Modulation transfer function for infrared reflectarrays

The quality of the image produced by optical reflectarrays as a function of the F/#, polarization, and wavelength is analyzed in this paper. The results are expressed as monochromatic and polychromatic modulation transfer functions. They show that large aperture multilevel reflectarrays perform quite close to the diffraction-limited case. The chromatic aberrations make these elements highly wavelength-selective.     

Design of a configurable multispectral imaging system based on an AOTF

In this paper, we present a configurable multispectral imaging system based on an acousto-optic tunable filter (AOTF). Typically, AOTFs are used to filter a single wavelength at a time, but thanks to the use of a versatile sweeping frequency generator implemented with a direct digital synthesizer, the imager may capture a configurable spectral range. Experimental results show a good spectral and imaging response of the system for spectral bandwidth up to a 50 nm.     

Novel strategies for the buccal delivery of macromolecules

For years now, the delivery of small molecules through the buccal mucosal route has been described in the literature, but it has only been over the past decade that investigations into macromolecule delivery via the buccal route have sharply increased. The administration of macromolecules such as proteins and peptides, antibodies, or nucleic acids by buccal administration would be greatly enhanced due to the avoidance of the gastrointestinal conditions, rapid uptake into systemic circulation, as well as the potential for controlled drug delivery. Since macromolecules are faced with a number of specific challenges related to permeation through the epithelium, several strategies have been employed historically to improve their buccal absorption and subsequent bioavailability. Several conventional strategies to improve macromolecule penetration include the use of chemical permeation enhancers, enzyme inhibitors and the use of mucoadhesive materials acting as carriers. More recent approaches include the incorporation of the macromolecule as part of nanostructured delivery systems to further enhance targeting and delivery. This review focuses on the different permeation enhancing strategies as well as formulation design that are tailored to meet the challenges of active macromolecule delivery using the buccal mucosal route of administration.     

A computational fluid dynamic model of the heat and moisture transfer during beef chilling

The unsteady heat and mass transfer process during beef carcass chilling was modelled for a three-dimensional beef carcass geometry. A three-step method was used to simulate the simultaneous heat and mass transfer process in order to reduce the computational time. In the first step, a steady state simulation of the flow field was conducted. In the second step, the local heat and mass transfer coefficients were calculated. Finally, the third step consists of the simultaneous heat and mass transfer process simulation on the meat carcass only. A separate 1-D grid was used to calculate the moisture diffusion in the meat. The simulation of a 20-h chilling run takes 5 days on a 2.5 GHz Pentium 4 computer. The model allows calculating and predicting the heat load, temperatures, weight loss and water activity. Local variations in the heat and mass transfer coefficients, temperature and water activity were found around the beef carcass. The CFD model gives temperature predictions that agree with experimental data better than any previous model. The weight loss tends to be over-predicted probably due to neglecting the resistance caused by the fat cover.     

The intervening effect of business innovation capability on the relationship between Total Quality Management and technological innovation

The growing diffusion and acceptance in the business world of Total Quality Management (TQM) has attracted greater interest on the part of academia. Although fundamental questions focus on how the different dimensions of TQM can bring about better business performance, a more recent recurring issue pertains to the relationship between TQM and technological innovation and whether technological innovation might provide a source of competitive advantage. Unfortunately, from both theoretical and empirical perspectives, the relationship between TQM and technological innovation appears contradictory and complex. This paper argues that the relationship might be better understood from the contingent perspective of strategic management and thus proposes a multidimensional intervening variable in the relationship, called Business Innovation Capability (BIC). An empirical study of 105 Spanish industrial firms reveals that the effect of some business practices suggested by TQM on technological innovation can be better understood when BIC dimensions are taken into account.     

A note on an assertion by E. Gutiérrez-Peña and A.F.M. Smith (Test, 1997, p.87)

In estimating the discrete parameter of a Binomial distribution, to choose a truncated Poisson model as the prior distribution of this parameter is shown to be unsuitable. This research has been partially supported by Proyect DGES-PB97-1403-C03     

Improving the Performance of Hyperspectral Image and Signal Processing Algorithms Using Parallel,Distributed and Specialized Hardware-Based Systems

Advances in sensor technology are revolutionizing the way remotely sensed data is collected, managed and analyzed. The incorporation of latest-generation sensors to airborne and satellite platforms is currently producing a nearly continual stream of high-dimensional data, and this explosion in the amount of collected information has rapidly created new processing challenges. For instance, hyperspectral signal processing is a new technique in remote sensing that generates hundreds of spectral bands at different wavelength channels for the same area on the surface of the Earth. Many current and future applications of remote sensing in Earth science, space science, and soon in exploration science will require (near) real-time processing capabilities. In recent years, several efforts have been directed towards the incorporation of high-performance computing (HPC) systems and architectures in remote sensing missions. With the aim of providing an overview of current and new trends in parallel and distributed systems for remote sensing applications, this paper explores three HPC-based paradigms for efficient implementation of the Pixel Purity Index (PPI) algorithm, available from the popular Kodak’s Research Systems ENVI software package, as a representative case study for demonstration purposes. Several different parallel programming techniques are used to improve the performance of the PPI on a variety of parallel platforms, including a set of message passing interface (MPI)-based implementations on a massively parallel Beowulf cluster at NASA’s Goddard Space Flight Center in Maryland and on a variety of heterogeneous networks of workstations at University of Maryland; a Handel-C implementation of the algorithm on a Virtex-II field programmable gate array (FPGA); and a compute unified device architecture (CUDA)-based implementation on graphical processing units (GPUs) of NVidia. Combined, these parts deliver an excellent snapshot of the state-of-the-art in those areas, and offer a thoughtful perspective on the potential and emerging challenges of adapting HPC systems to remote sensing problems.     

Uncoded optimal binary communication for sources with memory using the Burrows Wheeler Transform

Given an AWGN channel, we look at the problem of designing an optimal binary uncoded communication system for transmitting blocks of binary symbols generated by a stationary source with memory modelled by a Markov chain (MC) or a hidden Markov model (HMM). The goal is to minimize the average SNR required for a given block error rate. The particular case where the binary source is memoryless with nonuniform symbol probabilities has been studied by Korn et al. [Optimal binary communication with nonequal probabilities. IEEE Trans Commun 2003;51:1435–8] [1] by optimally allocating the energies of the transmitted signals. In this paper we generalize the previous work to include the important case of sources with memory. The proposed system integrates the block sorting Burrows Wheeler Transform (BWT, [Burrows M, Wheeler D. A block sorting lossless data compression algorithm. Research report 124. Digital Systems Center, 1994]) [2] with an optimal energy allocation scheme based on the first order probabilities of the transformed symbols. Analytical expressions are derived for the energy gain obtained with the proposed system when compared either with the optimal blockwise MAP receiver or with a standard source coded system consisting of an optimal source encoder followed by an optimal uncoded binary communication system, i.e. by a symbol-by-symbol MAP detector.