Our 3D ultrasound computer tomograph (USCT) is an device method aimed at early breast cancer diagnosis. It is capable of producing images with sub-millimeter resolution and high signal-to-noise ratio. This method is u...
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Our 3D ultrasound computer tomograph (USCT) is an device method aimed at early breast cancer diagnosis. It is capable of producing images with sub-millimeter resolution and high signal-to-noise ratio. This method is universally useable for the 3D analysis of sufficient small bodies similar to the size of a breast, which may be immersed in a liquid coupling medium. In this paper, an overview of the developed method and the first results for static test examples (phantoms) and the perspective of our 3D-USCT at Forschungszentrum Karlsruhe are presented. (c) 2007 Elsevier B.V. All rights reserved.
In this paper, the damage detection from non-stationary mechanical vibration signals collected during acceleration and deceleration was performed. A laboratory grinding spindle-typed rotor-bearing system was equipped,...
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In this paper, the damage detection from non-stationary mechanical vibration signals collected during acceleration and deceleration was performed. A laboratory grinding spindle-typed rotor-bearing system was equipped, and modal testing was carried out to identify system characteristics and operating range. Time-frequency analysis method such as Fast Fourier Transform (FFT), Short-Time Fourier Transform (STFT), Wigner-Ville Distribution (WVD), and Discrete Wavelet Transform (DWT) was applied to vibration data of normal rotor and shaft-cracked rotor in speed-varying process and the results of feature extraction from shaft-cracked condition were also compared with those in normal condition. (c) 2007 Elsevier B.V. All rights reserved.
This paper proposes a simple data hiding technique for binary images. The binary cover image is partitioned into equal-sized, non-overlapping blocks and the watermark will be embedded into blocks by flipping pixels. T...
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ISBN:
(纸本)9780769529943
This paper proposes a simple data hiding technique for binary images. The binary cover image is partitioned into equal-sized, non-overlapping blocks and the watermark will be embedded into blocks by flipping pixels. The weight mechanism is also proposed to find the most suitable flip pixel in the block. In order to improve the visual quality of the stego image, the boundary check is used to prevent the boundary distortion. Experimental results show that our method achieves a good visual quality for the watermarked image and has high capacity for embedding.
The general difference expansion method uses reversible integer transform to embed information into a digital image and perfectly restores the original image after removing the hidden data. In multilayer embedding app...
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ISBN:
(纸本)9780769529943
The general difference expansion method uses reversible integer transform to embed information into a digital image and perfectly restores the original image after removing the hidden data. In multilayer embedding applications, the operation of difference expansion may seriously degrade the visual quality of the embedded image. In this paper, we propose a reduced difference expansion method to solve this problem. Theoretically, in the worst case, the proposed method gains 6-dB improvement in visual quality of the embedded image compared with the general difference expansion method. Therefore, the proposed method is suitable for multilayer data embedding.
While the RNN is well studied in the traditional wired, disk-based client-server environment, it has not been tackled in a wireless broadcasting environment. The liner property of wireless broadcast media and power co...
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ISBN:
(纸本)0769529941
While the RNN is well studied in the traditional wired, disk-based client-server environment, it has not been tackled in a wireless broadcasting environment. The liner property of wireless broadcast media and power conserving requirement of mobile devices make the problem particularly interesting and challenging. In this paper, the issues involved with organizing location dependent data and answering RNN queries on air are investigated An efficient data organization, called Jump rdnn-tree, and the corresponding search algorithms are proposed Performance of the proposed Jump rdnn-tree and other traditional indexes (enhanced for wireless broadcast) is evaluated using both uniform and skew data. The results show that Jump rdnn-tree substantially outperforms the traditional indexes.
Watermarking is a very active research field and its application to 2D still images and audio signals have been widely used also, but watermarking of 3D mesh object has not been heavily researched, reversible 3D water...
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ISBN:
(纸本)9780769529943
Watermarking is a very active research field and its application to 2D still images and audio signals have been widely used also, but watermarking of 3D mesh object has not been heavily researched, reversible 3D watermarking especially. This paper proposes a reversible data hiding scheme for 3D vertex. We first select last few digits of vertices coordinate value which should be perceptually invisible and classify them base on some previous conditions. Then we find the proper coordinate to embed data. The original model can be perfectly recovered if it is intact. Our scheme is suitable for some specific applications where high accuracy of the original model must be guaranteed.
Accurate estimation of signal direction of arrival (DOA) has many applications in communication and radar systems. For example, in defense application, it is important to identify the direction of possible threat. One...
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ISBN:
(纸本)9781424410569
Accurate estimation of signal direction of arrival (DOA) has many applications in communication and radar systems. For example, in defense application, it is important to identify the direction of possible threat. One example of commercial application is to identify the direction of emergency cell phone call such that the rescue team can be dispatched to the proper location. DOA estimation using a fixed antenna has many limitations. Its resolution is limited by the mainlobe beamwidth of the antenna. Antenna mainlobe beamwidth is inversely proportional to its physical size. Improving the accuracy of angle measurement by increasing the physical aperture of the receiving antenna is not always a good option. Certain systems such as a missile seeker or aircraft antenna have physical size limitations;therefore, they have relatively wide mainlobe beamwidth. Consequently, the resolution is quite poor. Also, if there are multiple signals falling in the antenna mainlobe, it will be difficult to distinguish them. Instead of using a fixed antenna, an array antenna system with innovative signalprocessing would enhance the resolution of signal DOA. It also has the ability to identify multiple targets. Two types of signalprocessing methods, model based and eigen-analysis estimation techniques, are presented in this paper. The model based approach models the observed data as the output of a linear shift invariant system driven by zero mean white noise. The signal's DOA can be estimated by evaluating the model parameters. This approach has properties similar to the maximum entropy spectrum estimation [1]. Some of the problems in the maximum entropy method, such as the line splitting effect, are also observed in this method. Two different processing algorithms are used to obtain the model parameters, and they are: 1. Least Mean Square (LMS) and 2. Sample Matrix Inversion (SMI). The eigen-analysis method based on temporal averaging has been investigated by many authors in the past [
Frequent pattern mining is fundamental to many important data mining tasks. Many researchers had presented many mining methods in static database. Due to many special characters of data stream, those methods fail to b...
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ISBN:
(纸本)0769529941
Frequent pattern mining is fundamental to many important data mining tasks. Many researchers had presented many mining methods in static database. Due to many special characters of data stream, those methods fail to be used in dynamic environment. We develop a novel method mining frequent items from data stream based on sliding window model. We use some compact data structures which make uses of the limited space efficiently. The proposed method is an approximate algorithm, it can eliminate the influence of old data to mined result. And the mined results are kept in a heap. This data structure is seldom used in other methods, and the mined results can be inquired by top-k.
We propose an effective data hiding method based on the EMD embedding scheme proposed by Zhang et al. in order to enhance the embedding capacity. The main idea of our proposed scheme is to convert secret binary messag...
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ISBN:
(纸本)9780769529943
We propose an effective data hiding method based on the EMD embedding scheme proposed by Zhang et al. in order to enhance the embedding capacity. The main idea of our proposed scheme is to convert secret binary messages into a sequence of digits in an 8-ary notational system. Each secret digit is embedded into two cover pixels by modifying the least significant bits (LSBs). As the experimental results show, the embedding bit-rate of our scheme is 1.5 times better than the EMD embedding scheme. In a word, we propose a high-quality and high-capacity data hiding method that can ensure the stego-image quality and security.
Digital contents are easy to be pirated and to be distributed in today Internet Digital right management is an important topic to squash pop music pirates. In this paper, we will introduce the data hiding platform &qu...
ISBN:
(纸本)0769529941
Digital contents are easy to be pirated and to be distributed in today Internet Digital right management is an important topic to squash pop music pirates. In this paper, we will introduce the data hiding platform "MP3Stego" for MP3 files and we propose a "Fingerprinting with Error Correcting Coding (FPEcc)" method on MP3Stego to increase robustness for its weakness. Through analytical results, the proposed method shows obvious improvement to prevent attacks.
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