Abstract: Dynamic models of power converters are normally
time-varying because of their switching actions. Several approaches
are applied to analyze the power converters to achieve the timeinvariant
models suitable for system analysis and design via the
classical control theory. The paper presents how to derive dynamic
models of the power system consisting of a three-phase controlled
rectifier feeding an uncontrolled buck converter by using the
combination between the well known techniques called the DQ and
the generalized state-space averaging methods. The intensive timedomain
simulations of the exact topology model are used to support
the accuracies of the reported model. The results show that the
proposed model can provide good accuracies in both transient and
steady-state responses.
Abstract: This paper provides a new approach to solve the motion planning problems of flying robots in uncertain 3D dynamic environments. The robots controlled by this method can adaptively choose the fast way to avoid collision without information about the shapes and trajectories of obstacles. Based on sphere coordinates the new method accomplishes collision avoidance of flying robots without any other auxiliary positioning systems. The Self-protection System gives robots self-protection abilities to work in uncertain 3D dynamic environments. Simulations illustrate the validity of the proposed method.
Abstract: Yogurts are prepared by fermenting milk with bacterial cultures consisting of a mixture of Streptococcus ssp. thermophilus and Lactobacillus delbrueckii ssp. bulgaricus. The main aim of this investigation was to develop a majority goat yogurt, with the addition of sheep milk in order to have a final product with good physicochemical quality properties and sensorial attributes. Four types of yogurts were prepared presenting the following proportion of goat and sheep milk respectively: C100 – 100%; C80 – 80%/20%; C60 – 60%/40%; C50 – 50%/50%. The goat milk was from the Serrana Jarmelista breed and the sheep milk from the Serra da Estrela breed. The inclusion of sheep milk improved attractiveness to consumers, and it also improved the nutritional value of the product, mainly the fatty acid and mineral contents. The C50 yogurt was preferred by 28% of the panellists, followed by the C100 with 16% and the commercial cow yogurt was 40% of preferences.
Abstract: A mathematical model for the hydrodynamics of a
surface water treatment pilot plant was developed and validated by
the determination of the residence time distribution (RTD) for the
main equipments of the unit. The well known models of ideal/real
mixing, ideal displacement (plug flow) and (one-dimensional axial)
dispersion model were combined in order to identify the structure
that gives the best fitting of the experimental data for each equipment
of the pilot plant. RTD experimental results have shown that pilot
plant hydrodynamics can be quite well approximated by a
combination of simple mathematical models, structure which is
suitable for engineering applications. Validated hydrodynamic
models will be further used in the evaluation and selection of the
most suitable coagulation-flocculation reagents, optimum operating
conditions (injection point, reaction times, etc.), in order to improve
the quality of the drinking water.
Abstract: In this study, oxidative steam reforming of methanol (OSRM) over a Au/CeO2–Fe2O3 catalyst prepared by a depositionprecipitation (DP) method was studied to produce hydrogen in order to feed a Proton Exchange Membrane Fuel Cell (PEMFC). The support (CeO2, Fe2O3, and CeO2–Fe2O3) were prepared by precipitation and co-precipitation methods. The impact of the support composition on the catalytic performance was studied by varying the Ce/(Ce+Fe) atomic ratio, it was found that the 1%Au/CF(0.25) calcined at 300 °C exhibited the highest catalytic activity in the whole temperature studied. In addition, the effect of Au content was investigated and 3%Au/CF(0.25) exhibited the highest activity under the optimum condition in the temperature range of 200 °C to 400 °C. The catalysts were characterized by various techniques: XRD, TPR, XRF, and UV-vis.
Abstract: The study investigates the relationship between
education level, workplace learning behaviors, psychological
empowerment and burnout in a sample of 191 teachers. We
hypothesized that education level will positively affect psychological
state of increased empowerment and decreased burnout, and we
purposed that these effects will be mediated by workplace learning
behaviors. We used multiple regression analyses to test the model
that included also the 6 following control variables: The teachers'
age, gender, and teaching tenure; the schools' religious level, the
pupils' needs: regular/ special needs, and the class level: elementary/
high school. The results support the purposed mediating model.
Abstract: Postmenopausal osteoporosis is a disorder
characterized by the progressive bone loss induced by estrogen
deficiency in postmenopausal women. This imbalance affects
calcium–phosphate metabolism and results in secondary
hyperparathyroidism. Purariae Radix (PR), the root of P. lobata
(Wild.) Ohwi, is one of the earliest medicinal herbs employed in
ancient China. PR contains a high quantity of isoflavones and their
glycosides, which are regarded as phytoestrogen. Few investigations
of PR are related to its osteoprotective effects. The present study is
designed to administer PR water extract to ovariectomized (OVX)
female rats, for the investigation of its possibly protective actions on
bone and to delineate the potential mechanisms involved. Our results
demonstrated that long-term treatment of PR could not significantly
improve bone properties, whereas it greatly ameliorated the condition
of secondary hyperparathyroidism induced by ovariectomy in those
animals. PR might be useful as alternative regimen for protecting
against postmenopausal bone loss.
Abstract: The great majority of the electric installations belong
to the first and second category. In order to ensure a high level of
reliability of their electric system feeder, two power supply sources
are envisaged, one principal, the other of reserve, generally a cold
reserve (electric diesel group).
The principal source being under operation, its control can be ideal
and sure, however for the reserve source being in stop, a preventive
maintenance-s which proceeds on time intervals (periodicity) and
for well defined lengths of time are envisaged, so that this source will
always available in case of the principal source failure.
The choice of the periodicity of preventive maintenance of the
source of reserve influences directly the reliability of the electric
feeder system. On the basis of the semi-markovians processes, the
influence of the periodicity of the preventive maintenance of the
source of reserve is studied and is given the optimal periodicity.
Abstract: This is a genetic comparison study of Arabian Oryx
(Oryx leucoryx) population at two different locations (A &B) based
on nuclear microsatellite DNA markers. Arabian Oryx is listed as
vulnerable and endanger by the World Conservation Union (IUCN).
Thirty microsatellite markers from bovine family were applied to
investigate the genetic diversity of the Arabian Oryx and to set up a
molecular inventory. Among 30 microsatellite markers used, 13
markers were moderately polymorphic. Arabian Oryx at location A
has shown better gene diversity over location B. However, mean
number of alleles were less than location B. Data of within
population inbreeding coefficient indicates inbreeding at both
locations (A&B). Based on the analysis of polymorphic microsatellite
markers, the study revealed that Arabian Oryx need a genetically
designed breeding program.
Abstract: In this work, we present for the first time in our
perception an efficient digital watermarking scheme for mpeg audio
layer 3 files that operates directly in the compressed data domain,
while manipulating the time and subband/channel domain. In
addition, it does not need the original signal to detect the watermark.
Our scheme was implemented taking special care for the efficient
usage of the two limited resources of computer systems: time and
space. It offers to the industrial user the capability of watermark
embedding and detection in time immediately comparable to the real
music time of the original audio file that depends on the mpeg
compression, while the end user/audience does not face any artifacts
or delays hearing the watermarked audio file. Furthermore, it
overcomes the disadvantage of algorithms operating in the PCMData
domain to be vulnerable to compression/recompression attacks,
as it places the watermark in the scale factors domain and not in the
digitized sound audio data. The strength of our scheme, that allows it
to be used with success in both authentication and copyright
protection, relies on the fact that it gives to the users the enhanced
capability their ownership of the audio file not to be accomplished
simply by detecting the bit pattern that comprises the watermark
itself, but by showing that the legal owner knows a hard to compute
property of the watermark.
Abstract: Recent medical studies have investigated the importance of enteral feeding and the use of feeding pumps for recovering patients unable to feed themselves or gain nourishment and nutrients by natural means. The most of enteral feeding system uses a peristaltic tube pump. A peristaltic pump is a form of positive displacement pump in which a flexible tube is progressively squeezed externally to allow the resulting enclosed pillow of fluid to progress along it. The squeezing of the tube requires a precise and robust controller of the geared motor to overcome parametric uncertainty of the pumping system which generates due to a wide variation of friction and slip between tube and roller. So, this paper proposes fuzzy adaptive controller for the robust control of the peristaltic tube pump. This new adaptive controller uses a fuzzy multi-layered architecture which has several independent fuzzy controllers in parallel, each with different robust stability area. Out of several independent fuzzy controllers, the most suited one is selected by a system identifier which observes variations in the controlled system parameter. This paper proposes a design procedure which can be carried out mathematically and systematically from the model of a controlled system. Finally, the good control performance, accurate dose rate and robust system stability, of the developed feeding pump is confirmed through experimental and clinic testing.
Abstract: A social network is a set of people or organization or other social entities connected by some form of relationships. Analysis of social network broadly elaborates visual and mathematical representation of that relationship. Web can also be considered as a social network. This paper presents an innovative approach to analyze a social network using a variant of existing ant colony optimization algorithm called as Clever Ant Colony Metaphor. Experiments are performed and interesting findings and observations have been inferred based on the proposed model.
Abstract: Reactive powder concretes (RPC) are characterized by
particle diameter not exceeding 600 μm and having very high
compressive and tensile strengths. This paper describes a new
generation of micro concrete, which has an initial, as well as a final,
high physicomechanical performance. To achieve this, we replaced
the Portland cement (15% by weight) by materials rich in Silica (Slag
and Dune Sand).
The results obtained from tests carried out on RPC show that
compressive and tensile strengths increase when adding the additions,
thus improving the compactness of mixtures via filler and pozzolanic
effect.
With a reduction of the aggregate phase in the RPC and the
abundance of dune sand (south Algeria) and slag (industrial byproduct
of blast furnace), the use of the RPC will allow Algeria to
fulfil economical as well as ecological requirements.
Abstract: By taking advantage of both k-NN which is highly
accurate and K-means cluster which is able to reduce the time of classification, we can introduce Cluster-k-Nearest Neighbor as "variable k"-NN dealing with the centroid or mean point of all subclasses generated by clustering algorithm. In general the algorithm of K-means cluster is not stable, in term of accuracy, for that reason we develop another algorithm for clustering our space which gives a higher accuracy than K-means cluster, less
subclass number, stability and bounded time of classification with respect to the variable data size. We find between 96% and 99.7 % of accuracy in the lassification of 6 different types of Time series by using K-means cluster algorithm and we find 99.7% by using the new clustering algorithm.
Abstract: In this paper, we propose an advanced ILQ control for the buck-converter via two-degrees of freedom servo-system. Our presented strategy is based on Inverse Linear Quadratic (ILQ) servo-system controller without solving Riccati-s equation directly. The optimal controller of the current and voltage control system is designed. The stability and robust control are analyzed. A conscious and persistent effort has been made to improve ILQ control via two-degrees of freedom guarantees the optimal gains on the basis of polynomial pole assignment, which our results of the proposed strategy shows that the advanced ILQ control can be controlled independently the step response and the disturbance response by appending a feed-forward compensator.
Abstract: Ultrasound is useful in demonstrating bone mineral
density of regenerating osseous tissue as well as structural alterations.
A proposed ultrasound method, which included ultrasonography and
acoustic parameters measurement, was employed to evaluate its
efficacy in monitoring the bone callus changes in a rabbit tibial
distraction osteogenesis (DO) model.
The findings demonstrated that ultrasonographic images depicted
characteristic changes of the bone callus, typical of histology findings,
during the distraction phase. Follow-up acoustic parameters
measurement of the bone callus, including speed of sound, reflection
and attenuation, showed significant linear changes over time during
the distraction phase. The acoustic parameters obtained during the
distraction phase also showed moderate to strong correlation with
consolidated bone callus density and micro-architecture measured by
micro-computed tomography at the end of the consolidation phase.
The results support the preferred use of ultrasound imaging in the
early monitoring of bone callus changes during DO treatment.
Abstract: Command and Control (C2) system and its interfacethe
Common Operational Picture (COP) are main means that
supports commander in its decision making process. COP contains
information about friendly and enemy unit positions. The friendly
position is gathered via tactical network. In the case of tactical
network failure the information about units are not available. The
tactical simulator can be used as a tool that is capable to predict
movements of units in respect of terrain features. Article deals with
an experiment that was based on Czech C2 system that is in the case
of connectivity lost fed by VR Forces simulator. Article analyzes
maximum time interval in which the position created by simulator is
still usable and truthful for commander in real time.
Abstract: This paper presents functionality of negotiation agent
on value-based design decision. The functionality is based on the
characteristics of the system and goal specification. A Prometheus
Design Tool model was used for developing the system. Group
functionality will be the attribute for negotiation agents, which
comprises a coordinator agent and decision- maker agent. The results
of the testing of the system to a building system selection on valuebased
decision environment are also presented.
Abstract: To simulate expected climate change, we implemented a two-factor (temperature and soil moisture) field design in a forest in Ontario, Canada. To manipulate moisture input, we erected rain-exclusion structures. Under each structure, plots were watered with one of three treatments and thermally controlled with three heat treatments to simulate changes in air temperature and rainfall based on the climate model (GCM) predictions for the study area. Environmental conditions (including untreated controls) were monitored tracking air temperature, soil temperature, soil moisture, and photosynthetically active radiation. We measured rainfall and relative humidity at the site outside the rain-exclusion structures. Analyses of environmental conditions demonstrates that the temperature manipulation was most effective at maintaining target temperature during the early part of the growing season, but it was more difficult to keep the warmest treatment at 5º C above ambient by late summer. Target moisture regimes were generally achieved however incoming solar radiation was slightly attenuated by the structures.
Abstract: In the context of channel coding, the Generalized Belief Propagation (GBP) is an iterative algorithm used to recover the transmission bits sent through a noisy channel. To ensure a reliable transmission, we apply a map on the bits, that is called a code. This code induces artificial correlations between the bits to send, and it can be modeled by a graph whose nodes are the bits and the edges are the correlations. This graph, called Tanner graph, is used for most of the decoding algorithms like Belief Propagation or Gallager-B. The GBP is based on a non unic transformation of the Tanner graph into a so called region-graph. A clear advantage of the GBP over the other algorithms is the freedom in the construction of this graph. In this article, we explain a particular construction for specific graph topologies that involves relevant performance of the GBP. Moreover, we investigate the behavior of the GBP considered as a dynamic system in order to understand the way it evolves in terms of the time and in terms of the noise power of the channel. To this end we make use of classical measures and we introduce a new measure called the hyperspheres method that enables to know the size of the attractors.