In this paper, we present an approach for retrieving relevant articles from the biomedical corpus. Our first run considered four kinds of operators as query expansion. The operators are phrase, mandatory, optional and synonym set. The second run lowered the ranking of documents which contained query terms only in their MeSH fields. The results of the official runs and further experiments were l...

In this paper, at first we derive a family of maximum Tsallis entropy distributions under optional side conditions on the mean income and the Gini index. Furthermore, corresponding with these distributions a family of Lorenz curves compatible with the optional side conditions is generated. Meanwhile, we show that our results reduce to Shannon entropy as $beta$ tends to one. Finally, by using ac...

Two types of service; Re-service; Modified vacation; Balking; Service interruption Abstract This paper deals with the steady state analysis of batch arrival retrial queueing system with two types of service under modified vacation policy, where each type consists of an optional re-service. An arriving batch may balk the system at some particular times. After the completion of each types of serv...

Retrial queueing systems are characterized by the fact that a primary request, finding all servers and waiting positions busy upon arrival, leaves the service area but after some random time, repeats its demand. Between retrials, the customer is said to be in “Orbit”. So the repeated attempts for service from the group of blocked customers are super imposed on the normal stream of arrivals of p...

Display advertisements on the web are sold via ad exchanges that use real time auction. We describe the challenges of designing a suitable auction, and present a simple auction called the Optional Second Price (OSP) auction that is currently used in Doubleclick Ad Exchange.

Prosocial punishment has been proved to be a powerful mean to promote cooperation. Recent studies have found that social exclusion, which indeed can be regarded as a kind of punishment, can also support cooperation. However, if prosocial punishment and exclusion are both present, it is still unclear which strategy is more advantageous to curb free-riders. Here we first study the direct competit...