Markov Simulation and the more recent Poisson Simulation are two fully consistent ways of modelling, applicable to the same types of problems. A Markov model is based on a detailed description of every situation, called state, that a system can be in and every possible transition between these states. This approach allows powerful analysis and makes Markov models a fundamental part of the theor...

always allocate man - machine is considered as one of the main concerns of operation planners. utilize an appropriate using of workforce in situations that the operation is dependent on the capabilities of the workforce, can lead to improve the systems efficiency and productivity indicators. since these issues, categories in np-hard problems, so optimization and solving the mathematical model o...

In this paper, the particular solution technique for inverse simulation applied to the quadrotor maneuvering flight is investigated. The ‎trust-region dogleg (DL) technique which is proposed alleviates the weakness of Newton’s method used for numerical differentiation of system states in the solution process. The proposed technique emphasizes global convergence solution to the inverse simulatio...

many large oil and gas fields in the most productive world regions happen to be fractured. the exploration and development of these reservoirs is a true challenge for many operators. these difficulties are due to uncertainties in geological fracture properties such as aperture, length, connectivity and intensity distribution. to successfully address these challenges, it is paramount to improve ...

background: for an effective treatment planning in brachytherapy, it is necessary to know the accurate source dosimetric information such as air kerma strength, exposure rate constant, dose rate constant and redial dose distribution. the usual method to determine these factors is thermo luminescent dosimeter (tld) dosimetry. nowadays, another more accurate method is known to be the monte carlo ...

simulation optimization is a scientific tool that is widely used to design and optimize comminution circuits in mineral processing plants. In this research, first of all, in order to  determine the suitable d80 for cicuit hydrocyclone underflow, the requiremed parameters of simulator (residence time distribution, breakage function, selection function and Plitt’s model calibration) were determin...

introduction: with the rapid increase in use of lasers in medical treatments, it is important to understand the mechanisms of heat transfer in biological tissues in order to minimize damage to the tissues resulting from extra heat applied. the aim of this study is to investigate the temperature distribution in living biological tissues when laser irradiation is used in a treatment. methods:  in...

data grids support access to widely distributed storage for large numbers of users accessing potentially many files. to enhance access time, replication at nearby sites may be used. data replication, a technique much investigated bydata grid researchers in past years creates multiple replicas offile and places them in conventional locations to shorten fileaccess times. one of the problems in da...

projected global climate change may have a major influence on crop yield. the likely effects of climate change caused by increasing atmospheric carbon dioxide levels on rice yield in iran were evaluated using a mechanistic growth model for rice, gsac-rice, running under a climate change scenario predicted for a doubled-co2 (2xco2) atmosphere by the geophysical fluid dynamics laboratory (gfd...

introduction: the key characteristics of positron emission tomography (pet) are its quantitative capability and its sensitivity, which allow the in vivo imaging of biochemical interactions with small amounts of tracer concentrations. therefore, accurate quantification is important. however, it can be sensitive to several physical factors. the aim of this investigation is the assessment of the e...