Abstract: The purpose of this research is to reduce the amount of incomplete coating of stainless steel washers in the electrodeposition painting process by using an experimental design technique. The surface preparation was found to be a major cause of painted surface quality. The influence of pretreating and painting process parameters, which are cleaning time, chemical concentration and shape of hanger were studied. A 23 factorial design with two replications was performed. The analysis of variance for the designed experiment showed the great influence of cleaning time and shape of hanger. From this study, optimized cleaning time was determined and a newly designed electrical conductive hanger was proved to be superior to the original one. The experimental verification results showed that the amount of incomplete coating defects decreased from 4% to 1.02% and operation cost decreased by 10.5%.
Abstract: An improved topology of a voltage-fed quasi-resonant
soft switching LCrCdc series-parallel half bridge inverter with a constant-frequency for electronic ballast applications is proposed in this paper. This new topology introduces a low-cost solution to
reduce switching losses and circuit rating to achieve high-efficiency
ballast. Switching losses effect on ballast efficiency is discussed
through experimental point of view. In this discussion, an improved
topology in which accomplishes soft switching operation over a wide
power regulation range is proposed. The proposed structure uses reverse recovery diode to provide better operation for the ballast system. A symmetrical pulse wide modulation (PWM) control scheme is implemented to regulate a wide range of out-put power.
Simulation results are kindly verified with the experimental
measurements obtained by ballast-lamp laboratory prototype. Different load conditions are provided in order to clarify the
performance of the proposed converter.
Abstract: This study is to investigate the electroencephalogram (EEG) differences generated from a normal and Alzheimer-s disease (AD) sources. We also investigate the effects of brain tissue distortions due to AD on EEG. We develop a realistic head model from T1 weighted magnetic resonance imaging (MRI) using finite element method (FEM) for normal source (somatosensory cortex (SC) in parietal lobe) and AD sources (right amygdala (RA) and left amygdala (LA) in medial temporal lobe). Then, we compare the AD sourced EEGs to the SC sourced EEG for studying the nature of potential changes due to sources and 5% to 20% brain tissue distortions. We find an average of 0.15 magnification errors produced by AD sourced EEGs. Different brain tissue distortion models also generate the maximum 0.07 magnification. EEGs obtained from AD sources and different brain tissue distortion levels vary scalp potentials from normal source, and the electrodes residing in parietal and temporal lobes are more sensitive than other electrodes for AD sourced EEG.
Abstract: Imperfect knowledge cannot be avoided all the time. Imperfections may have several forms; uncertainties, imprecision and incompleteness. When we look to classification of methods for the management of imperfect knowledge we see fuzzy set-based techniques. The choice of a method to process data is linked to the choice of knowledge representation, which can be numerical, symbolic, logical or semantic and it depends on the nature of the problem to be solved for example decision support, which will be mentioned in our study. Fuzzy Logic is used for its ability to manage imprecise knowledge, but it can take advantage of the ability of neural networks to learn coefficients or functions. Such an association of methods is typical of so-called soft computing. In this study a new method was used for the management of imprecision for collected knowledge which related to economic analysis of construction industry in Turkey. Because of sudden changes occurring in economic factors decrease competition strength of construction companies. The better evaluation of these changes in economical factors in view of construction industry will made positive influence on company-s decisions which are dealing construction.
Abstract: The purpose of the present study is to analyze the
effect of the target plate-s curvature on the heat transfer in laminar
confined impinging jet flows. Numerical results from two
dimensional compressible finite volume solver are compared
between three different shapes of impinging plates: Flat, Concave
and Convex plates. The remarkable result of this study proves that
the stagnation Nusselt number in laminar range of Reynolds number
based on the slot width is maximum in convex surface and is
minimum in concave plate. These results refuse the previous data in
literature stating the amount of the stagnation Nusselt number is
greater in concave surface related to flat plate configuration.
Abstract: This paper characterizes the effects of artificial short
term aging in the laboratory on the rheological properties of virgin
80/100 penetration grade asphalt binder. After several years in
service, asphalt mixture started to deteriorate due to aging. Aging is a
complex physico-chemical phenomenon that influences asphalt
binder rheological properties causing a deterioration in asphalt
mixture performance. To ascertain asphalt binder aging effects, the
virgin, artificially aged and extracted asphalt binder were tested via
the Rolling Thin film Oven (RTFO), Dynamic Shear Rheometer
(DSR) and Rotational Viscometer (RV). A comparative study
between laboratory and field aging conditions were also carried out.
The results showed that the specimens conditioned for 85 minutes
inside the RTFO was insufficient to simulate the actual short term
aging caused that took place in the field under Malaysian field
conditions
Abstract: In the past decade, the development of microstrip
sensor application has evolved tremendously. Although cut and trial
method was adopted to develop microstrip sensing applications in the
past, Computer-Aided-Design (CAD) is a more effective as it ensures
less time is consumed and cost saving is achieved in developing
microstrip sensing applications. Therefore microstrip sensing
applications has gained popularity as an effective tool adopted in
continuous sensing of moisture content particularly in products that is
administered mainly by liquid content. In this research, the Cole-Cole
representation of reactive relaxation is applied to assess the
performance of the microstrip sensor devices. The microstrip sensor
application is an effective tool suitable for sensing the moisture
content of dielectric material. Analogous to dielectric relaxation
consideration of Cole-Cole diagrams as applied to dielectric
materials, a “reactive relaxation concept” concept is introduced to
represent the frequency-dependent and moisture content
characteristics of microstrip sensor devices.
Abstract: Nowadays, doping is an intricate dilemma. Wrestling
is the nationally popular sport in Iran. Also the prevalence of doping
may be high, due to its power demanding characteristics. So, we
aimed to assess the knowledge and attitudes toward doping among
the club wrestlers. In a cross sectional study, 426 wrestlers were
studied. For this reason, a researcher made questionnaire was used. In
this study, researchers selected the clubs by randomized clustered
sampling and distributed the questionnaire among wrestlers.
Knowledge of wrestlers in three categories of doping definitions,
recognition of prohibited drugs and side effects was poor or moderate
in 70.8%, 95.8% and 99.5%, respectively. Wrestlers have poor
knowledge in doping. Furthermore, they believe some myths which
are unfavorable. It seems necessary to design a comprehensive
educational program for all of the athletes and coaches.
Abstract: In switch mode power inverters, small sized inverters
can be obtained by increasing the switching frequency. Switching
frequency increment causes high driver losses. Also, high dt
di
and
dt
dv
produced by the switching action creates high Electromagnetic
Interference (EMI) and Radio Frequency Interference (RFI). In this
paper, a series half bridge series resonant inverter circuit is simulated
and evaluated practically to demonstrate the turn-on and turn-off
conditions during zero or close to zero voltage switching. Also, the
reverse recovery current effects of the body diode of the MOSFETs
were investigated by operating above and below resonant frequency.
Abstract: One of the key research issues in wireless sensor networks (WSNs) is how to efficiently deploy sensors to cover an area. In this paper, we present a Fishnet Based Dispatch Scheme (FiBDS) with energy aware mobility and interest based sensing angle. We propose two algorithms, one is FiBDS centralized algorithm and another is FiBDS distributed algorithm. The centralized algorithm is designed specifically for the non-time critical applications, commonly known as non real-time applications while the distributed algorithm is designed specifically for the time critical applications, commonly known as real-time applications. The proposed dispatch scheme works in a phase-selection manner. In this in each phase a specific constraint is dealt with according to the specified priority and then moved onto the next phase and at the end of each only the best suited nodes for the phase are chosen. Simulation results are presented to verify their effectiveness.
Abstract: This paper presents the study of induced currents and
temperature distribution in gear heated by induction process using 2D
finite element (FE) model. The model is developed by coupling
Maxwell and heat transfer equations into a multi-physics model. The
obtained results allow comparing the medium frequency (MF) and
high frequency (HF) cases and the effect of machine parameters on
the evolution of induced currents and temperature during heating.
The sensitivity study of the temperature profile is conducted and the
case hardness is predicted using the final temperature profile. These
results are validated using tests and give a good understanding of
phenomena during heating process.
Abstract: Synchronization is a difficult problem in CDMA
satellite communications. Due to the influence of additive noise and
fading in the mobile channel, it is not easy to keep up with the
attenuation and offset. This paper considers a recently proposed
approach to solve the problem of synchronization chaotic Chen
system in CDMA satellite communication in the presence of constant
attenuation and offset. An analytic algorithm that provides closed
form channel and carrier offset estimates is presented. The principle
of this approach is based on adding a compensation block before the
receiver to compensate the distortion of the imperfect channel by
using genetic algorithm.
The resultants presented, show that the receiver is able to recover
rapidly the synchronization with the transmitter.
Abstract: Effect of viscosity of media on kinetic parameters of the coupled enzyme system NADH:FMN-oxidoreductase–luciferase was investigated with addition of organic solvents (glycerol and sucrose), because bioluminescent enzyme systems based on bacterial luciferases offer a unique and general tool for analysis of the many analytes and enzymes in the environment, research and clinical laboratories and other fields. The possibility of stabilization and increase of activity of the coupled enzyme system NADH:FMN-oxidoreductase–luciferase activity in vicious aqueous-organic mixtures have been shown.
Abstract: Modern manufacturing facilities are large scale,
highly complex, and operate with large number of variables under
closed loop control. Early and accurate fault detection and diagnosis
for these plants can minimise down time, increase the safety of plant
operations, and reduce manufacturing costs. Fault detection and
isolation is more complex particularly in the case of the faulty analog
control systems. Analog control systems are not equipped with
monitoring function where the process parameters are continually
visualised. In this situation, It is very difficult to find the relationship
between the fault importance and its consequences on the product
failure. We consider in this paper an approach to fault detection and
analysis of its effect on the production quality using an adaptive
centring and scaling in the pickling process in cold rolling. The fault
appeared on one of the power unit driving a rotary machine, this
machine can not track a reference speed given by another machine.
The length of metal loop is then in continuous oscillation, this affects
the product quality. Using a computerised data acquisition system,
the main machine parameters have been monitored. The fault has
been detected and isolated on basis of analysis of monitored data.
Normal and faulty situation have been obtained by an artificial neural
network (ANN) model which is implemented to simulate the normal
and faulty status of rotary machine. Correlation between the product
quality defined by an index and the residual is used to quality
classification.
Abstract: Decision making preferences to certain criteria
usually focus on positive degrees without considering the negative
degrees. However, in real life situation, evaluation becomes more
comprehensive if negative degrees are considered concurrently.
Preference is expected to be more effective when considering both
positive and negative degrees of preference to evaluate the best
selection. Therefore, the aim of this paper is to propose the
conflicting bifuzzy preference relations in group decision making by
utilization of a novel score function. The conflicting bifuzzy
preference relation is obtained by introducing some modifications on
intuitionistic fuzzy preference relations. Releasing the intuitionistic
condition by taking into account positive and negative degrees
simultaneously and utilizing the novel score function are the main
modifications to establish the proposed preference model. The
proposed model is tested with a numerical example and proved to be
simple and practical. The four-step decision model shows the
efficiency of obtaining preference in group decision making.
Abstract: Having a very many number of pipelines all over the
country, Iran is one of the countries consists of various ecosystems
with variable degrees of fragility and robusticity as well as
geographical conditions. This study presents a state-of-the-art method
to estimate environmental risks of pipelines by recommending
rational equations including FES, URAS, SRS, RRS, DRS, LURS
and IRS as well as FRS to calculate the risks. This study was carried
out by a relative semi-quantitative approach based on land uses and
HVAs (High-Value Areas). GIS as a tool was used to create proper
maps regarding the environmental risks, land uses and distances. The
main logic for using the formulas was the distance-based approaches
and ESI as well as intersections. Summarizing the results of the
study, a risk geographical map based on the ESIs and final risk score
(FRS) was created. The study results showed that the most sensitive
and so of high risk area would be an area comprising of mangrove
forests located in the pipeline neighborhood. Also, salty lands were
the most robust land use units in the case of pipeline failure
circumstances. Besides, using a state-of-the-art method, it showed
that mapping the risks of pipelines out with the applied method is of
more reliability and convenience as well as relative
comprehensiveness in comparison to present non-holistic methods for
assessing the environmental risks of pipelines. The focus of the
present study is “assessment" than that of “management". It is
suggested that new policies are to be implemented to reduce the
negative effects of the pipeline that has not yet been constructed
completely
Abstract: The motorway segment between Tangier and Oued
R’mel has experienced, since the beginning of building works,
significant instability and landslides linked to a number of geological,
hydrogeological and geothermic factors affecting the different
formations.
The landslides observed are not fully understood, despite many
studies conducted on this segment. This study aims at producing new
methods to better explain the phenomena behind the landslides,
taking into account the geotechnical and geothermic contexts. This
analysis builds up on previous studies and geotechnical data collected
in the field.
The final body of data collected shall be processed through the
Plaxis software for a better and customizable view of the landslide
problems in the area, which will help tofind solutions and stabilize
land in the area.
Abstract: Genetic Zone Routing Protocol (GZRP) is a new
hybrid routing protocol for MANETs which is an extension of ZRP
by using Genetic Algorithm (GA). GZRP uses GA on IERP and BRP
parts of ZRP to provide a limited set of alternative routes to the
destination in order to load balance the network and robustness
during node/link failure during the route discovery process. GZRP is
studied for its performance compared to ZRP in many folds like
scalability for packet delivery and proved with improved results. This
paper presents the results of the effect of load balancing on GZRP.
The results show that GZRP outperforms ZRP while balancing the
load.
Abstract: In recent years, rehabilitation has been the subject of extensive research due to increased spending on building work and repair of built works. In all cases, it is absolutely essential to carry out methods of strengthening or repair of structural elements, and that following an inspection analysis and methodology of a correct diagnosis. The reinforced concrete columns are important elements in building structures. They support the vertical loads and provide bracing against the horizontal loads. This research about the behavior of reinforced concrete rectangular columns, rehabilitated by concrete liner, confinement FRP fabric, steel liner or cage formed by metal corners. It allows comparing the contributions of different processes used perspective section resistance elements rehabilitated compared to that is not reinforced or repaired. The different results obtained revealed a considerable gain in bearing capacity failure of reinforced sections cladding concrete, metal bracket, steel plates and a slight improvement to the section reinforced with fabric FRP. The use of FRP does not affect the weight of the structures, but the use of different techniques cladding increases the weight of elements rehabilitated and therefore the weight of the building which requires resizing foundations.
Abstract: Future astronomical projects on large space x-ray
imaging telescopes require novel substrates and technologies for the
construction of their reflecting mirrors. The mirrors must be
lightweight and precisely shaped to achieve large collecting area with
high angular resolution. The new materials and technologies must be
cost-effective. Currently, the most promising materials are glass or
silicon foils. We focused on precise shaping these foils by thermal
forming process. We studied free and forced slumping in the
temperature region of hot plastic deformation and compared the
shapes obtained by the different slumping processes. We measured
the shapes and the surface quality of the foils. In the experiments, we
varied both heat-treatment temperature and time following our
experiment design. The obtained data and relations we can use for
modeling and optimizing the thermal forming procedure.