Granularity measures and complexity measures of partition-based granular structures

The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.knosys.2018.10.015 © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/Granular computing is an emerging field of study in which the complexity of problem solving is reduced through granulation. Researchers have proposed various granularity measures of partitions to quantify the effects of granulation with respect to simplification. However, two important issues still remain and require careful investigation. The first issue is that a partition is only a simple two-level granular structure, which may not be sufficient for the full scope of granular computing. The second issue is a clarification of the differences between granularity and complexity. Although they are related to each other, they represent different things. To address the two issues, this paper makes three contributions. First, we extend the partition granulation scheme into multilevel granular structures based on progressive partitioning. Second, we propose a complexity measure of a partition that incorporates both the block-level interactions (interactions within a block) and the partition-level interactions (interactions between blocks of the partition). Third, we generalize the complexity measure to multilevel granular structures generated from a progressive partitioning process

Thermoacoustic Instabilities in Counterflow Diffusion Flames

Thermoacoustic instabilities arise in combustion systems from a coupling between the unsteady heat release of the flame and the underlying acoustic field. Although thermoacoustics have been studied extensively with regards to premixed flames, where the fuel and oxidizer are fully mixed before combustion, the study of thermoacoustics in diffusion flames is much more limited. However, thermoacoustic instabilities are also of interest for the design of systems which are better characterized by diffusion or nonpremixed flames, for example, liquid rocket engines. As such, this thesis aims to investigate, using an in-house developed combustion solver, the behaviour of thermoacoustic fluctuations in a diffusion flame. The thermoacoustics are studied in the counterflow diffusion flame configuration, where the flame exists between two opposed jets containing the fuel and oxidizer respectively. An unsteady compressible reactive flow solver is integrated into an in-house code. The code is then coupled to Cantera to obtain the transport and thermodynamic properties. Finally, to study the thermoacoustics, time-dependent Navier-Stokes Characteristic Boundary Conditions are implemented in the code to account for fully reflecting, partially reflecting, and nonreflecting boundary conditions. The code is validated against the steady solution obtained from Cantera. The flame under consideration consists of \chem{H_2} as the fuel and a mixture of \chem{O_2} and \chem{N_2} as the oxidizer. Two different strain rates are studied. Under the assumption of perfectly reflecting boundary conditions, the growth of the acoustic perturbations in the high strain rate case is much more significant than the low strain rate case. Under the partially reflecting boundary conditions, the high strain rate case also exhibits some slight growth of the acoustic perturbations. An underlying standing wave behaviour can be identified and the dominants modes extracted through a spectral analysis. For further investigation, a number of forced sinusoidal pulses were introduced into the fuel stream, and the response was measured via Rayleigh's criterion. The results show that the acoustic fluctuations are amplified for a larger range of frequencies in the high strain rate case compared to the low strain rate case, which helps to explain why the acoustic growth in the high strain rate case is much more significant

Locally-Adaptive Tabulation of Low-Dimensional Manifolds using Bezier Patch Reconstruction

An efficient tabulation strategy for turbulent combustion simulations is proposed. Using a locally adaptive arrangement of structured Bezier patches–often used in computer graphics–the combustion manifold can be efficiently tabulated; thus reducing the table size by over an order of magnitude while maintaining high accuracy. A hybrid search algorithm is implemented that uses a one-step quadrant analysis followed by a linear search to minimize the cost of the data retrieval. The present tabulation has been successfully applied to flamelet/progress variable approach (FPVA) and trajectory generated low-dimensional manifold (TGLDM). The error, computational size and search-and-retrieval time are quantified and compared against classical tabulation approaches.NSERC USRA NSERC RGPI

The Endogenous Th17 Response in NO<inf>2</inf>-Promoted Allergic Airway Disease Is Dispensable for Airway Hyperresponsiveness and Distinct from Th17 Adoptive Transfer

Severe, glucocorticoid-resistant asthma comprises 5-7% of patients with asthma. IL-17 is a biomarker of severe asthma, and the adoptive transfer of Th17 cells in mice is sufficient to induce glucocorticoid-resistant allergic airway disease. Nitrogen dioxide (NO2) is an environmental toxin that correlates with asthma severity, exacerbation, and risk of adverse outcomes. Mice that are allergically sensitized to the antigen ovalbumin by exposure to NO2 exhibit a mixed Th2/Th17 adaptive immune response and eosinophil and neutrophil recruitment to the airway following antigen challenge, a phenotype reminiscent of severe clinical asthma. Because IL-1 receptor (IL-1R) signaling is critical in the generation of the Th17 response in vivo, we hypothesized that the IL-1R/Th17 axis contributes to pulmonary inflammation and airway hyperresponsiveness (AHR) in NO2-promoted allergic airway disease and manifests in glucocorticoid-resistant cytokine production. IL-17A neutralization at the time of antigen challenge or genetic deficiency in IL-1R resulted in decreased neutrophil recruitment to the airway following antigen challenge but did not protect against the development of AHR. Instead, IL-1R-/- mice developed exacerbated AHR compared to WT mice. Lung cells from NO2-allergically inflamed mice that were treated in vitro with dexamethasone (Dex) during antigen restimulation exhibited reduced Th17 cytokine production, whereas Th17 cytokine production by lung cells from recipient mice of in vitro Th17-polarized OTII T-cells was resistant to Dex. These results demonstrate that the IL-1R/Th17 axis does not contribute to AHR development in NO2-promoted allergic airway disease, that Th17 adoptive transfer does not necessarily reflect an endogenously-generated Th17 response, and that functions of Th17 responses are contingent on the experimental conditions in which they are generated. © 2013 Martin et al

A comparison of phase imaging and quantitative susceptibility mapping in the imaging of multiple sclerosis lesions at ultrahigh field

Objective The aim of this study was to compare the use of high-resolution phase and QSM images acquired at ultra-high field in the investigation of multiple sclerosis (MS) lesions with peripheral rings, and to discuss their usefulness for drawing inferences about underlying tissue composition. Materials and methods Thirty-nine Subjects were scanned at 7 T, using 3D T2*-weighted and T1-weighted sequences. Phase images were then unwrapped and filtered, and quantitative susceptibility maps were generated using a thresholded k-space division method. Lesions were compared visually and using a 1D profiling algorithm. Results Lesions displaying peripheral rings in the phase images were identified in 10 of the 39 subjects. Dipolar projections were apparent in the phase images outside of the extent of several of these lesions; however, QSM images showed peripheral rings without such projections. These projections appeared ring-like in a small number of phase images where no ring was observed in QSM. 1D profiles of six well-isolated example lesions showed that QSM contrast corresponds more closely to the magnitude images than phase contrast. Conclusions Phase images contain dipolar projections, which confounds their use in the investigation of tissue composition in MS lesions. Quantitative susceptibility maps correct these projections, providing insight into the composition of MS lesions showing peripheral rings

A novel two-score system for interferon status segregates autoimmune diseases and correlates with clinical features

Measurement of type I interferon (IFN-I) has potential to diagnose and stratify autoimmune diseases, but existing results have been inconsistent. Interferon-stimulated-gene (ISG) based methods may be afected by the modularity of the ISG transcriptome, cell-specifc expression, response to IFN-subtypes and bimodality of expression. We developed and clinically validated a 2-score system (IFN-Score-A and -B) using Factor Analysis of 31 ISGs measured by TaqMan selected from 3-IFN-annotated modules. We evaluated these scores using in-vitro IFN stimulation as well as in sorted cells then clinically validated in a cohort of 328 autoimmune disease patients and healthy controls. ISGs varied in response to IFNsubtypes and both scores varied between cell subsets. IFN-Score-A diferentiated Systemic Lupus Erythematosus (SLE) from both Rheumatoid Arthritis (RA) and Healthy Controls (HC) (both p<0.001), while IFN-Score-B diferentiated SLE and RA from HC (both p<0.001). In SLE, both scores were associated with cutaneous and hematological (all p<0.05) but not musculoskeletal disease activity. Comparing with bimodal (IFN-high/low) classifcation, signifcant diferences in IFN-scores were found between diagnostic groups within the IFN-high group. Our continuous 2-score system is more clinically relevant than a simple bimodal classifcation of IFN status. This system should allow improvement in diagnosis, stratifcation, and therapy in IFN-mediated autoimmunity

KELT-24b: A 5M_J Planet on a 5.6 day Well-Aligned Orbit around the Young V=8.3 F-star HD 93148

We present the discovery of KELT-24 b, a massive hot Jupiter orbiting a bright (V=8.3 mag, K=7.2 mag) young F-star with a period of 5.6 days. The host star, KELT-24 (HD 93148), has a T_(eff) =6508±49 K, a mass of M∗ = 1.461^(+0.056)_(−0.060) M_⊙, radius of R∗ = 1.506±0.022 R_⊙, and an age of 0.77^(+0.61)_(−0.42) Gyr. Its planetary companion (KELT-24 b) has a radius of R_P = 1.272^(+0.021)_(−0.022) R_J, a mass of MP = 5.18^(+0.21)_(−0.22) M_J, and from Doppler tomographic observations, we find that the planet's orbit is well-aligned to its host star's projected spin axis (λ = 2.6^(+5.1)_(−3.6)). The young age estimated for KELT-24 suggests that it only recently started to evolve from the zero-age main sequence. KELT-24 is the brightest star known to host a transiting giant planet with a period between 5 and 10 days. Although the circularization timescale is much longer than the age of the system, we do not detect a large eccentricity or significant misalignment that is expected from dynamical migration. The brightness of its host star and its moderate surface gravity make KELT-24b an intriguing target for detailed atmospheric characterization through spectroscopic emission measurements since it would bridge the current literature results that have primarily focused on lower mass hot Jupiters and a few brown dwarfs