Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Time delay (4)
- PID (3)
- Antiferroelectric liquid crystal (2)
- Compensation (2)
- Photon correlation spectroscopy (2)
-
- 1 to 6 GHz S band SHF SMA connector UHF accuracy broadband antenna constant radiation pattern feedgap distance frequency range groundplane impedance bandwidth planar element (1)
- Aerosil Particles (1)
- Cells (1)
- Dead-time compensators (1)
- Dead-time compensators. (1)
- Ferroelectric (1)
- H-infinity (1)
- Liquid Crystal (1)
- Liquid Crystals (1)
- Open loop (1)
- Photon Correlation Spectroscopy (1)
- Static gain (1)
- Time constant (1)
- Time delay systems (1)
- Time domain (1)
- Tuning rules (1)
- Publication
Articles 1 - 10 of 10
Full-Text Articles in Engineering
The Appearance Of Ferrielectric Phases In Confined Liquid Crystal Studied By Photon Correlation Spectroscopy, Yuri Panarin, Fouad M. Aliev, Charles Rosenblatt
The Appearance Of Ferrielectric Phases In Confined Liquid Crystal Studied By Photon Correlation Spectroscopy, Yuri Panarin, Fouad M. Aliev, Charles Rosenblatt
Articles
The influence of confinement on the dynamic properties and appearance of ferrielectric phases has been investigated by dynamic light scattering, performed in the bulk AFLC as well as confined in 200 8, and 2000 8, cylindrical pores. The analysis of the experimental results shows that the ferrielectric phases are not formed in 200 A pores, while they appear in 2000 8, pores as well as in bulk.
The Dynamic Properties Of 5cb Filled With Aerosil Particles Investigated By Pcs, F.M. Aliev, M. Kreuzer, Yuri Panarin
The Dynamic Properties Of 5cb Filled With Aerosil Particles Investigated By Pcs, F.M. Aliev, M. Kreuzer, Yuri Panarin
Articles
Nematic liquid crystal filled with Aerosil particles, a prospective composite material for optoelectronic application, has been investigated by static light scattering and Photon Correlation Spectroscopy (PCS). The Aerosil particles in filled nematic liquid crystals (FN) form a network structure with LC domains about 2500 Å in size with a random distribution of the director orientation of each domain. We found that the properties of 5CB are considerably affected by the network. The N-I phase transition in filled 5CB was found to be smeared out and depressed. PCS experiments show that two new relaxation processes appear in filled 5CB in addition …
The Dynamic Properties Of Confined Antiferroelectric Liquid Crystal Investigated By Photon Correlation Spectroscopy, Yuri Panarin, C. Rosenblatr, F.M. Aliev
The Dynamic Properties Of Confined Antiferroelectric Liquid Crystal Investigated By Photon Correlation Spectroscopy, Yuri Panarin, C. Rosenblatr, F.M. Aliev
Articles
Dynamic light scattering was used to examine ferrielectric liquid crystalline phases in porous media. Whereas in larger pores (200 Å) ferrielectric phases were observed, they were not found in the smallest pores (200 Å). Additionally, the temperatures of SmC - SmA phase transition were found to be suppressed in the pores relative to bulk, while SmCA - SmCγ phase transition is not affected by the confinement. These observations have been explained by the structural aspects of antiferroelectric liquid crystalline materials in a confined geometry and show the importance of long range electrostatic interaction for existence of ferrielectric phases.
A Classification Of Techniques For The Compensation Of Time Delayed Processes. Part 2: Structurally Optimised Controllers, Aidan O'Dwyer, John Ringwood
A Classification Of Techniques For The Compensation Of Time Delayed Processes. Part 2: Structurally Optimised Controllers, Aidan O'Dwyer, John Ringwood
Conference papers
Following on from Part 1, Part 2 of the paper considers the use of structurally optimised controllers to compensate time delayed processes.
Pi And Pid Controller Tuning Rules For Time Delay Processes: A Summary. Part 2: Pid Controller Tuning Rules, Aidan O'Dwyer
Pi And Pid Controller Tuning Rules For Time Delay Processes: A Summary. Part 2: Pid Controller Tuning Rules, Aidan O'Dwyer
Conference papers
A summary of tuning rules for the PID control of single input, single output (SISO) processes with time delay, modeled in stable first order lag plus time delay (FOLPD) form, is provided in this part of the paper.
Estimation Of The Parameters Of A Delayed Process Using Open Loop Time Domain Techniques, Morena Stolfa, Aidan O'Dwyer
Estimation Of The Parameters Of A Delayed Process Using Open Loop Time Domain Techniques, Morena Stolfa, Aidan O'Dwyer
Conference papers
In this paper, we present three different approaches to fit the experimental data of a process with time delay in the time domain. Two of the proposed methods are based on the step response, and the third is based on the pulse response. The effectiveness of these techniques is verified by simulation results and by real-time experimental data. Only first order lag plus time delay models are considered in this paper.
A Classification Of Techniques For The Compensation Of Time Delayed Processes. Part 1: Parameter Optimised Controllers, Aidan O'Dwyer, John Ringwood
A Classification Of Techniques For The Compensation Of Time Delayed Processes. Part 1: Parameter Optimised Controllers, Aidan O'Dwyer, John Ringwood
Conference papers
An extensive literature exists on the compensation of time delayed processes. It is possible to identify themes that are common to many of the available techniques. The intention of the two parts of this paper is to provide a framework against which the literature may be viewed; Part 1 of the paper considers the use of parameter optimised controllers for the compensation problem, with Part 2 of the paper considering the use of structurally optimised compensators. Conclusions are drawn at the end of Part 2.
Robust Controller Design For Time Delay Systems Using H-Infinity Techniques, Susan Carr, Aidan O'Dwyer
Robust Controller Design For Time Delay Systems Using H-Infinity Techniques, Susan Carr, Aidan O'Dwyer
Conference papers
Using H-infinity control, the design problem is formulated in terms of user defined weighting polynomials on the process closed-loop sensitivity functions to achieve desired closed-loop performance and robust stability in the presence of process modelling error. In this paper stability conditions , in terms of the process sensitivity functions, are derived for processes containing a pure time delay for the following three design scenarios i) the time delay is neglected in the control design and is considered as part of the unmodelled process dynamics ii) A Pade approximation of the delay is included in the controller design and the effect …
Investigation Of The Thickness Mode In Surface Stabilized Ferroelectric Liquid Crystal Cells, O.E. Kalinovskaya, J.K. Vij, Yu. V. Tretyakov, Yuri Panarin, Yu. P. Kalmykov
Investigation Of The Thickness Mode In Surface Stabilized Ferroelectric Liquid Crystal Cells, O.E. Kalinovskaya, J.K. Vij, Yu. V. Tretyakov, Yuri Panarin, Yu. P. Kalmykov
Articles
Dielectric properties of surface stabilized ferroelectric liquid crystal (SSFLC) cells have been investigated both experimentally and theoretically. The thickness mode is found to consist of two relaxation processes. A decomposition of an analytical solution of the complex dielectric permittivitye(v) in terms ofthese processesis given. Theexperimental results showagreement with theory and lead to the conclusion that the thickness mode can be separated into two processes. It has been found that the ratio of the dielectric strengths for the two processes depends on the cell thickness, and that the ratio of their frequencies is approximately equal to 10. The lower frequency process …
Square Planar Monopole Antenna, Max Ammann
Square Planar Monopole Antenna, Max Ammann
Conference papers
A planar monopole may be realised by replacing the wire element of a conventional monopole with a planar element. In this case, the planar element which is square, is located above a groundplane and fed using an SMA connector as illustrated. The square monopole has a simple geometry and a smaller bandwidth compared to the circular-disc monopole. However, it is still a broadband antenna with a typical impedance bandwidth of 75 % at S band. This broadband antenna shows a constant radiation pattern over the impedance bandwidth. A simple formula for the frequency corresponding to the lower edge of the …