Abstract: A method for modulating a carrier signal used for transmitting analog or digital message signals is provided. The module k of elliptic functions is used as a modulation parameter instead of the amplitude or the frequency. The carrier signal modulated according to this modulation method is provided with a constant amplitude and a fixed frequency while the signal form is chronologically modified at the rhythm of the message that is to be transmitted.

Abstract: A subsea communication system includes devices in a wellbore and devices on a floor, where the devices in the wellbore and on the floor are able to communicate wirelessly with each other, such as through a formation.

Abstract: A method and circuit arrangement for transmission of messages in which a number of L components (m0, . . . , mL-1) are coded by means of orthogonal functions to a signal (s(t)), and in which approximations of hermitic functions are used as orthogonal functions. A Fourier transform is performed on the received signal and subsequently decoded with the aid of the orthogonal functions.

Abstract: The method serves to determine the vibrational state of turbine blades, arranged on a rotor shaft, mounted such as to rotate in a housing and/or of guide vanes. At least one electromagnetic wave is transmitted into a flow channel in the vicinity of the blades, using means for the generation of at least one electromagnetic wave. The electromagnetic waves are at least partly reflected from at least one blade. The reflected part of the at least one electromagnetic wave is received by means for receiving and the vibrational state of the corresponding blade is determined from a signal corresponding to the at least one received electromagnetic wave.

Abstract: The present invention relates to an asymmetrical encryption method. The public key is made up of a large composite number n; the private key is made up of the factors of the composite number. The encryption is made up of a number of iterations of individual encryption steps that are successively reversed during the decryption. In this context, the reversal of an individual encryption step requires the solving of a quadratic equation modulo m [sic]. The private key is preferably made up of the large prime numbers p and q. The public key is the product n of these two prime numbers, as well as a comparatively small integer L which is greater than one. The message m is made up of two integral values m1 and m2, thus m=(m1, m2), both values being in the set Zn={0, 1, 2, . . . , n?1}. The encryption is accomplished via the equation c=fL(m).

Abstract: A method and a circuit arrangement for efficient use of multistage modulation methods using orthogonal base functions for the representation of a signal to be transmitted. Signal points of a signal constellation are selected according to a respective predetermined and/or selected probabilities so as to optimize a respective signal energy and/or a respective signal data rate, the selected signal points each having a defined respective energy. A 16-QAM signal constellation can be used, for example, for transmitting at low data rates. In the circuit arrangement, a source (1) which supplies a data stream (2) and is connected to a code converter (3) for converting the data stream. The output of the code converter (3) is connected to a modulator (4) in which the corresponding signal points are selected according to the respective probabilities. The data stream (2) is then transmitted over a channel (5), and a demodulator (6) situated downstream from a code converter (7) carries out the inverse operation.

Abstract: A method for generating a digital signature s of a message m using a secret key including at least two large prime numbers p, q is provided. It is provided that s is the zero of the polynomial P(x)?m modulo n, P(x) being any permutation polynomial modulo n.

Abstract: Circuit arrangement for the switchable amplification of variable electrical signals having at least one signal input and a signal output. A switchable amplifier is present between signal input and signal output and is provided with an input, with an output and with a negative feedback path having at least one resistor between input and output. The circuit arrangement further comprises a voltage source, the polarity of which can be reversed by a switching element. In this case, the negative feedback path has a switchable bypass connected in parallel with the at least one resistor. The signals fed in at the amplifier input are furthermore to be fed to the amplifier output in amplified fashion via a first signal path or in unamplified fashion via a second signal path depending on the polarity of the voltage source.

Abstract: A method for representation, interpolation and/or compression of data includes identifying a two-dimensional interpolation function s(z) based on a sampling function a(z). A Cauchy integral theorem is applicable for the interpolation function s(z). The interpolation function s(z) is used for the representation, interpolation and/or compression of the data.

Abstract: The invention relates to a method of encrypting and decrypting information using a public key and a secret key. The invention is characterized in that the secret key consists of two very large primary numbers while the public key consists of the product of both primary numbers and a permutation polynomial.

Abstract: In a method for compressing data, in which, in a data stream composed of characters, character strings are checked for correlation with other character strings that are present at a given distance in the data stream, and in which, in each case, the number of correlating characters and the position of the correlating characters within the respective other character string constitute the compressed data, at least one character is allowed to differ in the correlation check and data for correcting the at least one differing character is inserted into the compressed data.

Abstract: A method and/or system is provided for generating pseudo-random sequences. The method and/or system may provide that the elements (&ggr;) of the pseudo-random sequences are discretely logarithmized.

Abstract: In a method for compressing data, in which, in a data stream composed of characters, character strings are checked for correlation with other character strings that are present at a given distance in the data stream, and in which, in each case, the number of correlating characters and the position of the correlating characters within the respective other character string constitute the compressed data, at least one character is allowed to differ in the correlation check and data for correcting the at least one differing character is inserted into the compressed data.

Abstract: With reference to a method and circuit arrangements, it is described how, using the Chebyshev polynomials, frequency multipliers as well as sine/cosine generators can be constructed in a general-purpose manner, i.e., circuits that are frequently required in telecommunications engineering. A number of Chebyshev modules and various multipliers and adders are realized in an integrated circuit which then carries out a wide range of different functions depending on the external wiring. Disclosed as further functions which can easily be technically realized with such a chip are the synthesis of any desired functions by representing the function by means of a Chebyshev series and the use of Tn(x) as an amplifier with the amplification factor n for sin(nx)≈nx, and odd n.

Abstract: A cosmetic composition is provided comprising: A) a cosmetically acceptable carrier; and B) 0.05 to 3.0% by weight, based on the weight of the total composition, of a &bgr;-1,3-scleroglucan having a three-dimensional crosslinked triple helix structure and having a mean molecular weight of 1×106 to 12×106.

Abstract: A method and circuit arrangement for frequency multiplication. A plurality of circuit modules for realizing Chebyshev polynomials of the nth order Tn(x)) are provided. The Chebyshev polynomials have arithmetic properties and are defined by Tn(cos(&ohgr;t))=cos(n&ohgr;t). The circuit modules are interconnected to form a modular circuit array or a modular circuit structure using one or more of the relations Tnm(x)=Tn(Tm(x)) and Tn+m(x)=Tn(x)Tm(x)−Tn−m(x). A cosinusoidal oscillation of a frequency is input into the Chebyshev circuit module (Tn(x)) to generate a cosinusoidal oscillation having n-fold frequency. Frequency multiplier circuits may be produced very simply and in modular form, making applications in telecommunications, in particular, very cost-effective.

Abstract: A mop to be fastened at the end of a mop handle, including a holding device to which a number of relatively mobile, absorbent strips made of a textile material are fixed essentially transversely to the axis of the handle. At least one spring body is provided, which causes the strips to spread apart, at least in the region of the holding device.

Abstract: A cosmetic composition is provided comprising:A) a cosmetically acceptable carrier; andB) 0.05 to 3.0 % by weight, based on the weight of the total composition, of a .beta.-1,3-scleroglucan having a three-dimensional crosslinked triple helix structure and having a mean molecular weight of 1.times.10.sup.6 to 12.times.10.sup.6.

Abstract: The invention describes a color former mixture comprising(a) a compound of formula (1) and/or of formula (2) and/or of formula (3) and(b) a compound of formula (4),or a color former mixture comprising at least two compounds of component (b).The color former mixture is suitable for pressure- and particularly for heat-sensitive recording materials and has excellent storage ability and superior paper whiteness.

Abstract: In a method for verifying the instant that a transaction is implemented or that a document is created, signed, sent and/or received, it is provided for a time marker to be inserted into the document in a tamper-proof manner, and for the time marker to correspond to a time stamp taken from a non-adjustable clock. An arrangement for performing the method is also provided.