Skip to content
Free planNo credit card requiredStart writing
AI for Research home
AI for Research home
Dashboard
Sign inGet started

Search 250 million research papers

Read the abstract, see who wrote it and who cites it, and get the citation in APA, MLA, Chicago or Harvard.

About 10,000 papers for “Distributed memory”

Distributed Shared Memory

Qiusheng Chen, Jennifer L. Welch, Qiusheng Chen · Distributed Computing · 2004

The Aleph Toolkit is a collection of Java packages that implements a simple, platform-independent dis tributed shared memory [MPH]. But currently it lacks of failure recovery mechanism and is not suitable for long-running distributed applications. The objective of this project is to make Aleph to be a fault-tolerant distributed shared memory computing platform.

Cited by 1Open access

Sparse distributed memory

Denning, Peter J. · NASA Technical Reports Server (NASA)

Sparse distributed memory was proposed be Pentti Kanerva as a realizable architecture that could store large patterns and retrieve them based on partial matches with patterns representing current sensory inputs. This memory exhibits behaviors, both in theory and in experiment, that resemble those previously unapproached by machines - e.g., rapid recognition of faces or odors, discovery of new connections between seemingly unrelated ideas, continuation of a sequence of events when given a cue from the middle, knowing that one doesn't know, or getting stuck with an answer on the tip of one's tongue. These behaviors are now within reach of machines that can be incorporated into the computing systems of robots capable of seeing, talking, and manipulating. Kanerva's theory is a break with the Western rationalistic tradition, allowing a new interpretation of learning and cognition that respects biology and the mysteries of individual human beings.

Cited by 6Open access

Dedicated distributed memory servers

Romero Pinon, Rodrigo Antonio · scholarworks - UTEP (The University of Texas at El Paso) · 2004

Availability of very high bandwidth in local area networks justifies consideration of network resources as potential components of a progressively tightly coupled distributed processing system. Without approaching the high performance limit where a distributed system would be considered completely equivalent to a parallel multiprocessor, this research explores the implications of the availability of high speed networks on memory organization at the network level and the introduction of dedicated distributed memory servers in the storage hierarchy as an approach to improve overall loosely coupled process performance. Simulation is used to study the behavior of this class of servers and investigate their effect on high performance distributed computations. This work especially focuses on utilization of remote memory for applications with memory size requirements far in excess of the configuration offered by any single node in the network. Results indicate that dedicated distributed memory servers are a viable solution to problems posed by workstation memory limitations for applications with very high memory demands. Furthermore, simulations show that availability of a high-bandwidth network not only speeds up processing, it also makes the dedicated distributed memory servers more scalable and allows maximum server utilization for a given application. Finally, implemented simulations also demonstrate that mixture distributions provide a superior representation for computational service times than representations based on any standard single analytical distribution.

Cited by 0

Extended Sparse Distributed Memory

Javier Snaider, Stan Franklin · Frontiers in artificial intelligence and applications · 2011

Sparse distributed memory is an auto-associative memory system that stores high dimensional Boolean vectors. Here we present an extension of the original SDM that uses word vectors of larger size than address vectors. This extension preserves many of the desirable properties of the original SDM: auto-associability, content addressability, distributed storage, robustness over noisy inputs. In addition, it adds new functionality, enabling an efficient auto-associative storage of sequences of vectors, as well as of other data structures such as trees.

Cited by 8

Distributed Software Transactional Memory

Anthony Cowley · 2013

This report describes an implementation of a distributed software transactional memory (DSTM) system in PLT Scheme. The system is built using PLT Scheme’s Unit construct to encapsulate the various concerns of the system, and allow for multiple communication layer backends. The front-end API exposes true parallel processing to PLT Scheme programmers, as well as cluster-based computing using a shared namespace for transactional variables. The ramifications of the availability of such a system are considered in the novel context of highly dynamic robot swarm programming scenarios. In robotics programming scenarios, difficulty with expressing complex distributed computing patterns often supersedes raw performance in importance. In fact, for many applications the data to be shared among networked peers is relatively small in size, but the manner in which data sharing is expressed leads to tremendous inefficiencies both at development time and runtime. In an effort to maintain focus on behavior specification, we reduce the emphasis on messaging protocols typically found in distributed robotics software, while providing even greater flexibility in terms of how data is mixed and matched as it moves over the network. 1.

Cited by 0

The Distributed Associative Memory

2005

This chapter contains section titled: The Paired Associate Task The Standard Pattern Associator Exploring the Distributed Associative Memory

Cited by 0

Distributed Shared Memory Tools

Manish Parashar, Sumir Chandra · 2004

This chapter presents tools and environments for distributed shared memory (DSM), a software abstraction of shared memory on a distributed memory multiprocessor or cluster of workstations. It outlines the properties and features of DSM systems and classifies them based on their architectures. The chapter then describes cache coherence protocols for hardware based DSM systems including CC-NUMA, COMA, S-COMA, hybrid schemes including R-NUMA and AS-COMA, and hardware-based environments such as the MIT Alewife Machine and the Stanford FLASH multiprocessor. Finally, existing DSM system such as TreadMarks, Brazos, Mirage+, Orca, SAM, Midway, CRL, and fine-grained Shasta DSM are described.

Cited by 1

Finite Memory Distributed Systems

Dorofeenko Victor, Shorish Jamsheed · RePEc: Research Papers in Economics

A distributed system model is studied, where individual agents play repeatedly against each other and change their strategies based upon previous play. It is shown how to model this environment in terms of continuous population densities of agent types. A complication arises because the population densities of different strategies depend upon each other not only through game payoffs, but also through the strategy distributions themselves. In spite of this, it is shown that when an agent imitates the strategy of his previous opponent at a sufficiently high rate, the system of equations which governs the dynamical evolution of agent populations can be reduced to one equation for the total population. In a sense, the dynamics 'collapse' to the dynamics of the entire system taken as a whole, which describes the behavior of all types of agents. We explore the implications of this model, and present both analytical and simulation results.

Cited by 0

Distributed multiport memory architecture

Kohl, W. H. · NASA Technical Reports Server (NASA)

A multiport memory architecture is diclosed for each of a plurality of task centers connected to a command and data bus. Each task center, includes a memory and a plurality of devices which request direct memory access as needed. The memory includes an internal data bus and an internal address bus to which the devices are connected, and direct timing and control logic comprised of a 10-state ring counter for allocating memory devices by enabling AND gates connected to the request signal lines of the devices. The outputs of AND gates connected to the same device are combined by OR gates to form an acknowledgement signal that enables the devices to address the memory during the next clock period. The length of the ring counter may be effectively lengthened to any multiple of ten to allow for more direct memory access intervals in one repetitive sequence. One device is a network bus adapter which serially shifts onto the command and data bus, a data word (8 bits plus control and parity bits) during the next ten direct memory access intervals after it has been granted access. The NBA is therefore allocated only one access in every ten intervals, which is a predetermined interval for all centers. The ring counters of all centers are periodically synchronized by DMA SYNC signal to assure that all NBAs be able to function in synchronism for data transfer from one center to another.

Cited by 0Open access

Checkpointing Distributed Shared Memory

Luis M. Silva, João Gabriel Silva · 1997

Distributed shared memory (DSM) is a very promising programming model for exploiting the parallelism of distributed memory systems, since it provides a higher level of abstraction than simple message passing. Although the nodes of standard distributed systems exhibit high crash rates only very few DSM environments have some kind of support for fault-tolerance. In this paper, we present a checkpointing mechanism for a DSM system that is efficient and portable. It offers some portability because it is built on top of MPI and uses only the services offered by MPI and a POSIX compliant local file system. As far as we know, this is the first real implementation of such a scheme for DSM. Along with the description of the algorithm we present experimental results obtained in a cluster of workstations. We hope that our research shows that efficient, transparent and portable checkpointing is viable for DSM systems. Keywords: Distributed Shared Memory, Checkpointing, Fault-Tolerance, Portabilit...

Cited by 0

Broadcast Distributed Shared Memory

Auld, Philip · W&M Publish (College of William & Mary) · 2001

Distributed shared memory (DSM) provides the illusion of shared memory processing to programs running on physically distributed systems. Many of these systems are connected by a broadcast medium network such as Ethernet. In this thesis, we develop a weakly coherent model for DSM that takes advantage of hardware-level broadcast. We define the broadcast DSM model (BDSM) to provide fine-grained sharing of user-defined locations. Additionally, since extremely weak DSM models are difficult to program, BDSM provides effective synchronization operations that allow it to function as a stronger memory. We show speedup results for a test suite of parallel programs and compare them to MPI versions.;To overcome the potential for message loss using broadcast on an Ethernet segment we have developed a reliable broadcast protocol, called Pipelined Broadcast Protocol (PBP). This protocol provides the illusion of a series of FIFO pipes among member process, on top of Ethernet broadcast operations. We discuss two versions of the PBP protocol and their implementations. Comparisons to TCP show the predicted benefits of using broadcast. PBP also shows strong throughput results, nearing the maximum of our 10Base-T hardware.;By combining weak DSM and hardware broadcast we developed a system that provides comparable performance to a common message-passing system, MPI. For our test programs that have all-to-all communication patterns, we actually see better performance than MPI. We show that using broadcast to perform DSM updates can be a viable alternative to message passing for parallel and distributed computation on a single Ethernet segment.

Cited by 1Open access

Transactional Distributed Shared Memory

Andrew B. Hastings · 1992

Atomic transactions have proven to be an important technique for constructing reliable applications. Traditionally, transactions have been extended to distributed environments through the use of function shipping, a technique in which message passing or remote procedure calls are used to invoke computational requests on remote nodes. Recently, the data sharing approach to constructing distributed applications has received attention in the form of distributed file systems and distributed shared virtual memory. Applying the data sharing approach to transactions produces transactional distributed shared memory (TDSM) which yields benefits for a certain class of distributed application. The union of transactions and distributed shared memory offers synergies in transaction recovery, concurrency control, and coherency control, but introduces challenges in transaction recovery. In this dissertation, I describe the design of a system that provides TDSM in the form of distributed recoverable virtual memory. Using the external pager interface of the Mach operating system, I implemented a prototype based on the Camelot distributed transaction facility. I analyze the prototype and its performance, offer techniques for improving the design of future TDSM systems, and characterize the applications for which TDSM is useful.

Cited by 5

Distributed shared object memory

Paulo Guedes, Miguel Castro · 2002

This paper describes the goals, programming model and design of DiSOM, a software based distributed shared memory system for a multicomputer composed of heterogeneous nodes connected by a high-speed network. A typical configuration is a cluster of tens of high-performance workstations and shared-memory multiprocessors of two or three different architectures, each with a processing power of a few hundred MIPS and several hundred kilobytes of memory, and connected by a high-speed interconnect such as ATM. Programs in DiSOM are written using a shared-memory multiprocessor model where synchronization objects are associated with data items. Programs use a threads library to start new threads, possibly at a specified node, and to synchronize between concurrent threads. Programs must call the synchronization primitives explicitly, as they would in a shared-memory multiprocessor. The system traps these calls and uses the information to drive both distributed synchronization and the memory coherence protocol. DiSOM uses the entry consistency memory model to ensure coherence. This model guarantees memory consistency, as long as an access to a data item is enclosed between an acquire and a release on the synchronization object associated with the data item. Stronger consistency models, such as release consistency and processor consistency, may also be supported.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Cited by 21