The study is part of a series investigating production and perception of lexical stress in a number of languages including Brazilian Portuguese, English, Estonian, French, Italian and Swedish. The ...production database contains data representing male and female speakers in the above languages in three speaking styles – spontaneous speech, phrase reading, and wordlist reading. Keywords from these recordings, representing male and female speakers and all speaking styles are used. The participants’ task is to judge the relative syllable prominences of the keywords presented one by one. In a previous study, subjects were native Swedish speakers. In the present study subjects are native speakers of Italian. In the analyses, perception results are correlated with acoustic variables shown to be important in the production studies. From the previous perception study we know that acoustic syllable prominence affects perceived syllable prominence. But there is also a possibility that listeners’ perception may be biased by expectations based on the listeners’ native language. The main result is that there are great similarities between the Swedish and Italian listeners in the way acoustic prominence affects perceived prominence, but we are also able to demonstrate a case of native language bias.
It is proved that the theory of the class of all betweenness spaces metrizable by real-valued metrics does not coincide with the theory of the class of all betweenness spaces metrizable by metrics ...taking values in any ordered field. This solves a problem raised by Mendris and Zlatoš.
This article focuses on the analysis of progressive control methods employed in power semiconductor converters. These advanced methods primarily aim to enhance regulation properties, particularly in ...scenarios involving overregulation values or settling times during failure mechanisms. Such failure mechanisms often manifest as step changes in the input voltage of the power converter or variations in the load resistance value. Within this article, we explore three methods: sliding mode control (SMC), model predictive control (MPC), and neural networks (NN). These methods are recognized as progressive methods in the literature, characterized by their improved regulation properties.
This paper explores the utilization of state space analysis as an analytical approach in addressing challenges within the domain of power semiconductor converters. The application of this method was ...a pivotal component of the Power Semiconductor Systems course, where students were tasked with the comprehensive analysis of fundamental power semiconductor systems. Specifically, this analysis encompassed the examination of essential converter topologies, including rectifiers, DC/DC converters, and inverters. In the course of their studies, students harnessed their proficiency in mathematics, power electronics, and power semiconductor converters to construct comprehensive mathematical models of these converters. Subsequently, they leveraged the versatile capabilities of the Matlab programming environment to execute simulations of these converters. This mul- tifaceted approach not only served to substantiate the method's efficacy but also functioned as a validation of the students' knowledge and understanding of this critical field.
This article deals with the analysis and control of the DC/DC converters. The objective is to summarize a simple procedure to express the power converter's control transfer function and to show its ...usability possibilities. The process of obtaining this transfer function includes the creation of a state space description of the given system. As an example of the use of the transfer function of the control, the design of the feedback controller constants can be mentioned, since it is a transfer function that has a non-negligible effect on the closed loop system, or there is also the possibility of the stability verification. The state space model, as well as the transfer function, are derived for both ideal and non-ideal cases of topology. For the nonideal topology, at least some parasitic parameters are considered. For the design of the constants of the controller, an application "Control System Designer" in Matlab was used, enabling their design based on various criteria. Additionally, a comparison of the transfer functions based on frequency characteristics is presented. The Forward type topology is given as an example providing the benefit of output galvanic isolation.
This work explores the application of various supervised classification approaches using prosodic information for the identification of spoken North Sámi language varieties. Dialects are language ...varieties that enclose characteristics specific for a given region or community. These characteristics reflect segmental and suprasegmental (prosodic) differences but also high-level properties such as lexical and morphosyntactic. One aspect that is of particular interest and that has not been studied extensively is how the differences in prosody may underpin the potential differences among different dialects. To address this, this work focuses on investigating the standard acoustic prosodic features of energy, fundamental frequency, spectral tilt, duration, and their combinations, using sequential and context-independent supervised classification methods, and evaluated separately over two different units in speech: words and syllables. The primary aim of this work is to gain a better understanding on the role of prosody in identifying among the different language varieties. Our results show that prosodic information holds an important role in distinguishing between the five areal varieties of North Sámi where the inclusion of contextual information for all acoustic prosodic features is critical for the identification of dialects for words and syllables.
This article deals with the design of an artificial neural network (ANN) capable of mitigating fundamental error mechanisms in power systems, such as step changes in input voltage and load ...resistance. The primary objective is to create an ANN tailored for a DC/DC buck converter. The exploration includes the selection of an appropriate ANN type and its structural configuration. Additionally, a crucial aspect involves the identification and creation of training input-output datasets, ensuring the ANN effectively serves its purpose. In this context, the aim is to substitute the conventional PID controller with this ANN, tasking it with generating the necessary duty cycle.
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