Association for Computing Machinery

Displaying 281-320 of 6435 results

  • White Papers // Dec 2013

    SoftCell: Scalable and Flexible Cellular Core Network Architecture

    Cellular core networks suffer from in flexible and expensive equipment, as well as from complex control-plane protocols. To address these challenges, the authors present SoftCell, a scalable architecture that supports fine-grained policies for mobile devices in cellular core networks, using commodity switches and servers. SoftCell enables operators to realize high-level...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    SHIFT: Shared History Instruction Fetch for Lean-Core Server Processors

    In server workloads, large instruction working sets result in high L1 instruction cache miss rates. Fast access requirements preclude large instruction caches that can accommodate the deep software stacks prevalent in server applications. Prefetching has been a promising approach to mitigate instruction-fetch stalls by relying on recurring instruction streams of...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Quantifying the Relationship between the Power Delivery Network and Architectural Policies in a 3D-Stacked Memory Device

    Many of the pins on a modern chip are used for power de-livery. If fewer pins were used to supply the same current, the wires and pins used for power delivery would have to carry larger currents over longer distances. This results in an \"IR-drop\" problem, where some of the...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Approximate Storage in Solid-State Memories

    Memories today expose an all-or-nothing correctness model that incurs significant costs in performance, energy, area, and design complexity. But not all applications need high-precision storage for all of their data structures all of the time. This paper proposes mechanisms that enable applications to store data approximately and shows that doing...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Kiln: Closing the Performance Gap Between Systems With and Without Persistence Support

    Persistent memory is an emerging technology which allows in-memory persistent data objects to be updated at much higher throughput than when using disks as persistent storage. Previous persistent memory designs use logging or copy-on-write mechanisms to update persistent data, which unfortunately reduces the system performance to roughly half that of...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Efficient Management of Last-Level Caches in Graphics Processors for 3D Scene Rendering Workloads

    Three-Dimensional (3D) scene rendering is implemented in the form of a pipeline in Graphics Processing Units (GPUs). In different stages of the pipeline, different types of data get accessed. These include, for instance, vertex, depth, stencil, render target (same as pixel color), and texture sampler data. The GPUs traditionally include...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Decoupled Compressed Cache: Exploiting Spatial Locality for Energy-Optimized Compressed Caching

    In multicore processor systems, Last-Level Caches (LLCs) play a crucial role in reducing system energy by filtering out expensive accesses to main memory and reducing the time spent executing in high-power states. Cache compression can increase effective cache capacity and reduce misses, improve performance, and potentially reduce system energy. However,...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Heterogeneous System Coherence for Integrated CPU-GPU Systems

    Many future heterogeneous systems will integrate CPUs and GPUs physically on a single chip and logically connect them via shared memory to avoid explicit data copying. Making this shared memory coherent facilitates programming and fine-grained sharing, but throughput-oriented GPUs can overwhelm CPUs with coherence requests not well-filtered by caches. Meanwhile,...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    RowClone: Fast and Energy-Efficient In-DRAM Bulk Data Copy and Initialization

    Several system-level operations trigger bulk data copy or initialization. Even though these bulk data operations do not require any computation, current systems transfer a large quantity of data back and forth on the memory channel to perform such operations. As a result, bulk data operations consume high latency, bandwidth, and...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Linearly Compressed Pages: A Low-Complexity, Low-Latency Main Memory Compression Framework

    Data compression is a promising approach for meeting the increasing memory capacity demands expected in future systems. Unfortunately, existing compression algorithms do not translate well when directly applied to main memory because they require the memory controller to perform non-trivial computation to locate a cache line within a compressed memory...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Meet the Walkers: Accelerating Index Traversals for In-Memory Databases

    The explosive growth in digital data and its growing role in real-time decision support motivate the design of high-performance DataBase Management Systems (DBMSs). Meanwhile, slowdown in supply voltage scaling has stymied improvements in core performance and ushered an era of power-limited chips. These developments motivate the design of DBMS accelerators...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    BulkCommit: Scalable and Fast Commit of Atomic Blocks in a Lazy Multiprocessor Environment

    To help improve the programmability and performance of shared memory multiprocessors, there are proposals of architectures that continuously execute atomic blocks of instructions - also called Chunks. To be competitive, these architectures must support chunk operations very efficiently. In particular, in a large manycore with lazy conflict detection, they must...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Energy Efficient GPU Transactional Memory via Space-Time Optimizations

    Many applications with regular parallelism have been shown to benefit from using Graphics Processing Units (GPUs). However, employing GPUs for applications with irregular parallelism tends to be a risky process, involving significant effort from the programmer. One major, non-trivial effort/risk is to expose the available parallelism in the application as...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Divergence-Aware Warp Scheduling

    In the face of diminished voltage scaling, massively multithreaded programmable accelerators, like Graphics Processing Units (GPUs), can potentially make more efficient use of the available chip power budget. This paper uses hardware thread scheduling to improve the performance and energy efficiency of divergent applications on GPUs. The authors propose Divergence-Aware...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    DESC: Energy-Efficient Data Exchange using Synchronized Counters

    Increasing cache sizes in modern microprocessors require long wires to connect cache arrays to processor cores. As a result, the Last-Level Cache (LLC) has become a major contributor to processor energy; necessitating techniques to increase the energy efficiency of data exchange over LLC interconnects. This paper presents an energy-efficient data...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Community Detection in Cellular Network Traces

    Studies of user behavior in cellular networks have served as a knowledge base for development of critical applications and services catered to specific user needs. In this paper, the authors examine community persistence in egocentric social graphs extracted from cellular network traces in the Cote d'Ivoire provided by Orange. Their...

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  • White Papers // Dec 2013

    Are TCP Extensions Middlebox-proof?

    Besides the traditional routers and switches, middleboxes such as NATs, rewalls, IDS or proxies have a growing importance in many networks, notably in enterprise and wire-less access networks. Many of these middleboxes modify the packets that they process. For this, they to implement (a subset of) protocols like TCP. Despite...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Kwaabana: File Sharing for Rural Networks

    As usage of online social networks and social media continues to experience exponential growth, the amount of data being shared between users is increasing without bound. While this has revolutionized communication for many Internet users, users in rural or developing areas connected behind slow, congested gateways are falling increasingly behind...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Utilizing Domain-Specific Keywords for Discovering Public SPARQL Endpoints: A Life-Sciences Use-Case

    The LOD cloud comprises of billions of facts covering hundreds of datasets. In accordance with the linked data principles, these datasets are connected by a variety of typed links, forming an interlinked \"Web of data\". The growing diversity of the web of data makes it more and more challenging for...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Smartphones as Practical and Secure Location Verification Tokens for Payments

    The authors propose a novel location-based second-factor authentication solution for modern Smartphones. They demonstrate their solution in the context of point of sale transactions and show how it can be effectively used for the detection of fraudulent transactions caused by card theft or counterfeiting. Their scheme makes use of Trusted...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Cyber-Secure Communication Architecture for Active Power Distribution Networks

    Active power distribution networks require sophisticated monitoring and control strategies for efficient energy management and automatic adaptive reconfiguration of the power infrastructure. Such requirements are realized by deploying a large number of various electronic automation and communication field devices, such as Phasor Measurement Units (PMUs) or Intelligent Electronic Devices (IEDs),...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Extracting Probable Command and Control Signatures for Detecting Botnets

    Botnets, which are networks of compromised machines under the control of a single malicious entity, are a serious threat to online security. The fact that botnets, by definition, receive their commands from a single entity can be leveraged to fight them. To this end, one requires techniques that can detect...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Anchor Points Algorithms for Hamming and Edit Distance

    Algorithms for computing similarity joins in MapReduce were offered in. Similarity joins ask to find input pairs that are within a certain distance d according to some distance measure. Here the authors explore the \"Anchor-points algorithm\". They continue looking at hamming distance, and show that the method of that paper...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Selecting Representative Benchmark Inputs for Exploring Microprocessor Design Spaces

    The design process of a microprocessor requires representative workloads to steer the search process toward an optimum design point for the target application domain. However, considering a broad set of workloads to cover the large space of potential workloads is infeasible given how time-consuming design space exploration typically is. Hence,...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Accelerating an Application Domain with Specialized Functional Units

    Hardware specialization has received renewed interest recently as chips are hitting power limits. Chip designers of traditional processor architectures have primarily focused on general-purpose computing, partially due to time-to-market pressure and simpler design processes. But new power limits require some chip specialization. Although hardware configured for a specific application yields...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Beyond Reuse Distance Analysis: Dynamic Analysis for Characterization of Data Locality Potential

    Emerging computer architectures will feature drastically decreased flops/byte (ratio of peak processing rate to memory bandwidth) as highlighted by recent studies on Exascale architectural trends. Further, flops are getting cheaper, while the energy cost of data movement is increasingly dominant. The understanding and characterization of data locality properties of computations...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    XLynx-An FPGA-based XML Filter for Hybrid XQuery Processing

    While offering unique performance and energy saving advantages, the use of Field-Programmable Gate Arrays (FPGAs) for database acceleration has demanded major concessions from system designers. Either the programmable chips have been used for very basic application tasks (such as implementing a rigid class of selection predicates), or their circuit definition...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    XLynx - An FPGA-Based XML Filter for Hybrid XQuery Processing

    While offering unique performance and energy saving advantages, the use of Field-Programmable Gate Arrays (FPGAs) for database acceleration has demanded major concessions from system designers. Either the programmable chips have been used for very basic application tasks (such as implementing a rigid class of selection predicates), or their circuit definition...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    QoS-Aware Scheduling in Heterogeneous Datacenters with Paragon

    Large-scale Data Centers (DCs) host tens of thousands of diverse applications each day. However, interference between colocated workloads and the difficulty of matching applications to one of the many hardware platforms available can degrade performance, violating the Quality of Service (QoS) guarantees that many cloud workloads require. While previous work...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2013

    Flexible Filters in Stream Programs

    The stream-processing model is a natural fit for multicore systems because it exposes the inherent locality and concurrency of a program and highlights its separable tasks for efficient parallel implementations. The authors present flexible filters, a load-balancing optimization technique for stream programs. Flexible filters utilize the programmability of the cores...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2013

    A Flexible Framework for Detecting IPv6 Vulnerabilities

    Security has recently become a very important concern for entities using IPv6 networks. This is especially true with the recent news reports where governments and companies have admitted to credible cyber attacks against them in which confidential information and the security of data have been compromised. In this paper, the...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2013

    Go with the Flow: Toward Workflow-Oriented Security Assessment

    In this paper, the authors advocate the use of workflow-describing how a system provides its intended functionality-as a pillar of cybersecurity analysis and propose a holistic workflow-oriented assessment framework. While workflow models are currently used in the area of performance and reliability assessment, these approaches are designed neither to assess...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2013

    Towards Minimal-Delay Deadline-Driven Data Center TCP

    Cloud datacenter applications such as web search, retail, advertising, and recommendation systems, etc., generate a diverse mix of short and long flows that carry widely varying deadlines due to their soft-real time nature. In this paper, the authors present MCP, a novel distributed and reactive transport protocol for Data Center...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2013

    Supporting End-to-End Social Media Data Analysis with the IndexedHBase Platform

    As data intensive applications evolve, many research projects involving big data require efficient extraction and analysis of specific data subsets, rather than the whole dataset. Social media data analysis is one such example. While social media platforms such as Twitter provide tremendous data about all kinds of social activities, most...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2013

    Load-Balanced Pipeline Parallelism

    Accelerating a single thread in current parallel systems remains a challenging problem, because sequential threads do not naturally take advantage of the additional cores. Recent paper shows that automatic extraction of pipeline parallelism is an effective way to speed up single thread execution. However, two problems remain challenging - load...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2013

    Tera-Scale 1D FFT With Low-Communication Algorithm and Intel R Xeon Phi Coprocessors

    In this paper, the authors demonstrate the first tera-scale performance of Intel Xeon Phi coprocessors on 1D FFT computations. Applying a disciplined performance programming methodology of sound algorithm choice, valid performance model, and well-executed optimizations, they break the tera-flop mark on a mere 64 nodes of Xeon Phi and reach...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2013

    Performance Evaluation of Intel Transactional Synchronization Extensions for High-Performance Computing

    Due to limits in technology scaling, software developers have come to rely on thread-level parallelism to obtain sustainable performance improvement. However, except for the case where the computation is massively parallel (e.g., data-parallel applications), performance of threaded applications is often limited by how inter-thread synchronization is performed. For example, using...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2013

    Location-Aware Cache Management for Many-Core Processors with Deep Cache Hierarchy

    As cache hierarchies become deeper and the number of cores on a chip increases, managing caches becomes more important for performance and energy. However, current hardware cache management policies do not always adapt optimally to the applications behavior: e.g., caches may be polluted by data structures whose locality cannot be...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2013

    Investigating Applications Portability with the Uintah DAG-Based Runtime System on PetaScale Supercomputers

    Present trends in high performance computing present formidable challenges for applications code using multicore nodes possibly with accelerators and/or co-processors and reduced memory while still attaining scalability. Software frameworks that execute machine independent applications code using a runtime system that shields users from architectural complexities offer a possible solution. The...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2013

    Feng Shui of Supercomputer Memory: Positional Effects in DRAM and SRAM Faults

    Several recent publications confirm that faults are common in high-performance computing systems. Therefore, further attention to the faults experienced by such computing systems is warranted. In this paper, the authors present a study of DRAM and SRAM faults in large high-performance computing systems. Their goal is to understand the factors...

    Provided By Association for Computing Machinery

  • White Papers // Aug 2009

    CADS: A Collaborative Adaptive Data Sharing Platform

    Content management tools like Microsoft's SharePoint allow users of an application domain to share documents and tag them in an ad-hoc way. Similarly, Google Base allows users to define attributes for their objects or choose from predefined templates. This ad-hoc or predefined annotation of the shared data incurs problems like...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2010

    Evolution of State-Dependent Risk Preferences

    Researchers have invested much e ort in constructing models of the state-dependent (Sometimes risk-averse and sometimes risk-prone) nature of human decision-making. An important open question is how state-dependent risk behavior can arise and remain prominent in populations. The authors believe that one part of the answer is the interplay between...

    Provided By Association for Computing Machinery

  • White Papers // Jan 2011

    SMARTINT: Using Mined Attribute Dependencies to Integrate Fragmented Web Databases

    Many web databases can be seen as providing partial and overlapping information about entities in the world. To answer queries effectively, the authors need to integrate the information about the individual entities that are fragmented over multiple sources. At first blush this is just the inverse of traditional database normalization...

    Provided By Association for Computing Machinery

  • White Papers // Sep 2009

    Confidentiality Preserving Distributed Proofs of Conjunctive Queries

    Distributed proof construction protocols have been shown to be valuable for reasoning about authorization decisions in open distributed environments such as pervasive computing spaces. Unfortunately, existing distributed proof protocols offer only limited support for protecting the confidentiality of sensitive facts, which limits their utility in many practical scenarios. In this...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2010

    A Conceptual Model of Self-Monitoring Multi-Core Systems

    The paper discusses a conceptual model of building a self monitoring mechanism in a multi-core system such that the health of the entire system can be monitored securely and in an implicit manner. Accordingly, a many-core system is vertically partitioned (from hardware to application level) so that a small set...

    Provided By Association for Computing Machinery

  • White Papers // Sep 2010

    Dynamically Managed Multithreaded Reconfigurable Architectures for Chip Multiprocessors

    Prior work has demonstrated that reconfigurable logic can significantly benefit certain applications. However, reconfigurable architectures have traditionally suffered from high area overhead and limited application coverage. This paper presents a dynamically managed multithreaded reconfigurable architecture consisting of multiple clusters of shared reconfigurable fabrics that greatly reduces the area overhead of...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2009

    Online Application Upgrade Using Edition-Based Redefinition

    Many database applications have a very High Availability (HA) requirement. Examples include electrical and telecommunication utility management systems. Those systems must be available all the time to manage the systems; for electrical utility system, it includes adjusting production, or energy trading. Another example is global customer support system for companies...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2009

    Efficient Systematic Testing for Dynamically Updatable Software

    Recent years have seen significant advances in Dynamic Software Updating (DSU) systems, which allow programs to be patched on the fly. However, a significant challenge remains: How can the authors ensure the act of applying a patch does not itself introduce errors? In this paper, they address this problem by...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2009

    Cooperative Update: A New Model for Dependable Live Update

    Many real-world systems require continuous operation. Downtime is ill-affordable and scheduling maintenance for regular software updates is a tremendous challenge for system administrators. For this reason, live update is a potential solution as it allows running software to be replaced by a newer version without stopping the system. The vast...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2009

    Migrating Protocols in Multi-Threaded Message-Passing Systems

    Dynamic software update is a technique by which a running program can be updated with new code and data without interrupting its execution. Often the authors will want to preserve properties of programs across update boundaries. Preserving simple typing across update boundaries for single-threaded programs is well studied. There are...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2009

    On Performance of Delegation in Java

    Delegation is an important design concept in object-oriented languages. In contrast to inheritance, which relates classes to each other, delegation operates on the level of objects and thus provides more flexibility. It is well known, that usage of delegation imposes performance penalties in the sense of delayed execution. But delegation...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2009

    Dynamic Software Updates for Real-Time Systems

    Seamlessly updating software in running systems has recently gained momentum. Dynamically updating the software of real-time embedded systems, however, still poses numerous challenges: such systems must meet hard deadlines, cope with limited resources, and adhere to high safety standards. This paper presents a solution for updating component-based cyclic embedded systems...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2009

    Ensembles in Adversarial Classification for Spam

    The standard method for combating spam, either in email or on the web, is to train a classifier on manually labeled instances. As the spammers change their tactics, the performance of such classifiers tends to decrease over time. Gathering and labeling more data to periodically retrain the classifier is expensive....

    Provided By Association for Computing Machinery

  • White Papers // Jun 2010

    Performance and Power Modeling in a Multi-Programmed Multi-Core Environment

    This paper describes a fast, automated technique for accurate on-line estimation of the performance and power consumption of interacting processes in a multi-programmed, multi-core environment. The proposed technique does not require modifying hardware or applications. The performance model uses reuse distance histograms, cache access frequencies, and the relationship between the...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2010

    High-Performance Operating System Controlled Online Memory Compression

    Online memory compression is a technology that increases the amount of memory available to applications by dynamically compressing and decompressing their working datasets on demand. It has proven extremely useful in embedded systems with tight physical RAM constraints. The technology can be used to increase functionality, reduce size, and reduce...

    Provided By Association for Computing Machinery

  • White Papers // Feb 2010

    Online Memory Compression for Embedded Systems

    Memory is a scarce resource during embedded system design. Increasing memory often increases packaging costs, cooling costs, size, and power consumption. This paper presents CRAMES, a novel and efficient software-based RAM compression technique for embedded systems. The goal of CRAMES is to dramatically increase effective memory capacity without hardware or...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2009

    Routing Without Routes: The Backpressure Collection Protocol

    Current data collection protocols for wireless sensor networks are mostly based on quasi-static minimum-cost routing trees. The authors consider an alternative, highly-agile approach called backpressure routing, in which routing and forwarding decisions are made on a per-packet basis. Although there is a considerable theoretical literature on backpressure routing, it has...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2010

    Markov-Optimal Sensing Policy for User State Estimation in Mobile Devices

    Mobile device based human-centric sensing and user state recognition provide rich contextual information for various mobile applications and services. However, continuously capturing this contextual information consumes significant amount of energy and drains mobile device battery quickly. In this paper, the authors propose a computationally efficient algorithm to obtain the optimal...

    Provided By Association for Computing Machinery

  • White Papers // Sep 2010

    Ad Hoc Networking Via Named Data

    The design of the Internet protocol stack, with IP at the waist of the hourglass, mandates that packet delivery is governed by the destination IP address. This design has enabled explosive growth of the wired Internet, but faces two basic issues when applied to mobile environments. First, many mobile networks,...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2010

    Patterns and Statistical Analysis for Understanding Reduced Resource Computing

    The authors present several general, broadly applicable mechanisms that enable computations to execute with reduced resources, typically at the cost of some loss in the accuracy of the result they produce. They identify several general computational patterns that interact well with these resource reduction mechanisms, present a concrete manifestation of...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2009

    Detecting Traffic Differentiation in Backbone ISPs With NetPolice

    Traffic differentiations are known to be found at the edge of the Internet in broadband ISPs and wireless carriers. The ability to detect traffic differentiations is essential for customers to develop effective strategies for improving their application performance. The authors build a system, called NetPolice that enables detection of content-...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2009

    TCP Revisited: A Fresh Look at TCP in the Wild

    Since the last in-depth studies of measured TCP traffic some 6- 8 years ago, the Internet has experienced significant changes, including the rapid deployment of backbone links with 1-2 orders of magnitude more capacity, the emergence of bandwidth-intensive streaming applications, and the massive penetration of new TCP variants. These and...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2009

    Dynamic Cross Domain Information Sharing- A Concept Paper on Flexible Adaptive Policy Management

    Information exchange across domains is essential for today's asymmetric warfare environment to make mission-critical information available to war fighters, no matter where it exists and when it becomes available. Dissemination of new information needs to carefully balance the need-to-know by consumers with the responsibility-to-share by providers. The right amount of...

    Provided By Association for Computing Machinery

  • White Papers // Apr 2010

    Safe Compositional Network Sketches: Formal Framework

    NetSketch is a tool for the specification of constrained-flow applications and the certification of desirable safety properties imposed thereon. NetSketch assists system integrators in two types of activities: Modeling and design. As a modeling tool, it enables the abstraction of an existing system while retaining sufficient information about it to...

    Provided By Association for Computing Machinery

  • White Papers // Dec 2010

    Who Is Tweeting on Twitter: Human, Bot, or Cyborg?

    Twitter is a new web application playing dual roles of online social networking and micro-blogging. Users communicate with each other by publishing text-based posts. The popularity and open structure of Twitter have attracted a large number of automated programs, known as bots, which appear to be a double-edged sword to...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2009

    SessionMagnifier: A Simple Approach to Secure and Convenient Kiosk Browsing

    Many people use public computers to browse the Web and perform important online activities. However, public computers are usually far less trustworthy than peoples' own computers because they are more vulnerable to various security attacks. In this paper, the authors propose SessionMagnifier, a simple approach to secure and convenient kiosk...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2009

    Battle of Botcraft: Fighting Bots in Online Games With Human Observational Proofs

    The abuse of online games by automated programs, known as game bots, for gaining unfair advantages has plagued millions of participating players with escalating severity in recent years. The current methods for distinguishing bots and humans are based on Human Interactive Proofs (HIPs), such as CAPTCHAs. However, HIP-based approaches have...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2010

    Detecting Algorithmically Generated Malicious Domain Names

    Recent Botnets such as Conficker, Kraken and Torpig have used DNS based "Domain fluxing" for command-and-control, where each Bot queries for existence of a series of domain names and the owner has to register only one such domain name. In this paper, the authors develop a methodology to detect such...

    Provided By Association for Computing Machinery

  • White Papers // Sep 2010

    Tool Support for Quality-Driven Development of Software Architectures

    In this paper, the authors present a prototype tool that supports the systematic development of software architectures driven by quality requirements using architectural tactics. The tool allows one to configure architectural tactics based on quality requirements and compose the configured tactics to produce an initial architecture for the system. They...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2010

    Accelerating SQL Database Operations on a GPU With CUDA

    Prior work has shown dramatic acceleration for various data-base operations on GPUs, but only using primitives that are not part of conventional database languages such as SQL. This paper implements a subset of the SQLite command processor directly on the GPU. This dramatically reduces the e ort required to achieve...

    Provided By Association for Computing Machinery

  • White Papers // Sep 2010

    Federation: Boosting Per-Thread Performance of Throughput-Oriented Manycore Architectures

    Manycore architectures designed for parallel workloads are likely to use simple, highly multi-threaded, in-order cores. This maximizes throughput, but only with enough threads to keep hardware utilized. For applications or phases with more limited parallelism, the authors describe creating an out-of-order processor on the fly, by federating two neighboring in-order...

    Provided By Association for Computing Machinery

  • White Papers // Jun 2010

    Refactoring and Representation Independence for Class Hierarchies [Extended Abstract]

    Refactoring transformations are important for productivity and quality in software evolution. Modular reasoning about semantics preserving transformations is difficult even in typed class-based languages because transformations can change the internal representations for multiple interdependent classes and because encapsulation can be violated by pointers to mutable objects. In this paper, an...

    Provided By Association for Computing Machinery

  • White Papers // Jan 2010

    Operating System Development With ATS

    Typical operating system design is marked by trade-offs between speed and reliability, features and security. Most systems are written in a low-level untyped programming language to achieve optimal hardware usage and for other practical reasons. But, this often results in CPU, memory, and I/O protection flaws due to mistakes in...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2009

    TrackBack Spam: Abuse and Prevention

    Contemporary blogs receive comments and TrackBacks, which result in cross-references between blogs. The authors conducted a longitudinal study of TrackBack spam, collecting and analyzing almost 10 million samples from a massive spam campaign over a one-year period. Unlike common delivery of email spam, the spammers did not use bots, but...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2009

    A Co-Classification Framework for Detecting Web Spam and Spammers in Social Media Web Sites

    Social media are becoming increasingly popular and have attracted considerable attention from spammers. Using a sample of more than ninety thousand known spam Web sites, the authors found between 7% to 18% of their URLs are posted on two popular social media Web sites, digg.com and delicious.com. In this paper,...

    Provided By Association for Computing Machinery

  • White Papers // Oct 2009

    Dynamic Software Updates: The State Mapping Problem

    The Dynamic Software Update (DSU) problem consists of two components. First, there is the need to determine if it is meaningful (safe) to map a state of the old application to a state of the new application, and, if it is, determine the required mapping - this is the state...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2010

    Joint Optimization of Idle and Cooling Power in Data Centers While Maintaining Response Time

    Server power and cooling power amount to a significant fraction of modern data centers' recurring costs. While data centers provision enough servers to guarantee response times under the maximum loading, data centers operate under much less loading most of the times (e.g., 30-70% of the maximum loading). Previous server-power proposals...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2010

    Probabilistic Job Symbiosis Modeling for SMT Processor Scheduling

    Symbiotic job scheduling boosts Simultaneous Multithreading (SMT) processor performance by co-scheduling jobs that have 'Compatible' demands on the processor's shared resources. Existing approaches however require a sampling phase, evaluate a limited number of possible co-schedules, use heuristics to gauge symbiosis, are rigid in their optimization target, and do not preserve...

    Provided By Association for Computing Machinery

  • White Papers // Mar 2010

    An Asymmetric Distributed Shared Memory Model for Heterogeneous Parallel Systems

    Heterogeneous computing combines general purpose CPUs with accelerators to efficiently execute both sequential control-intensive and data-parallel phases of applications. Existing programming models for heterogeneous computing rely on programmers to explicitly manage data transfers between the CPU system memory and accelerator memory. This paper presents a new programming model for heterogeneous...

    Provided By Association for Computing Machinery

  • White Papers // Nov 2009

    When Private Keys Are Public: Results From the 2008 Debian OpenSSL Vulnerability

    The authors report on the aftermath of the discovery of a severe vulnerability in the Debian Linux version of OpenSSL. Systems affected by the bug generated predictable random numbers, most importantly public/private keypairs. To study user response to this vulnerability, they collected a novel dataset of daily remote scans of...

    Provided By Association for Computing Machinery