Abstract: In this paper, backstepping method (BM) is proposed for a single-link flexible mechanical manipulator. In each step of this method a positive value is obtained. Selections of the gain factor values are very important because controller will have different behavior for each different set of values. Improper selection of these gains can lead to instability of the system. In order to choose proper values for gains BELBIC method has been used in this work. Finally, to prove the efficiency of this method, the obtained results of proposed model are compared with robust controller one. Results show that the combination of backstepping and BELBIC that is presented here, can stabilized the system with higher speed, shorter settling time and lower overshoot in than robust controller.
Abstract: A reconfigurable manufacturing system (RMS) is an
advanced system designed at the outset for rapid changes in its hardware
and software components in order to quickly adjust its production
capacity and functionally. Among various operational decisions, this
study considers the scheduling problem that determines the input
sequence and schedule at the same time for a given set of parts. In
particular, we consider the practical constraints that the numbers of
pallets/fixtures are limited and hence a part can be released into the
system only when the fixture required for the part is available. To
solve the integrated input sequencing and scheduling problems, we
suggest a priority rule based approach in which the two sub-problems
are solved using a combination of priority rules. To show the effectiveness
of various rule combinations, a simulation experiment was
done on the data for a real RMS, and the test results are reported.
Abstract: This paper focuses on a critical component of the situational awareness (SA), the control of autonomous vertical flight for vectored thrust aerial vehicle (VTAV). With the SA strategy, we proposed a flight control procedure to address the dynamics variation and performance requirement difference of flight trajectory for an unmanned helicopter model with vectored thrust configuration. This control strategy for chosen model of VTAV has been verified by simulation of take-off and forward maneuvers using software package Simulink and demonstrated good performance for fast stabilization of motors, consequently, fast SA with economy in energy can be asserted during search-and-rescue operations.
Abstract: MOSCAPs of various combinations of Hafnium
oxide and Titanium oxide of varying thickness with Aluminum as gate electrode have been fabricated and electrically characterized.
The effects of voltage stress on the I-V characteristics for prolonged time durations have been studied and compared. Results showed
hard breakdown and negligible degradation of reliability under stress.
Abstract: In this paper, the existence, multiplicity and
noexistence of positive solutions for a class of semipositone
discrete boundary value problems with two parameters is
studied by applying nonsmooth critical point theory and
sub-super solutions method.
Abstract: In this study, the static behavior of super elliptical Winkler plate is analyzed by applying the double side approach method. The lack of information about super elliptical Winkler plates is the motivation of this study and we use the double side approach method to solve this problem because of its superior ability on efficiently treating problems with complex boundary shape. The double side approach method has the advantages of high accuracy, easy calculation procedure and less calculation load required. Most important of all, it can give the error bound of the approximate solution. The numerical results not only show that the double side approach method works well on this problem but also provide us the knowledge of static behavior of super elliptical Winkler plate in practical use.
Abstract: In order to integrate knowledge in heterogeneous
case-based reasoning (CBR) systems, ontology-based CBR system
has become a hot topic. To solve the facing problems of
ontology-based CBR system, for example, its architecture is
nonstandard, reusing knowledge in legacy CBR is deficient, ontology
construction is difficult, etc, we propose a novel approach for
semi-automatically construct ontology-based CBR system whose
architecture is based on two-layer ontology. Domain knowledge
implied in legacy case bases can be mapped from relational database
schema and knowledge items to relevant OWL local ontology
automatically by a mapping algorithm with low time-complexity. By
concept clustering based on formal concept analysis, computing
concept equation measure and concept inclusion measure, some
suggestions about enriching or amending concept hierarchy of OWL
local ontologies are made automatically that can aid designers to
achieve semi-automatic construction of OWL domain ontology.
Validation of the approach is done by an application example.
Abstract: This paper presents a customized deformable model
for the segmentation of abdominal and thoracic aortic aneurysms in
CTA datasets. An important challenge in reliably detecting aortic
aneurysm is the need to overcome problems associated with intensity
inhomogeneities and image noise. Level sets are part of an important
class of methods that utilize partial differential equations (PDEs) and
have been extensively applied in image segmentation. A Gaussian
kernel function in the level set formulation, which extracts the local
intensity information, aids the suppression of noise in the extracted
regions of interest and then guides the motion of the evolving contour
for the detection of weak boundaries. The speed of curve evolution
has been significantly improved with a resulting decrease in
segmentation time compared with previous implementations of level
sets. The results indicate the method is more effective than other
approaches in coping with intensity inhomogeneities.
Abstract: Thermite welding is mainly used in world. The
reasons why the thermite welding method is widely used are
that the equipment has good mobility and total working time
of that is shorter than that of the enclosed arc welding method
on site. Moreover, the operating skill, which required for
thermite welding, is less than that of for enclosed arc welding.
In the present research work, heat treatment and combined
'expulsion and heat treatment' techniques were used improve
the mechanical properties and weldment structure. The
specimens were cut in the transverse direction from expulsion
with Heat treated and heat treated Thermite Welded rails.
Specimens were prepared according to AWS standard and
subjected to tensile test, Impact test and hardness and their
results were tabulated. Microstructural analysis was carried
out with the help of SEM. Then analyze to effect of heat
treated and 'expulsion with heat treated' with the properties of
their thermite welded rails. Compare the mechanical and
microstructural properties of thermite welded rails between
heat expulsion with heat treated and heat treated. Mechanical
and microstructural response expulsion with heat treated
thermite welded rail is higher value as compared to heat
treatment.
Abstract: Absorption spectra of infra-red (IR) radiation of the
disperse water medium absorbing the most important greenhouse
gases: CO2 , N2O , CH4 , C2H2 , C2H6 have been calculated by
the molecular dynamics method. Loss of the absorbing ability at the
formation of clusters due to a reduction of the number of centers
interacting with IR radiation, results in an anti-greenhouse effect.
Absorption of O3 molecules by the (H2O)50 cluster is investigated
at its interaction with Cl- ions. The splitting of ozone molecule on
atoms near to cluster surface was observed. Interaction of water
cluster with Cl- ions causes the increase of integrated intensity of
emission spectra of IR radiation, and also essential reduction of the
similar characteristic of Raman spectrum. Relative integrated
intensity of absorption of IR radiation for small water clusters was
designed. Dependences of the quantity of weight on altitude for
vapor of monomers, clusters, droplets, crystals and mass of all
moisture were determined. The anti-greenhouse effect of clusters was
defined as the difference of increases of average global temperature
of the Earth, caused by absorption of IR radiation by free water
molecules forming clusters, and absorption of clusters themselves.
The greenhouse effect caused by clusters makes 0.53 K, and the antigreenhouse
one is equal to 1.14 K. The increase of concentration of
CO2 in the atmosphere does not always correlate with the
amplification of greenhouse effect.
Abstract: For the improvement of the ability in detecting
small calcifications using Ultrasonography (US) we propose a
novel indicator of calcifications in an ultrasound B-mode image
without decrease in frame rate. Since the waveform of an
ultrasound pulse changes at a calcification position, the
decorrelation of adjacent scan lines occurs behind a
calcification. Therefore, we employ the decorrelation of
adjacent scan lines as an indicator of a calcification. The
proposed indicator depicted wires 0.05 mm in diameter at 2 cm
depth with a sensitivity of 86.7% and a specificity of 100%,
which were hardly detected in ultrasound B-mode images. This
study shows the potential of the proposed indicator to
approximate the detectable calcification size using an US
device to that of an X-ray imager, implying the possibility that
an US device will become a convenient, safe, and principal
clinical tool for the screening of breast cancer.
Abstract: the research was accomplished on fresh in Latvia wild
growing cranberries and cranberry cultivars. The aim of the study
was to evaluate effect of pretreatment method and drying conditions
on the volatile compounds composition in cranberries. Berries
pre-treatment methods were: perforation, halving and
steam-blanching. The berries before drying in a cabinet drier were
pre-treated using all three methods, in microwave vacuum
drier – using a steam-blanching and halving. Volatile compounds in
cranberries were analysed using GC-MS of extracts obtained by
SPME. During present research 21 various volatile compounds were
detected in fresh cranberries: the cultivar 'Steven' - 15, 'Bergman'
and 'Early black' – 13, 'Ben Lear' and 'Pilgrim' – 11 and wild
cranberries – 14 volatile compounds. In dried cranberries 20 volatile
compounds were detected. Mathematical data processing allows
drawing a conclusion that there exists the significant influence of
cranberry cultivar, pre-treatment method and drying condition on
volatile compounds in berries and new volatile compound formation.
Abstract: Different approaches for heating\cooling of stirred tanks, coils and jackets, are investigated using computational fluid dynamics (CFD).A time-dependant sliding mesh approach is applied to simulate the flow in both conditions. The investigations are carried out under the turbulent flow conditions for a Rushton impeller and heating elements are considered isothermal. The flow behavior and temperature distribution are studied for each case and heat transfer coefficient is calculated. Results show different velocity profiles for each case. Unsteady temperature distribution is not similar for different cases .In the case of the coiled stirred vessel more uniform temperature and higher heat transfer coefficient is resulted.
Abstract: Provision of optical devices without proper instruction
and training may cause frustration resulting in rejection or incorrect
use of the magnifiers. However training in the use of magnifiers
increases the cost of providing these devices. This study compared
the efficacy of providing instruction alone and instruction plus
training in the use of magnifiers. 24 participants randomly assigned
to two groups. 15 received instruction and training and 9 received
instruction only. Repeated measures of print size and reading speed
were performed at pre, post training and follow up. Print size
decreased in both groups between pre and post training maintained at
follow up. Reading speed increased in both groups over time with the
training group demonstrating more rapid improvement. Whilst
overall outcomes were similar, training decreased the time required
to increase reading speed supporting the use of training for increased
efficiency. A cost effective form of training is suggested.
Abstract: Thousands of masters athletes participate
quadrennially in the World Masters Games (WMG), yet this cohort
of athletes remains proportionately under-investigated. Due to a
growing global obesity pandemic in context of benefits of physical
activity across the lifespan, the prevalence of obesity in this unique
population was of particular interest. Data gathered on a sub-sample
of 535 football code athletes, aged 31-72 yrs ( =47.4, s =±7.1),
competing at the Sydney World Masters Games (2009) demonstrated
a significantly (p
Abstract: A gradient learning method to regulate the trajectories
of some nonlinear chaotic systems is proposed. The method is
motivated by the gradient descent learning algorithms for neural
networks. It is based on two systems: dynamic optimization system
and system for finding sensitivities. Numerical results of several
examples are presented, which convincingly illustrate the efficiency
of the method.
Abstract: When faced with stochastic networks with an uncertain
duration for their activities, the securing of network completion time
becomes problematical, not only because of the non-identical pdf of
duration for each node, but also because of the interdependence of
network paths. As evidenced by Adlakha & Kulkarni [1], many
methods and algorithms have been put forward in attempt to resolve
this issue, but most have encountered this same large-size network
problem. Therefore, in this research, we focus on network reduction
through a Series/Parallel combined mechanism. Our suggested
algorithm, named the Activity Network Reduction Algorithm
(ANRA), can efficiently transfer a large-size network into an S/P
Irreducible Network (SPIN). SPIN can enhance stochastic network
analysis, as well as serve as the judgment of symmetry for the Graph
Theory.
Abstract: Themain goal of this article is to find efficient
methods for elemental and molecular analysis of living
microorganisms (algae) under defined environmental conditions and
cultivation processes. The overall knowledge of chemical
composition is obtained utilizing laser-based techniques, Laser-
Induced Breakdown Spectroscopy (LIBS) for acquiring information
about elemental composition and Raman Spectroscopy for gaining
molecular information, respectively. Algal cells were suspended in
liquid media and characterized using their spectra. Results obtained
employing LIBS and Raman Spectroscopy techniques will help to
elucidate algae biology (nutrition dynamics depending on cultivation
conditions) and to identify algal strains, which have the potential for
applications in metal-ion absorption (bioremediation) and biofuel
industry. Moreover, bioremediation can be readily combined with
production of 3rd generation biofuels. In order to use algae for
efficient fuel production, the optimal cultivation parameters have to
be determinedleading to high production of oil in selected
cellswithout significant inhibition of the photosynthetic activity and
the culture growth rate, e.g. it is necessary to distinguish conditions
for algal strain containing high amount of higher unsaturated fatty
acids. Measurements employing LIBS and Raman Spectroscopy were
utilized in order to give information about alga Trachydiscusminutus
with emphasis on the amount of the lipid content inside the algal cell
and the ability of algae to withdraw nutrients from its environment
and bioremediation (elemental composition), respectively. This
article can serve as the reference for further efforts in describing
complete chemical composition of algal samples employing laserablation
techniques.
Abstract: A case study of the generation scheduling optimization
of the multi-hydroplants on the Yuan River Basin in China is reported
in this paper. Concerning the uncertainty of the inflows, the
long/mid-term generation scheduling (LMTGS) problem is solved by
a stochastic model in which the inflows are considered as stochastic
variables. For the short-term generation scheduling (STGS) problem, a
constraint violation priority is defined in case not all constraints are
satisfied. Provided the stage-wise separable condition and low
dimensions, the hydroplant-based operational region schedules
(HBORS) problem is solved by dynamic programming (DP). The
coordination of LMTGS and STGS is presented as well. The
feasibility and the effectiveness of the models and solution methods
are verified by the numerical results.