Abstract: This study presents a cost-effective approach for rapid
fabricating modeling platforms utilized in fused deposition modeling
system. A small-batch production of modeling platforms about 20
pieces can be obtained economically through silicone rubber mold
using vacuum casting without applying the plastic injection molding.
The air venting systems is crucial for fabricating modeling platform
using vacuum casting. Modeling platforms fabricated can be used for
building rapid prototyping model after sandblasting. This study offers
industrial value because it has both time-effectiveness and
cost-effectiveness.
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: This paper proposes a backward/forward sweep
method to analyze the power flow in radial distribution systems. The
distribution system has radial structure and high R/X ratios. So the
newton-raphson and fast decoupled methods are failed with
distribution system. The proposed method presents a load flow study
using backward/forward sweep method, which is one of the most
effective methods for the load-flow analysis of the radial distribution
system. By using this method, power losses for each bus branch and
voltage magnitudes for each bus node are determined. This method
has been tested on IEEE 33-bus radial distribution system and
effective results are obtained using MATLAB.
Abstract: The electric power supplied by a photovoltaic power
generation systems depends on the solar irradiation and temperature.
The PV system can supply the maximum power to the load at a
particular operating point which is generally called as maximum
power point (MPP), at which the entire PV system operates with
maximum efficiency and produces its maximum power. Hence, a
Maximum power point tracking (MPPT) methods are used to
maximize the PV array output power by tracking continuously the
maximum power point. The proposed MPPT controller is designed
for 10kW solar PV system installed at Cape Institute of Technology.
This paper presents the fuzzy logic based MPPT algorithm. However,
instead of one type of membership function, different structures of
fuzzy membership functions are used in the FLC design. The
proposed controller is combined with the system and the results are
obtained for each membership functions in Matlab/Simulink
environment. Simulation results are decided that which membership
function is more suitable for this system.
Abstract: Oases are complex and fragile agro-ecosystems. They
have always existed in environments characterized by an arid climate,
scarcity of rainfall, high temperatures and high evaporation. These
palms have grown up despite the severity of the physical
characteristics thanks to the water's existence and irrigation practice.
The oases are generally spread along non-perennial rivers (wadis),
shallow water table or deep artesian groundwater. However, the
sustainability of oasis system is threatened by water scarcity and
declining of water table levels particularly in arid areas. Located in
the southern east area of Morocco, Tafilalet plain encompasses one of
the largest palm groves in the kingdom. In recent years, this area has
become increasingly threatened by water shortage and has seen a
sharp deterioration under the effect of several combined
anthropogenic and climatic factors. The Bayoud disease, successive
years of drought, Hassan Addakhil dam construction etc are all
factors that have affected both water and phoenicicole heritage of the
area. The objective of this study is to understand the interaction
between qualitative and quantitative degradation of groundwater
resources, and the palm grove dynamics, while reviewing the
assumption that groundwater resources contribute in a direct way to
the conservation of this oasis agroecosystem. A historical analysis
tracing both the oasis dynamics and the groundwater evolution has
been established. Data were collected from satellite images, surveys
with different actors (farmers, Regional Office for Agricultural
Development, Basin agency...). They were complemented by a
synthesis of numerous technical reports in the area. The results
showed that within 40 years, the thickness of the groundwater table
has dropped in 50 %. Along with this, there has been a downsizing of
date palm by 50 %. Areas with higher groundwater level were the
least affected by the downsizing. So we can say that the shallow
groundwater contribute significantly and directly to the water supply
of date palm through its root system, and largely ensures the oasis
ecosystem sustainability.
Abstract: In this paper an isolated wind-diesel hybrid power
system has been considered for reactive power control study having
an induction generator for wind power conversion and synchronous
alternator with automatic voltage regulator (AVR) for diesel unit is
presented. The dynamic voltage stability evaluation is dependent on
small signal analysis considering a Static VAR Compensator (SVC)
and IEEE type -I excitation system. It's shown that the variable
reactive power source like SVC is crucial to meet the varying
demand of reactive power by induction generator and load and to
acquire an excellent voltage regulation of the system with minimum
fluctuations. Integral square error (ISE) criterion can be used to
evaluate the optimum setting of gain parameters. Finally the dynamic
responses of the power systems considered with optimum gain setting
will also be presented.
Abstract: Skin detection is an important task for computer
vision systems. A good method of skin detection means a good and
successful result of the system.
The colour is a good descriptor for image segmentation and
classification; it allows detecting skin colour in the images. The
lighting changes and the objects that have a colour similar than skin
colour make the operation of skin detection difficult.
In this paper, we proposed a method using the YCbCr colour space
for skin detection and lighting effects elimination, then we use the
information of texture to eliminate the false regions detected by the
YCbCr skin model.
Abstract: The Lean Environmental Management Integration
System (LEMIS) framework development is integration between lean
core element and ISO 14001. The curiosity on the relationship
between continuous improvement and sustainability of lean
implementation has influenced this study toward LEMIS.
Characteristic of ISO 14001 standard clauses and core elements of
lean principles are explored from past studies and literature reviews.
Survey was carried out on ISO 14001 certified companies to examine
continual improvement by implementing the ISO 14001 standard.
The study found that there is a significant and positive relationship
between Lean Principles: value, value stream, flow, pull and
perfection with the ISO 14001 requirements. LEMIS is significant to
support the continuous improvement and sustainability. The
integration system can be implemented to any manufacturing
company. It gives awareness on the importance on why organizations
need to sustain its environmental management system. In the
meantime, the lean principle can be adapted in order to streamline
daily activities of the company. Throughout the study, it had proven
that there is no sacrifice or trade-off between lean principles with ISO
14001 requirements. The framework developed in the study can be
further simplified in the future, especially the method of crossing
each sub requirements of ISO 14001 standard with the core elements
of Lean principles in this study.
Abstract: Frequency stability of microgrids under islanded
operation attracts particular attention recently. A new cooperative
frequency control strategy based on centralized multi-agent system
(CMAS) is proposed in this study. Based on this strategy, agents sent
data and furthermore each component has its own to center operating
decisions (MGCC).After deciding on the information, they are
returned. Frequency control strategies include primary and secondary
frequency control and disposal of multi-stage load in which this study
will also provide a method and algorithm for load shedding. This
could also be a big problem for the performance of micro-grid in
times of disaster. The simulation results show the promising
performance of the proposed structure of the controller based on
multi agent systems.
Abstract: This paper proposes the designing direct adaptive
neural controller to apply for a class of a nonlinear pendulum
dynamic system. The radial basis function (RBF) neural adaptive
controller is robust in presence of external and internal uncertainties.
Both the effectiveness of the controller and robustness against
disturbances are importance of this paper. The simulation results
show the promising performance of the proposed controller.
Abstract: The purpose of this study was to investigate
perceptions of climate change risk to forest ecosystems and forestbased
communities as well as perceived effectiveness of adaptation
strategies for climate change as well as challenges for adaptation.
Data was gathered using a pre-tested semi-structured questionnaire.
Simple random selection technique was applied. For the majority of
issues, the responses were obtained on multi-point likert scales, and
the scores provided were, in turn, used to estimate the means and
other useful estimates. A composite knowledge index developed
using correct responses to a set of self-rated statements were used to
evaluate the issues. The mean of the knowledge index was 0.64. Also
all respondents recorded values of the knowledge index above 0.25.
Increase forest fire was perceived by respondents as the greatest risk
to forest eco-system. Decrease access to water supplies was perceived
as the greatest risk to livelihoods of forest based communities. The
most effective adaptation strategy relevant to climate change risks to
forest eco-systems and forest based communities livelihoods in
Kathmandu valley in Nepal as perceived by the respondents was
reforestation and afforestation. As well, lack of public awareness was
perceived as the major limitation for climate change adaptation.
However, perceived risks as well as effective adaptation strategies
showed an inconsistent association with knowledge indicators and
social-cultural variables. The results provide useful information to
any party who involve with climate change issues in Nepal, since
such attempts would be more effective once the people’s perceptions
on these aspects are taken into account.
Abstract: The objective of the Economic Dispatch(ED) Problems
of electric power generation is to schedule the committed generating
units outputs so as to meet the required load demand at minimum
operating cost while satisfying all units and system equality and
inequality constraints. This paper presents a new method of ED
problems utilizing the Max-Min Ant System Optimization.
Historically, traditional optimizations techniques have been used,
such as linear and non-linear programming, but within the past
decade the focus has shifted on the utilization of Evolutionary
Algorithms, as an example Genetic Algorithms, Simulated Annealing
and recently Ant Colony Optimization (ACO). In this paper we
introduce the Max-Min Ant System based version of the Ant System.
This algorithm encourages local searching around the best solution
found in each iteration. To show its efficiency and effectiveness, the
proposed Max-Min Ant System is applied to sample ED problems
composed of 4 generators. Comparison to conventional genetic
algorithms is presented.
Abstract: Distributed Generation (DG) can help in reducing the
cost of electricity to the costumer, relieve network congestion and
provide environmentally friendly energy close to load centers. Its
capacity is also scalable and it provides voltage support at distribution
level. Hence, DG placement and penetration level is an important
problem for both the utility and DG owner. DG allocation and capacity
determination is a nonlinear optimization problem. The objective
function of this problem is the minimization of the total loss of the
distribution system. Also high levels of penetration of DG are a new
challenge for traditional electric power systems. This paper presents a
new methodology for the optimal placement of DG and penetration
level of DG in distribution system based on General Algebraic
Modeling System (GAMS) and Genetic Algorithm (GA).
Abstract: A series of polystyrene (PS) nanoparticles were
prepared by grafting polystyrene from both aggregated silica and
colloidally dispersed silica nanoparticles using atom-transfer radical
polymerisation (ATRP). Cross-linking and macroscopic gelation
were minimised by using a miniemulsion system. The thermal and
mechanical behaviour of the nanocomposites have been examined by
differential scanning calorimetry (DSC) and dynamic mechanical
thermal analysis (DMTA).
Abstract: The thermo-mechanical behaviour of concrete energy
pile foundations with different single and double U-tube shapes
incorporated was analysed using the Comsol Multi-physics package.
For the analysis, a 3D numerical model in real scale of the concrete
pile and surrounding soil was simulated regarding actual operation of
ground heat exchangers (GHE) and the surrounding ambient
temperature. Based on initial ground temperature profile measured in
situ, tube inlet temperature was considered to range from 6oC to 0oC
(during the contraction process) over a 30-day period. Extra thermal
stresses and deformations were calculated during the simulations and
differences arising from the use of two different systems (single-tube
and double-tube) were analysed. The results revealed no significant
difference for extra thermal stresses at the centre of the pile in either
system. However, displacements over the pile length were found to
be up to 1.5-fold higher in the double-tube system than the singletube
system.
Abstract: In this study, we aim to demonstrate a microgrid
system experimental simulation for an easy understanding of a
large-scale microgrid system. This model is required for industrial
training and learning environments. However, in order to create an
exact representation of a microgrid system, the laboratory-scale
system must fulfill the requirements of a grid-connected inverter, in
which power values are assigned to the system to cope with the
intermittent output from renewable energy sources. Aside from that,
during fluctuations in load capacity, the grid-connected system must
be able to supply power from the utility grid side and microgrid side in
a balanced manner. Therefore, droop control is installed in the
inverter’s control board to maintain a balanced power sharing in both
sides. This power control in a stand-alone condition and droop control
in a grid-connected condition must be implemented in order to
maintain a stabilized system. Based on the experimental results, power
control and droop control can both be applied in the system by
comparing the experimental and reference values.
Abstract: We introduced an all-optical multicasting
characteristics with wavelength conversion based on a novel
all-optical triode using negative feedback semiconductor optical
amplifier. This study was demonstrated with a transfer speed of 10
Gb/s to a non-return zero 231-1 pseudorandom bit sequence system.
This multi-wavelength converter device can simultaneously provide
three channels of output signal with the support of non-inverted and
inverted conversion. We studied that an all-optical multicasting and
wavelength conversion accomplishing cross gain modulation is
effective in a semiconductor optical amplifier which is effective to
provide an inverted conversion thus negative feedback. The
relationship of received power of back to back signal and output
signals with wavelength 1535 nm, 1540 nm, 1545 nm, 1550 nm, and
1555 nm with bit error rate was investigated. It was reported that the
output signal wavelengths were successfully converted and modulated
with a power penalty of less than 8.7 dB, which the highest is 8.6 dB
while the lowest is 4.4 dB. It was proved that all-optical multicasting
and wavelength conversion using an optical triode with a negative
feedback by three channels at the same time at a speed of 10 Gb/s is a
promising device for the new wavelength conversion technology.
Abstract: In new energy development, wind power has boomed.
It is due to the proliferation of wind parks and their operation in
supplying the national electric grid with low cost and clean resources.
Hence, there is an increased need to establish a proactive
maintenance for wind turbine machines based on remote control and
monitoring. That is necessary with a real-time wireless connection in
offshore or inaccessible locations while the wired method has many
flaws. The objective of this strategy is to prolong wind turbine
lifetime and to increase productivity. The hardware of a remote
control and monitoring system for wind turbine parks is designed. It
takes advantage of GPRS or Wi-Max wireless module to collect data
measurements from different wind machine sensors through IP based
multi-hop communication. Computer simulations with Proteus ISIS
and OPNET software tools have been conducted to evaluate the
performance of the studied system. Study findings show that the
designed device is suitable for application in a wind park.
Abstract: Nations are still finding it quite difficult to win mega
sport competitions despite the major contribution of sport to society
in terms of social and economic development, personal health, and in
education. Even though the world of sports has been transformed into
a huge global economy, it is important to note that the first step of
sport is usually its introduction to children at school through physical
education or PE. In other words, nations who do not win mega sport
competitions also suffer from a weak and neglected PE system. This
problem of the neglect of PE systems is the main motivation of this
research aimed at examining the factors affecting the perceived
awareness of physical education teachers on the ICTs that are
adoptable for the teaching and learning of physical education. Two
types of research objectives will materialize this aim: relevant
theories will be identified in relation to the analysis of the perceived
ICT awareness of PE teachers and subsequent models will be
compiled and designed from existing literature; the empirical testing
of such theories and models will also be achieved through the survey
of PE teachers from the Camperdown magisterial district of the
KwaZulu-Natal province of South Africa. The main hypothesis at the
heart of this study is the relationship between the demographics of PE
teachers, their behavior both as individuals and as social entities, and
their perceived awareness of the ICTs that are adoptable for PE, as
postulated by existing literature; except that this study categorizes
human behavior under performance expectancy, computer attitude,
and social influence. This hypothesis was partially confirmed by the
survey conducted by this research in the sense that performance
expectancy and teachers’ age, gender, computer usage, and class size
were found to be the only factors affecting their awareness of ICTs
for physical education.
Abstract: Since, today in most countries around the world much
attention is paid to planning the smallest unit in the city i.e. the
residential neighborhoods to achieve sustainable urban development
goals, a variety of assessment tools have been developed to assess
and monitor the sustainability of new developments. One of the most
reliable and widely used assessment tools is LEED-ND rating system.
This paper whit the aim of assessing sustainability level of Roshdieh
neighborhood in Tabriz, has introduced this rating system and applied
it in the study area. The results indicate that Roshdieh has the
potential of achieving the standards of sustainable neighborhoods, but
the present situation is far from the ideal point.