Abstract:
Safeguarding communication channels is required in particular in wireless networks. The use of encryption mechanisms in the form of software is limited by the required calculation and energy capacities of mobile terminals. Costs are of significance when using hardware solutions for cryptographic operations. The present invention provides an approach which simultaneously tackles all those points. It concerns a hardware accelerator for polynomial multiplication in extended Galois fields (GF), wherein the per se known Karatsuba method is iteratively applied in accordance with the invention. When using the invention the area requirement can be reduced for example from 6.2 mm2 to 2.1 mm2. The solution according to the invention also reduces the energy consumption in comparison with solutions in accordance with the state of the art by 30%.
Abstract:
The invention relates to a method for detecting accidental arcs (arc tracking) on a cable (1), especially on a cable of an aircraft electrical system. According to said method, an alternating current signal (I(t)) that has been detected is sampled time-discretely and a trigonometric function (I(k)) imitating the alternating current characteristic is determined by interpolation of a number of sampling values (y(k)). The current alternating frequency (ω) is then derived from this trigonometric function. The result of a comparison of the current alternating current frequency (ω) and a set or reference frequency (ω′) is used to determine the presence of an accidental arc (ISA,IGA) and a warning signal (Sarc) is optionally generated. A device which functions according to this method is advantageously integrated into a circuit-breaker (7) for the aircraft electrical system, so that the latter is equipped to detect and deactivate accidental arcs that occur on the electrical system cable (1).
Abstract:
Safeguarding communication channels is required in particular in wireless networks. The use of encryption mechanisms in the form of software is limited by the required calculation and energy capacities of mobile terminals. Costs are of significance when using hardware solutions for cryptographic operations. The present invention provides an approach which simultaneously tackles all those points. It concerns a hardware accelerator for polynomial multiplication in extended Galois fields (GF), wherein the per se known Karatsuba method is iteratively applied in accordance with the invention. When using the invention the area requirement can be reduced for example from 6.2 mm2 to 2.1 mm2. The solution according to the invention also reduces the energy consumption in comparison with solutions in accordance with the state of the art by 30%.
Abstract:
A filter arrangement has two hollow, coaxial, cylindrical filter elements, one of which is closed at one end and the other of which is connected to a clean fluid outlet. The outsides of the filter elements are separated from each other by an intermediate ring. A three-way valve is operable by an operating member to connect an inlet for the raw fluid to either or both of first and second filter elements. A control member operates valves for opening and closing an outlet for dirty fluid is operated at the same time with the three-way valve, dependent on its position. Both filter elements can be used simultaneously for filtering and also flow can be reversed through either filter element.
Abstract:
In order to be able to automatically locate and map ammunition over a large area without endangering the searching crew, ground-scanning sensors are mounted on a relatively light-weight, unmanned, remote-controlled vehicle which then travels over the area contaminated with ammunition. The controlled vehicle is controlled from, and the sensor signals are evaluated in, a second vehicle which is generally disposed in the immediate vicinity of the area being examined. The controlling vehicle, which is preferably armored, also accommodates the operating crew.
Abstract:
The construction of an arrangement for data transmission between a number of interconnection units should be realized so that, after a disturbance, an extensive reconfiguration of the arrangement is possible, so that all interconnection units which still communicate via a connection are interconnected by means of transmission paths which merely follow a different course in comparison with the non-disturbed state. In accordance with the invention each interconnection unit is provided with a device for generating synchronization information and in the case of a disturbance, appearing as a breakdown of the normal data stream, all interconnection units enter a test state in which test information is transmitted and possibly received test information is returned via all connections. Consequently, in each interconnection unit it can be autonomously decided which data paths are to be interconnected. In the case of at least three data connections per interconnection unit, different configurations are feasible which enable a complete reconfiguration to be realized also in the case of multiple disturbed connections between the interconnection units.
Abstract:
For radio communication with submarine vessels frequency ranges with very low frequencies are used. Even at these frequencies the penetration depth in salt water is only approximately 10 to 20 meters. In order to improve the signal noise ratio or to extend the submerging depth use is made of buoy antennas connected to the submarine vessel by a cable. In order to improve the manoeuvrability of the submarine vessel and to avoid the use of an active control system in the antenna, the antenna is constructed as a torpedo-like hollow body, which at the trailing part is equipped with two hydrofoils resembling a horizontal tail unit, which hydrofoils interconnect the top and bottom of the body to each other as an open arc. Both in the floating body and in the hydrofoils a loop of a crossed-loop antenna is incorporated, which loops are tuned in order to increase the sensitivity. Signal transmission to the submarine vessel is effected via an optical fibre guide, which also transmits the traction force.