Lack of information is a constraint but ignorance can sometimes assist the evolution of cooperation by constraining selfishness. We discuss examples involving both ignorance of role or pay-off and ignorance of relatedness. Ignorance can favour cooperative traits like grouping and warning coloration and reduce conflicts from meiotic drive, imprinting, greenbeards and various forms of nepotism.

Past studies on bimanual coordination have revealed a general preference to move the limbs in a symmetrical fashion, also denoted as the in-phase mode. Its counterpart, the asymmetrical or anti-phase mode, is performed with lower degrees of accuracy and stability. This ubiquitous tendency to activate the homologous muscle groups is referred to as the muscle grouping constraint (egocentric const...

Separating voiced speech from its mixtures with interferences in monaural condition is not only an important but also challenging task. As multipitch tracking can enable much better performance of speech separation for CASA systems, we propose a new multipitch determination algorithm, which can be used under various kinds of noise conditions. In the process of multipitch estimation, a new repre...

Massively Multiplayer Games (MMGs) is an attractive example of virtual environment applications on the Internet. In such application, a great deal of update messages will be introduced, and thus consume a large amount of network bandwidth and multicast addresses. Interest Management (IM) is a mechanism provided for diminishing the redundant communication traffics. In this paper, based on the we...

Aggregation queries are becoming increasingly common as databases continue to grow and provide parallel execution engines to enable complex queries over larger and larger amounts of data. Consequently , optimization of aggregation queries is becoming very important. In this paper we present a framework for reasoning with constraints arising from the use of aggregations. The framework introduces...

Aggregation queries are becoming increasingly common as databases continue to grow and provide parallel execution engines to enable complex queries over larger and larger amounts of data. Consequently , optimization of aggregation queries is becoming very important. In this paper we present a framework for reasoning with constraints arising from the use of aggregations. The framework introduces...

Non-orthogonal multiple access (NOMA) technology allows users to use the same time-frequency resource send signals, which can improve spectral efficiency and throughput. We study problems of user grouping power allocation in downlink a multi-carrier NOMA system. The sum rate is optimization goal. A step-by-step adopted. Users are grouped first then allocated. For grouping, method based on maxim...

The fault-tolerant control scheme utilizes grouping of currents to reduce the required number of controller outputs. Reduced current distribution matrices can be calculated with the constraint conditions of the controller outputs and the necessary condition for linearization. Decoupling chokes are not required for the control scheme with grouped currents since fluxes are isolated in C-cores. By...

Sorting and grouping are amongst the most costly operations performed during query evaluation. System R [6] used simple inference strategies to determine orderings held of intermediate relations to avoid unnecessary sorting, and to influence join plan selection. Since then, others have proposed using integrity constraint information to infer orderings of intermediate query results. However, the...