Data aggregation is an effectual approach for wireless sensor networks (WSNs) to save energy and prolong network lifetime. A novel unequal cluster-based data aggregation protocol is proposed in this paper. It divides the network into some grids with unequal sizes, and implements cluster head rotation in each grid respectively. It is able to balance energy dissipation by setting proper sizes of ...

We investigate, by means of Monte Carlo simulations, the role of ring architecture and topology on the relative sizes of two interacting polymers as a function of the distance between their centers-of-mass. As a general rule, polymers swell as they approach each other, irrespectively of their topologies. For each mutual separation, two identical linear polymers adopt the same average size. Howe...

Scott and Smith (1969) develop estimators for linear functions from a two stage cluster sample, with their discussion repeated in many places. This discussion was reviewed in c01ed13.doc. It is note-worthy that Scott and Smith allow expressions for the variance to depend on the cluster. A similar development is given by Vallient et al.. We repeated the derivation of Vallient et al using the fin...

Clustering provides an effective way for prolong5 ing the lifetime of a wireless sensor network. Current clus6 tering algorithms usually utilize two techniques, selecting 7 cluster heads with more residual energy and rotating clus8 ter heads periodically, to distribute the energy consumption 9 among nodes in each cluster and extend the network lifetime. 10 However, they rarely consider the hot ...

In this paper, we report the results of our investigation of an evolutionary approach for solving the unequal area multi-objective facility layout problem (FLP) using the variable neighborhood search (VNS) with an adaptive scheme that presents the final layouts as a set of Pareto-optimal solutions. The unequal area FLP comprises a class of extremely difficult and widely applicable optimization ...

The Unequal Area Facility Layout Problem (UA-FLP) has been addressed using several methods. However, the UA-FLP has only been solved for criteria that can be quantified. Our approach includes subjective features in the UA-FLP, which are difficult to take into account with a more classical heuristic optimization. In this respect, we propose an Interactive Genetic Algorithm (IGA) that allows an i...

A construction site represents a conflux of concerns, constantly calling for a broad and multi-criteria approach to solving problems related to site planning and design. As an important part of site planning and design, the objective of site-level facility layout is to allocate appropriate locations and areas for accommodating temporary site-level facilities such as warehouses, job offices, wor...