27 research outputs found

    中国与东盟互联互通建设及对南亚合作的启示

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    中国与东盟互联互通建设取得重要进展,有力地推动了中国—东盟自由贸易区建设及中国与东盟战略伙伴关系的发展。文章借鉴其经验,指出中国与南亚合作可以从加强交流,提高互信,高层持续注入政治支持;加强与南亚区域国际组织合作,积极参与南亚区域合作;建立互联互通合作机制,共同搭建合作平台;设立中国—南亚互联互通合作基金,推动重点合作项目建设;充分发挥地方政府积极性和主动性,推动国家间合作;扩大对南亚经贸合作等六个方面加以推进与建设

    Effect of Temperature on Sensing Performance of Optical Fiber Relative Humidity Sensor Based on Nafion-crystal Violet Film

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    The optical fiber relative humidity sensor based on Nafion-crystal violet film was developed. The effect of samples temperature in the range from 299.15 K to 324.15 K on the sensing performance of the sensor was investigated. The mathematical function between temperature and the sensitivity of the sensor was established according to the reactive theory of sensor to the relative humidity, which was validated with the experiment. With the research, the application range of the sensor was extended, which made the sensor keep a good veracity when it was used in situ.国家“八六三”计划海洋监测技术主题项目(批准号:818-09-07)资助

    Effect of temperature on sensing performance of optical fiber relative humidity sensor based on nafion-crystal violet film

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    The optical fiber relative humidity sensor based on Nafion-crystal violet film was developed. The effect of sample's temperature in the range from 299.15 K to 324.15 K on the sensing performance of the sensor was investigated. The mathematical function between temperature and the sensitivity of the sensor was established according to the reactive theory of sensor to the relative humidity, which was validated with the experiment. With the research, the application range of the sensor was extended, which made the sensor keep a good veracity when it was used in situ

    QoS Provisioning of the Broadband Residential Ethernet-Based Access Network

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    宽带社区网是下一代网络研究的主要领域之一,也是当前宽带多业务网实施的主要难点之一。今天,非对称数字用户环路和光纤同轴混合网掌握着市场的主要份额,这些宽带接入技术主要采用ATM技术。然而,IP协议已经成为一种最流行的网络层协议,越来越多的被用于不同的网络中。特别是,众多研究人员、网络设备制造商和标准化组织开始关注一种新的宽带IP接入技术,也就是基于以太网的宽带接入技术。基于以太网技术的宽带社区网相比于传统的接入网技术具有一系列优点,如经济、简单、高效率和高扩展性。但是,基于以太网技术的宽带社区网为了提供电话、电视、视频点播以及高速互联网接入等服务仍有很多技术难题需要解决。特别是如何确保多业务的服务质量的问题,也是宽带社区网的核心技术,没有很好的解决办法。本文通过服务质量的研究,提出基于以太网技术的宽带社区网确保服务质量的方法及相关网络机制。本文的主要贡献和创新点如下:1.提出在二层以太网域实现类似于RFC2475定义的区分服务,提供加速转发EF服务和保证转发AF服务。基于IEEE 802.IP和802.IO的队列机制,采用逐跳选择式背压流控机制和头端阻塞保护机制消除拥塞,改善系统性能。提议的二层以太网域区分服务方法在不改变以太网技术本质前提下,能够确保二层以太网域多业务的服务质量,进而在整个基于以太网技术的宽带社区网中,可以基于统一的区分服务方法确保服务质量。2.提出了一种基于以太网技术的宽带社区网中确保多业务服务质量的方法,既能有效地确保电视、电话、VOD和高速互联网接入的服务质量,又能实现高扩展性。结合CBR编码控制机制和限定服务类型提供可预测的通信量特征,简化了网络设计和服务质量方法的复杂度;采用区分服务方法,满足了大规模宽带社区网的高扩展性要求;结合网络容量规划、DiffSery框架和定价机制研究多业务的服务质量,确保了服务质量方法的有效性和可操作性。具体工作包括:I.提出了一种基于以太网技术的宽带社区网网络容量规划方法,可以估计各种业务带宽需求,合理安排链路带宽容量,减少宽带社区网工作在拥塞状态下的可能性,有效地实现了网络容量规划的目标;II.提出了一种宽带社区网的区分服务方法,基于每跳行为和每域行为确保实时业务服务质量,能够有效地确保VoIP、电视、VoD和高速互联网接入的服务质量;III,设计了一种基于以太网技术的宽带社区网定价机制,能够有效地帮助区分服务机制进行通信量管理。3.设计了一套支持单播业务和组播业务的链路聚合机制,可以线性地扩展系统带宽容量,并有效地增强网络链路的可用性。Marvell公司Galnet2+系列芯片的链路聚合机制不能很好地支持组播业务,组播业务流只能在一个链路聚合组的一条链路上传送。而基于以太网技术的宽带社区网利用组播机制传输广播性质的业务(如电视业务),组播业务流在整个网络中占有很大比重。本文基于Galnet2+芯片设计了能够很好地支持单播业务和组播业务的链路聚合机制。本文的研究工作提出了一种切实可行的基于以太网技术的宽带社区网中确保服务质量的方法,为基于以太网技术的宽带社区网的研究和实现打下了基础。Nowadays, the broadband residential access infrastructure remains one of the major research areas for the Next Generation Network (NGN) and also one of the major obstacles for implementation of a broadband network. Asymmetrical Digital Subscriber Loop (ADSL), Hybrid Fiber-Coax (HFC) based on ATM technique grabbed the main market share currently. Over the past decade, however, Internet Protocol (IP) has emerged as the undisputed protocol of choice at the network layer. IP is the one constant element in a network of diverse transport protocols, ranging from ATM and SONET to Ethernet, DOCSIS cable, Passive Optical Network (PON) and DSL. Nowadays, academic communities and industry from all over the world are increasingly showing great concern about a new broadband residential IP-based access technique, i.e. Ethernet technique in the subscriber access network or the broadband residential Ethernet-based access network. Indeed, Ethernet in the subscriber access network will offer several advantages over traditional first mile technologies in terms of cost, network simplicity, packet-based efficiency, bandwidth, scaling, and provisioning. It can easily meet the requirements of bandwidth of the residential customers, and promises a converged network. There are some broadband residential Ethernet-based access networks currently, but they only offer high-speed Internet access and VoD, not TV and VoIP. However, the carrier-grade broadband residential Ethernet-based access network, a converged residential access network which offer voice, TV, VoD and high-speed Internet access for residential customers, still needs to overcome many technical difficulties. Specially, multi-service QoS provisioning is a key technique of the broadband residential Ethernet access network, but there is short of the pragmatic good methods. This dissertation tries to find a scalable method to implement QoS provisioning of the broadband residential Ethernet-based access network. This paper presented a method of QoS provisioning in the broadband residential Ethernet-based access network. The contributions of this dissertation lists below: 1. Proposed that DiffServ defined by RFC 2475 is implemented in layer two (L2) domain over Ethernet, and L2 domain over Ethernet provides EF services and AF services. Our differentiated service approach of L2 domain over Ethernet based on IEEE 802.IP and 802.1Q. The approach combines hop-by-hop selective backpressure scheme with HOL protection to eliminate congestion and improve performance of switched Ethernet L2 domains instead of Random Early Drop (RED) scheme or its variants considering the characteristics of Ethernet technique. Noted, our differentiated service approach of L2 domain over Ethernet doesn't change the key features of Ethernet technique, and promises a same QoS architecture, i.e. DiffServ, in the whole broadband residential Ethernet-based access network. 2. Presented a scalable method of QoS provisioning in the broadband residential Ethernet-based access network that offers QoS guarantees for VoIP, TV, VoD, etc. The CBR encoding control scheme with fixed services promises predictable traffic characteristics, which simplifies QoS mechanisms and network designs; the differentiated approach promises a scalable QoS architecture for the carrier-grade broadband residential access network; combining network dimensioning, DiffServ and pricing promises QoS provisioning with effectiveness and operability. Details of research work listed: I. Presented a method of network dimensioning in the broadband residential Ethernet-based access network. This method of network dimensioning can appropriately estimate the requirements of bandwidth for the services, and allot the appropriate bandwidth for the links and prevent the networks from operating with overburden always; II. Presented a differentiated approach of the broadband residential Ethernet-based access network. Analyzed Per Hop Behavior and Per Domain Behavior of EF service based on Packet Scale Rate Guarantee theory, and give a method of EF implementation in the broadband residential Ethernet-based access network for VoIP, TV and VoD; III. Designed a QoS-enable pricing of the residential Ethernet-based multi-service access network. Our proposed pricing distinguishes between unicast applications and multicast applications. It not only considers the users' habit of the legacy services but also assists in congestion control or traffic management for DiffServ framework. 3. Designed a link aggregation mechanism over Marvell's Galnet24 chipsets, which suits to unicast applications and multicast applications, and the link aggregation mechanism can linearly expand the bandwidth capacity of systems and improve the availability of the network links. Marvell's Galnet2+chipsets cannot well support multicast applications over link aggregation, because multicast traffics can only be transported in one link of the aggregated links. We respectively design a link aggregation mechanism for unicast applications and multicast distributary mechanism for multicast applications, and these two mechanisms can operate well independently. This dissertation presents a pragmatic method of QoS provisioning in the broadband residential Ethernet-based access network. Our studies are fundamental for research and implementation of the broadband residential Ethernet-based access network, and pave the way for the future converged residential access network

    一种形状记忆合金执行器

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    本发明涉及一种形状记忆合金执行器,包括固定板,还包括执行机构,其PCB板通过金属螺钉与所述固定板固定连接,执行机构连接驱动单元,接收驱动单元的驱动信号,驱动信号控制执行机构运动,带动反馈机构的金属滑块移动;驱动单元,设置于PCB板的一侧,用于向执行机构发出驱动信号;反馈机构,其金属滑块通过金属螺钉与执行机构固定连接,通过测量阻值的变化来记录形状记忆合金执行器的位移参数。本发明驱动能力强、结构简单,具有价格低,重量轻,控制简单的优点,采用模块化设计形式,易于维护,同时执行器带有位置保护以及位移反馈功能,能够准确的记录形状记忆合金的驱动位移,可独立作为一种机器人动力执行装置,应用于柔性仿生机器人设计中

    MYO-based text input system and method

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    本发明涉及基于MYO的文本输入系统及方法,通过使用MYO腕带,设计并制造了一种交互自然、使用宽泛、效率更高的文本输入系统,包括MYO腕带、所述腕带内的肌电传感器和姿态传感器的使用、所述系统中的用户界面和虚拟键盘的设计以及所述系统中的传感器数据处理方法和机器学习算法;所述MYO腕带将肌电信号和姿态的信息通过蓝牙发送给所述服务器端;所述服务器端将得到的数据进行处理并提取相关特征,然后通过随机森林模型得到动作的类别;所述用户界面接收到服务器的动作类别信号后,做出对应的动作;所述用户界面的设计与颜色的搭配。本发明中将采集到的肌电信号和姿态传感器的信号进行融合分析,提高手势分类的准确度

    钢铁烧结机烟气多污染物协同控制技术评述

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    近期即将颁布实施的《钢铁工业大气污染物排放标准》对烧结烟气污染物的排放要求更加严格,多污染物的协同控制将是今后烧结烟气污染治理的必然趋势。本文针对国外典型钢铁烧结烟气多污染物协同控制技术进行了评述,分析了各项技术的主要特点及在国内的推广应用前景,提出开发适宜国内烧结烟气多污染物协同控制技术的必要性和紧迫性

    An hammerstein model based control method for shape memory alloy actuators

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    Shape memory alloy (SMA) is a promising smart metallic material, which has the ability to recover its shape when heated. This characteristic enables SMA to serve as an alternative to replace conventional actuators. However, there also exist hysteresis nonlinearities and parameter uncertainties, which make SMA actuators difficult to model and control. This paper develops a gray-box identification and control approach for SMA actuators. To copy with hysteresis nonlinearities, this plant is described as an Hammerstein model, which is a cascade connection of a nonlinear function followed by a linear sub-system. Then the parameter adaptation is performed based on a robust recursive estimator, and the control law compensates the modeling error through incorporating the unmodeled dynamics estimation. The system stability is ensured and the experimental results verify the effectiveness of the proposed method

    A Nonlinear Self-tuning Control Method Based on Neural Wiener Model

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    In this work, a novel nonlinear self-tuning adaptive control scheme based on the neural Wiener model has been proposed to copy with a class of nonlinear uncertain systems. First the parameterization model with uncertain parameters is derived based on a linear transfer function model followed by neural networks. Then based on the performance index, the adaptive control strategy includes the system parameters identification and the control law calculation. Since the networks are linearly described by some basis functions, the closed-loop system stability can be ensured under some realistic assumptions. Finally, the proposed controller is applied to a pH control problem. The simulation results have demonstrated that the proposed nonlinear self-tuning control method is applicable, especially for its reliable set-point tracking and adaptive abilities.</p
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