Abstract: In this paper we present a new multichannel high
voltage driver box to connect up to six MOEMS mirror devices to it that have resonant and also quasistatically driven actuating electrodes. It is possible to drive all resonant axes synchronously
while the amplitude of them can individually be controlled by separate microcontrollers that also operate the quasistatic axes.
Circuit simulations are compared with the measurements done on the
real system and also show the robust driving performance of a
MOEMS mirror.
Abstract: In this paper we propose a computational model for the representation and processing of morpho-phonological phenomena in a natural language, like Modern Greek. We aim at a unified treatment of inflection, compounding, and word-internal phonological changes, in a model that is used for both analysis and generation. After discussing certain difficulties cuase by well-known finitestate approaches, such as Koskenniemi-s two-level model [7] when applied to a computational treatment of compounding, we argue that a morphology-based model provides a more adequate account of word-internal phenomena. Contrary to the finite state approaches that cannot handle hierarchical word constituency in a satisfactory way, we propose a unification-based word grammar, as the nucleus of our strategy, which takes into consideration word representations that are based on affixation and [stem stem] or [stem word] compounds. In our formalism, feature-passing operations are formulated with the use of the unification device, and phonological rules modeling the correspondence between lexical and surface forms apply at morpheme boundaries. In the paper, examples from Modern Greek illustrate our approach. Morpheme structures, stress, and morphologically conditioned phoneme changes are analyzed and generated in a principled way.
Abstract: Inorganic nanoparticles filled polymer composites
have extended their multiple functionalities to various applications,
including mechanical reinforcement, gas barrier, dimensional
stability, heat distortion temperature, flame-retardant, and thermal
conductivity. Sodium stearate-modified calcium carbonate (CaCO3)
nanoparticles were prepared using surface modification method. The
results showed that sodium stearate attached to the surface of CaCO3
nanoparticles with the chemical bond. The effect of modified CaCO3
nanoparticles on thermal properties of polypropylene (PP) was
studied by means of differential scanning calorimetry (DSC) and
Thermogravimetric analysis (TGA). It was found that CaCO3
significantly affected the crystallization temperature and
crystallization degree of PP. Effect of the modified CaCO3 content on
mechanical properties of PP/CaCO3 nanocomposites was also
studied. The results showed that the modified CaCO3 can effectively
improve the mechanical properties of PP. In comparison with PP, the
impact strength of PP/CaCO3 nanocomposites increased by about
65% and the hardness increased by about 5%.
Abstract: In this paper, we apply and compare two generalized estimating equation approaches to the analysis of car breakdowns data in Mauritius. Number of breakdowns experienced by a machinery is a highly under-dispersed count random variable and its value can be attributed to the factors related to the mechanical input and output of that machinery. Analyzing such under-dispersed count observation as a function of the explanatory factors has been a challenging problem. In this paper, we aim at estimating the effects of various factors on the number of breakdowns experienced by a passenger car based on a study performed in Mauritius over a year. We remark that the number of passenger car breakdowns is highly under-dispersed. These data are therefore modelled and analyzed using Com-Poisson regression model. We use the two types of quasi-likelihood estimation approaches to estimate the parameters of the model: marginal and joint generalized quasi-likelihood estimating equation approaches. Under-dispersion parameter is estimated to be around 2.14 justifying the appropriateness of Com-Poisson distribution in modelling underdispersed count responses recorded in this study.
Abstract: To investigate the possible correlation between peer aggression and peer victimization, 148 sixth-graders were asked to respond to the Reduced Aggression and Victimization Scales (RAVS). RAVS measures the frequency of reporting aggressive behaviors or of being victimized during the previous week prior to the survey. The scales are composed of six items each. Each point represents one instance of aggression or victimization. Specifically, the Pearson Product-Moment Correlation Coefficient (PMCC) was used to determine the correlations between the scores of the sixthgraders in the two scales, both in individual items and total scores. Positive correlations were established and correlations were significant at the 0.01 levels.
Abstract: In this paper, we analyze the problem of quasiballistic electron transport in ultra small of mercury -cadmiumtelluride (Hg0.8Cd0.2Te -MCT) n+-n- n+ devices from hydrodynamic point view. From our study, we note that, when the size of the active layer is low than 0.1μm and for low bias application( ( ≥ 9mV), the quasi-ballistic transport has an important effect.
Abstract: Self-efficacy, self-reliance, and motivation were
examined in a quasi-experimental study with 178 sophomore
university students. Participants used an interactive cardiovascular
anatomy and physiology CD-ROM, and completed a 15-item
questionnaire. Reliability of the questionnaire was established using
Cronbach-s alpha. Post-tests and course grades were examined using
a t-test, demonstrating no significance. Results of an item-to-item
analysis of the questionnaire showed overall satisfaction with the
teaching methodology and varied results for self-efficacy, selfreliance,
and motivation. Kendall-s Tau was calculated for all items
in the questionnaire.
Abstract: In this paper we present the modeling, design, and
experimental testing of a nerve cuff multi-electrode system for
diameter-selective vagus nerve stimulation.
The multi-electrode system contained ninety-nine platinum
electrodes embedded within a self-curling spiral silicone sheet. The
electrodes were organized in a matrix having nine parallel groups,
each containing eleven electrodes.
Preliminary testing of the nerve cuff was performed in an isolated
segment of a swinish left cervical vagus nerve. For selective vagus
nerve stimulation, precisely defined current quasitrapezoidal,
asymmetric and biphasic stimulating pulses were applied to
preselected locations along the left vagus segment via appointed
group of three electrodes within the cuff. Selective stimulation was
obtained by anodal block. However, these pulses may not be safe for
a long-term application because of a frequently used high imbalance
between the cathodic and anodic part of the stimulating pulse.
Preliminary results show that the cuff was capable of exciting A
and B-fibres, and, that for a certain range of parameters used in
stimulating pulses, the contribution of A-fibres to the CAP was
slightly reduced and the contribution of B-fibres was slightly larger.
Results also showed that measured CAPs are not greatly
influenced by the imbalance between a charge Qc injected in cathodic
and Qa in anodic phase of quasitrapezoidal, asymmetric and biphasic
pulses.
Abstract: This study deals with the phenomena of reflection and transmission (refraction) of qSV-waves, for an incident of quasi transverse vertically waves, at a plane interface of two semi-infinite piezoelectric elastic media under the influence of the initial stresses. The relations governing the reflection and transmission coefficients of these reflected waves for various suitable boundary conditions are derived. We have shown analytically that reflection and transmission coefficients of (qP) and (qSV) waves depend upon the angle of incidence, the parameters of electric potential, the material constants of the medium as will as the initial stresses presented in the media. The numerical calculations of the reflection and transmission amplitude ratios for different values of initial stresses have been carried out by computer for different materials as examples and the results are given in the form of graphs. Finally, some of particular cases are considered.
Abstract: This paper deals with analysis of flexural stiffness,
indentation and their energies in three point loading of sandwich
beams with composite faces from Eglass/epoxy and cores from
Polyurethane or PVC. Energy is consumed in three stages of
indentation in laminated beam, indentation of sandwich beam and
bending of sandwich beam. Theory of elasticity is chosen to present
equations for indentation of laminated beam, then these equations
have been corrected to offer better results. An analytical model has
been used assuming an elastic-perfectly plastic compressive behavior
of the foam core. Classical theory of beam is used to describe three
point bending. Finite element (FE) analysis of static indentation
sandwich beams is performed using the FE code ABAQUS. The
foam core is modeled using the crushable foam material model and
response of the foam core is experimentally characterized in uniaxial
compression.
Three point bending and indentation have been done
experimentally in two cases of low velocity and higher velocity
(quasi-impact) of loading. Results can describe response of beam in
terms of core and faces thicknesses, core material, indentor diameter,
energy absorbed, and length of plastic area in the testing. The
experimental results are in good agreement with the analytical and
FE analyses. These results can be used as an introduction for impact
loading and energy absorbing of sandwich structures.
Abstract: Most of the nonlinear equation solvers do not converge always or they use the derivatives of the function to approximate the
root of such equations. Here, we give a derivative-free algorithm that guarantees the convergence. The proposed two-step method, which
is to some extent like the secant method, is accompanied with some
numerical examples. The illustrative instances manifest that the rate of convergence in proposed algorithm is more than the quadratically
iterative schemes.
Abstract: In this paper, transversal vibration of buried pipelines
during loading induced by underground explosions is analyzed. The
pipeline is modeled as an infinite beam on an elastic foundation, so
that soil-structure interaction is considered by means of transverse
linear springs along the pipeline. The pipeline behavior is assumed to
be ideal elasto-plastic which an ultimate strain value limits the plastic
behavior. The blast loading is considered as a point load, considering
the affected length at some point of the pipeline, in which the
magnitude decreases exponentially with time. A closed-form solution
for the quasi-static problem is carried out for both elastic and elasticperfect
plastic behaviors of pipe materials. At the end, a comparative
study on steel and polyethylene pipes with different sizes buried in
various soil conditions, affected by a predefined underground
explosion is conducted, in which effect of each parameter is
discussed.
Abstract: In the paper, the performance of quasi-synchronous
CDMA (QS-CDMA) system, which can allow an increased timing
error in synchronized access, is discussed. Average BER performance
of the system is analyzed in the condition of different access timing
error and different asynchronous users by simulation in AWGN
channel. The results show that QS-CDMA system is shown to have
great performance gain over the asynchronous system when access
timing error is within a few chips and asynchronous users is tolerable.
However, with access timing error increasing and asynchronous users
increasing, the performance of QS-CDMA will degrade. Also, we can
determine the number of tolerable asynchronous users for different
access timing error by simulation figures.
Abstract: The subcellular organelles called oil bodies (OBs) are lipid-filled quasi-spherical droplets produced from the endoplasmic reticulum (ER) and then released into the cytoplasm during seed development. It is believed that an OB grows by coalescence with other OBs and that its stability depends on the composition of oleosins, major proteins inserted in the hemi membrane that covers OBs. In this study, we measured the OB-volume distribution from different genotypes of A. thaliana after 7, 8, 9, 10 and 11 days of seed development. In order to test the hypothesis of OBs dynamics, we developed a simple mathematical model using non-linear differential equations inspired from the theory of coagulation. The model describes the evolution of OB-volume distribution during the first steps of seed development by taking into consideration the production of OBs, the increase of triacylglycerol volume to be stored, and the growth by coalescence of OBs. Fitted parameters values show an increase in the OB production and coalescence rates in A. thaliana oleosin mutants compared to wild type.
Abstract: Number of breakdowns experienced by a machinery is a highly under-dispersed count random variable and its value can be attributed to the factors related to the mechanical input and output of that machinery. Analyzing such under-dispersed count observations as a function of the explanatory factors has been a challenging problem. In this paper, we aim at estimating the effects of various factors on the number of breakdowns experienced by a passenger car based on a study performed in Mauritius over a year. We remark that the number of passenger car breakdowns is highly under-dispersed. These data are therefore modelled and analyzed using Com-Poisson regression model. We use quasi-likelihood estimation approach to estimate the parameters of the model. Under-dispersion parameter is estimated to be 2.14 justifying the appropriateness of Com-Poisson distribution in modelling under-dispersed count responses recorded in this study.
Abstract: Multimedia courseware has been accepted as a tool
that can support teaching and learning process. 'Li2D' courseware
was developed to assist student-s visualization on the topic of Loci in
Two Dimension. This paper describes an evaluation on the
effectiveness and usability of a 'Li2D' courseware. The quasi
experiment was used for the effectiveness evaluation. Usability
evaluation was accomplished based on four constructs of usability,
namely: efficiency, learnability, screen design and satisfaction. An
evaluation on the multimedia elements was also conducted. A total of
63 students of Form Two are involved in the study. The students are
divided into two groups: control and experimental. The experimental
group had to interact with 'Li2D' courseware as part of the learning
activities while the control group used the conventional learning
methods. The results indicate that the experimental group performed
better than the control group in understanding the Loci in Two
Dimensions topic. In terms of usability, the results showed that the
students agreed on the usability in multimedia elements in the 'Li2D'
courseware.
Abstract: The process for predicting the ballistic properties of a liquid rocket engine is based on the quantitative estimation of idealized performance deviations. In this aim, an equilibrium chemistry procedure is firstly developed and implemented in a Fortran routine. The thermodynamic formulation allows for the calculation of the theoretical performances of a rocket thrust chamber. In a second step, a computational fluid dynamic analysis of the turbulent reactive flow within the chamber is performed using a finite volume approach. The obtained values for the “quasi-real" performances account for both turbulent mixing and chemistryturbulence coupling. In the present work, emphasis is made on the combustion efficiency performance for which deviation is mainly due to radial gradients of static temperature and mixture ratio. Numerical values of the characteristic velocity are successfully compared with results from an industry-used code. The results are also confronted with the experimental data of a laboratory-scale rocket engine.
Abstract: In working mode some unexpected changes could
be arise in inner structure of electromagnetic device. They
influence modification in electromagnetic field propagation map.
The field values at an observed boundary are also changed. The
development of the process has to be watched because the arising
structural changes would provoke the device to be gone out later.
The probabilistic assessment of the state is possible to be made.
The numerical assessment points if the resulting changes have
only accidental character or they are due to the essential inner
structural disturbances.
The presented application example is referring to the 200MW
turbine-generator. A part of the stator core end teeth zone is
simulated broken. Quasi three-dimensional electromagnetic and
temperature field are solved applying FEM. The stator core state
diagnosis is proposed to be solved as an identification problem on
the basis of a statistical criterion.
Abstract: This study analyzed environmental health risks and
people-s perceptions of risks related to waste management in poor
settlements of Abidjan, to develop integrated solutions for health and
well-being improvement. The trans-disciplinary approach used relied
on remote sensing, a geographic information system (GIS),
qualitative and quantitative methods such as interviews and a
household survey (n=1800). Mitigating strategies were then
developed using an integrated participatory stakeholder workshop.
Waste management deficiencies resulting in lack of drainage and
uncontrolled solid and liquid waste disposal in the poor settlements
lead to severe environmental health risks. Health problems were
caused by direct handling of waste, as well as through broader
exposure of the population. People in poor settlements had little
awareness of health risks related to waste management in their
community and a general lack of knowledge pertaining to sanitation
systems. This unfortunate combination was the key determinant
affecting the health and vulnerability. For example, an increased
prevalence of malaria (47.1%) and diarrhoea (19.2%) was observed
in the rainy season when compared to the dry season (32.3% and
14.3%). Concerted and adapted solutions that suited all the
stakeholders concerned were developed in a participatory workshop
to allow for improvement of health and well-being.
Abstract: Using neural network we try to model the unknown function f for given input-output data pairs. The connection strength of each neuron is updated through learning. Repeated simulations of crisp neural network produce different values of weight factors that are directly affected by the change of different parameters. We propose the idea that for each neuron in the network, we can obtain quasi-fuzzy weight sets (QFWS) using repeated simulation of the crisp neural network. Such type of fuzzy weight functions may be applied where we have multivariate crisp input that needs to be adjusted after iterative learning, like claim amount distribution analysis. As real data is subjected to noise and uncertainty, therefore, QFWS may be helpful in the simplification of such complex problems. Secondly, these QFWS provide good initial solution for training of fuzzy neural networks with reduced computational complexity.