业务使能软交换技术在市场的推动下前进

最初的软交换技术在电信领域的商业化应用为VoIP长途电话业务,即C4替代。接着,C5替代和应用使能软交换系统受到关注。前者由于承载和业务开放性方面的限制、业务集成困难和端到端QoS的困难而停滞不前;相比之下,后者却受到了许多中小企业的欢迎。在应用使能软交换的基础上,UT斯达康公司倡导业务使能交换技术,其核心为电信业务网络技术,适用于基于IP的下一代宽带固定多媒体网络和第三代移动多媒体网络。     

Dynamically anchored conferencing handoff for dual-mode cellular/WLAN handsets

In this paper we consider vertical handoff for enterprise-based dual-mode (DM) cellular/WLAN handsets. When the handset roams out of WLAN coverage, the DM's cellular interface is used to maintain the call by anchoring it through an enterprise PSTN gateway/PBX. Soft handoff can be achieved in this case if the gateway supports basic conference bridging, since a new leg of the call can be established to the conference bridge while the existing media stream path is active. Unfortunately this requires that all intra-enterprise calls be routed through the gateway when the call is established. In this paper we consider a SIP based architecture to perform conferenced dual-mode handoff and propose a much more scalable mechanism for short-delay environments, whereby active calls are handed off into the conference bridge prior to the initiation of the vertical handoff. Results are presented which are taken from a dual-mode handset testbed, from analytic models, and from simulations which characterize the scalability of the proposed mechanism. Mohammed Smadi received the B.Eng and Mgmt and M.A.Sc degrees in Computer Engineering from McMaster University in Hamilton, Ontario, Canada. Mohammed received an NSERC doctoral award in 2005 and is currently a Ph.D. student at the Wireless Networking Group at McMaster University. Terence D. Todd received the B.A.Sc, M.A.Sc and Ph.D. degrees in Electrical Engineering from the University of Waterloo, Waterloo, Ontario, Canada. While at Waterloo he spent 3 years as a Research Associate with the Computer Communications Networks Group (CCNG). He is currently a Professor of Electrical and Computer Engineering at McMaster University in Hamilton, Ontario, Canada. Professor Todd spent 1991 on research leave in the Distributed Systems Research Department at AT&T Bell Laboratories in Murray Hill, NJ. He also spent 1998 on research leave at The Olivetti and Oracle Research Laboratory in Cambridge, England. While at ORL he worked on the piconet project which was an early embedded wireless network testbed. Dr. Todd’s research interests include metropolitan/local area networks, wireless communications and the performance analysis of computer communication networks and systems. He is a past Editor of the IEEE/ACM Transactions on Networking and currently holds the NSERC/RIM/CITO Chair on Pico-Cellular Wireless Internet Access Networks. Dr. Todd is a Professional Engineer in the province of Ontario and a member of the IEEE. Vytas Kezys was born in Hamilton, Canada in 1957. He received the B.Eng. degree in Electrical Engineering from McMaster University, Canada, in 1979. From 1979 to 1998, Mr. Kezys was involved in radar and communications research as Principal Research Engineer at the Communications Research Laboratory, McMaster University. While at McMaster, his research activities included array signal processing for low-angle tracking radar, radar signal processing, and smart antennas for wireless communications. Mr. Kezys was founder and President of TalariCom Inc., a start-up company that developed cost effective smart antenna technologies for broadband wireless access applications. Currently, Mr. Kezys is Director of Advanced Products at Research in Motion in Waterloo, Canada. Vahid S. Azhari received his B.S. and M.S. from the Department of Electrical and Computer Engineering, IUST and University of Tehran, Iran, in 2000 and 2003 respectively. His M.S. research focused on designing scheduling algorithms for switch fabrics. He also worked for two years for the Iranian Telecommunication Research Centre on developing software for SDH switches. He is currently pursuing his Ph.D. degree at the Wireless Networking Laboratory, McMaster University, Canada. His main area of research includes handoff management in integrated wireless networks, WLAN deployment techniques, and wireless mesh networks. Dongmei Zhao received the Ph.D. degree in Electrical and Computer Engineering from the University of Waterloo, Waterloo, Ontario, Canada in June 2002. Since July 2002 she has been with the Department of Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada where she is an assistant professor. Dr. Zhao’s research interests include modeling and performance analysis, quality-of-service provisioning, access control and admission control in wireless cellular networks and integrated cellular and ad hoc networks. Dr. Zhao is a member of the IEEE.     

汇川技术HD92高压变频器在皮带机多电机功率平衡上的应用

本文介绍了汇川HD92皮带机专用高压变频器在宁夏某煤矿主井(斜井)皮带机上的应用并从电气原理、性能、节能分析等各方面对高压变频器在皮带机上的应用做总结     

Soft error modeling and remediation techniques in ASIC designs

Soft errors due to cosmic radiations are the main reliability threat during lifetime operation of digital systems. Fast and accurate estimation of soft error rate (SER) is essential in obtaining the reliability parameters of a digital system in order to balance reliability, performance, and cost of the system. Previous techniques for SER estimation are mainly based on fault injection and random simulations. In this paper, we present an analytical SER modeling technique for ASIC designs that can significantly reduce SER estimation time while achieving very high accuracy. This technique can be used for both combinational and sequential circuits. We also present an approach to obtain uncertainty bounds on estimated error propagation probability (EPP) values used in our SER modeling framework. Comparison of this method with the Monte-Carlo fault injection and simulation approach confirms the accuracy and speed-up of the presented technique for both the computed EPP values and uncertainty bounds.Based on our SER estimation framework, we also present efficient soft error hardening techniques based on selective gate resizing to maximize soft error suppression for the entire logic-level design while minimizing area and delay penalties. Experimental results confirm that these techniques are able to significantly reduce soft error rate with modest area and delay overhead.     

A new approach to cell size scaling with a multi-dual cell and a buffer/background programming of unified RAM

New investigations are presented here on a high-density and DRAM-like high-speed non-volatile memory (NVM) application of unified RAM (URAM). For a high-density application of URAM, multiple data storage is demonstrated with a multi-dual cell (MDC). Because each NVM state can be split by programming with a one-transistor (1T) DRAM without a capacitor, the total number of memory states can be doubled. Furthermore, a high-speed DRAM-level NVM scheme is proposed for the joint operation of 1T DRAM buffer programming and NVM post-background programming. The MDC and the proposed scheme are unique URAM properties that can extend the application range of memory devices.     

Coronary Artery Stenosis Quantification for Computed Tomography Angiography Based on Modified Student's t‐Mixture Model

Coronary artery disease (CAD) is a major cause of death in the world. As a non‐invasive imaging modality, computed tomography angiography (CTA) is now usually used in clinical practice for CAD diagnosis. Precise quantification of coronary stenosis is of great interest for diagnosis and treatment planning. In this paper, a novel cluster method based on a Modified Student's t‐Mixture Model is applied to separate the region of vessel lumen from other tissues. Then, the area of the vessel lumen in each slice is computed and the estimated value of it is fitted with a curve. Finally, the location and the level of the most stenoses are captured by comparing the calculated and fitted areas of the vessel. The proposed method has been applied to 17 clinical CTA datasets and the results have been compared with reference standard degrees of stenosis defined by an expert. The results of the experiment indicate that the proposed method can accurately quantify the stenosis of the coronary artery in CTA.     

Nonlinear disturbance observers for robotic continuum manipulators

Robots are an indispensable part of modern production lines. Usually working in designated areas, they are separated from human workers in order to avoid collisions. A safe collaborative work environment is enabled by so-called soft robots, which constitute a human-friendly alternative to classical rigid industrial robots. However, modeling soft robots proves difficult and results in a lack of accuracy for control tasks. In this contribution, a disturbance observer-based control is proposed in order to improve tracking behavior. In doing so, unknown model errors are considered as disturbances and estimated by an observer. This estimate is used to actively reject the perturbation. Different disturbance observers are designed and implemented for a soft quasi-continuum manipulator, amongst them two nonlinear disturbance observers and two extended state observers. The distinction in the versions of the same observation concept lies in the disturbance dynamics assumption, which is either considered static or as a damped double integrator. All implemented concepts combined with a PD control show superior performance compared to an existing benchmark concept based on PID-like control. Thanks to the modularity of this approach, disturbance observers can be further investigated in combination with other control strategies.     

基于迭代并行干扰消除的低复杂度大规模MIMO信号检测算法

基于干扰消除思想该文提出一种适用于大规模MIMO系统上行链路的低复杂度迭代并行干扰消除算法,在算法实现中避免了线性检测算法所需的高复杂度$({\cal O}({K^3}))$矩阵求逆运算,将复杂度保持在$({\cal O}({K^2}))$。在此基础上,引入噪声预测机制,提出一种基于噪声预测的迭代并行干扰消除算法,进一步提高了硬判决检测性能。考虑天线间残留干扰,将干扰消除思想运用到软判决中,最后提出一种基于迭代并行干扰消除的低复杂度软输出信号检测算法。仿真结果表明：提出的信号检测方法的复杂度优于MMSE检测算法,经过几次简单的迭代,算法即快速收敛并获得接近甚至优于MMSE检测算法的误码率性能。     

High performance energy efficient radiation hardened latch for low voltage applications

Energy efficiency is considered to be the most critical design parameter for IoT and other ultra low power applications. However, energy efficient circuits show a lesser immunity against soft error, because of the smaller device node capacitances in nanoscale technologies and near-threshold voltage operation. Due to these reasons, the tolerance of the sequential circuits to SEUs is an important consideration in nanoscale near threshold CMOS design. This paper presents an energy efficient SEU tolerant latch. The proposed latch improves the SEU tolerance by using a clocked Muller- C and memory elements based restorer circuit. The parasitic extracted simulations using STMicroelectronics 65 nm CMOS technology show that by employing the proposed latch, an average improvement of ∼40% in energy delay product (EDP), is obtained over the recently reported latch. Moreover, the proposed latch is also validated in a TCAD calibrated PTM 32 nm framework and PTM 22 nm CMOS technology nodes. In 32 nm and 22 nm technologies, the proposed latch improves the EDP ∼12% and 59% over existing latches respectively.     

基于PR信道的BCJR检测

为了满足磁盘存储系统的高数据传输速率和高数据存储密度的需求,造成数字序列之间产生的码间干扰成为接收端获得可靠信息的主要阻碍。本文是以部分响应信号作为离散时间的ISI信道模型,采用基于MAP算法的对数域BCJR（log—MAP）算法进行信道检测。文章介绍了PR信道的模型,对算法的检测原理进行理论分析,并给出几种不同的部分响应信道下的计算机仿真。结果表明该算法能有效地对ISI信道进行检测,能应用于磁记录系统。