Stressed Syllable Determination for Romanian Words within Speech Synthesis Applications

This paper proposes and experimentally evaluates a method to determine the stressed syllable of a word in the framework of speech synthesis in Romanian. In order to produce high quality speech, a speech synthesis system needs information about the position of the stress for each word of a sentence to be generated. Otherwise, incorrect positioning of stress (or, in the worst case, completely ignoring it) translates into poor quality synthesized speech. Since Romanian is a free-stressed language (as is English, for example), the position of the stressed syllable within a word is not clearly defined. Consequently, a set of explicit rules that can determine the exact position of the stress is difficult to generate. In order to solve this problem, we propose an original method to find stressing rules for the Romanian language as well as an algorithm to implement this method. According to this algorithm, the position of the stressed syllable is computed according to a number of word parameters encompassing morphologic, phonetic, and lexical characteristics of the word. The experimental results show that the errors of the automatic stress assignment using our method do not exceed 6%.     

Photoreflectance Studies of SIMOX Materials

Photoreflectance (PR) was used to study SIMOX materials produced under various fabrication conditions. The position, amplitude and shape of the 3.4 eV PR response were monitored for three different sets of samples which provided information about the crystalline quality of the top silicon layer. Each sample of the first set underwent different annealing conditions. A second set of six samples was arranged such that one sample was removed at a different step of the process involving three implantation-anneal cycles. A third set of four samples was implanted with different doses of oxygen. In the first case the PR signal improved with longer annealing times and higher temperatures; in the second case the PR signal appeared to deteriorate with each cycle undergone by the samples, while in the third case the degradation of the structure increased with the increased implantation dosage. Transmission electron microscopy (TEM) was also performed in the last two cases, and its results supported the PR conclusions.     

Nutritional characterization of carbohydrates and proximal composition of cooked tropical roots and tubers produced in Costa Rica

Tropical roots and tubers (TRT) are important staple foods in the tropics. TRT are produced by small farmers and have received only limited attention. The objective of this paper was to evaluate nutritionally important carbohydrate fractions and proximal composition of cooked cassava (Manihot esculenta), cocoyam- or tannia- (Xantosoma sp) and yam (Dioscorea alata) grown in Costa Rica. Twenty boiled samples of each TRT were analyzed for proximal composition, following AOAC protocols. Carbohydrate fractions (dietary fiber, available and resistant starch) and alpha-amylolysis rate were assessed by enzymatic methods. All TRT analyzed consisted mainly of water and carbohydrates, representing moderate dietary fiber and energy sources. They show a low protein level and contain no fat. Moisture, protein, ashes and dietary fiber contents vary significantly (p<0.01) among the three species. In terms of their proximal composition, these locally grown TRT differ from TRTs cultivated in the South Pacific area, but appear similar to other Latin American varieties. In all samples most of the dietary fiber (84-88%) is insoluble; available starch ranges between 74 and 84% of the dry matter, whereas resistant starch content varied between 0.7 and 1.7%. Amylolysis rate was similar for cassava and cocoyam, whereas a significantly slower digestion (p<0.01) was recorded for yam. Compared to values reported in the literature for other starchy foods and to gelatinized potato starch, used as reference sample, the studied TRT showed intermediate amylolysis rates. It is concluded that consumption of these TRT may be promoted in Costa Rica and other countries with a similar nutritional situation.     

Study of polypropylene/polybutene blends modified by gamma irradiation and (high melt strength polypropylene)/polybutene blends

It is well-known that polypropylene (PP) is difficult to process as a consequence of its linear structure. It is also known that grafting of long-chain branches on PP backbone using ionizing radiation is an effective approach to achieve high melt strength polypropylene (HMS PP). Chain-scission and, in minor extend, crosslinking and grafting are the predominant reaction in order to branch PP backbone. However, if multifunctional monomers are used to promote the grafting reaction, crosslinking can surpass chain scission and grafting, reducing drawability. Therefore, in an effort to enhance the processability and so the drawability, it has been found helpful to add a small amount of polybutene-1. Gamma irradiation technique was used to induce chemical changes in blends of PP and polybutene in acetylene atmosphere (crosslinker promoter) and in HMSPP/polybutene blends. The samples were irradiated with a ⁶⁰Co source with doses of 12.5 and 20 kGy in the presence of acetylene. In this work, two different methods of blends processing were compared regarding rheological and mechanical properties. Effects on the strength and elongation at the yield point and at rupture were observed by mechanical tests and showed decrease of tensile strength and increase of elongation at rupture for samples obtained by irradiation of blends. The results from rheology demonstrated an increase in melt strength and drawability of blends.     

Energy-efficient scheduling for a flexible flow shop using an improved genetic-simulated annealing algorithm

The traditional production scheduling problem considers performance indicators such as processing time, cost, and quality as optimization objectives in manufacturing systems; however, it does not take energy consumption or environmental impacts completely into account. Therefore, this paper proposes an energy-efficient model for flexible flow shop scheduling (FFS). First, a mathematical model for a FFS problem, which is based on an energy-efficient mechanism, is described to solve multi-objective optimization. Since FFS is well known as a NP-hard problem, an improved, genetic-simulated annealing algorithm is adopted to make a significant trade-off between the makespan and the total energy consumption to implement a feasible scheduling. Finally, a case study of a production scheduling problem for a metalworking workshop in a plant is simulated. The experimental results show that the relationship between the makespan and the energy consumption may be apparently conflicting. In addition, an energy-saving decision is performed in a feasible scheduling. Using the decision method, there could be significant potential for minimizing energy consumption.     

Adaptive control for the discrete-time parametric-strict-feedback form

The design of a state feedback controller for a class of SISO non-linear discrete-time systems is proposed. Namely, an alternative adaptive scheme is stated for the parametric-strict-feedback form. The control objective is to achieve tracking of a reference signal. Backstepping control is combined with a parameter estimator based on an orthogonalization process which overcomes the drawback of over-parameterization. Without assuming any growth conditions on the non-linearities, global boundedness and convergence are obtained in the closed loop system.     

Influence of drying conditions on the gelling properties of the 7S and 11S soy protein fractions

Soy protein fractions rich in β-conglycinin (7S) or glycinin (11S) were freeze dried or spray dried at temperatures of 120, 150 or 180 °C. The fractions were characterized for their particle size distribution, sorption isotherms and by scanning differential calorimetry. The gelling capacity of the protein fractions was studied at pH values of 3 and 7 using oscillatory measurements, mechanical properties and water holding capacity. The rheological measurements showed that viscous modulus (G″) predominated at low temperatures and the elastic modulus (G′) at high temperatures. At pH 3, the G′–G″ crossover occurred at lower temperatures when compared to pH 7. This behaviour was more accentuated for the 11S fractions due to its capacity to form stronger gels. An increase of drying temperature led to a displacement of the gel point to higher temperatures and decreased the elasticity modulus or gelling capacity of protein fractions. These results were confirmed by the mechanical properties, since at higher temperatures the gels were more fragile and brittle, especially when formed at pH 7.     

Plant fibre reinforced cement components for roofing

Composites of blast furnace slag (BFS) based cement mortar reinforced with vegetable fibres are presented. Roofing components are produced with these composites through a simple and low-energy consuming method, including ordinary vibration and curing in a wet chamber. Composites reinforced with eucalyptus pulp, coir fibres and with a mixture of sisal fibre and eucalyptus pulp gave a suitable performance, with compressive strength higher than 20 MPa and modulus of rupture (MOR) higher than 3 MPa. The performance of tiles made with these composites is in accordance with international requirements, with maximum load higher than 450 N, in wet conditions.     

Obtaining the consensus and inconsistency among a set of assertions on a qualitative attribute

It is well understood how to compute the average or centroid of a set of numeric values, as well as their variance. In this way we handle inconsistent measurements of the same property. We wish to solve the analogous problem on qualitative data: How to compute the “average” or consensus of a set of affirmations on a non-numeric fact, as reported for instance by different Web sites? What is the most likely truth among a set of inconsistent assertions about the same attribute?Given a set (a bag, in fact) of statements about a qualitative feature, this paper provides a method, based in the theory of confusion, to assess the most plausible value or “consensus” value. It is the most likely value to be true, given the information available. We also compute the inconsistency of the bag, which measures how far apart the testimonies in the bag are. All observers are equally credible, so differences arise from perception errors, due to the limited accuracy of the individual findings (the limited information extracted by the examination method from the observed reality).Our approach differs from classical logic, which considers a set of assertions to be either consistent (True, or 1) or inconsistent (False, or 0), and it does not use Fuzzy Logic.