536 research outputs found
On the detection of nearly optimal solutions in the context of single-objective space mission design problems
When making decisions, having multiple options available for a possible realization of the same project can be advantageous. One way to increase the number of interesting choices is to consider, in addition to the optimal solution x*, also nearly optimal or approximate solutions; these alternative solutions differ from x* and can be in different regions – in the design space – but fulfil certain proximity to its function value f(x*). The scope of this article is the efficient computation and discretization of the set E of e–approximate solutions for scalar optimization problems. To accomplish this task, two strategies to archive and update the data of the search procedure will be suggested and investigated. To make emphasis on data storage efficiency, a way to manage significant and insignificant parameters is also presented. Further on, differential evolution will be used together with the new archivers for the computation of E. Finally, the behaviour of the archiver, as well as the efficiency of the resulting search procedure, will be demonstrated on some academic functions as well as on three models related to space mission design
EVALITA 2020: Overview of the 7th evaluation campaign of natural language processing and speech tools for Italian
The Evaluation Campaign of Natural Language Processing and Speech Tools for Italian (EVALITA) is the biennial initiative aimed at promoting the development of language and speech technologies for the Italian language. EVALITA is promoted by the Italian Association of Computational Linguistics (AILC) and it is endorsed by the Italian Association for Artificial Intelligence (AIxIA) and the Italian Association for Speech Sciences (AISV).
EVALITA provides a shared framework where different systems and approaches can be scientifically evaluated and compared with each other with respect to a large variety of tasks, suggested and organized by the Italian research community. The proposed tasks represent scientific challenges where methods, resources, and systems can be tested against shared benchmarks representing linguistic open issues or real world applications, possibly in a multilingual and/or multi-modal perspective. The collected data
sets provide big opportunities for scientists to explore old and new problems concerning NLP in Italian as well as to develop solutions and to discuss the NLP-related issues within the community. Some tasks are traditionally present in the evaluation campaign, while others are completely new.
This paper introduces the tasks proposed at EVALITA 2020 and provides an overview to the participants and systems whose descriptions and obtained results are reported in these Proceedings
Investigation of a novel silicon-on-insulator Rib-Slot photonic sensor based on the vernier effect and operating at 3.8 µm
In this paper, we present the theoretical investigation of photonic sensors based on Vernier effect with two cascade-coupled ring resonators in silicon on insulator technology. The photonic chip utilizes rib and slot waveguides designed to operate at 3.8 µm mid infrared wavelength, where a number of harmful gases, chemical and biochemical analytes are spectroscopically accessible. A rigorous algorithmic procedure has been implemented for the design of such devices and novel technological solutions have been proposed according to very recent experimental results. The rib-slot sensor architecture can exhibit wavelength sensitivities as high as 20.6 µm/RIU and limits of detection for homogeneous sensing as low as 3.675 x 10^-4 RIU
third order bragg grating filters in small soi waveguides
Third order grating filters fabricated in small Silicon-on-Insulator rib waveguides are demonstrated. Variations in grating etch depth and duty cycle are considered, and a maximum experimental reflection of 42% is demonstrated for gratings of 1500 µm in length, with a grating period of approximately 689nm and an etch depth of 200nm. Agreement with modeling is shown to be good
In-Line-Test of Variability and Bit-Error-Rate of HfOx-Based Resistive Memory
Spatial and temporal variability of HfOx-based resistive random access memory
(RRAM) are investigated for manufacturing and product designs. Manufacturing
variability is characterized at different levels including lots, wafers, and
chips. Bit-error-rate (BER) is proposed as a holistic parameter for the write
cycle resistance statistics. Using the electrical in-line-test cycle data, a
method is developed to derive BERs as functions of the design margin, to
provide guidance for technology evaluation and product design. The proposed BER
calculation can also be used in the off-line bench test and build-in-self-test
(BIST) for adaptive error correction and for the other types of random access
memories.Comment: 4 pages. Memory Workshop (IMW), 2015 IEEE Internationa
Expression and purification of the recombinant subunits of toluene/o-xylene monooxygenase and reconstitution of the active complex.
This paper describes the cloning of the genes coding for each component of the complex of toluene/o-xylene monooxygenase from Pseudomonas stutzeri OX1, their expression, purification and characterization. Moreover, the reconstitution of the active complex from the recombinant subunits has been obtained, and the functional role of each component in the electron transfer from the electron donor to molecular oxygen has been determined. The coexpression of subunits B, E and A leads to the formation of a subcomplex, named H, with a quaternary structure (BEA)2, endowed with hydroxylase activity. Tomo F component is an NADH oxidoreductase. The purified enzyme contains about 1 mol of FAD, 2 mol of iron, and 2 mol of acid labile sulfide per mol of protein, as expected for the presence of one [2Fe-2S] cluster, and exhibits a typical flavodoxin absorption spectrum. Interestingly, the sequence of the protein does not correspond to that previously predicted on the basis of DNA sequence. We have shown that this depends on minor errors in the gene sequence that we have corrected. C component is a Rieske-type ferredoxin, whose iron and acid labile sulfide content is in agreement with the presence of one [2Fe-2S] cluster. The cluster is very sensitive to oxygen damage. Mixtures of the subcomplex H and of the subunits F, C and D are able to oxidize p-cresol into 4-methylcathecol, thus demonstrating the full functionality of the recombinant subunits as purified. Finally, experimental evidence is reported which strongly support a model for the electron transfer. Subunit F is the first member of an electron transport chain which transfers electrons from NADH to C, which tunnels them to H subcomplex, and eventually to molecular oxyge
Quartz-enhanced photoacoustic spectroscopy exploiting low-frequency tuning forks as a tool to measure the vibrational relaxation rate in gas species
We demonstrated that quartz-enhanced photoacoustic spectroscopy (QEPAS) is an efficient tool to measure the vibrational relaxation rate of gas species, employing quartz tuning forks (QTFs) as sound detectors. Based on the dependence of the QTF resonance frequency on the resonator geometry, a wide range of acoustic frequencies with narrow detection bandwidth was probed. By measuring the QEPAS signal of the target analyte as well as the resonance properties of different QTFs as a function of the gas pressure, the relaxation time can be retrieved. This approach has been tested in the near infrared range by measuring the CH4 (nν4) vibrational relaxation rate in a mixture of 1% CH4, 0.15 % H2O in N2, and the H2O (ν1) relaxation rate in a mixture of 0.5 % H2O in N2. Relaxation times of 3.2 ms Torr and 0.25 ms Torr were estimated for CH4 and H2O, respectively, in excellent agreement with values reported in literature
Adipokines levels in HIV infected patients: Lipocalin-2 and fatty acid binding protein-4 as possible markers of HIV and antiretroviral therapy-related adipose tissue inflammation
Skeletal Muscle Mitochondrial and Perilipin Content in a Cohort of Obese Subjects Undergoing Moderate and High Intensity Training
Obesity is a complex condition characterized by abnormal and excessive fat accumulation, resulting in an increased risk for severe health problems. Skeletal muscles play a major role in movement and fat catabolism, but the insulin resistance that comes with obesity makes it difficult to fulfill these tasks. In this study, we analyse two types of training protocols, moderate intensity continuous training (MICT) versus high intensity interval training (HIIT), in a cohort of obese subjects to establish which muscle adaptations favour fat consumption in response to exercise. Mitochondria play a role in fat oxidation. We found protein upregulation of mitochondrial biomarkers, TOMM20 and Cox-4, in HIIT but not in MICT, without detecting any shifts in fibre composition phenotype of the vastus lateralis in both training groups. Interestingly, both MICT and HIIT protocols showed increased protein levels of perilipin PLIN2, which is involved in the delivery and consumption of fats. HIIT also augmented perilipin PLIN5. Perilipins are involved in fat storage in skeletal muscles and their upregulation, along with the analysis of circulatory lipid profiles reported in the present study, suggest important adaptations induced by the two types of training protocols that favour fat consumption and weight loss in obese subjects
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