawn from
three branches in Greater Cairo, Alexandria, and Port Said. The data
analysis used was SPSS 22 and AMOS 18.
Abstract: Ontologies provide a common understanding of a
specific domain of interest that can be communicated between people
and used as background knowledge for automated reasoning in a
wide range of applications. In this paper, we address the design of
multilingual ontologies following well-defined knowledge
engineering methodologies with the support of novel collaborative
development approaches. In particular, we present a collaborative
platform which allows ontologies to be developed incrementally in
multiple languages. This is made possible via an appropriate mapping
between language independent concepts and one lexicalization per
language (or a lexical gap in case such lexicalization does not exist).
The collaborative platform has been designed to support the
development of the Universal Knowledge Core, a multilingual
ontology currently in English, Italian, Chinese, Mongolian, Hindi and
Bangladeshi. Its design follows a workflow-based development
methodology that models resources as a set of collaborative objects
and assigns customizable workflows to build and maintain each
collaborative object in a community driven manner, with extensive
support of modern web 2.0 social and collaborative features.
Abstract: The fuzzy composition of objects depicted in images
acquired through MR imaging or the use of bio-scanners has often
been a point of controversy for field experts attempting to effectively
delineate between the visualized objects. Modern approaches in
medical image segmentation tend to consider fuzziness as a
characteristic and inherent feature of the depicted object, instead of
an undesirable trait. In this paper, a novel technique for efficient
image retrieval in the context of images in which segmented objects
are either crisp or fuzzily bounded is presented. Moreover, the
proposed method is applied in the case of multiple, even conflicting,
segmentations from field experts. Experimental results demonstrate
the efficiency of the suggested method in retrieving similar objects
from the aforementioned categories while taking into account the
fuzzy nature of the depicted data.
Abstract: Many problems in science and engineering field require
the solution of shifted linear systems with multiple right hand
sides and multiple shifts. To solve such systems efficiently, the
implicitly restarted global GMRES algorithm is extended in this
paper. However, the shift invariant property could no longer hold over
the augmented global Krylov subspace due to adding the harmonic
Ritz matrices. To remedy this situation, we enforce the collinearity
condition on the shifted system and propose shift implicitly restarted
global GMRES. The new method not only improves the convergence
but also has a potential to simultaneously compute approximate
solution for the shifted systems using only as many matrix vector
multiplications as the solution of the seed system requires. In
addition, some numerical experiments also confirm the effectiveness
of our method.