Loading...
Search for: privention
0.059 seconds

    Network Design Problem to Prevent Chaotic Flow

    , M.Sc. Thesis Sharif University of Technology Khademi, Mostafa (Author) ; Pourzahedi, Hossein (Supervisor)
    Abstract
    Two significant features of a transportation network, uncertainty and complexity, might cause some irregular behaviors. One example of such behaviors is chaotic flow in which the transportation system fails to reach equilibrium and people experience different daily travel times. These uncertainties are not controllable in any transportation system and, if not taken into consideration, will result to low levels of service and poor reliability. In this study, an evolutionary traffic assignmet model is used to illustrate when the network reaches bifurcation and chaos. Later, the effects of uncertainty in the parameters of supply and demand is tested on the evolutionary traffic assignment model.... 

    An Improved Clustering Method of Data Mining in Healthcare and Its Implementation

    , M.Sc. Thesis Sharif University of Technology Shourabizadeh, Hamed (Author) ; Akhavan Niaki, Taghi (Supervisor)
    Abstract
    In this study, a brief definition of data mining and its variants were mentioned. Then the methods and algorithms for clustering and their application in the field of healthcare is studied. Concidering the available data for anemia disease, including numeric and categorical attributes, the k-medoids clustering algorithm was selected. This algorithm is one of the simple, powerful and most widely used methods for clustering. The drawbacks of this algorithm are as follow: requires a user input on the number of clusters, depends on the initial data and traps in the local optima. In this thesis, an improved method of clustering-based on Random Forest and k-medoids algorithms has been developed.... 

    Stimulating Asphaltenic Oil Reservoirs, Experimental Investigation of Asphaltenic Sludge Formation to Plan Its Prevention

    , M.Sc. Thesis Sharif University of Technology Sisakhti, Hossein (Author) ; Ayatollahi, Shahaboddin (Supervisor) ; Shad, Saeed (Supervisor)
    Abstract
    Formation damage is probable to occur while drilling, work-over operations, and well completion in near wellbore zone due to different reasons; which leads to excess pressure drop through this area. Well stimulation operations are proposed to remove these damages and improve oil production; among which, acidizing is known as a traditional applicable method to stimulate oil and gas wells. Although this approach is accepted and chosen as a well stimulation method to remove formation damages, its poor design and implementation results in new formation damages. One of these arises when acid contacts asphaltic oil, which causes asphaltene particle instability and asphaltic sludge rapid...