Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1977. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Robert Philip Gilmore. / M.S.

M.A. Epstein. / "March 14, 1958"--Cover. "Reprinted from the 1958 IRE National Convention Record, Part 4"--P. 69. / Bibliography: p. 66. / Army Signal Corps Contract DA36-039-sc-64637. Dept. of the Army Task 3-99-06-108 and Project 3-99-00-100.

The current longitudinal research examined the story-writing development of students from Grades 4 to 6 (N = 178). All students began formal schooling in English in Grade 1. Students were classified in Grade 4 as typical readers (scoring above the 40th percentile in both decoding and reading comprehension; n = 72), poor decoders (scoring below the 30th percentile in decoding; n = 53), or poor comprehenders (scoring above the 40th percentile on decoding but below the 30th percentile, relative to their language group, in reading comprehension; n = 26). Students who spoke English as a first language (EL1s) and English language learners (ELLs) were proportionally represented in each reading group. A series of repeated measures ANOVAs tested the effects of language and reading group on students’ cognitive, linguistic and literacy development. Despite the fact that ELLs did not achieve native-like English language proficiency, showing delays in vocabulary and reading comprehension, they matched their EL1 peers in all other areas of cognitive and literacy development, including story-writing. Both EL1s and ELLs developed story-writing skills in a similar manner, showing significant growth from Grade 4 to Grade 6. Typically developing ELLs were thus able to attain age-appropriate story-writing levels. Additionally, poor decoders and poor comprehenders generally showed similar profiles of strengths and weaknesses, regardless of whether English was their first or second language. The major difference was that ELL poor comprehenders were more likely to have longstanding reading comprehension problems, while many EL1 poor comprehenders had improved by Grade 6. In general, poor decoders displayed more pervasive difficulties across cognitive, linguistic and literacy domains, while poor comprehenders had specific weakness in nonverbal reasoning, receptive vocabulary and listening comprehension. Nevertheless, both reading disorder groups had significant difficulties in story-writing, struggling with the mechanics of writing, sentence structure, and overall story organization. Regression analyses indicated that cognitive, linguistic and language skills were strong concurrent and longitudinal predictors of story-writing. However, the strongest predictor of Grade 6 story-writing skill was Grade 4 story-writing performance, suggesting that story-writing skills tend to be relatively stable over time. The results generally support the ‘simple view of writing’ (Berninger, 2000). Practical recommendations for assessment and instruction are presented.

The current longitudinal research examined the story-writing development of students from Grades 4 to 6 (N = 178). All students began formal schooling in English in Grade 1. Students were classified in Grade 4 as typical readers (scoring above the 40th percentile in both decoding and reading comprehension; n = 72), poor decoders (scoring below the 30th percentile in decoding; n = 53), or poor comprehenders (scoring above the 40th percentile on decoding but below the 30th percentile, relative to their language group, in reading comprehension; n = 26). Students who spoke English as a first language (EL1s) and English language learners (ELLs) were proportionally represented in each reading group. A series of repeated measures ANOVAs tested the effects of language and reading group on students’ cognitive, linguistic and literacy development. Despite the fact that ELLs did not achieve native-like English language proficiency, showing delays in vocabulary and reading comprehension, they matched their EL1 peers in all other areas of cognitive and literacy development, including story-writing. Both EL1s and ELLs developed story-writing skills in a similar manner, showing significant growth from Grade 4 to Grade 6. Typically developing ELLs were thus able to attain age-appropriate story-writing levels. Additionally, poor decoders and poor comprehenders generally showed similar profiles of strengths and weaknesses, regardless of whether English was their first or second language. The major difference was that ELL poor comprehenders were more likely to have longstanding reading comprehension problems, while many EL1 poor comprehenders had improved by Grade 6. In general, poor decoders displayed more pervasive difficulties across cognitive, linguistic and literacy domains, while poor comprehenders had specific weakness in nonverbal reasoning, receptive vocabulary and listening comprehension. Nevertheless, both reading disorder groups had significant difficulties in story-writing, struggling with the mechanics of writing, sentence structure, and overall story organization. Regression analyses indicated that cognitive, linguistic and language skills were strong concurrent and longitudinal predictors of story-writing. However, the strongest predictor of Grade 6 story-writing skill was Grade 4 story-writing performance, suggesting that story-writing skills tend to be relatively stable over time. The results generally support the ‘simple view of writing’ (Berninger, 2000). Practical recommendations for assessment and instruction are presented.

The growing need for designing and implementing reliable voice-based human-machine interfaces has inspired intensive research work in the field of voice-enabled systems, and greater robustness and reliability are being sought for those systems. Speech recognition has become ubiquitous. Automated call centers, smart phones, dictation and transcription software are among the many systems currently being designed and involving speech recognition. The need for highly accurate and optimized recognizers has never been more crucial. The research community is very actively involved in developing powerful techniques to combine the existing feature extraction methods for a better and more reliable information capture from the analog signal, as well as enhancing the language and acoustic modeling procedures to better adapt for unseen or distorted speech signal patterns. Most researchers agree that one of the most promising approaches for the problem of reducing the Word Error Rate (WER) in large vocabulary speech transcription, is to combine two or more speech recognizers and then generate a new output, in the expectation that it provides a lower error rate. The research work proposed here aims at enhancing and boosting even further the performance of the well-known Recognizer Output Voting Error Reduction (ROVER) combination technique. This is done through its integration with an error filtering approach. The proposed system is referred to as cROVER, for context-augmented ROVER. The principal idea is to flag erroneous words following the combination of the word transition networks through a scanning process at each slot of the resulting network. This step aims at eliminating some transcription errors and thus facilitating the voting process within ROVER. The error detection technique consists of spotting semantic outliers in a given decoder's transcription output. Due to the fact that most error detection techniques suffer from a high false positive rate, we propose to combine the error filtering techniques to compensate for the poor performance of each of the individual error classifiers. Experimental results, have shown that the proposed cROVER approach is able to reduce the relative WER by almost 10% through adequate combination of speech decoders. The approaches proposed here are generic enough to be used by any number of speech decoders and with any type of error filtering technique. A novel voting mechanism has also been proposed. The new confidence-based voting scheme has been inspired from the cROVER approach. The main idea consists of using the confidence scores collected from the contextual analysis, during the scoring of each word in the transition network. The new voting scheme outperformed ROVER's original voting, by up to 16% in terms of relative WER reduction.

Thesis (M.S.)--University of North Texas, August, 2009. / Title from title page display. Includes bibliographical references.

Thesis (Ph. D.)--University of California, San Diego, 2003. / Vita. Includes bibliographical references.

Ένα από τα βασικότερα τμήματα ενός συστήματος ψηφιακής μετάδοσης είναι η κωδικοποίηση καναλιού, η οποία στόχο έχει την ανίχνευση και διόρθωση των λαθών που εισάγονται στην πληροφορία μέσα στο κανάλι. Οι Bose, Chaudhuri και Hocquenghem (BCH) κώδικες είναι μία μεγάλη ομάδα ισχυρών κυκλικών κωδίκων διόρθωσης τυχαίων λαθών. Οι BCH κώδικες περιγράφονται με χρήση αλγεβρικών δομών που λέγονται πεπερασμένα πεδία. Για την κατανόηση των λειτουργιών κωδικοποίησης και αποκωδικοποίησης απαιτείται η προσεκτική μελέτη της άλγεβρας πεπερασμένων πεδίων και της αριθμητικής της. Οι BCH κώδικες χρησιμοποιούνται στο δορυφορικό πρότυπο DVB-S2, σε συνδυασμό με LDPC κώδικες. Στην παρούσα εργασία πραγματοποιήθηκε σχεδίαση και υλοποίηση κωδικοποιητών και αποκωδικοποιητών για κώδικες BCH(15,5,3) και BCH(16200,16008,12). Ο δεύτερος αποκωδικοποιητής σχεδιάστηκε με βάση της προδιαγραφές που θέτει το DVB-S2, και καλύπτει μία από τις περιπτώσεις κωδικοποίησης του συστήματος. Τέλος, αποδεικνύεται ότι με ελάχιστες μετατροπές ο ίδιος αποκωδικοποιητής μπορεί να καλύψει όλες τις περιπτώσεις διόρθωσης 12 λαθών ενός DVB-S2 συστήματος. / Channel coding is one of the most important parts of a digital transmission system, and it aims at the detection and correction of errors that might have occurred in a noisy channel. Bose, Chaudhuri and Hocquenghem (BCH) codes form a large class of powerful random error-correcting cyclic codes. BCH codes operate over algebraic structures called finite fields. Understanding the processes of encoding and decoding requires a careful study of finite field algebra and the associated arithmetic. DVB-S2 is a specification for satellite broadcasting that deploys BCH codes combined with LDPC codes. This thesis sets out to account for the design and implementation of encoders and decoders for the BCH(15,5,3) and BCH(16200,16008,12) codes. The BCH(16200,16008,12) encoder/decoder was designed according to the DVB-S2 standard. Proof is provided that the same encoder/decoder, with only some minor changes, can be used for all the 12 error-correcting codes used in DVB-S2.

No description available.

Thesis (M.Tech.: Electronic Engineering)-Dept. of Electronic Engineering, Durban University of Technology, 2007. 1 v. (various pagings) / The objective was to develop a turbo code demonstration system for educational use. The aim was to build a system that would execute rapidly and produce a graphical display exemplifying the power of turbo codes and showing the effects of parameter variation.