Association for Computing Machinery

Displaying 121-160 of 6819 results

  • White Papers // Apr 2014

    Ariadne: Managing Fine-Grained Provenance on Data Streams

    Managing fine-grained provenance is a critical requirement for Data Stream Management Systems (DSMS), not only to address complex applications that require diagnostic capabilities and assurance, but also for providing advanced functionality such as revision processing or query debugging. This paper introduces a novel approach that uses operator instrumentation, i.e., modifying...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2014

    A Hybrid Task Mapping Algorithm for Heterogeneous MPSoCs

    The application workloads in modern MPSoC-based embedded systems are becoming increasingly dynamic. Different applications concurrently execute and contend for resources in such systems, which could cause serious changes in the intensity and nature of the workload demands over time. To cope with the dynamism of application workloads at run time...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2014

    GDM: Device Memory Management for GPGPU Computing

    GPGPUs are evolving from dedicated accelerators towards mainstream commodity computing resources. During the transition, the lack of system management of device memory space on GPGPUs has become a major hurdle. In existing GPGPU systems, device memory space is still managed explicitly by individual applications, which not only increases the burden...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2014

    An Online Auction Framework for Dynamic Resource Provisioning in Cloud Computing

    Auction mechanisms have recently attracted substantial attention as an efficient approach to pricing and resource allocation in cloud computing. This work, to the authors' knowledge, represents the first online combinatorial auction designed in the cloud computing paradigm, which is general and expressive enough to both optimize system efficiency across the...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2014

    Scalable Performance Analysis of ExaScale MPI Programs through Signature-Based Clustering Algorithms

    Extreme-scale computing poses a number of challenges to application performance. Developers need to study application behavior by collecting detailed information with the help of tracing toolsets to determine shortcomings. But not only applications are \"Scalability challenged\", current tracing toolsets also fall short of exascale requirements for low back-ground overhead since...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2014

    Mining Latent Entity Structures from Massive Unstructured and Interconnected Data

    The \"Big data\" era is characterized by an explosion of information in the form of digital data collections, ranging from scientific knowledge, to social media, news, and everyone's daily life. Examples of such collections include scientific publications, enterprise logs, news articles, social media and general web pages. Valuable knowledge about...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2014

    Major Technical Advancements in Apache Hive

    Apache Hive is a widely used data warehouse system for Apache Hadoop, and has been adopted by many organizations for various big data analytics applications. Closely working with many users and organizations, the authors have identified several shortcomings of Hive in its file formats, query planning, and query execution, which...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2014

    CGPA: Coarse-Grained Pipelined Accelerators

    High-Level Synthesis (HLS) tools dramatically reduce the nonrecurring engineering cost of creating specialized hardware accelerators. Existing HLS tools are successful in synthesizing efficient accelerators for program kernels with regular memory accesses and simple control flows. For other programs, however, these tools yield poor performance because they invoke computation units for...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2014

    PSelInv - A Distributed Memory Parallel Algorithm for Selected Inversion : the Symmetric Case

    The authors describe an efficient parallel implementation of the selected inversion algorithm for distributed memory computer systems, which they call PSelInv. The PSelInv method computes selected elements of a general sparse matrix A that can be decomposed as A = LU, where L is lower triangular and U is upper...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2014

    Palette: Enabling Scalable Analytics for Big-Memory, Multicore Machines

    Hadoop and its variants have been widely used for processing large scale analytics tasks in a cluster environment. However, use of a commodity cluster for analytics tasks needs to be reconsidered based on two key observations: in recent years, large memory, multicore machines have become more affordable; and recent studies...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Maple: Scalable Multi-Dimensional Range Search over Encrypted Cloud Data with Tree-based Index

    Cloud computing promises users massive scale outsourced data storage services with much lower costs than traditional methods. However, privacy concerns compel sensitive data to be stored on the cloud server in an encrypted form. This papers a great challenge for effectively utilizing cloud data, such as executing common SQL queries....

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    A Study on Architectures for Embedded Devices

    Embedded designers can't afford "The blue screen of death". Desktop operating systems can get rebooted every so often, but embedded devices often have to run for years without a single reboot. Devices that are used in medical fields are one of the most appropriate examples in which reliability is more...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    A Probabilistic Model for Linking Named Entities in Web Text with Heterogeneous Information Networks

    Heterogeneous information networks that consist of multi-type, interconnected objects are becoming ubiquitous and increasingly popular, such as social media networks and bibliographic networks. The task to link named entity mentions detected from the unstructured Web text with their corresponding entities existing in a heterogeneous information network is of practical importance...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Model Selection for Semi-Supervised Clustering

    Although there is a large and growing literature that tackles the semi-supervised clustering problem (i.e., using some labeled objects or cluster-guiding constraints like \"Must-link\" or \"Cannot-link\"), the evaluation of semi-supervised clustering approaches has rarely been discussed. The application of cross-validation techniques, for example, is far from straightforward in the semi-supervised...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Understanding, Modelling, and Improving the Performance of Web Applications in Multicore Virtualised Environments

    As the computing industry enters the cloud era, multicore architectures and virtualization technologies are replacing traditional IT infrastructures. However, the complex relationship between applications and system resources in multi-core virtualized environments is not well understood. Work-loads such as web services and online financial applications have the requirement of high performance...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Stochastic Computation

    Stochastic computation, as presented in this paper, exploits the statistical nature of application-level performance metrics, and matches it to the statistical attributes of the underlying device and circuit fabrics. Nanoscale circuit fabrics are viewed as noisy communication channels/networks. Communications-inspired design techniques based on estimation and detection theory are proposed. Stochastic...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Host-Compiled Multi-Core System Simulation for Early Real-Time Performance Evaluation

    With increasing complexity and software content, modern embedded platforms employ a heterogeneous mix of multi-core processors along with hardware accelerators in order to provide high performance in limited power budgets. To evaluate real-time performance and other constraints, full-system simulations are essential. With traditional approaches being either slow or inaccurate, so-called...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    RML: A Generic Language for Integrated RDF Mappings of Heterogeneous Data

    Despite the significant number of existing tools, incorporating data from multiple sources and different formats into the linked open data cloud remains complicated. No mapping formalization exists to define how to map such heterogeneous sources into RDF in an integrated and interoperable fashion. This paper introduces the RML mapping language,...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Evaluating Storage Systems for Scientific Data in the Cloud

    Infrastructure-as-a-Service (IaaS) clouds are an appealing resource for scientific computing. However, the bare-bones presentation of raw Linux virtual machines leaves much to the application developer. For many cloud applications, effective data handling is critical to efficient application execution. This paper investigates the capabilities of a variety of POSIX-accessible distributed storage...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Heterogeneous-race-free Memory Models

    Commodity heterogeneous systems (e.g., integrated CPUs and GPUs), now support a unified, shared memory address space for all components. Because the latency of global communication in a heterogeneous system can be prohibitively high, heterogeneous systems (unlike homogeneous CPU systems) provide synchronization mechanisms that only guarantee ordering among a subset of...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Q100: The Architecture and Design of a Database Processing Unit

    In this paper, the authors propose Database Processing Units, or DPUs, a class of domain-specific database processors that can efficiently handle database applications. As a proof of concept, they present the instruction set architecture, microarchitecture, and hardware implementation of one DPU, called Q100. The Q100 has a collection of heterogeneous...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    EnCore: Exploiting System Environment and Correlation Information for Misconfiguration Detection

    As software systems become more complex and configurable, failures due to misconfigurations are becoming a critical problem. Such failures often have serious functionality, security and financial consequences. Further, diagnosis and remediation for such failures require reasoning across the software stack and its operating environment, making it difficult and costly. The...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Guardrail: A High Fidelity Approach to Protecting Hardware Devices from Buggy Drivers

    While device driver code is both critical to proper system operation and more susceptible to bugs than other system software, relatively little work has been done in the area of online driver correctness monitoring (perhaps due to the performance-sensitive nature of driver software). This paper demonstrate that decoupled correctness checking...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    I/O Paravirtualization at the Device File Boundary

    Paravirtualization is an important I/O virtualization technology since it uniquely provides all of the following benefits: the ability to share the device between multiple VMs, support for legacy devices without virtualization hardware, and high performance. However, existing paravirtualization solutions have one main limitation: they only support one I/O device class,...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    The Benefit of SMT in the Multi-Core Era: Flexibility Towards Degrees of Thread-Level Parallelism

    The number of active threads in a multi-core processor varies over time and is often much smaller than the number of supported hardware threads. This requires multi-core chip designs to balance core count and per-core performance. Low active thread counts benefit from a few big, high-performance cores, while high active...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Locality-Oblivious Cache Organization Leveraging Single-Cycle Multi-Hop NoCs

    Locality has always been a critical factor in on-chip data placement on Chip Multi-Processors (CMPs) as accessing further-away caches has in the past been more costly than accessing nearby ones. Substantial research on locality-aware designs have thus focused on keeping a copy of the data private. However, this complicates the...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    REF: Resource Elasticity Fairness with Sharing Incentives for Multiprocessors

    With the democratization of cloud and datacenter computing, users increasingly share large hardware platforms. In this setting, architects encounter two challenges: sharing fairly and sharing multiple resources. Drawing on economic game-theory, the authors rethink fairness in computer architecture. A fair allocation must provide Sharing Incentives (SI), Envy-Freeness (EF), and Pareto...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Price Theory Based Power Management for Heterogeneous Multi-Cores

    Heterogeneous multi-cores that integrate cores with different power-performance characteristics are promising alternatives to homogeneous systems in energy- and thermally constrained environments. However, the heterogeneity imposes significant challenges to power-aware scheduling. The authors present a price theory-based dynamic power management framework for heterogeneous multi-cores that co-ordinates various energy savings opportunities, such...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Sapper: A Language for Hardware- Level Security Policy Enforcement

    Privacy and integrity are important security concerns. These concerns are addressed by controlling information flow, i.e., restricting how information can flow through a system. Most proposed systems that restrict information flow make the implicit assumption that the hardware used by the system is fully \"Correct\" and that the hardware's instruction...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Scale-Out NUMA

    Emerging datacenter applications operate on vast datasets that are kept in DRAM to minimize latency. The large number of servers needed to accommodate this massive memory footprint requires frequent server-to-server communication in applications such as key-value stores and graph-based applications that rely on large irregular data structures. The fine-grained nature...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Integrated 3D-Stacked Server Designs for Increasing Physical Density of Key-Value Stores

    Key-value stores, such as Memcached, have been used to scale web services since the beginning of the Web 2.0 era. Data center real estate is expensive, and several industry experts the authors have spoken to have suggested that a significant portion of their data center space is devoted to key-value...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    K2: A Mobile Operating System for Heterogeneous Coherence Domains

    Mobile System-on-Chips (SoC) that incorporate heterogeneous coherence domains promise high energy efficiency to a wide range of mobile applications, yet are difficult to program. To exploit the architecture, a desirable, yet missing capability is to replicate Operating System (OS) services over multiple coherence domains with minimum inter-domain communication. In designing...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Sapper: A Language for Hardware-Level Security Policy Enforcement

    Privacy and integrity are important security concerns. These concerns are addressed by controlling information flow, i.e., restricting how information can flow through a system. Most proposed systems that restrict information flow make the implicit assumption that the hardware used by the system is fully \"Correct\" and that the hardware's instruction...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Rhythm: Harnessing Data Parallel Hardware for Server Workloads

    Trends in increasing web traffic demand an increase in server throughput while preserving energy efficiency and total cost of ownership. Present work in optimizing data center efficiency primarily focuses on the data center as a whole, using off-the-shelf hardware for individual servers. Server capacity is typically increased by adding more...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    iACT: A Software-Hardware Framework for Understanding the Scope of Approximate Computing

    Approximate computing has recently emerged as a paradigm for enabling energy efficient software and hardware implementations by exploiting the inherent resiliency in applications to impreciseness in their underlying computations. Much of the previous work in this area has demonstrated the potential for significant energy and performance improvements, but these works...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Shrinking the Hypervisor One Subsystem at a Time

    Efficient and secure networking between virtual machines is crucial in a time where a large share of the services on the Internet and in private datacenters run in virtual machines. To achieve this efficiency, virtualization solutions, such as Qemu/KVM, move towards a monolithic system architecture in which all performance critical...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    A Virtualized Separation Kernel for Mixed Criticality Systems

    Multi- and many-core processors are becoming increasingly popular in embedded systems. Many of these processors now feature hardware virtualization capabilities, such as the ARM Cortex A15, and x86 processors with Intel VT-x or AMD-V support. Hardware virtualization offers opportunities to partition physical resources, including processor cores, memory and I/O devices...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    ParallelJS: An Execution Framework for JavaScript on Heterogeneous Systems

    JavaScript has been recognized as one of the most widely used script languages. Optimizations of JavaScript engines on mainstream web browsers enable efficient execution of JavaScript programs on CPUs. However, running JavaScript applications on emerging heterogeneous architectures that feature massively parallel hardware such as GPUs has not been well studied....

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    A CPU-GPU Hybrid Implementation and Model-Driven Scheduling of the Fast Multipole Method

    This paper presents an optimized CPU-GPU hybrid implementation and a GPU performance model for the kernel-independent Fast Multipole Method (FMM). The authors implement an optimized kernel-independent FMM for GPUs, and combine it with their previous CPU implementation to create a hybrid CPU+GPU FMM kernel. When compared to another highly optimized...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2014

    Application-Aware Memory System for Fair and Efficient Execution of Concurrent GPGPU Applications

    The available computing resources in modern GPUs are growing with each new generation. However, as many general purpose applications with limited thread-scalability are tuned to take advantage of GPUs, available compute resources might not be optimally utilized. To address this, modern GPUs will need to execute multiple kernels simultaneously. As...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2012

    On Active Learning in Hierarchical Classification

    Most of the existing active learning algorithms assume all the category labels as independent or consider them in a "Flat" structure. However, in reality, there are many applications in which the set of possible labels are often organized in a hierarchical structure. In this paper, the authors consider the problem...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2013

    A Framework for High Performance Simulation of Transactional Data Grid Platforms

    One reason for the success of in-memory (transactional) data grids lies on their ability to t elasticity requirements imposed by the cloud oriented pay-as-you-go cost model. In fact, by relying on in-memory data maintenance, these platforms can be dynamically resized by simply setting up (or shutting down) instances of so...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2010

    An Evolutionary Algorithm to Optimize Log/Restore Operations within Optimistic Simulation Platforms

    In this paper, the authors address state recoverability in advanced optimistic simulation systems by proposing an Evolutionary Algorithm to optimize at run-time the parameters associated with state log/restore activities. Optimization takes place by adaptively selecting for each simulation object both the best suited log mode (incremental vs. non-incremental) and the...

    Provided By Association for Computing Machinery

  • White Papers // Jun 2012

    Brief Announcement: Application-Sensitive QoS Scheduling in Storage Servers

    The growing popularity of multi-tenant, cloud-based computing platforms is driving research into new QoS models that permit flexible sharing of the underlying infrastructure. In this paper, the authors reexamine the use of the popular proportional-share model for resource allocation, in the context of modern heterogeneous, multi-tiered storage systems. They highlight...

    Provided By Association for Computing Machinery

  • White Papers // Jun 2012

    Optimizing Latency and Throughput for Spawning Processes on Massively Multi-Core Processors

    The execution of a SPMD application involves running multiple instances of a process with possibly varying arguments. With the widespread adoption of massively multi-core processors, there has been a focus towards harnessing the abundant compute resources effectively in a power-efficient manner. Although much work has been done towards optimizing distributed...

    Provided By Association for Computing Machinery

  • White Papers // May 2013

    Non-Monetary Fair Scheduling - A Cooperative Game Theory Approach

    The authors consider a multi-organizational system in which each organization contributes processors to the global pool but also jobs to be processed on the common resources. The fairness of the scheduling algorithm is essential for the stability and even for the existence of such systems (as organizations may refuse to...

    Provided By Association for Computing Machinery

  • White Papers // Jun 2010

    Enabling Green Building Applications

    Office buildings contain large sensor network deployments to monitor and maintain their internal environment. They also consume a significant amount of energy. This paper proposes the use of the use of horizontal layering, rather than the current vertical-solution approach, to expose the building data plane and enable interoporable software services...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2012

    Design and Evaluation of a Wireless Magnetic-Based Proximity Detection Platform for Indoor Applications

    Many indoor sensing applications leverage knowledge of relative proximity among physical objects and humans, such as the notion of "Within arm's reach". In this paper, the authors quantify this notion using "Proximity zone", and propose a methodology that empirically and systematically compare the proximity zones created by various wireless technologies....

    Provided By Association for Computing Machinery

  • White Papers // Jun 2012

    Explicit Modeling of Control and Data for Improved NoC Router Estimation

    Networks-on-Chip (NoCs) are scalable fabrics for interconnection networks used in many-core architectures. ORION2.0 is a widely adopted NoC power and area estimation tool; however, its models for area, power and gate count can have large errors (up to 110% on average) versus actual implementation. In this paper, the authors propose...

    Provided By Association for Computing Machinery

  • White Papers // Sep 2010

    Destination-Based Adaptive Routing on 2D Mesh Networks

    The choice of routing algorithm plays a vital role in the performance of on-chip interconnection networks. Adaptive routing is appealing because it offers better latency and throughput than oblivious routing, especially under non-uniform and bursty traffic. The performance of an adaptive routing algorithm is determined by its ability to accurately...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2013

    Temperature Aware Workload Management in Geo-Distributed Datacenters

    Datacenters consume an enormous amount of energy with significant financial and environmental costs. For geo-distributed datacenters, a workload management approach that routes user requests to locations with cheaper and cleaner electricity has been shown to be promising lately. The authors consider two key aspects that have not been explored in...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2011

    STARR-DCS: Spatio-Temporal Adaptation of Random Replication for Data Centric Storage

    This paper presents a novel framework for Data Centric Storage in a Wireless Sensor and Actor Network (WSAN) that enables the use of a randomly-selected set of data replication nodes, which also change over the time. This enables reductions in the average network traffic and energy consumption by adapting the...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2012

    Generalized Resource Allocation for the Cloud

    Resource allocation is an integral, evolving part of many data center management problems such as virtual machine placement in data centers, network virtualization, and multi-path network routing. Since the problems are inherently NP-Hard, most existing systems use custom-designed heuristics to find a suitable solution. However, such heuristics are often rigid,...

    Provided By Association for Computing Machinery

  • White Papers // Jul 2012

    Network-Aware Service Placement in a Distributed Cloud Environment

    The authors consider a system of compute and storage resources geographically distributed over a large number of locations connected via a wide-area network. By distributing the resources, latency to users can be decreased, bandwidth costs reduced and availability increased. The challenge is to distribute services with varying characteristics among the...

    Provided By Association for Computing Machinery

  • White Papers // Jun 2010

    Elon: Enabling Efficient and Long-Term Reprogramming for Wireless Sensor Networks

    The authors present a new mechanism called Elon for enabling efficient and long-term reprogramming in wireless sensor networks. Elon reduces the transferred code size significantly by introducing the concept of replaceable component. It avoids the cost of hardware reboot with a novel software reboot mechanism. Moreover, it significantly prolongs the...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2013

    Web Data Indexing in the Cloud: Efficiency and Cost Reductions

    The authors propose architecture for warehousing large-scale web data, in particular XML, in a commercial cloud platform, specifically, Amazon Web Services. Since cloud users support monetary costs directly connected to their consumption of cloud resources, they focus on indexing content in the cloud. They examine the applicability of several indexing...

    Provided By Association for Computing Machinery

  • White Papers // May 2013

    See Through Walls with Wi-Fi!

    Wi-Fi signals are typically information carriers between a transmitter and a receiver. In this paper, the authors show that Wi-Fi can also extend their senses, enabling there to see moving objects through walls and behind closed doors. In particular, they can use such signals to identify the number of people...

    Provided By Association for Computing Machinery

  • White Papers // Sep 2011

    Large File Transmission in Network-Coded Networks with Packet Loss - A Performance Perspective

    Network coding can significantly improve the transmission rate of communication networks with packet loss compared with routing. But using network coding usually involves more computational and storage costs in network devices and terminals. The authors discuss some recent schemes for file transmission in networks employing coding and compare the computational...

    Provided By Association for Computing Machinery

  • White Papers // Jun 2011

    A Bayesian Approach to Online Performance Modeling for Database Appliances Using Gaussian Models

    In order to meet Service Level Agreements (SLAs) and to maintain peak performance for DataBase Management Systems (DBMS), DataBase Administrators (DBAs) need to implement policies for effective workload scheduling, admission control, and resource provisioning. Accurately predicting response times of DBMS queries is necessary for a DBA to effectively achieve these...

    Provided By Association for Computing Machinery

  • White Papers // Jun 2010

    Schema Clustering and Retrieval for Multi-Domain Pay-as-You-Go Data Integration Systems

    A data integration system offers a single interface to multiple structured data sources. Many application contexts (e.g., searching structured data on the web) involve the integration of large numbers of structured data sources. At web scale, it is impractical to use manual or semi-automatic data integration methods, so a pay-as-you-go...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2013

    Optimizing XML Querying Using Type-Based Document Projection

    XML data projection (or pruning) is a natural optimization for main memory query engines: given a query Q over a document D, the sub-trees of D that are not necessary to evaluate Q are pruned, thus producing a smaller document D; the query Q is then executed on D0, hence...

    Provided By Association for Computing Machinery

  • White Papers // Feb 2013

    Containment of Pattern-Based Queries over Data Trees

    The authors study static analysis, in particular the containment problem, for analogs of conjunctive queries over XML documents. The problem has been studied for queries based on arbitrary patterns, not necessarily following the tree structure of documents. However, many applications force the syntactic shape of queries to be tree-like, as...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2013

    Efficient Query Answering Against Dynamic RDF Databases

    A promising method for efficiently querying RDF data consists of translating SPARQL queries into efficient RDBMS-style operations. However, answering SPARQL queries requires handling RDF reasoning, which must be implemented outside the relational engines that do not support it. The authors introduce the DataBase (DB) fragment of RDF, going beyond the...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2011

    Pocket Cloudlets

    Cloud services accessed through mobile devices suffer from high network access latencies and are constrained by energy budgets dictated by the devices' batteries. Radio and battery technologies will improve over time, but are still expected to be the bottlenecks in future systems. Non-Volatile Memories (NVM), however, may continue experiencing significant...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2011

    Enhancing Cellular Infrastructures: A Reflective Approach

    In this paper, the authors make a case of a reflective architecture for cellular systems as means to support flexibility and evolvability of the existing cellular network infrastructure to deal with a new generation of adaptive environments and applications. Existing systems are event/request driven and mechanisms to enable seamless adaptivity...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2013

    Achieving Resilience of Heterogeneous Networks Through Predictive, Formal Analysis

    Rapid development and wide deployment of wireless technologies in recent years have brought an increasing number and variety of services that are accessible directly from mobile terminals via multiple network access technologies (e.g., Ethernet, WiFi, Bluetooth, LTE, etc). A particular traffic flow may go through different kinds of networks, which...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2011

    Developing Applications in the Cloud Through the SelfLet Framework

    Cloud computing is an emergent technology which allows the cost effective and flexible development of distributed applications including a large number of heterogeneous nodes, distributed across the cloud. These systems pose several new challenges such as the need for nodes to autonomously and dynamically manage themselves in order to achieve...

    Provided By Association for Computing Machinery

  • White Papers // Aug 2012

    Every Bit Counts - Fast and Scalable RFID Estimation

    Radio Frequency IDentification (RFID) systems have been widely deployed for various applications such as object tracking, 3D positioning, supply chain management, inventory control, and access control. This paper concerns the fundamental problem of estimating RFID tag population size, which is needed in many applications such as tag identification, warehouse monitoring,...

    Provided By Association for Computing Machinery

  • White Papers // Jun 2011

    Characterizing and Modeling Internet Traffic Dynamics of Cellular Devices

    Understanding Internet traffic dynamics in large cellular networks is important for network design, troubleshooting, performance evaluation, and optimization. In this paper, the authors present the results from their study, which is based upon a week-long aggregated flow level mobile device traffic data collected from a major cellular operator's core network....

    Provided By Association for Computing Machinery

  • White Papers // Mar 2012

    Firewall Policy Change-Impact Analysis

    Firewalls are the cornerstones of the security infrastructure for most enterprises. They have been widely deployed for protecting private networks. The quality of the protection provided by a firewall directly depends on the quality of its policy (i.e., configuration). Due to the lack of tools for analyzing firewall policies, many...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2012

    Mathematical Frameworks for Pricing in the Cloud: Revenue, Fairness, and Resource Allocations

    As more and more users begin to use the cloud for their computing needs, datacenter operators are increasingly pressed to effectively allocate their resources among these client users. Yet while much work has been done in this area, relatively little attention has been paid to studying perhaps the ultimate lever...

    Provided By Association for Computing Machinery

  • White Papers // Sep 2010

    Reliable Neighbor Discovery for Mobile Ad Hoc Networks

    The authors define a reliable neighbor discovery layer for mobile ad-hoc networks and present two algorithms that implement this layer as a service with varying progress guarantees. Their algorithms are implemented atop an abstract MAC layer, which deals with the lower level details of collision detection and contention. Specifically, they...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2013

    Securing Communications Between External Users and Wireless Body Area Networks

    Wireless Body Area Networks (BANs) are expected to play a crucial role in patient-health monitoring in the near future. Establishing secure communications between BAN sensors and external users is key to addressing the prevalent security and privacy concerns. In this paper, the authors propose the primitive functions to implement a...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2012

    Distributed Adaptive Routing for Big-Data Applications Running on Data Center Networks

    With the growing popularity of big-data applications, Data Center Networks increasingly carry larger and longer traffic flows. As a result of this increased flow granularity, static routing cannot efficiently load-balance traffic, resulting in an increased network contention and a reduced throughput. Unfortunately, while adaptive routing can solve this load-balancing problem,...

    Provided By Association for Computing Machinery

  • White Papers // Aug 2012

    Performance Evaluation and Design Trade-Offs for Wireless Network-on-Chip Architectures

    Massive levels of integration are making modern multicore chips all pervasive in several domains. High performance, robustness, and energy-efficiency are crucial for the widespread adoption of such platforms. Networks-on-Chip (NoCs) have emerged as communication backbones to enable a high degree of integration in multicore Systems-on-Chip (SoCs). Despite their advantages, an...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2011

    Modeling the Effect of Transmission Errors on TCP Controlled Transfers Over Infrastructure 802.11 Wireless LANs

    There have been several studies on the performance of TCP controlled transfers over an infrastructure IEEE 802.11 WLAN, assuming perfect channel conditions. In this paper, the authors develop an analytical model for the throughput of TCP controlled le transfers over the IEEE 802.11 DCF with different packet error probabilities for...

    Provided By Association for Computing Machinery

  • White Papers // Jun 2013

    Leveraging Endpoint Flexibility in Data-Intensive Clusters

    Many applications do not constrain the destinations of their network transfers. New opportunities emerge when such transfers contribute a large amount of network bytes. By choosing the endpoints to avoid congested links, completion times of these transfers as well as that of others without similar flexibility can be improved. In...

    Provided By Association for Computing Machinery

  • White Papers // Jun 2012

    Metrics and Techniques for Quantifying Performance Isolation in Cloud Environments

    The cloud computing paradigm enables the provision of cost-efficient IT-services by leveraging economies of scale and sharing data center resources efficiently among multiple independent applications and customers. However, the sharing of resources leads to possible interference between users and performance problems are one of the major obstacles for potential cloud...

    Provided By Association for Computing Machinery

  • White Papers // Aug 2012

    Integrating Meta-Path Selection with User-Guided Object Clustering in Heterogeneous Information Networks

    Real-world, multiple-typed objects are often interconnected, forming heterogeneous information networks. A major challenge for link-based clustering in such networks is its potential to generate many different results, carrying rather diverse semantic meanings. In order to generate desired clustering, the authors propose to use meta-path, a path that connects object types...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2011

    Policy Expressivity in the Anzere Personal Cloud

    The authors present a technique for partially replicating data items at scale according to expressive policy specifications. Recent projects have addressed the challenge of policy-based replication of personal data (photos, music, etc.) within a network of devices, as an alternative to centralized online services. To date, the policies supported by...

    Provided By Association for Computing Machinery