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Most Cited Digital Communications and Networks Articles

The most cited articles published since 2015, extracted from Scopus.

The challenges of M2M massive access in wireless cellular networks

Volume 1, Issue 1, February 2015, Pages 1-19
Andrea Biral | Marco Centenaro | Andrea Zanella | Lorenzo Vangelista | Michele Zorzi

© 2015 The Authors The next generation of communication systems, which is commonly referred to as 5G, is expected to support, besides the traditional voice and data services, new communication paradigms, such as Internet of Things (IoT) and Machine-to-Machine (M2M) services, which involve communication between Machine-Type Devices (MTDs) in a fully automated fashion, thus, without or with minimal human intervention. Although the general requirements of 5G systems are progressively taking shape, the technological issues raised by such a vision are still partially unclear. Nonetheless, general consensus has been reached upon some specific challenges, such as the need for 5G wireless access networks to support massive access by MTDs, as a consequence of the proliferation of M2M services. In this paper, we describe the main challenges raised by the M2M vision, focusing in particular on the problems related to the support of massive MTD access in current cellular communication systems. Then we analyze the most common approaches proposed in the literature to enable the coexistence of conventional and M2M services in the current and next generation of cellular wireless systems. We finally conclude by pointing out the research challenges that require further investigation in order to provide full support to the M2M paradigm.

Joint duplex mode selection, channel allocation, and power control for full-duplex cognitive femtocell networks

Volume 1, Issue 1, February 2015, Pages 30-44
Mingjie Feng | Shiwen Mao | Tao Jiang

© 2015 The Authors In this paper, we aim to maximize the sum rate of a full-duplex cognitive femtocell network (FDCFN) as well as guaranteeing the quality of service (QoS) of users in the form of a required signal to interference plus noise ratios (SINR). We first consider the case of a pair of channels, and develop optimum-achieving power control solutions. Then, for the case of multiple channels, we formulate joint duplex model selection, power control, and channel allocation as a mixed integer nonlinear problem (MINLP), and propose an iterative framework to solve it. The proposed iterative framework consists of a duplex mode selection scheme, a near-optimal distributed power control algorithm, and a greedy channel allocation algorithm. We prove the convergence of the proposed iterative framework as well as a lower bound for the greedy channel allocation algorithm. Numerical results show that the proposed schemes effectively improve the sum rate of FDCFNs.

Optical power allocation for adaptive transmissions in wavelength-division multiplexing free space optical networks

Volume 1, Issue 3, August 2015, Pages 171-180
Hui Zhou | Hui Zhou | Shiwen Mao | Prathima Agrawal

© 2015 The Authors Attracting increasing attention in recent years, the Free Space Optics (FSO) technology has been recognized as a cost-effective wireless access technology for multi-Gigabit rate wireless networks. Radio on Free Space Optics (RoFSO) provides a new approach to support various bandwidth-intensive wireless services in an optical wireless link. In an RoFSO system using wavelength-division multiplexing (WDM), it is possible to concurrently transmit multiple data streams consisting of various wireless services at very high rate. In this paper, we investigate the problem of optical power allocation under power budget and eye safety constraints for adaptive WDM transmission in RoFSO networks. We develop power allocation schemes for adaptive WDM transmissions to combat the effect of weather turbulence on RoFSO links. Simulation results show that WDM RoFSO can support high data rates even over long distance or under bad weather conditions with an adequate system design.

Visible light communication: Applications, architecture, standardization and research challenges

Volume 3, Issue 2, May 2017, Pages 78-88
Latif Ullah Khan

© 2016 Chongqing University of Posts and Telecommuniocations The Radio Frequency (RF) communication suffers from interference and high latency issues. Along with this, RF communication requires a separate setup for transmission and reception of RF waves. Overcoming the above limitations, Visible Light Communication (VLC) is a preferred communication technique because of its high bandwidth and immunity to interference from electromagnetic sources. The revolution in the field of solid state lighting leads to the replacement of florescent lamps by Light Emitting Diodes (LEDs) which further motivates the usage of VLC. This paper presents a survey of the potential applications, architecture, modulation techniques, standardization and research challenges in VLC.

Cognitive assisted living ambient system: a survey

Volume 1, Issue 4, November 2015, Pages 229-252
Ruijiao Li | Ruijiao Li | Bowen Lu | Bowen Lu | Klaus D. McDonald-Maier

© 2015 The Authors The demographic change towards an aging population is creating a significant impact and introducing drastic challenges to our society. We therefore need to find ways to assist older people to stay independently and prevent social isolation of these population. Information and Communication Technologies (ICT) provide various solutions to help older adults to improve their quality of life, stay healthier, and live independently for a time. Ambient Assisted Living (AAL) is a field to investigate innovative technologies to provide assistance as well as healthcare and rehabilitation to impaired seniors. The paper provides a review of research background and technologies of AAL.

3D depth image analysis for indoor fall detection of elderly people

Volume 2, Issue 1, February 2016, Pages 24-34
Lei Yang | Lei Yang | Yanyun Ren | Wenqiang Zhang

© 2015 The Authors This paper presents a new fall detection method of elderly people in a room environment based on shape analysis of 3D depth images captured by a Kinect sensor. Depth images are pre-processed by a median filter both for background and target. The silhouette of moving individual in depth images is achieved by a subtraction method for background frames. The depth images are converted to disparity map, which is obtained by the horizontal and vertical projection histogram statistics. The initial floor plane information is obtained by V disparity map, and the floor plane equation is estimated by the least square method. Shape information of human subject in depth images is analyzed by a set of moment functions. Coefficients of ellipses are calculated to determine the direction of individual. The centroids of the human body are calculated and the angle between the human body and the floor plane is calculated. When both the distance from the centroids of the human body to the floor plane and the angle between the human body and the floor plane are lower than some thresholds, fall incident will be detected. Experiments with different falling direction are performed. Experimental results show that the proposed method can detect fall incidents effectively.

A review on radio based activity recognition

Volume 1, Issue 1, February 2015, Pages 20-29
Shuangquan Wang | Shuangquan Wang | Gang Zhou

© 2015 The Authors Recognizing human activities in their daily living enables the development and widely usage of human-centric applications, such as health monitoring, assisted living, etc. Traditional activity recognition methods often rely on physical sensors (camera, accelerometer, gyroscope, etc.) to continuously collect sensor readings, and utilize pattern recognition algorithms to identify user׳s activities at an aggregator. Though traditional activity recognition methods have been demonstrated to be effective in previous work, they raise some concerns such as privacy, energy consumption and deployment cost. In recent years, a new activity recognition approach, which takes advantage of body attenuation and/or channel fading of wireless radio, has been proposed. Compared with traditional activity recognition methods, radio based methods utilize wireless transceivers in environments as infrastructure, exploit radio communication characters to achieve high recognition accuracy, reduce energy cost and preserve user׳s privacy. In this paper, we divide radio based methods into four categories: ZigBee radio based activity recognition, WiFi radio based activity recognition, RFID radio based activity recognition, and other radio based activity recognition. Some existing work in each category is introduced and reviewed in detail. Then, we compare some representative methods to show their advantages and disadvantages. At last, we point out some future research directions of this new research topic.

Bio-signal based control in assistive robots: a survey

Volume 1, Issue 2, April 2015, Pages 85-101
Ericka Janet Rechy-Ramirez | Huosheng Hu

© 2015 The Authors Recently, bio-signal based control has been gradually deployed in biomedical devices and assistive robots for improving the quality of life of disabled and elderly people, among which electromyography (EMG) and electroencephalography (EEG) bio-signals are being used widely. This paper reviews the deployment of these bio-signals in the state of art of control systems. The main aim of this paper is to describe the techniques used for (i) collecting EMG and EEG signals and diving these signals into segments (data acquisition and data segmentation stage), (ii) dividing the important data and removing redundant data from the EMG and EEG segments (feature extraction stage), and (iii) identifying categories from the relevant data obtained in the previous stage (classification stage). Furthermore, this paper presents a summary of applications controlled through these two bio-signals and some research challenges in the creation of these control systems. Finally, a brief conclusion is summarized.

Joint optimization of spectrum and energy efficiency in cognitive radio networks

Volume 1, Issue 3, August 2015, Pages 161-170
Shaowei Wang | Chonggang Wang

© 2015 The Authors In this paper, we discuss the joint improvement of the energy efficiency (EE) and the spectrum efficiency (SE) in OFDM-based cognitive radio (CR) networks. A multi-objective resource allocation task is formulated to optimize the EE and the SE of the CR system simultaneously with the consideration of the mutual interference and the spectrum sensing errors. We first exploit the EE–SE relations and demonstrate that the EE is a quasiconcave function of the SE, based on which the Pareto optimal set of the multi-objective optimization problem is characterized. To find a unique globally optimal solution, we propose a unified EE–SE tradeoff metric to transform the multi-objective optimization problem into a single-objective one which has a D.C. (difference of two convex functions/sets) structure and yields a standard convex optimization problem. We derive a fast method to speed up the time-consuming computation by exploiting the structure of the convex problem. Simulation results validate the effectiveness and efficiency of the proposed algorithms, which can produce the unique globally optimal solution of the original multi-objective optimization problem.

Topology control of tactical wireless sensor networks using energy efficient zone routing

Volume 2, Issue 1, February 2016, Pages 1-14
Preetha Thulasiraman | Kevin A. White

© 2016 The Authors The US Department of Defense (DoD) routinely uses wireless sensor networks (WSNs) for military tactical communications. Sensor node die-out has a significant impact on the topology of a tactical WSN. This is problematic for military applications where situational data is critical to tactical decision making. To increase the amount of time all sensor nodes remain active within the network and to control the network topology tactically, energy efficient routing mechanisms must be employed. In this paper, we aim to provide realistic insights on the practical advantages and disadvantages of using established routing techniques for tactical WSNs. We investigate the following established routing algorithms: direct routing, minimum transmission energy (MTE), Low Energy Adaptive Cluster Head routing (LEACH), and zone clustering. Based on the node die out statistics observed with these algorithms and the topological impact the node die outs have on the network, we develop a novel, energy efficient zone clustering algorithm called EZone. Via extensive simulations using MATLAB, we analyze the effectiveness of these algorithms on network performance for single and multiple gateway scenarios and show that the EZone algorithm tactically controls the topology of the network, thereby maintaining significant service area coverage when compared to the other routing algorithms.

Pheromone based alternative route planning

Volume 2, Issue 3, August 2016, Pages 151-158
Liangbing Feng | Liangbing Feng | Zhihan Lv | Gengchen Guo | Houbing Song

© 2016 Chongqing University of Posts and Telecommuniocations In this work, we propose an improved alternative route calculation based on alternative figures, which is suitable for practical environments. The improvement is based on the fact that the main traffic route is the road network skeleton in a city. Our approach using nodes may generate a higher possibility of overlapping. We employ a bidirectional Dijkstra algorithm to search the route. To measure the quality of an Alternative Figures (AG), three quotas are proposed. The experiment results indicate that the improved algorithm proposed in this paper is more effective than others.

Recent progress on high-speed optical transmission

Volume 2, Issue 2, May 2016, Pages 65-76
Jianjun Yu | Junwen Zhang | Junwen Zhang

© 2016 Chongqing University of Posts and Telecommuniocations The recently reported high spectral efficiency (SE) and high-baud-rate signal transmission are all based on digital coherent optical communications and digital signal processing (DSP). DSP simplifies the reception of advanced modulation formats and also enables the major electrical and optical impairments to be processed and compensated in the digital domain, at the transmitter or receiver side. In this paper, we summarize the research progress on high-speed signal generation and detection and also show the progress on DSP for high-speed signal detection. We also report the latest progress on multi-core and multi-mode multiplexing.

An efficient hybrid protection scheme with shared/dedicated backup paths on elastic optical networks

Volume 3, Issue 1, February 2017, Pages 11-18
Nogbou G. Anoh | Nogbou G. Anoh | Nogbou G. Anoh | Michel Babri | Ahmed D. Kora | Ahmed D. Kora | Roger M. Faye | Boko Aka | Claude Lishou

© 2016 Chongqing University of Posts and Telecommuniocations Fast recovery and minimum utilization of resources are the two main criteria for determining the protection scheme quality. We address the problem of providing a hybrid protection approach on elastic optical networks under contiguity and continuity of available spectrum constraints. Two main hypotheses are used in this paper for backup paths computation. In the first case, it is assumed that backup paths resources are dedicated. In the second case, the assumption is that backup paths resources are available shared resources. The objective of the study is to minimize spectrum utilization to reduce blocking probability on a network. For this purpose, an efficient survivable Hybrid Protection Lightpath (HybPL) algorithm is proposed for providing shared or dedicated backup path protection based on the efficient energy calculation and resource availability. Traditional First-Fit and Best-Fit schemes are employed to search and assign the available spectrum resources. The simulation results show that HybPL presents better performance in terms of blocking probability, compared with the Minimum Resources Utilization Dedicated Protection (MRU-DP) algorithm which offers better performance than the Dedicated Protection (DP) algorithm.

A survey of free space optical networks

Volume 3, Issue 2, May 2017, Pages 67-77
In Keun Son | Shiwen Mao

© 2017 Chongqing University of Posts and Telecommuniocations Free Space Optical (FSO) networks, also known as optical wireless networks, have emerged as viable candidates for broadband wireless communications in the near future. The range of the potential application of FSO networks is extensive, from home to satellite. However, FSO networks have not been popularized because of insufficient availability and reliability. Researchers have focused on the problems in the physical layer in order to exploit the properties of wireless optical channels. However, recent technological developments with successful results make it practical to explore the advantages of the high bandwidth. Some researchers have begun to focus on the problems of network and upper layers in FSO networks. In this survey, we classify prospective global FSO networks into three subnetworks and give an account of them. We also present state-of-the-art research and discuss what kinds of challenges exist.

Providing healthcare services on-the-fly using multi-player cooperation game theory in Internet of Vehicles (IoV) environment

Volume 1, Issue 3, August 2015, Pages 191-203
Neeraj Kumar | Kuljeet Kaur | Anish Jindal | Joel J.P.C. Rodrigues | Joel J.P.C. Rodrigues

© 2015 The Authors Internet of Vehicles (IoV) is a leading technology of the present era. It has gained huge attention with respect to its implementation in wide variety of domains ranging from traffic safety to infotainment applications. However, IoV can also be extended to healthcare domain, where the patients can be provided healthcare services on-the-fly. We extend this novel concept in this paper and refer it as “Healthcare services on-the-fly”. The concept of game theory has been used among the vehicles to access the healthcare services while traveling. The vehicles act as players in the game and tend to form and split coalitions to access these services. Learning automata (LA) act as the players for interaction with the environment and take appropriate actions based on reward and penalty. Apart from this, Virtual Machine (VM) scheduling algorithm for efficient utilization of resources at cloud level has also been formulated. A stochastic reward net (SRN)-based model is used to represent the coalition formation and splitting with respect to availability of resources at cloud level. The performance of the proposed scheme is evaluated using various performance evaluation metrics. The results obtained prove the effectiveness of the proposed scheme in comparison to the best, first, and random fit schemes.

Scalable privacy-preserving big data aggregation mechanism

Volume 2, Issue 3, August 2016, Pages 122-129
Dapeng Wu | Boran Yang | Ruyan Wang

© 2016 Chongqing University of Posts and Telecommuniocations As the massive sensor data generated by large-scale Wireless Sensor Networks (WSNs) recently become an indispensable part of ‘Big Data’, the collection, storage, transmission and analysis of the big sensor data attract considerable attention from researchers. Targeting the privacy requirements of large-scale WSNs and focusing on the energy-efficient collection of big sensor data, a Scalable Privacy-preserving Big Data Aggregation (Sca-PBDA) method is proposed in this paper. Firstly, according to the pre-established gradient topology structure, sensor nodes in the network are divided into clusters. Secondly, sensor data is modified by each node according to the privacy-preserving configuration message received from the sink. Subsequently, intra- and inter-cluster data aggregation is employed during the big sensor data reporting phase to reduce energy consumption. Lastly, aggregated results are recovered by the sink to complete the privacy-preserving big data aggregation. Simulation results validate the efficacy and scalability of Sca-PBDA and show that the big sensor data generated by large-scale WSNs is efficiently aggregated to reduce network resource consumption and the sensor data privacy is effectively protected to meet the ever-growing application requirements.

Sarcastic sentiment detection in tweets streamed in real time: a big data approach

Volume 2, Issue 3, August 2016, Pages 108-121
S. K. Bharti | B. Vachha | R. K. Pradhan | K. S. Babu | S. K. Jena

© 2016 Chongqing University of Posts and Telecommuniocations Sarcasm is a type of sentiment where people express their negative feelings using positive or intensified positive words in the text. While speaking, people often use heavy tonal stress and certain gestural clues like rolling of the eyes, hand movement, etc. to reveal sarcastic. In the textual data, these tonal and gestural clues are missing, making sarcasm detection very difficult for an average human. Due to these challenges, researchers show interest in sarcasm detection of social media text, especially in tweets. Rapid growth of tweets in volume and its analysis pose major challenges. In this paper, we proposed a Hadoop based framework that captures real time tweets and processes it with a set of algorithms which identifies sarcastic sentiment effectively. We observe that the elapse time for analyzing and processing under Hadoop based framework significantly outperforms the conventional methods and is more suited for real time streaming tweets.

Improving routing efficiency through intermediate target based geographic routing

Volume 1, Issue 3, August 2015, Pages 204-212
Zongming Fei | Jianjun Yang | Hui Lu

© 2015 The Authors The greedy strategy of geographical routing may cause the local minimum problem when there is a hole in the routing area. It depends on other strategies such as perimeter routing to find a detour path, which can be long and result in inefficiency of the routing protocol. In this paper, we propose a new approach called Intermediate Target based Geographic Routing (ITGR) to solve the long detour path problem. The basic idea is to use previous experience to determine the destination areas that are shaded by the holes. The novelty of the approach is that a single forwarding path can be used to determine a shaded area that may cover many destination nodes. We design an efficient method for the source to find out whether a destination node belongs to a shaded area. The source then selects an intermediate node as the tentative target and greedily forwards packets to it, which in turn forwards the packet to the final destination by greedy routing. ITGR can combine multiple shaded areas to improve the efficiency of representation and routing. We perform simulations and demonstrate that ITGR significantly reduces the routing path length, compared with existing geographic routing protocols.

Modeling and performance analysis for composite network–compute service provisioning in software-defined cloud environments

Volume 1, Issue 3, August 2015, Pages 181-190
Qiang Duan

© 2015 The Authors The crucial role of networking in Cloud computing calls for a holistic vision of both networking and computing systems that leads to composite network–compute service provisioning. Software-Defined Network (SDN) is a fundamental advancement in networking that enables network programmability. SDN and software-defined compute/storage systems form a Software-Defined Cloud Environment (SDCE) that may greatly facilitate composite network–compute service provisioning to Cloud users. Therefore, networking and computing systems need to be modeled and analyzed as composite service provisioning systems in order to obtain thorough understanding about service performance in SDCEs. In this paper, a novel approach for modeling composite network–compute service capabilities and a technique for evaluating composite network–compute service performance are developed. The analytic method proposed in this paper is general and agnostic to service implementation technologies; thus is applicable to a wide variety of network–compute services in SDCEs. The results obtained in this paper provide useful guidelines for federated control and management of networking and computing resources to achieve Cloud service performance guarantees.

Automatic gear sorting system based on monocular vision

Volume 1, Issue 4, November 2015, Pages 284-291
Wenqi Wu | Xingang Wang | Guan Huang | De Xu

© 2015 The Authors An automatic gear sorting system based on monocular vision is proposed in this paper. A CCD camera fixed on the top of the sorting system is used to obtain the images of the gears on the conveyor belt. The gears׳ features including number of holes, number of teeth and color are extracted, which is used to categorize the gears. Photoelectric sensors are used to locate the gears׳ position and produce the trigger signals for pneumatic cylinders. The automatic gear sorting is achieved by using pneumatic actuators to push different gears into their corresponding storage boxes. The experimental results verify the validity and reliability of the proposed method and system.

Development of a hospital mobile platform for logistics tasks

Volume 1, Issue 2, April 2015, Pages 102-111
Carlos Antonio Acosta Calderon | Elara Rajesh Mohan | Buck Sin Ng

© 2015 The Authors Healthcare services heavily rely on healthcare staff and subsequently, there is the need to improve healthcare staff׳s workflow. The deployment of an automated mobile base will help enhance the productivity of logistics tasks in the hospital, like collection and delivery. By improving such logistic tasks healthcare personal is able to focus on other tasks to serve the community better. Currently there are commercial solutions to deal with these logistic tasks, where a mobile base is able to move from one place to another in a structured environment like a hospital. In this paper, we present our approach to develop a cost effective mobile base to be used for delivery in healthcare amenities. The proposed approach is able to navigate among stations in the hospital by first creating a map of the floor and then indicating the location of these stations. This reduces the additional cost of drawing lines on the floor or to put laser markers and many of the commercial solutions required. In addition, the proposed solution is able to navigate while being safe for the people moving around and to the transported items. The paper discusses the design consideration of the system, the navigation and the battery management to ensure that the system is able to run autonomously without the need recharge often.

A roadmap for security challenges in the Internet of Things

Volume 4, Issue 2, April 2018, Pages 118-137
Arbia Riahi Sfar | Arbia Riahi Sfar | Enrico Natalizio | Yacine Challal | Zied Chtourou

© 2017 The Authors Unquestionably, communicating entities (object, or things) in the Internet of Things (IoT) context are playing an active role in human activities, systems and processes. The high connectivity of intelligent objects and their severe constraints lead to many security challenges, which are not included in the classical formulation of security problems and solutions. The Security Shield for IoT has been identified by DARPA (Defense Advanced Research Projects Agency) as one of the four projects with a potential impact broader than the Internet itself. To help interested researchers contribute to this research area, an overview of the IoT security roadmap overview is presented in this paper based on a novel cognitive and systemic approach. The role of each component of the approach is explained, we also study its interactions with the other main components, and their impact on the overall. A case study is presented to highlight the components and interactions of the systemic and cognitive approach. Then, security questions about privacy, trust, identification, and access control are discussed. According to the novel taxonomy of the IoT framework, different research challenges are highlighted, important solutions and research activities are revealed, and interesting research directions are proposed. In addition, current standardization activities are surveyed and discussed to the ensure the security of IoT components and applications.

Building technology platform aimed to develop service robot with embedded personality and enhanced communication with social environment

Volume 1, Issue 2, April 2015, Pages 112-124
Aleksandar Rodić | Miloš Jovanović | Ilija Stevanović | Branko Karan | Veljko Potkonjak

© 2015 The Authors The paper is addressed to prototyping of technology platform aimed to develop of ambient-aware human-centric indoor service robot with attributes of emotional intelligence to enhance interaction with social environment. The robot consists of a wheel-based mobile platform with spinal (segmented) torso, bi-manual manipulation system with multi-finger robot hands and robot head. Robot prototype was designed to see, hear, speak and use its multimodal interface for enhanced communication with humans. Robot is capable of demonstrating its affective and social behavior by using audio and video interface as well as body gestures. Robot is equipped with advanced perceptive system based on heterogeneous sensorial system, including laser range finder, ultrasonic distance sensors and proximity detectors, 3-axis inertial sensor (accelerometer and gyroscope), stereo vision system, 2 wide-range microphones, and 2 loudspeakers. The device is foreseen to operate autonomously but it may be also operated remotely from a host computer through wireless communication link as well as by use of a smart-phone based on advanced client-server architecture. Robot prototype has embedded attributes of artificial intelligence and utilizes advanced cognitive capabilities such as spatial reasoning, obstacle and collision avoidance, simultaneous localization and mapping, etc. Robot is designed in a manner to enable uploading of new or changing existing algorithms of emotional intelligence that should provide to robot human-like affective and social behavior. The key objective of the project presented in the paper regards to building advanced technology platform for research and development of personal robots aimed to use for different purpose, e.g. robot-entertainer, battler, robot for medical care, security robot, etc. In a word, the designed technology platform is expected to help in development human-centered service robots to be used at home, in the office, public institutions, etc.

Big data-enabled multiscale serviceability analysis for aging bridges

Volume 2, Issue 3, August 2016, Pages 97-107
Yu Liang | Dalei Wu | Guirong Liu | Yaohang Li | Cuilan Gao | Zhongguo John Ma | Weidong Wu

© 2016 Chongqing University of Posts and Telecommuniocations This work is dedicated to constructing a multi-scale structural health monitoring system to monitor and evaluate the serviceability of bridges based on the Hadoop Ecosystem (MS-SHM-Hadoop). By taking the advantages of the fault-tolerant distributed file system called the Hadoop Distributed File System (HDFS) and high-performance parallel data processing engine called MapReduce programming paradigm, MS-SHM-Hadoop features include high scalability and robustness in data ingestion, fusion, processing, retrieval, and analytics. MS-SHM-Hadoop is a multi-scale reliability analysis framework, which ranges from nationwide bridge-surveys, global structural integrity analysis, and structural component reliability analysis. This Nationwide bridge survey uses deep-learning techniques to evaluate the bridge serviceability according to real-time sensory data or archived bridge-related data such as traffic status, weather conditions and bridge structural configuration. The global structural integrity analysis of a targeted bridge is made by processing and analyzing the measured vibration signals incurred by external loads such as wind and traffic flow. Component-wise reliability analysis is also enabled by the deep learning technique, where the input data is derived from the measured structural load effects, hyper-spectral images, and moisture measurement of the structural components. As one of its major contributions, this work employs a Bayesian network to formulate the integral serviceability of a bridge according to its components serviceability and inter-component correlations. Here the inter-component correlations are jointly specified using a statistics-oriented machine learning method (e.g., association rule learning) or structural mechanics modeling and simulation.

Hop-by-hop Content Distribution with Network Coding in Multihop Wireless Networks

Volume 3, Issue 1, February 2017, Pages 47-54
Rami Halloush | Hang Liu | Lijun Dong | Mingquan Wu | Hayder Radha

© 2016 Chongqing University of Posts and Telecommuniocations The predominant use of today's networks is content access and distribution. Network Coding (NC) is an innovative technique that has potential to improve the efficiency of multicast content distribution over multihop Wireless Mesh Networks (WMNs) by allowing intermediate Forwarding Nodes (FNs) to encode and then forward data packets. Practical protocols are needed to realize the benefits of the NC technique. However, the existing NC-based multicast protocols cannot accurately determine the minimum number of coded packets that a FN should send in order to ensure successful data delivery to the destinations, so that many redundant packets are injected into the network, leading to performance degradation. In this paper, we propose HopCaster, a novel reliable multicast protocol that incorporates network coding with hop-by-hop transport. HopCaster completely eliminates the need for estimating the number of coded packets to be transmitted by a FN, and avoids redundant packet transmissions. It also effectively addresses the challenges of heterogeneous multicast receivers. Moreover, a cross-layer multicast rate adaptation mechanism is proposed, which enables HopCaster to optimize multicast throughput by dynamically adjusting wireless transmission rate based on the changes in the receiver population and channel conditions during the course of multicasting a coded data chunk. Our evaluations show that HopCaster significantly outperforms the existing NC-based multicast protocols.

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