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[en] A device is proposed for the frequency scan of an NMR radiospectrometer. The device contains a controlled oscillator, sources of control signals, and a frequency synthesizer connected to the driving oscillator. The proposed scan circuit extends the limits of measurements of the scanning of the detected spectra, increases the spectrum reproducibility and the accuracy of measurement of NMR parameters, reduces the scan nonlinearity and the time of measurement of the resonance frequencies of the spectral lines. The maximum spectrum scanning range is 1 MHz, and the minimum 0.1 Hz for the entire length of the detector chart strips
[en] The present paper deals with a mathematical problem, encountered when driving a fully programmable μ-processor controlled function generator. An algorithm is presented to approximate a desired function by a set of straight segments in such a way that additional restrictions (hardware imposed) are also satisfied. A computer program which incorporates this algorithm and automatically generates the necessary input for the function generator for a broad class of desired functions is also described
[en] The sinusoidal high frequency generator (HFG) with a para-mode output intended for joint operation with the quadrupole mass spectrometer (QMS) is described. It is known that the absolute resolution of the mass spectrometer is determined by electric symmetry of both HFG outputs in relation to zero potential. In order to obtain the output voltage disbalance not higher than 10-3 it is suggested to use HFG with self-symmetrization. In this HFG scheme the summing amplifier in the negative feedback circuit is applied. The analysis of HFG operation with symmetrization has shown that parallel to output voltage disbalance decrease, an additional disbalance caused by the summing up amplifier resistor unequality arises. To compensate this additional disbalance a fine-tuned resistor connected in series with one of the summing amplifier resistors
[en] We report the synthesis of a user-specified, shaped ultrafast pulse train by manipulating the spectral phases of Raman sidebands with a wide frequency spacing line-by-line. Trains of rectangular and triangular pulses are stably produced at an ultrahigh repetition rate of 10.6229 THz, reminiscent of an ultrafast function generator.
[en] This invention deals with an exponential function generator, and an application of this generator to simulating the criticality of a nuclear reactor for reactimeter calibration purposes. This generator, which is particularly suitable for simulating the criticality of a nuclear reactor to calibrate a reactimeter, can also be used in any field of application necessitating the generation of an exponential function in real time. In certain fields of thermodynamics, it is necessary to represent temperature gradients as a function of time. The generator might find applications here. Another application is nuclear physics where it is necessary to represent the attenuation of a neutron flux density with respect to time
[fr]La presente invention concerne un generateur de fonction exponentielle ainsi qu'une application de ce generateur a la simulation de divergence d'un reacteur nucleaire, pour l'etalonnage d'un reactimetre. Ce generateur, qui s'applique particulierement a la simulation de divergence d'un reacteur nucleaire, pour l'etalonnage d'un reactimetre, peut egalement s'appliquer a tous les domaines qui necessitent la generation, en temps reel, d'une exponentielle. Ce peut etre le cas en thermodynamique ou il est necessaire de representer les variations par rapport au temps de gradients de temperatures, en physique nucleaire, la ou il est necessaire de representer l'attenuation du debit de fluence neutronique par rapport au temps, etc
[en] A circuit of an exponential-stepped voltage generator providing time sweeping of an investigated energy spectrum in an electrostatic spectrometer is described. Operation of the generator is based on a continuous normalized discharge of a storage condenser with subsequent shaping of bipolar voltage symmetric about the neutral wire. The amplitude of the generator output voltage does not exceed 48 V. Error of the generator output voltage shape is no more than 2%, the thermal drift of output voltages constitutes 25 mV during 3 h
[en] Highlights: • Random selection of boolean functions and random selection of variable inputs for the functions. • Generating a combined function to use in different cryptographic modules. • Confirming high nonlinearity, resiliency and balance in outputs. • Non-dependency of input variables on the output analysis except variable length and expression length. - Abstract: Cryptanalysis analyses various combinations among plaintexts, ciphertexts and random keys; even using differential methods or analog methods, the attackers can interpret the keys depending upon the operations in the round functions or any subset of the algorithm. The previous research emphasizes on creation of different cryptographic functions, however the randomness of such functions has not been researched significantly so far. In this paper, we have shown a random function generator which can be used for any cryptographic algorithm. This generator outputs the combination of functions in random and cannot be traced back due its randomness. The objective of our research work is not to identify a particular boolean function that is balanced or symmetric based on its input variables, our proposed work provides a random combination of generic boolean functions as used in MD5 or SHA series, block cipher round functions and stream ciphers. Moreover, the random selection of input variables for a particular function also makes it desirable for cryptographic function modules. The results of our experimentation show that the functions generated by the proposed generator provide a good non-linearity, resiliency and balanced effect.