Predicting market direction with hidden Markov models

This paper develops the model of Bicego, Grosso, and Otranto (2008) and applies Hidden Markov Models to predict market direction. The paper draws an analogy between financial markets and speech recognition, seeking inspiration from the latter to solve common issues in quantitative investing. Whereas previous works focus mostly on very complex modifications of the original hidden markov model algorithm, the current paper provides an innovative methodology by drawing inspiration from thoroughly tested, yet simple, speech recognition methodologies. By grouping returns into sequences, Hidden Markov Models can then predict market direction the same way they are used to identify phonemes in speech recognition. The model proves highly successful in identifying market direction but fails to consistently identify whether a trend is in place. All in all, the current paper seeks to bridge the gap between speech recognition and quantitative finance and, even though the model is not fully successful, several refinements are suggested and the room for improvement is significant.

Knowledge management framework based on brain models and human physiology

The life of humans and most living beings depend on sensation and perception for the best assessment of the surrounding world. Sensorial organs acquire a variety of stimuli that are interpreted and integrated in our brain for immediate use or stored in memory for later recall. Among the reasoning aspects, a person has to decide what to do with available information. Emotions are classifiers of collected information, assigning a personal meaning to objects, events and individuals, making part of our own identity. Emotions play a decisive role in cognitive processes as reasoning, decision and memory by assigning relevance to collected information. The access to pervasive computing devices, empowered by the ability to sense and perceive the world, provides new forms of acquiring and integrating information. But prior to data assessment on its usefulness, systems must capture and ensure that data is properly managed for diverse possible goals. Portable and wearable devices are now able to gather and store information, from the environment and from our body, using cloud based services and Internet connections. Systems limitations in handling sensorial data, compared with our sensorial capabilities constitute an identified problem. Another problem is the lack of interoperability between humans and devices, as they do not properly understand human’s emotional states and human needs. Addressing those problems is a motivation for the present research work. The mission hereby assumed is to include sensorial and physiological data into a Framework that will be able to manage collected data towards human cognitive functions, supported by a new data model. By learning from selected human functional and behavioural models and reasoning over collected data, the Framework aims at providing evaluation on a person’s emotional state, for empowering human centric applications, along with the capability of storing episodic information on a person’s life with physiologic indicators on emotional states to be used by new generation applications.

Flood resilient housing recovery models: a theoretical case study in Maldives

Natural disasters are events that cause general and widespread destruction of the built environment and are becoming increasingly recurrent. They are a product of vulnerability and community exposure to natural hazards, generating a multitude of social, economic and cultural issues of which the loss of housing and the subsequent need for shelter is one of its major consequences. Nowadays, numerous factors contribute to increased vulnerability and exposure to natural disasters such as climate change with its impacts felt across the globe and which is currently seen as a worldwide threat to the built environment. The abandonment of disaster-affected areas can also push populations to regions where natural hazards are felt more severely. Although several actors in the post-disaster scenario provide for shelter needs and recovery programs, housing is often inadequate and unable to resist the effects of future natural hazards. Resilient housing is commonly not addressed due to the urgency in sheltering affected populations. However, by neglecting risks of exposure in construction, houses become vulnerable and are likely to be damaged or destroyed in future natural hazard events. That being said it becomes fundamental to include resilience criteria, when it comes to housing, which in turn will allow new houses to better withstand the passage of time and natural disasters, in the safest way possible. This master thesis is intended to provide guiding principles to take towards housing recovery after natural disasters, particularly in the form of flood resilient construction, considering floods are responsible for the largest number of natural disasters. To this purpose, the main structures that house affected populations were identified and analyzed in depth. After assessing the risks and damages that flood events can cause in housing, a methodology was proposed for flood resilient housing models, in which there were identified key criteria that housing should meet. The same methodology is based in the US Federal Emergency Management Agency requirements and recommendations in accordance to specific flood zones. Finally, a case study in Maldives – one of the most vulnerable countries to sea level rise resulting from climate change – has been analyzed in light of housing recovery in a post-disaster induced scenario. This analysis was carried out by using the proposed methodology with the intent of assessing the resilience of the newly built housing to floods in the aftermath of the 2004 Indian Ocean Tsunami.

The future of airline business models:

This research is titled “The Future of Airline Business Models: Which Will Win?” and it is part of the requirements for the award of a Masters in Management from NOVA BSE and another from Luiss Guido Carlo University. The purpose is to elaborate a complete market analysis of the European Air Transportation Industry in order to predict which Airlines, strategies and business models may be successful in the next years. First, an extensive literature review of the business model concept has been done. Then, a detailed overview of the main European Airlines and the strategies that they have been implementing so far has been developed. Finally, the research is illustrated with three case studies

Integração vertical de cuidados : o impacto nos custos do internamento hospitalar

RESUMO - Introdução: A integração vertical de cuidados surge em Portugal em 1999 com a criação da primeira Unidade Local de Saúde (ULS) em Matosinhos. Este modelo de gestão tem como principal objetivo reorganizar o sistema para responder de forma mais custo-efetiva às necessidades atuais. Objetivo: Analisar o impacto da criação das ULS nos custos do internamento hospitalar português. Metodologia: Para apurar o custo médio estimado por episódio de internamento hospitalar utilizou-se a metodologia dos Custos Estimados com base na Contabilidade Analítica. Contudo, não foram imputados custos por diária de internamento por centro de produção, mas apenas por doente saído em determinado hospital. Para efeitos de comparação dos modelos de gestão organizacionais consideraram-se variáveis demográficas e variáveis de produção. Resultados: Da análise global, os hospitais integrados em ULS apresentam um custo médio estimado por episódio de internamento inferior quando comparados com os restantes. Em 2004 os hospitais sem modelo de integração vertical de cuidados apresentam uma diferença de custos de aproximadamente 714,00€. No ano 2009, último ano em análise, esta diferença é mais ténue situando-se nos 232,00€ quando comparados com hospitais integrados em ULS. Discussão e Conclusão: Não existe uma tendência definida no que respeita à diferença de custos quando se comparam os diferentes modelos organizacionais. É importante que em estudos futuros se alargue a amostra ao total de prestadores e se aprofundem os fatores que influênciam os custos de internamento. A compreensão dos indicadores sociodemográficos, demora média, e produção realizada, numa ótica de custo efetividade e qualidade, permitirá resultados com menor grau de viés.

Building 3D City Models: Testing and Comparing Laser Scanning and Low-Cost UAV Data Using FOSS Technologies

Contém resumo

Factors that determine the level of care children and adolescents experiencing mental disorders receive

RESUMO: Resumo Uma prestação de serviços de saúde mental para crianças e adolescentes (CAMHS) oportuna, eficaz e baseada na evidência pode evitar incapacidade a longo prazo. No entanto, estes serviços são criticamente sub-financiados em todo o mundo. É um imperativo garantir que este precioso recurso não seja desperdiçado. Os governos e outras partes interessadas relevantes na área da saúde mental precisam de conhecer o estado de saúde mental da população, quais os recursos disponíveis e como melhor utilizar os recursos disponíveis para orientar uma política e decisões efectivas sobre os níveis de serviços. Objetivo: O objetivo deste artigo é explorar o papel da acuidade, gravidade e complexidade na determinação dos cuidados em saúde mental especializados recebidos por crianças e adolescentes que sofrem perturbações mentais. Métodos: Este estudo é exploratório envolvendo uma revisão sistemática da literatura. Foi realizada uma pesquisa com palavras-chave utilizando bases de dados PsychINFO, EMBASE, PubMed e MEDLINE. A literatura cinzenta também foi investigada com um enfoque nas abordagens sistémicas, organizacionais e políticas para a organização e comissionamento de CAMHS. Foram selecionados apenas documentos escritos em Inglês. Três países, Bélgica, Reino Unido e Estados Unidos, todos eles com modelos muito diferentes de organização de CAMHS, foram revistos para investigar de que forma os conceitos de acuidade, gravidade e complexidade foram utilizados na sua concepção de serviços para determinar o nível da assistência prestada. Resultados: Nem a Bélgica, nem o modelo norte-americano de CAMHS organização de serviço parecem estar alinhados com os principais conceitos na determinação do nível de prestação de serviços. O sistema de serviços do Reino Unido de CAMHS está mais estreitamente alinhado com esses conceitos e tem uma alocação de recursos mais equilibrada entre o hospital e a comunidade. O seu ponto fraco está na falta de flexibilidade entre os níveis de serviço e na falta de apoio para com o sector dos cuidados de saúde primários. Conclusões: A variabilidade na alocação de recursos a diferentes níveis especializados de CAMHS (em regime de internamento, ambulatório, e na comunidade) e o modelo diferente de estrutura de serviços entre os países estudados indica uma inconsistência na forma como as crianças e adolescentes que apresentam aos CAMHS são referenciados para os cuidados que recebem. Isto põe em questão se as crianças e adolescentes com perturbações mentais estão a receber o nível e tipo de cuidados concordantes com as suas necessidades. A concepção e o comissionamento de sistemas de CAMHS levam-nos à discussão de uma série de princípios fundamentais que devem ser considerados. O sistema perfeito no entanto, ainda está para ser encontrado. -------------------------------- ABSTRACT: Provision of timely, effective, evidence based mental health services to children and adolescents can prevent long term impairment, but they are critically underfunded across the globe. There is an imperative to ensure this precious resource is not wasted. Governments and other relevant mental health stakeholders need to know the mental health status of the population, what resources are available and how best to use the resources available to guide effective policy and decisions about service levels. Aim: The aim of this paper is to explore the role of acuity, severity and complexity in determining the specialist mental health care that children and adolescents experiencing mental disorders receive. Methods: This study is exploratory involving a systematic scan of the literature. A key word search was conducted using databases PSYCHINFO, EMBASE, PUBMED and MEDLINE. Grey literature was also searched to focus on systemic, organisational and policy approaches to the organisation and commissioning of CAMHS. Only documents written in English were selected. Three countries Belgium, UK and the US all with very different models of service organisation for CAMHS were reviewed to investigate how well the concepts of acuity, severity and complexity were used to determine the level of care delivered in their service design. Findings: Neither the Belgium nor the US model of CAMHS service organisation appear to align with the key concepts driving intensity of level of service provision. The UK CAMHS service system most closely aligns with the concepts. It has a more balanced resource allocation between hospital and community. Its downfall is in its lack of flexibility between service levels and its lack of support for the primary care sector. Conclusions: The variability in resource allocation to different service levels (inpatient, outpatient, community) within specialist CAMHS and the differing model of service structure across countries indicates an inconsistency in how children and adolescents presenting to CAMHS are allocated to the care they receive. This puts into question whether children and adolescent with mental disorders are receiving a level and type of care commensurate with their needs. In commissioning and designing CAMHS systems a number of key principles that should be considered are discussed. The perfect system however, is yet to be found.

Damage propagation in composite Materials meso-mechanical models

Composite materials have a complex behavior, which is difficult to predict under different types of loads. In the course of this dissertation a methodology was developed to predict failure and damage propagation of composite material specimens. This methodology uses finite element numerical models created with Ansys and Matlab softwares. The methodology is able to perform an incremental-iterative analysis, which increases, gradually, the load applied to the specimen. Several structural failure phenomena are considered, such as fiber and/or matrix failure, delamination or shear plasticity. Failure criteria based on element stresses were implemented and a procedure to reduce the stiffness of the failed elements was prepared. The material used in this dissertation consist of a spread tow carbon fabric with a 0°/90° arrangement and the main numerical model analyzed is a 26-plies specimen under compression loads. Numerical results were compared with the results of specimens tested experimentally, whose mechanical properties are unknown, knowing only the geometry of the specimen. The material properties of the numerical model were adjusted in the course of this dissertation, in order to find the lowest difference between the numerical and experimental results with an error lower than 5% (it was performed the numerical model identification based on the experimental results).

The role of dispersion into assets allocation

Dispersion of returns has gained a lot of attention as a measure to distinguish good and bad investment opportunities time. In the following dissertation, the cross-sectional returns volatility is analyzed over a fifteen year period across the S&P100 Index composition. The main inference drawn from the data sample is that the canonical measure of dispersion is highly macro-risk driven and therefore more biased towards returns volatility rather than its correlation component.

Understanding multi-asset factor models: Factor exposure interpretation

Field lab: Business project

Orthogonal models, structure crossing, nesting and inference

We intend to study the algebraic structure of the simple orthogonal models to use them, through binary operations as building blocks in the construction of more complex orthogonal models. We start by presenting some matrix results considering Commutative Jordan Algebras of symmetric matrices, CJAs. Next, we use these results to study the algebraic structure of orthogonal models, obtained by crossing and nesting simpler ones. Then, we study the normal models with OBS, which can also be orthogonal models. We intend to study normal models with OBS (Orthogonal Block Structure), NOBS (Normal Orthogonal Block Structure), obtaining condition for having complete and suffcient statistics, having UMVUE, is unbiased estimators with minimal covariance matrices whatever the variance components. Lastly, see ([Pereira et al. (2014)]), we study the algebraic structure of orthogonal models, mixed models whose variance covariance matrices are all positive semi definite, linear combinations of known orthogonal pairwise orthogonal projection matrices, OPOPM, and whose least square estimators, LSE, of estimable vectors are best linear unbiased estimator, BLUE, whatever the variance components, so they are uniformly BLUE, UBLUE. From the results of the algebraic structure we will get explicit expressions for the LSE of these models.

Dry matter allocation in Jessenia bataua (PALMAE)

There are few assessments of lifetime dry matter production for tropical trees. However, several studies, have been carried out for palms. This study measures dry matter production for Jessenia bataua,a useful palm common in many areas of the Amazon Valley. Palms In the Ducke Forest Reserve Of INPA were studied. Approximately 34% of total aboveground dry matter production in this palm was, alllocated to reproductive effort, eg., the production of in florescences and fruits. The meaning of this percentage, to discussed, relative to percentages identified in other Neotropical palms.

Cultural journalism in a digital environment : new models, practices and possibilities

Both culture coverage and digital journalism are contemporary phenomena that have undergone several transformations within a short period of time. Whenever the media enters a period of uncertainty such as the present one, there is an attempt to innovate in order to seek sustainability, skip the crisis or find a new public. This indicates that there are new trends to be understood and explored, i.e., how are media innovating in a digital environment? Not only does the professional debate about the future of journalism justify the need to explore the issue, but so do the academic approaches to cultural journalism. However, none of the studies so far have considered innovation as a motto or driver and tried to explain how the media are covering culture, achieving sustainability and engaging with the readers in a digital environment. This research examines how European media which specialize in culture or have an important cultural section are innovating in a digital environment. Specifically, we see how these innovation strategies are being taken in relation to the approach to culture and dominant cultural areas, editorial models, the use of digital tools for telling stories, overall brand positioning and extensions, engagement with the public and business models. We conducted a mixed methods study combining case studies of four media projects, which integrates qualitative web features and content analysis, with quantitative web content analysis. Two major general-interest journalistic brands which started as physical newspapers – The Guardian (London, UK) and Público (Lisbon, Portugal) – a magazine specialized in international affairs, culture and design – Monocle (London, UK) – and a native digital media project that was launched by a cultural organization – Notodo, by La Fábrica – were the four case studies chosen. Findings suggest, on one hand, that we are witnessing a paradigm shift in culture coverage in a digital environment, challenging traditional boundaries related to cultural themes and scope, angles, genres, content format and delivery, engagement and business models. Innovation in the four case studies lies especially along the product dimensions (format and content), brand positioning and process (business model and ways to engage with users). On the other hand, there are still perennial values that are crucial to innovation and sustainability, such as commitment to journalism, consistency (to the reader, to brand extensions and to the advertiser), intelligent differentiation and the capability of knowing what innovation means and how it can be applied, since this thesis also confirms that one formula doesn´t suit all. Changing minds, exceeding cultural inertia and optimizing the memory of the websites, looking at them as living, organic bodies, which continuously interact with the readers in many different ways, and not as a closed collection of articles, are still the main challenges for some media.

Development of human central nervous system 3D in vitro models for preclinical research

Neurological disorders are a major concern in modern societies, with increasing prevalence mainly related with the higher life expectancy. Most of the current available therapeutic options can only control and ameliorate the patients’ symptoms, often be-coming refractory over time. Therapeutic breakthroughs and advances have been hampered by the lack of accurate central nervous system (CNS) models. The develop-ment of these models allows the study of the disease onset/progression mechanisms and the preclinical evaluation of novel therapeutics. This has traditionally relied on genetically engineered animal models that often diverge considerably from the human phenotype (developmentally, anatomically and physiologically) and 2D in vitro cell models, which fail to recapitulate the characteristics of the target tissue (cell-cell and cell-matrix interactions, cell polarity). The in vitro recapitulation of CNS phenotypic and functional features requires the implementation of advanced culture strategies that enable to mimic the in vivo struc-tural and molecular complexity. Models based on differentiation of human neural stem cells (hNSC) in 3D cultures have great potential as complementary tools in preclinical research, bridging the gap between human clinical studies and animal models. This thesis aimed at the development of novel human 3D in vitro CNS models by integrat-ing agitation-based culture systems and a wide array of characterization tools. Neural differentiation of hNSC as 3D neurospheres was explored in Chapter 2. Here, it was demonstrated that human midbrain-derived neural progenitor cells from fetal origin (hmNPC) can generate complex tissue-like structures containing functional dopaminergic neurons, as well as astrocytes and oligodendrocytes. Chapter 3 focused on the development of cellular characterization assays for cell aggregates based on light-sheet fluorescence imaging systems, which resulted in increased spatial resolu-tion both for fixed samples or live imaging. The applicability of the developed human 3D cell model for preclinical research was explored in Chapter 4, evaluating the poten-tial of a viral vector candidate for gene therapy. The efficacy and safety of helper-dependent CAV-2 (hd-CAV-2) for gene delivery in human neurons was evaluated, demonstrating increased neuronal tropism, efficient transgene expression and minimal toxicity. The potential of human 3D in vitro CNS models to mimic brain functions was further addressed in Chapter 5. Exploring the use of 13C-labeled substrates and Nucle-ar Magnetic Resonance (NMR) spectroscopy tools, neural metabolic signatures were evaluated showing lineage-specific metabolic specialization and establishment of neu-ron-astrocytic shuttles upon differentiation. Chapter 6 focused on transferring the knowledge and strategies described in the previous chapters for the implementation of a scalable and robust process for the 3D differentiation of hNSC derived from human induced pluripotent stem cells (hiPSC). Here, software-controlled perfusion stirred-tank bioreactors were used as technological system to sustain cell aggregation and dif-ferentiation. The work developed in this thesis provides practical and versatile new in vitro ap-proaches to model the human brain. Furthermore, the culture strategies described herein can be further extended to other sources of neural phenotypes, including pa-tient-derived hiPSC. The combination of this 3D culture strategy with the implemented characterization methods represents a powerful complementary tool applicable in the drug discovery, toxicology and disease modeling.

The characteristics of social entrepreneurship business models in Portugal

This work project is based on the MIES (Map of Innovation and Social Entrepreneurship in Portugal) database and it aims to understand the characteristics of social business models in the context of the portuguese market, by determining whether they follow the proposed characteristics by John Elkington and Pamela Hartigan, and then adding to their matrix. Furthermore, it tries to determine success patterns by comparing a group of successful social ventures with a group of less successful ones, with the objective of increasing the knowledge of social entrepreneurship as it applies to Portugal and provide a framework for future study.