On the minimum of a positive polynomial over the standard simplex

We present a new positive lower bound for the minimum value taken by a polynomial P$P$ with integer coefficients in k$k$ variables over the standard simplex of R^k${\mathbb{R}}^k$, assuming that P$P$ is positive on the simplex. This bound depends only on the number of variables k$k$, the degree d$d$ and the bitsize τ$\tau$ of the coefficients of P$P$ and improves all the previous bounds for arbitrary polynomials which are positive over the simplex.     

The electro-structural behaviour of yarn-like carbon nanotube fibres immersed in organic liquids

Yarn-like carbon nanotube (CNT) fibres are a hierarchically-structured material with a variety of promising applications such as high performance composites, sensors and actuators, smart textiles, and energy storage and transmission. However, in order to fully realize these possibilities, a more detailed understanding of their interactions with the environment is required. In this work, we describe a simplified representation of the hierarchical structure of the fibres from which several mathematical models are constructed to explain electro-structural interactions of fibres with organic liquids. A balance between the elastic and surface energies of the CNT bundle network in different media allows the determination of the maximum lengths that open junctions can sustain before collapsing to minimize the surface energy. This characteristic length correlates well with the increase of fibre resistance upon immersion in organic liquids. We also study the effect of charge accumulation in open interbundle junctions and derive expressions to describe experimental data on the non-ohmic electrical behaviour of fibres immersed in polar liquids. Our analyses suggest that the non-ohmic behaviour is caused by progressively shorter junctions collapsing as the voltage is increased. Since our models are not based on any property unique to carbon nanotubes, they should also be useful to describe other hierarchical structures.     

An Analysis of Blockchain and GDPR under the Data Lifecycle Perspective

Mobile Networks and Applications - The purpose of this article is to present an analysis of the privacy principles of personal data prescribed in the General Data Protection Regulation and the...     

A geometric index reduction method for implicit systems of differential algebraic equations

This paper deals with the index reduction problem for the class of quasi-regular DAE systems. It is shown that any of these systems can be transformed to a generically equivalent first order DAE system consisting of a single purely algebraic (polynomial) equation plus an under-determined ODE (a differential Kronecker representation) in as many variables as the order of the input system. This can be done by means of a Kronecker-type algorithm with bounded complexity.     

Component-based waveform development: the Nucleus tool flow for efficient and portable software defined radio

With the advent of multi-processor systems on chip (MPSoCs) and due to the complexity and variety of modern wireless standards, academia and industry are moving towards software defined radio (SDR) solutions. It is the goal of the SDR approach to allow designers to describe a radio standard or waveform by means of a high level language. This allows faster waveform development cycles and makes it easier to migrate waveforms across different platforms. Out of many software paradigms, component-based software engineering (CBSE) is an attractive match for SDR, especially for baseband applications. It abstracts waveforms in the traditional way algorithm designers think of their applications and guarantees a high degree of portability. However, existing CBSE approaches for SDR have not been able to close the gap between specification and implementation so as to achieve the computational performance and the energy efficiency of handcrafted solutions. The main reason for this gap is that these flows rely on traditional compilers to lower the high level specification to the platform. The work presented in this paper builds on the Nucleus Concept (Ramakrishnan et al., IEEE Military Communications Conference (MILCOM 2009) [28]) in which computationally intensive kernels and their implementation characteristics on the target platform are known. This information allows a tool to close the performance gap, and thus enables efficient component-based SDR development. In this paper we present such a flow and its supporting environment, which includes state-of-the-art tools for system level design. The flow is demonstrated on a MIMO OFDM transceiver.     

Rational formulas for traces in zero-dimensional algebras

We present a rational expression for the trace of the multiplication map Times _r : A → A in a finite-dimensional algebra ${A := \mathbb {K}[x_1,\ldots,x_n] /\mathcal {I}}$ in terms of the generalized Chow form of ${\mathcal{I}}$ . Here, ${\mathcal{I} \subset \mathbb {K}[x_1,\ldots,x_n]}$ is a zero-dimensional ideal, ${\mathbb {K}}$ is a field of characteristic zero, and r(x ₁,..., x _n ) a rational function whose denominator is not a zero divisor in A. If ${\mathcal {I}}$ is a complete intersection in the torus, we get numerator and denominator formulas for traces in terms of sparse resultants.     

Immunophenotypic,immunocytochemistry, ultrastructural,and cytogenetic characterization of mesenchymal stem cells from equine bone marrow

The aim of this study was to isolate, culture, and characterize mesenchymal stem cells (MSCs) from horse bone marrow (BM) using the techniques of flow cytometry, immunocytochemistry, cytogenetics, and electron microscopy. Immunophenotypic analysis revealed the presence of MSCs with high expression of the CD90 marker, lower expression of the CD44 marker, and absent expression of the CD34 marker. In assays of differentiation, the positive response to osteogenic (OST), chondrogenic (CDG), and adipogenic (ADP) differentiation signals was observed and characterized by deposition of calcium‐rich extracellular matrix (OST), proteoglycans and collagen II (CDG) and intracellular deposition of fat drops (ADP). In immunocytochemical characterization, MSCs were immunopositive for CD44, vimentin, and PCNA, and they were negative for CD13. In the ultrastructural analysis of MSCs, the most outstanding characteristic was the presence of rough endoplasmic reticulum with very dilated cisterns filled with a low electrodensity material. Additionally, MSCs had normal karyotypes (2n = 64) as evidenced by cytogenetic analysis, and aneuploidy in metaphase was not observed. The protocols for isolating, culturing, and characterizing equine MSCs used in this study were shown to be appropriate for the production of a cell population with a good potential for differentiation and without aneuploidy that can be used to study future cellular therapies. Microsc. Res. Tech. 76:618–624, 2013. © 2013 Wiley Periodicals, Inc.     

ECRH for JET: A feasibility study

For JET to fulfil its mission in preparing ITER operation, the installation of an electron cyclotron resonance heating system on JET would be desirable. The study described in this paper has investigated the feasibility of installing such a system on JET. The principal goals of such a system are: current drive over a range of radii for NTM stabilization, sawtooth control and current profile tailoring and central electron heating to equilibrate electron and ion temperatures in high performance discharges. The study concluded that a 12 gyrotron, 10 MW, system at the ITER frequency (170 GHz) adapted for fields of 2.7–3.3 T would be appropriate for the operation planned in JET. An antenna allowing toroidal and poloidal steering over a wide range is being designed, using the ITER upper launcher steering mechanism. The use of ITER diamond windows and transmission line technology is suggested while power supply solutions partially reusing existing JET power supplies are proposed. Detailed planning shows that such a system can be operational in about 5 years from the time that the decision to proceed is taken. The cost and required manpower associated with implementing such a system on JET has also been estimated.