Abstract
This study provides an extensive examination of tourist perceptions during a visit to China, conducted within the framework of the Erasmus+ TourX project. The project includes participants from Spain, Italy, Germany, Greece, Belgium, and Portugal. Tourism is widely acknowledged as a mechanism for cultural exchange, fostering intercultural learning and broadening global perspectives. This research aims to empirically analyze the experiences and behaviors of tourists within an unfamiliar cultural environment. The findings contribute to the broader academic discourse on the role of tourism in facilitating cross-cultural engagement and its implications for the tourism industry in China. 

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Integrating citizen science with digital twin technology represents a significant development in oceanographic research and marine management. This paper examines how the Iliad project has successfully developed a comprehensive suite of digital twins of the ocean (DTOs) that leverage citizen science contributions to enhance data coverage, improve modelling accuracy, and foster public engagement with marine ecosystems. Through innovative technological solutions, including semantic interoperability frameworks, mobile applications, knowledge graphs, and gamification approaches, the project demonstrates the reciprocal benefits between citizen scientists, scientific research and digital twin ecosystems. The developments presented in this work illustrate how engaging the public in scientific research not only broadens the data foundation for digital twins but also creates pathways for citizens to gain valuable insights from these sophisticated digital representations of ocean environments.

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Whispers are common and essential for secondary communication. Nonetheless, individuals with aphonia, including laryngectomees, rely on whispers as their primary means of communication. Due to the distinct features between whispered and regular speech, debates have emerged in the field of speech recognition, highlighting the challenge of effectively converting between them. This study investigates the characteristics of whispered speech and proposes a system for converting whispered vowels into normal ones. The system is developed using multilayer perceptron networks and two types of generative adversarial networks. Three metrics are analyzed to evaluate the performance of the system: mel-cepstral distortion, root mean square error of the fundamental frequency, and accuracy with f1-score of a vowel classifier. Overall, the perceptron networks demonstrated better results, with no significant differences observed between male and female voices or the presence/absence of speech silence, except for improved accuracy in estimating the fundamental frequency during the conversion process. © 2025, Universidade do Porto - Faculdade de Engenharia. All rights reserved.

Abstract
The expansion of distributed renewable energy technologies like photovoltaic systems and electric vehicle (EV) charging stations and its active power electronics causes direct current (DC) emissions in the electrical AC distribution grids which are currently not monitored. Although emissions in the harmonic frequency range (50 Hz to 2 kHz) are well standardized, for DC emissions no standards are defined yet. However, failure to detect and standardize DC emissions do have a significant negative impact on the public grid through grid disturbances or quality losses. Measurement and protection systems are affected as well as thermal effects on cables or transformers are given. In this study the DC current emissions of EV charging stations and PV systems are analyzed and characterized at the reconstructed electrical distribution grid of the university of applied sciences Technikum Vienna. The results show that the DC current emissions depend on the design of the active power used in V2G chargers and photovoltaic systems and how they vary at different power levels (low power vs. high power). The research indicates that the emissions can reach up to 200 mA from a single EV charger. © 2025 IEEE.

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