it is shown in [1] that the optimal downlink radio resource allocation for non-realtime traffic in cellular cdma/tdma networks can be mapped to a multi-dimensional multiple-choice knapsack problem (mmkp) which is np-hard. in this correspondence we propose a heuristic algorithm with polynomial time complexity for this problem. numerical results indicate significant computational performance impr...

Multicast routing is one of the most important services in Multi Radio Multi Channel (MRMC) Wireless Mesh Networks (WMN). Multicast routing performance in WMNs could be improved by choosing the best routes and the routes that have minimum interference to reach multicast receivers. In this paper we want to address the multicast routing problem for a given channel assignment in WMNs. The channels...

One main group of a transportation network is a discrete hub covering problem that seeks to minimize the total transportation cost. This paper presents a multi-product and multi-mode hub covering model, in which the transportation time depends on travelling mode between each pair of hubs. Indeed, the nature of products is considered different and hub capacity constraint is also applied. Due to ...

this study examined the effects of task complexity on written narrative production under different task complexity conditions by efl learners at different proficiency levels. task complexity was manipulated along robinson’s (2001b) proposed task complexity dimension of here-and-now (simple) vs. there-and-then (complex) in. accordingly, three specific measures of the written narratives were targ...

We define a class of problems whose input is an n-sized set d-dimensional vectors, and where the problem first-order definable using comparisons between coordinates. This captures wide variety tasks, such as complex types orthogonal range search, model-checking properties on geometric intersection graphs, elementary questions multidimensional data like verifying Pareto optimality choice points....