Calibration Analysis of High-G MEMS Accelerometer Sensor Based on Wavelet and Wavelet Packet Denoising

High-G accelerometers are mainly used for motion measurement in some special fields, such as projectile penetration and aerospace equipment. This paper mainly explores the wavelet threshold denoising and wavelet packet threshold denoising in wavelet analysis, which is more suitable for high-G piezoresistive accelerometers. In this paper, adaptive decomposition and Shannon entropy criterion are used to find the optimal decomposition layer and optimal tree. Both methods use the Stein unbiased likelihood estimation method for soft threshold denoising. Through numerical simulation and Machete hammer test, the wavelet threshold denoising is more suitable for the dynamic calibration of a high-G accelerometer. The wavelet packet threshold denoising is more suitable for the parameter extraction of the oscillation phase.

Current strategic limitations of phylogenetic tools badly impact the inference of an evolutionary tree

For drawing an evolutionary relationship among several protein sequences, the phylogenetic tree is usually constructed through maximum likelihood-based algorithms. To improve the accuracy of these methodologies, many parameters like bootstrap methods, correlation coefficient and residue-substitution models are presumably over-ranked to derive biologically credible relationships. Although the accuracy of protein sequence alignment and the substitution matrix are preliminary constraints to define the biological accuracy of the overlapped sequences/residues, the alignment is not iteratively optimized through the statistical testing of residue-substitution models. The study majorly highlights the potential pitfalls that significantly affect the accuracy of an evolutionary protocol. It emphasizes the need for a more accurate scrutiny of the entire phylogenetic methodology. The need of iterative optimizations is illustrated to construct a biologically credible and not mathematically optimal tree for a sequence dataset.

The Roles of Protein Structure, Taxon Sampling, and Model Complexity in Phylogenomics: A Case Study Focused on Early Animal Divergences

Despite the long history of using protein sequences to infer the tree of life the potential for different parts of protein structures to retain historical signal remains unclear. We propose that it might be possible to improve analyses of phylogenomic datasets by incorporating information about protein structure; we test this idea using the position of the root of Metazoa (animals) as a model system. We examined the distribution of “strongly decisive” sites (alignment positions that support a specific tree topology) in a dataset comprising >1,500 proteins and almost 100 taxa. The proportion of each class of strongly decisive sites in different structural environments was very sensitive to the model used to analyze the data when a limited number of taxa were used but they were stable when taxa were added. As long as enough taxa were analyzed, sites in all structural environments supported the same topology (ctenophores sister to other animals) regardless of whether standard tree searches or decisive sites were used to select the optimal tree. However, the use of decisive sites revealed a difference between the support for minority topologies for sites in different structural environments; buried sites and sites in sheet and coil environments exhibited equal support for the minority topologies whereas solvent exposed and helix sites had unequal numbers of sites supporting the minority topologies. Given the plausible trees equal support for minority topologies is consistent with discordance among gene trees, making it possible the relatively slowly evolving buried (and sheet and coil) sites are giving an accurate picture of the true species tree as well as the amount of conflict among gene trees. Alternatively, the apparent support could reflect currently uncharacterized processes of molecular evolution. Regardless, it is clear that analyses of the deepest branches in the animal tree of life using sites in different structural environments are associated with a subtle data type effect that results in distinct phylogenetic signals.

FPGA Realization of the Reconfigurable Mesh Counting Algorithm

Pass transistor logic (PTL) is a circuit design technique wherein transistors are used as switches. The reconfigurable mesh (RM) is a model that exploits the power of PTLs signal switching, by enabling flexible bus connections in a grid of processing elements containing switches. RM algorithms have theoretical results proving that [Formula: see text] can speed up computations significantly. However, the RM assumes that the latency of broadcasting a signal through [Formula: see text] switches (bus length) is 1. This is an unrealistic assumption preventing physical realizations of the RM. We propose the restricted-RM (RRM) wherein the bus lengths are restricted to [Formula: see text], [Formula: see text]. We show that counting the number of 1-bits in an input of [Formula: see text] bits can be done in [Formula: see text] steps for [Formula: see text] by an [Formula: see text] RRM. An almost matching lower bound is presented, using a technique which adds to the few existing lower-bound techniques in this area. Finally, the algorithm was directly coded over an FPGA, outperforming an optimal tree of adders. This work presents an alternative way of counting, which is fundamental for summing, beating regular Boolean circuits for large numbers, where summing a vast amount of numbers is the basis of any accelerator in embedded systems such as neural-nets and streaming. a

Identification of transparent, compressed and encrypted data in network traffic

The article is dedicated to the problem of classifying network traffic into three categories: transparent, compressed and opaque, preferably in real-time. It begins with the description of the areas where this problem needs to be solved, then proceeds to the existing solutions with their methods, advantages and limitations. As most of the current research is done either in the area of separating traffic into transparent and opaque or into compressed and encrypted, the need arises to combine a subset of existing methods to unite these two problems into one. As later the main mathematical ideas and suggestions that lie behind the ideas used in the research done by other scientists are described, the list of the best performing of them is composed to be combined together and used as the features for the random forest classificator, which will divide the provided traffic into three classes. The best performing of these features are used, the optimal tree parameters are chosen and, what’s more, the initial three class classifier is divided into two sequential ones to save time needed for classifying in case of transparent packets. Then comes the proposition of the new method to classify the whole network flow as one into one of those three classes, the validity of which is confirmed on several examples of the protocols most specific in this area (SSH, SSL). The article concludes with the directions in which this research is to be continued, mostly optimizing it for real-time classification and obtaining more samples of traffic suitable for experiments and demonstrations.

Xenacoelomorpha flatworms are basal Deuterostome

Background: Whether position Xenacoelomorpha as an early branch of Bilateria (Protostomes + Deuterostomes) has been intensely debated during last several decades. Considering Darwin’s “tree of life”, with the “Phylogenetic Species Concept”, we choose mitochondrial genome as the subject to predict phylogenetic position of Xenacoelomorpha, by genes genealogy. Results: Herein, we sequence Heterochaerus australis’s mitochondrial genome and infer intrinsic relationships of Metazoan with Xenacoelomorpha. The optimal tree under the popular maximum likelihood (ML) and Bayesian phylogenetic reconstructions are consensus with each other being strongly supported. The relationship between Chordates, Ambulacrarians and Xenoturbella/Acoelomorph is resolved. To avoid previous query about alignment process, the datasets are alignmented and trimmed automatically. Reducing taxon or cutting outgroups can not affect the relationship between Xenacoelomorpha and other Metazoan. Meanwhile, analysis using CAT model and Dayhoff groups also supporting the prediction made by mtZOA, relaxing the restriction of alignment criteria ( MAFFT, strategy G–ins–1, BLOSUM 62, 45, 30 ) introducing potential misleading signals can not challenge the tree topology indicating our auto-alignmented mitochondrial dataset is not artificially restricted one. Conclusions: Finally, a repeatable prediction of the genes genealogy with reliable statistical support places Xenacoelomorpha as a basal Deuterostome.