As a foundation for providing semantics for aggregation within recursion, the structure of subsets of partially ordered domains is studied. We argue that the underlying cause of many of the di culties encountered in extending deductive database semantics to include aggregation is that set construction does not preserve the structure of the underlying domain very well. We study a binary relation...

Common approaches to provide group recommendations are based on the aggregation of the recommendations that are provided, for each group’s member, by an individual recommendation system, using social choice functions. These techniques do not consider factor like social interactions, roles, influences, and group members’ personality that model real group’s decision-making process. Recent approac...

Using a newly developed microfluidic chamber, we have demonstrated in vitro that Ca(2+) functions as a chemoattractant of aggregation-competent Dictyostelium discoideum amoebae, that parallel spatial gradients of cAMP and Ca(2+) are more effective than either alone, and that cAMP functions as a stronger chemoattractant than Ca(2+). Effective Ca(2+) gradients are extremely steep compared with ef...

A common characteristic of relational data sets —degree disparity—can lead relational learning algorithms to discover misleading correlations. Degree disparity occurs when the frequency of a relation is correlated with the values of the target variable. In such cases, aggregation functions used by many relational learning algorithms will result in misleading correlations and added complexity in...

A general model of aggregation of binary evaluations over interrelated issues, introduced by Wilson and further studied by Rubinstein and Fishburn and by the authors, is extended here to allow for abstentions on some of the issues. It is shown that the same structural conditions on the set of feasible evaluations that lead to dictatorship in the model without abstentions, lead to oligarchy in t...

Risk-mitigation decisions in risk-management systems are usually based on complex risk indicators. Therefore, aggregation is an important step during assessment. Aggregation when determining the of components or overall different areas organizational levels. In this article, authors identify scenarios. They summarize requirements functions and characterize aggregations according to these requir...

In the case of real-valued inputs, averaging aggregation functions have been studied extensively with results arising in fields including probability and statistics, fuzzy decision-making, and various sciences. Although much of the behavior of aggregation functions when combining standard fuzzy membership values is well established, extensions to interval-valued fuzzy sets, hesitant fuzzy sets,...

The paper concerns a dynamic model of influence in which agents make a yes-no decision. Each agent has an initial opinion which he may change during different phases of interaction, due to mutual influence among agents. We investigate a model of influence based on aggregation functions. Each agent modifies his opinion independently of the others, by aggregating the current opinion of all agents...

The problem of aggregating multiple criteria to form overall objective functions is of considerable importance in many disciplines. The most commonly used aggregation is based on the weighted sum. The ordered weighted averaging (OWA) aggregation, introduced by Yager, uses the weights assigned to the ordered values (i.e. to the worst value, the second worst and so on) rather than to the specific...

Aggregation modules within flow-based network monitoring tools make use of fast lookup methods to be able to quickly assign received packets to their corresponding flows. In software-based aggregators, hash tables are usually used for this task, as these offer constant lookup times under optimal conditions. The hash functions used for mapping flow keys to hash values need to be chosen carefully...