13 research outputs found
A system for tracking and characterizing acoustic impacts on large interactive surfaces
No full textThesis (M.Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.Includes bibliographical references.by Nisha Checka.M.Eng.and S.B
FDSOI Process Technology for Subthreshold-Operation Ultralow-Power Electronics
No full textUltralow-power electronics will expand the technological capability of handheld and wireless devices by dramatically improving battery life and portability. In addition to innovative low-power design techniques, a complementary process technology is required to enable the highest performance devices possible while maintaining extremely low power consumption. Transistors optimized for subthreshold operation at 0.3 V may achieve a 97% reduction in switching energy compared to conventional transistors. The process technology described in this article takes advantage of the capacitance and performance benefits of thin-body silicon-on-insulator devices, combined with a workfunction engineered mid-gap metal gate
Substrate noise analysis and techniques for mitigation in mixed-signal RF systems
No full textThesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 151-158).Mixed-signal circuit design has historically been a challenge for several reasons. Parasitic interactions between analog and digital systems on a single die are one such challenge. Switching transients induced by digital circuits inject noise into the common substrate creating substrate noise. Analog circuits lack the large noise margins of digital circuits, thus making them susceptible to substrate voltage variations. This problem is exacerbated at higher frequencies as the effectiveness of standard isolation technique diminishes considerably. Historically, substrate noise was not a problem because each system was fabricated in its own package shielding it from such interactions. The work in this thesis spans all areas of substrate noise: generation, propagation, and reception. A set of guidelines in designing isolation structures was developed to assist designers in optimizing these structures for a particular application. Furthermore, the effect of substrate noise on two key components of the RF front end, the voltage controlled oscillator (VCO) and the low noise amplifier (LNA), was analyzed. Finally, a CAD tool (SNAT) was developed to efficiently simulate large digital designs to determine substrate noise performance.(cont.) Existing techniques have prohibitively long simulation times and are only suitable for final verification. Determination of substrate noise coupling during the design phase would be extremely beneficial to circuit designers who can incorporate the effect of the noise and re-design accordingly before fabrication. This would reduce the turn around time for circuits and prevent costly redesign. SNAT can be used at any stage of the design cycle to accurately predict (less than 12% error when compared to measurements) the substrate noise performance of any digital circuit with a large degree of computational efficiency.by Nisha Checka.Ph.D
FDSOI Process Technology for Subthreshold-Operation Ultra-Low-Power Electronics
No full textUltralow-power electronics will expand the technological capability of handheld and wireless devices by dramatically improving battery life and portability. In addition to innovative low-power design techniques, a complementary process technology is required to enable the highest performance devices possible while maintaining extremely low power consumption. Transistors optimized for subthreshold operation at 0.3 V may achieve a 97% reduction in switching energy compared to conventional transistors. The process technology described in this article takes advantage of the capacitance and performance benefits of thin-body silicon-on-insulator devices, combined with a workfunction engineered mid-gap metal gate.</jats:p
Technology, performance, and computer-aided design of three-dimensional integrated circuits
No full textVillkor och praxis : Bedömning av lärarstudenters yrkeskunskaper under verksamhetsförlagd lärarutbildning
No full textI föreliggande studie granskas bedömningens villkor, innehåll och processer i verksamhetsförlagd utbildning (VFU) vid ett lärarprogram i Sverige. Syftet med studien motiveras utifrån två tidigare studiers resultat kring hur kunskapsmål/kriterier beskrivs (Author, 2007) och lärarstudenters yrkeskunskaper bedöms (Author, in press) i VFU, samt utifrån bristen på forskning om villkor för bedömning och bedömningsprocesser i VFU. Det empiriska underlaget består av stöddokument för bedömning, åtta bedömningssamtal mellan lärarutbildare, mentorer och lärarstudenter, samt intervjuer med lärarutbildarna i en VFU-kurs. De analysverktyg som används är dels ett kunskapsteoretiskt ramverk kring lärarkunskap, dels modeller för bedömning av yrkeskunskap. Resultaten bekräftar delvis en av de tidigare studiernas resultat; att bedömningen till stora delar uttrycks formativt, och att det uteslutande är lärarstudenters procedurkunskaper utifrån ett kunskap-i-praktiken-perspektiv som bedöms. Bedömningsprocesserna kännetecknas av en bedömningsmodell där formulerade kunskapsmål/kriterier inte utgör norm för bedömning av lärarstudenters yrkeskunskaper. Det betyder att lärarutbildarna och mentorerna inte enkelt kan checka av yrkeshandlingar mot formella mål/kriterier, utan behöver grunda sina bedömningar på sin egen kunskapsbas och sina erfarenheter som lärare. En diskussion förs om kunskapsmåls/kriteriers betydelse vid bedömning av lärarstudenters yrkeskunskaper i en skolverksamhetskontext.</p
