Nanyang Technological University

Displaying 1-40 of 188 results

  • White Papers // Jan 2015

    Optimal Energy Allocation Policy for Wireless Networks in the Sky

    Google's Project Loon was launched in 2013 with the aim of providing Internet access to rural and remote areas. In the Loon network, balloons travel around the Earth and bring access points to the users who cannot connect directly to the global wired Internet. The signals from the users will...

    Provided By Nanyang Technological University

  • White Papers // Jul 2014

    A Fluid Approach for Performance Analysis of LTE-A Networks with Relays

    In this paper, the authors address the problem of the impact of relays on the performance of a LTE-A based network. In this aim, they propose a new framework, the \"Fluid model for LTE-A networks with relays\". They derive from this model analytical simple formulas for the Signal to Interference...

    Provided By Nanyang Technological University

  • White Papers // Jul 2014

    Modeling and Simulation of Networked Low-Power Embedded Systems: A Taxonomy

    Simulation has been widely adopted for the evaluation of novel protocols or other designs for networked low-power embedded systems, especially for Wireless Sensor Networks (WSNs). A large number of simulation tools have been developed for WSNs in the past few years. However, different tools may emphasize on different features. For...

    Provided By Nanyang Technological University

  • White Papers // Dec 2013

    On the Effectiveness of Polynomial Realization of Reed-Solomon Codes for Storage Systems

    There are different ways to realize Reed Solomon (RS) codes. While in the storage community, using the generator matrices to implement RS codes is more popular, in the coding theory community the generator polynomials are typically used to realize RS codes. Prominent exceptions include HDFS-RAID, which uses generator polynomial based...

    Provided By Nanyang Technological University

  • White Papers // Nov 2013

    Analysis of BLAKE2

    The authors present a thorough security analysis of the hash function family BLAKE2, a recently proposed and already in use tweaked version of the SHA-3 finalist BLAKE. They study how existing attacks on BLAKE apply to BLAKE2 and to what extent the modifications impact the attacks. They design and run...

    Provided By Nanyang Technological University

  • White Papers // Nov 2013

    Revocable IBE Systems with Almost Constant-size Key Update

    It is sometimes necessary to remove keying material from use prior to the end of its normal crypto-period (or key lifetime) for reasons that include key compromise, removal of an entity from an organization, and so on. This process is known as key revocation and is used to explicitly revoke...

    Provided By Nanyang Technological University

  • White Papers // Nov 2013

    Developing a Grey Hat C2 and RAT for APT Security Training and Assessment

    A Remote Access Tool/Trojan (RAT) is a program that allows an external (malicious) operator to invisibly control a host. The operator may examine the system contents, transfer files, and run tools such key- and network sniffers to gain further access. RATs are often inserted on targets by forged e-mails or...

    Provided By Nanyang Technological University

  • White Papers // Nov 2013

    Cryptanalysis of Zorro

    At CHES 2013 was presented a new block cipher called zorro. Although it uses only 4 S-boxes per round, the designers showed the resistance of the cipher against various attacks, and concluded the cipher has a large security margin. In this paper, the authors give a key recovery attack on...

    Provided By Nanyang Technological University

  • White Papers // Oct 2013

    Kernelet: High-Throughput GPU Kernel Executions With Dynamic Slicing and Scheduling

    Graphics processors, or GPUs, have recently been widely used as accelerators in shared environments such as clusters and clouds. In such shared environments, many kernels are submitted to GPUs from different users, and throughput is an important metric for performance and total ownership cost. Despite recently improved runtime support for...

    Provided By Nanyang Technological University

  • White Papers // Oct 2013

    The Resistance of PRESENT-80 Against Related-Key Differential Attacks

    The authors examine the security of the 64-bit lightweight block cipher PRESENT-80 against related-key differential attacks. With a computer search they are able to prove that no related-key differential characteristic exists with probability higher than 2-64 for the full-round PRESENT-80. To overcome the exponential (in the state and key sizes)...

    Provided By Nanyang Technological University

  • White Papers // Oct 2013

    Write-Only Oblivious RAM Based Privacy-Preserved Access of Outsourced Data

    Oblivious RAM (ORAM) has recently attracted a lot of interest since it can be used to protect the privacy of data user's data access pattern from (honest but curious) outsourced storage. This is achieved by simulating each original data read or write operation with some read and write operations on...

    Provided By Nanyang Technological University

  • White Papers // Oct 2013

    AEGIS: A Fast Authenticated Encryption Algorithm

    In this paper the authors introduce a dedicated authenticated encryption algorithm AEGIS; AEGIS allows for the protection of associated data which makes it very suitable for protecting network packets. AEGIS- 128L uses eight AES round functions to process a 32-byte message block (one step). AEGIS-128 uses five AES round functions...

    Provided By Nanyang Technological University

  • White Papers // Sep 2013

    Toward Monetary Cost Effective Content Placement in Cloud Centric Media Network

    In recent years, technical challenges are emerging on how to efficiently distribute the rapid growing User-Generated Contents (UGCs) with long-tailed nature. To address this issue, the authors have previously proposed Cloud Centric Media Network (CCMN) for cost-efficient UGCs delivery. In this paper, they further study the content placement problem in...

    Provided By Nanyang Technological University

  • White Papers // Sep 2013

    The Parallel-Cut Meet-In-The-Middle Attack

    The authors propose a new type of meet-in-the-middle attack that splits the cryptographic primitive in parallel to the execution of the operations. The result of the division is two primitives that have smaller input sizes and thus require lower attack complexities. However, the division is not completely independent and the...

    Provided By Nanyang Technological University

  • White Papers // Sep 2013

    Cryptanalysis of Full RIPEMD-128

    In this paper the authors propose a new cryptanalysis method for double-branch hash functions that they apply on the standard RIPEMD-128, greatly improving over know results. Namely, they were able to build a very good differential path by placing one non-linear differential part in each computation branch of the RIPEMD-128...

    Provided By Nanyang Technological University

  • White Papers // Sep 2013

    Medusa: Simplified Graph Processing on GPUs

    Graphs are common data structures for many applications, and efficient graph processing is a must for application performance. Recently, the Graphics Processing Unit (GPU) has been adopted to accelerate various graph processing algorithms such as BFS and shortest paths. However, it is difficult to write correct and efficient GPU programs...

    Provided By Nanyang Technological University

  • White Papers // Aug 2013

    Parallel Graph Processing on Graphics Processors Made Easy

    In this paper, the authors demonstrate Medusa, a programming frame-work for parallel graph processing on Graphics Processor Units (GPUs). Medusa enables developers to leverage the massive parallelism and other hardware features of GPUs by writing sequential C/C++ code for a small set of APIs. This simplifies the implementation of parallel...

    Provided By Nanyang Technological University

  • White Papers // Aug 2013

    Revisiting Co-Processing for Hash Joins on the Coupled CPU GPU Architecture

    Query co-processing on Graphics Processor Units (GPUs) has become an effective means to improve the performance of main memory databases. However, the relatively low bandwidth and high latency of the PCI-e bus are usually bottleneck issues for co-processing. Recently, coupled CPU-GPU architectures have received a lot of attention, e.g. AMD...

    Provided By Nanyang Technological University

  • White Papers // Aug 2013

    OmniDB: Towards Portable and Efficient Query Processing on Parallel CPU/GPU Architectures

    Driven by the rapid hardware development of parallel CPU/GPU architectures, the authors have witnessed emerging relational query processing techniques and implementations on those parallel architectures. However, most of those implementations are not portable across different architectures, because they are usually developed from scratch and target at a specific architecture. This...

    Provided By Nanyang Technological University

  • White Papers // Aug 2013

    Multiple Limited-Birthday Distinguishers and Applications

    In this paper, the authors propose a new improvement of the rebound techniques, used for crypt-analyzing AES-like permutations during the past years. Their improvement, that allows to reduce the complexity of the attacks, increases the probability of the outbound part by considering a new type of differential paths. Moreover, they...

    Provided By Nanyang Technological University

  • White Papers // Aug 2013

    On Secret Sharing with Nonlinear Product Reconstruction

    Multiplicative linear secret sharing is a fundamental notion in the area of secure Multi-Party Computation (MPC) and, since recently, in the area of two-party cryptography as well. In a nutshell, this notion guarantees that \"The product of two secrets is obtained as a linear function of the vector consisting of...

    Provided By Nanyang Technological University

  • White Papers // Aug 2013

    Towards GPU-Accelerated Large-Scale Graph Processing in the Cloud

    Recently, the authors have witnessed that cloud providers start to offer heterogeneous computing environments. There have been wide interests in both cluster and cloud of adopting Graphics Processors Unit (GPUs) as accelerators for various applications. On the other hand, large-scale processing is important for many data-intensive applications in the cloud....

    Provided By Nanyang Technological University

  • White Papers // Jul 2013

    Characterizations and Construction Methods for Linear Functional-Repair Storage Codes

    The authors present a precise characterization of linear functional-repair storage codes in terms of admissible states, with each state made up from a collection of vector spaces over some fixed finite field. To illustrate the usefulness of their characterization, they provide several applications. They first describe a simple construction of...

    Provided By Nanyang Technological University

  • White Papers // Jul 2013

    Matrix Codes and Multitone Frequency Shift Keying for Power Line Communications

    Single-tone Frequency Shift Keying (FSK) modulation with permutation codes has been found to be useful in addressing the problem of narrowband noise disturbance in power line communications. However, this modulation scheme is restrictive since the number of frequencies used must be at least as large as the number of symbols...

    Provided By Nanyang Technological University

  • White Papers // Jul 2013

    Implementing Lightweight Block Ciphers on x86 Architectures

    Lightweight block ciphers are designed so as to fit into very constrained environments, but usually not really with software performance in mind. For classical lightweight applications where many constrained devices communicate with a server, it is also crucial that the cipher has good software performance on the server side. Recent...

    Provided By Nanyang Technological University

  • White Papers // Jun 2013

    Structural Evaluation of AES and Chosen-Key Distinguisher of 9-round AES-128

    Block ciphers and hash functions are among the most important primitives in cryptography and while their respective goals are different, they are related in many ways. While the symmetric-key cryptography community has now a good experience on how to build a secure and efficient fixed permutation, it remains an open...

    Provided By Nanyang Technological University

  • White Papers // May 2013

    Streamforce: Outsourcing Access Control Enforcement for Stream Data to the Clouds

    As tremendous amount of data being generated everyday from human activity and from devices equipped with sensing capabilities, cloud computing emerges as a scalable and cost-effective platform to store and manage the data. While benefits of cloud computing are numerous, security concerns arising when data and computation are outsourced to...

    Provided By Nanyang Technological University

  • White Papers // May 2013

    Storage Codes: Managing Big Data with Small Overheads

    Erasure coding provides a mechanism to store data redundantly for fault-tolerance in a cost-effective manner. Recently, there has been a renewed interest in designing new erasure coding techniques with different desirable properties, including good repairability and degraded read performance, or efficient redundancy generation processes. Very often, these novel techniques exploit...

    Provided By Nanyang Technological University

  • White Papers // May 2013

    Locally Repairable Codes With Multiple Repair Alternatives

    Distributed storage systems need to store data redundantly in order to provide some fault-tolerance and guarantee system reliability. Different coding techniques have been proposed to provide the required redundancy more efficiently than traditional replication schemes. However, compared to replication, coding techniques are less efficient for repairing lost redundancy, as they...

    Provided By Nanyang Technological University

  • White Papers // Apr 2013

    Network Performance Aware MPI Collective Communication Operations in the Cloud

    In this paper, the authors examine the performance of collective communication operations in Message Passing Interfaces (MPI) in the cloud computing environment. The awareness of network topology has been a key factor in performance optimizations for existing MPI implementations. However, virtualization in the cloud environment not only hides the network...

    Provided By Nanyang Technological University

  • White Papers // Apr 2013

    An Auction Mechanism for Resource Allocation in Mobile Cloud Computing Systems

    A mobile cloud computing system is composed of heterogeneous services and resources to be allocated by the cloud service provider to mobile cloud users. On one hand, some of these resources are substitutable (e.g., users can use storage from different places) that they have similar functions to the users. On...

    Provided By Nanyang Technological University

  • White Papers // Apr 2013

    A Real-Time Group Auction System for Efficient Allocation of Cloud Internet Applications

    Increasing number of the cloud-based Internet applications demands for efficient resource and cost management. This paper proposes a real-time group auction system for the cloud instance market. The system is designed based on a combinatorial double auction, and its applicability and effectiveness are evaluated in terms of resource efficiency and...

    Provided By Nanyang Technological University

  • White Papers // Mar 2013

    Towards Optimal Deployment of Cloud-Assisted Video Distribution Services

    For Internet video services, the high fluctuation of user demands in geographically distributed regions results in low resource utilizations of traditional CDN systems. Due to the capability of rapid and elastic resource provisioning, cloud computing emerges as a new paradigm to reshape the model of video distribution over the Internet,...

    Provided By Nanyang Technological University

  • White Papers // Mar 2013

    Optimizing and Auto-Tuning Iterative Stencil Loops for GPUs with the In-Plane Method

    Stencils represent an important class of computations that are used in many scientific disciplines. Increasingly, many of the stencil computations in scientific applications are being offloaded to GPUs to improve running times. Since a large part of the simulation time is spent inside the stencil kernels, optimizing the kernel is...

    Provided By Nanyang Technological University

  • White Papers // Feb 2013

    The CORE Storage Primitive: Cross-Object Redundancy for Efficient Data Repair & Access in Erasure Coded Storage

    Erasure codes are an integral part of many distributed storage systems aimed at Big Data, since they provide high fault-tolerance for low overheads. However, traditional erasure codes are inefficient on reading stored data in degraded environments (when nodes might be unavailable), and on replenishing lost data (vital for long term...

    Provided By Nanyang Technological University

  • White Papers // Feb 2013

    In-Network Redundancy Generation for Opportunistic Speedup of Data Backup

    Erasure coding is a storage-efficient alternative to replication for achieving reliable data backup in distributed storage systems. During the storage process, traditional erasure codes require a unique source node to create and upload all the redundant data to the different storage nodes. However, such a source node may have limited...

    Provided By Nanyang Technological University

  • White Papers // Jan 2013

    Community Detection in Weighted Networks: Algorithms and Applications

    Community detection is an important issue due to its wide use in designing network protocols such as data forwarding in Delay Tolerant Networks (DTN) and worm containment in Online Social Networks (OSN). However, most of the existing community detection algorithms focus on binary networks. Since most networks are weighted such...

    Provided By Nanyang Technological University

  • White Papers // Jan 2013

    Storage Codes - Coding Rate and Repair Locality

    The repair locality of a distributed storage code is the maximum number of nodes that ever needs to be contacted during the repair of a failed node. Having small repair locality is desirable, since it is proportional to the number of disk accesses during repair. However, recent publications show that...

    Provided By Nanyang Technological University

  • White Papers // Jan 2013

    Green Databases Through Integration of Renewable Energy

    Recently, a lot of energy efficient techniques have been developed to reduce the usage of the carbon intensive energy (brown energy) of databases. There is a new opportunity to reduce the brown energy usage: renewable energy (green energy) has been used to at least partially power computer systems. The key...

    Provided By Nanyang Technological University

  • White Papers // Jan 2013

    An Empirical Investigation of the Impact of Server Virtualization on Energy Efficiency for Green Data Center

    The swift adoption of cloud services is accelerating the deployment of data centers. These data centers are consuming a large amount of energy, which is expected to grow dramatically under the existing technological trends. Therefore, research efforts are in great need to architect green data centers with better energy efficiency....

    Provided By Nanyang Technological University

  • White Papers // Jan 2010

    IPV6 Network Mobility on Ad Hoc Network for Transportation Systems

    The authors introduce the network architecture which consists of fleets of mobile routers interconnected using the at ad hoc routing protocol and access router discovery protocol. This network backbone provides mobile user with Internet connectivity. They illustrate the usage of mobility support in IPv6 for the network and introduce a...

    Provided By Nanyang Technological University

  • White Papers // Mar 2011

    Easy Impossibility Proofs for K-Set Agreement in Message Passing Systems

    Despite of being quite similar agreement problems, consensus and general k-set agreement require surprisingly different techniques for proving the impossibility in asynchronous systems with crash failures: Rather than relatively simple bivalence arguments as in the impossibility proof for consensus (= 1-set agreement) in the presence of a single crash failure,...

    Provided By Nanyang Technological University

  • White Papers // Dec 2010

    Homophonic Coding Design for Communication Systems Employing the Encoding-Encryption Paradigm

    This paper addresses the design of a dedicated homophonic coding for a class of communication systems which, in order to provide both reliability and security, first encode the data before encrypting it, which is referred to as the encoding-encryption paradigm. The considered systems employ error-correction coding for reliability, a stream...

    Provided By Nanyang Technological University

  • White Papers // Nov 2010

    Secure Index Coding With Side Information

    The problem of Index Coding with Side Information (ICSI) was introduced by Birk and Kol,. It was motivated by applications such as audio and video-on-demand, and daily newspaper delivery. In these applications a server (sender) has to deliver some sets of data, audio or video files to the set of...

    Provided By Nanyang Technological University

  • White Papers // Apr 2010

    A Light-Weight Mutual Authentication and Key-Exchange Protocol Based on Elliptical Curve Cryptogaphy for Energy-Constrained Devices

    Wireless devices are characterized by low computational power and memory. Hence security protocols dealing with these devices have to be designed to give minimal computational and memory load. The authors present an efficient authentication and key exchange protocol for low-end wireless clients and high end servers, which is overall nearly...

    Provided By Nanyang Technological University

  • White Papers // Sep 2010

    SNAP: SNowbAll Multi-Tree Pushing for Peer-to-Peer Media Streaming

    Given the respective advantages of the two complimentary techniques for peer-to-peer media streaming (namely tree-based push and mesh-based pull), there is a strong trend of combining them into a hybrid streaming system. Backed by recently proposed mechanisms to identify stable peers, such a hybrid system usually consists of backbone trees...

    Provided By Nanyang Technological University

  • White Papers // Oct 2010

    Infinite Families of Optimal Splitting Authentication Codes Secure Against Spoofing Attacks of Higher Order

    In the standard model of authentication theory, a transmitter wants to send some information to a receiver across an insecure channel while an opponent with access to the channel wants to deceive the receiver. The opponent can either insert new messages into the channel, or intercept messages from the transmitter...

    Provided By Nanyang Technological University

  • White Papers // Oct 2010

    Energy-Efficient Multiprocessor Scheduling for Flow Time and Makespan

    The authors consider energy-efficient scheduling on multiprocessors, where the speed of each processor can be individually scaled, and a processor consumes power s if it runs at speed s, where > 1. A scheduling algorithm needs to decide both processor allocations and speeds for a set of parallel jobs whose...

    Provided By Nanyang Technological University

  • White Papers // Jul 2010

    Achieving the Scaling Law of SNR-Monitoring in Dynamic Wireless Networks

    Erasure codes provide a storage efficient alternative to replication based redundancy in (networked) storage systems. They however entail high communication overhead for maintenance, when some of the encoded fragments are lost and need to be replenished. Such overheads arise from the fundamental need to recreate (or keep separately) first a...

    Provided By Nanyang Technological University

  • White Papers // Jul 2010

    Self-Repairing Homomorphic Codes for Distributed Storage Systems

    Erasure codes provide a storage efficient alternative to replication based redundancy in (networked) storage systems. They however entail high communication overhead for maintenance, when some of the encoded fragments are lost and need to be replenished. Such overheads arise from the fundamental need to recreate (or keep separately) first a...

    Provided By Nanyang Technological University

  • White Papers // Jul 2010

    A 60 Ghz Analog Phase Shifter in 65 Nm Bulk CMOS Process

    A 60 GHz Analog Phase Shifter in 65nm bulk CMOS process has been explored for microwave frequency applications. It is an analog phase shifter with three transistors in the form of an active circulator and a LC network to attain the desired phase shift. This phase shifter is designed to...

    Provided By Nanyang Technological University

  • White Papers // Sep 2009

    Differential Privacy Via Wavelet Transforms

    Numerous organizations, like census bureaus and hospitals, maintain large collections of personal information (e.g., census data and medical records). Such data collections are of significant research value, and there is much benefit in making them publicly available. Nevertheless, as the data is sensitive in nature, proper measures must be taken...

    Provided By Nanyang Technological University

  • White Papers // Aug 2010

    Asia's Sovereign Wealth Funds And Reform Of The Global Reserve System

    This paper explores the potential contribution of Asia's Sovereign Wealth Funds (SWFs) to the reform of the global foreign exchange reserve system. By diversifying the investment of Asia's huge reserves into non-dollar denominated assets, Asian SWFs can help to dilute the dominant role of the US dollar as the global...

    Provided By Nanyang Technological University

  • White Papers // Nov 2009

    Making Palm Print Matching Mobile

    With the growing importance of personal identification and authentication in today's highly advanced world where most business and personal tasks are being replaced by electronic means, the need for a technology that is able to uniquely identify an individual and has high fraud resistance see the rise of biometric technologies....

    Provided By Nanyang Technological University

  • White Papers // Apr 2011

    Improved Meet-in-the-Middle Cryptanalysis of KTANTAN

    The authors revisit meet-in-the-middle attacks on block ciphers and recent developments in meet-in-the-middle preimage attacks on hash functions. Despite the presence of a secret key in the block cipher case, they identify techniques that can also be mounted on block ciphers, thus allowing one to improve the cryptanalysis of the...

    Provided By Nanyang Technological University

  • White Papers // May 2011

    Cloud-Based Semantic Service-Oriented Content Provisioning Architecture for Mobile Learning

    Exploiting mobile technologies for educational purposes has promises of realizing ubiquitous, unobtrusive, personal and situated learning. The advent of cloud computing has meant that all the information on web, and proprietary sources of information are available instantly. But mobile learning is non-trivial due to the challenges in the process of...

    Provided By Nanyang Technological University

  • White Papers // Dec 2010

    Cooperative Virtual Machine Management for Multi-Organization Cloud Computing Environment

    In cloud computing, organizations can form the cooperation to share the available resource to reduce the cost. This is referred to as the multi-organization cloud computing environment. In this paper, the authors address the issues of virtual machine management and cooperation formation in such an environment. First, for the cooperative...

    Provided By Nanyang Technological University

  • White Papers // Jul 2010

    Maximize Secondary User Throughput Via Optimal Sensing in Multi-Channel Cognitive Radio Networks

    In a cognitive radio network, the full-spectrum is usually divided into multiple channels. However, due to the hardware and energy constraints, a cognitive user (also called secondary user) may not be able to sense two or more channels simultaneously. As different channels may have different primary user activities and time-varying...

    Provided By Nanyang Technological University

  • White Papers // Jul 2010

    Optimal Content Transmission Policy in Publish-Subscribe Mobile Social Networks

    The authors consider the problem of dynamic content distribution in publish-subscribe mobile social networks. Mobile users subscribe to the content provider. Then, when new content is created, the provider transmits it to subscribers (i.e., mobile users) through the base station. The mobile users who have the social relationship (i.e., mobile...

    Provided By Nanyang Technological University

  • White Papers // Jul 2010

    Optimal Bandwidth Allocation With Dynamic Service Selection in Heterogeneous Wireless Networks

    Bandwidth allocation for different service classes in heterogeneous wireless networks is an important issue for service provider in terms of balancing service quality and profit. It is especially challenging when considering the dynamic competition both among service providers and among users. To address this problem, a two-level game framework is...

    Provided By Nanyang Technological University

  • White Papers // May 2010

    An Opportunistic Spectrum Scheduling Scheme for Multi-Channel Cognitive Radio Networks

    In this paper, the authors develop an opportunistic spectrum scheduling scheme for cognitive radio networks. In the proposed scheme, the channel status (i.e., whether being occupied by primary users) and the instantaneous channel quality (SNR at the secondary receiver) are assumed to vary fast within a frame which consists of...

    Provided By Nanyang Technological University

  • White Papers // Jan 2010

    A Neural Network Based Spectrum Prediction Scheme for Cognitive Radio

    The Cognitive Radio (CR) technology enables the unlicensed users to share the spectrum with the licensed users on a non-interfering basis. Spectrum sensing is an important function for the unlicensed users to determine availability of a channel in the licensed user's spectrum. However, spectrum sensing consumes considerable energy which can...

    Provided By Nanyang Technological University

  • White Papers // Jul 2011

    Payoff Allocation of Service Coalition in Wireless Mesh Network: A Cooperative Game Perspective

    In Wireless Mesh Network (WMN), multiple Service Providers (SPs) can cooperate to share resources (e.g., relay nodes and spectrum), to serve their collective subscribed customers for better service. As a reward, SPs are able to achieve more individual benefits, i.e., increased revenue or decreased cost, through efficient utilization of shared...

    Provided By Nanyang Technological University

  • White Papers // Jul 2011

    On Hierarchical Cooperation Formation in Mobile Infostation Networks

    Mobile infostation networks which achieve content distribution by exploiting the opportunistic contact among Mobile Users (MUs) and Access Points (APs) have attracted a lot of attention in the last few years. It is found that cooperation either between APs or MUs has a great impact on the network performance. However,...

    Provided By Nanyang Technological University

  • White Papers // Jul 2011

    Dynamic Bandwidth Allocation Under Uncertainty in Cognitive Radio Networks

    The authors consider the problem of dynamic bandwidth allocation among different service classes under uncertainty in cognitive radio networks. In such networks, the secondary users compete for bandwidth resources and the service providers compete for users access (e.g., subscription). To address this problem, a two-level dynamic game framework is developed....

    Provided By Nanyang Technological University

  • White Papers // Jan 2011

    Performance Analysis of Cognitive Radio Spectrum Access With Prioritized Traffic

    Dynamic Spectrum Access (DSA) is an important design aspect for the cognitive radio networks. Most of the existing DSA schemes are to govern the unlicensed user (i.e., secondary user) traffic in a licensed spectrum without compromising the transmissions of the licensed users, in which all the unlicensed users are typically...

    Provided By Nanyang Technological University

  • White Papers // Dec 2010

    Optimal Power Allocation for Secondary Users in Cognitive Relay Networks

    The authors consider a Cognitive Relay Network (CRN) where the Secondary Users (SUs) are involved as cooperative relays in a Primary User's (PU) communication. To avoid generating interference to PU transmissions, it is assumed that SUs can transmit only when the PU's channel is idle. On one hand, SUs use...

    Provided By Nanyang Technological University

  • White Papers // Dec 2010

    A Dynamic Relay Selection Scheme for Mobile Users in Wireless Relay Networks

    Cooperative communication has attracted dramatic attention in the last few years due to its advantage in mitigating channel fading. Despite much effort that has been made in theoretical analysis of the performance gain, cooperative relay selection, which is one of the fundamental issues in cooperative communications, is still left as...

    Provided By Nanyang Technological University

  • White Papers // Aug 2010

    Optimal Power Control in Interference-Limited Cognitive Radio Networks

    Power control for multiple cognitive radios is investigated for broadcast service under the coverage of primary base station. Multiple secondary broadcasting base stations are assumed to operate in the same frequency band as that of primary system. However, the performance of the primary users can be degraded due to the...

    Provided By Nanyang Technological University

  • White Papers // Oct 2010

    DelQue: A Socially-Aware Delegation Query Scheme in Delay Tolerant Networks

    In Delay Tolerant Networks (DTNs), information search is an important topic, which has not been widely investigated yet. Recently, pervasive and ubiquitous computing scenarios are pushing situations where it is the recipient (instead of the sender) who determines whether and how to seize data flowing in the network. Most existing...

    Provided By Nanyang Technological University

  • White Papers // Mar 2011

    Cooperative Retransmissions Through Collisions

    Interference in wireless networks is one of the key capacity-limiting factors. Recently developed interference-embracing techniques show promising performance on turning collisions into useful transmissions. However, the interference-embracing techniques are hard to apply in practical applications due to their strict requirements. In this paper, the authors consider utilising the interference-embracing techniques...

    Provided By Nanyang Technological University

  • White Papers // Oct 2009

    Probe Station Selection for Robust Network Monitoring

    Probing is a promising approach for network monitoring. An important problem that needs to be addressed while developing probing-based solutions is the selection of probe station nodes. Probe station nodes are the nodes that are instrumented with the functionality of sending probes and analyzing probe results. The placement of probe...

    Provided By Nanyang Technological University

  • White Papers // Mar 2010

    Building Latent Growth Models Using PROC CALIS: A Structural Equation Modeling Approach

    This paper illustrates the structural equation modeling approach of building Latent Growth Models (LGMs) using PROC CALIS. In the past decade, LGM has become one of the commonly used statistical models for analyzing longitudinal data analysis. Although recent years have seen the increase use of LGM to carry out research...

    Provided By Nanyang Technological University

  • White Papers // Aug 2009

    Business Process Management (BPM) Standards: A Survey

    Through the combination of SOA (Service Oriented Architecture) with an intelligent Business Process Management that guaranties the immediate execution of the defined processes in multiple IT-environments, SOA evolves into SOB (Service Oriented Business). SOB delivers a flexible and efficient business environment that supports and guides each and every person involved...

    Provided By Nanyang Technological University

  • White Papers // Feb 2010

    Multi-paths Routing with Load Balancing for Internet Access in Wireless Mesh Networks

    Wireless Mesh Networks (WMN) has different characteristics compared with the mobile ad hoc networks (MANET). The issue of Internet access with wireless mesh connectivity is a very important issue in the design of WMNs. In this paper, authors propose a novel multi-paths routing framework for the Internet access through WMNs...

    Provided By Nanyang Technological University

  • White Papers // Dec 2012

    Perceptually Motivated Shape Context Which Uses Shape Interiors

    In this paper, the authors identify some of the limitations of current-day shape matching techniques. They provide examples of how contour-based shape matching techniques cannot provide a good match for certain visually similar shapes. To overcome this limitation, they propose a perceptually motivated variant of the well-known shape context descriptor....

    Provided By Nanyang Technological University

  • White Papers // Feb 2011

    3DQS: Distributed Data Access in 3D Wireless Sensor Networks

    This paper proposes novel mechanisms to access sensory data in a distributed fashion in 3D wireless sensor networks. As these networks have their nodes deployed in 3D volumes, the authors first propose a volume parametrization algorithm to transform irregular volumes into a regular one; it also allows one to extend...

    Provided By Nanyang Technological University

  • White Papers // Jul 2010

    Channel Resource Allocation for VoIP Applications in Collaborative IEEE 802.11/802.16 Networks

    Collaborations between the IEEE 802.11 and the IEEE 802.16 networks operating in a common spectrum offers dynamic allocate bandwidth resources to achieve improved performance for network applications. This paper studies the bandwidth resource allocation of collaborative IEEE 802.11 and IEEE 802.16 networks. Consider delivering data packets between mobile stations and...

    Provided By Nanyang Technological University

  • White Papers // Jan 2011

    Ubiquitous Data Collection for Mobile Users in Wireless Sensor Networks

    The authors study the ubiquitous data collection for mobile users in wireless sensor networks. People with handheld devices can easily interact with the network and collect data. They propose a novel approach for mobile users to collect the network-wide data. The routing structure of data collection is additively updated with...

    Provided By Nanyang Technological University

  • White Papers // Aug 2010

    Tight Analysis of Shortest Path Convergecast in Wireless Sensor Networks

    The authors consider the convergecast problem in wireless sensor networks where readings generated by each sensor node are to reach the sink. Since a sensor reading can usually be encoded in a few bytes, more than one reading can readily fit into a standard transmission packet. They assume that any...

    Provided By Nanyang Technological University