On a damage-plasticity approach to model concrete failure

A damage-plasticity constitutive model for the description of fracture in plain concrete is presented. Two approaches, the local model comprising the adjustment of the softening modulus and the nonlocal model based on spatial averaging of history variables, are applied to the analysis of a concrete bar subjected to uniaxial tension and to a three-point bending test. The influence of mesh size and the decomposition into damage and plasticity components are discussed. It is shown that for the two examples studied, both approaches result in mesh-independent results. However, the nonlocal model, which relies on spatial averaging of history variables, exhibits sensitivity with respect to boundary conditions, which requires further studies.Comment: Revised version. Resubmitted to Engineering and Computational Mechanic

Computing Extensions of Linear Codes

This paper deals with the problem of increasing the minimum distance of a linear code by adding one or more columns to the generator matrix. Several methods to compute extensions of linear codes are presented. Many codes improving the previously known lower bounds on the minimum distance have been found.Comment: accepted for publication at ISIT 0

Experimental Implementation of a Codeword Stabilized Quantum Code

A five-qubit codeword stabilized quantum code is implemented in a seven-qubit system using nuclear magnetic resonance (NMR). Our experiment implements a good nonadditive quantum code which encodes a larger Hilbert space than any stabilizer code with the same length and capable of correcting the same kind of errors. The experimentally measured quantum coherence is shown to be robust against artificially introduced errors, benchmarking the success in implementing the quantum error correction code. Given the typical decoherence time of the system, our experiment illustrates the ability of coherent control to implement complex quantum circuits for demonstrating interesting results in spin qubits for quantum computing

Non-Additive Quantum Codes from Goethals and Preparata Codes

We extend the stabilizer formalism to a class of non-additive quantum codes which are constructed from non-linear classical codes. As an example, we present infinite families of non-additive codes which are derived from Goethals and Preparata codes.Comment: submitted to the 2008 IEEE Information Theory Workshop (ITW 2008

The politics of national diversity

On the consequences of the interplay between the diversity of ethnic, national, cultural and linguistic groupings in the Austro-Hungarian Empire

New self-dual additive F4\mathbb{F}_4-codes constructed from circulant graphs

In order to construct quantum $[[n,0,d]]$ codes for $(n,d)=(56,15)$, $(57,15)$, $(58,16)$, $(63,16)$, $(67,17)$, $(70,18)$, $(71,18)$, $(79,19)$, $(83,20)$, $(87,20)$, $(89,21)$, $(95,20)$, we construct self-dual additive $\mathbb{F}_4$-codes of length $n$ and minimum weight $d$ from circulant graphs. The quantum codes with these parameters are constructed for the first time.Comment: 11 page

Quantum Goethals-Preparata Codes

We present a family of non-additive quantum codes based on Goethals and Preparata codes with parameters ((2^m,2^{2^m-5m+1},8)). The dimension of these codes is eight times higher than the dimension of the best known additive quantum codes of equal length and minimum distance.Comment: Submitted to the 2008 IEEE International Symposium on Information Theor

Temperature and humidity profiles in the atmosphere from spaceborne lasers: A feasibility study

Computer simulations of the differential absorption lidar technique in a space craft for the purpose of temperature and humidity profiling indicate: (1) Current technology applied to O2 and H2O lines in the .7 to .8 micrometers wavelength band gives sufficiently high signal-to-noise ratios (up to 50 for a single pulse pair) if backscattering by aerosol particles is high, i.e. profiling accurate to 2 K for temperature and 10% for humidity should be feasible within the turbid lower troposphere in 1 km layers and with an averaging over approximately 100 pulses. (2) The impact of short term fluctuations in aerosol particle concentration is too big for a one laser system. Only a two laser system firing at a time lag of about 1 millisecond can surmount these difficulties. (3) The finite width of the laser line and the quasi-random shift of this line introduce tolerable, partly systematic errors

Quantum Block and Convolutional Codes from Self-orthogonal Product Codes

We present a construction of self-orthogonal codes using product codes. From the resulting codes, one can construct both block quantum error-correcting codes and quantum convolutional codes. We show that from the examples of convolutional codes found, we can derive ordinary quantum error-correcting codes using tail-biting with parameters [[42N,24N,3]]_2. While it is known that the product construction cannot improve the rate in the classical case, we show that this can happen for quantum codes: we show that a code [[15,7,3]]_2 is obtained by the product of a code [[5,1,3]]_2 with a suitable code.Comment: 5 pages, paper presented at the 2005 IEEE International Symposium on Information Theor