Abstract Older adults with complex memory problems benefit when they have the opportunity to consult with a specialist for a comprehensive cognitive assessment. Specialists such as geriatricians, psychogeriatricians or neurologists often work in major cities or large metropolitan towns. Travelling to see a specialist either alone or with a carer is complicated for an older person because of medical issues or disability. The use of videoconferencing may provide a way to link a specialist with a patient without the need for the patient, or the specialist, to travel long distances. Two literature reviews were carried out. The initial review identified studies of the diagnosis of cognition via telemedicine. Thirty-two studies were identified which assessed cognition via telephone or video conference. The focus of the study was either the administration of a standardised cognitive assessment tool (n=30) or an unstructured comprehensive cognitive assessment interview (all via video conference) (n=2). The sample sizes were small but the levels of agreement were high, suggesting that further work in this area may identify that diagnosis of dementia via video conference is reliable. There has been limited work in the area of diagnostic agreement when a specialist is assessing a patient for the first time via video conference, even less work in the area of mental health assessment of older people. The second literature review identified 19 studies of diagnostic agreement using video conference with a sample size of 20 or more. The fields of research were: Dermatology (n=10); Mental Health (n=4); Minor Injuries (n=2); Neurology (n=2); and Rheumatology (n=1). Of the four studies in the area of mental health, one focused on the diagnosis of dementia with the publication of a protocol for assessing Alzheimer’s disease (AD) via video conference. The review highlighted that diagnosis via video conference in other medical fields had been shown to be reliable but that limited work was evident regarding the reliability of diagnosing dementia via video conference. A range of statistical analyses have been used to measure agreement in studies of diagnosis via VC. Overall Proportional Agreement (Po) and Cohen’s kappa (K) are the two most common calculations. There was little uniformity of reporting in the studies identified in the literature review. The variation in reporting made it difficult to compare results or provide data for a meta-analysis of similar studies. Consideration of the methods for analysing diagnostic agreement was undertaken using the approaches identified in the literature review as a starting point. The aim of this research was to identify if a diagnosis of the presence of dementia in an older adult by a specialist is reliable when the assessment interview occurs via video conference. A pilot study was carried out prior to the implementation of a National Health and Medical Research Council (NHMRC) funded multi-site project to test inter-rater agreement for the diagnosis of dementia and subsidiary questions. The candidate is a Chief Investigator (CI) on the NHMRC project grant and participated in writing the grant submission. A pilot study was completed for the purpose of refining the research protocol and establishing preliminary data for the calculation of sample size. A geriatrician carried out a cognitive assessment via video conference with the patient and the carer. The doctor had access to the patient’s chart and the results of a battery of standardised cognitive assessments administered face-to-face (FTF) by the clinic nurse earlier in the day. A second interview was carried out, face-to-face, by a second doctor on the same day. Inter-rater reliability was assessed between doctors. To place the level of agreement in context, inter-rater reliability between paired face-to-face assessments was also measured. Forty-two participants were divided into two groups: paired face-to-face assessments (FF, n=22) or paired video conference and face-to-face assessments (FV/VF, n=20). Twenty-two participants were male. Their average age was 70 years (SD=11.1, Range 50-90). The mean Standardised Mini-Mental State Examination (SMMSE) score was 23.93 (SD=5.42, Range 8-30)[1]. The outcome of agreement was measured using PO and Cohen’s K. FF group (PO=0.636; K=0.430, p=0.005) and the FV/VF group (PO=0.650; K=0.650, p=0.004) showed similar levels of agreement. The main study was a non-inferiority, prospective cohort study following a similar format as the pilot. Patients were randomised to two groups. The first group participated in two interviews; one via VC, the other was face-to-face (FV/VF). The second group was subjected to dual face-to-face assessments (FF). The video conference interview consisted of real-time video conference with the doctor interacting with both the carer and the patient. A battery of standardised assessments, a medical history, imaging and blood tests were prepared before hand and available to the doctor for use in the interview. One hundred and fifty-five participants were divided into two groups: paired face-to-face assessments (FF, n=73) or paired video conference and face-to-face assessments (FV or VF, n=82). Seventy-five of the participants were male. The average age was 76-years (SD=9, Range 54-95). The mean SMMSE was 23.8 (SD=4.4, Range 8-30). Overall proportional agreement (Po) and Weighted K were calculated as a measure of agreement for the presence of dementia. The FF group (Po=0.740; K=0.57, p<0.0001) and the FV/VF group (Po=0.780; K=0.64, p<0.0001) showed similar levels of agreement. Using the same study cohort, additional data were collected to identify the significance of the physical examination (PE) for diagnosing dementia. One of two doctors was allocated the task of completing a physical examination of the patient following initial assessment interview and after the diagnosis decisions had been recorded. Following the physical examination a second record of diagnosis decisions were recorded by the same doctor. The doctor was asked to identify if the diagnosis, formulation, treating options or additional investigations had altered as a result of the in-person physical examination. The physical examination supported clarity of the diagnosis particularly if a vascular element was involved. This dissertation provides evidence of the reliability of a diagnosis of dementia obtained via video conference. Furthermore, the work detailed in this dissertation represents the largest international study on assessing diagnostic accuracy of cognition and makes a significant contribution to the work in telemedicine in the area of mental health. This dissertation provides generalisations that can impact the use of video conference for diagnosis across a range of specialities, with the ultimate goal of improving access to specialist advice for people living in rural areas.

Owing to its excellent scaling potential, low power consumption, high switching speed, and good retention, and endurance properties, Resistive Random Access Memory (RRAM) is one of the prime candidates to supplant current Nonvolatile Memory (NVM) based on the floating gate (FG) MOSFET transistor, which is at the end of its scaling capability. The RRAM technology comprises two subcategories: 1) the resistive phase change memory (PCM), which has been very recently deployed commercially, and 2) the filamentary conductive bridge RAM (CBRAM) which holds the promise of even better scaling potential, less power consumption, and faster access times. This thesis focuses on several aspects of the CBRAM technology. CBRAM devices are based on nanoionics transport and chemo-physical reactions to create filamentary conductive paths across a dielectric sandwiched between two metal electrodes. These nano-size filaments can be formed and ruptured reliably and repeatedly by application of appropriate voltages. Although, there exists a large body of literature on this topic, many aspects of the CBRAM mechanisms and are still poorly understood. In the next paragraph, the aspects of CBRAM studied in this thesis are spelled out in more detail. CBRAM cell is not only an attractive candidate for a memory cell but is also a good implementation of a new circuit element, called memristor, as postulated by Leon Chua. Basically, a memristor, is a resistor with a memory. Such an element holds the promise to mimic neurological switching of neuron and synapses in human brain that are much more efficient than the Neuman computer architecture with its current CMOS logic technology. A memristive circuitry can possibly lead to much more powerful neural computers in the future. In the course of the research undertaken in this thesis, many memristive properties of the resistive cells have been found and used in models to describe the behavior of the resistive switching devices. The research performed in this study has also an immediate commercial application. Currently, the semiconductor industry is faced with so-called latency scaling dilemma. In the past, the bottleneck for the signal propagation was the time delay of the transistor. Today, the transistors became so fast that the bottleneck for the signal propagation is now the RC time delay of the interconnecting metal lines. Scaling drives both, resistance and parasitic capacitance of the metal lines to very high values. In this context, one observes that resistive switching memory does not require a Si substrate. It is therefore an excellent candidate for its implementation as an o n-chip memory above the logic circuits in the CMOS back-end, thus making the signal paths between logic and memory extremely short. In the framework of a Semiconductor Research Corporation (SRC) project with Intel Corporation, this thesis investigated the breakdown and resistive switching properties of currently deployed low k interlayer dielectrics to understand the mechanisms and potential of different material choices for a realization of an RRAM memory to be implemented in the back-end of a CMOS process flow. / Master of Science

This thesis focuses on the development of a novel polymer based housing for power thyristor devices typically used in long distance high voltage direct current (HVDC) transmission. Power thyristor devices used in HVDC power conversion stations are typically packaged in a hermetically sealed ceramic housing and have demonstrated an excellent history of reliability and performance. However, to avoid increasing the number of thyristors in future higher powered HVDC schemes thyristors having higher power ratings at 8.5 kV and sizes at 125 mm and 150 mm diameters are sought for implementation to achieve higher transmission ratings of, for example, 4000 A at +/- 800 kV. The main disadvantages of such large ceramic-based packages are higher processing cost and weight whilst robustness is also a concern. To overcome these issues, replacing the current ceramic housing with a polymeric material has been investigated in this project. The advantages it is anticipated such packages will provide include lower cost, less weight, robustness, recyclability, etc. However, some challenges it will also offer are: non-hermeticity i.e. polymers are moisture and gas permeable, potentially more complex manufacturing routes, and different electrical, mechanical and thermal properties compared to ceramic materials. The work presented in this thesis was part of a larger project where these challenges have been addressed by developing and testing a prototype polymeric thyristor housing. The prototype is aimed at demonstrating that polymer packages can deliver performance and reliability comparable to, if not better than, current ceramic packages. In this thesis, it is the package development and reliability related studies that are discussed. Because the housings will experience severe electrical stresses and various thermal excursions during their service life, the electrical and thermo-mechanical behaviour of the polymer housing was studied using finite element analysis to gain an understanding of the effects of various design variables and materials properties on performance and the tradeoffs between performance and manufacturability. From these modelling studies, design guidelines have been established for the future development of polymer housings. On the other hand, to identify the physics-of-failure of the prototype that was manufactured as part of the project, accelerated life tests were performed to study its reliability. The knowledge gained from the polymer prototype development was then applied to the design of a larger 125 mm diameter housing using the Taguchi method of experimental design.

Instrumentos descritivos de avaliação funcional para portadores de distrofia muscular de Duchenne são limitados, pois classificam e não qualificam e/ou quantificam o desempenho motor. OBJETIVO: Elaborar escala de avaliação funcional do subir e descer escada para portadores de distrofia muscular de Duchenne e analisar confiabilidade intra e inter-examinadores. MÉTODO: 1. Elaboração de guia de avaliação a partir de revisão da literatura. 2. Avaliação do subir e descer escada de 120 registros filmados de 30 crianças com DMD (5 a 11 anos), utilizando o guia. 3. Elaboração da escala considerando grau de dificuldade. 4. Avaliação por peritos e reajustes para geração da versão final da escala e seu manual. 5. Análise estatística utilizando Índice de Correlação Intra-Classe e Correlação de Kappa Ponderado. RESULTADOS: A escala abrange cinco fases para o subir e quatro para o descer escada. Deve ser aplicada por profissional treinado, conforme normas do manual. Encontrou-se classificação excelente na análise da confiabilidade intra e interexaminadores, com valores da Correlação de Kappa Ponderado (> 0.78) e ICC > (0.89), com p < 0.05 entre todas as fases. CONCLUSÃO: A escala pode ser utilizada como ferramenta de avaliação fisioterapêutica descritiva e quantitativa com excelente repetibilidade e reprodutibilidade / Descriptive instruments of functional evaluation for carriers of duchenne muscular dystrophy are limited, because, they classify and do not qualify and/or quantify the motor performance. OBJECTIVE: To elaborate a scale of functional evaluation of going up and down stairs for DMD carriers and to analyze the realibility intra and inter examiner. METHODS: Elaboration of an evaluation guide from the literature review. 2. Evaluation of 120 registers filmed from 30 children (5 to 11 years) with duchenne muscular dystrophy going up and down stairs, using the guide. 3. Elaboration of the scale considering the degree of difficulty. 4. Evaluation by connoisseurs and readjustments for generation of the final version of the scale and its manual. 5. Statistical analysis using Intra-class Correlation Coefficient and Weighed Kappa. RESULTS: The scale encloses five phases for going up and four for going down stairs. It has to be applied by a trained professional, as norms of the manual. It was found an excellent classification on the reliability analysis intra and inter examiner, with values of Weighed Kappa Coefficient (> 0.78) and ICC > (0.89), with p < 0.05 between all phases. CONCLUSION: The scale can be used as a tool of physical therapy evaluation descriptive and quantitative with excellent repeatability and reproducibility

Instrumentos descritivos de avaliação funcional para portadores de distrofia muscular de Duchenne são limitados, pois classificam e não qualificam e/ou quantificam o desempenho motor. OBJETIVO: Elaborar escala de avaliação funcional do subir e descer escada para portadores de distrofia muscular de Duchenne e analisar confiabilidade intra e inter-examinadores. MÉTODO: 1. Elaboração de guia de avaliação a partir de revisão da literatura. 2. Avaliação do subir e descer escada de 120 registros filmados de 30 crianças com DMD (5 a 11 anos), utilizando o guia. 3. Elaboração da escala considerando grau de dificuldade. 4. Avaliação por peritos e reajustes para geração da versão final da escala e seu manual. 5. Análise estatística utilizando Índice de Correlação Intra-Classe e Correlação de Kappa Ponderado. RESULTADOS: A escala abrange cinco fases para o subir e quatro para o descer escada. Deve ser aplicada por profissional treinado, conforme normas do manual. Encontrou-se classificação excelente na análise da confiabilidade intra e interexaminadores, com valores da Correlação de Kappa Ponderado (> 0.78) e ICC > (0.89), com p < 0.05 entre todas as fases. CONCLUSÃO: A escala pode ser utilizada como ferramenta de avaliação fisioterapêutica descritiva e quantitativa com excelente repetibilidade e reprodutibilidade / Descriptive instruments of functional evaluation for carriers of duchenne muscular dystrophy are limited, because, they classify and do not qualify and/or quantify the motor performance. OBJECTIVE: To elaborate a scale of functional evaluation of going up and down stairs for DMD carriers and to analyze the realibility intra and inter examiner. METHODS: Elaboration of an evaluation guide from the literature review. 2. Evaluation of 120 registers filmed from 30 children (5 to 11 years) with duchenne muscular dystrophy going up and down stairs, using the guide. 3. Elaboration of the scale considering the degree of difficulty. 4. Evaluation by connoisseurs and readjustments for generation of the final version of the scale and its manual. 5. Statistical analysis using Intra-class Correlation Coefficient and Weighed Kappa. RESULTS: The scale encloses five phases for going up and four for going down stairs. It has to be applied by a trained professional, as norms of the manual. It was found an excellent classification on the reliability analysis intra and inter examiner, with values of Weighed Kappa Coefficient (> 0.78) and ICC > (0.89), with p < 0.05 between all phases. CONCLUSION: The scale can be used as a tool of physical therapy evaluation descriptive and quantitative with excellent repeatability and reproducibility