Sharif Digital Repository

Video-on-demand platforms are a type of disruptive innovation that has transformed the audiovisual industry by providing users with access to digital video content via the Internet. VOD platforms were introduced in Iran in the Iran, with a focus on analyzing changes in the industry's sectoral innovation system. Data was collected through unstructured interviews with 14 experts in the audiovisual industry, as well as by reviewing relevant documents, news articles, and public data. Thematic analysis was used to code the findings. The results of the research indicate that the emergence and development of VODs have had a significant impact on all aspects of the audiovisual industry's sectoral... 

One way for businesses to grow and compete, in any age (especially the digital age), is to create a Brand Relevance through creating or finding, and then owning new categories or subcategories. In this way, instead of beating competitors; they become irrelevant by enticing customers to buy a new category or subcategory for which other alternative brands are not considered relevant. Firms traditionally rely on interviews and focus groups to identify these subcategories and customer needs. Nowadays, with the growth of social media, user-generated content (UGC) is also a good alternative source. However, Due to the large size of UGC and the non-informative or repetitive data it contains,... 

Double cantilever beam (DCB) specimens were prepared according to standard surface mount technology (SMT). The samples were stored inside an environmental chamber at two different relative humidity values (i.e. 40 or 100%) for either 2 or 4 hours. Then they were aged at 25ºC, 75ºC or 125℃ for the same time. Finally, after being cooled to room temperature, fracture tests were performed under mode-I loading conditions at a strain rate of 0.03 s-1 at room temperature. Storage time did not have a significant effect on the fracture behavior. The fracture load and energy of the solder joints decreased significantly when the temperature was increased from 25 to 75℃. By further increase in the... 

One of the major challenges in Additive Manufacturing is the creation of residual stresses due to the high temperature gradient in the solidification zone. This will cause problems such as cracks in the structure, metallurgical defects as well as deformation and dimensional accuracy reduction in the finished product. The purpose of this study is to perform mathematical modeling and computer simulation of the selective laser melting process (SLM) to predict these stresses as well as identify the effective parameters on this phenomenon. The conditions were adjusted in this model with the actual coefficients of the device. Additionally, the powder used in this project is Ti6Al4V material. By... 

In the first description if we describe technology as a tool, Communication technologies or media should be consider as the most important element of today's technological world. This research is going to cover reconsidering and recreating the mean of media based on the Ideas of JacquesDerrida. In this regard, two major dichotomy is evident in the public understanding of media. meanwhile "media versus message" and on the other hand opposition between "media and audience". So deconstruction in the face of these binary oppositions, want to read out the notion that message is superior to media, and on the other hand to deconstruction of the hegemony of the media on the audience  

A new strategy for enhancing the efficiency of TiO2 dye sensitized solar cells (DSSCs) doped with Ni ions with different molar percentages (i.e., 0, 0.5, 1, 5 and 10 mol%) was reported. The samples were prepared by sol-gel route and characterized by means of XRD, DRS, UV-visible, FESEM and photovoltaic measurment techniques. It was found that Ni-doped TiO2 nanoparticles had a mixture of anatase, rutile and brookite crystal structures. Moreover, the band gap energy was decreased with increasing Ni molar ratio, The highest cell efficiency of 5.4% was achieved for 1mol% Ni-doped TiO2, being 42% greater than that of pure TiO2 nanoparticles  

Physical and mechanical properties of cast alloys is partly a function of the morphology and volume fraction of phases from freezing. The microstructure of the eutectic solidification is function of physical properties (especially mobility and surface tension) and the volume fraction of phases involved in the evolution. The prediction of solidification microstructures will be very helpful for improving the mechanical properties of casting alloys and designing of new families of alloys. The theoretical study of the formation of eutectic microstructures is very difficult and almost impossible in general cases and empirical studies are expensive. The purpose of this study is to predict the... 

More than 70 weight percentage of using parts in diverse industries (such as military, civil, automobile productions and etc.) are produceed by the casting processes. For each one of the casting procceses, mold cavity is requisite for arrived molten metal in the mold cavity to get eventuated as a solidified part. Based on mold ilk, if the mold is permanent, the cast part must be capable to be remoeved from the the mold inside. For the non-permanent mold (asssuming multi-piece and non-monolithic), if the model requires to be removed from the mold inside after molding and before casting, only model (no cast part) has to be moldable (why for removing the solidified cast part from the... 

Lead-containing solder alloys in particular Sn-37Pb is the most common alloy used in electronics industry, this alloy has the good mechanical properties and excellent wetting properties and low prices. Recently, increasing environmental and health concerns over the toxicity of lead combined with strict legislation to ban the use of lead-based solders have provided an inevitable driving force for the development of lead-free solder alloys. A group of these lead-free solders are nanocomposite solders that because of having the reinforcement nano particles exhibit lots of unique properties, such as good mechanical and thermal properties. The aim of this research produce a new tin base... 

In this thesis, by deliberately embedding “emplacements” in the system to locally break the inversion and the time reversal symmetries, the manifold of all possible microstructures is navigated in pursuit of the one that can give rise to maximal magnetoelectric effect mediated by elastic energy of piezoelectric-piezomagnetic phases via their interface --- needless to mention the low intensity of such an effect in single-phase multiferroics. The configuration with the maximal coupling is sought within the context of phase-field modeling. In order to numerically track the conserved dissipative dynamics of the interface (namely, the Cahn-Hilliard equation) --- that is nonlocal by the nature of... 

bulk metallic glass Unlike metal materials that have a crystalline structure, amorphous glass is an amorphous material with an irregular atomic structure that simultaneously has the same physical properties as metals. Due to the absence of crystal defects such as dislocation and grain boundaries, these materials show unique mechanical properties such as high strength and elastic strain, abrasion resistance and proper corrosion. However, their plastic deformation is heterogeneous, concentrated, and accompanied by sudden failure. Unlike metals, these materials do not have a long-range crystalline order, and their atomic structure includes short-range and mid-range order. The short-range order... 

Hyper-redundant manipulators have large number Degrees of Freedom. Because of their redundancy, such manipulators have the advantage of obstacle avoidance, overcoming singularities and intrusion into highly constrained environments. The most challenging task in designing hyper-redundant manipulators is the synthesis of actuating mechanisms with appropriate kinematics and effective power supply. Most of previous techniques in implementing hyper-redundant robots have the disadvantages of: -Using large number of actuators, -Heavy weight due to large number of actuators, -Complexity of the control system due to need of synchronizing subsets of motors. In this thesis a novel hyper redundant...