48 results about "Lorenz system" patented technology

A system and method for encoding zero and one bits for transmission, including generating a first signal from a non-linear chaotic system to represent the one bit, with the signal's embedded vectors being within the non-linear system's attractor set, and generating a second signal from the non-linear system to represent the zero bit, with the signal's embedded vectors being outside the non-linear system's attractor set. The second signal encoding the zero bit can be generated by adding together two chaotic signals arising from the non-linear system initialized with different initial conditions, and weighting the second signal to have approximately the same energy as the first signal. One suitable chaotic systems is a Lorenz system. Systems and methods for decoding a transmitted stream of signals compare a detection statistic of the received stream of signals to a threshold value that depends on the chaotic system.

The invention discloses a digital image encryption method based on a Cat mapping and hyper-chaos Lorenz system, and belongs to the field of image encryption. According to the digital image encryption method, a key length of an image encryption system is 247 digits and is higher than classical cryptography algorithms of the data encryption standard (DES, 56 digits), the advanced encryption standard (AES, the basic standard is 128 digits) and the international data encryption algorithm (IDEA, 128 digits). By introducing a secret key stream generative mechanism related to plaintexts, secret key streams are enabled to be related to both secret keys and the plaintexts, and even when the same diffusion secret keys are used to encrypt different plaintext images, the generated secret key streams are different. Therefore, the known-resistant/plaintext-selective attack capacity of the encryption system is obviously improved.

The invention relates to a different-dimensional switchable chaotic system design method and a circuit; a four-dimensional hyper-chaos system is constructed by adding variables and feeding back control items based on a three-dimensional generalized Lorenz system family; and a switchable different-dimensional chaotic circuit is designed through a plurality of switch controllers in Multisim software. An analog circuit constructed by the invention is convenient to use and easy to realize by hardware, and has relatively lower cost; the designed switchable circuit not only can flexibly realize the switching between a three-dimensional chaotic system and the four-dimensional hyper-chaos system, but also can return to realize the switch among three chaotic systems in the same dimension; and the systems can serve as practical chaotic modulation and chaotic encryption signals, and can be widely applied to the field of information security cryptography with higher requirements on confidentiality and reliability.

The invention relates to a 4-neighborhood exclusive or image encryption method based on a hyper-chaos Lorenz system. The method is characterized in that RGE three components of an original color image are extracted, the grey levels of all pixel points in the RGE three components are recorded as a two-dimensional matrix PR, a two-dimensional matrix PG and a two-dimensional matrix PB, scrambling is carried out on the matrix PR, the matrix PG and the matrix PB respectively by means of chaos sequences generated by the hyper-chaos Lorenz to obtain an image pixel matrix PR1, an image pixel matrix PG1 and an image pixel matrix PB1 after scrambling, and 4-neighborhood exclusive or encryption is carried out on the matrix PR1 through reusing of the processed chaos sequences of the Lorenz, the matrix PG1 and the matrix PB1 respectively, so the encryption process is completed. The scrambling and 4-neighborhood exclusive or encryption are carried out on the color image through the hyper-chaos Lorenz system, so the method has the advantages of being large in secret key space, good in safety and strong in plaintext attack resistance and is suitable for image secret communication.

The invention discloses a three-dimensional chaotic circuit, which comprises two analog multipliers, eight operational amplifiers, a resistor and a capacitor. By adopting the three-dimensional chaotic circuit disclosed by the invention, not only X-oscillograph, Y-oscillograph and Z-oscillograph but also X-Y phase diagram, X-Z phase diagram and Y-X phase diagram can be observed on a common oscilloscope. With the use of the three-dimensional chaotic circuit, a Lorenz system is enriched, and understanding of people on a chaotic system is deepen; and the three-dimensional chaotic circuit is suitable for chaotic science, experimental teaching and demonstration, popularization of science, experiment demonstration, and the like in universities. By using the three-dimensional chaotic circuit, various oscillographs, phase diagrams and chaotic evolution curves can be displayed.

The invention discloses a four-dimensional fractional-order time-delay chaotic circuit with a three-time magnetic control memristor. The four-dimensional fractional-order time-delay chaotic circuit comprises first to five channel circuits. According to the four-dimensional fractional-order time-delay chaotic circuit disclosed by the invention, on the basis of a deformed Lorenz system, a memristor unit is added, so that the non-linear characteristic of the system is enhanced; a time-delay unit is added; furthermore, fractional-order expansion of an integer-order system is carried out; therefore, the richness of the dynamic characteristic of the system is improved; different chaotic system circuits can be designed by combination of the order of a chaotic system and the structural type of a circuit unit; each circuit has the special dynamic behaviour; the output signal of the circuit has relatively high chaotic characteristic; this kind of fractional-order time-delay memristive chaotic system is applied to image encryption and secret communication; and thus, the complexity of a key and the anti-deciphering capability of the system are improved.

The invention discloses a wind speed interval prediction method and system based on a Lorenz system. The prediction method comprises: obtaining an original wind speed sequence; carrying out variational mode decomposition (VMD) on the wind speed sequence, and obtaining a denoising sequence and a noise remainder; establishing a long-short-term neural network prediction model (LSTM), and carrying outpreliminary prediction on the denoised sequence to obtain a preliminary prediction result; correcting the preliminary prediction result by defining a wind speed climbing event (WSR) and a wind speedclimbing rate to obtain a corrected wind speed prediction result; describing the influence of the atmospheric power system on the wind speed through a Lorenz equation, and obtaining a Lorenz disturbance sequence (LDS); fitting the LDS through a B spline interpolation method, fixing a confidence interval for a fitting result, and obtaining an upper limit and a lower limit of a wind speed disturbance interval; and summing the corrected wind speed prediction result and the wind speed disturbance interval to obtain an interval prediction result of the wind speed. According to the wind speed interval prediction method or system, the precision and reliability of the prediction model are remarkably improved, and a high-precision prediction result can be obtained.

A communications device includes a symbol encoder for receiving data comprising a symbol and for receiving a first signal having a positive entropy. The symbol encoder adds to the first signal a plurality of delayed versions of the first signal. Each delayed version of the plurality of delayed versions has a plurality of available values. The symbol is represented by a set of delay values, a delay value of the set of delay values including an available value of the plurality of available values for the each delayed version of the plurality of delayed versions. The communications device also includes a transmitter for receiving the encoded data from the symbol encoder and for transmitting the encoded data. For example, the first signal having positive entropy includes a chaotic signal, noise signal, or a positive entropy, baseband signal modulated onto a positive entropy signal having a higher frequency than the baseband signal. For example, the chaotic signal includes a Lorenz system-generated chaotic signal or a Rossler system-generated chaotic signal. The communications device supports bandwidth-efficient transmission in communications media.

The invention discloses an image encryption method based on heterogeneous chaos and a keccak hash function. The method includes the following steps: taking all image pixels of an image to be encryptedas input values of the keccak hash function, separately taking output values as initial values of a hyperchaotic Lorenz system and a hyperchaotic Chen system, and separately obtaining a first chaoticsequence and a second chaotic sequence; extending the image to be encrypted from a two-dimensional image to a three-dimensional space; iterating the first chaotic sequence and the second chaotic sequence to generate a pseudo random sequence, and then transforming the pseudo random sequence to obtain a location coordinate for disturbing the pixels; constructing a cipher substitution box S-Box according to the first chaotic sequence, and then selecting the execution order of three encryption strategies of the three-dimensional space according to the output values of the cipher substitution boxS-Box; and performing iteration for the set number of times, and finally reconstructing the image from the three-dimensional space into the two-dimensional image to obtain the encrypted image.

The invention relates to a wind power plant power prediction method considering an atmospheric disturbance effect. The method comprises the following steps of regarding an atmosphere nonlinear Lorenz system as a disturbance model, defining atmosphere nonlinear disturbance variables to eliminate nonlinear factors contained in original air speed data, and optimizing the input of a power prediction model, so that the wind power prediction with higher accuracy can be realized. According to the wind power plant power prediction method considering the atmospheric disturbance effect, on the basis of a conventional power prediction method, a power prediction disturbance formula is utilized to carry out nonlinear disturbance correction on a wind speed prediction result, and the influence of some nonlinear disturbance factors existing in original wind speed on the prediction result is eliminated, so that the aim of accurately predicting wind power is achieved. The experiment result shows that according to the method, the prediction accuracy of wind energy can be greatly improved, and the development of wind power industry is greatly promoted.

The present invention relates to a chaotic system synchronization method and a circuit, particularly to an adaptive synchronization method and adaptive synchronization circuit of y<2>-contained Chen hyper-chaotic system based on memristor. The memristor, served as a new physical component found by the HP labs in 2008, may take the place of the Chua's diode in the Chua's circuit to form the chaotic system, and also may be a component to be added into the three-dimensional chaotic systems, such as a Lorenz system, a Chen system and a Lorenz system, in order to form the hyper-chaotic system At present, the method and the circuit of serving the memristor as a component to form the choas or the hyper choas have come up, but the synchronization method of serving the memristor as a component to form the hyper-chaotic system has not yet come up, so that there is provided an inadequacy in the prior art. According to the invention, the y<2>-contained Chen hyper-chaotic system based on the memristor is put forward, and on this basis the adaptive synchronization method of y<2>-contained Chen hyper-chaotic system is provided.

The invention relates to chaotic system synchronization and a circuit, and especially relates to an adaptive synchronization method and circuit for a memristor-based Lorenz hyperchaotic system. As a newfound physical component in Hewlett-Packard Laboratories of 2008, the memristor can replace a Chua's diode in a Chua's circuit to form the chaotic system, and can also be added to three-dimensional chaotic systems as a component, such as a Lorenz system, a Chen system and a Lorenz system to form a hyperchaotic system; at present, the method and circuit of forming chaos or hyperchaos by taking the memristor as a component have been proposed, but a synchronization method for forming the hyperchaotic system by taking the memristor as a component has not been proposed yet and this is the disadvantage of the prior art; the invention provides a Lorenz hyperchaotic system by using the memristor, and the adaptive synchronization method of the chaotic system is provided on this basis.

The invention relates to a chaotic system synchronization method and a circuit, and particularly relates to a memristor-based Chen hyperchaotic system self-adaptive synchronization method and a circuit. As a physical element which is newly discovered in a Hewlett-Packard laboratory in 2008, a Memristor can replace a Chua diode in a Chua circuit to form a chaotic system, and can be used as an element to be added into a three-dimensional chaotic system, such as a Lorenz system, a Chen system and a Lorenz system to form a hyperchaotic system. At present, the fact that the memristor is used as an element to form a chaotic or hyperchaotic method and circuit is proposed, but the fact that the memristor is used as an element to form a hyperchaotic system synchronization method is not proposed. For shortcomings in the prior art, according to the invention, the memristor is used to propose a Chen hyperchaotic system, and the self-adaptive synchronization method of the chaotic system is proposed on the basis.

The invention relates to a synchronization method and circuit for a chaotic system, and in particular relates to a self-adaptive synchronization method and circuit for a Lorenz hyperchaotic system including y squared based on a memristor. The memristor is used as a physical component newly found in the hewlett-packard laboratory in 2008; the memristor not only can be used for replacing a chua's diode in a chua's circuit to form the chaotic system but also can be used as a component added into three-dimensional chaotic systems, such as a Lorenz system, a Chen system and the Lorenz system, so as to form the hyperchaotic system; currently, the chaotic or hyperchaotic method and circuit based on the memristor as one component are provided; but, the synchronization method of the hyperchaotic system based on the memristor as one component is still not provided, which is the deficiency in the prior art; the Lorenz hyperchaotic system including y squared is provided by utilizing the memristor; and the self-adaptive synchronization method of the chaotic system is provided on this basis.

The invention relates to a chaotic system synchronization method and circuit, in particular to an adaptive synchronization method and circuit of a memristor-based x-power-including Chen hyper-chaotic system. As a physical element being newly discovered by the HP Labs in 2008, a memristor can construct a chaotic system instead of a Chua's diode in a Chua's circuit, and can be added into a three-dimensional chaotic system such as a Lorenz system, a Chen system and a Lorenz system as an element, thereby forming a hyper-chaotic system. At present, a method and a circuit for forming chaos or hyper-chaos by taking the memristor as an element are already put forward. However, a synchronization method for forming the hyper-chaos system by taking the memristor as an element is not put forward yet, which is a defect in the prior art. The invention provides the x-power-including Chen hyper-chaotic system by using the memristor, and provides the adaptive synchronization method of the chaotic system on the basis.

A generalized chaotic synchronization method for controlled Lorenz system and Finance system applied to secure communication comprises the following steps: 1) description of the generalized chaotic synchronization problem; 2) state transformation and feedback of the response system; 3) state transition of driving system; 4) Generalized synchronization. The invention provides the generalized chaotic synchronization method for controlled Lorenz system and Finance system applied to secure communication, the Finance chaotic system is a driving system and the single input controlled Lorenz system is a respondence system, a chaotic synchronization algorithm based on the Lie derivative of vector field in differential geometry is designed, The generalized synchronization is realized and the control quality is high.

The invention discloses a generalized chaotic synchronization method for a controlled Lorenz system and a Genesio-Tesi system applied to secret communication. The method comprises the following stepsof 1, describing a generalized chaotic synchronization problem; 2, converting and feeding back the state of a response system; 3, converting the state of a driving system; and 4, generalized synchronization. According to the generalized chaotic synchronization method for the controlled Lorenz system and the Genesio-Tesi system applied to secret communication provided by the invention, the Genesio-Tesi chaos system is used as the driving system, the controlled Lorenz system with a single input is used as the response system, a lie derivative method in a vector field in differential geometry isused for designing a chaotic synchronization algorithm, the generalized synchronization is achieved, and the control quality is relatively high.

The invention discloses an FPGA chaotic signal generator, and is applied to different chaotic systems, for the purpose of reducing time needed for operation and reducing consumption of hardware resources at the same time. The FPGA chaotic signal generator comprises a chaotic system generation unit, a chaotic signal generation unit and a DA conversion unit, wherein the chaotic system generation unit is used for generating different chaotic systems through switching of switches and comprises a Lorenz system, a Chen system, a Lv system, a two-scroll Chua system, a four-scroll Chua system, a grid nine-scroll Chua chaotic system, a six-dimensional modulus discrete system and a six-dimensional sine iteration discrete system; the chaotic signal generation unit is used for generating needed chaotic signals according to the chaotic systems generated by the chaotic system generation unit; and the DA conversion unit is used for converting the chaotic signals into forms which can be displayed in an oscilloscope.