Many network devices such as routers and firewalls employ caches to take advantage of temporal locality of packet headers in order to speed up packet processing decisions. Traditionally, cache designs trade off time a...
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Many network devices such as routers and firewalls employ caches to take advantage of temporal locality of packet headers in order to speed up packet processing decisions. Traditionally, cache designs trade off time and space with the goal of balancing the overall cost and performance of the device. We examine another axis of the design space that has not been previously considered: accuracy. In particular, we quantify the benefits of relaxing the accuracy of the cache on the cost and performance of packet classification caches. Our cache design is based on the popular Bloom filter data structure. This paper provides a model for optimizing Bloom filters for this purpose, as well as extensions to the data structure to support graceful aging, bounded misclassification rates, and multiple binary predicates. Given this, we show that such caches can provide nearly an order of magnitude cost savings at the expense of misclassifying one billionth of packets for IPv6-based caches.
Regression testing is an important part of software quality assurance. We work to extend regression testing to include regression benchmarking, which applies benchmarking to detect regressions in performance. Given th...
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Data transformation problems are very common and are challenging to implement for large and complex datasets. We describe a new approach for specifying data mapping transformations between XML schemas using a combinat...
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ISBN:
(纸本)9780769521312
Data transformation problems are very common and are challenging to implement for large and complex datasets. We describe a new approach for specifying data mapping transformations between XML schemas using a combination of automated schema analysis agents and selective user interaction. A graphical tool visualizes parts of the two schemas to be mapped and a variety of agents analyze all or parts of the schema, voting on the likelihood of matching subsets. The user can confirm or reject suggestions, or even allow schema matches to be automatically determined, incrementally building up to a fully-mapped schema. An implementation of the mapping specification can then be generated.
Assertions had their origin in program verification. For the systems developed in industry, construction of assertions and their use in showing program correctness is a near-impossible task. However, they can be used ...
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Assertions had their origin in program verification. For the systems developed in industry, construction of assertions and their use in showing program correctness is a near-impossible task. However, they can be used to show that some key properties are satisfied during program execution. We first present a survey of the special roles that assertions can play in object oriented software construction. We then analyse such assertions by relating them to the case study of an automatic surveillance system. In particular, we address the following two issues: What types of assertions can be used most effectively in the context of object oriented software? How can you discover them and where should they be placed? During maintenance, both the design and the software are continuously changed. These changes can mean that the original assertions, if present, are no longer valid for the new software. Can we automatically derive assertions for the changed software?.
The paper introduces the concept of regression benchmarking as a variant of regression testing focused at detecting performance regressions. Applying the regression benchmarking in the area of middleware development, ...
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The paper introduces the concept of regression benchmarking as a variant of regression testing focused at detecting performance regressions. Applying the regression benchmarking in the area of middleware development, the paper explains how regression benchmarking differs from middleware benchmarking in general. On a real-world example of TAO, the paper shows why the existing benchmarks do not give results sufficient for regression benchmarking, and proposes techniques for detecting performance regressions using simple benchmarks.
This paper proposes a unified knowledge model establishing a core structure of knowledge representation in natural and artificial intelligence systems. The Concept Cell Model proposes the use of acyclic lattices to mo...
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This paper proposes a unified knowledge model establishing a core structure of knowledge representation in natural and artificial intelligence systems. The Concept Cell Model proposes the use of acyclic lattices to model a concept formed from a knowledge network of simpler concepts. Declarative and procedural knowledge are explicitly defined as the time-invariant and time-variant relationship of concepts. Examples of a Restaurant Servicing Concept Cell and an extended Shopping Complex Concept Cell are used to demonstrate the functionality of this model. Major existing theoretic and engineering Ontology knowledge schools are compared under this framework.
High-assurance development of large-scale, network-centric systems must address challenging engineering realities. Flow-Service-Quality (FSQ) engineering provides foundations and practices that accommodate these reali...
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High-assurance development of large-scale, network-centric systems must address challenging engineering realities. Flow-Service-Quality (FSQ) engineering provides foundations and practices that accommodate these realities to maintain intellectual control in system analysis, development, and evolution.
This paper gives contribution to the construction of an image mosaic by pasting together a sequence of photographs taken by a regular digital camera from the same position but in different directions. In order to find...
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This paper gives contribution to the construction of an image mosaic by pasting together a sequence of photographs taken by a regular digital camera from the same position but in different directions. In order to find the best match between two overlapping images, a fuzzy-genetic based algorithm is presented. A translation vector with a minimal difference between the common picture parts has to be found. The difference is defined using the fuzzyfied contours of each images. The search of the optimal translation is considered as a minimization process. This paper proposes a method that uses genetic algorithms to find the minimum point corresponding to the optimal translation. Using the fuzzy based comparison of the two images yields a fast fitness function, while the implementation of the proposed method in a genetic hardware has a low and variable computational cost. The precision of the method is inverse-proportional with the computational time, which makes it ideal to be used in real time systems.
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