Abstract: The lack of security obstructs a large scale de- ployment of the multicast communication model. There- fore, a host of research works have been achieved in order to deal with several issues relating to securing the multicast, such as confidentiality, authentication, non-repudiation, in- tegrity and access control. Many applications require au- thenticating the source of the received traffic, such as broadcasting stock quotes and videoconferencing and hence source authentication is a required component in the whole multicast security architecture. In this paper, we propose a new and efficient source au- thentication protocol which guarantees non-repudiation for multicast flows, and tolerates packet loss. We have simu- lated our protocol using NS-2, and the simulation results show that the protocol allows to achieve improvements over protocols fitting into the same category.
Abstract: FlexRay, as a communication protocol for automotive
control systems, is developed to fulfill the increasing demand on the
electronic control units for implementing systems with higher safety
and more comfort. In this work, we study the impact of
radiation-induced soft errors on FlexRay-based steer-by-wire system.
We injected the soft errors into general purpose register set of FlexRay
nodes to identify the most critical registers, the failure modes of the
steer-by-wire system, and measure the probability distribution of
failure modes when an error occurs in the register file.
Abstract: The paper is concerned with the state examination as
well as the problems during the post surgical (orthopedic)
rehabilitation of the knee and ankle joint. An observation of the
current appliances for a passive rehabilitation devices is presented.
The major necessary and basic features of the intelligent
rehabilitation devices are considered. An approach for a new
intelligent appliance is suggested. The main advantages of the device
are: both active as well as passive rehabilitation of the patient based
on the human - patient reactions and a real time feedback. The basic
components: controller; electrical motor; encoder, force – torque
sensor are discussed in details. The main modes of operation of the
device are considered.
Abstract: The problem of robust fuzzy control for a class of
nonlinear fuzzy impulsive singular perturbed systems with
time-varying delay is investigated by employing Lyapunov functions.
The nonlinear delay system is built based on the well-known T–S
fuzzy model. The so-called parallel distributed compensation idea is
employed to design the state feedback controller. Sufficient conditions
for global exponential stability of the closed-loop system are derived
in terms of linear matrix inequalities (LMIs), which can be easily
solved by LMI technique. Some simulations illustrate the effectiveness
of the proposed method.
Abstract: Adaptive observers used in sensorless control of induction motors suffer from instability especally in regenerating mode. In this paper, an optimal feed back gain design is proposed, it can reduce the instability region in the torque speed plane .
Abstract: In this study, we used shape memory alloys as
actuators to build a biomorphic robot which can imitate the motion of
an earthworm. The robot can be used to explore in a narrow space.
Therefore we chose shape memory alloys as actuators. Because of the
small deformation of a wire shape memory alloy, spiral shape memory
alloys are selected and installed both on the X axis and Y axis (each
axis having two shape memory alloys) to enable the biomorphic robot
to do reciprocating motion. By the mechanism we designed, the robot
can increase the distance as it moves in a duty cycle. In addition, two
shape memory alloys are added to the robot head for controlling right
and left turns. By sending pulses through the I/O card from the
controller, the signals are then amplified by a driver to heat the shape
memory alloys in order to make the SMA shrink to pull the mechanism
to move.
Abstract: Magneto-rheological (MR) fluid damper is a semiactive
control device that has recently received more attention by the
vibration control community. But inherent hysteretic and highly
nonlinear dynamics of MR fluid damper is one of the challenging
aspects to employ its unique characteristics. The combination of
artificial neural network (ANN) and fuzzy logic system (FLS) have
been used to imitate more precisely the behavior of this device.
However, the derivative-based nature of adaptive networks causes
some deficiencies. Therefore, in this paper, a novel approach that
employ genetic algorithm, as a free-derivative algorithm, to enhance
the capability of fuzzy systems, is proposed. The proposed method
used to model MR damper. The results will be compared with
adaptive neuro-fuzzy inference system (ANFIS) model, which is one
of the well-known approaches in soft computing framework, and two
best parametric models of MR damper. Data are generated based on
benchmark program by applying a number of famous earthquake
records.
Abstract: One of the main issues in Computer Vision is to extract the movement of one or several points or objects of interest in an image or video sequence to conduct any kind of study or control process. Different techniques to solve this problem have been applied in numerous areas such as surveillance systems, analysis of traffic, motion capture, image compression, navigation systems and others, where the specific characteristics of each scenario determine the approximation to the problem. This paper puts forward a Computer Vision based algorithm to analyze fish trajectories in high turbulence conditions in artificial structures called vertical slot fishways, designed to allow the upstream migration of fish through obstructions in rivers. The suggested algorithm calculates the position of the fish at every instant starting from images recorded with a camera and using neural networks to execute fish detection on images. Different laboratory tests have been carried out in a full scale fishway model and with living fishes, allowing the reconstruction of the fish trajectory and the measurement of velocities and accelerations of the fish. These data can provide useful information to design more effective vertical slot fishways.
Abstract: This paper addresses the controller synthesis problem of discrete-time switched positive systems with bounded time-varying delays. Based on the switched copositive Lyapunov function approach, some necessary and sufficient conditions for the existence of state-feedback controller are presented as a set of linear programming and linear matrix inequality problems, hence easy to be verified. Another advantage is that the state-feedback law is independent on time-varying delays and initial conditions. A numerical example is provided to illustrate the effectiveness and feasibility of the developed controller.
Abstract: Sufficient linear matrix inequalities (LMI) conditions for regularization of discrete-time singular systems are given. Then a new class of regularizing stabilizing controllers is discussed. The proposed controllers are the sum of predictive and memoryless state feedbacks. The predictive controller aims to regularizing the singular system while the memoryless state feedback is designed to stabilize the resulting regularized system. A systematic procedure is given to calculate the controller gains through linear matrix inequalities.
Abstract: The control of oxygen flow rate during growth of
titanium dioxide by mass flow controller in DC plasma sputtering
growth system is studied. The impedance of TiO2 films for inductance
effect is influenced by annealing time and oxygen flow rate. As
annealing time is increased, the inductance of TiO2 film is the more.
The growth condition of optimum and maximum inductance for TiO2
film to serve as sensing device are oxygen flow rate of 15 sccm and
large annealing time. The large inductance of TiO2 film will be
adopted to fabricate the biosensor to obtain the high sensitivity of
sensing in biology.
Abstract: This paper describes reactive neural control used to
generate phototaxis and obstacle avoidance behavior of walking
machines. It utilizes discrete-time neurodynamics and consists of
two main neural modules: neural preprocessing and modular neural
control. The neural preprocessing network acts as a sensory fusion
unit. It filters sensory noise and shapes sensory data to drive the
corresponding reactive behavior. On the other hand, modular neural
control based on a central pattern generator is applied for locomotion
of walking machines. It coordinates leg movements and can generate
omnidirectional walking. As a result, through a sensorimotor loop this
reactive neural controller enables the machines to explore a dynamic
environment by avoiding obstacles, turn toward a light source, and
then stop near to it.
Abstract: The aim of this paper is to compare the effectiveness and electrochemical behavior of typical oilfield corrosion inhibitors with previous oilfield corrosion inhibitors under the same electrochemical techniques to control preferential weld corrosion of X65 pipeline steel in artificial seawater saturated with carbon dioxide at a pressure of one bar. A secondary aim is to investigate the conditions under which current reversal takes place. A flow channel apparatus was used in the laboratory to simulate the actual condition that occurs in marine pipelines. Different samples from the parent metal, the weld metal and the heat affected zone in the pipeline steel were galvanically coupled. The galvanic currents flowing between the weld regions were recorded using zero-resistance ammeters and tested under static and flowing conditions in both inhibited and uninhibited media. The results show that a current reversal took place when 30ppm of both green oilfield inhibitors were present, resulting in accelerated weld corrosion.
Abstract: The acid rain causes change in pH level of soil it is
directly influence on root and leaf growth. Yield of the crop was
reduced if acidity of soil is more. Acid rain seeps into the earth and
poisons plants and trees by dissolving toxic substances in the soil,
such as aluminum, which get absorbed by the roots. In present
investigation, effect of acid rain on crop Vigna radiata was studied.
The effect of acid rain on change in soil fertility was detected in
which pH of control sample was 6.5 and pH of 1% H2SO4 and 1%
HNO3 were 3.5. Nitrogen nitrate in soil was high in 1% HNO3 treated
soil & Control sample. Ammonium nitrogen in soil was low in 1%
HNO3 & H2SO4 treated soil. Ammonium nitrogen was medium in
control and other samples. The effect of acid rain on seed
germination on 3rd day of germination control sample growth was
6.1cm with plumule 0.001% HNO3 & 0.001% H2SO4 was 5.5cm
with plumule and 8cm with plumule. On 10th day fungal growth was
observed in 1% and 0.1% H2SO4 concentrations when all plants were
dead. The effect of acid rain on crop productivity was investigated on
3rd day roots were developed in plants. On 12th day Vigna radiata
showed more growth in 0.1% HNO3 and 0.1% H2SO4 treated plants
as compare to control plants. On 20th day development of
discoloration of plant pigments were observed on acid treated plants
leaves. On 34th day Vigna radiata showed flower in 0.1% HNO3,
0.01% HNO3 and 0.01% H2SO4treated plants and no flowers were
observed on control plants. On 42th day 0.1% HNO3, 0.01% HNO
and 0.01% H2SO4 treated Vigna radiata variety and control plants
were showed seeds on plants. In Vigna radiate variety 0.1%, 0.01%
HNO3, 0.01% H2SO4treated plants were dead on 46th day and fungal
growth was observed. The toxicological study was carried out on
Vigna radiata plants exposed to 1% HNO3 cells were damaged more
than 1% H2SO4. Leaf sections exposed to 0.001% HNO3 & H2SO4
showed less damaged of cells and pigmentation observed in entire
slide when compare with control plant.
Abstract: Graph rewriting-based visual model processing is a
widely used technique for model transformation. Visual model
transformations often need to follow an algorithm that requires a
strict control over the execution sequence of the transformation steps.
Therefore, in Visual Model Processors (VMPs) the execution order
of the transformation steps is crucial. This paper presents the visual
control flow support of Visual Modeling and Transformation System
(VMTS), which facilitates composing complex model
transformations of simple transformation steps and executing them.
The VMTS Visual Control Flow Language (VCFL) uses stereotyped
activity diagrams to specify control flow structures and OCL
constraints to choose between different control flow branches. This
paper introduces VCFL, discusses its termination properties and
provides an algorithm to support the termination analysis of VCFL
transformations.
Abstract: Variable Structure Control (VSC) is one of the most useful tools handling the practical system with uncertainties and disturbances. Up to now, unfortunately, not enough studies on the input-saturated system with linear-growth-bound disturbances via VSC have been presented. Therefore, this paper proposes an asymp¬totic stability condition for the system via VSC. The designed VSC controller consists of two control parts. The linear control part plays a role in stabilizing the system, and simultaneously, the nonlinear control part in rejecting the linear-growth-bound disturbances perfectly. All conditions derived in this paper are expressed with Linear Matrices Inequalities (LMIs), which can be easily solved with an LMI toolbox in MATLAB.
Abstract: A measurement apparatus is designed and fabricated to
measure the effective thermal conductivity (keff) of a VIP (vacuum
insulation panel) core specimen under various vacuum states and
external loads. The apparatus consists of part for measuring keff, and
parts for controlling external load and vacuum condition. Uncertainty
of the apparatus is validated by measuring the standard reference
material and comparing with commercial devices with VIP samples.
Assessed uncertainty is maximum 2.5 % in case of the standard
reference material, 10 % in case of VIP samples. Using the apparatus,
keff of glass paper under various vacuum levels is examined.
Abstract: Design of an observer based controller for a class of
fractional order systems has been done. Fractional order mathematics
is used to express the system and the proposed observer. Fractional
order Lyapunov theorem is used to derive the closed-loop asymptotic
stability. The gains of the observer and observer based controller are
derived systematically using the linear matrix inequality approach.
Finally, the simulation results demonstrate validity and effectiveness
of the proposed observer based controller.
Abstract: In the process of polyethylene extrusion polymer
material similar to powder or granule is under compression, melting
and transmission operation and on base of special form, extrudate has
been produced. Twin-screw extruders are applicable in industries
because of their high capacity. The powder mixing with chemical
additives and melting with thermal and mechanical energy in three
zones (feed, compression and metering zone) and because of gear
pump and screw's pressure, converting to final product in latest plate.
Extruders with twin-screw and short distance between screws are
better than other types because of their high capacity and good
thermal and mechanical stress.
In this paper, process of polyethylene extrusion and various tapes
of extruders are studied. It is necessary to have an exact control on
process to producing high quality products with safe operation and
optimum energy consumption.
The granule size is depending on granulator motor speed. Results
show at constant feed rate a decrease in granule size was found whit
Increase in motor speed. Relationships between HDPE feed rate and
speed of granulator motor, main motor and gear pump are calculated
following as:
x = HDPE feed flow rate, yM = Main motor speed
yM = (-3.6076e-3) x^4+ (0.24597) x^3+ (-5.49003) x^2+ (64.22092)
x+61.66786 (1)
x = HDPE feed flow rate, yG = Gear pump speed
yG = (-2.4996e-3) x^4+ (0.18018) x^3+ (-4.22794) x^2+ (48.45536)
x+18.78880 (2)
x = HDPE feed flow rate, y = Granulator motor speed
10th Degree Polynomial Fit: y = a+bx+cx^2+dx^3... (3)
a = 1.2751, b = 282.4655, c = -165.2098,
d = 48.3106, e = -8.18715, f = 0.84997
g = -0.056094, h = 0.002358, i = -6.11816e-5
j = 8.919726e-7, k = -5.59050e-9
Abstract: A modified Genetic Algorithm (GA) based optimal selection of parameters for Automatic Generation Control (AGC) of multi-area electric energy systems is proposed in this paper. Simulations on multi-area reheat thermal system with and without consideration of nonlinearity like governor dead band followed by 1% step load perturbation is performed to exemplify the optimum parameter search. In this proposed method, a modified Genetic Algorithm is proposed where one point crossover with modification is employed. Positional dependency in respect of crossing site helps to maintain diversity of search point as well as exploitation of already known optimum value. This makes a trade-off between exploration and exploitation of search space to find global optimum in less number of generations. The proposed GA along with decomposition technique as developed has been used to obtain the optimum megawatt frequency control of multi-area electric energy systems. Time-domain simulations are conducted with trapezoidal integration along with decomposition technique. The superiority of the proposed method over existing one is verified from simulations and comparisons.