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tahmasebi--shirin
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Diagnosing anterior cruciate ligament injuries using a knee arthrometer: Design, fabrication, and clinical evaluation
, Article Biomedical Engineering - Applications, Basis and Communications ; Volume 23, Issue 3 , April , 2011 , Pages 181-192 ; 10162372 (ISSN) ; Sahraei, E ; Shirin, M. B ; Farahmand, F ; Tahmasebi, M. N ; Parnianpour, M ; Sharif University of Technology
2011
Abstract
Every year many people suffer from knee injuries. Previous studies on patients with knee injuries have shown that about 40% of knee injuries are Ligament injuries, and about 50% of the ligament injuries are the Anterior Cruciate Ligament (ACL) injuries. Along with other methods, knee arthrometers are widely used to diagnose ACL injuries. In the current research, a knee arthrometer was designed and developed to provide a reliable and repeatable measurement of knee laxity under anteriorposterior applied loads. Testretest configurations to examine repeatability of the device resulted in less than 1.5-mm difference for more than 97% of tests under applied loads of up to 90 N. These tests...
Tracking Consumers Throughout Their Purchase Journey: Using Deep Learning Methods
, M.Sc. Thesis Sharif University of Technology ; Aslani, Shirin (Supervisor)
Abstract
Over the past two decades, the interest in exploring consumers' behavior has risen to popularity. Nowadays, it is necessary for marketers to reach out to the right consumers at the right time and with the right message. Even though the positive impact of tracking consumers throughout their purchase journey and its managerial implications have been emphasized several times by academics, There is still a lack of practical research on how to discern the consumers' stage in the purchase journey from a holistic point of view. In this study, we develop several machine learning models, including RNNs (GRU and LSTM), Transformers, and XGBoost, by utilizing historical data of Yektanet (the leading...
A Study on Strategic Behavior of Drivers on Ride-hailing Platforms
, M.Sc. Thesis Sharif University of Technology ; Aslani, Shirin (Supervisor)
Abstract
Recently, the advent of online platforms as an intermediary tool has provided an opportunity for service providers and manufacturers to offer their services/products to consumers. Ride-hailing platforms are an example of these businesses where independent drivers and passengers are matched via an online platform. One of the most significant challenges faced by these companies is the emergence of strategic behaviors on both the demand and the supply side, which might affect the performance and profitability of the platform.In this thesis, we study the strategic behavior of drivers and its impact on their performance, using the data of one of the largest ride-hailing companies in Iran. We use...
Supply Chain Risk Study for Downstream Projects of Oil and Gas Industry in Iran
, M.Sc. Thesis Sharif University of Technology ; Aslani, Shirin (Supervisor)
Abstract
There are always some unpredictable phenomena happen in the process of constructing of a downstream petrochemichal plant resulting to delays that increase the cost compared with the benefits or sometimes cancelation of the projects that abodones the investors from the returns at all. On of the reasons that these issues can dwibdles the benefits is that most of Iranian’s downstream companies do not prepare suitable and sufficient capabilitities to cope with such a risks. In this thesis, at first, influensive risks on the downstream oil and gas projects in Iran have been studied based on a comprehensive litreture review, secondly using a questionnaire, these extracted risks have been assessed...
E-WOM and Customer Satisfaction in Robotic vs Traditional Hotels: A Topic Modeling Analysis
, M.Sc. Thesis Sharif University of Technology ; Aslani, Shirin (Supervisor)
Abstract
This research examines the attributes, themes, and topics discussed in electronic word-of-mouth (e-WOM) generated in TripAdvisor for robotic hotels in comparison to traditional ones. The first objective is to explore the themes and topics within TripAdvisor negative e-WOMs for both types of hotels and analyze how these topics differ between the two types of hotels, using the Latent Dirichlet Allocation (LDA) method. The research shows that which topics are mostly discussed in TripAdvisor negative e-WOMs for both types of hotels. Additionally, the research explores whether different themes, topics, and attributes have varying effects on user ratings in traditional hotels versus robotic ones,...
A Comparative Analysis of Positive eWOM Topics in Robotic and Conventional Hotels: Insights from TripAdvisor Reviews
, M.Sc. Thesis Sharif University of Technology ; Aslani, Shirin (Supervisor)
Abstract
This study explores topics discussed in positive eWOM of robotic and conventional hotels through a comprehensive analysis of online reviews using Latent Dirichlet Allocation (LDA). LDA is an advanced topic modeling technique. To uncover topics discussed in eWOM of robotic hotels and conventional hotels, and then compare them to see if there are any meaningful statistical differences between them, three separate LDA models were implemented on reviews of robotic hotels, conventional hotels, and the overall rereviews of all hotels, respectively. The results reveal that “service quality and overall atmosphere” is the most common topic discussed considering both hotel types, with key themes...
Sentiment-Based Topic Analysis on Product Demand Prediction: Pre-Release and Post-Release Study
, M.Sc. Thesis Sharif University of Technology ; Aslani, Shirin (Supervisor)
Abstract
This thesis examines the impact of electronic word-of-mouth (e-WOM) on product demand forecasting, specifically in the context of video game consoles. This study examines the importance of emotion-based topics and their impact on demand forecasting at two stages of the product life cycle: pre-launch and post-launch. Using sentiment analysis and topic modeling, this study uncovers product sales drivers and captures evolving consumer sentiment throughout the product lifecycle. By integrating insights from diffusion theory and consumer information search theory, this research contributes to the field of demand forecasting using social media data. This research shows that by using the topics...
Mining the Tenant Experience: Uncovering the Determinants of Residential Satisfaction through Topic Modelling of Online Rental Apartment Reviews
, M.Sc. Thesis Sharif University of Technology ; Aslani, Shirin (Supervisor)
Abstract
Residential satisfaction plays a pivotal role in shaping liveable cities, profoundly influencing individuals' health and well-being. In contrast, dissatisfaction in living environments often triggers relocation intentions, leading to significant vacancy costs for landlords and property managers. While previous studies predominantly relied on traditional methods like surveys and interviews, our research adopts a novel, bottom-up approach, analysing this phenomenon through the lens of residents themselves. Leveraging a custom-developed Python-based web scraper, we meticulously gathered 195,000 online reviews from apartments.com. This comprehensive dataset spans the most populous cities and...
Weak differentiability of solutions to SDEs with semi-monotone drifts
, Article Bulletin of the Iranian Mathematical Society ; Volume 41, Issue 4 , Sep , 2015 , Pages 873-888 ; 10186301 (ISSN) ; Zamani, S ; Sharif University of Technology
Iranian Mathematical Society
2015
Abstract
In this work we prove Malliavin differentiability for the solution to an SDE with locally Lipschitz and semi-monotone drift. To prove this formula, we construct a sequence of SDEs with globally Lipschitz drifts and show that the p-moments of their Malliavin derivatives are uniformly bounded
Simulation of HEMT (High Electron mobility Transistor) for Communication Applications
, M.Sc. Thesis Sharif University of Technology ; Sarvari, Reza (Supervisor)
Abstract
In this thesis, the simulation of HEMT for high frequency applications has been explored. It has been tried to examine the changes such as: gate recess, T-shaped gate, changing the channel length and doping of buffer layer on the performance of the proposed device. Simulation results show that the best way to improve the device performance, in particular its cut-off frequency, is increase in buffer layer doping density. Because it significantly increase the saturation current, electron mobility inside the channel, the transconductance and the cut-off frequency. If we need to lower the noise, the T-shaped gate can also be used. Also, by change in doping of donor layer, amount of 1017 cm-3 is...
Electrochemical Deposition of Zinc/Nickel Multilayer Coating and Investigating the Effect of Morphology and Phase Structure on the Dissolution of Zinc/Nickel Alloy Coating
, M.Sc. Thesis Sharif University of Technology ; Ghorbani, Mohammad (Supervisor)
Abstract
The multilayer coating (Zn-Ni)1/(Zn-Ni)2 is deposited from a single bath with a zincate-sulfate compound and by changing the current density. The effect of current density and the number of layers on the chemical composition, surface morphology, roughness, phase structure, and corrosion resistance of multilayer coatings respectively using atomic absorption spectroscopy, FE-SEM microscope, roughness tests, X-ray analysis, and electrochemical techniques such as Tafel polarization and impedance was investigated and compared with single-layer coatings. Because the amount of nickel in the composition of the coatings is less than 27%, in all the studied currents, the deposition is anomalous. The...
Effect of Efficient Management on Reconstruction of Apartment Buildingsi n Region 1 of Tehran City Using Hierarchical Analytical Model
, M.Sc. Thesis Sharif University of Technology ; Mofid, Massoud (Supervisor)
Abstract
Nowadays population growth, people housing demand and urbanization tendency has increased the land and house prices. So the constructers tend to build apartments. Time consuming and heavy costs of building and renovation has made the owners to rebuild the damages of their houses in case of an accident. Time and cost are the main factors in construction which includes rebuilding. Buildings and especially apartments renovation is expensive and prolonged. So the rebuilding tendency has been noted more than ever. In this study it has been tried to control costs and time by efficient management to save the rebuilding time and money. Two kinds of questionnaire has been applied to study different...
Scalable Architecture Based on Fog Computing and Blockchain for IoT Device Management
, M.Sc. Thesis Sharif University of Technology ; Habibi, Jafar (Supervisor)
Abstract
With the recent considerable developments in the Internet of Things (IoT), billions of resource-constrained devices are interconnected through the internet. Monitoring this huge number of IoT devices that are heterogeneous in terms of underlying communication protocols and data format is challenging. The majority of existing IoT device monitoring solutions heavily rely on centralized architectures. Since using centralized architectures comes at the expense of trusting an authority, it has several inherent drawbacks, including vulnerability to security attacks, lack of data privacy, and unauthorized data manipulation. Hence, a new decentralized approach is crucial to remedy these drawbacks....
Some improvements on the unfolding inverse finite element method for simulation of deep drawing process
, Article International Journal of Advanced Manufacturing Technology ; Vol. 72, issue. 1-4 , 2014 , pp. 447-456 ; ISSN: 02683768 ; Assempour, A ; Sharif University of Technology
2014
Abstract
The linear unfolding inverse finite element method (IFEM) has been modified and enhanced by implementing large deformation relations. The method is helpful to predict forming severity of the part that should be deep drawn as well as its blank shape and strain distribution in preliminary design stage. The approach deals with minimization of potential energy and large deformation relations with membrane elements. To reduce the computation time, the part is unfolded properly on the flat sheet and treated as 2D problem. Moreover, the nonlinear stress-strain relationship of plastic material properties has been considered to increase the accuracy of the results. An experiment set up has been...
A new mapping technique to consider intermediate stages in multistep deep drawing
, Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; Volume 228, Issue 9 , June , 2014 , Pages 1557-1569 ; ISSN: 09544062 ; Assempour, A ; Sharif University of Technology
2014
Abstract
The inverse solution is helpful to determine the drawability of a part and drawing parameters at the initial design stage. The usual inverse algorithms consider the drawing process that occurs in one step and therefore they are not able to analyze the processes which need more than one drawing step. Therefore, multistep inverse solution has been used for such problems. The multistep inverse solution deals with finding the initial guesses of nodal positions on intermediate stages and solving inverse equations between two consecutive steps. In this paper, a new mapping method has been developed to find the initial nodal positions on intermediate stages and the unfolding technique has been...
Examining Customer Behavior In Regarding OBA
, M.Sc. Thesis Sharif University of Technology ; Aslani, Shirin (Supervisor)
Abstract
In recent years, Internet advertising has become increasingly customized to individual users. As advertising carry on refining its capacities, it is more likely to be seen as insightful and useful by everyone. Consumers, particularly Gen Y and older members of Gen Z, are becoming more accepting of relevant advertising as digital acquaintance. Consumers now welcome active advertising that responds and reflects social activity, location, and brand and product preferences in real-time. This ability to be agile within the consumer’s connected experience is an emerging revenue driver and will continue to grow as ad platforms and ad presentations become smarter. But more personalization results in...
Investigation on the Effect of Product Involvement in Online Targeted Advertising
, M.Sc. Thesis Sharif University of Technology ; Aslani, Shirin (Supervisor)
Abstract
Nowadays, one of the most popular methods of advertising is online advertising, which is commonly used by many businesses. In the meantime, targeting the right person at the right moment to show an advertisement is always a major concern of advertisers and other players in this field. One of the areas of study in the literature in this field is the investigation of factors affecting the effectiveness of targeted advertising. The purpose of the upcoming research is to investigate the impact of the advertised product involvement in targeted online advertising. This level of effectiveness is measured by considering click intention as a measure of effectiveness and examining the impact of...
Synthesis and optical properties of Au decorated colloidal tungsten oxide nanoparticles
, Article Applied Surface Science ; Volume 355 , November , 2015 , Pages 884-890 ; 01694332 (ISSN) ; Mahdavi, S. M ; Sharif University of Technology
Elsevier
2015
Abstract
In this study, colloidal tungsten oxide nanoparticles were fabricated by pulsed laser ablation of tungsten target using the first harmonic of a Nd:YAG laser (1064 nm) in deionized water. After ablation, a 0.33 g/lit HAuCl4 aqueous solution was added into as-prepared colloidal nanoparticles. In this process, Au3+ ions were reduced to decorate gold metallic state (Au0) onto colloidal tungsten oxide nanoparticles surface. The morphology and chemical composition of the synthesized nanoparticles were studied by AFM, XRD, TEM and XPS techniques. UV-Vis analysis reveals a distinct absorption peak at ∼530 nm. This peak can be attributed to the surface plasmon resonance (SPR) of Au and confirms...
A novel adaptive approach to fingerprint enhancement filter design
, Article Signal Processing: Image Communication ; Volume 17, Issue 10 , 2002 , Pages 849-855 ; 09235965 (ISSN) ; Kasaei, S ; Sharif University of Technology
2002
Abstract
A novel procedure for fingerprint enhancement filter design is described. Fingerprints are best used as unique and invariant identifiers of individuals. Identification of fingerprint images is based on matching the features obtained from a query image against those stored in a database. Poor quality of fingerprint images makes serious problems in the performance of subsequent matching process. The main contribution of this work is to quantify and justify the functional relationship between image features and filter parameters. In this work, the enhancement process is adapted to the input image characteristics to improve its efficiency. Experimental results show the superiority of the...
Investigating the Factors Affecting the Migration of Iranian University Students Using the Clustering Method
, M.Sc. Thesis Sharif University of Technology ; Aslani, Shirin (Supervisor)
Abstract
Nowadays, the brain drain problem has become a challenge for countries of origin (COO) and a blessing for countries hosting student migrants. This issue has been studied in many domestic and international types of research. These studies' results can lead to the ability to identify the causes and discover methods to solve this problem. For several decades, the human capital flight has been one of the most challenging educational-economic-social problems in Iran and has grown significantly in recent years. The waste of the country's resources, the ineffectiveness of the education provided to students to improve the country's condition and its construction, the social and psychological...