Abstract: There are real needs to integrate types of Open
Educational Resources (OER) with an intelligent system to extract
information and knowledge in the semantic searching level. The
needs came because most of current learning standard adopted web
based learning and the e-learning systems do not always serve all
educational goals. Semantic Web systems provide educators,
students, and researchers with intelligent queries based on a semantic
knowledge management learning system. An ontology-based learning
system is an advanced system, where ontology plays the core of the
semantic web in a smart learning environment. The objective of this
paper is to discuss the potentials of ontologies and mapping different
kinds of ontologies; heterogeneous or homogenous to manage and
control different types of Open Educational Resources. The important
contribution of this research is that it uses logical rules and
conceptual relations to map between ontologies of different
educational resources. We expect from this methodology to establish
an intelligent educational system supporting student tutoring, self and
lifelong learning system.
Abstract: This paper presents a speed estimation scheme based
on second-order sliding-mode Super Twisting Algorithm (STA) and
Model Reference Adaptive System (MRAS) estimation theory for
Sensorless control of multiphase induction machine. A stator current
observer is designed based on the STA, which is utilized to take the
place of the reference voltage model of the standard MRAS
algorithm. The observer is insensitive to the variation of rotor
resistance and magnetizing inductance when the states arrive at the
sliding mode. Derivatives of rotor flux are obtained and designed as
the state of MRAS, thus eliminating the integration. Compared with
the first-order sliding-mode speed estimator, the proposed scheme
makes full use of the auxiliary sliding-mode surface, thus alleviating
the chattering behavior without increasing the complexity. Simulation
results show the robustness and effectiveness of the proposed
scheme.
Abstract: Environmental and functional conditions, sometimes,
necessitate the architectural plan of the building to be asymmetric,
and this result in an asymmetric structure. In such cases finding an
optimal pattern for locating the components of lateral load bearing
system, including shear walls, in the building’s plan is desired. In
case of shear wall in addition to the location the shape of the wall
cross-section is also an effective factor. Various types of shear walls
and their proper layout might come effective in better stiffness
distribution and more appropriate seismic response of the building.
Several studies have been conducted in the context of analysis and
design of shear walls; however, few studies have been performed on
making decisions for the location and form of shear walls in multistory
buildings, especially those with irregular plan. In this study, an
attempt has been made to obtain the most reliable seismic behavior of
multi-story reinforced concrete vertically chamfered buildings by
using more appropriate shear walls form and arrangement in 7-, 10-,
12-, and 15-stoy buildings. The considered forms and arrangements
include common rectangular walls and L-, T-, U- and Z-shaped plan,
located as the core or in the outer frames of the building structure.
Comparison of seismic behaviors of the buildings, including
maximum roof displacement and particularly formation of plastic
hinges and their distribution in the buildings’ structures, have been
done based on the results of a series of nonlinear time history
analyses, by using a set of selected earthquake records. Results show
that shear walls with U-shaped cross-section, placed as the building
central core, and also walls with Z-shaped cross-section, placed at the
corners give the building more reliable seismic behavior.
Abstract: This paper illustrates the background of various
concepts, approaches, terminologies used to describe the basic
framework of an Islamic Hotel Room design. This paper reviews the
theoretical views in establishing a suitable and optimum environment
for Muslim as well as non-Muslim guests in hotel rooms while
according to shariah. It involves a few research methodologies that
requires the researcher to study on a few characteristics needed to
create more efficient rooms in terms of social interaction, economic
growth and other tolerable elements. This paper intends on revealing
the elements that are vital and may contribute for hotels in achieving
a more conclusive research on space planning for hotel rooms
focusing on the shariah and Muslim guests. Malaysia is an Islamic
country and has billion of tourists coming over for business and
recreational purposes. Therefore, having a righteous environment that
best suit this target user is important in terms of generating the
economy as well as providing a better understanding to the
community on the benefits of applying these qualities in a
conventional resort design.
Abstract: Inference plays an important role in the learning
process and it can lead to a rapid acquisition of a second language.
When learning a non-native language i.e., a critical language like
Arabic, the students depend on the teacher’s support most of the time
to learn new concepts. The students focus on memorizing the new
vocabulary and stress on learning all the grammatical rules. Hence,
the students became mechanical and cannot produce the language
easily. As a result, they are unable to predicate the meaning of words
in the context by relying heavily on the teacher, in that they cannot
link their prior knowledge or even identify the meaning of the words
without the support of the teacher. This study explores how the
teacher guides students learning during the inference process and
what are the processes of learning that can direct student’s inference.
Abstract: This research studies the joint production,
maintenance and subcontracting control policy for an unreliable
deteriorating manufacturing system. Production activities are
controlled by a derivation of the Hedging Point Policy, and given that
the system is subject to deterioration, it reduces progressively its
capacity to satisfy product demand. Multiple deterioration effects are
considered, reflected mainly in the quality of the parts produced and
the reliability of the machine. Subcontracting is available as support
to satisfy product demand; also, overhaul maintenance can be
conducted to reduce the effects of deterioration. The main objective
of the research is to determine simultaneously the production,
maintenance and subcontracting rate, which minimize the total,
incurred cost. A stochastic dynamic programming model is
developed and solved through a simulation-based approach
composed of statistical analysis and optimization with the response
surface methodology. The obtained results highlight the strong
interactions between production, deterioration and quality, which
justify the development of an integrated model. A numerical example
and a sensitivity analysis are presented to validate our results.
Abstract: Plate is one of the popular structural elements used in a wide range of industries and structures. They may be subjected to blast loads during explosion events, missile attacks or aircraft attacks. This study is to investigate dynamic responses of the rectangular plate subjected to explosive loads. The effects of material properties and plate thickness on responses of the plate are to be investigated. The compressive pressure is applied to the surface of the plate. Different amounts of thickness in the range from 1mm to 30mm are considered for the plate to evaluate the changes in responses of the plate with respect to plate thickness. Two different properties are considered for the steel. First, the analysis is performed by considering only the elastic-plastic properties for the steel plate. Later on damping is considered to investigate its effects on the responses of the plate. To do analysis, numerical method using a finite element based package ABAQUS is applied. Finally, dynamic responses and graphs showing the relation between maximum displacement of the plate and aim parameters are provided.
Abstract: A teeming set of doctors that graduated from various
universities within and outside Nigeria with the hope of practicing in
the country, has their hope shattered because of poor financing, lack
of medical equipments and a very weak healthcare systems. Such
hydra headed challenges, allows room for quackery which
increasingly contributes to the cause of mortality in Nigeria. With a
view of reversing the challenges of healthcare delivery and financing
in Nigeria, African Health Market for Equity (AHME), a project
funded by the Bill and Melinda Gates foundation [With contribution
from Department For International Development (DFID)] and
currently implemented in three African Countries (Nigeria, Kenya
and Ghana) over a Five (5) year period supports the healthcare sector
via Medical credit fund (MCF). The study examines the impact of
credit policy and medical credit funding on Nigerian health market.
Ordinary least square analysis, correlation and granger causality tests
were employed to measure the extent to which the Nigerian
healthcare market has been influenced. Medical credit fund
significantly and positively influenced average monthly turnover of
private healthcare providers and Commercial bank’s lending rate had
a weak relationship with access to credit/approved loans (13.46%).
The programme has so far made 13.91% progress, which is very
poor, considering the minimum targeted private health care providers
(437.6) and expected number of loan approvals (180.4) for the two
years. Medical credit policy in Nigeria should be revised to include
private healthcare providers in rural area for more positive impact
and increased returns. Good brand advert and sensitization of the
programme to stakeholders and health pressure group, and an
extension of the programme beyond five years is necessary to better
address the issues raised in the study.
Abstract: A repairable mechanical system (as agricultural
tractor) is subject to deterioration or repeated failure and needs a
repair shops and also operator’s capability for the repair and
maintenance operations. Data are based on field visits and interviews
with 48MF 285 tractor operators from 14 villages collected in north
of Khouzestan province. The results showed that most operators were
lack the technical skill to service and repair tractors due to
insufficient training, specific education and work experience.
Inadequate repair and maintenance facilities, such as workshops,
mechanics and spare parts depots cause delays in repair work in the
survey areas. Farmers do not keep accurate service records and most
of them disregard proper maintenance and service of their tractors,
such as changing engine oil without following the manufacturer’s
recommendations. Since, Repair and maintenance facilities should be
established in village areas to guarantee timely repair in case of
breakdowns and to make spare parts available at low price. The
operators should keep service records accurately and adhere to
maintenance and service schedules according to the manufacturer’s
instructions. They should also be encouraged to do the service and
maintain their tractors properly.
Abstract: Review of studies carried out on the use of bagasse
ash for the improvement of deficient soils in Nigeria, with emphasis
on lateritic and black cotton soils is presented. Although, the bagasse
ash is mostly used as additive to the conventional soil stabilizers
(cement and lime), the studies generally showed improvement in the
geotechnical properties of the soils, either modified or stabilized with
the ash. This showed the potentials of using this agricultural waste
(bagasse ash) in the improvement of geotechnical properties of
deficient soils, thus suggesting that using this material at large scale
level in geotechnical engineering practice could help in the provision
of stable and durable structures, reduce cost of soil improvement and
also reduces environmental nuisance caused by the unused waste in
Nigeria.
Abstract: Multiphase Induction Machine (IM) is normally
controlled using rotor field oriented vector control. Under phase(s)
loss, the machine currents can be optimally controlled to satisfy
certain optimization criteria. In this paper we discuss the performance
of double manifold sliding mode observer (DM-SMO) in Sensorless
control of multiphase induction machine under unsymmetrical
condition (one phase loss). This observer is developed using the IM
model in the stationary reference frame. DM-SMO is constructed by
adding extra feedback term to conventional single mode sliding mode
observer (SM-SMO) which proposed in many literature. This leads to
a fully convergent observer that also yields an accurate estimate of
the speed and stator currents. It will be shown by the simulation
results that the estimated speed and currents by the method are very
well and error between real and estimated quantities is negligible.
Also parameter sensitivity analysis shows that this method is rather
robust against parameter variation.
Abstract: Chitosan polyacrylic acid composite membranes were
prepared by a bulk polymerization method in presence of N, N'-
methylene bisacrylamide (crosslinker) and ammonium persulphate as
initiator. Membranes prepared from this copolymer in presence and
absence of Ag nanoparticles were characterized by measuring
mechanical and physical properties, water up-take and antibacterial
properties. The results obtained indicated that the prepared
membranes have antibacterial properties which increase with adding
Ag nanoparticles.
Abstract: Salinity is one of the major factors limiting crop
production in an arid environment. Despite its global importance
soybean production suffer the problems of salinity stress causing
damages at plant development. So it is implacable to either search for
salinity enhancement of soybean plants. Therefore, in the current
study we try to clarify the mechanism that might be involved in the
ameliorating effects of osmo-protectants such as proline and glycine
betaine as well as, compost application on soybean plants grown
under salinity stress. The experiment was conducted under
greenhouse conditions at the Graduate School of Biosphere Science
Laboratory of Hiroshima University, Japan in 2011. The experiment
was designed as a spilt-split plot based on randomized complete
block design with four replications. The treatments could be
summarized as follows; (i) salinity concentrations (0 and 15 mM), (ii)
compost treatments (0 and 24 t ha-1) and (iii) the exogenous, proline
and glycine betaine concentrations (0 mM and 25 mM) for each.
Results indicated that salinity stress induced reduction in growth and
physiological aspects (dry weight per plant, chlorophyll content, N
and K+ content) of soybean plant compared with those of the
unstressed plants. On the other hand, salinity stress led to increases in
the electrolyte leakage ratio, Na and proline contents. Special
attention was paid to, the tolerance against salt stress was observed,
the improvement of salt tolerance resulted from proline, glycine
betaine and compost were accompanied with improved K+, and
proline accumulation. While, significantly decreased electrolyte
leakage ratio and Na+ content. These results clearly demonstrate that
harmful effect of salinity could reduce on growth aspects of soybean.
Consequently, exogenous osmoprotectants combine with compost
will effectively solve seasonal salinity stress problem and are a good
strategy to increase salinity resistance of soybean in the drylands.
Abstract: The current study aims to highlight the loading
characteristics impact on the time evolution (focusing particularly on
long term effects) of the deformation of realized reinforced concrete
beams. Namely the tension stiffening code provisions (i.e. within
Eurocode 2) are reviewed with a clear intention to reassess their
operational value and predicting capacity. In what follows the
experimental programme adopted along with some preliminary
findings and numerical modeling attempts are presented. For a range of long slender reinforced concrete simply supported
beams (4200 mm) constant static sustained and repeated cyclic
loadings were applied mapping the time evolution of deformation.
All experiments were carried out at the Heavy Structures Lab of the
University of Leeds. During tests the mid-span deflection, creep
coefficient and shrinkage strains were monitored for duration of 90
days. The obtained results are set against the values predicted by
Eurocode 2 and the tools within an FE commercial package (i.e.
Midas FEA) to yield that existing knowledge and practise is at times
over-conservative.
Abstract: In this study, failure analysis of pipe system at a micro
hydroelectric power plant is investigated. Failure occurred at the pipe
system in the powerhouse during shut down operation of the water
flow by a valve. This locking had caused a sudden shock wave, also
called “Water-hammer effect”, resulting in noise and inside pressure
increase. After visual investigation of the effect of the shock wave on
the system, a circumference crack was observed at the pipe flange
weld region. To establish the reason for crack formation, calculations
of pressure and stress values at pipe, flange and welding seams were
carried out and concluded that safety factor was high (2.2), indicating
that no faulty design existed. By further analysis, pipe system and
hydroelectric power plant was examined. After observations it is
determined that the plant did not include a ventilation nozzle (air
trap), that prevents the system of sudden pressure increase inside the
pipes which is caused by water-hammer effect. Analyses were carried
out to identify the influence of water-hammer effect on inside
pressure increase and it was concluded that, according Jowkowsky’s
equation, shut down time is effective on inside pressure increase. The
valve closing time was uncertain but by a shut down time of even one
minute, inside pressure would increase by 7.6 bar (working pressure
was 34.6 bar). Detailed investigations were also carried out on the
assembly of the pipe-flange system by considering technical
drawings. It was concluded that the pipe-flange system was not
installed according to the instructions. Two of five weld seams were
not applied and one weld was carried out faulty. This incorrect and
inadequate weld seams resulted in; insufficient connection of the pipe
to the flange constituting a strong notch effect at weld seam regions,
increase in stress values and the decrease of strength and safety
factor.
Abstract: Nitrification is essential to biological processes
designed to remove ammonia and/or total nitrogen. It removes excess
nitrogenous compound in wastewater which could be very toxic to
the aquatic fauna or cause serious imbalance of such aquatic
ecosystem. Efficient nitrification is linked to an in-depth knowledge
of the structure and dynamics of the nitrifying community structure
within the wastewater treatment systems. In this study, molecular
technique was employed for characterizing the microbial structure of
activated sludge [ammonia oxidizing bacteria (AOB) and nitrite
oxidizing bacteria (NOB)] in a municipal wastewater treatment with
intention of linking it to the plant efficiency. PCR based phylogenetic
analysis was also carried out. The average operating and
environmental parameters as well as specific nitrification rate of plant
was investigated during the study. During the investigation the average temperature was 23±1.5oC.
Other operational parameters such as mixed liquor suspended solids
and chemical oxygen demand inversely correlated with ammonia
removal. The dissolved oxygen level in the plant was constantly
lower than the optimum (between 0.24 and 1.267 mg/l) during this
study. The plant was treating wastewater with influent ammonia
concentration of 31.69 and 24.47 mg/L. The influent flow rates
(ML/Day) was 96.81 during period. The dominant nitrifiers include:
Nitrosomonas spp. Nitrobacter spp. and Nitrospira spp. The AOB
had correlation with nitrification efficiency and temperature. This
study shows that the specific ammonia oxidizing rate and the specific
nitrate formation rates can serve as good indicator of the plant overall
nitrification performance.
Abstract: This paper discusses the general methods to saturation
in the steady-state, two axis (d & q) frame models of synchronous
machines. In particular, the important role of the magnetic coupling
between the d-q axes (cross-magnetizing phenomenon), is
demonstrated. For that purpose, distinct methods of saturation
modeling of dumper synchronous machine with cross-saturation are
identified, and detailed models synthesis in d-q axes. A number of
models are given in the final developed form. The procedure and the
novel models are verified by a critical application to prove the
validity of the method and the equivalence between all developed
models is reported. Advantages of some of the models over the
existing ones and their applicability are discussed.
Abstract: There are a number of Distributed Generations (DGs)
installed in microgrid, which may have diverse path and direction of
power flow or fault current. The overcurrent protection scheme for the
traditional radial type distribution system will no longer meet the
needs of microgrid protection. Integrating the Intelligent Electronic
Device (IED) and a Supervisory Control and Data Acquisition
(SCADA) with IEC 61850 communication protocol, the paper
proposes a Microgrid Protection Management System (MPMS) to
protect power system from the fault. In the proposed method, the
MPMS performs logic programming of each IED to coordinate their
tripping sequence. The GOOSE message defined in IEC 61850 is used
as the transmission information medium among IEDs. Moreover, to
cope with the difference in fault current of microgrid between
grid-connected mode and islanded mode, the proposed MPMS applies
the group setting feature of IED to protect system and robust
adaptability. Once the microgrid topology varies, the MPMS will
recalculate the fault current and update the group setting of IED.
Provided there is a fault, IEDs will isolate the fault at once. Finally, the
Matlab/Simulink and Elipse Power Studio software are used to
simulate and demonstrate the feasibility of the proposed method.
Abstract: This study presents a hybrid metaheuristic algorithm
to obtain optimum designs for steel space buildings. The optimum
design problem of three-dimensional steel frames is mathematically
formulated according to provisions of LRFD-AISC (Load and
Resistance factor design of American Institute of Steel Construction).
Design constraints such as the strength requirements of structural
members, the displacement limitations, the inter-story drift and the
other structural constraints are derived from LRFD-AISC
specification. In this study, a hybrid algorithm by using teachinglearning
based optimization (TLBO) and harmony search (HS)
algorithms is employed to solve the stated optimum design problem.
These algorithms are two of the recent additions to metaheuristic
techniques of numerical optimization and have been an efficient tool
for solving discrete programming problems. Using these two
algorithms in collaboration creates a more powerful tool and
mitigates each other’s weaknesses. To demonstrate the powerful
performance of presented hybrid algorithm, the optimum design of a
large scale steel building is presented and the results are compared to
the previously obtained results available in the literature.
Abstract: Although there has been a growing interest in the
hybrid free-space optical link and radio frequency FSO/RF
communication system, the current literature is limited to results
obtained in moderate or cold environment. In this paper, using a soft
switching approach, we investigate the effect of weather
inhomogeneities on the strength of turbulence hence the channel
refractive index under Qatar harsh environment and their influence
on the hybrid FSO/RF availability. In this approach, either FSO/RF
or simultaneous or none of them can be active. Based on soft
switching approach and a finite state Markov Chain (FSMC) process,
we model the channel fading for the two links and derive a
mathematical expression for the outage probability of the hybrid
system. Then, we evaluate the behavior of the hybrid FSO/RF under
hazy and harsh weather. Results show that the FSO/RF soft switching
renders the system outage probability less than that of each link
individually. A soft switching algorithm is being implemented on
FPGAs using Raptor code interfaced to the two terminals of a
1Gbps/100 Mbps FSO/RF hybrid system, the first being implemented
in the region. Experimental results are compared to the above
simulation results.