8052541
Applications of probabilistic quorums to iterative algorithms
Presents a definition of a read-write register that sometimes returns out-of-date values, shows that the definition is implemented by the probabilistic quorum algorithm of D. Malkhi et al. (1997), and shows how to program with such registers using the framework of A. U/spl uml/resin and M. Dubois (1990). Consequently, existing iterative algorithms for an interesting class of problems (including finding shortest paths, constraint satisfaction and transitive closure) converge with high probability if executed in a system in which the shared data is implemented with registers satisfying the new definition. Furthermore, the algorithms in this framework inherit positive attributes concerning load and availability from the underlying register implementation. A monotone version of the new register definition is specified and implemented; it can provide improved expected convergence time and message complexity for iterative algorithms.
9646078
Parallel hashing algorithms on BSP and QSM models
Summary form only given. We study two parallel computing models - the bulk synchronous parallel (BSP) and the queued shared memory (QSM) - as alternatives to the PRAM model to provide more accurate performance predictions and analyses, and compares the two models in detail. As a case study, we consider a simple hashing problem, design the two versions - the message passing version and the shared memory version - of the algorithm, and compare their run time analytically. The message passing version of the algorithm is implemented and the experiments are performed to display the accuracy and the limitations of the predicted performance analysis.
15518000
MediAssist: Using Content-Based Analysis and Context to Manage Personal Photo Collections
We present work which organises personal digital photo collections based on contextual information, such as time and location, combined with content-based analysis such as face detection and other feature detectors. The MediAssist demonstration system illustrates the results of our research into digital photo management, showing how a combination of automatically extracted context and content-based information, together with user annotation, facilitates efficient searching of personal photo collections.
19026342
Eager writeback - a technique for improving bandwidth utilization
Modern high-performance processors utilize multi-level cache structures to help tolerate the increasing latency of main memory. Most of these caches employ either a writeback or a write-through strategy to deal with store operations. Write-through caches propagate data to more distant memory levels at the time each store occurs, which requires a very large bandwidth between the memory hierarchy levels. Writeback caches can significantly reduce the bandwidth requirements between caches and memory by marking cache lines as dirty when stores are processed and writing those lines to the memory system only when that dirty line is evicted. Unfortunately, for applications that experience significant numbers of cache misses due to streaming data, writeback cache designs can degrade overall system performance by clustering bus activity when dirty lines contend with data being fetched into the cache. In this paper we present a new technique called Eager Writeback, which re-distributes and balances memory traffic by writing and "cleaning" dirty cache lines prior to their eviction. Eager Writeback can be viewed as a compromise between write-through and writeback policies, in which dirty lines are written later than write-through, but prior to writeback. We will show that this approach can reduce the large number of writes seen in a write-through design, while avoiding the performance degradation caused by clustering bus traffic in a writeback approach.
2979889
An effective customization procedure with configurable standard models
In electronic catalogs, commodities such as computers and electronic equipment are specified as standard models although a variety of possible alternative specifications can exist as a combination of selected options; therefore, customized configurations are essential to support various customers with individual needs. Thus, the problem here is the selection of a standard model and reconfiguration with this selected model. An issue is that requirements may be fulfilled by more than one standard model. To develop an algorithm that can find the near minimum price without causing unacceptable computation effort, we devised the Standard Model Selection and Modification (SMSM) Algorithm. To establish the SMSM Algorithm, we propose the Concurrent Local Propagation procedure complemented with pruning capability owing to the nature of standard models. The effective strategies for selection of seed variables and stopping rules are devised through comparative experiments.For the experiment, we use Dell's personal computer (PC) products consisting of 42 standard models with 25 specification variables. The SMSM Algorithm is tested with 75 experimental cases, and we found that the most similar standard models could discover the minimum price only in 24 out of 75 cases and that the SMSM procedure could reduce the price by 6.04% from the one offered by the most similar standard models.
30313812
A flexible agent system for change adaptation in supply chains
The importance of supply chain management is increasing with globalization and the advancement of electronic business. Supply chains are dynamic due to frequent changes in suppliers, customers, and products. However, information systems for supply chains are not flexible enough to adapt to the changes, requiring high cost and time for re-implementation and re-customization. This paper suggests a flexible agent system for supply chains that can adapt to the changes in transactions introduced by new products or new trading partners. The flexible agent system consists of an interpretable conversation policy model, a procedure for exchanging new conversation policies, and a mechanism for actual transactions with newly acquired conversation policies. By using the flexible agent system, formation of supply chains becomes more robust to the dynamic changes. To show how the approach can be realized, a PC supply chain application is illustrated with a prototype agent platform.
7999511
A proportional-share scheduler for multimedia applications
This paper presents a proportional-share CPU scheduler which can support multimedia applications in a general-purpose workstation environment. For this purpose, we have extended the stride scheduler which is designed originally for conventional tasks. New scheduling parameters are introduced to specify timing requirements of multimedia applications. Through the, use of the rate regulator, the accuracy error of the scheduling is reduced to O(1). Separate task groups are proposed to represent both relative shares and absolute shares. The proposed scheduler is evaluated using a simulation study. The results show that the proposed scheduler achieves improved accuracy and adaptability as well as fairness.