Design and implementation of a DSP based MPEG-1 audio encoder

The speed of current PCs enables them to decode and play an MPEG bitstream in real time. The encoding process, however, cannot be done in real-time. The purpose of this thesis is to produce a low-cost real-time Digital Signal Processor (DSP) implementation of an MPEG encoder. The DSP will provide an MPEG bitstream to the PC that can be saved to disk. The input to the DSP will be an analog audio signal. A codec provides the DSP with 16-bit samples of the signal. The DSP compresses these 16-bit samples using MPEG-1 layer 1 compression. Then it formats the compressed data to the correct MPEG-1 bitstream, and transmits it to the PC over its byte-wide host interface. On the PC side, a program receives the data from the DSP and saves the MPEG data to the disk. An MPEG-1 layer 1 player can play the resulting file

Shear Thickening of Dense Suspensions: The Role of Friction

Shear thickening of particle suspensions is characterized by a transition between lubricated and frictional contacts between the particles. Using 3D numerical simulations, we study how the inter-particle friction coefficient influences the effective macroscopic friction coefficient and hence the microstructure and rheology of dense shear thickening suspensions. We propose expressions for effective friction coefficient in terms of distance to jamming for varying shear stresses and particle friction coefficient values. We find effective friction coefficient to be rather insensitive to interparticle friction, which is perhaps surprising but agrees with recent theory and experiments

Impact of hot-carrier degradation on the low-frequency noise in MOSFETs under steady-state and periodic large-signal excitation

This letter reports the diagnostic power of the low-frequency noise analysis (steady-state and periodic large-signal excitation) in MOSFETs subjected to hot-carrier degradation. The LF noise under periodic large-signal excitation is shown to increase more rapidly than the LF noise in steady-state. Moreover the improvement in the LF noise performance due to periodic large-signal excitation, observed for fresh devices, gradually diminishes as the devices are subjected to hot-carrier stress

Visualisation Techniques for Random Telegraph Signals in MOSFETs

In the study of LF noise in MOSFETS, it has become clear that Random Telegraph Signals (RTS) are dominant. When a MOSFET is subjected to large-signal excitation, the RTS noise is influenced. In this paper, we present different visualizations of the transient behaviour of the RT

Low-Frequency Noise Phenomena in Switched MOSFETs

In small-area MOSFETs widely used in analog and RF circuit design, low-frequency (LF) noise behavior is increasingly dominated by single-electron effects. In this paper, the authors review the limitations of current compact noise models which do not model such single-electron effects. The authors present measurement results that illustrate typical LF noise behavior in small-area MOSFETs, and a model based on Shockley-Read-Hall statistics to explain the behavior. Finally, the authors treat practical examples that illustrate the relevance of these effects to analog circuit design. To the analog circuit designer, awareness of these single-electron noise phenomena is crucial if optimal circuits are to be designed, especially since the effects can aid in low-noise circuit design if used properly, while they may be detrimental to performance if inadvertently applie

The predicate-argument relation and the structure of . . .

This article provides an analysis of some fragments of discourse taken from the Corpus Spoken Frisian. It is claimed that the predicate-argument relation provides structure to such discourse fragments, provided that the argument position of the predicate can be occupied not just by a NP or CP but also by a list of clauses and phrases. The scope of the predicate argument relation is thus extended from intrasentential structure to discourse structure. In addition, attention is drawn to two syntactic phenomena which are present in lists of clauses and phrases of spoken Frisian, but absent from written Frisian: complementiser repetition around a phrase and the use of fan ('like') to introduce direct speech

In situ entry of oligonucleotides into brain cells can occur through a nucleic acid channel

Brain tissue has become a challenging therapeutic target, in part because of failure of conventional treatments of brain tumors and a gradually increasing number of neurodegenerative diseases. Because antisense oligonucleotides are readily internalized by neuronal cells in culture, these compounds could possibly serve as novel therapeutic agents to meet such a challenge. In previous in vitro work using cell culture systems, we have demonstrated that intracellular delivery requires a vector such as cationic liposomes since free oligonucleotides remain largely trapped in the endocytic pathway following cellular uptake. Here we studied the cellular uptake properties of oligonucleotides by explants of rat brain (brain slices), and by in vivo brain tissue after administration of oligonucleotides by bolus injection. In contrast to in vitro uptake, we show that in brain slices oligonucleotides were taken up by neuronal and nonneuronal cells, irrespective of their assembly with cationic liposomes. In either case, a diffuse distribution of oligonucleotides was seen in the cytosol and/or nucleus. Uptake of oligonucleotides by brain slices as a result of membrane damage, potentially arising from the isolation procedure, could be excluded. Interestingly, internalization was inhibited following treatment of the tissue with antibody GN-2640, directed against a nucleic acid channel, present in rat kidney cells. Our data support the view that an analogous channel is present in brain tissue, allowing entry of free oligonucleotides but not plasmids. Indeed, for delivery of the latter and accomplishment of effective transfection, cationic lipids were needed for gene translocation into both brain slices and brain tissue in vivo. These data imply that for antisense therapy to become effective in brain, cationic lipid-mediated delivery will only be needed for specific cell targeting but not necessarily for delivery per se to accomplish nuclear deposition of oligonucleotides into brain cells and subsequent down-regulation of disease-related targets.</p