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423 results on '"Nie, Yuan"'

3. RimiRec: Modeling Refined Multi-interest in Hierarchical Structure for Recommendation

Author

Pei, Haolei, Xu, Yuanyuan, Zhu, Yangping, and Nie, Yuan

Subjects
Computer Science - Information Retrieval
Abstract

Industrial recommender systems usually consist of the retrieval stage and the ranking stage, to handle the billion-scale of users and items. The retrieval stage retrieves candidate items relevant to user interests for recommendations and has attracted much attention. Frequently, a user shows refined multi-interests in a hierarchical structure. For example, a user likes Conan and Kuroba Kaito, which are the roles in hierarchical structure "Animation, Japanese Animation, Detective Conan". However, most existing methods ignore this hierarchical nature, and simply average the fine-grained interest information. Therefore, we propose a novel two-stage approach to explicitly modeling refined multi-interest in a hierarchical structure for recommendation. In the first hierarchical multi-interest mining stage, the hierarchical clustering and transformer-based model adaptively generate circles or sub-circles that users are interested in. In the second stage, the partition of retrieval space allows the EBR models to deal only with items within each circle and accurately capture users' refined interests. Experimental results show that the proposed approach achieves state-of-the-art performance. Our framework has also been deployed at Lofter., Comment: 4 pages, 4 figures

Published
2024

5. The nature of epidemic criticality in temporal networks

Author

Cai, Chao-Ran, Nie, Yuan-Yuan, and Holme, Petter

Subjects
Physics - Physics and Society, Quantitative Biology - Populations and Evolution
Abstract

Analytical studies of network epidemiology almost exclusively focus on the extreme situations where the time scales of network dynamics are well separated (longer or shorter) from that of epidemic propagation. In realistic scenarios, however, these time scales could be similar, which has profound implications for epidemic modeling (e.g., one can no longer reduce the dimensionality of epidemic models). We build a theory for the critical behavior of susceptible-infected-susceptible (SIS) epidemics in the vicinity of the critical threshold on the activity-driven model of temporal networks. We find that the persistence of links in the network leads to increasing recovery rates reducing the threshold. Dynamic correlations (coming from being close to infected nodes increases the likelihood of infection) drive the threshold in the opposite direction. These two counteracting effects make epidemic criticality in temporal networks a remarkably complex phenomenon.

Published
2023
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28. Synthetic design and analysis on microwave dielectric properties of novel garnet-type Ca3MTiGe3O12(M = Co, Ni) ceramics

Author

Nie, Yuan, Liu, Yanjun, Zhao, Ziqi, Zhang, Wenjie, Huang, Fangyi, and Zhou, Huanfu

Abstract

In this paper, novel Ca3CoTiGe3O12(CCTG) and Ca3NiTiGe3O12(CNTG) ceramics with transition metal elements and Ti co-occupying the B-site were designed by calculating the tolerance factor of the garnet structure. CCTG and CNTG ceramics sintered at optimal temperatures exhibit excellent microwave dielectric properties with εr = 11.64, Q×f = 45474.73 GHz, τf = −42.01 ppm/°C and εr = 11.58, Q×f = 41346.11 GHz, τf = −45.53 ppm/°C, respectively. X-ray diffraction analysis shows that the CCTG is single phase while secondary phase is present in CNTG. The analysis of density and surface micromorphology for the ceramics synthesized in this study reveals that both possess high densities. Raman analysis shows that the half-width (FWHM) corresponding to the peak of the A1gmode is closely related to the dielectric loss of both ceramics. The lattice energy and packing fraction are both critical factors that influence the Q×fvalue of CCTG ceramics. The influence of the secondary phase on the Q×fvalue of CNTG ceramics cannot be ignored. Both the bond valence and bond energy of the B-site cation are factors that affect τf. In conclusion, the two ceramics studied in this paper have great application prospects in the field of microwave communications.

Published
2025
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37. Calculation of Network Security Index Based on Convolution Neural Networks

Author

Yang, Hang, Jia, Yan, Han, Wei-Hong, Nie, Yuan-Ping, Li, Shu-Dong, Zhao, Xiao-Juan, Hutchison, David, Editorial Board Member, Kanade, Takeo, Editorial Board Member, Kittler, Josef, Editorial Board Member, Kleinberg, Jon M., Editorial Board Member, Mattern, Friedemann, Editorial Board Member, Mitchell, John C., Editorial Board Member, Naor, Moni, Editorial Board Member, Pandu Rangan, C., Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Terzopoulos, Demetri, Editorial Board Member, Tygar, Doug, Editorial Board Member, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Sun, Xingming, editor, Pan, Zhaoqing, editor, and Bertino, Elisa, editor

Published
2019
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43. A Fast and Sensitive Current Differential Protection for MMC-HVDC Lines

Author

Nie, Yuan, Liu, Yu, Lu, Dayou, Xie, Yuhao, Zou, Xinchen, and Wang, Haoyu

Abstract

This article proposes a fast and sensitive current differential protection (CDP) for modular multilevel converter based high voltage direct current lines. This method utilizes the fully distributed and frequency dependent (FD) line model to compensate for the influence of FD parameters, thus achieving high sensitivity. The improved curve fitting scheme in the FD line model is provided to enable the formulation of the differential current. Then, a fast time domain convolution scheme is specially designed to achieve the capability of the real-time calculation with the FD line model, and therefore guarantee the high response speed. A comparative analysis between the proposed CDP and the existing Bergeron based CDP is utilized to demonstrate the superior sensitivity and faster response speed of the proposed method. Moreover, the proposed method only requires a relatively low sampling rate and can complete internal fault detection within 3 ms after the fault occurs. Hardware-in-the-loop experiments using real time digital simulator are also conducted to verify the proposed method.

Published
2024
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45. Investigation of the Overall Damage Assessment Method Used for Unmanned Aerial Vehicles Subjected to Blast Waves.

Author

Feng, Xiaowei, Yang, Zezhou, and Nie, Yuan

Subjects
BLAST waves, SHEARING force, DRONE aircraft, NUMERICAL calculations, BLAST effect
Abstract

With the aim of investigating the assessment methodology for the overall damage effects on an unmanned aerial vehicle (UAV) subjected to a blast wave, the failure criteria for the typical UAV was formulated through an analysis of the structural strength design standards. Specifically, the shear force associated with wing failure can serve as a critical parameter for assessing the overall damage inflicted on the UAV by blast waves. According to the design load criterion of the aircraft, the shear force value corresponding to the overall failure of the typical UAV was calculated. Numerical simulations were conducted to investigate the mechanical response of UAV structures under blast wave loading generated by a 500 g explosive. Combining the critical shear force values obtained from theoretical calculations with the numerical simulation results, two distances between the explosives and the UAV that could produce different damage effects were estimated, namely 1 m and 2.5 m. Subsequently, static explosion experiments with equivalent explosive charges were performed, revealing different damage effects on a typical UAV at two specific distances. The numerical simulation results were highly consistent with the experimental observations, further validating the scientific and rational basis for using shear force as a primary parameter in assessing overall structural damage to fixed-wing UAVs. [ABSTRACT FROM AUTHOR]

Published
2024
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46. Mechanisms and applications of third-order nonlinear optics in 2D lead halide perovskites.

Author

Nie, Yuan, Hu, Jinming, Zhang, Yinan, Gu, Min, and Zhang, Qiming

Subjects
*LEAD halides, *NONLINEAR optics, *OPTOELECTRONIC devices, *PEROVSKITE, *SOLAR cells, *QUANTUM wells
Abstract

The unique optical and electrical characteristics of lead halide perovskites have garnered considerable interest, and they are highly suitable for use in devices such as solar cells and other optoelectronic equipment. The discovery of nonlinear optical characteristics in lead halide perovskites, especially those with a two-dimensional quantum well structure, has been a recent development. These substances demonstrate remarkable third-order nonlinear phenomena, such as saturation absorption, two-photon absorption, and nonlinear refraction, positioning them as a likely emerging focus in the realm of nonlinear optics. In this review, we present the structure and attributes of two-dimensional lead halide perovskites, delve into their diverse third-order nonlinear optical traits, and encapsulate their applications rooted in third-order nonlinear optics. Additionally, we offer a perspective on potential future trajectories in this area of study. [ABSTRACT FROM AUTHOR]

Published
2024
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