Abstract: In this paper the combination of thermal oxidation and
electrochemical anodizing processes is used to produce titanium
oxide layers. The response of titanium alloy Ti6Al4V to oxidation
processes at various temperatures and electrochemical anodizing in
various voltages are investigated. Scanning electron microscopy
(SEM); X-Ray Diffraction (XRD) and porosity determination have
been used to characterize the oxide layer thickness, surface
morphology, oxide layer-substrate adhesion and porosity. In the first
experiment, samples modified by thermal oxidation process then
followed by electrochemical anodizing. Second experiment consists
of surfaces modified by electrochemical anodizing process and then
followed by thermal oxidation. The first method shows better
properties than other one. In second experiment, Surfaces modified
were achieved by thicker and more adherent thick oxide layers on
titanium surface. The existence of an electrochemical anodized oxide
layer did not improve the adhesion of thermal oxide layer. The high
temperature, thermal formation of an oxide layer leads to a coarse
oxide grain morphology and a complete oxidative particle. In
addition, in high temperature oxidation porosity content is increased.
The oxide layer of thermal oxidation and electrochemical anodizing
processes; on Ti–6Al–4V substrate was covered with different
colored oxide layers.
Abstract: Text categorization is the problem of classifying text documents into a set of predefined classes. After a preprocessing step the documents are typically represented as large sparse vectors. When training classifiers on large collections of documents, both the time and memory restrictions can be quite prohibitive. This justifies the application of features selection methods to reduce the dimensionality of the document-representation vector. Four feature selection methods are evaluated: Random Selection, Information Gain (IG), Support Vector Machine (called SVM_FS) and Genetic Algorithm with SVM (GA_FS). We showed that the best results were obtained with SVM_FS and GA_FS methods for a relatively small dimension of the features vector comparative with the IG method that involves longer vectors, for quite similar classification accuracies. Also we present a novel method to better correlate SVM kernel-s parameters (Polynomial or Gaussian kernel).
Abstract: Groundlessness of application probability-statistic methods are especially shown at an early stage of the aviation GTE technical condition diagnosing, when the volume of the information has property of the fuzzy, limitations, uncertainty and efficiency of application of new technology Soft computing at these diagnosing stages by using the fuzzy logic and neural networks methods. It is made training with high accuracy of multiple linear and nonlinear models (the regression equations) received on the statistical fuzzy data basis. At the information sufficiency it is offered to use recurrent algorithm of aviation GTE technical condition identification on measurements of input and output parameters of the multiple linear and nonlinear generalized models at presence of noise measured (the new recursive least squares method (LSM)). As application of the given technique the estimation of the new operating aviation engine D30KU-154 technical condition at height H=10600 m was made.
Abstract: A Web-based learning tool, the Learn IN Context
(LINC) system, designed and being used in some institution-s
courses in mixed-mode learning, is presented in this paper. This
mode combines face-to-face and distance approaches to education.
LINC can achieve both collaborative and competitive learning. In
order to provide both learners and tutors with a more natural way to
interact with e-learning applications, a conversational interface has
been included in LINC. Hence, the components and essential features
of LINC+, the voice enhanced version of LINC, are described. We
report evaluation experiments of LINC/LINC+ in a real use context
of a computer programming course taught at the Université de
Moncton (Canada). The findings show that when the learning
material is delivered in the form of a collaborative and voice-enabled
presentation, the majority of learners seem to be satisfied with this
new media, and confirm that it does not negatively affect their
cognitive load.
Abstract: Traditionally, Yemini Sidr honey has been reported to
cure liver problems, stomach ulcers, and respiratory disorders. In this
experiment, we evaluated Yemeni Sidr honey for its ability to protect
inflammations caused by acetic acid and formalin -induced writhing,
carrageenan and histamine-induced paw oedema in experimental rat
model. Hyperpyrexia, membrane stabilizing activity, and
phytochemical screening of the honey was also examined. Yemini
Sidr Honey at (100, 200 and 500 mg/kg) exhibited a concentration
dependant inhibition of acetic acid induced and formalin induced
writhing, paw oedema induced by carrageenan & histamine, and
hyperpyrexia induced by brewer's yeast, it also inhibited membrane
stabilizing activity. Phytochemical screenings of the honey reveal the
presence of flavonoids, steroid, alkaloids, saponins and tannins. This
study suggested that Yemeni Sidr honey possess very strong antiinflammatory,
analgesic and antipyretic effects and these effects
would be a result of the phytochemicals present.
Abstract: Ultra-low-power (ULP) circuits have received
widespread attention due to the rapid growth of biomedical
applications and Battery-less Electronics. Subthreshold region of
transistor operation is used in ULP circuits. Major research challenge
in the subthreshold operating region is to extract the ULP benefits
with minimal degradation in speed and robustness. Process, Voltage
and Temperature (PVT) variations significantly affect the
performance of subthreshold circuits. Designed performance
parameters of ULP circuits may vary largely due to temperature
variations. Hence, this paper investigates the effect of temperature
variation on device and circuit performance parameters at different
biasing voltages in the subthreshold region. Simulation results clearly
demonstrate that in deep subthreshold and near threshold voltage
regions, performance parameters are significantly affected whereas in
moderate subthreshold region, subthreshold circuits are more
immune to temperature variations. This establishes that moderate
subthreshold region is ideal for temperature immune circuits.
Abstract: Academic digital libraries emerged as a result of advances in computing and information systems technologies, and had been introduced in universities and to public. As results, moving in parallel with current technology in learning and researching environment indeed offers myriad of advantages especially to students and academicians, as well as researchers. This is due to dramatic changes in learning environment through the use of digital library system which giving spectacular impact on these societies- way of performing their study/research. This paper presents a survey of current criteria for evaluating academic digital libraries- performance. The goal is to discuss criteria being applied so far for academic digital libraries evaluation in the context of user-centered design. Although this paper does not comprehensively take into account all previous researches in evaluating academic digital libraries but at least it can be a guide in understanding the evaluation criteria being widely applied.
Abstract: Problem Statement:Rapid technological developments of the 21st century have advanced our daily lives in various ways. Particularly in education, students frequently utilize technological resources to aid their homework and to access information. listen to radio or watch television (26.9 %) and e-mails (34.2 %) [26]. Not surprisingly, the increase in the use of technologies also resulted in an increase in the use of e-mail, instant messaging, chat rooms, mobile phones, mobile phone cameras and web sites by adolescents to bully peers. As cyber bullying occurs in the cyber space, lesser access to technologies would mean lesser cyber-harm. Therefore, the frequency of technology use is a significant predictor of cyber bullying and cyber victims. Cyber bullies try to harm the victim using various media. These tools include sending derogatory texts via mobile phones, sending threatening e-mails and forwarding confidential emails to everyone on the contacts list. Another way of cyber bullying is to set up a humiliating website and invite others to post comments. In other words, cyber bullies use e-mail, chat rooms, instant messaging, pagers, mobile texts and online voting tools to humiliate and frighten others and to create a sense of helplessness. No matter what type of bullying it is, it negatively affects its victims. Children who bully exhibit more emotional inhibition and attribute themselves more negative self-statements compared to non-bullies. Students whose families are not sympathetic and who receive lower emotional support are more prone to bully their peers. Bullies have authoritarian families and do not get along well with them. The family is the place where the children-s physical, social and psychological needs are satisfied and where their personalities develop. As the use of the internet became prevalent so did parents- restrictions on their children-s internet use. However, parents are unaware of the real harm. Studies that explain the relationship between parental attitudes and cyber bullying are scarce in literature. Thus, this study aims to investigate the relationship between cyber bullying and parental attitudes in the primary school. Purpose of Study: This study aimed to investigate the relationship between cyber bullying and parental attitudes. A second aim was to determine whether parental attitudes could predict cyber bullying and if so which variables could predict it significantly. Methods:The study had a cross-sectional and relational survey model. A demographics information form, questions about cyber bullying and a Parental Attitudes Inventory were conducted with a total of 346 students (189 females and 157 males) registered at various primary schools. Data was analysed by multiple regression analysis using the software package SPSS 16.
Abstract: This paper discusses two observers, which are used
for the estimation of parameters of PMSM. Former one, reduced
order observer, which is used to estimate the inaccessible parameters
of PMSM. Later one, full order observer, which is used to estimate
all the parameters of PMSM even though some of the parameters are
directly available for measurement, so as to meet with the
insensitivity to the parameter variation. However, the state space
model contains some nonlinear terms i.e. the product of different
state variables. The asymptotic state observer, which approximately
reconstructs the state vector for linear systems without uncertainties,
was presented by Luenberger. In this work, a modified form of such
an observer is used by including a non-linear term involving the
speed. So, both the observers are designed in the framework of
nonlinear control; their stability and rate of convergence is discussed.
Abstract: Equilibrium and stability equations of a thin rectangular plate with length a, width b, and thickness h(x)=C1x+C2, made of functionally graded materials under thermal loads are derived based on the first order shear deformation theory. It is assumed that the material properties vary as a power form of thickness coordinate variable z. The derived equilibrium and buckling equations are then solved analytically for a plate with simply supported boundary conditions. One type of thermal loading, uniform temperature rise and gradient through the thickness are considered, and the buckling temperatures are derived. The influences of the plate aspect ratio, the relative thickness, the gradient index and the transverse shear on buckling temperature difference are all discussed.
Abstract: Primary studies are being carried out in Turkey for
expanding information and communication technologies (ICT) aided instruction activities. Subject of the present study is to identify
whether those studies achieved their goals in the application. Information technologies (IT) formative teachers in the primary
schools, and academicians in the faculties of education were interviewed to investigate the process and results of implementing
computer-aided instruction methods whose basis is strengthened in theory. Analysis of the results gained from two separate surveys
demonstrated that capability of the teachers in elementary education institutions for carrying into effect computer-aided instruction and
technical infrastructure has not been established for computer-aided instruction practices yet. Prospective teachers must be well-equipped in ICT to duly fulfill requirements of modern education and also
must be self-confident. Finally, scope and intensity of the courses given in connection with teaching of the ICT in faculties of education needs to be revised.
Abstract: Explosive welding is a process which uses explosive
detonation to move the flyer plate material into the base material to
produce a solid state joint. Experimental tests have been carried out
by other researchers; have been considered to explosively welded
aluminium 7039 and steel 4340 tubes in one step. The tests have been
done using various stand-off distances and explosive ratios. Various
interface geometries have been obtained from these experiments. In
this paper, all the experiments carried out were simulated using the
finite element method. The flyer plate and collision velocities
obtained from the analysis were validated by the pin-measurement
experiments. The numerical results showed that very high localized
plastic deformation produced at the bond interface. The
Ls_dyna_971 FEM has been used for all simulation process.
Abstract: This study presents an exact general solution for
steady-state conductive heat transfer in cylindrical composite
laminates. Appropriate Fourier transformation has been obtained
using Sturm-Liouville theorem. Series coefficients are achieved by
solving a set of equations that related to thermal boundary conditions
at inner and outer of the cylinder, also related to temperature
continuity and heat flux continuity between each layer. The solution
of this set of equations are obtained using Thomas algorithm. In this
paper, the effect of fibers- angle on temperature distribution of
composite laminate is investigated under general boundary
conditions. Here, we show that the temperature distribution for any
composite laminates is between temperature distribution for
laminates with θ = 0° and θ = 90° .
Abstract: In this paper a multi-objective nonlinear programming
model of cellular manufacturing system is presented which minimize
the intercell movements and maximize the sum of reliability of cells.
We present a genetic approach for finding efficient solutions to the
problem of cell formation for products having multiple routings.
These methods find the non-dominated solutions and according to
decision makers prefer, the best solution will be chosen.
Abstract: Schema matching plays a key role in many different
applications, such as schema integration, data integration, data
warehousing, data transformation, E-commerce, peer-to-peer data
management, ontology matching and integration, semantic Web,
semantic query processing, etc. Manual matching is expensive and
error-prone, so it is therefore important to develop techniques to
automate the schema matching process. In this paper, we present a
solution for XML schema automated matching problem which
produces semantic mappings between corresponding schema
elements of given source and target schemas. This solution
contributed in solving more comprehensively and efficiently XML
schema automated matching problem. Our solution based on
combining linguistic similarity, data type compatibility and structural
similarity of XML schema elements. After describing our solution,
we present experimental results that demonstrate the effectiveness of
this approach.
Abstract: Urinary Tract Infections (UTI) account for an estimated 25-40% nosocomial infection, out of which 90% are associated with urinary catheter, called Catheter associated urinary tract infection (CAUTI). The microbial populations within CAUTI frequently develop as biofilms. In the present study, microbial contamination of indwelling urinary catheters was investigated. Biofilm forming ability of the isolates was determined by tissue culture plate method. Prevention of biofilm formation in the urinary catheter by Pseudomonas aeruginosa was also determined by coating the catheter with some enzymes, gentamycin and EDTA. It was found that 64% of the urinary catheters get contaminated during the course of catheterization. Of the total 6 isolates, biofilm formation was seen in 100% Pseudomonas aeruginosa and E. coli, 90% in Enterococci, 80% in Klebsiella and 66% in S. aureus. It was noted that the biofilm production by Pseudomonas was prolonged by 7 days in amylase, 8 days in protease, 6 days in lysozyme, 7days in gentamycin and 5 days in EDTA treated catheter.
Abstract: Grid computing is growing rapidly in the distributed
heterogeneous systems for utilizing and sharing large-scale resources
to solve complex scientific problems. Scheduling is the most recent
topic used to achieve high performance in grid environments. It aims
to find a suitable allocation of resources for each job. A typical
problem which arises during this task is the decision of scheduling. It
is about an effective utilization of processor to minimize tardiness
time of a job, when it is being scheduled. This paper, therefore,
addresses the problem by developing a general framework of grid
scheduling using dynamic information and an ant colony
optimization algorithm to improve the decision of scheduling. The
performance of various dispatching rules such as First Come First
Served (FCFS), Earliest Due Date (EDD), Earliest Release Date
(ERD), and an Ant Colony Optimization (ACO) are compared.
Moreover, the benefit of using an Ant Colony Optimization for
performance improvement of the grid Scheduling is also discussed. It
is found that the scheduling system using an Ant Colony
Optimization algorithm can efficiently and effectively allocate jobs
to proper resources.
Abstract: Distance protection of transmission lines including advanced flexible AC transmission system (FACTS) devices has been a very challenging task. FACTS devices of interest in this paper are static synchronous series compensators (SSSC) and unified power flow controller (UPFC). In this paper, a new algorithm is proposed to detect and classify the fault and identify the fault position in a transmission line with respect to a FACTS device placed in the midpoint of the transmission line. Discrete wavelet transformation and wavelet entropy calculations are used to analyze during fault current and voltage signals of the compensated transmission line. The proposed algorithm is very simple and accurate in fault detection and classification. A variety of fault cases and simulation results are introduced to show the effectiveness of such algorithm.
Abstract: A new method for color image segmentation using fuzzy logic is proposed in this paper. Our aim here is to automatically produce a fuzzy system for color classification and image segmentation with least number of rules and minimum error rate. Particle swarm optimization is a sub class of evolutionary algorithms that has been inspired from social behavior of fishes, bees, birds, etc, that live together in colonies. We use comprehensive learning particle swarm optimization (CLPSO) technique to find optimal fuzzy rules and membership functions because it discourages premature convergence. Here each particle of the swarm codes a set of fuzzy rules. During evolution, a population member tries to maximize a fitness criterion which is here high classification rate and small number of rules. Finally, particle with the highest fitness value is selected as the best set of fuzzy rules for image segmentation. Our results, using this method for soccer field image segmentation in Robocop contests shows 89% performance. Less computational load is needed when using this method compared with other methods like ANFIS, because it generates a smaller number of fuzzy rules. Large train dataset and its variety, makes the proposed method invariant to illumination noise
Abstract: Extraction of edge-end-pixels is an important step for the edge linking process to achieve edge-based image segmentation. This paper presents an algorithm to extract edge-end pixels together with their directional sensitivities as an augmentation to the currently available mathematical models. The algorithm is implemented in the Java environment because of its inherent compatibility with web interfaces since its main use is envisaged to be for remote image analysis on a virtual instrumentation platform.