Abstract: Validation of an automation system is an important issue. The goal is to check if the system under investigation, modeled by a Petri net, never enters the undesired states. Usually, tools dedicated to Petri nets such as DESIGN/CPN are used to make reachability analysis. The biggest problem with this approach is that it is impossible to generate the full occurence graph of the system because it is too large. In this paper, we show how computational methods such as temporal logic model checking and Groebner bases can be used to verify the correctness of the design of an automation system. We report our experimental results with two automation systems: the Automated Guided Vehicle (AGV) system and the traffic light system. Validation of these two systems ranged from 10 to 30 seconds on a PC depending on the optimizing parameters.
Abstract: In this paper we study a system composed by carbon
nanotube (CNT) and bundle of carbon nanotube (BuCNT) interacting
with a specific fatty acid as molecular probe. Full system is
represented by open nanotube (or nanotubes) and the linoleic acid
(LA) relaxing due the interaction with CNT and BuCNT. The LA has
in his form an asymmetric shape with COOH termination provoking
a close BuCNT interaction mainly by van der Waals force field. The
simulations were performed by classical molecular dynamics with
standard parameterizations.
Our results show that these BuCNT and CNT are dynamically
stable and it shows a preferential interaction position with LA
resulting in three features: (i) when the LA is interacting with CNT
and BuCNT (including both termination, CH2 or COOH), the LA is
repelled; (ii) when the LA terminated with CH2 is closer to open
extremity of BuCNT, the LA is also repelled by the interaction
between them; and (iii) when the LA terminated with COOH is
closer to open extremity of BuCNT, the LA is encapsulated by the
BuCNT. These simulations are part of a more extensive work on
searching efficient selective molecular devices and could be useful to
reach this goal.
Abstract: The social force model which belongs to the
microscopic pedestrian studies has been considered as the supremacy
by many researchers and due to the main feature of reproducing the
self-organized phenomena resulted from pedestrian dynamic. The
Preferred Force which is a measurement of pedestrian-s motivation to
adapt his actual velocity to his desired velocity is an essential term on
which the model was set up. This Force has gone through stages of
development: first of all, Helbing and Molnar (1995) have modeled
the original force for the normal situation. Second, Helbing and his
co-workers (2000) have incorporated the panic situation into this
force by incorporating the panic parameter to account for the panic
situations. Third, Lakoba and Kaup (2005) have provided the
pedestrians some kind of intelligence by incorporating aspects of the
decision-making capability. In this paper, the authors analyze the
most important incorporations into the model regarding the preferred
force. They make comparisons between the different factors of these
incorporations. Furthermore, to enhance the decision-making ability
of the pedestrians, they introduce additional features such as the
familiarity factor to the preferred force to let it appear more
representative of what actually happens in reality.
Abstract: Natural resources management including water resources requires reliable estimations of time variant environmental parameters. Small improvements in the estimation of environmental parameters would result in grate effects on managing decisions. Noise reduction using wavelet techniques is an effective approach for preprocessing of practical data sets. Predictability enhancement of the river flow time series are assessed using fractal approaches before and after applying wavelet based preprocessing. Time series correlation and persistency, the minimum sufficient length for training the predicting model and the maximum valid length of predictions were also investigated through a fractal assessment.
Abstract: The paper focuses on the enhanced stiffness modeling
of robotic manipulators by taking into account influence of the external force/torque acting upon the end point. It implements the
virtual joint technique that describes the compliance of manipulator elements by a set of localized six-dimensional springs separated by
rigid links and perfect joints. In contrast to the conventional
formulation, which is valid for the unloaded mode and small
displacements, the proposed approach implicitly assumes that the loading leads to the non-negligible changes of the manipulator posture and corresponding amendment of the Jacobian. The
developed numerical technique allows computing the static
equilibrium and relevant force/torque reaction of the manipulator for
any given displacement of the end-effector. This enables designer
detecting essentially nonlinear effects in elastic behavior of
manipulator, similar to the buckling of beam elements. It is also proposed the linearization procedure that is based on the inversion of
the dedicated matrix composed of the stiffness parameters of the
virtual springs and the Jacobians/Hessians of the active and passive
joints. The developed technique is illustrated by an application example that deals with the stiffness analysis of a parallel
manipulator of the Orthoglide family
Abstract: Web usage mining algorithms have been widely
utilized for modeling user web navigation behavior. In this study we
advance a model for mining of user-s navigation pattern. The model
makes user model based on expectation-maximization (EM)
algorithm.An EM algorithm is used in statistics for finding maximum
likelihood estimates of parameters in probabilistic models, where the
model depends on unobserved latent variables. The experimental
results represent that by decreasing the number of clusters, the log
likelihood converges toward lower values and probability of the
largest cluster will be decreased while the number of the clusters
increases in each treatment.
Abstract: Fabrication and efficiency enhancement of non-mercury, high efficiency and green field emission lamps using carbon nano-materials such as carbon nanotubes as cathode field emitters was studied. Phosphor was coated on the ITO glass or metal substrates as the anode. The luminescence efficiency enhancement was carried out by upgrading the uniform of the emitters, improving electron and thermal conductivity of the phosphor and the optimization of the design of different cathode/anode configurations. After evaluation of the aforementioned parameters, the luminescence efficiency of the field emission lamps was raised.
Abstract: This paper examines many mathematical methods for
molding the hourly price forward curve (HPFC); the model will be
constructed by numerous regression methods, like polynomial
regression, radial basic function neural networks & a furrier series.
Examination the models goodness of fit will be done by means of
statistical & graphical tools. The criteria for choosing the model will
depend on minimize the Root Mean Squared Error (RMSE), using the
correlation analysis approach for the regression analysis the optimal
model will be distinct, which are robust against model
misspecification. Learning & supervision technique employed to
determine the form of the optimal parameters corresponding to each
measure of overall loss. By using all the numerical methods that
mentioned previously; the explicit expressions for the optimal model
derived and the optimal designs will be implemented.
Abstract: The structural stability of the model of a nonelectroneutral current sheath is investigated. The stationary model of a current sheath represents the system of four connected nonlinear differential first-order equations and thus they should manifest structural instability property, i.e. sensitivity to the infinitesimal changes of parameters and starting conditions. Domains of existence of the solutions of current sheath type are found. Those solutions of the current sheath type are realized only in some regions of sevendimensional space of parameters of the problem. The phase volume of those regions is small in comparison with the whole phase volume of the definition range of those parameters. It is shown that the offered model of a nonelectroneutral current sheath is applicable for theoretical interpretation of the bifurcational current sheaths observed in the magnetosphere.
Abstract: Falls are the primary cause of accidents in people over
the age of 65, and frequently lead to serious injuries. Since the early
detection of falls is an important step to alert and protect the aging
population, a variety of research on detecting falls was carried out
including the use of accelerators, gyroscopes and tilt sensors. In
exiting studies, falls were detected using an accelerometer with
errors. In this study, the proposed method for detecting falls was to
use two accelerometers to reject wrong falls detection. As falls are
accompanied by the acceleration of gravity and rotational motion, the
falls in this study were detected by using the z-axial acceleration
differences between two sites. The falls were detected by calculating
the difference between the analyses of accelerometers placed on two
different positions on the chest of the subject. The parameters of the
maximum difference of accelerations (diff_Z) and the integration of
accelerations in a defined region (Sum_diff_Z) were used to form the
fall detection algorithm. The falls and the activities of daily living
(ADL) could be distinguished by using the proposed parameters
without errors in spite of the impact and the change in the positions
of the accelerometers. By comparing each of the axial accelerations,
the directions of falls and the condition of the subject afterwards
could be determined.In this study, by using two accelerometers
without errors attached to two sites to detect falls, the usefulness of
the proposed fall detection algorithm parameters, diff_Z and
Sum_diff_Z, were confirmed.
Abstract: Solidification cracking and hydrogen cracking are some defects generated in the fusion welding of ultrahigh carbon steels. However, friction stir welding (FSW) of such steels, being a solid-state technique, has been demonstrated to alleviate such problems encountered in traditional welding. FSW include different process parameters that must be carefully defined prior processing. These parameters included but not restricted to: tool feed, tool RPM, tool geometry, tool tilt angle. These parameters form a key factor behind avoiding warm holes and voids behind the tool and in achieving a defect-free weld. More importantly, these parameters directly affect the microstructure of the weld and hence the final mechanical properties of weld. For that, 3D finite element (FE) thermo-mechanical model was developed using DEFORM 3D to simulate FSW of carbon steel. At points of interest in the joint, tracking is done for history of critical state variables such as temperature, stresses, and strain rates. Typical results found include the ability to simulate different weld zones. Simulations predictions were successfully compared to experimental FSW tests. It is believed that such a numerical model can be used to optimize FSW processing parameters to favor desirable defect free weld with better mechanical properties.
Abstract: Delayed wound healing in diabetes is primarily
associated with hyperglycemia, over-expression of inflammatory
marker, oxidative stress and delayed collagen synthesis. This
unmanaged wound is producing high economic burden on the
society. Thus research is required to develop new and effective
treatment strategies to deal with this emerging issue. Our present
study incorporates the evaluation of wound healing effects of 50%
ethanol extract of Ocimum sanctum (OSE) in streptozotocin
(45mg/kg)-induced diabetic rats with concurrent wound ulcer. The
animals showing diabetes (Blood glucose level >140 and
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: Deep cold rolling (DCR) and low plasticity burnishing (LPB) process are cold working processes, which easily produce a smooth and work-hardened surface by plastic deformation of surface irregularities. The present study focuses on the surface roughness and surface hardness aspects of AISI 4140 work material, using fractional factorial design of experiments. The assessment of the surface integrity aspects on work material was done, in order to identify the predominant factors amongst the selected parameters. They were then categorized in order of significance followed by setting the levels of the factors for minimizing surface roughness and/or maximizing surface hardness. In the present work, the influence of main process parameters (force, feed rate, number of tool passes/overruns, initial roughness of the work piece, ball material, ball diameter and lubricant used) on the surface roughness and the hardness of AISI 4140 steel were studied for both LPB and DCR process and the results are compared. It was observed that by using LPB process surface hardness has been improved by 167% and in DCR process surface hardness has been improved by 442%. It was also found that the force, ball diameter, number of tool passes and initial roughness of the workpiece are the most pronounced parameters, which has a significant effect on the work piece-s surface during deep cold rolling and low plasticity burnishing process.
Abstract: Sedimentation in reservoirs and the corresponding
loss of storage capacity is one of the most serious problems in dam
engineering. Pressurized flushing, a way to remove sediments from the reservoir, is flushing under a pressurized flow condition and
nearly constant water level. Pressurized flushing has only local
effects around the outlet. Sediment in the vicinity of the outlet openings is scoured and a funnel shaped crater is created. In this study, the temporal development of flushing cone under various
hydraulic conditions was studied experimentally. Time variations of
parameters such as maximum length and width of flushing and also
depth of scouring cone was measured. Results indicated that an
increase in flow velocity (and consequently in Froude number)
established new hydraulically conditions for flushing mechanism and
so a sudden growth was observed in the amount of sediment released
and also scouring dimenssions. In addition, a set of nondimensional
relationships were identified for temporal variations of flushing scour
dimenssions, which can eventuallt be used to estimate the development of flushing cone.
Abstract: Fermented beverages have high expression in the
market for beverages in general, is increasingly valued in situations
where the characteristic aroma and flavor of the material that gave
rise to them are kept after processing. This study aimed to develop a
distilled beverage from passion fruit, and assess, by sensory tests and
chromatographic profile, the influence of different treatments (FM1-
spirit with pulp addiction and FM2 – spirit with bigger ratio of pulp
in must) in the setting of volatiles in the fruit drink, and performing
chemical characterization taking into account the main parameters of
quality established by the legislation. The chromatograms and the
first sensorial tests had indicated that sample FM1 possess better
characteristics of aroma, as much of how much quantitative the
qualitative point of view. However, it analyzes it sensorial end
(preference test) disclosed the biggest preference of the cloth provers
for sample FM2-2 (note 7.93), being the attributes of decisive color
and flavor in this reply, confirmed for the observed values lowest of
fixed and total acidity in the samples of treatment FM2.
Abstract: In this work, we experimentally study heat transfer
from exhaust particulate air of detergent spray drying tower to water
by using coiled tube heat exchanger. Water flows in the coiled
tubes, where air loaded with detergent particles of 43 micrometers
in diameter flows within the shell. Four coiled tubes with different
coil pitches are used in a counter-current flow configuration. We
investigate heat transfer coefficients of inside and outside the heat
transfer surfaces through 400 experiments. The correlations between
Nusselt number and Reynolds number, Prandtl number, mass flow
rate of particulates to mass flow rate of air ratio and coiled tube
pitch parameter are proposed. The correlations procured can be used
to predicted heat transfer between tube and shell of the heat
exchanger.
Abstract: Rapid enlargement and physical development of cities
have facilitated the emergence of a number of city life crises and
decrease of environment quality. Subsequently, the need for noticing
the concept of quality and its improvement in urban environments,
besides quantitative issues, is obviously recognized. In the domain of
urban ideas the importance of taking these issues into consideration
is obvious not only in accordance to sustainable development
concepts and improvement of public environment quality, but also in
the enhancement of social and behavioral models.
The major concern of present article is to study the nature of urban
environment quality in urban development plans, which is important
not only in the concept and the aim of projects but also in their
execution procedure. As a result, this paper is going to utilize
planning capacities caused by environmental virtues in the planning
procedure of Moft Abad neighborhood. Thus, at the first step,
applying the Analytical Hierarchy Process (AHP), it has assessed
quantitative environmental issues. The present conditions of Moft
Abad state that “the neighborhood is generally suffering from the
lack of qualitative parameters, and the previously formed planning
procedures could not take the sustainable and developmental paths
which are aimed at environment quality virtues." The diminution of
economical and environmental virtues has resulted in the diminution
of residential and social virtues. Therefore, in order to enhance the
environment quality in Moft Abad, the present paper has tried to
supply the subject plans in order to make a safe, healthy, and lively
neighborhood.
Abstract: Connected dominating set (CDS) problem in unit disk
graph has signi£cant impact on an ef£cient design of routing protocols
in wireless sensor networks, where the searching space for a
route is reduced to nodes in the set. A set is dominating if all the
nodes in the system are either in the set or neighbors of nodes in the
set. In this paper, a simple and ef£cient heuristic method is proposed
for £nding a minimum connected dominating set (MCDS) in ad hoc
wireless networks based on the new parameter support of vertices.
With this parameter the proposed heuristic approach effectively
£nds the MCDS of a graph. Extensive computational experiments
show that the proposed approach outperforms the recently proposed
heuristics found in the literature for the MCD
Abstract: Linear stability of wake-shear layers in two-phase
shallow flows is analyzed in the present paper. Stability analysis is
based on two-dimensional shallow water equations. It is assumed that
the fluid contains uniformly distributed solid particles. No dynamic
interaction between the carrier fluid and particles is expected in the
initial moment. Linear stability curves are obtained for different
values of the particle loading parameter, the velocity ratio and the
velocity deficit. It is shown that the increase in the velocity ratio
destabilizes the flow. The particle loading parameter has a stabilizing
effect on the flow. The role of the velocity deficit is also
destabilizing: the increase of the velocity deficit leads to less stable
flow.