Iris recognition: an emerging biometric technology

This paper examines automated iris recognition as a biometrically based technology for personal identification and verification. The motivation for this endeavor stems from the observation that the human iris provides a particularly interesting structure on which to base a technology for noninvasive biometric assessment. In particular the biomedical literature suggests that irises are as distinct as fingerprints or patterns of retinal blood vessels. Further, since the iris is an overt body, its appearance is amenable to remote examination with the aid of a machine vision system. The body of this paper details issues in the design and operation of such systems. For the sake of illustration, extant systems are described in some amount of detail     

GMPLS controlled ethernet: an emerging packet-oriented transport technology

Most of the world?s traffic is now packetbased. While SONET/SDH transport technology continues to evolve, there are now major standardization efforts to develop a native packet-oriented transport technology. Ethernet, long dominant in the enterprise, is one of the fastest developing technologies for the transport layer. GMPLS, based on mature signaling and routing protocols, is gaining traction as a transport control plane, providing fast restoration and supporting automation of provisioning. We will briefly highlight recent Ethernet standardization and then introduce the concepts and standards work allowing GMPLS to control Ethernet.     

Cableless LANs: An emerging technology

During the last year, the concept of Wireless Communications received enormous attention in the trade and financial journals worldwide. Unfortunately, as often occurs, everything from high-performance LANs to cordless telephones is being lumped together, creating a great deal of confusion in the user community. So as not to add to that confusion, it should be made clear that this article deals exclusively with wireless systems for data communications.     

A model of market entry in an emerging technology market

The timing of market entry is a critical decision, involving the need to balance the risk of premature entry with the problems of missed opportunities as a result of late entry. Drawing from several theoretical perspectives, we propose a model for explaining the reasons for early or delayed entry into an emerging technology market. A novel feature of our study is the use of a hazard modeling framework to analyze longitudinal data pertaining to over 3500 entrants and nonentrants during the emergence of the automated teller machine market. This approach alleviates the sample selection problems associated with prior entry research. With caution in generalizing the results to other settings, we find compelling evidence in support of the model, extending our knowledge of the dynamics surrounding entry into certain technology markets.     

Power electronics-an emerging technology

The author presents a tutorial review of power electronics and drives in which the status of the technology and its future are discussed. He focuses on power semiconductor devices, converter circuits, AC machine control, and microcomputer applications in power electronics systems. He examines the impact of computer-aided design and artificial intelligence, and he summarizes the technological trends. He predicts that the technology will grow with increasing momentum as component technologies continue to grow     

EEGBRP: an energy-efficient grid-based routing protocol for underwater wireless sensor networks

Wireless Networks - Underwater sensor networks (UWSN) include a set of sensor nodes equipped with limited batteries. These batteries are not rechargeable and replacement of them is difficult and...     

EMGGR: an energy-efficient multipath grid-based geographic routing protocol for underwater wireless sensor networks

Routing in underwater wireless sensor networks (UWSN) is an important and a challenging activity due to the nature of acoustic channels and to the harsh environment. This paper extends our previous work [Al-Salti et al. in Proceedings of cyber-enabled distributed computing and knowledge discovery (CyberC), Shanghai, pp 331–336, 2014] that proposed a novel multipath grid-based geographical routing (MGGR) protocol for UWSNs. The extended work, EMGGR, viewed the network as logical 3D grids. Routing is performed in a grid-by-grid manner via gateways that use disjoint paths to relay data packets to the sink node. The algorithm consists of three main components: (1) a gateway election algorithm; responsible for electing gateways based on their locations and remaining energy level (2) a mechanism for updating neighboring gateways’ information; allowing sensor nodes to memorize gateways in local and neighboring cells, and (3) a packet forwarding mechanism; in charge of constructing disjoint paths from source cells to destination cells, forwarding packets to the destination and dealing with holes (i.e. cells with no gateways) in the network. The performance of EMGGR has been assessed using Aqua-Sim, which is an NS2 based simulator for UWSNs. Results show that EMGGR is an energy efficient protocol in all simulation setups used in the study. Moreover, EMGGR can also maintain good delivery ratio and end-to-end delay.

     

Superconductivity: fact vs. fancy

The two-part special report discusses the recently developed high-temperature superconducting ceramics. The first part describes promising processing advances and examines concerns about critical current density and brittleness. Both problems present a serious roadblock to practical use of these materials. The second part investigates the more interesting and feasible applications, which appear to be several years away. An accompanying box insert on theory explains what is known about superconductivity in these ceramics     

Connectivity in emerging regions: the need for improved technology and business models

The digital divide is a pressing challenge for both technology and policy professionals. Connectivity is one aspect of the divide, albeit an important one. Availability and affordability remain important issues, but these depend on not only technology choices, but also business and regulatory models. While mobile phones have achieved spectacular growth in emerging regions, Internet access, especially broadband, lags far behind. A generalized model of costing broadband indicates that limited uplinking (interconnection) is a significant barrier to widespread and affordable connectivity, but last mile access also remains a challenge. In addition, policy distortions and regulations raise costs dramatically. Because of these, new technologies, business models, and regulations may be required to make connectivity available and affordable in emerging economies. These include advanced wireless technologies, greater fiber utilization, and open access networking     

Magnetic bubbles—An emerging new memory technology

Magnetic bubbles-an emerging storage technique-promise to bridge the capacity-data retrieval time gap left vacant by magnetic core and semiconductor devices on one side and the electromechanical magnetic tape and disk on the other. Improvements in bubble materials, circuit processing, and device design have advanced bubble technology to where it is a solid candidate for applications requiring 10⁶-10⁸bits and retrieval times less than 0.005 s. Bubble chips as large as 65 kbits are currently under development. In this paper, the reader is first introduced to the topics of bubble statics and bubble dynamics, including a discussion of hard bubbles. Next, the operation of bubble devices such as propagation, generation, detection, and replication is described, as well as chip organizations using these functions. Temperature plays an important role and its effect on domain generation and data longevity is described. Fabrication techniques for bubble chips used in prototype mass memory modules and an experimental memory for a repertory telephone are given as are the overall systems' performance. Details of a 32-pin dual in-line bubble package are described. Finally, some predictions into the future are attempted for this technology. This discussion includes self-structuring propagation of bubbles and the bubble lattice file memory concept.     

Rapid thermal magnetic annealing as an emerging technology in field-annealing of thin magnetic films for recording heads

An emerging field where rapid thermal processing (RTP) is now rapidly finding its first acceptance is in the industrial manufacturing of thin-film head devices for magnetic recording. Here soft-magnetic thin-film flux guide structures (usually composed of high-moment alloys containing iron, etc.) are applied onto ceramic substrate wafers (such as Al₂O₃–TiC) of sizes up to 150 mm and subsequently ‘activated' by heating and cooling in a magnetic field.We assessed the advantages of rapid thermal magnetic annealing (RTMA) in a new prototype reactor with an external electromagnet, capable of generating an extremely homogeneous magnetic field of 660 Oe (52.8 kA/m) with field lines parallel across the entire wafer area (150 mm in diameter). Samples with 1 μm thick amorphous iron-alloy layers (Fe₇₇Nb₁₁N₁₀Si₂) sputter-deposited onto ceramic substrates of single-crystalline GGG-garnet (Gd₃Ga₅O₁₂) were conventionally annealed and RTMA-annealed in N₂/H₂ at temperatures between 550 and 700°C. Structural analysis by transmission electron microscopy (TEM) and electron diffraction showed that the enhanced performance of the RTMA-annealed layers is due to the different nanocrystallization kinetics induced by the fast heating and cooling rates of RTMA.The ceramic substrate materials normally used in head manufacturing (such as Al₂O₃–TiC) have favorable grey-body properties with high emissivity (≥0.7) over a wide range of temperatures (25–700°C) and wavelengths (1.5–10 μm), which excludes the difficulties encountered in pyrometric temperature control of infrared-transparent substrates such as silicon. We conclude that RTMA yields superior soft-magnetic materials, where throughput numbers of ≥30 wafers/h are possible.     

U-blox 5 GPS方案

U-blox 5 50通道芯片组和模块于2006年推出,基于改进的CMOS技术,显著缩小了芯片尺寸,可以进行大量并行卫星搜索.     

EEDOS: an energy-efficient and delay-aware offloading scheme based on device to device collaboration in mobile edge computing

Telecommunication Systems - Device to device (D2D) communication and mobile edge computing (MEC) are two promising technologies in fifth generation (5G) cellular mobile communication. Besides MEC,...     

The energy-efficient implementation of an adaptive-filtering-based QRS complex detection method for wearable devices

Electrocardiogram (ECG) can be used as a valid way for diagnosing heart disease. To fulfill ECG processing in wearable devices by reducing computation complexity and hardware cost, two kinds of adaptive filters are designed to perform QRS complex detection and motion artifacts removal, respectively. The proposed design achieves a sensitivity of 99.49% and a positive predictivity of 99.72%, tested under the MIT-BIH ECG database. The proposed design is synthesized under the SMIC 65-nm CMOS technology and verified by post-synthesis simulation. Experimental results show that the power consumption and area cost of this design are of 160 μW and 1.09×10⁵ μm², respectively.     

基于共享树的能量优化多播路由算法

为了延长多播中共享树的工作时间,要求尽量减少节点的能量消耗。利用基于共享树的能量优化的分布式多播路由算法D-REMiT,能够降低共享树的总能耗和延长共享树的使用寿命。模拟结果显示,D-REMiT算法付出很少的共享树总能耗代价,大大提高了共享树的生存时间,有较好的收敛性,比已有的算法G-REMiT更适用于自组网环境。