Miracle-dz/UniFAR-FTUs huggingface dataset:
Extracting scaling laws from numerical dynamo models

Earth's magnetic field is generated by processes in the electrically conducting, liquid outer core, subsumed under the term 'geodynamo'. In the last decades, great effort has been put into the numerical simulation of core dynamics following from the magnetohydrodynamic equations. However, the numerical simulations are far from Earth's core in terms of several control parameters. Different scaling analyses found simple scaling laws for quantities like heat transport, flow velocity, magnetic field strength and magnetic dissipation time. We use an extensive data set of 116 numerical dynamo models compiled by Christensen and co-workers to analyse these scalings from a rigorous model selection point of view. Our method of choice is leave-one-out cross-validation which rates models according to their predictive abilities. In contrast to earlier results, we find that diffusive processes are not negligible for the flow velocity and magnetic field strength in the numerical dynamos. Also the scaling of the magnetic dissipation time turns out to be more complex than previously suggested. Assuming that the processes relevant in the numerical models are the same as in Earth's core, we use this scaling to estimate an Ohmic dissipation of 3-8 TW for the core. This appears to be consistent with recent high core mantle boundary heat flux scenarios.
Energy-Efficient Black Hole Router Detection in Network-on-Chip

The Network-on-Chip (NoC) is the communication heart in Multiprocessors System-on-Chip (MPSoC). It offers an efficient and scalable interconnection platform, which makes it a focal point of potential security threats. Due to outsourcing design, the NoC can be infected with a malicious circuit, known as Hardware Trojan (HT), to leak sensitive information or degrade the system’s performance and function. An HT can form a security threat by consciously dropping packets from the NoC, structuring a Black Hole Router (BHR) attack. This paper presents an end-to-end secure interconnection network against the BHR attack. The proposed scheme is energy-efficient to detect the BHR in runtime with 1% and 2% average throughput and energy consumption overheads, respectively.
ON PULSAR DISTANCE MEASUREMENTS AND THEIR UNCERTAINTIES

Accurate distances to pulsars can be used for a variety of studies of the Galaxy and its electron content. However, most distance measures to pulsars have been derived from the absorption (or lack thereof) of pulsar emission by Galactic H i gas, which typically implies that only upper or lower limits on the pulsar distance are available. We present a critical analysis of all measured H i distance limits to pulsars and other neutron stars, and translate these limits into actual distance estimates through a likelihood analysis that simultaneously corrects for statistical biases. We also apply this analysis to parallax measurements of pulsars in order to obtain accurate distance estimates and find that the parallax and H i distance measurements are biased in different ways, because of differences in the sampled populations. Parallax measurements typically underestimate a pulsar's distance because of the limited distance to which this technique works and the consequential strong effect of the Galactic pulsar distribution (i.e., the original Lutz–Kelker bias), in H i distance limits, however, the luminosity bias dominates the Lutz–Kelker effect, leading to overestimated distances because the bright pulsars on which this technique is applicable are more likely to be nearby given their brightness.
Low-Resistance Ta/Al/Ni/Au Ohmic Contact and Formation Mechanism on AlN/GaN HEMT

In this article, we systematically investigated the Ta/Al/Ni/Au and Ti/Al/Ni/Au ohmic contacts, and contact formation mechanism on ultrawide bandgap (UWBG) AlN barrier heterostructure without using the source–drain regrowth technique. The excellent ohmic contact performance of the Ta-based scheme was observed. The transmission line model (TLM) results depicted an ultralow contact resistance of <inline-formula> <tex-math notation="LaTeX">$0.08 \Omega \cdot $ </tex-math></inline-formula>mm and a specific contact resistance of <inline-formula> <tex-math notation="LaTeX">$1.06\times 10^{-{7}} \,\, \Omega \cdot $ </tex-math></inline-formula>cm2. Atomic force microscope (AFM) shows that the Ta/Al/Ni/Au sample presents a surface morphology improvement compared with the Ti/Al/Ni/Au sample. Transmission electron microscope (TEM) illustrated that the dominant contact mechanism for ultralow resistance is direct contact through TaxAlyAuz alloy penetration. Meanwhile, the difficulty of contact formation for the Ti-based sample was also discussed through the microstructural analysis. These results demonstrate that the proposed Ta/Al/Ni/Au metal scheme is a high-performance and cost-effective ohmic contact technique well suited for AlN/GaN HEMT fabrication process.
Detection and Prediction of Sleep Disorders by Covert Bed-Integrated RF Sensors

Objective: Respiratory disturbances during sleep are a prevalent health condition that affects a large adult population. The gold standard to evaluate sleep disorders including apnea is overnight polysomnography, which requires a trained technician for live monitoring and post-processing scoring. Currently, the disorder events can hardly be predicted using the respiratory waveforms preceding the events. The objective of this paper is to develop an autonomous system to detect and predict respiratory events reliably based on real-time covert sensing. Methods: A bed-integrated radio-frequency (RF) sensor by near-field coherent sensing (NCS) was employed to retrieve continuous respiratory waveforms without user's awareness. Overnight recordings were collected from 27 patients in the Weill Cornell Center for Sleep Medicine. We extracted respiratory features to feed into the random-forest machine learning model for disorder detection and prediction. The technician annotation, derived from observation by polysomnography, was used as the ground truth during the supervised learning. Results: Apneic event detection achieved a sensitivity and specificity up to 88.6% and 89.0% for k-fold validation, and 83.1% and 91.6% for subject-independent validation. Prediction of forthcoming apneic events could be made up to 90 s in advance. Apneic event prediction achieved a sensitivity and specificity up to 81.3% and 82.1% for k-fold validation, and 80.5% and 82.4% for subject-independent validation. The most important features for event detection and prediction can be assessed in the learning model. Conclusion: A bed-integrated RF sensor can covertly and reliably detect and predict apneic events. Significance: Predictive warning of the sleep disorders in advance can intervene serious apnea, especially for infants, servicemen, and patients with chronic conditions.
Digital Economy and the Upgrading of the Global Value Chain of China's Service Industry

China’s service trade competitiveness is weak, and the service industry occupies a low position in the GVC (Global Value Chain); therefore, promoting the upgrade of the GVC of China’s service industry is worth studying. Under the new situation of the continuous integration of the digital economy and the real economy, the digital economy has injected new momentum into the mid-to-high end of the GVC of China’s service industry. Based on the panel data of the service industry sub-sectors, the mediating effect model is constructed, and the system GMM (Generalized Method of Moments) is used to empirically determine whether the digital economy can significantly improve the participation and position of China’s service industry in the GVC, and promote the upgrading of the GVC of China’s service industry. This conclusion still holds after replacing the independent variable measurement indicator, adding control variables, considering changes in industry trends, and using quantile regression and other robustness tests. The promotion effect of the digital economy on the upgrading of the GVC of China’s service industry shows heterogeneity in different service objects and service industries with different factor intensities, indicating that the digital economy will affect the internal structure of the upgrading of the GVC of China’s service industry. The results of the mediation test found that the service trade cost, multilateral resistance to service trade, service industry structure, financial development level, human capital and service export complexity are the mechanisms for the digital economy to enable the upgrading of the GVC of China’s service industry. This study improves the analysis of the impact factors of the GVC in the service industry, enriches the theory of the GVC, and improves the research content of digital economy theory. This study also provides a reference for other developing countries similar to China on how to promote the upgrading of the GVC of the service industry in the process of digital economy development.
Transcriptome Remodeling in Response to Leaf Removal and Exogenous Abscisic Acid in Berries of Grapevine (Vitis vinifera L.) Fruit Cuttings

Climate change is known to simultaneously increase berry sugars but decrease anthocyanins, leading to an imbalance between sugars and anthocyanins in grape berries. To restore the balance of sugars and anthocyanins, carbon limitation by leaf removal and exogenous abscisic acid (ABA) were separately or simultaneously applied to Vitis vinifera cv. Cabernet Sauvignon fruit cuttings to decipher their effects on berry quality with metabolite and whole-genome transcriptome analyses. Carbon limitation decreased the hexose concentration and fully blocked the accumulation of anthocyanins. However, exogenous ABA increased the anthocyanin concentration under both carbon limitation and sufficient conditions. Carbon limitation and exogenous ABA induced the profound remodeling of the whole-genome transcriptome and altered the anthocyanin concentration by regulating the transcription levels of genes involved in the anthocyanin biosynthesis pathways as well as in the genes involved in various types of hormone signaling. Moreover, two pertinent candidate genes were identified based on the co-expression network analysis between the berry metabolite and transcriptome results, including a transcriptional factor, ERF2, and a calcineurin B-like protein-interacting protein kinase gene, CIPK25. In summary, simultaneously modifying the carbon supply by leaf removal and spraying exogenous ABA could re-establish the balance between sugars and anthocyanins to improve the qualities of grape berries via whole-genome transcriptome remodeling.
Collisionless Weibel shocks: full formation mechanism and timing

Collisionless shocks in plasmas play an important role in space physics (Earth's bow shock) and astrophysics (supernova remnants, relativistic jets, gamma-ray bursts, high energy cosmic rays). While the formation of a fluid shock through the steepening of a large amplitude sound wave has been understood for long, there is currently no detailed picture of the mechanism responsible for the formation of a collisionless shock. We unravel the physical mechanism at work and show that an electromagnetic Weibel shock always forms when two relativistic collisionless, initially unmagnetized, plasma shells encounter. The predicted shock formation time is in good agreement with 2D and 3D particle-in-cell simulations of counterstreaming pair plasmas. By predicting the shock formation time, experimental setups aiming at producing such shocks can be optimised to favourable conditions.
Color Gradients Detected in the HD 15115 Circumstellar Disk

We report HST NICMOS coronagraphic images of the HD 15115 circumstellar disk at 1.1 μm. We find a similar morphology to that seen in the visible and at H band—an edge-on disk that is asymmetric in surface brightness. Several aspects of the 1.1 μm data are different, highlighting the need for multiwavelength images of each circumstellar disk. We find a flattening to the western surface brightness profile at 1.1 μm interior to 2″ (90 AU) and a warp in the western half of the disk. We measure the surface brightness profiles of the two disk lobes and create a measure of the dust scattering efficiency between 0.55 and 1.65 μm at 1″, 2″, and 3″. At 2″ the western lobe has a neutral spectrum up to 1.1 μm and a strong absorption or blue spectrum >1.1 μm, while a blue trend is seen in the eastern lobe. At 1″ the disk has a red F 110W − H color in both lobes.
A Generalized Non-Carrier Modulation Technique for an Asymmetric Source Configuration of Single-Phase CHB-MLI Topology Using PLECS Tool

For single phase Cascaded H-Bridge (CHB)-Multilevel Inverter (MLI) topology, a generalized modulation technique without carrier signals have been implemented in this paper. When considering symmetric source arrangement, the CHB architecture typically necessitates a greater number of cells/units and segregated DC sources to provide higher levels of output and increasing the cost need. An asymmetric source arrangement with fewer modules and segregated DC sources is described in the literature to produce greater level output. The CHB-topology delivers 27 and 19 levels of output with only three modules and three DC sources by considering trinary (1:3:9) and quasi-linear (1:2:6) source configurations. Most control approaches requires high switching frequency carrier signals and states to decoder arrangement in order to provide a specific level output. However, the proposed control technique does not require states to decoder and carrier signals then reducing control complexity and computational strain on the processor. This control approach also produces less Total Harmonic Distortion (THD) then the filtering requirements are minimal. It is well suitable for an asymmetric source configuration of CHB-MLI topology without aid of high switching frequency carrier signals. The PLECS platform is used to validate the operation and proposed control mechanism.
Improving the Force Display of Haptic Device Based on Gravity Compensation for Surgical Robotics

Haptic devices are applied as masters to provide force displays for telemedicinal robots. Gravity compensation has been proven to be crucial for the accuracy and capability of force displays, which are critical for haptic devices to assist operators. Therefore, the existing method suffers from an unsatisfactory effect, a complex implementation, and low efficiency. In this paper, an approach combining active and passive gravity compensation is proposed to improve the performance of a force display. The passive compensation is conducted by counterweights fixed with the moving platform and pantographs to offset most of the gravity and reduce the loads of the motors, while the peak capability of the force display is enhanced. The required weight is optimized by a multi-objective genetic algorithm in terms of the maximum torque of the motors in the global workspace. As a supplement, the residual gravity is eliminated by active compensation to extend the accuracy of the force display. The balancing forces in the discretized workspace are entirely calibrated, and the required force for the arbitrary configuration is calculated by interpolations. The decisions regarding the algorithm parameters are also discussed to achieve a compromise between the effect and elapsed time. Finally, the prototype with a compensation mechanism is implemented and experiments are carried out to verify the performance of the proposed method. The results show that the peak capability of the force display is enhanced by 45.43% and the maximum deviation is lowered to 0.6 N.
Joint Analog and Digital Self-Interference Cancellation for Full Duplex Transceiver With Frequency-Dependent I/Q Imbalance

An effective and practical joint analog and digital self-interference cancellation (SIC) scheme without additional signalling overhead for an I/Q imbalanced full duplex transceiver is proposed in this paper. This scheme combines an I/Q imbalanced analog least mean square (ALMS) loop at the transceiver radio frequency frontend and a two-stage digital signal processing (DSP) at the digital baseband to achieve excellent SIC performance with low complexity. The steady state weighting coefficients of the I/Q imbalanced ALMS loop with periodical transmitted signal and the loop’s convergence behaviour are firstly analysed. The residual SI is then modelled as the output of a time-varying widely linear system. With a track/hold control mechanism applied to the ALMS loop, the system model for digital SIC is further presented, followed by the DSP algorithms suitable for real-time implementation. The noise enhancement in each stage digital cancellation is also analysed and formulated. Finally, simulation results are provided to verify the theoretical analyses and demonstrate the overall SIC performance.
MMF-based Data Center Interconnect using Commercial Coherent Transceivers

In this manuscript we present an experimental analysis of a multi-mode fiber (MMF) link based on coherent detection. We propose the use of a commercial coherent transceiver to increase the transmission speed of a short-reach optical communication system over 300 m OM3 fiber. The performance of the system is studied in terms of bit rate as a function of the power budget margin (PBM) defined as the extra attenuation that can be introduced on the optical path. We investigate polarization multiplexed (PM) QPSK and 16-QAM modulation formats achieving up to 400 Gbps net bit rate transmission. Moreover, we analyze the impact of the lateral offset introduced by the connectors between MMF segments, showing decreasing PBM for increasing lateral offset. Nevertheless, PBM in excess of 28 dB for PM-QPSK modulation at 100G and 200G, 23 dB for 200G PM-16QAM modulation and 16 dB for 400G PM-16QAM, shows that commercial coherent transceivers can be used on MMF links up to much higher bit rates than those achieved by current VCSEL+direct detection based systems, provided that connections along the MMF have connectors connectors with offsets in the 3 $\mu m$ to 6 $\mu m$ range.
Spatiotemporal clustering and separation in regional earthquakes

Spatiotemporal clustering of earthquake events is a generally-established fact, and is important for designing models and assessment techniques in seismicity. Here, we investigate how this behavior can manifest in the statistical distributions of inter-event distances and times between earthquakes from different regional catalogs. We complement the analysis of previous authors (Touati et al., PRL 102, 168501 (2009)) and observe histograms best described by a superposition of two component distributions for "short" and "long" distances and times. Our results quantify the spatiotemporal clustering of earthquakes that are possibly generated by the same triggering mechanism. Independent earthquakes, on the other hand, are found to be separated by long inter-event distances and times. The statistics presented reveal regional differences, suggesting non-universality of the distributions.
Kinegami: Algorithmic Design of Compliant Kinematic Chains From Tubular Origami

Origami processes can generate both rigid and compliant structures from the same homogeneous sheet material. In this article, we advance the origami robotics literature by showing that it is possible to construct an arbitrary rigid kinematic chain with prescribed joint compliance from a single tubular sheet. Our “Kinegami” algorithm converts a Denavit–Hartenberg specification into a single-sheet crease pattern for an equivalent serial robot mechanism by composing origami modules from a catalogue. The algorithm arises from the key observation that tubular origami linkage design reduces to a Dubins path planning problem. The automatically generated structural connections and movable joints that realize the specified design can also be endowed with independent user-specified compliance. We apply the Kinegami algorithm to a number of common robot mechanisms and hand-fold their algorithmically generated single-sheet crease patterns into functioning kinematic chains. We believe this is the first completely automated end-to-end system for converting an abstract manipulator specification into a physically realizable origami design that requires no additional human input.
Anisotropy test of the axion-like particle Universe opacity effect: a case for the Cherenkov Telescope Array

The opacity of the Universe to gamma rays is still poorly measured, in particular anomalies may have been observed. Assuming that such anomalies find their origin in conventional physics like intrinsic source spectra or the density of the extragalactic background light, they would be evenly distributed over the sky. If they exist, axion-like particles (ALPs) would have a potential effect on the opacity of the Universe to gamma rays, possibly related to the anomalies in the spectral indices of distant gamma-ray sources. Under the assumption that distant sources offer suitable environments for their production, ALPs convert back to photons in the Galactic magnetic field and their effect on the opacity is expected to depend on the position of the sources. In that case the anomaly is expected to exhibit peculiar correlations on the sky. We propose a method to test the origin of the opacity anomaly, based on angular correlations of spectral softening anomalies. Such a diagnosis requires a wide-field survey of high-energy gamma-ray sources over a broad range of energy. The future Cherenkov Telescope Array (CTA) is perfectly suited to perform such a study. It is shown that while the current sample of sources is not large enough to base conclusions on, with this method CTA will be sensitive to ALP couplings to gamma rays of the order of 3 ? 10? 11GeV? 1 for ALP masses below 10? 8 eV.
The IQA Energy Partition in a Drug Design Setting: A Hepatitis C Virus RNA-Dependent RNA Polymerase (NS5B) Case Study

The interaction of the thumb site II of the NS5B protein of hepatitis C virus and a pair of drug candidates was studied using a topological energy decomposition method called interacting quantum atoms (IQA). The atomic energies were then processed by the relative energy gradient (REG) method, which extracts chemical insight by computation based on minimal assumptions. REG reveals the most important IQA energy contributions, by atom and energy type (electrostatics, sterics, and exchange–correlation), that are responsible for the behaviour of the whole system, systematically from a short-range ligand–pocket interaction until a distance of approximately 22 Å. The degree of covalency in various key interatomic interactions can be quantified. No exchange–correlation contribution is responsible for the changes in the energy profile of both pocket–ligand systems investigated in the ligand–pocket distances equal to or greater than that of the global minimum. Regarding the hydrogen bonds in the system, a “neighbour effect” was observed thanks to the REG method, which states that a carbon atom would rather not have its covalent neighbour oxygen form a hydrogen bond. The combination of IQA and REG enables the automatic identification of the pharmacophore in the ligands. The coarser Interacting Quantum Fragments (IQF) enables the determination of which amino acids of the pocket contribute most to the binding and the type of energy of said binding. This work is an example of the contribution topological energy decomposition methods can make to fragment-based drug design.