Contemporary and future speech telecommunication systems now utilise low bit rate (LBR) speech coding techniques in efforts to eliminate bandwidth expansion as a disadvantage of digital coding and transmission. These speech coders employ model-based approaches in compressing human speech into a number of parameters, using a well-known process known as linear predictive coding (LPC). However, a major side-effect observed in these coders is that errors in the model parameters have noticeable and undesirable consequences on the synthesised speech quality, and unless they are protected from such corruptions, the level of service quality will deteriorate rapidly. Traditionally, forward error correction (FEC) coding is used to remove these errors, but these require substantial redundancy. Therefore, a different perspective of the error control problems and solutions is necessary. In this thesis, emphasis is constantly placed on exploiting the constraints and residual redundancies present in the model parameters. It is also shown that with such source criteria in the LBR speech coders, varying degrees of error protection from channel corruptions are feasible. From these observations, error control requirements and methodologies, using both block- and parameter-orientated aspects, are analysed, devised and implemented. It is evident, that under the unusual circumstances which LBR speech coders have to operate in, the importance and significance of source reliant error control will continue to attract research and commercial interests. The work detailed in this thesis is focused on two LPC-based speech coders. One of the ideas developed for these two coders is an advanced zero redundancy scheme for the LPC parameters which is designed to operate at high channel error rates. Another concept proposed here is the use of source criteria to enhance the decoding capabilities of FEC codes to exceed that of maximum likelihood decoding performance. Lastly, for practical operation of LBR speech coders, lost frame recovery strategies are viewed to be an indispensable part of error control. This topic is scrutinised in this thesis by investigating the behaviour of a specific speech coder under irrecoverable error conditions. In all of the ideas pursued above, the effectiveness of the algorithms formulated here are quantified using both objective and subjective tests. Consequently, the capabilities of the techniques devised in this thesis can be demonstrated, examples of which are: (1) higher speech quality produced under noisy channels, using an improved zero-redundancy algorithm for the LPC filter coefficients; (2) as much as 50% improvement in the residual BER and decoding failures of FEC schemes, through the utilisation of source criteria in LBR speech coders; and (3) acceptable speech quality produced under high frame loss rates (14%), after formulating effective strategies for recovery of speech coder parameters. It is hoped that the material described here provide concepts which can help achieve the ideals of maximum efficiency and quality in LBR speech telecommunications.

Zero-Correlation-Zone (ZCZ) codes differ from traditional spreading codes because they contain a region in their correlation functions where the correlation values are null. In these regions the spreading codes are considered ideal, and because of the ZCZ the inter-symbol interference (ISI) and multiple-access interference (MAI) are reduced leading to an increase in capacity and bitrate. This thesis will present a study of ZCZ codes and then will propose a new CDMA system that employs the use of ZCZ codes in particular Loosely Synchronous (LS) codes. This new system shall have its performance compared with an equivalent existing CDMA system (IS-95) and the results shall be shown and discussed. In this comparative study the thesis will also present and examine a tracking performance comparison between ZCZ codes and a traditional spreading code such as m-sequences. It is shown that the performance of the new CDMA system employing ZCZ codes outperforms the traditional CDMA system in a multi-user multipath environment. It is also found that based on the study performed there appears to be no advantage in tracking between a ZCZ code and m-sequences however a more comprehensive study in a multi-user environment is still needed before a conclusion on tracking can be made. / Master of Engineering (Hons.)

Magister Public Health - MPH / Background: The Provincial Government Western Cape (PGWC) Department of Health identified a lack of data on inpatient diagnoses and procedures in a form suitable to use for operational, strategic as well as financial health care planning. The only format in which diagnostic and procedure data was available was a paper based one encompassing individual patient notes in folders and discharge summaries. Making the data available in a coded format within an electronic database would facilitate storage, analysis and utilisation of that data for health service planning. Recognising the lack of availability of such coded data, this study was undertaken to evaluate different coding systems for their ability to code data in order to assist in deciding which coding systems best fit the need to facilitate easy and accurate recording of data on diagnoses and procedures from patient records. The identification of the most appropriate coding system for the context in which the PGWC Department of health functions should facilitate the easy recording, storage and retrieval of data that is accurate, reliable and useful for management decision making and would support optimal patient care. Aim: The aim of the study was to evaluate a selection of potentially suitable coding systems in order to determine which would be best able to code public sector district and regional hospital diagnostic and procedure data in the Western Cape Province. Method: A cross sectional analytical study design was used. Discharge diagnosis and procedure data were extracted from 342 patient folders from 3 district and 3 regional public hospitals in the Western Cape. This yielded 221 different diagnostic concepts and 126 different procedure concepts. The diagnostic concepts were further grouped into “all” diagnostic concepts recorded, diagnostic concepts recorded as “symptoms only” and diagnostic concepts recorded as “proper diagnoses”. The diagnostic coding systems evaluated were ICD-10 (International Classification of Diseases), ICPC-2 (International Classification of Primary Care 2nd edition) and ICD-10 Condensed Morbidity List. The procedure coding systems evaluated were CCSA-2001 (Current Procedure Terminology for South Africa) ICD-9-CM (International Classification of Diseases Clinical Modification 9th revision) and ICPC-2. The diagnoses and procedures were then coded in all of the coding systems being evaluated. Each diagnosis and procedure concept was matched with its representing concept in the coding system and scored according to the ability of the coding system to provide an “exact” match which was scored as (3) or a “partial” match scored as (2) or a “poor” match scored as (1) or “no” match scored as (0). Results: ICD-10 was better able to code diagnoses obtained from district and regional hospitals in the Western Cape compared to ICPC-2 and ICD-10 Condensed Morbidity list. For all recorded diagnostic concepts, ICD-10 was able to score 82% of the concepts as either an “exact” or a “partial” match compared to 79% in ICPC-2 and 30% in ICD-10-CL. ICD-10 consistently performed best across different stratification of diagnostic concepts namely concepts recorded as “proper diagnoses”, concepts recorded from regional hospitals only, concepts recorded from district hospitals only, concepts designated as “common diagnoses” and for concepts designated as “very common diagnoses”. In addition ICD-10 had zero diagnostic concepts for which “no match” could be found. CCSA -2001 proved to be the best coding system for coding procedures across all hospitals with an overall percentage of “exact” and “partial” matches of 83% compared to 65% for ICD-9-CM and 39% for ICPC-2 and also proved to be best across all strata. Conclusion: There were striking differences between the evaluated coding systems with regard to their ability to code diagnoses and procedures in the evaluated district and regional hospitals in the Western Cape Province. ICD-10 covers the scope of clinical diagnoses in more accurate and specific detail than ICPC-2 and ICD-10 CL. Though ICPC-2 is simpler and easier to use than ICD-10, it is not as detailed and specific as the latter but it proved ideal for symptoms rather than for specific diagnoses. ICD-10 Condensed Morbidity List was shown to be inadequate for coding diagnoses. However the difference between the two, although statistically significant were not very large and given the ease of use of ICPC-2, it could be recommended for use. As for procedures CCSA-2001 was assessed as being the most appropriate for coding procedures recorded in this setting compared to the other coding systems. ICPC-2 performed poorest for coding procedures across all evaluated settings and thus would be inappropriate to use. ICD-10 in most comparisons performed second best to ICPC-2 in terms of coding ability for diagnoses and could be considered for recommendation as a diagnostic coding tool.

Introdução - Uma das formas de se aumentar a qualidade das informações sobre causas de morte é automatizar o processo de sua elaboração. O software Iris é um dos mecanismos disponíveis para esse fim. Suas principais características é que ele segue as regras internacionais de mortalidade e ele é independente de idioma. Objetivo - Elaborar para o Iris um dicionário na língua portuguesa e avaliar a sua completitude para a codificação das causas de morte. Método - O dicionário criado com dados do arquivo eletrônico do volume 1 da CID-10 e com o Tesauro da Classificação Internacional de Atenção Primária. Foi utilizado o Iris V4.0.34 e, como codificação manual, o que o Programa de Aprimoramento das Informações de Mortalidade no Município de São Paulo (PRO-AIM) da Secretaria Municipal de Saúde de São Paulo escreveu nas declarações de óbito. Caso o Iris não codificasse as causas de morte, ajustes eram feitos no dicionário ou na tabela de padronização. Resultado - O Iris é capaz de codificar as causas de morte e selecionar a causa básica de morte, ambas automaticamente, é um software recente que está em constantes adequações, é independente de idioma e para usá-lo em cada país é necessário realizar somente um dicionário de causas de morte. No teste para avaliação da primeira versão do dicionário em português, o Iris apresentou um desempenho satisfatório. Foi capaz de codificar diretamente 50,6 por cento das declarações de óbito e, após ajustes e acréscimos no dicionário e na tabela de padronização, o software codificou todas as linhas em 94,44 por cento das declarações. Das declarações não codificadas completamente 89,19 por cento delas tinham algum diagnóstico contido no capítulo XX da CID-10. O Iris apresentou 63,1 por cento de concordância nas declarações de óbito pareadas considerando todas as causas de morte com códigos completos de 4 caracteres da CID-10. Conclusão - A realização dos ajustes no dicionário ou na padronização faz parte do processo de desenvolvimento do dicionário e que esse processo é continuo. Com as novas versões do Iris e atualizações e aprimoramento da codificação das causas externas, avanços serão feitos para que ele seja mais compatível com a realidade brasileira. Somado a isso, as futuras versões do Iris com um dicionário mais desenvolvido podem satisfazer as necessidades de codificação automática e melhorar a precisão dos dados de causa morte paras estudos de saúde pública. / Introduction - One way to increase the quality of causes-of-death statistics is to use computers for applying the rules systematically. Iris software is an available system for this purpose. Its main characteristics are that it follows international rules of mortality and it is language independent. Objective - Produce a Portuguese dictionary for Iris and assess its completeness of coding of causes of death. Methods - The creation of the dictionary used two sources: the electronic file of volume 1 of ICD-10 and Thesaurus of Classificação Internacional de Atenção Primária. Was used Iris V4.0.34 and for manual coding the codes at the Programa de Aprimoramento das Informações de Mortalidade no Município de São Paulo (PRO-AIM) of Secretaria Municipal de Saúde of São Paulo has written on death certificates. If Iris couldnt codify the causes of death, adjustments were made in the dictionary or standardization table. Results - Iris is able to encode causes of death and select the underlying cause of death, either automatically; is a recent software that is in constant adjustments; is a language independent software and to use it in your country you need only dictionary of causes of death. In the test for evaluation the first version of the Portuguese dictionary Iris showed satisfactory performance. He was able to code directly for 50.6 per cent of death certificates and, after adjustments and additions in the dictionary and standardization table, the software coded all lines in 94.44 per cent of death certificate. The statements do not fully coded 89.19 per cent had a diagnosis contained in Chapter XX of ICD-10. Iris presented 63,1 per cent agreement on paired death certificates considering all causes of death and 4-digit ICD-10 code level. Conclusion - making adjustments in the dictionary or the standardization is part of the development process of the dictionary and that this process is ongoing. With new Iris versions and updates in the management of the coding external causes, progress will be made to make it more compatible with the Brazilian reality. Added to this, future versions of Iris with a dictionary more developed can meet the needs of auto-tagging and improve the accuracy of data causes death to public health studies.

Orientador: Prof. Dr. Guiou Kobayashi / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia da Informação, 2014. / A computação atual vem demandando, cada vez mais, formas avançadas de interação com os computadores. A interface do humano com seus dispositivos móveis carece de métodos mais avançados, e um recurso automático de reconhecimento de expressões faciais seria uma maneira de alcançar patamares maiores nessa escala de evolução. A forma como se dá o reconhecimento de emoções humanas e o que as expressões faciais representam em uma comunicação face-a-face vem sendo referência no desenvolvimento desses sistemas computacionais e com isso, pode-se elencar três grandes desafios para implementar o algoritmo de analise de expressões: Localizar o rosto na imagem, extrair os elementos faciais relevantes e classificar os estados de emoções. O melhor método de resolução de cada um desses sub-desafios, que se relacionam fortemente, determinará a viabilidade, a eficiência e a relevância de um novo sistema de análise de expressões embarcada nos dispositivos portáteis. Este estudo tem como objetivo avaliar a viabilidade da implantação de um sistema automático de reconhecimento de expressões faciais por imagens, em dispositivo móvel, utilizando a plataforma iOS da Apple, integrada com a biblioteca de código aberto e muito utilizada na comunidade da computação visual, o OpenCV. O algoritmo Local Binary Pattern, implementado pelo OpenCV, foi escolhido como lógica de rastreamento da face. Os algorítmos Adaboost e Eigenface foram ,respectivamente, adotados para extração e classificação da emoção e ambos são também suportados pela mencionada biblioteca. O Módulo de Classificação Eigenface demandou um treinamento adicional em um ambiente de maior capacidade de processamento e externo a plataforma móvel; posteriormente, apenas o arquivo de treino foi exportado e consumido pelo aplicativo modelo. O estudo permitiu concluir que o Local Binary Pattern é muito robusto a variações de iluminação e muito eficiente no rastreamento da face; o Adaboost e Eigenface produziram eficiência de aproximadamente 65% na classificação da emoção, quando utilizado apenas as imagens de pico no treino do módulo, condição essa, necessária para manutenção do arquivo de treino em um tamanho compatível com o armazenamento disponível nos dispositivos dessa categoria. / The actual computing is demanding, more and more, advanced forms of interaction with computers. The interfacing from man with their mobile devices lacks more advanced methods, and automatic facial expression recognition would be a way to achieve greater levels in this scale of evolution. The way how is the human emotion recognition and what facial expressions represents in a face to face communication is being reference for development of these computer systems and thus, it can list three major implementation challenges for algorithm analysis of expressions: location of the face in the image, extracting the relevant facial features and emotions¿ states classification. The best method to solve each of these strongly related sub- challenges, determines the feasibility, the efficiency and the relevance of a new expressions analysis system, embedded in portable devices. To evaluate the feasibility of developing an automatic recognition of facial expressions in images, we implemented a mobile system model in the iOS platform with integration to an open source library that is widely used in visual computing community: the OpenCV. The Local Binary Pattern algorithm implemented by OpenCV, was chosen as the face tracking logic; the Eigenface and AdaBoost, respectively, were adopted for extraction and classification of emotion and both are also supported by the library. The Eigenface Classification Module was trained in a more robust and external environment to the mobile platform and subsequently only the training file was exported and consumed by the model application. With this experiment it was concluded that the Local Binary Pattern is very robust to lighting variations and very efficient to tracking the face; the Adaboot and Eigenface resulted in approximately 65% of efficiency when used only maximum emotion images to training the module, a condition necessary for maintenance of the cascade file in a compatible size to available storage on the mobile platform.

Introdução - Uma das formas de se aumentar a qualidade das informações sobre causas de morte é automatizar o processo de sua elaboração. O software Iris é um dos mecanismos disponíveis para esse fim. Suas principais características é que ele segue as regras internacionais de mortalidade e ele é independente de idioma. Objetivo - Elaborar para o Iris um dicionário na língua portuguesa e avaliar a sua completitude para a codificação das causas de morte. Método - O dicionário criado com dados do arquivo eletrônico do volume 1 da CID-10 e com o Tesauro da Classificação Internacional de Atenção Primária. Foi utilizado o Iris V4.0.34 e, como codificação manual, o que o Programa de Aprimoramento das Informações de Mortalidade no Município de São Paulo (PRO-AIM) da Secretaria Municipal de Saúde de São Paulo escreveu nas declarações de óbito. Caso o Iris não codificasse as causas de morte, ajustes eram feitos no dicionário ou na tabela de padronização. Resultado - O Iris é capaz de codificar as causas de morte e selecionar a causa básica de morte, ambas automaticamente, é um software recente que está em constantes adequações, é independente de idioma e para usá-lo em cada país é necessário realizar somente um dicionário de causas de morte. No teste para avaliação da primeira versão do dicionário em português, o Iris apresentou um desempenho satisfatório. Foi capaz de codificar diretamente 50,6 por cento das declarações de óbito e, após ajustes e acréscimos no dicionário e na tabela de padronização, o software codificou todas as linhas em 94,44 por cento das declarações. Das declarações não codificadas completamente 89,19 por cento delas tinham algum diagnóstico contido no capítulo XX da CID-10. O Iris apresentou 63,1 por cento de concordância nas declarações de óbito pareadas considerando todas as causas de morte com códigos completos de 4 caracteres da CID-10. Conclusão - A realização dos ajustes no dicionário ou na padronização faz parte do processo de desenvolvimento do dicionário e que esse processo é continuo. Com as novas versões do Iris e atualizações e aprimoramento da codificação das causas externas, avanços serão feitos para que ele seja mais compatível com a realidade brasileira. Somado a isso, as futuras versões do Iris com um dicionário mais desenvolvido podem satisfazer as necessidades de codificação automática e melhorar a precisão dos dados de causa morte paras estudos de saúde pública. / Introduction - One way to increase the quality of causes-of-death statistics is to use computers for applying the rules systematically. Iris software is an available system for this purpose. Its main characteristics are that it follows international rules of mortality and it is language independent. Objective - Produce a Portuguese dictionary for Iris and assess its completeness of coding of causes of death. Methods - The creation of the dictionary used two sources: the electronic file of volume 1 of ICD-10 and Thesaurus of Classificação Internacional de Atenção Primária. Was used Iris V4.0.34 and for manual coding the codes at the Programa de Aprimoramento das Informações de Mortalidade no Município de São Paulo (PRO-AIM) of Secretaria Municipal de Saúde of São Paulo has written on death certificates. If Iris couldnt codify the causes of death, adjustments were made in the dictionary or standardization table. Results - Iris is able to encode causes of death and select the underlying cause of death, either automatically; is a recent software that is in constant adjustments; is a language independent software and to use it in your country you need only dictionary of causes of death. In the test for evaluation the first version of the Portuguese dictionary Iris showed satisfactory performance. He was able to code directly for 50.6 per cent of death certificates and, after adjustments and additions in the dictionary and standardization table, the software coded all lines in 94.44 per cent of death certificate. The statements do not fully coded 89.19 per cent had a diagnosis contained in Chapter XX of ICD-10. Iris presented 63,1 per cent agreement on paired death certificates considering all causes of death and 4-digit ICD-10 code level. Conclusion - making adjustments in the dictionary or the standardization is part of the development process of the dictionary and that this process is ongoing. With new Iris versions and updates in the management of the coding external causes, progress will be made to make it more compatible with the Brazilian reality. Added to this, future versions of Iris with a dictionary more developed can meet the needs of auto-tagging and improve the accuracy of data causes death to public health studies.