Saturday, July 23, 2011

TIMIT What Is It?

    TIMIT is a corpus of phonemically and lexically transcribed speech of American English speakers of different sexes and dialects. Each transcribed element has been delineated in time.
TIMIT was designed to further acoustic-phonetic knowledge and automatic speech recognition systems. It was commissioned by DARPA and worked on by many sites, including Texas Instruments (TI) and Massachusetts Institute of Technology (MIT), hence the corpus' name.[1] There is also a telephone bandwidth version called NTIMIT (Network TIMIT).
 
       The Texas Instruments/Massachusetts Institute of Technology (TIMIT)corpus of read speech has been designed to provide speech data for theacquisition of acoustic-phonetic knowledge and for the development andevaluation of automatic speech recognition systems. TIMIT containsspeech from 630 speakers representing 8 major dialect divisions ofAmerican English, each speaking 10 phonetically-rich sentences. TheTIMIT corpus includes time-aligned orthographic, phonetic, and wordtranscriptions, as well as speech waveform data for each spokensentence. The release of TIMIT contains several improvements over thePrototype CD-ROM released in December, 1988: (1) full 630-speakercorpus, (2) checked and corrected transcriptions, (3) word-alignmenttranscriptions, (4) NIST SPHERE-headered waveform files and headermanipulation software, (5) phonemic dictionary, (6) new test andtraining subsets balanced for dialectal and phonetic coverage, and (7)more extensive documentation.


Via@http://en.wikipedia.org/wiki/TIMIT
Via@http://adsabs.harvard.edu/abs/1993STIN...9327403G

Plasma Gases and Its Affects on underwater travel

   DARPA’s Underwater Express Program has a characteristically brief description. It is intended to: ”...demonstrate stable and controllable high-speed underwater transport through supercavitation. The intent is to determine the feasibility for supercavitation technology to enable a new class of high-speed underwater craft for future littoral missions that could involve the transport of high-value cargo and/or small units of personnel. The program will investigate and resolve critical technological issues associated with the physics of supercavitation and will culminate in a credible demonstration at a significant scale to prove that a supercavitating underwater craft is controllable at speeds up to 100 knots.”
                    Supercavitation is the use of cavitation effects to create a large bubble of gas inside a liquid. The cavity (the bubble) reduces the drag on the object, since drag is normally about 1,000 times greater in liquid water than in a gas. Current applications are mainly limited to very fast torpedoes.
Turning science fiction in fact once again, DARPA, is ready to begin testing phase of a new ultra-fast mini submarine, capable of traveling at 100 knots.
In the United States the primary DARPA contracts for the "100-knot submarine" have been awarded to General Dynamics/Electric Boat, Northrop Grumman, New Systems Tech, and the University of Pennsylvania 's Applied Physics Laboratory.
       DARPA calls this program underwater express.  

Underwater Express

The goal of the Underwater Express program is to explore the application of supercavitation technology to underwater vehicles, enabling high-speed transport of personnel and/or supplies. Supercavitation places the vehicle inside a cavity where vapor replaces water, reducing both the drag due to fluid viscosity by orders-of-magnitude and power requirements dramatically. This program will use modeling, simulation, experiments and testing to understand the physical phenomena associated with supercavitation and its application to underwater vehicles.