95 GHz millimeter wave signal generation using an arrayed waveguide grating dual wavelength semiconductor laser

We report the generation of a 95?GHz carrier frequency by optical heterodyning of two wavelengths from adjacent channels from an arrayed waveguide grating-based multiwavelength laser. The extended cavity structure of the device provides low phase noise and narrow optical linewidth, further enhanced by the intracavity filter effect of the arrayed waveguide grating. We demonstrate that the generated RF beat note, at 95?GHz, has a -3 dB linewidth of 250?kHz. To the best of our knowledge, this is the narrowest RF linewidth generated from a free-running dual-wavelength semiconductor laser. The device is realized as a photonic integrated circuit using active-passive integration technology, and fabricated on a multiproject wafer run, constituting a novel approach for a compact, low-cost dual-wavelength heterodyne source.     

Direct loading of polymer matrices in plastic microchips for rapid DNA analysis: A comparative study

We report the design and performance validation of microfluidic separation technologies for human identification using a disposable plastic device suitable for integration into an automated rapid DNA analysis system. A fabrication process for a 15-cm long hot-embossed plastic microfluidic devices with a smooth semielliptical cross section out of cyclic olefin copolymer is presented. We propose a mixed polymer solution of 95% w/v hydroxyethylcellulose and 5% w/v polyvinylpyrrolidone for a final polymer concentration of 2.5 or 3.0% to be used as coating and sieving matrix for DNA separation. This formulation allows preparing the microchip without pretreatment in a single-loading step and provides high-resolution separation (≈1.2 bp for fragments <200 bp), which is superior to existing commercial matrices under the same conditions. The hot-embossed device performance is characterized and compared to injection-molded devices made out of cyclic olefin copolymer based on their respective injector geometry, channel shape, and surface charges. Each device design is assessed by fluorescence videomicroscopy to evaluate the formation of injection plugs, then by comparing electropherograms for the separation of a DNA size standard relevant to human identification.     

Design and FPGA-realization of a self-synchronizing chaotic decoder in the presence of noise

This paper describes requirement for wireless transmission of Chaotic Code Division Multiplexed Access (Chaotic CDMA) and it focuses on real-time synchronization algorithm embedded into electronic programmable device. CDMA with quasi-orthogonal codes is used to allow multi-users to transmit simultaneously in the same channel. Since the channel is shared between all users, the receiver system has to cope with channel noise and overall with interference from other users. As a result, one of the main problems of communication with quasi-orthogonal chaotic codes is to implement a real time decoder in presence of noise. Even if set-membership algorithm are efficient in real time synchronization of chaotic discrete generators in the presence of noise, these algorithms require a large memory resource. In this paper, we propose an evolution of set-membership algorithm toward genetic algorithm to be implemented into electronic programmable device. The advantage of genetic algorithm compared with set-membership algorithm is that they require a fixed size of memory.     

Ethylene/1,3-Cyclohexadiene Copolymerization by Means of Methylaluminoxane Activated Half-Sandwich Complexes

Ethylene copolymerization with 1,3-cyclohexadiene (CHD) was investigated by using methylaluminoxane (MAO) activated single-site catalysts including bridged and non-bridged titanium half-sandwich and bimetallic cobalt(I) complexes. MAO activated CpTiCl₂[NP(^tBu)₃] (Cp = cyclopentadienyl, ^tBu = tert-butyl) gave high molecular weight CHD copolymers without encountering catalyst activity losses. According to the NMR microstructure investigation the resulting copolymers are highly regioregular.     

Network Bending: Expressive Manipulation of Generative Models in Multiple Domains

This paper presents the network bending framework, a new approach for manipulating and interacting with deep generative models. We present a comprehensive set of deterministic transformations that can be inserted as distinct layers into the computational graph of a trained generative neural network and applied during inference. In addition, we present a novel algorithm for analysing the deep generative model and clustering features based on their spatial activation maps. This allows features to be grouped together based on spatial similarity in an unsupervised fashion. This results in the meaningful manipulation of sets of features that correspond to the generation of a broad array of semantically significant features of the generated results. We outline this framework, demonstrating our results on deep generative models for both image and audio domains. We show how it allows for the direct manipulation of semantically meaningful aspects of the generative process as well as allowing for a broad range of expressive outcomes.     

Rhombus Tilings: Decomposition and Space Structure

We study the spaces of rhombus tilings, i.e. the graphs whose vertices are tilings of a fixed zonotope. Two tilings are linked if one can pass from one to the other by a local transformation, called a flip. We first use a decomposition method to encode rhombus tilings and give a useful characterization for a sequence of bits to encode a tiling. We use the previous coding to get a canonical representation of tilings, and two order structures on the space of tilings. In codimension 2 we prove that the two order structures are equal. In larger codimensions we study the lexicographic case, and get an order regularity result.     

Representing knowledge about linear programming formulation

This paper describes a system, LPFORM, that enables users to design linear programming models interactively, using graphics. An output of the system is an algebraic statement of the model and data references that are subsequently used to generate the input for a solver in the standard MPS format. The emphasis of this paper is on the types of knowledge one has on the submodels that make up larger models and how this knowledge can be organized.     

The Axisymmetric Deformation of a Thin,or Moderately Thick,Elastic Spherical Cap

A refined shell theory is developed for the elastostatics of a moderately thick spherical cap in axisymmetric deformation. This is a two-term asymptotic theory, valid as the dimensionless shell thickness tends to zero.The theory is more accurate than “thin shell” theory, but is still much more tractable than the full three-dimensional theory. A fundamental difficulty encountered in the formulation of shell (and plate) theories is the determination of correct two-dimensional boundary conditions, applicable to the shell solution, from edge data prescribed for the three-dimensional problem. A major contribution of this article is the derivation of such boundary conditions for our refined theory of the spherical cap. These conditions are more difficult to obtain than those already known for the semi-infinite cylindrical shell, since they depend on the cap angle as well as the dimensionless thickness. For the stress boundary value problem, we find that a Saint-Venant-type principle does not apply in the refined theory, although it does hold in thin shell theory. We also obtain correct boundary conditions for pure displacement and mixed boundary data. In these cases, conventional formulations do not generally provide even the first approximation solution correctly. As an illustration of the refined theory, we obtain two-term asymptotic solutions to two problems, (i) a complete spherical shell subjected to a normally directed equatorial line loading and (ii) an unloaded spherical cap rotating about its axis of symmetry.     

Un Groupe Hyperbolique Est Determine Par Son Bord

We construct on the boundary of a hyperbolic group (in Gromov'ssense) a natural visual measure and a natural crossratio. Weprove that the I-quasiconformal homeomorphisms (in Pansu's sense)between the boundaries of hyperbolic groups are the quasimöbiusmaps (that is, the bijections that almost preserve the crossratios),and that they are the extensions of the quasi-isometries betweenthe groups. We define a barycentre for every probability measureon the boundary without atom, extending the Douady-Earle construction.     

Thermal analysis of some metal n-benzoyl-n-phenylhydroxylamine chelates

The preparation and thermal analysis of the metal chelates of N-benzoyl-N-phenylhydroxylamine (BPHA) with Al(III), Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II) and Zn(II) is discussed. The differential thermal analysis apparatus is described in detail. DTA and TGA curves of BPHA arid the chelates from 25 to 700° in oxygen and in nitrogen are presented.