A Note on Contact Networks for Switching Functions of Four Variables

AbstractContact networks provide insights on disease spread due to the duration of close proximity interactions. For systems governed by consensus dynamics, network structure is key to optimising the spread of information. For disease spread over contact networks, the structure would be expected to be similarly influential. However, metrics that are essentially agnostic to the network’s structure, such as weighted degree (strength) centrality and its variants, perform near-optimally in selecting effective spreaders. These degree-based metrics outperform eigenvector centrality, despite disease spread over a network being a random walk process. This paper improves eigenvector-based spreader selection by introducing the non-linear relationship between contact time and the probability of disease transmission into the assessment of network dynamics. This approximation of disease spread dynamics is achieved by altering the Laplacian matrix, which in turn highlights why nodes with a high degree are such influential disease spreaders. From this approach, a trichotomy emerges on the definition of an effective spreader where, for susceptible-infected simulations, eigenvector-based selections can either optimise the initial rate of infection, the average rate of infection, or produce the fastest time to full infection of the network. Simulated and real-world human contact networks are examined, with insights also drawn on the effective adaptation of ant colony contact networks to reduce pathogen spread and protect the queen ant.

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Optimal Operation of the Voltage-Doubler Boost Converter through an Evolutionary Algorithm

Mathematics ◽

10.3390/math9040423 ◽

2021 ◽

Vol 9 (4) ◽

pp. 423

Author(s):

Cesar Ibarra-Nuño ◽

Alma Rodríguez ◽

Avelina Alejo-Reyes ◽

Erik Cuevas ◽

Juan M. Ramirez ◽

...

Keyword(s):

Evolutionary Algorithm ◽

Numerical Optimization ◽

Boost Converter ◽

Optimal Operation ◽

Input Current ◽

Voltage Gain ◽

Duty Cycles ◽

Switching Functions ◽

Voltage Doubler ◽

Current Ripple

This manuscript presents the numerical optimization (through a mathematical model and an evolutionary algorithm) of the voltage-doubler boost converter, also called the series-capacitor boost converter. The circuit is driven by two transistors, each of them activated according to a switching signal. In the former operation, switching signals have an algebraic dependence from each other. This article proposes a new method to operate the converter. The proposed process reduces the input current ripple without changing any converter model parameter, only the driving signals. In the proposed operation, switching signals of transistors are independent of each other, providing an extra degree of freedom, but on the other hand, this produces an infinite number of possible combinations of duty cycles (the main parameter of switching signals) to achieve the desired voltage gain. In other words, this leads to a problem with infinite possible solutions. The proposed method utilizes an evolutionary algorithm to determine the switching functions and, at the same time, to minimize the input current ripple of the converter. A comparison made between the former and the proposed operation shows that the proposed process achieves a lower input current ripple while achieving the desired voltage gain.

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Functional and sociocultural attitudes of code-switching and its relation to the meaning-making process: The case of dubbing Kim Possible into Arabic

International Journal of Bilingualism ◽

10.1177/13670069211019482 ◽

2021 ◽

pp. 136700692110194

Author(s):

Rashid Yahiaoui ◽

Marwa J Aldous ◽

Ashraf Fattah

Keyword(s):

Meaning Making ◽

Code Switching ◽

Power Dynamics ◽

Sociocultural Attitudes ◽

Switching Patterns ◽

Switching Functions ◽

Switching Type ◽

Lebanese Arabic ◽

Research Questions

Aims and objectives/purpose/research questions: The aim of this study is to investigate the sociolinguistic functions of code-switching and its relation to the meaning-making process by using the animated series Kim Possible as a case study. Design/methodology/approach: This study employs Muysken’s taxonomy to draw on code-switching patterns in lexico-grammar in relation to human behavior. The study also uses the functional approaches of Muysken and Appel and Gumperz as binary investigatory frameworks to locate interlingual and intralingual code-switching particularities and to elaborate on code-switching functions. Data and analysis: The analysis encompasses 48 episodes. Firstly, we extracted and transcribed code-switching occurrences in light of Muysken’s typology episode-by-episode and categorized them according to their code-switching type (interlingual or intralingual). Secondly, we quantified the occurrences according to their syntactic form to make more systematic claims about code-switching patterns. Next, we triangulated the patterns by examining the context of utterances and extralinguistic factors in the original series vis-à-vis the dubbed version to draw upon information beyond the structure or grammar. Findings/conclusions: The Arabic dubbed version was able to communicate the characters’ cosmopolitan diversity, which correlates with the series’ sense of linguistic modernity and humor. At the same time, the Arabic version was able to portray the extralinguistic reality of Lebanon and its multi-linguistic tapestry. Originality: This research is original because it focuses on Lebanese-Arabic, a dialect seldom discussed in the context of translation. The research also examines language variations in the context of dubbed discourse, where code-switching is integrally pertinent to visual-signs and the cultural background of characters. Significance/implications: The study recognizes the intricacy of code-switching as a reflective phenomenon of social reality and power dynamics; therefore, it contributes in the fields of translation and sociolinguistics.

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