927 resultados para Distance between Populations based on Continuous and Discrete Variables


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Current fusion devices consist of multiple diagnostics and hundreds or even thousands of signals. This situation forces on multiple occasions to use distributed data acquisition systems as the best approach. In this type of distributed systems, one of the most important issues is the synchronization between signals, so that it is possible to have a temporal correlation as accurate as possible between the acquired samples of all channels. In last decades, many fusion devices use different types of video cameras to provide inside views of the vessel during operations and to monitor plasma behavior. The synchronization between each video frame and the rest of the different signals acquired from any other diagnostics is essential in order to know correctly the plasma evolution, since it is possible to analyze jointly all the information having accurate knowledge of their temporal correlation. The developed system described in this paper allows timestamping image frames in a real-time acquisition and processing system using 1588 clock distribution. The system has been implemented using FPGA based devices together with a 1588 synchronized timing card (see Fig.1). The solution is based on a previous system [1] that allows image acquisition and real-time image processing based on PXIe technology. This architecture is fully compatible with the ITER Fast Controllers [2] and offers integration with EPICS to control and monitor the entire system. However, this set-up is not able to timestamp the frames acquired since the frame grabber module does not present any type of timing input (IRIG-B, GPS, PTP). To solve this lack, an IEEE1588 PXI timing device its used to provide an accurate way to synchronize distributed data acquisition systems using the Precision Time Protocol (PTP) IEEE 1588 2008 standard. This local timing device can be connected to a master clock device for global synchronization. The timing device has a buffer timestamp for each PXI trigger line and requires tha- a software application assigns each frame the corresponding timestamp. The previous action is critical and cannot be achieved if the frame rate is high. To solve this problem, it has been designed a solution that distributes the clock from the IEEE 1588 timing card to all FlexRIO devices [3]. This solution uses two PXI trigger lines that provide the capacity to assign timestamps to every frame acquired and register events by hardware in a deterministic way. The system provides a solution for timestamping frames to synchronize them with the rest of the different signals.

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We study how to use quantum key distribution (QKD) in common optical network infrastructures and propose a method to overcome its distance limitations. QKD is the first technology offering information theoretic secret-key distribution that relies only on the fundamental principles of quantum physics. Point-to-point QKD devices have reached a mature industrial state; however, these devices are severely limited in distance, since signals at the quantum level (e.g. single photons) are highly affected by the losses in the communication channel and intermediate devices. To overcome this limitation, intermediate nodes (i.e. repeaters) are used. Both, quantum-regime and trusted, classical, repeaters have been proposed in the QKD literature, but only the latter can be implemented in practice. As a novelty, we propose here a new QKD network model based on the use of not fully trusted intermediate nodes, referred as weakly trusted repeaters. This approach forces the attacker to simultaneously break several paths to get access to the exchanged key, thus improving significantly the security of the network. We formalize the model using network codes and provide real scenarios that allow users to exchange secure keys over metropolitan optical networks using only passive components.

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A MATLAB-based computer code has been developed for the simultaneous wavelet analysis and filtering of multichannel seismic data. The considered time–frequency transforms include the continuous wavelet transform, the discrete wavelet transform and the discrete wavelet packet transform. The developed approaches provide a fast and precise time–frequency examination of the seismograms at different frequency bands. Moreover, filtering methods for noise, transients or even baseline removal, are implemented. The primary motivation is to support seismologists with a user-friendly and fast program for the wavelet analysis, providing practical and understandable results.

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In broader catchment scale investigations, there is a need to understand and ultimately exploit the spatial variation of agricultural crops for an improved economic return. In many instances, this spatial variation is temporally unstable and may be different for various crop attributes and crop species. In the Australian sugar industry, the opportunity arose to evaluate the performance of 231 farms in the Tully Mill area in far north Queensland using production information on cane yield (t/ha) and CCS ( a fresh weight measure of sucrose content in the cane) accumulated over a 12-year period. Such an arrangement of data can be expressed as a 3-way array where a farm x attribute x year matrix can be evaluated and interactions considered. Two multivariate techniques, the 3-way mixture method of clustering and the 3-mode principal component analysis, were employed to identify meaningful relationships between farms that performed similarly for both cane yield and CCS. In this context, farm has a spatial component and the aim of this analysis was to determine if systematic patterns in farm performance expressed by cane yield and CCS persisted over time. There was no spatial relationship between cane yield and CCS. However, the analysis revealed that the relationship between farms was remarkably stable from one year to the next for both attributes and there was some spatial aggregation of farm performance in parts of the mill area. This finding is important, since temporally consistent spatial variation may be exploited to improve regional production. Alternatively, the putative causes of the spatial variation may be explored to enhance the understanding of sugarcane production in the wet tropics of Australia.

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The preparation and characterisation of collagen: PCL, gelatin: PCL and gelatin/collagen:PCL biocomposites for manufacture of tissue engineered skin substitutes are reported. Films of collagen: PLC, gelatin: PCL (1:4, 1:8 and 1:20 w/w) and gelatin/collagen:PCL (1:8 and 1:20 w/w) biocomposites were prepared by impregnation of lyophilised collagen and/or gelatin mats by PCL solutions followed by solvent evaporation. In vitro assays of total protein release of collagen:PCL and gelatin: PCL biocomposite films revealed an expected inverse relationship between the collagen release rate and the content of synthetic polymer in the biocomposite samples that may be exploited for controlled presentation and release of biopharmaceuticals such as growth factors. Good compatibility of all biocomposite groups was proven by interaction with 3T3 fibroblasts, normal human epidermal keratinocytes (NHEK), and primary human epidermal keratinocytes (PHEK) and dermal fibroblasts (PHDF) in vitro respectively. The 1:20 collagen: PCL materials exhibiting good cell growth curves and mechanical characteristics were selected for engineering of skin substitutes in this work. The tissue-engineered skin model based on single-donor PHEK and PHDF with differentiated confluent epidermal layer and fibrous porous dermal layer was then developed successfully in vitro proven by SEM and immunohistochemistry assay. The following in vivo animal study on athymic mice revealed early complete wound healing in 10 days and good integration of co-cultured skin substitutes with adjacent mice skin structures. Thus the co-cultured skin substitutes based on 1:20 collagen: PCL biocomposite membranes was proven in principle. The approach to skin modelling reported here may find application in wound treatment, gene therapy and screening of new pharmaceuticals.

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The preparation and characterisation of collagen:PCL composites for manufacture of tissue engineered skin substitutes and models are reported. Films having collagen:PCL (w/w) ratios of 1:4, 1:8 and 1:20 were prepared by impregnation of lyophilised collagen mats by PCL solutions followed by solvent evaporation. In vitro assays of collagen release and residual collagen content revealed an expected inverse relationship between the collagen release rate and the content of synthetic polymer in the composite that may be exploited for controlled presentation and release of biopharmaceuticals such as growth factors. DSC analysis revealed the characteristic melting point of PCL at around 60°C and a tendency for the collagen component, at high loading, to impede crystallinity development within the PCL phase. The preparation of fibroblast/composite constructs was investigated using cell culture as a first stage in mimicking the dermal/epidermal structure of skin. Fibroblasts were found to attach and proliferate on all the composites investigated reaching a maximum of 2×105/cm2 on 1:20 collagen:PCL materials at day 8 with cell numbers declining thereafter. Keratinocyte growth rates were similar on all types of collagen:PCL materials investigated reaching a maximum of 6.6×104/cm2 at day 6. The results revealed that composite films of collagen and PCL are favourable substrates for growth of fibroblasts and keratinocytes and may find utility for skin repair. © 2003 Elsevier Ltd. All rights reserved.

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A nonlinear polarization rotation based all-fiber passively modelocked Tm3+-doped fiber laser is demonstrated by using a 45° tilted fiber grating (TFG) as an in-line polarizer. The 45° TFG centered at 2000 nm with polarization dependent loss (PDL) of >12 dB at 1850 nm∼2150 nm range was UV inscribed for the first time in SM28 fiber using a 244 nm Ar+ continuous wave laser and a phase mask with 25 mm long uniform pitch and titled period pattern of 33.7° with respect to the fiber axis. Stable soliton pulses centered at 1992.7 nm with 2.02 nm FWHM bandwidth were produced at a repetition rate of 1.902 MHz with pulse duration of 2.2 ps and pulse energy of 74.6 pJ. As increased pump power, the laser also can operate at noise-like regime with 18.1 nm FWHM bandwidth and pulse energy of up to 250.1 nJ. Using the same 45° TFG, both stable soliton and noise-like mode-locking centered at ∼1970 nm and ∼2050 nm, were also achieved by shortening and extending the length of Tm3+-doped fiber, respectively, exhibiting advantages of broadband and low insertion loss at 2 μm band.

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The UK government aims at achieving 80% CO2 emission reduction by 2050 which requires collective efforts across all the UK industry sectors. In particular, the housing sector has a large potential to contribute to achieving the aim because the housing sector alone accounts for 27% of the total UK CO2 emission, and furthermore, 87% of the housing which is responsible for current 27% CO2 emission will still stand in 2050. Therefore, it is essential to improve energy efficiency of existing housing stock built with low energy efficiency standard. In order for this, a whole‐house needs to be refurbished in a sustainable way by considering the life time financial and environmental impacts of a refurbished house. However, the current refurbishment process seems to be challenging to generate a financially and environmentally affordable refurbishment solution due to the highly fragmented nature of refurbishment practice and a lack of knowledge and skills about whole‐house refurbishment in the construction industry. In order to generate an affordable refurbishment solution, diverse information regarding costs and environmental impacts of refurbishment measures and materials should be collected and integrated in right sequences throughout the refurbishment project life cycle among key project stakeholders. Consequently, various researchers increasingly study a way of utilizing Building Information Modelling (BIM) to tackle current problems in the construction industry because BIM can support construction professionals to manage construction projects in a collaborative manner by integrating diverse information, and to determine the best refurbishment solution among various alternatives by calculating the life cycle costs and lifetime CO2 performance of a refurbishment solution. Despite the capability of BIM, the BIM adoption rate is low with 25% in the housing sector and it has been rarely studied about a way of using BIM for housing refurbishment projects. Therefore, this research aims to develop a BIM framework to formulate a financially and environmentally affordable whole‐house refurbishment solution based on the Life Cycle Costing (LCC) and Life Cycle Assessment (LCA) methods simultaneously. In order to achieve the aim, a BIM feasibility study was conducted as a pilot study to examine whether BIM is suitable for housing refurbishment, and a BIM framework was developed based on the grounded theory because there was no precedent research. After the development of a BIM framework, this framework was examined by a hypothetical case study using BIM input data collected from questionnaire survey regarding homeowners’ preferences for housing refurbishment. Finally, validation of the BIM framework was conducted among academics and professionals by providing the BIM framework and a formulated refurbishment solution based on the LCC and LCA studies through the framework. As a result, BIM was identified as suitable for housing refurbishment as a management tool, and it is timely for developing the BIM framework. The BIM framework with seven project stages was developed to formulate an affordable refurbishment solution. Through the case study, the Building Regulation is identified as the most affordable energy efficiency standard which renders the best LCC and LCA results when it is applied for whole‐house refurbishment solution. In addition, the Fabric Energy Efficiency Standard (FEES) is recommended when customers are willing to adopt high energy standard, and the maximum 60% of CO2 emissions can be reduced through whole‐house fabric refurbishment with the FEES. Furthermore, limitations and challenges to fully utilize BIM framework for housing refurbishment were revealed such as a lack of BIM objects with proper cost and environmental information, limited interoperability between different BIM software and limited information of LCC and LCA datasets in BIM system. Finally, the BIM framework was validated as suitable for housing refurbishment projects, and reviewers commented that the framework can be more practical if a specific BIM library for housing refurbishment with proper LCC and LCA datasets is developed. This research is expected to provide a systematic way of formulating a refurbishment solution using BIM, and to become a basis for further research on BIM for the housing sector to resolve the current limitations and challenges. Future research should enhance the BIM framework by developing more detailed process map and develop BIM objects with proper LCC and LCA Information.

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The article focuses on the labour market situation and opportunities of the Hungarian vocational students. After briefly placing the topic in an international context, the study introduces the findings of the Hungarian empirical researches. Due to the differences between the various national education systems, it is not easy to make international comparisons; therefore I chose former socialist countries with characteristics similar to those of Hungary. When comparing the relevant data, it became clear that obtaining a diploma provides more advantages in Hungary. Hungarian researches suggest that vocational schools mostly attract students with poor competence test scores at the end of primary school. Also a significant proportion of these students are disadvantaged. Vocational students are the most likely to drop out of the system and their return to the school later is sporadic at best. Although a completed VET improves their employment conditions and prospects, many of the graduates will leave their profession or do unskilled labour. Their labour income varies greatly depending on their type of trade and experience gained.

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Nanocomposites based on polyaniline (PANI) and carbon nanostructures (CNSs) (graphene (G) and multiwall carbon nanotubes (MWCNTs)) were prepared by in situ electrochemical polymerization. CNSs were inserted into the PANI matrix by dispersing them into the electrolyte before the electropolymerization. Electrochemical characterization by means of cyclic voltammetry and steady state polarization were performed in order to determine conditions for electro- polymerization. Electro-polymerization of the PANI based nanocomposites was carried out at 0.75 V vs. saturated calomel electrode (SCE) for 40 and 60 minutes. The morphology and structural characteristics of the obtained nanocomposites were studied by scanning electron microscopy (SEM) and Raman spectroscopy, while thermal stability was determined using thermal gravimetric analysis (TGA). According to the morphological and structural study, fibrous and porous structure of PANI based nanocomposites was detected well embedding both G and MWCNTs. Also, strong interaction between quinoidal structure of PANI with carbon nanostructures via π–π stacking was detected by Raman spectroscopy. TGA showed the increased thermal stability of composites reinforced with CNSs, especially those reinforced with graphene.

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A NOx reduction efficiency higher than 95% with NH3 slip less than 30 ppm is desirable for heavy-duty diesel (HDD) engines using selective catalytic reduction (SCR) systems to meet the US EPA 2010 NOx standard and the 2014-2018 fuel consumption regulation. The SCR performance needs to be improved through experimental and modeling studies. In this research, a high fidelity global kinetic 1-dimensional 2-site SCR model with mass transfer, heat transfer and global reaction mechanisms was developed for a Cu-zeolite catalyst. The model simulates the SCR performance for the engine exhaust conditions with NH3 maldistribution and aging effects, and the details are presented. SCR experimental data were collected for the model development, calibration and validation from a reactor at Oak Ridge National Laboratory (ORNL) and an engine experimental setup at Michigan Technological University (MTU) with a Cummins 2010 ISB engine. The model was calibrated separately to the reactor and engine data. The experimental setup, test procedures including a surrogate HD-FTP cycle developed for transient studies and the model calibration process are described. Differences in the model parameters were determined between the calibrations developed from the reactor and the engine data. It was determined that the SCR inlet NH3 maldistribution is one of the reasons causing the differences. The model calibrated to the engine data served as a basis for developing a reduced order SCR estimator model. The effect of the SCR inlet NO2/NOx ratio on the SCR performance was studied through simulations using the surrogate HD-FTP cycle. The cumulative outlet NOx and the overall NOx conversion efficiency of the cycle are highest with a NO2/NOx ratio of 0.5. The outlet NH3 is lowest for the NO2/NOx ratio greater than 0.6. A combined engine experimental and simulation study was performed to quantify the NH3 maldistribution at the SCR inlet and its effects on the SCR performance and kinetics. The uniformity index (UI) of the SCR inlet NH3 and NH3/NOx ratio (ANR) was determined to be below 0.8 for the production system. The UI was improved to 0.9 after installation of a swirl mixer into the SCR inlet cone. A multi-channel model was developed to simulate the maldistribution effects. The results showed that reducing the UI of the inlet ANR from 1.0 to 0.7 caused a 5-10% decrease in NOx reduction efficiency and 10-20 ppm increase in the NH3 slip. The simulations of the steady-state engine data with the multi-channel model showed that the NH3 maldistribution is a factor causing the differences in the calibrations developed from the engine and the reactor data. The Reactor experiments were performed at ORNL using a Spaci-IR technique to study the thermal aging effects. The test results showed that the thermal aging (at 800°C for 16 hours) caused a 30% reduction in the NH3 stored on the catalyst under NH3 saturation conditions and different axial concentration profiles under SCR reaction conditions. The kinetics analysis showed that the thermal aging caused a reduction in total NH3 storage capacity (94.6 compared to 138 gmol/m3), different NH3 adsorption/desorption properties and a decrease in activation energy and the pre-exponential factor for NH3 oxidation, standard and fast SCR reactions. Both reduction in the storage capability and the change in kinetics of the major reactions contributed to the change in the axial storage and concentration profiles observed from the experiments.

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The comparative study based on spectroscopic analysis of the materials used to produce four sixteenth-century Manueline Charters (the Charters of Alcochete, Terena, Alandroal and Evora) was performed following a systematic analytical approach. SEM–EDS, l-Raman and l-FTIR analysis highlighted interesting features between them, namely the use of different pigments and colourants (such as different green and yellow pigments), the presence of pigments alterations and the use of a non-expected extemporaneous material (with the presence of titanium white in the Charter of Alcochete). Principal component analysis restricted to the C–H absorption region (3000–2840 cm-1) was applied to 36 infrared spectra of blue historical samples from the Charters of Alcochete,Terena, Alandroal and Évora, suggesting the use of a mixture of a triglyceride and polysaccharide as binder.

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Lepidocharax, new genus, and Lepidocharax diamantina and L. burnsi new species from eastern Brazil are described herein. Lepidocharax is considered a monophyletic genus of the Stevardiinae and can be distinguished from the other members of this subfamily except Planaltina, Pseudocorynopoma, and Xenurobrycon by having the dorsal-fin origin vertically aligned with the anal-fin origin, vs. dorsal fin origin anterior or posterior to anal-fin origin. Additionally the new genus can be distinguished from those three genera by not having the scales extending over the ventral caudal-fin lobe modified to form the dorsal border of the pheromone pouch organ or to represent a pouch scale in sexually mature males. In this paper, we describe these two recently discovered species and the ultrastructure of their spermatozoa.

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Egg and pupa of Lobeza dentilinea Schaus, 1901 are described and illustrated for the first time. Eggs are smooth, dome-shaped, and greenish at oviposition. Last instar larvae have an aposematic coloration and the chaetotaxy is very similar to other notodontines, except for the number of lateral setae: L. dentilinea has three instead of four lateral setae on abdominal segments A3-A6. Pupae are light brown and typical of the family, with the last abdominal segments broadly round. Evidence from the adult morphology supporting the placement of the genus in Notodontinae includes proboscis smaller than the length of the head, epiphysis with more than half the length of tibia, tarsal claws simple, and labial palpi short. Male and female are confidently associated, and a redescription of the species is presented based on both sexes. Larvae of L. dentilinea are here recorded feeding on a Melastomataceae.

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We evaluated the genetic and physiological variability of Moniliophthora perniciosa obtained from healthy and diseased branches of cacao (Theobroma cacao) plants. The diversity of the isolates was evaluated by RAPD technique and by studies of virulence and exoenzyme production. The genetic variability of endophytic and pathogenic M. perniciosa was evaluated in association with pathogenicity assays. RAPD analysis showed eight genetic groups, which were not related to plant disease status (healthy versus diseased branches). Isolates from cacao were included in three groups, excluding isolates from other host plants. Pathogenicity and enzyme analysis showed that the virulence of the isolates is not related to exoenzyme production. This is the first evidence that M. perniciosa colonizes healthy parenchymatic tissues, showing that endophytic behavior may occur in this species.