基于融合技术的新一代联络中心的研究与设计

随着通信和信息技术的跨越式发展,传统呼叫中心已经难以满足企业快速增长的需求,同时以客户为中心和以服务为导向的经营理念对新一代联络中心提出了更高的要求。在联络中心技术快速革新的背景下,文中以软交换、NGN和分布式技术为基础,深入研究了基于融合技术的新一代联络中心的系统架构和软交换平台的逻辑关系,构建了支持全媒体业务和标准化SIP的统一通信平台。文章以联络中心中实时和非实时业务为例,分析设计了适合联络中心典型的话务和多媒体业务的信令流程,提出了适应新一代联络中心的业务部署方式,利用模糊综合评价方法对不同部署方式的特点进行对比评估,为新一代联络中心在大型企业中推广和应用提供重要的理论和实践依据。     

面向Internet的模具知识本体的构建研究

通过对Internet上模具知识特点的分析,提出通过修改模具论坛的发贴模板的方法来获取论坛贴子的标签,然后利用"七步法"构建Internet上模具知识本体,并初步提出语义搜索概念模型,为基于Internet模具知识的搜索引擎的实现提供理论和实践基础。     

gain bounds for systems with sector bounded and slope‐restricted nonlinearities

This paper proposes a new method for calculating a bound on the gain of a system comprising a linear time invariant part and a static nonlinear part, which is odd, bounded, zero at zero and has a restriction on its slope. The nonlinear part is also assumed to be sector bounded, with the sector bound being (possibly) different from that implied by the slope restriction. The computation of the gain bound is found by solving a set of linear matrix inequalities, which arise from an integral quadratic constraint formulation of a multiplier problem involving both Zames‐Falb and Popov multipliers. Examples illustrate the effectiveness of the results, and comparisons are made against the state‐of‐the‐art. Copyright © 2011 John Wiley & Sons, Ltd.     

Intelligent control of doubly‐fed induction generator systems using PIDNNs

An intelligent control for a stand‐alone doubly‐fed induction generator (DFIG) system using a proportional‐integral‐derivative neural network (PIDNN) is proposed in this study. This system can be applied as a stand‐alone power supply system or as the emergency power system when the electricity grid fails for all sub‐synchronous, synchronous, and super‐synchronous conditions. The rotor side converter is controlled using field‐oriented control to produce 3‐phase stator voltages with constant magnitude and frequency at different rotor speeds. Moreover, the grid side converter, which is also controlled using field‐oriented control, is primarily implemented to maintain the magnitude of the DC‐link voltage. Furthermore, the intelligent PIDNN controller is proposed for both the rotor and grid side converters to improve the transient and steady‐state responses of the DFIG system for different operating conditions. Both the network structure and online learning algorithm are introduced in detail. Finally, the feasibility of the proposed control scheme is verified through experimentation. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

The volume integral method of eddy-current modeling: Verification

The volume integral method of eddy-current modeling represents a flaw in metal as a set of electric dipoles located within volume elements or cells defining the flaw volume. Given this dipole distribution, impedance changes may be computed. The electric field of the dipole distribution is determined by an integral equation relating, by means of the electric field Green's tensor, the electric field due to the source to the total electric field in the flaw. The integral equation is solved by assuming that the total electric field is constant in each volume element, resulting in a matrix equation. The method has been programmed for use on a microcomputer. The method and computer program are verified using the analytical solution for a small spherical flaw and three sets of measured impedance data, measured by air-core coils along profiles overlying both surface-breaking and buried simulated flaws of known dimensions. Operating frequencies ranged between 900 and 4000 Hz. Generally agreement is good at lower frequencies ( 1000 Hz). At higher frequencies ( 4000 Hz), the agreement is not as good. This is thought to be due to the inability of the constant electric field approximation to model the steep electric field gradients present in the host metal at high frequency. The results are also sensitive to the method of computation of the electric field due to the source. Some improvements can and should be made to the method.     

结合局部特征和全局信息的自适应活动轮廓模型

提出一种新的基于全局图像信息和局部图像特征的活动轮廓分割模型。模型的总能量函数主要包括3项:全局能量项、局部能量项和自适应调节项。其中,全局能量项整合了图像的全局信息,局部能量项则考虑了图像的局部特征,而二者的权重会根据上下文内容自适应调整。由于在模型中充分利用了图像全局信息和局部特征,因而有效地提高了分割的精度。此外,加入了凸优化技术,以获取模型的全局最优解。最后,采用Split-Bregman方法进行快速求解,使得模型的分割效率大大提高。实验结果表明,该模型对初始化具有较好的鲁棒性,在分割精度上有了较大的提升,特别是分割速度比C-V模型快1.5倍到2倍。     

数值模拟铸件充型过程中的液/固两相流动

铸造过程中熔融金属内的固体渣粒的运动轨迹是非常重要的。文中给出了粒子传输轨迹的数学模型,该数学模型采用显示法来确定粒子的位置。模拟研究结果与用其它数学模型的模拟结果比较,吻合良好。该模型可用于固体粒子位置的确定,并应用到SUTCAST软件中。     

Mensuration and simulation of mold filling process in semi-solid die-cast of aluminum alloy

To understand the flow trace of semi-solid slurry in mold cavity, some thermocouples were inserted in mold cavity, and the reaction timing of thermocouples showed the arrival of fluid. The filling time and rate were estimated by comparison between the experiment and calculation. The introduction of computer simulation technique based on ADSTEFAN was to predict injectionforming process and to prevent defects during trial manufacture of various parts. By comparing the formed appearance of parts in experiment and in simulation, and observing the relationship between internal defects inspected by X-ray or microscope and the flow field obtained in simulation, it was indicated that both have quite good agreement in simulation and experiment. Right predictions for cast defects resulted from mold filling can be carried out and proper direction was also proposed. The realization of numerical visualization for filling process during semi-solid die-cast process will play an important role in optimizing technology plan.     

模具敏捷制造系统研究

针对模具设计制造过程复杂、条件苛刻和单件或小批量生产的特点 ,论述了模具产业发展敏捷制造技术的必要性。提出了模具敏捷制造系统框架和基于STEP与特征技术实现信息集成与过程集成的运行机制。阐述了基于Internet/Intranet的开放式可视化协同工作平台的模具敏捷制造实施方案。     

20 kg铝锭铸造机铸模改进方案探讨

为了适应火车全面调速后货运高度的要求，提出了有效的铸模改进方案。对铸模改造前后的使用寿命进行了分析。通过改造达到了降低铝锭垛高的目的，同时延长了铸模的使用寿命。