An efficient hardware architecture for a neural network activation function generator

This paper proposes an efficient hardware architecture for a function generator suitable for an artificial neural network (ANN). A spline-based approximation function is designed that provides a good trade-off between accuracy and silicon area, whilst also being inherently scalable and adaptable for numerous activation functions. This has been achieved by using a minimax polynomial and through optimal placement of the approximating polynomials based on the results of a genetic algorithm. The approximation error of the proposed method compares favourably to all related research in this field. Efficient hardware multiplication circuitry is used in the implementation, which reduces the area overhead and increases the throughput

A splitting theorem for Kahler manifolds whose Ricci tensors have constant eigenvalues

It is proved that a compact Kahler manifold whose Ricci tensor has two distinct, constant, non-negative eigenvalues is locally the product of two Kahler-Einstein manifolds. A stronger result is established for the case of Kahler surfaces. Irreducible Kahler manifolds with two distinct, constant eigenvalues of the Ricci tensor are shown to exist in various situations: there are homogeneous examples of any complex dimension n > 1, if one eigenvalue is negative and the other positive or zero, and of any complex dimension n > 2, if the both eigenvalues are negative; there are non-homogeneous examples of complex dimension 2, if one of the eigenvalues is zero. The problem of existence of Kahler metrics whose Ricci tensor has two distinct, constant eigenvalues is related to the celebrated (still open) Goldberg conjecture. Consequently, the irreducible homogeneous examples with negative eigenvalues give rise to complete, Einstein, strictly almost Kahler metrics of any even real dimension greater than 4.Comment: 18 pages; final version; accepted for publication in International Journal of Mathematic

Biomimetic Planar Polymer Membranes Decorated with Enzymes as Functional Surfaces

Functional surfaces were generated by a combination of enzymes with polymer membranes composed of an amphiphilic, asymmetric block copolymer poly(ethyleneglycol)-block-poly(γ-methyl-ε-caprolactone)-block-poly[(2-dimethylamino)ethylmethacrylate]. First, polymer films formed at the air–water interface were transferred in different sequences onto silica solid support using the Langmuir–Blodgett technique, generating homogeneous monolayers and bilayers. A detailed characterization of these films provided insight into their properties (film thickness, wettability, topography, and roughness). On the basis of these findings, the most promising membranes were selected for enzyme attachment. Functional surfaces were then generated by the adsorption of two model enzymes that can convert phenol and its derivatives (laccase and tyrosinase), well known as high-risk pollutants of drinking and natural water. Both enzymes preserved their activity upon immobilization with respect to their substrates. Depending on the properties of the polymer films, different degrees of enzymatic activity were observed: bilayers provided the best conditions in terms of both overall stability and enzymatic activity. The interaction between amphiphilic triblock copolymer films and enzymes is exploited to engineer “active surfaces” with specific functionalities and high efficacy resulting from the intrinsic activity of the biomolecules that is preserved by an appropriate synthetic environment

RESEARCH ON THE FERTILIZATION OF SWEET POTATOES ACCORDING TO THE NUTRITIONAL SPACE, IN THE SANDY SOIL CONDITIONS FROM ROMANIA

Research conducted during 2015-2017, in the climatic conditions of sandy soils in Romania, highlights the role of fertilization and plant density on the growth and development of sweet potato plants (Ipomoea batatas). The obtained results, show the positive implications of chemical and foliar fertilization on the physiological processes in the plant and on the quantity and quality of the obtained production. The fertilization of the sweet potato culture with N150P80K80, prior to planting and the use of a density of 50000 plants / ha led to a maximum yield of 27907 kg / ha. From the point of view of the quality of the production, the application of two foliar fertilizations with the product Timasol in a concentration of 1%, having N15P15K30 + 13 microelements, determined the increase of the biochemical components from the sweet potato tubers, compared to the only radicular fertilized

The general form of supersymmetric solutions of N=(1,0) U(1) and SU(2) gauged supergravities in six dimensions

We obtain necessary and sufficient conditions for a supersymmetric field configuration in the N=(1,0) U(1) or SU(2) gauged supergravities in six dimensions, and impose the field equations on this general ansatz. It is found that any supersymmetric solution is associated to an $SU(2)\ltimes \mathbb{R}^4$ structure. The structure is characterized by a null Killing vector which induces a natural 2+4 split of the six dimensional spacetime. A suitable combination of the field equations implies that the scalar curvature of the four dimensional Riemannian part, referred to as the base, obeys a second order differential equation. Bosonic fluxes introduce torsion terms that deform the $SU(2)\ltimes\mathbb{R}^4$ structure away from a covariantly constant one. The most general structure can be classified in terms of its intrinsic torsion. For a large class of solutions the gauge field strengths admit a simple geometrical interpretation: in the U(1) theory the base is K\"{a}hler, and the gauge field strength is the Ricci form; in the SU(2) theory, the gauge field strengths are identified with the curvatures of the left hand spin bundle of the base. We employ our general ansatz to construct new supersymmetric solutions; we show that the U(1) theory admits a symmetric Cahen-Wallach$_4\times S^2$ solution together with a compactifying pp-wave. The SU(2) theory admits a black string, whose near horizon limit is $AdS_3\times S_3$. We also obtain the Yang-Mills analogue of the Salam-Sezgin solution of the U(1) theory, namely $R^{1,2}\times S^3$, where the $S^3$ is supported by a sphaleron. Finally we obtain the additional constraints implied by enhanced supersymmetry, and discuss Penrose limits in the theories.Comment: 1+29 pages, late

Interpreting microarray experiments via co-expressed gene groups analysis

International audienceMicroarray technology produces vast amounts of data by measuring simultaneously the expression levels of thousands of genes under hundreds of biological conditions. Nowadays, one of the principal challenges in bioinformatics is the interpretation of huge data using different sources of information. We propose a novel data analysis method named CGGA (Co-expressed Gene Groups Analysis) that automatically finds groups of genes that are functionally enriched, i.e. have the same functional annotations, and are co- expressed. CGGA automatically integrates the information of microarrays, i.e. gene expression profiles, with the functional annotations of the genes obtained by the genome-wide information sources such as Gene Ontology (GO)1. By applying CGGA to well-known microarray experiments, we have identified the principal functionally enriched and co-expressed gene groups, and we have shown that this approach enhances and accelerates the interpretation of DNA microarray experiments

Functional Surfaces: Bio-Hybrid Membranes for Biosensing

Combining natural enzymes with synthetic membranes on solid support enables creation of functional surfaces able to serve for efficient biosensing. Enzymes (laccase and tyrosinase) integrated on soft copolymer mono- and bilayer membranes preserve their activity and specifically detect the presence of phenols. The straightforward approach to create these bio-hybrid membranes allows changing the enzyme type and thus producing functional surfaces for sensitive detection of desired molecules

PRELIMINARY RESULTS ON THE ACTION OF PLANT EXTRACTS ON GERMINATION AND ROOT GROWTH PROCESSES IN SEEDS OF PLANT SPECIES GROWN ON SANDY SOILS

In the context of global climate change, Romania is also seeing changes related mainly to the annual average temperature increase of about 1.6 ° C, the increase in summer temperatures (July and August), which led to changes in the biology of the diseases and pests. Combating crop pests is done through several methods: physical-mechanical (thermal disinfections of seeds), chemical (using pesticides), agro-technical (through soil works, including weeds) but also biological (by using natural and of antagonistic organisms). Bioproducts are biological means made on the basis of natural compounds (plant extracts) with a complex action on crop plants, biopreparations that have been shown to be stimulants of vegetative growth. Application of bioproducts is done by treatments, which are either seed treatments or treatments in vegetation (sprays with different volumes of liquid). In 2016 at CCDCPN Dăbuleni, were tested the basil oil for cowpea seeds, mint oil for peanut seeds, santal oil  for green melon seeds to germination and root growth.

International organisations and anti-terrorist sanctions: no accountability for human rights violations?

The targeted sanctions adopted by the UN Security Council against individuals and entities suspected of association with terrorism are managed through procedures that infringe fundamental human rights, and there are no mechanisms for actual accountability. With the exception of the ECJ in Kadi, municipal and regional courts tend to consider the UN Security Council's resolutions and domestic measures implementing them outside the scope of judicial review. This article argues that the Security Council is bound to observe human rights even in the context of international security action, and that States are not exonerated from international responsibility for violations committed under the umbrella of Chapter VII resolutions

Supersymmetric AdS_5 solutions of M-theory

We analyse the most general supersymmetric solutions of D=11 supergravity consisting of a warped product of five-dimensional anti-de-Sitter space with a six-dimensional Riemannian space M_6, with four-form flux on M_6. We show that M_6 is partly specified by a one-parameter family of four-dimensional Kahler metrics. We find a large family of new explicit regular solutions where M_6 is a compact, complex manifold which is topologically a two-sphere bundle over a four-dimensional base, where the latter is either (i) Kahler-Einstein with positive curvature, or (ii) a product of two constant-curvature Riemann surfaces. After dimensional reduction and T-duality, some solutions in the second class are related to a new family of Sasaki-Einstein spaces which includes T^{1,1}/Z_2. Our general analysis also covers warped products of five-dimensional Minkowski space with a six-dimensional Riemannian space.Comment: 40 pages. v2: minor changes, eqs. (2.22) and (D.12) correcte