Abstract: This article describes the results of research focused
on quality of railway freight transport services. Improvement of these
services has a crucial importance in customer considering on the
future use of railway transport. Processes filling the customer
demands and output quality assessment were defined as a part of the
research. In this contribution is introduced the map of quality
planning and the algorithm of applied methodology. It characterizes a
model which takes into account characters of transportation with
linking a perception services quality in ordinary and extraordinary
operation. Despite the fact that rail freight transport has its solid
position in the transport market, lots of carriers worldwide have been
experiencing a stagnation for a couple of years. Therefore, specific
results of the research have a significant importance and belong to
numerous initiatives aimed to develop and support railway transport
not only by creating a single railway area or reducing noise but also
by promoting railway services. This contribution is focused also on
the application of dynamic quality models which represent an
innovative method of evaluation quality services. Through this
conception, time factor, expected, and perceived quality in each
moment of the transportation process can be taken into account.
Abstract: The growth in the demand of electrical energy is
leading to load on the Power system which increases the occurrence
of frequent oscillations in the system. The reason for the oscillations
is due to the lack of damping torque which is required to dominate
the disturbances of Power system. By using FACT devices, such as
Unified Power Flow Controller (UPFC) can control power flow,
reduce sub-synchronous resonances and increase transient stability.
Hence, UPFC is used to damp the oscillations occurred in Power
system. This research focuses on adapting the neuro fuzzy controller
for the UPFC design by connecting the infinite bus (SMIB - Single
machine Infinite Bus) to a linearized model of synchronous machine
(Heffron-Phillips) in the power system. This model gains the
capability to improve the transient stability and to damp the
oscillations of the system.
Abstract: Prediction of maximum local scour is necessary for
the safety and economical design of the bridges. A number of
equations have been developed over the years to predict local scour
depth using laboratory data and a few pier equations have also been
proposed using field data. Most of these equations are empirical in
nature as indicated by the past publications. In this paper attempts
have been made to compute local depth of scour around bridge pier in
dimensional and non-dimensional form by using linear regression,
simple regression and SVM (Poly & Rbf) techniques along with few
conventional empirical equations. The outcome of this study suggests
that the SVM (Poly & Rbf) based modeling can be employed as an
alternate to linear regression, simple regression and the conventional
empirical equations in predicting scour depth of bridge piers. The
results of present study on the basis of non-dimensional form of
bridge pier scour indicate the improvement in the performance of
SVM (Poly & Rbf) in comparison to dimensional form of scour.
Abstract: In this paper, a comparative performance analysis of
mostly used four nonlinearity cancellation techniques used to realize
the passive resistor by MOS transistors, is presented. The comparison
is done by using an integrator circuit which is employing sequentially
Op-amp, OTRA and ICCII as active element. All of the circuits are
implemented by MOS-C realization and simulated by PSPICE
program using 0.35μm process TSMC MOSIS model parameters.
With MOS-C realization, the circuits became electronically tunable
and fully integrable which is very important in IC design. The output
waveforms, frequency responses, THD analysis results and features
of the nonlinearity cancellation techniques are also given.
Abstract: Here, we have shown the reaction of [Cr(ArN(CH2)3NAr)2Cl2] (1) where (Ar = 2,6-Pri
2C6H3) and in presence of NaCp (2) (Cp= C5H5 = cyclopentadien), with a center
coordination η5 interaction between Cp as co-ligand and chromium
metal center, for optimization we used density functional theory
(DFT), under methods, explicitly including electrons correlations, for
the final calculations as MB3LYP (Becke) (Lee–Yang–Parr) level of
theory we used to obtain more exact results. This complex was
calculated as electronic energy for molecular system, because the
calculation accounting all electrons correlations interactions. The
optimised of [Cr(ArN(CH2)3NAr)2(η5-Cp)] (Ar = 2,6-Pri2C6H3 and Cp = C5H5) was found to be thermally stable. By using Dewar-Chatt-Duncanson model, as a basis of the molecular orbital (MO) analysis
and showed the highest occupied molecular orbital (HOMO) and
lowest occupied molecular orbital LUMO.
Abstract: A numerical study is made in a parallel-plate porous
channel subjected to an oscillating flow and an exothermic chemical
reaction on its walls. The flow field in the porous region is modeled
by the Darcy–Brinkman–Forchheimer model and the finite volume
method is used to solve the governing equations. The effects of the
modified Frank-Kamenetskii (FKm) and Damköhler (Dm) numbers,
the amplitude of oscillation (A), and the Strouhal number (St) are
examined. The main results show an increase of heat and mass
transfer rates with A and St, and their decrease with FKm and Dm.
Abstract: The critical concern of satellite operations is to ensure
the health and safety of satellites. The worst case in this perspective
is probably the loss of a mission, but the more common interruption
of satellite functionality can result in compromised mission
objectives. All the data acquiring from the spacecraft are known as
Telemetry (TM), which contains the wealth information related to the
health of all its subsystems. Each single item of information is
contained in a telemetry parameter, which represents a time-variant
property (i.e. a status or a measurement) to be checked. As a
consequence, there is a continuous improvement of TM monitoring
systems to reduce the time required to respond to changes in a
satellite's state of health. A fast conception of the current state of the
satellite is thus very important to respond to occurring failures.
Statistical multivariate latent techniques are one of the vital learning
tools that are used to tackle the problem above coherently.
Information extraction from such rich data sources using advanced
statistical methodologies is a challenging task due to the massive
volume of data. To solve this problem, in this paper, we present a
proposed unsupervised learning algorithm based on Principle
Component Analysis (PCA) technique. The algorithm is particularly
applied on an actual remote sensing spacecraft. Data from the
Attitude Determination and Control System (ADCS) was acquired
under two operation conditions: normal and faulty states. The models
were built and tested under these conditions, and the results show that
the algorithm could successfully differentiate between these
operations conditions. Furthermore, the algorithm provides
competent information in prediction as well as adding more insight
and physical interpretation to the ADCS operation.
Abstract: In this study, the commercial finite element software
ABAQUS was used to develop a three-dimensional nonlinear finite
element model capable of simulating the pull-out test of reinforcing
bars from underwater concrete. The results of thirty-two pull-out tests
that have different parameters were implemented in the software to
study the effect of the concrete cover, the bar size, the use of stirrups,
and the compressive strength of concrete. The interaction properties used in the model provided accurate
results in comparison with the experimental bond-slip results, thus
the model has successfully simulated the pull-out test. The results of
the finite element model are used to better understand and visualize
the distribution of stresses in each component of the model, and to
study the effect of the various parameters used in this study including
the role of the stirrups in preventing the stress from reaching to the
sides of the specimens.
Abstract: Hydrogels are three-dimensional, hydrophilic,
polymeric networks composed of homopolymers or copolymers and
are insoluble in water due to the presence of chemical or physical
cross-links. When hydrogels come in contact with aqueous solutions,
they can effectively sorb and retain the dissolved substances,
depending on the nature of the monomeric units comprising the
hydrogel. For this reason, hydrogels have been proposed in several
studies as water purification agents. At the present work anionic
hydrogels bearing negatively charged –COO- groups were prepared
and investigated. These gels are based on sodium acrylate (ANa),
either homopolymerized (poly(sodiumacrylate), PANa) or
copolymerized (P(DMAM-co-ANa)) with N,N Dimethylacrylamide
(DMAM). The hydrogels were used to extract some model organic
dyes from water. It is found that cationic dyes are strongly sorbed and
retained by the hydrogels, while sorption of anionic dyes was
negligible. In all cases it was found that both maximum sorption
capacity and equilibrium binding constant varied from one dye to the
other depending on the chemical structure of the dye, the presence of
functional chemical groups and the hydrophobic-hydrophilic balance.
Finally, the nonionic hydrogel of the homopolymer poly(N,Ndimethylacrylamide),
PDMAM, was also used for reasons of
comparison.
Abstract: This paper presents the advantages of fuzzy control use in technological processes control. The paper presents a real application of the Linguistic Fuzzy-Logic Control, developed at the University of Ostrava for the control of physical models in the Intelligent Systems Laboratory. The paper presents an example of a sensitive non-linear model, such as a magnetic levitation model and obtained results which show how modern information technologies can help to solve actual technical problems. A special method based on the LFLC controller with partial components is presented in this paper followed by the method of automatic context change, which is very helpful to achieve more accurate control results. The main advantage of the used system is its robustness in changing conditions demonstrated by comparing with conventional PID controller. This technology and real models are also used as a background for problem-oriented teaching, realized at the department for master students and their collaborative as well as individual final projects.
Abstract: This paper evaluates the accrual based scheduling for
cloud in single and multi-resource system. Numerous organizations
benefit from Cloud computing by hosting their applications. The
cloud model provides needed access to computing with potentially
unlimited resources. Scheduling is tasks and resources mapping to a
certain optimal goal principle. Scheduling, schedules tasks to virtual
machines in accordance with adaptable time, in sequence under
transaction logic constraints. A good scheduling algorithm improves
CPU use, turnaround time, and throughput. In this paper, three realtime
cloud services scheduling algorithm for single resources and
multiple resources are investigated. Experimental results show
Resource matching algorithm performance to be superior for both
single and multi-resource scheduling when compared to benefit first
scheduling, Migration, Checkpoint algorithms.
Abstract: This paper presents a model predictive control (MPC)
of a utility interactive three phase inverter (TPI) for a photovoltaic
(PV) system at commercial level. The proposed model uses phase
locked loop (PLL) to synchronize the TPI with the power electric
grid (PEG) and performs MPC control in a dq reference frame. TPI
model consists of a boost converter (BC), maximum power point
tracking (MPPT) control, and a three-leg voltage source inverter
(VSI). The operational model of VSI is used to synthesize the
sinusoidal current and track the reference. The model is validated
using a 35.7 kW PV system in Matlab/Simulink. Implementation
results show simplicity and accuracy, as well as reliability of the
model.
Abstract: This research presents the design and analysis of solar
air-conditioning systems particularly solar chimney which is a
passive strategy for natural ventilation, and demonstrates the
structures of these systems’ using Computational Fluid Dynamic
(CFD) and finally compares the results with several examples, which
have been studied experimentally and carried out previously. In order
to improve the performance of solar chimney system, highly efficient
sub-system components are considered for the design. The general
purpose of the research is to understand how efficiently solar
chimney systems generate cooling, and is to improve the efficient of
such systems for integration with existing and future domestic
buildings.
Abstract: Spectrum handover is a significant topic in the
cognitive radio networks to assure an efficient data transmission in
the cognitive radio user’s communications. This paper proposes a
comparison between three spectrum handover models: VIKOR, SAW
and MEW. Four evaluation metrics are used. These metrics are,
accumulative average of failed handover, accumulative average of
handover performed, accumulative average of transmission
bandwidth and, accumulative average of the transmission delay. As a difference with related work, the performance of the three
spectrum handover models was validated with captured data of
spectrum occupancy in experiments performed at the GSM frequency
band (824 MHz - 849 MHz). These data represent the actual behavior
of the licensed users for this wireless frequency band. The results of the comparison show that VIKOR Algorithm
provides a 15.8% performance improvement compared to SAW
Algorithm and, it is 12.1% better than the MEW Algorithm.
Abstract: In this numerical study, effects of using Al2O3-water
nanofluid on the rate of heat transfer have been investigated. Physical
model is a square enclosure with insulated top and bottom horizontal
walls, while the vertical walls are kept at different constant
temperatures. Two appropriate models are used to evaluate the
viscosity and thermal conductivity of nanofluid. The governing
stream-vorticity equations are solved using a second order central
finite difference scheme, coupled to the conservation of mass and
energy. The study has been carried out for the nanoparticle diameter
30, 60 and 90 nm and the solid volume fraction 0 to 0.04. Results are
presented by average Nusselt number and normalized Nusselt number
in different range of φ and D for mixed convection dominated
regime. It is found that different heat transfer rate is predicted when
the effect of nanoparticle diameter is taken into account.
Abstract: This paper develops a multiple channel assignment
model, which allows to take advantage of spectrum opportunities in
cognitive radio networks in the most efficient way. The developed
scheme allows making several assignments of available and
frequency adjacent channel, which require a bigger bandwidth, under
an equality environment. The hybrid assignment model it is made by
two algorithms, one that makes the ranking and selects available
frequency channels and the other one in charge of establishing the
Max-Min Fairness for not restrict the spectrum opportunities for all
the other secondary users, who also claim to make transmissions.
Measurements made were done for average bandwidth, average
delay, as well as fairness computation for several channel
assignments. Reached results were evaluated with experimental
spectrum occupational data from captured GSM frequency band. The
developed model shows evidence of improvement in spectrum
opportunity use and a wider average transmission bandwidth for each
secondary user, maintaining equality criteria in channel assignment.
Abstract: This study, tries to suggest a design method based on
displacement using finite difference numerical modeling in
reinforcing soil retaining wall with steel strip. In this case, dynamic
loading characteristics such as duration, frequency, peak ground
acceleration, geometrical characteristics of reinforced soil structure
and type of the site are considered to correct the pseudo static method
and finally introduce the pseudo static coefficient as a function of
seismic performance level and peak ground acceleration. For this
purpose, the influence of dynamic loading characteristics,
reinforcement length, height of reinforced system and type of the site
are investigated on seismic behavior of reinforcing soil retaining wall
with steel strip. Numerical results illustrate that the seismic response
of this type of wall is highly dependent to cumulative absolute
velocity, maximum acceleration, and height and reinforcement length
so that the reinforcement length can be introduced as the main factor
in shape of failure. Considering the loading parameters, geometric parameters of the
wall and type of the site showed that the used method in this study
leads to efficient designs in comparison with other methods, which
are usually based on limit-equilibrium concept. The outputs show the
over-estimation of equilibrium design methods in comparison with
proposed displacement based methods here.
Abstract: In IA-MDT, the magnetic implants are placed
strategically at the target site to greatly and locally increase the
magnetic force on MDCPs and help to attract and retain the MDCPs
at the targeted region. In the present work, we develop a
mathematical model to study the capturing of magnetic nanoparticles
flowing within a fluid in an implant assisted cylindrical channel
under magnetic field. A coil of ferromagnetic SS-430 has been
implanted inside the cylindrical channel to enhance the capturing of
magnetic nanoparticles under magnetic field. The dominant magnetic
and drag forces, which significantly affect the capturing of
nanoparticles, are incorporated in the model. It is observed through
model results that capture efficiency increases as we increase the
magnetic field from 0.1 to 0.5 T, respectively. The increase in capture
efficiency by increase in magnetic field is because as the magnetic
field increases, the magnetization force, which is attractive in nature
and responsible to attract or capture the magnetic particles, increases
and results the capturing of large number of magnetic particles due to
high strength of attractive magnetic force.
Abstract: Nowadays, illegal logging has been causing many
effects including flash flood, avalanche, global warming, and etc. The
purpose of this study was to maintain the earth ecosystem by keeping
and regulate Malaysia’s treasurable rainforest by utilizing a new
technology that will assist in real-time alert and give faster response
to the authority to act on these illegal activities. The methodology of
this research consisted of design stages that have been conducted as
well as the system model and system architecture of the prototype in
addition to the proposed hardware and software that have been
mainly used such as microcontroller, sensor with the implementation
of GSM, and GPS integrated system. This prototype was deployed at
Royal Belum forest in December 2014 for phase 1 and April 2015 for
phase 2 at 21 pinpoint locations. The findings of this research were
the capture of data in real-time such as temperature, humidity,
gaseous, fire, and rain detection which indicate the current natural
state and habitat in the forest. Besides, this device location can be
detected via GPS of its current location and then transmitted by SMS
via GSM system. All of its readings were sent in real-time for further
analysis. The data that were compared to meteorological department
showed that the precision of this device was about 95% and these
findings proved that the system is acceptable and suitable to be used
in the field.
Abstract: The Greater Athens Area (GAA) faces photochemical
and particulate pollution episodes as a result of the combined effects
of local pollutant emissions, regional pollution transport, synoptic
circulation and topographic characteristics. The area has undergone
significant changes since the Athens 2004 Olympic Games because
of large scale infrastructure works that lead to the shift of population
to areas previously characterized as rural, the increase of the traffic
fleet and the operation of highways. However, few recent modelling
studies have been performed due to the lack of an accurate, updated
emission inventory. The photochemical modelling system
MM5/CAMx was applied in order to study the photochemical and
particulate pollution characteristics above the GAA for two distinct
ten-day periods in the summer of 2006 and 2010, where air pollution
episodes occurred. A new updated emission inventory was used
based on official data. Comparison of modeled results with
measurements revealed the importance and accuracy of the new
Athens emission inventory as compared to previous modeling
studies. The model managed to reproduce the local meteorological
conditions, the daily ozone and particulates fluctuations at different
locations across the GAA. Higher ozone levels were found at
suburban and rural areas as well as over the sea at the south of the
basin. Concerning PM10, high concentrations were computed at the
city centre and the southeastern suburbs in agreement with measured
data. Source apportionment analysis showed that different sources
contribute to the ozone levels, the local sources (traffic, port
activities) affecting its formation.