Device and circuit engineering
 
Category: Device and circuit engineering
Classical multidimensional wavelet bases are based on the multiresolution approach and variable separation in each spatial direction. In particular, N-dimensional wavelet basis can be obtained by tensor products of two one-dimensional functions (the basic wavelet and scale function)[6]. Such wavelet bases require 2N ¡ 1 types of functions and are intrinsically anisotropic.
1181 days ago
 
Traditional wavelets are not very effective in dealing with images that contain orientated discontinuities (edges). To achieve a more efficient representation one has to use basis elements with much higher directional sensitivity. In recent years several approaches like curvelets
1181 days ago
 
In conventional Fourier transform, we use sinusoids for basis functions. It can only provide the frequency information. Temporal information is lost in this transformation process. In some applications, we need to know the frequency and temporal information at the same time, such as a musical score, we want to know not only the notes (frequencies) we want to play but also when to play them
1181 days ago
 
To reach that goal, we must first generalize wavelet theory for Rd to a more abstract setting. A number of authors have extended wavelet theories to locally compact groups G other than Rd; see, for example, [7, 10, 12, 15, 19, 21]. However, those generalizations required the group G to contain a discrete subgroup, just as Rd contains the discrete lattice Zd. The more abstract generalized multiresolution analyses in [1, 22] are even broader
1181 days ago
 
The EZW encoder is based on progressive encoding to compress an image into a bit stream with increasing accuracy. This means that when more bits are added to the stream, the decoded image will contain more detail, a property similar to JPEG encoded images. It is also similar to the representation of a number like p. Every digit we add increases the accuracy of the number, but we can stop at any accuracy we like. Progressive encoding is also known as embedded encoding, which explains the E in EZW.
1181 days ago
 
of wavelet are apparent from a few examples. A di erence of two Dirac functions separated by a time  (Fig. 1), used to build struc- ture functions, has an extended Fourier spec- trum (Fig. 2). The Haar function has com- pact support also, and an extended oscillatory spectrum (1=!2 decay) as a consequence.
1181 days ago
 
Multiresoltion analysis (MRA) based compactly supported wavelet frames constructedfrom the unitary extension principle (UEP), as in [7], are considered throughout this paper. The lifting [10] like schemes are given to increase the number of vanishing moments of wavelet frames
1181 days ago
 
Subband coding is a speech compression technique dating from the late 7O', and was generalized to images'9'2' and video8 in the 80's. The introduction of wavelets6 was soon followed by the recognition that they have a close connection to subband coding.9 By now, subband coding of images using a wavelet-like decomposition are very popular
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There are two related speech tasks: speech understanding and speech recognition. Speech understanding is getting the meaning of an utterance such that one can respond properly whether or not one has correctly recognized all ofthe words.
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concatenative speech synthesis (unit selection) has emerged as a promising methodology to solve the problems with the xed-size unit inventory synthesis, e.g. diphone synthesis [3-7]. In corpusbased systems, the acoustic units of varying sizes are selected from a large speech corpus and concatenated. The speech corpus contains more than one instance of each unit to capture prosodic and spectral variability found in natural speech;
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Speech recognition basically means talking to a computer, having it recognize what we are saying, and lastly, doing this in real time. This process fundamentally functions as a pipeline that converts PCM (Pulse Code Modulation) digital audio from a sound card into recognized speech
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Speaker recognition encompasses verification and identification. Automatic speaker verification (ASV) is the use of a machine to verify a person’s claimed identity from his voice. The literature abounds with different terms for speaker verification, including voice verification, speaker authentication, voice authentication, talker authentication, and talker verification.
1181 days ago
 
The short-time Fourier transform (STFT), or alternatively short-term Fourier transform, is a Fourier-related transform used to determine the sinusoidal frequency and phase content of local sections of a signal as it changes over time.
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Many signals such as speech can be compressed and recovered using a form of coding known as linear predictive coding (LPC). This lab will examine this LPC model which is illustrated in Figure 1. Hence speech can be produced by taking a autoregressive (AR) lter (an all-pole lter) and exciting it with either a periodic pulse train or white noise to produce the various components of speech. Hence, to synthesize speech we need to be able to determine the AR lter coecients (the analysis part) which are then transmitted to the synthesizer
1181 days ago
 
The first step in most applications of digital speech processing is to convert the acoustic waveform to a sequence of numbers. Most modern A-to-D converters operate by sampling at a very high rate, applying a digital low pass filter with cutoff set to preserve a prescribed bandwidth, and then reducing the sampling rate to the desired sampling rate, which can be as low as twice the cutoff frequency of the sharp-cutoff digital filter
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systems merge interdisciplinary technologies from Signal Processing, Pattern Recognition, Natural Language, and Linguistics into a unified statistical framework. These systems, which have applications in a wide range of signal processing problems, represent a revolution in Digital Signal Processing (DSP).
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Systems Development Life Cycle • Phases are not necessarily sequential o Sequential o Parallel • Each phase has a specific outcome and deliverable • Individual companies use customized life cycle
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A mechanism for scheduling jobs or processes. Scheduling can be as simple as running the next process, or it can use relatively complex rules to pick a running process. A method for simultaneous CPU execution and IO handling. Processing is going on even as IO is occurring in preparation for future CPU work.
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To understand the role that scheduling and schedulability analysis plays in predicting that realtime applications meet their deadlines To understand the cyclic executive approach and its limitations
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”Any system in which the time at which output is produced is significant. This is usually because the input corresponds to some movement in the physical world, and the output has to relate to that same movement. The lag from input time to output time must be sufficiently small for acceptable timeliness.”
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Systems which monitor and control theirenvironmen Inevitably associated with hardware devices • Sensors: Collect data from the system environment • Actuators: Change (in some way) the system's environment
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• A computer file is a named collection of stored data. • An executable file contains the instructions that tell a computer how to perform a specific task; for instance, the files that are used while the computer starts are executable.
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• Embedded computing systems – Computing systems embedded within electronic devices – Hard to define. Nearly any computing system other than a desktop computer – Billions of units produced yearly, versus millions of desktop units
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Specifying the right reference and applying it correctly is a more difficult task than one might first surmise, considering that references are only 2- or 3-terminal devices. Although the word “accuracy” is most often spoken in reference to references
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Much has been written about terminating PCB traces in their characteristic impedance, to avoid signal reflections. However, it may not be clear when transmission line techniques are appropriate. A good guideline to determine when the transmission line approach is necessary for logic signals is as follows: Terminate the transmission line in its characteristic impedance when the one-way propagation delay of the PCB track is equal to or greater than one-half the applied signal rise/fall time (whichever edge is faster). For example, a 2 inch microstrip line over an Er = 4.0 dielectric would have a delay of about 270 ps. Using the above rule strictly, termination would be appropriate whenever the signal rise time is less than approximately 500 ps.
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