Abstract: In this paper a new design of a broadband microwave
power limiter is presented and validated into simulation by using
ADS software (Advanced Design System) from Agilent technologies.
The final circuit is built on microstrip lines by using identical Zero
Bias Schottky diodes. The power limiter is designed by Associating 3
stages Schottky diodes. The obtained simulation results permit to
validate this circuit with a threshold input power level of 0 dBm until
a maximum input power of 30 dBm.
Abstract: The exact theoretical expression describing the
probability distribution of nonlinear sea-surface elevations derived
from the second-order narrowband model has a cumbersome form
that requires numerical computations, not well-disposed to theoretical
or practical applications. Here, the same narrowband model is reexamined
to develop a simpler closed-form approximation suitable
for theoretical and practical applications. The salient features of the
approximate form are explored, and its relative validity is verified
with comparisons to other readily available approximations, and
oceanic data.
Abstract: Taking the design tolerance into account, this paper
presents a novel efficient approach to generate iso-scallop tool path for
five-axis strip machining with a barrel cutter. The cutter location is
first determined on the scallop surface instead of the design surface,
and then the cutter is adjusted to locate the optimal tool position based
on the differential rotation of the tool axis and satisfies the design
tolerance simultaneously. The machining strip width and error are
calculated with the aid of the grazing curve of the cutter. Based on the
proposed tool positioning algorithm, the tool paths are generated by
keeping the scallop height formed by adjacent tool paths constant. An
example is conducted to confirm the validity of the proposed method.
Abstract: In this study, we are interested in a species of the
family of Asteraceae (Tagetes erecta). This family is considered as a
source of antimicrobial extracts with strong capacity. The extraction
of the flavonoids is carried out by the method of liquid/liquid with the
use of successive solvents. Afterwards, we evaluated the biological
activity of the flavonoids on five pathogenic bacterial stocks such as
Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae,
Pseudomonas aeruginosa and Staphylococcus aureus and two stocks
of yeasts to knowing Candida albicans) and Saccharomyces
cerevisiae, by employing the method of the aromatogramme starting
from a solid disc. The result of the antimicrobial activity shows an
action and a variable degree of sensitivity according to bacterial
stocks tested. It will be noted that the flavonoids have an inhibiting
effect on E. coli, B. subtilis, K. pneumoniae and S. aureus. But a
resistance with respect to the extract by P. aeruginosa, C. albicans
and S. cerevisiae is to be mentioned.
Abstract: The use of eXtensible Markup Language (XML) in
web, business and scientific databases lead to the development of
methods, techniques and systems to manage and analyze XML data.
Semi-structured documents suffer due to its heterogeneity and
dimensionality. XML structure and content mining represent
convergence for research in semi-structured data and text mining. As
the information available on the internet grows drastically, extracting
knowledge from XML documents becomes a harder task. Certainly,
documents are often so large that the data set returned as answer to a
query may also be very big to convey the required information. To
improve the query answering, a Semantic Tree Based Association
Rule (STAR) mining method is proposed. This method provides
intentional information by considering the structure, content and the
semantics of the content. The method is applied on Reuter’s dataset
and the results show that the proposed method outperforms well.
Abstract: A field experiment was carried out at Arab El-
Awammer Research Station, Agric. Res. Center. Assiut Governorate
during summer seasons of 2013 and 2014. The present study assessed
the effect of cowpea with maize intercropping on yield and its
components. The experiment comprised of three treatments (sole
cowpea, sole maize and cowpea-maize intercrop). The experimental
design was a randomized complete block with four replications.
Results indicated that intercropped maize plants with cowpea,
exhibited greater potentiality and resulted in higher values of most of
the studied criteria viz., plant height, number of ears/plant, number of
rows/ear, number of grains/row, grains weight/ear, 100–grain weight
and straw and grain yields. Fresh and dry forage yields of cowpea
were lower in intercropping with maize than sole. Furthermore, the
combined of the two seasons revealed that the total Land Equivalent
Ratio (LER) between cowpea and maize was 1.65. The Aggressivity
(A) maize was 0.45 and cowpea was -0.45. This showed that maize
was the dominant crop, whereas cowpea was the dominated. The
Competitive Ratio (CR) indicated that maize more competitive than
cowpea, maize was 1.75 and cowpea was 0.57. The Actual Yield
Loss (AYL) maize was 0.05 and cowpea was -0.40. The Monetary
Advantage Index (MAI) was 2360.80.
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: At present, the evaluation of voltage stability
assessment experiences sizeable anxiety in the safe operation of
power systems. This is due to the complications of a strain power
system. With the snowballing of power demand by the consumers
and also the restricted amount of power sources, therefore, the system
has to perform at its maximum proficiency. Consequently, the
noteworthy to discover the maximum ability boundary prior to
voltage collapse should be undertaken. A preliminary warning can be
perceived to evade the interruption of power system’s capacity. The
effectiveness of line voltage stability indices (LVSI) is differentiated
in this paper. The main purpose of the indices used is to predict the
proximity of voltage instability of the electric power system. On the
other hand, the indices are also able to decide the weakest load buses
which are close to voltage collapse in the power system. The line
stability indices are assessed using the IEEE 14 bus test system to
validate its practicability. Results demonstrated that the implemented
indices are practically relevant in predicting the manifestation of
voltage collapse in the system. Therefore, essential actions can be
taken to dodge the incident from arising.
Abstract: In this research, waterglass based aerogel powder was
prepared by sol–gel process and ambient pressure drying. Inspired by
limited dust releasing, aerogel powder was introduced to the PET
electrospinning solution in an attempt to create required bulk and
surface structure for the nanofibers to improve their hydrophobic and
insulation properties. The samples evaluation was carried out by
measuring density, porosity, contact angle, heat transfer, FTIR, BET,
and SEM. According to the results, porous silica aerogel powder was
fabricated with mean pore diameter of 24 nm and contact angle of
145.9º. The results indicated the usefulness of the aerogel powder
confined into nanofibers to control surface roughness for
manipulating superhydrophobic nanowebs with water contact angle
of 147º. It can be due to a multi-scale surface roughness which was
created by nanowebs structure itself and nanofibers surface
irregularity in presence of the aerogels while a layer of fluorocarbon
created low surface energy. The wettability of a solid substrate is an
important property that is controlled by both the chemical
composition and geometry of the surface. Also, a decreasing trend in
the heat transfer was observed from 22% for the nanofibers without
any aerogel powder to 8% for the nanofibers with 4% aerogel
powder. The development of thermal insulating materials has become
increasingly more important than ever in view of the fossil energy
depletion and global warming that call for more demanding energysaving
practices.
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: Real time image and video processing is a demand in
many computer vision applications, e.g. video surveillance, traffic
management and medical imaging. The processing of those video
applications requires high computational power. Thus, the optimal
solution is the collaboration of CPU and hardware accelerators. In
this paper, a Canny edge detection hardware accelerator is proposed.
Edge detection is one of the basic building blocks of video and image
processing applications. It is a common block in the pre-processing
phase of image and video processing pipeline. Our presented
approach targets offloading the Canny edge detection algorithm from
processing system (PS) to programmable logic (PL) taking the
advantage of High Level Synthesis (HLS) tool flow to accelerate the
implementation on Zynq platform. The resulting implementation
enables up to a 100x performance improvement through hardware
acceleration. The CPU utilization drops down and the frame rate
jumps to 60 fps of 1080p full HD input video stream.
Abstract: Learning through creation of contextual games is a
very promising approach when undertaking interdisciplinary and
international group projects. During 2013 and 2014 the authors
organized two intensive student projects. The two projects were in
different countries and different conditions. Between them, the two
projects involved 68 students and 12 mentors from five EU countries
and from various academic disciplines. In this paper we share our
experience of these two projects and we suggest approaches that can
be utilized to strengthen the chances of succeeding in short (12-15
days long) intensive student projects.
Abstract: This paper investigates the viability of using carbon
fiber reinforced epoxy composites modified with carbon nanotubes to
strengthening reinforced concrete (RC) columns. Six RC columns
was designed and constructed according to ASCE standards. The
columns were wrapped using carbon fiber sheets impregnated with
either neat epoxy or CNTs modified epoxy. These columns were then
tested under concentric axial loading. Test results show that;
compared to the unwrapped specimens; wrapping concrete columns
with carbon fiber sheet embedded in CNTs modified epoxy resulted
in an increase in its axial load resistance, maximum displacement,
and toughness values by 24%, 109% and 232%, respectively. These
results reveal that adding CNTs into epoxy resin enhanced the
confinement effect, specifically, increased the axial load resistance,
maximum displacement, and toughness values by 11%, 6%, and
19%, respectively compared with columns strengthening with carbon
fiber sheet embedded in neat epoxy.
Abstract: Cloud computing has provided the impetus for change
in the demand, sourcing, and consumption of IT-enabled services.
The technology developed from an emerging trend towards a ‘musthave’.
Many organizations harnessed on the quick-wins of cloud
computing within the last five years but nowadays reach a plateau
when it comes to sustainable savings and performance. This study
aims to investigate what is needed from an organizational perspective
to make cloud computing a sustainable success. The study was
carried out in Germany among senior IT professionals, both in
management and delivery positions. Our research shows that IT
executives must be prepared to realign their IT workforce to sustain
the advantage of cloud computing for today and the near future.
While new roles will undoubtedly emerge, roles alone cannot ensure
the success of cloud deployments. What is needed is a change in the
IT workforce’s business behaviour, or put more simply, the ways in
which the IT personnel works. It gives clear guidance on which
dimensions of an employees’ working behaviour need to be adapted.
The practical implications are drawn from a series of semi-structured
interviews, resulting in a high-level workforce enablement plan.
Lastly, it elaborates on tools and gives clear guidance on which
pitfalls might arise along the proposed workforce enablement
process.
Abstract: Software Architecture is the basic structure of
software that states the development and advancement of a software
system. Software architecture is also considered as a significant tool
for the construction of high quality software systems. A clean design
leads to the control, value and beauty of software resulting in its
longer life while a bad design is the cause of architectural erosion
where a software evolution completely fails. This paper discusses the
occurrence of software architecture erosion and presents a set of
methods for the detection, declaration and prevention of architecture
erosion. The causes and symptoms of architecture erosion are
observed with the examples of prescriptive and descriptive
architectures and the practices used to stop this erosion are also
discussed by considering different types of software erosion and their
affects. Consequently finding and devising the most suitable
approach for fighting software architecture erosion and in some way
reducing its affect is evaluated and tested on different scenarios.
Abstract: This work presents a new planar multiband antenna
based on fractal geometry. This structure is optimized and validated
into simulation by using CST-MW Studio. To feed this antenna we
have used a CPW line which makes it easy to be incorporated with
integrated circuits. The simulation results presents a good matching
input impedance and radiation pattern in the GSM band at 900 MHz
and ISM band at 2.4 GHz. The final structure is a dual band fractal
antenna with 70 x 70 mm² as a total area by using an FR4 substrate.
Abstract: This paper presents a novel design of a microstrip
fractal antenna based on the use of Sierpinski triangle shape, it’s
designed and simulated by using FR4 substrate in the operating
frequency bands (GPS, WiMAX), the design is a fractal antenna with
a modified ground structure. The proposed antenna is simulated and
validated by using CST Microwave Studio Software, the simulated
results presents good performances in term of radiation pattern and
matching input impedance.
Abstract: This paper presents observations on the early
supervised internships in Psychology, currently called basic
internships in Brazil, and its importance in professional training. The
work is an experience report and focuses on the Professional training,
illustrated by the reality of a Brazilian institution, used as a case
study. It was developed from the authors' experience as academic
supervisors of this kind of practice throughout this undergraduate
course, combined with aspects investigated in the post-doctoral
research of one of them. Theoretical references on the subject and
related national legislation are analyzed, as well as reports of students
who experienced at least one semester of this type of practice,
articulated to the observations of the authors. The results demonstrate
the importance of the early supervised internships as a way of
creating opportunities for the students of a first contact with the
professional reality and the practice of psychologists in different
fields of insertion, preparing them for further experiments that require
more involvement in activities of training and practices in
Psychology.
Abstract: Logistics distributors face the issue of having to
provide increasing service levels while being forced to reduce costs at
the same time. Same-day delivery, quick order processing and rapidly
growing ranges of articles are only some of the prevailing challenges.
One key aspect of the performance of an intra-logistics system is how
often and in which amplitude congestions and dysfunctions affect the
processing operations. By gaining knowledge of the so called
‘performance availability’ of such a system during the planning stage,
oversizing and wasting can be reduced whereas planning
transparency is increased. State of the art for the determination of this
KPI is simulation studies. However, their structure and therefore their
results may vary unforeseeably. This article proposes a concept for
the establishment of ‘certified’ and hence reliable and comparable
simulation models.
Abstract: We present a trigonometric scheme to approximate a
circular arc with its two end points and two end tangents/unit
tangents. A rational cubic trigonometric Bézier curve is constructed
whose end control points are defined by the end points of the circular
arc. Weight functions and the remaining control points of the cubic
trigonometric Bézier curve are estimated by variational approach to
reproduce a circular arc. The radius error is calculated and found less
than the existing techniques.