In appropriate ranges of parameters, laser-driven nonlinear optical cavities can support a wide variety of optical patterns, which could be used to carry information. The intensity peaks appearing in these patterns ar...
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In appropriate ranges of parameters, laser-driven nonlinear optical cavities can support a wide variety of optical patterns, which could be used to carry information. The intensity peaks appearing in these patterns are called cavity solitons and are individually addressable. Using the Lugiato-Lefever equation to model a perfectly homogeneous cavity, we show that cavity solitons can only be located at discrete points and at a minimal distance from the edges. Other localized states which are attached to the edges are identified. By interpreting these patterns in an information coding frame, the information capacity of this dynamical system is evaluated. The results are explained analytically in terms of the the tail characteristics of the cavity solitons. Finally, the influence of boundaries and of cavity imperfections on cavity solitons are compared.
The strong capacity of a particular channel can be interpreted as a sharp limit on the amount of information which can be transmitted reliably over that channel. To evaluate the strong capacity of a particular channel...
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The strong capacity of a particular channel can be interpreted as a sharp limit on the amount of information which can be transmitted reliably over that channel. To evaluate the strong capacity of a particular channel one must prove both the direct part of the channel coding theorem and the strong converse for the channel. Here we consider the strong converse theorem for the periodic quantum channel and show some rather surprising results. We first show that the strong converse does not hold in general for this channel and therefore the channel does not have a strong capacity. Instead, we find that there is a scale of capacities corresponding to error probabilities between integer multiples of the inverse of the periodicity of the channel. A similar scale also exists for the random channel.
Dynamics of coded information over Bloch channels is investigated. We show that the coded information is sent with high accuracy over the Bloch channel by increasing the absolute equilibrium value of the information c...
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Dynamics of coded information over Bloch channels is investigated. We show that the coded information is sent with high accuracy over the Bloch channel by increasing the absolute equilibrium value of the information carrier or decreasing the ratio of relaxation time. The robustness of coded information in maximum and partial entangled states is discussed. It is shown that, the maximum entangled states are more robust than the partial entangled state over these types of channels. The dynamics of the local and the non-local information is investigated for different values of the channel's parameters and the initial state setting. It is found that by increasing the absolute equilibrium values for both qubits, the local information of both qubits decreases faster and consequently the information gained by the eavesdropper increases.
Nuclide production cross sections measured at the Institute for Theoretical and Experimental Physics (ITEP) for the targets of natCr, 56Fe, natNi, 93Nb, 181Ta, natW, natPb, and 209Bi irradiated by protons with energie...
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Nuclide production cross sections measured at the Institute for Theoretical and Experimental Physics (ITEP) for the targets of natCr, 56Fe, natNi, 93Nb, 181Ta, natW, natPb, and 209Bi irradiated by protons with energies from 40 to 2600 MeV were used to estimate the predictive accuracy of several popular high-energy transport codes. A general agreement of the ITEP data with the data obtained by other groups, including the numerous GSI data measured by the inverse kinematics method was found. Simulations of the measured data were performed with the mcnpx (bertini and isabel options), cem03.02, incl4.2 + abla, incl4.5 + abla07, phits, and cascade.07 codes. Deviation factors between the calculated and experimental cross sections have been estimated for each target and for the whole energy range covered by our measurements. Two-dimensional diagrams of deviation factor values were produced for estimating the predictive power of every code for intermediate, not measured masses of nuclei targets and bombarding energies of protons. Further improvements of all tested here codes are recommended. In addition, new measurements at ITEP of nuclide yields from the 208Pb target irradiated by 500-MeV protons are presented. A good agreement between these new data and the GSI measurements obtained by the inverse kinematics method was found.
The purpose of the present research was to show that satisfaction of the psychological needs of autonomy, competence, and relatedness constitutes a basic component characterizing autobiographical memories. In Study 1,...
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The purpose of the present research was to show that satisfaction of the psychological needs of autonomy, competence, and relatedness constitutes a basic component characterizing autobiographical memories. In Study 1, a coding scheme and a self-rating method for measuring need satisfaction in memories were developed and shown to be highly related to each other. Across 3 studies using graduate and undergraduate students (Study 1: N = 244;Study 2: N = 309;Study 3: N = 159), need satisfaction was found to be moderately associated with well-being measures, over and above several other memory components usually assessed in research on autobiographical memories. In addition, this association between need satisfaction in autobiographical memories and well-being held, even after controlling for person-level measures, such as personality traits, self-determined orientation, or experience of need satisfaction in general in one's life, thus suggesting that autobiographical memory and semantic self-knowledge are distinct databases.
A new scheme of quantum key distribution （QKD） using frequency and time coding is proposed, in which the security is based on the frequency-time uncertainty relation. In this scheme, the binary information sequence ...
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A new scheme of quantum key distribution （QKD） using frequency and time coding is proposed, in which the security is based on the frequency-time uncertainty relation. In this scheme, the binary information sequence is encoded randomly on either the centrM frequency or the time delay of the optical pulse at the sender. The central frequency of the single photon pulse is set as w1 for bit 0 and set as w2 for bit 1 when frequency coding is selected. However, the single photon pulse is not delayed for bit 0 and is delayed in τ for 1 when time coding is selected. At the receiver, either the frequency or the time delay of the pulse is measured randomly, and the final key is obtained after basis comparison, data reconciliation and privacy amplification. With the proposed method, the effect of the noise in the fiber channel and environment on the QKD system can be reduced effectively.
In this paper we propose memory protection architectures based on nonlinear single-error-correcting, double-error-detecting (SEC-DED) codes. Linear SEC-DED codes widely used for design of reliable memories cannot dete...
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In this paper we propose memory protection architectures based on nonlinear single-error-correcting, double-error-detecting (SEC-DED) codes. Linear SEC-DED codes widely used for design of reliable memories cannot detect and can miscorrect lots of errors with large Hamming weights. This may be a serious disadvantage for many modern technologies when error distributions are hard to estimate and multi-bit errors are highly probable. The proposed protection architectures have fewer undetectable errors and fewer errors that are miscorrected by all codewords than architectures based on linear codes with the same dimension at the cost of a small increase in the latency penalty, the area overhead and the power consumption. The nonlinear SEC-DED codes are generalized from the existing perfect nonlinear codes (Vasil'ev codes, Probl Kibern 8:375-378, 1962;Phelps codes, SIAM J Algebr Discrete Methods 4:398-403, 1983;and the codes based on one switching constructions, Etzion and Vardy, IEEE Trans Inf theory 40:754-763, 1994). We present the error correcting algorithms, investigate and compare the error detection and correction capabilities of the proposed nonlinear SEC-DED codes to linear extended Hamming codes and show that replacing linear extended Hamming codes by the proposed nonlinear SEC-DED codes results in a drastic improvement in the reliability of the memory systems in the case of repeating errors or high multi-bit error rate. The proposed approach can be applied to RAM, ROM, FLASH and disk memories.
The non-linear filtering is a commonly used time-domain technique for narrowband interference (NBI) suppression in the direct-sequence spread spectrum (DSSS) communication systems. In this study, the authors analyse h...
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The non-linear filtering is a commonly used time-domain technique for narrowband interference (NBI) suppression in the direct-sequence spread spectrum (DSSS) communication systems. In this study, the authors analyse how the decision feedback error of the spread spectrum (SS) signal influences the performance of the NBI prediction. A partial-code-aided scheme is proposed, which despreads partial chips in a spreading sequence and reconstructs the rest part by spreading the bit decision. This method utilises partial spreading gain to improve the decision accuracy of the SS signals while keeping similar time consumption and implementation complexity with the traditional scheme. It has been verified by simulation that with different NBI models and under different channel conditions, the proposed non-linear filtering method always outperforms the traditional one with chip-wise decision feedback.
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