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This study deals with the stability analysis of a flexible structure with one and only one boundary control. The system is composed of three parts: a cart (motorized platform), a flexible cable, and a load mass attached to the lower part of the cable. This situation leads to a hybrid system as a mathematical model for the cable dynamics: one partial differential equation coupled to two ordinary differential equations. Despite the presence of a time-delay in the top-end of the cable, we are able to prove that the hybrid system is well-posed in the sense of semigroups theory and more importantly, only one boundary control can guarantee the exponentially decay of the energy of the system under reasonable conditions on the parameters of the system. This outcome considerably improves the result recently established in [17], where two more controls are required: one interior (Kelvin–Voigt) damping which acts over the entire cable and another boundary control which is exerted on the lower-end of the cable. Furthermore, we provide an estimate of the exponential decay of the system by means an appropriate Lyapunov functional. Lastly, numerical examples are presented in order to ascertain and highlight our theoretical outcomes. 相似文献
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本文介绍了利用EBZ-型掘进机液压系统对锚索加压机的改装与应用。改善并提高了锚网巷道支护对锚索加压的质量与效益,实现了对锚索加压的机械自动化,大大减轻了工人的劳动强度。具有良好的经济效益和广阔的推广价值。 相似文献
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Xiang Liu Hua Zhang Liangliang Lv Fujun Peng Guoping Cai 《Journal of The Franklin Institute》2018,355(5):2424-2435
This paper presents a control strategy of using cable actuators to control the vibration of a membrane antenna structure. The tension cables of the membrane antenna structure are used as actuators, the vibration of the structure can be suppressed by controlling the tension force in the cable actuators. First, the antenna structure with cable actuators is discretized by the finite element method (FEM), and governing equation of the whole structure is established. Then, a controller is designed based on the Lyapunov's stability theory, and the mechanism of this controller is studied through a simple single-degree-of-freedom (SDOF) system. The optimal placement of the cable actuators is also studied numerically in this paper. Simulation results indicate that vibration of the membrane antenna structure can be suppressed effectively by the cable actuators, and optimally placed cable actuators can produce better control effect with smaller control input. 相似文献
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基于复杂理论的知识创造机理研究 总被引：6，自引：0，他引：6
本文把复杂理论与知识创造相结合,提出基于复杂理论的知识创造机理。文章运用这一机理分别对促进知识创造的正例和抑制知识创造的反例进行了分析。分析表明:在影子系统和合法系统的作用下,清华同方核技术公司占据了创造性空间,获得知识创造;而不适应性学习的存在、影子系统和合法系统对创新的规避,致使成都某电缆公司不能占据创造性空间,从而抑制知识创造。 相似文献
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利用MS1000高精度旋转扫描声纳系统在渤海海域平台上或近平台区域进行海底管道电缆及地貌调查,可以有效的获得近平台区域的海底管道电缆精确位置、障碍物大小和分布情况以及周边地貌情况。本文深入讨论旋转扫描声纳系统在近平台区域海底管道电缆及地貌调查的方法、技术特点及技术优势,有效的解决了海上近平台区域海底管道电缆和地貌调查较难实现的困难。为以后近平台区域海底管道电缆及地貌调查提供了指导、参考及借鉴。 相似文献
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冯成 《科技成果管理与研究》2008,(11):61-62,85
目前电力电缆已被广泛应用,如何避免电缆在运行中发生问题,确保系统安全可靠运行,是需要探究的问题。本文通过对近年来发生的电力电缆问题进行分析,找出了主要原因,并提出相应的防范对策。 相似文献
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《Journal of The Franklin Institute》2022,359(7):3238-3290
The space debris removal system (SDRS) of tethered space tug is modelled as a cable dragged flexible spacecraft. The main goal of this paper is to develop a dynamic modeling approach for mode characteristics analysis and forced vibration analysis of the planar motion of a cable dragged flexible spacecraft. Solar arrays of the spacecraft are modelled as multi-beams connected by joints with additional rotating spring where the nonlinear stiffness, damping and friction are considered. Using the Global mode method (GMM), a novel analytical and low-dimensional nonlinear dynamic model is developed for vibration analysis of SDRS to enhance the design capacity for better fulfillment of space tasks. The linear and nonlinear partial differential equations that governing transverse vibration of solar arrays, transverse and longitudinal vibrations of cable are derived, along with the matching and boundary conditions. The natural frequencies and analytical global mode shapes of SDRS are determined, and orthogonality relations of the global mode shapes are established. Dynamical equations of the system are truncated to a set of ordinary differential equations with multiple-DOF. The validity of the method is verified by comparing the natural frequencies obtained from the characteristic equation with those obtained from FEM. Interesting mode localization and mode shift phenomena are observed in mode analysis. Dynamic responses of the system excitated by fluctuation of attitude control torque and short-time attitude control torque are worked out, respectively. Nonlinear behaviors are observed such as hardening, jump and super-harmonic resonances. Residual vibration of the overall system with considering the varous values of nonlinear stiffness, damping coefficient and friction coefficient has shown that the nonlinearity of joints has a great influence on the vibration of the overall system. 相似文献
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文章在现有金属飞机钢索变形理论的基础上,对复材飞机操纵钢索的设计和应用进行了详细的论述。总结性地提出了软式钢索操纵的设计步骤,在已有钢索变形量计算理论的基础上,考虑热、结构、座舱增压等因素的影响,计算钢索变形量并确定了钢索初始张力的予加原则,并给出钢索张力示例曲线,为钢索张力维护和调节提供理论依据。 相似文献
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关于高校新图书馆综合布线系统设计的探讨 总被引：1，自引：0，他引：1
综合布线是图书馆实现网络化、自动化、数字化、智能化建设的一项重要的基础工作，本文较详尽地论述了当前图书馆综合布线系统申的布线原则、基本结构、线绳选择、系统测试等几个热点问题，并对当前综合布线的设计方案进行了比较分析。 相似文献
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无应力索长控制索力,是当下斜拉桥梁段拼装广泛应用的索力监控方法。针对此文章所阐述的中承式系杆拱桥,利用无应力索长控制方法结合温度应变,很好地解决了接近300米中拱在整体提升前临时拉索索力确定问题。 相似文献
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苏坤 《科技成果管理与研究》2010,(8):80-82
文章主要介绍辐射模电缆（漏泄同轴电缆）。文章采用一种以长天线辐射波瓣图为基础的更直观的分析方法，直接对辐射模电缆进行了理论分析，分析了辐射模电缆的特性，介绍这种辐射模电缆的设计。 相似文献
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长江三峡工程是一个利国利民的大工程,影响和制约着当地国民经济的可持续发展。本文针对长江三峡库区水位测量与控制,提出了一种基于GPRS的水位监控系统。本系统分为监控中心和测量终端。测量终端采用液位传感器,将液位传感器接上线缆后沉入水底,将测出来的水压信号转变成电信号通过电缆传输到测量终端CPU,CPU将此数据转换为水位高度后通过GPRS网络以数据报的形式传输到监控中心实时显示出来。如果水位高度超出阈值,监控中心将发出报警信息通知监控人员以便及时作出处理。 相似文献
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论述了矿井测井技术的主要特点,较详细地介绍了矿井电缆测井系统、全方位钻孔测斜仪、选择伽玛组合测井仪、顺煤层钻进监测系统准直伽玛测量仪和煤矿井下随钻测量系统的组成、测量原理和工作方法,并提出了矿井测井技术的发展趋势,将地面测井技术移植井下,开发出适合煤矿井下的随钻测量技术。 相似文献