Proprietary technologies have resulted in patents:
Method For Measuring Ultrasonic Transit Times
Embodiments of the invention provide an algorithm for enhancing the transit time measurement of an ultrasonic wave through a fluid, and criteria for evaluating the suitability for various waveforms with regard to noise rejection. The transit time calculation provides a greater noise immunity and accuracy than techniques used in the prior art, and allows a measure of weighting of dispersed signals with different arrival times. The transit time calculation utilizes either the transmitted signal or the measurement of a reference system, the calculation of the squared convolution of this signal with the received signal, and the calculation of the transit time from the time-weighted squared convolution signal over a suitable interval defined by the minimums of the squared convolution signal. In the case of dispersion where the arrival times are symmetrically displaced around a mean transit time, or if asymmetric dispersion is suitably within the main lobe, the calculation properly weights the composite signal. The symmetry of the calculated autocorrelation function predicts the accuracy of the algorithm, and deconvolution can be used to estimate the composition of the composite delay function in such cases.
Electronic signature management method
An apparatus for creating a framework for the creation, editing, signing and signature verification of multiple documents includes a master, or cover, document as a holder and display source for the subdocuments created within the cover document. The cover document is protected against direct modification with the possible exception of the addition of comments that do not affect digital signatures in the cover document. Access to the subdocuments for editing, signature generation and signature verification is through a menu associated with the cover document. A method of creating a hierarchy of approval signatures on the cover document encompassing subdocuments and nested approval signatures is described.
Additional patents assigned to clients:
Processor control of an audio transducer
A controller, either a microprocessor or finite state machine, is used to generate a pulse train whose frequency and duty cycle can be varied to alter the frequency and amplitude of the output of a driven audio transducer. The ability to control both frequency and amplitude allows programmatic synthesis of many audio effects such as steady tones, warbles, beeps, sirens and chimes with no hardware or circuit changes. The transducer can be a piezoelectric bender or a speaker. The output of the controller controls a switch that builds current in an inductor when the switch is on. When the switch is turned off, the energy stored in the inductor is dumped into the audio transducer, either directly or through intermediate capacitor storage. This allows the generation of voltages across the transducer many times the supply voltage.
Bus safety controller method and system
System and method for automatically broadcasting voice-based prompt warnings toward an embarkation and/or disembarkation location at which passengers such as students and others may or will be present. The method is multi-model providing voice messages during an approach mode, a stop mode and a standby mode. Recorded human voice messages are employed for the prompt and are the recorded voices of one or more people having voice characteristics generally recognizable by the passengers to an extent effective to supplement the function of the immature prefrontal cortex.