Effect of Central Body Size on the Leading Edge Vortex of a Rotating Insect Wing

The stable attachment of a leading-edge vortex (LEV) is responsible for the high lift observed from insect wings. In experiments, we study the flow structure over a model wing mounted on a central body. The diameter of the central body and the change in Rossby number (Ro) due to placement of the wing root away from the centre can affect the flow structure. Normally, the LEV splits to form dual LEVs in a rotating wing, with the spanwise split location changing with Reynolds number. The results presented here show that the LEV structure is minimally affected by changes in the central body size for a wide range of body sizes

Hybrid dynamic chunk ensemble model for multi-class data streams

In the analysis more specifically in the classification of continuous data stream using machine learning algorithms joint occurrence of concept drift and imbalanced issue becomes more provocative. Also, imbalance issue is again more challenging when the data stream is multi-class with minority class and that is too with data-difficulty factors. Incremental learning with ensemble models found more promising in handling theses issues. But most of the approaches are for two-class data streams which can’t be utilized for multiclass data streams. In this paper we have designed hybrid dynamic chunk ensemble model (HDCEM) for the classification of multi-class insect-data stream for handling imbalance and concept drift issue. To deal with imbalance issue we have proposed effective split bagging algorithm which has achieved better performance on minority class recall and F-measure on arriving dynamic chunks of data from multi-class data stream. HDCEM model can adapt to abrupt and gradual drift because it has combined features of both online and chunk-based learning together. It has achieved average 78% minority class recall in abrupt insect data stream and 71% in gradual drift insect stream

Bounds on the moduli of eigenvalues of rational matrices

A rational matrix is a matrix-valued function $R(\lambda): \mathbb{C} \rightarrow M_p$ such that $R(\lambda) = \begin{bmatrix} r_{ij}(\lambda) \end{bmatrix}_{p\times p}$, where $r_{ij}(\lambda)$ are scalar complex rational functions in $\lambda$ for $i,j=1,2,\ldots,p$. The aim of this paper is to obtain bounds on the moduli of eigenvalues of rational matrices in terms of the moduli of their poles. To a given rational matrix $R(\lambda)$ we associate a block matrix $\mathcal{C}_R$ whose blocks consist of the coefficient matrices of $R(\lambda)$, as well as a scalar real rational function $q(x)$ whose coefficients consist of the norm of the coefficient matrices of $R(\lambda)$. We prove that a zero of $q(x)$ which is greater than the moduli of all the poles of $R(\lambda)$ will be an upper bound on the moduli of eigenvalues of $R(\lambda)$. Moreover, by using a block matrix associated with $q(x)$, we establish bounds on the zeros of $q(x)$, which in turn yields bounds on the moduli of eigenvalues of $R(\lambda)$.Comment: A few grammatical mistakes have been corrected. Two new references have been adde

On coneigenvalues of quaternion matrices: location and perturbation

We derive some localization and perturbation results for coneigenvalues of quaternion matrices. In localization results, we derive Ger\v{s}gorin type theorems for right and left coneigenvalues of quaternion matrices. We prove that certain coneigenvalues lie in the union of Ger\v{s}gorin balls, in contrast to the complex situation where all eigenvalues lie in the union of Ger\v{s}gorin discs. In perturbation results, we derive a result analogous to the Hoffman-Wielandt inequality for basal right coneigenvalues of conjugate normal quaternion matrices. Results analogous to the Bauer-Fike theorem and a generalization of the Hoffman-Wielandt inequality are discussed for basal right coneigenvalues of condiagonalizable quaternion matrices. Finally, we define spectral variation and Hausdorff distance between right (con)eigenvalues of two quaternion matrices and obtain bounds on them.Comment: We have added two examples to illustrate theorems. An error in the statement of a theorem is corrected. Grammatical errors are correcte

Hoffman-Wielandt type inequality for block companion matrices of certain matrix polynomials

Matrix polynomials with unitary/doubly stochastic coefficients form the subject matter of this manuscript. We prove that if $P(\lambda)$ is a quadratic matrix polynomial whose coefficients are either unitary matrices or doubly stochastic matrices, then under certain conditions on these coefficients, the corresponding block companion matrix $C$ is diagonalizable. Consequently, if $Q(\lambda)$ is another quadratic matrix polynomial with corresponding block companion matrix $D$, then a Hoffman-Wielandt type inequality holds for the block companion matrices $C$ and $D$. Condiagonalizability of the block companion matrix of a matrix polynomial and a Hoffman-Wielandt type inequality involving coneigenvalues are also discussed.Comment: Title of the manuscript has been changed. Few more examples are added wherever necessar

Eigenvalue location of certain matrix polynomials

It is known that a matrix polynomial with unitary matrix coefficients has its eigenvalues in the annular region $\frac{1}{2} < |\lambda| < 2$. We prove in this short note that under certain assumptions, matrix polynomials with either doubly stochastic matrix coefficients or Schur stable matrix coefficients also have eigenvalues in similar annular regions

The Hoffman-Wielandt (type) inequality for quaternion matrices and quaternion matrix polynomials

The purpose of this manuscript is to derive the Hoffman-Wielandt inequality and its most general form for quaternion matrices. Diagonalizabilty of the block companion matrix of certain quadratic (linear) quaternion matrix polynomials is brought out. As a consequence, we prove that if $Q(\lambda)$ is another quadratic (linear) quaternion matrix polynomial, then the Hoffman-Wielandt type inequality for their corresponding block companion matrices holds

Impact of Immersion Cooling on Thermo-Mechanical Properties of PCB\u27s and Reliability of Electronic Packages

Immersion cooling technique is used for the thermal management of high-density data centers to avoid overheating of components and failure of servers. However, to use this as a viable cooling technique, the effect of dielectric coolants on the reliability of server components needs to be evaluated. Previous work reported contradicting findings for Young’s modulus of PCBs, providing motivation for this work. This study focuses on effect of immersion cooling on the thermos-mechanical properties of printed circuit board (PCB) and its impact on reliability of electronic packages. Changes in thermo-mechanical properties like Young’s modulus (E), Glass transition temperature (Tg), Coefficient of thermal expansion (CTE) of PCB and its layers due to aging in dielectric coolant are studied. Two types of PCBs using different material namely 370HR and 185HR are studied. To characterize Young’s modulus, Tg and CTE, dynamic mechanical analyzer (DMA) and Thermo-mechanical Analyzer (TMA) is used. Major finding is Young’s modulus and CTE is decreasing for PCBs after immersion in dielectric coolant which is likely to increase reliability of electronics package

Area Under Curve by UV Spectrophotometric Method for Determination Albendazole in Bulk

The aim of present investigation is to establish simple, precise, and rapid Spectrophotometric method for the quantification of Albendazole in Active Pharmaceutical Ingredient. In this, work is carried out to for estimation of Albendazole bulk by utilizing an Area under Curve (AUC) method using UV – Visible Spectrophotometry. The study is designed to validate the developed methods as per ICH guidelines. For this purpose the wavelength range between 200-400 nm was selected. Methanolic distilled water (50 ml methanol used for stock solution and serial dilution in 25 ml distilled water) was used as a solvent throughout the work. Linearity was obtained in concentration range 2 to 10 ɥg/ml (r2 = 0.992) for the method. The developed method was found to be simple, linear, accurate, precise and highly sensitive and which can be used for routine quality control analysis for Spectrophotometric estimation of Active Pharmaceutical Ingredient. KeywordS: Albendazole, linearity, AUC, spectrophotometer, methanol, distilled water