Application of Ultrasonics on Preparation of Magnesium Alloys

This chapter mainly describes the application of ultrasonic on preparation of magnesium alloys, which includes all of the interesting and novel research results of authors in the past decade. The chapter includes the following topics to readers: the ultrasonic cavitation behavior in magnesium alloys; the effect of ultrasonic treatment on melt structure; ultrasonic degassing of magnesium alloys; effect of ultrasonic melt treatment on microstructure of magnesium alloys; dual-frequency ultrasonic treatment on solidification of magnesium alloys; and ultrasonic direct-chill (DC) casting process of magnesium alloys billets, including the novel variable-frequency ultrasonic technology. The chapter almost covers all the aspects of ultrasonic application on preparation of magnesium alloys and can help readers have a systematic understanding of ultrasonic melt treatment on magnesium alloys

Parity-time symmetric holographic principle

Originating from the Hamiltonian of a single qubit system, the phenomenon of the avoided level crossing is ubiquitous in multiple branches of physics, including the Landau-Zener transition in atomic, molecular and optical physics, the band structure of condensed matter physics and the dispersion relation of relativistic quantum physics. We revisit this fundamental phenomenon in the simple example of a spinless relativistic quantum particle traveling in (1+1)-dimensional space-time and establish its relation to a spin-1/2 system evolving under a $\mathcal{PT}$-symmetric Hamiltonian. This relation allows us to simulate 1-dimensional eigenvalue problems with a single qubit. Generalizing this relation to the eigenenergy problem of a bulk system with $N$ spatial dimensions reveals that its eigenvalue problem can be mapped onto the time evolution of the edge state with $(N-1)$ spatial dimensions governed by a non-Hermitian Hamiltonian. In other words, the bulk eigenenergy state is encoded in the edge state as a hologram, which can be decoded by the propagation of the edge state in the temporal dimension. We argue that the evolution will be $\mathcal{PT}$-symmetric as long as the bulk system admits parity symmetry. Our work finds the application of $\mathcal{PT}$-symmetric and non-Hermitian physics in quantum simulation and provides insights into the fundamental symmetries.Comment: 8 pages, 4 figure

Virtual fashion influencers: towards a more sustainable consumer behaviour of generation Z?

Since the end of 2019, online platforms have flourished as offline activities were significantly reduced due to the epidemic. To survive in such a context, some fashion brands took advantage of the growing CGI(Computer-generated images) technology, allowing VIs and virtual models to be used as vehicles for fashion presentations. Gen Zers, who grew up in the digital generation, are very receptive to such VIs and are full of novelty. At the same time, Gen Z is the biggest consumer group in fashion, and the positive influence of Gen Z on fashion consumption can make the whole fashion consumer market develop in a more positive direction. It is necessary to explore the direction of VI design to guide GenZ to a more sustainable fashion consumption concept. Therefore, I set "what kind of design of virtual fashion influencers can lead the consumer behavior of Generation Z towards more sustainable attitudes and behaviors?" as the research question of this thesis and found the five categories of VI influence research proposed by Batista da Silva Oliveira & Chimenti and applied them to my research. Based on this five-category theory, the thesis discusses the factors of VI design success concerning the current VIs and how the five categories impact Gen Z's intention of sustainable fashion. I provided guidelines and principles for designing VI based on different aspects through three research methods: case studies, surveys, and semi-conducted interviews, and I answered the research questions. Through the case study analysis, I compared the current successful VI cases. I summarized the practices and principles and the operation methods of the team behind them to improve the impact of VIs. Also, I conducted a survey distributed among people interested in VIs and fashion and collected data for analysis. I inspected and verified that a higher index of the five categories would lead to a higher intention of Gen Z to consume sustainable fashion. To get more insights from these professionals and to represent the group's perspective as Gen Z, I interviewed people from the sustainable fashion industry and virtual human and digital art industry. This study summarized the key points that can be used to improve the impact of VIs and proofs that the attractiveness, authenticity, controllability, anthropomorphism, and scalability of VI will positively contribute to consumers' intention to support sustainable fashion. This thesis also concluded with design guides about physical appearance design, psychological character design, and the operation mode of Virtual influencers that promote sustainable fashion

3D-Aware Visual Question Answering about Parts, Poses and Occlusions

Despite rapid progress in Visual question answering (VQA), existing datasets and models mainly focus on testing reasoning in 2D. However, it is important that VQA models also understand the 3D structure of visual scenes, for example to support tasks like navigation or manipulation. This includes an understanding of the 3D object pose, their parts and occlusions. In this work, we introduce the task of 3D-aware VQA, which focuses on challenging questions that require a compositional reasoning over the 3D structure of visual scenes. We address 3D-aware VQA from both the dataset and the model perspective. First, we introduce Super-CLEVR-3D, a compositional reasoning dataset that contains questions about object parts, their 3D poses, and occlusions. Second, we propose PO3D-VQA, a 3D-aware VQA model that marries two powerful ideas: probabilistic neural symbolic program execution for reasoning and deep neural networks with 3D generative representations of objects for robust visual recognition. Our experimental results show our model PO3D-VQA outperforms existing methods significantly, but we still observe a significant performance gap compared to 2D VQA benchmarks, indicating that 3D-aware VQA remains an important open research area.Comment: Accepted by NeurIPS202