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Structural network alignment utilizes the topological structure information to find correspondences between nodes of two networks. Researchers have proposed a line of useful algorithms which usually require a prior mapping of seed...
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Structural network alignment utilizes the topological structure information to find correspondences between nodes of two networks. Researchers have proposed a line of useful algorithms which usually require a prior mapping of seeds acting as landmark points to align the rest nodes. Several seed-free algorithms are developed to solve the cold-start problem. However, existing approaches suffer high computational cost and low reliability, limiting their applications to large-scale network alignment. Moreover, there is a lack of useful metrics to quantify the credibility of seed mappings. To address these issues, we propose a credible seed identification framework and develop a metric to assess the reliability of a mapping. To tackle the cold-start problem, we employ graph embedding techniques to represent nodes by structural feature vectors in a latent space. We then leverage point set registration algorithms to match nodes algebraically and obtain an initial mapping of nodes. Besides, we propose a heuristic algorithm to improve the credibility of the initial mapping by filtering out mismatched node pairs. To tackle the computational problem in large-scale network alignment, we propose a divide-and-conquer scheme to divide large networks into smaller ones and then match them individually. It significantly improves the recall of mapping results. Finally, we conduct extensive experiments to evaluate the effectiveness and efficiency of our new approach. The results illustrate that the proposed method outperforms the state-of-the-art approaches in terms of both effectiveness and efficiency.
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In recent years, the continued miniaturization of VLSI circuits leads to the need for more efficient simulation of large-scale linear dynamical systems with ever-increasing state-space dimension. The linear dynamical systems in VL...
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In recent years, the continued miniaturization of VLSI circuits leads to the need for more efficient simulation of large-scale linear dynamical systems with ever-increasing state-space dimension. The linear dynamical systems in VLSI circuit simulation are RC or RCL models of the VLSI circuit's interconnected system. Model-order reduction is an important technique to reduce such a high complexity. Along the technology scaling, the indetermination in the manufacturing process causes variations in the critical dimensions and interlevel dielectric thickness of interconnects, which could make the system performance unpredictable and produce a significant parametric yield loss. An efficient exploitation of these design activities results in a parameterized model-order reduction technique able to reduce large systems of equations with respect to all of the variable parameters of the circuit, (i.e., resistance, capacitance, and inductance). For this purpose, we propose a novel parameterized model-order reduction method for interconnect variation systems, which is based on an efficient and reliable combination of invariable structure-preserving model-order reduction (SPMOR) methods and variable parameter retaining schemes. It is referred to as a parameterized interconnect model-order reduction via structure-preserving algorithm. The SPMOR model yields the same form of the original state equation and preserves the passivity of the parameterized RC and RLC networks, like the well-known passive reduced-order interconnect algorithm for nonparameterized RC and RLC networks. The most important benefit it entails is the ability to preserve the probability characteristic of the original interconnect systems. Pertinent numerical examples are proposed to validate the proposed SPMOR approach.
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As a classic positioning algorithm with a simple principle and low computational complexity, the trilateration positioning algorithm utilizes the coordinates of three anchor nodes to determine the position of an unknown node, whic...
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As a classic positioning algorithm with a simple principle and low computational complexity, the trilateration positioning algorithm utilizes the coordinates of three anchor nodes to determine the position of an unknown node, which is widely applied in various positioning scenes. However, due to the environmental noise, environmental interference, the distance estimation error, the uncertainty of anchor nodes’ coordinates, and other negative factors, the positioning error increases significantly. For this problem, we propose a new trilateration algorithm based on the combination and K-Means clustering to effectively remove the positioning results with significant errors in this paper, which makes full use of the position and distance information of the anchor nodes in the area. In this method, after analyzing the factors affecting the optimization of the trilateration and selecting optimal parameters, we carry out experiments to verify the effectiveness and feasibility of the proposed algorithm. We also compare the positioning accuracy and positioning efficiency of the proposed algorithm with those of other algorithms in different environments. According to the comparison of the least-squares method, the maximum likelihood method, the classical trilateration and the proposed trilateration, the results of the experiments show that the proposed trilateration algorithm performs well in the positioning accuracy and efficiency in both light-of-sight (LOS) and non-light-of-sight (NLOS) environments. Then, we test our approach in three realistic environments, i.e., indoor, outdoor and hall. The experimental results show that when there are few available anchor nodes, the proposed localization method reduces the mean distance error compared with the classical trilateration, the least-squares method, and the maximum likelihood.
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This work develops a high-frequency high-sensitivity inlaid cylindrical hydroacoustic transducer by enhancing the electromechanical coupling coefficient, amplifying stress, and adopting circumferential inlaid techniques. Equivalen...
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This work develops a high-frequency high-sensitivity inlaid cylindrical hydroacoustic transducer by enhancing the electromechanical coupling coefficient, amplifying stress, and adopting circumferential inlaid techniques. Equivalent circuit and finite element simulation methods were used to determine the optimum parameters of the unit, then the transducer was fabricated. Tests show that the resonant frequency of every array unit was 220 kHz. The maximum emission voltage response and reception sensitivity were respectively about 172 dB and -177 dB, with emission and reception bandwidths both about 40 kHz at 3 dB loss. The horizontal and vertical beamwidths were 15 degrees and 4 degrees for each unit respectively.
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Since similar to 40 Ma the eastward extrusion of the Songpan-Ganzi Terrane (SGT), induced by the continuous convergence of the Indian Plate and Eurasia, was resisted by the Sichuan Basin which led to complex crustal rotational def...
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Since similar to 40 Ma the eastward extrusion of the Songpan-Ganzi Terrane (SGT), induced by the continuous convergence of the Indian Plate and Eurasia, was resisted by the Sichuan Basin which led to complex crustal rotational deformation of the basin edge. The interaction between the eastward extrusion of the SGT and crustal rotational movement of the Sichuan Basin is the key to understand the Cenozoic crustal deformation of the eastern edge of the Tibetan Plateau. However, we lack information about the dynamic mechanism of the branching of the eastward extrusion of the SGT and the characteristics of the crustal rotation of the Sichuan Basin. In the present study, the comprehensive analysis of Cretaceous and Paleogene paleomagnetic data from the southern edge of the Sichuan Basin shows a significant correlation between the locations of sampling sections on the edge of the basin and their corresponding amount of rotation. This indicates that since the time no earlier than 40 Ma (more likely since the Late Paleogene), the upper crust of the Sichuan Basin commenced passive integral clockwise rotation, relative to the eastern edge of the South China Block/Europe, which not only played an important role in promoting the eastward extrusion of the SGT dividing into the northeastern and southern branches at the eastern edge of the Tibetan Plateau, but was also probably correlative with the partial decoupling between the upper and lower crusts of the eastern edge of the Tibetan Plateau.
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As the demand for high-performance hydrophones for marine communication systems grows, this paper develops a high-frequency unfilled layered symmetrical piezoelectric material with high effective electromechanical coupling coeffic...
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As the demand for high-performance hydrophones for marine communication systems grows, this paper develops a high-frequency unfilled layered symmetrical piezoelectric material with high effective electromechanical coupling coefficient. The k t vibration mode of piezoelectric material is converted into k 33 vibration mode of the piezoelectric pillar to improve the effective electromechanical coupling coefficient of the material. The material is determined by the equivalent circuit method and ANSYS finite element simulation method. Test results show that the resonant frequency is 117.8 kHz and the effective electromechanical coupling coefficient is 0.67, which shows that the developed material has a good electromechanical conversion performance.
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In order to tackle the electromagnetic pollution caused by the application of electromagnetic wave (EMW) in wireless communication, military industry, and other fields, broadband EMW absorption materials are urgently needed. To ac...
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In order to tackle the electromagnetic pollution caused by the application of electromagnetic wave (EMW) in wireless communication, military industry, and other fields, broadband EMW absorption materials are urgently needed. To achieve this goal, emerging methods resort to constructing multivariate synergistic composites with unique morphology to enhance EMW absorption through diverse loss mechanisms and prominent structural advantage. Herein, a spatially tuned confinement pyrolysis strategy is proposed to design pomegranate-like MnO@NC absorption material. Unique hierarchical structure and more scattering sites are accessed via well-designed one-shell multiple cores nanostructure. N-doped carbon acts as an interwoven conductive network and restricts the movement of EMW in the shell, while nano-MnO acts as an impedance matching phase and interferes with the continuity of EMW. Moreover, the intercalation of dispersed MnO also amplifies the contribution of interfacial effect to EMW absorption, which can be verified by the calculation of the surface work function. The optimized composite possesses a maximum absorption bandwidth of 6.51 GHz at 2.4 mm and its maximum reflection loss reaches - 58.4 dB (d = 2.3 mm). The synthesis of pomegranate-like composite provides a new direction for fabricating advanced carbonate-based EMW absorbers which are toward practical application.
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Social media has become an essential part of people's lives with the rapid development of the Internet and mobile technologies. Although social media has brought great convenience for people to communicate, it also powers misinfor...
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Social media has become an essential part of people's lives with the rapid development of the Internet and mobile technologies. Although social media has brought great convenience for people to communicate, it also powers misinformation such as rumors to reach more people in a short time than ever before. Moreover, social networks are interconnected with each other since users may join multiple social media simultaneously, which makes the situation even worse. Therefore, it is urgent to model the propagation of rumors across multiple social media and investigate mitigation strategies. In this paper, we propose an improved energy model to characterize the propagation of rumors on social networks quantitatively. We also introduce negative energy to simulate the mitigation process of rumors. Finally, we apply our proposed models to study the impact of the linkage rates on rumor propagation across multiple social networks. We conduct extensive experiments based on real social networks to evaluate the impacts of model parameters, network structures, and effective linkage rates. The experimental results demonstrate the effectiveness of our model in characterizing rumor propagation on multiple social networks. We also obtain valuable findings for effective rumor mitigation. (C) 2019 Elsevier B.V. All rights reserved.
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In wireless sensor networks, due to the significance of the location information of mobile nodes for many applications, location services are the basis of many application scenarios. However, node state and communication uncertain...
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In wireless sensor networks, due to the significance of the location information of mobile nodes for many applications, location services are the basis of many application scenarios. However, node state and communication uncertainty affect the distance estimation and position calculation of the range-based localization method, which makes it difficult to guarantee the localization accuracy and the system robustness of the distributed localization system. In this paper, we propose a distributed localization method based on anchor nodes selection and particle filter optimization. In this method, we first analyze the uncertainty of error propagation to the least-squares localization method. According to the proportional relation between localization error and uncertainty propagation, anchor nodes are selected optimally in real-time during the movement of mobile nodes. Then we use the ranging and position of the optimally selected anchor nodes to obtain the location information of the mobile nodes. Finally, the particle filter (PF) algorithm is utilized to gain the optimal estimation of the localization results. The experimental evaluation results verified that the proposed method effectively improves the localization accuracy and the robustness of the distributed system.
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In recent years, CID sensors have displayed great development potential in parameter measurement of gas–liquid two-phase flow in small channels. However, the fundamental/mechanism research on the response characteristics of CID s...
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In recent years, CID sensors have displayed great development potential in parameter measurement of gas–liquid two-phase flow in small channels. However, the fundamental/mechanism research on the response characteristics of CID sensors is relatively insufficient. This work focuses on the investigation of the influence of separation distance between slugs on the impedance (real part, imaginary part and amplitude) response characteristics of slug flow in small channels. Experiments were carried out with the CID sensors in four small channels with inner pipe diameters of 1.96 mm, 2.48 mm, 3.02 mm and 3.54 mm, respectively. The experimental results show that for a CID sensor, the slug separation distance has significant influence on the impedance response characteristics. There is a critical value of slug separation distance. When the slug separation distance is larger than the critical value, the impedance response characteristics of each slug can be considered independent of each other, i.e., there is no interaction between the slugs. When the slug separation distance is less than the critical value, the impedance response characteristics show obvious interaction between the slugs. It is indicated that the ratios of the critical values to the pipe inner diameters are approximate 100.
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