Scheduled System Maintenance:
On May 6th, single article purchases and IEEE account management will be unavailable from 8:00 AM - 5:00 PM ET (12:00 - 21:00 UTC). We apologize for the inconvenience.
By Topic

Popular Articles (March 2015)

Includes the top 50 most frequently downloaded documents for this publication according to the most recent monthly usage statistics.
  • 1. Information Security in Big Data: Privacy and Data Mining

    Publication Year: 2014 , Page(s): 1149 - 1176
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (14013 KB) |  | HTML iconHTML  

    The growing popularity and development of data mining technologies bring serious threat to the security of individual,'s sensitive information. An emerging research topic in data mining, known as privacy-preserving data mining (PPDM), has been extensively studied in recent years. The basic idea of PPDM is to modify the data in such a way so as to perform data mining algorithms effectively without compromising the security of sensitive information contained in the data. Current studies of PPDM mainly focus on how to reduce the privacy risk brought by data mining operations, while in fact, unwanted disclosure of sensitive information may also happen in the process of data collecting, data publishing, and information (i.e., the data mining results) delivering. In this paper, we view the privacy issues related to data mining from a wider perspective and investigate various approaches that can help to protect sensitive information. In particular, we identify four different types of users involved in data mining applications, namely, data provider, data collector, data miner, and decision maker. For each type of user, we discuss his privacy concerns and the methods that can be adopted to protect sensitive information. We briefly introduce the basics of related research topics, review state-of-the-art approaches, and present some preliminary thoughts on future research directions. Besides exploring the privacy-preserving approaches for each type of user, we also review the game theoretical approaches, which are proposed for analyzing the interactions among different users in a data mining scenario, each of whom has his own valuation on the sensitive information. By differentiating the responsibilities of different users with respect to security of sensitive information, we would like to provide some useful insights into the study of PPDM. View full abstract»

    Open Access
  • 2. Millimeter Wave Mobile Communications for 5G Cellular: It Will Work!

    Publication Year: 2013 , Page(s): 335 - 349
    Cited by:  Papers (74)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (14815 KB) |  | HTML iconHTML  

    The global bandwidth shortage facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks. There is, however, little knowledge about cellular mm-wave propagation in densely populated indoor and outdoor environments. Obtaining this information is vital for the design and operation of future fifth generation cellular networks that use the mm-wave spectrum. In this paper, we present the motivation for new mm-wave cellular systems, methodology, and hardware for measurements and offer a variety of measurement results that show 28 and 38 GHz frequencies can be used when employing steerable directional antennas at base stations and mobile devices. View full abstract»

    Open Access
  • 3. A Survey on Internet of Things From Industrial Market Perspective

    Publication Year: 2014 , Page(s): 1660 - 1679
    Subject Categories: Communications technology;  Consumer electronics;  Systems, man, and cybernetics
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (29963 KB) |  | HTML iconHTML  

    The Internet of Things (IoT) is a dynamic global information network consisting of Internet-connected objects, such as radio frequency identifications, sensors, and actuators, as well as other instruments and smart appliances that are becoming an integral component of the Internet. Over the last few years, we have seen a plethora of IoT solutions making their way into the industry marketplace. Context-aware communications and computing have played a critical role throughout the last few years of ubiquitous computing and are expected to play a significant role in the IoT paradigm as well. In this paper, we examine a variety of popular and innovative IoT solutions in terms of context-aware technology perspectives. More importantly, we evaluate these IoT solutions using a framework that we built around well-known context-aware computing theories. This survey is intended to serve as a guideline and a conceptual framework for context-aware product development and research in the IoT paradigm. It also provides a systematic exploration of existing IoT products in the marketplace and highlights a number of potentially significant research directions and trends. View full abstract»

    Open Access
  • 4. 3D Printing for the Rapid Prototyping of Structural Electronics

    Publication Year: 2014 , Page(s): 234 - 242
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (8749 KB) |  | HTML iconHTML  

    In new product development, time to market (TTM) is critical for the success and profitability of next generation products. When these products include sophisticated electronics encased in 3D packaging with complex geometries and intricate detail, TTM can be compromised - resulting in lost opportunity. The use of advanced 3D printing technology enhanced with component placement and electrical interconnect deposition can provide electronic prototypes that now can be rapidly fabricated in comparable time frames as traditional 2D bread-boarded prototypes; however, these 3D prototypes include the advantage of being embedded within more appropriate shapes in order to authentically prototype products earlier in the development cycle. The fabrication freedom offered by 3D printing techniques, such as stereolithography and fused deposition modeling have recently been explored in the context of 3D electronics integration - referred to as 3D structural electronics or 3D printed electronics. Enhanced 3D printing may eventually be employed to manufacture end-use parts and thus offer unit-level customization with local manufacturing; however, until the materials and dimensional accuracies improve (an eventuality), 3D printing technologies can be employed to reduce development times by providing advanced geometrically appropriate electronic prototypes. This paper describes the development process used to design a novelty six-sided gaming die. The die includes a microprocessor and accelerometer, which together detect motion and upon halting, identify the top surface through gravity and illuminate light-emitting diodes for a striking effect. By applying 3D printing of structural electronics to expedite prototyping, the development cycle was reduced from weeks to hours. View full abstract»

    Open Access
  • 5. Big Data Deep Learning: Challenges and Perspectives

    Publication Year: 2014 , Page(s): 514 - 525
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (3976 KB) |  | HTML iconHTML  

    Deep learning is currently an extremely active research area in machine learning and pattern recognition society. It has gained huge successes in a broad area of applications such as speech recognition, computer vision, and natural language processing. With the sheer size of data available today, big data brings big opportunities and transformative potential for various sectors; on the other hand, it also presents unprecedented challenges to harnessing data and information. As the data keeps getting bigger, deep learning is coming to play a key role in providing big data predictive analytics solutions. In this paper, we provide a brief overview of deep learning, and highlight current research efforts and the challenges to big data, as well as the future trends. View full abstract»

    Open Access
  • 6. Challenges of System-Level Simulations and Performance Evaluation for 5G Wireless Networks

    Publication Year: 2014 , Page(s): 1553 - 1561
    Subject Categories: Communications technology;  Computers and information processing
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (7185 KB) |  | HTML iconHTML  

    With the evaluation and simulation of long-term evolution/4G cellular network and hot discussion about new technologies or network architecture for 5G, the appearance of simulation and evaluation guidelines for 5G is in urgent need. This paper analyzes the challenges of building a simulation platform for 5G considering the emerging new technologies and network architectures. Based on the overview of evaluation methodologies issued for 4G candidates, challenges in 5G evaluation are formulated. Additionally, a cloud-based two-level framework of system-level simulator is proposed to validate the candidate technologies and fulfill the promising technology performance identified for 5G. View full abstract»

    Open Access
  • 7. Device-to-Device Communications for National Security and Public Safety

    Publication Year: 2014 , Page(s): 1510 - 1520
    Subject Categories: Communications technology;  Vehicular and wireless technologies
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (19642 KB) |  | HTML iconHTML  

    Device-to-device (D2D) communications have been proposed as an underlay to long-term evolution (LTE) networks as a means of harvesting the proximity, reuse, and hop gains. However, D2D communications can also serve as a technology component for providing public protection and disaster relief (PPDR) and national security and public safety (NSPS) services. In the United States, for example, spectrum has been reserved in the 700-MHz band for an LTE-based public safety network. The key requirement for the evolving broadband PPDR and NSPS services capable systems is to provide access to cellular services when the infrastructure is available and to efficiently support local services even if a subset or all of the network nodes become dysfunctional due to public disaster or emergency situations. This paper reviews some of the key requirements, technology challenges, and solution approaches that must be in place in order to enable LTE networks and, in particular, D2D communications, to meet PPDR and NSPS-related requirements. In particular, we propose a clustering-procedure-based approach to the design of a system that integrates cellular and ad hoc operation modes depending on the availability of infrastructure nodes. System simulations demonstrate the viability of the proposed design. The proposed scheme is currently considered as a technology component of the evolving 5G concept developed by the European 5G research project METIS. View full abstract»

    Open Access
  • 8. A biped gait learning algorithm for humanoid robots based on environmental impact assessed artificial bee colony

    Publication Year: 2015 , Page(s): 13 - 26
    Subject Categories: Computational and artificial intelligence;  Robotics and automation
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (49938 KB) |  | HTML iconHTML  

    Gait pattern performance is a very important issue in the field of humanoid robots, and more and more researchers are now engaged in such studies. However, the tuning processes of the parameters or postures are very tedious and time-consuming. In order to solve this problem, an artificial bee colony (ABC) learning algorithm for a central pattern generator (CPG) gait produce method is proposed in this paper. Furthermore, the fitness of the bee colony is considered through environmental impact assessment, and it is also estimated from the cause of colony collapse disorder from the results of recent investigations in areas, such as pesticides, electromagnetic waves, viruses, and the timing confusion of the bee colony caused by climate change. Each environmental disaster can be considered by its adjustable weighting values. In addition, the developed biped gait learning method is called the ABC-CPG algorithm, and it was verified in a self-developed high-integration simulator. The strategy systems, motion control system, and gait learning system of the humanoid robot are also integrated through the proposed 3-D simulator. Finally, the experimental results show that the proposed environmental-impact-assessed ABC-CPG gait learning algorithm is feasible and can also successfully achieve the best gait pattern in the humanoid robot. View full abstract»

    Open Access
  • 9. Big Data and the SP Theory of Intelligence

    Publication Year: 2014 , Page(s): 301 - 315
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (2233 KB) |  | HTML iconHTML  

    This paper is about how the SP theory of intelligence and its realization in the SP machine may, with advantage, be applied to the management and analysis of big data. The SP system-introduced in this paper and fully described elsewhere-may help to overcome the problem of variety in big data; it has potential as a universal framework for the representation and processing of diverse kinds of knowledge, helping to reduce the diversity of formalisms and formats for knowledge, and the different ways in which they are processed. It has strengths in the unsupervised learning or discovery of structure in data, in pattern recognition, in the parsing and production of natural language, in several kinds of reasoning, and more. It lends itself to the analysis of streaming data, helping to overcome the problem of velocity in big data. Central in the workings of the system is lossless compression of information: making big data smaller and reducing problems of storage and management. There is potential for substantial economies in the transmission of data, for big cuts in the use of energy in computing, for faster processing, and for smaller and lighter computers. The system provides a handle on the problem of veracity in big data, with potential to assist in the management of errors and uncertainties in data. It lends itself to the visualization of knowledge structures and inferential processes. A high-parallel, open-source version of the SP machine would provide a means for researchers everywhere to explore what can be done with the system and to create new versions of it. View full abstract»

    Open Access
  • 10. Integration of SDR and SDN for 5G

    Publication Year: 2014 , Page(s): 1196 - 1204
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (7850 KB) |  | HTML iconHTML  

    Wireless networks have evolved from 1G to 4G networks, allowing smart devices to become important tools in daily life. The 5G network is a revolutionary technology that can change consumers' Internet use habits, as it creates a truly wireless environment. It is faster, with better quality, and is more secure. Most importantly, users can truly use network services anytime, anywhere. With increasing demand, the use of bandwidth and frequency spectrum resources is beyond expectations. This paper found that the frequency spectrum and network information have considerable relevance; thus, spectrum utilization and channel flow interactions should be simultaneously considered. We considered that software defined radio (SDR) and software defined networks (SDNs) are the best solution. We propose a cross-layer architecture combining SDR and SDN characteristics. As the simulation evaluation results suggest, the proposed architecture can effectively use the frequency spectrum and considerably enhance network performance. Based on the results, suggestions are proposed for follow-up studies on the proposed architecture. View full abstract»

    Open Access
  • 11. Algorithms for Smartphone and Tablet Image Analysis for Healthcare Applications

    Publication Year: 2014 , Page(s): 831 - 840
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (3885 KB) |  | HTML iconHTML  

    Smartphones and tablets are finding their way into healthcare delivery to the extent that mobile health (mHealth) has become an identifiable field within eHealth. In prior work, a mobile app to document chronic wounds and wound care, specifically pressure ulcers (bedsores) was developed for Android smartphones and tablets. One feature of the mobile app allowed users to take images of the wound using the smartphone or tablet's integrated camera. In a user trial with nurses at a personal care home, this feature emerged as a key benefit of the mobile app. This paper developed image analysis algorithms that facilitate noncontact measurements of irregularly shaped images (e.g., wounds), where the image is taken with a sole smartphone or tablet camera. The image analysis relies on the sensors integrated in the smartphone or tablet with no auxiliary or add-on instrumentation on the device. Three approaches to image analysis were developed and evaluated: 1) computing depth using autofocus data; 2) a custom sensor fusion of inertial sensors and feature tracking in a video stream; and 3) a custom pinch/zoom approach. The pinch/zoom approach demonstrated the strongest potential and thus developed into a fully functional prototype complete with a measurement mechanism. While image analysis is a very well developed field, this paper contributes to image analysis applications and implementation in mHealth, specifically for wound care. View full abstract»

    Open Access
  • 12. Recent Progress on C-RAN Centralization and Cloudification

    Publication Year: 2014 , Page(s): 1030 - 1039
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (14055 KB) |  | HTML iconHTML  

    This paper presents the latest progress on cloud RAN (C-RAN) in the areas of centralization and virtualization. A C-RAN system centralizes the baseband processing resources into a pool and virtualizes soft base-band units on demand. The major challenges for C-RAN including front-haul and virtualization are analyzed with potential solutions proposed. Extensive field trials verify the viability of various front-haul solutions, including common public radio interface compression, single fiber bidirection and wavelength-division multiplexing. In addition, C-RANs facilitation of coordinated multipoint (CoMP) implementation is demonstrated with 50%-100% uplink CoMP gain observed in field trials. Finally, a test bed is established based on general purpose platform with assisted accelerators. It is demonstrated that this test bed can support multi-RAT, i.e., Time-Division Duplexing Long Term Evolution, Frequency-Division Duplexing Long Term Evolution, and Global System for Mobile Communications efficiently and presents similar performance to traditional systems. View full abstract»

    Open Access
  • 13. A Low-Cost Open-Source Metal 3-D Printer

    Publication Year: 2013 , Page(s): 803 - 810
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (14571 KB) |  | HTML iconHTML  

    Technical progress in the open-source self replicating rapid prototyper (RepRap) community has enabled a distributed form of additive manufacturing to expand rapidly using polymer-based materials. However, the lack of an open-source metal alternative and the high capital costs and slow throughput of proprietary commercialized metal 3-D printers has severely restricted their deployment. The applications of commercialized metal 3-D printers are limited to only rapid prototyping and expensive finished products. This severely restricts the access of the technology for small and medium enterprises, the developing world and for use in laboratories. This paper reports on the development of a open-source metal 3-D printer. The metal 3-D printer is controlled with an open-source micro-controller and is a combination of a low-cost commercial gas-metal arc welder and a derivative of the Rostock, a deltabot RepRap. The bill of materials, electrical and mechanical design schematics, and basic construction and operating procedures are provided. A preliminary technical analysis of the properties of the 3-D printer and the resultant steel products are performed. The results of printing customized functional metal parts are discussed and conclusions are drawn about the potential for the technology and the future work necessary for the mass distribution of this technology. View full abstract»

    Open Access
  • 14. Some Fundamental Cybersecurity Concepts

    Publication Year: 2014 , Page(s): 116 - 124
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (549 KB) |  | HTML iconHTML  

    The results of successful hacking attacks against commercially available cybersecurity protection tools that had been touted as secure are distilled into a set of concepts that are applicable to many protection planning scenarios. The concepts, which explain why trust in those systems was misplaced, provides a framework for both analyzing known exploits and also evaluating proposed protection systems for predicting likely potential vulnerabilities. The concepts are: 1) differentiating security threats into distinct classes; 2) a five layer model of computing systems; 3) a payload versus protection paradigm; and 4) the nine Ds of cybersecurity, which present practical defensive tactics in an easily remembered scheme. An eavesdropping risk, inherent in many smartphones and notebook computers, is described to motivate improved practices and demonstrate real-world application of the concepts to predicting new vulnerabilities. Additionally, the use of the nine Ds is demonstrated as analysis tool that permits ranking of the expected effectiveness of some potential countermeasures. View full abstract»

    Open Access
  • 15. A Neo-Reflective Wrist Pulse Oximeter

    Publication Year: 2014 , Page(s): 1562 - 1567
    Subject Categories: Biomedical Engineering;  Signal processing
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (10809 KB) |  | HTML iconHTML  

    This paper relates to a genuine wrist pulse oximeter, which is a noninvasive medical device that can measure the pulse rate and oxygen saturation level in a person's blood. The device is novel due to its innovative design. It is a new type of reflective oximeter, which has a concave structure for housing the optical source and sensor. The neo-reflective sensor module of the device is designed to send the sensor data to a nearby intelligent mobile phone using wireless data transmission. The pulse oximeter has been developed and calibrated, and the calibration curve was analyzed. The innovative design of this pulse oximeter would enable the user to wear the low-cost device on one wrist continuously throughout the day, without the inconvenience of a conventional finger pulse oximeter. View full abstract»

    Open Access
  • 16. Radio interface evolution towards 5G and enhanced local area communications

    Publication Year: 2014 , Page(s): 1005 - 1029
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (17343 KB) |  | HTML iconHTML  

    The exponential growth of mobile data in macronetworks has driven the evolution of communications systems toward spectrally efficient, energy efficient, and fast local area communications. It is a well-known fact that the best way to increase capacity in a unit area is to introduce smaller cells. Local area communications are currently mainly driven by the IEEE 802.11 WLAN family being cheap and energy efficient with a low number of users per access point. For the future high user density scenarios, following the 802.11 HEW study group, the 802.11ax project has been initiated to improve the WLAN system performance. The 3GPP LTE-advanced (LTE-A) also includes new methods for pico and femto cell's interference management functionalities for small cell communications. The main problem with LTE-A is, however, that the physical layer numerology is still optimized for macrocells and not for local area communications. Furthermore, the overall complexity and the overheads of the control plane and reference symbols are too large for spectrally and energy efficient local area communications. In this paper, we provide first an overview of WLAN 802.11ac and LTE/LTE-A, discuss the pros and cons of both technology areas, and then derive a new flexible TDD-based radio interface parametrization for 5G local area communications combining the best practices of both WiFi and LTE-A technologies. We justify the system design based on local area propagation characteristics and expected traffic distributions and derive targets for future local area concepts. We concentrate on initial physical layer design and discuss how it maps to higher layer improvements. This paper shows that the new design can significantly reduce the latency of the system, and offer increased sleeping opportunities on both base station and user equipment sides leading to enhanced power savings. In addition, through careful design of the control overhead, we are able to improve the channel utilization when compared- with LTE-A. View full abstract»

    Open Access
  • 17. Physical Layer Authentication via Fingerprint Embedding Using Software-Defined Radios

    Publication Year: 2015 , Page(s): 81 - 88
    Subject Categories: Communications technology;  Computers and information processing;  Signal processing
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (7712 KB) |  | HTML iconHTML  

    The use of fingerprint embedding at the physical layer enables a receiver to authenticate a transmitter by detecting a low-power authentication tag superimposed upon the message waveform; a theoretical framework for such fingerprinting has been outlined. We carry out single-carrier single-antenna software defined radio (SDR) experiments with a wireless communications link over which we transmit and receive packets with the embedded fingerprinting. We analyze these experimental results and find they match well with theoretical predictions. This paper demonstrates that the method of superimposed fingerprints can deliver high probability of authentication without additional bandwidth and with minimal impact on bit-error rate in SDR systems. View full abstract»

    Open Access
  • 18. A Modeling Framework for Studying Quantum Key Distribution System Implementation Nonidealities

    Publication Year: 2015 , Page(s): 110 - 130
    Subject Categories: Communications technology;  Photonics
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (11554 KB) |  | HTML iconHTML  

    Quantum key distribution (QKD) is an innovative technology that exploits the laws of quantum mechanics to generate and distribute unconditionally secure shared key for use in cryptographic applications. However, QKD is a relatively nascent technology where real-world system implementations differ significantly from their ideal theoretical representations. In this paper, we introduce a modeling framework built upon the OMNeT++ discrete event simulation framework to study the impact of implementation nonidealities on QKD system performance and security. Specifically, we demonstrate the capability to study the device imperfections and practical engineering limitations through the modeling and simulation of a polarization-based, prepare and measure BB84 QKD reference architecture. The reference architecture allows users to model and study complex interactions between physical phenomenon and system-level behaviors representative of real-world design and implementation tradeoffs. Our results demonstrate the flexibility of the framework to simulate and evaluate current, future, and notional QKD protocols and components. View full abstract»

    Open Access
  • 19. Circularly Polarized Patch Antenna for Future 5G Mobile Phones

    Publication Year: 2014 , Page(s): 1521 - 1529
    Subject Categories: Antennas and propagation;  Communications technology
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (8622 KB) |  | HTML iconHTML  

    A circularly polarized patch antenna for future fifth-generation mobile phones is presented in this paper. Miniaturization and beamwidth enhancement of a patch antenna are the two main areas to be discussed. By folding the edge of the radiating patch with loading slots, the size of the patch antenna is 44.8% smaller than a conventional half wavelength patch, which allows it to be accommodated inside handsets easily. Wide beamwidth is obtained by surrounding the patch with a dielectric substrate and supporting the antenna by a metallic block. A measured half power beamwidth of 124° is achieved. The impedance bandwidth of the antenna is over 10%, and the 3-dB axial ratio bandwidth is 3.05%. The proposed antenna covers a wide elevation angle and complete azimuth range. A parametric study of the effect of the metallic block and the surrounding dielectric substrate on the gain at a low elevation angle and the axial ratio of the proposed antenna are presented. View full abstract»

    Open Access
  • 20. Cognitive Control: Theory and Application

    Publication Year: 2014 , Page(s): 698 - 710
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (2411 KB) |  | HTML iconHTML  

    From an engineering point-of-view, cognitive control is inspired by the prefrontal cortex of the human brain; cognitive control may therefore be viewed as the overarching function of a cognitive dynamic system. In this paper, we describe a new way of thinking about cognitive control that embodies two basic components: learning and planning, both of which are based on two notions: 1) two-state model of the environment and the perceptor and 2) perception-action cycle, which is a distinctive characteristic of the cognitive dynamic system. Most importantly, it is shown that the cognitive control learning algorithm is a special form of Bellman's dynamic programming. Distinctive properties of the new algorithm include the following: 1) optimality of performance; 2) algorithmic convergence to optimal policy; and 3) linear law of complexity measured in terms of the number of actions taken by the cognitive controller on the environment. To validate these intrinsic properties of the algorithm, a computational experiment is presented, which involves a cognitive tracking radar that is known to closely mimic the visual brain. The experiment illustrates two different scenarios: 1) the impact of planning on learning curves of the new cognitive controller and 2) comparison of the learning curves of three different controllers, based on dynamic optimization, traditional (Q) -learning, and the new algorithm. The latter two algorithms are based on the two-state model, and they both involve the use of planning. View full abstract»

    Open Access
  • 21. Biometric Antispoofing Methods: A Survey in Face Recognition

    Publication Year: 2014 , Page(s): 1530 - 1552
    Subject Categories: Computational and artificial intelligence;  Signal processing
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (10682 KB) |  | HTML iconHTML  

    In recent decades, we have witnessed the evolution of biometric technology from the first pioneering works in face and voice recognition to the current state of development wherein a wide spectrum of highly accurate systems may be found, ranging from largely deployed modalities, such as fingerprint, face, or iris, to more marginal ones, such as signature or hand. This path of technological evolution has naturally led to a critical issue that has only started to be addressed recently: the resistance of this rapidly emerging technology to external attacks and, in particular, to spoofing. Spoofing, referred to by the term presentation attack in current standards, is a purely biometric vulnerability that is not shared with other IT security solutions. It refers to the ability to fool a biometric system into recognizing an illegitimate user as a genuine one by means of presenting a synthetic forged version of the original biometric trait to the sensor. The entire biometric community, including researchers, developers, standardizing bodies, and vendors, has thrown itself into the challenging task of proposing and developing efficient protection methods against this threat. The goal of this paper is to provide a comprehensive overview on the work that has been carried out over the last decade in the emerging field of antispoofing, with special attention to the mature and largely deployed face modality. The work covers theories, methodologies, state-of-the-art techniques, and evaluation databases and also aims at providing an outlook into the future of this very active field of research. View full abstract»

    Open Access
  • 22. New and Emerging Energy Sources for Implantable Wireless Microdevices

    Publication Year: 2015 , Page(s): 89 - 98
    Subject Categories: Biomedical Engineering;  Nanotechnology;  Power electronics;  Sensors
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (33605 KB) |  | HTML iconHTML  

    In this paper, we review new and emerging energy sources for wireless implantable microdevices. After a brief historical background, we review the developments in power sources in the decades following the pioneering works of Zworykin and Mackay in the late 1950s. These include deployment of lithium batteries and inductive powering in the 1970s, which resulted in significant growth and commercialization of implantable medical devices, such as cardiac pacemakers and cochlear implants. Recent research in nanoscale materials for energy generation has created intriguing possibilities for next generation implantable power sources in the form of flexible and biodegradable batteries and supercapacitors. In addition, energy harvesting/remote powering from various environmental physical and chemical sources within the body utilizing nanoscale materials can also offer unique possibilities for autonomous implantable microscale and nanoscale devices. View full abstract»

    Open Access
  • 23. Potentials and Challenges of C-RAN Supporting Multi-RATs Toward 5G Mobile Networks

    Publication Year: 2014 , Page(s): 1187 - 1195
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (5050 KB) |  | HTML iconHTML  

    This paper presents an overview of the cloud radio access network (C-RAN), which is a key enabler for future mobile networks in order to meet the explosive capacity demand of mobile traffic, and reduce the capital and operating expenditure burden faced by operators. We start by reviewing the requirements of future mobile networks, called 5G, followed by a discussion on emerging network concepts for 5G network architecture. Then, an overview of C-RAN and related works are presented. As a significant scenario of a 5G system, the ultra dense network deployment based on C-RAN is discussed with focuses on flexible backhauling, automated network organization, and advanced mobility management. Another import feature of a 5G system is the long-term coexistence of multiple radio access technologies (multi-RATs). Therefore, we present some directions and preliminary thoughts for future C-RAN-supporting Multi-RATs, including joint resource allocation, mobility management, as well as traffic steering and service mapping. View full abstract»

    Open Access
  • 24. Lightweight mobile core networks for machine type communications

    Publication Year: 2014 , Page(s): 1128 - 1137
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (7106 KB) |  | HTML iconHTML  

    Machine type communications (MTCs) enable the communications of machines (devices) to machines over mobile networks. Besides simplifying our daily lives, the MTC business represents a promising market for mobile operators to increase their revenues. However, before a complete deployment of MTC over mobile networks, there is need to update the specifications of mobile networks in order to cope with the expected high number (massive deployment) of MTC devices. Indeed, large scale deployment of MTC devices represents an important challenge as a high number of MTC devices, simultaneously connecting to the mobile network, may cause congestion and system overload, which can degrade the network performance and even result in network node failures. Several activities have been led by 3GPP to alleviate system overload introduced by MTC. Most of the devised approaches represent only incremental solutions. Unlike these solutions, we devise a complete new architectural vision to support MTC in mobile networks. This vision relies on the marriage of mobile networks and cloud computing, specifically exploiting recent advances in network function virtualization (NFV). The aim of the proposed vision, namely LightEPC, is: 1) to orchestrate the on-demand creation of cloud-based lightweight mobile core networks dedicated for MTC and 2) to simplify the network attach procedure for MTC devices by creating only one NFV MTC function that groups all the usual procedures. By doing so, LightEPC is able to create and scale instances of NFV MTC functions on demand and in an elastic manner to cope with any sudden increase in traffic generated by MTC devices. To evaluate LightEPC, some preliminary analysis were conducted and the obtained analytical results indicate the ability of LightEPC in alleviating congestion and scaling up fast with massive numbers of MTC devices in mobile networks. Finally, a real-life implementation of LightEPC on top of cloud platform is discussed. View full abstract»

    Open Access
  • 25. Confidentiality-Preserving Image Search: A Comparative Study Between Homomorphic Encryption and Distance-Preserving Randomization

    Publication Year: 2014 , Page(s): 125 - 141
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1186 KB) |  | HTML iconHTML  

    Recent years have seen increasing popularity of storing and managing personal multimedia data using online services. Preserving confidentiality of online personal data while offering efficient functionalities thus becomes an important and pressing research issue. In this paper, we study the problem of content-based search of image data archived online while preserving content confidentiality. The problem has different settings from those typically considered in the secure computation literature, as it deals with data in rank-ordered search, and has a different security-efficiency requirement. Secure computation techniques, such as homomorphic encryption, can potentially be used in this application, at a cost of high computational and communication complexity. Alternatively, efficient techniques based on randomizing visual feature and search indexes have been proposed recently to enable similarity comparison between encrypted images. This paper focuses on comparing these two major paradigms of techniques, namely, homomorphic encryption-based techniques and feature/index randomization-based techniques, for confidentiality-preserving image search. We develop novel and systematic metrics to quantitatively evaluate security strength in this unique type of data and applications. We compare these two paradigms of techniques in terms of their search performance, security strength, and computational efficiency. The insights obtained through this paper and comparison will help design practical algorithms appropriate for privacy-aware cloud multimedia systems. View full abstract»

    Open Access
  • 26. Sparse Signal Processing Concepts for Efficient 5G System Design

    Publication Year: 2015 , Page(s): 195 - 208
    Subject Categories: Communications technology;  Signal processing
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (7914 KB) |  | HTML iconHTML  

    As it becomes increasingly apparent that 4G will not be able to meet the emerging demands of future mobile communication systems, the question what could make up a 5G system, what are the crucial challenges, and what are the key drivers is part of intensive, ongoing discussions. Partly due to the advent of compressive sensing, methods that can optimally exploit sparsity in signals have received tremendous attention in recent years. In this paper, we will describe a variety of scenarios in which signal sparsity arises naturally in 5G wireless systems. Signal sparsity and the associated rich collection of tools and algorithms will thus be a viable source for innovation in 5G wireless system design. We will also describe applications of this sparse signal processing paradigm in Multiple Input Multiple Output random access, cloud radio access networks, compressive channel-source network coding, and embedded security. We will also emphasize an important open problem that may arise in 5G system design, for which sparsity will potentially play a key role in their solution. View full abstract»

    Open Access
  • 27. Rethinking the Data Center Networking: Architecture, Network Protocols, and Resource Sharing

    Publication Year: 2014 , Page(s): 1481 - 1496
    Subject Categories: Communications technology;  Systems engineering and theory
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (16181 KB) |  | HTML iconHTML  

    Large-scale data centers enable the new era of cloud computing and provide the core infrastructure to meet the computing and storage requirements for both enterprise information technology needs and cloud-based services. To support the ever-growing cloud computing needs, the number of servers in today's data centers are increasing exponentially, which in turn leads to enormous challenges in designing an efficient and cost-effective data center network. With data availability and security at stake, the issues with data center networks are more critical than ever. Motivated by these challenges and critical issues, many novel and creative research works have been proposed in recent years. In this paper, we investigate in data center networks and provide a general overview and analysis of the literature covering various research areas, including data center network interconnection architectures, network protocols for data center networks, and network resource sharing in multitenant cloud data centers. We start with an overview on data center networks and together with its requirements navigate the data center network designs. We then present the research literature related to the aforementioned research topics in the subsequent sections. Finally, we draw the conclusions. View full abstract»

    Open Access
  • 28. Event-Based Mobile Social Networks: Services, Technologies, and Applications

    Publication Year: 2014 , Page(s): 500 - 513
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (6390 KB) |  | HTML iconHTML  

    Event-based mobile social networks (MSNs) are a special type of MSN that has an immanently temporal common feature, which allows any smart phone user to create events to share group messaging, locations, photos, and insights among participants. The emergence of Internet of Things and event-based social applications integrated with context-awareness ability can be helpful in planning and organizing social events like meetings, conferences, and tradeshows. This paper first provides review of the event-based social networks and the basic principles and architecture of event-based MSNs. Next, event-based MSNs with smartphone contained technology elements, such as context-aware mobility and multimedia sharing, are presented. By combining the feature of context-aware mobility with multimedia sharing in event-based MSNs, event organizers, and planners with the service providers optimize their capability to recognize value for the multimedia services they deliver. The unique features of the current event-based MSNs give rise to the major technology trends to watch for designing applications. These mobile applications and their main features are described. At the end, discussions on the evaluation of the event-based mobile applications based on their main features are presented. Some open research issues and challenges in this important area of research are also outlined. View full abstract»

    Open Access
  • 29. Energy Efficiency Benefits of RAN-as-a-Service Concept for a Cloud-Based 5G Mobile Network Infrastructure

    Publication Year: 2014 , Page(s): 1586 - 1597
    Subject Categories: Communications technology;  Computers and information processing
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (10013 KB) |  | HTML iconHTML  

    This paper focuses on energy efficiency aspects and related benefits of radio-access-network-as-a-service (RANaaS) implementation (using commodity hardware) as architectural evolution of LTE-advanced networks toward 5G infrastructure. RANaaS is a novel concept introduced recently, which enables the partial centralization of RAN functionalities depending on the actual needs as well as on network characteristics. In the view of future definition of 5G systems, this cloud-based design is an important solution in terms of efficient usage of network resources. The aim of this paper is to give a vision of the advantages of the RANaaS, to present its benefits in terms of energy efficiency and to propose a consistent system-level power model as a reference for assessing innovative functionalities toward 5G systems. The incremental benefits through the years are also discussed in perspective, by considering technological evolution of IT platforms and the increasing matching between their capabilities and the need for progressive virtualization of RAN functionalities. The description is complemented by an exemplary evaluation in terms of energy efficiency, analyzing the achievable gains associated with the RANaaS paradigm. View full abstract»

    Open Access
  • 30. Think Small: Nanopores for Sensing and Synthesis

    Publication Year: 2014 , Page(s): 1396 - 1408
    Subject Categories: Biomedical Engineering;  Nanotechnology;  Sensors
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (11045 KB) |  | HTML iconHTML  

    It is now possible to manipulate individual molecules using a nanopore to read DNA and proteins, or write DNA by inserting mini-genes into cells. Furthermore, development of these methodologies will kick open the door to new biology and chemistry that has been logistically intractable previously. Nanopore technology will place molecular and sub-molecular analysis within the reach of the typical bench-top scientist or clinical lab-no longer limited to genomics or mass spectrometry specialists. Moreover, the prospects for synthetic biology-using nanopores to program or reprogram cells-are promising as well, but have been examined only at the level of a single cell, so far. View full abstract»

    Open Access
  • 31. Microwave System for the Early Stage Detection of Congestive Heart Failure

    Publication Year: 2014 , Page(s): 921 - 929
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (11642 KB) |  | HTML iconHTML  

    Fluid accumulation inside the lungs, known as cardiac pulmonary edema, is one of the main early symptoms of congestive heart failure (CHF). That accumulation causes significant changes in the electrical properties of the lung tissues, which in turn can be detected using microwave techniques. To that end, the design and implementation of an automated ultrahigh-frequency microwave-based system for CHF detection and monitoring is presented. The hardware of the system consists of a wideband folded antenna attached to a fully automated vertical scanning platform, compact microwave transceiver, and laptop. The system includes software in the form of operational control, signal processing, and visualizing algorithms. To detect CHF, the system is designed to vertically scan the rear side of the human torso in a monostatic radar approach. The collected data from the scanning is then visualized in the time domain using the inverse Fourier transform. These images show the intensity of the reflected signals from different parts of the torso. Using a differential based detection technique, a threshold is defined to differentiate between healthy and unhealthy cases. This paper includes details of developing the automated platform, designing the antenna with the required properties imposed by the system, developing a signal processing algorithm, and introducing differential detection technique besides investigating miscellaneous probable CHF cases. View full abstract»

    Open Access
  • 32. Dense Dielectric Patch Array Antenna With Improved Radiation Characteristics Using EBG Ground Structure and Dielectric Superstrate for Future 5G Cellular Networks

    Publication Year: 2014 , Page(s): 909 - 913
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (7555 KB) |  | HTML iconHTML  

    In this paper, a new dense dielectric (DD) patch array antenna prototype operating at 28 GHz for future fifth generation (5G) cellular networks is presented. This array antenna is proposed and designed with a standard printed circuit board process to be suitable for integration with radio frequency/microwave circuitry. The proposed structure employs four circular-shaped DD patch radiator antenna elements fed by a 1-to-4 Wilkinson power divider. To improve the array radiation characteristics, a ground structure based on a compact uniplanar electromagnetic bandgap unit cell has been used. The DD patch shows better radiation and total efficiencies compared with the metallic patch radiator. For further gain improvement, a dielectric layer of a superstrate is applied above the array antenna. The measured impedance bandwidth of the proposed array antenna ranges from 27 to beyond 32 GHz for a reflection coefficient (S11) of less than -10 dB. The proposed design exhibits stable radiation patterns over the whole frequency band of interest, with a total realized gain more than 16 dBi. Due to the remarkable performance of the proposed array, it can be considered as a good candidate for 5G communication applications. View full abstract»

    Open Access
  • 33. Latent fingerprint matching: A survey

    Publication Year: 2014 , Page(s): 982 - 1004
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (99319 KB) |  | HTML iconHTML  

    Latent fingerprint has been used as evidence in the court of law for over 100 years. However, even today, a completely automated latent fingerprint system has not been achieved. Researchers have identified several important challenges in latent fingerprint recognition: 1) low information content; 2) presence of background noise and nonlinear ridge distortion; 3) need for an established scientific procedure for matching latent fingerprints; and 4) lack of publicly available latent fingerprint databases. The process of automatic latent fingerprint matching is divided into five definite stages, and this paper discusses the existing algorithms, limitations, and future research directions in each of the stages. View full abstract»

    Open Access
  • 34. Wireless Video Surveillance: A Survey

    Publication Year: 2013 , Page(s): 646 - 660
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (7892 KB) |  | HTML iconHTML  

    A wireless video surveillance system consists of three major components: 1) the video capture and preprocessing; 2) the video compression and transmission in wireless sensor networks; and 3) the video analysis at the receiving end. A myriad of research works have been dedicated to this field due to its increasing popularity in surveillance applications. This survey provides a comprehensive overview of existing state-of-the-art technologies developed for wireless video surveillance, based on the in-depth analysis of the requirements and challenges in current systems. Specifically, the physical network infrastructure for video transmission over wireless channel is analyzed. The representative technologies for video capture and preliminary vision tasks are summarized. For video compression and transmission over the wireless networks, the ultimate goal is to maximize the received video quality under the resource limitation. This is also the main focus of this survey. We classify different schemes into categories including unequal error protection, error resilience, scalable video coding, distributed video coding, and cross-layer control. Cross-layer control proves to be a desirable measure for system-level optimal resource allocation. At the receiver's end, the received video is further processed for higher-level vision tasks, and the security and privacy issues in surveillance applications are also discussed. View full abstract»

    Open Access
  • 35. BSIM—SPICE Models Enable FinFET and UTB IC Designs

    Publication Year: 2013 , Page(s): 201 - 215
    Cited by:  Papers (5)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (28248 KB) |  | HTML iconHTML  

    Two turn-key surface potential-based compact models are developed to simulate multigate transistors for integrated circuit (IC) designs. The BSIM-CMG (common-multigate) model is developed to simulate double-, triple-, and all-around-gate FinFETs and it is selected as the world's first industry-standard compact model for the FinFET. The BSIM-IMG (independent-multigate) model is developed for independent double-gate, ultrathin body (UTB) transistors, capturing the dynamic threshold voltage adjustment with back gate bias. Starting from long-channel devices, the basic models are first obtained using a Poisson-carrier transport approach. The basic models agree with the results of numerical two-dimensional device simulators. The real-device effects then augment the basic models. All the important real-device effects, such as short-channel effects (SCEs), quantum mechanical confinement effects, mobility degradation, and parasitics are included in the models. BSIM-CMG and BSIM-IMG have been validated with hardware silicon-based data from multiple technologies. The developed models also meet the stringent quality assurance tests expected of production level models. View full abstract»

    Open Access
  • 36. MIMO Characterization on System Level of 5G Microbase Stations Subject to Randomness in LOS

    Publication Year: 2014 , Page(s): 1064 - 1077
    Subject Categories: Antennas and propagation;  Communications technology;  Vehicular and wireless technologies
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (66757 KB) |  | HTML iconHTML  

    Wireless systems have become more and more advanced in terms of handling the statistical properties of wireless channels. For example, the 4G long term evolution (LTE) system takes advantage of multiport antennas [multiple-input multiple-output (MIMO) technology] and orthogonal frequency division multiplexing (OFDM) to improve the detection probability of single bitstream by diversity in the spatial and frequency domains, respectively. The 4G system also supports transmission of two bitstreams by appropriate signal processing of the MIMO subchannels. The reverberation chamber emulates according to previous works rich isotropic multipath (RIMP) and has proven to be very useful for characterizing smart phones for LTE systems. The measured throughput can be accurately modeled by the simple digital threshold receiver, accounting accurately for both the MIMO and OFDM functions. The throughput is equivalent to the probability of detection (PoD) of the transmitted bitstream. The purpose of this paper is to introduce a systematic approach to include the statistical properties of the user and his or her terminal, when characterizing the performance. The user statistics will have a larger effect in environments with stronger line-of-sight (LOS), because the angle of arrival and the polarization of the LOS contribution vary due to the user's orientation and practices. These variations are stochastic, and therefore, we introduce the term random-LOS to describe this. This paper elaborates on the characterization of an example antenna in both RIMP and random-LOS. The chosen antenna is a wideband microbase transceiver station (BTS) antenna. We show how to characterize the micro-BTS by the PoD of one and two bitstreams in both RIMP and random-LOS, by considering the user randomly located and oriented within the angular coverage sector. We limit the treatment to a wall-mounted BTS antenna, and assume a desired hemispherical coverage. The angular coverages of both one and two bitst- eams for the random-LOS case are plotted as MIMO-coverage radiation patterns of the whole four-port digital antenna system. Such characterizations in terms of PoD have never been done before on any practical antenna system. The final results are easy to interpret, and they open up a new world of opportunities for designing and optimizing 5G antennas on system level. View full abstract»

    Open Access
  • 37. Design and Construction of Arduino-Hacked Variable Gating Distortion Pedal

    Publication Year: 2014 , Page(s): 1409 - 1417
    Subject Categories: Circuits and systems;  Consumer electronics
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (14397 KB) |  | HTML iconHTML  

    This paper describes the distortion effects often used in an electric guitar. Distortion is an added effect in an electric guitar, which compresses the peaks of the sound waves produced by the musical instrument, to produce a large number of added overtones, which here is done by rigging up a circuit in collaboration with the Arduino UNO circuit board. The digital potentiometer controlled by the Arduino (microcontroller) was an improvement and was able to produce satisfactory results, as compared with the analog potentiometer without the Arduino control. The complex circuitry of a three-stage distortion circuit with the analog potentiometer was replaced by a digital potentiometer controlled by a microcontroller, with better results. This variable-gating distortion pedal has an added advantage of being compact, light, and inexpensive. View full abstract»

    Open Access
  • 38. Backpacking: Energy-Efficient Deployment of Heterogeneous Radios in Multi-Radio High-Data-Rate Wireless Sensor Networks

    Publication Year: 2014 , Page(s): 1281 - 1306
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (45098 KB) |  | HTML iconHTML  

    The early success of wireless sensor networks has led to a new generation of increasingly sophisticated sensor network applications, such as HP's CeNSE. These applications demand high network throughput that easily exceeds the capability of the low-power 802.15.4 radios most commonly used in today's sensor nodes. To address this issue, this paper investigates an energy-efficient approach to supplementing an 802.15.4-based wireless sensor network with high bandwidth, high power, longer range radios, such as 802.11. Exploiting a key observation that the high-bandwidth radio achieves low energy consumption per bit of transmitted data due to its inherent transmission efficiency, we propose a hybrid network architecture that utilizes an optimal density of dual-radio (802.15.4 and 802.11) nodes to augment a sensor network having only 802.15.4 radios. We present a cross-layer mathematical model to calculate this optimal density, which strikes a delicate balance between the low energy consumption per transmitted bit of the high-bandwidth radio and low sleep power of the 802.15.4. Experimental results obtained using a wireless sensor network testbed reveal that our architecture improves the average energy per bit, time elapsed before the first node drains its battery, time elapsed before half of the nodes drain their batteries, and end-to-end delay by significant margins compared with a network having only 802.15.4. View full abstract»

    Open Access
  • 39. Large-Scale Deep Belief Nets With MapReduce

    Publication Year: 2014 , Page(s): 395 - 403
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (3347 KB) |  | HTML iconHTML  

    Deep belief nets (DBNs) with restricted Boltzmann machines (RBMs) as the building block have recently attracted wide attention due to their great performance in various applications. The learning of a DBN starts with pretraining a series of the RBMs followed by fine-tuning the whole net using backpropagation. Generally, the sequential implementation of both RBMs and backpropagation algorithm takes significant amount of computational time to process massive data sets. The emerging big data learning requires distributed computing for the DBNs. In this paper, we present a distributed learning paradigm for the RBMs and the backpropagation algorithm using MapReduce, a popular parallel programming model. Thus, the DBNs can be trained in a distributed way by stacking a series of distributed RBMs for pretraining and a distributed backpropagation for fine-tuning. Through validation on the benchmark data sets of various practical problems, the experimental results demonstrate that the distributed RBMs and DBNs are amenable to large-scale data with a good performance in terms of accuracy and efficiency. View full abstract»

    Open Access
  • 40. fgCAPTCHA: Genetically Optimized Face Image CAPTCHA 5

    Publication Year: 2014 , Page(s): 473 - 484
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (14035 KB) |  | HTML iconHTML  

    The increasing use of smartphones, tablets, and other mobile devices poses a significant challenge in providing effective online security. CAPTCHAs, tests for distinguishing human and computer users, have traditionally been popular; however, they face particular difficulties in a modern mobile environment because most of them rely on keyboard input and have language dependencies. This paper proposes a novel image-based CAPTCHA that combines the touch-based input methods favored by mobile devices with genetically optimized face detection tests to provide a solution that is simple for humans to solve, ready for worldwide use, and provides a high level of security by being resilient to automated computer attacks. In extensive testing involving over 2600 users and 40000 CAPTCHA tests, fgCAPTCHA demonstrates a very high human success rate while ensuring a 0% attack rate using three well-known face detection algorithms. View full abstract»

    Open Access
  • 41. Synchrophasor Measurement Technology in Power Systems: Panorama and State-of-the-Art

    Publication Year: 2014 , Page(s): 1607 - 1628
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1056 KB) |  | HTML iconHTML  

    Phasor measurement units (PMUs) are rapidly being deployed in electric power networks across the globe. Wide-area measurement system (WAMS), which builds upon PMUs and fast communication links, is consequently emerging as an advanced monitoring and control infrastructure. Rapid adaptation of such devices and technologies has led the researchers to investigate multitude of challenges and pursue opportunities in synchrophasor measurement technology, PMU structural design, PMU placement, miscellaneous applications of PMU from local perspectives, and various WAMS functionalities from the system perspective. Relevant research articles appeared in the IEEE and IET publications from 1983 through 2014 are rigorously surveyed in this paper to represent a panorama of research progress lines. This bibliography will aid academic researchers and practicing engineers in adopting appropriate topics and will stimulate utilities toward development and implementation of software packages. View full abstract»

    Open Access
  • 42. Proactive Recovery of Electric Power Assets for Resiliency Enhancement

    Publication Year: 2015 , Page(s): 99 - 109
    Subject Categories: Power engineering and energy;  Systems engineering and theory
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (3426 KB) |  | HTML iconHTML  

    This paper presents a significant change in current electric power grid response and recovery schemes by developing a framework for proactive recovery of electric power assets with the primary objective of resiliency enhancement. Within the proposed framework, which can potentially present the next generation decision-making tool for proactive recovery, several coordinated models will be developed including: 1) the outage models to indicate the impact of hurricanes on power system components; 2) a stochastic pre-hurricane crew mobilization model for managing resources before the event; and 3) a deterministic post-hurricane recovery model for managing resources after the event. Proposed models will be extended to ensure applicability to a variety of electric power grids with different technologies and regulatory issues. The theoretical and practical implications of the developed models will push the research frontier of proactive response and recovery schemes in electric power grids, while its flexibility will support application to a variety of infrastructures, in response to a wide range of extreme weather events and natural disasters. View full abstract»

    Open Access
  • 43. Fault Diagnosis in Hybrid Electric Vehicle Regenerative Braking System

    Publication Year: 2014 , Page(s): 1225 - 1239
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (8937 KB) |  | HTML iconHTML  

    Regenerative braking is one of the most promising and environmentally friendly technologies used in electric and hybrid electric vehicles to improve energy efficiency and vehicle stability. This paper presents a systematic data-driven process for detecting and diagnosing faults in the regenerative braking system of hybrid electric vehicles. The diagnostic process involves signal processing and statistical techniques for feature extraction, data reduction for implementation in memory-constrained electronic control units, and variety of fault classification methodologies to isolate faults in the regenerative braking system. The results demonstrate that highly accurate fault diagnosis is possible with the classification methodologies. The process can be employed for fault analysis in a wide variety of systems, ranging from automobiles to buildings to aerospace systems. View full abstract»

    Open Access
  • 44. Compact MOSFET Modeling for Process Variability-Aware VLSI Circuit Design

    Publication Year: 2014 , Page(s): 104 - 115
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (4265 KB) |  | HTML iconHTML  

    This paper presents a systematic methodology to develop compact MOSFET models for process variability-aware VLSI circuit design. Process variability in scaled CMOS technologies severely impacts the functionality, yield, and reliability of advanced integrated circuit devices, circuits, and systems. Therefore, variability-aware circuit design techniques are required for realistic assessment of the impact of random and systematic process variability in advanced VLSI circuit performance. However, variability-aware circuit design requires compact MOSFET variability models for computer analysis of the impact of process variability in VLSI circuit design. This paper describes a generalized methodology to determine the major set of device parameters sensitive to random and systematic process variability in nanoscale MOSFET devices, map each variability-sensitive device parameter to the corresponding compact model parameter of the target compact model, and generate statistical compact MOSFET models for variability-aware VLSI circuit design. View full abstract»

    Open Access
  • 45. Intermittent Electrical Contact Resistance as a Contributory Factor in the Loss of Automobile Speed Control Functional Integrity

    Publication Year: 2014 , Page(s): 258 - 289
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (34117 KB) |  | HTML iconHTML  

    For three decades, sudden acceleration (SA) incidents have been reported, where automobiles accelerate without warning. These incidents are often diagnosed as no fault found. Investigators, who follow the line of diagnostic reasoning from the 1989 National Highway Traffic Safety Administration (NHTSA) SA report, tend to conclude that SAs are caused by driver pedal error. This paper reviews the diagnostic process in the NHTSA report and finds that: 1) it assumes that an intermittent electronic malfunction should be reproducible either through in-vehicle or laboratory bench tests without saying why and 2) the consequence of this assumption, for which there appears to be no forensic precedent, is to recategorize possible intermittent electronic failures as proven to be nonelectronic. Showing that the supposedly inescapable conclusions of the NHTSA report concerning electronic malfunctions are without foundation opens the way for this paper to discuss electronic intermittency as a potential factor in SA incidents. It then reports a simple practical experiment that shows how mechanically induced electrical contact intermittencies can generate false speed signals that an automobile speed control system may accept as true and that do not trigger any diagnostic fault codes. Since the generation of accurate speed signals is essential for the proper functioning of a number of other automobile safety-critical control systems, the apparent ease with which false speed signals can be generated by vibration of a poor electrical contact is obviously a matter of general concern. Various ways of reducing the likelihood of SAs are discussed, including electrical contact improvements to reduce the likelihood of generating false speed signals, improved battery maintenance, and the incorporation of an independent fail-safe that reduces engine power in an emergency, such as a kill switch. View full abstract»

    Open Access
  • 46. Cloud-RAN Architecture for Indoor DAS

    Publication Year: 2014 , Page(s): 1205 - 1212
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (4962 KB) |  | HTML iconHTML  

    A cloud radio access network (Cloud-RAN) is a new cellular technology that brings baseband processing units for a set of base stations into a central server retaining only the radio front-ends at the cell sites. This new architecture opens up opportunities for algorithms that require centralized processing. However, efficient implementation of the algorithms presents a number of challenges the most critical being latency, fronthaul capacity, and resource control. In this paper, we propose a software-defined radio-based architecture that addresses these problems and can be implemented on a cloud of general purpose computing platforms. We also present the practical implementation of Cloud-RAN running on an off-the-shelf server to validate the flexibility of the architecture. The implementation is able to realize various cellular networks, including heterogeneous networks, distribute-antenna systems, and transmission schemes, such as transmit antenna selection and open-loop transmit diversity. View full abstract»

    Open Access
  • 47. Achieving Source Location Privacy and Network Lifetime Maximization Through Tree-Based Diversionary Routing in Wireless Sensor Networks

    Publication Year: 2014 , Page(s): 633 - 651
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (8262 KB) |  | HTML iconHTML  

    Wireless sensor networks (WSNs) have been proliferating due to their wide applications in both military and commercial use. However, one critical challenge to WSNs implementation is source location privacy. In this paper, we propose a novel tree-based diversionary routing scheme for preserving source location privacy using hide and seek strategy to create diversionary or decoy routes along the path to the sink from the real source, where the end of each diversionary route is a decoy (fake source node), which periodically emits fake events. Meanwhile, the proposed scheme is able to maximize the network lifetime of WSNs. The main idea is that the lifetime of WSNs depends on the nodes with high energy consumption or hotspot, and then the proposed scheme minimizes energy consumption in hotspot and creates redundancy diversionary routes in nonhotspot regions with abundant energy. Hence, it achieves not only privacy preservation, but also network lifetime maximization. Furthermore, we systematically analyze the energy consumption in WSNs, and provide guidance on the number of diversionary routes, which can be created in different regions away from the sink. In addition, we identify a novel attack against phantom routing, which is widely used for source location privacy preservation, namely, direction-oriented attack. We also perform a comprehensive analysis on how the direction-oriented attack can be defeated by the proposed scheme. Theoretical and experimental results show that our scheme is very effective to improve the privacy protection while maximizing the network lifetime. View full abstract»

    Open Access
  • 48. Assessing Intervention Timing in Computer-Based Education Using Machine Learning Algorithms

    Publication Year: 2014 , Page(s): 78 - 87
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (7267 KB) |  | HTML iconHTML  

    The use of computer-based and online education systems has made new data available that can describe the temporal and process-level progression of learning. To date, machine learning research has not considered the impacts of these properties on the machine learning prediction task in educational settings. Machine learning algorithms may have applications in supporting targeted intervention approaches. The goals of this paper are to: 1) determine the impact of process-level information on machine learning prediction results and 2) establish the effect of type of machine learning algorithm used on prediction results. Data were collected from a university level course in human factors engineering (n=35), which included both traditional classroom assessment and computer-based assessment methods. A set of common regression and classification algorithms were applied to the data to predict final course score. The overall prediction accuracy as well as the chronological progression of prediction accuracy was analyzed for each algorithm. Simple machine learning algorithms (linear regression, logistic regression) had comparable performance with more complex methods (support vector machines, artificial neural networks). Process-level information was not useful in post-hoc predictions, but contributed significantly to allowing for accurate predictions to be made earlier in the course. Process level information provides useful prediction features for development of targeted intervention techniques, as it allows more accurate predictions to be made earlier in the course. For small course data sets, the prediction accuracy and simplicity of linear regression and logistic regression make these methods preferable to more complex algorithms. View full abstract»

    Open Access
  • 49. Sparse Beamforming and User-Centric Clustering for Downlink Cloud Radio Access Network

    Publication Year: 2014 , Page(s): 1326 - 1339
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (6218 KB) |  | HTML iconHTML  

    This paper considers a downlink cloud radio access network (C-RAN) in which all the base-stations (BSs) are connected to a central computing cloud via digital backhaul links with finite capacities. Each user is associated with a user-centric cluster of BSs; the central processor shares the user's data with the BSs in the cluster, which then cooperatively serve the user through joint beamforming. Under this setup, this paper investigates the user scheduling, BS clustering, and beamforming design problem from a network utility maximization perspective. Differing from previous works, this paper explicitly considers the per-BS backhaul capacity constraints. We formulate the network utility maximization problem for the downlink C-RAN under two different models depending on whether the BS clustering for each user is dynamic or static over different user scheduling time slots. In the former case, the user-centric BS cluster is dynamically optimized for each scheduled user along with the beamforming vector in each time-frequency slot, whereas in the latter case, the user-centric BS cluster is fixed for each user and we jointly optimize the user scheduling and the beamforming vector to account for the backhaul constraints. In both cases, the nonconvex per-BS backhaul constraints are approximated using the reweighted ℓ1-norm technique. This approximation allows us to reformulate the per-BS backhaul constraints into weighted per-BS power constraints and solve the weighted sum rate maximization problem through a generalized weighted minimum mean square error approach. This paper shows that the proposed dynamic clustering algorithm can achieve significant performance gain over existing naive clustering schemes. This paper also proposes two heuristic static clustering schemes that can already achieve a substantial portion of the gain. View full abstract»

    Open Access
  • 50. On Recognizing Face Images With Weight and Age Variations

    Publication Year: 2014 , Page(s): 822 - 830
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (25229 KB) |  | HTML iconHTML  

    With the increase in age, there are changes in skeletal structure, muscle mass, and body fat. For recognizing faces with age variations, researchers have generally focused on the skeletal structure and muscle mass. However, the effect of change in body fat has not been studied with respect to face recognition. In this paper, we incorporate weight information to improve the performance of face recognition with age variations. The proposed algorithm utilizes neural network and random decision forest to encode age variations across different weight categories. The results are reported on the WhoIsIt database prepared by the authors containing 1109 images from 110 individuals with age and weight variations. The comparison with existing state-of-the-art algorithms and commercial system on WhoIsIt and FG-Net databases shows that the proposed algorithm outperforms existing algorithms significantly. View full abstract»

    Open Access

Aims & Scope

IEEE Access® is an interdisciplinary, applications-oriented, all-electronic archival journal continuously presenting the results of original research or development across all of IEEE's fields of interest. Supported by author publication fees, its hallmarks are a rapid peer review and publication process with open access to all readers.

Full Aims & Scope

Meet Our Editors


Michael Pecht, Ph.D.
Professor and Director
University of Maryland