one of the new topics in dea is the data with integer values. in dea classic models, it is assumed that input and output variables have real values. however, in many cases, some inputs or outputs can have integer values. measuring cost efficiency is another method to evaluate the performance and assess the capabilities of a single decision-making unit for manufacturing current products at a min...

In the traditional cost-efficiency model, the information about each decision unit includes inputs, outputs, and the input prices are fixed and specific. In practice, the price of the inputs often fluctuates at different times, and these prices for the decision-making unit are time-dependent. By the traditional method, the efficiency of decision units is impossible in the presence of time-depen...

In this paper a gas turbine power plant including air preheater (recuperator), heat recovery steam generator and air cooler system was modeled. Eight parameters were selected as the design variables.  Fast and elitist non-dominated sorting genetic algorithm (NSGA-II) was applied (to maximize the exergy efficiency and to minimize the total cost rate) for the mentioned cogeneration system. Th...

In many organizations and financial institutions, we don't always have acsses to inputs and outputs to evaluate the decision-making units (DMUs), but rather only a ratio of inputs to outputs ( or reverse) might be available. In DEA, cost efficiency determines input standards based on input costs. In multi-stage network DEA processes, in addition to input standards, cost efficiency would determi...

in this paper, the cost and income efficiency models have been considered with regard to the multiple objective programming structures. for finding the efficient points in purposed molp problem, some various methods like lexicography & the weighted sum can be used. so by introducing the molp problem the cost & income efficiencies will be achieved. in the present study, the molp problem ...

Based on the aggregated findings of 25 studies from the literature, this paper presents a comprehensive overview of the impacts, motivation, and success factors of the adoption of the IS/IT service management reference framework ITIL in IS/IT service organizations in practice. Positive effects across studies include increased customer satisfaction, service quality, and the increase of time and ...

The Swedish Transport Administration is introducing a new regime, called maintenance windows, for allocating train free slots reserved for maintenance tasks on the railway infrastructure. In this paper, a model for the assessment and the dimensioning of such maintenance windows is presented, which considers marginal effects on both the maintenance cost and the expected train traffic demand. The...

Voice over IP (VoIP) technology is being extensively and rapidly deployed. The flexibility and cost efficiency are the key factors luring enterprises to transition to VoIP. Some security problems may surface with the widespread deployment of VoIP. This article presents an overview of VoIP systems and its security issues. First, we briefly describe basic VoIP architecture and its fundamental dif...

In multi-division organizations, goal congruence between different divisions and top management is critical to the success of management. In this paper, drawing upon a nonparametric framework to model production technology, we derive a necessary and sufficient condition for a firm with multiple divisions to be goal-congruent, and then extend it to a goal congruence testing measure, which coinci...

We introduce average cost optimal adaptive policies in a class of discrete-time Markov control processes with Borel state and action spaces, allowing unbounded costs. The processes evolve according to the system equations xt+1 = F (xt, at, ξt), t = 1, 2, . . . , with i.i.d. R -valued random vectors ξt, which are observable but whose density ̺ is unknown.