SystemC Model Generation for Realistic Simulation of Networked Embedded Systems

Verification and design-space exploration of today's embedded systems require the simulation of heterogeneous aspects of the system, i.e., software, hardware, communications. This work shows the use of SystemC to simulate a model-driven specification of the behavior of a networked embedded system together with a complete network scenario consisting of the radio channel, the IEEE 802.15.4 protocol for wireless personal area networks and concurrent traffic sharing the medium. The paper describes the main issues addressed to generate SystemC modules from Matlab/Stateflow descriptions and to integrate them in a complete network scenario. Simulation results on a healthcare wireless sensor network show the validity of the approach

Network-aware design-space exploration of a power-efficient embedded application

The paper presents the design and multi-parameter optimization of a networked embedded application for the health-care domain. Several hardware, software, and application parameters, such as clock frequency, sensor sampling rate, data packet rate, are tuned at design- and run-time according to application specifications and operating conditions to optimize hardware requirements, packet loss, power consumption. Experimental results show that further power efficiency can be achieved by considering also communication aspects during design space exploratio

Programmability and Performance of Parallel ECS-based Simulation of Multi-Agent Exploration Models

While the traditional objective of parallel/distributed simulation techniques has been mainly in improving performance and making very large models tractable, more recent research trends targeted complementary aspects, such as the “ease of programming”. Along this line, a recent proposal called Event and Cross State (ECS) synchronization, stands as a solution allowing to break the traditional programming rules proper of Parallel Discrete Event Simulation (PDES) systems, where the application code processing a specific event is only allowed to access the state (namely the memory image) of the target simulation object. In fact with ECS, the programmer is allowed to write ANSI-C event-handlers capable of accessing (in either read or write mode) the state of whichever simulation object included in the simulation model. Correct concurrent execution of events, e.g., on top of multi-core machines, is guaranteed by ECS with no intervention by the programmer, who is in practice exposed to a sequential-style programming model where events are processed one at a time, and have the ability to access the current memory image of the whole simulation model, namely the collection of the states of any involved object. This can strongly simplify the development of specific models, e.g., by avoiding the need for passing state information across concurrent objects in the form of events. In this article we investigate on both programmability and performance aspects related to developing/supporting a multi-agent exploration model on top of the ROOT-Sim PDES platform, which supports ECS

The pairing Hamiltonian for one pair of identical nucleons bound in a potential well

The problem of one pair of identical nucleons sitting in ${\cal N}$ single particle levels of a potential well and interacting through the pairing force is treated introducing even Grassmann variables. The eigenvectors are analytically expressed solely in terms of these with coefficients fixed by the eigenvalues and the single particle energies. When the latter are those of an harmonic oscillator well an accurate expression is derived for both the collective eigenvalue and for those trapped in between the single particle levels, for any strength of the pairing interaction and for any number of levels. Notably the trapped solutions are labelled through an index upon which they depend parabolically.Comment: 5 pages, 1 postscript figur

Delayed priming promotes CNS regeneration post-rhizotomy in Neurocan and Brevican-deficient mice

A wealth of literature has provided evidence that reactive tissue at the site of CNS injury is rich in chondroitin sulfate proteoglycans which may contribute to the non-permissive nature of the CNS. We have recently demonstrated using a murine model of human brachial plexus injury that the chondroitin sulfate proteoglycans Neurocan and Brevican are differentially expressed by two subsets of astrocytes in the spinal cord dorsal root entry zone (DREZ) following dorsal root lesion (Beggah et al., Neuroscience 133: 749-762, 2005). However, direct evidence for a growth-inhibitory role of these proteoglycans in vivo is still lacking. We therefore performed dorsal root lesion (rhizotomy) in mice deficient in both Neurocan and Brevican. Rhizotomy in these animals resulted in no significant increase in the number of sensory fibres regenerating through the DREZ compared to genetically matched controls. Likewise, a conditioning peripheral nerve lesion prior to rhizotomy, which increases the intrinsic growth capacity of sensory neurons, enhanced growth to the same extent in transgenic and control mice, indicating that absence of these proteoglycans alone is not sufficient to further promote entry into the spinal cord. In contrast, when priming of the median nerve was performed at a clinically relevant time, i.e. 7 weeks post-rhizotomy, the growth of a subpopulation of sensory axons across the DREZ was facilitated in Neurocan/Brevican-deficient, but not in control animals. This demonstrates for the first time that (i) Neurocan and/or Brevican contribute to the non-permissive environment of the DREZ several weeks after lesion and that (ii) delayed stimulation of the growth program of sensory neurons can facilitate regeneration across the DREZ provided its growth-inhibitory properties are attenuated. Post-injury enhancement of the intrinsic growth capacity of sensory neurons combined with removal of inhibitory chondroitin sulfate proteoglycans may therefore help to restore sensory function and thus attenuate the chronic pain resulting from human brachial plexus injur

A 1.8-3.2 GHz Doherty Power Amplifier in quasi-MMIC Technology

This letter presents the design and characterization of a quasi-integrated Doherty power amplifier for base-station applications. The prototype is based on GaN on SiC 0.25-μm 50-V transistors, whereas the passive matching networks are realized on a GaAs substrate. The design, based on a dual-input Doherty architecture, achieves a continuous-wave (CW) output power higher than 42 dBm and a backoff efficiency higher than 38% over the 1.8-3.2-GHz frequency band. By using an off-chip coupler, a single-input operation is also possible with a slight reduction in performance, i.e., CW output power and backoff efficiency higher than 41.4 dBm and 36%, respectively, on the 1.8-3.2-GHz band. System-level characterization shows higher peak power achievable than in CW condition as well as the linearizability of the amplifier under modulated signal conditions

EXPO-AGRI: Smart Automatic Greenhouse Control

Predicting and controlling plant behavior in con- trolled environments is a growing requirement in precision agri- culture. In this context sensor networks and artificial intelligence methods represent key aspects for optimizing the processes of data acquisition, mathematical modeling and decision making. In this paper we present a general architecture for automatic greenhouse control. In particular, we focus on a preliminary model for predicting the risk of new infections of downy mildew of basil (Peronospora belbahrii) on sweet basil. The architecture has three main elements of innovation: new kinds of sensors are used to extract information about the state of the plants, model predictors are generated from this information by non-trivial processing methods, and informative predictors are automatically selected using regularization techniques

Methods for enzyme library creation: which one will you choose? A guide for novices and experts to introduce genetic diversity

Enzyme engineering allows to explore sequence diversity in search for new properties. The scientific literature is populated with methods to create enzyme libraries for engineering purposes, however, choosing a suitable method for the creation of mutant libraries can be daunting, in particular for the novices. Here, we address both novices and experts: how can one enter the arena of enzyme library design and what guidelines can advanced users apply to select strategies best suited to their purpose? Section I is dedicated to the novices and presents an overview of established and standard methods for library creation, as well as available commercial solutions. The expert will discover an up-to-date tool to freshen up their repertoire (Section I) and learn of the newest methods that are likely to become a mainstay (Section II). We focus primarily on in vitro methods, presenting the advantages of each method. Our ultimate aim is to offer a selection of methods/strategies that we believe to be most useful to the enzyme engineer, whether a first-timer or a seasoned user

Self-Assembly of Polyhedral Hybrid Colloidal Particles

We have developed a new method to produce hybrid particles with polyhedral shapes in very high yield (liter quantities at up to 70% purity) using a combination of emulsion polymerization and inorganic surface chemistry. The procedure has been generalized to create complex geometries, including hybrid line segments, triangles, tetrahedra, octahedra, and more. The optical properties of these particles are tailored for studying their dynamics and self-assembly. For example, we produce systems that consist of index-matched spheres allowing us to define the position of each elementary particle in three-dimensional space. We present some preliminary studies on the self-assembly of these complex shaped systems based on electron and optical microscopy.Engineering and Applied SciencesPhysic

Trace Metals in Pork Meat Products Marketed in Italy: Occurrence and Health Risk Characterization

This study provides valuable information on the levels of various trace metals (Pb, Cd, Hg, Zn, Cu, Cr) in meat products (baked ham, raw ham, mortadella, cured sausage, würstel, salami) from South Italy and calculates potential health risk toxicity associated with their consumption for the total population and for children. In the samples studied metal concentrations are within the permissible legal limits (Cd: 0.01–0.03 μg g−1 w.w., Hg: 0.01–0.02 μg g−1 w.w., Zn: 5.71–7.32 μg g−1 w.w., Cu: 1.08–1.21 μg g−1 w.w., Cr: 0.15–0.23 μg g−1 w.w.), except for Pb (Pb: 0.22–0.38 μg g−1 w.w.). The estimated intake values are within the provisional tolerable daily intake limits for toxic metals and recommended daily intake values for essential metals in both tested groups. The noncarcinogenic risk values of the individual metals indicate that there is no health risk, but their combined effects might constitute a potential risk for children. Furthermore, the cumulative cancer risk of all samples studied exceeds the recommended threshold risk limit (> 10−4) in both total population and children, indicating a risk of potential health problems for consumers especially for children, who are more vulnerable to toxic metal exposure