Miracle-dz/UniFAR-FTUs huggingface dataset:
Antenna-coupled direct detector for millimetre and submillimetre astronomy based on 2D electron gas in semiconducting heterostructure

The energy resolution of a detector is related to the figure of merit NEP×√τ which is proportional to the heat capacity of the detector. Hot electron (cold electron) devices have much lower heat capacity than bolometers with silicon nitride based thermal isolation. Traditional hot electron bolometers (HEB) require sub-micron fabrication for use at submm wavelengths and it is difficult to simultaneously couple radiation and read out these devices. The 2D electron gas (2DEG) in a semiconductor heterojunction effectively acts as a metal film with a thickness of a few angstroms and a tunable density and electron mobility. We describe a HEB that uses a 2DEG as an absorber and present simulations of optical coupling schemes for this type of detector including an antenna coupled to a coplanar waveguide with distributed 2DEG absorbers.
Improved Thermal Stability of a Fiber Optic Gyroscope Using a Geometric Birefringence-Enhanced Polarization- Maintaining Fiber

In this paper, we propose and experimentally demonstrate an interferometric fiber optic gyroscope (IFOG) composed of an optimized elliptical-core Panda polarization-maintaining fiber (PMF) based on a comprehensive analysis of the design principle of PMFs for IFOGs. The improvement mechanism of the geometric birefringence on the performance of the Panda PMF was analyzed using the finite element model, and the optimized structural parameters were selected for fiber fabrication. The extinction ratio, polarization crosstalk, and assembled closed-loop IFOG output were tested and compared for fiber coils wound by different fiber structures under different temperature loads. An angle random walk performance of 0.001723 °/√h was achieved, which is a significant improvement over the traditional IFOG. The experimental results confirmed the proposed design basis that the elliptical-core Panda PMF with both higher birefringence and lower effective mode refractive index can improve the temperature stability of the IFOG.
The Interaction of Anthracycline Based Quinone-Chelators with Model Lipid Membranes: 1H NMR and MD Study

Anthracycline antibiotics, e.g., doxorubicin, daunomycin, and other anthraquinones, are an important family of antitumor agents widely used in chemotherapy, which is currently the principal method for treating many malignancies. Thus, development of improved antitumor drugs with enhanced efficacy remains a high priority. Interaction of anthraquinone-based anticancer drugs with cell membranes attracts significant attention due to its importance in the eventual overcoming of multidrug resistance (MDR). The use of drugs able to accumulate in the cell membrane is one of the possible ways of overcoming MDR. In the present work, the aspects of interaction of anthraquinone 2-phenyl-4-(butylamino)naphtho[2,3-h]quinoline-7,12-dione) (Q1) with a model membrane were studied by means of NMR and molecular dynamics simulations. A fundamental shortcoming of anthracycline antibiotics is their high cardiotoxicity caused by reactive oxygen species (ROS). The important feature of Q1 is its ability to chelate transition metal ions responsible for ROS generation in vivo. In the present study, we have shown that Q1 and its chelating complexes penetrated into the lipid membrane and were located in the hydrophobic part of the bilayer near the bilayer surface. The chelate complex formation of Q1 with metal ions increased its penetration ability. In addition, it was found that the interaction of Q1 with lipid molecules could influence lipid mobility in the bilayer. The obtained results have an impact on the understanding of molecular mechanisms of Q1 biological activity.
Perspective neglect: Inadequate perspective taking limits coordination

People need to take others’ perspectives into account in order to successfully coordinate their actions and optimally allocate limited resources like time, attention, or space. And yet, people often face frequent, but avoidable, coordination failures in the form of wait times, crowding, and unavailability of desirable options. Such poor coordination suggests that the necessary perspective taking (i.e., considering the likely motivations and behavior of others) may be either inadequate or incorrect. The current research suggests that coordination in such situations is frequently unsuccessful, not because people try to take others’ perspectives and are mistaken, but because they neglect to consider those perspectives sufficiently in the first place. Six experiments across a range of limited-resource contexts (e.g., choosing when to visit a store, stream on a limited bandwidth service, go to a popular vacation location, etc.) find that encouraging decision makers to consider what others might do and why they might do it can ameliorate such coordination problems. We further demonstrate a boundary condition: in situations where people’s motivations are inherently obvious, decision makers are naturally able to coordinate without an explicit nudge to perspective take. This research sheds light on a unique class of coordination problems in which people must consider others’ motivations without directly communicating with them, and provides theoretical and practical contributions with the potential to ameliorate common coordination failures.
Behavior of agreement measures in the presence of zero cells and biased marginal distributions

Abstract Kappa and B assess agreement between two observers independently classifying N units into k categories. We study their behavior under zero cells in the contingency table and unbalanced asymmetric marginal distributions. Zero cells arise when a cross-classification is never endorsed by both observers; biased marginal distributions occur when some categories are preferred differently between the observers. Simulations studied the distributions of the unweighted and weighted statistics for k=4, under fixed proportions of diagonal agreement and different patterns off-diagonal, with various sample sizes, and under various zero cell count scenarios. Marginal distributions were first uniform and homogeneous, and then unbalanced asymmetric distributions. Results for unweighted kappa and B statistics were comparable to work of Muñoz and Bangdiwala, even with zero cells. A slight increased variation was observed as the sample size decreased. Weighted statistics did show greater variation as the number of zero cells increased, with weighted kappa increasing substantially more than weighted B. Under biased marginal distributions, weighted kappa with Cicchetti weights were higher than with squared weights. Both statistics for observer agreement behaved well under zero cells. The weighted B was less variable than the weighted kappa under similar circumstances and different weights. In general, B's performance and graphical interpretation make it preferable to kappa under the studied scenarios.
Agricultural Eco-Efficiency Response and Its Influencing Factors from the Perspective of Rural Population Outflowing: A Case Study in Qinan County, China

Agriculture is the source of human clothing and food, but it also brings negative externalities to the environment. The outflow of the rural population is one of the factors for changes in the characteristics of the rural population. Farmers’ decisions on agricultural production can affect agricultural ecological efficiency. Therefore, it is necessary to study the relationship between the two in rural development. Taking Qin’an County in the Loess Hilly Region of central Gansu, China, as an example, this paper analyzed the demographic characteristics and the evolution characteristics of agricultural eco-efficiency under the background of rural population outflowing, and the impact of the former on the latter, based on the panel statistical data of 17 villages and towns from 2001 to 2020. The results show that (1) From 2001 to 2020, the non-agricultural level of Qin’an County’s labor force showed an upward fluctuation trend. The level of aging was relatively stable, and the per capita disposable income was significantly increased. (2) From 2001 to 2020, the agricultural eco-efficiency of Qin’an County showed a wavy change, but there were some towns and villages that have not been effectively developed. The regional differences are significantly different. (3) The non-agriculturalization level of the labor force promotes agricultural eco-efficiency through the direct effect rather than the space spillover effect. The positive effect of aging on agricultural eco-efficiency was mainly reflected through direct effect rather than spatial spillover effect. Per capita, disposable income has a significant positive spatial spillover effect on agricultural eco-efficiency. Finally, this paper provides a scientific reference for promoting the improvement of agricultural eco-efficiency and sustainable development. This is of great theoretical and practical significance for the realization of rural revitalization.
A Theoretical and Experimental Investigation of the Lift and Drag Characteristics of Hydrofoils at Subcritical and Supercritical Speeds

A theoretical and experimental investigation at subcavitation speeds was made of the effect of the free-water surface and rigid boundaries on the lift and drag of an aspect-ratio-10 hydrofoil at both subcritical and supercritical speeds and of an aspect ratio-4 hydrofoil at supercritical speeds. Approximate theoretical solutions for the effects of the free-water surface and rigid boundaries on drag at subcritical speeds are developed. An approximate theoretical solution for the effects of these boundaries on drag at subcritical speeds is also presented. The agreement between theory and experiment at both supercritical and subcritical speeds is satisfactory for engineering calculations of hydrofoil characteristics from aerodynamic data. The experimental investigation indicated no appreciable effect of the limiting speed of wave propagation on lift-curve slope or angle of zero lift. It also showed that the increase in drag as the critical speed is approached from the supercritical range is gradual. The result is contrary to the abrupt increase at the critical speed predicted by theory.
Activism and Resistance from the Trenches: Crisscrossing Comparison and Undocumented Migrant Experiences in China and the United States

This article explores critical ways that migrant groups engage in diverse forms of resistance. In this comparative case study, we draw on our longitudinal ethnographic research on migrant groups, particularly those that are characterized as undocumented, with a focus on the ways in which they engage in activism and resistance in China and the United States, respectively. We aim to expand the literature about comparison by asking: how is comparison understood differently through the lens of crisscrossing, and what productive insights can be uncovered through this theoretically informed approach? What implications might crisscrossing have for studying grassroots level resistance from migrants across borders?
Mutual Information-Driven Feature Reduction for Hyperspectral Image Classification

A hyperspectral image (HSI), which contains a number of contiguous and narrow spectral wavelength bands, is a valuable source of data for ground cover examinations. Classification using the entire original HSI suffers from the “curse of dimensionality” problem because (i) the image bands are highly correlated both spectrally and spatially, (ii) not every band can carry equal information, (iii) there is a lack of enough training samples for some classes, and (iv) the overall computational cost is high. Therefore, effective feature (band) reduction is necessary through feature extraction (FE) and/or feature selection (FS) for improving the classification in a cost-effective manner. Principal component analysis (PCA) is a frequently adopted unsupervised FE method in HSI classification. Nevertheless, its performance worsens when the dataset is noisy, and the computational cost becomes high. Consequently, this study first proposed an efficient FE approach using a normalized mutual information (NMI)-based band grouping strategy, where the classical PCA was applied to each band subgroup for intrinsic FE. Finally, the subspace of the most effective features was generated by the NMI-based minimum redundancy and maximum relevance (mRMR) FS criteria. The subspace of features was then classified using the kernel support vector machine. Two real HSIs collected by the AVIRIS and HYDICE sensors were used in an experiment. The experimental results demonstrated that the proposed feature reduction approach significantly improved the classification performance. It achieved the highest overall classification accuracy of 94.93% for the AVIRIS dataset and 99.026% for the HYDICE dataset. Moreover, the proposed approach reduced the computational cost compared with the studied methods.
Design and fabrication of Fabry–Perot filters for infrared hyperspectral imagers

Abstract. Hyperspectral infrared imagers are of great interest in applications requiring remote identification of complex chemical agents. The combination of mercury cadmium telluride detectors and Fabry–Perot filters (FPFs) is highly desirable for hyperspectral detection over a broad wavelength range. The geometries of distributed Bragg reflector (DBR)-based tunable FPFs are modeled to achieve a desired spectral resolution and wavelength range. Additionally, acceptable fabrication tolerances are determined by modeling the spectral performance of the FPFs as a function of DBR surface roughness and membrane curvature. These fabrication nonidealities are then mitigated by developing an optimized DBR process flow yielding high-performance FPF cavities suitable for integration with hyperspectral imagers.
Conditional Linear Mixed Models

The main advantage of longitudinal studies is that they can distinguish changes over time within individuals (longitudinal effects) from differences among subjects at the start of the study (cross-sectional effects). In observational studies, however, longitudinal changes need to be studied after correction for potential important cross-sectional differences between subjects. It will be shown that, in the context of linear mixed models, the estimation of longitudinal effects may be highly influenced by the assumptions about cross-sectional effects. Furthermore, aspects from conditional and mixture inference will be combined, yielding so-called conditional linear mixed models that allow estimation of longitudinal effects (average trends as well as subject-specific trends), independent of any cross-sectional assumptions. These models will be introduced and justified, and extensively illustrated in the analysis of longitudinal data from 680 participants in the Baltimore Longitudinal Study of Aging.
Influence of Polarization on the Spectral Changes of Stochastic Electromagnetic Pulsed Beams

An analytical expression for the spectrum of stochastic spatially and temporally partially coherent electromagnetic Gaussian Schell-model pulsed (GSMP) beams is derived, and used to study the spectral changes of electromagnetic GSMP beams in free space. The influence of polarization on the on-axis relative spectral shift is emphasized. It is shown that the on-axis relative spectral shift increases with increasing the degree of polarization of source P0 for the case of δxx≠δyy, i.e. the spatial coherence length δxx of x component of the electric field at the source is not equal to that of y component. For δxx=δyy or δxx→∞ and δyy→∞, the on-axis relative spectral shift is independent of P0.
Upsets in Round Robin Tournaments

Consider a round robin tournament in which each of n players is required to play precisely one game with each other player, and assume that each game ends in a win or a loss. The results of such a tournament can be conveniently recorded in a square (0, 1)-matrix T = (tij ) of order n by setting tij = 1 if player i defeats player j , tij = 0 if player i loses to player j , and tii = 0. Thus T has 0's along the main diagonal, and in the off-diagonal positions T satisfies the "skew-symmetry" condition that tij = 1 if and only if tji = 0. We call such a (0, 1)-matrix T a tournament matrix.
Progress toward automatic classification of human brown adipose tissue using biomedical imaging

Brown adipose tissue (BAT) is a small but significant tissue, which may play an important role in obesity and the pathogenesis of metabolic syndrome. Interest in studying BAT in adult humans is increasing, but in order to quantify BAT volume in a single measurement or to detect changes in BAT over the time course of a longitudinal experiment, BAT needs to first be reliably differentiated from surrounding tissue. Although the uptake of the radiotracer 18F-Fluorodeoxyglucose (18F-FDG) in adipose tissue on positron emission tomography (PET) scans following cold exposure is accepted as an indication of BAT, it is not a definitive indicator, and to date there exists no standardized method for segmenting BAT. Consequently, there is a strong need for robust automatic classification of BAT based on properties measured with biomedical imaging. In this study we begin the process of developing an automated segmentation method based on properties obtained from fat-water MRI and PET-CT scans acquired on ten healthy adult subjects.
Hydrodynamic studies on two traveling wavy foils in tandem arrangement

In this study, the hydrodynamic interactions between two tandem foils undergoing fishlike swimming motion are investigated numerically by solving the Navier–Stokes equations with the immersed-boundary method. The two foils represent two tandem propellers attached on a concept ship. The thrusts and efficiencies at three typical Strouhal numbers, i.e., St=0.4, 0.6, and 0.8, are investigated. The results show that a fish situated directly behind another one does not always undergo a lower thrust. Whether it experiences a thrust enhancement or reduction depends on the Strouhal number. At a relatively low Strouhal number (e.g., St=0.4), the usual wake drag-reduction effect predominates over the drag-enhancement effect caused by the reverse von Karman vortices, resulting in a thrust enhancement. The opposite happens at a relatively high Strouhal number (e.g., St=0.8). The downstream fish can benefit from the upstream one by slalom between the vortices rather than through them. For the upstream fish, the thrusts.
A Formalization of Group Decision Making in Multi-viewpoints Design

Complex systems are typically designed collaboratively by stakeholders from different domains. This multi viewpoints paradigm promotes the separation of concerns since separate teams, from different business viewpoints, build partial models describing the system. These partial models are naturally heterogeneous. So, it is difficult to ensure their intermodel consistency if kept separately. For that, we propose a collaborative approach that combines Group Decision Making (GDM) and Model-Based Engineering (MBE). This paper highlights the GDM part of our approach and especially the concept of decision policy that enables coming up with collective decisions in group decision-making contexts.
The measurement of ion acoustic turbulence and reduced thermal conductivity caused by a large temperature gradient in a laser heated plasma

An extensive account is given of experiments in which an homogeneous preformed plasma of density 6*1016 cm-3 was heated by 10.6 mu m radiation focused on 1011 W cm-2. Ruby laser scattering gave space and time resolved measurements of the resultant density and temperature, showing large temperature gradients up to lambda e mod Delta T mod /T=0.5. Enhanced low frequency turbulence was observed. When compared with a one dimensional computer code, the observed temperature gradients imply that the heat flux was limited to 4+or-2% of the free streaming limit but that the absorption was 1.1+or-0.5 times the classical inverse bremsstrahlung absorption rate. The observed Te/Ti and lambda e mod Delta T mod /T were sufficient to excite heat flux driven ion acoustic turbulence, which explains the observed low frequency turbulence. This turbulence level is shown to be large enough to account for the observed thermal conductivity.
Form-Invariance of Maxwell's Equations in Waveguide Cross-Section Transformations

Abstract We present a novel coordinate transformation technique that controls the propagation of waves inside a waveguide, such that the waveguide behaves as if it is a “reshaped” waveguide. In this technique, the spatial domain of the waveguide is mapped to that of its reshaped equivalent, yielding an anisotropic medium inside the waveguide. In other words, the waveguide in the transformed space can be imagined as if it is filled with an anisotropic metamaterial whose spatially varying constitutive parameters reflect the effect of the coordinate transformation on the field quantities. In this anisotropic metamaterial, Maxwell's equations are still satisfied due to their form-invariance property under coordinate transformations. The most appealing feature of the proposed method is that it renders a waveguide to support electromagnetic wave propagation below the cutoff frequency; thus, it can be utilized in waveguide miniaturization. However, this technique is more general, and it can transform a waveguide into another waveguide having an arbitrary miniaturized (or “maxiaturized”) shape without changing its propagation characteristics. Thus, the proposed method can be employed for the elimination of discontinuities in abrupt waveguide-to-waveguide transitions. We report numerical results for finite element simulations of various waveguides.
MapChain-D: A Distributed Blockchain for IIoT Data Storage and Communications

With the rapid growth of Industrial Internet of Things (IIoT) devices, managing an extensive volume of IIoT data becomes a significant challenge. While the conventional cloud storage approaches with centralized data centers suffer from high latency for large-scale IIoT data storage due to increased communication and latency overheads, distributed storage frameworks, such as blockchains, have become promising solutions. In this article, we design and analyze a dual-blockchain framework for secure and scalable distributed data management in large-scale IIoT networks. The proposed framework, named MapChain-D, consists of a data chain that is mapped to an index chain to provide efficient data storage and lookup. MapChain-D is designed for practical IIoT applications with storage, latency, and communication constraints. Detailed data exchange protocols are presented for data insertion and retrieval operations in MapChain-D. Based on these, theoretical analyses are provided on the space, time, and communication complexities of MapChain-D compared with conventional single-chain frameworks with local and distributed data storage. We implement our MapChain-D prototype using open-source LoRaWAN communications with multiple Raspberry Pi and Arduino devices, Kademlia-based distributed hash table, and Ethereum-based blockchain with proof-of-authority consensus. Experimental results from our prototype show that MapChain-D is more suitable to be deployed on resource-constrained IIoT devices. We also highlight the scalability and flexibility of MapChain-D with different number of edge nodes in the system.