1,453 research outputs found
Expansion of the investor base for the energy transition
Despite the emergence of the green bond market, the Energy Service Company (ESCO) model and green investment banks, the opportunities which the world’s capital markets present to increase the pool of potential investors and reduce project financing costs for renewable, energy efficient and low carbon assets remain under-exploited. This has been a persistent concern for policy-makers. We review the appeal of this sector to different classes of investor and assess the successes and failures of several innovative products including securitisations, yieldcos, green bonds, green investment banks and crowdfunding. We analyse the experiences with these products and suggest that policy needs to recognise how
fiscal initiatives can leverage their inherent appeal
Process Mining of Disease Trajectories: A Feasibility Study
Modelling patient disease trajectories from evidence in electronic health records could help clinicians and medical researchers develop a better understanding of the progression of diseases within target populations. Process mining provides a set of well-established tools and techniques that have been used to mine electronic health record data to understand healthcare care pathways. In this paper we explore the feasibility for using a process mining methodology and toolset to automate the identification of disease trajectory models. We created synthetic electronic health record data based on a published disease trajectory model and developed a series of event log transformations to reproduce the disease trajectory model using standard process mining tools. Our approach will make it easier to produce disease trajectory models from routine health data
Clann: investigating phylogenetic information through supertree analyses
Summary: Clann has been developed in order to provide
methods of investigating phylogenetic information through the
application of supertrees.
Availability: Clann has been precompiled for Linux, Apple
Macintosh and Windows operating systems and is available
from http://bioinf.may.ie/software/clann. Source code is
available on request from the authors.
Supplementary information: Clann has been written in
the C programming language. Source code is available on
request
Spatio-temporal metrics that distinguish play outcomes: A pilot study
In team invasion sports, tactical behaviour can be examined using spatio-temporal data, i.e. the position of the players at a given time. A review of the spatio-temporal metrics used in team invasion sports performance analysis indicated that thousands of variations of metrics being used. Information about the distribution of metrics' individual effects can inform us of the best variable-selection method. The aim of this pilot study was to estimate the distribution of strong marginal effects of spatio-temporal metrics of field hockey plays. With institutional ethical approval, the Womens’ and Mens’ gold medal games from the EuroHockey 2015 field hockey tournament were recorded. Best, acceptable and worst-case outcomes for plays were described by 1,837 spatio-temporal metrics. Each metric's marginal effects were estimated using Cramér's V, Mutual Information and the I-score. Values for Cramér's V of 0.2 and 0.4 to mark the boundaries of small, moderate and large effects. Less than 1% of metrics show large effects with > 87% of all metrics showing small effects as per the Cramér's V thresholds. These large effect metrics where all within the 98th percentile of Mutual Information values and within the 96th percentile of the I-score values, which supports the Cramér's V distribution of marginal effects. Therefore, according to the recommendations of Tibshirani (1996), univariate variable-selection methods will be the most appropriate for selecting important metrics
Heterogeneous models place the root of the placental mammal phylogeny
Heterogeneity among life traits in mammals has resulted in considerable phylogenetic conflict, particularly concerning the position of the placental root. Layered upon this are gene- and lineage-specific variation in amino acid substitution rates and compositional biases. Life trait variations that may impact upon mutational rates are longevity, metabolic rate, body size, and germ line generation time. Over the past 12 years, three main conflicting hypotheses have emerged for the placement of the placental root. These hypotheses place the Atlantogenata (common ancestor of Xenarthra plus Afrotheria), the Afrotheria, or the Xenarthra as the sister group to all other placental mammals. Model adequacy is critical for accurate tree reconstruction and by failing to account for these compositional and character exchange heterogeneities across the tree and data set, previous studies have not provided a strongly supported hypothesis for the placental root. For the first time, models that accommodate both tree and data set heterogeneity have been applied to mammal data. Here, we show the impact of accurate model assignment and the importance of data sets in accommodating model parameters while maintaining the power to reject competing hypotheses. Through these sophisticated methods, we demonstrate the importance of model adequacy, data set power and provide strong support for the Atlantogenata over other competing hypotheses for the position of the placental root
Knowledge of Dementia: Do family members understand dementia as a terminal condition?
Current research identifies advanced dementia to be the terminal phase of this progressive and incurable condition. However, there has been relatively little investigation into how family members of people with advanced dementia understand their relative's condition. In this article, we report on semi-structured interviews with 10 family members of people with advanced dementia, in a residential aged care facility. Using a qualitative, descriptive design, we explored family members' understandings of dementia, whether they were aware that it was a terminal condition, and the ways they developed their understandings. Findings revealed that the majority of family members could not recognize the terminal nature of dementia. Relying on predominantly lay understandings, they had little access to formal information and most failed to conceptualize a connection between dementia and death. Moreover, family members engaged in limited dialogue with aged care staff about such issues, despite their relatives being in an advanced stage of the disease. Findings from our study suggest that how family members understand their relative's condition requires greater attention. The development of staff/family partnerships that promote shared communication about dementia and dying may enhance family members' understandings of the dementia trajectory and the types of decisions they may be faced with during the more advanced stages of the disease
Towards a Framework for Nonlinear Predictive Control using Derivative-Free Optimization
The use of derivative-based solvers to compute solutions to optimal control
problems with non-differentiable cost or dynamics often requires reformulations
or relaxations that complicate the implementation or increase computational
complexity. We present an initial framework for using the derivative-free Mesh
Adaptive Direct Search (MADS) algorithm to solve Nonlinear Model Predictive
Control problems with non-differentiable features without the need for
reformulation. The MADS algorithm performs a structured search of the input
space by simulating selected system trajectories and computing the subsequent
cost value. We propose handling the path constraints and the Lagrange cost term
by augmenting the system dynamics with additional states to compute the
violation and cost value alongside the state trajectories, eliminating the need
for reconstructing the state trajectories in a separate phase. We demonstrate
the practicality of this framework by solving a robust rocket control problem,
where the objective is to reach a target altitude as close as possible, given a
system with uncertain parameters. This example uses a non-differentiable cost
function and simulates two different system trajectories simultaneously, with
each system having its own free final time.Comment: Accepted for presentation at the 7th IFAC Conference on Nonlinear
Model Predictive Contro
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