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	Time division exchange system having functions of compressing and expanding information - Patent 4823342 (Site not responding. Last check: 2007-11-06)
		Signals on the links 115 and 116 and the signal path 117 are combined by the multiplex transmission apparatus 114 into a multiple signal, which is sent to the multiplex transmission line 160.
		In the present case, a signal from the facsimile subscriber 103 is sent in the form of a signal of 64 Kbps between the facsimile subscriber 103 and the input terminal 110a of the compression circuit 110, and between the output terminal 140b of the expansion circuit 140 and the facsimile subscriber 133.
		That is, the controller 107 connects the telephone subscriber 105 to the input terminal 111a of the compression circuit 111 for the B-compression law, and connects the output terminal 111b of the circuit 111 to the input terminal 113b of the multiplexer 113, with the aid of the switching function of the PBX switch 106.
	www.freepatentsonline.com /4823342.html (3900 words)

	Signal compression
		Signals such as speech and image data are stored and processed in computers as files or collections of bits.
		Signal compression or data compression is concerned with reducing the number of bits required to describe a signal to a prescribed accuracy.
		Signal compression is a key technology for multimedia applications on the NII.
	users.ece.gatech.edu /~vkm/nii/node36.html (1099 words)

	[No title]
		The compression ratio is defined as the ratio of the length of the encoded output data to the length of the original input data.
		The code signal from the register 119 and the character signal from the register 116 are gated via busses 125 and 126 respectively to the hash function circuit 127 which generates a hash address for that combination.
		Thereafter, the code signal in the code register 172, which is the prefix code for the present string, is transferred to the RAM address register 165 via the bus 176 and the Next Character State is entered to effect normal processing of the remainder of this string.
	lpf.ai.mit.edu /Patents/abstracts/compression (21440 words)

	Magnetic video recording/reproducing apparatus for video signals of different aspect ratios adapter unit - Patent ...
		The output signals of the two circuits 23 and 24 are frequency multiplexed by means of the mixer circuit 25 operable to mix the Y and C signals during recording and they are recorded on the magnetic tape 3 through the recording amplifier 26 and recording head 27.
		Firstly, a signal recorded on the magnetic tape 3 is reproduced by means of the reproducing head 401 and the amplitude of a reproduced signal is amplified to a necessary value by the reproducing amplifier 402.
		The output signal of the Y signal reproduction processing circuit 403 is also supplied to the first PLL circuit 405 in which the synchronization signal is separated from the reproduced signal to extract a pulse signal having the frequency f.sub.H of the horizontal synchronization signal.
	www.freepatentsonline.com /5122885.html (9038 words)

	Definition: signal compression (Site not responding. Last check: 2007-11-06)
		Note 2: Instantaneous values of the input signal that are low, relative to the reference level, are increased, and those that are high are decreased.
		Note 3: Signal compression is usually accomplished by separate devices called "compressors." It is used for many purposes, such as (a) improving signal-to-noise ratios prior to digitizing an analog signal for transmission over a digital carrier system, (b) preventing overload of succeeding elements of a system, or (c) matching the dynamic ranges of two devices.
		Note 4: Signal compression (in dB) may be a linear or nonlinear function of the signal level across the frequency band of interest and may be essentially instantaneous or have fixed or variable delay times.
	www.atis.org /tg2k/_signal_compression.html (243 words)

	Compression Algorithms
		The restoration of signal after compression by reducing number of samples shows divergence which is greater than after compression by reducing the number of quantization levels.
		When compression by reducing number of samples was used the divergence was caused by quantization noise which was caused by amplitude quantization, in this case (compression by reducing number of samples) divergence is caused by time quantization (remember we halved sampling frequency).
		Compression of images is segment of data compression which was probably mostly exploited.
	oldwww.rasip.fer.hr /research/compress/algorithms/fund/pcm (2082 words)

	Internet Telephony and Voice Compression
		This is due to the complexity of the compression algorithm used (it takes time for the signal to be compressed and expanded) and the traffic on the network.
		TrueSpeech 8.5 is a speech compression algorithm with relatively low complexity, with a 15:1 compression ratio and a MOS of 3.7.
		Compression techniques were discussed to provide a background to understand the issues involved with voice compression, however, the proprietary algorithms used in specific Internet telephony software is not known.
	www.cis.upenn.edu /~kellyann/papers/iphone.html (3136 words)

	TVTechnology - Inside Audio
		Audio compression refers to the regulation of the amplitude of a signal as a function of the signal itself.
		The dynamic range of audio signals is huge, and in most cases, we need to reduce that range in order to effectively transmit the signal to the listener.
		At the level detector, the signal is converted to a DC-control voltage that varies as a function of the signal level.
	www.tvtechnology.com /features/Inside-Audio/Moulton.shtml (1009 words)

	[No title]
		Hard knee is where the signal is compressed the moment it goes above the threshold to the full extent of the ratio that is set.
		Some people think that even though the signal is peaking out during recording, they can compress the signal in the mix and it will be the same.
		Compression should be applied and monitored by using the peak display meters on your compressor or mixer.
	www.recordingwebsite.com /articles/compression.php (1809 words)

	Signal Compression by Second Order Polynomials and Piecewise Non-Interpolating Approximation (ResearchIndex)
		Abstract: In this paper we present a time domain signal compression scheme based on the coding of line segments which are used to approximate the signal.
		ECG signal compression has traditionally been tackled by heuristic approaches.
		Compressing ECG Signals by Piecewise Polynomial Approximation - Nygaard, Haugland (1998)
	citeseer.ist.psu.edu /346531.html (329 words)

	Research
		In order to compress data by a large factor, an algorithm must be lossy, i.e., it must throw out some of the information.
		The following is an example of running a signal through the filter banks and an analysis of the error produced.
		By listening to these various compression schemes, we can determine how good the sound quality is as compared to the original signal with 16-bit quantization.
	is.rice.edu /~welsh/elec431/projectResearch.html (1716 words)

	Ecg Signal (Site not responding. Last check: 2007-11-06)
		Assessing ECG signal quality on a coronary care unit Assessing ECG signal quality on a coronary care unit Assessing ECG signal quality on a coronary care unit Poor electrocardiograph (ECG) signal quality is associated with an increase in the number of false alarms, may degrade diagnostic...
		Signal averaged ECG (SAECG) is a technique involving computerized analysis of small segments of a standard...
		The ECG signal is collected by probes located on skin near the...
	www.ecg-77.info /ecg/ecg-signal.html (484 words)

	EEG Signal Compression with ADPCM Subband Coding (ResearchIndex)
		Abstract: An EEG signal compression method that combines both octave-band filter bank frequency decomposition and coding in subbands using adaptive differential pulse code modulation (ADPCM) is proposed.
		Higher compression rate are obtained by increasing the order of the predictor used.
		Analysis Of LVQ In The Context Of Spontaneous EEG Signal..
	citeseer.ist.psu.edu /66972.html (253 words)

	EE587 Data and Signal Compression (Site not responding. Last check: 2007-11-06)
		The need for signal and data compression is ubiquitous in image, video, and speech processing, finance, and computational science.
		This course addresses both the theoretical basis and practical algorithms for data and signal compression.
		The relation between compression schemes and probabilistic data modeling is emphasized in conjunction with each technique.
	www.cse.ogi.edu /courses/EE587 (209 words)

	Signal Compression Based on Models of Human Perception (Site not responding. Last check: 2007-11-06)
		The basic thrust of the paper is that compression algorithms should be designed to minimize perceptually meaningful measures of signal distortion rather than the traditional measure of mean squared distance between i/p and o/p waveforms.
		To that end the paper is a compilation of the necessary signal processing background and the work done in the field.
		The treatment of the material is shallow -- the paper tries to reference as much work as possible and, as such, seems most useful as a survey paper to someone already in the field.
	bmrc.berkeley.edu /people/radhika/cs294-3/sigComp.html (129 words)

	Signal Compression Based on Models of Human Perception (Site not responding. Last check: 2007-11-06)
		The problem of coding is to achieve a low bit rate in the digital representation of an input signal with minimum perceived loss of signal quality.
		In coding signals such as speech, audio, image and video, the ultimate criterion of signal quality is usually that judged or measured by the human receiver.
		This talk develops the notion of perceptual coding based on models of distortion-masking by the signal being compressed, and describes how the field has progressed as a result of advances in classical coding theory, modelling of human perception, and digital signal processing.
	www.cs.uiowa.edu /Events/Colloquia/1994/colloquium.1994.02.04.html (189 words)

	III
		Compression Pointers on compression, also concentrating on wavelet and fractal methods, but providing links to the Apple Quicktime and other popular commercial pages.
		Signal processing is only one component of the field, which also includes networking, databases, and operating systems at its heart.
		Compression with Reversible Embedded Wavelets (CREW) A commercial variation of the EZW compression scheme developed by RICOH California Research Center.
	www-ee.stanford.edu /~gray/iii.html (2212 words)

	Lossless Signal Compression Using Adaptive Lifting I2I Transforms (Site not responding. Last check: 2007-11-06)
		This paper aims to show that the signal compression algorithms using the implementation of a wavelet filter bank based on the "traditional lifting scheme" could be improved through the concept of "adaptive lifting".
		Three types of signals have been considered in the experimental tests: artificially generated AR signals, real speech and standard MPEG audio signals.
		He is coauthor of two books and more than 90 publications in the fields of signal compression, image processing and system identification.
	www.ici.ro /ici/revista/sic2002_4/art3.htm (549 words)

	Signal Compression and Classification Group (Site not responding. Last check: 2007-11-06)
		The Signal Compression and Classification Group is a research group in the Information Systems Laboratory, which is part of the Department of Electrical Engineering.
		Related topics in signal processing are also considered, including enhancement, segmentation, regression, detection, estimation, prediction, video coding, and motion estimation.
		A common theme of the work is the interplay of compression and classification, especially of tree-structured algorithms and clustering for vector quantization for simultaneous compression and classification.
	www.stanford.edu /group/compression (162 words)

	Signal Compression and Classification Group
		Stanford University does research on the theory, algorithm design, simulation, and quality evaluation of systems for signal compression, quantization, source coding with a fidelity criterion, and classification.
		Image Compression, Classification, and Universal Coding, transparencies for an invited talk at the Erlangen Workshop on Advances in Digital Image Communication, University of Erlangen/Nuremburg, 25 April 1997.
		Lossy Compressed Medical Images and Measurement Accuracy, Sharon M. Perlmutter, Pamela C. Cosman, Chien-Wen Tseng, Richard A. Olshen, and Robert M. Gray, King C. Li, and Colleen J. Bergin.
	www-ee.stanford.edu /~gray/compression.html (988 words)

	Next-Generation Signal Compression And Reconstruction Transforms
		Better image compression is critical for a new generation of UAVs that will require high definition quality TV feedback to remote operators 1000s of miles from the battlefield.
		To address the challenge of improved image file compression, the AFRL team first defined three possible approaches: (1) decrease one- and two-dimensional (1-D and 2-D) mean squared error (MSE) while maintaining file size, (2) maintain MSE while increasing 1-D and 2-D signal compression (decreasing file size), or (3) decrease both MSE and file size.
		The students' third research objective was to determine whether they could further compress image file size by adjusting standard wavelet transform coefficients using a GA. Their results revealed that researchers can indeed realize an approximate 19% compression improvement - without adversely affecting MSE results - using the evolved coefficients.
	www.spacewar.com /news/milspace-comms-05zzzq.html (1466 words)

	ANALOG DEVICES SIGNAL COMPRESSION DEVICES (Site not responding. Last check: 2007-11-06)
		Variable-gain amplifiers use technology which allows the amplifier gain to be varied as the dynamic range of the input signal changes.
		Logarithmic amplifiers provide output voltage proportional to logarithmic of input voltage for signal from DC to 120MHz.
		Ideal for applications that require compression of wide-range analog input data.
	www.newark.com /product-details/text/CD121/9874.html (87 words)

	Stuart Compression Pointers Page (Site not responding. Last check: 2007-11-06)
		Compression resources, conferences, and some research groups and companies, are listed towards the end of this page.
		Featured books from Text Compression, by, Witten and Cleary --- This is the book that everyhas in their possession The Data Compression, by and --- Source code to all the algorithms that you need Bell Managing by atabases, images.
		Lossless Image it appeared compression, computer science for in a strong database.
	www.internz.com /compression-pointers.html (436 words)

	Amazon.ca: Books: Vector Quantization and Signal Compression (Site not responding. Last check: 2007-11-06)
		Many useful concepts of digital compression can be found in this book.
		It does not cover major topics, such as.gif/ graphic file compression.
		On the positive side it is well-written, organized, multiple equation in some chapters, descriptive in others.
	www.amazon.ca /exec/obidos/ASIN/0792391810 (313 words)

	Fuzzy Heuristic Signal Compression Based On Linguistic Variables (ResearchIndex) (Site not responding. Last check: 2007-11-06)
		Fuzzy Heuristic Signal Compression Based On Linguistic Variables
		Abstract: This paper presents an original approach to signal compression that makes use of fuzzy techniques and concepts like linguistic variables and values.
		In particular, two aspects are addressed: on one side, the tuning of the proposed fuzzy compression and decompression algorithm by means of an evolutionary algorithm; on the other side, the incorporation of available heuristic knowledge of the contents of an image in the proposed approach in order to achieve better performances.
	citeseer.csail.mit.edu /61240.html (313 words)

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