Abstract:
Methodology and concomitant circuitry to generate cryptographically strong pseudo-random bit streams utilize secure block cypher encoders. Each block cypher encoder (550) has a random key (540) and a first seed (510) as an input, and the output of each encoder is fed back to connect to its input. The first seed serves as the initial input, and each subsequent input is the immediate output of the block cypher encoder. Each bit in the cryptographically strong pseudo-random bit stream is related to a first inner product between input to the block cypher encoder and a second seed (520) and a second inner product (560) between the random key and a third seed (570).
Abstract:
A birefringence-free semiconductor waveguide comprising on a substrate (10) a plurality of layers (18) some of which (62) are in tensile strain with respect to the substrate and others of which (64) are in compressive strain. Birefringent-free behavior with respect to a guided light signal traveling in the waveguiding structure and possessing a photon energy lower than the bandgap of the constituent waveguide layers is obtained when birefringence introduced into the individual layers of the waveguiding structure by the strain is sufficient to compensate for the intrinsic geometric modal birefringence of the waveguiding structure that exists in the case where all layers are not strained. This is achieved through the introduction of a predetermined amount of tensile strain and a predetermined amount of compressive strain into one or more layers. In this manner, waveguiding structures that are substantially free of modal birefringence may be obtained to avoid any strain-induced defects.
Abstract:
A bandwidth management system (120) manages a plurality of virtual data connections within a communications network. The system includes an input (122) for receiving data cells, wherein each cell is associated with a particular one of the virtual connections. The system also includes a cell pool, coupled to the input for storing the cells, first and second queues (126-128) for ordering the virtual connections, and an output (137) for transmitting cells from the cell pool. The relative position of a virtual connection in the first queue is determined by an eligibility variable that varies according to an anticipated data rate associated with the particular virtual connection and according to an amount of time that the particular virtual connection has been in the first queue. The relative position of a virtual connection in the second queue varies according to a predetermined quality of service that is assigned to each of the virtual connections.
Abstract:
LiCoO2 and LiNiO2 are fully delithiated electrochemically using solid state electrolytic cells and oxidation-resistant electrolytes to yield new, stable phases of CoO2 and NiO2
Abstract:
A rechargeable battery comprises a laminate electrolytic cell in which a flexible plasticized polymer hybrid electrolyte/separator layer is interposed between positive and negative electrode layers of lithium-ion intercalating polymeric matrix compositions bearing respective current collector foils (11, 19). An elongate laminar cell (10) is formed into a unified battery by means of an initial transverse fold (23) disposing one electrode/collector within the structure and with subsequent sequential folds (25, 27, 29) spiralling the cell, without need for interposed insulation, outwardly toward the electrode ends where the collectors accommodate battery terminals (22, 24). Immersion of the structure in a solvent extracts the polymer plasticizer which is subsequently replaced by contact with lithium salt solution electrolyte to activate the battery.
Abstract:
Coupling between two side circuits and a phantom circuit in a quaded cable (200) is compensated for at the receiving end of a transmission system. Known signals are separately transmitted on each circuit and coupling between each circuit is estimated based on a measured signal received at the receiving end of the quaded cable for initialization. During data transmission, received data signals are modified in accordance with the initially determined coupling to produce estimated transmitted data signals. Reestimation of the coupling between each circuit is performed during data transmission by storing (303) N received data signals and N estimated transmitted data signals on each circuit. The coupling between circuits is determined as a function of the covariance of the N received signals and covariance of the N estimated transmitted signals on each circuit. The reestimated coupling is used to modify (302) subsequent received data signals on each circuit.
Abstract:
A polymeric film useful as an interelectrode separator or electrolyte member in electrolytic devices, such as rechargeable batteries, comprises a copolymer of vinylidene fluoride and hexafluoropropylene, a medium to high-boiling plasticizer, and a finely divided inorganic filler which has been subjected to actinic radiation or thermal energy to cause crosslinking thereof in the presence of a crosslinking agent selected from the group consisting of an acrylate ester, di- or triallyl ester and a di- or triglycidyl ether.
Abstract:
The present invention is generally directed to the transmission of data in various types of communication systems, including local area networks (LANs) and wide area networks (WANs). A main object of the present invention is to provide a system (2) based on a parallel structure that can assemble (3) and disassemble (4) packet information (1) in constant time, no matter how corrupted, out of order, duplicated the arriving packets (1a, 1b). A further object of the present invention is to provide a system (2) that would improve efficiency in broadband networks, particularly if implemented in a VLSI chip using the low complexity architecture-and-reassembly of the present invention.
Abstract:
Echo cancellation can be used to increase the reach or noise margin of a channel to make use of the low frequency portion of the cable spectrum. A generalization of previously described cancelers, when properly optimized, results in significant complexity reduction. The generalization applies to the Cyclic Echo Synthesizer (CES), which forms the time-domain processing portion of the canceler. By expanding the achievable CES input range and optimizing the temporal alignment between transmitter (82) and echo canceler (78), canceler computational complexity is reduced.
Abstract:
A method and system for managing telephone calls includes a personal telephone manager (PTM) (12) and uses out-of-band, wireless, two-way signaling, messaging and alerting to screen, control, route and respond to incoming telephone calls and to communicate called party text messages in auditory form to the caller. Using an out-of-band signaling/messaging path (16), the PTM (12) frees the called party from the need to maintain telephone network connectivity, from having to inform others of his/her current location, and from having to subscribe to and use cellular telephone service. Two-way wireless data messaging to a portable computer (18) equipped with radio transceivers is also provided. This feature enables the system to provide a set of real-time options including: call screening by the called party based on information identifying the caller's telephone number; call redirection to a wireline or wireless telephone number as specified by the called party; call redirection to a third party or to a voice mail system; or the return of a text message specified by the called party to the caller in auditory form.