Abstract: The shielding ability of a shielding cavity with an
aperture will be greatly degraded at resonance frequencies, and the
resonance modes and frequencies are affected by aperture resonances
and aperture-cavity coupling, which are closely related with aperture
sizes. The equivalent circuit method and numerical method of
Transmission Line Matrix (TLM) are used to analyze the effects of
aperture resonances and aperture-cavity coupling on the
electromagnetic resonances of a cavity with an aperture in this paper.
Both analytical and numerical results show that the resonance modes
of a shielding cavity with an aperture consist of cavity resonance
modes and aperture resonance modes, and the resonance frequencies
will shift with the change of the aperture sizes because of the aperture
resonances and aperture-cavity coupling. Variation rules of
electromagnetic resonances with aperture sizes for a cavity with an
aperture are given, which will be useful for design of shielding
cavities.
Abstract: This paper contributes to the ongoing debate as to the relevance of translation studies to professional practitioners. It exposes the various misconceptions permeating the links between theory and practice in the translation landscape in the Arab World. It is a thesis of this paper that specialization in translation should be redefined; taking account of the fact, that specialized knowledge alone is neither crucial nor sufficient in technical translation. It should be tested against the readability of the translated text, the appropriateness of its style and the usability of its content by endusers to carry out their intended tasks. The paper also proposes a preliminary model to establish a working link between theory and practice from the perspective of professional trainers and practitioners, calling for the latter to participate in the production of knowledge in a systematic fashion. While this proposal is driven by a rather intuitive conviction, a research line is needed to specify the methodological moves to establish the mediation strategies that would relate the components in the model of knowledge transfer proposed in this paper.
Abstract: The purpose of this study is to identify human walking vertical force by using FFT power spectrum density from the experimental acceleration data of the human body. An experiment on human walking is carried out on a stationary floor especially paying attention to higher components of dynamic vertical walking force. Based on measured acceleration data of the human lumbar part, not only in-phase component with frequency of 2fw, 3fw, but also in-opposite-phase component with frequency of 0.5 fw, 1.5 fw, 2.5 fw where fw is the walking rate is observed. The vertical vibration of pedestrian bridge induced by higher components of human walking vertical force is also discussed in this paper. A full scale measurement for the existing pedestrian bridge with center span length of 33 m is carried out focusing on the resonance phenomenon due to higher components of human walking vertical force. Dynamic response characteristics excited by these vertical higher components of human walking are revealed from the dynamic design viewpoint of pedestrian bridge.
Abstract: This paper presents a grid synchronization technique based on adaptive notch filter for SPV (Solar Photovoltaic) system along with MPPT (Maximum Power Point Tracking) techniques. An efficient grid synchronization technique offers proficient detection of various components of grid signal like phase and frequency. It also acts as a barrier for harmonics and other disturbances in grid signal. A reference phase signal synchronized with the grid voltage is provided by the grid synchronization technique to standardize the system with grid codes and power quality standards. Hence, grid synchronization unit plays important role for grid connected SPV systems. As the output of the PV array is fluctuating in nature with the meteorological parameters like irradiance, temperature, wind etc. In order to maintain a constant DC voltage at VSC (Voltage Source Converter) input, MPPT control is required to track the maximum power point from PV array. In this work, a variable step size P & O (Perturb and Observe) MPPT technique with DC/DC boost converter has been used at first stage of the system. This algorithm divides the dPpv/dVpv curve of PV panel into three separate zones i.e. zone 0, zone 1 and zone 2. A fine value of tracking step size is used in zone 0 while zone 1 and zone 2 requires a large value of step size in order to obtain a high tracking speed. Further, adaptive notch filter based control technique is proposed for VSC in PV generation system. Adaptive notch filter (ANF) approach is used to synchronize the interfaced PV system with grid to maintain the amplitude, phase and frequency parameters as well as power quality improvement. This technique offers the compensation of harmonics current and reactive power with both linear and nonlinear loads. To maintain constant DC link voltage a PI controller is also implemented and presented in this paper. The complete system has been designed, developed and simulated using SimPower System and Simulink toolbox of MATLAB. The performance analysis of three phase grid connected solar photovoltaic system has been carried out on the basis of various parameters like PV output power, PV voltage, PV current, DC link voltage, PCC (Point of Common Coupling) voltage, grid voltage, grid current, voltage source converter current, power supplied by the voltage source converter etc. The results obtained from the proposed system are found satisfactory.
Abstract: To decrease the grating scale thermal expansion error,
a novel method which based on multiple temperature detection is
proposed. Several temperature sensors are installed on the grating
scale and the temperatures of these sensors are recorded. The
temperatures of every point on the grating scale are calculated by
interpolating between adjacent sensors. According to the thermal
expansion principle, the grating scale thermal expansion error model
can be established by doing the integral for the variations of position
and temperature. A novel compensation method is proposed in this
paper. By applying the established error model, the grating scale
thermal expansion error is decreased by 90% compared with no
compensation. The residual positioning error of the grating scale is
less than 15μm/10m and the accuracy of the machine tool is
significant improved.
Abstract: Fiber Reinforced Polymer (FRP) is a composite material with exceptional properties that are capable to replace conventional steel reinforcement in reinforced and pre-stressed concrete structures. However, the main obstacle for their wide use in pre-stressed concrete application is the anchorage system. Due to the weakness of FRP in the transverse direction, the pre-stressing capacity of FRP bars are limited. This paper investigates the modification of the conventional wedge anchorage system to be used for stressing of FRP bars in pre-stressed applications. Epoxy adhesive material with glass FRP (GFRP) bars and conventional steel wedge were used in this paper. The GFRP bars are encased with epoxy at the anchor zone and the wedge system was used in pull-out test. The results showed a loading capacity of 47.6 kN which is 69% of the bar ultimate capacity. Additionally, nylon wedge was made with the same dimensions of the steel wedge and tested for GFRP bars without epoxy layer. The nylon wedge showed a loading capacity of 19.7 kN which is only 28.5% of the ultimate bar capacity.
Abstract: Mobile Ad Hoc Networks (MANETs) is a collection
of mobile devices forming a communication network without
infrastructure. MANET is vulnerable to security threats due to
network’s limited security, dynamic topology, scalability and the lack
of central management. The Quality of Service (QoS) routing in such
networks is limited by network breakage caused by node mobility or
nodes energy depletions. The impact of node mobility on trust
establishment is considered and its use to propagate trust through a
network is investigated in this paper. This work proposes an
enhanced Associativity Based Routing (ABR) with Fuzzy based
Trust (Fuzzy- ABR) routing protocol for MANET to improve QoS
and to mitigate network attacks.
Abstract: A compact Ultra Wide Band (UWB) antenna with coplanar
waveguide feed has been designed and results are verified in
this paper. The antenna has been designed on FR4 substrate with
dielectric constant (εr) of 4.4 and dimensions of 32mm x 26mm x
0.8mm. The presented antenna shows return loss characteristics in the
band of 3.1 to 10.6 GHz as prescribed by FCC, USA. Parametric
studies have been done and results thus obtained have been
presented. Simulated results have been verified on Rohde & Swartz
VNA. The measured results are in good agreement with simulated
results which make the presented antenna suitable to be used for
wearable applications. Performance analysis of antenna has also been
shown in the presence of three layered Human Arm model. Results
obtained in presence of Human Arm model has been compared with
that in free space.
Abstract: Different designs of attenuator systems have been
studied in this research; new analysis have been done on existed
designs considering fibers effect on air flow; it was comprehended
that, at fibers presence, there is an air flow which agglomerates fibers
as a negative effect. So some new representations have been designed
and CFD analysis has been done on them. Afterwards, one of these
representations selected as the most optimum and effective design
which is brought in this paper.
Abstract: In this paper, the secure BioSemantic Scheme is
presented to bridge biological/biomedical research problems and
computational solutions via semantic computing. Due to the diversity
of problems in various research fields, the semantic capability
description language (SCDL) plays and important role as a common
language and generic form for problem formalization. SCDL is
expected the essential for future semantic and logical computing in
Biosemantic field. We show several example to Biomedical problems
in this paper. Moreover, in the coming age of cloud computing, the
security problem is considered to be crucial issue and we presented a
practical scheme to cope with this problem.
Abstract: This paper presents the local mesh co-occurrence
patterns (LMCoP) using HSV color space for image retrieval system.
HSV color space is used in this method to utilize color, intensity and
brightness of images. Local mesh patterns are applied to define the
local information of image and gray level co-occurrence is used to
obtain the co-occurrence of LMeP pixels. Local mesh co-occurrence
pattern extracts the local directional information from local mesh
pattern and converts it into a well-mannered feature vector using gray
level co-occurrence matrix. The proposed method is tested on three
different databases called MIT VisTex, Corel, and STex. Also, this
algorithm is compared with existing methods, and results in terms of
precision and recall are shown in this paper.
Abstract: This paper presents modeling and simulation of
flexible robot in an underwater environment. The underwater
environment completely contrasts with ground or space environment.
The robot in an underwater situation is subjected to various dynamic
forces like buoyancy forces, hydrostatic and hydrodynamic forces.
The underwater robot is modeled as Rayleigh beam. The developed
model further allows estimating the deflection of tip in two
directions. The complete dynamics of the underwater robot is
analyzed, which is the main focus of this investigation. The control of
robot trajectory is not discussed in this paper. Simulation is
performed using Symbol Shakti software.
Abstract: The MEMS pressure sensor has been introduced and
presented in this paper. The types of pressure sensor and its theory of
operation are also included. The latest MEMS technology, the
fabrication processes of pressure sensor are explored and discussed.
Besides, various device applications of pressure sensor such as tire
pressure-monitoring system, diesel particulate filter and others are
explained. Due to further miniaturization of the device nowadays, the
pressure sensor with nanotechnology (NEMS) is also reviewed. The
NEMS pressure sensor is expected to have better performance as well
as lower in its cost. It has gained an excellent popularity in many
applications.
Abstract: Despite the advances made in various new
technologies, application of these technologies for agriculture still
remains a formidable task, as it involves integration of diverse
domains for monitoring the different process involved in agricultural
management. Advances in ambient intelligence technology represents
one of the most powerful technology for increasing the yield of
agricultural crops and to mitigate the impact of water scarcity,
climatic change and methods for managing pests, weeds and diseases.
This paper proposes a GPS-assisted, machine to machine solutions
that combine information collected by multiple sensors for the
automated management of paddy crops. To maintain the economic
viability of paddy cultivation, the various techniques used in
agriculture are discussed and a novel system which uses ambient
intelligence technique is proposed in this paper. The ambient
intelligence based agricultural system gives a great scope.
Abstract: The reduction of phosphorus and sulfur in engine oil
are the main topics of this paper. Very reproducible boundary
lubrication tests were conducted as part of Design of Experiment
software (DOE) to study the behavior of fluorinated catalyst iron
fluoride (FeF3), and polutetrafluoroethylene or Teflon (PTFE) in
developing environmentally friendly (reduced P and S) anti-wear
additives for future engine oil formulations. Multi-component
Chevron fully formulated oil (GF3) and Chevron plain oil were used
with the addition of PTFE and catalyst to characterize and analyze
their performance. Lower phosphorus blends were the goal of the
model solution. Experiments indicated that new sub-micron FeF3
catalyst played an important role in preventing breakdown of the
tribofilm.
Abstract: There have been rigorous research and development
of unmanned aerial vehicles in the field of search and rescue (SAR)
operation recently. UAVs reduce unnecessary human risks while
assisting rescue efforts through aerial imagery, topographic mapping
and emergency delivery. The application of UAVs in offshore and
nearshore marine SAR missions is discussed in this paper. Projects
that integrate UAV technology into their systems are introduced to
highlight the great advantages and capabilities of UAVs. Scenarios
where UAVs could provide invaluable assistance are also suggested.
Abstract: By the evolvement in technology, the way of
expressing opinions switched direction to the digital world. The
domain of politics, as one of the hottest topics of opinion mining
research, merged together with the behavior analysis for affiliation
determination in texts, which constitutes the subject of this paper.
This study aims to classify the text in news/blogs either as
Republican or Democrat with the minimum number of features. As
an initial set, 68 features which 64 were constituted by Linguistic
Inquiry and Word Count (LIWC) features were tested against 14
benchmark classification algorithms. In the later experiments, the
dimensions of the feature vector reduced based on the 7 feature
selection algorithms. The results show that the “Decision Tree”,
“Rule Induction” and “M5 Rule” classifiers when used with “SVM”
and “IGR” feature selection algorithms performed the best up to
82.5% accuracy on a given dataset. Further tests on a single feature
and the linguistic based feature sets showed the similar results. The
feature “Function”, as an aggregate feature of the linguistic category,
was found as the most differentiating feature among the 68 features
with the accuracy of 81% in classifying articles either as Republican
or Democrat.
Abstract: An investigation of adaptable winglets for enhancing
morphing aircraft performance is described in this paper. The
concepts investigated consist of various winglet configurations
fundamentally centered on a baseline swept wing. The impetus for
the work was to identify and optimize winglets to enhance the
aerodynamic efficiency of a morphing aircraft. All computations
were performed with Athena Vortex Lattice modelling with varying
degrees of twist and cant angle considered. The results from this
work indicate that if adaptable winglets were employed on aircraft’s
improvements in aircraft performance could be achieved.
Abstract: Computational fluid dynamics analysis of the burning
of syngas fuels derived from biomass and plastic solid waste mixture
through gasification process is presented in this paper. The syngas
fuel is burned in gas turbine can combustor. Gas turbine can
combustor with swirl is designed to burn the fuel efficiently and
reduce the emissions. The main objective is to test the impact of the
alternative syngas fuel compositions and lower heating value on the
combustion performance and emissions. The syngas fuel is produced
by blending palm kernel shell (PKS) with polyethylene (PE) waste
via catalytic steam gasification (fluidized bed reactor). High
hydrogen content syngas fuel was obtained by mixing 30% PE waste
with PKS. The syngas composition obtained through the gasification
process is 76.2% H2, 8.53% CO, 4.39% CO2 and 10.90% CH4. The
lower heating value of the syngas fuel is LHV = 15.98 MJ/m3. Three
fuels were tested in this study natural gas (100%CH4), syngas fuel
and pure hydrogen (100% H2). The power from the combustor was
kept constant for all the fuels tested in this study. The effect of syngas
fuel composition and lower heating value on the flame shape, gas
temperature, mass of carbon dioxide (CO2) and nitrogen oxides
(NOX) per unit of energy generation is presented in this paper. The
results show an increase of the peak flame temperature and NO mass
fractions for the syngas and hydrogen fuels compared to natural gas
fuel combustion. Lower average CO2 emissions at the exit of the
combustor are obtained for the syngas compared to the natural gas
fuel.
Abstract: Five palm oil ether monoesters utilized as novel
biodiesels were synthesized and structurally identified in the paper.
The investigation was made on the effect of ether species on
physicochemical properties of the palm oil ether monoesters. The
results showed that density, kinematic viscosity, smoke point, and
solidifying point increase linearly with their –CH2 group number in
certain relationships. Cetane number is enhanced whereas heat value
decreases linearly with –CH2 group number. In addition, the
influencing regularities of the volumetric content of the palm oil ether
monoesters on the fuel properties were also studied when the ether
monoesters are used as diesel fuel additives.