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sheikhzadeh--mohammad-sajjad
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Produce of Antibacterial Composite Coating of PTFE+Ag+TiO2 On 316SS and Study Its Properties
, M.Sc. Thesis Sharif University of Technology ; Afshar, Abdollah (Supervisor)
Abstract
This research investigated the corrosion and antibacterial properties of PTFE+TiO2/Ag coating and its adhesion to 316L stainless steel. To increase adhesion, polydopamine coating was created as an intermediate layer by chemical deposition method on stainless steel, then PTFE + TiO2 coating was created on the sample by immersion method, and then silver nanoparticles were applied as the third layer by chemical deposition method. According to the polarization curves, the most corrosion-resistant coatings with corrosion current density of 3.34×10-5 and 3.25×10-4 μA are coatings PTFE+TiO2 and PTFE/PTFE+TiO2/Ag respectively. In terms of antibacterial activity, according to the non-growth halo...
Experimental Investigation of Fretting Fatigue of Titanium Specimens Made by Additive Manufacturing Method
, M.Sc. Thesis Sharif University of Technology ; Adibnazari, Saeed (Supervisor)
Abstract
Additive manufacturing (AM) has gained significant attention in recent years as a novel approach to fabricate three-dimensional parts. Its advantages, including high speed, low-cost production for small-scale batches, and greater design freedom, have made it a competitive alternative to traditional manufacturing methods. However, the application of AM for components subjected to fretting fatigue requires careful evaluation. Fretting fatigue is a major cause of failure in turbines, particularly at the contact interface between turbine blade roots and disk. In this study, the influence of AM and post-processing treatments on the fretting fatigue life of Ti-6Al-4V alloy was investigated. Five...
Product bundling: Impacts of product heterogeneity and risk considerations
, Article International Journal of Production Economics ; Volume 144, Issue 1 , July , 2013 , Pages 209-222 ; 09255273 (ISSN) ; Elahi, E ; Sharif University of Technology
2013
Abstract
Bundling has been extensively studied in the literature and its benefits have been manifested through three perspectives of achieving better price discrimination, helping to save costs, and preserving the power for deterring a potential entrant. In this study, we examine two aspects of bundling which have not been studied before. We examine the impact of product heterogeneity on bundling decisions. We also address risk considerations in a bundling problem. Specifically, we consider a retailer who has the option of selling a bundle of two products (pure bundling policy), or selling the products separately (no-bundling policy). The retailer could also face a product selection problem for which...
A Framework for Price Negotiations in Presence of Alternative Options
, M.Sc. Thesis Sharif University of Technology ; Sheikhzadeh, Mehdi (Supervisor)
Abstract
The present research investigates the conjunction of two areas of pricing and negotiation techniques to find a relationship between price and other key factors such as quality, quantity, time, etc. and observe the overall effect of these factors on how to design and implement negotiations over price in B2B environment. The research presents a model to describe the process of negotiation and applies quantitative methods to rank negotiable scenarios. This set of scenarios, then is sorted in a triangular model of negotiation strategy and is used as a roadmap for negotiation. Furthermore, researcher evaluates effective tactics and their implementation to drive negotiation sessions based on...
Optimal Pricing of “Software as a Service” with Risk Considerations
, M.Sc. Thesis Sharif University of Technology ; Sheikhzadeh, Mahdi (Supervisor)
Abstract
The recent advances in communications and processing technologies have paved the way for a new business model in IT industry. In this new model, frequently called “software as a service” or in short SAAS, software is hosted on servers operated by a software vendor instead of customers and all required transactions take place through the network, especially through World Wide Web. There are several differences between traditional business models and SAAS, including pricing and revenue model. Given the fact that vendor’s can monitor the customer usage, new and more complicated price structures such as usage-based pricing is possible, In this new business model. Although this pricing structure...
Value-Based Method in Selecting and Purchasing High-Tech Products
, M.Sc. Thesis Sharif University of Technology ; SheikhZadeh, Mahdi (Supervisor)
Abstract
People often conduct extensive searches in Internet, when they are involved in purchasing process of digital products. One primary challenge with the method of such searches is this fact that they heavily rely on a wide variety of technical characteristics, while buyers not being well familiar with such attributes. As such, they frequently fail to identify and purchase the right product. To address this issue, value-based approach is proposed by which the decision process is expected to be facilitated and become more efficient since it is based upon direct comparison of values gained by each product. In this thesis, as a case study for digital products, value attributes of mobile products...
Developing an Integrated Framework for Outsourcing in the Auto Industry
, M.Sc. Thesis Sharif University of Technology ; Sheikhzadeh, Mehdi (Supervisor)
Abstract
Outsourcing is currently a challenging issue in the auto industry. On one hand, outsourcing has be-come a competitive imperative for automakers due to its significant benefits. On the other hand, it involves many aspects of risks that could potentially hurt core competencies of a firm. As such, in the auto industry, it is highly critical to make optimal outsourcing decisions for which an integrated framework offering a holistic view seems quite necessary. In this thesis, based on four fundamental research questions of “Who?”, “What?”, “Whom?” and “How?”, an integrated framework for outsourcing in the auto industry is developed in order to identify effective outsourcing factors and associated...
A Study on the Effect of Multi-domain Mental Conceptual Network on Metaphorical Creativity
, M.Sc. Thesis Sharif University of Technology ; Khosravizadeh, Parvaneh (Supervisor)
Abstract
This thesis was an attempt to find the effect of having multi-domain conceptual network on metaphorical creativity. The purpose of this research was to answer the following question: By extending and expanding the mental conceptual network, could one increase their potential creativity; In other words, is expansion of the mental conceptual network one of the parameters of creativity or not.To answer this question, a questionnaire and a test were developped. Through the questionnaire, we divided the sample group into the test and control groups. And the test indicated how creative each individual is.There were three different ways the sample group was divided. The criteria for dividing the...
Toward an Integrated Framework for Supply Chain Performance Measurement
, M.Sc. Thesis Sharif University of Technology ; Sheikhzadeh, Mehdi (Supervisor)
Abstract
Proficient management of Supply Chain (SC) necessitates an efficient evaluation of SC performance. This highlights cardinal role of performance measurement in management of SC. However, SC has multidisciplinary nature in its wide spectrum of activities including planning, control and coordination of intra- and inter-firm players from upstream suppliers to downstream customers. As such, performance measurement of SC is a quite complex task and an effective assessment can significantly help enterprises in achieving their business goals. Objective of this study is to provide a comprehensive structural framework to facilitate assessment of various aspects contributing on SC performance....
Analysis of Success Factors in Technological Cooperations in Nanotech Industry-a Multiple Case Study
, M.Sc. Thesis Sharif University of Technology ; Sheikhzadeh, Mehdi (Supervisor)
Abstract
Innovative small tech companies are required to often have cooperation with large companies in order to scale-up and commercialize their products. Such cooperation is referred as “Technological Cooperation” since it relies on development and commercialization of technology. In this research, as a multiple-case study in the arena of nanotechnology, five cases of technological cooperation are analyzed and key successful factors are identified. In this endeavor, 15 comprehensive interviews were conducted with both small tech companies and technology applicant companies, including experts of Nanotechnology Innovative Council (INIC) – playing the role of a mediator. Due to lack of a comprehensive...
Capability and recruitment patterns of trunk during isometric uniaxial and biaxial upright exertion
, Article Clinical Biomechanics ; Volume 23, Issue 5 , 2008 , Pages 527-535 ; 02680033 (ISSN) ; Parnianpour, M ; Nordin, M ; Sharif University of Technology
2008
Abstract
Background: Work-related risk factors of low back disorders have been identified to be external moments, awkward postures, and asymmetrical dynamic lifting amongst others. The distinct role of asymmetry of load versus posture is hard to discern from the literature. Hence, the aim of this study is to measure isometric trunk exertions at upright standing posture at different exertion level and degree of asymmetry to further delineate the effects of exertion level and asymmetry on neuromuscular capability response. Methods: Fifteen healthy volunteers randomly performed trunk exertions at three levels (30%, 60%, and 100% of maximum voluntary exertion and five different angles (0°, 45°, 90°,...
Syllable duration prediction for Farsi text-to-speech systems
, Article Scientia Iranica ; Volume 11, Issue 3 , 2004 , Pages 225-233 ; 10263098 (ISSN) ; Nayebi, K ; Sheikhzadeh, H ; Sharif University of Technology
Sharif University of Technology
2004
Abstract
In this paper, two different statistical approaches are used for duration prediction of the Farsi language. These two statistical models are Neural Networks (NN) and Classification And Regression Trees (CART). The first step in this work was to create a database and develop a flexible feature extraction and selection module. In the next step, the output of the feature selection module was used to train both models. The results of the trained models are further studied to determine the most important parameters affecting the syllable duration in Farsi, The model accuracy is evaluated by using separate training and test data. In the third step of this work, ah automatic rule generator module...
Face Forgery Detection Through Statistical Analysis and Local Correlation Investigation
, M.Sc. Thesis Sharif University of Technology ; Ghaemmaghami, Shahrokh (Supervisor) ; Amini, Sajjad (Supervisor)
Abstract
Existing face forgery detection methods mainly focus on certain features of images, such as features related to image noise, local textures or frequency statistics of images for forgery detection. This makes the extracted representations and the final decision depend on the data in the database and makes it difficult to detect forgery with unknown manipulation methods. Solving this challenge, which is called the generalization challenge in artificial intelligence literature, has become the main goal of researchers in this field. In this thesis, the focus is on extracting effective features for success in forgery detection and preventing the performance of the forgery detection network from...
Pricing of Service Advance Sale System with Risk Consideration
, M.Sc. Thesis Sharif University of Technology ; Sheikhzadeh, Mehdi (Supervisor)
Abstract
Today service sector is an important part of economy in many countries and it accounts for a great portion of GDP in developed countries. The importance of the service sector has led to an expansion in research worldwide on services. Service has some unique specifications that make it different from product and research in this field is more challenging than production field. Pricing is one of the great challenges in service sector. Due to its intangibility and perishability, managing and pricing of service is complicated and ervice firms consistently seek for method and approaches to better manage their demand, capacity and prices. Advance sale is an effective approach which is commonly...
Analysis of Launch Time in New Product Development With Risk Considerations
,
M.Sc. Thesis
Sharif University of Technology
;
Sheikhzadeh, Mehdi
(Supervisor)
Abstract
The importance of New Product Development (NPD) projects has been realized more and more in recent years. Among different decisions to be made in NPD process, one of the most critical decisions is about the best time to launch new product(s). Due to existence of many internal and external influential factors, determining the optimal launch time is often too complicated and it is quite hard to systematically analyze it. Despite risky nature of NPD, risk considerations in determining the optimal launch time have not been addressed in literature due to the mentioned complexity. In this research, we developed a model that takes in to account risk considerations while systematically determining...
A textural approach for recognizing architectural distortion in mammograms
, Article Iranian Conference on Machine Vision and Image Processing, MVIP ; September , 2013 , Pages 136-140 ; 21666776 (ISSN) ; 9781467361842 (ISBN) ; Fatemizadeh, E ; Sheikhzadeh, H ; Khoubani, S ; Sharif University of Technology
IEEE Computer Society
2013
Abstract
Breast cancer is considered as the most important cause of death among women. Architectural distortions are very important signs of breast cancer and early detection of them is a rewarding work. In this paper we propose a method to recognize architectural distortion from normal parenchyma. In our proposed method, appropriate features are extracted by the analysis of oriented textures with the application of orientation component of recent the state-of-the-art local texture descriptor called Monogenic Binary Coding (MBC). In addition, we transform Region of Interests (ROIs) to polar coordinates in order to highlight some specific patterns in mammograms. Various classifiers are used over a set...
Promoting the Potential Investors’ Trust in Investment Through Equity-based Crowdfunding Platforms in Iran
, M.Sc. Thesis Sharif University of Technology ; Sheikhzadeh, Mahdi (Supervisor) ; Talebian, Masoud (Supervisor)
Abstract
Regarding to the technology development during recent years, many businesses have lost their traditional style and lots of web-based services have emerged. Also, nowadays one of the most attractive business model is platform-based services. Among these, investment industry is not exceptional and crowdfunding platforms are known as new channel of investment. With respect to this fact that investment by itself can help the economic growth in countries and proper status of Iran from investment viewpoint, developing such platforms may facilitate the investment processes. Regarding to the researches, considering the high amount of uncertainty in platforms and investment processes, especially...
Analysis and Enhancement of Low Voltage Ride Through Of Wind Turbines with Brushless Doubly Fed Induction Generator
, Ph.D. Dissertation Sharif University of Technology ; Oraee Mirzamani, Hashem (Supervisor) ; Tohidi, Sajjad (Co-Advisor)
Abstract
Wind energy technologies guarantee low pollution and operational costs. Using a DFIG and a fractionally rated power electronics converter gives variable speed operation with a low cost drive train. As energy policy organizations have allocated a considerable quota of wind energy generation to offshore wind farms, the absence of slip rings and brushes in the brushless DFIG (BDFIG) is an advantage for offshore wind turbines where maintenance is vital and expensive. With increasing wind power penetration in power systems, grid code requirements are an important consideration for the ride-through capability of wind farms through voltage dips, particularly for multi- MW wind turbine generators....
Breach by the Player in Iranian Football
,
M.Sc. Thesis
Sharif University of Technology
;
Sheikhzadeh, Mehdi
(Supervisor)
;
Talebian, Masoud
(Co-Supervisor)
Abstract
Nowadays, companies trade with each other to prosper, and the role of trading in the growth of businesses is undeniable. Many of them procure raw materials from their suppliers or sell their products to retailers. A contract is the first step to form such interaction. In a contract, each company has specific purposes which are ambiguous at the time of signing a contract. These objects and expectations are determined at the beginning of a contract, whereas both parties of a contract are uncertain about the future circumstances. In many cases, the future conditions cause one party of a contract breaches and terminates it. One of the most common reasons for breaching is the emergence of a new...
Optical bistability in fiber ring resonator containing an erbium doped fiber amplifier and quantum dot doped fiber saturable absorber
, Article Applied Optics ; Volume 51, Issue 29 , 2012 , Pages 7016-7024 ; 1559128X (ISSN) ; Farshemi, S. S ; Sajjad, B ; Shahshahani, F ; Bahrampour, A. R ; Sharif University of Technology
2012
Abstract
In this paper we study the optical bistability in a double coupler fiber ring resonator which consists of an erbium doped fiber amplifier (EDFA) in half part of the fiber ring and a quantum dot doped fiber (QDF) saturable absorber in the other half. The bistability is provided by the QDF section of the ring resonator. The EDFA is employed to reduce the switching power. The transmitted and reflected bistability characteristics are investigated. It is shown that the switching power for this new bistable device is less than 10 mW