Sharif Digital Repository

Low back pain is a common medical problem around the world afflicting 80% of the population some time in their life. Low back injury can result from a loss of torso stability. This investigation seeks to apply existing methods to new applications and to develop new methods to assess spinal stability during its dynamical activities. In this study, firstly, optimization method is utilized as an appropriate explanation of role of nervous system in controlling of spine movements. Spine which is a complex structure of vertebrae and cartilage has been modeled by a 3D inverted pendulum with a ball and socket joint at L5/S1 incorporated with 18 muscle fascicles. Planning of point-to-point spine... 

User-generated data in TripAdvisor.com consists of considerable amount of useful information that can help managers to provide better services to their customers. In this study reviews to all hotels of Tehran, Iran and Auckland, New Zealand on TripAdvisor.com as real data are selected and scraped by Java programming language. In addition, information about hotels (e.g. name of hotel, overall rating, hotel’s class, total reviews, and hotel’s amenities) and information about the reviews and reviewers (e.g. date of review, country of the reviewer, contribution rate, rate to the hotel, text of review, date of stay, trip type, and years in TripAdvisor) are extracted as well. 64 and 190 hotels of... 

In recent years, the tendency to use biodegradable and biocompatible polymer nanoparticles for drug delivery applications has been increasing, the reason for this being the possibility of precise control of the drug release rate, ease of use, and no need for external Surgery after the release of the drug, increases the therapeutic efficiency of the drug and reduces the side effects with its precise transfer. In this research work, drug carrier nanocomposites were prepared from polylactic acid (PLA), polyethylene glycol (PEG) and hydroxyapatite (HAp) and for the controlled release of ciprofloxacin (CIP). It was used to treat bone infections. The drug loading efficiency for nano-carriers was... 

Tuned Mass Damper (TMD) is one of the most popular device implemented in structures in order to control the motion induced by wind. The performance of TMD has correlation with its design, which is depending on the Structure dynamic properties as well as the specifications of lateral loading. During the earthquake since the both of the mentioned parameters will be uncertain, hence, the reduction of TMD’s sensitivity to its design parameters is vital. In this regard, in 2012, Maurizio De Angelis et al. tested the unconventional TMD – it has a large mass ratio – and corroborated its merit. The results were limited to short structures with linear behavior. This research not only verified... 

The tuned mass dampers (TMD) are being used more often in structures to control the wind-induced vibrations. However, their performance during an earthquake deteriorates due to a relatively wide frequency bandwidth of seismic input as well as nonlinear structural behavior. Increasing the mass of TMD to enhance its performance whilst reducing its sensitivity to detuning has its own limitation in terms of deploying large masses at usually the roof level of the building structures. In that regard, the researchers have employed the inerter, a mechanical device that is able to produce relatively large moment of inertias with a relatively small mass of flywheel, to improve the performance of the... 

In present research work, methods of preparing ion exchange membranes, especially anion exchange membranes, were studied and chemical modification of polysulfone was chosen as a safe and economical method for preparing anion exchange membranes. The chloromethylated polysulfone was characterized by HNMR spectroscopy and functionalization degree was determined according to peak area integration. Membranes were produced by mixing and amination of the chloromethylated and normal polysulfone (40-100% wt). Morphology and chemical structure of membranes were investigated by SEM images and FTIR spectroscopy.The ionic conductivity, ion exchange capacity and water content of samples were measured. The... 

In recent years, requirement engineering and goal modeling have gained more attention among different organisations. Therefore, different methods have been designed to discover stakeholders’ requirements and translate them into process and organizational goals. Various goal models have been introduced to represent these goals and their relations towards each other. Still, these methods are manual representations of different process scenarios and do not relate to the actual behavior. In 2014, Map Miner Method (MMM) was introduced to discover intentional process models from event logs. MMM uses Hidden Markov Model (HMM) as a means to represent the process as a map model of strategies and... 

Recommending routes to city taxis in order to improve their performance in finding passengers can reduce traffic, pollution and waiting time for passengers, as well as this, increasing the efficiency of taxis can increase their income. In this study, by analyzing trajectory data obtained from 536 taxis in San Francisco over a period of one month, we generated networks of cells, each of which has time-dependent characteristics such as the probability of finding a passenger, the capacity of each cell, or the amount of demand exists is in the cell and the average speed of passing through that cell. also, the connections between these cells in order to make more use of the experiences of taxi... 

The purpose of the present study is to develop neural network estimation method for hybrid or panel data which have a combination of two cross-sectional and time series structures and because of the features of both structures, their use in different sciences offers many advantages; and the analytical methods for this data structure are also different from other one-dimensional structures, so different and specific regression models are presented for this data structure. However, in the artificial neural network method, modeling the development for this data structure is neglected, so in the present study, using the concepts of panel regression methods and their application to the... 

One of the utmost important factors during salvage operation of drowned ships is raising velocity. Uncontrolled raise is a dynamic phenomenon which can lead to the sudden tensions, collapse in airbags or ships. Studing this issue helps the engineers which kinds of problems are more important during salvage operations. This study focus on modeling and analysis of raising movment of the ship with FLOW-3D and ABAQUS software.
In FLOW-3D environment, hydrodynamic analysis of rising movment of drowned ship has been done. We should mention that applied forces and velocities and other parameters from the FLOW-3D output should be passed IMCA Criteria to avoid uncontrollable raise. In ABAQUS...