National University of Singapore

Displaying 1-40 of 200 results

  • White Papers // Jul 2014

    Recent Advances in Joint Wireless Energy and Information Transfer

    In this paper, the authors provide an overview of the recent advances in microwave-enabled Wireless Energy Transfer (WET) technologies and their applications in wireless communications. Specifically, they divide their discussions into three parts. First, they introduce the state-of-the-art WET technologies and the signal processing techniques to maximize the energy transfer...

    Provided By National University of Singapore

  • White Papers // Feb 2014

    Effective Multi-Modal Retrieval Based on Stacked Auto-Encoders

    Multi-modal retrieval is emerging as a new search paradigm that enables seamless information retrieval from various types of media. For example, users can simply snap a movie poster to search relevant reviews and trailers. To solve the problem, a set of mapping functions are learned to project high-dimensional features extracted...

    Provided By National University of Singapore

  • White Papers // Jan 2014

    Random Number Conversion and LOCC Conversion via Restricted Storage

    The authors consider Random Number Conversion (RNC) through random number storage with restricted size. They clarify the relation between the performance of RNC and the size of storage in the framework of first- and second-order asymptotics, and derive their rate regions. Then, they show that the results for RNC with...

    Provided By National University of Singapore

  • White Papers // Jan 2014

    Ubiquitous Memory Introspection

    Modern memory systems play a critical role in the performance of applications, but a detailed understanding of the application behavior in the memory system is not trivial to attain. It requires time consuming simulations and detailed modeling of the memory hierarchy, often using long address traces. It is increasingly possible...

    Provided By National University of Singapore

  • White Papers // Dec 2013

    Efficient In-Memory Data Management: An Analysis

    Given the explosion of big data analytics, it is important to understand the performance costs and limitations of existing approaches for in-memory data management. Broadly, in-memory data management covers two main types of roles: supporting analytics operations such as iterative algorithms and supporting storage and retrieval operations on arbitrary key-value...

    Provided By National University of Singapore

  • White Papers // Oct 2013

    Real-time and Low Power Embedded l1-Optimization Solver Design

    Basis Pursuit DeNoising (BPDN) is an optimization method used in cutting edge computer vision and compressive sensing research. Although hosting a BPDN solver on an embedded platform is desirable because analysis can be performed in real-time, existing solvers are generally unsuitable for embedded implementation due to either poor run-time performance...

    Provided By National University of Singapore

  • White Papers // Aug 2013

    A Performance Study of Three Disk-Based Structures for Indexing and Querying Frequent Itemsets

    Frequent itemset mining is an important problem in the data mining area. Extensive efforts have been devoted to developing efficient algorithms for mining frequent itemsets. However, not much attention is paid on managing the large collection of frequent itemsets produced by these algorithms for subsequent analysis and for user exploration....

    Provided By National University of Singapore

  • White Papers // Aug 2013

    Efficient Indexing for Diverse Query Results

    In this paper, the authors examine the problem of computing diverse query results which is useful for browsing search results in online shopping applications. The search results are diversified wrt a sequence of output attributes (termed d-order) where an attribute that appears earlier in the d-order has higher priority for...

    Provided By National University of Singapore

  • White Papers // Aug 2013

    A Quantitative Evaluation of Privilege Separation in Web Browser Designs

    Privilege separation is a fundamental security concept that has been used in designing many secure systems. A number of recent works propose redesigning web browsers with greater privilege separation for better security. However, privilege-separated designs require a fine balance between security benefits and other competing concerns, such as performance. In...

    Provided By National University of Singapore

  • White Papers // Aug 2013

    MAMPSx: A Design Framework for Rapid Synthesis of Predictable Heterogeneous MPSoCs

    Heterogeneous Multi-Processor System-on-Chip (HMPSoC) is becoming popular as a means of meeting energy efficiency requirements of modern embedded systems. However, as these HMPSoCs run multimedia applications as well, they also need to meet real-time requirements. Designing these predictable HMPSoCs is a key challenge, as the current design methods for these...

    Provided By National University of Singapore

  • White Papers // Aug 2013

    Power-Performance Modeling on Asymmetric Multi-Cores

    Asymmetric multi-core architectures have recently emerged as a promising alternative in a power and thermal constrained environment. They typically integrate cores with different power and performance characteristics, which makes mapping of workloads to appropriate cores a challenging task. Limited number of performance counters and heterogeneous memory hierarchy increase the difficulty...

    Provided By National University of Singapore

  • White Papers // Jul 2013

    Run-Time Mapping for Reliable Many-Cores Based on Energy/Performance Trade-offs

    To accommodate the applications' ever-increasing demands and to achieve and exploit easily-manageable scalability, complex many-core systems are built by integrating low-cost Commercial Off-The-Shelf (COTS) components. Most recent many-core systems consist of processing nodes interconnected via Network-on-Chips (NoCs) in a mesh-based architecture. This paper presents a run-time resource manager for NoC-based...

    Provided By National University of Singapore

  • White Papers // Jul 2013

    Introduction to Malware Analysis

    Malware has become the spotlight of security threats on the virtual world. Many different kind of malware exist. Some have destruction capability such as deletion of data, while the other is more stealthy (eg. log keystrokes). The foremost goal of malware analysis is to understand malware behaviors. Through the understanding...

    Provided By National University of Singapore

  • White Papers // Jul 2013

    Aging-Aware Hardware-Software Task Partitioning for Reliable Reconfigurable Multiprocessor Systems

    Homogeneous multiprocessor systems with reconfigurable area (also known as reconfigurable multiprocessor systems) are emerging as a popular design choice in current and future technology nodes to meet the heterogeneous computing demand of a multitude of applications enabled on these platforms. Application specific mapping decisions on such a platform involve partitioning...

    Provided By National University of Singapore

  • White Papers // Jul 2013

    Enhancing VHDL Learning Through a Light-Weight Integrated Environment for Development and Automated Checking

    The development environments for Hardware Description Languages (HDLs) are essentially meant and designed for highly trained professionals/ engineers and as such are not suitable for use as an introductory tool for students learning HDLs. With students adopting a variety of operating systems, there is a need for a light-weight and...

    Provided By National University of Singapore

  • White Papers // Jun 2013

    Implementation of Core Coalition on FPGAs

    Embedded systems increasingly need to support dynamic and diverse application landscape. In response, performance asymmetric multi-cores, comprising of identical instruction-set architecture but micro-architecturally distinct set of simple and complex cores, have emerged as an attractive alternative to accommodate software diversity. Dynamic heterogeneous multi-core architectures take this concept forward by allowing...

    Provided By National University of Singapore

  • White Papers // Jun 2013

    Incorporating Energy and Throughput Awareness in Design Space Exploration and Run-time Mapping for Heterogeneous MPSoCs

    The advancement in process technology has enabled integration of different types of processing cores into a single chip towards creating heterogeneous Multi-Processor Systems-on-Chip (MPSoCs). While providing high level of computation power to support complex applications, these modern systems also introduce novel challenges for system designers, like managing a huge number...

    Provided By National University of Singapore

  • White Papers // Jun 2013

    Task Scheduling on Adaptive Multi-Core

    Multi-cores have become ubiquitous both in the general-purpose computing and the embedded domain. The current technology trends show that the number of on-chip cores is rapidly increasing, while their complexity is decreasing due to power and thermal constraints. Increasing number of simple cores enable parallel applications benefit from abundant Thread-Level...

    Provided By National University of Singapore

  • White Papers // Jun 2013

    RAPIDITAS: RAPId Design-Space-Exploration Incorporating Trace-Based Analysis and Simulation

    Simulation-based Design Space Exploration (DSE) to evaluate all possible mappings for a given application and Multi-Processor System-on-Chip (MPSoC) platform is computationally costly for large problems. Even using efficient exploration methodologies to evaluate the mappings cannot overcome the evaluation time bottleneck. This paper presents a novel DSE methodology that analyzes the...

    Provided By National University of Singapore

  • White Papers // Jun 2013

    Energy-Aware Dynamic Reconfiguration of Communication-Centric Applications for Reliable MPSoCs

    To accommodate the ever increasing demands of applications and for the ease of scalability, Multi-Processor system-on-chips (MPSoCs) are becoming a popular design choice in current and future technologies with streaming multimedia and other communication-centric applications constituting a large fraction of the application space. Mapping and scheduling of these applications on...

    Provided By National University of Singapore

  • White Papers // May 2013

    Converse Bounds for Assorted Codes in the Finite Blocklength Regime

    The authors study converse bounds for unequal error protection codebooks with k > 1 different classes of codewords. They dub these unequal error protection codes "Assorted codes". They extend a finite blocklength converse bound due to Polyanskiy-Poor-Verdu to apply to assorted codes and use this extension to obtain a refined...

    Provided By National University of Singapore

  • White Papers // May 2013

    On the Dispersions of the Discrete Memoryless Interference Channel

    In this paper, achievable dispersions for the Discrete Memoryless Interference Channel (DM-IC) are derived. In other words, they characterize the backoff from the Han-Kobayashi (HK) achievable region, the largest inner bound known to date for the DM-IC. In addition, they also characterize the backoff from Sato's region in the strictly...

    Provided By National University of Singapore

  • White Papers // May 2013

    Efficient Routing on Multilayered Communication Networks

    The authors study the optimal routing on multilayered communication networks, which are composed of two layers of sub-networks. One is a wireless network, and the other is a wired network. They develop a simple recurrent algorithm to find an optimal routing on this kind of multilayered network, where the single-channel...

    Provided By National University of Singapore

  • White Papers // May 2013

    Communication and Migration Energy Aware Task Mapping for Reliable Multiprocessor Systems

    Heterogeneous Multi-Processor Systems-on-Chip (MPSoCs) are emerging as a promising solution in deep sub-micron technology nodes to satisfy design performance and power requirements. However, shrinking transistor geometry and aggressive voltage scaling are negatively impacting the dependability of these MPSoCs by increasing the chances of failures. This paper proposes an offline (design-time)...

    Provided By National University of Singapore

  • White Papers // Apr 2013

    A Formula for the Capacity of the General Gelfand-Pinsker Channel

    The authors consider the Gel'fand-Pinsker problem in which the channel and state are general, i.e., possibly non-stationary, non-memoryless and non-ergodic. Using the information spectrum method and a non-trivial modification of the piggyback coding lemma by Wyner, they prove that the capacity can be expressed as an optimization over the difference...

    Provided By National University of Singapore

  • White Papers // Apr 2013

    Towards General Security Support in the Browser Environment

    The web browser has evolved into a complex execution environment for rich Internet applications, providing support for advanced layout and various executable components. However, the security mechanisms in browsers do not evolve at the same pace to provide adequate protection for web applications. In this paper, the authors give a...

    Provided By National University of Singapore

  • White Papers // Mar 2013

    CoMP Meets Energy Harvesting: A New Communication and Energy Cooperation Paradigm

    In this paper, the authors investigate joint communication and energy cooperation in cellular networks for the Coordinated Multi-Point (CoMP) downlink transmission with Base Stations (BSs) powered by renewable energy. For the purpose of exposition, they consider a simplified CoMP model with two BSs cooperatively serving two Mobile Stations (MSs), where...

    Provided By National University of Singapore

  • White Papers // Mar 2013

    Multiuser MISO Beamforming for Simultaneous Wireless Information and Power Transfer

    In this paper, the authors study a multiuser Multiple-Input Single-Output (MISO) broadcast system for Simultaneous Wireless Information and Power Transfer (SWIPT), where a multi-antenna Access Point (AP) sends information and energy simultaneously via beam-forming to multiple single-antenna receivers. They maximize the weighted sum-power transferred to Energy Harvesting (EH) receivers subject...

    Provided By National University of Singapore

  • White Papers // Feb 2013

    Splash: Fast Data Dissemination With Constructive Interference in Wireless Sensor Networks

    It is well-known that the time taken for disseminating a large data object over a wireless sensor network is dominated by the overhead of resolving the contention for the underlying wireless channel. In this paper, the authors propose a new dissemination protocol called Splash that eliminates the need for contention...

    Provided By National University of Singapore

  • White Papers // Feb 2013

    Opportunistic Wireless Energy Harvesting in Cognitive Radio Networks

    Wireless networks can be self-sustaining by harvesting energy from ambient Radio-Frequency (RF) signals. Recently, researchers have made progress on designing efficient circuits and devices for RF energy harvesting suitable for low-power wireless applications. Motivated by this and building upon the classic Cognitive Radio (CR) network model, this paper proposes a...

    Provided By National University of Singapore

  • White Papers // Feb 2013

    MIMO Broadcasting for Simultaneous Wireless Information and Power Transfer

    Wireless Energy Transfer (WET) is a promising technology to provide virtually perpetual energy supplies to wireless networks. Generally speaking, WET is implementable by either the "Near-field" ElectroMagnetic (EM) induction or the "Far-field" EM radiation, for short and long range applications, respectively. In this paper, the latter case in the particular...

    Provided By National University of Singapore

  • White Papers // Feb 2013

    Wireless Information and Power Transfer: A Dynamic Power Splitting Approach

    Energy harvesting is a promising solution to prolong the operation time of energy-constrained wireless networks. In particular, scavenging energy from ambient radio signals, namely Wireless Energy Harvesting (WEH), has recently drawn significant attention. In this paper, the authors consider a point-to-point wireless link over the flat-fading channel, where the receiver...

    Provided By National University of Singapore

  • White Papers // Jan 2013

    A Novel Mode Switching Scheme Utilizing Random Beamforming for Opportunistic Energy Harvesting

    Since radio signals carry both energy and information simultaneously, a unified study on Simultaneous Wireless Information and Power Transfer (SWIPT) has recently attracted a great deal of attention for providing wireless energy to communication devices. This paper proposes a novel receiver mode switching scheme for SWIPT and the enabling transmitter...

    Provided By National University of Singapore

  • White Papers // Jan 2013

    Energy Cooperation in Cellular Networks With Renewable Powered Base Stations

    In this paper, the authors propose a model for energy cooperation between cellular Base Stations (BSs) with individual renewable energy sources, limited energy storages and connected by resistive power lines for energy sharing. When the renewable energy profile and energy demand profile at all BSs are deterministic or known ahead...

    Provided By National University of Singapore

  • White Papers // Dec 2012

    Speeding Up Ate Pairing Computation in Affine Coordinates

    At Pairing 2010, researcher's analysis showed that Ate pairing computation in affine coordinates may be much faster than projective coordinates at high security levels. In this paper, the authors further investigate techniques to speed up ate pairing computation in affine coordinates. They first analyze ate pairing computation using 4-ary miller...

    Provided By National University of Singapore

  • White Papers // Dec 2012

    Communication and Migration Energy Aware Design Space Exploration for Multicore Systems with Intermittent Faults

    Shrinking feature-size and growing transistor density are negatively impacting the dependability of Multi-Processor System-on-Chips (MPSoCs) by increasing the chances of faults (permanent, intermittent and transient). Recently, intermittent device defects are gaining significant attention among research community. These are a class of hardware faults occurring frequently but irregularly over a period...

    Provided By National University of Singapore

  • White Papers // Dec 2012

    Reliability-Driven Task Mapping for Lifetime Extension of Networks-on-Chip Based Multiprocessor Systems

    Shrinking transistor geometries, aggressive voltage scaling and higher operating frequencies have negatively impacted the lifetime reliability of embedded multi-core systems. In this paper, a convex optimization-based task-mapping technique is proposed to extend the lifetime of a Multi-Processor Systems-on-Chip (MPSoCs). The proposed technique generates mappings for every application enabled on the...

    Provided By National University of Singapore

  • White Papers // Dec 2012

    A Preference Model for Deciding the Market Share of Network Service Providers

    Started with a single best-effort service, the Internet has evolved to an ecosystem where different Service Providers (SPs), e.g., Internet Service Providers (ISPs) and Content Distribution Networks (CDNs) provide different types of services, e.g., IP transit and content caching/distribution. In this paper, the authors propose a preference model on how...

    Provided By National University of Singapore

  • White Papers // Dec 2012

    CADSE: Communication Aware Design Space Exploration for Efficient Run-Time MPSoC Management

    Real-time multi-media applications are increasingly mapped on modern embedded systems based on Multi-Processor Systems-on-Chip (MPSoC). Tasks of the applications need to be mapped on the MPSoC resources efficiently in order to satisfy their performance constraints. Exploring all the possible mappings, i.e., tasks to resources combinations exhaustively may take days or...

    Provided By National University of Singapore

  • White Papers // Nov 2012

    Optimal Power and Range Adaptation for Green Broadcasting

    Improving energy efficiency is key to network providers maintaining profit levels and an acceptable carbon footprint in the face of rapidly increasing data traffic in cellular networks in the coming years. The energy-saving concept studied in this paper is the adaptation of a Base Station's (BS's) transmit power levels and...

    Provided By National University of Singapore

  • White Papers // Jan 2009

    Protecting Infrastructure Networks From Cost-Based Attacks

    It has been known that heterogeneous networks are vulnerable to the intentional removal of a small fraction of highly connected or loaded nodes, which implies that, to protect a network effectively, a few important nodes should be allocated with more defense resources than the others. However, if too many resources...

    Provided By National University of Singapore

  • White Papers // Jan 2009

    End-to-End Outage Minimization in OFDM Based Linear Relay Networks

    Multi-hop relaying is an economically efficient architecture for coverage extension and throughput enhancement in future wireless networks. OFDM, on the other hand, is a spectrally efficient physical layer modulation technique for broadband transmission. As a natural consequence of combining OFDM with multi-hop relaying, the allocation of per-hop subcarrier power and...

    Provided By National University of Singapore

  • White Papers // Feb 2011

    Competition And Innovation: The Inverted-U Relationship Revisited

    The author re-examines the inverted-U relationship between competition and innovation (originally modeled and tested by Aghion et al. [2005]) by using data from publicly traded manufacturing firms in the US. The author controls for the possible endogeneity of competition by using various measures of foreign competition as instruments. The author...

    Provided By National University of Singapore

  • White Papers // Mar 2011

    Authenticating Aggregate Range Queries Over Dynamic Multidimensional Dataset

    The authors are interested in the integrity of the query results from an outsourced database service provider. Alice passes a set D of d-dimensional points, together with some authentication tag T, to an untrusted service provider Bob. Later, Alice issues some query over D to Bob, and Bob should produce...

    Provided By National University of Singapore

  • White Papers // Mar 2011

    Authenticating Aggregate Range Queries Over Multidimensional Dataset

    The authors are interested in the integrity of the query results from an outsourced database service provider. Alice passes a set D of d-dimensional points, together with some authentication tag T, to an untrusted service provider Bob. Later, Alice issues some query over D to Bob, and Bob should produce...

    Provided By National University of Singapore

  • White Papers // Mar 2011

    Perspectives on Crowdsourcing Annotations for Natural Language Processing

    Crowdsourcing has emerged as a new method for obtaining annotations for training models for machine learning. While many variants of this process exist, they largely differ in their method of motivating subjects to contribute and the scale of their applications. To date, however, there has yet to be a study...

    Provided By National University of Singapore

  • White Papers // Jan 2011

    NPIC: Hierarchical Synthetic Image Classification Using Image Search and Generic Features

    The authors introduce NPIC, an image classification system that focuses on synthetic (e.g., non-photographic) images. They use class-specific keywords in an image search engine to create a noisily labeled training corpus of images for each class. NPIC then extracts both Content-Based Image Retrieval (CBIR) features and metadata-based textual features for...

    Provided By National University of Singapore

  • White Papers // Aug 2009

    FireCite: Lightweight Real-Time Reference String Extraction From Webpages

    The authors present FireCite, a Mozilla Firefox browser extension that helps scholars assess and manage scholarly references on the web by automatically detecting and parsing such reference strings in real-time. FireCite has two main components: A reference string recognizer that has a high recall of 96%, and a reference string...

    Provided By National University of Singapore

  • White Papers // Jan 2011

    Video Retrieval Using High Level Features: Exploiting Query Matching and Confidence-Based Weighting

    Recent research in video retrieval has focused on automated, high-level feature indexing on shots or frames. One important application of such indexing is to support precise video retrieval. The authors report on extensions of this semantic indexing on news video retrieval. First, they utilize extensive query analysis to relate various...

    Provided By National University of Singapore

  • White Papers // Jun 2010

    Extracting Formulaic and Free Text Clinical Research Articles Metadata Using Conditional Random Fields

    The authors explore the use of Conditional Random Fields (CRFs) to automatically extract important metadata from clinical research papers. These metadata fields include formulaic metadata about the authors, extracted from the title page, as well as free text fields concerning the study's critical parameters, such as longitudinal variables and medical...

    Provided By National University of Singapore

  • White Papers // Apr 2011

    Robust Argumentative Zoning for Sensemaking in Scholarly Documents

    The authors present an automated approach to classify sentences of scholarly work with respect to their rhetorical function. While previous work that achieves this task of argumentative zoning requires richly annotated input, the approach is robust to noise and can process raw text. Even in cases where the input has...

    Provided By National University of Singapore

  • White Papers // Jun 2010

    Hierarchical Cost-Sensitive Web Resource Acquisition for Record Matching

    Web information is increasingly used as evidence in solving various problems, including record matching. However, acquiring web-based resources is slow and can incur other access costs. As such, solutions often acquire only a subset of the resources to achieve a balance between acquisition cost and benefit. Unfortunately, existing work has...

    Provided By National University of Singapore

  • White Papers // Jan 2009

    Practical Connectivity-Based Routing in Wireless Sensor Networks Using Dimension Reduction

    Connectivity-based routing protocols provide an attractive option for point to point communication in wireless networks due to its potential for low routing overhead. However, when the entire hopcount vector is used to address each node, the communication and storage overhead in the packets are often so high that it is...

    Provided By National University of Singapore

  • White Papers // Jan 2009

    DEAL: Discover and Exploit Asymmetric Links in Dense Wireless Sensor Networks

    Asymmetric links commonly exist in low power wireless sensor networks. However, it is difficult to discover and exploit them efficiently. In this paper, the authors propose DEAL, a link management scheme to Discover and Exploit Asymmetric Links efficiently in dense wireless sensor networks. Equipped with a novel feedback mechanism, DEAL...

    Provided By National University of Singapore

  • White Papers // Jan 2010

    Pritrans: A Prioritized Converge-Cast Scheme Using Consensus Ranking in Wireless Sensor Networks

    Data packets collected in wireless sensor networks may contain information of different importance, including regular updates and critical data triggered by important events. In a converge-cast tree, packets routed towards the data sink may be dropped due to network contention. In order to improve the reliability of critical packets, the...

    Provided By National University of Singapore

  • White Papers // Aug 2009

    Incentive-Compatible Resource Allocation in Overlapping Heterogeneous Wireless Networks

    This paper considers the coordinated radio resource allocation problem for users which are simultaneously covered by multiple overlapping heterogeneous wireless networks. As the resource allocation decision depends on the channel measurement and feedback from users, inefficiency and instability arise if a selfish user can manipulate its measured channel state to...

    Provided By National University of Singapore

  • White Papers // Oct 2008

    Link Lifetimes: Distribution, Estimation and Application in Mobile Ad Hoc Networks

    Lifetime of a link defines the amount of time the link is available for transmission. In this paper, the authors begin with associating a statistical parametric model for link lifetime distribution for commonly used mobility patterns. The study reveals interesting properties about link lifetimes, including findings showing that lifetimes of...

    Provided By National University of Singapore

  • White Papers // Aug 2009

    Sync-TCP: A New Approach to High Speed Congestion Control

    As bandwidth in the Internet continues to grow, there will be more and more long fat network pipes with abundant residual bandwidth. At the same time, there is also a gradual and steady increase in the deployment of Internet endpoints equipped with different variants of high speed TCP. In this...

    Provided By National University of Singapore

  • White Papers // Nov 2010

    Capitalizing On Capitol Hill: Informed Trading By Hedge Fund Managers

    In this paper, the authors examine the hypothesis that hedge fund managers obtain an informational advantage in securities trading through their connections with lobbyists. Using datasets on hedge fund long-equity holdings and lobbying expenses from 1999 to 2008, they show that hedge funds that are connected to lobbyists tend to...

    Provided By National University of Singapore

  • White Papers // Jan 2009

    Effective XML Keyword Search With Relevance Oriented Ranking

    Inspired by the great success of Information Retrieval (IR) style keyword search on the web, keyword search on XML has emerged recently. The difference between text database and XML database results in three new challenges: firstly, identify the user search intention, i.e. identify the XML node types that user wants...

    Provided By National University of Singapore

  • White Papers // Jan 2009

    Demonstrating Effective Ranked XML Keyword Search With Meaningful Result Display

    In this paper, the authors demonstrate an effective ranked XML keyword search with meaningful result display. The system, named ICRA, recognizes a set of object classes in XML data for result display, defines the matching semantics that meet user's search needs more precisely, captures the ID references in XML data...

    Provided By National University of Singapore

  • White Papers // Dec 2009

    Efficient Label Encoding for Range-Based Dynamic XML Labeling Schemes

    Designing dynamic labeling schemes to support order-sensitive queries for XML documents has been recognized as an important research problem. In this paper, the authors consider the problem of making range-based XML labeling schemes dynamic through the process of encoding. The authors point out the problems of existing encoding algorithms which...

    Provided By National University of Singapore

  • White Papers // Dec 2009

    Towards an Effective XML Keyword Search

    Inspired by the great success of Information Retrieval (IR) style keyword search on the web, keyword search on XML has emerged recently. The difference between text database and XML database results in three new challenges: Identify the user search intention, i.e. identify the XML node types that user wants to...

    Provided By National University of Singapore

  • White Papers // Jan 2010

    Extended XML Tree Pattern Matching: Theories and Algorithms

    As business and enterprises generate and exchange XML data more often, there is an increasing need for efficient processing of queries on XML data. Searching for the occurrences of a tree pattern query in an XML database is a core operation in XML query processing. Prior works demonstrate that holistic...

    Provided By National University of Singapore

  • White Papers // Oct 2009

    Pharmaco-Cybernetics as an Interactive Component of Pharma-Culture: Empowering Drug Knowledge Through User-, Experience-And Activity-Centered Designs

    The advent of the World Wide Web (WWW) has led to the creation of many web publishing platforms. Patients are becoming more well-informed through drug and health-related information over the internet. The integration of interactive media technologies and the WWW provides an opportunity to improve the pharmaceutical care of patients...

    Provided By National University of Singapore

  • White Papers // Sep 2009

    A Graph Theoretic Approach for Optimizing Key Pre-Distribution in Wireless SensorNetworks

    Finding an optimal key assignment (subject to given constraints) for a key predistribution scheme in wireless sensor networks is a difficult task. Hence, most of the practical schemes are based on probabilistic key assignment, which leads to sub-optimal schemes requiring key storage linear in the total number of nodes. A...

    Provided By National University of Singapore

  • White Papers // Apr 2009

    Multi-Label Sparse Coding for Automatic Image Annotation

    Automatic image annotation, whose goal is to automatically assign the images with the keywords, has been an active research topic owing to its great potentials in image retrieval and management systems. Image annotation is essentially a typical multi-label learning problem, where each image could contain multiple objects and therefore could...

    Provided By National University of Singapore

  • White Papers // Mar 2010

    Blind Motion Deblurring From a Single Image Using Sparse Approximation

    Restoring a clear image from a single motion-blurred image due to camera shake has long been one challenging problem in digital imaging. Existing blind deblurring techniques either only can remove simple motion blurring, or need user interactions to work on more complex cases. In this paper, the authors present an...

    Provided By National University of Singapore

  • White Papers // Apr 2009

    Verification of Population Ring Protocols in PAT

    The population protocol model has emerged as an elegant paradigm for describing mobile ad hoc networks, consisting of a number of nodes that interact with each other to carry out a computation. One essential property of self-stabilizing population protocols is that all nodes must eventually converge to the correct output...

    Provided By National University of Singapore

  • White Papers // Feb 2013

    Wireless Information and Power Transfer: A Dynamic Power Splitting Approach

    Energy harvesting is a promising solution to prolong the operation time of energy-constrained wireless networks. In particular, scavenging energy from ambient radio signals, namely Wireless Energy Harvesting (WEH), has recently drawn significant attention. In this paper, the authors consider a point-to-point wireless link over the flat-fading channel, where the receiver...

    Provided By National University of Singapore

  • White Papers // Nov 2012

    Optimal Power and Range Adaptation for Green Broadcasting

    Improving energy efficiency is key to network providers maintaining profit levels and an acceptable carbon footprint in the face of rapidly increasing data traffic in cellular networks in the coming years. The energy-saving concept studied in this paper is the adaptation of a Base Station's (BS's) transmit power levels and...

    Provided By National University of Singapore

  • White Papers // Jan 2013

    A Novel Mode Switching Scheme Utilizing Random Beamforming for Opportunistic Energy Harvesting

    Since radio signals carry both energy and information simultaneously, a unified study on Simultaneous Wireless Information and Power Transfer (SWIPT) has recently attracted a great deal of attention for providing wireless energy to communication devices. This paper proposes a novel receiver mode switching scheme for SWIPT and the enabling transmitter...

    Provided By National University of Singapore

  • White Papers // Feb 2013

    MIMO Broadcasting for Simultaneous Wireless Information and Power Transfer

    Wireless Energy Transfer (WET) is a promising technology to provide virtually perpetual energy supplies to wireless networks. Generally speaking, WET is implementable by either the "Near-field" ElectroMagnetic (EM) induction or the "Far-field" EM radiation, for short and long range applications, respectively. In this paper, the latter case in the particular...

    Provided By National University of Singapore

  • White Papers // Jan 2013

    Energy Cooperation in Cellular Networks With Renewable Powered Base Stations

    In this paper, the authors propose a model for energy cooperation between cellular Base Stations (BSs) with individual renewable energy sources, limited energy storages and connected by resistive power lines for energy sharing. When the renewable energy profile and energy demand profile at all BSs are deterministic or known ahead...

    Provided By National University of Singapore

  • White Papers // Sep 2012

    Cognitive Energy Harvesting and Transmission From a Network Perspective

    Wireless networks can be self-sustaining by harvesting energy from Radio-Frequency (RF) signals. Building on classic cognitive radio networks, the authors propose a novel method for network coexisting where mobiles from a secondary network, called Secondary Transmitters (STs), either harvest energy from transmissions by nearby transmitters from a primary network, called...

    Provided By National University of Singapore

  • White Papers // Feb 2013

    Opportunistic Wireless Energy Harvesting in Cognitive Radio Networks

    Wireless networks can be self-sustaining by harvesting energy from ambient Radio-Frequency (RF) signals. Recently, researchers have made progress on designing efficient circuits and devices for RF energy harvesting suitable for low-power wireless applications. Motivated by this and building upon the classic Cognitive Radio (CR) network model, this paper proposes a...

    Provided By National University of Singapore

  • White Papers // Mar 2013

    Multiuser MISO Beamforming for Simultaneous Wireless Information and Power Transfer

    In this paper, the authors study a multiuser Multiple-Input Single-Output (MISO) broadcast system for Simultaneous Wireless Information and Power Transfer (SWIPT), where a multi-antenna Access Point (AP) sends information and energy simultaneously via beam-forming to multiple single-antenna receivers. They maximize the weighted sum-power transferred to Energy Harvesting (EH) receivers subject...

    Provided By National University of Singapore

  • White Papers // Jul 2012

    On Capacity and Optimal Scheduling for the Half-Duplex Multiple-Relay Channel

    The authors study the Half-Duplex Multiple-Relay Channel (HD-MRC) where every node can either transmit or listen but cannot do both at the same time. They obtain a capacity upper bound based on a max-flow min-cut argument and achievable transmission rates based on the Decode-Forward (DF) coding strategy, for both the...

    Provided By National University of Singapore

  • White Papers // Dec 2008

    Achievable Rates and Schedules for Half Duplex Phase Fading Multiple-Relay Networks

    The authors present part of their work on the capacity upper bound, achievable rates, and scheduling for the Half Duplex Multiple-Relay Channel (HD MRC) where every node can either transmit or listen, but not both, at any time. They derive a capacity upper bound based on the cut-set argument, and...

    Provided By National University of Singapore

  • White Papers // Mar 2013

    CoMP Meets Energy Harvesting: A New Communication and Energy Cooperation Paradigm

    In this paper, the authors investigate joint communication and energy cooperation in cellular networks for the Coordinated Multi-Point (CoMP) downlink transmission with Base Stations (BSs) powered by renewable energy. For the purpose of exposition, they consider a simplified CoMP model with two BSs cooperatively serving two Mobile Stations (MSs), where...

    Provided By National University of Singapore