Abstract: Iterative learning control aims to achieve zero tracking
error of a specific command. This is accomplished by iteratively
adjusting the command given to a feedback control system, based on
the tracking error observed in the previous iteration. One would like
the iterations to converge to zero tracking error in spite of any error
present in the model used to design the learning law. First, this need
for stability robustness is discussed, and then the need for robustness
of the property that the transients are well behaved. Methods of
producing the needed robustness to parameter variations and to
singular perturbations are presented. Then a method involving
reverse time runs is given that lets the world behavior produce the
ILC gains in such a way as to eliminate the need for a mathematical
model. Since the real world is producing the gains, there is no issue
of model error. Provided the world behaves linearly, the approach
gives an ILC law with both stability robustness and good transient
robustness, without the need to generate a model.
Abstract: This paper examines the relationships between and
among the various drivers of climate change that have both climatic
and ecological consequences for vegetation and land cover change in
arctic areas, particularly in arctic Alaska. It discusses the various
processes that have created spatial and climatic structures that have
facilitated observable vegetation and land cover changes in the
Arctic. Also, it indicates that the drivers of both climatic and
ecological changes in the Arctic are multi-faceted and operate in a
system with both positive and negative feedbacks that largely results
in further increases or decreases of the initial drivers of climatic and
vegetation change mainly at the local and regional scales. It
demonstrates that the impact of arctic warming on land cover change
and the Arctic ecosystems is not unidirectional and one dimensional
in nature but it represents a multi-directional and multi-dimensional
forces operating in a feedback system.
Abstract: This paper describes design of a digital feedback loop
for a low switching frequency dc-dc switching converters. Low
switching frequencies were selected in this design. A look up table
for the digital PID (proportional integrator differentiator)
compensator was implemented using Altera Stratix II with built-in
ADC (analog-to-digital converter) to achieve this hardware
realization. Design guidelines are given for the PID compensator,
high frequency DPWM (digital pulse width modulator) and moving
average filter.
Abstract: The problem of robust disturbance rejection (RDR) using a proportional state feedback controller is studied for the case of Left Invertible MIMO generalized state space linear systems with nonlinear uncertain structure. Sufficient conditions for the problem to have a solution are established. The set of all proportional feedback controllers solving the problem subject to these conditions is analytically determined.
Abstract: In this paper, we are presenting a new type of pointing interface for computers which provides mouse functionalities with near surface haptic feedback. Further, it can be configured as a haptic display where users may feel the basic geometrical shapes in the GUI by moving the finger on top of the device surface. These functionalities are achieved by tracking three dimensional positions of the neodymium magnet using Hall Effect sensors grid and generating like polarity haptic feedback using an electromagnet array. This interface brings the haptic sensations to the 3D space where previously it is felt only on top of the buttons of the haptic mouse implementations.
Abstract: This paper presents the adaptive control scheme
with sliding mode compensator for vibration control problem
in the presence of disturbance. The dynamic model of the
flexible cantilever beam using finite element modeling is
derived. The adaptive control with sliding mode compensator
using output feedback for output tracking is developed to
reject the external disturbance, and to improve the tracking
performance. Satisfactory simulation results verify that the
effectiveness of adaptive control scheme with sliding mode
compensator.
Abstract: Business and IT alignment has continued as a
top concern for business and IT executives for almost three
decades. Many researchers have conducted empirical studies on
the relationship between business-IT alignment and performance.
Yet, these approaches, lacking a social perspective, have had little
impact on sustaining performance and competitive advantage. In
addition to the limited alignment literature that explores
organisational learning that is represented in shared understanding,
communication, cognitive maps and experiences.
Hence, this paper proposes an integrated process that enables
social and intellectual dimensions through the concept of
organisational learning. In particular, the feedback and feedforward
process which provide a value creation across dynamic
multilevel of learning. This mechanism enables on-going
effectiveness through development of individuals, groups and
organisations, which improves the quality of business and IT
strategies and drives to performance.
Abstract: This paper presents an investigation into the design of a flight control system, using a robust sliding mode control structure, designed using the exact feedback linearization procedure of the dynamic of a small-size autonomous helicopter in hover. The robustness of the controller in the context of stabilization and trajectory tracking with respect to small body forces and air resistance on the main and tail rotor, is analytically proved using Lyapunov approach. Some simulation results are presented to illustrate the performance and robustness of such controller in the presence of small body forces and air resistance.
Abstract: Introducing Electromagnetic Interference and Electromagnetic Compatibility, or “The Art of Black Magic", for engineering students might be a terrifying experience both for students and tutors. Removing the obstacle of large, expensive facilities like a fully fitted EMC laboratory and hours of complex theory, this paper demonstrates a design of a laboratory setup for student exercises, giving students experience in the basics of EMC/EMI problems that may challenge the functionality and stability of embedded system designs. This is done using a simple laboratory installation and basic measurement equipment such as a medium cost digital storage oscilloscope, at the cost of not knowing the exact magnitude of the noise components, but rather if the noise is significant or not, as well as the source of the noise. A group of students have performed a trial exercise with good results and feedback.
Abstract: Our Medicine-oriented research is based on a medical
data set of real patients. It is a security problem to share
patient private data with peoples other than clinician or hospital
staff. We have to remove person identification information
from medical data. The medical data without private data
are available after a de-identification process for any research
purposes. In this paper, we introduce an universal automatic
rule-based de-identification application to do all this stuff on an
heterogeneous medical data. A patient private identification is
replaced by an unique identification number, even in burnedin
annotation in pixel data. The identical identification is used
for all patient medical data, so it keeps relationships in a data.
Hospital can take an advantage of a research feedback based
on results.
Abstract: Continuously growing needs for Internet applications
that transmit massive amount of data have led to the emergence of
high speed network. Data transfer must take place without any
congestion and hence feedback parameters must be transferred from
the receiver end to the sender end so as to restrict the sending rate in
order to avoid congestion. Even though TCP tries to avoid
congestion by restricting the sending rate and window size, it never
announces the sender about the capacity of the data to be sent and
also it reduces the window size by half at the time of congestion
therefore resulting in the decrease of throughput, low utilization of
the bandwidth and maximum delay. In this paper, XCP protocol is
used and feedback parameters are calculated based on arrival rate,
service rate, traffic rate and queue size and hence the receiver
informs the sender about the throughput, capacity of the data to be
sent and window size adjustment, resulting in no drastic decrease in
window size, better increase in sending rate because of which there is
a continuous flow of data without congestion. Therefore as a result of
this, there is a maximum increase in throughput, high utilization of
the bandwidth and minimum delay. The result of the proposed work
is presented as a graph based on throughput, delay and window size.
Thus in this paper, XCP protocol is well illustrated and the various
parameters are thoroughly analyzed and adequately presented.
Abstract: A linear feedback shift register (LFSR) is proposed which targets to reduce the power consumption from within. It reduces the power consumption during testing of a Circuit Under Test (CUT) at two stages. At first stage,
Control Logic (CL) makes the clocks of the switching units
of the register inactive for a time period when output from
them is going to be same as previous one and thus reducing
unnecessary switching of the flip-flops. And at second stage,
the LFSR reorders the test vectors by interchanging the bit
with its next and closest neighbor bit. It keeps fault coverage
capacity of the vectors unchanged but reduces the Total Hamming Distance (THD) so that there is reduction in power
while shifting operation.
Abstract: This paper introduces a high-gain observer based state of charge(SOC) estimator for lithium-Ion batteries. The proposed SOC estimator has a high-gain observer(HGO) structure. The HGO scheme enhances the transient response speed and diminishes the effect of uncertainties. Furthermore, it guarantees that the output feedback controller recovers the performance of the state feedback controller when the observer gain is sufficiently high. In order to show the effectiveness of the proposed method, the linear RC battery model in ADVISOR is used. The performance of the proposed method is compared with that of the conventional linear observer(CLO) and some simulation result is given.
Abstract: This paper is taken into consideration the problem of cryptanalysis of stream ciphers. There is some attempts need to improve the existing attacks on stream cipher and to make an attempt to distinguish the portions of cipher text obtained by the encryption of plain text in which some parts of the text are random and the rest are non-random. This paper presents a tutorial introduction to symmetric cryptography. The basic information theoretic and computational properties of classic and modern cryptographic systems are presented, followed by an examination of the application of cryptography to the security of VoIP system in computer networks using LFSR algorithm. The implementation program will be developed Java 2. LFSR algorithm is appropriate for the encryption and decryption of online streaming data, e.g. VoIP (voice chatting over IP). This paper is implemented the encryption module of speech signals to cipher text and decryption module of cipher text to speech signals.
Abstract: This paper addresses linear quadratic regulation (LQR)
for variable speed variable pitch wind turbines. Because of the
inherent nonlinearity of wind turbine, a set of operating conditions is
identified and then a LQR controller is designed for each operating
point. The feedback controller gains are then interpolated linearly to
get control law for the entire operating region. Besides, the
aerodynamic torque and effective wind speed are estimated online to
get the gain-scheduling variable for implementing the controller. The
potential of the method is verified through simulation with the help of
MATLAB/Simulink and GH Bladed. The performance and
mechanical load when using LQR are also compared with that when
using PI controller.
Abstract: Biological evolution has generated a rich variety of
successful solutions; from nature, optimized strategies can be
inspired. One interesting example is the ant colonies, which are able
to exhibit a collective intelligence, still that their dynamic is simple.
The emergence of different patterns depends on the pheromone trail,
leaved by the foragers. It serves as positive feedback mechanism for
sharing information.
In this paper, we use the dynamic of TASEP as a model of
interaction at a low level of the collective environment in the ant-s
traffic flow. This work consists of modifying the movement rules of
particles “ants" belonging to the TASEP model, so that it adopts with
the natural movement of ants. Therefore, as to respect the constraints
of having no more than one particle per a given site, and in order to
avoid collision within a bidirectional circulation, we suggested two
strategies: decease strategy and waiting strategy. As a third work
stage, this is devoted to the study of these two proposed strategies-
stability. As a final work stage, we applied the first strategy to the
whole environment, in order to get to the emergence of traffic flow,
which is a way of learning.
Abstract: In a wind power generator using doubly fed induction
generator (DFIG), the three-phase pulse width modulation (PWM)
voltage source converter (VSC) is used as grid side converter (GSC)
and rotor side converter (RSC). The standard linear control laws
proposed for GSC provides not only instablity against comparatively
large-signal disturbances, but also the problem of stability due to
uncertainty of load and variations in parameters. In this paper, a
nonlinear controller is designed for grid side converter (GSC) of a
DFIG for wind power application. The nonlinear controller is
designed based on the input-output feedback linearization control
method. The resulting closed-loop system ensures a sufficient
stability region, make robust to variations in circuit parameters and
also exhibits good transient response. Computer simulations and
experimental results are presented to confirm the effectiveness of the
proposed control strategy.
Abstract: The posteroanterior manipulation technique is usually include in the procedure of the lumbar spine to evaluate the intervertebral motion according to mechanical resistance. The mechanical device with visual feedback was proposed that allows one to analysis the lumbar segments mobility “in vivo" facilitating for the therapist to take its treatment evolution. The measuring system uses load cell and displacement sensor to estimate spine stiffness. In this work, the device was tested by 2 therapists, female, applying posteroanterior force techniques to 5 volunteers, female, with frequency of approximately 1.2-1.8 Hz. A test-retest procedure was used for 2 periods of day. The visual feedback results small variation of forces and cycle time during 6 cycles rhythmic application. The stiffness values showed good agreement between test-retest procedures when used same order of maximum forces.
Abstract: In this note, the robust static output feedback
stabilisation of an induction machine is addressed. The machine is
described by a non homogenous bilinear model with structural
uncertainties, and the feedback gain is computed via an iterative LMI
(ILMI) algorithm.
Abstract: In this project, a tele-operated anthropomorphic
robotic arm and hand is designed and built as a versatile robotic arm
system. The robot has the ability to manipulate objects such as pick
and place operations. It is also able to function by itself, in
standalone mode.
Firstly, the robotic arm is built in order to interface with a personal
computer via a serial servo controller circuit board. The circuit board
enables user to completely control the robotic arm and moreover,
enables feedbacks from user. The control circuit board uses a
powerful integrated microcontroller, a PIC (Programmable Interface
Controller). The PIC is firstly programmed using BASIC (Beginner-s
All-purpose Symbolic Instruction Code) and it is used as the 'brain'
of the robot. In addition a user friendly Graphical User Interface
(GUI) is developed as the serial servo interface software using
Microsoft-s Visual Basic 6.
The second part of the project is to use speech recognition control
on the robotic arm. A speech recognition circuit board is constructed
with onboard components such as PIC and other integrated circuits. It
replaces the computers- Graphical User Interface. The robotic arm is
able to receive instructions as spoken commands through a
microphone and perform operations with respect to the commands
such as picking and placing operations.