The authors propose a fast lossy compression algorithm for medical image compression. This algorithm has been designed taking into account the peculiarities of medical images. The uniform distribution of errors is app...
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ISBN:
(纸本)9781509022267
The authors propose a fast lossy compression algorithm for medical image compression. This algorithm has been designed taking into account the peculiarities of medical images. The uniform distribution of errors is applied. A comparative analysis of the proposed algorithm with known compressionalgorithms which use the wavelet transform is performed. The simulation results confirm the high efficiency of the proposed algorithm.
Testing large circuits requires compression of test patterns before transferring them to the tested circuit and decompression on board. The compression and decompression mechanism may be built according to the linear ...
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ISBN:
(纸本)9798350344196
Testing large circuits requires compression of test patterns before transferring them to the tested circuit and decompression on board. The compression and decompression mechanism may be built according to the linear block code rules. Broadening the decompressor structure search space to those using nonlinear block code is possible. Nonlinear block codes outperform their linear counterparts' compression ability. Their usage is limited due to the intricate search process. The code words' interconnectedness is difficult to exploit in the code word creation process as too many mutual dependencies exist among the code word bits. For this reason, random and partially random code word search methods were investigated in the past. This paper proposes two fully deterministic nonlinear code construction approaches. The obtained codes are significantly more efficient and easily scalable than the linear ones. We demonstrate their efficiency on codes with the number of specified bits equal to two, three, and four. The proposed methods may be used to create extensive codes, which are unachievable for previously published methods due to the explosion of computation time.
Deployments of high-sampling rate synchronised phasor measurement units (PMUs) are growing rapidly throughout the world, and with the advent of microPMUs, spreading from bulk transmission through distribution systems....
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Deployments of high-sampling rate synchronised phasor measurement units (PMUs) are growing rapidly throughout the world, and with the advent of microPMUs, spreading from bulk transmission through distribution systems. The growing volume of PMU data presents challenges in its communication and storage, motivating consideration of compressionalgorithms. This study presents a novel lossy compression algorithm that exploits particular characteristics of power system measurements to improve the compression. Concepts successfully applied in image compression are tailored to the spatio-temporal correlations induced between electrical quantities via their network interconnections. The quality of the resulting compression is judged on the balance of storage space savings versus the accuracy of data reconstruction. In representative real-world and transient simulation datasets, the technique developed can provide storage compression in the range of 40:1 when different physical quantities are compressed together. The compression ratios can be in the range of 90:1 for voltage magnitudes and 190:1 for frequency when the measurements are compressed separately. The high-compression ratios are achieved while maintaining low-loss (high-accuracy) reconstruction.
Electrocardiogram monitoring is crucial for the prevention and treatment of cardiovascular diseases. In this paper, we developed a wearable device involving multiple leads that monitors cardiac electrical activity usi...
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Electrocardiogram monitoring is crucial for the prevention and treatment of cardiovascular diseases. In this paper, we developed a wearable device involving multiple leads that monitors cardiac electrical activity using very large-scale integration technology to facilitate long-term activity monitoring. In addition to using limb leads and augmented limb leads for monitoring heart activity, six unipolar chest leads were attached to six positive electrodes and placed on the surface of the chest to record electrical activity of different regions of the heart. The multiple leads lie perpendicular to the frontal plane and were integrated within a single circuit to reduce hardware costs and size of the device. The proposed architecture also allows users to switch between lossless and lossycompression to control the power consumption and bit compression ratio. The effectiveness of the proposed approach was verified by fabricating a chip using 0.18-mu m CMOS technology. The proposed architecture core has an operating frequency of 41 MHz and a gate count of 4K.
Energy efficiency of resource-constrained wireless sensor networks is critical in applications such as real-time monitoring/surveillance. To improve the energy efficiency and reduce the energy consumption, the time se...
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Energy efficiency of resource-constrained wireless sensor networks is critical in applications such as real-time monitoring/surveillance. To improve the energy efficiency and reduce the energy consumption, the time series data can be compressed before transmission. However, most of the compressionalgorithms for time series data were developed only for single variate scenarios, while in practice there are often multiple sensor nodes in one application and the collected data is actually multivariate time series. In this paper, we propose to compress the time series data by the Lasso (least absolute shrinkage and selection operator) approximation. We show that, our approach can be naturally extended for compressing the multivariate time series data. Our extension is novel since it constructs an optimal projection of the original multivariates where the best energy efficiency can be realized. The two algorithms are named by ULasso (Univariate Lasso) and MLasso (Multivariate Lasso), for which we also provide practical guidance for parameter selection. Finally, empirically evaluation is implemented with several publicly available real-world data sets from different application domains. We quantify the algorithm performance by measuring the approximation error, compression ratio, and computation complexity. The results show that ULasso and MLasso are superior to or at least equivalent to compression performance of LTC and PLAMlis. Particularly, MLasso can significantly reduce the smooth multivariate time series data, without breaking the major trends and important changes of the sensor network system.
This paper is about the methods of sound data compression. The development of audio data compression has significantly made our lives easier. The technological progress has facilitated the process of recording audio o...
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ISBN:
(纸本)9783642292187
This paper is about the methods of sound data compression. The development of audio data compression has significantly made our lives easier. The technological progress has facilitated the process of recording audio on different media such as CD-Audio. In recent years. much has been achieved in the field of audio and speech compression. Many standards have been established In order to compare methods of sound data compression I have used Adobe Audition 3.0 software and computer program of the sound compression system from manufacturers' side. They are characterized by more better sound quality at lower bit rate. It allows recording the same CD-Audio formats using "lossy" or lossless compressionalgorithms in order to reduce the amount of data surface area at almost noticeable difference in the quality of the recording. To illustrate the problem, I have used the graphs of the spectrum and musical composition spectrograms. The comparison has been done on the basis of uncompressed music track from the original CD-Audio) lines before and after the abstract. This document is in the required format.
This paper describes the performance of beat detection and heart rate variability (HRV) feature extraction on electrocardiogram signals which have been compressed and reconstructed with a lossy compression algorithm. ...
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ISBN:
(纸本)9781424441242
This paper describes the performance of beat detection and heart rate variability (HRV) feature extraction on electrocardiogram signals which have been compressed and reconstructed with a lossy compression algorithm. The set partitioning in hierarchical trees (SPIHT) compressionalgorithm was used with sixteen compression ratios (CR) between 2 and 50 over the records of the MIT/BIH arrhythmia database. Sensitivities and specificities between 99% and 85% were computed for each CR utilised. The extracted HRV features were between 99% and 82% similar to the features extracted from the annotated records. A notable accuracy drop over all features extracted was noted beyond a CR of 30, with falls of 10% accuracy beyond this compression ratio.
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