Sharif Digital Repository

In nature, tidal currents are visible in gorges and in saltwater and freshwater collisions. In the study of behavior of different types of flow, it is usually assumed that the pressure is hydrostatic and the equations are solved based on this assumption. In the Approach Controlled regime observed during the double layer in 1993, the modeling performed using the equations derived from this assumption did not fit the results of the experiments. This demonstrates the inability of the hydrostatic pressure assumption to solve this particular regime. Hence, the equations were written on the basis of non-hydrostatic pressure and then the observed results were in accordance with the results of the... 

Scheduling problem specially surgery room scheduling is noteworthy and well known in optimization and machine learning literature which improve resource usage means cost reduction and patient experience means satisfaction increase.Surgery Rooms are one of the most costly section of the hospital. In addition to this, Surgeon are expensive resource and all the hospitals have limited capacity. By scheduling we can improve patient’s experience and resource management. That’s why scheduling Surgery Room is important and noteworthy.In this research we consider surgery duration and patient length of stay(LOS) probabilistic. Our approach for handling this is stochastic programming in which our... 

Fog computing environment consists of several devices which distribute across an arbitrary topology. Each of these devices is capable of carrying out a designated computation simultaneously with other devices. One of the common ways of describing a computation is through the usage of workflows. Workflow is a flexible and formal way of modeling tasks and their requirements for execution. A workflow is essentially a DAG. Therefore, it can model the data dependency between tasks quite accurately. The complex structure of a workflow in conjunction with the homogenous nature of devices in a fog environment makes it difficult to find a resource management algorithm to minimize execution time, used... 

This project focuses on the design of fuel drop tanks for airplanes that add minimal drag and positive lift to the flying object. This will obviously effect the stability and dynamic performance of the airplane. To reduce adverse dynamic effects the tank was divided to several segment with a special emptying sequence. The add-on tank has to have no interference with the object existing systems and require minimum structural changes in the object. Several designs were proposed and the one gaining highest marks was selected. The flow field and the dynamic behavior of combined vehicle and drop tanks were studied using FE simulations. The result shows that adding a drop tank with optimized... 

The purpose of this study is to present a suitable model for calculating the costs imposed on society due to deaths and injuries due to infrastructure failure due to earthquakes, which is used in the analysis of community resilience. Much research has been done to date to calculate the economic costs of infrastructure failure. However, no suitable analytical framework has been provided to quantify the costs of deaths and injuries to people due to earthquake failure. Previous research has provided methods such as the value of statistical life to quantify the social costs caused by accidents and environmental pollution. However, the literature review results in the field of seismic resilience... 

Cancer can be defined as a stochastic phenomenon. Thus, the tumor growth can be defined as a stochastic process. A Cancer tumor can be analyzed by its geometric shape. Furthermore, computing fractal dimension of shapes is a useful technique to analyze chaosity and complexity of shapes. This approach can be used to compare results from laboratory with simulated results of a mathematical model. A stochastic model of tumor growth will be presented. And some geometrical properties will be analyzed through computer simulation of the model  

The effects of combined task demands on the way muscles are recruited to balance external loads during posture and movement is of great importance in quantitative analysis of upper arm function. Pain and disability of shoulder joint is becoming more important as population spends more often interacting with computers in seated position and carrying repetitive tasks using upper extremities. Shoulder joint that is more dependent on the muscles for its normal function than other joints such as hip due to its small articular surface and large range motion has been used here to study its coordination during isometric exertions. Since, the numbers of tasks that could be performed are enormous. In... 

In the present study, the axisymmetric liquid gas/air diffusion flame in the presence of fuel concentration oscillations and velocity perturbations has been investigated experimentally. Several industrial combustions take a place by diffusion mechanism which necessitate scientists to make far better understanding of diffusion flames. In order to study diffusion flames, the instrument with two separated lines of fuel and air has been developed. Nitrogen is used for fuel dilution oscillatory with pulse of 1, 2, and 4 Hz frequencies. The pulse duration effects on flame structure are also studied. The flame shape has been captured by high speed camera and the results are processed by image... 

The purpose of this study was to create a three-cationic electro phosphate coating of zinc-nickel-manganese by cathodic method and to investigate the effect of operating variables on the properties of zinc-nickel-manganese tri-cationic electro phosphate coating. Hence, the effects of variables such as coating acidity, coating thickness, coating temperature, coating time and concentration of manganese were studied in the bath on the properties such as coating morphology, corrosion resistance, coating thickness. Coating morphology was characterized by scanning electron microscopy and corrosion resistance by polarization test. The pH values of 1.4, 1.8, 2 and 2.2 were selected, and the results... 

Burner scaling criteria have been studied and the most appropriate one has been selected to scale down a large industrial burner. The sub-scaled non-premixed swirl-stabilized burner is manufactured to ensure that the available experimental setup and equipment are sufficient and practical for characterizing the burner. The aim of the research is to assist the future design optimization with the identifications which have been done. The constant residence time method is selected in this project and it is shown that this is the proper criteria for non-premixed and swirl-stabilized burners. For better identification, stability maps of the flame are extracted with the experimental methodology for... 

This research evaluates the effect of external corrosion geometry and bending moment on the burst pressure of pipes. In recent decades, the use of natural resources of offshore oil and gas has increased, as a result, the use of offshore pipelines for transferring products has grown dramatically. At the same time, numerous accidents and explosions in offshore pipelines and its economic and environmental consequences indicates the importance of ensuring safe operation. Pipeline Integrity Management has been developed to ensure safe and efficient operation of pipelines. Integrity management includes planning, inspection, evaluation and repair. This cycle is checked continuously. The importance... 

Airport saturation is one of the important issues which have always been of the specialists’ concern. One of the major applications of this subject is at the airport approach problems. While using current conventional approach procedures have many disadvantages regarding high fuel consumption and subsequent much environmental and noise pollution, the CDA concept which is one of the modern topics introduced in consequence of free flight theory, has less such disadvantages compared to conventional approach. Subject of this study is to investigate whether Procedural approach or CDA saturates an aiport sooner if the traffic flow increases. In this dissertation, using BADA database, CDA... 

Study of the structural flexibility of large-scale wind turbine components on aeroelastic performance is important under the existence of critical atmospheric conditions. Prediction and control the critical deformations, identifying maximum local deformation and modeling the forces involved, are required. Aeroelasticity analysis is a suitable method for studying the coupling effects of wind turbine aerodynamics, dynamics and structures. This research has been done by modeling wind turbine components including blades, hub, nacelle and tower, taking into account aerodynamic couplings, dynamics and structures. Considering the large scale of reference wind turbine, nonlinear equations have added... 

The problem of science-religion relation is considered here, considering realism and the cognitive status of religious statements and accepting the existence of common issues between science and religion. Different approaches have been adopted to explain this relation. One of the approaches which have been proposed in recent years has been the issue of religious science, which is considered to solve incompatible issues between science and religion. The possibility of religious science is one of the important problems that have attracted the mind of some Muslim scholars and some devoted Muslims. Some motivation could be mentioned for bringing in this issue, like the removal of conflict... 

Connections have a crucial role in the behavior of every structure. Amongst various types of connections used in steel structures are those used to connect the columns to the foundations, namely Base Plates. As other types of connections, base plates control the behavior of the structure in various respects including affecting the effective length of columns. The main task of any base plate is to distribute the forces of the column on the foundation in such a manner that the stresses in concrete are below their allowable values. Different configurations, with or without various attachments, are used for designing the base plates hence achieving various types of behavior with various levels... 

Networked business is a kind of businesses, relatively new and very complex, worthy of more analysis and study. From all types of networked businesses, “Platform based” ones are subject of this study. To solve “the problem of networked business”, in this study we try to develop a conceptual framework, using different disciplines especially:
- Business model studies
- Network science and social network studies
- Economic and strategic studies of platforms
Besides some new business concepts defined and theorized in this study, reader will find the conceptual architecture, applicable to the general of the business