STC-MIMO Block Spread OFDM in Frequency Selective Rayleigh Fading Channels

In this paper, we expand the idea of spreading the transmitted symbols in OFDM systems by unitary spreading matrices based on the rotated Hadamard or rotated Discrete Fourier Transform (DFT) matrices proposed in the literature to apply to Space-Time Coded Multiple-Input Multiple-Output OFDM(STC-MIMO-OFDM) systems. We refer the resulting systems to as STC-MIMO Block Spread OFDM (STC-MIMO-BOFDM) systems. In the proposed systems, a multi-dimensional diversity, including time, frequency, space and modulation diversities, can be used, resulting in better bit error performance in frequency selective Rayleigh fading channels compared to the conventional OFDM systems with or without STCs. Simulations carried out with the Alamouti code confirm the advantage of the proposed STC-MIMO-BOFDM systems

Fringe calibration using neural network signal mapping for structured light profilometers

We present a novel neural network signal calibration technique to improve the performance of triangulation based structured light profilometers. The performance of such profilometers is often hindered by the capture of noisy and aberrated pattern intensity distributions. We address this problem by employing neural networks and a spatial digital filter in a signal mapping approach. The performance of the calibration technique is gauged through both simulation and experimentation, with simulation results indicating that accuracy can be improved by more than 80%

Optimisation of triangulation based optical profilometers utilising digital video projection technology

Fast, high precision and automated optical noncontact surface profile and shape measurement has been an extensively studied research area due to its many potential applications including 3D sensing, industrial monitoring, mechanical engineering, medicine, robotics, machine vision,animation, virtual reality, dressmaking, prosthetics, ergonomics. Among others, structured light approaches including fringe profilometry have proven to be one of the most promising techniques. In such profilometry techniques a structured light pattern, generally composed of parallel lines is projected onto a diffuse surface to be measured and viewed from an offset angle. The observed pattern is distorted by the object in such a way that represents information about the height of the object perpendicular to the plane of observation. The distorted structured light pattern is recorded, commonly by a CCD camera and through computer analysis of the recorded image the object can be recreated in 3D space, typically with a high degree of precision

The crisis in ICT education: an academic perspective

A national Discipline-Based Initiative project for ICT, funded by the ALTC, has sought to identify the issues and challenges facing the sector. The crisis in ICT education spans high schools, universities and industry. The demand for skilled ICT graduates is increasing yet enrolments are declining. Several factors contribute to this decline including the perceived quality of teaching and a poor perception of the ICT profession amongst the general public. This paper reports on a consultation process with the academic community. Academic concerns include the capacity of the sector to survive the downturn, and improving relationships with industry which should benefit students, academics and industry. An outcome of the consultation process has been the formation of the Australian Council of Deans of ICT (ACDICT) which will have broad responsibility for addressing the issues affecting ICT higher education

Fringe Calibration using Neural Network Signal Mapping for Structured Light Profilometers

We present a novel neural network signal calibration technique to improve the performance of triangulation based structured light profilometers. The performance of such profilometers is often hindered by the capture of noisy and aberrated pattern intensity distributions. We address this problem by employing neural networks and a spatial digital filter in a signal mapping approach. The performance of the calibration technique is gauged through both simulation and experimentation, with simulation results indicating that accuracy can be improved by more than 80%

Climate change vulnerability assessment of the main marine commercial fish and invertebrates of Portugal

This is the first attempt to apply an expert-based ecological vulnerability assessment of the effects of climate change on the main marine resources of Portugal. The vulnerability, exposure, sensitivity, adaptive capacity, and expected directional effects of 74 species of fish and invertebrates of commercial interest is estimated based on criteria related to their life-history and level of conservation or exploitation. This analysis is performed separately for three regions of Portugal and two scenarios of climate change (RCP 4.5 and RCP 8.5). To do that, the fourth assessment report IPCC framework for vulnerability assessments was coupled to the outputs of a physical-biogeochemical model allowing to weight the exposure of the species by the expected variability of the environmental variables in the future. The highest vulnerabilities were found for some migratory and elasmobranch species, although overall vulnerability scores were low probably due to the high adaptive capacity of species from temperate ecosystems. Among regions, the highest average vulnerability was estimated for the species in the Central region while higher vulnerabilities were identified under climate change scenario RCP 8.5 in the three regions, due to higher expected climatic variability. This work establishes the basis for the assessment of the vulnerability of the human activities relying on marine resources in the context of climate change.FCT: UIDB/04326/2020/ UIDP/50017/2020+UIDB/50017/2020; MAR2020-FEAMP through project CLIMA-PESCA: MAR-01.03.02-FEAMP-0052/ n2/SAICT/2017-SAICT/ SAICT-45-2017-02/ ALG-01-0145-FEDER-028518/ PTDC/ASP-PES/28518/2017info:eu-repo/semantics/publishedVersio

Dietary b-glucan (MacroGard®) enhances survival of first feeding turbot (Scophthalmus maximus) larvae by altering immunity, metabolism and microbiota

Reflecting the natural biology of mass spawning fish aquaculture production of fish larvae is often hampered by high and unpredictable mortality rates. The present study aimed to enhance larval performance and immunity via the oral administration of an immunomodulator, β-glucan (MacroGard®) in turbot (Scophthalmus maximus). Rotifers (Brachionus plicatilis) were incubated with or without yeast β-1,3/1,6-glucan in form of MacroGard® at a concentration of 0.5 g/L. Rotifers were fed to first feeding turbot larvae once a day. From day 13 dph onwards all tanks were additionally fed untreated Artemia sp. nauplii (1 nauplius ml/L). Daily mortality was monitored and larvae were sampled at 11 and 24 dph for expression of 30 genes, microbiota analysis, trypsin activity and size measurements. Along with the feeding of β-glucan daily mortality was significantly reduced by ca. 15% and an alteration of the larval microbiota was observed. At 11 dph gene expression of trypsin and chymotrypsin was elevated in the MacroGard® fed fish, which resulted in heightened tryptic enzyme activity. No effect on genes encoding antioxidative proteins was observed, whilst the immune response was clearly modulated by β-glucan. At 11 dph complement component c3 was elevated whilst cytokines, antimicrobial peptides, toll like receptor 3 and heat shock protein 70 were not affected. At the later time point (24 dph) an anti-inflammatory effect in form of a down-regulation of hsp 70, tnf-α and il-1β was observed. We conclude that the administration of MacroGard® induced an immunomodulatory response and could be used as an effective measure to increase survival in rearing of turbot

Development of Gene Expression Markers of Acute Heat-Light Stress in Reef-Building Corals of the Genus Porites

Coral reefs are declining worldwide due to increased incidence of climate-induced coral bleaching, which will have widespread biodiversity and economic impacts. A simple method to measure the sub-bleaching level of heat-light stress experienced by corals would greatly inform reef management practices by making it possible to assess the distribution of bleaching risks among individual reef sites. Gene expression analysis based on quantitative PCR (qPCR) can be used as a diagnostic tool to determine coral condition in situ. We evaluated the expression of 13 candidate genes during heat-light stress in a common Caribbean coral Porites astreoides, and observed strong and consistent changes in gene expression in two independent experiments. Furthermore, we found that the apparent return to baseline expression levels during a recovery phase was rapid, despite visible signs of colony bleaching. We show that the response to acute heat-light stress in P. astreoides can be monitored by measuring the difference in expression of only two genes: Hsp16 and actin. We demonstrate that this assay discriminates between corals sampled from two field sites experiencing different temperatures. We also show that the assay is applicable to an Indo-Pacific congener, P. lobata, and therefore could potentially be used to diagnose acute heat-light stress on coral reefs worldwide

Displacement Estimation Based on Model Calibration in Weak Feedback Optical Self-Mixing System

This paper presents a novel method to estimate displacement of a moving object based on model calibration in a weak feedback laser diode self-mixing system. A hybrid genetic algorithm is employed to locate the global minimum for the cost function which is constructed as the discrepancy between theoretically calculated system output and the experimental data. In turn, displacement measurement is achieved by identifying the optimal parameters for the system model. The proposed method is tested by both simulation and experimental setup with measuring accuracy better than 25nm