in this paper, we present a genetic algorithm (ga) for optimization of a multi-mode resource constrained time cost trade off (mrctct) problem. the proposed ga, each activity has several operational modes and each mode identifies a possible executive time and cost of the activity. beyond earlier studies on time-cost trade-off problem, in mrctct problem, resource requirements of each execution mo...

the present paper aims to investigate the effects of modularity and the layout of subsystems and parts of a complex system on its maintainability. for this purpose, four objective functions have been considered simultaneously: i) maximizing the level of accordance between system design and optimum modularity design,ii) maximizing the level of accessibility and the maintenance space required,iii...

1. THE PROBLEM. Something is rotten in the electoral state of the United States. Mathematics is involved. Advances in computer technology—hardware and software— have permitted a great leap “forward” in the fine art of political gerrymandering—“the practice of dividing a geographical area into electoral districts, often of highly irregular shape, to give one political party an unfair advantage b...

Aggregating areas into larger regions is a common problem in spatial planning, geographic information science, and cartography. The aim can be to group administrative areal units into electoral districts or sales territories, in which case the problem is known as districting. In other cases, area aggregation is seen as a generalization or visualization task, which aims to reveal spatial pattern...

multi-echelon inventory systems are one of the most important and attractive areas in modelling supply chain management so that several researches and studies have been done about. in this paper, the total cost function of a two-echelon inventory system with central warehouse and many identical retailers controlled by continuous review inventory policy is estimated. we have assumed the demand i...

this paper presents a new strategy based on multi-stage fuzzy (msf) pid controller based on artificial bee colony (abc) for damping power system stabilizer (pss) in multi-machine environment. the recent studies in artificial intelligence demonstrated that the abc optimization is strong intelligent method in complicated stability problems. also, finding the parameters of pid controller in power ...

a few of the presented soil behavior models are capable of predicting the triggering and post liquefaction and also shear band mechanism through the soil media. the assessment of earth-dam body behavior as a soil structure made of cohesive soil in core and non-cohesive soil as the core supports, including water interaction at upstream through earthquake upon a multi-line constitutive equations ...