There are two approaches for simulating memory as well as learning in artificial intelligence; the functionalistic approach and the cognitive approach. The necessary condition to put the second approach into account is to provide a model of brain activity that contains a quite good congruence with observational facts such as mistakes and forgotten experiences. Given that human memory has a solid core that includes the components of our identity, our family and our hometown, the major and determinative events of our lives, and the countless repeated and accepted facts of our culture, the more we go to the peripheral spots the data becomes flimsier and more easily exposed to oblivion. It was essential to propose a model in which the topographical differences are quite distinguishable. In our proposed model, we have translated this topographical situation into quantities, which are attributed to the nodes. The result is an edge-weighted graph with mass-based values on the nodes which demonstrates the importance of each atomic proposition, as a truth, for an intelligent being. Furthermore, it dynamically develops and modifies, and in successive phases, it changes the mass of the nodes and weight of the edges depending on gathered inputs from the environment.

In this work, the rising of a single bubble in a quiescent liquid under microgravity condition was simulated. In addition to general studies of microgravity effects, the initiation of hydrodynamic convection, solely due to the variations of interface curvature (surface tension force) and thus the generation of shearing forces at the interfaces was also studied. Then, the variation of surface tension due to the temperature gradient (Marangoni convection), which can initiate the onset of convection even in the absence of buoyancy, was studied. The related unsteady incompressible full Navier-Stokes equations were solved using a finite difference method with a structured staggered grid. The interface was tracked explicitly by connected marker points via a hybrid front capturing and tracking method. A one field approximation was used where one set of governing equations is only solved in the entire domain and different phases are treated as one fluid with variable physical properties, while the interfacial effects are accounted for by adding appropriate source terms to the governing equations. Also, a Multi-grid technique, in the context of the projection method, improved convergences and COMPUTATIONAL stiffness. The results show that the bubble moves in a straight path under microgravity condition, compared to the zigzag motion of bubbles in the presence of gravity. Also, in the absence of gravity, the variation of surface tension force due to interface curvature or temperature gradient can still cause the upward motion of the bubble. This phenomenon was explicitly shown in the results of this paper.

In this study, the effects of two boundary conditions: (1) the same flow rate in all outlets and (2) the same static pressure equal to zero in all outlets has been numerically examined in an asymmetrical model of trachea-bronchial tract. Correspondingly, the effects of the inlet flow rate changes on the flow distribution, flow patterns and the reverse flow zones were studied in breathing rates 12 and 48 lit/min which represent respectively laminar and turbulent flow for a 3D non-planar model of trachea-bronchial airways consists of 4 generations. The estimation of flow distribution obtained from the second boundary condition was more accurate when compared to the real distribution in the lungs. Using the first boundary condition, the flow distribution did not change when the inlet flow rate was increased. However, for the second boundary condition, little changes revealed. The flow pattern in the lower sections was more complex than the upper sections due to the bifurcations’ curvature that causes the Dean-flow particularly when this curvature is in non-planar to the previous bifurcation. When the second boundary condition was used, the number of generated reverse flow zones was more than the other conditions and increased with increasing the inlet flow rate.

In the present study, the Large Eddy SIMULATION (LES) turbulence closure is applied for the fi rst time, to the best of our knowledge, to investigate the viability of air conditioning systems in a large space. The results of LESs were validated against experimental measurements and the model was used to study the effect of different design variables including Air Changes per Hour (ACH), supply temperature, and return air vent height on design objectives such as local and global thermal comfort indexes and energysaving parameter by using a systematic multi-objective optimization approach. Sensitivity analysis showed that global and local thermal comfort indexes were highly sensitive to the air supply temperature, while energy saving was sensitive to ACH and the supply temperature to the same extent. In addition, it was found that height of the return air vent affected energy saving more than other factors. Finally, an energy saving rate of 22. 9% along with thermal comfort indexes within the allowable range is achievable by using the best design through the multi-objective optimization.

A one-dimensional, transient and thermal degradation model for predicting responses of composite materials when are exposed to the fire is presented. The presented model simulates ablation of composites with different layers of materials and considers material properties as functions of temperature. The reactions are modeled by using Arrhenius-type parameters and density-temperature diagrams which are obtained by specific experimental techniques such as thermogravimetric analysis. This transient thermal model has been implemented in form of a computer code by means of new numerical methods in order to predict the temperature distribution in the liner, the amount of char and erosion, and the liner thickness variations with time. By using implemented computer code, ablation phenomena in a glass-filled phenolic composite has been simulated with the same parameters of a similar experiment. The results are in a good agreement with the experimental data and the model can successfully be used in the design of thermal protection shields as an aid of material and thickness selection.

In this work, rising of a single bubble in a quiescent liquid under microgravity condition was simulated. The related unsteady incompressible full Navier-Stokes equations were solved using a conventional finite difference method with a structured staggered grid. The interface was tracked explicitly by connected marker points via hybrid front capturing and tracking method. One field approximation was used, while one set of governing equations was only solved in the entire domain and different phases treated as one fluid with variable physical properties. The interfacial effects are accounted for by adding appropriate source terms to the governing equations. The results show that the bubble moves in a straight path under microgravity condition, compared to the zigzag motion of bubbles in the presence of gravity. Also, in the absence of gravity and temperature gradients, the hydrodynamic effect can still cause the upward motion of the bubble. This phenomenon was explicitly shown in our results.

Background: Accurate voxel phantom is needed for dosimetric SIMULATION in radiation therapy for malignant tumors in female pelvic region. However, most of the existing voxel phantoms are constructed on the basis of Caucasian or non-Chinese population. Materials and Methods: A COMPUTATIONAL framework for constructing female pelvic voxel phantom for radiation dosimetry was performed based on Chinese Visible Human (CVH) datasets. First, several organs within pelvic region were segmented from CVH datasets. Then, polygonization and voxelization were performed based on the segmented organs and a 3D COMPUTATIONAL phantom is built in the form of a set of voxel arrays. Results: The generated phantom can be converted and loaded into treatment planning system for radiation dosimetry calculation. From the observed dosimetric results of those organs and structures, we can evaluate their absorbed dose and implement some SIMULATION studies. Conclusion: A voxel female pelvic phantom was developed from CVH datasets. It can be utilized for dosimetry evaluation and planning SIMULATION, which would be very helpful to improve the clinical performance and reduce the radiation toxicity on organ at risk (OAR).

In the present study the generation and the propagation of sound wave in low Mach number flows are numerically studied. Since one of the major problems in aeroengine design is the reduction of noise pollution, the exact prediction of sonic behavior is of special importance. The target of this study is to simulate a leakage, as a free jet. The basis of this study is the hybrid method for which benchmark Reynolds stress turbulence model is applied in solving the flow field and the Lighthill analogy is used for acoustic field analysis. Meanwhile, the continuous filter white noise is applied for solving the instantaneous velocity. Accordingly, the sound pressure level profiles for axial and transverse directions are plotted. Comparison of our results with existing benchmark data is satisfactory.

Hydrocyclones are the most efficient used classifiers in the grinding circuits. Hydrocyclones are normally modeled and simulated using empirical models. These models can only be used within the range of the experimental data from which the model parameters have been derived. COMPUTATIONAL fluid dynamics (CFD) is a powerful tool in simulating fluid flow in hydrocyclones. This research work deals with 3D SIMULATION and modeling of fluid flow in a single phase hydrocyclone using CFD. The main SIMULATION steps include preparing the geometry, meshing it, defining the properties of the materials involved, and setting the boundary layer and conditions. The experimenal data measured in a laboratory hydrocyclone were used for validation of the model. The SIMULATION results indicated that the tangential velocity increased traversing towards the core, before decreasing at the interface with the air core. The liquid axial velocity inside the hydrocyclone varied from-1. 59 m/s to 6. 52 m/s. The axial velocity is a result of two swirling flows, the inner upward flowing inside the air core and the outer downward flowing near the cyclone wall. The liquid axial velocity inside the hydrocyclone varied from-5. 58 m/s to 5. 46 m/s. The LES model showed the least error on predicting the velocity profiles, the air core dimensions (7. 8%), the pressure drop (7. 52%) and the mass split ratio to overflow (0. 18%). The effect of various geometric (spigot diameter, vortex diameter and cone angle) and process (feed flow rate) parameters on tangential velocity of the fluid was investigated.