Search results for " processing"
showing 10 items of 7549 documents
Iterative Learning Applied to Hydraulic Pressure Control
2018
This paper addresses a performance limiting phenomenon that may occur in the pressure control of hydraulic actuators subjected to external velocity disturbances. It is demonstrated that under certain conditions a severe peaking of the control error may be observed that significantly degrades the performance of the system due to the presence of nonlinearities. The phenomenon is investigated numerically and experimentally using a system that requires pressure control of two hydraulic cylinders. It is demonstrated that the common solution of feed forwarding the velocity disturbance is not effective in reducing the peaking that occurs as a result of this phenomenon. To improve the system perfor…
On Prefix Normal Words
2011
We present a new class of binary words: the prefix normal words. They are defined by the property that for any given length $k$, no factor of length $k$ has more $a$'s than the prefix of the same length. These words arise in the context of indexing for jumbled pattern matching (a.k.a. permutation matching or Parikh vector matching), where the aim is to decide whether a string has a factor with a given multiplicity of characters, i.e., with a given Parikh vector. Using prefix normal words, we give the first non-trivial characterization of binary words having the same set of Parikh vectors of factors. We prove that the language of prefix normal words is not context-free and is strictly contai…
THE SCENOGRAPHY OF SERPOTTA STUCCOES REVISITED - MATERIAL AND FORM
2015
The material that lies beneath the smooth shining surface of the stuccoes of the Serpotta family who used to work in Sicily from 1670 to 1730, has been thoroughly studied in previous papers, disclosing the deep, albeit empirical, knowledge of materials science that guided the artists in creating their masterpieces. In this work, attention is focused on the solid perspective and on the scenographic sculpture by Giacomo Serpotta, who is acknowledged as the leading exponent of the School. The study deals with some particular works of the artist, the “small-scaled plastic theatres”, so-called “teatrini”, which he made for the San Lorenzo Oratory in Palermo. On the basis of archival documents an…
Neural phoneme discrimination in variable speech in newborns – associations with dyslexia risk and later language skills
2023
AbstractA crucial skill in infant language acquisition is learning of the native language phonemes. This requires the ability to group complex sounds into distinct auditory categories based on their shared features. Problems in phonetic learning have been suggested to underlie language learning difficulties in dyslexia, a developmental reading-skill deficit. We investigated auditory abilities important for language acquisition in newborns with or without a familial risk for dyslexia with electrophysiological mismatch responses (MMRs). We presented vowel changes in a sequence of acoustically varying vowels, requiring grouping of the stimuli to two phoneme categories. The vowel changes elicit…
The Fuzzy Concept of Idiom and What It Might Mean for Bilingual Dictionaries
2019
Linguistic categories were developed as tools for describing language systems and making them easier to learn. However, like many theoretical concepts and systems, they do not fully represent the real world and, in some cases, seek to imprison linguistic units within a well-ordered system – a procrustean bed as it were. Besides, although the most general categories are universal, the lower-ranking ones are often language-specific. Idiom (or phraseologism) is a very unclear linguistic concept, subject to never-ending debate. However, a strict adherence to categorisation is observable in practical bilingual lexicography and phraseography. This may lead to unwanted compartmentalisation and a…
Aluminum tri-isopropoxide as an alternative precursor for atomic layer deposition of aluminum oxide thin films
2019
Due to the safety challenges associated with the use of trimethylaluminum as a metal precursor for the deposition of alumina, different chemicals have been investigated over the years to replace it. The authors have investigated the use of aluminum tri-isopropoxide (TIPA) as an alternative alkoxide precursor for the safe and cost-effective deposition of alumina. In this work, TIPA is used as a stable Al source for atomic layer deposition (ALD) of Al2O3 when different oxidizing agents including water, oxygen plasma, water plasma, and ozone are employed. The authors have explored the deposition of Al2O3 using TIPA in ALD systems operating in vacuum and atmospheric pressure conditions. For the…
Active lighting applied to three-dimensional reconstruction of specular metallic surfaces by polarization imaging
2006
International audience; In the field of industrial vision, the three-dimensional inspection of highly reflective metallic objects is still a delicate task. We deal with a new automated three-dimensional inspection system based on polarization analysis. We first present an extension of the shape-from-polarization method for dielectric surfaces to metallic surfaces. Then, we describe what we believe to be a new way of solving the ambiguity concerning the normal orientation with an active lighting system. Finally, applications to shape-defect detection are discussed, and the efficiency of the system to discriminate defects on specular metallic objects made by stamping and polishing is presente…
On the effectiveness of different additives and concentrations on the re-building of the molecular structure of degraded polyethylene
2006
Mechanical recycling is an easy and economic way to re-use plastic waste as secondary materials, but, in general, their properties are worse with respect to the reclaimed materials and the virgin polymer. The aim of this work was to study the effect of concentration and reaction kinetics of two additives, an ethylene-co-glycidyl methacrylate (Lotader) and a hydroxylamine derivative (CGX), in the re-building of a degraded polyethylene. CGX is a nitroxyl radical generator able to form branching in polyolefins while the epoxy groups of Lotader can react with the functional groups present in the recycled polyethylene. The results indicate that the CGX has a higher reaction rate than Lotader, pr…
On the Preparation and the Characterization of Polyethylene/Polyamide Blends by Melt Processing in the Presence of an Ethylene(co)acrylic Acid Copoly…
2006
Samples of HDPE and PA6 have been meltprocessed in the presence of two new phosphazene compounds, CP-2EPOX and CP-2OXA together with an ethylene/ acrylic acid copolymer. The blends have been prepared in an industrial twin-screw extruder by using PA6 and PE in weight ratios of 25/75 and 75/25. When used, 5 phr of EAA and 0.2 phr of CP have been added. The materials have been completely characterized from a rheological, morphological, and mechanical point of view. The results indicate that the additives used caused an increase in the rupture tensile properties, of the impact strength and viscosity especially in the PE-rich blend in the presence of CP-2EPOX. This result can be attributed both …
Blends using brabender farinograph and E6 Haubelt flourgraph
2010
The aim of this work is to establish correlations between the values of the Brabender Farinograph and the E6 Haubert Flourgraph. We analyzed two types of flours, white flour with additives (WF add) and brown flour with additives (BF add). The following parameters were varied: water absorption capacity, development time, the stability, the degree of softening and the quality number of wheat and potato flour mixture. A statistical analysis was made from linear regression equations. The obtained values for the E6 Flourgraph are comparable with Farinograph values and units. Hydration capacity values, calculated for a standard consistency of 500 HE, UF, obtained on these two devices are in a clo…