A Note on the Shannon Entropy of Short Sequences

For source sequences of length L symbols we proposed to use a more realistic value to the usual benchmark of number of code letters by source letters. Our idea is based on a quantifier of information fluctuation of a source, F(U), which corresponds to the second central moment of the random variable that measures the information content of a source symbol. An alternative interpretation of typical sequences is additionally provided through this approach.Comment: 3 figure

Visualization of Skewed Data: A Tool in R

In this work we present a visualization tool specifically tailored to deal with skewed data. The technique is based upon the use of two types of notched boxplots (the usual one, and one which is tuned for the skewness of the data), the violin plot, the histogram and a nonparametric estimate of the density. The data is assumed to lie on the same line, so the plots are compatible. We show that a good deal of information can be extracted from the inspection of this tool; in particular, we apply the technique to analyze data from synthetic aperture radar images. We provide the implementation in R.Comment: Submitted to the Revista Colombiana de Estad\'istic

Centrolene savagei

Number of Pages: 11Geological SciencesIntegrative Biolog

Identifying networks with common organizational principles

Many complex systems can be represented as networks, and the problem of network comparison is becoming increasingly relevant. There are many techniques for network comparison, from simply comparing network summary statistics to sophisticated but computationally costly alignment-based approaches. Yet it remains challenging to accurately cluster networks that are of a different size and density, but hypothesized to be structurally similar. In this paper, we address this problem by introducing a new network comparison methodology that is aimed at identifying common organizational principles in networks. The methodology is simple, intuitive and applicable in a wide variety of settings ranging from the functional classification of proteins to tracking the evolution of a world trade network.Comment: 26 pages, 7 figure

Using new and innovative technologies to assess clinical stage in early intervention youth mental health services: Evaluation study

Background: Globally there is increasing recognition that new strategies are required to reduce disability due to common mental health problems. As 75% of mental health and substance use disorders emerge during the teenage or early adulthood years, these strategies need to be readily accessible to young people. When considering how to provide such services at scale, new and innovative technologies show promise in augmenting traditional clinic-based services. Objective: The aim of this study was to test new and innovative technologies to assess clinical stage in early intervention youth mental health services using a prototypic online system known as the Mental Health eClinic (MHeC). Methods: The online assessment within the MHeC was compared directly against traditional clinician assessment within 2 Sydney-based youth-specific mental health services (headspace Camperdown and headspace Campbelltown). A total of 204 young people were recruited to the study. Eligible participants completed both face-to-face and online assessments, which were randomly allocated and counterbalanced at a 1-to-3 ratio. These assessments were (1) a traditional 45- to 60-minute headspace face-to-face assessment performed by a Youth Access Clinician and (2) an approximate 60-minute online assessment (including a self-report Web-based survey, immediate dashboard of results, and a video visit with a clinician). All assessments were completed within a 2-week timeframe from initial presentation. Results: Of the 72 participants who completed the study, 71% (51/72) were female and the mean age was 20.4 years (aged 16 to 25 years); 68% (49/72) of participants were recruited from headspace Camperdown and the remaining 32% (23/72) from headspace Campbelltown. Interrater agreement of participants’ stage, as determined after face-to-face assessment or online assessment, demonstrated fair agreement (kappa=.39, P\u3c.001) with concordance in 68% of cases (49/72). Among the discordant cases, those who were allocated to a higher stage by online raters were more likely to report a past history of mental health disorders (P=.001), previous suicide planning (P=.002), and current cannabis misuse (P=.03) compared to those allocated to a lower stage. Conclusions: The MHeC presents a new and innovative method for determining key clinical service parameters. It has the potential to be adapted to varied settings in which young people are connected with traditional clinical services and assist in providing the right care at the right tim

Academic goals orientation questionnaire for Colombian nursing students:Validity and reliability study

Background Academic motivation guides students toward the achievement of academic objectives and influences their learning. However, there is little research on this subject in nursing education, and validated instruments are not available in Latin America. Objective To determine the validity and reliability of the Academic Goals Orientation Questionnaire in Colombian nursing students. Design Cross-sectional psychometric study developed in the second semester of 2016. Settings and participants. Undergraduate students in nursing at the National University of Colombia (n = 323). Methods The Academic Goals Orientation Questionnaire was administered electronically. In addition, the variables of age, sex and academic year were collected. An analysis of construct validity was carried out by exploratory and confirmatory factor analysis. The reliability of the questionnaire was studied with Cronbach's alpha. Results The exploratory factor analysis revealed the presence of four factors that explain 53.4% of the total variance and that correspond to the dimensions of the original instrument. The overall reliability was α = 0.714. The confirmatory factor analysis verified a good fit of the model (χ2 = 128, p = .024); its standardized mean square residue (SRMR) was 0.0471; the root mean square error of approximation (RMSEA) was 0.03 (IC95% = 0.011–0.044), and the comparative fit index (CFI) was 0.972. The learning or task goal obtained the highest average score (m = 4.67, 95% CI = 4.629–4.712), and the Work avoidance goal was the worst rated (m = 2.126, 95% CI = 2.055–2.198) by the students. Conclusion The Academic Goal Orientation Questionnaire has an adequate validity and reliability in the Colombian context that allows it to be applied in nursing students. However, it is recommended to expand the study with larger samples and other countries in the same context

Model-based guidance and control for atmospheric guided entry

This paper presents a solution of the translational control for a biconic atmospheric entry capsule using the bank angle as a command. The control algorithm is separated into path planning and reference-path tracking. The path-planning algorithm computes the entry trajectory from the navigated state at the Entry Interface Point until the desired Parachute Deployment Point. The algorithm aims to recover the landing site uncertainty caused by Entry Interface Point dispersions. Atmospheric and aerodynamic dispersions are compensated in real-time following the Embedded Model Control methodology in which parametric uncertainty is estimated and rejected as an external disturbance. A hierarchical control structure is designed for facilitating non-linear dynamic inversion of the altitude/density relation and tuning of noise estimators and control laws. Both path planning and reference-path tracking exploit longitudinal and lateral decomposition of the translational dynamics, as well as state equation linearization around a reference trajectory. The main concepts and solutions of the algorithms are presented without formal proofs of convergence, performance and stability. The results of a Monte Carlo simulation campaign conducted on a high fidelity simulator are provided and discussed

Colombian vanilla and its microbiota. III. Diversity and structure of the endophytic community

Endophytic fungal communities are well-recognised entities within plants worldwide. They hold species with potential in medicinal affairs, biological control of pests, industry, and more. Nevertheless, ecological data about structure and dynamics of endophytic communities are scarce. In this study we sampled root, stem and leaf tissues of Colombian vanilla species in order of both, identifying endosymbionts and characterising the community they belong to. An interesting array of endophytic species was found, including taxa that function as pathogens, saprotrophs, and dermatophytes in other plants/scenarios. Ecological parameters show a moderate diversity with a lognormal arrangement of species quite similar to communities of macroorganisms. Many species here reported belong to taxa broadly reported as sources of biologically active compounds, so they are good candidates for bioprospecting research

Estimation of Sensitivities: Low-rank Approach and Online Algorithms for Streaming Measurements

This paper focuses on the estimation of sensitivity matrices in power grids, with applications in both transmission and distribution systems. By leveraging a low-rank approximation of certain classes of sensitivity matrices, the paper proposes a robust nuclear norm minimization method to estimate sensitivities from measurements. Relative to existing methods based on the least-squares approach, the proposed method can obtain meaningful estimates with a smaller number of measurements and when the regression model is underdetermined; the method can also identify faulty measurements and handle missing data. Furthermore, an online proximal-gradient method is proposed to estimate sensitivities on-the-fly from real-time measurements; convergence results in terms of dynamic regret are offered in this case. Tests corroborate the effectiveness of the novel approach.Comment: Submitted to IEEE Transactions on Smart Gri