Abstract: Unmanned Aerial Vehicles (UAVs) have gained tremendous importance, in both Military and Civil, during first decade of this century. In a UAV, onboard computer (autopilot) autonomously controls the flight and navigation of the aircraft. Based on the aircraft role and flight envelope, basic to complex and sophisticated controllers are used to stabilize the aircraft flight parameters. These controllers constitute the autopilot system for UAVs. The autopilot systems, most commonly, provide lateral and longitudinal control through Proportional-Integral-Derivative (PID) controllers or Phase-lead or Lag Compensators. Various techniques are commonly used to ‘tune’ gains of these controllers. Some techniques used are, in-flight step-by-step tuning, software-in-loop or hardware-in-loop tuning methods. Subsequently, numerous in-flight tests are required to actually ‘fine-tune’ these gains. However, an optimization-based tuning of these PID controllers or compensators, as presented in this paper, can greatly minimize the requirement of in-flight ‘tuning’ and substantially reduce the risks and cost involved in flight-testing.
Abstract: In this paper we introduced new wavelet based algorithm for speckle reduction of synthetic aperture radar images, which uses combination of undecimated wavelet transformation, wiener filter (which is an adaptive filter) and mean filter. Further more instead of using existing thresholding techniques such as sure shrinkage, Bayesian shrinkage, universal thresholding, normal thresholding, visu thresholding, soft and hard thresholding, we use brute force thresholding, which iteratively run the whole algorithm for each possible candidate value of threshold and saves each result in array and finally selects the value for threshold that gives best possible results. That is why it is slow as compared to existing thresholding techniques but gives best results under the given algorithm for speckle reduction.
Abstract: This paper aims to present the design, fabrication and test of a novel piezoelectric actuated, check-valves embedded micropump having the advantages of miniature size, light weight and low power consumption. This device is designed to pump gases and liquids with the capability of performing the self-priming and bubble-tolerant work mode by maximizing the stroke volume of the membrane as well as the compression ratio via minimization of the dead volume of the micropump chamber and channel. By experiment apparatus setup, we can get the real-time values of the flow rate of micropump, the displacement of the piezoelectric actuator and the deformation of the check valve, simultaneously. The micropump with check valve 0.4 mm in thickness obtained higher output performance under the sinusoidal waveform of 120 Vpp. The micropump achieved the maximum pumping rates of 42.2 ml/min and back pressure of 14.0 kPa at the corresponding frequency of 28 and 20 Hz. The presented micropump is able to pump gases with a pumping rate of 196 ml/min at operating frequencies of 280 Hz under the sinusoidal waveform of 120 Vpp.
Abstract: Schools today face ever-increasing demands in their attempts to ensure that students are well equipped to enter the workforce and navigate a complex world. Research indicates that computer technology can help support learning, implementation of various experiments or learning games, and that it is especially useful in developing the higher-order skills of critical thinking, observation, comprehension, implementation, comparison, analysis and active attention to activities such as research, field work, simulations and scientific inquiry. The ICT in education supports the learning procedure by enabling it to be more flexible and effective, create a rich and attractive training environment and equip the students with knowledge and potential useful for the competitive social environment in which they live. This paper presents the design, the development, and the results of the evaluation analysis of an interactive educational game which using real electric vehicles - toys (material) on a toy race track. When the game starts each student selects a specific vehicle toy. Then students are answering questionnaires in the computer. The vehicles' speed is related to the percentage of right answers in a multiple choice questionnaire (software). Every question has its own significant value depending of the different level of questionnaire. Via the developed software, each right or wrong answers in questionnaire increase or decrease the real time speed of their vehicle toys. Moreover the rate of vehicle's speed increase or decrease depends on the difficulty level of each question. The aim of the work is to attract the student’s interest in a learning process and also to improve their scores. The developed real time game was tested using independent populations of students of age groups: 8-10, 11-14, 15-18 years. Standard educational and statistical analysis tools were used for the evaluation analysis of the game. Results reveal that students using the developed real time control game scored much higher (60%) than students using a traditional simulation game on the same questionnaire. Results further indicate that student's interest in repeating the developed real time control gaming was far higher (70%) than the interest of students using a traditional simulation game.
Abstract: In order to better understand the performance of
screen channel liquid acquisition devices (LADs) in liquid oxygen (LOX), a computational fluid dynamics (CFD) simulation of LOX passing through a LAD screen channel was conducted. In the
simulation, the screen is taken as a 'porous jump' where the pressure
drop across the screen depends on the incoming velocity and is formulated by Δp = Av + Bv2
. The CFD simulation reveals the importance of the pressure losses due to the flow entering from
across the screen and impacting and merging with the channel flow
and the vortices in the channel to the cumulative flow resistance. In fact, both the flow resistance of flows impact and mergence and the
resistance created by vortices are much larger than the friction and dynamic pressure losses in the channel and are comparable to the
flow resistance across the screen. Therefore, these resistances in the
channel must be considered as part of the evaluation for the LAD
channel performance. For proper operation of a LAD in LOX these resistances must be less than the bubble point pressure for the screen
channel in LOX. The simulation also presents the pressure and velocity distributions within the LAD screen channel, expanding the understanding of the fluid flow characteristics within the channel.
Abstract: Attack graph is an integral part of modeling the
overview of network security. System administrators use attack graphs to determine how vulnerable their systems are and to determine
what security measures to deploy to defend their systems. Previous methods on AGG(attack graphs generation) are aiming at
the whole network, which makes the process of AGG complex and
non-scalable. In this paper, we propose a new approach which is
simple and scalable to AGG by decomposing the whole network into atomic domains. Each atomic domain represents a host with a specific privilege. Then the process for AGG is achieved by communications
among all the atomic domains. Our approach simplifies the process
of design for the whole network, and can gives the attack graphs including each attack path for each host, and when the network changes we just carry on the operations of corresponding atomic
domains which makes the process of AGG scalable.
Abstract: The migration of a deformable drop in simple shear
flow at finite Reynolds numbers is investigated numerically by
solving the full Navier-Stokes equations using a finite
difference/front tracking method. The objectives of this study are to
examine the effectiveness of the present approach to predict the
migration of a drop in a shear flow and to investigate the behavior of
the drop migration with different drop sizes and non-unity viscosity
ratios. It is shown that the drop deformation depends strongly on the
capillary number, so that; the proper non-dimensional number for the
interfacial tension is the capillary number. The rate of migration
increased with increasing the drop radius. In other words, the
required time for drop migration to the centreline decreases. As the
viscosity ratio increases, the drop rotates more slowly and the
lubrication force becomes stronger. The increased lubrication force
makes it easier for the drop to migrate to the centre of the channel.
The migration velocity of the drop vanishes as the drop reaches the
centreline under viscosity ratio of one and non-unity viscosity ratios.
To validate the present calculations, some typical results are
compared with available experimental and theoretical data.
Abstract: Business Process Reengineering (BPR) is an essential tool before an information system project implementation. Enterprise Resource Planning (ERP) projects definitely require the standardization and fixation of business processes from customer order to shipment. Therefore, ERP implementations are well proven to be coupled with BPR, although the extend and timing of BPR with respect to ERP implementation differ. This study aims at analyzing the effects of BPR on ERP implementation success. Basing on two Turkish ERP implementations in pharmaceutical sector, a comparative study is performed. One of the ERP implementations took place after a BPR implementation, whereas the other implementation was without a prior BPR application. Both implementations have been realized with the same consultant team, the case with prior BPR implementation going live first. The results of the case study reveal that if business processes are not optimized and improved before an ERP implementation, ERP live system would face with disharmony problems of processes and processes automated by ERP. This suggests a definite precedence relationship between BPR and ERP applications
Abstract: A block backward differentiation formula of uniform
order eight is proposed for solving first order stiff initial value
problems (IVPs). The conventional 8-step Backward Differentiation
Formula (BDF) and additional methods are obtained from the same
continuous scheme and assembled into a block matrix equation which
is applied to provide the solutions of IVPs on non-overlapping
intervals. The stability analysis of the method indicates that the
method is L0-stable. Numerical results obtained using the proposed
new block form show that it is attractive for solutions of stiff problems
and compares favourably with existing ones.
Abstract: This paper discusses a new heavy tailed distribution based data hiding into discrete cosine transform (DCT) coefficients of image, which provides statistical security as well as robustness against steganalysis attacks. Unlike other data hiding algorithms, the proposed technique does not introduce much effect in the stegoimage-s DCT coefficient probability plots, thus making the presence of hidden data statistically undetectable. In addition the proposed method does not compromise on hiding capacity. When compared to the generic block DCT based data-hiding scheme, our method found more robust against a variety of image manipulating attacks such as filtering, blurring, JPEG compression etc.
Abstract: This paper presents a comparative study on dry and wet grinding through experimental investigation in the grinding of CSM glass fibre reinforced polymer laminates using a pink aluminium oxide wheel. Different sets of experiments were performed to study the effects of the independent grinding parameters such as grinding wheel speed, feed and depth of cut on dependent performance criteria such as cutting forces and surface finish. Experimental conditions were laid out using design of experiment central composite design. An effective coolant was sought in this study to minimise cutting forces and surface roughness for GFRP laminates grinding. Test results showed that the use of coolants reduces surface roughness, although not necessarily the cutting forces. These research findings provide useful economic machining solution in terms of optimized grinding conditions for grinding CSM GFRP.
Abstract: In this chapter, we have studied Variation of velocity in incompressible fluid over a moving surface. The boundary layer equations are on a fixed or continuously moving flat plate in the same or opposite direction to the free stream with suction and injection. The boundary layer equations are transferred from partial differential equations to ordinary differential equations. Numerical solutions are obtained by using Runge-Kutta and Shooting methods. We have found numerical solution to velocity and skin friction coefficient.
Abstract: In this paper, self-starting block hybrid method of
order (5,5,5,5)T is proposed for the solution of the special second
order ordinary differential equations with associated initial or
boundary conditions. The continuous hybrid formulations enable us
to differentiate and evaluate at some grids and off – grid points to
obtain four discrete schemes, which were used in block form for
parallel or sequential solutions of the problems. The computational
burden and computer time wastage involved in the usual reduction of
second order problem into system of first order equations are avoided
by this approach. Furthermore, a stability analysis and efficiency of
the block method are tested on stiff ordinary differential equations,
and the results obtained compared favorably with the exact solution.
Abstract: Paleoclimate was reconstructed by the clay mineral
assemblages of shale units of Pabdeh (Paleocene- Oligocene), Gurpi
(Upper Cretaceous), Kazhdumi (Albian-Cenomanian) and Gadvan
(Aptian-Neocomian) formations in the Bangestan anticline. To
compare with clay minerals assemblages in these formations,
selected samples also taken from available formations in drilled wells
in Ahvaz, Marun, Karanj, and Parsi oil fields. Collected samples
prepared using standard clay mineral methodology. They were
treated as normal, glycolated and heated oriented glass slides. Their
identification was made on X-Ray diffractographs. Illite % varies
from 8 to 36. Illite quantity increased from Pabdeh to Gurpi
Formation. This may be due to dominant dry climate. Kaolinite is in
range of 12-49%. Its variation style in different formations could be a
marker of climate changes from wet to dry which is supported by the
lithological changes. Chlorite (4-28%) can also be detected in those
samples without any kaolinite. Mixed layer minerals as the mixture
of illite-chlorite and illite-vermiculite-montmorillonite are varied
from 6 to 36%, decreased during Kazhdumi deposition from the base
to the top. This result may be according to decreasing of illite
leaching process. Vermiculite was also determined in very less
quantity and found in those units without kaolinite. Montmorillonite
varies from 8 to 43%, and its presence is due to terrestrial
depositional condition. Stratigraphical documents is also supported
this idea that clay mineral distribution is a function of the climate
changes. It seems, thus, the present results can be indicated a possible
procedure for ancient climate changes evaluation.
Abstract: An important official knowledge in each country is to
have a comprehensive knowledge about markets of each group of
products. Drink markets are one the most important markets of each
country as a sub-group of nourishment markets. This paper is going
to study these markets in Iran. To do so, first, two drink products are
selected as pilot, including milk and concentrate. Then, for each
product, two groups of information are estimated for the last five
years, including 1) total consumption (demand) and 2) total
production. Finally, the two groups of productions are compared
statistically by means of two statistical tests called t test and Mann-
Whitney test. The implemented Different related tables and figures
are also illustrated to show the method more explicitly.
Abstract: In studies on psychological health and children-s personality development and in researches on emotional distresses, children-s behavioral disorders associated with mother deprivation, are known as the major cause of mental disorders. Therefore, for identification of children-s attachment styles in nursery-s children are of significant importance. For this purpose, to compare the attachment styles between children of nursery with those provided care by their families, the Separation Anxiety Test (SAT) of Slough and et al was administered on 72 children (36 in nursery and 36 family-cared). The results indicated, almost half of children in both groups have insecure attachment styles. Tendency ratio of both groups of children towards Secure and Ambivalent Insecure styles are almost the same. However the avoidant style of attachment in children of nursery is more than those provided care by their families. The children under family care compared to the children of nursery, in the situations of separation from their mothers in the first day of school and sleeping in their room, have shown more self reliance.
Abstract: The performance of ground to deep space optical
communication systems is degraded by distortion of the beam as it
propagates through the turbulent atmosphere. Turbulence causes
fluctuations in the intensity of the received signal which ultimately
affects the acquisition time required to acquire and locate the spaceborne
target using narrow laser beam. In this paper, performance of
free-space optical (FSO) communication system in atmospheric
turbulence has been analyzed in terms of acquisition time for
coherent and non-coherent modulation schemes. Numerical results
presented in graphical and tabular forms show that the acquisition
time increases with the increase in turbulence level. This is true for
both schemes. The BPSK has lowest acquisition time among all
schemes. In non-coherent schemes, M-PPM performs better than the
other schemes. With the increase in M, acquisition time becomes
lower, but at the cost of increase in system complexity.
Abstract: In space during functioning, a satellite will be heated
up due to the behavior of its components such as power electronics.
In order to prevent problems in the satellite, this heat has to be
released in space thanks to the cooling system. This system consists
of a loop heat pipe (LHP), in which a fluid streams through an
evaporator and a condenser. In the evaporator, the fluid captures the
heat from the satellite and evaporates. Then it flows to the condenser
where it releases the heat and it condenses. In this project, the two
mains parts of a cooling system are studied: the evaporator and the
condenser. The study of the diphasic loop was done starting from
digital simulations carried out under Matlab and Femlab.
Abstract: In Egypt, the concept of Asset Management (AM) is
new; however, the need for applying it has become crucial because
deteriorating or losing an asset is unaffordable in a developing
country like Egypt. Therefore the current study focuses on
educational buildings as one of the most important assets regarding
planning, building, operating and maintenance expenditures. The
main objective of this study is to develop a SAMF for educational
buildings in Egypt. The General Authority for Educational Buildings
(GAEB) was chosen as a case study of the current research as it
represents the biggest governmental organization responsible for
planning, operating and maintaining schools in Egypt. To achieve the
research objective, structured interviews were conducted with senior
managers of GAEB using a pre designed questionnaire to explore the
current practice of AM. Gab analysis technique was applied against
best practices compounded from a vast literature review to identify
gaps between current practices and the desired one. The previous
steps mainly revealed; limited knowledge about strategic asset
management, no clear goals, no training, no real risk plan and lack of
data, technical and financial resources. Based on the findings, a
SAMF for GAEB was introduced and Framework implementation
steps and assessment techniques were explained in detail.
Abstract: Studies were carried out on the comparative study of the production of Avicelase enzyme using sugarcane bagasse-SCB in two different statuses (i.e. treated and untreated SCB) by thermophilic Geobacillus stearothermophilus at 50ºC. Only four thermophilic bacterial isolates were isolated and assayed for Avicelase production using UntSCB and TSCB. Only one isolate selected as most potent and identified as G. stearothermophilus used in this study. A specific endo-β-1,4-D-glucanase (Avicelase EC 3.2.1.91) was partially purified from a thermophilic bacterial strain was isolated from different soil samples when grown on cellulose enrichment SCB substrate as the sole carbon source. Results shown that G. stearothermophilus was the better Avicelase producer strain. Avicelase had an optimum pH and temperature 7.0 and 50ºC for both UntSCB and TSCB and exhibited good pH stability between "5-8" and "4-9", however, good temperature stability between (30-80ºC) for UntSCB and TSCB, respectively. Other factors affecting the production of Avicelase were compared (i.e. SCB concentration, inoculum size and different incubation periods), all results observed and obtained were revealed that the TSCB was exhibited maximal enzyme activity in comparison with the results obtained from UntSCB, so, the TSCB was enhancing the Avicelase production.