Abstract: A solution to the music-on-hold problem associated with audio conference calls. The music on-hold-problem occurs when a conferee having music-on-hold puts the conference call on hold, resulting in a continuous stream of music being transmitted to the other conferees. Such a conferee is called an offending conferee. The solution presented herein is to prevent music-on-hold signals emanating from an offending conferee from being passed through an audio conference bridge to the other conferees. This is accomplished, in particular embodiments, by directing a merging/summing subsystem of the audio conference bridge to temporarily stop combining audio emanating from the offending conferee from being combined or merged onto audio channels through which the other conferees communicate on the audio conference.

Abstract: Verification systems which employ automata-theoretic formal verification use a model automaton made from a system process (203) representing the system and a task automaton (205) representing the task and use the model automaton to test (217) whether the language of the system process is contained in the language of the task automaton. An improved technique reduces the computational complexity of the language containment testing by producing a model (216) which represents a system which has been automatically localized with regard to a task. Another technique reduces the computational complexity of stepwise refinement (208). In stepwise refinement, the system automaton is refined a step at a time until it reaches the complexity of a practical implementation. The computational complexity of the stepwise refinement is reduced by a technique which permits language containment to be tested using a set of models made from process-automaton pairs rather than process-process pairs.

Abstract: A method of training a TTS or other system to assign intonational features, such as intonational phrase boundaries, is described. The method of training involves taking a set of predetermined text (not speech or a signal representative of speech) and having a human annotate it with intonational feature annotations. This results in annotated text. Next, the structure of the set of predetermined text is analyzed to generate information. This information is used, along with the intonational feature annotations, to generate a statistical representation. The statistical representation may then be stored and repeatedly used to generate synthesized speech from new sets of input text without training the TTS system further.

Abstract: A method wherein a verification tool checks the properties of a system model by performing a partial search of the system-model state space. A partial search is a search wherein the verification tool inputs, at each state of the system-model state space, only a subset or fraction of the complete set of inputs that would have been used during a conventional search. Performing a partial search, instead of a conventional search, reduces the total number of inputs that the verification tool will input to the system model during a search of the system-model state space, thus reducing the amount of computational resources and/or time needed by the verification tool to verify given properties of the system model. Moreover, performing a partial search, instead of a conventional search, does not substantially reduce the ability of the verification tool to identify errors in the system-model.

Abstract: A method and apparatus for defining a system design specification by using a finite set of templates that have a format for accepting a set of system expression such that a selected template, when filled with the system expressions, defines an intended behavioral attribute of the system. In one illustrative embodiment, each template has a set of qualifiers and a set of entry blanks, wherein each qualifier is associated with an entry blank. In such an embodiment, the set of entry spaces may comprise a fulfilling condition entry space for accepting a system expression that defines a required or assumed event of the system model, an enabling condition entry space for accepting a system expression that defines a precondition for starting a check of the required or assumed event, and a discharging condition entry space for accepting a system expression that defines a condition after which said fulfilling condition is no longer required or assumed by the system model.

Abstract: The invention presents a method and apparatus for forming a restricted model from a system model to reduce the computational resources required to formally verify the system design, without substantially reducing the ability to test all system model functions, or properties. In general, the restricted model is formed by restricting the range of assumable values of system model variables and system model inputs to a restricted set of values, based on the values assumed by the system model variables and system model inputs during a partial search of the system model. The restricted model can then be fully searched by a conventional verification tool to identify system design errors. Advantageously, the restricted model requires less computational resources to verify the system design (i.e. through a full search) than the original system model.

Abstract: A method and apparatus for verifying the behavior of properties or functions of a system by forming a reduced model for each property of the system, and running a given simulation operation on the reduced model to verify the behavior of each said property. When a property or function does not behave as expected, the system model is adjusted, and only those functions having a property affected by the adjustment are rechecked. In one illustrative embodiment, a system model is reduced by eliminating all variables having no effect on the function or property being checked. The resulting reduced model can be further reduced by adjusting the range of each variable therein to a minimum range necessary to check the behavior of that specific property. If it becomes necessary to change the system model in order to fix a problem relative to one property, then only those properties having a reduced model affected by that change or fix are re-verified.

Abstract: The invention presents a method and apparatus for forming a restricted model from a system model to reduce the computational resources required to formally verify the system design, without substantially reducing the ability to test all system model functions, or properties. In general, the restricted model is formed by restricting the range of assumable values of system model variables and system model inputs to a restricted set of values, based on the values assumed by the system model variables and system model inputs during a partial search of the system model. The restricted model can then be fully searched by a conventional verification tool to identify system design errors. Advantageously, the restricted model requires less computational resources during a fall search than the original system model.

Abstract: A system and method for selectively controlling database access by providing a system and method that allows a network administrator or manager to restrict specific system users from accessing information from certain public or otherwise uncontrolled databases (i.e., the WWW and the Internet). The invention employs a relational database to determine access rights, and this database may be readily updated and modified by an administrator. Within this relational database specific resource identifiers (i.e., URLs) are classified as being in a particular access group. The relational database is arranged so that for each user of the system a request for a particular resource will only be passed on from the local network to a server providing a link to the public/uncontrolled database if the resource identifier is in an access group for which the user has been assigned specific permissions by an administrator. The invention is implemented as part of a proxy server within the user's local network.

Abstract: A thermionic cathode having an overcoating of emissive material having a position including a mixture Aluminum Tungstate and Scandium Tungstate which react, when heated, to provide the cathode with enhanced electron emissions.

Abstract: A permanent magnet structure providing an internal magnetic field having an djustable magnitude and direction. The structure utilizes a shell composed of a predetermined number of concentric permanent magnet cylinders, each of which generates a discrete tunable magnetic field for tuning the magnitude and direction of the internal working field. Depending on the magnitude and direction of each discrete magnetic field, the magnitude and direction of the working field can be controlled and adjusted as desired.

Abstract: A simplified method of making permanent magnet structures, such as magic rings and magic spheres, from a uniformly magnetized permanent magnet shell. Thus, through the inventive method, building such structures requires only one remanence. For example, to make a magic ring providing a uniform internal magnetic field that can be accessed through non-distorting ports, a uniformly magnetized cylindrical shall is cut into ultra-thin washer shaped pieces. One half of the washer shaped pieces are radially cut into pie shaped pieces. The pie shaped pieces of each sliced-up washer-shaped piece are then rotated or transposed to form ultra-thin magic ring slices. The magic ring slices are then alternately stacked with the remaining washer shaped pieces to form a magic ring having predetermined regions wherein the shell magnetization is zeroized. Thus, the shell material in these regions can be removed to provide distortion-free access to the internal field.

Abstract: This invention provides a method for substantially reducing the time drift f a network clock in a frequency hopping communications system, without the need for a master unit to keep network time. The automatic network time tracking mechanism of each receiver is disabled when a network time update is received within a critical period of time from the closest synchronization update time or frequency hop time. The critical period is defined as the time between the closest synchronization update time to the local time when reception occurs less one-half the minimum tracking adjustment of the receiver plus the minimum processing or decoding delay, and that closest synchronization update time plus one half the minimum tracking adjustment of the receiver plus the maximum processing or decoding delay.

Abstract: A photon triggered RF radiator that is composed of a photoconductive subste having a ground plane electrode on its bottom surface and a top surface electrode having separate sections to perform energy storage and energy radiation functions. The energy storage section has a bulk-type photoconductive switch position therein such that any energy stored in the energy storage section of the top surface electrode is instantaneously discharged through the substrate to the ground plane, thus causing a pulse of nanosecond pulsewidth dimension to radiate from the energy radiation section of the top surface electrode.

Abstract: A magic sphere that provides a uniform internal field within an enlarged king space that can be accessed from large chambers that penetrate deep into the cavity of the magic sphere without substantially disrupting the magnitude or uniformity of the internal field.

Abstract: A photon triggered RF radiator having separate sections to perform the eny storage and the energy radiation functions. The energy storage function is performed by at least one charging electrode positioned on the upper surface of a photoconductive dielectric substrate, whereas the energy radiation function is performed by a charging electrode positioned adjacent to the charging electrode on the upper surface of the substrate. The charging electrode and the radiating electrode are separated by a predetermined gap distance that is large enough to insure there is no surface flashover between the electrodes and small enough to insure the efficiency of energy discharge from the charging pad to the spiral antenna is maximized.

Abstract: A system that provides an automated simultaneous measurement of the electal characteristics of a ferromagnetic material as a function of temperature and electric potential. The system utilizes a personal computer that interfaces with a DUT fixture through an interface measuring circuit that provides a means for remote control of the measurement process and insures a more timely and less manually intensive measuring process. The interface measuring circuit is composed of a temperature measuring circuit for measuring the temperature applied to the DUT, a capacitor measuring circuit for measuring the electric potential applied to the DUT, a high voltage power supply, a temperature plate power supply, a high voltage power supply driver, a digital voltage meter (DVM), and a DVM multiplexer. The system can utilize a humidity-free "dry" chamber (i.e. a desiccation chamber) to insure that the measurements of the DUT are reliable and accurate.

Abstract: A ferroelectric phase shifter for shifting the phase of a radio frequency F) signal. The phase shifter includes a conductor line, a ground plane and a ferroelectric element between the conductor line and the ground plane to form a microstrip circuit through which the RF signal propagates. The ferroelectric element has a dielectric constant that can be varied as a function of a DC voltage applied to the ferroelectric element wherein the speed of the RF signal propagating through the ferroelectric element is a function of the dielectric constant. The phase shifter further includes a DC voltage source connected across the conductor line and the ground plane. The DC voltage source applies a variable DC voltage to the ferroelectric element in response to a control signal thereby to vary the dielectric constant of the ferroelectric element.

Abstract: A device for measuring the electrical characteristics of a ferromagnetic erial as a function of temperature, such as its dielectric constant verses temperature characteristics. The device having a quick mount fixture that utilizes a gravity feed and thermal grease to insure a quick reliable thermal connection between the temperature controller and the device under test (DUT). In addition, the device can be remotely controlled by a computer to automate the measuring procedure, thus reducing measuring time and alleviating the intensive manual procedure of making such measurements. Moreover, the device is easily mountable in a humidity-free or desiccation chamber to insure the measurements are reliable and accurate.

Abstract: A 20 mR (5.16 * 10.sup.-3 C/Kg) full-scale carbon fiber dosimeter that provides a direct reading of low-level Gamma and neutron exposure in real-time. To attain this, the dosimeter utilizes an enlarged ionization chamber that has a cylindrical shape with an inside diameter at least 1 inch (2.54 cm), an outside diameter at least 1.1 inches (2.794 cm), an inside height at least 0.725 inch (1.8415 cm), and an outside at least 1 inch (2.54 cm). Moreover, the inner wall of the dosimeter's ionization chamber is lined with either a predetermined hydrogenous or non-hydrogenous material having different sensitivity to gamma ray and neutron exposure.