Design of integrated circuits: directions and challenges

Several of the dimensions of IC CAE technology are discussed, focusing on two design styles: custom design, used for commodity products such as DRAMs, microprocessors, etc., where large volume production is planned and area reduction and performance maximization can be expected to return large dividends; and the design of application-specific integrated circuits (ASICs), utilizing either very regular, prepatterned silicon arrays customized at the interconnect level or predesigned, parameterized libraries of cells that are usually arranged in rows and interconnected. The design research that will be required in order to attain the objectives of highly automated design systems and shorter product design cycles for integrated circuits are outlined. Metrics for design system performance are discussed     

Resilient network design: challenges and future directions

This paper highlights the complexity and challenges of providing reliable services in the evolving communications infrastructure. The hurdles in providing end-to-end availability guarantees are discussed and research problems identified. Avenues for overcoming some of the challenges examined are presented. This includes the use of a highly available network spine embedded in a physical network together with efficient crosslayer mapping to offer survivability and differentiation of traffic into classes of resilience.     

Fuzzy-based techniques for clustering in wireless sensor networks (WSNs): Recent advances,challenges, and future directions

A wireless sensor network (WSN) is a network of tiny sensors deployed to collect data. These sensors are powered with batteries that have limited power. Recharging and/or replacement of these batteries, however, are not always feasible. Over the past few years, WSN applications are being deployed in diverse fields such as military, manufacturing, healthcare, agriculture, and so on. With the ever-increasing applications of WSNs, improving the energy efficiency of the WSNs still remains to be a challenge. Applying fuzzy logic to the problem of clustering exploits the uncertainty associated with the factors that affect the lifetime of these sensors and enables the development of models that would improve their performance in real-world applications. We present a comprehensive review of various fuzzy-based techniques for clustering in WSNs whose main goal is to optimize energy usage in WSNs while simultaneously improving their overall performance.     

Future challenges and directions for nitride materials and lightemitters

A review is presented of future issues on wide-bandgap group-III nitride materials and device technology for optoelectronic and high-temperature devices such as LEDs     

An approach to sequential circuit diagnosis based on formal verification techniques

This article deals with the generation of exact diagnostic trees for real-size synchronous sequential circuits. Starting from existing detection-oriented test patterns, a modified fault simulator is used for assessing their diagnostic power, which, in general, is not satisfactory. A diagnostic procedure for improving it is described that successfully exploits symbolic FSM equivalence proof algorithms. In order to resort to costly techniques, such as product machine traversal, only when really needed, special checks are performed to verify combinational identity and identity on reachable states. As all faults are attributed to theirequivalence class, a complete and exact diagnostic tree can be built. Experimental results on ISCAS'89 circuits show the feasibility of the approach and support the claim that, for the first time, diagnosing real-world synchronous sequential circuits has become feasible.     

Fixed broadband wireless access: state of the art, challenges, andfuture directions

This article provides an overview of fixed broadband wireless access technology. Focusing on the band below 3 GHz, we describe BWA service and carrier needs, deployment scenarios, architectural requirements, physical layer, medium access control, and radio link protocol requirements. We characterize fixed BWA channels, outline the major challenges of fixed BWA, and study requirements for future BWA systems. Finally, we show that the use of multiple antennas at both ends of a fixed wireless link provides significant leverages     

Cluster-based location service schemes in VANETs: current state,challenges and future directions

Vehicular Ad hoc Networks (VANETs) have drawn incredible interest in both academic and industrial sectors due to their potential applications and services. Vehicles’ position plays a significant role in many location-based applications and services such as public emergency, vehicles tracking, resource discovery, traffic monitoring and position-based routing. A location service is used to keep up-to-date records of current positions of vehicles. However, locating vehicles’ positions and maintaining an accurate view of the entire network are quite challenging tasks due to the high number of nodes, and high and fast nodes mobility which results in rapid topological changes and sudden network disconnections. In the past literature, various location-based services have been proposed to solve the above mentioned issues. Moreover, the cluster-based location service schemes have gained a growing interest due to their advantages over non-cluster-based schemes. The cluster-based schemes improve the network scalability, reduce the communications overhead and resolve the mobility issues within the clusters preventing them from propagating in the whole network. Therefore, this paper presents the taxonomy of the existing location service schemes, inspects the cluster-based location service by highlighting their strengths and limitations, and provides a comparison between location-based clustering and application specific clustering such as the one used in routing, information dissemination, channel access management and security. In addition, the existing clustering schemes, challenges and future directions for efficient cluster-based location service are also discussed.

     

波分复用系统的发展和面临的挑战

密集波分复用系统的发展光纤传输技术在十九世纪就开始出现，但是直到二十世纪后半叶才开始得到迅速发展。WDM系统从二十世纪九十年代中期开始商用，短短的几年时间里使整个电信业发生了翻天覆地的变化。从骨干网、区域网到城域网甚至接入网，WDM技术已被公认为是一种最佳的网络扩容方式。目前，WDM技术已经发展到了相当成熟的阶段，点到点的WDM系统正在大规模商用，信道数从8波发展到160波，单波长信道速率已从2.5Gb/s上升到10Gb/s、正向40Gb/s迈进，基于波长交换的全光网络也逐步开始商用。但是，随着业务量的进一步增长，业务种类…     

On applying molecular computation to binary linear codes

Adleman's (1994) successful solution of a seven-vertex instance of the NP-complete Hamiltonian directed path problem by a DNA algorithm initiated the field of biomolecular computing. In this correspondence, we describe DNA algorithms based on the sticker model to perform encoding, minimum-distance computation, and maximum-likelihood (ML) decoding of binary linear codes. We also discuss feasibility and limitations of the sticker algorithms     

IP resilience within an autonomous system: current approaches, challenges, and future directions

Network survivability is gaining increasing attention from the Internet research community. The ubiquity of IP services has fueled increasing interest in ensuring their dependability, by making IP networks more disruption-tolerant. After providing a brief overview of how routing is accomplished in the Internet, this article reviews how the protocols react to failures or changes in network state within an autonomous system. The problems associated with current restoration schemes, with respect to newer and more stringent requirements posed by emerging services such as voice over IP, are identified. We present an overview of the schemes proposed to ameliorate fault recovery and critique their contributions. We also outline future research directions for improving IP resilience.     

Quality of service provisioning in 802.11e networks: challenges, approaches, and future directions

In order to support diverse application requirements, a new standard called IEEE 802.11e is being proposed to improve quality of service in wireless LAN networks. There are, however, a few remaining challenges that need to be addressed in order to enable comprehensive QoS support using 802.11e. In this article we provide an overview of a few of these challenges, describe their possible impact on QoS, and provide a survey of techniques that potentially could be used to address the identified challenges. Specifically, we focus on three challenges: handling time-varying network conditions, adapting to varying application profiles, and managing link layer resources. Additionally, we present several potential future directions toward improved QoS in wireless networks.     

On applying a minimization technique to the harmonic elimination PWM control: the bipolar waveform

The well-known harmonic elimination pulse-width modulation (HE-PWM) method for inverter control is revisited. The HE-PWM waveform presents many challenges. It has multiple solutions that not only need to be found as easily and as fast as possible, but must also be evaluated in order to identify the best technique when overall harmonic performance is concerned. Algorithms presented so far rely on starting values that are close to the exact solutions to ensure convergence. A new method based on resultant theory promises limited success since it can only work when a small number of harmonics is to be eliminated. In this paper, it is shown that a minimization technique in combination with a random search results in a relatively simple approach that finds all possible sets of solutions. It is confirmed that numerous independent sets of solutions exist and the ones that offer better harmonic performance are identified. Three cases are reported in detail, including when two, four and six nontriplen odd harmonics are to be eliminated.     

医疗保健提供商须了解的应用、分析及IT方向

本文从唯一设备标识、医院物联网、纳米医学、实时医疗保健成本计算和危急状况监视系统五个方面介绍了医疗保健行业的发展和动态.     

Deep learning based physical layer wireless communication techniques:opportunities and challenges

The development of the fifth-generation wireless communications (5G) system is promoted by the high requirements of the high reliability and super-high network capacity.However,existing communication techniques are hard to achieve the high requirements due to the more and more complexity design in 5G system.Currently,deep learning is considered one of effective tools to handle the physical layer wireless communications.Several potential applications based on deep learning were reviewed,and their effectiveness were confirmed.Finally,several potential techniques in deep learning based physical layer wireless communications were pointed out.     

Impact of applying pre-processing techniques for improving classification accuracy

Image denoising is a procedure aimed at removing noise from images while retaining as many important signal features as possible. Many images suffer from poor contrast due to inadequate illumination or finite sensitivity of the imaging device, electronic sensor noise or atmospheric disturbances. This paper proposes a hybrid directional lifting technique for image denoising to retain the original information present in the images. The primary objective of this paper is to show the impact of applying preprocessing techniques for improving classification accuracy. In order to classify the image accurately, effective preservation of edges and contour details of an image is essential. The discrete wavelet transform-based interpolation technique is developed for resolution enhancement. The image is then classified using support vector machine classifier, which is well suitable for image classification. The efficiency of the classifier is analyzed based on receiver operating characteristic (ROC) curves. The quantitative performance measures peak signal to noise ratio and ROC analysis show the significance of the proposed techniques.