• Title/Summary/Keyword: Topological protection

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Retrieval of Non-rigid 3D Models Based on Approximated Topological Structure and Local Volume

  • Hong, Yiyu;Kim, Jongweon
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.8
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    • pp.3950-3964
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    • 2017
  • With the increasing popularity of 3D technology such as 3D printing, 3D modeling, etc., there is a growing need to search for similar models on the internet. Matching non-rigid shapes has become an active research field in computer graphics. In this paper, we present an efficient and effective non-rigid model retrieval method based on topological structure and local volume. The integral geodesic distances are first calculated for each vertex on a mesh to construct the topological structure. Next, each node on the topological structure is assigned a local volume that is calculated using the shape diameter function (SDF). Finally, we utilize the Hungarian algorithm to measure similarity between two non-rigid models. Experimental results on the latest benchmark (SHREC' 15 Non-rigid 3D Shape Retrieval) demonstrate that our method works well compared to the state-of-the-art.

Effective Coupling of a Topological Corner-state Nanocavity to Various Plasmon Nanoantennas

  • Ma, Na;Jiang, Ping;Zeng, You Tao;Qiao, Xiao Zhen;Xu, Xian Feng
    • Current Optics and Photonics
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    • v.6 no.5
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    • pp.497-505
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    • 2022
  • Topological photonic nanocavities are considered to possess outstanding optical performance, and provide new platforms for realizing strong interaction between light and matter, due to their robustness to impurities and defects. Here hybrid plasmonic topological photonic nanocavities are proposed, by embedding various plasmon nanoantennas such as gold nanospheres, cylinders, and rectangles in a topological photonic crystal corner-state nanocavity. The maximum quality factor Q and minimum effective mode volume Veff of these hybrid nanocavities can reach the order of 104 and 10-4 (𝜆/n)3 respectively, and the high figures of merit Q/Veff for all of these hybrid nanocavites are stable and on the order of 105 (𝜆/n)-3. The relative positions of the plasmon nanoantennas will influence the coupling strength between the plasmon structures and the topological nanocavity. The hybrid nanocavity with gold nanospheres possesses much higher Q, but relatively large Veff. The presence of a gold rectangular structure can confine more electromagnetic energy within a smaller space, since its Veff is smallest, although Q is lowest among these structures. This work provides an outstanding platform for cavity quantum electrodynamics and has a wide range of applications in topological quantum light sources, such as single-photon sources and nanolasers.

Development of a structure analytic hierarchy approach for the evaluation of the physical protection system effectiveness

  • Zou, Bowen;Wang, Wenlin;Liu, Jian;Yan, Zhenyu;Liu, Gaojun;Wang, Jun;Wei, Guanxiang
    • Nuclear Engineering and Technology
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    • v.52 no.8
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    • pp.1661-1668
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    • 2020
  • A physical protection system (PPS) is used for the protection of critical facilities. This paper proposes a structure analytic hierarchy approach (SAHA) for the hierarchical evaluation of the PPS effectiveness in critical infrastructure. SAHA is based on the traditional analysis methods "estimate of adversary sequence interruption, EASI". A community algorithm is used in the building of the SAHA model. SAHA is applied to cluster the associated protection elements for the topological design of complicated PPS with graphical vertexes equivalent to protection elements.

A Novel Online Multi-section Weighed Fault Matching and Detecting Algorithm Based on Wide-area Information

  • Tong, Xiaoyang;Lian, Wenchao;Wang, Hongbin
    • Journal of Electrical Engineering and Technology
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    • v.12 no.6
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    • pp.2118-2126
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    • 2017
  • The large-scale power system blackouts have indicated that conventional protection relays that based on local signals cannot fit for modern power grids with complicated setting or heavily loaded-flow transfer. In order to accurately detect various faulted lines and improve the fault-tolerance of wide-area protection, a novel multi-section weighed fault matching and detecting algorithm is proposed. The real protection vector (RPV) and expected section protection vectors (ESPVs) for five fault sections are constructed respectively. The function of multi-section weighed fault matching is established to calculate the section fault matching degrees between RPV and five ESPVs. Then the fault degree of protected line based on five section fault degrees can be obtained. Two fault detecting criterions are given to support the higher accuracy rate of detecting fault. With the enumerating method, the simulation tests illustrate the correctness and fault-tolerance of proposed algorithm. It can reach the target of 100% accuracy rate under 5 bits error of wide-area protections. The influence factors of fault-tolerance are analyzed, which include the choosing of wide-area protections, as well as the topological structures of power grid and fault threshold.

A Watermarking Algorithm of 3D Mesh Model Using Spherical Parameterization (구면 파라미터기법을 이용한 3차원 메쉬 모델의 워더마킹 알고리즘)

  • Cui, Ji-Zhe;Kim, Jong-Weon;Choi, Jong-Uk
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.18 no.1
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    • pp.149-159
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    • 2008
  • In this paper, we propose a blind watermarking algorithm of 3d mesh model using spherical parameterization. Spherical parameterization is a useful method which is applicable to 3D data processing. Especially, orthogonal coordinate can not analyse the feature of the vertex coordination of the 3D mesh model, but this is possible to analyse and process. In this paper, the centroid center of the 3D model was set to the origin of the spherical coordinate, the orthogonal coordinate system was transformed to the spherical coordinate system, and then the spherical parameterization was applied. The watermark was embedded via addition/modification of the vertex after the feature analysis of the geometrical information and topological information. This algorithm is robust against to the typical geometrical attacks such as translation, scaling and rotation. It is also robust to the mesh reordering, file format change, mesh simplification, and smoothing. In this case, the this algorithm can extract the watermark information about $90{\sim}98%$ from the attacked model. This means it can be applicable to the game, virtual reality and rapid prototyping fields.

Characteristics of Interface States in One-dimensional Composite Photonic Structures

  • Zhang, Qingyue;Mao, Weitao;Zhao, Qiuling;Wang, Maorong;Wang, Xia;Tam, Wing Yim
    • Current Optics and Photonics
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    • v.6 no.3
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    • pp.270-281
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    • 2022
  • Based on the transfer-matrix method (TMM), we report the characteristics of the interface states in one-dimensional (1D) composite structures consisting of two photonic crystals (PCs) composed of binary dielectrics A and B, with unit-cell configurations ABA (PC I) and BAB (PC II). The dependence of the interface states on the number of unit cells N and the boundary factor x are displayed. It is verified that the interface states are independent of N when the PC has inversion symmetry (x = 0.5). Besides, the composite structures support the formation of interface states independent of the PC symmetry, except that the positions of the interface states will be varied within the photonic band gaps. Moreover, the robustness of the interface states against nonuniformities is investigated by adding Gaussian noise to the layer thickness. In the case of inversion symmetry (x = 0.5) the most robust interface states are achieved, while for the other cases (x ≠ 0.5) interface states decay linearly with position inside the band gap. This work could shed light on the development of robust photonic devices.

FPGA integrated IEEE 802.15.4 ZigBee wireless sensor nodes performance for industrial plant monitoring and automation

  • Ompal, Ompal;Mishra, Vishnu Mohan;Kumar, Adesh
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2444-2452
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    • 2022
  • The field-programmable gate array (FPGA) is gaining popularity in industrial automation such as nuclear power plant instrumentation and control (I&C) systems due to the benefits of having non-existence of operating system, minimum software errors, and minimum common reason failures. Separate functions can be processed individually and in parallel on the same integrated circuit using FPGAs in comparison to the conventional microprocessor-based systems used in any plant operations. The use of FPGAs offers the potential to minimize complexity and the accompanying difficulty of securing regulatory approval, as well as provide superior protection against obsolescence. Wireless sensor networks (WSNs) are a new technology for acquiring and processing plant data wirelessly in which sensor nodes are configured for real-time signal processing, data acquisition, and monitoring. ZigBee (IEEE 802.15.4) is an open worldwide standard for minimum power, low-cost machine-to-machine (M2M), and internet of things (IoT) enabled wireless network communication. It is always a challenge to follow the specific topology when different Zigbee nodes are placed in a large network such as a plant. The research article focuses on the hardware chip design of different topological structures supported by ZigBee that can be used for monitoring and controlling the different operations of the plant and evaluates the performance in Vitex-5 FPGA hardware. The research work presents a strategy for configuring FPGA with ZigBee sensor nodes when communicating in a large area such as an industrial plant for real-time monitoring.