Abstract: This paper proposes a new technique to design a
fixed-structure robust loop shaping controller for the pneumatic
servosystem. In this paper, a new method based on a particle swarm
optimization (PSO) algorithm for tuning the weighting function
parameters to design an H∞ controller is presented. The PSO
algorithm is used to minimize the infinity norm of the transfer
function of the nominal closed loop system to obtain the optimal
parameters of the weighting functions. The optimal stability margin is
used as an objective in PSO for selecting the optimal weighting
parameters; it is shown that the proposed method can simplify the
design procedure of H∞ control to obtain optimal robust controller for
pneumatic servosystem. In addition, the order of the proposed
controller is much lower than that of the conventional robust loop
shaping controller, making it easy to implement in practical works.
Also two-degree-of-freedom (2DOF) control design procedure is
proposed to improve tracking performance in the face of noise and
disturbance. Result of simulations demonstrates the advantages of the
proposed controller in terms of simple structure and robustness
against plant perturbations and disturbances.
Abstract: The in-cylinder flow and mixture formations are
significant in view of today’s increasing concern on environmental
issues and stringent emission regulations. In this paper, the numerical
simulations of a SI engine at different engine speeds (2000-5000
rpm) at fixed intake flow pressure of 1 bar are studied using the AVL
FIRE software. The simulation results show that when the engine
speed at fixed intake flow pressure is increased, the volumetric
efficiency of the engine decreases. This is due to a richer fuel
conditions near the engine cylinder wall when engine speed is
increased. Significant effects of impingement are also noted on the
upper and side walls of the engine cylinder. These variations in
mixture formation before ignition could affect the thermodynamics
efficiency and specific fuel consumption that would lead to a reduced
engine performance.
Abstract: Ontologies provide a common understanding of a
specific domain of interest that can be communicated between people
and used as background knowledge for automated reasoning in a
wide range of applications. In this paper, we address the design of
multilingual ontologies following well-defined knowledge
engineering methodologies with the support of novel collaborative
development approaches. In particular, we present a collaborative
platform which allows ontologies to be developed incrementally in
multiple languages. This is made possible via an appropriate mapping
between language independent concepts and one lexicalization per
language (or a lexical gap in case such lexicalization does not exist).
The collaborative platform has been designed to support the
development of the Universal Knowledge Core, a multilingual
ontology currently in English, Italian, Chinese, Mongolian, Hindi and
Bangladeshi. Its design follows a workflow-based development
methodology that models resources as a set of collaborative objects
and assigns customizable workflows to build and maintain each
collaborative object in a community driven manner, with extensive
support of modern web 2.0 social and collaborative features.
Abstract: The financial crises caused a collapse in prices of
most asset classes, raising the attention on alternative investments
such as sukuk, a smaller, fast growing but often misunderstood
market. We study diversification benefits of sukuk, their correlation
with other asset classes and the effects of their inclusion in
investment portfolios of institutional and retail investors, through a
comprehensive comparison of their risk/return profiles during and
after the financial crisis.
We find a beneficial performance adjusted for the specific
volatility together with a lower correlation especially during the
financial crisis. The distribution of sukuk returns is positively skewed
and leptokurtic, with a risk/return profile similarly to high yield
bonds. Overall, our results suggest that sukuk present diversification
opportunities, a significant volatility-adjusted performance and lower
correlations especially during the financial crisis.
Our findings are relevant for a number of institutional investors.
Long term investors, such as life insurers would benefit from sukuk’s
protective features during financial crisis yet keeping return and
growth opportunities, whereas banks would gain due to their role of
placers, advisors, market makers or underwriters.
Abstract: Regardless of the manufacturing process used,
subtractive or additive, material, purpose and application, produced
components are conventionally solid mass with more or less complex
shape depending on the production technology selected. Aspects
such as reducing the weight of components, associated with the low
volume of material required and the almost non-existent material
waste, speed and flexibility of production and, primarily, a high
mechanical strength combined with high structural performance, are
competitive advantages in any industrial sector, from automotive,
molds, aviation, aerospace, construction, pharmaceuticals, medicine
and more recently in human tissue engineering. Such features,
properties and functionalities are attained in metal components
produced using the additive technique of Rapid Prototyping from
metal powders commonly known as Selective Laser Melting (SLM),
with optimized internal topologies and varying densities. In order to
produce components with high strength and high structural and
functional performance, regardless of the type of application, three
different internal topologies were developed and analyzed using
numerical computational tools. The developed topologies were
numerically submitted to mechanical compression and four point
bending testing. Finite Element Analysis results demonstrate how
different internal topologies can contribute to improve mechanical
properties, even with a high degree of porosity relatively to fully
dense components. Results are very promising not only from the
point of view of mechanical resistance, but especially through the
achievement of considerable variation in density without loss of
structural and functional high performance.
Abstract: In this paper, the formulation of a new group explicit
method with a fourth order accuracy is described in solving the two
dimensional Helmholtz equation. The formulation is based on the
nine-point fourth order compact finite difference approximation
formula. The complexity analysis of the developed scheme is also
presented. Several numerical experiments were conducted to test the
feasibility of the developed scheme. Comparisons with other existing
schemes will be reported and discussed. Preliminary results indicate
that this method is a viable alternative high accuracy solver to the
Helmholtz equation.
Abstract: In this paper, Least Mean Square (LMS) adaptive
noise reduction algorithm is proposed to enhance the speech signal
from the noisy speech. In this, the speech signal is enhanced by
varying the step size as the function of the input signal. Objective and
subjective measures are made under various noises for the proposed
and existing algorithms. From the experimental results, it is seen that
the proposed LMS adaptive noise reduction algorithm reduces Mean
square Error (MSE) and Log Spectral Distance (LSD) as compared to
that of the earlier methods under various noise conditions with
different input SNR levels. In addition, the proposed algorithm
increases the Peak Signal to Noise Ratio (PSNR) and Segmental SNR
improvement (ΔSNRseg) values; improves the Mean Opinion Score
(MOS) as compared to that of the various existing LMS adaptive
noise reduction algorithms. From these experimental results, it is
observed that the proposed LMS adaptive noise reduction algorithm
reduces the speech distortion and residual noise as compared to that
of the existing methods.
Abstract: Underwater acoustic network is one of the rapidly
growing areas of research and finds different applications for
monitoring and collecting various data for environmental studies. The
communication among dynamic nodes and high error probability in
an acoustic medium forced to maximize energy consumption in
Underwater Sensor Networks (USN) than in traditional sensor
networks. Developing energy-efficient routing protocol is the
fundamental and a curb challenge because all the sensor nodes are
powered by batteries, and they cannot be easily replaced in UWSNs.
This paper surveys the various recent routing techniques that mainly
focus on energy efficiency.
Abstract: The research conducted in early seventies apparently
assumed the existence of a universal decision model for union
negotiators and furthermore tended to regard financial information as
a ‘neutral’ input into a rational decision making process. However,
research in the eighties began to question the neutrality of financial
information as an input in collective bargaining rather viewing it as a
potentially effective means for controlling the labour force.
Furthermore, this later research also started challenging the simplistic
assumptions relating particularly to union objectives which have
underpinned the earlier search for universal union decision models.
Despite the above developments there seems to be a dearth of studies
in developing countries concerning the use of financial information in
collective bargaining. This paper seeks to begin to remedy this
deficiency. Utilising a case study approach based on two enterprises,
one in the public sector and the other a multinational, the universal
decision model is rejected and it is argued that the decision whether
or not to use financial information is a contingent one and such a
contingency is largely defined by the context and environment in
which both union and management negotiators work. An attempt is
also made to identify the factors constraining as well as promoting
the use of financial information in collective bargaining, these being
regarded as unique to the organisations within which the case studies
are conducted.
Abstract: To practically apply vacuum insulation panels (VIPs)
to buildings or home appliances, VIPs have demanded long-term
lifespan with outstanding insulation performance. Service lives of
VIPs enveloped with Al-foil and three-layer Al-metallized envelope
are calculated. For Al-foil envelope, the service life is longer but edge
conduction is too large compared with the Al-metallized envelope. To
increase service life even more, the proposed double enveloping
method and metal-barrier-added enveloping method are further
analyzed. The service lives of the VIP to employ two enveloping
methods are calculated. Also, pressure increase and thermal insulation
performance characteristics are investigated. For the metalbarrier-
added enveloping method, effective thermal conductivity
increase with time is close to that of Al-foil envelope, especially, for
getter-inserted VIPs. For double enveloping method, if water vapor is
perfectly adsorbed, the effect of service life enhancement becomes
much greater. From these methods, the VIP can be guaranteed for
service life of more than 20 years.
Abstract: Enterprise Architecture (EA) is a strategy that is
employed by enterprises in order to align their business and
Information Technology (IT). EA is managed, developed, and
maintained through Enterprise Architecture Implementation
Methodology (EAIM). Effectiveness of EA implementation is the
degree in which EA helps to achieve the collective goals of the
organization. This paper analyzes the results of a survey that aims to
explore the factors that affect the effectiveness of EAIM and
specifically the relationship between factors and effectiveness of the
output and functionality of EA project. The exploratory factor
analysis highlights a specific set of five factors: alignment,
adaptiveness, support, binding, and innovation. The regression
analysis shows that there is a statistically significant and positive
relationship between each of the five factors and the effectiveness of
EAIM. Consistent with theory and practice, the most prominent
factor for developing an effective EAIM is innovation. The findings
contribute to the measuring the effectiveness of EA implementation
project by providing an indication of the measurement
implementation approaches which is used by the Enterprise
Architects, and developing an effective EAIM.
Abstract: The dramatic rise in the use of Social Media (SM)
platforms such as Facebook and Twitter provide access to an
unprecedented amount of user data. Users may post reviews on
products and services they bought, write about their interests, share
ideas or give their opinions and views on political issues. There is a
growing interest in the analysis of SM data from organisations for
detecting new trends, obtaining user opinions on their products and
services or finding out about their online reputations. A recent
research trend in SM analysis is making predictions based on
sentiment analysis of SM. Often indicators of historic SM data are
represented as time series and correlated with a variety of real world
phenomena like the outcome of elections, the development of
financial indicators, box office revenue and disease outbreaks. This
paper examines the current state of research in the area of SM mining
and predictive analysis and gives an overview of the analysis
methods using opinion mining and machine learning techniques.
Abstract: Augmented Reality is a technology that involves the
overlay of virtual content, which is context or environment sensitive,
on images of the physical world in real time. This paper presents the
development of a catalog system that facilitates and allows the
creation, publishing, management and exploitation of augmented
multimedia contents and Augmented Reality applications, creating an
own space for anyone that wants to provide information to real
objects in order to edit and share it then online with others. These
spaces would be built for different domains without the initial need of
expert users. Its operation focuses on the context of Web 2.0 or
Social Web, with its various applications, developing contents to
enrich the real context in which human beings act permitting the
evolution of catalog’s contents in an emerging way.
Abstract: The importance of using mother tongue and
translation in foreign language classrooms cannot be ignored and
translation can be utilized as a method in English Language Teaching
courses. There exist researches advocating or objecting to the use of
translation in foreign language learning but they all have a point in
common: Translation should be used as an aid to teaching, not an end
in itself. In this research, prospective English language teachers’
opinions about translation use and use of mother tongue in foreign
language teaching are investigated and according to the findings,
some explanations and recommendations are made.
Abstract: Guided by the theory of learning styles, this study is
based on the development of a multimedia learning application for
students with mastery learning style. The learning material was
developed by applying a graduated difficulty learning strategy.
Algebra was chosen as the learning topic for this application. The
effectiveness of this application in helping students learn is measured
by giving a pre- and post-test. The result shows that students who
learn using the learning material that matches their preferred learning
style perform better than the students with a non-personalized
learning material.
Abstract: In this paper, the influence of upstream structures on the flow patternaround and inside the wind-catcher is experimentally investigated by smoke flow visualization techniques. Wind-catchers are an important part of natural ventilation in residential buildings or public places such as shopping centers, libraries, etc. Wind-catchers might be also used in places of high urban densities; hence their potential to provide natural ventilation is dependent on the presence of upstream structures. In this study, the two-sided wind-catcher model was based on a real wind-catcher observed in the city of Yazd, Iran. The present study focuses on the flow patterns around and inside the isolated two-sided wind-catcher, and on a two-sided wind-catcher in the presence of an upstream structure. The results show that the presence of an upstream structure influences the airflow pattern force and direction. Placing a high upstream structure reverses the airflow direction inside the wind-catcher.
Abstract: Domestic goats (Capra hircus) are extremely diverse
species and principal animal genetic resource of the developing
world. These facilitate a persistent supply of meat, milk, fibre, and
skin and are considered as important revenue generators in small
pastoral environments. This study aimed to fingerprint β-LG gene at
PCR-RFLP level in native Saudi goat breeds (Ardi, Habsi and Harri)
in an attempt to have a preliminary image of β-LG genotypic patterns
in Saudi breeds as compared to other foreign breeds such as Indian
and Egyptian. Also, the Phylogenetic analysis was done to investigate
evolutionary trends and similarities among the caprine β-LG gene
with that of the other domestic specie, viz. cow, buffalo and sheep.
Blood samples were collected from 300 animals (100 for each breed)
and genomic DNA was extracted. A fragment of the β-LG gene
(427bp) was amplified using specific primers. Subsequent digestion
with Sac II restriction endonuclease revealed two alleles (A and B)
and three different banding patterns or genotypes i.e. AA, AB and
BB. The statistical analysis showed a general trend that β-LG AA
genotype had higher milk yield than β-LG AB and β-LG BB
genotypes. Nucleotide sequencing of the selected β-LG fragments
was done and submitted to GenBank NCBI (Accession No.
KJ544248, KJ588275, KJ588276, KJ783455, KJ783456 and
KJ874959). Phylogenetic analysis on the basis of nucleotide
sequences of native Saudi goats indicated evolutional similarity with
the GenBank reference sequences of goat, Bubalus bubalis and Bos
taurus. However, the origin of sheep which is the most closely
related from the evolutionary point of view, was located some
distance away.
Abstract: Nitrogen-doped graphene quantum dots (N-GQDs)
were fabricated by microwave-assisted hydrothermal technique. The
optical properties of the N-GQDs were studied. The luminescence of
the N-GQDs can be tuned by varying the excitation wavelength.
Furthermore, two-photon luminescence of the N-GQDs excited by
near-infrared laser can be obtained. It is shown that N-doping play a
key role on two-photon luminescence. The N-GQDs are expected to
find application in biological applications including bioimaging and
sensing.
Abstract: Asphaltic concrete for pavement construction in India
are produced by using crushed stone, gravels etc. as aggregate. In
north-Eastern region of India, there is a scarcity of stone aggregate.
Therefore the road engineers are always in search of an optional
material as aggregate which can replace the regularly used material.
The purpose of this work was to evaluate the utilization of
substandard or marginal aggregates in flexible pavement
construction. The investigation was undertaken to evaluate the effects
of using lower quality aggregates such as over burnt brick aggregate
on the preparation of asphalt concrete for flexible pavements. The
scope of this work included a review of available literature and
existing data, a laboratory evaluation organized to determine the
effects of marginal aggregates and potential techniques to upgrade
these substandard materials, and a laboratory evaluation of these
upgraded marginal aggregate asphalt mixtures. Over burnt brick
aggregates are water susceptible and can leads to moisture damage.
Moisture damage is the progressive loss of functionality of the
material owing to loss of the adhesion bond between the asphalt
binder and the aggregate surface. Hence zycosoil as an anti striping
additive were evaluated in this study. This study summarizes the
results of the laboratory evaluation carried out to investigate the
properties of asphalt concrete prepared with zycosoil modified over
burnt brick aggregate. Marshall specimen were prepared with stone
aggregate, zycosoil modified stone aggregate, over burnt brick
aggregate and zycosoil modified over burnt brick aggregate. Results
show that addition of zycosoil with stone aggregate increased
stability by 6% and addition of zycosoil with over burnt brick
aggregate increased stability by 30%.
Abstract: This paper discusses the potential benefits of an
interactive multimedia information representation in enhancing
students’ critical thinking aligned with history reasoning in learning
history amongst Secondary School students in Malaysia. Two modes
of multimedia information representation were implemented;
chronologic and thematic information representations. A qualitative
study of an unstructured interview was conducted among two history
teachers, one history education lecturer, two i-think experts, and five
students from Form Four secondary school. The interview was to
elicit their opinions on the implementation of thinking maps and
interactive multimedia information representation in history learning.
The key elements of the interactive multimedia (e.g. multiple media,
user control, interactivity and use of timelines and concept maps)
were then considered to improve the learning process. Findings of the
preliminary investigation reveal that the interactive multimedia
information representations have the potential benefits to be
implemented as an instructional resource in enhancing students’
higher order thinking skills (HOTs). This paper concludes by giving
suggestions for future work.