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Voice Morphing

Voice morphing means the transition of one speech signal into another. Like image morphing, speech morphing aims to preserve the shared characteristics of the starting and final signals, while generating a smooth transition between them. Speech morphing is analogous to image morphing. In image morphing the in-between images all show one face smoothly changing its shape and texture until it turns into the target face. It is this feature that a speech morph should possess. One speech signal should smoothly change into another, keeping the shared characteristics of the starting and ending signals but smoothly changing the other properties. The major properties of concern as far as a speech signal is concerned are its pitch and envelope information. These two reside in a convolved form in a speech signal. Hence some efficient method for extracting each of these is necessary. We have adopted an uncomplicated approach namely cepstral analysis to do the same. Pitch and formant information in each signal is extracted using the cepstral approach. Necessary processing to obtain the morphed speech signal include methods like Cross fading of envelope information, Dynamic Time Warping to match the major signal features (pitch) and Signal Re-estimation to convert the morphed speech signal back into the acoustic waveform.

Speech morphing can be achieved by transforming the signal’s representation from the acoustic waveform obtained by sampling of the analog signal, with which many … Read the rest

Proteomics

Proteomics is something new in the field of biotechnology. It is basically the study of the proteome, the collective body of proteins made y a person’s cells and tissues.

Since it is proteins, and to a much lesser extent, other types of biological molecules that are directly involved in both normal and disease-associated biochemical processes, a more complete understanding of the disease may be gained by directly looking at the proteins present within a diseased cell or tissue and this is achieved through the study of the proteome, Proteomics. For, Proteomics, we need 2-D electrophoresis equipment ot separate the proteins, mass spectrometry to identify them and x-ray crystallography to know more of the structure and function of the proteins. These equipments are essential in the study of proteomics.

Genomics has provided a vast amount of information linking gene activity with disease. It is now recognized that gene sequence information and pattern of gene activity in a cell do not provide a complete and accurate profile of a protein’s abundance or its final structure and state of activity.

The day of spotlight of the human genome is now coming to an end. Researchers are now concentrating on the human proteome, the collective body of all the proteins made by a person’s cells and tissues. The genome- the full set of information in the body-contains only the recipes for making proteins; it … Read the rest

Optical Switching

Explosive information demand in the internet world is creating  enormous needs for capacity expansion in next generation telecommunication networks. It is expected that the data- oriented network traffic will double every year.

Optical networks are widely regarded as the ultimate solution to the bandwidth needs of future communication systems. Optical fiber links deployed between nodes are capable to carry terabits of information but the electronic switching at the nodes limit the bandwidth of a network. Optical switches at the nodes will overcome this limitation. With  their improved efficiency and lower costs, Optical switches provide the key to both manage the new capacity Dense Wavelength Division Multiplexing (DWDM) links as well as gain a competitive advantage for provision of new band width hungry services. However, in an optically switched network the challenge lies in overcoming signal impairment and network related parameters. Let us discuss the present status, advantages and challenges and future trends in optical  switches.

OPTICAL FIBERS

A fiber consists of a glass core and a surrounding layer called the cladding. The core and cladding have carefully chosen indices of refraction to ensure that the photos propagating in the core are always reflected at the interface of the cladding. The only way the light can enter and escape is through the ends of the fiber. A transmitter either alight emitting diode or a laser sends electronic data that have been … Read the rest

MOCT

An accurate electric current transducer is a key component of any power system instrumentation. To measure currents power stations and substations conventionally employ inductive type current transformers with core and windings. For high voltage applications, porcelain insulators and oil-impregnated materials have to be used to produce insulation between the primary bus and the secondary windings. The insulation structure has to be designed carefully to avoid electric field stresses, which could eventually cause insulation breakdown. The electric current path of the primary bus has to be designed properly to minimize the mechanical forces on the primary conductors for through faults. The reliability of  conventional high-voltage current transformers have been questioned because of their violent destructive failures which caused fires and impact damage to adjacent apparatus in the switchyards, electric damage to relays, and power service disruptions.

With short circuit capabilities of power systems getting larger, and the voltage levels going higher the conventional current transformers becomes  more and more bulky and costly also the saturation of the iron core under fault current and the low frequency response make it difficult to obtain accurate current signals under power system transient conditions. In addition to the concerns, with the computer control techniques and digital protection devices being introduced  into power systems, the conventional current transformers have caused further difficulties, as they are likely to introduce electro-magnetic interference through the ground loop into the … Read the rest