Abstract: Total liquid ventilation can support gas exchange in animal models of lung injury. Clinical application awaits further technical improvements and performance verification. Our aim was to develop a liquid ventilator, able to deliver accurate tidal volumes, and a computerized system for measuring lung mechanics. The computer-assisted, piston-driven respirator controlled ventilatory parameters that were displayed and modified on a real-time basis. Pressure and temperature transducers along with a lineal displacement controller provided the necessary signals to calculate lung mechanics. Ten newborn lambs (
Abstract: The main objective of Automatic Generation Control (AGC) is to balance the total system generation against system load losses so that the desired frequency and power interchange with neighboring systems is maintained. Any mismatch between generation and demand causes the system frequency to deviate from its nominal value. Thus high frequency deviation may lead to system collapse. This necessitates a very fast and accurate controller to maintain the nominal system frequency. This paper deals with a novel approach of artificial intelligence (AI) technique called Hybrid Neuro-Fuzzy (HNF) approach for an (AGC). The advantage of this controller is that it can handle the non-linearities at the same time it is faster than other conventional controllers. The effectiveness of the proposed controller in increasing the damping of local and inter area modes of oscillation is demonstrated in a two area interconnected power system. The result shows that intelligent controller is having improved dynamic response and at the same time faster than conventional controller.
Abstract: In this article, a high vacuum system for the evaporation of organic semiconductors is introduced and a mathematical model is given. Based on the exact input output linearization a deposition rate controller is designed and tested with different evaporation materials.
Abstract: Total liquid ventilation can support gas exchange in animal models of lung injury. Clinical application awaits further technical improvements and performance verification. Our aim was to develop a liquid ventilator, able to deliver accurate tidal volumes, and a computerized system for measuring lung mechanics. The computer-assisted, piston-driven respirator controlled ventilatory parameters that were displayed and modified on a real-time basis. Pressure and temperature transducers along with a lineal displacement controller provided the necessary signals to calculate lung mechanics. Ten newborn lambs (
Abstract: Full - Scale Accelerated Loading System, one part of
“the Eleventh - Five - Year National Grand Technology Infrastructure
Program" is a facility to evaluate the performance and service life of
different kinds of pavements subjected to traffic loading under full -
controlled environment. While simulating the environments of frigid
zone and permafrost zone, the accurate control of air temperature, road
temperature and roadbed temperature are the key points and also
aporias for the designment. In this paper, numerical simulations are
used to determine the design parameters of the frozen soil simulation
system. At first, a brief introduction of the Full - Scale Accelerate
Loading System was given. Then, the temperature control method of
frozen soil simulation system was proposed. Finally, by using finite
element simulations, the optimal design of frozen soil simulation
system was obtained. This proposed design, which was obtained by
finite element simulations, provided significant referents to the
ultimate design of the environment simulation system.
Abstract: Due to their high power-to-weight ratio and low cost,
pneumatic actuators are attractive for robotics and automation
applications; however, achieving fast and accurate control of their
position have been known as a complex control problem. A
methodology for obtaining high position accuracy with a linear
pneumatic actuator is presented. During experimentation with a
number of PID classical control approaches over many operations of
the pneumatic system, the need for frequent manual re-tuning of the
controller could not be eliminated. The reason for this problem is
thermal and energy losses inside the cylinder body due to the
complex friction forces developed by the piston displacements.
Although PD controllers performed very well over short periods, it
was necessary in our research project to introduce some form of
automatic gain-scheduling to achieve good long-term performance.
We chose a fuzzy logic system to do this, which proved to be an
easily designed and robust approach. Since the PD approach showed
very good behaviour in terms of position accuracy and settling time,
it was incorporated into a modified form of the 1st order Tagaki-
Sugeno fuzzy method to build an overall controller. This fuzzy gainscheduler
uses an input variable which automatically changes the PD
gain values of the controller according to the frequency of repeated
system operations. Performance of the new controller was
significantly improved and the need for manual re-tuning was
eliminated without a decrease in performance. The performance of
the controller operating with the above method is going to be tested
through a high-speed web network (GRID) for research purposes.
Abstract: Optical burst switching (OBS) has been proposed to
realize the next generation Internet based on the wavelength division
multiplexing (WDM) network technologies. In the OBS, the burst
contention is one of the major problems. The deflection routing has
been designed for resolving the problem. However, the deflection
routing becomes difficult to prevent from the burst contentions as the
network load becomes high. In this paper, we introduce a flow rate
control methods to reduce burst contentions. We propose new flow
rate control methods based on the leaky bucket algorithm and
deflection routing, i.e. separate leaky bucket deflection method, and
dynamic leaky bucket deflection method. In proposed methods, edge
nodes which generate data bursts carry out the flow rate control
protocols. In order to verify the effectiveness of the flow rate control in
OBS networks, we show that the proposed methods improve the
network utilization and reduce the burst loss probability through
computer simulations.
Abstract: A fuzzy predictive pursuit guidance is proposed as an
alternative to the conventional methods. The purpose of this scheme
is to obtain a stable and fast guidance. The noise effects must be
reduced in homing missile guidance to get an accurate control. An
aerodynamic missile model is simulated first and a fuzzy predictive
pursuit control algorithm is applied to reduce the noise effects. The
performance of this algorithm is compared with the performance of
the classical proportional derivative control. Stability analysis of the
proposed guidance method is performed and compared with the
stability properties of other guidance methods. Simulation results
show that the proposed method provides the satisfying performance.
Abstract: In this paper, we have presented the effect of varying
time-delays on performance and stability in the single-channel multirate
sampled-data system in hard real-time (RT-Linux) environment.
The sampling task require response time that might exceed the
capacity of RT-Linux. So a straight implementation with RT-Linux is
not feasible, because of the latency of the systems and hence,
sampling period should be less to handle this task. The best sampling
rate is chosen for the sampled-data system, which is the slowest rate
meets all performance requirements. RT-Linux is consistent with its
specifications and the resolution of the real-time is considered 0.01
seconds to achieve an efficient result. The test results of our
laboratory experiment shows that the multi-rate control technique in
hard real-time operating system (RTOS) can improve the stability
problem caused by the random access delays and asynchronization.
Abstract: This paper presents a video transmission system using
layered multiple description (coding (MDC) and multi-path transport
for reliable video communications in wireless ad-hoc networks.
The proposed MDC extends a quality-scalable H.264/AVC video
coding algorithm to generate two independent descriptions. The two
descriptions are transmitted over different paths to a receiver in order
to alleviate the effect of unstable channel conditions of wireless adhoc
networks. If one description is lost due to transmission erros,
then the correctly received description is used to estimate the lost
information of the corrupted description. The proposed MD coder
maintains an adequate video quality as long as both description are
not simultaneously lost. Simulation results show that the proposed
MD coding combined with multi-path transport system is largely
immune to packet losses, and therefore, can be a promising solution
for robust video communications over wireless ad-hoc networks.
Abstract: Due to their high power-to-weight ratio and low cost, pneumatic actuators are attractive for robotics and automation applications; however, achieving fast and accurate control of their position have been known as a complex control problem. The paper presents a methodology for obtaining controllers that achieve high position accuracy and preserve the closed-loop characteristics over a broad operating range. Experimentation with a number of conventional (or "classical") three-term controllers shows that, as repeated operations accumulate, the characteristics of the pneumatic actuator change requiring frequent re-tuning of the controller parameters (PID gains). Furthermore, three-term controllers are found to perform poorly in recovering the closed-loop system after the application of load or other external disturbances. The key reason for these problems lies in the non-linear exchange of energy inside the cylinder relating, in particular, to the complex friction forces that develop on the piston-wall interface. In order to overcome this problem but still remain within the boundaries of classical control methods, we designed an auto selective classicaql controller so that the system performance would benefit from all three control gains (KP, Kd, Ki) according to system requirements and the characteristics of each type of controller. This challenging experimentation took place for consistent performance in the face of modelling imprecision and disturbances. In the work presented, a selective PID controller is presented for an experimental rig comprising an air cylinder driven by a variable-opening pneumatic valve and equipped with position and pressure sensors. The paper reports on tests carried out to investigate the capability of this specific controller to achieve consistent control performance under, repeated operations and other changes in operating conditions.
Abstract: The influence of human activities produced by dams
along the river beds is minor, but the location of accumulation of
water directly influences the hydrological regime. The most
important effect of the influence of damming on the way water flows
decreases the frequency of floods. The water rate controls the water
flow of the dams. These natural reservoirs become dysfunctional and,
as a result, a new distribution of flow in the downstream sector,
where maximum flow is, brings about, in this case, higher values. In
addition to fishing, middle and lower courses of rivers located by
accumulation also have a role in mitigating flood waves, thus
providing flood protection. The Vaslui also ensures a good part of the
needs of the town water supply. The most important lake is Solesti,
close to the Vaslui River, opened in 1974. A hydrological regime of
accumulation is related to an anthropogenic and natural drainage
system. The design conditions and their manoeuvres drain or fill the
water courses.