Abstract: This article discusses stress analysis and the shape characteristics of the inflatable wing, and then introduces the design method of inflatable wing, in order to accurately approximate a standard airfoil. It specifically analyses the aerodynamic characteristics of the inflatable wing with the method of CFD, along with comparing to standard airfoil, afterwards we carries out the manufacture of inflatable wing and the flight test.
Abstract: A glider is in essence an unpowered vehicle and in this project we designed and built an oceanic glider, designed to operate underwater. This Glider was designed to collect ocean data such as temperature, pressure and (in future measures physical dimensions of the operating environment) and output this data to an external source. Development of the Oceanic Glider required research into various actuation systems that control buoyancy, pitch and yaw and the dynamics of these systems. It also involved the design and manufacture of the Glider and the design and implementation of a controller that enabled the Glider to navigate and move in an appropriate manner.
Abstract: Currently, web usage make a huge data from a lot of
user attention. In general, proxy server is a system to support web
usage from user and can manage system by using hit rates. This
research tries to improve hit rates in proxy system by applying data
mining technique. The data set are collected from proxy servers in the
university and are investigated relationship based on several features.
The model is used to predict the future access websites. Association
rule technique is applied to get the relation among Date, Time, Main
Group web, Sub Group web, and Domain name for created model.
The results showed that this technique can predict web content for the
next day, moreover the future accesses of websites increased from
38.15% to 85.57 %.
This model can predict web page access which tends to increase
the efficient of proxy servers as a result. In additional, the
performance of internet access will be improved and help to reduce
traffic in networks.
Abstract: The primary cause of Total Hip Replacement (THR)
failure for younger patients is aseptic loosening. This complication is
twice more likely to happen in acetabular cup than in femoral stem.
Excessive micromotion between bone and implant will cause
loosening and it depends in patient activities, age and bone. In this
project, the effects of different metal back design of press fit on
osseointegration of the acetabular cup are carried out. Commercial
acetabular cup designs, namely Spiked, Superfix and Quadrafix are
modelled and analyzed using commercial finite element software.
The diameter of acetabular cup is based on the diameter of acetabular
rim to make sure the component fit to the acetabular cavity. A new
design of acetabular cup are proposed and analyzed to get better
osseointegration between the bones and implant interface. Results
shows that the proposed acetabular cup designs are more stable
compared to other designs with respect to stress and displacement
aspects.
Abstract: The purpose of this study was to explore the complex
flow structure a novel active-type micromixer that based on concept of
Wankle-type rotor. The characteristics of this micromixer are two
folds; a rapid mixing of reagents in a limited space due to the
generation of multiple vortices and a graduate increment in dynamic
pressure as the mixed reagents is delivered to the output ports.
Present micro-mixer is consisted of a rotor with shape of triangle
column, a blending chamber and several inlet and outlet ports. The
geometry of blending chamber is designed to make the rotor can be
freely internal rotated with a constant eccentricity ratio. When the
shape of the blending chamber and the rotor are fixed, the effects of
rotating speed of rotor and the relative locations of ports on the mixing
efficiency are numerical studied. The governing equations are
unsteady, two-dimensional incompressible Navier-Stokes equation
and the working fluid is the water. The species concentration equation
is also solved to reveal the mass transfer process of reagents in various
regions then to evaluate the mixing efficiency.
The dynamic mesh technique was implemented to model the
dynamic volume shrinkage and expansion of three individual
sub-regions of blending chamber when the rotor conducted a complete
rotating cycle. Six types of ports configuration on the mixing
efficiency are considered in a range of Reynolds number from 10 to
300. The rapid mixing process was accomplished with the multiple
vortex structures within a tiny space due to the equilibrium of shear
force, viscous force and inertial force. Results showed that the highest
mixing efficiency could be attained in the following conditions: two
inlet and two outlet ports configuration, that is an included angle of 60
degrees between two inlets and an included angle of 120 degrees
between inlet and outlet ports when Re=10.
Abstract: In this work study the location of interface in a stirred vessel with a Concave impeller by computational fluid dynamic was presented. To modeling rotating the impeller, sliding mesh (SM) technique was used and standard k-ε model was selected for turbulence closure. Mean tangential, radial and axial velocities and also turbulent kinetic energy (k) and turbulent dissipation rate (ε) in various points of tank was investigated. Results show sensitivity of system to location of interface and radius of 7 to 10cm for interface in the vessel with existence characteristics cause to increase the accuracy of simulation.
Abstract: This paper proposes the concept of aerocapture with
aerodynamic-environment-adaptive variable geometry flexible
aeroshell that vehicle deploys. The flexible membrane is composed
of thin-layer film or textile as its aeroshell in order to solve some
problems obstructing realization of aerocapture technique.
Multi-objective optimization study is conducted to investigate
solutions and derive design guidelines. As a result, solutions which
can avoid aerodynamic heating and enlarge the corridor width up
to 10% are obtained successfully, so that the effectiveness of this
concept can be demonstrated. The deformation-use optimum
solution changes its drag coefficient from 1.6 to 1.1, along with the
change in dynamic pressure. Moreover, optimization results show
that deformation-use solution requires the membrane for which
upper temperature limit and strain limit are more than 700 K and
120%, respectively, and elasticity (Young-s modulus) is of order of
106 Pa.
Abstract: A manufacturing inventory model with shortages with
carrying cost, shortage cost, setup cost and demand quantity as
imprecise numbers, instead of real numbers, namely interval number
is considered here. First, a brief survey of the existing works on
comparing and ranking any two interval numbers on the real line
is presented. A common algorithm for the optimum production
quantity (Economic lot-size) per cycle of a single product (so as
to minimize the total average cost) is developed which works well
on interval number optimization under consideration. Finally, the
designed algorithm is illustrated with numerical example.
Abstract: There are two common methodologies to verify
signatures: the functional approach and the parametric approach. This
paper presents a new approach for dynamic handwritten signature
verification (HSV) using the Neural Network with verification by the
Conjugate Gradient Neural Network (NN). It is yet another avenue in
the approach to HSV that is found to produce excellent results when
compared with other methods of dynamic. Experimental results show
the system is insensitive to the order of base-classifiers and gets a
high verification ratio.
Abstract: A large quantity of world-s oil reserves exists in
carbonate reservoirs. Carbonate reservoirs are very sensitive to
chemical enhanced oil recovery process because of containing large
amount of calcite, dolomite and calcium sulfate minerals. These
minerals cause major obstacles during alkali-surfactant-polymer
(ASP) flooding. Alkali reacts with these minerals and form undesired
precipitations which plug effective porous openings, reduce
permeability and cause scale occurrence at the wellbore. In this
paper, a new chemical combination consists of acrylic acid and alkali
was used to minimize precipitation problem during ASP flooding. A
series of fluid-fluid compatibility tests were performed using acrylic
acid and different concentrations of alkaline. Two types of alkalis
namely; sodium carbonate and sodium metaborate were screened. As
a result, the combination of acrylic acid and sodium carbonate was
not effective in preventing calcium and magnesium precipitations.
However, acrylic acid and sodium metaborate showed promising
results for keeping all solutions without any precipitations. The ratio
of acrylic acid to sodium metaborate of 0.7:1.0 was found to be
optimum for achieving a compatible solution for 30 days at 80oC.
Abstract: Bones are dynamic and responsive organs, they
regulate their strength and mass according to the loads which they are subjected. Because, the Wnt/β-catenin pathway has profound
effects on the regulation of bone mass, we hypothesized that mechanical loading of bone cells stimulates Wnt/β-catenin signaling, which results in the generation of new bone mass.
Mechanical loading triggers the secretion of the Wnt molecule, which after binding to transmembrane proteins, causes GSK-3β (Glycogen synthase kinase 3 beta) to cease the phosphorylation of β-catenin. β-catenin accumulation in the cytoplasm, followed by its
transport into the nucleus, binding to transcription factors (TCF/LEF)
that initiate transcription of genes related to bone formation. To test this hypothesis, we used TOPGAL (Tcf Optimal Promoter
β-galactosidase) mice in an experiment in which cyclic loads were
applied to the forearm. TOPGAL mice are reporters for cells effected
by the Wnt/β-catenin signaling pathway. TOPGAL mice are genetically engineered mice in which transcriptional activation of β-
catenin, results in the production of an enzyme, β-galactosidase. The
presence of this enzyme allows us to localize transcriptional
activation of β-catenin to individual cells, thereby, allowing us to quantify the effects that mechanical loading has on the Wnt/β-catenin pathway and new bone formation. The ulnae of loaded TOPGAL
mice were excised and transverse slices along different parts of the
ulnar shaft were assayed for the presence of β-galactosidase.
Our results indicate that loading increases β-catenin transcriptional
activity in regions where this pathway is already primed (i.e. where basal activity is already higher) in a load magnitude dependent
manner. Further experiments are needed to determine the temporal and spatial activation of this signaling in relation to bone formation.
Abstract: Recently, a great amount of interest has been shown
in the field of modeling and controlling hybrid systems. One of the
efficient and common methods in this area utilizes the mixed logicaldynamical
(MLD) systems in the modeling. In this method, the
system constraints are transformed into mixed-integer inequalities by
defining some logic statements. In this paper, a system containing
three tanks is modeled as a nonlinear switched system by using the
MLD framework. Comparing the model size of the three-tank system
with that of a two-tank system, it is deduced that the number of
binary variables, the size of the system and its complexity
tremendously increases with the number of tanks, which makes the
control of the system more difficult. Therefore, methods should be
found which result in fewer mixed-integer inequalities.
Abstract: Role of acoustic driving pressure on the
translational-radial dynamics of a moving single bubble
sonoluminescence (m-SBSL) has been numerically
investigated. The results indicate that increase in the
amplitude of the driving pressure leads to increase in the
bubble peak temperature. The length and the shape of the
trajectory of the bubble depends on the acoustic pressure and
because of the spatially dependence of the radial dynamics of
the moving bubble, its peak temperature varies during the
acoustical pulses. The results are in good agreement with the
experimental reports on m-SBSL.
Abstract: In this paper, a one-dimensional numerical approach is
used to study the effect of applying electrohydrodynamics on the
temperature and species mass fraction profiles along the microcombustor.
Premixed mixture is H2-Air with a multi-step chemistry
(9 species and 19 reactions). In the micro-scale combustion because
of the increasing ratio of area-to-volume, thermal and radical
quenching mechanisms are important. Also, there is a significant heat
loss from the combustor walls. By inserting a number of electrodes
into micro-combustor and applying high voltage to them corona
discharge occurs. This leads in moving of induced ions toward
natural molecules and colliding with them. So this phenomenon
causes the movement of the molecules and reattaches the flow to the
walls. It increases the velocity near the walls that reduces the wall
boundary layer. Consequently, applying electrohydrodynamics
mechanism can enhance the temperature profile in the microcombustor.
Ultimately, it prevents the flame quenching in microcombustor.
Abstract: The data exchanged on the Web are of different nature
from those treated by the classical database management systems;
these data are called semi-structured data since they do not have a
regular and static structure like data found in a relational database;
their schema is dynamic and may contain missing data or types.
Therefore, the needs for developing further techniques and
algorithms to exploit and integrate such data, and extract relevant
information for the user have been raised. In this paper we present
the system OSIX (Osiris based System for Integration of XML
Sources). This system has a Data Warehouse model designed for the
integration of semi-structured data and more precisely for the
integration of XML documents. The architecture of OSIX relies on
the Osiris system, a DL-based model designed for the representation
and management of databases and knowledge bases. Osiris is a viewbased
data model whose indexing system supports semantic query
optimization. We show that the problem of query processing on a
XML source is optimized by the indexing approach proposed by
Osiris.
Abstract: Representing objects in a dynamic domain is essential
in commonsense reasoning under some circumstances. Classical logics
and their nonmonotonic consequences, however, are usually not
able to deal with reasoning with dynamic domains due to the fact that
every constant in the logical language denotes some existing object
in the static domain. In this paper, we explore a logical formalization
which allows us to represent nonexisting objects in commonsense
reasoning. A formal system named N-theory is proposed for this
purpose and its possible application in computer security is briefly
discussed.
Abstract: Recurrent event data is a special type of multivariate
survival data. Dynamic and frailty models are one of the approaches
that dealt with this kind of data. A comparison between these two
models is studied using the empirical standard deviation of the
standardized martingale residual processes as a way of assessing the
fit of the two models based on the Aalen additive regression model.
Here we found both approaches took heterogeneity into account and
produce residual standard deviations close to each other both in the
simulation study and in the real data set.
Abstract: In this paper, a new technique of signal detection has been proposed for detecting the orthogonal frequency-division multiplexing (OFDM) signal in the presence of nonlinear distortion.There are several advantages of OFDM communications system.However, one of the existing problems is remain considered as the nonlinear distortion generated by high-power-amplifier at the transmitter end due to the large dynamic range of an OFDM signal. The proposed method is the maximum likelihood detection with the symbol estimation. When the training data are available, the neural network has been used to learn the characteristic of received signal and to estimate the new positions of the transmitted symbol which are provided to the maximum likelihood detector. Resulting in the system performance, the nonlinear distortions of a traveling wave tube amplifier with OFDM signal are considered in this paper.Simulation results of the bit-error-rate performance are obtained with 16-QAM OFDM systems.
Abstract: This paper is motivated by the aspect of uncertainty in
financial decision making, and how artificial intelligence and soft
computing, with its uncertainty reducing aspects can be used for
algorithmic trading applications that trade in high frequency.
This paper presents an optimized high frequency trading system that
has been combined with various moving averages to produce a hybrid
system that outperforms trading systems that rely solely on moving
averages. The paper optimizes an adaptive neuro-fuzzy inference
system that takes both the price and its moving average as input,
learns to predict price movements from training data consisting of
intraday data, dynamically switches between the best performing
moving averages, and performs decision making of when to buy or
sell a certain currency in high frequency.
Abstract: In order to make surfing the internet faster, and to save redundant processing load with each request for the same web page, many caching techniques have been developed to reduce latency of retrieving data on World Wide Web. In this paper we will give a quick overview of existing web caching techniques used for dynamic web pages then we will introduce a design and implementation model that take advantage of “URL Rewriting" feature in some popular web servers, e.g. Apache, to provide an effective approach of caching dynamic web pages.