Abstract: Composite materials, due to their unique properties
such as high strength to weight ratio, corrosion resistance, and impact
resistance have huge potential as structural materials in automotive,
construction and transportation applications. However, these
properties often come at higher cost owing to complex design
methods, difficult manufacturing processes and raw material cost.
Traditionally, tapered laminated composite structures are
manufactured using autoclave manufacturing process by ply drop off
technique. Autoclave manufacturing though very powerful suffers
from high capital investment and higher energy consumption. As per
the current trends in composite manufacturing, Out of Autoclave
(OoA) processes are looked as emerging technologies for
manufacturing the structural composite components for aerospace
and defense applications. However, there is a need for improvement
among these processes to make them reliable and consistent. In this
paper, feasibility of using out of autoclave process to manufacture the
variable thickness cantilever beam is discussed. The minimum weight
design for the composite beam is obtained using constant stress beam
concept by tailoring the thickness of the beam. Ply drop off
techniques was used to fabricate the variable thickness beam from
glass/epoxy prepregs. Experiments were conducted to measure
bending stresses along the span of the cantilever beam at different
intervals by applying the concentrated load at the free end.
Experimental results showed that the stresses in the bean at different
intervals were constant. This proves the ability of OoA process to
manufacture the constant stress beam. Finite element model for the
constant stress beam was developed using commercial finite element
simulation software. It was observed that the simulation results
agreed very well with the experimental results and thus validated
design and manufacturing approach used.
Abstract: A capacity spectrum method (CSM), one of methodologies to evaluate seismic fragilities of building structures, has been long recognized as the most convenient method, even if it contains several limitations to predict the seismic response of structures of interest. This paper proposes the procedure to estimate seismic fragility curves using an incremental dynamic analysis (IDA) rather than the method adopting a CSM. To achieve the research purpose, this study compares the seismic fragility curves of a 5-story reinforced concrete (RC) moment frame obtained from both methods; an IDA method and aCSM. Both seismic fragility curves are similar in slight and moderate damage states whereas the fragility curve obtained from the IDA method presents less variation (or uncertainties) in extensive and complete damage states. This is due to the fact that the IDA method can properly capture the structural response beyond yielding rather than the CSM and can directly calculate higher mode effects. From these observations, the CSM could overestimate seismic vulnerabilities of the studied structure in extensive or complete damage states.
Abstract: A thermosyphon system is a heat transfer loop which
operates on the basis of gravity and buoyancy forces. It guarantees a
good reliability and low maintenance cost as it does not involve any
mechanical pump. Therefore, it can be used in many industrial
applications such as refrigeration and air conditioning, electronic
cooling, nuclear reactors, geothermal heat extraction, etc. But flow
instabilities and loop configuration are the major problems in this
system. Several previous researchers studied that stabilities can be
suppressed by using nanofluids as loop fluid. In the present study a
rectangular thermosyphon loop with end heat exchangers are
considered for the study. This configuration is more appropriate for
many practical applications such as solar water heater, geothermal
heat extraction, etc. In the present work, steady-state analysis is
carried out on thermosyphon loop with parallel flow coaxial heat
exchangers at heat source and heat sink. In this loop nanofluid is
considered as the loop fluid and water is considered as the external
fluid in both hot and cold heat exchangers. For this analysis onedimensional
homogeneous model is developed. In this model,
conservation equations like conservation of mass, momentum, energy
are discretized using finite difference method. A computer code is
written in MATLAB to simulate the flow in thermosyphon loop. A
comparison in terms of heat transfer is made between water and
nanofluid as working fluids in the loop.
Abstract: A Distributed Denial of Service (DDoS) attack is a
major threat to cyber security. It originates from the network layer or
the application layer of compromised/attacker systems which are
connected to the network. The impact of this attack ranges from the
simple inconvenience to use a particular service to causing major
failures at the targeted server. When there is heavy traffic flow to a
target server, it is necessary to classify the legitimate access and
attacks. In this paper, a novel method is proposed to detect DDoS
attacks from the traces of traffic flow. An access matrix is created
from the traces. As the access matrix is multi dimensional, Principle
Component Analysis (PCA) is used to reduce the attributes used for
detection. Two classifiers Naive Bayes and K-Nearest neighborhood
are used to classify the traffic as normal or abnormal. The
performance of the classifier with PCA selected attributes and actual
attributes of access matrix is compared by the detection rate and
False Positive Rate (FPR).
Abstract: We present a solution to the Maxmin u/E parameters
estimation problem of possibility distributions in m-dimensional
case. Our method is based on geometrical approach, where minimal
area enclosing ellipsoid is constructed around the sample. Also we
demonstrate that one can improve results of well-known algorithms
in fuzzy model identification task using Maxmin u/E parameters
estimation.
Abstract: In this paper, we propose a method for three-dimensional
(3-D)-model indexing based on defining a new
descriptor, which we call new descriptor using spherical harmonics.
The purpose of the method is to minimize, the processing time on the
database of objects models and the searching time of similar objects
to request object.
Firstly we start by defining the new descriptor using a new
division of 3-D object in a sphere. Then we define a new distance
which will be used in the search for similar objects in the database.
Abstract: A strain of Monascus purpureus CMU001 was used to
prepare red yeast rice from Thai glutinous rice Korkor 6 (RD 6).
Adding of different amounts of histidine (156, 312, 625 and 1250 mg
in 100 g of rice grains)) under aerobic and air limitation (air-lock)
condition were used in solid fermentation. Determination of the yield
as well as monacolin K content was done. Citrinin content was also
determined in order to confirm the safety use of prepared red yeast
rice. It was found that under air-lock condition with 1250 mg of
histidine addition gave the highest yield of 37.40 g of dried red yeast
rice prepared from 100 g of rice. Highest 5.72 mg content of
monacolin K was obtained under air-lock condition with 312 mg
histidine addition. In the other hand, citrinin content was found to be
less than 24462 ng/g of all dried red yeast rice samples under the
experimental methods used in this work.
Abstract: Worldwide, most PILC MV underground cables in use
are approaching the end of their design life; hence, failures are likely
to increase. This paper studies the electric field and potential
distributions within the PILC insulted cable containing common
void-defect. The finite element model of the performance of the
belted PILC MV underground cable is presented. The variation of the
electric field stress within the cable using the Finite Element Method
(FEM) is concentrated. The effects of the void-defect within the
insulation are given. Outcomes will lead to deeper understanding of
the modeling of Paper Insulated Lead Covered (PILC) and electric
field response of belted PILC insulted cable containing void defect.
Abstract: The main aim of a communication system is to
achieve maximum performance. In Cognitive Radio any user or
transceiver has ability to sense best suitable channel, while channel is
not in use. It means an unlicensed user can share the spectrum of a
licensed user without any interference. Though, the spectrum sensing
consumes a large amount of energy and it can reduce by applying
various artificial intelligent methods for determining proper spectrum
holes. It also increases the efficiency of Cognitive Radio Network
(CRN). In this survey paper we discuss the use of different learning
models and implementation of Artificial Neural Network (ANN) to
increase the learning and decision making capacity of CRN without
affecting bandwidth, cost and signal rate.
Abstract: Spam is any unwanted electronic message or material
in any form posted too many people. As the world is growing as
global world, social networking sites play an important role in
making world global providing people from different parts of the
world a platform to meet and express their views. Among different
social networking sites Facebook become the leading one. With
increase in usage different users start abusive use of Facebook by
posting or creating ways to post spam. This paper highlights the
potential spam types nowadays Facebook users’ faces. This paper
also provide the reason how user become victim to spam attack. A
methodology is proposed in the end discusses how to handle different
types of spam.
Abstract: In this study, data loss tolerance of Support Vector Machines (SVM) based activity recognition model and multi activity classification performance when data are received over a lossy wireless sensor network is examined. Initially, the classification algorithm we use is evaluated in terms of resilience to random data loss with 3D acceleration sensor data for sitting, lying, walking and standing actions. The results show that the proposed classification method can recognize these activities successfully despite high data loss. Secondly, the effect of differentiated quality of service performance on activity recognition success is measured with activity data acquired from a multi hop wireless sensor network, which introduces high data loss. The effect of number of nodes on the reliability and multi activity classification success is demonstrated in simulation environment. To the best of our knowledge, the effect of data loss in a wireless sensor network on activity detection success rate of an SVM based classification algorithm has not been studied before.
Abstract: Replacement of plastics used in the food industry
seems to be a serious issue to overcome mainly the environmental
problems in recent years. This study investigates the hydrophilicity
and permeability properties of starch biopolymer which ethylene
vinyl alcohol (EVOH) (0-10%) and nanocrystalline cellulose (NCC)
(1-15%) were used to enhance its properties. Starch -EVOH
nanocomposites were prepared by casting method in different
formulations. NCC production by acid hydrolysis was confirmed by
scanning electron microscopy. Solubility, water vapor permeability,
water vapor transmission rate and moisture absorbance were
measured on each of the nanocomposites. The results were analyzed
by SAS software. The lowest moisture absorbance was measured in
pure starch nanocomposite containing 8% NCC. The lowest
permeability to water vapor belongs to starch nanocomposite
containing 8% NCC and the sample containing 7.8% EVOH and 13%
NCC. Also the lowest solubility was observed in the composite
contains the highest amount of EVOH. Applied Process resulted in
production of bio films which have good resistance to water vapor
permeability and solubility in water. The use of NCC and EVOH
leads to reduced moisture absorbance property of the biofilms.
Abstract: Locating Radio Controlled (RC) devices using their
unintended emissions has a great interest considering security
concerns. Weak nature of these emissions requires near field
localization approach since it is hard to detect these signals in far
field region of array. Instead of only angle estimation, near field
localization also requires range estimation of the source which makes
this method more complicated than far field models. Challenges of
locating such devices in a near field region and real time environment
are analyzed in this paper. An ESPRIT like near field localization
scheme is utilized for both angle and range estimation. 1-D search
with symmetric subarrays is provided. Two 7 element uniform linear
antenna arrays (ULA) are employed for locating RC source.
Experiment results of location estimation for one unintended emitting
walkie-talkie for different positions are given.
Abstract: In the scope of application of technical textiles, Non-
Crimp Fabrics are increasingly used. In general, NCF exhibit
excellent load bearing properties, but caused by the manufacturing
process, there are some remaining disadvantages which have to be
reduced. Regarding to this, a novel technique of processing NCF was
developed substituting the binding-thread by an adhesive. This stitchfree
method requires new manufacturing concept as well as new basic
methods to prove adhesion of glue at fibres and textiles. To improve
adhesion properties and the wettability of carbon-fibres by the
adhesive, oxy-fluorination was used. The modification of carbonfibres
by oxy-fluorination was investigated via scanning electron
microscope, X-ray photoelectron spectroscopy and single fibre
tensiometry. Special tensile tests were developed to determine the
maximum force required for detachment.
Abstract: An exploration of the related literature reveals that all
instruction methods aim at training autonomous learners. After the
turn of second language pedagogy toward learner-oriented strategies,
learners’ needs were more focused. Yet; the historical, social and
political aspects of learning were still neglected. The present study
investigates the notion of autonomous learning and explains its
various facets from a pedagogical point of view. Furthermore;
different elements, fields and scopes of autonomous learning will be
explored. After exploring different aspects of autonomy, it is
postulated that liberatory autonomy is highlighted since it not only
covers social autonomy but also reveals learners’ capabilities and
human potentials. It is also recommended that learners consider
different elements of autonomy such as motivation, knowledge,
confidence, and skills.
Abstract: In this study, we propose a novel technique for acoustic
echo suppression (AES) during speech recognition under barge-in
conditions. Conventional AES methods based on spectral subtraction
apply fixed weights to the estimated echo path transfer function
(EPTF) at the current signal segment and to the EPTF estimated until
the previous time interval. However, the effects of echo path changes
should be considered for eliminating the undesired echoes. We
describe a new approach that adaptively updates weight parameters in
response to abrupt changes in the acoustic environment due to
background noises or double-talk. Furthermore, we devised a voice
activity detector and an initial time-delay estimator for barge-in speech
recognition in communication networks. The initial time delay is
estimated using log-spectral distance measure, as well as
cross-correlation coefficients. The experimental results show that the
developed techniques can be successfully applied in barge-in speech
recognition systems.
Abstract: An efficient and green method for oxidation of thiols
to the corresponding disulfides is reported using ionic liquid
[HSO3N(C2H4OSO3H)3] in the presence of free nano-Fe2O3 at 60°C.
Ionic liquid is selective oxidant for S-S Coupling variety aliphatic
and aromatic of thiols to corresponding disulfide in the presence of
free nano-Fe2O3 as recoverable catalyst. Reaction has been performed
in methanol as an inexpensive solvent. This reaction is clean and easy
work-up with no side reaction.
Abstract: Food as perishable goods represents a specific and
sensitive part in the supply chain theory, since changing physical or
chemical characteristics considerably influence the approach to stock
management. The most delicate phase of this process is
transportation, where it becomes difficult to ensure the stable
conditions which limit deterioration, since the value of the
deterioration rate could be easily influenced by the mode of
transportation. The fuzzy definition of variables allows one to take
these variations into account. Furthermore, an appropriate choice of
the defuzzification method permits one to adapt results to real
conditions as far as possible. In this article those methods which take
into account the relationship between the deterioration rate of
perishable goods and transportation by ship will be applied with the
aim of (a) minimizing the total cost function, defined as the sum of
the ordering cost, holding cost, disposing cost and transportation
costs, and (b) improving the supply chain sustainability by reducing
environmental impact and waste disposal costs.
Abstract: In this paper we describe the Levenvberg-Marquardt
(LM) algorithm for identification and equalization of CDMA
signals received by an antenna array in communication channels.
The synthesis explains the digital separation and equalization of
signals after propagation through multipath generating intersymbol
interference (ISI). Exploiting discrete data transmitted and three
diversities induced at the reception, the problem can be composed
by the Block Component Decomposition (BCD) of a tensor of
order 3 which is a new tensor decomposition generalizing the
PARAFAC decomposition. We optimize the BCD decomposition by
Levenvberg-Marquardt method gives encouraging results compared to
classical alternating least squares algorithm (ALS). In the equalization
part, we use the Minimum Mean Square Error (MMSE) to perform
the presented method. The simulation results using the LM algorithm
are important.
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.