摘要:
Catalyst systems and methods of forming the catalyst systems are described herein. The methods generally include contacting a support material with an activator to form a support composition, contacting a component with at least a portion of an aluminum containing compound including TIBAl, wherein the component is selected from the support composition, the transition metal catalyst compound and combinations thereof and contacting the support composition with a transition metal catalyst compound to form a supported catalyst system.
摘要:
The disclosure details methods of measuring the quality of service of received media signals by analyzing digital watermarks embedded in such signals. The quality of a received video or audio signal can thereby be assessed without having the original version of the signal before transmission. Instead, the strength or quality of the embedded digital watermark is analyzed to determine the quality of the received signal. The degradation of a watermark signal is used to assess quality of service of signals, such as audio and video.
摘要:
A reversible watermarking method embeds auxiliary data into a data set, such as an image, audio, video or other data, in a manner that enables full recovery of the original, un-modified data set. This method may be used to determine whether the data set has been tampered. To improve embedding capacity without the need for compression of the auxiliary data, the method uses an expansion technique. One particular approach exploits the correlation or redundancy within the data set to convert the data to a set of small, expandable values, such as difference values. These small values are then expanded by inserting auxiliary data as one or more additional bits, increasing the number of bits without causing an underflow or overflow. This approach also uses a property of the data set that is invariant to the embedding operation to identify embedding locations, obviating the need for separate data to identify where data is embedded in a data set.
摘要:
The present invention discloses a phase imbalance monitoring apparatus, an amplitude imbalance monitoring apparatus, as well as an apparatus incorporating the same. The phase imbalance monitoring apparatus is for use in an apparatus in which imbalance between an I branch signal and a Q branch signal in quadrature to each other is required to be monitored, and is characterized in comprising a preprocessing unit, for performing preprocessing on the I branch signal and the Q branch signal to extract essential information relevant to correlation of the signals; and a correlation unit, for performing correlation processing on the extracted essential information to learn of the phase imbalance between the I branch signal and the Q branch signal.
摘要:
A method of authenticating a media signal and related software, systems and applications. The method transforms at least a portion of the media signal into a set of frequency coefficients in a frequency domain. For example, it applies a Fast Fourier Transform (FFT) or other frequency transform to blocks of a media signal, such as an image, audio or video signal. It adjusts a relationship between selected frequency coefficients to a reference value. This adjustment is selected so that an alteration to be detected, such as a re-sampling operation or digital to analog—analog to digital conversion, alters the relationship. To detect the alteration, a detector computes the relationship in a potentially corrupted version of the signal. It then compares the result with a threshold value to detect whether the alteration has occurred.
摘要:
Reversible watermarking methods enable auxiliary data to be embedded in data sets, such as images, audio, video and software. The reversible nature of the method enables the original data set to be perfectly restored. Control systems with feedback loops are used to optimize embedding based on distortion or auxiliary data capacity constraints. The watermarking may be applied recursively to embed several layers, where subsequent layers are embedded into a previously watermarked data set. To recover the original data, each layer is extracted and the data restored in reverse order of the embedding. Sets of elements that are expanded to carry auxiliary data in each layer overlap or are interleaved to maximize embedding capacity or quality of the host data.
摘要:
A process for preparing low melting copolymers comprising contacting a mixture of olefin monomers with a CpFlu-type metallocene catalyst under reaction conditions sufficient to form a copolymer. The copolymers thus prepared desirably display melt temperatures from about 100° C. to about 140° C. and may be produced with reduced amounts of ethylene. The copolymers may also exhibit reduced levels of undesirable xylene solubles, relatively narrow molecular weight distribution, and other improved optical and physical properties.
摘要:
Reversible watermarking methods enable auxiliary data to be embedded in data sets, such as images, audio, video and software. The reversible nature of the method enables the original data set to be perfectly restored. Control systems with feedback loops are used to optimize embedding based on distortion or auxiliary data capacity constraints. The watermarking may be applied recursively to embed several layers, where subsequent layers are embedded into a previously watermarked data set. To recover the original data, each layer is extracted and the data restored in reverse order of the embedding. Sets of elements that are expanded to carry auxiliary data in each layer overlap or are interleaved to maximize embedding capacity or quality of the host data.
摘要:
Supported metallocene catalysts and processes for the use of such catalysts in isotactic polymerization of a C3+ ethylenically unsaturated monomer. The supported catalysts comprise a particulate silica support, an alkyl alumoxane component, and a metallocene catalyst component. The support has an average particle size of 10-50 microns, a surface area of 200-800 m2/g and a pore volume of 0.9-2.1 milliliters per gram (ml/g). Alumoxane is incorporated onto the support to provide a weight ratio of alumoxane to silica of at least 0.8:1. The metallocene is present in an amount of at least 1 weight percent of the silica and the alumoxane and is of the formula B(CpRaRb)(Fl′)MQ2 in which Fl′ is an unsubstituted fluorenyl group or a fluorenyl group symmetrically substituted at the 3 and 6 positions, B is a structural bridge between Cp and Fl′, Ra is a bulky substituent in a distal position, Rb is a less bulky substituent proximal to the bridge and non-vicinal to the distal substituent, M is a Group IVB transition metal or vanadium, and Q is a halogen or a Cl-C4 alkyl group.
摘要:
A watermark embedder decomposes a media signal from its perceptual domain to subbands and embeds a message signal in the edge information of neighboring coefficients of those subbands. A compatible watermark decoder decomposes the watermarked signal into subbands and demodulates the message signal from the edge information of neighboring coefficients. In addition to the message signal, the embedder may also encode an orientation signal to synchronize the decoder with the embedded signal in a distorted version of the watermarked signal. The watermark system may be used in a variety of applications, including robustly carrying metadata or links to metadata, and to detect alterations of the watermarked signal, such as alterations due to printing, scanning, compression, etc.