University of Hong Kong

Displaying 1-40 of 63 results

  • White Papers // Oct 2014

    Power Allocation with Stackelberg Game in Femtocell Networks: A Self-Learning Approach

    In this paper, the authors investigate the energy-efficient power allocation for a two-tier, underlaid femtocell network. The behaviors of the Macrocell Base Station (MBS) and the Femtocell Users (FUs) are modeled hierarchically as a Stackelberg game. The MBS guarantees its own QoS requirement by charging the FUs individually according to...

    Provided By University of Hong Kong

  • White Papers // May 2013

    Forensics-as-a-Service (FaaS): Computer ForensicWorkflow Management and Processing Using Cloud

    Digital forensics is a critical technology for obtaining evidences in crime investigation. Now-a-days, the overwhelming magnitude of data and the lack of easy-to-deploy software are among the major obstacles in the field of digital forensics. Cloud computing, which is designed to support large scale data processing on commodity hardware, provides...

    Provided By University of Hong Kong

  • White Papers // Jan 2013

    Continuous Remote Mobile Identity Management Using Biometric Integrated Touch-Display

    While enriching the user experiences, the development of mobile devices and applications introduces new security and privacy vulnerabilities for the remote services accessed by mobile device users. A trusted and usable authentication architecture for mobile devices is thus in high demand. In this paper, the authors leverage a unified structure,...

    Provided By University of Hong Kong

  • White Papers // Nov 2012

    Attack Against Electricity Market-Attacker and Defender Gaming

    Application of cyber technologies improves the quality of monitoring and decision making in smart grid. These cyber technologies are vulnerable to malicious attacks, and compromising them can have serious technical and economical problems. This paper specifies the effect of compromising each measurement on the prices of electricity, so that the...

    Provided By University of Hong Kong

  • White Papers // Oct 2012

    Bad Data Injection Attack and Defense in Electricity Market Using Game Theory Study

    Applications of cyber technologies improve the quality of monitoring and decision making in smart grid. These cyber technologies are vulnerable to malicious attacks, and compromising them can have serious technical and economical problems. This paper specifies the effect of compromising each measurement on the price of electricity, so that the...

    Provided By University of Hong Kong

  • White Papers // Sep 2012

    A Coarray Fortran Implementation to Support Data-Intensive Application Development

    In this paper, the authors describe their experiences in implementing and applying Co-Array Fortran (CAF) for the development of data-intensive applications in the domain of oil and gas exploration. The successful porting of Reverse Time Migration (RTM), a data-intensive algorithm and one of the largest uses of computational resources in...

    Provided By University of Hong Kong

  • White Papers // Sep 2012

    A Plugin for HDF5 using PLFS for Improved I/O Performance and Semantic Analysis

    HDF5 is a data model, library and file format for storing and managing data. It is designed for flexible and efficient I/O for high volume and complex data. Natively, it uses a single-file format where multiple HDF5 objects are stored in a single file. In a parallel HDF5 application, multiple...

    Provided By University of Hong Kong

  • White Papers // Jul 2012

    Voronoi-Based Nearest Neighbor Search for Multi-Dimensional Uncertain Databases

    Nearest neighbor queries are the fundamental procedures for many similarity search and location-based query applications for location-based services. In particular, a nearest-neighbor query allows users to retrieve the most similar object to a given query object or to retrieve a location from a geospatial database that is closest to her...

    Provided By University of Hong Kong

  • White Papers // May 2012

    Physical-Layer Network Coding for VPN in TDM-PON

    The authors experimentally demonstrate a novel optical Physical-layer Network Coding (PNC) scheme over Time-Division Multiplexing (TDM) Passive Optical Network (PON). Full-duplex error-free communications between optical network units (ONUs) at 2.5 Gb/s are shown for all-optical Virtual Private Network (VPN) applications. Compared to the conventional half-duplex communications set-up, their scheme can...

    Provided By University of Hong Kong

  • White Papers // May 2012

    Interference-Aware Resource Allocation for Device-to-Device Communications as an Underlay Using Sequential Second Price Auction

    An innovative resource allocation scheme is pro-posed to improve the performance of Device-To-Device (D2D) communications as an underlay in the DownLink (DL) cellular networks. To optimize the system sum rate over the resource sharing of both D2D and cellular modes, the authors introduce a sequential second price auction as the...

    Provided By University of Hong Kong

  • White Papers // May 2012

    Power Allocation Using Vickrey Auction and Sequential First-Price Auction Games for Physical Layer Security in Cognitive Relay Networks

    The authors consider a cognitive radio network in which multiple pairs of Secondary Users (SUs) communicate by a one-way relay node over orthogonal channels with the existence of an eavesdropper close to the destination. The transmit power of the relay needs efficient distribution for maximizing the sum secrecy rate of...

    Provided By University of Hong Kong

  • White Papers // May 2012

    Sampling Spectrum Occupancy Data Over Random Fields: A Matrix Completion Approach

    The performance of cognitive radio networks is fundamentally determined by the availability of spectrum re-sources. Detailed measurement campaigns are needed to collect the spectrum occupancy data to obtain a deeper understanding of the spectrum usage characteristics in cognitive radio networks. This approach, however, is usually inefficient due to the ignorance...

    Provided By University of Hong Kong

  • White Papers // May 2012

    Multiple Operator and Multiple Femtocell Networks: Distributed Stable Matching

    The authors propose distributed matching algorithms for an uplink communication network comprised of multiple Femtocell Access Points (FAPs), multiple Wireless Operators (WOs) which own multiple Macrocell Access Points (MAPs) and multiple Final Users (FUs) subscribed to these WOs. In particular, they propose two algorithms: the first algorithm matches the FAPs...

    Provided By University of Hong Kong

  • White Papers // Feb 2012

    Physical Layer Security for Two-Way Untrusted Relaying with Friendly Jammers

    In this paper, the authors consider a two-way relay network where two sources can communicate only through an un trusted intermediate relay, and investigate the physical layer security issue of this two way relay scenario. Specifically, they treat the intermediate relay as an eavesdropper from which the information transmitted by...

    Provided By University of Hong Kong

  • White Papers // Dec 2011

    Testing Pervasive Software in the Presence of Context Inconsistency Resolution Services

    Pervasive computing software adapts its behavior according to the changing contexts. Nevertheless, contexts are often noisy. Context inconsistency resolution provides a cleaner pervasive computing environment to context-aware applications. A faulty context-aware application may, however, mistakenly mix up inconsistent contexts and resolved ones, causing incorrect results. This paper studies how such...

    Provided By University of Hong Kong

  • White Papers // Dec 2011

    Privacy-Preserving Stream Aggregation With Fault Tolerance

    The authors consider applications where an untrusted aggregator would like to collect privacy sensitive data from users, and compute aggregate statistics periodically. For example, imagine a smart grid operator who wishes to aggregate the total power consumption of a neighborhood every ten minutes; or a market researcher who wishes to...

    Provided By University of Hong Kong

  • White Papers // Oct 2011

    Low-Redundancy Two-Dimensional RAID Arrays

    One of the major issues in storage technology is finding cost-effective solutions for the long-term storage of archival data. The topic is growing in importance as more organizations now maintain larger amounts of data online. Archival storage systems differ from other storage systems in two important ways; the data they...

    Provided By University of Hong Kong

  • White Papers // Aug 2011

    Exact Regenerating Codes for Byzantine Fault Tolerance in Distributed Storage

    Due to the use of commodity software and hardware, crash-stop and Byzantine failures are likely to be more prevalent in today's large-scale distributed storage systems. Regenerating codes have been shown to be a more efficient way to disperse information across multiple nodes and recover crash-stop failures in the literature. In...

    Provided By University of Hong Kong

  • White Papers // May 2011

    Implementation and Application of a Multi-Radio Wireless Sensor Networks Testbed

    The authors propose EasiTest, a multi-radio testbed for heterogeneous Wireless Sensor Networks (WSNs). Two types of sensor nodes, specifically, high-speed multi-radio node (EZ271) and low-speed single-radio node (EZ521) are developed. An administration platform is provided to monitor and control the testbed. EasiTest enjoys high flexibility, powerful processing capability and ease...

    Provided By University of Hong Kong

  • White Papers // May 2011

    Friends or Foes: Detecting Dishonest Recommenders in Online Social Networks

    Viral marketing is becoming important due to the popularity of Online Social Networks (OSNs) and the fact that many users have integrated OSNs into their daily activities, e.g., they provide recommendations to their friends on the products they purchased, or they make decision based on received recommendations. Nevertheless, this also...

    Provided By University of Hong Kong

  • White Papers // Mar 2011

    Non-Transferable Proxy Re-Encryption Scheme for Data Dissemination Control

    A Proxy Re-Encryption (PRE) scheme allows a proxy to re-encrypt a ciphertext for Alice (delegator) to a ciphertext for Bob (delegatee) without seeing the underlying plaintext. With the help of the proxy, Alice can delegate the decryption right to any delegatee. However, existing PRE schemes generally suffer from at least...

    Provided By University of Hong Kong

  • White Papers // Feb 2011

    An Efficient Scheme for Hard Disk Integrity Check in Digital Forensics by Hashing With Combinatorial Group Testing

    In this paper, the authors describe the problem of checking the integrity of a hard disk for forensics investigation after the computer of a suspect has been seized. Existing solutions do not provide a satisfactory solution to solve the problem. They either require a huge amount of storage to store...

    Provided By University of Hong Kong

  • White Papers // Jan 2011

    On Dynamic Server Provisioning in Multi-Channel P2P Live Streaming

    To guarantee the streaming quality in live Peer-To-Peer (P2P) streaming channels, it is preferable to provision adequate levels of upload capacities at dedicated streaming servers, compensating for peer instability and time-varying peer upload bandwidth availability. Most commercial P2P streaming systems have resorted to the practice of over-provisioning a fixed amount...

    Provided By University of Hong Kong

  • White Papers // Jan 2011

    Data Centric Storage With Diffuse Caching in Sensor Networks

    In a sensor network that adopts Data-Centric Storage (DCS), information of the same kind is kept in the same set of nodes. That is, when a sensor detects a certain event, no matter where it is, it sends the information to the designated location. When another node wants the information,...

    Provided By University of Hong Kong

  • White Papers // Jan 2011

    Efficient Event and Query Distribution in Sensor Networks

    A sensor network consists of a large number of sensors which are equipped with sensing, computation, and communication devices. Due to limitation in size, a sensor has only limited energy and storage. Traditional wireless network protocols cannot be applied in sensor networks directly. The authors study the distribution of events...

    Provided By University of Hong Kong

  • White Papers // Jan 2011

    HyBloc: Localization in Sensor Networks With Adverse Anchor Placement

    To determine the geographical positions of sensors, numerous localization algorithms have been proposed in recent years. The positions of sensors are inferred from the connectivity between sensors and a set of nodes called anchors which know their precise locations. The authors investigate the effect of adverse placement and density of...

    Provided By University of Hong Kong

  • White Papers // Jan 2011

    Maximizing Network Utilization for Streaming Video

    Transmission of Variable-Bit-Rate (VBR) video over packet switched networks is a very challenging problem, and has received much attention in the research community. The burstiness of VBR video makes it very hard to design efficient transmission schemes that will achieve a high level of network utilization. Promising work has been...

    Provided By University of Hong Kong

  • White Papers // Dec 2010

    Privacy-Preserving Aggregation of Time-Series Data

    The authors consider how an untrusted data aggregator can learn desired statistics over multiple participants' data, without compromising each individual's privacy. They propose a construction that allows a group of participants to periodically upload encrypted values to a data aggregator, such that the aggregator is able to compute the sum...

    Provided By University of Hong Kong

  • White Papers // Nov 2010

    A Novel Probabilistic Pruning Approach to Speed Up Similarity Queries in Uncertain Databases

    In this paper, the authors propose a novel, effective and efficient probabilistic pruning criterion for probabilistic similarity queries on uncertain data. Their approach supports a general uncertainty model using continuous probabilistic density functions to describe the (possibly correlated) uncertain attributes of objects. In a nutshell, the problem to be solved...

    Provided By University of Hong Kong

  • White Papers // Sep 2010

    Binary is Good: A Binary Inference Framework for Primary User Separation in Cognitive Radio Networks

    Primary Users (PU) separation concerns with the issues of distinguishing and characterizing primary users in Cognitive Radio (CR) networks. The authors argue the need for PU separation in the context of collaborative spectrum sensing and monitor selection. In this paper, they model the observations of monitors as boolean OR mixtures...

    Provided By University of Hong Kong

  • White Papers // Sep 2010

    Deterministic Online Call Control in Cellular Networks and Triangle-Free Cellular Networks

    Wireless Communication Networks based on Frequency Division Multiplexing (FDM in short) plays an important role in the field of communications, in which each request can be satisfied by assigning a frequency. To avoid interference, each assigned frequency must be different to the neighboring assigned frequencies. Since frequency is a scarce...

    Provided By University of Hong Kong

  • White Papers // Jul 2010

    Simplified Ordering for Fixed-Complexity Sphere Decoder

    This paper proposes a simplified ordering algorithm for the Fixed Complexity Sphere decoder (FSD). The new algorithm is developed from the analysis of the ordering for FSD from a geometrical point of view. Computer simulation is used to assess the improvements in Bit-Error Rate (BER) performances of MIMO systems using...

    Provided By University of Hong Kong

  • White Papers // Apr 2010

    Future Application Scenarios for MANET-Based Intelligent Transportation Systems

    Road transportation systems are traditionally characterized by how efficient they direct traffic in a non-congested manner towards their destinations. Improvement in car electronics, sensors, and navigation systems all help in realizing this goal of "Destination-driven" and "No-hassle" driving. With the advent of wireless communications and networking technologies, the future transportation...

    Provided By University of Hong Kong

  • White Papers // Feb 2010

    A Testbed for TCP in Heterogeneous Wired/Wireless Networks

    Transmission Control Protocol (TCP) design in heterogeneous wired/wireless networks is challenging due to packet reordering and error-prone channels. The paper has implemented a testbed for evaluating the performance of TCP variants under packet reordering, congestive loss, and non-congestive loss. The demonstration shows the flexibility of the testbed to accommodate channels...

    Provided By University of Hong Kong

  • White Papers // Feb 2010

    Financial Literacy And Household Investments In Structured Financial Products

    Classical portfolio theory suggests that investors would shun away from unfamiliar financial products. This familiarity bias holds especially for unsophisticated household investors. However, the rapid growth of the credit derivatives market indicates that other factors may have played important role in such investment process. Using unique household investment data from...

    Provided By University of Hong Kong

  • White Papers // Jan 2010

    Anonymous Fuzzy Identity-Based Encryption for Similarity Search

    In this paper, the authors consider the problem of predicate encryption and focus on the predicate for testing whether the hamming distance between the attribute X of a data item and a target V is equal to (or less than) a threshold t where X and V are of length...

    Provided By University of Hong Kong

  • White Papers // Nov 2009

    On the Robustness of Wireless Opportunistic Routing Toward Inaccurate Link-Level Measurements

    The quality of wireless links is inherently dynamic, and this often makes the measurements of link delivery probabilities inaccurate over short timescales. The authors present Stable Opportunistic Routing (SOR), which improves unicast throughput for wireless mesh routing in the presence of inaccurate link-level measurements. In essence, SOR integrates two key...

    Provided By University of Hong Kong

  • White Papers // Sep 2009

    Achieving Capacity of Bi-Directional Tandem Collision Network by Joint Medium-Access Control and Channel-Network Coding

    In ALOHA-type packetized network, the transmission times of packets follow a stochastic process. In this paper, the authors advocate a deterministic approach for channel multiple-access. Each user is statically assigned a periodic protocol signal, which takes value either zero or one, and transmits packets whenever the value of the protocol...

    Provided By University of Hong Kong

  • White Papers // Sep 2009

    On Securing Perimeter Coverage in Wireless Sensor Networks

    The coverage problem in which a set of sensors is required to collaborate so as to preserve the whole perimeter of a big object is known as the perimeter coverage problem. With the assumption that two sensors are neighbors and connected if they have overlapping cover ranges, the authors have...

    Provided By University of Hong Kong

  • White Papers // Aug 2009

    An ISP-Friendly File Distribution Protocol: Analysis, Design and Implementation

    In the past few years, P2P file distribution applications (e.g., BitTorrent) are becoming so popular that they are the dominating source of Internet traffic. This creates significant problems to Internet Service Providers (ISPs), not only because of the added complexity in traffic engineering, but the increase of traffic, in particular...

    Provided By University of Hong Kong

  • White Papers // Dec 2008

    On Attack-Resilient Wireless Sensor Networks With Novel Recovery Strategies

    Security is always a critical issue in Wireless Sensor Networks (WSNs). Among all threats, node capture attack is one of the most challenging problems. When an adversary physically captures one or more sensor nodes, all the information stored on these nodes may be exposed completely. Consequently, the adversary can use...

    Provided By University of Hong Kong

  • White Papers // Jan 2011

    Data Centric Storage With Diffuse Caching in Sensor Networks

    In a sensor network that adopts Data-Centric Storage (DCS), information of the same kind is kept in the same set of nodes. That is, when a sensor detects a certain event, no matter where it is, it sends the information to the designated location. When another node wants the information,...

    Provided By University of Hong Kong

  • White Papers // Sep 2009

    On Securing Perimeter Coverage in Wireless Sensor Networks

    The coverage problem in which a set of sensors is required to collaborate so as to preserve the whole perimeter of a big object is known as the perimeter coverage problem. With the assumption that two sensors are neighbors and connected if they have overlapping cover ranges, the authors have...

    Provided By University of Hong Kong

  • White Papers // Jun 2009

    On Perimeter Coverage Scheduling in Wireless Sensor Networks

    Many sensor network applications require the tracking and the surveillance of target objects. The authors are specifically interested in the coverage problem known as perimeter coverage that the perimeter of the whole target has to be monitored while a single sensor can only monitor a certain portion of the perimeter....

    Provided By University of Hong Kong

  • White Papers // Aug 2009

    Perimeter Coverage Made Practical in Wireless Sensor Networks

    Many sensor network applications require the tracking and the surveillance of target objects. However, it is generally assumed that the whole target object can be monitored by a sensor in case the target falls within its sensing range. Unfortunately, this assumption may not be realistic in case the target object...

    Provided By University of Hong Kong

  • White Papers // Jan 2011

    Efficient Event and Query Distribution in Sensor Networks

    A sensor network consists of a large number of sensors which are equipped with sensing, computation, and communication devices. Due to limitation in size, a sensor has only limited energy and storage. Traditional wireless network protocols cannot be applied in sensor networks directly. The authors study the distribution of events...

    Provided By University of Hong Kong

  • White Papers // May 2011

    Implementation and Application of a Multi-Radio Wireless Sensor Networks Testbed

    The authors propose EasiTest, a multi-radio testbed for heterogeneous Wireless Sensor Networks (WSNs). Two types of sensor nodes, specifically, high-speed multi-radio node (EZ271) and low-speed single-radio node (EZ521) are developed. An administration platform is provided to monitor and control the testbed. EasiTest enjoys high flexibility, powerful processing capability and ease...

    Provided By University of Hong Kong

  • White Papers // Feb 2011

    An Efficient Scheme for Hard Disk Integrity Check in Digital Forensics by Hashing With Combinatorial Group Testing

    In this paper, the authors describe the problem of checking the integrity of a hard disk for forensics investigation after the computer of a suspect has been seized. Existing solutions do not provide a satisfactory solution to solve the problem. They either require a huge amount of storage to store...

    Provided By University of Hong Kong

  • White Papers // Jul 2009

    Scalable Probabilistic Similarity Ranking in Uncertain Databases

    This paper introduces a scalable approach for probabilistic top-k similarity ranking on uncertain vector data. Each uncertain object is represented by a set of vector instances that are assumed to be mutually-exclusive. The objective is to rank the uncertain data according to their distance to a reference object. The authors...

    Provided By University of Hong Kong

  • White Papers // Dec 2011

    Privacy-Preserving Stream Aggregation With Fault Tolerance

    The authors consider applications where an untrusted aggregator would like to collect privacy sensitive data from users, and compute aggregate statistics periodically. For example, imagine a smart grid operator who wishes to aggregate the total power consumption of a neighborhood every ten minutes; or a market researcher who wishes to...

    Provided By University of Hong Kong

  • White Papers // Aug 2009

    An ISP-Friendly File Distribution Protocol: Analysis, Design and Implementation

    In the past few years, P2P file distribution applications (e.g., BitTorrent) are becoming so popular that they are the dominating source of Internet traffic. This creates significant problems to Internet Service Providers (ISPs), not only because of the added complexity in traffic engineering, but the increase of traffic, in particular...

    Provided By University of Hong Kong

  • White Papers // May 2011

    Friends or Foes: Detecting Dishonest Recommenders in Online Social Networks

    Viral marketing is becoming important due to the popularity of Online Social Networks (OSNs) and the fact that many users have integrated OSNs into their daily activities, e.g., they provide recommendations to their friends on the products they purchased, or they make decision based on received recommendations. Nevertheless, this also...

    Provided By University of Hong Kong

  • White Papers // May 2009

    Impact of Altruism on Opportunistic Communications

    Opportunistic networking largely relies on human-carried devices as relays to move data across the network. Human altruistic behavior is an important factor in the feasibility and performance of such a system. In this paper, the authors study the impact of different altruism distributions on the system throughput and delay of...

    Provided By University of Hong Kong

  • White Papers // May 2012

    Physical-Layer Network Coding for VPN in TDM-PON

    The authors experimentally demonstrate a novel optical Physical-layer Network Coding (PNC) scheme over Time-Division Multiplexing (TDM) Passive Optical Network (PON). Full-duplex error-free communications between optical network units (ONUs) at 2.5 Gb/s are shown for all-optical Virtual Private Network (VPN) applications. Compared to the conventional half-duplex communications set-up, their scheme can...

    Provided By University of Hong Kong

  • White Papers // Jul 2012

    Voronoi-Based Nearest Neighbor Search for Multi-Dimensional Uncertain Databases

    Nearest neighbor queries are the fundamental procedures for many similarity search and location-based query applications for location-based services. In particular, a nearest-neighbor query allows users to retrieve the most similar object to a given query object or to retrieve a location from a geospatial database that is closest to her...

    Provided By University of Hong Kong

  • White Papers // Sep 2010

    Binary is Good: A Binary Inference Framework for Primary User Separation in Cognitive Radio Networks

    Primary Users (PU) separation concerns with the issues of distinguishing and characterizing primary users in Cognitive Radio (CR) networks. The authors argue the need for PU separation in the context of collaborative spectrum sensing and monitor selection. In this paper, they model the observations of monitors as boolean OR mixtures...

    Provided By University of Hong Kong

  • White Papers // Oct 2012

    Bad Data Injection Attack and Defense in Electricity Market Using Game Theory Study

    Applications of cyber technologies improve the quality of monitoring and decision making in smart grid. These cyber technologies are vulnerable to malicious attacks, and compromising them can have serious technical and economical problems. This paper specifies the effect of compromising each measurement on the price of electricity, so that the...

    Provided By University of Hong Kong

  • White Papers // May 2012

    Interference-Aware Resource Allocation for Device-to-Device Communications as an Underlay Using Sequential Second Price Auction

    An innovative resource allocation scheme is pro-posed to improve the performance of Device-To-Device (D2D) communications as an underlay in the DownLink (DL) cellular networks. To optimize the system sum rate over the resource sharing of both D2D and cellular modes, the authors introduce a sequential second price auction as the...

    Provided By University of Hong Kong

  • White Papers // May 2012

    Power Allocation Using Vickrey Auction and Sequential First-Price Auction Games for Physical Layer Security in Cognitive Relay Networks

    The authors consider a cognitive radio network in which multiple pairs of Secondary Users (SUs) communicate by a one-way relay node over orthogonal channels with the existence of an eavesdropper close to the destination. The transmit power of the relay needs efficient distribution for maximizing the sum secrecy rate of...

    Provided By University of Hong Kong

  • White Papers // May 2012

    Sampling Spectrum Occupancy Data Over Random Fields: A Matrix Completion Approach

    The performance of cognitive radio networks is fundamentally determined by the availability of spectrum re-sources. Detailed measurement campaigns are needed to collect the spectrum occupancy data to obtain a deeper understanding of the spectrum usage characteristics in cognitive radio networks. This approach, however, is usually inefficient due to the ignorance...

    Provided By University of Hong Kong

  • White Papers // May 2012

    Multiple Operator and Multiple Femtocell Networks: Distributed Stable Matching

    The authors propose distributed matching algorithms for an uplink communication network comprised of multiple Femtocell Access Points (FAPs), multiple Wireless Operators (WOs) which own multiple Macrocell Access Points (MAPs) and multiple Final Users (FUs) subscribed to these WOs. In particular, they propose two algorithms: the first algorithm matches the FAPs...

    Provided By University of Hong Kong

  • White Papers // Feb 2012

    Physical Layer Security for Two-Way Untrusted Relaying with Friendly Jammers

    In this paper, the authors consider a two-way relay network where two sources can communicate only through an un trusted intermediate relay, and investigate the physical layer security issue of this two way relay scenario. Specifically, they treat the intermediate relay as an eavesdropper from which the information transmitted by...

    Provided By University of Hong Kong

  • White Papers // Mar 2011

    Non-Transferable Proxy Re-Encryption Scheme for Data Dissemination Control

    A Proxy Re-Encryption (PRE) scheme allows a proxy to re-encrypt a ciphertext for Alice (delegator) to a ciphertext for Bob (delegatee) without seeing the underlying plaintext. With the help of the proxy, Alice can delegate the decryption right to any delegatee. However, existing PRE schemes generally suffer from at least...

    Provided By University of Hong Kong

  • White Papers // Jan 2010

    Anonymous Fuzzy Identity-Based Encryption for Similarity Search

    In this paper, the authors consider the problem of predicate encryption and focus on the predicate for testing whether the hamming distance between the attribute X of a data item and a target V is equal to (or less than) a threshold t where X and V are of length...

    Provided By University of Hong Kong

  • White Papers // Sep 2009

    Achieving Capacity of Bi-Directional Tandem Collision Network by Joint Medium-Access Control and Channel-Network Coding

    In ALOHA-type packetized network, the transmission times of packets follow a stochastic process. In this paper, the authors advocate a deterministic approach for channel multiple-access. Each user is statically assigned a periodic protocol signal, which takes value either zero or one, and transmits packets whenever the value of the protocol...

    Provided By University of Hong Kong

  • White Papers // Jan 2011

    On Dynamic Server Provisioning in Multi-Channel P2P Live Streaming

    To guarantee the streaming quality in live Peer-To-Peer (P2P) streaming channels, it is preferable to provision adequate levels of upload capacities at dedicated streaming servers, compensating for peer instability and time-varying peer upload bandwidth availability. Most commercial P2P streaming systems have resorted to the practice of over-provisioning a fixed amount...

    Provided By University of Hong Kong

  • White Papers // May 2009

    Haven't Learned From The Past? -A Common Symptom Of Asset Price Bubble Implosions

    By reviewing the previous three asset bubble implosions, viz. The "Lost Decade" of Japan in the 1980s; the Asian Financial Crisis in Hong Kong in 1997; and the Financial Tsunami in the USA in 2008, a common symptom of negative real interest rate is very clearly revealed before the implosion...

    Provided By University of Hong Kong

  • White Papers // Nov 2010

    A Novel Probabilistic Pruning Approach to Speed Up Similarity Queries in Uncertain Databases

    In this paper, the authors propose a novel, effective and efficient probabilistic pruning criterion for probabilistic similarity queries on uncertain data. Their approach supports a general uncertainty model using continuous probabilistic density functions to describe the (possibly correlated) uncertain attributes of objects. In a nutshell, the problem to be solved...

    Provided By University of Hong Kong

  • White Papers // Feb 2009

    Robot Assisted Emergency Search and Rescue System With a Wireless Sensor Network

    The unprecedented number and scales of natural and human-induced disasters in the past decade has urged the emergency search and rescue community around the world to seek a newer, more effective equipment to enhance their efficiency. Search and rescue technology to-date still rely on old technologies such as search dogs,...

    Provided By University of Hong Kong

  • White Papers // Nov 2009

    On the Robustness of Wireless Opportunistic Routing Toward Inaccurate Link-Level Measurements

    The quality of wireless links is inherently dynamic, and this often makes the measurements of link delivery probabilities inaccurate over short timescales. The authors present Stable Opportunistic Routing (SOR), which improves unicast throughput for wireless mesh routing in the presence of inaccurate link-level measurements. In essence, SOR integrates two key...

    Provided By University of Hong Kong

  • White Papers // Feb 2010

    Financial Literacy And Household Investments In Structured Financial Products

    Classical portfolio theory suggests that investors would shun away from unfamiliar financial products. This familiarity bias holds especially for unsophisticated household investors. However, the rapid growth of the credit derivatives market indicates that other factors may have played important role in such investment process. Using unique household investment data from...

    Provided By University of Hong Kong

  • White Papers // Mar 2009

    Does Trade Credit Help? Evidence From China

    A counterexample to the findings in the finance and development literature is that firms have achieved good performance in many developing economies where the financial sector is far from established. One widely suggested mechanism in the literature is that firms in these developing economies use a high ratio of informal...

    Provided By University of Hong Kong

  • White Papers // Jan 2009

    Picking Up The Losses: The Impact Of The Cultural Revolution On Human Capital Reinvestment In Urban China

    Using the Cultural Revolution of China as a quasi-experiment, this paper analyzes the long-term impact of interrupted education in the midst of economic transition with booming opportunities that highly reward educational qualifications. The authors focus on the remedial human capital investment decisions taken by individuals whose education has been interrupted...

    Provided By University of Hong Kong

  • White Papers // Apr 2010

    Future Application Scenarios for MANET-Based Intelligent Transportation Systems

    Road transportation systems are traditionally characterized by how efficient they direct traffic in a non-congested manner towards their destinations. Improvement in car electronics, sensors, and navigation systems all help in realizing this goal of "Destination-driven" and "No-hassle" driving. With the advent of wireless communications and networking technologies, the future transportation...

    Provided By University of Hong Kong

  • White Papers // Dec 2008

    Realistic Radio Propagation Models (RPMs) for VANET Simulations

    Deploying and testing Vehicular Ad hoc NETworks (VANETs) involves high cost and intensive labor. Hence simulation is a useful alternative prior to actual implementation. Most works found in the literature employ very simplistic Radio Propagation Models (RPMs), ignoring the dramatic effects presented by buildings on radio signals. In this paper,...

    Provided By University of Hong Kong

  • White Papers // Jan 2009

    A Distributed Multihop Time Synchronization Protocol for Wireless Sensor Networks Using Pairwise Broadcast Synchronization

    Recently, a time synchronization algorithm called Pairwise Broadcast Synchronization (PBS) is proposed. With PBS, a sensor can be synchronized by overhearing synchronization packet exchange among its neighbouring sensors without sending out any packet itself. In an one-hop sensor network where every node is a neighbour of each other, a single...

    Provided By University of Hong Kong

  • White Papers // Aug 2009

    Aggregation-Based QoS Routing in the Internet

    In this paper, the authors study the problem of QoS routing with two concave constraints in the Internet. They propose an efficient approach for computing the supported QoS across domains based on the aggregated intra-domain topology. The time complexity of their approach is polynomial. Moreover, their approach can be incorporated...

    Provided By University of Hong Kong

  • White Papers // May 2009

    Routing With QoS Information Aggregation in Hierarchical Networks

    In this paper, the authors consider the problem of routing with two additive constraints in the hierarchical networks, such as the Internet. In order for scalability, the supported QoS information in the hierarchical networks has to be aggregated. They propose a novel method for aggregating the QoS information. To the...

    Provided By University of Hong Kong

  • White Papers // Jan 2011

    HyBloc: Localization in Sensor Networks With Adverse Anchor Placement

    To determine the geographical positions of sensors, numerous localization algorithms have been proposed in recent years. The positions of sensors are inferred from the connectivity between sensors and a set of nodes called anchors which know their precise locations. The authors investigate the effect of adverse placement and density of...

    Provided By University of Hong Kong

  • White Papers // Jul 2010

    Simplified Ordering for Fixed-Complexity Sphere Decoder

    This paper proposes a simplified ordering algorithm for the Fixed Complexity Sphere decoder (FSD). The new algorithm is developed from the analysis of the ordering for FSD from a geometrical point of view. Computer simulation is used to assess the improvements in Bit-Error Rate (BER) performances of MIMO systems using...

    Provided By University of Hong Kong