Abstract: The electromagnetic spectrum is a natural resource
and hence well-organized usage of the limited natural resources is the
necessities for better communication. The present static frequency
allocation schemes cannot accommodate demands of the rapidly
increasing number of higher data rate services. Therefore, dynamic
usage of the spectrum must be distinguished from the static usage to
increase the availability of frequency spectrum. Cognitive radio is not
a single piece of apparatus but it is a technology that can incorporate
components spread across a network. It offers great promise for
improving system efficiency, spectrum utilization, more effective
applications, reduction in interference and reduced complexity of
usage for users. Cognitive radio is aware of its environmental,
internal state, and location, and autonomously adjusts its operations
to achieve designed objectives. It first senses its spectral environment
over a wide frequency band, and then adapts the parameters to
maximize spectrum efficiency with high performance. This paper
only focuses on the analysis of Bit-Error-Rate in cognitive radio by
using Particle Swarm Optimization Algorithm. It is theoretically as
well as practically analyzed and interpreted in the sense of
advantages and drawbacks and how BER affects the efficiency and
performance of the communication system.
Abstract: One challenging direction of mobile commerce (mcommerce)
that is getting a great deal of attention globally is mobile
financing. The smart-phone and PDA users all around the world are
facing difficulties to become accustomed and trust in m-commerce.
The main rationale can be the slow variation and lack of trust in
mobile payment systems. Mobile payment systems that are in use
need to be more effective and efficient. This paper proposes: the
interface design is not the only factor affecting the m-commerce
adoption and lack of trust; in fact it is the combined effect of
interface usability and trustworthy mobile payment systems, because
it-s the money that the user has to spend at the end of the day, which
the user requires to get transferred securely. The purpose of this
research is to identify the problems regarding the trust and adaption
of m-commerce applications by mobile users and to provide the best
possible solution with respect to human computer interaction (HCI)
principles.
Abstract: In this research, Response Surface Methodology (RSM) is used to investigate the effect of four controllable input variables namely: discharge current, pulse duration, pulse off time and applied voltage Surface Roughness (SR) of on Electrical Discharge Machined surface. To study the proposed second-order polynomial model for SR, a Central Composite Design (CCD) is used to estimation the model coefficients of the four input factors, which are alleged to influence the SR in Electrical Discharge Machining (EDM) process. Experiments were conducted on AISI D2 tool steel with copper electrode. The response is modeled using RSM on experimental data. The significant coefficients are obtained by performing Analysis of Variance (ANOVA) at 5% level of significance. It is found that discharge current, pulse duration, and pulse off time and few of their interactions have significant effect on the SR. The model sufficiency is very satisfactory as the Coefficient of Determination (R2) is found to be 91.7% and adjusted R2-statistic (R2 adj ) 89.6%.
Abstract: Prospective readers can quickly determine whether a document is relevant to their information need if the significant phrases (or keyphrases) in this document are provided. Although keyphrases are useful, not many documents have keyphrases assigned to them, and manually assigning keyphrases to existing documents is costly. Therefore, there is a need for automatic keyphrase extraction. This paper introduces a new domain independent keyphrase extraction algorithm. The algorithm approaches the problem of keyphrase extraction as a classification task, and uses a combination of statistical and computational linguistics techniques, a new set of attributes, and a new machine learning method to distinguish keyphrases from non-keyphrases. The experiments indicate that this algorithm performs better than other keyphrase extraction tools and that it significantly outperforms Microsoft Word 2000-s AutoSummarize feature. The domain independence of this algorithm has also been confirmed in our experiments.
Abstract: The psychological and physical trauma associated with the loss of a human limb can severely impact on the quality of life of an amputee rendering even the most basic of tasks very difficult. A prosthetic device can be of great benefit to the amputee in the performance of everyday human tasks. This paper outlines a proposed mechanical design of a 12 degree-of-freedom SMA actuated artificial hand. It is proposed that the SMA wires be embedded intrinsically within the hand structure which will allow for significant flexibility for use either as a prosthetic hand solution, or as part of a complete lower arm prosthetic solution. A modular approach is taken in the design facilitating ease of manufacture and assembly, and more importantly, also allows the end user to easily replace SMA wires in the event of failure. A biomimetric approach has been taken during the design process meaning that the artificial hand should replicate that of a human hand as far as is possible with due regard to functional requirements. The proposed design has been exposed to appropriate loading through the use of finite element analysis (FEA) to ensure that it is structurally sound. Theoretical analysis of the mechanical framework was also carried out to establish the limits of the angular displacement and velocity of the finger tip as well finger tip force generation. A combination of various polymers and Titanium, which are suitably lightweight, are proposed for the manufacture of the design.
Abstract: Data mining uses a variety of techniques each of which
is useful for some particular task. It is important to have a deep
understanding of each technique and be able to perform sophisticated
analysis. In this article we describe a tool built to simulate a variation
of the Kohonen network to perform unsupervised clustering and
support the entire data mining process up to results visualization. A
graphical representation helps the user to find out a strategy to
optimize classification by adding, moving or delete a neuron in order
to change the number of classes. The tool is able to automatically
suggest a strategy to optimize the number of classes optimization, but
also support both tree classifications and semi-lattice organizations of
the classes to give to the users the possibility of passing from one
class to the ones with which it has some aspects in common.
Examples of using tree and semi-lattice classifications are given to
illustrate advantages and problems. The tool is applied to classify
macroeconomic data that report the most developed countries- import
and export. It is possible to classify the countries based on their
economic behaviour and use the tool to characterize the commercial
behaviour of a country in a selected class from the analysis of
positive and negative features that contribute to classes formation.
Possible interrelationships between the classes and their meaning are
also discussed.
Abstract: In this paper, the effect of modified clay on the
mechanical efficiency of epoxy resin is examined. Studies by X ray
diffraction and microscopic transient electron method show that
modified clay distribution in polymer area is intercalated kind.
Examination the results of mechanical tests shows that existence of
modified clay in epoxy area increases pressure yield strength, tension
module and nano composite fracture toughness in relate of pure
epoxy. By microscopic examinations it is recognized too that the
action of toughness growth of this kind of nano composite is due to
crack deflection, formation of new surfaces and fracture of clay piles.
Abstract: The sensitivity of UAVs to the atmospheric effects are
apparent. All the same the meteorological support for the UAVs
missions is often non-adequate or partly missing.
In our paper we show a new complex meteorological support
system for different types of UAVs pilots, specialists and decision
makers, too. The mentioned system has two important parts with
different forecasts approach such as the statistical and dynamical
ones.
The statistical prediction approach is based on a large
climatological data base and the special analog method which is able
to select similar weather situations from the mentioned data base to
apply them during the forecasting procedure.
The applied dynamic approach uses the specific WRF model runs
twice a day and produces 96 hours, high resolution weather forecast
for the UAV users over the Hungary. An easy to use web-based
system can give important weather information over the Carpathian
basin in Central-Europe. The mentioned products can be reached via
internet connection.
Abstract: A variable structure model reference adaptive control
(VS-MRAC) strategy for active steering assistance of a two wheel
steering car is proposed. An ideal steering system with fixed
properties and moving on an ideal road is used as the reference
model, and the active steering assistance system is forced to attain
the same behavior as the reference model. The proposed system can
treat the nonlinear relationships between the side slip angles and
lateral forces on tire, and the uncertainties on friction of the road
surface, whose compensation are very important under critical
situations. Simulation results show improvements on yaw rate and
side slip.
Abstract: A method to predict the column size for displacement based design of reinforced concrete frame buildings with higher target inter storey drift is reported here. The column depth derived from empirical relation as a function of given beam section, target inter-story drift, building plan features and common displacement based design parameters is used. Regarding the high drift requirement, a minimum column-beam moment capacity ratio is maintained during capacity design. The method is used in designing four, eight and twelve story frame buildings with displacement based design for three percent target inter storey drift. Non linear time history analysis of the designed buildings are performed under five artificial ground motions to show that the columns are found elastic enough to avoid column sway mechanism assuring that for the design the column size can be used with or without minor changes.
Abstract: This evaluation of land supply system performance in
China shall examine the combination of government functions and
national goals in order to perform a cost-benefit analysis of system
results. From the author's point of view, it is most productive to
evaluate land supply system performance at moments of system
transformation for the following reasons. The behavior and
input-output change of beneficial results at different times can be
observed when the system or policy changes and system performance
can be evaluated through a cost-benefit analysis during the process of
system transformation. Moreover, this evaluation method can avoid
the influence of land resource endowment. Different land resource
endowment methods and different economy development periods
result in different systems. This essay studies the contents, principles
and methods of land supply system performance evaluation. Taking
Beijing as an example, this essay optimizes and classifies the land
supply index, makes a quantitative evaluation of land supply system
performance through principal component analysis (PCA), and finally
analyzes the factors that influence land supply system performance at
times of system transformation.
Abstract: The paper proposes a methodology to process the signals coming from the Transcranial Magnetic Stimulation (TMS) in order to identify the pathology and evaluate the therapy to treat the patients affected by demency diseases. In particular, a fuzzy model is developed to identify the demency of the patients affected by Subcortical Ischemic Vascular Dementia (SIVD) and to measure the effect of a repetitive TMS on their motor performances. A tool is also presented to support the mentioned analysis.
Abstract: Corrosion of metallic water pipelines buried below
ground surface is a function of the nature of the surrounding soil and
groundwater. This gives the importance of knowing the physical and
chemical characteristics of the pipe-s surrounding environment. The
corrosion of externally – unprotected metallic water pipelines,
specially ductile iron pipes, in localities with aggressive soil
conditions is becoming a significant problem. Anticorrosive
protection for metallic water pipelines, their fittings and accessories
is very important, because they may be attached by corrosion with
time. The tendency of a metallic substrate to corrode is a function of
the surface characteristics of the metal and of the metal/protective
film interface, the physical, electrical and electrochemical properties
of the film, and the nature of the environment in which the pipelines
system is placed. In this work the authors have looked at corrosion
problems of water pipelines and their control. The corrosive
properties of groundwater and soil environments are reviewed, and
parameters affecting corrosion are discussed. The purpose of this
work is to provide guidelines for materials selection in water and soil
environments, and how the water pipelines can be protected against
metallic corrosion.
Abstract: A number of automated shot-change detection
methods for indexing a video sequence to facilitate browsing and
retrieval have been proposed in recent years. This paper emphasizes
on the simulation of video shot boundary detection using one of the
methods of the color histogram wherein scaling of the histogram
metrics is an added feature. The difference between the histograms of
two consecutive frames is evaluated resulting in the metrics. Further
scaling of the metrics is performed to avoid ambiguity and to enable
the choice of apt threshold for any type of videos which involves
minor error due to flashlight, camera motion, etc. Two sample videos
are used here with resolution of 352 X 240 pixels using color
histogram approach in the uncompressed media. An attempt is made
for the retrieval of color video. The simulation is performed for the
abrupt change in video which yields 90% recall and precision value.
Abstract: One of the approaches enabling people with amputated
limbs to establish some sort of interface with the real world includes
the utilization of the myoelectric signal (MES) from the remaining
muscles of those limbs. The MES can be used as a control input to a
multifunction prosthetic device. In this control scheme, known as the
myoelectric control, a pattern recognition approach is usually utilized
to discriminate between the MES signals that belong to different
classes of the forearm movements. Since the MES is recorded using
multiple channels, the feature vector size can become very large. In
order to reduce the computational cost and enhance the generalization
capability of the classifier, a dimensionality reduction method is
needed to identify an informative yet moderate size feature set. This
paper proposes a new fuzzy version of the well known Fisher-s
Linear Discriminant Analysis (LDA) feature projection technique.
Furthermore, based on the fact that certain muscles might contribute
more to the discrimination process, a novel feature weighting scheme
is also presented by employing Particle Swarm Optimization (PSO)
for estimating the weight of each feature. The new method, called
PSOFLDA, is tested on real MES datasets and compared with other
techniques to prove its superiority.
Abstract: The aim of this qualitative case study is to examine how school principals perform their new roles and responsibilities defined in accordance with the new curriculum. Of ten primary schools that the new curriculum was piloted in Istanbul in school year of 2004-2005, one school was randomly selected as the sample of the study. The participants of the study were comprised of randomly-selected 26 teachers working in the case school. To collect data, an interview schedule was developed based on the new role definitions for school principals by the National Ministry of Education. Participants were interviewed on one-to-one basis in February and March 2007. Overall results showed that the school principal was perceived to be successful in terms of the application of the new curriculum in school. According to the majority of teachers, the principal has done his best to establish the infrastructure that is necessary for successful application of the new program. In addition to these, the principal was reported to adopt a collegial and participatory leadership style by creating a positive school atmosphere that enables the school community (teachers, parents and students) to involve school more than before. Keywordscase study, curriculum implementation, school principals and curriculum
Abstract: Wall-surface jet induced by the dielectric barrier
discharge (DBD) has been proposed as an actuator for active flow
control in aerodynamic applications. Discharge plasma evolution of
the DBD plasma actuator was simulated based on a simple fluid model,
in which the electron, one type of positive ion and negative ion were
taken into account. Two-dimensional simulation was conducted, and
the results are in agreement with the insights obtained from
experimental studies. The simulation results indicate that the discharge
mode changes depending on applied voltage slope; when the applied
voltage is positive-going with high applied voltage slope, the
corona-type discharge mode turns into the streamer-type discharge
mode and the threshold voltage slope is around 300 kV/ms in this
simulation. The characteristics of the electrohydrodynamic (EHD)
force, which is the source of the wall-surface jet, also change
depending on the discharge mode; the tentative peak value of the EHD
force during the positive-going voltage phase is saturated by the
periodical formation of the streamer-type discharge.
Abstract: As the demand and prices of various petroleum products have been on the rise in recent years, there is a growing need for alternative fuels. Biodiesel, which consists of alkyl monoesters of fatty acids from vegetable oils and animal fats, is considered as an alternative to petroleum diesel. Biodiesel has comparable performance with that of diesel and has lower brake specific fuel consumption than diesel with significant reduction in emissions of CO, hydrocarbons (HC) and smoke with however, a slight increase in NOx emissions. This paper analyzes the effect of cooled exhaust gas recirculation in the combustion characteristics of a direct injection compression ignition engine using biodiesel blended fuel as opposed to the conventional system. The combustion parameters such as cylinder pressure, heat release rate, delay period and peak pressure were analyzed at various loads. The maximum cylinder pressure reduces as the fraction of biodiesel increases in the blend the maximum rate of pressure rise was found to be higher for diesel at higher engine loads.
Abstract: This paper proposes an improved approach based on
conventional particle swarm optimization (PSO) for solving an
economic dispatch(ED) problem with considering the generator
constraints. The mutation operators of the differential evolution (DE)
are used for improving diversity exploration of PSO, which called
particle swarm optimization with mutation operators (PSOM). The
mutation operators are activated if velocity values of PSO nearly to
zero or violated from the boundaries. Four scenarios of mutation
operators are implemented for PSOM. The simulation results of all
scenarios of the PSOM outperform over the PSO and other existing
approaches which appeared in literatures.
Abstract: In this paper we report a study aimed at determining
the effects of animation on usability and appeal of educational
software user interfaces. Specifically, the study compares 3
interfaces developed for the Mathsigner™ program: a static
interface, an interface with highlighting/sound feedback, and an
interface that incorporates five Disney animation principles. The
main objectives of the comparative study were to: (1) determine
which interface is the most effective for the target users of
Mathsigner™ (e.g., children ages 5-11), and (2) identify any Gender
and Age differences in using the three interfaces. To accomplish
these goals we have designed an experiment consisting of a
cognitive walkthrough and a survey with rating questions. Sixteen
children ages 7-11 participated in the study, ten males and six
females. Results showed no significant interface effect on user task
performance (e.g., task completion time and number of errors);
however, interface differences were seen in rating of appeal, with
the animated interface rated more 'likeable' than the other two.
Task performance and rating of appeal were not affected
significantly by Gender or Age of the subjects.