Abstract: This paper proposes a synchronized random switching frequency pulse width modulation (SRSFPWM). In this technique, the clock signal is used to control the random noise frequency which is produced by the feedback voltage of a hysteresis circuit. These make the triangular carrier frequency equaling to the random noise frequency in each switching period with the symmetrical positive and negative slopes of triangular carrier. Therefore, there is no error voltage in PWM signal. The PSpice simulated results shown the proposed technique improved the performance in case of low frequency harmonics of PWM signal comparing with conventional random switching frequency PWM.
Abstract: The proper assessment of interaxial distance and
convergence control are important factors in stereoscopic imaging
technology to make an efficient 3D image. To control interaxial
distance and convergence for efficient 3D shooting, horizontal 3D
camera rig is designed using some hardware components like 'LM
Guide', 'Goniometer' and 'Rotation Stage'. The horizontal 3D camera
rig system can be properly aligned by moving the two cameras
horizontally in same or opposite directions, by adjusting the camera
angle and finally considering horizontal swing as well as vertical
swing. In this paper, the relationship between interaxial distance and
convergence angle control are discussed and intensive experiments are
performed in order to demonstrate an easy and effective 3D shooting.
Abstract: School physical education, through its objectives and
contents, efficiently valorizes the pupils- abilities, developing them,
especially the coordinative skill component, which is the basis of
movement learning, of the development of the daily motility and also
of the special, refined motility required by the practice of certain
sports. Medium school age offers the nervous and motor substratum
needed for the acquisition of complex motor habits, a substratum that
is essential for the coordinative skill. Individuals differ as to the level
at which this function is performed, the extent to which this function
turns an individual into a person that is adapted and adaptable to
complex and various situations. Spatio-temporal orientation, together
with movement combination and coupling, and with kinesthetic,
balance, motor reaction, movement transformation and rhythm
differentiation form the coordinative skills. From our viewpoint,
these are characteristic features with high levels of manifestation in a
complex psychomotor act - valorizing the quality of one-s talent - as
well as indices pertaining to one-s psychomotor intelligence and
creativity.
Abstract: The design of a complete expansion that allows for
compact representation of certain relevant classes of signals is a
central problem in signal processing applications. Achieving such a
representation means knowing the signal features for the purpose of
denoising, classification, interpolation and forecasting. Multilayer
Neural Networks are relatively a new class of techniques that are
mathematically proven to approximate any continuous function
arbitrarily well. Radial Basis Function Networks, which make use of
Gaussian activation function, are also shown to be a universal
approximator. In this age of ever-increasing digitization in the
storage, processing, analysis and communication of information,
there are numerous examples of applications where one needs to
construct a continuously defined function or numerical algorithm to
approximate, represent and reconstruct the given discrete data of a
signal. Many a times one wishes to manipulate the data in a way that
requires information not included explicitly in the data, which is
done through interpolation and/or extrapolation.
Tidal data are a very perfect example of time series and many
statistical techniques have been applied for tidal data analysis and
representation. ANN is recent addition to such techniques. In the
present paper we describe the time series representation capabilities
of a special type of ANN- Radial Basis Function networks and
present the results of tidal data representation using RBF. Tidal data
analysis & representation is one of the important requirements in
marine science for forecasting.
Abstract: Users of computer systems may often require the
private transfer of messages/communications between parties across
a network. Information warfare and the protection and dominance of
information in the military context is a prime example of an
application area in which the confidentiality of data needs to be
maintained. The safe transportation of critical data is therefore often
a vital requirement for many private communications. However,
unwanted interception/sniffing of communications is also a
possibility. An elementary stealthy transfer scheme is therefore
proposed by the authors. This scheme makes use of encoding,
splitting of a message and the use of a hashing algorithm to verify the
correctness of the reconstructed message. For this proof-of-concept
purpose, the authors have experimented with the random sending of
encoded parts of a message and the construction thereof to
demonstrate how data can stealthily be transferred across a network
so as to prevent the obvious retrieval of data.
Abstract: This paper discusses coordinated reactive power -
voltage (Q-V) control in a multi machine steam power plant. The
drawbacks of manual Q-V control are briefly listed, and the design
requirements for coordinated Q-V controller are specified.
Theoretical background and mathematical model of the new
controller are presented next followed by validation of developed
Matlab/Simulink model through comparison with recorded
responses in real steam power plant and description of practical
realisation of the controller. Finally, the performance of
commissioned controller is illustrated on several examples of
coordinated Q-V control in real steam power plant and compared
with manual control.
Abstract: In this study an extensive experimental research is
carried out to develop a better understanding of the effects of Piano Key (PK) weir geometry on weir flow threshold submergence.
Experiments were conducted in a 12 m long, 0.4 m wide and 0.7 m deep rectangular glass wall flume. The main objectives were to
investigate the effect of the PK weir geometries including the weir
length, weir height, inlet-outlet key widths, upstream and
downstream apex overhangs, and slopped floors on threshold submergence and study the hydraulic flow characteristics. From the
experimental results, a practical formula is proposed to evaluate the flow threshold submergence over PK weirs.
Abstract: The purpose of this paper is to describe the process of
setting up a learning community within an elementary school in
Ontario, Canada. The description is provided through reflection and
examination of field notes taken during the yearlong training and
implementation process. Specifically the impact of teachers- capacity
on the creation of a learning community was of interest. This paper is
intended to inform and add to the debate around the tensions that
exist in implementing a bottom-up professional development model
like the learning community in a top-down organizational structure.
My reflections of the process illustrate that implementation of the
learning community professional development model may be
difficult and yet transformative in the professional lives of the
teachers, students, and administration involved in the change process.
I conclude by suggesting the need for a new model of professional
development that requires a transformative shift in power dynamics
and a shift in the view of what constitutes effective professional
learning.
Abstract: There are multiple reasons to expect that detecting the
word order errors in a text will be a difficult problem, and detection
rates reported in the literature are in fact low. Although grammatical
rules constructed by computer linguists improve the performance of
grammar checker in word order diagnosis, the repairing task is still
very difficult. This paper presents an approach for repairing word
order errors in English text by reordering words in a sentence and
choosing the version that maximizes the number of trigram hits
according to a language model. The novelty of this method concerns
the use of an efficient confusion matrix technique for reordering the
words. The comparative advantage of this method is that works with
a large set of words, and avoids the laborious and costly process of
collecting word order errors for creating error patterns.
Abstract: In open settings, the participants in virtual
organization are autonomous and there is no central authority to
ensure the felicity of their interactions. When agents interact in such
settings, each relies upon being able to model the trustworthiness of
the agents with whom it interacts. Fundamentally, such models must
consider the past behavior of the other parties in order to predict their
future behavior. Further, it is sensible for the agents to share
information via referrals to trustworthy agents. In this article, trust is
a bet on the future contingent actions of others" and enumerates six
major factors supporting it: (1) reputation, (2) performance, (3)
appearance, (4) accountability, (5) precommitment, and (6)
contextual facilitation.
Abstract: During the past decade, pond aeration systems have
been developed which will sustain large quantities of fish and
invertebrate biomass. Dissolved Oxygen (DO) is considered to be
among the most important water quality parameters in fish culture.
Fishponds in aquaculture farms are usually located in remote areas
where grid lines are at far distance. Aeration of ponds is required to
prevent mortality and to intensify production, especially when
feeding is practical, and in warm regions. To increase pond
production it is necessary to control dissolved oxygen. Artificial
intelligence (AI) techniques are becoming useful as alternate
approaches to conventional techniques or as components of
integrated systems. They have been used to solve complicated
practical problems in various areas and are becoming more and more
popular nowadays. This paper presents a new design of diffused
aeration system using fuel cell as a power source. Also fuzzy logic
control Technique (FLC) is used for controlling the speed of air flow
rate from the blower to air piping connected to the pond by adjusting
blower speed. MATLAB SIMULINK results show high performance
of fuzzy logic control (FLC).
Abstract: This work deals with the initial applications and formulation of an anisotropic plastic-damage constitutive model proposed for non-linear analysis of reinforced concrete structures submitted to a loading with change of the sign. The original constitutive model is based on the fundamental hypothesis of energy equivalence between real and continuous medium following the concepts of the Continuum Damage Mechanics. The concrete is assumed as an initial elastic isotropic medium presenting anisotropy, permanent strains and bimodularity (distinct elastic responses whether traction or compression stress states prevail) induced by damage evolution. In order to take into account the bimodularity, two damage tensors governing the rigidity in tension or compression regimes are introduced. Then, some conditions are introduced in the original version of the model in order to simulate the damage unilateral effect. The three-dimensional version of the proposed model is analyzed in order to validate its formulation when compared to micromechanical theory. The one-dimensional version of the model is applied in the analyses of a reinforced concrete beam submitted to a loading with change of the sign. Despite the parametric identification problems, the initial applications show the good performance of the model.
Abstract: This article is investigating Boria which is a kind of common performance in Malaysia. Boria has been known as Boria and Borea and both are correct, but Boria is more common. Boria is a folk performance unique to Penang. This theatre style reached Penang in the mid-19th century and is believed to be derived from the Shia Islamic Passion play performed during the Muslim month of Muharram to commemorate the martyrs of Kerbela. These days in Malaysia (especially Penang) Boria mentions to a choral street performance performed annually by a number of groups composed mostly of Sunni Malaysian. Boria are performed for entertainment and often include an annual singing competition. The size, membership, themes and movements of each Boria troupe may vary from year to year. Similarly, the themes and contents of the Boria performed by the different troupes also changes each year and can have a comical, political or satirical notion. It is common to most groups during the first ten days of Muharram Boria generally is done.
Abstract: For the characterization of the weld defect region in the radiographic image, looking for features which are invariant regarding the geometrical transformations (rotation, translation and scaling) proves to be necessary because the same defect can be seen from several angles according to the orientation and the distance from the welded framework to the radiation source. Thus, panoply of geometrical attributes satisfying the above conditions is proposed and which result from the calculation of the geometrical parameters (surface, perimeter, etc.) on the one hand and the calculation of the different order moments, on the other hand. Because the large range in values of the raw features and taking into account other considerations imposed by some classifiers, the scaling of these values to lie between 0 and 1 is indispensable. The principal component analysis technique is used in order to reduce the number of the attribute variables in the aim to give better performance to the further defect classification.
Abstract: Dual motor drives fed by single inverter is
purposely designed to reduced size and cost with respect to
single motor drives fed by single inverter. Previous researches
on dual motor drives only focus on the modulation and the
averaging techniques. Only a few of them, study the
performance of the drives based on different speed controller
other than Proportional and Integrator (PI) controller. This
paper presents a detailed comparative study on fuzzy rule-base
in Fuzzy Logic speed Controller (FLC) for Dual Permanent
Magnet Synchronous Motor (PMSM) drives. Two fuzzy speed
controllers which are standard and simplified fuzzy speed
controllers are designed and the results are compared and
evaluated. The standard fuzzy controller consists of 49 rules
while the proposed controller consists of 9 rules determined by
selecting the most dominant rules only. Both designs are
compared for wide range of speed and the robustness of both
controllers over load disturbance changes is tested to
demonstrate the effectiveness of the simplified/reduced rulebase.
Abstract: In [4], Kipnis and Shamir have cryptanalised
a version of HFE of degree 2. In this paper, we describe the
generalization of this attack of HFE of degree more than 2.
We are based on Fourier Transformation to acheive partially
this attack.
Abstract: In the present work, we have developed a symmetric electrochemical capacitor based on the nanostructured iron oxide (Fe3O4)-activated carbon (AC) nanocomposite materials. The physical properties of the nanocomposites were characterized by Scanning Electron Microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis. The electrochemical performances of the composite electrode in 1.0 M Na2SO3 and 1.0 M Na2SO4 aqueous solutions were evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The composite electrode with 4 wt% of iron oxide nanomaterials exhibits the highest capacitance of 86 F/g. The experimental results clearly indicate that the incorporation of iron oxide nanomaterials at low concentration to the composite can improve the capacitive performance, mainly attributed to the contribution of the pseudocapacitance charge storage mechanism and the enhancement on the effective surface area of the electrode. Nevertheless, there is an optimum threshold on the amount of iron oxide that needs to be incorporated into the composite system. When this optimum threshold is exceeded, the capacitive performance of the electrode starts to deteriorate, as a result of the undesired particle aggregation, which is clearly indicated in the SEM analysis. The electrochemical performance of the composite electrode is found to be superior when Na2SO3 is used as the electrolyte, if compared to the Na2SO4 solution. It is believed that Fe3O4 nanoparticles can provide favourable surface adsorption sites for sulphite (SO3 2-) anions which act as catalysts for subsequent redox and intercalation reactions.
Abstract: In this study, a 3D combustion chamber was simulated
using FLUENT 6.32. Aim to obtain detailed information on
combustion characteristics and _ nitrogen oxides in the furnace and
the effect of oxygen enrichment in a combustion process. Oxygenenriched
combustion is an effective way to reduce emissions. This
paper analyzes NO emission, including thermal NO and prompt NO.
Flow rate ratio of air to fuel is varied as 1.3, 3.2 and 5.1 and the
oxygen enriched flow rates are 28, 54 and 68 lit/min. The 3D
Reynolds Averaged Navier Stokes (RANS) equations with standard
k-ε turbulence model are solved together by Fluent 6.32 software.
First order upwind scheme is used to model governing equations and
the SIMPLE algorithm is used as pressure velocity coupling. Results
show that for AF=1.3, increase the oxygen flow rate of oxygen
reduction in NO emissions is Lance. Moreover, in a fixed oxygen
enrichment condition, increasing the air to fuel ratio will increase the
temperature peak, but not the NO emission rate. As a result, oxygen
enrichment can reduce the NO emission at this kind of furnace in low
air to fuel rates.
Abstract: UML is a collection of notations for capturing a software system specification. These notations have a specific syntax defined by the Object Management Group (OMG), but many of their constructs only present informal semantics. They are primarily graphical, with textual annotation. The inadequacies of standard UML as a vehicle for complete specification and implementation of real-time embedded systems has led to a variety of competing and complementary proposals. The Real-time UML profile (UML-RT), developed and standardized by OMG, defines a unified framework to express the time, scheduling and performance aspects of a system. We present in this paper a framework approach aimed at deriving a complete specification of a real-time system. Therefore, we combine two methods, a semiformal one, UML-RT, which allows the visual modeling of a realtime system and a formal one, CSP+T, which is a design language including the specification of real-time requirements. As to show the applicability of the approach, a correct design of a real-time system with hard real time constraints by applying a set of mapping rules is obtained.