In this paper, a bi-objective model is proposed for designing a pre-positioning network of pharmaceutical supplies considering their limited shelf-life. The presented model aims to consider both cost efficiency and responsiveness by minimization of total cost and the maximum amount of unmet demand under uncertainties in demand and supply sides’ data. Moreover, for effective distribution of reli...

A cost-sharing problem is defined by a set of players vying to receive some good or service, and a cost function describing the cost incurred by the auctioneer as a function of the set of winners. A costsharing mechanism is a protocol that decides which players win the auction and at what prices. Three desirable but provably mutually incompatible properties of a cost-sharing mechanism are: ince...

data envelopment analysis (dea) is a non-parametric technique for evaluation of relative efficiency of decision making units described by multiple inputs and outputs. it is based on solving linear programming problems. since 1978 when basic dea model was introduced many its modifications were formulated. among them are two or multi-stage models with serial or parallel structure often called net...

In the facility location problem usually reducing total transferring cost and time are common objectives. Designing of a network with hub facilities can improve network efficiency. In this study a new model is presented for P-hub covering location problem. In the p-hub covering problem it is attempted to locate hubs and allocate customers to established hubs while allocated nodes to hubs are in...

The human cerebral cortex is a complex network of functionally specialized regions interconnected by axonal fibers, but the organizational principles underlying cortical connectivity remain unknown. Here, we report evidence that one such principle for functional cortical networks involves finding a balance between maximizing communication efficiency and minimizing connection cost, referred to a...

As mobile data traffic increases, and the number of services provided by the mobile network increases, service load flows as well, which requires changing in the principles, models, and strategies for media transmission streams serving to guarantee the given nature of giving a wide scope of services in Flexible and cost-effective. Right now, the fundamental question remains what number of netwo...

Joux’s multicollision attack is one of the most striking results on hash functions and also one of the simplest: it computes a k-collision on iterated hashes in time ⌈log2 k⌉ · 2 , whereas k! · 2 was thought to be optimal. Kelsey and Schneier improved this to 3 · 2 if storage 2 is available and if the compression functions admits easily found fixed-points. This paper presents a simple technique...

Calculating the mean physical stock in a simple periodic review inventory system seems to be straightforward. However, the standard approximate expressions appear to yield inaccurate results, especially for low service levels. Low service levels are frequently encountered at intermediate nodes in cost-optimal solutions for multiechelon systems. In this note, we present an improved approximate m...

Social media has found its place in the digital economy. Social media tools offer easy, interactive and cost-efficient possibilities to interact with various stakeholders. Not only the mere availability of social media tools but also their implementation renders benefits to an organization. Consequently, evidence from practice indicates that social media is an appropriate way to establish stake...