ESD–RF co-design methodology for the state of the art RF-CMOS blocks

This paper describes an approach to design ESD protection for integrated low noise amplifier (LNA) circuits used in narrowband transceiver front-ends. The RF constraints on the implementation of ESD protection devices are relaxed by co-designing the RF and the ESD blocks, considering them as one single circuit to optimise. The method is applied for the design of 0.25 μm CMOS LNA. Circuit protection levels higher than 3 kV HBM stress are achieved using conventional highly capacitive ggNMOS snapback devices. The methodology can be extended to other RF-CMOS circuits requiring ESD protection by merging the ESD devices in the functionality of the corresponding matching blocks.     

Noise figure of saturated 1310-nm polarization insensitive multiple-quantum-well optical amplifiers

The noise figure degradation due to saturation by amplified spontaneous emission of high-gain 1310-nm polarization insensitive multiple-quantum-well optical amplifiers has been investigated systematically by studying amplifiers of different lengths. It is found that the intrinsic noise figure of 4 dB of a device with 20-dB single-pass gain is degraded to about 5 dB for a device having 36-dB single-pass gain. This degradation in noise figure is very modest, compared to results reported earlier for semiconductor optical amplifiers with bulk-gain media, illustrating the benefits of using a quantum-well gain medium in semiconductor optical amplifiers.     

Business process model abstraction: a definition, catalog, and survey

The discipline of business process management aims at capturing, understanding, and improving work in organizations by using process models as central artifacts. Since business-oriented tasks require different information from such models to be highlighted, a range of abstraction techniques has been developed over the past years to manipulate overly detailed models. At this point, a clear understanding of what distinguishes these techniques and how they address real world use cases has not yet been established. In this paper we systematically develop, classify, and consolidate the use cases for business process model abstraction and present a case study to illustrate the value of this technique. The catalog of use cases that we present is based on a thorough evaluation of the state of the art, as well as on our cooperation with end users in the health insurance sector. It has been subsequently validated by experts from the consultancy and tool vendor domains. Based on our findings, we evaluate how the existing business process model abstraction approaches support the discovered use cases and reveal which areas are not adequately covered, as such providing an agenda for further research in this area.     

Science in Brazil. Part 1: A macro-level comparative study

Summary In the present paper, the evolution of publication activity and citation impact in Brazil is studied for the period 1991-2003. Besides the analysis of trends in publication and citation patterns and of national publication profiles, an attempt is made to find statistical evidences of the relation between international co-authorship and both research profile and citation impact in the Latin American region. Despite similarities and strong co-publication links with the other countries in the region, Brazil has nonetheless a specific research profile, and forms the largest potential in the region.     

A Multiphase Pore Scale Network Model of Gas Exchange in Apple Fruit

A multiphase pore scale network model was developed to describe mass transfer in apple fruit. The 3D microscale geometry of the tissue was reconstructed from synchrotron radiation tomography images. Individual cells and pores were identified using a watershed segmentation procedure on a Euclidean distance map of the tissue microstructure. Further morphological characteristics of each individual pore, including its volume, connections to the neighbors and the connected area between the pore and its neighbors, were determined. The tissue was represented by a network of nodes (simplified individual pores and cells) that were interconnected by tubes. The transport of the respiratory gases O₂ and CO₂ between two nodes was modelled using diffusion laws and irreversible thermodynamics, while respiration was taken into account in the individual cellular nodes. A numerical procedure was applied to simulate the gas transport within the discrete network and to compute the local diffusivities of the links in the network. The predicted overall gas diffusivities compared well to experimental data and results computed from a microscale continuum model, thereby validating the pore scale network model. This approach is a computationally attractive alternative to a continuum multiphase approach for modelling gas transport in fruit.     

3D Virtual Pome Fruit Tissue Generation Based on Cell Growth Modeling

A 3D virtual fruit tissue generator is presented that can distinctly define the microstructural components of a fruit tissue and that can be used to model important physical processes such as gas transport during controlled atmosphere storage. The model is based on the biomechanics of plant cells in tissues. The main merit of this algorithm is that it can account for typical differences in intercellular air space networks and in cell size and shape found between different fruit species and tissues. The cell is considered as a closed thin walled structure, maintained in tension by turgor pressure. The cell walls of adjacent cells are modeled as parallel, linear elastic elements which obey Hooke's law. A 3D Voronoi tessellation is used to generate the initial topology of the cells. Intercellular air spaces of schizogenous origin are generated by separating the Voronoi cells along the edges where three Voronoi cells are in contact; while intercellular air spaces of lysigenous origin are generated by deleting (killing) some of the Voronoi cells randomly. Cell expansion then results from turgor pressure acting on the yielding cell wall material. To find the sequence of positions of each vertex and thus the shape of the tissue with time, a system of differential equations for the positions and velocities of each vertex is established and solved using a Matlab ordinary differential equation solver. Statistical comparison with synchrotron tomography images of fruit tissue is excellent. The virtual tissues can be used to study tissue mechanics and exchange processes of important metabolites.     

Organizational Characteristics Influencing SME Information Security Maturity

In the current business environment, many organizations use popular standards such as the ISO 27000x series, COBIT, and related frameworks to protect themselves against security incidents. However, these standards and frameworks are overly complicated for small to medium-sized enterprises, leaving these organizations with no easy to understand toolkit to address their security needs. This research builds upon the recent Information Security Focus Area Maturity (ISFAM) model for SME information security as a cornerstone in the development of an assessment tool for tailor-made, fast, and easy-to-use information security advice for SMEs. By performing an extensive literature review and evaluating the results with security experts, we propose the Characterizing Organizations’ Information Security for SMEs (CHOISS) model to relate measurable organizational characteristics in four categories through 47 parameters to help SMEs distinguish and prioritize which risks to mitigate.     

Use of locality sensitive hashing (LSH) algorithm to match Web of Science and Scopus

Scientometrics - A novel hashing algorithm is applied to match two prominent and important bibliographic databases at the paper level. In the literature, such tasks have been studied and conducted...