Low thermal budget epitaxial lift off (ELO) for Ge (111)-on-insulator structure

Germanium-on-Insulator (GeOI) structures with the surface orientation of (111) have been successfully fabricated by using low thermal budget epitaxial-lift-off (ELO) technology via direct bonding and selective etching. The material characteristics and transport properties of the Ge(111)OI structure have been systematically investigated through secondary-ion mass spectrometry, Raman spectroscopy, X-ray diffraction, high-resolution transmission electron microscope, and Hall measurement. The transferred Ge (111) layer remained almost intact from the as-grown epitaxial layers, indicating the benefits of ELO technology. The low thermal budget ELO technology demonstrated in this work is promising to integrate Ge channels with different surface orientations on Si (100) substrates for future monolithic 3D applications.

A dual formulation of wavefield reconstruction inversion for large-scale seismic inversion

Many of the seismic inversion techniques currently proposed that focus on robustness with respect to the background model choice are not apt to large-scale 3D applications, and the methods that are computationally feasible for industrial problems, such as full waveform inversion, are notoriously limited by convergence stagnation and require adequate starting models. We propose a novel solution that is both scalable and less sensitive to starting models or inaccurate parameters (such as anisotropy) that are typically kept fixed during inversion. It is based on a dual reformulation of the classical wavefield reconstruction inversion, whose empirical robustness with respect to these issues is well documented in the literature. While the classical version is not suited to 3D, as it leverages expensive frequency-domain solvers for the wave equation, our proposal allows the deployment of state-of-the-art time-domain finite-difference methods, and is potentially mature for industrial-scale problems.

Survey on 3D Content Encryption

<p class="0abstract">The rapidly growing 3D content exchange over the internet makes securing 3D content became a very important issue. The solution for this issue is to encrypting data of 3D content, which included two main parts texture map and 3D models. The standard encryption methods such as AES and DES are not a suitable solution for 3D applications due to the structure of 3D content, which must maintain dimensionality and spatial stability. So, these problems are overcome by using chaotic maps in cryptography, which provide confusion and diffusion by providing uncorrelated numbers and randomness. Various works have been applied in the field of 3D content-encryption based on the chaotic system. This survey will attempt to review the approaches and aspects of the structure used for 3D content encryption methods for different papers. It found the methods that used chaotic maps with large keyspace are more robust to various attacks than other methods that used encryption schemes without chaotic maps. The methods that encrypting texture, polygon, and vertices for 3D content provide full protection than another method that provides partial protection.</p>

Laboratory-Based Nano-Computed Tomography and Examples of Its Application in the Field of Materials Research

In a comprehensive study, we demonstrate the performance and typical application scenarios for laboratory-based nano-computed tomography in materials research on various samples. Specifically, we focus on a projection magnification system with a nano focus source. The imaging resolution is quantified with common 2D test structures and validated in 3D applications by means of the Fourier Shell Correlation. As representative application examples from nowadays material research, we show metallization processes in multilayer integrated circuits, aging in lithium battery electrodes, and volumetric of metallic sub-micrometer fillers of composites. Thus, the laboratory system provides the unique possibility to image non-destructively structures in the range of 170–190 nanometers, even for high-density materials.

Magnetic Configurations in Modulated Cylindrical Nanowires

Cylindrical magnetic nanowires show great potential for 3D applications such as magnetic recording, shift registers, and logic gates, as well as in sensing architectures or biomedicine. Their cylindrical geometry leads to interesting properties of the local domain structure, leading to multifunctional responses to magnetic fields and electric currents, mechanical stresses, or thermal gradients. This review article is summarizing the work carried out in our group on the fabrication and magnetic characterization of cylindrical magnetic nanowires with modulated geometry and anisotropy. The nanowires are prepared by electrochemical methods allowing the fabrication of magnetic nanowires with precise control over geometry, morphology, and composition. Different routes to control the magnetization configuration and its dynamics through the geometry and magnetocrystalline anisotropy are presented. The diameter modulations change the typical single domain state present in cubic nanowires, providing the possibility to confine or pin circular domains or domain walls in each segment. The control and stabilization of domains and domain walls in cylindrical wires have been achieved in multisegmented structures by alternating magnetic segments of different magnetic properties (producing alternative anisotropy) or with non-magnetic layers. The results point out the relevance of the geometry and magnetocrystalline anisotropy to promote the occurrence of stable magnetochiral structures and provide further information for the design of cylindrical nanowires for multiple applications.

APPLICATION OF ARTIFICIAL INTELLIGENCE METHODS IN 3D SIMULATORS BASED ON FUNCTIONAL AND LOGICAL MODELS

The article presents an approach to the use of artificial intelligence methods in the development of imitation professional simulators. The analysis of the use of artificial intelligence tools for the development of 3D applications is carried out, typical components and their functions are considered, the drawbacks that limit the use of these methods in professional simulators are revealed. The proposed approach is based on adapting these standard tools and supplementing them with functional-logical models that perform control functions. As an example, the implementation of the approach in the Unity cross-platform development environment is proposed. The results of the work have been tested in the development of simulators in the field of labor protection.

Embodied 3D isovists: A method to model the visual perception of space

Isovist analysis has been typically applied for the study of human perception in indoor built-up spaces. Albeit predominantly in 2D, recent works have explored isovist techniques in 3D. However, 3D applications of isovist analysis simply extrapolate the assumptions of its 2D counterpart, without questioning whether these assumptions remain valid in 3D. They do not: because human perception is embodied, the perception of vertical space differs from the perception of horizontal space. We present a user study demonstrating that an embodied 3D isovist that accounts for this phenomenon (formalised based on the notion of spatial artefacts) predicts human perception of space more accurately than the generic volumetric 3D isovist, specifically with respect to spaciousness and complexity. We suggest that the embodied 3D isovist should be used for 3D analyses in which human perception is of key interest.