275 results about "Reverse transformation" patented technology

The present invention relates to a system and methodology to facilitate interoperability and compatibility between disparate data systems. In one aspect, a file transformation system is provided having at least one file associated with one or more unstructured properties. A file property handler manipulates the unstructured properties in accordance with one or more structured properties associated with a structured object store environment. If an unstructured file is to be operated in the context of a structured object store environment, a promotion operation is performed to update unstructured properties in the file with structured properties suitable for operation in the structured object store environment. If a promoted item were to be manipulated in the structured object store environment, a demotion operation or reverse transformation is performed to update properties in the file.

Portable electronic storage devices with hardware based security are described. According to one exemplary embodiment of the present invention, a portable electronic storage device (PESD) comprises a security engine integrated thereon. The security engine is configured to provide data encryption, data decryption, and encryption / decryption key (referred to as a key) generation according to a security standard (e.g., Advance Encryption Standard (AES)). AES is a symmetric encryption algorithm processing data in block of 128 bits. Under the influence of a key, a 128-bit data block is encrypted by transforming the data block in a unique way into a new data block of the same size. AES is symmetric sine the same key is used for encryption and the reverse transformation (i.e., decryption). The only secret necessary to keep for security is the key. AES may use different key-lengths (i.e., 128-bit, 192-bits and 256-bits).

A method to at least one of compress and decompress data includes providing a string (T) consisting of multiple given substrings. Identification symbols ($,$1,$2,$3) are assigned to the substrings of the string (T). The substrings of the string (T) are transferred by permutation into a permuted string (O(T),O*(T)). The permuted string (O(T),O*(T)) is sorted into a sorted permuted string (oSort(T), oSort*(T)) according to a given sorting criterion. The identification symbols ($,$1,$2,$3) are permuted and sorted together with the substrings of the sting (T) so that, in a partial inverse transformation step, characters of an Nth substring are sequentially determined within the permuted string (O(T),O*(T)) after determining a position (P) of an Nth identification symbol ($,$1,$2,$3) assigned to an Nth substring within the sorted permuted string (oSort(T),oSort*(T)) without reading characters of other substrings of the permuted string (O(T),O*(T)).

The present invention relates to a system and methodology to facilitate interoperability and compatibility between disparate data systems. In one aspect, a file transformation system is provided having at least one file associated with one or more unstructured properties. A file property handler manipulates the unstructured properties in accordance with one or more structured properties associated with a structured object store environment. If an unstructured file is to be operated in the context of a structured object store environment, a promotion operation is performed to update unstructured properties in the file with structured properties suitable for operation in the structured object store environment. If a promoted item were to be manipulated in the structured object store environment, a demotion operation or reverse transformation is performed to update properties in the file.

The invention provides an infrared image and visible image fusion method based on guide filtering. The method comprises the steps of: firstly, expanding the guide filtering to multiple scales, and performing multi-scale decomposition on an infrared image and a visible image by using the multi-scale guide filtering, so as to obtain a low-frequency subband and a high-frequency subband; performing nonsubsampled directional filtering on the high-frequency subband, so as to obtain a directional subband coefficient; applying different fusion rules to the directional subband coefficient and a low-frequency subband coefficient, so as to obtain the corresponding directional subband coefficient and the low-frequency subband coefficient after fusion, and finally, performing directional filtering reconstruction and multi-scale reverse transformation based on the guide filtering, so as to obtain a final fusion image. According to a fusion result obtained by adopting the method, the edge and thermal radiation characteristics of an infrared image object are preferably kept, scene details of the visible image can be preferably reserved, and the information content of a fusion image is increased, so that the edge and details of the fusion image are enriched.

The invention provides a method for reducing the peak-to-average power ratio, which comprises distributing the code-modulated signals on a plurality of sub-carrier waves, and combining the sub carrier waves into a plurality of physical resource blocks; combining the physical resource blocks into a plurality of subsequences; searching the optimal phase after respectively subjecting each of the subsequences to the rapid Fourier reverse transformation; and carrying out the phase rotation according to the optimal phase corresponding to each of the subsequences. With the method and the device, the signals of the multicarrier are divided into the subsequences and then the phase rotation is carried out based on the PRB; and since the data and the pilot-frequency information is in the same PRB, a transmitting terminal can accurately demodulate without need of a transmission side band information receiving terminal while carrying out the phase rotation to the subsequences, and the BER deterioration is also prevented.

The invention discloses a morphology and PCA (principal component analysis) based contourlet fusion method for infrared and visible light images. The method includes: firstly, subjecting two images to morphology-hat transformation respectively and subjecting the two obtained images to contourlet decomposition to form a high-frequency image and a low-frequency image respectively; then, fusing the low-frequency image by a PCA method; fusing the high-frequency image by means of average gradient adaptive weighted processing; reconstructing a fused image by means of contourlet reverse transformation. The morphology and PCA based contourlet fusion method for the infrared and visible light images is used for image fusion of the infrared and visible light images, so that the fused image is high in contrast ratio, rich in information and clear in texture detail.

The invention generally relates to computational transformation process, which has applications in cryptography, random number generation, hash code generation etc. The computational transformation module uses a keyset, which is designed using a two dimensional array. Since the process of forward transformation used in the invention is a symmetric encryption process and if used to send data securely over a communications network, the same keyset needs to be present at the sending computer to encrypt the data and the receiving computer to go through a reverse transformation and decrypt the data. When the first ‘n’ bit block of input-data is transformed into the first ‘m’ bit block of output-data, the keyset is transformed into a different keyset based on a nonlinear or one-way transformation on the keyset. The next input block is encrypted using a transformed keyset, hence satisfying Shanons theory of perfect secrecy. It uses the same logic with additional parameters and operations to create random numbers and unique hash codes. The computational transformation process is a one-way process which is based on a principle where given the input value ‘x’, it is easy to transform ‘x’ to ‘y’ using a function ‘F’ i.e. F(x)=y. However, given ‘y’ in the range of F, it is hard to find an x such that F(x)=y. In this system, the same transformation function and same keyset is used for both encryption as well as decryption with only a change in the constant value.

The invention provides a permanent-magnet synchronous motor start-up smooth switching method. The method includes the following steps: presupposing that given torque current is identically 1.5 times that of rated current of a permanent magnet synchronous motor; presupposing that a rotor position angle is increased progressively at a T-squared growth rate, and enabling the permanent magnet synchronous motor to rotate at a constant accelerated speed; when the speed of the permanent magnet synchronous motor reaches 30% of a rated rotation speed, beginning to carry out switching transition, enabling a rotor position angle used for PARK transformation and reverse transformation to gradually approach an actual rotor position angle acquired by a position and speed estimator, and meanwhile, enabling the presupposed torque current to gradually approach torque current calculated by adopting the actual rotor position angle; and when time for switching transition arrives, switching closed-loop control states of the speed, the position and the current. The method can achieve the purposes that the rotor position and phase current are undistorted and the rotation speed does not oscillate in start-up switching of the permanent-magnet synchronous motor only by one-time parameter setting under any load.

The invention provides a visible light and infrared image fusion algorithm based on non-subsample contourlet transform (NSCT) domain bottom layer visual features.Firstly, visible light and infrared images are subjected to NSCT, high and low frequency subband coefficients of the visible light and the infrared images are obtained, then phase equalization, neighborhood space frequency, neighborhood energy and other information are combined, the pixel active levels of the low frequency subband coefficients are comprehensively measured, fusion weights of the low frequency subband coefficients of the visible light and infrared images are obtained respectively, and therefore low frequency subband coefficients of fusion images are obtained; the pixel active levels of the high frequency subband coefficients are measured through the combination of phase equalization, definition, brightness and other information, fusion weights of the high frequency subband coefficients of the visible light and infrared images are obtained respectively, then high frequency subband coefficients of the fusion images are obtained, finally, NSCT reverse transformation is utilized, and final fusion images are obtained.Detail information of source images can be effectively reserved, and meanwhile useful information of the visible light images and the infrared images is synthesized.

The invention relates to a method for embedding a reversible watermark in a digital image and a method for extracting the reversible watermark from the digital image, and belongs to the field of information technology. The method for embedding the reversible watermark comprises the following steps of: dividing a carrier image and establishing a location mark sequence LMC, and dividing all pixels into three parts of I1, I2, and I3; embedding watermark in the pixel blocks in the I1 and I3; recording the lowest effective bit in the I1 into a sequence C, and using the LMC to replace the lowest effective bit in the I1; and finally, embedding the sequence C into an embeddable pixel block in the I2. The method for extracting the reversible watermark comprises the following steps of: dividing the carrier image and extracting the location mark sequence LMC; then dividing the pixel blocks into three parts of I1, I2, and I3; performing reverse transformation on the pixel blocks in the I2 according to the LMC to obtain an original pixel value sequence C; replacing the lowest effective bit in the I1 by the value in the sequence C; and finally, performing reverse transformation on the pixel blocks in the I1 and I3 according to the LMC to acquire an original pixel value and embedded watermark information. The method for embedding the reversible watermark in the digital image and the method for extracting the reversible watermark from the digital image improve the embedding capacity and do not need the original images during extraction.

The invention relates to a fusion method of SAR (Synthetic Aperture Radar) images and visible light images on the basis of NSCT (Non Subsampled Contourlet Transform). The fusion method is characterized by comprising the following steps of: firstly, carrying out NSCT decomposition on the SAR images and the visible light images respectively; then adopting different fusion rules to carry out fusion treatment on NSCT low-frequency and high-frequency subband coefficients, wherein according to the decomposition coefficient characteristics of noise and signals in an NSCT domain, carrying out hard-threshold denoising on the NSCT high-frequency subband coefficient of the SAR images under the maximum decomposition scale, then respectively adopting different fusion rules to carry out fusion processing on the NSCT high-frequency subband coefficient under the maximum decomposition scale and other decomposition scales by adopting the coefficients with threshold processing as the basis; and finally,carrying out NSCT reverse transformation on the fused NSCT coefficients and obtaining fused images. The fusion method takes denoising as the basis of the fusion rule design, considers noise suppression while fusion treatment is carried out, is simple and easy to operate, can be used for obtaining a good fusion effect and is especially more applicable to the SAR images and the visible light imageswith serious spot and noise pollution.

The invention discloses a traveling-wave differential protection method suitable for a series capacitor compensation circuit. The method comprises the steps: 1) current calculation under a mold domain, calculating mold currents im<x> and in<x> flowing into a series capacitor device from onside and offside; 2) establishment of differential equation; 3) resolution of differential currents, utilizingthe reverse transformation of phase molds to solve vectors icd<phi> of the differential currents of each fault phase and each non-fault phase; 4) action judgment of a differential relay: utilizing the fault-phase action amount as braking, and adding an appropriate fixing threshold. The invention can effectively solve the effect of capacitor current on differential protection of long-distance transmission lines, can be well suitable for the series capacitor compensation circuit, and enhances the sensitivity of differential protection.

The invention relates to a controller PI parameter tuning method based on rotational inertia of a motor. Firstly, the rotational inertia of the motor is recognized, and then speed controller PI parameters are adjusted according to the relation between the rotational inertia and the PI parameters and the minimum resonance peak principle. According to the method, a rotation speed signal and a current signal of the motor are acquired, the motor is controlled through a rotation speed calculation module, coordinate conversion, a PI controller, SVPWM and IGBT reverse transformation, then output rotation speed and current serve as input of a recognition module, an S function is set according to the feedback principle, error accumulation values between rotation inertias J in different time periods are calculated, and different gain factors are selected according to different errors so as to improve recognition accuracy and quickness. After the rotational inertia is recognized, the speed controller PI parameters are adjusted according to the relation between the rotational inertia and the PI parameters, and stability and anti-interference capacity of a system are improved.

This invention solves problems due to employing error degraded data in digital processing. It particularly solves multi-generation problems wherein transform data degrade during each inverse transform and forward transform cycle even without any processing due to the rounding and clipping errors. It provides methods, systems and devices for reduced-error processing of transform-coded data. After inverse transformation of transform data, high-precision numbers are manipulated. The converting to integers and clipping to an allowed range steps are executed at any stage in the manipulation to obtain integer representation of the inverse transformed data such as for displaying of the data. However, further processing including forward transforming back to the transform domain is executed on the high-precision numbers. Thus, the rounding and clipping errors are not present in the processed data. Although advantageous to many applications employing digital transformed data, the invention is particularly advantageous for use in digital studios during editing of MPEG-coded, JPEG-coded and wavelet-coded video and audio data.

The present invention provides an improved current regulator for PWM based drives for electric motors. The invention provides compensation for the rotor position signal for delays introduced due to the PWM algorithm and for digital sampling present in such a drive. Current regulator commonly operate in a two-phase reference frame, requiring forward and reverse coordinate transformations between the physical current values and the two-phase reference frame variables. The present invention provides an improved compensation in the forward transformation by determining the phase lag between the commanded voltage reference and the output voltage reference and by further compensating the forward transformation for errors introduced due to sampling the current either at different sampling instances than the rotor position or at multiple sampling instances during a carrier period. Additionally, compensation during the reverse transformation is provided to compensate for errors introduced due to sampling the current and rotor position.

The invention discloses a template attack method in allusion to SM4 cipher algorithm round output. According to the method disclosed by the invention, special channel input is taken as a premise, the SM4 algorithm round output is used as an attack point, the hamming weight or the hamming distance of the round output is selected to establish a template, and template attack in allusion to the SM4 cipher algorithm round output can be realized by a small number of templates. Meanwhile, selective input is taken as a basis in a template matching stage, a support vector machine is used to act as a tool for judgment and analysis, a bit of linear transformation output can be broken by only two times of matching, and then a round sub-key is reversely derived by inverse transformation of nonlinear transformation and linear transformation. The method disclosed by the invention effectively solves a problem that template attack in allusion to the SM4 cipher algorithm round number is infeasible at the present stage.

The invention relates to a method for fusing Shearlet domain multi-spectral and full-color images based on spectral characteristics. The method comprises the steps of (1) performing IHS transformation for a multi-spectral image; (2) performing Shearlet transformation and decomposition for the BIMFs and the full-color image to obtain a low-frequency sub-band and a plurality of high-frequency sub-band; (3) building a fusion rule and selecting fusion coefficients, namely, decomposing the low-frequency coefficients through laplacian pyramid, selecting the low-frequency fusion coefficients by the comparing and bigger selection method, and fusing the corresponding high-frequency coefficients according to the fusion rule based on PCNN (Pulse Coupled Neural Network); (4) performing IHS reverse transformation to obtain the final fused image. With the adoption of the fusion algorithm, the spectrum information of the images is protected while the space details expression capacity is improved, and thus the fusion effect is improved.

The invention discloses a natural image noise removal method based on dual redundant dictionary learning, aiming at mainly solving the problem that texture details are easy to lose in the existing natural image noise removal method. The natural image noise removal method based on dual redundant dictionary learning comprises the following steps: (1) inputting an image Y to be subjected to noise removal; (2) unfolding the image Y to be subjected to noise removal under a multi-scale redundant stable wavelet dictionary R to obtain coefficient components betaj of the image Y on different scales, wherein j is 1, 2,... and N; (3) initializing each variable to make a dictionary Dj be a redundant dictionary DCT, and updating atoms and corresponding coefficient matrixes of the dictionary Dj by adopting the KSVD algorithm; (4) calculating the estimation value of the noise removal results of all the coefficient components betaj; and (5) carrying out multi-scale redundant reverse transformation on all the coefficient components betaj subjected to noise removal to obtain the noise removal result of the image Y to be subjected to noise removal. Compared with the existing classical noise removal method, the natural image noise removal method based on dual redundant dictionary learning can better keep the texture detail information in the image to be subjected to noise removal and can be used for natural image noise removal.

A guide wire that due to its wide elastic region and high Young's modulus, simultaneously has pliability and pushability, and that even when its surface is coated with a plastic material of high melting point, is highly impervious to influences of heat treatment, and that has excellent slidability and excels in weldability between a distal-end-side base material and a proximal-end-side core material. The guide wire has a core material comprising a distal-end-side core material and a proximal-end-side core material. The distal-end-side core material is made of an iron alloy having shape memorycapability and superelasticity, consisting essentially of two phases of gamma-phase and gamma'-phase and exhibiting, in a thermal hysteresis of martensite transformation and reverse transformation, adifference between reverse transformation completion temperature (Af-point) and martensite transformation starting temperature (Ms-point) of 100 DEG C or below. The proximal-end-side core material ismade of an alloy containing iron and has an elastic modulus higher than that of the distal-end-side core material. The distal-end-side core material and the proximal-end-side core material are weldedtogether.

In accordance with an embodiment of the invention, precision control of error injection may be accomplished by way of synchronous error signals accompanying data transfers along various pipeline stages of a data path. The synchronous error signals may be used to trigger error events in a given protocol logic block (i.e. in a given sub-component of the data path). The protocol logic block is configurable to determine whether any action is to be taken upon the assertion of the error signal. Multiple error events may be triggered as the data signal (and its accompanying synchronous error signal) passes through pipelined functions of the data path so as to create complex error conditions. In addition, deterministic handling of created errors may be accomplished using a loopback path with bypassable blocks on both forward and reverse transformations. Other embodiments, aspects and features are also disclosed.

The invention discloses a multiple wave suppression method based on dual parabolic Radon transformation. The method includes the steps that a pre-stack CMP trace gather is processed, an objective function is established, positive Radon transformation is performed on the pre-stack CMP trace gather, one-time reflected waves and multiple waves are separated in the Radon area, and data of the one-time reflected waves are estimated. The method solves the problems that an existing multiple wave attenuation technology based on convectional Radon transformation can not simulate AVO features of seismic data, the false phenomenon is generated in the positive transformation, the smearing exists, the distortion of the amplitude of the one-time reflected waves happens and leakage of the amplitude is caused in the reverse transformation, transformation of the shape of the seismic same-phase axis and the amplitude can be achieved in the Radon area, the movement features and the AVO features of seismic data can be separated better in the Radon area, the false phenomenon generated in the positive transformation process is weakened, accurate restoring of energy of the one-time reflected waves is achieved, the AVO features of the seismic data are protected, and the subsequent seismic inversion and explanation reliability is improved.

The invention discloses a storage method and device for laser radar point cloud data. The storage method comprises the following steps that the coordinate transformation is carried out on each laser point in the original laser point cloud data; each laser point after the coordinate transformation is detected, whether the currently detected laser point is a starting point of a new scanning line is judged by using the change of a laser point coordinate value; when the condition that the currently scanned laser is the starting point of the newly scanned line is judged, the laser point cloud data on a former scanning line is stored into a buffer region, and the coordinate reverse transformation is carried out on each laser point of the former scanning line in the buffer region; a space index is built for the affiliated scanning line of the laser point subjected to the coordinate reverse transformation, and is stored; the next scanning line is processed, and the steps are repeated until the laser point cloud data on all scanning lines is completely stored. The device mainly comprises a coordinate transformation unit, a detection judgment unit, a cache unit and a storage unit. Through the technical scheme, the subsequent data processing efficiency can be improved.

The invention discloses a wind speed modeling method for a large-sized wind power plant in a mountainous area. The method comprises: 1, sampling historically recorded wind speed of the wind power plant, and calculating parameters c and k of wind speed Weibull distribution of each fan group of the wind power plant; 2, calculating a rank correlation coefficient Rho Rr of each fan group in the wind power plant, and constructing a historical wind speed rank correlation coefficient Rr of the wind power plant; 3, calculating related wind speed normal Copula functions of the wind power plant to obtain a joint probability distribution function, defined in the specification, of modeled and predicted wind speed with correlation, and edge probability distribution functions u1 to un of wind speed of fan groups; and 4, performing equiprobable reverse transformation of the Weibull distribution parameters c and k on the edge probability distribution functions of the wind speed of the fan groups to realize wind speed prediction. According to the method, the technical problem that a characteristic that wind speed in a wind power plant has correlation cannot be truly and effectively reflected, electric power distribution and safety operation of a power system are influenced due to direct influence of the correlation of the wind speed in the wind power plant on output of the wind power plant, and the like in the prior art are solved.

The invention belongs to the fields of image processing and computer vision detection, and relates to an initial estimation improvement-based image super-resolution reconstruction method. The method comprises the steps of shooting similar but not completely same image sequences of a same scene by utilizing a camera, calculating transformation matrixes, relative to a reference image, of other images by taking a first image as the reference image, reserving sub-pixel displacement between the images, performing reverse transformation on the image sequences, and interpolating and amplifying the reference image by 4 times to serve as initial estimation of a high-resolution image; and correcting the initial estimation by utilizing the image sequences subjected to the reverse transformation to obtain a corrected high-resolution image, performing iterative correction on each pixel point of the image by utilizing a convex set projection algorithm until an iterative condition is met, and finally obtaining a reconstructed high-resolution image. According to the method, the pixels of the high-resolution image are properly improved before being subjected to projection correction, so that mean square errors of reconstruction are reduced and higher image reconstruction quality is achieved.

The invention discloses a method for SPEED rapid magnetic resonance imaging based on wavelet domain sparse representation. The method for SPEED rapid magnetic resonance imaging based on wavelet domain sparse representation comprises two steps of regular under-sampled data collection and SPEED image reconstruction based on wavelet domain sparse representation. The regular under-sampled data collection comprises two steps of k-space regular under-sampling and k-space central domain complete sampling. The SPEED image reconstruction based on wavelet domain sparse representation comprises seven steps of zero filling Fourier reconstruction, discrete wavelet transformation, wavelet domain double-layer sparse ghost model construction, overlapped ghost separation based on a least square error method, discrete wavelet reverse transformation, rectification summation of a plurality of ghost images and image reconstruction. The discrete wavelet transformation is used for SPEED data sparse representation, the sparseness of the image is improved through discrete wavelet transformation, and further the quality of the SPEED reconstruction image is improved.

An iron-based alloy having shape memory properties and superelasticity, which has a composition comprising 25-35% by mass of Ni, 13-25% by mass of Co, 2-8% by mass of Al, and 1-20% by mass in total of at least one selected from the group consisting of 1-5% by mass of Ti, 2-10% by mass of Nb and 3-20% by mass of Ta, the balance being substantially Fe and inevitable impurities, and a recrystallization texture substantially comprising a γ phase and a γ′ phase, particular crystal orientations of the γ phase being aligned, and the difference between a reverse transformation-finishing temperature and a martensitic transformation-starting temperature being 100° C. or less in the thermal hysteresis of martensitic transformation and reverse transformation.

The invention discloses a channel estimation channel, which belongs to the technical field of digital information transmission. The method comprises the following steps: removing intersymbol interference and noise from linear convolution of data of the previous frame and channel impulse response to obtain novel linear convolution; calculating the pseudo random sequence of the current frame and the linear convolution for initial channel estimation; reconstructing the linear convolution of the current frame; respectively transforming the pseudo random sequence of the current frame and the reconstructed linear convolution; carrying out reverse transformation of the ratio after transformation to obtain novel channel estimation; and accumulating the iteration times, and using the novel channel estimation as the initial channel estimation for further iteration if the iteration times does not reach the preset maximal value, or else, setting the novel channel estimation as the final channel estimation. The channel estimation method can acquire more accurate channel estimation, eliminate intersymbol interference caused by multi-path channels and reduce the processing complexity for channel estimation and balance a of multi-carrier or single carrier transmission system based on pseudo random sequence filling.

The invention relates to a transmission method for reducing interference and code sequence multiplexing among code sequences in a code division multiple access system. The transmission method relates to the technical field of communication and solves the problems of the interference and the insufficient code sequences in the code sequences in the existing CDMA system, the steps are as follows: a data source is sent to a transformation module at a transmitter end after the digital modulation and the PN source spread spectrum, the transformation module carries out the 4-th weighted fractional Fourier transform of data under the control of a parameter Alpha, and the data after the digital carrier modulation is further sent to a channel for transmission after the upper frequency conversion; the data after the lower frequency conversion is sent to a reverse transformation module at a receiver end, a CDMA signal after the spread spectrum is obtained after carrying out the demodulation, the dispread spectrum and the 4-th weighted fractional Fourier transform under the control of the parameter Alpha in the reverse transformation module, and then the CDMA signal is output to the outside through the digital demodulation work. The use of the method can reduce the interference among CDMA users and improve the capacity of the system; furthermore, the optimization and the reuse of the code sequences of the CDMA system can be realized under the condition of not occupying additional spectrum, time and code resources.