M.Ing.(Electrical and Electronic Engineering) / In the ideal communication system no noise is present and no errors will be made. However, in practice, communication is over noisy channels which cause errors in the information. There is thus a necessity for the control of these errors. Furthermore, several channels impose runlength or disparity constraints on the bit stream. Until recently, the error control on these channels was applied separately to imposing the input restrictions with constrained codes. Such a system leads to poor performance under certain conditions. and is more complex and expensive to apply than systems where the error control is an integral part of the constrained code or decoder. In this study, we firstly investigate the error multiplication phenomena of constrained codes. An algorithm is presented that minimizes the error propagation probabilities of memoryless decoders according to two criteria. Another algorithm is presented along with the first to calculate the resulting bit error probabilities. The second approach to the error control of constrained codes is the construction of combined error-correcting constrained finite-state machine codes. We investigate the known construction techniques and construct several new codes using extensions of the known techniques. These codes complement or improve on the known error-correcting constrained codes with regards to either complexity, rate or error-correcting capability. Furthermore, these codes have good error behaviour and favourable power spectral densities.

Memoria (licenciado en ciencias jurídicas y sociales) / No autorizada por el autor para ser publicada a texto completo / El derecho de los contratos es una de las ramas más ricas en contenido doctrinario y su evolución se observa desde las sociedades más arcaicas hasta nuestros días. Su sustento se encuentra en lo que denominamos autonomía de la voluntad, en el sentido de que las personas, en condiciones totales de libertad, tienen el derecho a contratar con quienes deseen, bajo las reglas que estimen convenientes. Si bien en un primer momento el objetivo de nuestro trabajo era revisar, por un lado, el rol de la excusabilidad en el error, y por otro, proponer argumentos para acercarnos a una visión objetiva del dolo; durante el avance de la investigación advertimos que ambos vicios encontraban un punto de conexión en la información. De esta forma, la revisión de la excusabilidad del error y la subjetividad del dolo encontraron como eje principal el grado de conocimiento de que disponen las partes al momento de contratar. En la medida que un sujeto obtenga mayor información se encontrará en mejor pie para representarse fielmente la realidad, por lo que los criterios para determinar si es procedente la existencia de error o dolo pueden realizarse a partir de la información como un bien que interesa no sólo a las partes sino a la sociedad toda. Al intentar conjugar la información con los principios de que “nadie puede beneficiarse de su propia negligencia”, en el caso del error, y la “buena fe”, en el caso del dolo, derivamos en la idea de que los deberes de informarse y de informar al momento de contratar pueden ser la piedra angular para solucionar los problemas de indeterminación que presentan estos vicios en el caso concreto. En directa relación con lo anterior, pensamos que el desarrollo de la economía y los negocios en materia de contratación ameritan este intento de abrir un debate en torno a las exigencias previas que se pueden imponer a las partes al celebrar un contrato.

D. Ing. / The digital transmission of information necessitates the compensation for disturbances introduced by the channel. The compensation method usually used in digital communications is error correcting coding. The errors usually encountered are additive in nature, i.e. errors where only symbol values are changed. Understandably, the field of additive error correcting codes has become a mature research field. Remarkable progress has been made during the past 50 years, to such an extent that near Shannon capacity can be reached using suitable coding techniques. Sometimes the channel disturbances may result in the loss and/or gain of symbols and a subsequent loss of word or frame synchronisation. Unless some precautions were made, a synchronisation error may propagate and corrupt large blocks of data. Typical precautions taken against synchronisation errors are: out-of-band clock signals distributed to the transmission equipment in a network; stringent requirements on clock stability and jitter; limits on the number of repeaters and regeneration to curb jitter and delays; line coding to facilitate better clock extraction; and - use of framing methods on the coding level. Most transmission systems in use today will stop data transmission until reliable synchronisation is restored. El multiplexing systems are still the predominantly used technology in fixed telephone line operators and GSM operators, and recovering from a loss of synchronisation (the FAS alarm) typically lasts approximately 10 seconds. Considering that the transmission speed is 2048 KB/s, a large quantity of data is lost in during this process. The purpose of this study is therefore to broaden the understanding of insertion/deletion correcting binary codes. This will be achieved by presenting new properties and coding techniques for multiple insertion/deletion correcting codes. Mostly binary codes will be considered, but in some instances, the results may also hold for non-binary codes. As a secondary purpose, we hope to generate interest in this field of study and enable other researchers to continue to deeper explore the mechanisms of insertion and/or deletion correcting codes.

When only whole years of age are recorded in survey data, children who experienced a birthday since the beginning of the school year may appear to be of school-age when they are not, or vice-versa. This creates an error in estimates of school participation indicators based on such data. This issue is well-known in education statistics, and several procedures attempting to correct for this error have been proposed. The present study critiques current practice and demonstrates that its limitations continue to confound educational research and high-stakes policy conclusions: speculative explanations have been proposed for what is actually a measurement artefact. An alternative adjustment strategy is proposed that coherently exploits all available information and explicitly indicates the remaining uncertainty. The application of the method is illustrated by a number of empirical case studies using recent household survey data. These examples demonstrate that the method is feasible, accurate, and that taking survey timing into account can significantly alter how these data are interpreted.

No description available.

A dissertation submitted in ful lment of the requirements for the degree of Masters in Science in the Information Engineering School of Electrical and Information Engineering August 2016 / The work presented extends and contributes to research in error-control coding and information theory. The work focuses on the construction of block codes using an IIR lter structure. Although previous works in this area uses FIR lter structures for error-detection, it was inherently used in conjunction with other error-control codes, there has not been an investigation into using IIR lter structures to create codewords, let alone to justify its validity. In the research presented, linear block codes are created using IIR lters, and the error-correcting capabilities are investigated. The construction of short codes that achieve the Griesmer bound are shown. The potential to construct long codes are discussed and how the construction is constrained due to high computational complexity is shown. The G-matrices for these codes are also obtained from a computer search, which is shown to not have a Quasi-Cyclic structure, and these codewords have been tested to show that they are not cyclic. Further analysis has shown that IIR lter structures implements truncated cyclic codes, which are shown to be implementable using an FIR lter. The research also shows that the codewords created from IIR lter structures are valid by decoding using an existing iterative soft-decision decoder. This represents a unique and valuable contribution to the eld of error-control coding and information theory. / MT2017

Thesis advisor: Henry Braun / The measurement of student academic growth is one of the most important statistical tasks in an educational accountability system. The current methods of measuring student growth adopted in most states have various drawbacks in terms of sensitivity, accuracy, and interpretability. In this thesis, we apply the conditional growth chart method, a well-developed diagnostic tool in pediatrics, to student longitudinal test data to produce descriptive and diagnostic statistics about students' academic growth trajectory. We also introduce an innovative simulation-extrapolation (SIMEX) method which corrects for measurement error-induced bias in the estimation of the conditional growth model. Our simulation study shows that the proposed method has an advantage in terms of mean squared error of the estimators, when compared with the growth model that ignores measurement error. Our data analysis demonstrates that the conditional growth chart method, when combined with the SIMEX method, can be a powerful tool in the educational accountability system. It produces more sensitive and accurate measures of student growth than the other currently available methods; it provides diagnostic information that is easily understandable to teachers, parents and students themselves; the individual level growth measures can also be aggregated to school level as an indicator of school growth. / Thesis (PhD) — Boston College, 2009. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Research, Measurement, and Evaluation.

Thesis advisor: Audrey Friedman / This mixed-method study, combining both qualitative and quantitative procedures, aimed at investigating the impact of Palestinian EFL teachers' attitudes toward oral errors on their students' attitudes and choice of oral error correction strategies. The study sample consisted of (151) high elementary and secondary school Palestinian EFL teachers and (774) of their students, distributed proportionately between males and females. Both groups responded to a teacher and a student questionnaire respectively. The sample also included (12) teacher participants, each of whom was observed and interviewed twice in the course of the study, and (12) student participants, each of whom took part in two focus group interviews. Data obtained from different sources (i.e. case study vignettes, questionnaires, interviews, focus groups, and observations) provided significant evidence that the majority of both Palestinian EFL teachers and students had positive attitudes toward oral errors and their correction as they generally agreed that error correction was necessary for the enhancement of language teaching and learning. However, the data also revealed some discrepancy between students and teachers regarding what, how often, when, how, and by whom errors should be corrected. The study also showed that although students wanted to improve their accuracy in English to be well prepared for accuracy-oriented formal tests, the majority of them preferred not to be marked down on every error they made. Further, the study revealed that different error correction strategies had different cognitive, affective, and behavioral impacts on different students. The study recommends that both EFL teachers and learners develop more positive attitudes toward oral errors and their correction. In addition, teachers should have at their disposal a wide variety of error correction strategies to be able to deal more appropriately and effectively with student oral errors. The study also recommends that teachers get the right amount and timing of error correction for each individual student preferences, language proficiency, personality type, and learning styles, which cannot be achieved without the teachers having a dialogic interaction with their students and students being able to voice up what their perceptions of and preferences for oral error correction strategies are, what errors they want to be corrected, and who should correct them. / Thesis (PhD) — Boston College, 2010. / Submitted to: Boston College. Lynch School of Education. / Discipline: Teacher Education, Special Education, Curriculum and Instruction.

Thesis (Master of Engineering in Electrical Engineering)--Cape Peninsula University of Technology, 2018. / This thesis will focus on preventing and overcoming the effects of radiation in RAM on board the ZA cube 2 nanosatellite. The main objective is to design, implement and test an effective error detection and correction (EDAC) system for nanosatellite applications using a SoC development board. By conducting an in-depth literature review, all aspects of single-event effects are investigated, from space radiation right up to the implementation of an EDAC system. During this study, Hamming code was identified as a suitable EDAC scheme for the prevention of single-event effects. During the course of this thesis, a detailed radiation study of ZA cube 2’s space environment is conducted. This provides insight into the environment to which the satellite will be exposed to during orbit. It also provides insight which will allow accurate testing should accelerator tests with protons and heavy ions be necessary. In order to understand space radiation, a radiation study using ZA cube 2’s orbital parameters was conducted using OMERE and TRIM software. This study included earth’s radiation belts, galactic cosmic radiation, solar particle events and shielding. The results confirm that there is a need for mitigation techniques that are capable of EDAC. A detailed look at different EDAC schemes, together with a code comparison study was conducted. There are two types of error correction codes, namely error detection codes and error correction codes. For protection against radiation, nanosatellites use error correction codes like Hamming, Hadamard, Repetition, Four Dimensional Parity, Golay, BCH and Reed Solomon codes. Using detection capabilities, correction capabilities, code rate and bit overhead each EDAC scheme is evaluated and compared. This study provides the reader with a good understanding of all common EDAC schemes. The field of nanosatellites is constantly evolving and growing at a very fast speed. This creates a growing demand for more advanced and reliable EDAC systems that are capable of protecting all memory aspects of satellites. Hamming codes are extensively studied and implemented using different approaches, languages and software. After testing three variations of Hamming codes, in both Matlab and VHDL, the final and most effective version was Hamming [16, 11, 4]2. This code guarantees single error correction and double error detection. All developed Hamming codes are suited for FPGA implementation, for which they are tested thoroughly using simulation software and optimised.

by Lai Siu Wai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1989. / Bibliography: leaves 50-52.