Abstract: This paper describes a sliding mode controller for
autonomous underwater vehicles (AUVs). The dynamic of AUV
model is highly nonlinear because of many factors, such as
hydrodynamic drag, damping, and lift forces, Coriolis and centripetal
forces, gravity and buoyancy forces, as well as forces from thruster.
To address these difficulties, a nonlinear sliding mode controller is
designed to approximate the nonlinear dynamics of AUV and
improve trajectory tracking. Moreover, the proposed controller can
profoundly attenuate the effects of uncertainties and external
disturbances in the closed-loop system. Using the Lyapunov theory
the boundedness of AUV tracking errors and the stability of the
proposed control system are also guaranteed. Numerical simulation
studies of an AUV are included to illustrate the effectiveness of the
presented approach.
Abstract: In recent years, new techniques for solving complex
problems in engineering are proposed. One of these techniques is
JPSO algorithm. With innovative changes in the nature of the jump
algorithm JPSO, it is possible to construct a graph-based solution
with a new algorithm called G-JPSO. In this paper, a new algorithm
to solve the optimal control problem Fletcher-Powell and optimal
control of pumps in water distribution network was evaluated.
Optimal control of pumps comprise of optimum timetable operation
(status on and off) for each of the pumps at the desired time interval.
Maximum number of status on and off for each pumps imposed to the
objective function as another constraint. To determine the optimal
operation of pumps, a model-based optimization-simulation
algorithm was developed based on G-JPSO and JPSO algorithms.
The proposed algorithm results were compared well with the ant
colony algorithm, genetic and JPSO results. This shows the
robustness of proposed algorithm in finding near optimum solutions
with reasonable computational cost.
Abstract: Three purified diets were formulated using fish meal,
soya bean, wheat flour, palm oil, minerals and maltose. The
carbohydrate in the diets was increased from 5 to 15% by changing
the cellulose content to study the effect of dietary carbohydrate level
on the growth parameters of Nile tilapia Oreochromis niloticus. The
protein and the lipid contents were kept constant in all the diets. The
results showed that, weight gain, protein efficiency ratio, net protein
utilisation and hepatosomatic index of fish fed the diet containing
15% cellulose were the lowest among all groups. Addition, the fish
fed the diet containing 5% cellulose had the best specific growth rate,
and food conversion ratio. While, there was no effect of the dietary
cellulose levels on condition factor and survival rate. These results
indicate that Nile tilapia fingerlings are able to utilize dietary
cellulose does not exceed 10% in their feed for optimum growth.
Abstract: The purpose of this paper is to examine the effects and
relationship of stress and social support towards the quality of life
among flood victims in Malaysia. A total of 764 respondents took
part in the survey via convenience sampling. The Depression,
Anxiety and Stress scale (DASS) was utilized to measure stress while
The Multidimensional Scale of Perceived Social Support was used to
measure social support. To measure quality of life, the combination
of WHO Quality of Life – BREF (WHOQOL-BREF) and The Impact
of Event Scale – Revised (IES-R) were utilized. The findings of this
study indicate that there were significant correlations between
variables in the study. The findings showed a significant negative
relation between stress and quality of life; and significant positive
correlations between support from family as well as support from
friends with quality of life. Stress and support from family were
found to be significant predictors that influence the quality of life
among flood victims.
Abstract: Carefully scheduling the operations of pumps can be
resulted to significant energy savings. Schedules can be defined
either implicit, in terms of other elements of the network such as tank
levels, or explicit by specifying the time during which each pump is
on/off. In this study, two new explicit representations based on timecontrolled
triggers were analyzed, where the maximum number of
pump switches was established beforehand, and the schedule may
contain fewer switches than the maximum. The optimal operation of
pumping stations was determined using a Jumping Particle Swarm
Optimization (JPSO) algorithm to achieve the minimum energy cost.
The model integrates JPSO optimizer and EPANET hydraulic
network solver. The optimal pump operation schedule of VanZyl
water distribution system was determined using the proposed model
and compared with those from Genetic and Ant Colony algorithms.
The results indicate that the proposed model utilizing the JPSO
algorithm is a versatile management model for the operation of realworld
water distribution system.
Abstract: This paper introduces a method to optimal design of a
hybrid Wind/Photovoltaic/Fuel cell generation system for a typical
domestic load that is not located near the electricity grid. In this
configuration the combination of a battery, an electrolyser, and a
hydrogen storage tank are used as the energy storage system. The aim
of this design is minimization of overall cost of generation scheme
over 20 years of operation. The Matlab/Simulink is applied for
choosing the appropriate structure and the optimization of system
sizing. A teaching learning based optimization is used to optimize the
cost function. An overall power management strategy is designed for
the proposed system to manage power flows among the different
energy sources and the storage unit in the system. The results have
been analyzed in terms of technical and economic. The simulation
results indicate that the proposed hybrid system would be a feasible
solution for stand-alone applications at remote locations.
Abstract: Electrohydraulic servo system have been used in
industry in a wide number of applications. Its dynamics are highly
nonlinear and also have large extent of model uncertainties and
external disturbances. In this paper, a robust back-stepping control
(RBSC) scheme is proposed to overcome the problem of disturbances
and system uncertainties effectively and to improve the tracking
performance of EHS systems. In order to implement the proposed
control scheme, the system uncertainties in EHS systems are
considered as total leakage coefficient and effective oil volume. In
addition, in order to obtain the virtual controls for stabilizing system,
the update rule for the system uncertainty term is induced by
the Lyapunov control function (LCF). To verify the performance and
robustness of the proposed control system, computer simulation of
the proposed control system using Matlab/Simulink Software
is executed. From the computer simulation, it was found that the
RBSC system produces the desired tracking performance and has
robustness to the disturbances and system uncertainties of EHS
systems.
Abstract: In this research, thorium dioxide mesoporous
nanocrystalline powder was synthesized through the sol-gel method
using hydrated thorium nitrate and ammonium hydroxide as starting
materials and Triton X100 as surfactant. ThO2 gel was characterized
by thermogravimetric (TGA), and prepared ThO2 powder was
subjected to scanning electron microscopy (SEM), X-ray diffraction
(XRD), and Brunauer-Emett-Teller (BET) analyses studies. Detailed
analyses show that prepared powder consisted of phase with the
space group Fm3m of thoria and its crystalline size was 12.6 nm. The
thoria possesses 16.7 m2/g surface area and the pore volume and size
calculated to be 0.0423 cc/g and 1.947 nm, respectively.
Abstract: Cyber exercises used to assess the preparedness of a
community against cyber crises, technology failures and Critical
Information Infrastructure (CII) incidents. The cyber exercises also
called cyber crisis exercise or cyber drill, involved partnerships or
collaboration of public and private agencies from several sectors.
This study investigates Organisation Cyber Resilience (OCR) of
participation sectors in cyber exercise called X Maya in Malaysia.
This study used a principal based cyber resilience survey called CSuite
Executive checklist developed by World Economic Forum in
2012. To ensure suitability of the survey to investigate the OCR, the
reliability test was conducted on C-Suite Executive checklist items.
The research further investigates the differences of OCR in ten
Critical National Infrastructure Information (CNII) sectors
participated in the cyber exercise. The One Way ANOVA test result
showed a statistically significant difference of OCR among ten CNII
sectors participated in the cyber exercise.
Abstract: The using of waste materials in the construction
industry can reduce the dependence on the natural aggregates which
are going at the end to deplete. The glass waste is generated in a huge
amount which can make one of its disposals in concrete industry
effective not only as a green solution but also as an advantage to
enhance the performance of mechanical properties and durability of
concrete. This article reports the performance of concrete specimens
containing different percentages of milled glass waste as a partial
replacement of cement (Powder), when they are subject to cycles of
freezing and thawing. The tests were conducted on 75-mm cubes and
75 x 75 x 300-mm prisms. Compressive strength based on laboratory
testing and non-destructive ultrasonic pulse velocity test were
performed during the action of freezing-thawing cycles (F/T). The
results revealed that the incorporation of glass waste in concrete
mixtures is not only feasible but also showed generally better strength
and durability performance than control concrete mixture. It may be
said that the recycling of waste glass in concrete mixes is not only a
disposal way, but also it can be an exploitation in concrete industry.
Abstract: Neural activity in the human brain starts from the
early stages of prenatal development. This activity or signals
generated by the brain are electrical in nature and represent not only
the brain function but also the status of the whole body. At the
present moment, three methods can record functional and
physiological changes within the brain with high temporal resolution
of neuronal interactions at the network level: the
electroencephalogram (EEG), the magnet oencephalogram (MEG),
and functional magnetic resonance imaging (fMRI); each of these has
advantages and shortcomings. EEG recording with a large number of
electrodes is now feasible in clinical practice. Multichannel EEG
recorded from the scalp surface provides very valuable but indirect
information about the source distribution. However, deep electrode
measurements yield more reliable information about the source
locations intracranial recordings and scalp EEG are used with the
source imaging techniques to determine the locations and strengths of
the epileptic activity. As a source localization method, Low
Resolution Electro-Magnetic Tomography (LORETA) is solved for
the realistic geometry based on both forward methods, the Boundary
Element Method (BEM) and the Finite Difference Method (FDM). In
this paper, we review the findings EEG- LORETA about epilepsy.
Abstract: One of the functions of the commercial heavy vehicle
is to safely and efficiently transport goods and people. Due to its size
and carrying capacity, it is important to study the vehicle dynamic
stability during cornering. Study has shown that there are a number of
overloaded heavy vehicles or permissible Gross Vehicle Weight
(GVW) violations recorded at selected areas in Malaysia assigned by
its type and category. Thus, the objective of this study is to
investigate the correlation and effect of the GVW on heavy vehicle
stability during cornering event using simulation. Various selected
heavy vehicle types and category are simulated using IPG/Truck
Maker® with different GVW and road condition (coefficient of
friction of road surface), while the speed, driver characteristic, center
of gravity of load and road geometry are constant. Based on the
analysis, the relationship between GVW and lateral acceleration were
established. As expected, on the same value of coefficient of friction,
the maximum lateral acceleration would be increased as the GVW
increases.
Abstract: Electrohydraulic servo system have been used in industry in a wide number of applications. Its dynamics are highly nonlinear and also have large extent of model uncertainties and external disturbances. In this paper, a robust back-stepping control (RBSC) scheme is proposed to overcome the problem of disturbances and system uncertainties effectively and to improve the tracking performance of EHS systems. In order to implement the proposed control scheme, the system uncertainties in EHS systems are considered as total leakage coefficient and effective oil volume. In addition, in order to obtain the virtual controls for stabilizing system, the update rule for the system uncertainty term is induced by the Lyapunov control function (LCF). To verify the performance and robustness of the proposed control system, computer simulation of the proposed control system using Matlab/Simulink Software is executed. From the computer simulation, it was found that the RBSC system produces the desired tracking performance and has robustness to the disturbances and system uncertainties of EHS systems.
Abstract: The fatigue life of tubular joints commonly found in
offshore industry is not only dependent on the value of hot-spot stress
(HSS), but is also significantly influenced by the through-thethickness
stress distribution characterized by the degree of bending
(DoB). The determination of DoB values in a tubular joint is essential
for improving the accuracy of fatigue life estimation using the stresslife
(S–N) method and particularly for predicting the fatigue crack
growth based on the fracture mechanics (FM) approach. In the
present paper, data extracted from finite element (FE) analyses of
tubular KT-joints, verified against experimental data and parametric
equations, was used to investigate the effects of geometrical
parameters on DoB values at the crown 0°, saddle, and crown 180°
positions along the weld toe of central brace in tubular KT-joints
subjected to axial loading. Parametric study was followed by a set of
nonlinear regression analyses to derive DoB parametric formulas for
the fatigue analysis of KT-joints under axial loads. The tubular KTjoint
is a quite common joint type found in steel offshore structures.
However, despite the crucial role of the DoB in evaluating the fatigue
performance of tubular joints, this paper is the first attempt to study
and formulate the DoB values in KT-joints.
Abstract: Networking is important among students to achieve
better understanding. Social networking plays an important role in the
education. Realizing its huge potential, various organizations,
including institutions of higher learning have moved to the area of
social networks to interact with their students especially through
Facebook. Therefore, measuring the effectiveness of Facebook as a
learning tool has become an area of interest to academicians and
researchers. Therefore, this study tried to integrate and propose new
theoretical and empirical evidences by linking the western idea of
adopting Facebook as an alternative learning platform from a
Malaysian perspective. This study, thus, aimed to fill a gap by being
among the pioneering research that tries to study the effectiveness of
adopting Facebook as a learning platform across other cultural
settings, namely Malaysia. Structural equation modeling was
employed for data analysis and hypothesis testing. This study finding
has provided some insights that would likely affect students’
awareness towards using Facebook as an alternative learning
platform in the Malaysian higher learning institutions. At the end,
future direction is proposed.
Abstract: The Scheduling and mapping of tasks on a set of
processors is considered as a critical problem in parallel and
distributed computing system. This paper deals with the problem of
dynamic scheduling on a special type of multiprocessor architecture
known as Linear Crossed Cube (LCQ) network. This proposed
multiprocessor is a hybrid network which combines the features of
both linear types of architectures as well as cube based architectures.
Two standard dynamic scheduling schemes namely Minimum
Distance Scheduling (MDS) and Two Round Scheduling (TRS)
schemes are implemented on the LCQ network. Parallel tasks are
mapped and the imbalance of load is evaluated on different set of
processors in LCQ network. The simulations results are evaluated
and effort is made by means of through analysis of the results to
obtain the best solution for the given network in term of load
imbalance left and execution time. The other performance matrices
like speedup and efficiency are also evaluated with the given
dynamic algorithms.
Abstract: Transmission system performance analysis is vital to
proper planning and operations of power systems in the presence of
deregulation. Key performance indicators (KPIs) are often used as
measure of degree of performance. This paper gives a novel method
to determine the transmission efficiency by evaluating the ratio of
real power losses incurred from a specified transfer direction.
Available Transmission Transfer Efficiency (ATTE) expresses the
percentage of real power received resulting from inter-area available
power transfer. The Tie line (Rated system path) performance is seen
to differ from system wide (Network response) performance and
ATTE values obtained are transfer direction specific. The required
sending end quantities with specified receiving end ATC and the
receiving end power circle diagram are obtained for the tie line
analysis. The amount of real power loss load relative to the available
transfer capability gives a measure of the transmission grid
efficiency.
Abstract: In the present work, the dielectric properties of
Epoxy/MWCNT-muscovite HYBRID and MIXED composites based
on a ratio 30:70 were studied. The multi-wall carbon nanotubes
(MWCNT) were prepared using two methods: (a) MWCNTmuscovite
hybrids were synthesised by chemical vapour deposition
(CVD) and (b) physically mixing muscovite with MWCNT. The
effects of different preparation of the composites and filler loading
were evaluated. It was revealed that the dielectric constants of
HYBRID epoxy composites are slightly higher than MIXED epoxy
composites. It was also indicated that the dielectric constant increased
by increasing the MWCNT filler loading.
Abstract: Neuroplasticity or the flexibility of the neural system
is the ability of the brain to adapt to the lack or deterioration of sense
and the capability of the neural system to modify itself through
changing shape and function. Not only have studies revealed that
neuroplasticity does not end in childhood, but also they have proven
that it continues till the end of life and is not limited to the neural
system and covers the cognitive system as well. In the field of
cognition, neuroplasticity is defined as the ability to change old
thoughts according to new conditions and the individuals' differences
in using various styles of cognitive regulation inducing several social,
emotional and cognitive outcomes. This paper attempts to discuss and
define major theories and principles of neuroplasticity and elaborate
on nature or nurture.
Abstract: In Jordan having deficit atmospheric precipitation, an
increase in water demand occurs during summer months. Jordan can
be regarded with a relatively high potential for wastewater recycling
and reuse. The main purpose of this paper was to investigate the
removal of total suspended solids (TSS) and chemical oxygen
demand (COD) for olive mill wastewater (OMW) by
electrocoagulation (EC) process. In the combination of
electrocoagulation by using coupled iron–aluminum electrodes, the
optimum working pH was found to be around 6. Results indicated
that the electrocoagulation process allowed removal of TSS and COD
of about 82.5% and 47.5%, respectively at 45 mA/cm2 after 70
minutes by using coupled iron–aluminum electrodes. It was
demonstrated that the maximum TSS and COD removals were
obtained at some optimum experimental parameters for current
density, pH, and reaction time.