43 research outputs found
On the complexity of computing the -restricted edge-connectivity of a graph
The \emph{-restricted edge-connectivity} of a graph , denoted by
, is defined as the minimum size of an edge set whose removal
leaves exactly two connected components each containing at least vertices.
This graph invariant, which can be seen as a generalization of a minimum
edge-cut, has been extensively studied from a combinatorial point of view.
However, very little is known about the complexity of computing .
Very recently, in the parameterized complexity community the notion of
\emph{good edge separation} of a graph has been defined, which happens to be
essentially the same as the -restricted edge-connectivity. Motivated by the
relevance of this invariant from both combinatorial and algorithmic points of
view, in this article we initiate a systematic study of its computational
complexity, with special emphasis on its parameterized complexity for several
choices of the parameters. We provide a number of NP-hardness and W[1]-hardness
results, as well as FPT-algorithms.Comment: 16 pages, 4 figure
A tool for predicting the thermal performance of a diesel engine
This paper presents a thermal network model for the simulation of the transient response of diesel engines. The model was
adjusted by using experimental data from a completely instrumented engine run under steady-state and transient conditions.
Comparisons between measured and predicted material temperatures over a wide range of engine running conditions show
a mean error of 7â—¦C. The model was then used to predict the thermal behavior of a different engine. Model results were
checked against oil and coolant temperatures measured during engine warm-up at constant speed and load, and on a New
European Driving Cycle. Results show that the model predicts these temperatures with a maximum error of 3â—¦C.Torregrosa, AJ.; Olmeda González, PC.; MartĂn DĂaz, J.; Romero Piedrahita, CA. (2011). A tool for predicting the thermal performance of a diesel engine. Heat Transfer Engineering. 32(10):891-904. doi:10.1080/01457632.2011.548639S891904321
Unicast-based Multicast Communication . . .
This paper presents efficient algorithms to implement multicast communication in scalable, wormhole-routed multiprocessors. A multicast communication service may in turn be used to support various higher-level operations for data movement and global process control. The algorithms presented are applicable to many existing scalable architectures, in particular, those using wormhole routing and n-dimensional mesh network topologies. Performance evaluation of implementations on a 64-node nCUBE-2 and a 168-node Symult 2010 are given