Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: Current and advanced act control system definition study. Volume 2: Appendices

The current status of the Active Controls Technology (ACT) for the advanced subsonic transport project is investigated through analysis of the systems technical data. Control systems technologies under examination include computerized reliability analysis, pitch axis fly by wire actuator, flaperon actuation system design trade study, control law synthesis and analysis, flutter mode control and gust load alleviation analysis, and implementation of alternative ACT systems. Extensive analysis of the computer techniques involved in each system is included

Stochastic resonance in electrical circuits—I: Conventional stochastic resonance.

Stochastic resonance (SR), a phenomenon in which a periodic signal in a nonlinear system can be amplified by added noise, is introduced and discussed. Techniques for investigating SR using electronic circuits are described in practical terms. The physical nature of SR, and the explanation of weak-noise SR as a linear response phenomenon, are considered. Conventional SR, for systems characterized by static bistable potentials, is described together with examples of the data obtainable from the circuit models used to test the theory

Preliminary design of a 100 kW turbine generator

The National Science Foundation and the Lewis Research Center have engaged jointly in a Wind Energy Program which includes the design and erection of a 100 kW wind turbine generator. The machine consists primarily of a rotor turbine, transmission, shaft, alternator, and tower. The rotor, measuring 125 feet in diameter and consisting of two variable pitch blades operates at 40 rpm and generates 100 kW of electrical power at 18 mph wind velocity. The entire assembly is placed on top of a tower 100 feet above ground level

High Speed All Optical Switching and Encryption using Ultrafast Devices

The next generation of fiber-optic communication system demands ultra-high speed data processing and switching components. Conventional electro-optical parts have reached their bottleneck both speed-wise and efficiency-wise. The idea of manipulating high speed data in all-optical domain is gaining more popularity. In this PhD dissertation, I showed the design and performance analysis of two kinds of ultra-fast all-optical latches, Set-Reset latch and D-flip-flop, based on two different schemes: (1) cross gain and phase modulation (XGM and XPM) in quantum dot semiconductor optical amplifiers (QD-SOA) and (2) two-photon absorption (TPA) in bulk semiconductor optical amplifiers. Design and simulation of a scheme to realize high speed all-optical encryption and decryption using key-stream generators and XOR gates based on QD-SOA are included in this dissertation. We also proposed and simulated all-optical Boolean logic functions with improved output quality using binary phase shift keyed signal based on QD-SOA. A fiber ring laser system with charcoal nano-particles as saturable absorber inside the cavity has been designed and experimentally demonstrated. This fiber ring laser system can generate optical pulse train @ 20Gb/s with improved stability and smaller pulse width comparing with the system without nano-particles in the cavity

An Octave-Range, Watt-Level, Fully-Integrated CMOS Switching Power Mixer Array for Linearization and Back-Off-Efficiency Improvement

The power mixer array is presented as a novel power generation approach for non-constant envelope signals. It comprises several power mixer units that are dynamically turned on and off to improve the linearity and back-off efficiency. At the circuit level, the power mixer unit can operate as a switching amplifier to achieve high peak power efficiency. Additional circuit level linearization and back-off efficiency improvement techniques are also proposed. To demonstrate the feasibility of this idea, a fully-integrated octave-range CMOS power mixer array is implemented in a 130 nm CMOS process. It is operational between 1.2 GHz and 2.4 GHz and can generate an output power of +31.3 dBm into an external 50 Ω load with a PAE of 42% and a gain compression of only 0.4 dB at 1.8 GHz. It achieves a PAE of 25%, at an average output power of +26.4 dBm, and an EVM of 4.6% with a non-constant-envelope 16 QAM signal. It can also produce arbitrary signal levels down to -70 dBm of output power with the 16 QAM-modulated signal without any RF gain control circuit

Electronic filters, hearing aids and methods

An electronic filter for an electroacoustic system. The system has a microphone for generating an electrical output from external sounds and an electrically driven transducer for emitting sound. Some of the sound emitted by the transducer returns to the microphone means to add a feedback contribution to its electrical output. The electronic filter includes a first circuit for electronic processing of the electrical output of the microphone to produce a first signal. An adaptive filter, interconnected with the first circuit, performs electronic processing of the first signal to produce an adaptive output to the first circuit to substantially offset the feedback contribution in the electrical output of the microphone, and the adaptive filter includes means for adapting only in response to polarities of signals supplied to and from the first circuit. Other electronic filters for hearing aids, public address systems and other electroacoustic systems, as well as such systems and methods of operating them are also disclosed

Digital-flutter-suppression-system investigations for the active flexible wing wind-tunnel model

Active flutter suppression control laws were designed, implemented, and tested on an aeroelastically-scaled wind tunnel model in the NASA Langley Transonic Dynamics Tunnel. One of the control laws was successful in stabilizing the model while the dynamic pressure was increased to 24 percent greater than the measured open-loop flutter boundary. Other accomplishments included the design, implementation, and successful operation of a one-of-a-kind digital controller, the design and use of two simulation methods to support the project, and the development and successful use of a methodology for on-line controller performance evaluation