نتایج جستجو برای: grade uncertainty

تعداد نتایج: 288908  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده مهندسی 1389

abstract type-ii fuzzy logic has shown its superiority over traditional fuzzy logic when dealing with uncertainty. type-ii fuzzy logic controllers are however newer and more promising approaches that have been recently applied to various fields due to their significant contribution especially when the noise (as an important instance of uncertainty) emerges. during the design of type- i fuz...

Push back design as a complex task, is one of the major steps in the open pit mines planning. Push backs can be generated by varying economic factors such as commodity price, mining cost, processing cost, etc. Another important issue in generating push backs is grade uncertainty, which can cause the problem be more complex. Conventional methods of push back design ignore grade uncertainty. To o...

Metal price is one of the most important parameters in the calculation of cut- off grade. The cut- off grade has the main role in determination of mine layout. Mine layout actuates mineable reserve, mine life and economic profitability. Not considering the uncertainty in metal prices can lead to a non-optimal layout. In this paper optimum underground mine layout is determined by expected utilit...

Due to uncertain nature of grade in ore deposits, considering uncertainty is inevitable in geological modelling of resources and mine planning. In other words, uncertainty in grade of mineralized materials, is one of the most significant parameters need attention in mine planning. In this paper, a comparative procedure utilizing Sequential Gaussian Simulation (SGS) and traditional Ordinary Krig...

2010
G. W. Evatt P. V. Johnson P. W. Duck S. D. Howell

Mining companies world-wide are faced with the problem of how to accurately value and plan extraction projects subject to uncertainty in both future price and ore grade. Whilst the methodology of modelling price uncertainty is reasonably well understood, modelling ore-grade uncertainty is a much harder problem to formulate, and when attempts have been made the solutions take unfeasibly long tim...

In order to catch up with reality, all the macro-decisions related to long-term mining production planning must be made simultaneously and under uncertain conditions of determinant parameters. By taking advantage of the chance-constrained programming, this paper presents a stochastic model to create an optimal strategy for producing bimetallic deposit open-pit mines under certain and uncertain ...

The mine production planning defines a sequence of block extraction to obtain the highest NPV under a number of constraints. Mathematical programming has become a widespread approach to optimize production planning, for open pit mines since the 1960s. However, the previous and existing models are found to be limited in their ability to explicitly incorporate the ore grade uncertainty into the p...

پایان نامه :دانشگاه آزاد اسلامی واحد علوم پزشکی تهران - دانشکده پزشکی 1389

مقدمه: فرکتالها عبارتند از ساختارهای هندسی پیچیده. علم فرکتال که به بررسی این ساختارها می پردازد در سال 1975 ابداع گردید و امروزه نه تنها در علوم مهندسی بلکه در علوم پزشکی نیز جایگاه ویژه ای یافته است. فرکتال ها در تشخیص بیماری های استخوانی و مدل سازی ساختار استخوانها و تحلیل تغییرات ساختار آنها و تحلیل ریتم و ضربان قلب و تشخیص بیماری های قلبی کاربرد دارند. هرچند به نظر می رسد هرکجا که یک بی نظ...

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