Parallel Pairs Research Articles

Discrete and Parallel Frequency‐Bin Entanglement Generation from Quantum Frequency Comb

AbstractPhotons’ frequency degree of freedom is promising to realize large‐scale quantum information processing. Quantum frequency combs (QFCs) generated in integrated nonlinear microresonators can produce multiple frequency modes with narrow linewidth. Here, polarization‐entangled QFCs are utilized to generate discrete frequency‐bin entangled states. Fourteen pairs of polarization‐entangled photons with different frequencies are simultaneously transformed into frequency‐bin entangled states. The characteristic of frequency‐bin entanglement is demonstrated by Hong‐Ou‐Mandel interference, which can be performed with single or multiple frequency pairs in parallel. This work paves the way for harnessing large‐scale frequency‐bin entanglement and converting between different degrees of freedom in quantum information processing.

Statistics and evolution of Reynolds shear stress structure in cylinder-wake/boundary-layer interaction

The three-dimensional structures based on the quadrant classification of the tangential Reynolds stress (Qs), are studied in direct numerical simulations of cylinder-wake/boundary-layer interaction with a moderate gap ratio (G/D=1.0) and low or middle Reynolds numbers. In this paper, direct numerical simulations are performed using the immersed boundary lattice Boltzmann method (LBM). We utilize a three-dimensional clustering method to identify Reynolds shear stress structures (Qs-structures) associated with intense events. The kinematic characteristics of coherent structures are discussed through the statistical properties of Qs-structures. The spatial relationship of between vortex clusters and Qs-structures (mainly Q2-structures as well as Q4-structures) is explained by their evolution characteristics. The spatial distribution of Qs-structures, determined by the volume distribution of the minimum and maximum wall distances (ymin and ymax), are found to be similar to that of vortex clusters in the cylinder/wall interaction. In the near-wall statistical region, the secondary vortex clusters are surrounded by the parallel Q2 and Q4 pairs, and mostly lodged within the Q2. During the evolution process of coherent structures, the Q2-structures and the secondary vortex clusters developed into hairpin-like structures, respectively. The conditional average results demonstrated that the generated hairpin vortex structures are attributed to the momentum transfers.

Structural Models of the First Molecular Events in the Heliorhodopsin Photocycle.

Retinylidene conformations and rearrangements of the hydrogen-bond network in the vicinity of the protonated Schiff base (PSB) play a key role in the proton transfer process in the Heliorhodopsin photocycle. Photoisomerization of the retinylidene chromophore and the formation of photoproducts corresponding to the early intermediates were modeled using a combination of molecular dynamics simulations and quantum mechanical/molecular mechanics calculations. The resulting structures were refined, and the respective excitation energies were calculated. Aided by metadynamics simulations, we constructed a photoisomerized intermediate where the 13-cis retinylidene chromophore is rotated about a parallel pair of double bonds at C13=C14 and C15=NZ double bonds. We demonstrate how the deprotonation of the Schiff base and the concomitant protonation of the Glu107 counterion are only favored because of these rearrangements.

Deorphanization of G Protein Coupled Receptors: A Historical Perspective.

Counting over 800 members, G protein coupled receptors (GPCRs) form the largest family of membrane receptors encoded in the human genome. Since the discovery of G proteins and GPCRs in the late 1970s and early 1980s, a significant portion of the GPCR research has been focused on identifying ligand/receptor pairs in parallel to studies related to their signaling properties. Despite significant advancements, about a fourth of the ∼400 nonodorant GPCRs are still considered orphan because their natural or endogenous ligands have yet to be identified. We should consider that every GPCR was once an orphan and that endogenous ligands have often been associated with biologic effects without a complete understanding of the molecular identity of their target receptors. Within this framework, this review offers a historical perspective on deorphanization processes for representative GPCRs, including the ghrelin receptor, γ aminobutyric acid B receptor, apelin receptor, cannabinoid receptors, and GPR15. It explores three main scenarios encountered in deorphanization efforts and discusses key questions and methodologies employed in elucidating ligand-receptor interactions, providing insights for future research endeavors. SIGNIFICANCE STATEMENT: Understanding how scientists have historically approached the issue of GPCR deorphanization and pairing of biologically active ligands with their cognate receptors are relevant topics in pharmacology. In fact, the biology of each GPCR, including its pathophysiological involvement, has often been uncovered only after its deorphanization, illuminating druggable targets for various diseases. Furthermore, uncovered endogenous ligands have therapeutic value as many ligands-or derivates thereof-are developed into drugs.

Endurance results of a refuels fleet test in a real application based on directly comparable truck test pairs

AbstractSynthetic fuels from a renewable base are an essential part of a greenhouse gas-neutral mobility, especially in transport sector. While scaling production of e-fuels (fuels based on electrolysis hydrogen) is ongoing, HVO called paraffinic diesel fuels are already available. Their production is based on the hydrogenation of waste and residues and they are established as diesel substitute in several applications. With regard to the approval of these fuels in German regulation, the question repeatedly arises as to whether they can be used easily and what effects can be achieved. This article describes an application in a real logistics application, in which both the everyday use and the concrete comparability to a refueling with conventional gas station diesel were ensured. The use of several parallel active and different truck pairs has shown that the use of HVO in existing vehicles has achieved the desired CO2 reduction. A detailed analysis of the engine oil also showed that no undesirable effects could be observed here either. From the perspective of this project, HVO fuels are ready for use for a significant greenhouse gas reduction in logistics.

Compositional Confluence Criteria

We show how confluence criteria based on decreasing diagrams are generalized to ones composable with other criteria. For demonstration of the method, the confluence criteria of orthogonality, rule labeling, and critical pair systems for term rewriting are recast into composable forms. We also show how such a criterion can be used for a reduction method that removes rewrite rules unnecessary for confluence analysis. In addition to them, we prove that Toyama's parallel closedness result based on parallel critical pairs subsumes his almost parallel closedness theorem.

High‐gain horizontally polarised omnidirectional planar antenna using parasitic directors for wireless sensor networks

SummaryWireless sensor networks (WSNs) are used to monitor the real‐time parameters of remote/restricted access areas of automation industries which are tightly sealed. In such scenarios, the main challenge is signal transmission in sealed environments. An omnidirectional radiation pattern is preferred as a control link for receiving packets or periodic updates from its neighbouring nodes. However, the gain and directivity of omnidirectional antenna should be sufficient enough to transfer the data to the collecting node. This paper proposes a high‐gain horizontally polarised omnidirectional radiation pattern planar antenna resonating at the 2.45 GHz. The developed microstrip planar antenna offers a very simple and compact structure printed on either side of FR4 epoxy substrate (ε = 4.4) suitable for WSN nodes. A printed dipole director is arranged orthogonally and offers horizontal polarisation. A pair of parasitic elements is placed parallel to dipole radiators to improve the total gain of the antenna. A parallel pair of parasitic elements is placed on an inclination of 45° in antenna design plane for uniform distribution of surface current to achieve the omnidirectional antenna. The symmetrical structure of the radiating element on either side of the substrate avoids the design of the traditional balun structure to reduce the complexity of feeding network. The developed antenna is simulated, fabricated, measured and tested using WSN. The measured radiation (directivity = 3.9 dBi) is maximum at Ⴔ = 0° and Ⴔ = 90°. The frequency response of the antenna indicates a −10 dB fractional bandwidth of 380 MHz (2.24 GHz–2.62 GHz). The measured far‐field response shows a stable average gain of 3.9 dBi over the ISM band. The real‐time received signal strength indicator (RSSI) of the antenna installed in the sensor node observed a success rate of 79.46% with a transmission error of 10%. The observed response of an antenna makes it well‐suitable for WSN in industrial automation.

New approximation algorithms for RNA secondary structures prediction problems by local search

This paper investigates two combinatorial problems from RNA secondary structure prediction with arbitrary pseudoknots. Given a RNA sequence and a set of base pairs, two parallel and adjacent base pairs constitute a stacking. The Maximum Stacking Base Pairs problem (MSBP) aims at finding a maximum number of based pairs, all of which form stackings, while the Maximum Base Pair Stackings problem (MBPS) is to find a maximum number of stackings. Both problems are NP-hard. We present two new approximation algorithms for the two problems by local search methods. For MSBP, the approximation factor is improved from 52 to 73; as for the MBPS, the approximation factor is improved from 83 to 52.

A cross-guidance cross-lingual model on generated parallel corpus for classical Chinese machine reading comprehension

Chinese diachronic gap is a key issue in classical Chinese machine reading comprehension (CCMRC). Preceding work on bridging this gap has been mostly restricted to limited monolingual classical Chinese corpora pre-training and lexical knowledge integration, which require a great deal of human resources. In this paper, we propose a cross-guidance cross-lingual model (CGCLM), pre-trained on a classical and modern Chinese parallel corpus generated from a large language model, to bridge the Chinese diachronic gap and reduce the manual effort. The CGCLM facilitates accurate translation by providing in-context examples and feedback based on the longest common substring between source and target sentences, thereby avoiding untranslated Chinese words. Specifically, we consider three pre-training tasks, i.e., cross-masked language modeling, linguistic label cross-prediction, and semantic cross-aware translation language modeling. The knowledge acquired from masked tokens uncovering and linguistic label predicting can lead to the implicit semantic alignment between two language styles. Taking advantage of the semantic similarity between the same syntactic levels of parallel pairs, cross-aware modeling integrates and transmits contextualized semantic information. We utilize an 18.6G monolingual corpus to create a 37.2G parallel corpus. Manual evaluation has resulted in only acceptable discrepancies between our generated and human-edited parallel corpora. Extensive experimental results show that our proposed model outperforms the state-of-the-art by an average accuracy of 3.13%, 2.44%, and 2.17% on CCMRC, classical Chinese language understanding evaluation (CCLUE), and modern Chinese language understanding evaluation (MCLUE) tasks.

Biomechanical evaluation of CAD/CAM magnesium miniplates as a fixation strategy for the treatment of segmental mandibular reconstruction with a fibula free flap

Titanium patient-specific (CAD/CAM) plates are frequently used in mandibular reconstruction. However, titanium is a very stiff, non-degradable material which also induces artifacts in the imaging. Although magnesium has been proposed as a potential material alternative, the biomechanical conditions in the reconstructed mandible under magnesium CAD/CAM plate fixation are unknown. This study aimed to evaluate the primary fixation stability and potential of magnesium CAD/CAM miniplates. The biomechanical environment in a one segmental mandibular reconstruction with fibula free flap induced by a combination of a short posterior titanium CAD/CAM reconstruction plate and two anterior CAD/CAM miniplates of titanium and/or magnesium was evaluated, using computer modeling approaches. Output parameters were the strains in the healing regions and the stresses in the plates. Mechanical strains increased locally under magnesium fixation. Two plate-protective constellations for magnesium plates were identified: (1) pairing one magnesium miniplate with a parallel titanium miniplate and (2) pairing anterior magnesium miniplates with a posterior titanium reconstruction plate. Due to their degradability and reduced stiffness in comparison to titanium, magnesium plates could be beneficial for bone healing. Magnesium miniplates can be paired with titanium plates to ensure a non-occurrence of plate failure.

Research on Time-Varying Meshing Stiffness of Marine Beveloid Gear System

Beveloid gears have the advantages of compensating for axial error, providing smooth transmission, and eliminating turning error. Therefore, they are widely used in applications that require high transmission accuracy and stability. However, research on calculating the time-varying meshing stiffness of beveloid gears is still limited, and there is an urgent need to propose a method that can calculate the meshing stiffness of beveloid gears quickly and accurately. We first established the tooth profile expressions, assuming a pair of beveloid gears meshing with the same rack, and the contact line equations of parallel axis beveloid gear pairs were derived. Next, we analyzed the contact process of beveloid gears. We propose an analytical algorithm based on the slicing method to calculate the meshing stiffness of helical gears, straight beveloid gears, and helical beveloid gears. Then, the influence of different parameters on the meshing stiffness of helical beveloid gears was analyzed by changing the respective parameters. Finally, the finite element method (FEM) was used to verify the correctness of the analytical results, and then the errors were analyzed. The study demonstrates that the results obtained from the analytical algorithm we proposed have the same magnitude as those obtained by the FEM for the time-varying meshing stiffness calculation of beveloid gears.

Investigating how lower secondary school students reason about quadrilaterals emerging in dynamic constructions

This contribution focuses on reasoning about quadrilaterals provided by lower secondary school students when working with pre-prepared dynamic constructions. On this topic, we present an exploratory empirical qualitative study carried out within a GeoGebra Classroom environment, and our diagnostic instrument consists of a set of dynamic constructions of quadrilaterals that are based just on a composition of lines and circles. The dynamic constructions consist of the same construction steps as with a straightedge and a compass on paper, without any relational or measurement information provided by the software. The hierarchy in the dynamic constructions is tied to properties of diagonals and takes on various levels and structure (one level, two consecutive levels, two parallel pairs of consecutive levels). For each of the constructions, the participants of the study reasoned which shapes could be found in the construction and why. Various levels of reasoning as well as various levels of students’ understanding of quadrilaterals appeared in data. The findings indicate that, at least for the lower secondary school students, the combination of dynamic manipulations and geometric constructions could form a significant space for scaffolding the identification of the features of quadrilaterals and the comprehension of the inclusive relations between them.

Multi-view fusion for universal translation quality estimation

Machine translation quality estimation (QE) aims to evaluate the result of translation without reference. Despite the progress it has made, state-of-the-art QE models are proven to be biased. More specifically, they over-rely on spurious statistical features while ignoring the bilingual semantic adequacy, leading to performance degradation. Besides, existing approaches require large amounts of annotation data, restricting their applications in new domains and languages. In this work, we propose a universal framework for quality estimation based on multi-view fusion. We first introduce noise to the target side of the parallel sentence pair, either by pre-trained language model or by large language model. After that, with the clean parallel pairs and the noised pairs as different views, the QE model is trained to distinguish the clean pairs from the noised ones. Our method can improve the accuracy and generalizability in supervised scenario, and can solely perform estimation in zero-shot scenario. We perform experiments on WMT QE evaluation datasets under different scenarios, verifying the effectiveness of our method. We also make an in-depth investigation of the bias of QE model.

A 54 µW CMOS Auto-Trimming Bandgap References (ATBGR) Achieving 90 dB PSRR for Artificial Intelligence of Things (AIoT) Chips.

An Auto-Trimming CMOS Bandgap References Circuit (ATBGR) with PSRR enhancement circuit for Artificial Intelligence of Things (AIoT) chips is presented in this paper. The ATBGR is designed with a first-order temperature compensation technique providing a stable reference voltage of 1.25 V in the ranges of input voltages from 1.65 V to 4.5 V. An auto-trimming circuit is integrated into a PTAT resistor of BGR to minimize the influences of the process variations. The four parallel resistor pairs with PMOS switches are connected in series with the PTAT resistor. The reference voltage, VREF, is compared to an external constant value, 1.25 V, through an operational amplifier, and the output of the de-multiplexer is used to configure the PMOS switches. High power supply rejection is achieved through a PSRR enhancement circuit constituting a cascaded PMOS common gate pair. The ATBGR circuit is fabricated in 180 nm CMOS technology, consuming an area of 0.03277 mm2. The auto-trimming method yields an average temperature coefficient of 9.99 ppm/°C with temperature ranges from -40 °C to 125 °C, and a power supply rejection ratio of -90 dB at 100 MHz is obtained. The line regulation of the proposed circuit is 0.434%/V with power consumption of 54.12 µW at room temperature.

Scalable Multipartite Entanglement Created by Spin Exchange in an Optical Lattice.

Ultracold atoms in optical lattices form a competitive candidate for quantum computation owing to the excellent coherence properties, the highly parallel operations over spins, and the ultralow entropy achieved in qubit arrays. For this, a massive number of parallel entangled atom pairs have been realized in superlattices. However, the more formidable challenge is to scale up and detect multipartite entanglement, the basic resource for quantum computation, due to the lack of manipulations over local atomic spins in retroreflected bichromatic superlattices. In this Letter, we realize the functional building blocks in quantum-gate-based architecture by developing a cross-angle spin-dependent optical superlattice for implementing layers of quantum gates over moderately separated atoms incorporated with a quantum gas microscope for single-atom manipulation and detection. Bell states with a fidelity of 95.6(5)% and a lifetime of 2.20±0.13 s are prepared in parallel, and then connected to multipartite entangled states of one-dimensional ten-atom chains and two-dimensional plaquettes of 2×4 atoms. The multipartite entanglement is further verified with full bipartite nonseparability criteria. This offers a new platform toward scalable quantum computation and simulation.

Counting pairs of saddle connections

We show that for almost every translation surface the number of pairs of saddle connections with bounded magnitude of the cross product has asymptotic growth like cR2 where the constant c depends only on the area and the connected component of the stratum. The proof techniques combine classical results for counting saddle connections with the crucial result that the Siegel–Veech transform is in L2. In order to capture information about pairs of saddle connections, we consider pairs with bounded magnitude of the cross product since the set of such pairs can be approximated by a fibered set which is equivariant under geodesic flow. In the case of lattice surfaces, small bounded magnitude of the cross product is equivalent to counting parallel pairs of saddle connections, which also have a quadratic growth of cR2 where c depends in this case on the given lattice surface.

Do de re necessities express semantic rules?

ABSTRACT Amie Thomasson's Norms and Necessity offers a non-factualist theory of the language of metaphysical necessity, centering on the idea that statements of necessity express semantic norms. This article identifies a potential problem for the view by distinguishing two kinds of conditional necessity, investigates a solution derived from a well-known parallel pair of conditional necessities in deontic logic, but finds it is not up to the job. The last part of the paper suggests a different route, largely in keeping with the underlying ideas behind Thomasson's approach.

Mach–Zehnder-like interferometry with graphene nanoribbon networks

We study theoretically electron interference in a Mach–Zehnder-like geometry formed by four zigzag graphene nanoribbons arranged in parallel pairs, one on top of the other, such that they form intersection angles of 60∘. Depending on the interribbon separation, each intersection can be tuned to act either as an electron beam splitter or as a mirror, enabling tuneable circuitry with interfering pathways. Based on the mean-field Hubbard model and Green’s function techniques, we evaluate the electron transport properties of such eight-terminal devices and identify pairs of terminals that are subject to self-interference. We further show that the scattering matrix formalism in the approximation of independent scattering at the four individual junctions provides accurate results as compared with the Green’s function description, allowing for a simple interpretation of the interference process between two dominant pathways. This enables us to characterize the device sensitivity to phase shifts from an external magnetic flux according to the Aharonov–Bohm effect as well as from small geometric variations in the two path lengths. The proposed devices could find applications as magnetic field sensors and as detectors of phase shifts induced by local scatterers on the different segments, such as adsorbates, impurities or defects. The setup could also be used to create and study quantum entanglement.

Cone-beam CT sampling incompleteness: analytical and empirical studies of emerging systems and source-detector orbits.

Motivated by emerging cone-beam computed tomography (CBCT) systems and scan orbits, we aim to quantitatively assess the completeness of data for 3D image reconstruction-in turn, related to "cone-beam artifacts." Fundamental principles of cone-beam sampling incompleteness are considered with respect to an analytical figure-of-merit [FOM, denoted ] and related to an empirical FOM (denoted ) for measurement of cone-beam artifact magnitude in a test phantom. A previously proposed analytical FOM [, defined as the minimum angle between a point in the 3D image reconstruction and the x-ray source over the scan orbit] was analyzed for a variety of CBCT geometries. A physical test phantom was configured with parallel disk pairs (perpendicular to the -axis) at various locations throughout the field of view, quantifying cone-beam artifact magnitude in terms of (the relative signal modulation between the disks). Two CBCT systems were considered: an interventional C-arm (Cios Spin 3D; Siemens Healthineers, Forcheim Germany) and a musculoskeletal extremity scanner; Onsight3D, Carestream Health, Rochester, United States)]. Simulations and physical experiments were conducted for various source-detector orbits: (a)a conventional 360deg circular orbit, (b)tilted and untilted semi-circular (196deg) orbits, (c)multi-source (three x-ray sources distributed along the axis) semi-circular orbits, and (d)a non-circular (sine-on-sphere, SoS) orbit. The incompleteness of sampling [] and magnitude of cone-beam artifacts () were evaluated for each system and orbit. The results show visually and quantitatively the effect of system geometry and scan orbit on cone-beam sampling effects, demonstrating the relationship between analytical and empirical . Advanced source-detector orbits (e.g., three-source and SoS orbits) exhibited superior sampling completeness as quantified by both the analytical and the empirical FOMs. The test phantom and metric were sensitive to variations in CBCT system geometry and scan orbit and provided a surrogate measure of underlying sampling completeness. For a given system geometry and source-detector orbit, cone-beam sampling completeness can be quantified analytically (in terms arising from Tuy's condition) and/or empirically (using a test phantom for quantification of cone-beam artifacts). Such analysis provides theoretical and practical insight on sampling effects and the completeness of data for emerging CBCT systems and scan trajectories.

Realization of a novel dual-band bandpass filter with coupled series gaps and stepped impedance complementary split ring resonators

In this article, a bandpass filter (BPF) is proposed by etching stepped impedance complementary split ring resonators (SICSRRs) pairs in parallel with series gaps on the top side of a coplanar waveguide (CPW). The Nicolson-Ross-Weir (NRW) method is used to analyze the left-handed (LH) behavior of the filter. The effects of the resonators parameters on the left-handed BPF are studied. The parameters and number of the resonators are adjusted properly to obtain the desired filter characteristics. Split ring resonators (SRRs) are magnetically coupled to the BPF to realize a novel left-handed dual-band bandpass filter. Besides, The dual-band filter is described by means of the lumped-element equivalent circuit model. Also, the quasi-static analysis is used to obtain the equations for the resonant frequencies of the resonators. The efficient electrical size of the dual-band filter is 0.51λg × 0.42λg where λg represents the guided wavelength at the first passband center frequency. The prototype of the compact dual-band BPF is fabricated and measured. The measured results reveal low insertion loss and high return loss at the passbands along with wide upper stopband attenuation. The measured result is in a good agreement with the corresponding simulation result.