Serialized Asynchronous Links for NoC

This paper proposes an asynchronous serialized link for NoC that can achieve the same levels of performance in terms of flits per second as a synchronous link but with a reduced number of wires in the point to point switch links and reduced power consumption. This is achieved by employing serialization in the asynchronous domain as opposed to synchronous to facilitate the removal of global clocking on the serial links. Based on transistor level simulations using 0.12 ?m foundry models it has been shown that it is possible to achieve the same level of performance as synchronous but with 75% reduction in wires and 65% reduction in power for a 300 MFlit/s link with 8 buffers with a switch clock speed of 300 MHz. Furthermore the paper presents the design requirements arising from interfacing switches of synchronous NoC and asynchronous serial links

BESO approach to topology optimization of GaN phononic crystals

The use of Phononic Crystals (PnC) in suspended structures and microstructures, such as plates and slabs, has gained a lot of attention in the past years for the wide range of feasible applications (acoustic waveguides, acoustic insulation, acoustic cloaking) and for the easy fabrication technique. Since the performance of the device is related to the band of frequencies reflected by the PnC and since this band (called bandgap) depends on the geometric and material properties of the fundamental unit cell of the PnC, a useful tool for the design of those structures is topology optimization. This paper is focused on a novel and fast engineering use of Bidirectional Evolutionary Structural Optimization for the definition of the optimal hole configuration in air-solid PnC. The technique adopted finds the optimal shape of the hole in less than 20 iterations, and it is easy implemented in a 2D plane strain Matlab finite element solver

Shape optimization of solid-air porous phononic crystal slabs with widest full 3D bandgap for in-plane acoustic waves

The use of Phononic Crystals (PnCs) as smart materials in structures and microstructures is growing due to their tunable dynamical properties and to the wide range of possible applications. PnCs are periodic structures that exhibit elastic wave scattering for a certain band of frequencies (called bandgap), depending on the geometric and material properties of the fundamental unit cell of the crystal. PnCs slabs can be represented by plane-extruded structures composed of a single material with periodic perforations. Such a configuration is very interesting, especially in Micro Electro-Mechanical Systems industry, due to the easy fabrication procedure. A lot of topologies can be found in the literature for PnCs with square-symmetric unit cell that exhibit complete 2D bandgaps; however, due to the application demand, it is desirable to find the best topologies in order to guarantee full bandgaps referred to in-plane wave propagation in the complete 3D structure. In this work, by means of a novel and fast implementation of the Bidirectional Evolutionary Structural Optimization technique, shape optimization is conducted on the hole shape obtaining several topologies, also with non-square-symmetric unit cell, endowed with complete 3D full bandgaps for in-plane waves. Model order reduction technique is adopted to reduce the computational time in the wave dispersion analysis. The 3D features of the PnC unit cell endowed with the widest full bandgap are then completely analyzed, paying attention to engineering design issues

Spatial analysis for an evaluation of monitoring networks: examples from the Italian seismic and accelerometric networks

AbstractIn this work, we propose a statistical approach to evaluate the coverage of a network based on the spatial distribution of its nodes and the target information, including all those data related to the final objectives of the network itself. This statistical approach encompasses descriptive spatial statistics in combination with point pattern techniques. As case studies, we evaluate the spatial arrangements of the stations within the Italian National Seismic Network and the Italian Strong Motion Network. Seismic networks are essential tools for observing earthquakes and assessing seismic hazards, while strong motion (accelerometric) networks allow us to describe seismic shaking and to measure the expected effects on buildings and infrastructures. The capability of both networks is a function of an adequate number of optimally distributed stations. We compare the seismic network with the spatial distributions of historical and instrument seismicity and with the distribution of well-known seismogenic sources, and we compare the strong motion station distribution with seismic hazard maps and the population distribution. This simple and reliable methodological approach is able to provide quantitative information on the coverage of any type of network and is able to identify critical areas that require optimization and therefore address areas of future development

Enhancements of G3-PLC technology for smart-home/building applications

To enable the smart grid concept, it is fundamental to consider the in-home/building context where, beside the conventional home networking services, home automation and smart energy management services have to be offered. In this paper, we consider the in-home/building scenario, for which we propose a convergent network architecture to enhance the performance of the narrowband power line communication (PLC) G3-PLC technology through its integration with an Ethernet-based network. To this end, we define the protocols characterizing the network modules, namely, switches and routers, which allow for integrating the G3-PLC with Ethernet devices. Since Ethernet represents a convergent standard for many communication devices, by adding this functionality to G3-PLC, interconnectivity with other heterogeneous nodes can be offered. Furthermore, since the G3-PLC medium access control layer is based on a carrier sense multiple access scheme, its performance decreases when the number of network nodes contending for the channel increases. Therefore, we evaluate the network performance when an optimized time division multiple access scheme is adopted. The proposed convergent network architecture has been implemented in the OMNeT++ network simulator

Coherence build up and laser thresholds from nanolasers to macroscopic lasers

We detail the derivation of nanolaser models that include coherent and incoherent variables and predict the existence of a laser threshold, irrespective of cavity size and emitter number, for both single- and multi-electron systems. The growth in photon number in the lasing mode is driven by an increase in correlation between absorption and emission processes, leading to the onset of self-sustained stimulated emission (laser threshold), followed, in turn, by a correlation decrease and ending with the dominance of coherent emission. The first-order coherence $g^{(1)}$ steadily increases, as the pump grows towards the laser threshold value, and reaches unity at or beyond threshold. The transition toward coherent emission becomes increasingly sharp as the number of emitters and of the coupled electromagnetic cavity modes increase, continuously connecting, in the thermodynamic limit, the physics of nano- and macroscopic lasers at threshold. Our predictions are in remarkable agreement with experiments whose first-order coherence measurements have so far been explained only phenomenologically. A consistent evaluation of different threshold indicators provides a tool for a correct interpretation of experimental measurements at the onset of laser action.Comment: 11 pages, 5 figure

Environmental tobacco smoke: health policy and focus on Italian legislation.

Worldwide tobacco smoking kills nearly 6 million people each year, including more than 600,000 non-smokers who die from smoke exposure. Environmental tobacco smoke (ETS, also called secondhand smoke, involuntary smoke, or passive smoke) is the combination of sidestream smoke, the smoke given off by a burning tobacco product and mainstream smoke, the smoke exhaled by smokers. People may be exposed to ETS in homes, cars, workplaces, and public places, such as bars, restaurants, and recreational settings. In addition, there is another type of smoke which until now has not been recognized: the so-called thirdhand smoke, that comes from the reaction of mainstream smoke and environmental nitrous acid (HNO2) making carcinogenic tobacco-specific nitrosamines (TSNAs). The effects of ETS on human health are well-known, passive smoking is harmful to those who breathe the toxins and it is a serious problem for public health. The smoking ban in Italy had reduced ETS pollution, as in the United States and in other countries all over the world. However, the implementation of comprehensive legislation on smoking policy will necessitate other tobacco control measures for its successful fulfillment: increased media awareness, telephone smoking cessation helplines and smoking cessation support services could be an opportunity to ensure awareness, comprehension and support to those who want to quit smoking. The effectiveness of legislative efforts will also depend on successful enforcement of smoking bans and compliance with the legislation. This review summarizes the evidences about the effect of ETS and provides an overview of smoke-free laws and policies

Increased levels of DNA methyltransferases are associated with the tumorigenic capacity of prostate cancer cells

DNA methylation might be the earliest somatic genome changes in prostate cancer that also play an important role in the process of tumor invasion, growth and metastasis. In recent years, several inhibitors of DNA methyltransferases (DNMTis) have been developed and evaluated in pre-clinical models and in clinical trials. While these compounds are effective in the treatment of hematological conditions, clinical trials in solid tumors and in prostate cancer have shown limited or no efficacy. This may be attributed to inappropriate dose regimens leading to toxicity-related adverse events. As with other anti-target compounds, one of the obstacles encountered with DNMTis in prostate cancer could be the inability to select patients for the clinical studies as well as the inability to monitor the efficacy of the drug if not the conclusion of the study. Primary cultures derived from human prostatic tissues harvested from patients with benign prostatic hyperplasia (BPH) and prostate cancer (PCa) as well as neoplastic and non-neoplastic prostate cell lines were tested for DNMT expression/activity and to monitor azacitidine molecular efficacy. We observed that in primary cultures the levels of DNMT activity as well as the protein levels of DNMT1, DNMT3a and DNMT3b were higher in cultures derived from PCa compared to BPH tissue samples and significantly higher in cultures derived from PCa with Gleason scores ≥7 compared to those observed in cultures derived from Gleason scores <7. In addition, DNMT activity as well as DNMT1, DNMT3a and DNMT3b levels were higher in PCa cell lines compared to their non-neoplastic counterparts. Although DNMT activity was higher in high tumorigenic/aggressive PCa cell lines compared to low tumorigenic/aggressive cell lines, only the levels of DNMT3a and DNMT3b were significantly higher in the first group of cells, suggesting that DNMT1 activity is related to the transition to non-neoplastic versus neoplastic phenotype whereas the de novo methylation enzymes were mainly related to progression. Nevertheless, the comparison in the more aggressive PC3 cell derivatives (PC3-LN4 cells) also possessed higher levels of DNMT1 compared to PC3 and PC3M from which these cells were derived. Collectively, our results confirm previous data on the increased methylation in more aggressive tumors supporting the use of DNMTis in advanced prostate cancer. In addition, since glutathione S-transferase-π (GSTP1) was re-expressed or its protein levels were increased after treatment with non-toxic azacitidine doses and since GSTP1 can easily be measured in patient sera, the monitoring of this protein may aide in the evaluation of therapy in future clinical trials

A new dissimilarity measure for clustering seismic signals

Hypocenter and focal mechanism of an earthquake can be determined by the analysis of signals, named waveforms, related to the wave field produced and recorded by a seismic network. Assuming that waveform similarity implies the similarity of focal parameters, the analysis of those signals characterized by very similar shapes can be used to give important details about the physical phenomena which have generated an earthquake. Recent works have shown the effectiveness of cross-correlation and/or cross-spectral dissimilarities to identify clusters of seismic events. In this work we propose a new dissimilarity measure between seismic signals whose reliability has been tested on real seismic data by computing external and internal validation indices on the obtained clustering. Results show its superior quality in terms of cluster homogeneity and computational time with respect to the largely adopted cross correlation dissimilarity