Structuring total angular momentum of light along the propagation direction with polarization-controlled meta-optics

Recent advances in wavefront shaping have enabled complex classes of Structured Light which carry spin and orbital angular momentum, offering new tools for light-matter interaction, communications, and imaging. Controlling both components of angular momentum along the propagation direction can potentially extend such applications to 3D. However, beams of this kind have previously been realized using bench-top setups, requiring multiple interaction with light of a fixed input polarization, thus impeding their widespread applications. Here, we introduce two classes of metasurfaces that lift these constraints, namely: i) polarization-switchable plates that couple any pair of orthogonal polarizations to two vortices in which the magnitude and/or sense of vorticity vary locally with propagation, and ii) versatile plates that can structure both components of angular momentum, spin and orbital, independently, along the optical path while operating on incident light of any polarization. Compact and integrated devices of this type can advance light-matter interaction and imaging and may enable applications that are not accessible via other wavefront shaping tools.

Capital Expenditure and Operating Efficiency from Vertical Integration in the Global Semiconductor Industry

This paper uses a nonparametric production frontier approach to investigate the operating efficiency differences by the impacts of business model and capital expenditure in the global semiconductor industry. Handling the impact of capital expenditure as fixed input by the directional distance estimator, this study compares the operating efficiencies between the integrated device manufacturers and the fabless and foundry firms in the global semiconductor industry over 1999–2018. The estimation results indicate that vertically integrated manufacturers dominate the semiconductor industry, and the capital-intensive companies operate more efficiently than the asset-light fabless firms on average.

Effects of the Configuration of Hearing Loss on Consonant Perception between Simulated Bimodal and Electric Acoustic Stimulation Hearing

Background Cochlear implant technology allows for acoustic and electric stimulations to be combined across ears (bimodal) and within the same ear (electric acoustic stimulation [EAS]). Mechanisms used to integrate speech acoustics may be different between the bimodal and EAS hearing, and the configurations of hearing loss might be an important factor for the integration. Thus, differentiating the effects of different configurations of hearing loss on bimodal or EAS benefit in speech perception (differences in performance with combined acoustic and electric stimulations from a better stimulation alone) is important. Purpose Using acoustic simulation, we determined how consonant recognition was affected by different configurations of hearing loss in bimodal and EAS hearing. Research Design A mixed design was used with one between-subject variable (simulated bimodal group vs. simulated EAS group) and one within-subject variable (acoustic stimulation alone, electric stimulation alone, and combined acoustic and electric stimulations). Study Sample Twenty adult subjects (10 for each group) with normal hearing were recruited. Data Collection and Analysis Consonant perception was unilaterally or bilaterally measured in quiet. For the acoustic stimulation, four different simulations of hearing loss were created by band-pass filtering consonants with a fixed lower cutoff frequency of 100 Hz and each of the four upper cutoff frequencies of 250, 500, 750, and 1,000 Hz. For the electric stimulation, an eight-channel noise vocoder was used to generate a typical spectral mismatch by using fixed input (200–7,000 Hz) and output (1,000–7,000 Hz) frequency ranges. The effects of simulated hearing loss on consonant recognition were compared between the two groups. Results Significant bimodal and EAS benefits occurred regardless of the configurations of hearing loss and hearing technology (bimodal vs. EAS). Place information was better transmitted in EAS hearing than in bimodal hearing. Conclusion These results suggest that configurations of hearing loss are not a significant factor for integrating consonant information between acoustic and electric stimulations. The results also suggest that mechanisms used to integrate consonant information may be similar between bimodal and EAS hearing.

CNN-BASED MULTI-SCALE HIERARCHICAL LAND USE CLASSIFICATION FOR THE VERIFICATION OF GEOSPATIAL DATABASES

Land use is an important piece of information with many applications. Commonly, land use is stored in geospatial databases in the form of polygons with corresponding land use labels and attributes according to an object catalogue. The object catalogues often have a hierarchical structure, with the level of detail of the semantic information depending on the hierarchy level. In this paper, we extend our prior work for the CNN (Convolutional Neural Network)-based prediction of land use for database objects at multiple semantic levels corresponding to different levels of a hierarchical class catalogue. The main goal is the improvement of the classification accuracy for small database objects, which we observed to be one of the largest problems of the existing method. In order to classify large objects using a CNN of a fixed input size, they are split into tiles that are classified independently before fusing the results to a joint prediction for the object. In this procedure, small objects will only be represented by a single patch, which might even be dominated by the background. To overcome this problem, a multi-scale approach for the classification of small objects is proposed in this paper. Using this approach, such objects are represented by multiple patches at different scales that are presented to the CNN for classification, and the classification results are combined. The new strategy is applied in combination with the earlier tiling-based approach. This method based on an ensemble of the two approaches is tested in two sites located in Germany and improves the classification performance up to +1.8% in overall accuracy and +3.2% in terms of mean F1 score.

Thermodynamic Implementations of Quantum Processes

Recent understanding of the thermodynamics of small-scale systems have enabled the characterization of the thermodynamic requirements of implementing quantum processes for fixed input states. Here, we extend these results to construct optimal universal implementations of a given process, that is, implementations that are accurate for any possible input state even after many independent and identically distributed (i.i.d.) repetitions of the process. We find that the optimal work cost rate of such an implementation is given by the thermodynamic capacity of the process, which is a single-letter and additive quantity defined as the maximal difference in relative entropy to the thermal state between the input and the output of the channel. Beyond being a thermodynamic analogue of the reverse Shannon theorem for quantum channels, our results introduce a new notion of quantum typicality and present a thermodynamic application of convex-split methods.

Exoplanet mass estimation for a sample of targets for the Ariel mission

Ariel’s ambitious goal to survey a quarter of known exoplanets will transform our knowledge of planetary atmospheres. Masses measured directly with the radial velocity technique are essential for well determined planetary bulk properties. Radial velocity masses will provide important checks of masses derived from atmospheric fits or alternatively can be treated as a fixed input parameter to reduce possible degeneracies in atmospheric retrievals. We quantify the impact of stellar activity on planet mass recovery for the Ariel mission sample using Sun-like spot models scaled for active stars combined with other noise sources. Planets with necessarily well-determined ephemerides will be selected for characterisation with Ariel. With this prior requirement, we simulate the derived planet mass precision as a function of the number of observations for a prospective sample of Ariel targets. We find that quadrature sampling can significantly reduce the time commitment required for follow-up RVs, and is most effective when the planetary RV signature is larger than the RV noise. For a typical radial velocity instrument operating on a 4 m class telescope and achieving 1 m s−1 precision, between ~17% and ~ 37% of the time commitment is spent on the 7% of planets with mass Mp < 10 M⊕. In many low activity cases, the time required is limited by asteroseismic and photon noise. For low mass or faint systems, we can recover masses with the same precision up to ~3 times more quickly with an instrumental precision of ~10 cm s−1.

ПАРАМЕТРЫ ГАЗОВОЙ ФАЗЫ И РЕЖИМЫ РЕАКТИВНО-ИОННОГО ТРАВЛЕНИЯ Si И SiO2 В БИНАРНЫХ СМЕСЯХ Ar + CF4/C4F8

The comparative study of plasma electro-physical parameters, steady-state gas phase compositions and reactive-ion etching kinetics for Si and SiO2 in binary CF4 + Ar and C4F8 + Ar gas mixtures were studied under conditions of 13.56 MHz inductive RF discharge. As fixed input parameters, we used the total pressure of feed gas (6 mTorr) as well as power levels supplied by plasma excitation source (700 W) and bias source (200 W). The investigation approach combined plasma diagnostics experiments with double Langmuir probe and 0-dimensional (global) model for the chemistry of neutral species. It was shown that investigated gas mixtures exhibit quite close properties in respect to both ions-related parameters and electron gas while are characterized by sufficient differences in kinetics of atoms and radicals. The features of C4F8 + Ar gas under the given set of processing conditions are the higher density of polymerizing radicals, the lower density of F atoms as well as the weaker sensitivity the last parameter to the change in Ar fraction in a feed gas. Etching experiments indicated that a) an increase in Ar fraction in CF4 + Ar and C4F8 + Ar gas mixtures results in qualitatively different changes in Si and SiO2 etching rates; and b) obtained dependencies of etching rates on Ar fraction in both gas mixtures contradict with the behavior of F atom flux. Obviously, such situation corresponds to the change in reaction probability of F atoms with the treated surface. It was suggested that an increase of Ar fraction in the low-polymerizing CF4 + Ar plasma activates the heterogeneous chemical reaction through the intensification of ion-stimulated desorption of etching products and/or surface amorphization. The similar effect for the high-polymerizing C4F8 + Ar plasma may be related to decreasing fluorocarbon film thickness that provides the better access of F atoms to the etched surface.

Generative Design of Articulated Rod of Radial Engine

The constant need for improvement drives humans to look for the best possible option in every field. Computer Aided Design (CAD) is no exception, to follow the best method of designing a product and finalizing it, researchers came up with an idea to generate multiple designs using fixed input values and finalizing the most appropriate one. The objective is achieved using an iterative design process based on algorithms by a specific software. Generative design introduces a new experience based on the Integration of machine dynamics in the manufacturing of objects and about experience. In this work generative design method was investigated on an articulated rod, one of the most important components of the rotary engine, to effectively improve the overall working performance of the engine and enhance its performance by decreasing its mass. Since fuel consumption by the machine can be greatly reduced by lowering the mass, so the goal is to minimize the weight of the rod while mechanical characteristics have to be within the acceptable values. Also, finite element analysis (FEA) was investigated on the part as to ensure the reliability of the rod before and after optimization.

Optimality Conditions of Agricultural Production With Fixed Input Costs

We present a computational procedure to maximize the production of a given agricultural crop with limited inputs (water-nitrogen), and where a fixed cost (or expense) of the inputs (general problem of agricultural production) is imposed. Theoretically the procedure is based on the Karush-Kuhn-Tucker optimality conditions and numerically was tested with three different scenarios defined in the literature, for the cultures: Lettuce, Oats, Onions and Melons. In each agricultural scenario considered, it was possible to verify that the procedure is a reliable alternative in making agribusiness economic decisions.

Asymptotic Performance of Port-Based Teleportation

Quantum teleportation is one of the fundamental building blocks of quantum Shannon theory. While ordinary teleportation is simple and efficient, port-based teleportation (PBT) enables applications such as universal programmable quantum processors, instantaneous non-local quantum computation and attacks on position-based quantum cryptography. In this work, we determine the fundamental limit on the performance of PBT: for arbitrary fixed input dimension and a large number N of ports, the error of the optimal protocol is proportional to the inverse square of N. We prove this by deriving an achievability bound, obtained by relating the corresponding optimization problem to the lowest Dirichlet eigenvalue of the Laplacian on the ordered simplex. We also give an improved converse bound of matching order in the number of ports. In addition, we determine the leading-order asymptotics of PBT variants defined in terms of maximally entangled resource states. The proofs of these results rely on connecting recently-derived representation-theoretic formulas to random matrix theory. Along the way, we refine a convergence result for the fluctuations of the Schur–Weyl distribution by Johansson, which might be of independent interest.