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Near threshold computing (NTC) has significant role in reducing the energy consumption of modern very large scale integrated circuits designs. However, NTC designs suffer from functional failures and performance loss. Understanding the characteristics of the functional failures and variability effects is of decisive importance in order to mitigate them, and get the utmost NTC benefits. This paper presents a comprehensive cross-layer reliability analysis framework to assess the effect of soft error, aging, and process variation in the operation of near threshold voltage caches. The objective is to quantify the reliability of different SRAM designs, evaluate voltage scaling potential of caches, and to find a reliability-performance optimal cache organization for an NTC microprocessor. In this paper, the soft error rate (SER) and static noise margin (SNM) of 6T and 8T SRAM cells and their dependencies on aging and process variation are investigated by considering device, circuit, and architecture level analysis. Their experimental results show that in NTC, process variation and aging-induced SNM degradation is $2.5{\boldsymbol \times }$ higher than in the super threshold domain while SER is $8{\boldsymbol \times }$ higher. At NTC, the use of 8T instead of 6T SRAM cells can reduce the system-level SNM and SER by 14% and 22%, respectively. Besides, we observe that we can find the right balance between performance and reliability by using an appropriate cache organization at NTC which is different from the super threshold. [ABSTRACT FROM AUTHOR]

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Data centers play an important role in today’s Internet development. Research to find scalable architecture and efficient routing algorithms for data center networks has gained popularity. The fat-tree architecture, which is essentially a folded version of a Clos network, has proved to be readily implementable and is scalable. In this paper, we investigate routing on a fat-tree network by deriving its global packing number and by presenting explicit algorithms for the construction of optimal, load-balanced routing solutions. Consider an optical network that employs wavelength division multiplexing in which every user node sets up a connection with every other user node. The global packing number is basically the number of wavelengths required by the network to support such a traffic load, under the restriction that each source-to-destination connection is assigned a wavelength that remains constant in the network. In mathematical terms, consider a bidirectional, simple graph, G and let N\subseteq V(G) be a set of nodes. A path system \mathcal P of G with respect to N consists of |N|(|N|-1) directed paths, one path to connect each of the source-destination node pairs in N . The global packing number of a path system , denoted by \Phi (G,N,\mathcal {P}) , is the minimum integer k to guarantee the existence of a mapping \phi :\mathcal P\to \1,2,\ldots, k\ , such that \phi (P)\neq \phi (\widehat P) if P and \widehat {P} have common arc(s). The global packing number of (G,N) , denoted by \Phi (G,N) , is defined to be the minimum \Phi (G,N,\mathcal {P}) among all possible path systems \mathcal {P} . In additional to wavelength division optical networks, this number also carries significance for networks employing time division multiple access. In this paper, we compute by explicit route construction the global packing number of (\text Tn,N) , where Tn denotes the topology of the n -ary fat-tree network, and $N$ is considered to be the set of all edge switches or the set of all supported hosts. We show that the constructed routes are load-balanced and require minimal link capacity at all network links. [ABSTRACT FROM AUTHOR]

Computer science (CS) is becoming an increasingly diverse domain. This paper reports on an initiative designed to introduce underrepresented populations to computing using an eclectic, multifaceted approach. As part of a yearlong computing course, students engage in Maker activities, participatory simulations, and computing projects that foreground the social and collaborative aspects of CS. Collectively, these activities are designed to introduce learners to the growing diversity of what CS looks like in the 21st century. This paper lays out the practical and theoretical motivations for the Computational Thinking for Girls (CT4G) project, specifically highlighting the use of Making through physical and social computing as ways to engage students in CS. A snapshot of one activity from the program is provided—Wearing the Web—in which students use open-hardware programmable badges to explore the underlying structure and technology that enables the Internet. Data from the first year of the CT4G program are presented to show the positive effects that this diverse introduction to CS is having on the students with respect to their attitudes toward CS. [ABSTRACT FROM PUBLISHER]

Numerous approaches have been proposed to solve shortest path query problems (SPQPs) in either static or time-dependent spatial networks; however, these approaches are neither appropriately nor efficiently used to find the nearest shelter with fastest paths in disaster evacuations. In disasters, segments of a path computed and saved as the fastest might become impassable. The nearest shelter differs for people depending on their locations and can also change on the basis of an unpredictable and highly dynamic edge cost (e.g., maximum passable vehicle speed), which is influenced by disaster events. To solve this problem, this paper proposes a dynamic network model, which is called an event-dependent network, to represent a spatial network in a disaster. Effective approaches using multiple algorithms are proposed for on-the-fly computation of the nearest shelter and fastest paths in a disaster. A distributed system consisting of a server and multiple mobile clients using our approaches is presented for navigating the fastest paths for people to evacuate a disaster area. Real-world maps, such as a map of California, were used in our experiments. The results revealed that our approaches require less than 2 ms to find a new nearest shelter and its fastest paths, which is faster than other approaches for solving the fastest-path problem. [ABSTRACT FROM AUTHOR]

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This paper addresses the problem of online tracking and classification of multiple objects in an image sequence. Our proposed solution is to first track all objects in the scene without relying on object-specific prior knowledge, which in other systems can take the form of hand-crafted features or user-based track initialization. We then classify the tracked objects with a fast-learning image classifier, that is based on a shallow convolutional neural network architecture and demonstrate that object recognition improves when this is combined with object state information from the tracking algorithm. We argue that by transferring the use of prior knowledge from the detection and tracking stages to the classification stage, we can design a robust, general purpose object recognition system with the ability to detect and track a variety of object types. We describe our biologically inspired implementation, which adaptively learns the shape and motion of tracked objects, and apply it to the Neovision2 Tower benchmark data set, which contains multiple object types. An experimental evaluation demonstrates that our approach is competitive with the state-of-the-art video object recognition systems that do make use of object-specific prior knowledge in detection and tracking, while providing additional practical advantages by virtue of its generality. [ABSTRACT FROM PUBLISHER]

For complex datapaths, resource sharing can help reduce area consumption. Traditionally, resource sharing is applied when the same resource can be scheduled for different uses in different cycles, often resulting in a longer schedule. Multipumping is a method whereby a resource is clocked at a frequency that is a multiple of the surrounding circuit, thereby offering multiple executions per global clock cycle. This allows a single resource to be shared among multiple uses in the same cycle. This concept maps well to modern field-programmable gate arrays (FPGAs), where hard macro blocks are typically capable of running at higher frequencies than most designs implemented in the logic fabric. While this technique has been demonstrated for static resources, modern digital signal processing (DSP) blocks are flexible, supporting varied operations at runtime. In this paper, we demonstrate multipumping for resource sharing of the flexible DSP48E1 macros in Xilinx FPGAs. We exploit their dynamic programmability to enable resource sharing for the full set of supported DSP block operations, and compare this to multipumping only multipliers and DSP blocks with fixed configurations. The proposed approach saves on average 48% DSP blocks at a cost of 74% more LUTs, effectively saving 30% equivalent LUT area and is feasible for the majority of designs, in which clock frequency is typically below half the maximum supported by the DSP blocks. [ABSTRACT FROM PUBLISHER]

In the event of natural or man-made disasters, providing rapid situational awareness through video/image data collected at salient incident scenes is often critical to the first responders. However, computer vision techniques that can process the media-rich and data-intensive content obtained from civilian smartphones or surveillance cameras require large amounts of computational resources or ancillary data sources that may not be available at the geographical location of the incident. In this paper, we propose an incident-supporting visual cloud computing solution by defining a collection, computation, and consumption (3C) architecture supporting fog computing at the network edge close to the collection/consumption sites, which is coupled with cloud offloading to a core computation, utilizing software-defined networking (SDN). We evaluate our 3C architecture and algorithms using realistic virtual environment test beds. We also describe our insights in preparing the cloud provisioning and thin-client desktop fogs to handle the elasticity and user mobility demands in a theater-scale application. In addition, we demonstrate the use of SDN for on-demand compute offload with congestion-avoiding traffic steering to enhance remote user quality of experience in a regional-scale application. The optimization between fogs computing at the network edge with core cloud computing for managing visual analytics reduces latency, congestion, and increases throughput. [ABSTRACT FROM PUBLISHER]

Presents the second bibliography on issues related to transmission access in electric power systems. Citations referenced in the bibliography; List of web sites devoted to energy and power engineering; Government web sites; Conclusions.

The network link speed is growing at an ever-increasing rate, which requires all network functions on routers/switches to keep pace. Bloom filter is a widely-used membership check data structure in networking applications. Correspondingly, it also faces the urgent demand of improving the performance in membership check speed. To this end, this paper proposes a new Bloom filter variant called Ultra-Fast Bloom Filters (UFBF), by leveraging the Single Instruction Multiple Data (SIMD) techniques. We make three improvements for UFBF to accelerate the membership check speed. First, we develop a novel hash computation algorithm which can compute multiple hash functions in parallel with the use of SIMD instructions. Second, we elaborate a Bloom filter’s bit-test process from sequential to parallel, enabling more bit-tests per unit time. Third, we improve the cache efficiency of membership check by encoding an element’s information to a small block so that it can fit into a cache-line. We further generalize UFBF, called c-UFBF, to make UFBF supporting large number of hash functions. Both theoretical analysis and extensive evaluations show that the UFBF greatly outperforms the state-of-the-art Bloom filter variants on membership check speed. [ABSTRACT FROM AUTHOR]

Nowadays, by integrating the cloud radio access network (C-RAN) with the mobile edge cloud computing (MEC) technology, mobile service provider (MSP) can efficiently handle the increasing mobile traffic and enhance the capabilities of mobile devices. But the power consumption has become skyrocketing for MSP and it gravely affects the profit of MSP. Previous work often studied the power consumption in C-RAN and MEC separately while less work had considered the integration of C-RAN with MEC. In this paper, we present an unifying framework for the power-performance tradeoff of MSP by jointly scheduling network resources in C-RAN and computation resources in MEC to maximize the profit of MSP. To achieve this objective, we formulate the resource scheduling issue as a stochastic problem and design a new optimization framework by using an extended Lyapunov technique. Specially, because the standard Lyapunov technique critically assumes that job requests have fixed lengths and can be finished within each decision making interval, it is not suitable for the dynamic situation where the mobile job requests have variable lengths. To solve this problem, we extend the standard Lyapunov technique and design the VariedLen algorithm to make online decisions in consecutive time for job requests with variable lengths. Our proposed algorithm can reach time average profit that is close to the optimum with a diminishing gap (1/V) for the MSP while still maintaining strong system stability and low congestion. With extensive simulations based on a real world trace, we demonstrate the efficacy and optimality of our proposed algorithm. [ABSTRACT FROM AUTHOR]

While development of the Internet has contributed to the spread of online education, online exams have not been widely adopted. An online exam is defined here as one that takes place over the insecure Internet, and where no proctor is in the same location as the examinees. This paper proposes an enhanced secure online exam management environment mediated by group cryptography using remote monitoring and control of ports and input. The target domain of this paper is that of online exams for math or English contests in middle or high school, as well as exams in online university courses with students in remote locations. [ABSTRACT FROM AUTHOR]

This paper focuses on the application of model predictive control (MPC) for the spacecraft trajectory tracking problems. The motivation of the use of MPC, also known as receding horizon control, relies on its ability in dealing with control, state, and path constraints that naturally arise in practical trajectory planning problems. Two different MPC schemes are constructed to solve the reconnaissance trajectory tracking problem. Since the MPC solves the online optimal control problems at each sampling instant, the computational cost associated with it can be high. In order to decrease the computational demand due to the optimization process, a newly proposed two-nested gradient method is used and embedded in the two MPC schemes. Simulation results are provided to illustrate the effectiveness and feasibility of the two MPC tracking algorithms combined with the improved optimization technique. [ABSTRACT FROM AUTHOR]

An important concept in the fifth generation of mobile networks is multitenancy, which allows diverse operators sharing the same wireless infrastructure. To support this feature in conjunction with the challenging performance requirements of future networks, more automated and faster planning of the required radio capacity is needed. Likewise, installing small cells is an effective resource to provide greater performance and capacity to both indoor and outdoor places. This paper proposes a new framework for automated cell planning in multitenant small cell networks. In particular, taking advantage of the available network data, a set of detailed planning specifications over time and space domains are generated in order to meet the contracted capacity by each tenant. Then, the network infrastructure and configuration are updated according to an algorithm that considers different actions such as adding/removing channels and adding or relocating small cells. The simulation results show the effectiveness of various methods to derive the planning specifications depending on the correlation between the tenant's and network's traffic demands. [ABSTRACT FROM PUBLISHER]

This paper presents a novel online diagnostics method capable of detecting winding deformations in two-winding single-phase transformers. The main idea is to identify changes in the short-circuit impedance. The combination of 3-D Lissajous curve methods with a Butterworth low-pass filter allows for the accurate determination of winding deformation of large power transformers in real time. The method is very robust and capable of detecting deformations at the early stage even when the measurements are noisy. Only information already available to the differential protection relay is needed. The proposed diagnostics method has been validated with circuit and finite-element simulations plus a lab experiment. The results show that the proposed online diagnostics technique has the ability to identify winding deformation problems under severe conditions, such as nonsinusoidal input, nonlinear loading, and measurement noise. Under ideal conditions (no signal noise), the inductive identification error of the proposed online diagnostics method identifies the parameters with less than 0.09% error. When accepting a measurement noise of 1%, the error on the identification of inductance is less than 0.13%. [ABSTRACT FROM PUBLISHER]

A social approach can be exploited for the Internet of Things (IoT) to manage a large number of connected objects. These objects operate as autonomous agents to request and provide information and services to users. Establishing trustworthy relationships among the objects greatly improves the effectiveness of node interaction in the social IoT and helps nodes overcome perceptions of uncertainty and risk. However, there are limitations in the existing trust models. In this paper, a comprehensive model of trust is proposed that is tailored to the social IoT. The model includes ingredients such as trustor, trustee, goal, trustworthiness evaluation, decision, action, result, and context. Building on this trust model, we clarify the concepts of trust in the social IoT in five aspects such as: 1) mutuality of trustor and trustee; 2) inferential transfer of trust; 3) transitivity of trust; 4) trustworthiness update; and 5) trustworthiness affected by dynamic environment. With network connectivities that are from real-world social networks, a series of simulations are conducted to evaluate the performance of the social IoT operated with the proposed trust model. An experimental IoT network is used to further validate the proposed trust model. [ABSTRACT FROM PUBLISHER]

A trend for low-power conversion system is to integrate every component to a single chip. Magnetic component has been the key to determine the power density of the integrated switching power converter. In this paper, a hybrid resonant buck-type converter with an ultracompact custom-designed coupled inductor is presented for low-power integrated on-chip applications. This converter achieves zero-voltage switching for the high-side switch and near zero-voltage zero-current switching for low-side and auxiliary switches. The soft-switching condition allows the circuit operating at high switching frequencies. An ultracompact planar coupled inductor with a dimension of 5.25 mm × 1.95 mm × 3.86 mm is designed and customized for future integrated on-chip applications. The high-power density of this magnetics component is achieved by high switching frequency and optimized printed circuit board (PCB) windings design. A hardware prototype with 24 to 60-V input and 3.3 to 5-V, 3-A output operating at 2–3 MHz is presented to verify the circuit operation. The prototype achieves a peak efficiency of 90.7% using silicon devices at 2-MHz switching frequency. [ABSTRACT FROM PUBLISHER]

This paper presents an agent cooperation mechanism for scheduling operations in a manufacturing network, while allowing manufacturers to absolutely control their scheduling activities. The study includes a thorough review of recent publications, a real-life industrial use case of a manufacturing network, an agent-based model of the network simulated with recursive porous agent simulation toolkit, the Muth and Thompson (MT10) scheduling data set, and the visualization of results in Microsoft Project. Results of a study of a four-layer cooperation mechanism showed that for the MT10 problem, manufacturer arrangement 0–5–7–2–3–8–1–9–6–4–0 was found to maximize the utilitarian social welfare of the manufacturing network. In terms of make-span, the network achieved a maximum of 1125 which was beyond the known optimal 930. Results suggest that manufacturers could express their scheduling goals and their preferences with whom they wanted to cooperate. These were measured by the time incentive and compatibility indicators. The latter could also be used to track the optimality loss in make-span optimization when implementing the decentralized scheduling approach in the context of manufacturing networks. [ABSTRACT FROM PUBLISHER]

These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal. [ABSTRACT FROM PUBLISHER]

Do users from Carnegie Mellon University form social communities on Facebook? Do signal processing researchers tightly collaborate with each other? Do Chinese restaurants in Manhattan cluster together? These seemingly different problems share a common structure: an attribute that may be localized on a graph. In other words, nodes activated by an attribute form a subgraph that can be easily separated from other nodes. In this paper, we thus focus on the task of detecting localized attributes on a graph. We are particularly interested in categorical attributes such as attributes in online social networks, ratings in recommender systems, and viruses in cyber-physical systems because they are widely used in numerous data mining applications. To solve the task, we formulate a statistical hypothesis testing problem to decide whether a given attribute is localized or not. We propose two statistics: Graph wavelet statistic and graph scan statistic, both of which are provably effective in detecting localized attributes. We validate the robustness of the proposed statistics on both simulated data and two real-world applications: High air-pollution detection and keyword ranking in a coauthorship network collected from IEEE Xplore. Experimental results show that the proposed graph wavelet statistic and graph scan statistic are effective and efficient. [ABSTRACT FROM PUBLISHER]

In a blog network, there are special users who induce other users to actively utilize blogs. Identifying such influential users is important when establishing business policy and business models for the blog network. This paper defines the users whose contents exhibit significant influence over other users as content power users (CPUs) and proposes a method of identifying them. We analyze the performance of the proposed method by applying it to an actual blog network and comparing its results with those of preexisting methods for determining power users. The experimental results demonstrate that the definition of CPUs is adequate to address the dynamic nature of the blogosphere and the main concerns of the blog industry. We also discuss the business models based on CPUs that could be used to stimulate user activities in a blog network. [ABSTRACT FROM PUBLISHER]

The problem of routing/scheduling in a wireless network with partial/delayed network (channel and queue) state information (NSI) is studied in this paper. Two cases are considered: (i) centralized routing/scheduling, where a central controller obtains heterogeneously delayed information from each of the nodes (thus, the controller has NSI with different delays from different nodes), and makes routing/scheduling decisions; (ii) decentralized routing/scheduling, where each node makes a decision based on its current channel and queue states along with homogeneous delayed NSI from other nodes. For each of the cases (with additional flow restrictions for the decentralized routing/scheduling case), the optimal network throughput regions are characterized under the above described NSI models and it is shown that the throughput regions shrinks with the increase of delay. Further, channel and queue length based routing/scheduling algorithms that achieve the above throughput regions are proposed in this paper. [ABSTRACT FROM PUBLISHER]

This paper formulates a self-organization algorithm to address the problem of global behavior supervision in engineered swarms of arbitrarily large population sizes. The swarms considered in this paper are assumed to be homogeneous collections of independent identical finite-state agents, each of which is modeled by an irreducible finite Markov chain. The proposed algorithm computes the necessary perturbations in the local agents' behavior, which guarantees convergence to the desired observed state of the swarm. The ergodicity property of the swarm, which is induced as a result of the irreducibility of the agent models, implies that while the local behavior of the agents converges to the desired behavior only in the time average, the overall swarm behavior converges to the specification and stays there at all times. A simulation example illustrates the underlying concept. [ABSTRACT FROM AUTHOR]

Light-trail is proposed as a candidate to carry IP traffic over wavelength-division multiplexing optical networks given its capability of enabling high-speed provisioning and accommodating multigranularity traffic. In a light-trail, the optical shutters at the start node and the end node are configured to be in OFF state and the optical shutters at the intermediate nodes are configured to be in ON state. Thus, an optical bus is formed, allowing traffic multiplexing without the state change of any optical shutter. This, however, limits the system throughput and also makes it impossible to implement a fully distributed medium access control (MAC) protocol to assure quality of service (QoS) in a light-trail. With the recent development on ultrafast optical shutter, we propose an improved light-trail architecture, called opportunistic hyperchannel in this paper. In an opportunistic hyperchannel, an intermediate node can dynamically control its optical shutter which makes it possible to design a fully distributed QoS assuring MAC protocol. We then present a QoS assuring distributed dynamic scheduling protocol, namely, minimum source round robin (minSrcRR) protocol, for opportunistic hyperchannels. Theoretical analysis on the effectiveness of the proposed QoS assuring protocol and the worst-case delay bound are also derived in this paper. The simulation results quantitatively demonstrate the advantage of opportunistic hyperchannels and the effectiveness of minSrcRR protocol. [ABSTRACT FROM AUTHOR]

The article discusses various reports published within the issue, including one by Julien Maisonneuve, Muriel Deschanel, Juergen Heiles on Internet Protocol Television (IPTV) standards development, one by Gyu Myoung Lee, Chae Sub Lee, and Woo Seop Rhee on the functional architecture for next generation network and IPTV, and one by Marcel Wagner, Ivan Kopilovic, and Harald Fuchs on two major transport protocols for IPTV.

This paper considers the performance of time-domain power-allocation schemes with average and peak power constraints and proposes a constant-power allocation (CPA) scheme. In a Nakagami-m fading environment, an exact closed-form expression for the ergodic capacity of the proposed CPA scheme is derived, and the effect of the fading parameter m on the performance degradation due to a peak power constraint is investigated. The proposed scheme shows a near-optimum performance within 5% of the optimal capacity and provides a noticeable performance improvement as it reduces the peak-to-average power ratio (PAPR) with a signal-to-noise ratio (SNR) gain of approximately 8.5 dB while also mitigating the intercell interference in the uplink. [ABSTRACT FROM AUTHOR]

In this paper, we revisit the supernode-shape selection problem, which has been widely discussed in the bibliography. In general, the selection of the supernode transformation greatly affects the parallel execution time of the transformed algorithm. Since the minimization of the overall parallel execution time via an appropriate supernode transformation is very difficult to accomplish, researchers have focused on scheduling-aware supernode transformations that maximize parallelism during the execution. In this paper, we argue that the communication volume of the transformed algorithm is an important criterion, and its minimization should be given high priority. For this reason, we define the metric of the per-process communication volume and propose a method to minimize this metric by selecting a communication-aware supernode shape. Our approach is equivalent to defining a proper Cartesian process grid with MPI_Cart_Create, which means that it can be incorporated in applications in a straightforward manner. Our experimental results illustrate that by selecting the tile shape with the proposed method, the total parallel execution time is significantly reduced due to the minimization of the communication volume, despite the fact that a few more parallel execution steps are required. [ABSTRACT FROM AUTHOR]

The IEEE 802.11 standard has enabled low-cost and effective wireless local area network (WLAN) services. It is widely believed that WLANs will become a major portion of the fourth-generation cellular system. The seamless handoff problem in WLANs is a very important design issue to support the new astounding and amazing applications in WLANs, particularly for a user in a mobile vehicle. The entire delay time of a handoff is divided into probe, authentication, and reassociation delay times. Because the probe delay occupies most of the handoff delay time, efforts have mainly focused on reducing the probe delay to develop faster handoff schemes. This paper presents a new fast handoff scheme (i.e., the DeuceScan scheme) to further reduce the probe delay for IEEE-802.11-based WLANs. The proposed scheme can be useful to improve wireless communication qualities on vehicles. A spatiotemporal approach is developed in this paper to utilize a spatiotemporal graph to provide spatiotemporal information for making accurate handoff decisions by correctly searching for the next access point. The DeuceScan scheme is a prescan approach that efficiently reduces the Iayer-2 handoff latency. Two factors of stable signal strength and variable signal strength are used in our developed DeuceScan scheme. Finally, simulation results illustrate the performance achievements of the DeuceScan scheme in reducing handoff delay time and packet loss rate and improving link quality. [ABSTRACT FROM AUTHOR]

The advent of high-speed, lightweight, and durable sensor technologies opens new possibilities for field monitoring applications. In particular, under natural or man-made loading conditions, applying these new technologies to the monitoring of building interiors may substantially help rescue and reconnaissance crews during postevent evaluations. To test such a methodology, in this paper, we develop a specialized network of conventional analog and digital (camera) sensors and use them in monitoring nonstructural components subjected to vibration loading within a demonstration building structure. A full-scale vibration experiment is conducted with a research team from the University of California, Los Angeles, on a vacant structure damaged during the 1994 Northridge Earthquake. The building of interest is a four-story office building located in Sherman Oaks, CA. The investigation has two primary objectives: 1) to characterize the seismic response of an important class of equipment and building contents and 2) to study the applicability of tracking the response of these equipment and contents using arrays of image-based monitoring systems. In this paper, we describe the experimental field setup, including the analog and camera sensor systems and the networking hardware used to collect data, present the testing matrix, and sample the processed analog data results. We summarize the difficulties encountered in the field implementation of these types of monitoring systems while highlighting their potential benefits. In a companion paper, we present the analysis methodology applied to the image sequences collected and summarize needs for future work if such systems are to be robustly employed in the field. [ABSTRACT FROM AUTHOR]

This paper presents the design and analysis of general packet radio service (GPRS)-wireless local area network (WLAN) mobility gateway (GWMG) for the integration of GPRS and WLANs. The interworking between GPRS and WLANs is achieved by the GWMG that resides on the border of GPRS and WLAN systems. The design goal is to minimize the modifications in GPRS and WLANs as both systems are already widely available. By deploying the GWMG, users can seamlessly roam among the two systems. Unlike other related work, the proposed GWMG could be used when either the GPRS or WLAN is a user's home network. Both mathematical analysis and simulation are developed to analyze the performance. The proposed GWMG has also been implemented in a testbed comprising a commercial GPRS system. The results show that the GWMG could achieve a design goal that will effectively integrate GPRS and WLANs. [ABSTRACT FROM AUTHOR]

Applying IP and web technologies and the inherent properties of a broadband router widely used at home or in small business, this paper presents a paperless, sharable, plug-and-play, web-based fax server for multiple users. Instead of using email via a digital network as FoIP, the proposed fax server sends and receives fax documents via the public switched telephone network like the conventional analog fax machines do. The fax server users handle incoming and outgoing faxes by only web browsers through an IP-based local area network composed of an off-the-shelf broadband router, the proposed fax server, and the users' computers. This paper introduces the system architecture and software driving techniques of the proposed fax server. [ABSTRACT FROM AUTHOR]

Universal mobile-telecommunication system supports IP multimedia services through the IP multimedia core-network subsystem (IMS). This paper proposes a prepaid application server (PAS) to handle both the prepaid calls and messaging services in the IMS. When both voice and messaging are simultaneously offered, a potential problem is that the delivery of a message during a call may result in force-termination of that call due to credit depletion. To address this issue, we describe a strategy to determine if a prepaid message can be sent out during a call session. We propose an analytic model to investigate the performance of this strategy. This paper provides guidelines to select appropriate input parameters for the PAS. [ABSTRACT FROM AUTHOR]

The support of voice over Internet Protocol (VoIP) services in next-generation wireless systems requires the coupling of mobility with quality of service. The mobile node can experience disruptions or even intermittent disconnections of an ongoing real-time session due to handovers. The duration of such interruptions is called disruption time or handover delay and can heavily affect user satisfaction. Therefore, this delay needs to be minimized to provide good-quality VoIP services. In this paper, the focus is on the network layer mobility, specifically on mobile Internet Protocols (MIPs), since they are natural candidates for providing mobility at layer 3. Using analytical models, the authors evaluate MIPv4, MIPv6, fast MIPv6 (FMIPv6), and hierarchical MIPv6 (HMIPv6) and compare their performances in terms of handover delay for VoIP services. To optimize the handover delay, the authors propose to use the adaptive retransmission timer described in this paper. The results obtained using the adaptive timer technique show that for a 3% frame error rate and a 128-kb/s channel, the handoff delay is about 0.075 s (predictive) and 0.051 s (reactive) for FMIPv6. It is around 0.047 s [intra-mobile anchor point (MAP)] and 1.47 s (inter-MAP) for HMIPv6, around 1 s for MIPv6, and 0.26 s for MIPv4. [ABSTRACT FROM AUTHOR]

This paper studies the problem of structured data extraction from arbitrary Web pages. The objective of the proposed research is to automatically segment data records in a page, extract data items/fields from these records, and store the extracted data in a database. Existing methods addressing the problem can be classified into three categories. Methods in the first category provide some languages to facilitate the construction of data extraction systems. Methods in the second category use machine learning techniques to learn wrappers (which are data extraction programs) from human labeled examples. Manual labeling is time-consuming and is hard to scale to a large number of sites on the Web. Methods in the third category are based on the idea of automatic pattern discovery. However, multiple pages that conform to a common schema are usually needed as the input. In this paper, we propose a novel and effective technique (called DEPTA) to perform the task of Web data extraction automatically. The method consists of two steps: 1) identifying individual records in a page and 2) aligning and extracting data items from the identified records. For step 1, a method based on visual information and tree matching is used to segment data records. For step 2, a novel partial alignment technique is proposed. This method aligns only those data items in a pair of records that can be aligned with certainty, making no commitment on the rest of the items. Experimental results obtained using a large number of Web pages from diverse domains show that the proposed two-step technique is highly effective. [ABSTRACT FROM AUTHOR]

As the demand for high-quality Internet increases, emerging network applications are spurring the need for faster, feature-rich, and cost-effective routers. Multifield packet classification in routers has been a computation-intensive data path function for software implementation. Therefore, solutions for packet classification based on hardware design, such as Ternary Content Addressable Memory (TCAM), are necessary to sustain gigabit line processing rate. Traditionally, TCAMs have been designed for storing prefixes. However, multifield packet classification usually involves two fields of arbitrary ranges that are TCP/IP layer 4 source and destination ports. Storing ranges in TCAMs relies on decomposing each individual range into multiple prefixes, which leads to range-to-prefix blowout. To reduce the total number of prefixes needed to represent all ranges, this paper proposes a 2-level TCAM architecture and two range-to-prefix conversion schemes. In the first proposed scheme, designed for disjoint ranges, the maximum number of entries needed in TCAM is 2m - 1 for m disjoint ranges. In the second proposed scheme, designed for contiguous ranges, only m TCAM entries are needed. In a general case of n arbitrary ranges, all ranges can first be converted into disjoint ranges or contiguous ranges and then the proposed algorithms can be applied. As a result, only 4n - 3 TCAM entries are needed for the disjoint ranges and only 2n + 1 TCAM entries are needed for contiguous ranges. This paper also proposes insertion and deletion algorithms to accommodate incremental changes to the range sets. The experiments made show that the proposed range-to-prefix conversion schemes perform better than the existing schemes in terms of the number of required TCAM entries and execution time for range update operations. [ABSTRACT FROM AUTHOR]

The Internet is the most widely used medium to access remote sites. Data sent and received using transmission control protocol/Internet Protocol (TCP/IP) is in plain text format and can be accessed and tampered with quite easily and, hence, provides no data security. This is the case especially if the data are confidential and access to the gateway server has to be strictly controlled, although there are several protocols and mechanisms that have been thoroughly scrutinized to tackle these problems. This paper also intends to provide a model that uses secure socket layer (SSL) to provide a secure channel between client and gateway server. A smart card will be used for client authentication and encryption/decryption of the data. [ABSTRACT FROM AUTHOR]

This paper provides a summary of the state of electric power engineering education through descriptions of professional society activities, Internet resources, and results of a world-wide survey conducted in March 2003. [ABSTRACT FROM AUTHOR]

Vehicular ad hoc networks (VANETs) have recently received significant attention in improving traffic safety and efficiency. However, communication trust and user privacy still present practical concerns to the deployment of VANETs, as many existing authentication protocols for VANETs either suffer from the heavy workload of downloading the latest revocation list from a remote authority or cannot allow drivers on the road to decide the trustworthiness of a message when the authentication on messages is anonymous. In this paper, to cope with these challenging concerns, we propose a new authentication protocol for VANETs in a decentralized group model by using a new group signature scheme. With the assistance of the new group signature scheme, the proposed authentication protocol is featured with threshold authentication, efficient revocation, unforgeability, anonymity, and traceability. In addition, the assisting group signature scheme may also be of independent interest, as it is characterized by efficient traceability and message linkability at the same time. Extensive analyses indicate that our proposed threshold anonymous authentication protocol is secure, and the verification of messages among vehicles can be accelerated by using batch message processing techniques. [ABSTRACT FROM AUTHOR]

Software testing began as an empirical activity, and remains part of engineering practice without a widely accepted theoretical foundation. The overwhelming majority of test methods are designed to find software errors, termed faults, in program source code, but not to assess software operational quality. To go beyond fault-seeking requires a theory that relates static program properties to executions. In the 1970s and 1980s, Gerhart, Howden, and others developed a sound functional theory of program testing. Then Duran and others used this theory to precisely define the notions of random testing and operational reliability. In the Gerhart-Howden-Duran theory, a program's behavior is a pure input-output mapping. This paper extends the theory to include persistent state, by adding a state space to the input space, and a state mapping to a program's output mapping. The extended theory is significantly different because test states, unlike inputs, cannot be chosen arbitrarily. The theory is used to analyze state-based testing methods, to examine the practicality of reliability assessment, and to suggest experiments that would increase understanding of the statistical properties of software. [ABSTRACT FROM AUTHOR]

Recently, a structure of an optimal linear precoder for multi cell downlink systems has been described, and many other references have used simplified versions of this precoder to obtain promising performance gains. These gains have been hypothesized to stem from the additional degrees of freedom that allow for interference mitigation through interference relegation to orthogonal subspaces. However, no conclusive or rigorous understanding has yet been developed. In this paper, we build on an intuitive interference induction trade-off and the aforementioned preceding structure to propose an interference aware RZF (iaRZF) preceding scheme for multi cell downlink systems, and we analyze its rate performance. Special emphasis is placed on the induced interference mitigation mechanism of iaRZF. For example, we will verify the intuitive expectation that the precoder structure can either completely remove induced inter-cell or intra-cell interference. We state new results from large-scale random matrix theory that make it possible to give more intuitive and insightful explanations of the precoder behavior, also for cases involving imperfect channel state information (CSI). We remark especially that the interference-aware precoder makes use of all available information about interfering channels to improve performance. Even very poor CSI allows for significant sum-rate gains. Our obtained insights are then used to propose heuristic precoder parameters for arbitrary systems, whose effectiveness are shown in more involved system scenarios. Furthermore, calculation and implementation of these parameters does not require explicit inter base station cooperation. [ABSTRACT FROM PUBLISHER]

There is a large variety of trackers, which have been proposed in the literature during the last two decades with some mixed success. Object tracking in realistic scenarios is a difficult problem, therefore, it remains a most active area of research in computer vision. A good tracker should perform well in a large number of videos involving illumination changes, occlusion, clutter, camera motion, low contrast, specularities, and at least six more aspects. However, the performance of proposed trackers have been evaluated typically on less than ten videos, or on the special purpose datasets. In this paper, we aim to evaluate trackers systematically and experimentally on 315 video fragments covering above aspects. We selected a set of nineteen trackers to include a wide variety of algorithms often cited in literature, supplemented with trackers appearing in 2010 and 2011 for which the code was publicly available. We demonstrate that trackers can be evaluated objectively by survival curves, Kaplan Meier statistics, and Grubs testing. We find that in the evaluation practice the F-score is as effective as the object tracking accuracy (OTA) score. The analysis under a large variety of circumstances provides objective insight into the strengths and weaknesses of trackers. [ABSTRACT FROM AUTHOR]

This paper describes a novel method to acquire depth images using a pair of ToF (Time-of-Flight) cameras. As opposed to approaches that filter, calibrate or do 3D reconstructions posterior to the image acquisition, we combine the measurements of the two cameras within a modified acquisition procedure. The new proposed stereo-ToF acquisition is composed of three stages during which we actively modify the infrared lighting of the scene: first, the two cameras emit an infrared signal one after the other (stages 1 and 2), and then, simultaneously (stage 3). Assuming the scene is static during the three stages, we gather the depth measurements obtained with both cameras and define a cost function to optimize the two depth images. A qualitative and quantitative evaluation of the performance of the proposed stereo-ToF acquisition is provided both for simulated and real ToF cameras. In both cases, the stereo-ToF acquisition produces more accurate depth measurements. Moreover, an extension to the multi-view ToF case and a detailed study on the interference specifications of the system are included. [ABSTRACT FROM AUTHOR]

With the ever-increasing use of smartphones and tablet devices, location-based services (LBSs) have experienced explosive growth in the past few years. To scale up services, there has been a rising trend of outsourcing data management to Cloud service providers, which provide query services to clients on behalf of data owners. However, in this data-outsourcing model, the service provider can be untrustworthy or compromised, thereby returning incorrect or incomplete query results to clients, intentionally or not. Therefore, empowering clients to authenticate query results is imperative for outsourced databases. In this paper, we study the authentication problem for location-based arbitrary-subspace skyline queries (LASQs), which represent an important class of LBS applications. We propose a basic Merkle Skyline R-tree method and a novel Partial S4-tree method to authenticate one-shot LASQs. For the authentication of continuous LASQs, we develop a prefetching-based approach that enables clients to compute new LASQ results locally during movement, without frequently contacting the server for query re-evaluation. Experimental results demonstrate the efficiency of our proposed methods and algorithms under various system settings. [ABSTRACT FROM PUBLISHER]

Cloud computing economically enables customers with limited computational resources to outsource large-scale computations to the cloud. However, how to protect customers' confidential data involved in the computations then becomes a major security concern. In this paper, we present a secure outsourcing mechanism for solving large-scale systems of linear equations (LE) in cloud. Because applying traditional approaches like Gaussian elimination or LU decomposition (aka. direct method) to such large-scale LEs would be prohibitively expensive, we build the secure LE outsourcing mechanism via a completely different approach—iterative method, which is much easier to implement in practice and only demands relatively simpler matrix-vector operations. Specifically, our mechanism enables a customer to securely harness the cloud for iteratively finding successive approximations to the LE solution, while keeping both the sensitive input and output of the computation private. For robust cheating detection, we further explore the algebraic property of matrix-vector operations and propose an efficient result verification mechanism, which allows the customer to verify all answers received from previous iterative approximations in one batch with high probability. Thorough security analysis and prototype experiments on Amazon EC2 demonstrate the validity and practicality of our proposed design. [ABSTRACT FROM AUTHOR]