Multivariate Hyper-Rotated GARCH-BEKK

For large multivariate models of generalized autoregressive conditional heteroskedasticity (GARCH), it is important to reduce the number of parameters to cope with the ‘curse of dimensionality’. Recently, Laurent, Rombouts and Violante (2014 “Multivariate Rotated ARCH Models” Journal of Econometrics 179: 16–30) developed the rotated multivariate GARCH model, which focuses on the parameters for standardized variables. This paper extends the rotated multivariate GARCH model by considering a hyper-rotation, which uses a more flexible structure for the rotation matrix. The paper shows an alternative representation based on a random coefficient vector autoregressive and moving-average (VARMA) process, and provides the regularity conditions for the consistency and asymptotic normality of the quasi-maximum likelihood (QML) estimator for VARMA with hyper-rotated multivariate GARCH. The paper investigates the finite sample properties of the QML estimator for the new model. Empirical results for four exchange rate returns show the new specifications works satisfactory for reducing the number of parameters.

Advanced fluid models for resonant online oil condition monitoring systems

Two main topics are presented in this work which enable more efficient use of oil condition monitoring systems based on resonant fluid sensing. A new fluid model for a recently introduced compact measurement unit for oil condition monitoring based on simultaneous measurement of viscosity and density is discussed. It is shown that a new fluid model allows achieving higher accuracies, which is demonstrated by comparison to earlier models. The second topic deals with measuring fluid parameters over varying temperatures and thus providing additional monitoring parameters and enhanced data consistency. We propose an alternative representation of the Vogel model using transformed parameters having a clear physical meaning and which are more stable in presence of measurement noise.

Methodology of determining of the transfer function of engagement kinematics of accelerations of an aircraft and its elliptic coordinates in alternative representation

In this work, simplified expressions have been obtained that describe the kinematics parameters of the aircraft movement and its accelerations. These expressions are needed to obtain an optimal linear control law in order to provide movement of the aircraft using the hyperbola guidance method with a time difference of arrival navigation system. The key feature of the hyperbola navigation method is the ability to reduce the number of navigation positions by one when the on-board navigation equipment operates in a passive mode, carrying out only the reception of navigation information, like consumers of satellite navigation information.

Using Non-Additive Entropy to Enhance Convolutional Neural Features for Texture Recognition

Here we present a study on the use of non-additive entropy to improve the performance of convolutional neural networks for texture description. More precisely, we introduce the use of a local transform that associates each pixel with a measure of local entropy and use such alternative representation as the input to a pretrained convolutional network that performs feature extraction. We compare the performance of our approach in texture recognition over well-established benchmark databases and on a practical task of identifying Brazilian plant species based on the scanned image of the leaf surface. In both cases, our method achieved interesting performance, outperforming several methods from the state-of-the-art in texture analysis. Among the interesting results we have an accuracy of 84.4% in the classification of KTH-TIPS-2b database and 77.7% in FMD. In the identification of plant species we also achieve a promising accuracy of 88.5%. Considering the challenges posed by these tasks and results of other approaches in the literature, our method managed to demonstrate the potential of computing deep learning features over an entropy representation.

Uncertainty modelling and computational aspects of data association

A novel solution to the smoothing problem for multi-object dynamical systems is proposed and evaluated. The systems of interest contain an unknown and varying number of dynamical objects that are partially observed under noisy and corrupted observations. In order to account for the lack of information about the different aspects of this type of complex system, an alternative representation of uncertainty based on possibility theory is considered. It is shown how analogues of usual concepts such as Markov chains and hidden Markov models (HMMs) can be introduced in this context. In particular, the considered statistical model for multiple dynamical objects can be formulated as a hierarchical model consisting of conditionally independent HMMs. This structure is leveraged to propose an efficient method in the context of Markov chain Monte Carlo (MCMC) by relying on an approximate solution to the corresponding filtering problem, in a similar fashion to particle MCMC. This approach is shown to outperform existing algorithms in a range of scenarios.

Taxallnomy: an extension of NCBI Taxonomy that produces a hierarchically complete taxonomic tree

Background NCBI Taxonomy is the main taxonomic source for several bioinformatics tools and databases since all organisms with sequence accessions deposited on INSDC are organized in its hierarchical structure. Despite the extensive use and application of this data source, an alternative representation of data as a table would facilitate the use of information for processing bioinformatics data. To do so, since some taxonomic-ranks are missing in some lineages, an algorithm might propose provisional names for all taxonomic-ranks. Results To address this issue, we developed an algorithm that takes the tree structure from NCBI Taxonomy and generates a hierarchically complete taxonomic table, maintaining its compatibility with the original tree. The procedures performed by the algorithm consist of attempting to assign a taxonomic-rank to an existing clade or “no rank” node when possible, using its name as part of the created taxonomic-rank name (e.g. Ord_Ornithischia) or interpolating parent nodes when needed (e.g. Cla_of_Ornithischia), both examples given for the dinosaur Brachylophosaurus lineage. The new hierarchical structure was named Taxallnomy because it contains names for all taxonomic-ranks, and it contains 41 hierarchical levels corresponding to the 41 taxonomic-ranks currently found in the NCBI Taxonomy database. From Taxallnomy, users can obtain the complete taxonomic lineage with 41 nodes of all taxa available in the NCBI Taxonomy database, without any hazard to the original tree information. In this work, we demonstrate its applicability by embedding taxonomic information of a specified rank into a phylogenetic tree and by producing metagenomics profiles. Conclusion Taxallnomy applies to any bioinformatics analyses that depend on the information from NCBI Taxonomy. Taxallnomy is updated periodically but with a distributed PERL script users can generate it locally using NCBI Taxonomy as input. All Taxallnomy resources are available at http://bioinfo.icb.ufmg.br/taxallnomy.

“We were at this crossroads”

People and societies are guided by what they imagine to lie beyond the present, by what can and should be the case in the future. Yet people do not always agree about the form, content or path to realisation of a given imagined future. As a result, conflicts can arise over something that does not exist yet. In this paper, I propose to integrate theories of social and alternative representations with a sociocultural psychological interpretation of imagination, in order to explore the addressivity of futures and to call for more studies that explicitly take into account the future’s role in the present. I draw on a dialogical case study that was carried out on the Faroe Islands, more precisely on the island of Suðuroy. Whereas the Faroe Islands are experiencing a rapid acceleration in growth, Suðuroy has failed to keep pace and has witnessed decades of emigration and a worsening of its population’s relative socio-economic situation. Islanders liken the current situation to standing at a crossroads, while being unable to agree on which path must be taken in order to reinvigorate a shrinking future. By analysing how one of the two major social representations constructs the other – its alternative representation – I suggest that the absence of transformative dialogue results from incompatible futures. Furthermore, in line with a sociocultural psychological perspective, I also attempt to move beyond the homogenising force inherent in social representation theory by introducing Ingolf and Karin, whose stories illustrate how social and alternative representations are not uniformly shared and enacted, but take different forms in light of unique life experiences.

Making my bed : Tracey Emin's hysterical confessions of the abject

Tracey Emin's My Bed (1998) presents an alternative representation to normative notions of the body, offending hegemonic propriety so greatly that it caused a tabloid media sensation when it was shortlisted for the 1999 Turner Prize. Emin applies certain feminist notions as she continues the motif of the reclining nude, offering semiotic gestures that indicate evidence of the body rather that the body itself. My Bed is the site of trauma and disgust, with all of the abjection left intact, and above all, a self expressionist piece documenting her personal trauma. The expressionist qualities harkens back to cultural discourse of hysteria, reinforcing the legitimacy of the feminist lens. Hysteria is a performance that Emin represents through confessing her traumatic history. Like the archetypal reality television star, she confesses personal emotions and histories, but breaks the status quo by offering an alternative representation with the abjected authenticity of the bed.

Making my bed : Tracey Emin's hysterical confessions of the abject

Tracey Emin's My Bed (1998) presents an alternative representation to normative notions of the body, offending hegemonic propriety so greatly that it caused a tabloid media sensation when it was shortlisted for the 1999 Turner Prize. Emin applies certain feminist notions as she continues the motif of the reclining nude, offering semiotic gestures that indicate evidence of the body rather that the body itself. My Bed is the site of trauma and disgust, with all of the abjection left intact, and above all, a self expressionist piece documenting her personal trauma. The expressionist qualities harkens back to cultural discourse of hysteria, reinforcing the legitimacy of the feminist lens. Hysteria is a performance that Emin represents through confessing her traumatic history. Like the archetypal reality television star, she confesses personal emotions and histories, but breaks the status quo by offering an alternative representation with the abjected authenticity of the bed.