Abstract: Centralized controllers for a photovoltaic-enabled distribution grid are described herein. Photovoltaic cells may generate electricity that may be supplied to the distribution grid, which may experience unexpected abnormal power loads. The controllers utilize photovoltaic inverters connected to the photovoltaic cells to optimize the performance of the grid by absorbing or injecting reactive power. These controllers are particularly efficient in handling unexpected abnormal power loads.

Abstract: Real-time detection of high-impedance faults in a distribution circuit is described. The real-time detection of high-impedance faults includes two steps. First, adaptive soft denoising is employed to perform a filtering process on a healthy dataset, and to determine a threshold. This reduces the rate of false alarms. Second, faulty datasets are prefiltered via adaptive soft denoising, then the denoised signals are processed via discrete wavelet transform to perform high-impedance fault detection using the threshold.

Abstract: Orthogonal frequency division multiplexing schemes are described for power line communications to combat frequency-selective fading and intersymbol interference. These orthogonal frequency division multiplexing systems may employ space-time coding and/or parallel cancellation to provide low receiver complexity, two-branch diversity, and much higher carrier-to-intercarrier-interference ratio as compared to other methods, such as self-cancellation.

Abstract: Real-time detection of high-impedance faults in a distribution circuit is described. The real-time detection of high-impedance faults includes two steps. First, adaptive soft denoising is employed to perform a filtering process on a healthy dataset, and to determine a threshold. This reduces the rate of false alarms. Second, faulty datasets are prefiltered via adaptive soft denoising, then the denoised signals are processed via discrete wavelet transform to perform high-impedance fault detection using the threshold.

Abstract: Centralized controllers for a photovoltaic-enabled distribution grid are described herein. Photovoltaic cells may generate electricity that may be supplied to the distribution grid, which may experience unexpected abnormal power loads. The controllers utilize photovoltaic inverters connected to the photovoltaic cells to optimize the performance of the grid by absorbing or injecting reactive power. These controllers are particularly efficient in handling unexpected abnormal power loads.

Abstract: A system and method for reducing ICI in multicarrier systems is disclosed. The system uses a primary transmission path to transmit a first signal using the same techniques as conventional OFDM and a second transmission path to transmit a conjugate of the first signal. The differing transmission paths can be implemented on separate channels via a variety of multiplexing and/or diversity techniques.

Abstract: A parallel orthogonal frequency division multiplexed (OFDM) communications system includes a transmitter and receiver, the transmitter having a parallel fast Fourier transform (FFT) module operating in parallel to a conventional inverse fast Fourier transform (IFFT) module for providing respective orthogonal outputs received by the receiver. The receiver has a parallel IFFT module and a conventional FFT module for providing respective orthogonal outputs. The respective orthogonal outputs are combined to form a composite signal that provides improved insensitivity to relative frequency offsets and Doppler frequency offsets. The parallel FFT and IFFT modules in the OFDM communication system provides improved signal diversity and performance in the presence of relative frequency offsets and Doppler frequency offsets, and provides improved tracking capability for the receiver with backward compatibility.

Abstract: A system and method for reducing ICI in multicarrier systems is disclosed. The system uses a primary transmission path to transmit a first signal using the same techniques as conventional OFDM and a second transmission path to transmit a conjugate of the first signal. The differing transmission paths can be implemented on separate channels via a variety of multiplexing and/or diversity techniques.

Abstract: A parallel orthogonal frequency division multiplexed (OFDM) communications system includes a transmitter and receiver, the transmitter having a parallel fast Fourier transform (FFT) module operating in parallel to a conventional inverse fast Fourier transform (IFFT) module for providing respective orthogonal outputs received by the receiver. The receiver has a parallel IFFT module and a conventional FFT module for providing respective orthogonal outputs. The respective orthogonal outputs are combined to form a composite signal that provides improved insensitivity to relative frequency offsets and Doppler frequency offsets. The parallel FFT and IFFT modules in the OFDM communication system provides improved signal diversity and performance in the presence of relative frequency offsets and Doppler frequency offsets, and provides improved tracking capability for the receiver with backward compatibility.

Abstract: The presentation is a low-cost, two-way communication system and method for aid in locating an object, such as a container or a package and reporting the contents of the object to a site remote from the location of the object. In one embodiment, the system includes two modules. A remote module includes a directional antenna array mounted on the top of the module (i.e., in a remote site), a processor including a direction-finding software, and a display for pointing the direction of the container's location relative to the remote site.

Abstract: A system for locating a vehicle that is parked in a parking lot, a parking garage or on a street. The system comprises two separate signal generator/processor circuits, each circuit being contained in a module, one being a hand-held locator module and the other, a receive/response module that is installed in a vehicle. Both modules, when activated by user, communicate with the other by means of specially encoded radio signals. To find a parked vehicle, a user merely presses a pushbutton on the locator module which transmits a high frequency search signal. In response, the receive/response module emits a direction indicating signal to the locator module, which then displays the direction and elevation of the vehicle with respect to the user location. Provision is made for the receive/response module to operate without a connection to a vehicle battery if necessary, allowing the module to be used portably. The system is small in size, inexpensive and easy to use.

Abstract: A system for locating a vehicle that is parked in a parking lot, a parking garage or on a street. The system comprises two separate signal generator/processor circuits, each circuit being contained in a module, one being a hand-held locator module and the other, a receive/response module that is installed in a vehicle. Both modules, when activated by user, communicate with the other by means of specially encoded radio signals. To find a parked vehicle, a user merely presses a pushbutton on the locator module which transmits a high frequency search signal. In response, the receive/response module emits a direction indicating signal to the locator module, which then displays the direction and elevation of the vehicle with respect to the user location. Provision is made for the receive/response module to operate without a connection to a vehicle battery if necessary, allowing the module to be used portably. The system is small in size, inexpensive and easy to use.

Abstract: A method for nodulizing silicon crystals in casting Aluminum-(8-12%)Silicon alloys is described. An initial alloy melt is refined by addition of a master alloy containing elements of titanium, phosphorous, boron, zirconium and rare earths to the initial molten alloy, and then through conventional heat treatment and aging. Testing the alloys shows that the nodulized silicon crystals are blunted in shape and well distributed, resulting in a high resistance to wear and high ultimate tensile strength at room temperature and at 300 deg. C. Machinability of the Al-Si alloys is also greatly improved by the process.

Abstract: A method and apparatus for processing signals representative of a complex matrix/vector equation. More particularly, signals representing an orderly sequence of the combined matrix and vector equation, known as a Kalman filter algorithm, are processed in real time in accordance with the principles of this invention. The Kalman filter algorithm is rearranged into a Faddeeva algorithm, which is a matrix-only algorithm that is modified to represent both the matrix and vector portions of the Kalman filter algorithm. The modified Faddeeva algorithm is embodied into electrical signals which are applied as inputs to a systolic array processor. The processor performs triangulation and nullification on the input signals, and delivers an output signal which is a real-time solution to the input signals.