Abstract: Apparatus for resolving movement of a mass within a defined space utilizes at least one electrode proximate to the space to be observed. An AC signal is applied to the electrode, and the current measured from that electrode and also to any other electrodes included in the system, and which are effectively connected to the ground return of the AC-coupled electrode. A person (or object) to be sensed intercepts a part of the electric field extending beween the AC-coupled "sending" electrode and the other "receiving" electrodes, the amount of the field intercepted depending on the size and orientation of the sensed person, whether or not the person provides a grounding path, and the geometry of the distributed electrodes. Given the nonlinear spatial dependence of the field, multiple electrodes can reliably distinguish among a set of expected cases.

Abstract: Apparatus and methods for resolving movement of a mass within a defined space utilizes at least one electrode proximate to the space to be observed. An AC signal is applied to the electrode, and the current measured from that electrode and also to any other electrodes included in the system and which are effectively connected to the ground return of the AC-coupled electrode. A person (or object) to be sensed intercepts a part of the electric field extending beween the AC-coupled "sending" electrode and the other "receiving" electrodes, the amount of the field intercepted depending on the size and orientation of the sensed person, whether or not the person provides a grounding path, and the geometry of the distributed electrodes. Given the nonlinear spatial dependence of the field, multiple electrodes can reliably distinguish among a set of expected cases.

Abstract: A planar electromagnetic resonator utilizes an electromagnetically active material located between the capacitive or inductive elements of the resonator. A microscopic electrical property of this material is altered by an external condition, and that alteration, in turn, affects the behavior of the resonator in a consistent and predictable manner.

Abstract: A quasi-electrostatic sensing system surrounds an electrically conductive mass with an electric field, the magnitude of which is sensed at one or more locations to resolve a property of interest concerning the mass. The object intercepts a part of the electric field extending beween the AC-coupled "sending" electrode and the other "receiving" electrodes, the amount of the field intercepted depending on the size and orientation of the sensed mass, whether or not the mass provides a grounding path, and the geometry of the distributed electrodes. Because the response of the field to an object is a complex nonlinear function, adding electrodes can always distinguish among more cases. In other words, each electrode represents an independent weighting of the mass within the field; adding an electrode provides information regarding that mass that is not redundant to the information provided by the other electrodes.

Abstract: Efficient synthesis of complex, driven systems is accomplished using a probabilistic framework according to which the physics of system behavior are modeled in terms of the effective degrees of freedom relevant to observed behavior, instead of modeling the physical configuration or the output waveform. A replica of the system's behavior in response to external stimulus is developed computationally, and the model used to replace (or facilitate replacement) of the system with, for example, a physical representation programmed to behave in accordance with the model. The invention may be applied to develop a model capturing the behavior of a complex musical instrument such as a violin; the model then may be embodied in any physically appealing format (e.g., as a plastic replica of the original violin that would, absent the implemented model, produce no sound if bowed; or a keyboard or other musical instrument whose response to being "played" is to generate the sounds of the original violin).

Abstract: A method for resolving presence, orientation and activity of a person within a defined space utilizes at least two electrodes proximate to the space to be observed. A characterization of the position and orientation is obtained by providing a pattern of measurement clusters each associated with a position and an orientation. An AC signal is applied to one electrode, and the current measured from that electrode to any other electrodes included in the system, and which are effectively connected to the ground return of the AC-coupled electrode. A person (or object) to be sensed intercepts a part of the electric field extending between the AC-coupled "sending" electrode and the other "receiving" electrodes, the amount of the field intercepted depending on the size and orientation of the sensed person, whether or not the person provides a grounding path, and the geometry of the distributed electrodes.

Abstract: An approach to processing quantum information uses a bulk ensemble of a very large number of identical entities as its source of quantum degrees of freedom. The information is represented as the deviation from uniform population probability for at least one of the quantum states of the ensemble. Coherences between quantum states, created when the ensemble is modified in a way that removes it from thermal equilibrium can serve as effective degrees of freedom. A bulk thermal ensemble of nuclear spins in a static magnetic field is treated using nuclear magnetic resonance pulses for preparation of an initial pure state, and effecting arbitrary single-spin and coupled multi-spin rotations. Readout of the result is accomplished by observation of the magnetization of the ensemble.

Abstract: Apparatus and methods for resolving presence, orientation and activity of a person within a defined space utilizes at least one electrode proximate to the space to be observed. An AC signal is applied to the electrode, and the current measured from that electrode and also to any other electrodes included in the system, and which are effectively connected to the ground return of the AC-coupled electrode. A person (or object) to be sensed intercepts a part of the electric field extending beween the AC-coupled "sending" electrode and the other "receiving" electrodes, the amount of the field intercepted depending on the size and orientation of the sensed person, whether or not the person provides a grounding path, and the geometry of the distributed electrodes. Given the nonlinear spatial dependence of the field, multiple electrodes can reliably distinguish among a set of expected cases. The invention can be configured to detect not only static positions and orientations, but also motion through a defined space.

Abstract: A quasi-electrostatic sensing system surrounds an electrically conductive mass with an electric field, the magnitude of which is sensed at one or more locations to resolve a property of interest concerning the mass. The object intercepts a part of the electric field extending between the AC-coupled "sending" electrode and the other "receiving" electrodes, the amount of the field intercepted depending on the size and orientation of the sensed mass, whether or not the mass provides a grounding path, and the geometry of the distributed electrodes. Because the response of the field to an object is a complex nonlinear function, adding electrodes can always distinguish among more cases. In other words, each electrode represents an independent weighting of the mass within the field; adding an electrode provides information regarding that mass that is not redundant to the information provided by the other electrodes.

Abstract: The multiple scattering of coherent radiation in an inhomogeneous medium is used to detect attempted intrusions into a protected area or into a tamper-proof package for such purposes as preventing the unauthorized detection and copying of electronic information used for authentication and coding in electronic commerce, communications, command, and control systems. A key advantage is that any intrusion into the sensed volume will produce a detected change in the measured intensity which will be equal to the full amplitude range if the intrusion is into a cylinder with radius comparable to the wavelength of the sensing radiation. The response of the medium can also be used to provide a unique identity key.

Abstract: A communication and/or measurement system includes in a a transmitter an analog feedback system that modulates a pseudo-random noise signal with a message signal to produce a wideband signal for transmission. A receiver, which demodulates the wideband signal to recover the message signal, includes an associated analog feedback system that reproduces the noise signal based on the received signal. The analog feedback systems (AFS) are continuous-time generalizations of a linear feedback shift register ("LFSR"). The AFS are characterized by a function that agrees with the function that characterizes the LFSR, at the points at which that function is defined. Further, the AFS characterizing function has stable periodic orbits at these values, and the stable periodic orbits are attractors. The AFS thus produces a signal that relaxes on to a nearest periodic orbit that generalizes to continuous time the maximal sequence produced by the corresponding LFSR.

Abstract: An optical communication and/or measurement system includes a transmitter that modulates a pseudo-random noise signal with a message signal to produce a wideband signal for transmission. A receiver, which demodulates the wideband signal to recover the message signal, includes an "analog" feedback shift register ("AFSR") that reproduces the noise signal based on samples of the received signal. The AFSR is a generalization of a linear feedback shift register ("LFSR"). The AFSR is characterized by a function that agrees with the function that characterizes the LFSR, at the points at which that function is defined. The AFSR includes beam splitters that are spaced in accordance with the associated pseudorandom code. The AFSR's function has stable fixed points at integer values and unstable fixed points at half-integer values and, the stable fixed points act as attractors. The AFSR thus produces a sequence that relaxes to the nearest integer-valued sequence.

Abstract: A communication and/or measurement system includes a transmitter that modulates a pseudo-random noise signal with a message signal to produce a wideband signal for transmission. A receiver, which demodulates the wideband signal to recover the message signal, includes an "analog" feedback shift register that reproduces the noise signal based on samples of the received signal. The analog feedback shift register ("AFSR") is a generalization of a linear feedback shift register ("LFSR"). The AFSR is characterized by a function that agrees with the function that characterizes the LFSR, at the points at which that function is defined. Further, the AFSR characterizing function has stable fixed points at these values, i.e., it has a slope of less than one in these regions. Specifically, the AFSR's function has stable fixed points at integer values and unstable fixed points at half-integer values and, the stable fixed points act as attractors.

Abstract: A communication and/or measurement system includes a transmitter that modulates a pseudo-random noise signal with a message signal to produce a wideband signal for transmission. A receiver, which demodulates the wideband signal to recover the message signal, includes an "analog" feedback shift register that reproduces the noise signal based on samples of the received signal. The AFSR is characterized by a function that agrees with the function that characterizes the LFSR, at the points at which that function is defined. Further, the AFSR characterizing function has stable fixed points at these values, i.e., it has a slope of less than one in these regions. Specifically, the AFSR's function has stable fixed points at integer values and unstable fixed points at half-integer values and, the stable fixed points act as attractors. The AFSR thus produces a sequence that relaxes to the nearest integer-valued sequence.

Abstract: A preferred embodiment of the invention is an apparatus for measuring the position of a point with respect to at least one axis. The apparatus includes a reference electrode located at the reference point and at least one axial electrode fixed along the at least one axis. The axial electrode has a signal transmission property, such as resistivity, as measured between a first end and a point along the axis, which signal transmission property varies with the location of the point of measurement. The axial electrode is coupled to the reference electrode, typically capacitively. The apparatus also includes means for applying an electric signal to the reference electrode; means for measuring an output electric signal at the first end of the at least one axial electrode; and means for evaluating the relation between the output electric signal and the input electric signal to determine the position of the reference point relative to the axis.

Abstract: A cermet thin film resistor having small particles of a refractory metal embedded in a ceramic insulator at compositions near the percolation transition. The cermets are produced by co-deposition in a dual-electron beam evaporator. The refractory metal is typically Mo or Pt. The insulator is typically a Al.sub.2 O.sub.3, although other insulators, for example SiO.sub.2 may be used. Deposition occurs onto a suitable substrate such as a sapphire under an oxygen environment, typically 10.sup.-5 Torr O.sub.2 with the stage heated in the range of typically 400.degree. C. Such is done to increase the size of the metallic regions. The microstructure is 10-50 .ANG. embedded metal in the ceramic. The resulting films are in the range of 1500 .ANG. thick which provides a film having a typical resistivity of 400 m.OMEGA. - cm which may then be patterned using lithography techniques to form two or four terminal resistors.