We use an improved reversible parking lot model to study the compaction of vibrated polydisperse media. The particle sizes are distributed according to a truncated power law. We introduce a self-consistent desorption mechanism with a hierarchical initialization of the system. In this way, we approach densities close to unity. The final density depends on the polydispersity of the system as well...

Everyday scenes often contain sets of similar objects. Perceptual representations may summarize these with statistical descriptors. After determining the psychological mean of two sizes, we measured thresholds for judging the mean with arrays of 12 circles of heterogeneous sizes. They were close to those for the size of elements in homogeneous arrays and single elements, and were little affecte...

In the determination of suitable frame sizes associated with dynamic framed slotted Aloha used in radio frequency identification tag identification processes, the widely imposed constraint Q L 2 = often yields inappropriate values deviating far from the optimal values, while a straightforward use of the estimated optimal frame sizes causes frequent restarts of read procedures, both resulting in...

One aspect that has mostly been overlooked in traditional economic lot-sizing is the implication of decisions on manual tasks and workload. Although lot-sizing decisions can have a significant impact on required manual material handling and on human performance, works that consider ergonomic aspects in lot-sizing are rare. This paper presents a model that integrates ergonomic aspect in terms of...

This paper considers a single machine capacitated lot-sizing and scheduling problem. The problem is to determine the lot sizes and the sequence of lots while satisfying the demand requirements and the machine capacity in each period of a planning horizon. In particular, we consider sequence-dependent setup costs that depend on the type of the lot just completed and on the lot to be processed. T...