Abstract: In this paper, a few chattering-free Sliding Mode Controllers (SMC) are proposed to stabilize an Active Magnetic Bearing (AMB) system with gyroscopic effect that is proportional to the rotor speed. The improved switching terms of the controller inherited from the saturation-type function and boundary layer control technique is shown to be able to achieve bounded and asymptotic stability, respectively, while the chattering effect in the input is attenuated. This is proven to be advantageous for AMB system since minimization of chattering results in optimized control effort. The performance of each controller is demonstrated via result of simulation in which the measurement of the total consumed energy and maximum control magnitude of each controller illustrates the effectiveness of the proposed controllers.
Abstract: Highly ordered TiO2 nanotube (TNT) arrays were
fabricated onto a pre-treated titanium foil by anodic oxidation with a
voltage of 20V in phosphoric acid/sodium fluoride electrolyte. A pretreatment
of titanium foil involved washing with acetone,
isopropanol, ethanol and deionized water. Carbon doped TiO2
nanotubes (C-TNT) was fabricated 'in-situ' with the same method in
the presence of polyvinyl alcohol and urea as carbon sources. The
affects of polyvinyl alcohol concentration and oxidation time on the
composition, morphology and structure of the C-TN were studied by
FE-SEM, EDX and XRD techniques. FESEM images of the
nanotubes showed uniform arrays of C-TNTs. The density and
microstructures of the nanotubes were greatly affected by the content
of PVA. The introduction of the polyvinyl alcohol into the electrolyte
increases the amount of C content inside TiO2 nanotube arrays
uniformly. The influence of carbon content on the photo-current of
C-TNT was investigated and the I-V profiles of the nanotubes were
established. The preliminary results indicated that the 'in-situ'
doping technique produced a superior quality nanotubes compared to
post doping techniques.
Abstract: The affect of the attendance percentage, the overall
GPA and the number of credit hours the student is enrolled in at
specific semester on the grade attained in specific course has been
studied. This study has been performed on three courses offered in
industrial engineering department at the Hashemite University in
Jordan. Study has revealed that the grade attained by a student is
strongly affected by the attendance percentage and his overall GPA
with a value of R2 of 52.5%. Another model that has been
investigated is the relation between the semester GPA and the
attendance percentage, the number of credit hours enrolled in at
specific semester, and the overall GPA. This model gave us a strong
relationship between the semester GPA and attendance percentage
and the overall GPA with a value of R2 of 76.2%.
Abstract: Cement stabilization has been widely used for
improving the strength and stiffness of soft clayey soils. Cement
treated soil specimens used to investigate the stress-strain behaviour in
the laboratory study are usually cured for 7 days. This paper examines
the effects of curing time on the strength and stress strain behaviour of
cement treated marine clay under triaxial loading condition.
Laboratory-prepared cement treated Singapore marine clay with
different mix proportion S-C-W (soil solid-cement solid-water) and
curing time (7 days to 180 days) was investigated through conducting
unconfined compressive strength test and triaxial test. The results
show that the curing time has a significant effect on the unconfined
compressive strength u q , isotropic compression behaviour and stress
strain behaviour. Although the primary yield loci of the cement treated
soil specimens with the same mix proportion expand with curing time,
they are very narrowly banded and have nearly the same shape after
being normalized by isotropic compression primary stress '
py p . The
isotropic compression primary yield stress '
py p was shown to be
linearly related to unconfined compressive strength u q for specimens
with different curing time and mix proportion. The effect of curing
time on the hardening behaviour will diminish with consolidation
stress higher than isotropic compression primary yield stress but its
damping rate is dependent on the cement content.
Abstract: This study was conducted in order to determine the physical properties and stability of mayonnaise-like emulsions as affected by modified yam starches. Native yam starch was modified via pre-gelatinization and cross-linking phosphorylation procedures. The emulsions (50% oil dispersed phase) were prepared with 0.3% native potato, native yam, pre-gelatinized yam and cross-linking phosphorylation yam starches. The droplet size of surface weighted mean diameter was found to be significantly (p < 0.05) lower in the sample with cross-linking phosphorylation yam starch as compared to other samples. Moreover, the viscosity of the sample with pregelatinized yam starch was observed to be higher than that of other samples. The phase separation stability was low in the freshly prepared and stored (45 days, 5°C) emulsions containing native yam starch. This study thus generally suggested that modified yam starches were more suitable (i.e. better physical properties and stability) to be used as stabilizers in a similar system i.e. light mayonnaises, rather than a native yam starch.
Abstract: Family structure that is culturally constructed in every
society is the basic unit of social structure. Purpose of the study was
to compare family structure, including marriage, residence, family
size, type, role sharing, authority, and communication patterns
between Muslim and Santal communities in rural Bangladesh. For
this we assumed that family structure with the elements was
significantly different between the two communities in rural
Bangladesh. In so doing, 288 active couples (145 for Muslim and 143
for Santal) selected by cluster random sampling were intensively
interviewed with a semi-structured questionnaire method. The results
of Pearson Chi-Squire Test reveal that there were significant
differences in the family structure followed by the two communities
in the study area. Further cross-cultural study should be done on why
family structure varies between the communities in Bangladesh.
Abstract: In modern era, the biggest challenge facing the
software industry is the upcoming of new technologies. So, the
software engineers are gearing up themselves to meet and manage
change in large software system. Also they find it difficult to deal
with software cognitive complexities. In the last few years many
metrics were proposed to measure the cognitive complexity of
software. This paper aims at a comprehensive survey of the metric of
software cognitive complexity. Some classic and efficient software
cognitive complexity metrics, such as Class Complexity (CC),
Weighted Class Complexity (WCC), Extended Weighted Class
Complexity (EWCC), Class Complexity due to Inheritance (CCI) and
Average Complexity of a program due to Inheritance (ACI), are
discussed and analyzed. The comparison and the relationship of these
metrics of software complexity are also presented.
Abstract: MicroRNAs (miRNAs) are small, non-coding and
regulatory RNAs about 20 to 24 nucleotides long. Their conserved
nature among the various organisms makes them a good source of
new miRNAs discovery by comparative genomics approach. The
study resulted in 21 miRNAs of 20 pre-miRNAs belonging to 16
families (miR156, 157, 158, 164, 165, 168, 169, 172, 319, 390, 393,
394, 395, 400, 472 and 861) in evergreen spruce tree (Picea). The
miRNA families; miR 157, 158, 164, 165, 168, 169, 319, 390, 393,
394, 400, 472 and 861 are reported for the first time in the Picea. All
20 miRNA precursors form stable minimum free energy stem-loop
structure as their orthologues form in Arabidopsis and the mature
miRNA reside in the stem portion of the stem loop structure. Sixteen
(16) miRNAs are from Picea glauca and five (5) belong to Picea
sitchensis. Their targets consist of transcription factors, growth
related, stressed related and hypothetical proteins.
Abstract: Spent Sulfidic Caustic was biologically treated and
regenerated for reusing by Thiobacillus denitrificans bacteria, sulfide
content oxidized and RSNa reduced dramatically.PH in this test was
11.8 and no neutralization has been done on spent caustic, so spent
caustic as the most difficult of industrial wastes to dispose could be
regenerate and reuse instead of disposing to sea or deep wells
Abstract: The triumph of inductive neuro-stimulation since its rediscovery in the 1980s has been quite spectacular. In lots of branches ranging from clinical applications to basic research this system is absolutely indispensable. Nevertheless, the basic knowledge about the processes underlying the stimulation effect is still very rough and rarely refined in a quantitative way. This seems to be not only an inexcusable blank spot in biophysics and for stimulation prediction, but also a fundamental hindrance for technological progress. The already very sophisticated devices have reached a stage where further optimization requires better strategies than provided by simple linear membrane models of integrate-and-fire style. Addressing this problem for the first time, we suggest in the following text a way for virtual quantitative analysis of a stimulation system. Concomitantly, this ansatz seems to provide a route towards a better understanding by using nonlinear signal processing and taking the nerve as a filter that is adapted for neuronal magnetic stimulation. The model is compact and easy to adjust. The whole setup behaved very robustly during all performed tests. Exemplarily a recent innovative stimulator design known as cTMS is analyzed and dimensioned with this approach in the following. The results show hitherto unforeseen potentials.
Abstract: As wireless sensor networks are energy constraint networks
so energy efficiency of sensor nodes is the main design issue.
Clustering of nodes is an energy efficient approach. It prolongs the
lifetime of wireless sensor networks by avoiding long distance communication.
Clustering algorithms operate in rounds. Performance of
clustering algorithm depends upon the round time. A large round
time consumes more energy of cluster heads while a small round
time causes frequent re-clustering. So existing clustering algorithms
apply a trade off to round time and calculate it from the initial
parameters of networks. But it is not appropriate to use initial
parameters based round time value throughout the network lifetime
because wireless sensor networks are dynamic in nature (nodes can be
added to the network or some nodes go out of energy). In this paper
a variable round time approach is proposed that calculates round
time depending upon the number of active nodes remaining in the
field. The proposed approach makes the clustering algorithm adaptive
to network dynamics. For simulation the approach is implemented
with LEACH in NS-2 and the results show that there is 6% increase
in network lifetime, 7% increase in 50% node death time and 5%
improvement over the data units gathered at the base station.
Abstract: The objective of this work is to study the influence of the properties of the substrate on the retrofit (thin repair) of damaged concrete elements, with the SCC. Fluidity, principal characteristic of the SCC, would enable it to cover and adhere to the concrete to be repaired. Two aspects of repair are considered, the bond (Adhesion) and the tensile strength and the cracking. The investigation is experimental; It was conducted over test specimens made up of ordinary concrete prepared and hardened in advance (the material to be repaired) over which a self compacting concrete layer is cast. Three alternatives of SC concrete and one ordinary concrete (comparison) were tested. It appears that the self-compacting concrete constitutes a good material for repairing. It follows perfectly the surfaces- forms to be repaired and allows a perfect bond. Fracture tests made on specimens of self-compacting concrete show a brittle behaviour. However when a small percentage of fibres is added, the resistance to cracking is very much improve.
Abstract: Deprivation indices are widely used in public health
study. These indices are also referred as the index of inequalities or
disadvantage. Even though, there are many indices that have been
built before, it is believed to be less appropriate to use the existing
indices to be applied in other countries or areas which had different
socio-economic conditions and different geographical characteristics.
The objective of this study is to construct the index based on the
geographical and socio-economic factors in Peninsular Malaysia
which is defined as the weighted household-based deprivation index.
This study has employed the variables based on household items,
household facilities, school attendance and education level obtained
from Malaysia 2000 census report. The factor analysis is used to
extract the latent variables from indicators, or reducing the
observable variable into smaller amount of components or factor.
Based on the factor analysis, two extracted factors were selected,
known as Basic Household Amenities and Middle-Class Household
Item factor. It is observed that the district with a lower index values
are located in the less developed states like Kelantan, Terengganu
and Kedah. Meanwhile, the areas with high index values are located
in developed states such as Pulau Pinang, W.P. Kuala Lumpur and
Selangor.
Abstract: Compensating physiological motion in the context
of minimally invasive cardiac surgery has become an attractive
issue since it outperforms traditional cardiac procedures offering
remarkable benefits. Owing to space restrictions, computer vision
techniques have proven to be the most practical and suitable solution.
However, the lack of robustness and efficiency of existing methods
make physiological motion compensation an open and challenging
problem. This work focusses on increasing robustness and efficiency
via exploration of the classes of 1−and 2−regularized optimization,
emphasizing the use of explicit regularization. Both approaches are
based on natural features of the heart using intensity information.
Results pointed out the 1−regularized optimization class as the best
since it offered the shortest computational cost, the smallest average
error and it proved to work even under complex deformations.
Abstract: e-Government is already in its second decade. Prerequisite for further development and adaptation to new realities is the optimal management of administrative information and knowledge production by those involved, i.e. the public sector, citizens and businesses. Nowadays, the amount of information displayed or distributed on the Internet has reached enormous dimensions, resulting in serious difficulties when extracting and managing knowledge. The semantic web is expected to play an important role in solving this problem and the technologies that support it. In this article, we address some relevant issues.
Abstract: This paper is based on a study conducted in 2006 to assess the impact of computer usage on health of National Institute for Medical Research (NIMR) staff. NIMR being a research Institute, most of its staff spend substantial part of their working time on computers. There was notion among NIMR staff on possible prolonged computer usage health hazards. Hence, a study was conducted to establish facts and possible mitigation measures. A total of 144 NIMR staff were involved in the study of whom 63.2% were males and 36.8% females aged between 20 and 59 years. All staff cadres were included in the sample. The functions performed by Institute staff using computers includes; data management, proposal development and report writing, research activities, secretarial duties, accounting and administrative duties, on-line information retrieval and online communication through e-mail services. The interviewed staff had been using computers for 1-8 hours a day and for a period ranging from 1 to 20 years. The study has indicated ergonomic hazards for a significant proportion of interviewees (63%) of various kinds ranging from backache to eyesight related problems. The authors highlighted major issues which are substantially applicable in preventing occurrences of computer related problems and they urged NIMR Management and/or the government of Tanzania opts to adapt their practicability.
Abstract: Gasoline Octane Number is the standard measure of
the anti-knock properties of a motor in platforming processes, that is
one of the important unit operations for oil refineries and can be
determined with online measurement or use CFR (Cooperative Fuel
Research) engines. Online measurements of the Octane number can
be done using direct octane number analyzers, that it is too
expensive, so we have to find feasible analyzer, like ANFIS
estimators.
ANFIS is the systems that neural network incorporated in fuzzy
systems, using data automatically by learning algorithms of NNs.
ANFIS constructs an input-output mapping based both on human
knowledge and on generated input-output data pairs.
In this research, 31 industrial data sets are used (21 data for training
and the rest of the data used for generalization). Results show that,
according to this simulation, hybrid method training algorithm in
ANFIS has good agreements between industrial data and simulated
results.
Abstract: Computer programming is considered a very difficult
course by many computer science students. The reasons for the
difficulties include cognitive load involved in programming,
different learning styles of students, instructional methodology and
the choice of the programming languages. To reduce the difficulties
the following have been tried: pair programming, program
visualization, different learning styles etc. However, these efforts
have produced limited success. This paper reviews the problem and
proposes a framework to help students overcome the difficulties
involved.
Abstract: The continued interest in the use of distributed generation in recent years is leading to the growth in number of distributed generators connected to distribution networks. Steady state voltage rise resulting from the connection of these generators can be a major obstacle to their connection at lower voltage levels. The present electric distribution network is designed to keep the customer voltage within tolerance limit. This may require a reduction in connectable generation capacity, under utilization of appropriate generation sites. Thus distribution network operators need a proper voltage regulation method to allow the significant integration of distributed generation systems to existing network. In this work a voltage rise problem in a typical distribution system has been studied. A method for voltage regulation of distribution system with multiple DG system by coordinated operation distributed generator, capacitor and OLTC has been developed. A sensitivity based analysis has been carried out to determine the priority for individual generators in multiple DG environment. The effectiveness of the developed method has been evaluated under various cases through simulation results.
Abstract: The study describes chitosan membrane platform
modified with nanostructure pattern which using nanotechnology to
fabricate. The cell-substrate interaction between neuro-2a neuroblasts
cell lines and chitosan membrane (flat, nanostructure and
nanostructure pattern types) was investigated. The adhered
morphology of neuro-2a cells depends on the topography of chitosan
surface. We have found that neuro-2a showed different morphogenesis
when cells adhered on flat and nanostructure chitosan membrane. The
cell projected area of neuro-2a on flat chitosan membrane is larger
than on nanostructure chitosan membrane. In addition, neuro-2a cells
preferred to adhere on flat chitosan surface region than on
nanostructure chitosan membrane to immobilize and differentiation.
The experiment suggests surface topography can be used as a critical
mechanism to isolate group of neuro-2a to a particular rectangle area
on chitosan membrane. Our finding will provide a platform to take
patch clamp to record electrophysiological behavior about neurons in
vitro in the future.