Abstract: Modelling of the earth's surface and evaluation of
urban environment, with 3D models, is an important research topic.
New stereo capabilities of high resolution optical satellites images,
such as the tri-stereo mode of Pleiades, combined with new image
matching algorithms, are now available and can be applied in urban
area analysis. In addition, photogrammetry software packages gained
new, more efficient matching algorithms, such as SGM, as well as
improved filters to deal with shadow areas, can achieve more dense
and more precise results.
This paper describes a comparison between 3D data extracted
from tri-stereo and dual stereo satellite images, combined with pixel
based matching and Wallis filter. The aim was to improve the
accuracy of 3D models especially in urban areas, in order to assess if
satellite images are appropriate for a rapid evaluation of urban
environments.
The results showed that 3D models achieved by Pleiades tri-stereo
outperformed, both in terms of accuracy and detail, the result
obtained from a Geo-eye pair. The assessment was made with
reference digital surface models derived from high resolution aerial
photography. This could mean that tri-stereo images can be
successfully used for the proposed urban change analyses.
Abstract: Interaction between human, location and activity
defines space. In the framework of these relations, space is a
container for current specifications in relations of the 3 mentioned
elements. The change of land utility considered with average
performance range, urban regulations, society requirements etc. will
provide welfare and comfort for citizens. From an engineering view it
is fundamental that choosing a proper location for a specific civil
activity requires evaluation of locations from different perspectives.
The debate of desirable establishment of municipal service elements
in urban regions is one of the most important issues related to urban
planning. In this paper, the research type is applicable based on goal,
and is descriptive and analytical based on nature. Initially existing
terminals in Esfahan are surveyed and then new locations are
presented based on evaluated criteria. In order to evaluate terminals
based on the considered factors, an AHP model is used at first to
estimate weight of different factors and then existing and suggested
locations are evaluated using Arc GIS software and AHP model
results. The results show that existing bus terminals are located in
fairly proper locations. Further results of this study suggest new
locations to establish terminals based on urban criteria.
Abstract: Sandwich structure composites produced by epoxy
core and aluminium skin were developed as potential building
materials. Interface bonding between core and skin was controlled by
varying kenaf content. Five different weight percentage of kenaf
loading ranging from 10 wt% to 50 wt% were employed in the core
manufacturing in order to study the mechanical properties of the
sandwich composite. Properties of skin aluminium with epoxy were
found to be affected by drying time of the adhesive. Mechanical
behavior of manufactured sandwich composites in relation with
properties of constituent materials was studied. It was found that 30
wt% of kenaf loading contributed to increase the flexural strength and
flexural modulus up to 102 MPa and 32 GPa, respectively. Analysis
were done on the flatwise and edgewise compression test. For
flatwise test, it was found that 30 wt% of fiber loading could
withstand maximum force until 250 kN, with compressive strength
results at 96.94 MPa. However, at edgewise compression test, the
sandwich composite with same fiber loading only can withstand 31
kN of the maximum load with 62 MPa of compressive strength
results.
Abstract: This paper presents the details of a numerical study of
buckling and post buckling behaviour of laminated carbon fiber
reinforced plastic (CFRP) thin-walled cylindrical shell under axial
compression using asymmetric meshing technique (AMT) by
ABAQUS. AMT is considered to be a new perturbation method to
introduce disturbance without changing geometry, boundary
conditions or loading conditions. Asymmetric meshing affects both
predicted buckling load and buckling mode shapes. Cylindrical shell
having lay-up orientation [0^o/+45^o/-45^o/0^o] with radius to thickness
ratio (R/t) equal to 265 and length to radius ratio (L/R) equal to 1.5 is
analysed numerically. A series of numerical simulations
(experiments) are carried out with symmetric and asymmetric
meshing to study the effect of asymmetric meshing on predicted
buckling behaviour. Asymmetric meshing technique is employed in
both axial direction and circumferential direction separately using
two different methods, first by changing the shell element size and
varying the total number elements, and second by varying the shell
element size and keeping total number of elements constant. The
results of linear analysis (Eigenvalue analysis) and non-linear
analysis (Riks analysis) using symmetric meshing agree well with
analytical results. The results of numerical analysis are presented in
form of non-dimensional load factor, which is the ratio of buckling
load using asymmetric meshing technique to buckling load using
symmetric meshing technique. Using AMT, load factor has about 2%
variation for linear eigenvalue analysis and about 2% variation for
non-linear Riks analysis. The behaviour of load end-shortening curve
for pre-buckling is same for both symmetric and asymmetric meshing
but for asymmetric meshing curve behaviour in post-buckling
becomes extraordinarily complex. The major conclusions are:
different methods of AMT have small influence on predicted
buckling load and significant influence on load displacement curve
behaviour in post buckling; AMT in axial direction and AMT in
circumferential direction have different influence on buckling load
and load displacement curve in post-buckling.
Abstract: Image search engines rely on the surrounding textual
keywords for the retrieval of images. It is a tedious work for the
search engines like Google and Bing to interpret the user’s search
intention and to provide the desired results. The recent researches
also state that the Google image search engines do not work well on
all the images. Consequently, this leads to the emergence of efficient
image retrieval technique, which interprets the user’s search intention
and shows the desired results. In order to accomplish this task, an
efficient image re-ranking framework is required. Sequentially, to
provide best image retrieval, the new image re-ranking framework is
experimented in this paper. The implemented new image re-ranking
framework provides best image retrieval from the image dataset by
making use of re-ranking of retrieved images that is based on the
user’s desired images. This is experimented in two sections. One is
offline section and other is online section. In offline section, the reranking
framework studies differently (reference classes or Semantic
Spaces) for diverse user query keywords. The semantic signatures get
generated by combining the textual and visual features of the images.
In the online section, images are re-ranked by comparing the
semantic signatures that are obtained from the reference classes with
the user specified image query keywords. This re-ranking
methodology will increases the retrieval image efficiency and the
result will be effective to the user.
Abstract: It has experimentally been proved that the
performance of compression ignition (C.I.) engine is spray
characteristics related. In modern diesel engine the spray formation
and the eventual combustion process are the vital processes that offer
more challenges towards enhancing the engine performance. In the
present work the numerical simulation has been carried out for
evaporating diesel sprays using Fluent software. For computational
fluid dynamics simulation “Meshing” is done using Gambit software
before transmitting it into Fluent. The simulation is carried out using
hot bomb conditions under varying chamber conditions such as gas
pressure, nozzle diameter and fuel injection pressure. For comparison
purpose, the numerical simulations the chamber conditions were kept
the same as that of the experimental data. At varying chamber
conditions the spray penetration rates are compared with the existing
experimental results.
Abstract: Solenoid operated electromagnetic control valve
(ECV) playing an important role for car’s air conditioning control
system. ECV is used in external variable displacement swash plate
type compressor and controls the entire air conditioning system by
means of a pulse width modulation (PWM) input signal supplying
from an external source (controller). Complete form of ECV contains
number of internal features like valve body, core, valve guide,
plunger, guide pin, plunger spring, bellows etc. While designing the
ECV; dimensions of different internal items must meet the standard
requirements as it is quite challenging. In this research paper,
especially the dimensioning of ECV body and its three pressure ports
through which the air/refrigerant passes are considered. Here internal
leakage test analysis of ECV body is being carried out from its
discharge port (Pd) to crankcase port (Pc) when the guide valve is
placed inside it. The experiments have made both in ordinary and
digital system using different assumptions and thereafter compare the
results.
Abstract: Fracture in hot precision forging of engine valves was
investigated in this paper. The entire valve forging procedure was
described and the possible cause of the fracture was proposed. Finite
Element simulation was conducted for the forging process, with
commercial Finite Element code DEFORMTM. The effects of
material properties, the effect of strain rate and temperature were
considered in the FE simulation. Two fracture criteria were discussed
and compared, based on the accuracy and reliability of the FE
simulation results. The selected criterion predicted the fracture
location and shows the trend of damage increasing with good
accuracy, which matches the experimental observation. Additional
modification of the punch shapes was proposed to further reduce the
tendency of fracture in forging. Finite Element comparison shows a
great potential of such application in the mass production.
Abstract: Performance of different filtering approaches depends
on modeling of dynamical system and algorithm structure. For
modeling and smoothing the data the evaluation of posterior
distribution in different filtering approach should be chosen carefully.
In this paper different filtering approaches like filter KALMAN,
EKF, UKF, EKS and smoother RTS is simulated in some trajectory
tracking of path and accuracy and limitation of these approaches are
explained. Then probability of model with different filters is
compered and finally the effect of the noise variance to estimation is
described with simulations results.
Abstract: This paper presents a novel statistical description of
the counterpoise effective length due to lightning surges, where the
(impulse) effective length had been obtained by means of regressive
formulas applied to the transient simulation results. The effective
length is described in terms of a statistical distribution function, from
which median, mean, variance, and other parameters of interest could
be readily obtained. The influence of lightning current amplitude,
lightning front duration, and soil resistivity on the effective length has
been accounted for, assuming statistical nature of these parameters. A
method for determining the optimal counterpoise length, in terms of
the statistical impulse effective length, is also presented. It is based on
estimating the number of dangerous events associated with lightning
strikes. Proposed statistical description and the associated method
provide valuable information which could aid the design engineer in
optimising physical lengths of counterpoises in different grounding
arrangements and soil resistivity situations.
Abstract: Examining existing experimental results for shallow
rigid foundations subjected to vertical centric load (N), accompanied
or not with a bending moment (M), two main non-linear mechanisms
governing the cyclic response of the soil-foundation system can be
distinguished: foundation uplift and soil yielding. A soil-foundation
failure limit, is defined as a domain of resistance in the two
dimensional (2D) load space (N, M) inside of which lie all the
admissible combinations of loads; these latter correspond to a pure
elastic, non-linear elastic or plastic behavior of the soil-foundation
system, while the points lying on the failure limit correspond to a
combination of loads leading to a failure of the soil-foundation
system. In this study, the proposed resistance domain is constructed
analytically based on mechanics. Original elastic limit, uplift
initiation limit and iso-uplift limits are constructed inside this
domain. These limits give a prediction of the mechanisms activated
for each combination of loads applied to the foundation. A
comparison of the proposed failure limit with experimental tests
existing in the literature shows interesting results. Also, the
developed uplift initiation limit and iso-uplift curves are confronted
with others already proposed in the literature and widely used due to
the absence of other alternatives, and remarkable differences are
noted, showing evident errors in the past proposals and relevant
accuracy for those given in the present work.
Abstract: It is difficult to study the effect of various variables on
cycle fitting through actual experiment. To overcome such difficulty,
the forward dynamics of a musculoskeletal model was applied to cycle
fitting in this study. The measured EMG data weres compared with the
muscle activities of the musculoskeletal model through forward
dynamics. EMG data were measured from five cyclists who do not
have musculoskeletal diseases during three minutes pedaling with a
constant load (150 W) and cadence (90 RPM). The muscles used for
the analysis were the Vastus Lateralis (VL), Tibialis Anterior (TA),
Bicep Femoris (BF), and Gastrocnemius Medial (GM). Person’s
correlation coefficients of the muscle activity patterns, the peak timing
of the maximum muscle activities, and the total muscle activities were
calculated and compared. BIKE3D model of AnyBody (Anybodytech,
Denmark) was used for the musculoskeletal model simulation. The
comparisons of the actual experiments with the simulation results
showed significant correlations in the muscle activity patterns (VL:
0.789, TA: 0.503, BF: 0.468, GM: 0.670). The peak timings of the
maximum muscle activities were distributed at particular phases. The
total muscle activities were compared with the normalized muscle
activities, and the comparison showed about 10% difference in the VL
(+10%), TA (+9.7%), and BF (+10%), excluding the GM (+29.4%).
Thus, it can be concluded that muscle activities of model &
experiment showed similar results. The results of this study indicated
that it was possible to apply the simulation of further improved
musculoskeletal model to cycle fitting.
Abstract: In this paper, we present preconditioned generalized
accelerated overrelaxation (GAOR) methods for solving certain
nonsingular linear system. We compare the spectral radii of the
iteration matrices of the preconditioned and the original methods. The
comparison results show that the preconditioned GAOR methods
converge faster than the GAOR method whenever the GAOR method
is convergent. Finally, we give two numerical examples to confirm our
theoretical results.
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: E-learning has become an efficient and widespread
means of education at all levels of human activities. Statistics is no
exception. Unfortunately the main focus in statistics teaching is
usually paid to the substitution in formulas. Suitable websites can
simplify and automate calculations and provide more attention and
time to the basic principles of statistics, mathematization of real-life
situations and following interpretation of results. We now introduce
our own web-site for hypothesis testing. Its didactic aspects, the
technical possibilities of the individual tools, the experience of use
and the advantages or disadvantages are discussed in this paper. This
web-site is not a substitute for common statistical software but should
significantly improve the teaching of statistics at universities.
Abstract: The main purpose of this research is to
comprehensively explore and identify the problems of attestation of
the public servants and to propose solutions for these issues through
deeply analyzing laws and the legal theoretical literature. For the
detailed analysis of the above-mentioned problems we will use some
research methods, the implementation of which has a goal to ensure
the objectivity and clarity of scientific research and its results.
Abstract: Red blood cells (RBC) are the most common types of
blood cells and are the most intensively studied in cell biology. The
lack of RBCs is a condition in which the amount of hemoglobin level
is lower than normal and is referred to as “anemia”. Abnormalities in
RBCs will affect the exchange of oxygen. This paper presents a
comparative study for various techniques for classifying the RBCs as
normal or abnormal (anemic) using WEKA. WEKA is an open
source consists of different machine learning algorithms for data
mining applications. The algorithms tested are Radial Basis Function
neural network, Support vector machine, and K-Nearest Neighbors
algorithm. Two sets of combined features were utilized for
classification of blood cells images. The first set, exclusively consist
of geometrical features, was used to identify whether the tested blood
cell has a spherical shape or non-spherical cells. While the second
set, consist mainly of textural features was used to recognize the
types of the spherical cells. We have provided an evaluation based on
applying these classification methods to our RBCs image dataset
which were obtained from Serdang Hospital - Malaysia, and
measuring the accuracy of test results. The best achieved
classification rates are 97%, 98%, and 79% for Support vector
machines, Radial Basis Function neural network, and K-Nearest
Neighbors algorithm respectively.
Abstract: This paper presents a hybrid fuzzy logic control
strategy for a unicycle trajectory following robot on irregular terrains.
In literature, researchers have presented the design of path tracking
controllers of mobile robots on non-frictional surface. In this work,
the robot is simulated to drive on irregular terrains with contrasting
frictional profiles of peat and rough gravel. A hybrid fuzzy logic
controller is utilised to stabilise and drive the robot precisely with the
predefined trajectory and overcome the frictional impact. The
controller gains and scaling factors were optimised using spiral
dynamics optimisation algorithm to minimise the mean square error
of the linear and angular velocities of the unicycle robot. The robot
was simulated on various frictional surfaces and terrains and the
controller was able to stabilise the robot with a superior performance
that is shown via simulation results.
Abstract: In structures, stress concentration is a factor of fatigue
fracture. Basically, the stress concentration is a phenomenon that
should be avoided. However, it is difficult to avoid the stress
concentration. Therefore, relaxation of the stress concentration is
important. The stress concentration arises from notches and circular
holes. There is a relaxation method that a composite patch covers a
notch and a circular hole. This relaxation method is used to repair
aerial wings, but it is not systematized. Composites are more
expensive than single materials. Accordingly, we propose the
relaxation method that a single material patch covers a notch and a
circular hole, and aim to systematize this relaxation method.
We performed FEA (Finite Element Analysis) about an object by
using a three-dimensional FEA model. The object was that a patch
adheres to a plate with a circular hole. And, a uniaxial tensile load acts
on the patched plate with a circular hole. In the three-dimensional FEA
model, it is not easy to model the adhesion layer. Basically, the yield
stress of the adhesive is smaller than that of adherents. Accordingly,
the adhesion layer gets to plastic deformation earlier than the adherents
under the yield load of adherents. Therefore, we propose the
three-dimensional FEA model which is applied a nonlinear elastic
region to the adhesion layer. The nonlinear elastic region was
calculated by a bilinear approximation. We compared the analysis
results with the tensile test results to confirm whether the analysis
model has usefulness. As a result, the analysis results agreed with the
tensile test results. And, we confirmed that the analysis model has
usefulness.
As a result that the three-dimensional FEA model was used to the
analysis, it was confirmed that an out-of-plane deformation occurred
to the patched plate with a circular hole. The out-of-plane deformation
causes stress increase of the patched plate with a circular hole.
Therefore, we investigated that the out-of-plane deformation affects
relaxation of the stress concentration in the plate with a circular hole
on this relaxation method. As a result, it was confirmed that the
out-of-plane deformation inhibits relaxation of the stress concentration
on the plate with a circular hole.
Abstract: The reachable set bounding estimation for distributed
delay systems with disturbances is a new problem. In this paper,we
consider this problem subject to not only time varying delay and
polytopic uncertainties but also distributed delay systems which is
not studied fully untill now. we can obtain improved non-ellipsoidal
reachable set estimation for neural networks with time-varying delay
by the maximal Lyapunov-Krasovskii fuctional which is constructed
as the pointwise maximum of a family of Lyapunov-Krasovskii
fuctionals corresponds to vertexes of uncertain polytope.On the other
hand,matrix inequalities containing only one scalar and Matlabs
LMI Toolbox is utilized to give a non-ellipsoidal description of the
reachable set.finally,numerical examples are given to illustrate the
existing results.