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Unified description of sand behavior

Feng ZHANG, Bin YE, Guanlin YE

《结构与土木工程前沿（英文）》 2011年第5卷第2期页码 121-150 doi: 10.1007/s11709-011-0104-z

摘要： In this paper, the mechanical behavior of sand, was systematically described and modeled with a elastoplastic model proposed by Zhang et al. [ ]. Without losing the generality of the sand, a specific sand called as Toyoura sand, a typical clean sand found in Japan, has been discussed in detail. In the model, the results of conventional triaxial tests of the sand under different loading and drainage conditions were simulated with a fixed set of material parameters. The model only employs eight parameters among which five parameters are the same as those used in Cam-clay model. Once the parameters are determined with the conventional drained triaxial compression tests and undrained triaxial cyclic loading tests, then they are fixed to uniquely describe the overall mechanical behaviors of the Toyoura sand, without changing the values of the eight parameters irrespective of what kind of the loadings or the drainage conditions may be. The capability of the model is discussed in a theoretical way.

关键词： constitutive model sand stress-induced anisotropy density structure

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Unified cycle model of a class of internal combustion engines and their optimum performance characteristics

Shiyan ZHENG

《能源前沿（英文）》 2011年第5卷第4期页码 367-375 doi: 10.1007/s11708-011-0170-x

摘要： The unified cycle model of a class of internal combustion engines is presented, in which the influence of the multi-irreversibilities mainly resulting from the adiabatic processes, finite-time processes and heat leak loss through the cylinder wall on the performance of the cycle are taken into account. Based on the thermodynamic analysis method, the mathematical expressions of the power output and efficiency of the cycle are calculated and some important characteristic curves are given. The influence of the various design parameters such as the high-low pressure ratio, the high-low temperature ratio, the compression and expansion isentropic efficiencies etc. on the performance of the cycle is analyzed. The optimum criteria of some important parameters such as the power output, efficiency and pressure ratio are derived. The results obtained from this unified cycle model are very general and useful, from which the optimal performance of the Atkinson, Otto, Diesel, Dual and Miller heat engines and some new heat engines can be directly derived.

关键词： internal combustion engine irreversibility power output efficiency optimization

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微波无线能量收集技术——统一模型、自动化整流天线设计及前沿技术 Review

Si-Ping Gao, Jun-Hui Ou, Xiuyin Zhang, Yongxin Guo

《工程（英文）》 2023年第30卷第11期页码 32-48 doi: 10.1016/j.eng.2023.05.019

摘要：

While sufficient review articles exist on inductive short-range wireless power transfer (WPT), long-haul microwave WPT (MWPT) for solar power satellites, and ambient microwave wireless energy harvesting (MWEH) in urban areas, few studies focus on the fundamental modeling and related design automation of receiver systems. This article reviews the development of MWPT and MWEH receivers, with a focus on rectenna design automation. A novel rectifier model capable of accurately modeling the rectification process under both high and low input power is presented. The model reveals the theoretical boundary of radio frequency-to-direct current (dc) power conversion efficiency and, most importantly, enables an automated system design. The automated rectenna design flow is sequential, with the minimal engagement of iterative optimization. It covers the design automation of every module (i.e., rectifiers, matching circuits, antennae, and dc–dc converters). Scaling-up of the technique to large rectenna arrays is also possible, where the challenges in array partitioning and power combining are briefly discussed. In addition, several cutting-edge rectenna techniques for MWPT and MWEH are reviewed, including the dynamic range extension technique, the harmonics-based retro-directive technique, and the simultaneous wireless information and power transfer technique, which can be good complements to the presented automated design methodology.

关键词：微波无线能量传输微波无线能量收集统一整流器模型自动化整流天线设计新兴整流天线技术

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一种集成的统一建模语言框架

Mohammad ALSHAYEB,Nasser KHASHAN,Sajjad MAHMOOD

《信息与电子工程前沿（英文）》 2016年第17卷第2期页码 143-159 doi: 10.1631/FITEE.1500094

摘要：

The unified modeling language (UML) is one of the most commonly used modeling languages in the software industry.It simplifies the complex process of design by providing a set of graphical notations, which helps express the objectoriented analysis and design of software projects. Although UML is applicable to different types of systems, domains, methods,and processes, it cannot express certain problem domain needs. Therefore, many extensions to UML have been proposed. In this paper, we propose a framework for integrating the UML extensions and then use the framework to propose an integrated unified modeling language-graphical (iUML-g) form. iUML-g integrates the existing UML extensions into one integrated form. This includes an integrated diagram for UML class, sequence, and use case diagrams. The proposed approach is evaluated using a case study. The proposed iUML-g is capable of modeling systems that use different domains.

关键词： Unified modeling language (UML) Integration Modeling System analysis and design

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再生与原生混凝土结构构件统一设计理论的基础问题 Article

肖建庄, 张凯建, 丁陶, 张青天, 肖绪文

《工程（英文）》 2023年第29卷第10期页码 188-197 doi: 10.1016/j.eng.2023.03.017

摘要：

再生混凝土作为一种低碳混凝土，成为近20年来国内外的研究热点，但是目前再生混凝土结构的设计仍是一个挑战。本文从原生与再生混凝土结构构件统一设计的新需求出发，剖析了两者统一设计的必要性，并从强度取值、受压本构关系以及结构构件设计方法等方面进行了深入论证。分析发现，再生混凝土的强度变异系数总体上高于原生混凝土，再生混凝土的抗压强度及抗拉强度代表值的定义和取值方法与原生混凝土一致；原生与再生混凝土的单轴受压本构关系具有统一的数学表达形式，但与原生混凝土相比，再生混凝土弹性模量降低、脆性增加。最后，提出了再生混凝土构件安全可靠度调整系数，实现了再生与原生混凝土构件承载力设计公式的统一，并从概念设计和构造措施上，论证了考虑时变强度与钢筋锈蚀等影响的时变可靠度统一的可行性。本文的工作，丰富和发展了混凝土结构基本理论。

关键词：再生混凝土原生混凝土强度取值本构关系可靠度统一设计方法

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reference tracking control design for a class of nonlinear systems with time-varying delays

Mei-qin LIU,Hai-yang CHEN,Sen-lin ZHANG

《信息与电子工程前沿（英文）》 2015年第16卷第9期页码 759-768 doi: 10.1631/FITEE.1500053

摘要： This paper investigates the trajectory tracking control for a class of nonlinear systems with timevarying delays by virtue of Lyapunov-Krasovskii stability theory and the linear matrix inequality (LMI) technique. A unified model consisting of a linear delayed dynamic system and a bounded static nonlinear operator is introduced, which covers most of the nonlinear systems with bounded nonlinear terms, such as the one-link robotic manipulator, chaotic systems, complex networks, the continuous stirred tank reactor (CSTR), and the standard genetic regulatory network (SGRN). First, the definition of the tracking control is given. Second, the performance analysis of the closed-loop system including this unified model, reference model, and state feedback controller is presented. Then criteria on the tracking controller design are derived in terms of LMIs such that the output of the closed-loop system tracks the given reference signal in the sense. The reference model adopted here is modified to be more flexible. A scaling factor is introduced to deal with the disturbance such that the control precision is improved. Finally, a CSTR system is provided to demonstrate the effectiveness of the established control laws.

关键词： H∞ reference tracking Nonlinear system State feedback control Time-varying delays Unified model

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通讯式学习——统一的机器学习模式 Review

袁路遥, 朱松纯

《工程（英文）》 2023年第25卷第6期页码 77-100 doi: 10.1016/j.eng.2022.10.017

摘要：

In this article, we propose a communicative learning (CL) formalism that unifies existing machine learning paradigms, such as passive learning, active learning, algorithmic teaching, and so forth, and facilitates the development of new learning methods. Arising from human cooperative communication, this formalism poses learning as a communicative process and combines pedagogy with the burgeoning field of machine learning. The pedagogical insight facilitates the adoption of alternative information sources in machine learning besides randomly sampled data, such as intentional messages given by a helpful teacher. More specifically, in CL, a teacher and a student exchange information with each other collaboratively to transmit and acquire certain knowledge. Each agent has a mind, which includes the agent's knowledge, utility, and mental dynamics. To establish effective communication, each agent also needs an estimation of its partner's mind. We define expressive mental representations and learning formulation sufficient for such recursive modeling, which endows CL with human-comparable learning efficiency. We demonstrate the application of CL to several prototypical collaboration tasks and illustrate that this formalism allows learning protocols to go beyond Shannon's communication limit. Finally, we present our contribution to the foundations of learning by putting forth hierarchies in learning and defining the halting problem of learning.

关键词： Artificial intelligencehine Cooperative communication Machine learning Pedagogy Theory of mind

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知识论框架通向信息-知识-智能统一的理论

钟义信

《中国工程科学》 2000年第2卷第9期页码 50-64

摘要：

知识是人类所创造的宝贵财富，但至今没有形成系统的知识理论。文章旨在提出和建立知识论的框架体系，包括它的基础和主体两部分。基础部分主要给出知识的概念、定义、表示、度量、推理和决策规则；主体部分的核心是阐明由信息提炼知识（知识生成）以及由知识形成智能（知识激活）的机理。知识论的建立将为信息论-知识论-智能论的统一理论奠定坚实的基础，促进人们在更高的水平上利用信息和知识，研究、设计和应用各种智能机器，推动经济和社会的发展。

关键词：知识知识量知识生成知识激活信息-知识-智能的统一理论

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Unified calculation method and its application in determining the uniaxial mechanical properties of concrete

Faxing DING, Xiaoyong YING, Linchao ZHOU, Zhiwu YU

《结构与土木工程前沿（英文）》 2011年第5卷第3期页码 381-393 doi: 10.1007/s11709-011-0118-6

摘要： This paper presents a unified calculation method and its application in determining the uniaxial mechanical properties of concrete with concrete strengths ranging from 10 to 140 MPa. By analyzing a large collection of test results of the uniaxial mechanical properties of normal-strength, high-strength and super high-strength concrete in China and performing a regression analysis, unified calculation formulas for the mechanical indexes of concrete are proposed that can be applied to various grades of concrete for determining the size coefficient, uniaxial compressive strength, uniaxial tensile strength, elastic modulus, and strain at peak uniaxial compression and tension. Optimized mathematical equations for the nonlinear stress-strain relationship of concrete, including the ascending and descending branches under uniaxial stress, are also established. The elastic modulus is almost constant throughout the elastic stage for the ascending branches of the stress-strain relationship for concrete. The proposed stress-strain relationship of concrete was applied to the nonlinear finite element analysis of both a steel-concrete composite beam and a concrete-filled steel tubular stub column. The analytical results are in good agreement with the experiment results, indicating that the proposed stress-strain relationship of concrete is applicable. The achievements presented in this paper can be used as references for the design and nonlinear finite element analysis of concrete structures.

关键词： concrete mechanical properties stress-strain relationship uniaxial stress application

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A unified power electronic controller for wind driven grid connected wound rotor induction generator

D. R. BINU BEN JOSE, N. AMMASAI GOUNDEN, Raavi SRI NAGA RAMESH

《能源前沿（英文）》 2013年第7卷第1期页码 39-48 doi: 10.1007/s11708-012-0229-3

摘要： The implementation of a simple power converter for a wound rotor induction generator employing a three phase diode bridge rectifier and a line commutated inverter in the rotor circuit for super synchronous speeds has been proposed. The detailed working of the system in power smoothing mode and maximum power point tracking mode is presented. The current flow in the rotor circuit is controlled (by controlling the firing angle of the line commutated inverter) for controlling the stator power in both the modes. An 8 bit PIC microcontroller has been programmed to vary the firing angle of the line commutated inverter. Experiments have been carried out on a 3-phase, 3.73 kW, 400 V, 50 Hz, 4-pole, 1500 r/min wound rotor induction generator and the results obtained with the generator supplying power in both the modes are furnished. The complete scheme has been modeled using MATLAB/SIMULINK blocks and a simulation study has been conducted. The experimental waveforms are compared with the simulation results and a very close agreement between them is observed.

关键词： line commutated inverter MPPT power smoothing wound rotor induction generator

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Unified power quality conditioner based on a three-level NPC inverter using fuzzy control techniques

Salim CHENNAI,M-T BENCHOUIA

《能源前沿（英文）》 2014年第8卷第2期页码 221-239 doi: 10.1007/s11708-014-0317-7

摘要： This paper presents a novel and efficient control scheme for unified power quality conditioner (UPQC) based on three-level neutral point clamped (NPC) inverter using fuzzy logic techniques. The proposed UPQC is capable of mitigating source current harmonics and compensate all voltage disturbances such as voltage sags, swells, unbalances and harmonics. It is designed by the integration of series and shunt active filters (AFs) sharing a common DC bus capacitor. The DC voltage is maintained constant using proportional integral voltage controller. The synchronous reference frame (SRF) theory is used to get the reference signals for shunt active power filters (APFs) and the power reactive theory (p-q theory) for series APFs. The shunt and series APF reference signals derived from the control algorithm and sensed signals are injected in two controllers to generate switching signals. To improve the UPQC capability, fuzzy logic techniques are introduced to control the series APF. The performances of the proposed UPQC system are evaluated in terms of power factor correction, mitigation of voltage or current harmonics and all other voltage disturbances compensation using Matlab-Simulink software and SimPowerSystem toolbox. The simulation results illustrate the performance of the proposed UPQC at the common connection point of the nonlinear load to improve the power energy quality.

关键词： three-level neutral point clamped (NPC) inverter unified power quality conditioner (UPQC) current harmonics mitigation fuzzy logic controller voltage disturbance compensation shunt active filter series active filter power quality energy improvement

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Unified solution of limit loads of thick wall cylinder subject to external pressure considering strain

CHEN Changfu, XIAO Shujun, YANG Yu

《结构与土木工程前沿（英文）》 2007年第1卷第3期页码 329-333 doi: 10.1007/s11709-007-0043-x

摘要： Based on the unified strength theory [1], a unified strength criterion for strain softening materials, such as concrete or rock, was derived, and the elastic and plastic limit loads of a thick-walled cylinder made of these materials subject to external pressure were also given. In addition, the influence of some factors on the limit loads of such cylinders as the ratio of the external radius to internal radius,/, the coefficient , which reflects the effect of medium principal stress and the normal stress of the relevant surface on the material destroy degree, the ratio of tensile strength to compressed strength of the material, , and the damage variable

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知行学引论——信息知识智能的统一理论

钟义信

《中国工程科学》 2004年第6卷第6期页码 1-8

摘要：

资源乃人类生存之源。科学技术的任务就要揭示资源的性质及其转换规律，以创造先进工具，扩展人的能力，改善人类的生存发展条件。近代科学揭示了物质和能量两类资源的性质和转换规律，创造和不断改进了人力工具和动力工具，创造了辉煌的工业时代文明：文章试图总结信息资源的性质及其转换规律，阐明信息—知识—智能的统一理论，构建知行学，为创造各种智能工具奠定理论基础。

关键词：信息论知识论智能论知行学

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我国自主研制的全球/区域一体化数值天气预报系统GRAPES的应用与展望

陈德辉,薛纪善,沈学顺,孙健,万齐林,金之雁,李兴良

《中国工程科学》 2012年第14卷第9期页码 46-54

摘要：

介绍了中国气象局自主研制的新一代全球与区域一体化数值天气预报系统（GRAPES）,着重讨论了该系统的全可压/非静力平衡动力框架，全球模式/区域模式一体化设计，半隐式-半拉格朗日差分方案，标准化、模块化、并行化、模式程序软件体系等核心技术特点。GRAPES系统已在国家级、区域级气象业务中心，以及一些大学和研究所得到应用，并在不断地完善和发展。

关键词：数值预报天气预报全球/区域一体化模式动力框架资料同化物理过程参数化

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迈向L5级自动驾驶汽车的发展原则 Article

王建强, 黄荷叶, 李克强, 李骏

《工程（英文）》 2021年第7卷第9期页码 1313-1325 doi: 10.1016/j.eng.2020.10.018

摘要：

自动驾驶汽车的快速发展给现有交通出行方式带来了全新面貌和潜在挑战。目前，L3 级及以下驾驶辅助系统已经量产，L4 级在特定场景下的一些应用也逐步开发，通过逐渐提高车辆的自动化、智能化程度来不断向完全自动驾驶发展。然而，针对L5 级自动驾驶汽车的发展思路始终未明确，而现有针对L0~L4级自动驾驶发展过程的研发方式主要基于任务驱动来进行特定场景下的功能开发，难以揭示高等级自动驾驶汽车所需解决问题的本质逻辑和物理机制，进而阻碍了迈向L5 级自动驾驶的途径。本文通过探索高等级自动驾驶系统背后的物理机制，并从驾驶的本质出发，采用推理演绎方式，提出“大脑-小脑-器官”协调平衡框架，基于“乌鸦推理+鹦鹉学舌”的混合模式，探索“自主学习+先验知识”的研究范式，实现自动驾驶汽车“自学习、自适应、自超越”特性。从系统、统一、均衡的角度出发，基于最小作用量原理和统一安全场思想，旨在为高等级自动驾驶汽车，尤其是L5 级自动驾驶的研发提供一种全新的研发思路与有效途径。

关键词：自动驾驶汽车最小作用量原理行车安全场自主学习基础范式