26842026
Effective Memory Bandwidth and Processor Blocking Probability in Multiple-Bus Systems
This correspondence presents two expressions in calculating effective memory bandwidth for a wide range of multiple-bus configurations. Also presented is an analytical solution for determining each processor's blocking probability in a multiple-bus system where different priorities are assigned to the processors.
19595078
Analysis of Prioritized Crossbar Multiprocessor Systems
Abstract This paper analyzes the performance of crossbar multiprocessor systems under the assumption that processors are organized in a priority hierarchy. A basic model is derived for estimating the probability of acceptance of a memory request for each individual processor with a different priority. Improvements are made by using an adjusted memory request rate. Analytical results are validated by comparison with simulation data for configurations up to 64 X 64 with request rate ⩽ 1. Finally, it is shown that the effective memory bandwidth can be calculated accurately from acceptance probabilities of individual processors.
903407
On integrating fluid models with packet simulation
Fluid models have been shown to he efficient and accurate in modelling large IP networks. However, unlike packet models, it is difficult to extract packet-level information from them. In this paper, we present a hybrid simulation method that maintains the performance advantage of fluid models while providing detailed packet level information for selected packet traffic flows. We propose two models to account for the interaction between background TCP traffic in a fluid network and foreground packet traffic of interest. The first assumes that the packet traffic poses a negligible load on the fluid network whereas the second accounts for the added load by transforming the packet traffic into fluid flows and solving the resulting enhanced fluid model. The first of these yields an efficient one pass solution algorithm whereas the second requires an additional pass to account for the packet traffic load. We establish the correctness of both approaches and present their implementation within ns-2. Comparisons between the hybrid models and a classical packet simulation show the two pass approach to be quite accurate and computationally efficient.
1850975
Using classic problems to teach Java framework design
Abstract All programmers should understand the concept of software families and know the techniques for constructing them. This paper suggests that classic problems, such as well-known algorithms and data structures, are good sources for examples to use in a study of software family design. The paper describes two case studies that can be used to introduce students in a Java software design course to the construction of software families using software frameworks. The first is the family of programs that use the well-known divide and conquer algorithmic strategy. The second is the family of programs that carry out traversals of binary trees.
7923791
Discontinuity-Based Simplification of Free Form Surface From a Range Image
This paper improves an existing method for more accurate simplification of free form surface represented as dense points. The main improvement lies in two aspects: one is the introduction of a novel transformation of curvatures, the other is to propose sampling points using both curvature information and curvature variation information. The experimental results based on real images show that the original object surface has been better approximated and the majority of the surface discontinuities have been better preserved with considerably few sampled (5%) data points
11775729
Routing Correlated Data with Fusion Cost in Wireless Sensor Networks
In this paper, we propose a routing algorithm called minimum fusion Steiner tree (MFST) for energy efficient data gathering with aggregation (fusion) in wireless sensor networks. Different from existing schemes, MFST not only optimizes over the data transmission cost, but also incorporates the cost for data fusion, which can be significant for emerging sensor networks with vectorial data and/or security requirements. By employing a randomized algorithm that allows fusion points to be chosen according to the nodes' data amounts, MFST achieves an approximation ratio of 5/4log(k + 1), where k denotes the number of source nodes, to the optimal solution for extremely general system setups, provided that fusion cost and data aggregation are nondecreasing against the total input data. Consequently, in contrast to algorithms that only excel in full or nonaggregation scenarios without considering fusion cost, MFST can thrive in a wide range of applications
11535936
Efficient implementation of tuple pattern based retrieval
Tuple pattern based retrieval is a language construct that matches a tuple pattern against a set of tuples to retrieve components of those tuples. This high-level abstraction allows programs to be written more easily and clearly than otherwise. This paper describes a clean and automatic method for transforming tuple pattern based retrievals into efficient implementations. The paper also presents two systems that implement the method, and describes successful experience and experiments in generating efficient implementations for graph algorithms, program analysis, security, and other applications.