Design of delayed reconfigurable manufacturing system based on part family grouping and machine selection

To improve the convertibility of reconfigurable manufacturing system (RMS), the concept of delayed reconfigurable manufacturing system (D-RMS) was proposed. RMS and D-RMS are both constructed around part family. However, D-RMS may suffer from ultra-long system problem with unacceptable idle machines using generic RMS part families. Besides, considering the complex basic system structure of D-RMS, machine selection of D-RMS should be addressed, including dedicated machine, flexible machine, and reconfigurable machine. Therefore, a system design method for D-RMS based on part family grouping and machine selection is proposed. Firstly, a part family grouping method is proposed for D-RMS that groups the parts with more former common operations into the same part family. The concept of longest relative position common operation subsequence (LPCS) is proposed. The similarity coefficient among the parts is calculated based on LPCS. The reciprocal value of the operation position of LPCS is adopted as the characteristic value. The average linkage clustering (ALC) algorithm is used to cluster the parts. Secondly, a machine selection method is proposed to complete the system design of D-RMS, including machine selection rules and the dividing point decision model. Finally, a case study is given to implement and verify the proposed system design method for D-RMS. The results show that the proposed system design method is effective, which can group parts with more former common operations into the same part family and select appropriate machine types.     

基于可重构FPGA技术的自适应FIR滤波器的实现

有限冲激响应(FIR)滤波器设计遇到的难题是滤波要进行大量乘法运算,即使是在全定制的专用集成电路中也会导致过大的面积与功耗.对于用硬件实现系数是常量的专用滤波器,可以通过分解系数变为应用加、减和移位而实现乘法.FIR滤波器的复杂性主要由用于系数乘法的加法器/减法器的数量决定.而对于自适应FIR滤波器,大多数场合下可用数字信号处理器(DSP)或CPU通过软件编程的方法来实现,但是对于要求高速运算的场合,VLSI实现是很好的选择.基于这一考虑,可以用符号数的正则表示(CSD)码表示系数, 再利用可重构现场可编程门阵列(FPGA)技术实现.可重构结构的应用,能保证系统的其余部分同时处于运行状态时实现FIR滤波器系数的更新.文中利用CSD码和可重构思想,提出了用FPGA实现自适应FIR滤波器的一种方案.     

Reconfiguration Aspects and a Reconfigurable Outer Block Interleaver for 3G Applications

Reconfiguration concept represents reconfigurable functionalities of the radio interface for mobile radio systems. Particularly for the physical layer, some possible reconfigurable architectures can be identified. We focus on outer interleaving for turbo codes, which can improve their performance in flat Rayleigh fading environment. The larger the number of columns in the outer interleaver, the better is the performance, but with the penalty of more complexity and delay. Furthermore, an incorrect choice of the number of columns can increase the bit and frame error rates. Therefore, it would be advantageous to reconfigure the outer interleaver in different operating environments with the optimum number of columns. Using two different data frame lengths, in this contribution simulation results are presented for the four possible outer block interleaver configurations specified for the 3GPP mobile standard in the case of flat Rayleigh fading channel. It is shown that different operating environments require an optimum number of columns in terms of bit error rate and frame error rate performance. Finally, frame fade duration is considered and the effect of the product of the Doppler frequency with the frame duration on the performance for the four different 3GPP outer block interleaver configurations is discussed. Costas Chaikalis was born in Athens, Greece, on March 7, 1973. He received the B.Sc. degree in electrical engineering in 1995 from Technological Educational Institute of Lamia, Greece. He also received the M.Sc. and Ph.D. degrees from Department of Electronics and Telecommunications, University of Bradford, Bradford, UK in 1999 and 2003, respectively. During his doctoral studies he worked as a Research Assistant for Mobile Virtual Center of Excellence (Mobile VCE), Terminals Group, UK. Since 2003, he is a lecturer in the Department of Electrical Engineering, Technological Educational Institute of Lamia, Greece. His research interests are in all areas of mobile communications but especially in forward error correction coding, reconfigurable (software radio) architectures, cross layer architectures and DSP applications.     

Reconfigurable Microstrip Patch Antenna with Switchable Polarization

A novel reconfigurable microstrip patch antenna with frequency and polarization diversities is proposed. A U‐slot is incorporated into a square patch, and a PIN diode is utilized to switch the slot on and off, which realizes the frequency diversity characteristic. The polarization diversities among linear polarization (LP), right‐hand circular polarization (RHCP), and left‐hand circular polarization (LHCP) are also obtained by switching three PIN diodes on the slot and the truncating corners of a square patch on and off. The antenna design and experimental results are presented.     

基于虚拟可重构平台的时序电路演化设计

目前,电路进化设计是演化硬件研究的主要方向之一。而时序电路由于存在反馈环不便于进行电路描述和软件仿真。文中对时序电路的演化设计方法进行了改进,提出了专门针对时序电路演化的虚拟可重构平台,建立起电路编码与HDL代码的映射关系。应用TEXTIO和MATLAB来辅助仿真测试过程,使测试向量数量巨大、难以处理的问题得到很好地解决。最后调用ModelSim完成了FSM的演化实验。实验结果验证了基于此平台演化时序电路的可行性和有效性。     

可重构电解加工机床研究

电解加工机床通常是根据用户具体需求单机生产，机床研制周期长、设计重复、成本高。为此，提出采用开放式控制系统、模块化思想开发可重构电解机床，并对机床的机械部分、控制系统及通信系统进行了研究。     

A simple planar monopole UWB slot antenna with dual independently and reconfigurable band‐notched characteristics

An extremely simple and compact planar monopole ultrawideband (UWB) slot antenna with dual band‐notched characteristics is proposed. The antenna is composed of a circular radiation patch, a microstrip‐fed line, and a partial ground. By etching an arc‐shaped slot on the radiation patch and a C‐like slot on the feed line, dual notched frequency bands at 3.3–3.7 GHz for WiMAX and 5.15–5.825 GHz for WLAN are achieved. And, the two notched bands can be adjusted independently by varying the length of the slots. Moreover, the band‐notched characteristics can be reconfigurable by shorting the corresponding slots. So, the antenna is capable of operating in one of multiple modes which makes it an excellent candidate for UWB applications. Meanwhile, experimental results indicate that the antenna has an available impendence bandwidth from 2.9 to 11 GHz which covers the UWB frequency band, and nearly omnidirectional patterns, stable gains, small group delay in operating band except rejected bands. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:706–712, 2014.     

企业可重构竞争力系统中和谐思维方式研究

和谐竞争观是企业可重构竞争力系统所固有的组成部分,也是该系统可持续发展的必要条件。认为和谐是企业可重构竞争力系统的特性之一;和谐思维方式促使企业可重构竞争力系统功能得到极大化发挥。结合系统论、复杂科学理论,讨论企业可重构竞争力系统中和谐思维方式是如何体现在各层级之间的和谐关系之中,并且定量分析了和谐度对竞争力系统功能发挥的影响。     

基于CCM的可重构企业信息系统框架设计

从软件重用的角度对企业信息系统进行研究,提出了一种基于CCM的可重构企业信息系统框架。通过对框架的几个重要组成部分的设计出发详细阐述了可重构企业信息系统框架的实现方案,同时通过扩展CCM业务构件中消息和通知服务以实现框架中构件的组装和集成。     

可重构计算在提高数据采集系统容错中的应用

可重构计算技术在数据采集系统中的应用越来越广泛,这不仅得益于可重构计算技术能够更快的对数据进行处理、降低系统能耗,还得益于其可以提高系统的可靠性。该文介绍了如何利用可重构计算技术,提高数据采集系统的容错能力,使数据采集系统在出现硬件故障时能保持正常工作的能力。