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: 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: 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: 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: Current advancements in nanotechnology are dependent
on the capabilities that can enable nano-scientists to extend their eyes
and hands into the nano-world. For this purpose, a haptics (devices
capable of recreating tactile or force sensations) based system for
AFM (Atomic Force Microscope) is proposed. The system enables
the nano-scientists to touch and feel the sample surfaces, viewed
through AFM, in order to provide them with better understanding of
the physical properties of the surface, such as roughness, stiffness and
shape of molecular architecture. At this stage, the proposed work uses
of ine images produced using AFM and perform image analysis to
create virtual surfaces suitable for haptics force analysis. The research
work is in the process of extension from of ine to online process
where interaction will be done directly on the material surface for
realistic analysis.
Abstract: Continuously variable transmission (CVT) is a type of
automatic transmission that can change the gear ratio to any arbitrary
setting within the limits. The most common type of CVT operates on
a pulley system that allows an infinite variability between highest and
lowest gears with no discrete steps. However, the current CVT
system with hydraulic actuation method suffers from the power loss.
It needs continuous force for the pulley to clamp the belt and hold the
torque resulting in large amount of energy consumption. This study
focused on the development of an electromechanical actuated control
CVT to eliminate the problem that faced by the existing CVT. It is
conducted with several steps; computing and selecting the
appropriate sizing for stroke length, lead screw system and etc. From
the visual observation it was found that the CVT system of this
research is satisfactory.
Abstract: The use of plastic materials in agriculture causes
serious hazards to the environment. The introduction of biodegradable materials, which can be disposed directly into the soil
can be one possible solution to this problem. In the present research results of experimental tests carried out on biodegradable film
fabricated from natural waste (corn husk) are presented. The film was
characterized by Fourier transform infrared spectroscopy (FTIR),
differential scanning calorimeter (DSC), thermal gravimetric analysis
(TGA) and atomic force microscope (AFM) observation. The film is
shown to be readily degraded within 7-9 months under controlled soil
conditions, indicating a high biodegradability rate. The film
fabricated was use to produce biodegradable pot (BioPot) for
seedlings plantation. The introduction and the expanding use of
biodegradable materials represent a really promising alternative for
enhancing sustainable and environmentally friendly agricultural
activities.
Abstract: Researches on the general rules of temperature field
changing and their effects on the bridge in construction are necessary.
This paper investigated the rules of temperature field changing and its
effects on bridge using onsite measurement and computational
analysis. Guanyinsha Bridge was used as a case study in this research.
The temperature field was simulated in analyses. The effects of certain
boundary conditions such as sun radiance, wind speed, and model
parameters such as heat factor and specific heat on temperature field
are investigated. Recommended values for these parameters are
proposed. The simulated temperature field matches the measured
observations with high accuracy. At the same time, the stresses and
deflections of the bridge computed with the simulated temperature
field matches measured values too. As a conclusion, the temperature
effect analysis of reinforced concrete box girder can be conducted
directly based on the reliable weather data of the concerned area.
Abstract: This paper proposed classification models that would
be used as a proxy for hard disk drive (HDD) functional test equitant
which required approximately more than two weeks to perform the
HDD status classification in either “Pass" or “Fail". These models
were constructed by using committee network which consisted of a
number of single neural networks. This paper also included the
method to solve the problem of sparseness data in failed part, which
was called “enforce learning method". Our results reveal that the
constructed classification models with the proposed method could
perform well in the sparse data conditions and thus the models,
which used a few seconds for HDD classification, could be used to
substitute the HDD functional tests.
Abstract: The purpose of this article is to propose a model designed to achieve Total Knowledge Transfer in the public health sector. The Total Knowledge Transfer Model integrated four essential organizational factors which have been under examined in totality in the literature. The research design was inductive in nature and used a case study for accomplishing the research objectives. The researcher investigated the factors that created a base to design a framework for total knowledge transfer in the public health sector. The results of this study are drawn from a fairly large sample in only two hospitals. A further research can be conducted to cover more responses from a wider health sector. The Total Knowledge Transfer Model is essential to improve the transfer and application of total common health knowledge.
Abstract: When dealing with safety in structures, the connections between structural components play an important role. Robustness of a structure as a whole depends both on the load- bearing capacity of the structural component and on the structures capacity to resist total failure, even though a local failure occurs in a component or a connection between components. To avoid progressive collapse it is necessary to be able to carry out a design for connections. A connection may be executed with anchors to withstand local failure of the connection in structures built with prefabricated components. For the design of these anchors, a model is developed for connections in structures performed in prefabricated autoclaved aerated concrete components. The design model takes into account the effect of anchors placed close to the edge, which may result in splitting failure. Further the model is developed to consider the effect of reinforcement diameter and anchor depth. The model is analytical and theoretically derived assuming a static equilibrium stress distribution along the anchor. The theory is compared to laboratory test, including the relevant parameters and the model is refined and theoretically argued analyzing the observed test results. The method presented can be used to improve safety in structures or even optimize the design of the connections
Abstract: Diesel Engines emit complex mixtures of inorganic
and organic compounds in the form of both solid and vapour phase
particles. Most of the particulates released are ultrafine nanoparticles
which are detrimental to human health and can easily enter the body
by respiration. The emissions standards on particulate matter release
from diesel engines are constantly upgraded within the European
Union and with future regulations based on the particles numbers
released instead of merely mass, the need for effective aftertreatment
devices will increase. Standard particulate filters in the form of wall
flow filters can have problems with high soot accumulation,
producing a large exhaust backpressure. A potential solution would
be to combine the standard filter with a flow through filter to reduce
the load on the wall flow filter. In this paper soot particle trapping has
been simulated in different continuous flow filters of monolithic
structure including the use of promoters, at laminar flow conditions.
An Euler Lagrange model, the discrete phase model in Ansys used
with user defined functions for forces acting on particles. A method
to quickly screen trapping of 5 nm and 10 nm particles in different
catalysts designs with tracers was also developed.
Simulations of square duct monoliths with promoters show that the
strength of the vortices produced are not enough to give a high
amount of particle deposition on the catalyst walls. The smallest
particles in the simulations, 5 and 10 nm particles were trapped to a
higher extent, than larger particles up to 1000 nm, in all studied
geometries with the predominant deposition mechanism being
Brownian diffusion. The comparison of the different filters designed
with a wall flow filter does show that the options for altering a design
of a flow through filter, without imposing a too large pressure drop
penalty are good.
Abstract: Nowadays, keyless entry systems are widely adopted
for vehicle immobilizer systems due to both advantages of security and
convenience. Keyless entry systems could overcome brute-force key
guessing attack, statistics attack and masquerade attack, however,
they can't prevent from thieves stealing behavior. In this paper, we
proposed a new architecture try to improve the existent flaws. The
integration of the keyless entry system and the fingerprint
identification technology is more suitable to implement on the
portable transponder to achieve higher security needs. We also adopt
and modify AES security protocol for life expectancy and security of
the portable transponder. In addition, the identification of a driver's
fingerprint makes the service of automatic reinstatement of a driver's
preferences become possible. Our design can satisfy not only the three
kinds of previous illegal attacks, but also the stealing situation.
Furthermore, many practical factors, such as costs, life expectancy and
performance, have been well considered in the design of portable
transponder.
Abstract: In today-s competitive market, most companies
develop manufacturing systems that can help in cost reduction and
maximum quality. Human issues are an important part of
manufacturing systems, yet most companies ignore their effects on
production performance. This paper aims to developing an integrated
workforce planning system that incorporates the human being.
Therefore, a multi-objective mixed integer nonlinear programming
model is developed to determine the amount of hiring, firing,
training, overtime for each worker type. This paper considers a
workforce planning model including human aspects such as skills,
training, workers- personalities, capacity, motivation, and learning
rates. This model helps to minimize the hiring, firing, training and
overtime costs, and maximize the workers- performance. The results
indicate that the workers- differences should be considered in
workforce scheduling to generate realistic plans with minimum costs.
This paper also investigates the effects of human learning rates on the
performance of the production systems.
Abstract: The commercial white tyres are usually used for forklifts in food and medicine industries. Conventionally, silica is used as reinforcement in the tyres. However, the adhesion between silica particles and rubber is remarkably poor. To improve the problem of adhesion and hence enhance wear resistance, modification of silica surface is one of the solutions. In this work, the natural rubber compound blending with polyisoprene-coated silica prepared by admicellar polymerization technique was studied to compare with the natural rubber compound of unmodified silica. The surface characterization of modified silica was also examined by SEM, FTIR, and TGA. The results show that polyisoprene-coated silica/natural rubber compound gave better overall mechanical properties, especially wear resistance with the improvement of the adhesion between silica and natural rubber matrix that can be seen in the SEM micrograph.
Abstract: Most of researches for conventional simulations were
studied focusing on flocks with a single species. While there exist the
flocking behaviors with a single species in nature, the flocking
behaviors are frequently observed with multi-species. This paper
studies on the flocking simulation for heterogeneous agents. In order
to simulate the flocks for heterogeneous agents, the conventional
method uses the identifier of flock, while the proposed method defines
the feature vector of agent and uses the similarity between agents by
comparing with those feature vectors. Based on the similarity, the
paper proposed the attractive force and repulsive force and then
executed the simulation by applying two forces. The results of
simulation showed that flock formation with heterogeneous agents is
very natural in both cases. In addition, it showed that unlike the
existing method, the proposed method can not only control the density
of the flocks, but also be possible for two different groups of agents to
flock close to each other if they have a high similarity.
Abstract: At present, dictionary attack has been the basic tool for
recovering key passwords. In order to avoid dictionary attack, users
purposely choose another character strings as passwords. According to
statistics, about 14% of users choose keys on a keyboard (Kkey, for
short) as passwords. This paper develops a framework system to attack
the password chosen from Kkeys and analyzes its efficiency. Within
this system, we build up keyboard rules using the adjacent and parallel
relationship among Kkeys and then use these Kkey rules to generate
password databases by depth-first search method. According to the
experiment results, we find the key space of databases derived from
these Kkey rules that could be far smaller than the password databases
generated within brute-force attack, thus effectively narrowing down
the scope of attack research. Taking one general Kkey rule, the
combinations in all printable characters (94 types) with Kkey adjacent
and parallel relationship, as an example, the derived key space is about
240 smaller than those in brute-force attack. In addition, we
demonstrate the method's practicality and value by successfully
cracking the access password to UNIX and PC using the password
databases created
Abstract: Textile structures are engineered and fabricated to
meet worldwide structural applications. Nevertheless, research
varying textile structure on natural fibre as composite reinforcement
was found to be very limited. Most of the research is focusing on
short fibre and random discontinuous orientation of the reinforcement
structure. Realizing that natural fibre (NF) composite had been
widely developed to be used as synthetic fibre composite
replacement, this research attempted to examine the influence of
woven and cross-ply laminated structure towards its mechanical
performances. Laminated natural fibre composites were developed
using hand lay-up and vacuum bagging technique. Impact and
flexural strength were investigated as a function of fibre type (coir
and kenaf) and reinforcement structure (imbalanced plain woven,
0°/90° cross-ply and +45°/-45° cross-ply). Multi-level full factorial
design of experiment (DOE) and analysis of variance (ANOVA) was
employed to impart data as to how fibre type and reinforcement
structure parameters affect the mechanical properties of the
composites. This systematic experimentation has led to determination
of significant factors that predominant influences the impact and
flexural properties of the textile composites. It was proven that both
fibre type and reinforcement structure demonstrated significant
difference results. Overall results indicated that coir composite and
woven structure exhibited better impact and flexural strength. Yet,
cross-ply composite structure demonstrated better fracture resistance.
Abstract: Two geometrically nonlinear plate theories, based either on first- or third-order transverse shear deformation theory are used for finite element modeling and simulation of the transient response of smart structures incorporating piezoelectric layers. In particular the time histories of nonlinear vibrations and sensor voltage output of a thin beam with a piezoelectric patch bonded to the surface due to an applied step force are studied.
Abstract: Here we have considered non uniform microstrip
leaky-wave antenna implemented on a dielectric waveguide by a
sinusoidal profile of periodic metallic grating. The non distribution of
the attenuation constant α along propagation axis, optimize the
radiating characteristics and performances of such antennas. The
method developped here is based on an integral method where the
formalism of the admittance operator is combined to a BKW
approximation. First, the effect of the modeling in the modal analysis
of complex waves is studied in detail. Then, the BKW model is used
for the dispersion analysis of the antenna of interest. According to
antenna theory, a forced continuity of the leaky-wave magnitude at
discontinuities of the non uniform structure is established. To test the
validity of our dispersion analysis, computed radiation patterns are
presented and compared in the millimeter band.