1532090
Fast knockout algorithm for self-route concentration
Concentration has been a popular technique for resolving contention in switching. In particular, self-route concentration is useful inside ATM switching fabrics in many ways. This paper presents an efficient algorithm for the construction of self-route concentrators from multi-stage cascades of 2x2 sorters, where the main criterion on the complexity is the number of stages in the cascade. The algorithm extensively generalizes the existing Fast Knockout algorithm and mixes in some k-sorting technique. The result includes a best known construction of m-to-n self-route concentrator for all m and n within the practical range.
45808479
Recursive Construction of Distributors by Merging
37409414
Algorithms for flow control and call set-up in multi-hop broadband ISDN
An algorithm for the decentralized control of traffic flow in multihop broadband ISDN and a concomitant algorithm for call setup are proposed. The approach in flow control is to strategically detain packets at points along their routes in anticipation of probable congestion ahead of them. The goal is to avoid buffer overflowing caused by concentrated packet accumulation at a single node on the network. A typical traffic control decision involves just two primitive operations: a READ and a logical AND. Hence, a submicrosecond execution time is expected. This quickness enables the traffic control to be implementable on the packet (or cell) level for broadband communications with a moderate packet size. This algorithm also strives for high utilization of broadband facilities and preserves the order among sequential packets. The concomitant algorithm for call setup is solely executed at the traffic originating node(s) and thus requires no internode communications. This leads to a simple process of calls setup that ensures the continuous flow of ongoing calls and, at the same time, avoids buffer overflowing.<<ETX>>
2426410
Network information flow
We introduce a new class of problems called network information flow which is inspired by computer network applications. Consider a point-to-point communication network on which a number of information sources are to be multicast to certain sets of destinations. We assume that the information sources are mutually independent. The problem is to characterize the admissible coding rate region. This model subsumes all previously studied models along the same line. We study the problem with one information source, and we have obtained a simple characterization of the admissible coding rate region. Our result can be regarded as the max-flow min-cut theorem for network information flow. Contrary to one's intuition, our work reveals that it is in general not optimal to regard the information to be multicast as a "fluid" which can simply be routed or replicated. Rather, by employing coding at the nodes, which we refer to as network coding, bandwidth can in general be saved. This finding may have significant impact on future design of switching systems.
15838609
Linear network coding
Consider a communication network in which certain source nodes multicast information to other nodes on the network in the multihop fashion where every node can pass on any of its received data to others. We are interested in how fast each node can receive the complete information, or equivalently, what the information rate arriving at each node is. Allowing a node to encode its received data before passing it on, the question involves optimization of the multicast mechanisms at the nodes. Among the simplest coding schemes is linear coding, which regards a block of data as a vector over a certain base field and allows a node to apply a linear transformation to a vector before passing it on. We formulate this multicast problem and prove that linear coding suffices to achieve the optimum, which is the max-flow from the source to each receiving node.
39573562
Binary Trees and Uniform Distribution of Traffic Cutback
Abstract This article introduces the notion of the External Left Length (ELL) of binary trees, which is analogous to the notion of the External Path Length (EPL), and derives theorems about the ELL which correspond to well-known facts about the EPL. Results are applied to the analysis of the optimization of an algorithm for the smooth traffic cutback in data communication.
3862682
Modeling distributed GIS data production workflow
Real-time access to status of project progress, control of production processes and activities, and automation of production procedures are major hurdles in further improving production throughput and project management in distributed GIS data production projects. Workflow technology promises to address these issues by facilitating, automating or controlling GIS data production processes. The success of applying workflow technologies to distributed GIS data production requires comprehensive understanding of the underlying production processes. This paper presents the first research effort on rigorously modeling distributed GIS data production workflows, with particular attention to a GIS data quality control process using the Internet-based workflow management technologies. Existing practices of distributed GIS data production projects are used as the essential sources for modeling the required workflow. The paper discusses some issues faced and concepts such as workflow process repository and GIS data QC testing program repository.
31495802
A New Hybrid GA/SA Algorithm for the Job Shop Scheduling Problem
Among the modern heuristic methods, simulated annealing (SA) and genetic algorithms (GA) represent powerful combinatorial optimization methods with complementary strengths and weaknesses. Borrowing from the respective advantages of the two paradigms, an effective combination of GA and SA, called Genetic Simulated Algorithm (GASA), is developed to solve the job shop scheduling problem (JSP). This new algorithm incorporates metropolis acceptance criterion into crossover operator, which could maintain the good characteristics of the previous generation and reduce the disruptive effects of genetic operators. Furthermore, we present two novel features for this algorithm to solve JSP. Firstly, a new full active schedule (FAS) based on the operation-based representation is presented to construct schedule, which can further reduce the search space. Secondly, we propose a new crossover operator, named Precedence Operation Crossover (POX), for the operation-based representation. The approach is tested on a set of standard instances and compared with other approaches. The Simulation results validate the effectiveness of the proposed algorithm.
16791890
JComp: A Reuse-Driven Componentization Framework for Java Applications
Program componentization has been proved to be an effective way to increase the speed and cost-effectiveness of reusing, maintaining, and understanding existing software systems. JComp is a componentization framework that supports semi-automatically extracting reusable components from an existing Java system and automatically transforming the existing system into a component-based system. Based on the automated class dominance analysis and domain knowledge, JComp introduces a novel technique to incrementally identify reusable components in a low cost but high precision way. Also, JComp provides a methodology to automate the transformation of existing object-oriented systems into component-based systems
15518182
Human-style interaction with a robot for cooperative learning of scene objects
In research on human-robot interaction the interest is currently shifting from uni-modal dialog systems to multi-modal interaction schemes. We present a system for human-style interaction with a robot that is integrated on our mobile robot BIRON. To model the dialog we adopt an extended grounding concept with a mechanism to handle multi-modal in- and output where object references are resolved by the interaction with an object attention system (OAS). The OAS integrates multiple input from, e.g., the object and gesture recognition systems and provides the information for a common representation. This representation can be accessed by both modules and combines symbolic verbal attributes with sensor-based features. We argue that such a representation is necessary to achieve a robust and efficient information processing.
18989576
Fast marching method to correct for refraction in ultrasound computed tomography
A significant obstacle in the advancement of ultrasound computed tomography has been the lack of efficient and precise methods for the tracing of the bent rays that result from the interaction of sound with refractive media. In this paper, we propose the use of the fast marching method (FMM) to solve the eikonal equation which governs the propagation of sound waves. The FMM enables us to determine with great accuracy and ease the distorted paths that the sound rays take from an emitter to the receivers. We show that knowledge of the accurate path proves crucial for an object reconstruction at high fidelity and accurate geometry. We employ a two-phase approach with an iterative method, SART, to faithfully reconstruct two tissue properties relevant in clinical diagnosis, such as mammography: speed of sound and sound attenuation. We demonstrate our results by ways of a newly designed analytical ultrasound breast phantom