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Georgia Tech Patents

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Now showing 1 - 10 of 314
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Methods For Dewatering Solid-liquid Matrices

The present invention provides novel processes for the dewatering of a wide variety of solid-liquid matrices, including primary and secondary sludge, which involve the simultaneous application of pressure and heat to the solid-liquid matrices.

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Telemedicine System Using Voice Video And Data Encapsulation And De-encapsulation For Communicating Medical Information Between Central Monitoring Stations And Remote Patient Monitoring Stations

The present invention provides a packet-based telemedicine system for communicating video, voice and medical data between a central monitoring station and a patient monitoring station which is remotely-located with respect to the central monitoring station. The patient monitoring station obtains digital video, voice and medical measurement data from a patient and encapsulates the data in packets and sends the packets over a network to the central monitoring station. Since the information is encapsulated in packets, the information can be sent over multiple types or combinations of network architectures, including a Community access Television (CATV) network, the Public Switched Telephone Network (PSTN), the Integrated Services Digital Network (ISDN), the Internet, a local area network (LAN), a wide are network (WAN), over a wireless communications network, or over an asynchronous transfer mode (ATM) network. Thus, a separate transmission protocol is not required for each different type of transmission media. Rather, a single transport/network layer protocol is used for encapsulating the information in packets at the sending end and for de-encapsulating the information at the receiving end. Furthermore, by sending the information in packets, the video, voice and measurement data can be integrated and sent over a single network.

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Methods And Apparatus For Acoustic Fiber Fractionation

Methods and apparatus for acoustic fiber fractionation using a plane ultrasonic wave field interacting with water suspended fibers circulating in a channel flow using acoustic radiation forces to separate fibers into two or more fractions based on fiber radius, with applications of the separation concept in the pulp and paper industry. The continuous process relies on the use of a wall-mounted, rectangular cross-section piezoelectric ceramic transducer to selectively deflect flowing fibers as they penetrate the ultrasonic field. The described embodiment uses a transducer frequency of approximately 150 kHz. Depending upon the amount of dissolved gas in water, separation is obtained using a standing or a traveling wave field.

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Arrangement, Dopant Source, And Method For Making Solar Cells

Disclosed is an arrangement, dopant source and method used in the fabrication of photocells that minimize handling of cell wafers and involve a single furnace step. First, dopant sources are created by depositing selected dopants onto both surfaces of source wafers. The concentration of dopant that is placed on the surface is relatively low so that the sources are starved sources. These sources are stacked with photocell wafers in alternating orientation in a furnace. Next, the temperature is raised and thermal diffusion takes place whereby the dopant leaves the source wafers and becomes diffused in a cell wafer creating the junctions necessary for photocells to operate. The concentration of dopant diffused into a single side of the cell wafer is proportional to the concentration placed on the respective dopant source facing the side of the cell wafer. Then, in the same thermal cycle, a layer of oxide is created by introducing oxygen into the furnace environment after sufficient diffusion has taken place. Finally, the cell wafers receive an anti-reflective coating and electrical contacts for the purpose of gathering electrical charge.

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Method And System For Generating And Implementing Orientational Filters For Real-time Computer Vision Applications

Methods for generating and implementing digital orientational filters. A first method of the present invention is provided for generating digital orientational filters of uniform size but each having a different fixed orientation. A second method provides for dilation of the digital orientation filters generated by the first method, both in a decimated and an undecimated format. A third method of the present invention provides for steering the orientation of the filters generated by the first method. Also, associated VLSI hardware based systems implementing the above methods are disclosed. The above methods and systems allow digital orientational filters to be utilized in computer vision and other applications requiring a large amount of video signal data to be processed in real-time.

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Method And Apparatus For Control Of A Switched Reluctance Motor

A method for estimating and controlling the rotor position of a SRM comprises the steps of sampling phase currents and estimating phase fluxes from at least one excited phase of the SRM, sampling phase currents and estimating phase inductances from at least one unexcited phase of the SRM, and estimating the rotor position by determining a rotor position that is common to the estimated phase flux and the estimated phase inductance solutions to predetermining flux and inductance models. The estimation of rotor position can be less sensitive to measurement noise by applying a least squares technique. Once the rotor position has been estimated by the above method, the position of the rotor can be controlled so as to provide an overall effective control of the SRM. In particular, once the position of the rotor is estimated, the excitation provided to the motor is then adjusted to urge the rotor from its current position, velocity or torque toward a desired position, velocity or torque.

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Non-vibrating Capacitance Probe For Wear Monitoring

A non-vibrating capacitance probe for use as a non-contact sensor for tribological wear on a component. The device detects surface charge through temporal variation in the work function of a material. A reference electrode senses changing contact potential difference over the component surface, owing to compositional variation on the surface. Temporal variation in the contact potential difference induces a current through an electrical connection. This current is amplified and converted to a voltage signal by an electronic circuit with an operational amplifier.

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Synthetic Jet Actuators For Modifiying The Direction Of Fluid Flows

In a first preferred embodiment for an improved synthetic jet actuator, the orifice shape is altered by either a flap or adjusting the housing walls. If the flap is deployed outward from the wall just above the orifice of a synthetic jet actuator, the synthetic jet flow will be vectored upward, toward the flap. Similarly, if the upper wall forming the orifice is moved outward from the jet chamber interior with respect to an opposing wall forming the orifice, the flow will also vector upward. In the second preferred embodiment of an improved synthetic jet actuator, an opening in addition to the orifice, may be formed in one or more walls of the housing. A louver is aligned with the opening in the housing and permits fluid flow in only one direction, either into the chamber or out of the chamber. When the louver permits fluid flow into the chamber, the jet actuator can operate at high speeds since fluid can enter the chamber through a greater surface area. Another preferred embodiment for an improved synthetic jet actuator comprises two concentric tubular sections normal to an outside surface of a solid body). In operation, the innermost section is connected to a vacuum device and constantly pulls fluid down its length from the ambient fluid above the outer surface. Meanwhile, the outer section ejects fluid into the ambient environment by pulses. Such an operation will cause a synthetic fluid jet to form above the constant suction synthetic jet actuator.

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Poly(vinyl Alcohol) Cryogel

The present invention includes a poly(vinyl alcohol) hydrogel construct having a wide range of mechanical strengths for use as a human tissue replacement. A process in connection with the present invention eliminates any step involved with dehydration of the hydrogel prior to implantation thereof. The hydrogel construct may include a tissue scaffolding, a load bearing surface within a joint, or any other structure which is suitable for supporting the growth of tissue.

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Video Coding System And Method For Noisy Signals

A video coding system and method enable communication of a noisy video signal over communications channels, such as low capacity channels (e.g., telephone lines), by efficiently decomposing the video signal into an underlying structure component and a texture component using subband decomposition. Because much of a texture component is random noise, the texture component lends itself to temporal decimation. This predicament results in a texture frame being encoded and transmitted once every Dt frames and allows texture frames to be sent at a lower rate than underlying structure frames. Because the underlying structure component contains most of the information related to structure, it is decimated in the spatial domain, which allows for maximum data transfer. The texture component and underlying structure component are then coded for transmission over the communications channel, such as a low capacity conventional telephone line, using a method which exploits the characteristic noise and the quasiperiodic nature of the signal.