Complementary Structures Research Articles

Precise and selective macroscopic assembly of a dual lock-and-key structured hydrogel.

Macroscopic assembly offers immense potential for constructing complex systems due to the high design flexibility of the building blocks. In such assembly systems, hydrogels are promising candidates for building blocks due to their versatile chemical compositions and ease of property tuning. However, two major challenges must be addressed to facilitate application in a broader context: the precision of assembly and the quantity of orthogonally matching pairs must both be increased. Although previous studies have attempted to address these challenges, none have successfully dealt with both simultaneously. Here, we propose topology-based design criteria for the selective assembly of hydrogel building blocks. By introducing the dual lock-and-key structures, we demonstrate highly precise assembly exclusively between the matching pairs. We establish principles for selecting multiple orthogonally matching pairs and achieve selective assembly involving simple one-to-one matching and complex assemblies with multiple orthogonal matching points. Moreover, by harnessing hydrogel tunability and the abundance of matching pairs, we synthesize complementary single-stranded structures for programmable assembly and successfully assemble them in the correct order. Finally, we demonstrate a hydrogel-based self-assembled logic gate system, including a YES gate, an OR gate, and an AND gate. The output is generated only when the corresponding inputs are provided according to each logic.

Analyzing Eye Paths Using Fractals.

Visual patterns reflect the anatomical and cognitive background underlying process governing how we perceive information, influenced by stimulus characteristics and our own visual perception. These patterns are both spatially complex and display self-similarity seen in fractal geometry at different scales, making them challenging to measure using the traditional topological dimensions used in Euclidean geometry.However, methods for measuring eye gaze patterns using fractals have shown success in quantifying geometric complexity, matchability, and implementation into machine learning methods. This success is due to the inherent capabilities that fractals possess when reducing dimensionality using Hilbert curves, measuring temporal complexity using the Higuchi fractal dimension (HFD), and determining geometric complexity using the Minkowski-Bouligand dimension.Understanding the many applications of fractals when measuring and analyzing eye gaze patterns can extend the current growing body of knowledge by identifying markers tied to neurological pathology. Additionally, in future work, fractals can facilitate defining imaging modalities in eye tracking diagnostics by exploiting their capability to acquire multiscale information, including complementary functions, structures, and dynamics.

Circular dichroism in two-dimensional BC6N and B3C2N3 in absence of intervalley excitonic coupling

Two-dimensional (2D) noncentrosymmetric systems offer potential opportunities for exploiting the valley degrees of freedom for advanced information processing, owing to non-zero Berry curvature. However, such valley polarization in 2D materials is crucially governed by the intervalley excitonic scattering in momentum space due to reduced electronic degrees of freedom and consequent enhanced electronic correlation. Here, we study the valley excitonic properties of two 2D noncentrosymmetric complementary structures, namely, BC6N and B3C2N3 using first principles-based GW calculations combined with the Bethe–Salpeter equation, that brings the many-body interactions among the quasiparticles. The k-resolved oscillator strength of their first bright exciton indicates their ability to exhibit valley polarization under the irradiation of circularly polarized light of different chiralities. Both the systems show significant singlet excitonic binding energies of 0.74 eV and 1.31 eV, respectively. Higher stability of dark triplet excitons as compared to the singlet one can lead to higher quantum efficiency in both the systems. The combination of large excitonic binding energies and the valley polarization ability with minimal intervalley scattering make them promising candidates for applications in advanced optical devices and information storage technologies.

Linear time manageable edge-aware filtering on complementary tree structures

Typical non-local edge-aware filtering methods build long-range connections by deriving a minimum spanning tree (MST) from the input image. Each pixel on the MST only connects to a sub-set of pixels in the 8-connected neighborhood, resulting in piece-wise constant output with fake edges among sub-trees for the unbalanced information propagation along eight directions. In this paper, we propose two complementary spatial trees to incorporate information from the entire image. The structure of each tree depends on the spatial relationships of neighboring pixels. The distances between any two pixels in both spatial space and intensity space are the shortest distances on each tree. We introduce an efficient algorithm to recursively compute the output and the normalization constant on each tree with linear time complexity. For each pixel, we first calculate the outputs from eight subtrees and then fuse them to obtain the result on each tree structure. The final filtering output of our method is the weighted average of the results from two complementary spatial trees. Moreover, we present a distance mapping scheme to adjust the intensity distance between neighboring pixels, enabling our method to filter out a manageable degree of low-amplitude structures while sharpening major edges. Extensive experiments in graphic applications, such as image denoising, JPEG artifact removal, tone mapping, detail enhancement, and colorization, demonstrate the effectiveness and versatility of our method.

Chemo-Enzymatic Synthesis of Isomeric I-branched Polylactosamines Using Traceless Blocking Groups.

Poly-N-acetyl lactosamines (polyLacNAc) are common structural motifs of N- and O-linked glycan, glycosphingolipids and human milk oligosaccharides. They can be branched by the addition of β1,6-linked N-acetyl-glucosamine (GlcNAc) moieties to internal galactoside (Gal) residues by the I-branching enzyme beta-1,6-N-acetylglucosaminyltransferase 2 (GCNT2). I-branching has been implicated in many biological processes and is also associated with various diseases such as cancer progression. Currently, there is a lack of methods that can install, in a regioselective manner, I-branches and allows the preparation of isomeric poly-LacNAc derivatives. Here, we described a chemo-enzymatic strategy that addresses this deficiency and is based on the enzymatic assembly of an oligo-LacNAc chain that at specific positions is modified by a GlcNTFA moiety. Replacement of the trifluoroacetyl (TFA) moiety by tert-butyloxycarbonyl (Boc) gives compounds in which the galactoside at the proximal site is blocked from modification by GCNT2. After elaboration of the antennae, the Boc group can be removed, and the resulting amine acetylated to give natural I-branched structures. It is also shown that fucosides can function as a traceless blocking group that can provide complementary I-branched structures from a single precursor. The methodology made it possible to synthesize a library of polyLacNAc chains having various topologies.

Hybrid impedance and admittance control for optimal robot–environment interaction

AbstractCompliant interaction between robots and the environment is crucial for completing contact-rich tasks. However, obtaining and implementing optimal interaction behavior in complex unknown environments remains a challenge. This article develops a hybrid impedance and admittance control (HIAC) scheme for robots subjected to the second-order unknown environment. To obtain the second-order target impedance model that represents the optimal interaction behavior without the accurate environment dynamics and acceleration feedback, an impedance adaptation method with virtual inertia is proposed. Since impedance control and admittance control have complementary structures and result in unsatisfactory performance in a wide range of environmental stiffness due to their fixed causality, a hybrid system framework suitable for the second-order environment is proposed to generate a series of intermediate controllers which interpolate between the responses of impedance and admittance controls by using a switching controller and adjusting its switching duty cycle. In addition, the optimal intermediate controller is selected using a mapping of the optimal duty cycle to provide the optimal implementation performance for the target impedance model. The proposed HIAC scheme can achieve the desired interaction and impedance implementation performance while ensuring system stability. Simulation and experimental studies are performed to verify the effectiveness of our scheme with a 2-DOF manipulator and a 7-DOF Franka EMIKA panda robot, respectively.

Analisis Kelaikan Fungsi Jalan Menggunakan Metode AHP dan Maut pada Ruas Jalan A.H. Nasution (Medan) dan Jalan Ngumban Surbakti (Medan)

Road infrastructure is an important aspect in supporting economic growth and human mobility. Good and safe road conditions will increase the effectiveness and efficiency of transportation. However, in reality, some road sections still do not meet fairly strict standards, both in terms of feasibility and safety. The roads of A.H. Nasution (Medan) and Ngumban Surbakti (Medan) have never undergone a feasibility test before. Therefore, in this study a ranking will be formed to determine the level of feasibility of the function of both. This study was conducted to evaluate the feasibility of A.H. Nasution (Medan) and Ngumban Surbakti (Medan) roads using the AHP (Analytical Hierarchy Process) method and the MAUT (Multi-Attribute Utility Theory) method. The data that has been collected will be processed and analyzed using the AHP and MAUT methods. The AHP method and the MAUT method are used to determine the relative weight of each of the factors affecting roadworthiness. Assessment of respondent data using the AHP method obtained the largest weight on road technical by 3.36 on the A.H. Nasution road section and 3.04 on the Ngumban Surbakti road section. While the smallest weight on technical road equipment is 0.592 on the A.H. Nasution road section and the utilization of the road section is 0.3 on the Ngumban Surbakti road section. The assessment of respondents' data using the MAUT method obtained the largest weight on road complementary building structures of 1,265 on the A.H. Nasution road section and 1,140 on the Ngumban Surbakti road section. While the smallest weight on the utilization of road sections is 0.04 on the A.H. Nasution road section and 0.413 on the Ngumban Surbakti road section.

84 Advances, Challenges and Prospects for the Sustainable Use of the chigüiro in Colombia

Abstract The sustainable use of chigüiro or capybara is a strategy proposal to prevent the decline of the species population by maintaining and conserving appropriate habitats, reducing illegal capture, promoting its recognition, and achieving a better distribution of its benefits and its environmental services. The objective of this work is to present the progress made toward the sustainable use of capybaras in Colombia. The biological information compiled during the last 15 years indicates that the density of the populations of this species is heterogeneous throughout the flooded savannahs with space-time variations between < 1 individual/ha, and up to 6 individual/ha. These variations are associated with strong climatic variations, changes in habitat quality, and the impact of a series of conditioning factors, both natural (water availability over time) and anthropogenic origin (hunting, land use, eventual competition with cattle, and the incidence of burning). Commercial hunting as a sustainable strategy includes the identification of various products and by-products of the species, as well as its linkage in Bioeconomy projects (Figure 1) through the compliance of associated normative, the reinforcement of environmental authorities, an effective communication strategy and user commitment. Capybara meat is characterized by having a low-fat content and a protein ratio greater than 20%; and its carcass meat performance is between 44% and 53%. In addition to the training in the preparation of various meat by-products and the analysis and processing of the fur, there is an updated market study that includes an interview phase, a pilot test of exploitation, yields and tastings for approach to the actor of the commercial chain and meet future investors or buyers. With these results, a financial model was formulated with all the necessary costs to make use of the Chigüiro products. Additionally, a prototype processing plant was designed and it has three mobile components (A, B, C); two complementary fixed structures (D, E) and a module for the processing of by-products and waste (Figure 2). Finally, linking capybara population concentration points within ecotourism activities will expand the options for its use and conservation of the Chigüiro population and its habitats. Among the actual limitations for Chigüiro use we have the delay in issuing the resolution for the allocation of the global utilization quota, and the modification of the closure to increase the period of use. These resolutions will encourage the participation of other users and local investors, which is expected to reduce the transformation of natural ecosystems and their associated biodiversity.

Linear Time Non-Local Cost Aggregation on Complementary Spatial Tree Structures

Studies on many dense correspondence tasks in the field of computer vision attempt to find spatially smooth results. A typical way to solve these problems is by smoothing the matching costs using edge-preserving filters. However, local filters generate locally optimal results, in that they only take the costs over a small support window into account, and non-local filters based on a minimum spanning tree (MST) tend to overuse the piece-wise constant assumption. In this paper, we propose a linear time non-local cost aggregation method based on two complementary spatial tree structures. The geodesic distances in both the spatial and intensity spaces along the tree structures are used to evaluate the similarity of pixels, and the final aggregated cost is the sum of the outputs from these two trees. The filtering output of a pixel on each tree can be obtained by recursively aggregating the costs along eight sub-trees with linear time complexity. The only difference between the filtering procedures on these two spatial tree structures is the order of the filtering. Experimental results in optical flow estimation and stereo matching on the Middlebury and KITTI datasets demonstrate the effectiveness and efficiency of our method. It turns out that our method outperforms typical non-local filters based on the MST in cost aggregation. Moreover, a comparison of handcrafted features and deep features learned by convolutional neural networks (CNNs) in calculating the matching cost is also provided. The code will be available soon.

A dual-band low-profile Fabry–Perot resonator antenna with single partially reflecting surface

ABSTRACTThis paper presents a novel design for a low-profile Fabry–Perot resonator antenna (FPRA) that operates at two distinct frequency bands using a single partially reflecting surface (PRS). The PRS is composed of two different types of unit cells arranged in a staggered fashion. These unit cells are comprised of double-sided complementary structures, including a square patch with a square aperture and a circular ring with a circular ring slot. To reduce the overall profile of the antenna, an artificial magnetic conductor (AMC) surface is utilized as the reflection plane. The proposed design employs a dual-band slotted patch antenna as the primary source. The overall dimensions of the FPRA are 91 mm×91 mm×5.54 mm. The performance of the prototype antenna is validated through measurement, demonstrating peak gains of 14.1 and 16.1 dBi at frequencies of 6.65 and 12.05 GHz, respectively. Additionally, the antenna exhibits −10 dB impedance bandwidths of 6.5–6.8 GHz and 12.15–12.23 GHz at the two frequency bands.

ALLOSTERIC BOOSTING OFAFFINITY SORPTION

Affinity chromatography belongs to the classic preparative and research methods of biochemistry, molecular biology, and biotechnology. This method is based on the application of the affinity of biological molecules to complementary structures. One of the complex-forming participants is immobilized on an insoluble matrix, and the second one is in solution. According to a fairly conventional separation, one of these components contains a binding site that interacts with the complementary grouping of the second component. In this work, a complicated variant of affinity sorption is considered, in which the allosteric site additionally participates in the process of complex formation. Using the example of the activation cascade of the blood clotting system, the possibilities of using such a scheme are considered.

Simultaneous transmissive and reflective polarization conversion cross different operating bands in a single metasurface

This paper proposes a bifunctional linear-to linear polarization converter with a sandwich structure that enables transmissive and reflective polarization conversions in different operating bands, simultaneously. The unit cell of the converter metasurface comprises an S-shaped wire, a dielectric slab, and an S-shaped slot, where the S-shaped wire and slot have complementary structures and a 30° difference in orientation. When an x-polarized electromagnetic wave is incident on the proposed metasurface, most of the transmitted wave is y-polarized in the frequency range of 7.07 GHz to 7.46 GHz, while most of the reflected wave is y-polarized in the frequency range of 16.59 GHz to 16.91 GHz. The physical mechanism underlying these two types of polarization conversions was analyzed based on the surface current, and electric field distributions. Notably, the transmissive polarization conversion was primarily attributed to magnetic resonance, while its reflective counterpart was ascribed to electric resonance. In addition, the Jones vector and Stokes parameters were analyzed thereby elucidating the polarization characteristics of the proposed metasurface. Furthermore, simulation data demonstrated excellent agreement with the measured results of polarization conversion. The designed metasurface will promote subsequent research on bifunctional polarization converters.

MuxGNN: Multiplex Graph Neural Network for Heterogeneous Graphs.

Graph neural networks (GNNs) have become effective learning techniques for many downstream network mining tasks including node and graph classification, link prediction, and network reconstruction. However, most GNN methods have been developed for homogeneous networks with only a single type of node and edge. In this work we present muxGNN, a multiplex graph neural network for heterogeneous graphs. To model heterogeneity, we represent graphs as multiplex networks consisting of a set of relation layer graphs and a coupling graph that links node instantiations across multiple relations. We parameterize relation-specific representations of nodes and design a novel coupling attention mechanism that models the importance of multi-relational contexts for different types of nodes and edges in heterogeneous graphs. We further develop two complementary coupling structures: node invariant coupling suitable for node- and graph-level tasks, and node equivariant coupling suitable for link-level tasks. Extensive experiments conducted on six real-world datasets for link prediction in both transductive and inductive contexts and graph classification demonstrate the superior performance of muxGNN over state-of-the-art heterogeneous GNNs. In addition, we show that muxGNN's coupling attention discovers interpretable connections between different relations in heterogeneous networks.

Development of Cross-Border E-commerce between China and Russia as part of the Belt and Road Initiative: Opportunities and Challenges

This paper researches the opportunities and challenges of cross-border e-commerce development between Russia and China under the One Belt One Road initiative. Using SWOT analysis and official data, introduce the strengths, weaknesses, opportunities as well as threats of cross-border e-commerce development between Russia and China. The conclusion is that the current e-commerce market in China and Russia has great potential and has become a new growth point for foreign trade promotion and economic recovery, and its development has the strengths of political support and complementary product trade structures in both countries. In addition, the Belt and Road Initiative promotes the development of logistics infrastructure, an the rapid development of Internet technology and online trade provides opportunities for the development of e-commerce in China and Russia. However, in the current complex international situation, the development of cross-border e-commerce in both countries faces threats and challenges, such as the slow global economic recovery after the epidemic and the sanctions imposed on the Russian economy by Europe and the US. There are also its own weaknesses: imperfect cross-border payment and credit systems, limited trade models on the platform, and untimely logistics and delivery. Therefore, optimization and improvement of platforms, cross-border payments and cross-border logistics are needed. This study will contribute to enterprises exploring new paths for their own development, and optimizing the foreign trade structure of China and Russia as well as economic recovery.

Dual-bionic superwetting gears with liquid directional steering for oil-water separation

Developing an effective and sustainable method for separating and purifying oily wastewater is a significant challenge. Conventional separation membrane and sponge systems are limited in their long-term usage due to weak antifouling abilities and poor processing capacity for systems with multiple oils. In this study, we present a dual-bionic superwetting gears overflow system with liquid steering abilities, which enables the separation of oil-in-water emulsions into pure phases. This is achieved through the synergistic effect of surface superwettability and complementary topological structures. By applying the surface energy matching principle, water and oil in the mixture rapidly and continuously spread on preferential gear surfaces, forming distinct liquid films that repel each other. The topological structures of the gears facilitate the overflow and rapid transfer of the liquid films, resulting in a high separation flux with the assistance of rotational motion. Importantly, this separation model mitigates the decrease in separation flux caused by fouling and maintains a consistently high separation efficiency for multiple oils with varying densities and surface tensions.

Independently Tunable Triband Patch Antenna with Band-Notched Characteristics for X-Band Applications

This paper presents a triband antenna with a simple design for X-band applications. The proposed antenna is designed based on a patch with a truncated corner slot and complementary split-ring resonators in the ground plane. In this way, the antenna exhibits three operating bands and its resonant frequencies can be controlled independently by changing dimensions of the slot in the patch and the resonator structures in the ground plane. In addition, due to the antiresonant behavior of the complementary split-ring resonator structures, the antenna exhibits a notch-band characteristic at 10.7 GHz. A parametric study is performed to provide a detailed understanding of the independent resonance tuning behavior of the antenna. Both simulated and measured results of the proposed antenna are presented, which are in good agreement. The proposed antenna shows three operating bands in the X-band including (with absolute and relative bandwidths) 9.4–9.7 GHz (300 MHz, 3.14%), 10.3–10.6 GHz (300 MHz, 2.86%), and 11.05–11.32 GHz (297 MHz, 2.66%). In addition to that, a notched band of 10.6–11.05 GHz is introduced to exclude operation in the frequency bands of radiometric observation systems (10.6–10.7 GHz). To the best of our knowledge, this work is unique in its combination of independent tuning of three frequency bands of operation with single-layer implementation in the X-band. Such a structure provides additional degrees of freedom to the antenna design, customizing operation in the required bands while avoiding operation in other bands.

Babinet-complementary structures for implementation of pseudospin-polarized waveguides.

In this work, a theorem is proved stating that in various types of waveguides with mirror reflection symmetries, the electromagnetic duality correspondence between eigenmodes of complementary structures induces counterpropagating spin-polarized states. The mirror reflection symmetries may be preserved around one or more arbitrary planes. Pseudospin-polarized waveguides supporting one-way states manifest robustness. This is similar to topologically non-trivial direction-dependent states guided by photonic topological insulators. Nevertheless, a remarkable aspect of our structures is that they can be implemented in extremely broad bandwidth by simply using complementary structures. Based on our theory, the concept of the pseudospin polarized waveguide can be realized using dual impedance surfaces ranging from microwave to optical regime. Consequently, there is no need to employ bulk electromagnetic materials to suppress backscattering in waveguiding structures. This also includes pseudospin-polarized waveguides with perfect electric conductor-perfect magnetic conductor boundaries where the boundary conditions limit the bandwidth of waveguides. We design and develop various unidirectional systems and the spin-filtered feature in the microwave regime is further investigated.

Broadband transparency of Babinet complementary metamaterials

According to the Babinet principle, the diffraction pattern from an opaque body is identical to that from a hole of the same shape and size. Intuitively, placing two complementary structures such as an opaque metal body and its transparent counterpart one by one may result in destructive or constructive interference leading to unexpected electromagnetic response. We propose a Babinet principle-based metamaterial made of two complementary metal/hole checkerboards. The unit cell of each layer is either a metal square with 1/4 of 8 neighboring squares, four of which are made of metal, whereas the other four are square holes, or vice versa. Being placed complementary at optimal distance equal to three-unit cell length, the compound bi-layered Babinet structure demonstrates absolute transparency in a very broad frequency range. The observed absolute transparency of the bi-layered Babinet metasurface is the result of the modified multipole interaction of layers with shifted centers of radiation. We demonstrate both theoretically and experimentally absolute transmission of 0 dB for the Babinet metamaterial made of 3 cm sized Cu squares and complementary holes in the broad frequency range from 4.5 to 6.62 GHz in simulations and from 4.6 to 6.4 GHz in the experiment when the distance between two layers is 1.2 cm. Moving layers toward each other leads to blurring of the resonances. The proven concept of simple, reproducible, and scalable design of the Babinet metamaterial paves the way for the fabrication of broadband transparent devices at any frequency, including THz and optical ranges. The main advantage of broadband Babine metamaterials is applications in optical switching, sensing, filtering, and slow light devices.

High Restore Yield NVSRAM Structures With Dual Complementary RRAM Devices for High-Speed Applications

Static random access memory (SRAM) plays a key role in the overall performance of electronic systems because of its rapid data processing and transmission speed; however, when the system power supply is cut off, the data stored in the nodes are lost. Thus, this article proposes four nonvolatile SRAM (NVSRAM) cells that use unilateral or bilateral structures with dual complementary series resistive random access memory (RRAM) devices. It is found that the read, write, and hold static noise margins (HSNMs) are comparable with those of the standard 6T-SRAM. Moreover, the store and restore operations operate in parallel at high speed. The store operation delay is only 6 ns for unilateral structures and 5 ns for bilateral structures, and the restore delay is only 10 ns for unilateral structures and 6 ns for bilateral structures. The maximum power consumption among the four structures for storing and restoring a “1” are 1.545 pJ/bit and 134.5 fJ/bit, respectively. Furthermore, the dual complementary series resistor structures can achieve a high restore yield at a resistance ratio of 1.5. Therefore, a high restore yield can be achieved even with large resistance fluctuations caused by the voltage, time, and process.

The Linguistic Concept’s Reduction Methods under Symmetric Linguistic-Evaluation Information

Knowledge reduction is a crucial topic in formal concept analysis. There always exists uncertain, symmetric linguistic-evaluation information in social life, which leads to high complexity in the process of knowledge representation. In order to overcome this problem, we are focused on studying the linguistic-concept-reduction methods in an uncertain environment with fuzzy linguistic information. Based on three-way decisions and an attribute-oriented concept lattice, we construct a fuzzy-object-induced three-way attribute-oriented linguistic (FOEAL) concept lattice, which provides complementary conceptual structures of a three-way concept lattice with symmetric linguistic-evaluation information. Through the granular concept of the FOEAL lattice, we present the corresponding linguistic concept granular consistent set and granular reduction. Then, we further employ the linguistic concept discernibility matrix and discernibility function to calculate the granular reduction set. A similar issue on information entropy is investigated to introduce a method of entropy reduction for the FOEAL lattice, and the relation between the linguistic concept granular reduction and entropy reduction is discussed. The efficiency of the proposed method is depicted by some examples and comparative analysis.