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An optimized time-adaptive aerothermal coupling calculation method for aerothermal analysis of disc cavity system

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Chinese Journal of Aeronautics 2024年第9期37卷 164-177页

作者： Shuai BI Junkui MAO Lei WANG Feng HAN College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 20016China AECC Aeroengine Control system Institute Wuxi 214063China integrated Energy Institute Nanjing University of Aeronautics and AstronauticsNanjing 210016China

In order to further achieve the balance between the calculation accuracy and efficiency of the transient analysis of the aero-engine disc cavity system,an Optimized Time-adaptive Aerother-mal Coupling calculation(OTAC)method has been *** combines one-dimensional tran-sient calculation of air system,Conventional Sequence Staggered(CSS)method,Time-adaptive Aerothermal Coupling calculation(TAC)method and differential evolution optimization algorithm to obtain an efficient and high-precision aerothermal coupling calculation method of air *** both the heat conduction in the solid domain and the flow in the fluid domain as unsteady states in the OTAC,the interaction of fluid-solid information within a single coupling time step size was implemented based on the CSS ***,the coupling time step size was automatically adjusted with the number of iterations by using the Proportional-Integral-Deri vative(PID)*** show that when compared with the traditional loosely coupling method with a fixed time step size,the computational accuracy and efficiency of the OTAC method are improved by 8.9%and 30%,*** with the tight coupling calculation,the OTAC method can achieve a speedup of 1 to 2 orders of magnitude,while the calculation error is maintained within 6.1%.

关键词： Air system 1D-3D coupling Conjugate heat transfer Transient calculation Adaptive time step size

Tunnel silicon nitride manipulated reconfigurable bi-mode nociceptor analog

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Photonics Research 2024年第8期12卷 1820-1827页

作者： CHENGDONG YANG YILONG LIU LINLIN SU XINWEI LI LIHUA XU QIMEI CHENG Jiangsu Province Engineering Research Center of integrated Circuit Reliability Technology and Testing system Wuxi UniversityWuxi 214105China

Neuromorphic applications have shown great promise not only for efficient parallel computing mode to hold certain computational tasks,such as perception and recognition,but also as key biomimetic elements for th intelligent sensory system of next-generation ***,achieving such a biomimetic nociceptor tha can adaptively switch operation mode with a stimulation threshold remains a *** rational design of material properties and device structures,we realized an easily-fabricated,low-energy,and reconfigurable no *** is capable of threshold-triggered adaptive bi-mode jump that resembles the biological alarm system With a tunnel silicon nitride(Si_(3)N_(4))we mimicked the intensity-and rehearsal-triggered jump by means of th tunneling mode transition of Si_(3)N_(4)*** threshold signals the device can also express some common synaptic functions with an extremely low energy density of 33.5 f J∕μm^(2).In addition,through the modulation o Si_(3)N_(4)thickness it is relatively easy to fabricate the device with differing pain *** nociceptor analog based on a tunneling layer provides an opportunity for the analog pain alarm system and opens up a new path toward threshold-related novel applications.

关键词： Tunnel tunneling rational

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CATCAM: a 28 nm constant-time alteration TCAM enabling less than 50 ns update latency

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Science China(Information Sciences) 2024年第4期67卷 345-346页

作者： Chenchen DENG Tianzhu XIONG Zhaoshi LI Zhiwei LIU Yao WANG Jianfeng ZHU Jun YANG Shaojun WEI Leibo LIU Beijing National Research Center for Information Science and Technology Tsinghua University National ASIC system Engineering Center School of Integrated CircuitsSoutheast University School of integrated Circuits Tsinghua University

Ternary content-addressable memory(TCAM) is an indispensable component of lookup tables in switches or ***, it suffers from expensive and inflexible update operations and cannot fulfill the demand for rule updates in switches enabling software-defined networking(SDN). The main reason is that TCAM stores rules from top to bottom in decreasing order of priority for disambiguation. Updating a TCAM is similar to the insertion sort that takes O(n) time,

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Contact engineering for temperature stability improvement of Bi-contacted MoS2 field effect transistors

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Science China(Information Sciences) 2024年第6期67卷 172-179页

作者： Zizheng LIU Qing ZHANG Xiaohe HUANG Chunsen LIU Peng ZHOU State Key Laboratory of integrated Chip and systems School of MicroelectronicsZhangjiang Fudan International Innovation CenterFudan University Frontier Institute of Chip and system Shanghai Key Lab for Future Computing Hardware and SystemFudan University Shaoxin Laboratory

Semimetallic bismuth（Bi） is one of the most effective strategies for reducing the contact resistance of two-dimensional transition metal dichalcogenide field effect transistors（FETs）. However, the low melting point of Bi contact（271.5℃） limits its reliable applications. In this study, we demonstrated that the temperature stability of Bi-contacted electrodes could be improved by inserting a high-melting point semimetallic antimony（Sb） between the Bi contacting layer and the gold（Au） capping layer. The proposed Bi/Sb/Au contact electrodes tended to form a metal mixture with a continuous surface during the heating process（Voids appeared on the surface of the Bi/Au contact electrodes after heating at 120℃）. Because of the improved contacting layer formed by the semimetal Bi/Sb alloy, the fabricated Bi/Sb/Au-contacted molybdenum sulfide（MoS2） FETs with different gate lengths demonstrated higher on-state current stability after heating treatment than the Bi/Au contact. Because of the Bi/Sb/Au contact and poly（methyl methacrylate） package, the MoS2FETs demonstrated time stability of at least two months from the almost unchanged transfer characteristics. The electrical stability indicates that the insertion of semimetallic Sb is a promising technology for reliable Bi-based contact.

关键词： temperature stability semimetallic bismuth contact semimetallic antimony contact MoS$_{2}$ FETs time stability

Closed-form solution to the dynamic programming for a heavy-duty parallel hybrid vehicle energy management

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Journal of Control and Decision 2024年第1期11卷 107-116页

作者： Tao Zhang Zhongjun Yu Huangda Lin National Key Laboratory for Vessel integrated Power system Technology Naval University of EngineeringWuhanPeople’s Republic of China

Dynamic programming(DP)is frequently used to obtain the optimal solution to the hybrid electric vehicle(HEV)energy *** trade-off between the accuracy and the computational effort is the biggest problem for the DP *** closed-form solution to the DP is proposed to solve this ***,the affine linear model of the engine fuel rate is obtained based on engine test *** piecewise linear approximation of the motor power demand is obtained considering the different energy flows in the charging and discharging stages of the ***,the second-order Taylor expansion for the cost matrix at each time and state grid point is introduced to get the closed-form solution of the optimal torque *** results show that this method can greatly reduce the computing burden by 93%while ensuring near-optimal fuel economy compared with the conventional DP method.

关键词： Dynamic programming energy management closed-form solutions fuel economy hybrid electric vehicles

UAV-assisted cooperative offloading energy efficiency system for mobile edge computing

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Digital Communications and Networks 2024年第1期10卷 16-24页

作者： Xue-Yong Yu Wen-Jin Niu Ye Zhu Hong-Bo Zhu Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Nanjing210003China Engineering Research Centerof health Service system Based on Ubiquitous Wireless Networks Ministry of EducationNanjng Universityof Posts and Telecommunications Nanjing210003China

Reliable communication and intensive computing power cannot be provided effectively by temporary hot spots in disaster areas and complex terrain ground *** this has greatly developed the application and integration of UAV and Mobile Edge Computing(MEC)to the Internet of Things(loT).However,problems such as multi-user and huge data flow in large areas,which contradict the reality that a single UAV is constrained by limited computing power,still *** to allowing UAV collaboration to accomplish complex tasks,cooperative task offloading between multiple UAVs must meet the interdependence of tasks and realize parallel processing,which reduces the computing power consumption and endurance pressure of *** the computing requirements of the user terminal,delay constraint of a computing task,energy constraint,and safe distance of UAV,we constructed a UAV-Assisted cooperative offloading energy efficiency system for mobile edge computing to minimize user terminal energy ***,the resulting optimization problem is originally nonconvex and thus,difficult to solve *** tackle this problem,we developed an energy efficiency optimization algorithm using Block Coordinate Descent(BCD)that decomposes the problem into three convex ***,we jointly optimized the number of local computing tasks,number of computing offloaded tasks,trajectories of UAV,and offloading matching relationship between multi-UAVs and multiuser *** results show that the proposed approach is suitable for different channel conditions and significantly saves the user terminal energy consumption compared with other benchmark schemes.

关键词： Computation offloading Internet of things(IoT) Mobile edge computing(MEC) Block coordinate descent(BCD)

The Rising Burden of Hepatocellular Carcinoma: Is the Gender Gap Narrowing?

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Journal of Clinical and Translational Hepatology 2024年第9期12卷 763-764页

作者： James K.H.Ho Prem H.Thurairajah Daniel Q.Huang Kristie H.Fan Division of Gastroenterology and Hepatology National University HospitalNational University Health SystemSingaporeSingapore

Dear Editors,The landscape of hepatocellular carcinoma(HCC)is continuously *** global trends indicate a significant shift in the epidemiology of HCC from viral-related to non-viral-related ***-associated fatty liver disease has emerged as the fastest-growing contributor to HCC in recent years,due to the increased prevalence of obesity and metabolic risk factors.

关键词： Carcinoma epidemiology obesity

Is it necessary to stop glucagon-like peptide-1 receptor agonists prior to endoscopic procedure? A retrospective study

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World Journal of Gastroenterology 2024年第26期30卷 3221-3228页

作者： Haider Ghazanfar Nismat Javed Abeer Qasim Franklin Sosa Faryal Altaf Shazia Khan Jaydeep Mahasamudram Abhilasha Jyala Sameer Datta Kandhi Dongmin Shin Nikhitha Mantri Haozhe Sun Siddarth Hanumanthu Harish Patel Jasbir Makker Bhavna Balar Anil Dev Sridhar Chilimuri Division of Gastroenterology Department of Internal MedicineBronxCare Health SystemIcahn School of Medicine at Mount SinaiBronxNY 10457United States Department of Internal Medicine BronxCare Health SystemIcahn School of Medicine at Mount SinaiBronxNY 10457United States

BACKGROUND Glucagon-like peptide-1 receptor agonists(GLP-1 RA)are effective in diabetes and obesity,reducing hyperglycemia by increasing insulin release and delaying gastric ***,they can cause gastroparesis,raising concerns about aspiration during *** guidelines advise discontinuing GLP-1 RA before surgery to reduce the risk of pulmonary *** To evaluate the effect of GLP-1 RAs on gastric residual contents during endosco-pic *** A retrospective chart review at BronxCare health system,New York,from January 2019 to October 2023,assessed gastric residue and aspiration in GLP-1 RA patients undergoing endoscopic *** groups were compared based on dietary status before the *** included demographics,symptoms of gastroparesis,opiate use,hemoglobin A1c,GLP-1 agonist indication,endo-scopic details,and aspiration *** SPSS was used for analysis,cal-culating means,standard deviations,and applying Pearson’s chi-square and t-tests for associations,with P<0.05 as being *** During the study,306 patients were included,with 41.2%on a clear liquid/low residue diet and 58.8%on a regular diet before *** patients(63.1%)were male,with a mean age of 60±12 *** majority(85.6%)were on GLP-1 RAs for diabetes,and 10.1%reported digestive symptoms before *** those on a clear liquid diet,1.5%had residual food at endoscopy compared to 10%on a regular diet,which was statistically significant(P=0.03).Out of 31 patients with digestive symptoms,13%had residual food,all from the regular diet group(P=0.130).No complications were reported during or after the *** The study reflects a significant rise in GLP-1 RA use for diabetes and obesity.A 24-hour liquid diet seems safe for endoscopic procedures without *** with upper gastrointestinal symptoms might have a higher residual food risk,though not statistically *** research is needed

关键词： Glucagon-like peptide-1 agonists Gastroparesis Endoscopic procedures Residual food Complications

Time-varying parameters estimation with adaptive neural network EKF for missile-dual control system

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Journal of systems Engineering and Electronics 2024年第2期35卷 451-462页

作者： YUAN Yuqi ZHOU Di LI Junlong LOU Chaofei School of Astronautics Harbin Institute of TechnologyHarbin 150001China Beijing Institute of Electronic system Engineering Beijing 100854China

In this paper, a filtering method is presented to estimate time-varying parameters of a missile dual control system with tail fins and reaction jets as control variables. In this method, the long-short-term memory(LSTM) neural network is nested into the extended Kalman filter(EKF) to modify the Kalman gain such that the filtering performance is improved in the presence of large model uncertainties. To avoid the unstable network output caused by the abrupt changes of system states,an adaptive correction factor is introduced to correct the network output online. In the process of training the network, a multi-gradient descent learning mode is proposed to better fit the internal state of the system, and a rolling training is used to implement an online prediction logic. Based on the Lyapunov second method, we discuss the stability of the system, the result shows that when the training error of neural network is sufficiently small, the system is asymptotically stable. With its application to the estimation of time-varying parameters of a missile dual control system, the LSTM-EKF shows better filtering performance than the EKF and adaptive EKF(AEKF) when there exist large uncertainties in the system model.

关键词： long-short-term memory(LSTM)neural network extended Kalman filter(EKF) rolling training time-varying parameters estimation missile dual control system

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