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Th. Credit-Risk Decision Mech.nism on Fixed Loan Interest Rate with.Imperfect Information

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Journal of Systems Engineering and Electronics 2001年第3期12卷 20-24页

作者： Pang, S. Liu, Y. Wang, Y. yao, h. Department of Math.matics Jinan University Guangzhou 510632 China

In th.s paper, decision mech.nism of credit-risk for banks is studied wh.n th. loan interest rate is fixed with.asymmetry information in credit market. We give out th. designs of rationing and non-rationing on credit risky decision mech.nism wh.n collateral value provided by an entrepreneur is not less th.n th. minimum demands of th. bank. It sh.ws th.t under th. action of th. mech.nism, banks could efficiently identify th. risk size of th. project. Finally, th. condition of th. project investigation of bank is given over again.

关键词： Classification (of information) Financial data processing Risk assessment

Evolutions　of　flow　field　and　h.at　exch.nge　on　equa-torial　Pacific　surface　in　El　Nino-La　Nina　cycle

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Acta Oceanologica Sinica 1997年第2期16卷 157-170页

作者： Ma K. yao h. Lin Z. Ch.o J. Department of Atmosph.ric Sciences Nanjing University Nanjing 210093 China Climate Center of Ch.na Beijing 100081 China

Ｉｎｔｈｉｓｐａｐｅｒ，ｔｈｅｍｏｎｔｈｌｙａｖｅｒａｇｅｓａｎｄｄｅｖｉａｔｉｏｎｓｏｆｔｅｍｐｅｒａｔｕｒｅ，ｐｒｅｓｓｕｒｅ，ｚｏｎａｌｗｉｎｄ，ｓｐｅｃｉｆｉｃｈｕｍｉｄｉｔｙ，ｃｌｏｕｄｃｏｖｅｒａｎｄｔｈ... 详细信息

Ｉｎｔｈｉｓｐａｐｅｒ，ｔｈｅｍｏｎｔｈｌｙａｖｅｒａｇｅｓａｎｄｄｅｖｉａｔｉｏｎｓｏｆｔｅｍｐｅｒａｔｕｒｅ，ｐｒｅｓｓｕｒｅ，ｚｏｎａｌｗｉｎｄ，ｓｐｅｃｉｆｉｃｈｕｍｉｄｉｔｙ，ｃｌｏｕｄｃｏｖｅｒａｎｄｔｈｅｃｏｍｐｏｎｅｎｔｓｏｆｈｅａｔｂｕｄｇｅｔｈａｖｅｂｅｅｎｍｐｕｔｅｄｏｎｔｈｅｅｑｕａｔｏｒｉａｌ（５．Ｓ－３．Ｎ）Ｐａｃｉｆｉｃｓｕｒｆａｃｅ（ＥＰＳ）ｂａｓｅｄｏｎｔｈｅ２．ｘ２．ｇｒｉｄｄａｔａｏｆＣＯＡＤＳｆｒｏｍ１９５０ｔｏ１９８７ａｎｄｔｈｅｅｖｏｌｕｔｉｏｎｓｏｆｔｈｅｓｅｅｌｅｍｅｎｔｓｈａｔｅｂｅｅｎｐｒｏｖｉｄｅｄ．ＴｗｏｆｅｅｄｂａｃｋｍｅｃｈａｎｉｓｍｓｏｆＥｌＮｉｎｏ－ＬａＮｉｎａｃｙｃｌｅｗｈｉｃｈｉｎｃｌｕｄｅｔｈｅｄｙｎａｍｉｃ，ｔｈｅｒｔｔａｌａｎｄｈｙｄｒｏｌｏｇｉｃｔｌｐｒｏｃｅｓｓｅｓｉｎｔｈｅｏｏｕｐｌｅｄａｉｒｔｓｅａｓｙｓｔｅｍａｒｅｖｅｒｉｆｉｅｄ．ＤｕｒｉｎｇＥ１Ｎｉｎｏ．ｔｈｅｐｒｅｓｓｕｒｅｇｒａｄｉｅｎｔａｎｄｔｒａｄｅｗｉｎｄｄｅｃｒｅａｓｅｄｏｎｔｈｅＥＰＳ，ｔｈｅｓｅｎｓｉｂｌｅａｎｄｌａｔｅｎｔｈｅａｔｅｘｃｈａｎｇｅｓｅｎｌ

关键词： Nino-La Nina cycle surface Pacific El Evolutions La h.at flow

Estimating Critical Clearing Time of Grid Faults Using DA of State-Reduction Model of Power Systems

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 807-820页

作者： Yang Liu Zh.ngyang Ch.n h.anjin yao Lin Yi Q.h.Wu Sch.ol of Electric Power Engineering South China University of TechnologyGuangzhou 510640China Ch.na South.rn Power Grid Research.Institute Guangzhou 510663China

Th.s paper proposes a critical clearing time (CCT) estimation meth.d by th. domain of attraction (DA) of a state-reduction model of power systems using sum of squares (SOS) programming. By exploiting th. property of th. Jacobian matrix and th. structure of th. boundary of th. DA, it is found th. DA of th. state-reduction model and th.t of th. full model of a power system are topological isomorph.sm. Th.re are one-to-one correspondence relationsh.ps between th. number of equilibrium points, th. type of equilibrium points, and solutions of th. two system models. Based on th.se findings, an expanding interior algorith. is proposed with.SOS programming to estimate th. DA of th. state-reduction model. State trajectories of th. full model can be transformed to th.se of th. state-reduction model by orth.gonal or equiradius projection. In th.s way, CCT of a grid fault is estimated with.th. DA of th. state-reduction model. Th. calculational burden of SOS programming in th. DA estimation using th. state-reduction model is rath.r small compared with.using th. full model. Simulation results sh.w th. proposed expanding interior algorith. is able to provide a tigh. estimation of DA of power systems with.h.gh.r accuracy and lower time costs.

关键词： Critical clearing time domain of attraction expanding interior algorith. state-reduction model SOS programming

A novel topology with.controllable wideband baseband impedance for power amplifiers

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Frontiers of Information Tech.ology & Electronic Engineering 2024年第2期25卷 308-315页

作者： yao yao Zh.jiang DAI Mingyu LI Sch.ol of Intelligent Tech.ology and Engineering Chongqing University of Science and TechnologyChongqing400065China Sch.ol of Microelectronics and Communication Engineering Chongqing UniversityChongqing400065China

Th.s paper presents a novel topology to control th. baseband impedance of a power amplifier(PA)to avoid performance deterioration in concurrent dual-band *** topology can avoid pure resonance of capacitors and inductors LC,wh.ch.leads to a h.gh.impedance at some frequency ***,it can be applied to transmitters th.t are excited by broadband *** particular,by adjusting th. circuit parameters and increasing stages,th. impedance of th. key frequency bands can be flexibly controlled.A PA is designed to support th.s design *** saturated output power is around 46.7 dBm,and th. drain efficiency is>68.2%(1.8-2.3 Gh.).Under concurrent two-tone excitation,th. drain efficiency reach.s around 40%even under 5.5 dB back-off power with.th. tone spacing from 10 Mh. to 500 *** results demonstrate th.t th. proposed topology is capable of controlling wideband baseband impedance.

关键词： Baseband impedance Concurrent dual-band Power amplifier

Reinforcement learning based adaptive control for uncertain mech.nical systems with.asymptotic tracking

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Defence Tech.ology（防务技术） 2024年第4期34卷 19-28页

作者： Xiang-long Liang Zh.-kai yao yao-wen Ge Jian-yong yao Sch.ol of Mech.nical Engineering Nanjing University of Science and TechnologyNanjing210094China College of Automation&College of Artificial Intelligence Nanjing University of Post and TelecommunicationNanjing210023China

Th.s paper mainly focuses on th. development of a learning-based controller for a class of uncertain mech.nical systems modeled by th. Euler-Lagrange *** considered system can depict th. beh.vior of a large class of engineering systems,such.as veh.cular systems,robot manipulators and *** th.se systems are often ch.racterized by h.gh.y nonlinear ch.racteristics,h.avy modeling uncertainties and unknown perturbations,th.refore,accurate-model-based nonlinear control approach.s become *** by th. ch.llenge,a reinforcement learning(RL)adaptive control meth.dology based on th. actor-critic framework is investigated to compensate th. uncertain mech.nical *** approximation inaccuracies caused by RL and th. exogenous unknown disturbances are circumvented via a continuous robust integral of th. sign of th. error(RISE)control *** from a classical RISE control law,a tanh.·)function is utilized instead of a sign(·)function to acquire a more smooth.control *** developed controller requires very little prior knowledge of th. dynamic model,is robust to unknown dynamics and exogenous disturbances,and can ach.eve asymptotic output ***,co-simulations th.ough.ADAMS and MATLAB/Simulink on a th.ee degrees-of-freedom(3-DOF)manipulator and experiments on a real-time electromech.nical servo system are performed to verify th. performance of th. proposed approach.

关键词： Adaptive control Reinforcement learning Uncertain mech.nical systems Asymptotic tracking

Fresh.Keeping Decision and Coordination of Fresh.Agricultural Product Supply Ch.in Considering Carbon Cap-and-Trade under Different Dominance

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Journal of Systems Science and Systems Engineering 2024年第1期33卷 30-51页

作者： Yang Yang Guanxin yao Ch.na Institute for Agricultural Equipment Industrial Development Jiangsu UniversityZhenjiang212013China Jiangsu Modern Logistics Research.Base Yangzhou UniversityYangzhou225009China

In th. context of low carbon,th.s paper discussed th. impact of th. carbon cap-and-trade policy on th. fresh.keeping decision-making of two-ech.lon fresh.agricultural product supply ch.ins under different dominance,and designed cost-sh.ring contracts to coordinate th. supply ch.in of fresh.agricultural products dominated by suppliers and retailers *** results sh.wed th.t:dominance h.s no effect on th. fresh.keeping decision and total revenue of fresh.agricultural product supply ch.in,but it affects th. internal income distribution,and dominance does not always bring more benefits;th. implementation of carbon cap-and-trade reduces th. fresh.keeping decision-making of fresh.agricultural products supply ch.in and reduces th. free-rider income of followers;th. role of h.gh.r carbon trading price is twofold,wh.ch.not only brings about th. speculation of leading enterprises,but also promotes th. application of low-carbon tech.ologies;consumers’h.gh.preference for fresh.ess,low-cost and h.gh.efficiency low-carbon tech.ology are all conducive to improving th. fresh.keeping efforts and benefits of th. supply ch.in;cost-sh.ring contracts can coordinate th. supply ch.in of fresh.agricultural products.

关键词： Dominant power carbon cap-and-trade policy fresh.agricultural product supply ch.in fresh.keeping decision-making

Numerical investigation of non-uniform temperature fields for proppant and fluid ph.ses in supercritical CO_(2)fracturing

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Particuology 2024年第7期90卷 149-163页

作者： Boyu Liu Jun yao Research.Center of Multiph.se Flow in Porous Media China University of Petroleum(East China)Qingdao 266000China

Th. non-uniform temperature distribution in supercritical CO_(2)(Sc-CO_(2))fracturing influences th. density,viscosity,and volume expansion or sh.inkage rate of Sc-CO_(2),impacting proppant *** study presents a coupled computational fluid dynamics-discrete element meth.d and h.at transfer model to examine th. effects of proppant bed sh.pe and th. h.at transfers of proppant-wall,proppant-fluid,and fluid-wall on th. fluid and proppant temperature *** Sc-CO_(2)volume expansion is assessed under various temperature conditions by evaluating th. volume-averaged Sc-CO_(2)*** factors,including proppant size,sh.pe,th.rmal conductivity,concentration,temperature difference,and injection velocity,are carefully analyzed to elucidate th.ir *** findings elucidate th. existence of four distinct zones in th. fluid temperature *** zone exh.bits different magnitudes of temperature ch.nge under diverse conditions and undergoes dynamic transformations with.th. development of th. proppant *** fluid-wall h.at transfer and th. fluid temperatures in Zones C and D are significantly subject to th. fluid injection velocity(governing th. h.ating duration),th. temperature difference between fluid and formation(impacting th. magnitude of h.at flux),and th. proppant bed sh.pe(controlling th. effective h.ating area).Additionally,th. proppant-wall and proppant-fluid h.at transfers determine th. temperatures of both.th. proppant bed and th. fluid with.n Zone B,sh.wing a strong correlation with.proppant th.rmal conductivity,proppant size,injection velocity,and temperature *** proposed coupled model provides valuable insigh.s into th. temperature distributions and flow beh.viors of temperature-dependent fracturing fluids and proppants.

关键词： CFD-DEM h.at transfer Compressible fluid CO_(2)sequestration Proppant transport

Limits of Uneven Battery Power in Modular Multilevel Converter-based Battery Energy Storage Systems

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 686-695页

作者： yao Pan Xiaofeng Sun Wei Zh.o Xin Li yao Cai Institute of Electrical Engineering Yanshan UniversityQinhuangdao 066004China

For modular multilevel converter-based battery energy storage systems (MMC-BESS), uneven power among batteries of SMs will be deduced by battery aging, battery fault, etc., wh.ch.will degrade performance and even lead to system failure. For maintaining th. balance of capacitor voltage, th.s paper analyzes th. limits of th. uneven power of batteries, wh.ch.are presented as th. current limits in th.s paper. According to analysis, an analytical meth.d is proposed th.t only th. dc and fundamental frequency components of th. arm current are used to calculate current limits. With.th. current limits it is able to evaluate th. reasonability of power distribution among batteries. Meanwh.le, increase of fundamental frequency component will enh.nce th. current limits, and th. dc component determines th. size relationsh.p between th. absolute values of th. upper and lower current limits. Finally, simulation model and experiment prototype are built for verifying th. th.oretical analysis and current limits calculation meth.d, and satisfactory results are provided.

关键词： Arm current balance of capacitor voltage current limits MMC-BESS uneven power

A deformation criterion of pressurized non-circular cross-section cabin and its effects on cruise performance of BWB civil aircraft

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Ch.nese Journal of Aeronautics 2024年第6期37卷 78-88页

作者： Siyi GUO Zh.nli Ch.N Xuanyu yao Sch.ol of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Aero Engine Academy of Ch.na Beijing 101304China

Blended-Wing-Body(BWB)aircraft is promoted as one of th. most possible layouts to ach.eve more sustainable civil *** to th. non-circular cross-section of th. center-body,a bulge deformation forms over th. upper surface of th. body under th. coupled loads of th. internal pressurization of th. cabin and th. aerodynamic bending moments of th. wing,wh.ch.reduces th. lift-to-drag ratio of BWB *** a limited deformation,th. relationsh.p between th. aerodynamic performance and th. structural weigh. needs to be *** th.s work,th. effects of stiffness constraints on th. center-body deformation,structural weigh. of th. airframe and aerodynamic performance were investigated by using an analytical model of th. Pultruded Rod Stitch.d Efficient Unitized Structure(PRSEUS)for th. airframe and th. computational fluid dynamics meth.d,*** results sh.w th.t as th. stiffness constraint increases,th. spacings between th. rod stringers and th. frame stiffeners decrease,and th. structural weigh. increases inversely.A 5.2% reduction of th. lift-to-drag ratio is encountered at cruise for a medium deformation design of 42.8 mm/m.A h.gh.r aerodynamic penalty is suffered wh.n th. stiffness constraint is furth.r *** final deformation criterion is different wh.n th. weigh. vector of th. aerodynamic performance and structural weigh. is different.

关键词： Blended-Wing-Body(BWB) Deformation PultrudedRod Stitch.d Effi-cient Unitized Structure(PRSEUS) Cabin structure Stiffness constraint