Abstract: A DC servomotor position control system using a Fuzzy Logic Sliding mode Model Following Control or FLSMFC approach is presented. The FLSMFC structure consists of an integrator and variable structure system. The integral control is introduced into it in order to eliminated steady state error due to step and ramp command inputs and improve control precision, while the fuzzy control would maintain the insensitivity to parameter variation and disturbances. The FLSMFC strategy is implemented and applied to a position control of a DC servomotor drives. Experimental results indicated that FLSMFC system performance with respect to the sensitivity to parameter variations is greatly reduced. Also, excellent control effects and avoids the chattering phenomenon.
Abstract: The performance of modified Fenton (MF) treatment
to promote PAH oxidation in artificially contaminated soil was
investigated in packed soil column with a hydrogen peroxide (H2O2)
delivery system simulating in situ injection. Soil samples were spiked
with phenanthrene (low molecular weight PAH) and fluoranthene
(high molecular weight PAH) to an initial concentration of 500
mg/kg dried soil each. The effectiveness of process parameters
H2O2/soil, iron/soil, chelating agent/soil weight ratios and reaction
time were studied using a 24 three level factorial design experiments.
Statistically significant quadratic models were developed using
Response Surface Methodology (RSM) for degrading PAHs from the
soil samples. Optimum operating condition was achieved at mild
range of H2O2/soil, iron/soil and chelating agent/soil weight ratios,
indicating cost efficient method for treating highly contaminated
lands.
Abstract: This paper presents the development of a hybrid
thermal model for the EVO Electric AFM 140 Axial Flux Permanent
Magnet (AFPM) machine as used in hybrid and electric vehicles. The
adopted approach is based on a hybrid lumped parameter and finite
difference method. The proposed method divides each motor
component into regular elements which are connected together in a
thermal resistance network representing all the physical connections
in all three dimensions. The element shape and size are chosen
according to the component geometry to ensure consistency. The
fluid domain is lumped into one region with averaged heat transfer
parameters connecting it to the solid domain. Some model parameters
are obtained from Computation Fluid Dynamic (CFD) simulation and
empirical data. The hybrid thermal model is described by a set of
coupled linear first order differential equations which is discretised
and solved iteratively to obtain the temperature profile. The
computation involved is low and thus the model is suitable for
transient temperature predictions. The maximum error in temperature
prediction is 3.4% and the mean error is consistently lower than the
mean error due to uncertainty in measurements. The details of the
model development, temperature predictions and suggestions for
design improvements are presented in this paper.
Abstract: The paper structures research approaches to the crisis
and its management. It focuses on approaches – psychological,
sociological, economic, ethical and technological. Furthermore, it
describes the basic features of models chosen according to those
approaches. By their comparison it shows how the crisis influences
organizations and individuals, and their mutual interaction.
Abstract: Few studies have been conducted on polymeric strip
and the behavior of soil retaining walls. This paper will present the
effect of frequency on the dynamic behavior of reinforced soil
retaining walls with polymeric strips. The frequency content
describes how the amplitude of a ground motion is distributed among
different frequencies. Since the frequency content of an earthquake
motion will strongly influence the effects of that motion, the
characterization of the motion cannot be completed without the
consideration of its frequency content. The maximum axial force of
reinforcements and horizontal displacement of the reinforced walls
are focused in this research. To clarify the dynamic behavior of
reinforced soil retaining walls with polymeric strips, a numerical
modeling using Finite Difference Method is benefited. As the results
indicate, the frequency of input base acceleration has an important
effect on the behavior of these structures. Because of resonant in the
system, where the frequency of the input dynamic load is equal to the
natural frequency of the system, the maximum horizontal
displacement and the maximum axial forces in polymeric strips is
occurred. Moreover, they were to increase the structure flexibility
because of the main advantages of polymeric strips; i.e. being simple
method of construction, having a homogeneous behavior with soils,
and possessing long durability, which are of great importance in
dynamic analysis.
Abstract: The floating body effect is a serious problem for the
PDSOI MOSFET, and the H-gate layout is frequently used as the body contact to eliminate this effect. Unfortunately, most of the standard commercial SOI MOSFET model is for the device with finger gate, the
necessity of the new models for the H-gate device arises. A simulation
model for the H-gate PDSOI MOSFET is proposed based on the 0.35μm PDSOI process developed by the Institute of Microelectronics
of the Chinese Academy of Sciences (IMECAS), and then the model is well verified by the ring-oscillator.
Abstract: This paper presents a model for analysis the induced voltage of transmission lines (energized) acting on neighboring distribution lines (de-energized). From environmental restrictions, 22 kV distribution lines need to be installed under 115 kV transmission lines. With the installation of the two parallel circuits like this, they make the induced voltage which can cause harm to operators. This work was performed with the ATP-EMTP modeling to analyze such phenomenon before field testing. Simulation results are used to find solutions to prevent danger to operators who are on the pole.
Abstract: In this paper the effect of faults in the elements and
parts of discrete event systems is investigated. In the occurrence of
faults, some states of the system must be changed and some of them
must be forbidden. For this goal, different states of these elements are
examined and a model for fail-safe behavior of each state is
introduced. Replacing new models of the target elements in the
preliminary model by a systematic method, leads to a fail-safe
discrete event system.
Abstract: Launch and recovery helicopter wind envelope for a
ship type was determined as the first step to the helicopter
qualification program. Flight deck velocities data were obtained by
means of a two components laser Doppler anemometer testing a
1/50th model in the wind tunnel stream. Full-scale flight deck
measurements were obtained on board the ship using a sonic
anemometer. Wind tunnel and full-scale measurements were
compared, showing good agreement and finally, a preliminary launch
and recovery helicopter wind envelope for this specific ship was
built.
Abstract: Motion control of flexible arms is more difficult than
that of rigid arms, however utilizing its dynamics enables improved
performance such as a fast motion in short operation time. This paper
investigates a ball throwing robot with one rigid link and one flexible
link. This robot throws a ball at a set speed with a proper control torque.
A mathematical model of this ball throwing robot is derived through
Hamilton’s principle. Several patterns of torque input are designed and
tested through the proposed simulation models. The parameters of
each torque input pattern is optimized and determined by chaos
embedded vector evaluated particle swarm optimization (CEVEPSO).
Then, the residual vibration of the manipulator after throwing is
suppressed with input shaping technique. Finally, a real experiment is
set up for the model checking.
Abstract: This paper provides a replacement policy for warranty products with different failure rate from the consumer-s viewpoint. Assume that the product is replaced once within a finite planning horizon, and the failure rate of the second product is lower than the failure rate of the first product. Within warranty period (WP), the failed product is corrected by minimal repair without any cost to the consumers. After WP, the failed product is repaired with a fixed repair cost to the consumers. However, each failure incurs a fixed downtime cost to the consumers over a finite planning horizon. In this paper, we derive the model of the expected total disbursement cost within a finite planning horizon and some properties of the optimal replacement policy under some reasonable conditions are obtained. Finally, numerical examples are given to illustrate the features of the optimal replacement policy under various maintenance costs.
Abstract: A study concerning the photocatalytic decolourization
of Congo red (CR) dye, over artificial UV irradiation is presented.
Photocatalysts based on a commercial titanium dioxide (TiO2)
modified with transition metals (Ni, Cu and Zn) were used. The
dopage method used was wet impregnation. A TiO2 sample without
salt was subjected to the same hydrothermal treatment to be used as
reference. Congo red solutions to several pH conditions (natural and
basic) were used to evaluate photocatalytic performance of each
doped catalysts. Photodecolourization percentage was measured
spectrofotrometically after 3 h of treatment to 499 nm as response
variable. Kinetics investigations of photodegradation indicated that
reactions obey to Langmuir-Hinshelwood model and pseudo–first
order law. The rate constant studies of photocatalytic decolourization
reactions for Zn–TiO2 and Cu–TiO2 photocatalysts indicated that in
all cases the rate constant of the reaction was higher than that of TiO2
undoped. These results show that nature of the metal modifying the
TiO2 influence on the efficiency of the photocatalyst evaluated in
process. Ni does not present an additional effect compared with TiO2,
while Zn enhances the photoactivity due to its electronic properties.
Abstract: The paper presents a set of guidelines for analysis of industrial embedded distributed systems and introduces a mathematical model derived from these guidelines. In this study, the author examines a set of modern communication technologies that are or possibly can be used to build communication links between the subsystems of a distributed embedded system. An investigation of these guidelines results in a algorithm for analysis of specific use cases of target technologies. A goal of the paper acts as an important base for ongoing research on comparison of communication technologies. The author describes the principles of the model and presents results of the test calculations. Practical implementation of target technologies and empirical experiment data are based on a practical experience during the design and test of specific distributed systems in Latvian market.
Abstract: Object-oriented simulation is considered one of the most sophisticated techniques that has been widely used in planning, designing, executing and maintaining construction projects. This technique enables the modeler to focus on objects which is extremely important for thorough understanding of a system. Thus, identifying an object is an essential point of building a successful simulation model. In a maintenance process an object is a maintenance work order (MWO). This study demonstrates a maintenance simulation model for the building maintenance division of Saudi Consolidated Electric Company (SCECO) in Dammam, Saudi Arabia. The model focused on both types of maintenance processes namely: (1) preventive maintenance (PM) and (2) corrective maintenance (CM). It is apparent from the findings that object-oriented simulation is a good diagnostic and experimental tool. This is because problems, limitations, bottlenecks and so forth are easily identified. These features are very difficult to obtain when using other tools.
Abstract: In this study, cometabolic biodegradation of
chloroform was experimented with mixed cultures in the presence of
various organic solvents like methanol, ethanol, isopropanol, acetone,
acetonitrile and toluene as these are predominant discharges in
pharmaceutical industries. Toluene and acetone showed higher
specific chloroform degradation rate when compared to other
compounds. Cometabolic degradation of chloroform was further
confirmed by observation of free chloride ions in the medium. An
extended Haldane model, incorporating the inhibition due to
chloroform and the competitive inhibition between primary
substrates, was developed to predict the biodegradation of primary
substrates, cometabolic degradation of chloroform and the biomass
growth. The proposed model is based on the use of biokinetic
parameters obtained from single substrate degradation studies. The
model was able to satisfactorily predict the experimental results of
ternary and quaternary mixtures. The proposed model can be used for
predicting the performance of bioreactors treating discharges from
pharmaceutical industries.
Abstract: We developed a new method based on quasimolecular
modeling to simulate the cavity flow in three cavity
shapes: rectangular, half-circular and bucket beer in cgs units. Each
quasi-molecule was a group of particles that interacted in a fashion
entirely analogous to classical Newtonian molecular interactions.
When a cavity flow was simulated, the instantaneous velocity vector
fields were obtained by using an inverse distance weighted
interpolation method. In all three cavity shapes, fluid motion was
rotated counter-clockwise. The velocity vector fields of the three
cavity shapes showed a primary vortex located near the upstream
corners at time t ~ 0.500 s, t ~ 0.450 s and t ~ 0.350 s, respectively.
The configurational kinetic energy of the cavities increased as time
increased until the kinetic energy reached a maximum at time t ~
0.02 s and, then, the kinetic energy decreased as time increased. The
rectangular cavity system showed the lowest kinetic energy, while
the half-circular cavity system showed the highest kinetic energy.
The kinetic energy of rectangular, beer bucket and half-circular
cavities fluctuated about stable average values 35.62 x 103, 38.04 x
103 and 40.80 x 103 ergs/particle, respectively. This indicated that the
half-circular shapes were the most suitable shape for a shrimp pond
because the water in shrimp pond flows best when we compared with
rectangular and beer bucket shape.
Abstract: With continuous rise of oil price, how to develop alternative energy source has become a hot topic around the world. This study discussed the dynamic characteristics of an island power system operating under random wind speed lower than nominal wind
speeds of wind turbines. The system primarily consists of three diesel engine power generation systems, three constant-speed variable-pitch wind turbines, a small hydraulic induction generation system, and lumped static loads. Detailed models based on Matlab/Simulink were developed to cater for the dynamic behavior of the system. The results suggested this island power system can operate stably in this operational mode. This study can serve as an important reference for planning, operation, and further expansion of island power systems.
Abstract: The Canadian aerospace industry faces many
challenges. One of them is the difficulty in estimating costs. In
particular, the design effort required in a project impacts resource
requirements and lead-time, and consequently the final cost. This
paper presents the findings of a case study conducted for recognized
global leader in the design and manufacturing of aircraft engines. The
study models parametric cost estimation relationships to estimate the
design effort of integrated blade-rotor low-pressure compressor fans.
Several effort drivers are selected to model the relationship.
Comparative analyses of three types of models are conducted. The
model with the best accuracy and significance in design estimation is
retained.
Abstract: Simulation is a very helpful and valuable work tool in
manufacturing. It can be used in industrial field allowing the
system`s behavior to be learnt and tested. Simulation provides a low
cost, secure and fast analysis tool. It also provides benefits, which
can be reached with many different system configurations. Topics to
be discussed include: Applications, Modeling, Validating, Software
and benefits of simulation. This paper provides a comprehensive
literature review on research efforts in simulation.
Abstract: Traditionally, wind tunnel models are made of metal
and are very expensive. In these years, everyone is looking for ways
to do more with less. Under the right test conditions, a rapid
prototype part could be tested in a wind tunnel. Using rapid prototype
manufacturing techniques and materials in this way significantly
reduces time and cost of production of wind tunnel models. This
study was done of fused deposition modeling (FDM) and their ability
to make components for wind tunnel models in a timely and cost
effective manner. This paper discusses the application of wind tunnel
model configuration constructed using FDM for transonic wind
tunnel testing. A study was undertaken comparing a rapid
prototyping model constructed of FDM Technologies using
polycarbonate to that of a standard machined steel model. Testing
covered the Mach range of Mach 0.3 to Mach 0.75 at an angle-ofattack
range of - 2° to +12°. Results from this study show relatively
good agreement between the two models and rapid prototyping
Method reduces time and cost of production of wind tunnel models.
It can be concluded from this study that wind tunnel models
constructed using rapid prototyping method and materials can be
used in wind tunnel testing for initial baseline aerodynamic database
development.