Imputation and classification of time series with missing data using machine learning

This work is about classifying time series with missing data with the help of imputation and selected machine learning algorithms and methods. The author has used imputation to replace missing values in two data sets, one containing surgical site infection (SSI) data of 11 types of blood samples of patients over 20 days, and another data set called uwave which contain 3D accelerometer data of several patterns made by a subset of people, where two patterns were selected. The SSI data set is known to possess informative missingness. For the uwave data, missing data was simulated by removing data points in an informative (not random) way to simulate missing data. The DTW and Euclidean distances were computed for each imputed data set to make distance grid matrices, and used to performed classification on the data using the K Nearest Neighbour (KNN) classifier and the Support Vector Machine (SVM) classifier. Furthermore the data set features were augmented by adding masks that indicate the presence of missing data and counters of consecutive spells of missing data to help exploit informative missingness. The augmented dataset was used to classify the data using the same classifiers and distance methods mentioned earlier, in addition to a newer classifier called the Temporal Convolution Network (TCN), which used the augmented data in combination with imputation of the original data. It was found that applying Dynamic Time Warping (DTW) was unnecessary for the KNN classifier, and that Euclidean distance was sufficient. Augmenting the data was found to improve the overall results for the SVM and KNN classifier. The TCN was found to need more work due to giving unstable test results with much lower values than the validation would imply

Utilizing public repositories to improve the decision process for security defect resolution and information reuse in the development environment

Security risks are contained in solutions in software systems that could have been avoided if the design choices were analyzed by using public information security data sources. Public security sources have been shown to contain more relevant and recent information on current technologies than any textbook or research article, and these sources are often used by developers for solving software related problems. However, solutions copied from public discussion forums such as StackOverflow may contain security implications when copied directly into the developers environment. Several different methods to identify security bugs are being implemented, and recent efforts are looking into identifying security bugs from communication artifacts during software development lifecycle as well as using public security information sources to support secure design and development. The primary goal of this thesis is to investigate how to utilize public information sources to reduce security defects in software artifacts through improving the decision process for defect resolution and information reuse in the development environment. We build a data collection tool for collecting data from public information security sources and public discussion forums, construct machine learning models for classifying discussion forum posts and bug reports as security or not-security related, as well as word embedding models for finding matches between public security sources and public discussion forum posts or bug reports. The results of this thesis demonstrate that using public information security sources can provide additional validation layers for defect classification models, as well as provide additional security context for public discussion forum posts. The contributions of this thesis are to provide understanding of how public information security sources can better provide context for bug reports and discussion forums. Additionally, we provide data collection APIs for collecting datasets from these sources, and classification and word embedding models for recommending related security sources for bug reports and public discussion forum posts.Masteroppgave i Programutvikling samarbeid med HVLPROG399MAMN-PRO

The impact of debt maturity on stock returns : A quantitative study of the Japanese stock market

This thesis presents how debt maturity affects equity returns in the Japanese stock market. Some studies have been done on the topic in the US, but the research in Japan is limited. When applying a cross-sectional approach to our dataset, we find that a shorter maturity structure is associated with a positive premium. Further, we make portfolios based on different leverage metrics. The portfolios with a high amount of short-term leverage have a higher average return than the portfolios with a low amount of short-term leverage. We also regress the portfolios against the CAPM, FF3 and FF5 to study the exposure to systematic risk. We do not find a significant alpha, but there is a positive significant loading on several of the systematic risk factors.nhhma

Building capacity for public and population health research in Africa : the consortium for advanced research training in Africa (CARTA) model

Background: Globally, sub-Saharan Africa bears the greatest burden of disease. Strengthened research capacity to understand the social determinants of health among different African populations is key to addressing the drivers of poor health and developing interventions to improve health outcomes and health systems in the region. Yet, the continent clearly lacks centers of research excellence that can generate a strong evidence base to address the region’s socio-economic and health problems. Objective and program overview: We describe the recently launched Consortium for Advanced Research Training in Africa (CARTA), which brings together a network of nine academic and four research institutions from West, East, Central, and Southern Africa, and select northern universities and training institutes. CARTA’s program of activities comprises two primary, interrelated, and mutually reinforcing objectives: to strengthen research infrastructure and capacity at African universities; and to support doctoral training through the creation of a collaborative doctoral training program in population and public health. The ultimate goal of CARTA is to build local research capacity to understand the determinants of population health and effectively intervene to improve health outcomes and health systems. Conclusions: CARTA’s focus on the local production of networked and high-skilled researchers committed to working in sub-Saharan Africa, and on the concomitant increase in local research and training capacity of African universities and research institutes addresses the inability of existing programs to create a critical mass of well-trained and networked researchers across the continent. The initiative’s goal of strengthening human resources and university-wide systems critical to the success and sustainability of research productivity in public and population health will rejuvenate institutional teaching, research, and administrative systems

ISSUES IN MEDICINE: Will clinical associates be effective for South Africa?

South Africa has developed an innovative mid-level medical worker model that can contribute substantively to the development of quality district-level health care. These clinical associates entered the South African job market in 2011 and have reportedly been received favourably. The first cohorts performed well on local and national examinations, with pass rates >95%. They have demonstrated confidence and competence in the common procedures and conditions encountered in district hospitals;reportedly fitted in well at most of the sites where they commencedworking; and made a significant contribution to the health team, resulting in a demand for more clinical associates. Universities and provinces involved in producing clinical associates are enthusiastic and committed. However, priorities are to establish sustainable funding sources for training and deployment, provide adequate supervision and support, monitor the initial impact of the new cadre on health services, and manage the sensitivities of the medical and nursing professions around scopes of practice and post levels. Longer-term concerns are national leadership and support, scaling up of training, the development of career pathways, and the improvement of working conditions at district hospitals

Aligning vertical interventions to health systems: a case study of the HIV monitoring and evaluation system in South Africa

<p>Abstract</p> <p>Background</p> <p>Like many low- and middle-income countries, South Africa established a dedicated HIV monitoring and evaluation (M&E) system to track the national response to HIV/AIDS. Its implementation in the public health sector has however not been assessed. Since responsibility for health services management lies at the district (sub-national) level, this study aimed to assess the extent to which the HIV M&E system is integrated with the overall health system M&E function at district level. This study describes implementation of the HIV M&E system, determines the extent to which it is integrated with the district health information system (DHIS), and evaluates factors influencing HIV M&E integration.</p> <p>Methods</p> <p>The study was conducted in one health district in South Africa. Data were collected through key informant interviews with programme and health facility managers and review of M&E records at health facilities providing HIV services. Data analysis assessed the extent to which processes for HIV data collection, collation, analysis and reporting were integrated with the DHIS.</p> <p>Results</p> <p>The HIV M&E system is top-down, over-sized, and captures a significant amount of energy and resources to primarily generate antiretroviral treatment (ART) indicators. Processes for producing HIV prevention indicators are integrated with the DHIS. However processes for the production of HIV treatment indicators by-pass the DHIS and ART indicators are not disseminated to district health managers. Specific reporting requirements linked to ear-marked funding, politically-driven imperatives, and mistrust of DHIS capacity are key drivers of this silo approach.</p> <p>Conclusions</p> <p>Parallel systems that bypass the DHIS represent a missed opportunity to strengthen system-wide M&E capacity. Integrating HIV M&E (staff, systems and process) into the health system M&E function would mobilise ear-marked HIV funding towards improving DHIS capacity to produce quality and timely HIV indicators that would benefit both programme and health system M&E functions. This offers a practical way of maximising programme-system synergies and translating the health system strengthening intents of existing HIV policies into tangible action.</p

Fra David til Goliat: En studie av representasjoner av Israel/Palestina konfliktene i norsk presse mellom 1948-2009

Da staten Israel ble opprettet i 1948 fikk Norge et nært forhold til Israel, og det ble vist støtte og sympati med landet. I de senere årene har det kommet frem mer kritiske synspunkter rundt Israel og handlingene deres. Denne masteroppgaven utforsker hvordan offerrollediskursen og legitimeringen av staten Israel utfordres og endres gjennom perioden 1948-2009 i de to avisene Aftenposten og Arbeiderbladet (fra 1997 Dagsavisen). Foucaults diskursanalyse blir brukt for å analysere utvalgte tekster fra de to avisene gjennom ulike konflikter i Midtøsten. Problemstillingen som denne oppgaven skal forsøke å besvare er «Hvordan har Israel/Palestina konfliktene blitt representert i de to avisene Aftenposten og Arbeiderbladet (Dagsavisen) mellom 1948-2009?» Studien tar for seg utvalgte avisartikler i Arbeiderbladet (Dagsavisen) og Aftenposten, fra syv konflikter i Midtøsten samt Oslo-avtalen i perioden 1948-2009. Frem til 1967 viser analyser av diskursen i avisene en tydelig støtte og sympati til Israel. Etter Seksdagerskrigen begynner det å komme noen Israel-kritiske tekster i avisene, likevel er det ikke før i 1988 det kommer et større brudd i diskursen. Tekstene i avisene går fra å sette Israel i en offerrolle og tydelig vise sympati med landet, til å beskylde Israel for å drive apartheid og sammenligner handlingene deres med nazistene. Israel går fra å ha rollen som David, til å bli presentert som Goliat i Midtøsten.When the state of Israel was established in 1948, Norway developed a close relationship with Israel, and support and sympathy were shown with the country. In recent years, more critical views have emerged about Israel and their actions. This master's thesis explores how the victimhood discourse and the legitimation of the state of Israel are challenged and changed during the period 1948-2009 in the two newspapers Aftenposten and Arbeiderbladet (from 1997 Dagsavisen). Foucault's discourse analysis is used to analyze selected texts from the two newspapers through various conflicts in the Middle East. The problem that this thesis will try to answer is: “How have the Israel/Palestine conflicts been represented in the two newspapers Aftenposten and Arbeiderbladet (Dagsavisenn) between 1948-2009? The study deals with selected newspaper articles in Arbeiderbladet (Dagsavisen) and Aftenposten, from seven conflicts in the Middle East and the Oslo peace process in the period 1948-2009. Until 1967, analyzes of the discourse in the newspapers show a clear support and sympathy for Israel. After the Six-Day War, some Israeli-critical texts begin to appear in the newspapers, yet it was not until 1988 that there was a clearer break in the discourse. Texts in the newspapers changes from placing Israel as a victim and clearly showing sympathy with the country, to accusing Israel of pursuing apartheid and comparing their actions with the Nazis. Israel goes from having the role of David, to being presented as Goliath in the Middle East