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期刊论文 6

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主动式队列管理；传输控制协议；往返时滞；史密斯预估器 1

可逆信息隐藏；Transformer；自适应嵌入策略 1

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Predictor-corrector algorithm for solving quasi-separated-flow and transient distributed-parameter model

Ping ZHANG, Guoliang DING

《能源前沿（英文）》 2010年 第4卷 第4期   页码 535-541 doi: 10.1007/s11708-010-0113-y

摘要： The successive sub?stitution (SS) method is a suitable approach to solving the transient distributed-parameter model for heat exchangers. However, this method must be enhanced because its convergence heavily depends on the iterative initial pressure. When the iterative initial pressure is improperly assigned, the calculated flow rates become negative values, causing the state parameters to exhibit negative values as well. Therefore, a predictor-corrector algorithm (PCA) is proposed to improve the convergence of the SS method. A predictor is developed to determine an appropriate iterative initial pressure. Total fluid mass is adopted as the convergence criterion of pressure iteration instead of outlet flow rate as is done in the SS method. Convergence analysis and case study of the PCA and SS method are conducted, which show that the PCA has better convergence than the SS method under the same working conditions.

关键词： algorithm     convergence     heat exchanger     modeling     transient    

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Analysis of stability and nonlinear response of rotor system with elliptical sliding bearing supports

LU Yanjun, LIU Heng, YU Lie, LI Qi, JIANG Ming, ZHANG Zhiyu

《机械工程前沿（英文）》 2007年 第2卷 第1期   页码 37-45 doi: 10.1007/s11465-007-0006-x

摘要： Based on the variational constraint approach, the variational form of Reynolds equation in hydrodynamic lubrication is revised continuously to satisfy certain constraints in the cavitation zone of oil film field. According to the physical characteristic of oil film, an eight-node isoparametric finite element method is used to convert the revised variational form of Reynolds equation to a discrete form of finite dimensional algebraic variational equation. By this approach, a perturbance equation can be obtained directly on the finite element equation. Consequently, nonlinear oil film forces and their Jacobian matrices are calculated simultaneously, and compatible accuracy is obtained without increasing the computational costs. A method, which is a combination of predictor corrector mechanism and Newton Raphson method, is presented to calculate equilibrium position and critical speed corresponding to Hopf bifurcation point of bearing-rotor system, as by-product dynamic coefficients of bearing are obtained. The timescale, i.e., the unknown whirling period of Hopf bifurcation solution of bearing-rotor system is drawn into the iterative process using Poincar?Newton Floquet method. The stability of the Hopf bifurcation solution can be detected when estimating Hopf bifurcation solution and its periods. The nonlinear unbalanced periodic responses of the system are obtained by using PNF method and path-following technique. The local stability and bifurcation behaviors of periodic motions are analyzed by Floquet theory. Chaotic motions are analyzed by Lyapunov exponents. The numerical results revealed the rich and complex nonlinear behavior of the system, such as periodic, quasiperiodic, jumped solution, chaos, and coexistence of multisolution, and so on.

关键词： computational     corrector mechanism     predictor corrector     multisolution     quasiperiodic    

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Stability and coupling dynamic behavior of nonlinear journal active electromagnetic bearing rotor system

LU Yanjun, HEI Di, WANG Yuan, DAI Rong, LU Yanjun, LIU Heng, YU Lie

《机械工程前沿（英文）》 2008年 第3卷 第2期   页码 193-199 doi: 10.1007/s11465-008-0023-4

摘要： The stability and coupling dynamic behavior of a journal active electromagnetic bearing rotor system are analyzed. The gyroscopic effect is considered in the rotor model. The system equations are formulated by combining equations for rotor motion and decentralized proportional integral differential (PID) controllers. A method combining the predictor-corrector mechanism and the Netwon-Raphson method is presented to calculate the critical speed at the corresponding Hopf bifurcation point of the system. For periodic motions, a continuation method combining the predictor-corrector mechanism and shooting method is presented. Nonlinear unbalanced periodic motions and their stability margins are obtained using the shooting method and established continuation method for periodic motions. With the change of control parameters, the system local stability and bifurcation behaviors are obtained using the Floquet theory. The numerical examples show that the schemes not only significantly save computing cost, but also have high precision.

关键词： proportional integral     bifurcation     corresponding     integral differential     predictor-corrector mechanism    

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Stevens–Johnson syndrome and toxic epidermal necrolysis in China: evaluation of risk models and new predictor

Yanhong Shou, Lu Yang, Yongsheng Yang, Xiaohua Zhu, Feng Li, Bo Yin, Yingyan Zheng, Jinhua Xu

《医学前沿（英文）》 2021年 第15卷 第4期   页码 585-593 doi: 10.1007/s11684-020-0817-2

摘要： Stevens--Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but severe diseases. This study aimed to validate the predictive ability of risk models in patients with SJS/TEN and propose possible refinement in China. Patients in the Department of Dermatology of Huashan Hospital from January 2008 to January 2019 were included. Results showed that the severity-of-illness score for TEN (SCORTEN) had a good discrimination (area under the receiver operating characteristic curve (AUC), 0.78), and it was superior to auxiliary score (AS) and ABCD-10, which indicates age, bicarbonate level, cancer, dialysis, and 10% involved body surface area (AUC, 0.69 and 0.68, respectively). The calibration of SCORTEN (Hosmer–Lemeshow goodness-of-fit test, = 0.69) was also better than that of AS ( = 0.25) and ABCD-10 ( = 0.55). SCORTEN and ABCD-10 were similar (Brier score (BS), 0.04 and 0.04) in terms of accuracy of predictions. In addition, the imaging appearance of pulmonary consolidation on computed tomography was associated with high mortality. Refined models were formed using the variables and this imaging appearance. The refined AS and ABCD-10 models were similar in discrimination compared with the original SCORTEN (0.74 vs. 0.78, = 0.23; 0.74 vs. 0.78, = 0.30, respectively). Therefore, SCORTEN showed good discrimination performance, calibration, and accuracy, and refined AS or ABCD-10 model may be an option when SCORTEN variables are not available.

关键词： Stevens–Johnson syndrome     toxic epidermal necrolysis     auxiliary score     ABCD-10     pulmonary consolidation    

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面向TCP/AQM网络系统基于史密斯预估器的比例积分控制器的设计与分析 Research Articles

Ouassim MENACER1, Abderraouf MESSAI1, Lazhar KASSA-BAGHDOUCHE2

《信息与电子工程前沿（英文）》 2022年 第23卷 第2期   页码 291-303 doi: 10.1631/FITEE.2000245

摘要： 主动式队列管理（AQM）对于预防具有往返时滞的TCP/AQM系统的服务质量退化至关重要。往返时滞主要由数据包传播时延引起，但也可由队列操作的处理时间和动态改变的网络情况引起。本文聚焦带有时延不确定性的主动式队列管理数字控制器的设计与分析。该控制器基于史密斯预估器算法，我们称其为SMITHPI控制器。本文同时证明了该控制器的稳定性和抵御网络参数变化的鲁棒性，如传输控制协议源的数量、时延、用户数据电报协议流。运用NS-2仿真评估所提SMITHPI控制器的性能、鲁棒性和有效性。最后，将SMITHPI控制器与著名的主动式队列管理（称为比例积分控制器）进行性能比较。

关键词： 主动式队列管理；传输控制协议；往返时滞；史密斯预估器    

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基于transformer和自适应嵌入策略的可逆信息隐藏 Research Article

周琳娜1,陆智高2,尤玮珂1,房笑妃2

《信息与电子工程前沿（英文）》 2023年 第24卷 第8期   页码 1143-1155 doi: 10.1631/FITEE.2300041

摘要： 在可逆信息隐藏（RDH）领域中，设计高精度预测器以减少嵌入失真和开发有效的嵌入策略以最小化由嵌入信息引起的失真是提高RDH性能的两个关键方面。本文提出一种新的RDH方法，包括基于transformer的预测器和具有多个嵌入规则的新嵌入策略。在预测器部分，我们首先设计了一个基于transformer的预测器。然后，提出一种图像分割方法，将图像分成4部分，可以使用更多的像素作为上下文。与其他预测器相比，我们的预测器可以将用于预测的像素范围从相邻像素扩展到全局像素，从而使其在减少嵌入失真方面更为准确。在嵌入策略部分，我们首先提出了能够利用目标块中像素的复杂性度量。然后，开发了一种改进的预测误差排序规则。最后，我们首次提出一种包含多个嵌入规则的嵌入策略。本文中的RDH方法可以有效减少失真，同时在提高隐藏图像的视觉质量方面提供令人满意的结果。实验结果表明，本文中提出的RDH算法的性能处于领先地位。

关键词： 可逆信息隐藏；Transformer；自适应嵌入策略    

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标题 作者 时间 类型 操作

Predictor-corrector algorithm for solving quasi-separated-flow and transient distributed-parameter model

Ping ZHANG, Guoliang DING

期刊论文

Analysis of stability and nonlinear response of rotor system with elliptical sliding bearing supports

LU Yanjun, LIU Heng, YU Lie, LI Qi, JIANG Ming, ZHANG Zhiyu

期刊论文

Stability and coupling dynamic behavior of nonlinear journal active electromagnetic bearing rotor system

LU Yanjun, HEI Di, WANG Yuan, DAI Rong, LU Yanjun, LIU Heng, YU Lie

期刊论文

Stevens–Johnson syndrome and toxic epidermal necrolysis in China: evaluation of risk models and new predictor

Yanhong Shou, Lu Yang, Yongsheng Yang, Xiaohua Zhu, Feng Li, Bo Yin, Yingyan Zheng, Jinhua Xu

期刊论文

面向TCP/AQM网络系统基于史密斯预估器的比例积分控制器的设计与分析

Ouassim MENACER1, Abderraouf MESSAI1, Lazhar KASSA-BAGHDOUCHE2

期刊论文

基于transformer和自适应嵌入策略的可逆信息隐藏

周琳娜1,陆智高2,尤玮珂1,房笑妃2

期刊论文