Korea Advanced Institute of Science and Technology

Displaying 1-40 of 75 results

  • White Papers // Dec 2013

    A Survey on Intrusion-Tolerant System

    Many information systems that provide useful services to people are connected to the Internet for convenience and efficiency. However, improper accessibility might make the systems susceptible to a variety of attacks. Although existing security solutions such as an intrusion detection system, intrusion prevention system, and firewalls have been designed to...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Feb 2013

    Comments on an Improved RFID Security Protocol for ISO/IEC WD 29167-6

    With the rapid progress of RFID security technologies, the international standard group ISO/IEC JTC 1/SC 31 is developing a few security technologies for RFID systems. One of the initial proposals is ISO/IEC Working Draft (WD) 29167-6. Recently, Song and others stated that Protocol 1 of ISO/IEC WD 29167-6 is vulnerable...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Oct 2012

    One-to-N Wireless Power Transmission System Based on Multiple Access One-Way In-Band Communication

    For an efficient wireless charging to multiple devices, Transmitter (TX) system should be able to control the transmitting power-level by monitoring number of Receiver (RX) devices via their identification information and charging status and capacity of each receivers. This paper proposes a one-way in-band communication scheme, corresponding system structure, and...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Oct 2012

    MNK: Configurable Hybrid Flash Translation Layer for Multi-Channel SSD

    For multi-channel Solid State Disks (SSDs), hybrid Flash Translation Layer (FTL) schemes were developed for increasing I/O parallelism and reducing garbage collection overhead. However, they still suffer from the high read and write latency, block thrashing problem, and load balancing problem. In order to overcome these problems, the authors design...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Oct 2012

    OPAMP: Evaluation Framework for Optimal Page Allocation of Hybrid Main Memory Architecture

    Main memory as a hybrid between DRAM and nonvolatile memory is rapidly considered as a basic building block of computing systems. Despite widely-performed researches no one can confirm whether hybrid memory is at its full performance in terms of energy consumption, time delay or both. The main problem is that...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Sep 2012

    Security Weakness in the Proof of Storage with Deduplication

    Achieving both security and efficiency is the challenging issue for a data outsourcing service in the cloud computing. Proof Of Storage with Deduplication (POSD) is the first solution that addresses the issue for the cloud storage. However, the validity of the POSD scheme stands on the strong assumption that all...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Sep 2012

    R-Barrier: Rapid Barrier for Software RAID Cache Using Hints From Journaling Filesystem

    While adopting cache in software RAID brings performance benefit, it can cause data loss at power failure which results in the broken file-system consistency. Though I/O Barrier can be used to remove the consistency issue, it sacrifices the write performance of software RAID. To mitigate this tradeoff, the authors suggest...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Aug 2012

    Design of Multimedia Matching Service Using Manycores and GPGPU

    Now-a-days, many users are spending their time with enjoying multimedia, and this trend spreads rapidly according to the propagation of Smartphones. Multimedia services have tried to attach tag for information of merchandizes related to multimedia, so the multimedia consumers can get detail of those merchandizes, such as price or purchasing...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // May 2012

    Adaptive Tuning Method for Maximizing Capacity in Magnetic Induction Communication

    Sensors are embedded in dense mediums, such as walls of building and underground, for various applications. However, traditional wireless communication using Electro-Magnetic (EM) waves does not operate well in this embedded sensor networks because the EM waves are attenuated severely in new propagation mediums including rock, soil, and water. Magnetic...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // May 2012

    A Group-Based Communication Scheme Based on the Location Information of MTC Devices in Cellular Networks

    Recent standardization efforts in the 3rd Generation Partnership Project (3GPP) have made the Long Term Evolution (LTE) system a very attractive radio access technology for various types of devices and applications. However, the system has not yet been optimized to support diverse traffic profiles. In this paper, the authors propose...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // May 2012

    Smart Scanning for Mobile Devices in WLANs

    A recent proliferation of mobile devices led to immense deployment of WLAN Access Points (APs). IEEE 802.11 mobile devices periodically perform active background scanning to discover available APs in the vicinity. However, this periodic active scanning imposes unnecessary overhead in a static WLAN environment. This paper addresses this scanning overhead...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // May 2012

    Modeling and Analysis of an Energy-Efficient Sleep-Mode Operation in IEEE 802.16e System

    Power saving mechanisms with sleep-mode operations have been used in IEEE 802.16e in order to extend the battery lifetime of mobile devices. The standard sleep-mode operation needs to meet a given delay constraint. However, it may incur unnecessary energy consumption due to frequent state transitions. In this paper, the authors...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // May 2012

    Parallel LDPC Decoder Implementation on GPU Based on Unbalanced Memory Coalescing

    The authors consider flexible decoder implementation of Low Density Parity Check (LDPC) codes via Compute-Unified-Device Architecture (CUDA) programming on Graphics Processing Unit (GPU), a research subject of considerable recent interest. An important issue in LDPC decoder design based on CUDA-GPU is realizing coalesced memory access, a technique that reduces memory...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // May 2012

    Dynamic Virtual Machine Scheduling in Clouds for Architectural Shared Resources

    Although Virtual Machine (VM) migration has been used to avoid conflicts on traditional system resources like CPU and memory, micro-architectural resources such as shared caches, memory controllers, and Non-Uniform Memory Access (NUMA) affinity, have only relied on intra-system scheduling to reduce contentions on them. This paper shows that live VM...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Mar 2012

    Power Saving Scheme Based on Joint Control of Buffer-Threshold and Timer in Binary Exponential Sleep Mode

    The authors propose a new power saving scheme based on a buffer-threshold and timer in wireless packet networks. In a standard sleep mode operation with a binary exponential algorithm, a Mobile Station (MS) can begin a wake period if it is aware of the existence of its own downlink packets...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Mar 2012

    Optimal Design for Dynamic Spectrum Access in Cognitive Radio Networks Under Rayleigh Fading

    The authors consider a time slotted cognitive radio network under Rayleigh fading where multiple Secondary Users (SUs) contend for spectrum usage over available primary users' channels. They analyze the performance of a channel access policy where each SU stochastically determines whether to access a wireless channel or not based on...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Mar 2012

    A Location Update Scheme Using Multi-Hop Pointer Forwarding in Low-Rate Wireless Mesh Networks

    Recently, a Pointer Forwarding Scheme (PFS) was proposed to reduce location update overhead in wireless mesh networks. Using the PFS, location update is replaced with a simple forwarding pointer setup between two neighboring MRs until the forwarding chain K is less than or equal to the configurable parameter K-max for...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Mar 2012

    Performance Analysis of OSTBC in Gamma-Gamma Fading Channels

    The Multi-Input Multi-Output (MIMO) system with a Subcarrier Intensity Modulation (SIM) scheme in Free-Space Optics (FSO) has a huge merit for ultra wide band communications mainly due to its diversity gain to be able to mitigate the signal scintillation caused by the atmospheric turbulence. In this paper, the authors have...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Mar 2012

    Orthogonal Beamforming for Overlay Mode of OFDMA-Based Rural Broadband Wireless Access

    The authors consider an overlay mode of an Orthogonal Frequency Division Multiple Access (OFDMA) based cellular system using orthogonal beam-forming to provide broadband wireless access for rural users. In overlay mode, since the signals transmitted to rural users should not interfere with mobile users of higher priority in the OFDMA-based...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Feb 2012

    Efficient Detection Using Sequential Probability Ratio Test in Mobile Cognitive Radio Systems

    This paper proposes a smart design strategy for a sequential detector to reliably detect the primary user's signal, especially in fast fading environments. The authors study the computation of the log-likelihood ratio for coping with a fast changing received signal and noise sample variances, which are considered random variables. They...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2012

    Power Minimization in Decode-and-XOR-Forward Two-Way Relay Networks

    The authors consider a two-way relay network where two sources exchange information. A relay helps the two sources exchange information using the decode-and-XOR-forward protocol. They investigate the power minimization problem with minimum rate constraints. The system needs two time slots and in each time slot the required rate pair should...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2012

    Unmasking the Growing UDP Traffic in a Campus Network

    Transmission Control Protocol (TCP) has been the dominating protocol for Internet traffic for the past decades. Most network research based on traffic analysis (e.g., router buffer sizing and traffic classification) has been conducted assuming the dominance of TCP over other protocols. However, a few recent traffic statistics are showing a...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Dec 2011

    Privacy-Preserving PKI Design Based on Group Signature

    Nowadays, Internet becomes a part of the peoples' life. The authors can make use of numerous services with personal computer, laptop, tablet, smart phone or smart TV. These devices with network make one enjoy ubiquitous computing life. Sometimes, online services request one authentication or identification for access control and authorization,...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Oct 2011

    Emerging Ubiquitous Knowledge Services: From Mobile Sensing to Ubiquitous Crowdsourcing and Beyond

    Recent advances of information and communication technologies (e.g., smartphones and Web 2.0) have facilitated ubiquitous sensing and networked collaboration among people. This trend has significantly lowered the knowledge transfer barriers and has broadened the range of knowledge services, thus enabling new types of services called "Ubiquitous knowledge services." The goal...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Aug 2011

    Energy Minimization of 3D Cache-Stacked Processor Based on Thin-Film Thermoelectric Coolers

    In this paper, the authors explore the energy optimization of the processor with 3D stacked cache memory based on Thin-Film Thermo-Electric Coolers (TFTEC). 3D integrated circuit is suitable for applications requiring small size, high performance and memory capacity. However, 3D integration incurs high power density owing to high temperature and...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jul 2011

    Power-Aware Memory Management for Hybrid Main Memory

    In this paper, the authors propose the main memory management mechanism of the Operating System (OS) for the hybrid main memory which combines both advantages of DRAM and PRAM (Phase Change RAM). They separate memory pages into hot and cold pages, and dynamically located them to the proper memory region....

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jul 2011

    Infrastructure Support Increases the Capacity of Ad Hoc Wireless Networks

    Ad hoc wireless networks have been extensively studied since they can be used for future networks with various specific purposes. Because they can operate in an easily deployable, self-configurable, and highly flexible manner, it is clear that they will play an indispensable role in distributed wireless networks. A key concern...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jun 2011

    TLB Index-based Tagging for Cache Energy Reduction

    Conventional cache tag matching is based on addresses to identify correct data in caches. However, this tagging scheme is not efficient because tag bits are unnecessarily large. From the authors' observations, there are not many unique tag bits due to typically small working sets, which are conventionally captured by TLBs....

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Feb 2011

    Spectrum Leasing Via Cooperation for Enhanced Physical-Layer Secrecy

    Spectrum leasing via cooperation refers to the possibility for primary users to lease part of the spectral resources to secondary users in exchange for cooperation. This paper proposes a novel implementation of this concept in which secondary cooperation aims at improving the secrecy of the primary link. In particular, a...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Feb 2011

    Optimal Design and Analysis of a Two-Hop Relay Network Under Rayleigh Fading for Packet Delay Minimization

    In this paper, the authors consider a wireless network consisting of a source node, a destination node and multiple relay nodes under Rayleigh fading. Cooperative diversity in the network is achieved by selecting an opportunistic relay node with the best channel condition to the destination node. They focus on the...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Feb 2011

    Diffusion-Confusion Based Light-Weight Security for Item-RFID Tag-Reader Communication

    In this paper the authors propose a challenge-response protocol called: DCSTaR, which takes a novel approach to solve security issues that are specific to low-cost item-RFID tags. DCSTaR protocol is built upon light-weight primitives such as 16 bit: Random Number Generator, Exclusive-OR, and Cyclic Redundancy Check and utilizing these primitives...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2011

    An Enhanced Security Policy Framework for Android

    Googles Android, a smartphone operating system, is used by many users, and the number of its users is increasing. However, because in Android Market, the application store only for Android, there is no examination of security of applications and Android users can install applications without stores; malicious applications can circumvent...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2011

    An Efficient and Privacy-Preserving Authentication Protocol for HAN

    The SG (Smart Grid) system provides advantages for its stakeholders, which can not only reduce wasted energy and maintenance cost but also increase reliability with transparency during delivering electricity from suppliers to customer. The HAN (Home Area Network), consisting of smart appliances, smart meter and management system; can enable an...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2011

    Secure, Fast Rebuilding, and Energy Efficient Routing Protocol for Mission-Critical Application Over Wireless Sensor Networks

    The mission-critical application over Wireless Sensor Network (WSN) such as fire alarm, radiation leak, and surveillance reconnaissance should support fast, reliable, and fault tolerant on its routing protocol. Otherwise, the application cannot support its own functionality and bring unexpected losses. However, the existing routing protocols are believed neither to consider...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2011

    Resuscitating Privacy-Preserving Mobile Payment With Customer in Complete Control

    Credit/debit card payment transactions do not protect the privacy of the customer. Once the card is handed over to the merchant for payment processing, customers are "No longer in control" on how their card details and money are handled. This leads to card fraud, identity theft, and customer profiling. Therefore...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2011

    On the Design of Content-Centric MANETs

    Content-centric networking focuses on data delivery rather than end-to-end reachability by decoupling resources from the hosts they reside on. The authors consider content-centric networking as a fundamental driver for Mobile Ad hoc NETwork (MANET) protocol design. They systematically evaluate the suitability and effectiveness of existing approaches toward designing a content-centric...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2011

    Performance Analysis of Decentralized RAN (Radio Access Network) Discovery Schemes

    As more wireless access networks become available, there is a new challenge emerged: how to discover currently available Radio Access Networks (RANs). To discover available RANs without help from centralized servers, each mobile host periodically turns on network interfaces to discover available networks. Performance of a RAN discovery scheme may...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2011

    Efficient Network Management Based on Fast Fault Discovery for Indoor WiBro System

    Indoor WiBro system, which is gaining attention as the efficient alternative of WLAN, is promising to expand coverage and improve system performance in the indoor environment. Main framework of indoor WiBro system is based on the existing outdoor WiBro system, however more optimized for indoor requirements such as static channel...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Dec 2010

    Performance Analysis of Single Source and Single Relay Cooperative ARQ Protocols Under Time Correlated Rayleigh Fading Channel

    In this paper, the authors analyze the performance of a cooperative Automatic-Repeat-reQuest (ARQ) protocol under Poisson arrivals and time-correlated Rayleigh fading. The conventional non-cooperative ARQ protocol under the same channel environment is also analyzed to compare its performance with that of the cooperative ARQ protocol. A two dimensional discrete time...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Dec 2010

    Behavior-Based Mobility Prediction for Seamless Handoffs in Mobile Wireless Networks

    The field of wireless networking has received unprecedented attention from the research community during the last decade due to its great potential to create new horizons for communicating beyond the Internet. Wireless LANs (WLANs) based on the IEEE 802.11 standard have become prevalent in public as well as residential areas,...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2011

    Performance Analysis of Decentralized RAN (Radio Access Network) Discovery Schemes

    As more wireless access networks become available, there is a new challenge emerged: how to discover currently available Radio Access Networks (RANs). To discover available RANs without help from centralized servers, each mobile host periodically turns on network interfaces to discover available networks. Performance of a RAN discovery scheme may...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Oct 2011

    Emerging Ubiquitous Knowledge Services: From Mobile Sensing to Ubiquitous Crowdsourcing and Beyond

    Recent advances of information and communication technologies (e.g., smartphones and Web 2.0) have facilitated ubiquitous sensing and networked collaboration among people. This trend has significantly lowered the knowledge transfer barriers and has broadened the range of knowledge services, thus enabling new types of services called "Ubiquitous knowledge services." The goal...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2011

    On the Design of Content-Centric MANETs

    Content-centric networking focuses on data delivery rather than end-to-end reachability by decoupling resources from the hosts they reside on. The authors consider content-centric networking as a fundamental driver for Mobile Ad hoc NETwork (MANET) protocol design. They systematically evaluate the suitability and effectiveness of existing approaches toward designing a content-centric...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Feb 2011

    Optimal Design and Analysis of a Two-Hop Relay Network Under Rayleigh Fading for Packet Delay Minimization

    In this paper, the authors consider a wireless network consisting of a source node, a destination node and multiple relay nodes under Rayleigh fading. Cooperative diversity in the network is achieved by selecting an opportunistic relay node with the best channel condition to the destination node. They focus on the...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Aug 2009

    Performance Modeling and Analysis of IEEE 802.15.4 Slotted CSMA/CA Protocol With ACK Mode

    In this paper, the authors propose an analytic model to analyze a Wireless Sensor Network (WSN) operating the IEEE 802.15.4 slotted CSMA/CA protocol with ACK mode. Based on the renewal approximation, they first develop an analytic model for a homogeneous WSN where all nodes in the network have the same...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2010

    Capacity Optimal Design of a Two-Hop Relay Network

    In this paper, the authors consider a decode-and-forward two-hop relay network exploiting spatial diversity. By considering transmission overheads in detail to exploit spatial diversity, they derive an explicit expression for the average transmission capacity of the relay network, which is a function of the transmission time and coding rate by...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Dec 2009

    Design and Analysis of an Adaptive Guard Channel Based Cac Scheme in a 3G-WLAN Integrated Network

    In wireless networks, guard channel based Call Admission Control (CAC) schemes are widely used to protect handoff calls for seamless wireless services. However, the introduction of guard channels in wireless networks results in the increase in the new call blocking probability. This general situation also occurs in a 3G-WLAN integrated...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Aug 2009

    Traffic Modelling and Bandwidth Allocation Algorithm for Video Telephony Service Traffic

    In this paper, the authors analyze the stochastic characteristics of the measured video telephony service traffic and propose a mathematical model of the video telephony service traffic based on the analyzed stochastic characteristics. From their analysis, voice traffic can be modelled by a renewal process with deterministic inter-arrival times and...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Oct 2009

    Crowdsourced Radiomap for Room-Level Place Recognition in Urban Environment

    The proliferation of WLAN infrastructures has facilitated numerous indoor localization techniques using WLAN fingerprints. In particular, identifying a room or a place in urban environments could be usefully utilized in many application domains such as ubiquitous health. However, it is not straightforward how to bootstrap such a localization system because...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Dec 2011

    Privacy-Preserving PKI Design Based on Group Signature

    Nowadays, Internet becomes a part of the peoples' life. The authors can make use of numerous services with personal computer, laptop, tablet, smart phone or smart TV. These devices with network make one enjoy ubiquitous computing life. Sometimes, online services request one authentication or identification for access control and authorization,...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Dec 2010

    A Context-Aware Framework Using Ontology for Smart Phone Platform

    Context-awareness has been considered as promising topic in pervasive computing area, but a review of the existing approaches shown that developing diverse application services in this area is still motivated based on the analysis of existing approaches in literature. This paper proposed a context-aware system, which can provide more specific...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2012

    Power Minimization in Decode-and-XOR-Forward Two-Way Relay Networks

    The authors consider a two-way relay network where two sources exchange information. A relay helps the two sources exchange information using the decode-and-XOR-forward protocol. They investigate the power minimization problem with minimum rate constraints. The system needs two time slots and in each time slot the required rate pair should...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jan 2012

    Unmasking the Growing UDP Traffic in a Campus Network

    Transmission Control Protocol (TCP) has been the dominating protocol for Internet traffic for the past decades. Most network research based on traffic analysis (e.g., router buffer sizing and traffic classification) has been conducted assuming the dominance of TCP over other protocols. However, a few recent traffic statistics are showing a...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Apr 2009

    CASFI Data Sharing Platform

    Effective data management has become a key in promoting data sharing within measurement-based research community. In this paper, the authors propose a framework that helps one to share not only the data, but also the data management platform in order to promote collaboration across multiple institutions. They have designed and...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jul 2011

    Infrastructure Support Increases the Capacity of Ad Hoc Wireless Networks

    Ad hoc wireless networks have been extensively studied since they can be used for future networks with various specific purposes. Because they can operate in an easily deployable, self-configurable, and highly flexible manner, it is clear that they will play an indispensable role in distributed wireless networks. A key concern...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Mar 2012

    Power Saving Scheme Based on Joint Control of Buffer-Threshold and Timer in Binary Exponential Sleep Mode

    The authors propose a new power saving scheme based on a buffer-threshold and timer in wireless packet networks. In a standard sleep mode operation with a binary exponential algorithm, a Mobile Station (MS) can begin a wake period if it is aware of the existence of its own downlink packets...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Mar 2012

    Optimal Design for Dynamic Spectrum Access in Cognitive Radio Networks Under Rayleigh Fading

    The authors consider a time slotted cognitive radio network under Rayleigh fading where multiple Secondary Users (SUs) contend for spectrum usage over available primary users' channels. They analyze the performance of a channel access policy where each SU stochastically determines whether to access a wireless channel or not based on...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Dec 2010

    Performance Analysis of Single Source and Single Relay Cooperative ARQ Protocols Under Time Correlated Rayleigh Fading Channel

    In this paper, the authors analyze the performance of a cooperative Automatic-Repeat-reQuest (ARQ) protocol under Poisson arrivals and time-correlated Rayleigh fading. The conventional non-cooperative ARQ protocol under the same channel environment is also analyzed to compare its performance with that of the cooperative ARQ protocol. A two dimensional discrete time...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Mar 2010

    Analysis of Short Term Fairness and Its Impact on Packet Level Performance

    In this paper, the authors consider the one-bit feedback scheduler with a threshold in a wireless network. Due to its feedback reduction structure, the one-bit feedback scheduler has been studied as one of good candidates implementable in a practical wireless network, and it is important to determine the threshold value...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jul 2009

    Packet Level Performance Analysis of a Packet Scheduler Exploiting Multiuser Diversity

    In this paper, the authors consider a packet scheduler exploiting multiuser diversity in a wireless network with AMC (Adaptive Modulation and Coding), and propose a packet level performance model based on the effective bandwidth theory to investigate the joint effect of the AMC and the multiuser diversity scheduling on the...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Dec 2010

    Precoder Design for Blind Channel Estimation in Multiple OFDM Systems

    The problem of blind channel estimation for multiple single-antenna Orthogonal Frequency Division Multiplexing (OFDM) systems coexisting in the same band is considered. Based on the previous work on linear precoding for blind channel estimation for OFDM systems, a new precoder design based on zero-hole matrices is proposed and optimal design...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // May 2012

    Dynamic Virtual Machine Scheduling in Clouds for Architectural Shared Resources

    Although Virtual Machine (VM) migration has been used to avoid conflicts on traditional system resources like CPU and memory, micro-architectural resources such as shared caches, memory controllers, and Non-Uniform Memory Access (NUMA) affinity, have only relied on intra-system scheduling to reduce contentions on them. This paper shows that live VM...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Dec 2010

    Behavior-Based Mobility Prediction for Seamless Handoffs in Mobile Wireless Networks

    The field of wireless networking has received unprecedented attention from the research community during the last decade due to its great potential to create new horizons for communicating beyond the Internet. Wireless LANs (WLANs) based on the IEEE 802.11 standard have become prevalent in public as well as residential areas,...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // May 2012

    Adaptive Tuning Method for Maximizing Capacity in Magnetic Induction Communication

    Sensors are embedded in dense mediums, such as walls of building and underground, for various applications. However, traditional wireless communication using Electro-Magnetic (EM) waves does not operate well in this embedded sensor networks because the EM waves are attenuated severely in new propagation mediums including rock, soil, and water. Magnetic...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // May 2012

    A Group-Based Communication Scheme Based on the Location Information of MTC Devices in Cellular Networks

    Recent standardization efforts in the 3rd Generation Partnership Project (3GPP) have made the Long Term Evolution (LTE) system a very attractive radio access technology for various types of devices and applications. However, the system has not yet been optimized to support diverse traffic profiles. In this paper, the authors propose...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // May 2012

    Smart Scanning for Mobile Devices in WLANs

    A recent proliferation of mobile devices led to immense deployment of WLAN Access Points (APs). IEEE 802.11 mobile devices periodically perform active background scanning to discover available APs in the vicinity. However, this periodic active scanning imposes unnecessary overhead in a static WLAN environment. This paper addresses this scanning overhead...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // May 2012

    Modeling and Analysis of an Energy-Efficient Sleep-Mode Operation in IEEE 802.16e System

    Power saving mechanisms with sleep-mode operations have been used in IEEE 802.16e in order to extend the battery lifetime of mobile devices. The standard sleep-mode operation needs to meet a given delay constraint. However, it may incur unnecessary energy consumption due to frequent state transitions. In this paper, the authors...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // May 2012

    Parallel LDPC Decoder Implementation on GPU Based on Unbalanced Memory Coalescing

    The authors consider flexible decoder implementation of Low Density Parity Check (LDPC) codes via Compute-Unified-Device Architecture (CUDA) programming on Graphics Processing Unit (GPU), a research subject of considerable recent interest. An important issue in LDPC decoder design based on CUDA-GPU is realizing coalesced memory access, a technique that reduces memory...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Mar 2012

    A Location Update Scheme Using Multi-Hop Pointer Forwarding in Low-Rate Wireless Mesh Networks

    Recently, a Pointer Forwarding Scheme (PFS) was proposed to reduce location update overhead in wireless mesh networks. Using the PFS, location update is replaced with a simple forwarding pointer setup between two neighboring MRs until the forwarding chain K is less than or equal to the configurable parameter K-max for...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Mar 2012

    Performance Analysis of OSTBC in Gamma-Gamma Fading Channels

    The Multi-Input Multi-Output (MIMO) system with a Subcarrier Intensity Modulation (SIM) scheme in Free-Space Optics (FSO) has a huge merit for ultra wide band communications mainly due to its diversity gain to be able to mitigate the signal scintillation caused by the atmospheric turbulence. In this paper, the authors have...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Mar 2012

    Orthogonal Beamforming for Overlay Mode of OFDMA-Based Rural Broadband Wireless Access

    The authors consider an overlay mode of an Orthogonal Frequency Division Multiple Access (OFDMA) based cellular system using orthogonal beam-forming to provide broadband wireless access for rural users. In overlay mode, since the signals transmitted to rural users should not interfere with mobile users of higher priority in the OFDMA-based...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Feb 2012

    Efficient Detection Using Sequential Probability Ratio Test in Mobile Cognitive Radio Systems

    This paper proposes a smart design strategy for a sequential detector to reliably detect the primary user's signal, especially in fast fading environments. The authors study the computation of the log-likelihood ratio for coping with a fast changing received signal and noise sample variances, which are considered random variables. They...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Sep 2012

    Security Weakness in the Proof of Storage with Deduplication

    Achieving both security and efficiency is the challenging issue for a data outsourcing service in the cloud computing. Proof Of Storage with Deduplication (POSD) is the first solution that addresses the issue for the cloud storage. However, the validity of the POSD scheme stands on the strong assumption that all...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Feb 2013

    Comments on an Improved RFID Security Protocol for ISO/IEC WD 29167-6

    With the rapid progress of RFID security technologies, the international standard group ISO/IEC JTC 1/SC 31 is developing a few security technologies for RFID systems. One of the initial proposals is ISO/IEC Working Draft (WD) 29167-6. Recently, Song and others stated that Protocol 1 of ISO/IEC WD 29167-6 is vulnerable...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Dec 2010

    Iterative Algorithm for Interference Alignment in Multiuser MIMO Interference Channels

    Algorithms for designing beamforming matrices for interference alignment in multiuser time-invariant multi-input multi-output interference channels are proposed. Based on a new formulation for the necessary and sufficient condition for interference alignment, the proposed algorithm iteratively minimizes overall interference misalignment in a least squares sense. Additional modified algorithms are also considered....

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Dec 2010

    Linux Kernel Support to Exploit Phase Change Memory

    Recently, phase change memory (PRAM) has been developed as a next generation memory technology. Because PRAM can be accessed as word-level using memory interface of DRAM and offer more density compared to DRAM, PRAM is expected as an alternative main memory device. Moreover, it can be used as additional storage...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Jul 2011

    Power-Aware Memory Management for Hybrid Main Memory

    In this paper, the authors propose the main memory management mechanism of the Operating System (OS) for the hybrid main memory which combines both advantages of DRAM and PRAM (Phase Change RAM). They separate memory pages into hot and cold pages, and dynamically located them to the proper memory region....

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Oct 2012

    MNK: Configurable Hybrid Flash Translation Layer for Multi-Channel SSD

    For multi-channel Solid State Disks (SSDs), hybrid Flash Translation Layer (FTL) schemes were developed for increasing I/O parallelism and reducing garbage collection overhead. However, they still suffer from the high read and write latency, block thrashing problem, and load balancing problem. In order to overcome these problems, the authors design...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Sep 2012

    R-Barrier: Rapid Barrier for Software RAID Cache Using Hints From Journaling Filesystem

    While adopting cache in software RAID brings performance benefit, it can cause data loss at power failure which results in the broken file-system consistency. Though I/O Barrier can be used to remove the consistency issue, it sacrifices the write performance of software RAID. To mitigate this tradeoff, the authors suggest...

    Provided By Korea Advanced Institute of Science and Technology

  • White Papers // Oct 2012

    OPAMP: Evaluation Framework for Optimal Page Allocation of Hybrid Main Memory Architecture

    Main memory as a hybrid between DRAM and nonvolatile memory is rapidly considered as a basic building block of computing systems. Despite widely-performed researches no one can confirm whether hybrid memory is at its full performance in terms of energy consumption, time delay or both. The main problem is that...

    Provided By Korea Advanced Institute of Science and Technology