On the Computation of the Gaussian Rate-Distortion-Perception Function

In this paper, we study the computation of the rate-distortion-perception function (RDPF) for a multivariate Gaussian source under mean squared error (MSE) distortion and, respectively, Kullback-Leibler divergence, geometric Jensen-Shannon divergence, squared Hellinger distance, and squared Wasserstein-2 distance perception metrics. To this end, we first characterize the analytical bounds of the scalar Gaussian RDPF for the aforementioned divergence functions, also providing the RDPF-achieving forward "test-channel" realization. Focusing on the multivariate case, we establish that, for tensorizable distortion and perception metrics, the optimal solution resides on the vector space spanned by the eigenvector of the source covariance matrix. Consequently, the multivariate optimization problem can be expressed as a function of the scalar Gaussian RDPFs of the source marginals, constrained by global distortion and perception levels. Leveraging this characterization, we design an alternating minimization scheme based on the block nonlinear Gauss-Seidel method, which optimally solves the problem while identifying the Gaussian RDPF-achieving realization. Furthermore, the associated algorithmic embodiment is provided, as well as the convergence and the rate of convergence characterization. Lastly, for the "perfect realism" regime, the analytical solution for the multivariate Gaussian RDPF is obtained. We corroborate our results with numerical simulations and draw connections to existing results.Comment: This paper has been submitted for journal publicatio

Local E-Government in Cyprus: A Comparison of Perceptions Between Citizens and Decision Makers

This paper identifies attitudes and perceptions on e-government among two key populations: citizens of the Republic of Cyprus and local government decision makers. The research methodology is based on both secondary and primary data collection, with the latter including a questionnaire survey of the public and another of major local governments\u27 officials who were directly involved in the decision making of the services provided through local egovernment initiatives. The results of the surveys are analysed and cross-related The research has reached three principal clusters of conclusions. The first relates to a number of discrepancies found when comparing the public\u27s perceptions, needs and potentialities on e-government and the corresponding perceptions of the municipality decision makers. The second cluster relates to the wider potentialities of local e-government in Cyprus. The third cluster is provides directions and towards a successful local e-government implementation in Cyprus

Assessing public preferences for a wildfire mitigation policy in Crete, Greece

The increased frequency and severity of wildfires in the Mediterranean region generates significant damages in ecosystems and landscapes while harming human populations. Institutional complexities, along with socioeconomic and demographic changes encouraging development into the wildland-urban interface, rural abandonment, and focus on fire suppression, are increasing the vulnerability and flammability of Mediterranean ecosystems. Developing effective strategies for managing wildfire incidence and its aftermath requires understanding of the public preferences for wildfire policy characteristics. Here we elicit public preferences for wildfire mitigation policies employing a stated choice experiment applied in Crete, Greece. A region with typical Mediterranean landscape experiencing significant development and rural-to-urban migration that disrupts existing fire regimes. We estimate conditional logit, mixed logit and latent class models to study the general public's preferences and willingness to pay for limiting wildfire frequency and agricultural land burnt, maintaining landscape features, and managing post-wildfire recovery. Results of our study show that measures to manage post-wildfire damage are consistently valued as the most positive amongst the sampled respondents, achieving values that range between €25.92 in conditional logit model to €46 in one of the latent classes identified. Improving the landscape quality follows in importance, although it shows more heterogeneity in the responses. The latent class approach allowed to identify that those associated with either the agricultural or the tourism sector of the sampled individuals, displayed significantly different preferences for the proposed attributes. Overall, our findings indicate that there is a strong preference amongst the general public to shift current policies based on suppression towards more integrated approaches dealing both with prevention and post-fire management. The outcomes of this study serve to guide decision makers on targeted management plans based on their audience

Validity and reliability of the Dutch translation of the VISA-P questionnaire for patellar tendinopathy

Background: The VISA-P questionnaire evaluates severity of symptoms, knee function and ability to play sports in athletes with patellar tendinopathy. This English-language self-administered brief patient outcome score was developed in Australia to monitor rehabilitation and to evaluate outcome of clinical studies. Aim of this study was to translate the questionnaire into Dutch and to study the reliability and validity of the Dutch version of the VISA-P. Methods: The questionnaire was translated into Dutch according to internationally recommended guidelines. Test-retest reliability was determined in 99 students with a time interval of 2.5 weeks. To determine discriminative validity of the Dutch VISA-P, 18 healthy students, 15 competitive volleyball players (at-risk population), 14 patients with patellar tendinopathy, 6 patients who had surgery for patellar tendinopathy, 17 patients with knee injuries other than patellar tendinopathy, and 9 patients with symptoms unrelated to their knees completed the Dutch VISA-P. Results: The Dutch VISA-P questionnaire showed satisfactory test-retest reliability (ICC = 0.74). The mean (+/- SD) VISA-P scores were 95 (+/- 9) for the healthy students, 89 (+/- 11) for the volleyball players, 58 (+/- 19) for patients with patellar tendinopathy, and 56 (+/- 21) for athletes who had surgery for patellar tendinopathy. Patients with other knee injuries or symptoms unrelated to the knee scored 62 (+/- 24) and 77 (+/- 24). Conclusion: The translated Dutch version of the VISA-P questionnaire is equivalent to its original version, has satisfactory test-retest reliability and is a valid score to evaluate symptoms, knee function and ability to play sports of Dutch athletes with patellar tendinopathy

Modelling Human-Fire Interactions: Combining Alternative Perspectives and Approaches

Although it has long been recognised that human activities affect fire regimes, the interactions between humans and fire are complex, imperfectly understood, constantly evolving, and lacking any kind of integrative global framework. Many different approaches are used to study human-fire interactions, but in general they have arisen in different disciplinary contexts to address highly specific questions. Models of human-fire interactions range from conceptual local models to numerical global models. However, given that each type of model is highly selective about which aspects of human-fire interactions to include, the insights gained from these models are often limited and contradictory, which can make them a poor basis for developing fire-related policy and management practices. Here, we first review different approaches to modelling human-fire interactions and then discuss ways in which these different approaches could be synthesised to provide a more holistic approach to understanding human-fire interactions. We argue that the theory underpinning many types of models was developed using only limited amounts of data and that, in an increasingly data-rich world, it is important to re-examine model assumptions in a more systematic way. All of the models are designed to have practical outcomes but are necessarily simplifications of reality and as a result of differences in focus, scale and complexity, frequently yield radically different assessments of what might happen. We argue that it should be possible to combine the strengths and benefits of different types of model through enchaining the different models, for example from global down to local scales or vice versa. There are also opportunities for explicit coupling of different kinds of model, for example including agent-based representation of human actions in a global fire model. Finally, we stress the need for co-production of models to ensure that the resulting products serve the widest possible community

Efficacy of customised foot orthoses in the treatment of achilles tendinopathy : study protocol for a randomised trial

BACKGROUND: Achilles tendinopathy is a common condition that can cause marked pain and disability. Numerous non-surgical treatments have been proposed for the treatment of this condition, but many of these treatments have a poor or non-existent evidence base. The exception to this is eccentric calf muscle exercises, which have become a standard non-surgical intervention for Achilles tendinopathy. Foot orthoses have also been advocated as a treatment for Achilles tendinopathy, but the long-term efficacy of foot orthoses for this condition is unknown. This manuscript describes the design of a randomised trial to evaluate the efficacy of customised foot orthoses to reduce pain and improve function in people with Achilles tendinopathy. METHODS: One hundred and forty community-dwelling men and women aged 18 to 55 years with Achilles tendinopathy (who satisfy inclusion and exclusion criteria) will be recruited. Participants will be randomised, using a computer-generated random number sequence, to either a control group (sham foot orthoses made from compressible ethylene vinyl acetate foam) or an experimental group (customised foot orthoses made from semi-rigid polypropylene). Both groups will be prescribed a calf muscle eccentric exercise program, however, the primary difference between the groups will be that the experimental group receive customised foot orthoses, while the control group receive sham foot orthoses. The participants will be instructed to perform eccentric exercises 2 times per day, 7 days per week, for 12 weeks. The primary outcome measure will be the total score of the Victorian Institute of Sport Assessment - Achilles (VISA-A) questionnaire. The secondary outcome measures will be participant perception of treatment effect, comfort of the foot orthoses, use of co-interventions, frequency and severity of adverse events, level of physical activity and health-related quality of life (assessed using the Short-Form-36 questionnaire - Version two). Data will be collected at baseline, then at 1, 3, 6 and 12 months. Data will be analysed using the intention to treat principle. DISCUSSION: This study is the first randomised trial to evaluate the long-term efficacy of customised foot orthoses for the treatment of Achilles tendinopathy. The study has been pragmatically designed to ensure that the study findings are generalisable to clinical practice. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry Number: ACTRN12609000829213

TANGLE: Two-Level Support Vector Regression Approach for Protein Backbone Torsion Angle Prediction from Primary Sequences

Protein backbone torsion angles (Phi) and (Psi) involve two rotation angles rotating around the Cα-N bond (Phi) and the Cα-C bond (Psi). Due to the planarity of the linked rigid peptide bonds, these two angles can essentially determine the backbone geometry of proteins. Accordingly, the accurate prediction of protein backbone torsion angle from sequence information can assist the prediction of protein structures. In this study, we develop a new approach called TANGLE (Torsion ANGLE predictor) to predict the protein backbone torsion angles from amino acid sequences. TANGLE uses a two-level support vector regression approach to perform real-value torsion angle prediction using a variety of features derived from amino acid sequences, including the evolutionary profiles in the form of position-specific scoring matrices, predicted secondary structure, solvent accessibility and natively disordered region as well as other global sequence features. When evaluated based on a large benchmark dataset of 1,526 non-homologous proteins, the mean absolute errors (MAEs) of the Phi and Psi angle prediction are 27.8° and 44.6°, respectively, which are 1% and 3% respectively lower than that using one of the state-of-the-art prediction tools ANGLOR. Moreover, the prediction of TANGLE is significantly better than a random predictor that was built on the amino acid-specific basis, with the p-value<1.46e-147 and 7.97e-150, respectively by the Wilcoxon signed rank test. As a complementary approach to the current torsion angle prediction algorithms, TANGLE should prove useful in predicting protein structural properties and assisting protein fold recognition by applying the predicted torsion angles as useful restraints. TANGLE is freely accessible at http://sunflower.kuicr.kyoto-u.ac.jp/~sjn/TANGLE/

NetTurnP – Neural Network Prediction of Beta-turns by Use of Evolutionary Information and Predicted Protein Sequence Features

UNLABELLED: β-turns are the most common type of non-repetitive structures, and constitute on average 25% of the amino acids in proteins. The formation of β-turns plays an important role in protein folding, protein stability and molecular recognition processes. In this work we present the neural network method NetTurnP, for prediction of two-class β-turns and prediction of the individual β-turn types, by use of evolutionary information and predicted protein sequence features. It has been evaluated against a commonly used dataset BT426, and achieves a Matthews correlation coefficient of 0.50, which is the highest reported performance on a two-class prediction of β-turn and not-β-turn. Furthermore NetTurnP shows improved performance on some of the specific β-turn types. In the present work, neural network methods have been trained to predict β-turn or not and individual β-turn types from the primary amino acid sequence. The individual β-turn types I, I', II, II', VIII, VIa1, VIa2, VIba and IV have been predicted based on classifications by PROMOTIF, and the two-class prediction of β-turn or not is a superset comprised of all β-turn types. The performance is evaluated using a golden set of non-homologous sequences known as BT426. Our two-class prediction method achieves a performance of: MCC=0.50, Qtotal=82.1%, sensitivity=75.6%, PPV=68.8% and AUC=0.864. We have compared our performance to eleven other prediction methods that obtain Matthews correlation coefficients in the range of 0.17-0.47. For the type specific β-turn predictions, only type I and II can be predicted with reasonable Matthews correlation coefficients, where we obtain performance values of 0.36 and 0.31, respectively. CONCLUSION: The NetTurnP method has been implemented as a webserver, which is freely available at http://www.cbs.dtu.dk/services/NetTurnP/. NetTurnP is the only available webserver that allows submission of multiple sequences

Coordinated parallelizing compiler optimizations and high-level synthesis

We present a high-level synthesis methodology that applies a coordinated set of coarse-grain and fine-grain parallelizing transformations. The transformations are applied both during a presynthesis phase and during scheduling, with the objective of optimizing the results of synthesis and reducing the impact of control flow constructs on the quality of results. We first apply a set of source level presynthesis transformations that include common sub-expression elimination (CSE), copy propagation, dead code elimination and loop-invariant code motion, along with more coarse-level code restructuring transformations such as loop unrolling. We then explore scheduling techniques that use a set of aggressive speculative code motions to maximally parallelize the design by re-ordering, speculating and sometimes even duplicating operations in the design. In particular, we present a new technique called "Dynamic CSE" that dynamically coordinates CSE and code motions such as speculation and conditional speculation during scheduling. We implemented our parallelizing high-level synthesis in the SPARK framework. This framework takes a behavioral description in ANSI-C as input and generates synthesizable register-transfer level VHDL. Our results from computationally expensive portions of three moderately complex design targets, namely, MPEG-1, MPEG-2 and the GIMP image processing too], validate the utility of our approach to the behavioral synthesis of designs with complex control flows