A number of commercial companies are now attempting to develop production quality parallel processing systems. These systems are often targeted to take over the role of Vector/Parallel supercomputers. While these systems have excellent raw compute power for their cost, they lag behind traditional supercomputers in a number of important areas. One important area is the ability to deal with wide ...

This paper introduces a spatial indexing structure that adjusts itself so as to provide faster access to spatially referenced data most in demand. The structure is a hybrid of a splay tree and a quadtree. The quadtree is a well-known spatial data structure that successively segments a spatial data area into quadrants, preserving the spatial arrangement of the data. Access to data is based on a ...

In an ad hoc network, the wireless media is shared by multiple nodes. The contention among neighbors for the access to the shared media is the major cause fornelwork congestion. As wireless links usually have low capacity, congestion in ad hoc networks is a morc severe problem than in wired networks. The main thrust of our work is to avoid congestion at IP layer by minimizing conlemions for cha...

We propose a new way to self-adjust the mutation rate in population-based evolutionary algorithms in discrete search spaces. Roughly speaking, it consists of creating half the offspring with a mutation rate that is twice the current mutation rate and the other half with half the current rate. The mutation rate is then updated to the rate used in that subpopulation which contains the best offspr...

A data structure is said to be self-adjusting if it dynamically reorganizes itself to adapt to the pattern of accesses. Efficiency is typically measured in terms of amortized complexity, that is, the average running time of an access over an arbitrary sequence of accesses. The best known example of such a data structure is Sleator and Tarjan’s splay tree. In this paper, we introduce a self-adju...

We present a genetic algorithm (GA) whose population possesses a spatial structure. The GA is formulated as a probabilistic cellular automaton: The individuals are distributed over a connected graph and the genetic operators are applied locally in some neighborhood of each individual. By adding a self–organizing acceptance threshold schedule to the proportionate reproduction operator we can pro...

OBJECTIVE To examine the association between socioeconomic status (SES), self-rated health (SRH), and mortality separately by race-ethnicity in a nationally representative sample of US adults. METHODS We analyzed data from 16 716 adult women and men who were followed up for mortality for up to 12 years as part of the third National Health and Nutrition Examination survey (NHANES III). Poverty...

Data Mining in non-stationary data streams is particularly relevant in the context of the Internet of Things and Big Data. Its challenges arise from fundamentally different drift types violating assumptions of data independence or stationarity. Available methods often struggle with certain forms of drift or require unavailable a priori task knowledge. We propose the Self-Adjusting Memory (SAM) ...

We consider a distributed communication network with many terminals which are distributed in space and wish to communicate with each other using a common radio channel. Choosing the transmission range in such a network involves the following tradeoff: a long range enables messages to reach their destinations in a few hops, but increases the amount of traffic competing for the channel at