Sharif Digital Repository

Today, pure titanium and its alloys, including Ti-6Al-4V and Ti-6Al-7Nb, are widely used in medicine for manufacturing orthopedic and dental implants, screws and plates for bone fracture fixation, and heart valves. However, due to problems such as low hardness, low wear resistance compared to other alloys such as Co-Cr-Mo alloys, and lack of excellent biocompatibility, surface modification of these alloys is necessary. Also, pure titanium and its alloys are inert materials and after being placed in the body environment, a layer of fibrosis surrounds them and causes them to detach from the host tissue. Therefore, by using surface modification methods, the surface of these materials can be... 

Sequencing and scheduling of jobs are decision making processes that are used in many manufacturing and service industries. In the traditional scheduling models, it is assumed that the values for all the problem parameters are constant and known in advance. However, production environments in the real world are subject to many sources of uncertainty or randomness. This research investigates three different types of stochastic scheduling problems. In the first case, the problem is minimizing the number of tardy jobs in the class of static list policies, where the job processing times are random variables. For this case, the stochastic problems in single machine and flow shop environments are... 

Today, advances in technology caused the emergence of a need for intelligent systems which can operate without human supervision, and have variety of applications in security, industry, transportation and sport events. Most of these systems require faster and more accurate object tracking. Lots of surveillance and computer vision applications need a process to detect and track objects. For example, the exact location of objects or people is part of the input for applications like movement analysis, counting the number of items, and recognition of people’s behavior. Occlusion is one of the major obstacles in performance of auto-tracking systems. There are several methods to address this... 

The electric vehicle inverter, as one of the most important components of the vehicle, needs to have a high efficiency and also be able to work at high temperatures. Due to passing a large part of the battery power through this part and being one of the components that has the biggest power in an electric vehicle , traction inverter Efficiency has a big impact on the total efficiency of the whole vehicle . By increasing the battery voltage of electric vehicles, in order to achieve a higher charging power, the electric vehicle inverter must be able to withstand a voltage of about 800 volts input .On the other hand, in electric car inverters, the goal is to reach a power density of 100kw / L.... 

Based on the importance of DNA/RNA binding proteins in different cellular processes, finding binding sites of them play crucial role in many applications, like designing drug/vaccine, designing protein, and cancer control. Many studies target this issue and try to improve the prediction accuracy with three strategies: complex neural-network structures, various types of inputs, and ML methods to extract input features. But due to the growing volume of sequences, these methods face serious processing challenges. So, this paper presents KDeep, based on CNN-LSTM and the primary form of DNA/RNA sequences as input. As the key feature improving the prediction accuracy, we propose a new encoding... 

In this project, in order to model the flat rolling problems, an analytical method based on Bezier functions has been presented. To this goal, using the Bezier functions, the velocity field of the flat rolling has been stablished and the volume constancy condition and velocity boundary conditions have been considered in calculations. Using the achieved velocity field, the strain rate and strain fields has been determined. Then, with derived fields, power, pressure, and force of the deformation in flat-rolled billets from different materials such as copper, aluminium and steel have been calculated. To verify the accuracy of the results, the rolling process has been carried out on the... 

Speech synthesis and its applications have been very attractive recently. The main purpose of this technique is to produce a speech signal with natural characteristics of human speech like prosody and emotion. Among all existing methods for speech synthesis, statistical parametric speech synthesis methods are more promising because ofhigher flexibility in comparison to other methods. One of the applications of speech synthesis is speech to speech translation. In these systems, the generated voice in target language should have the same characteristics as the input voice in source language. The main purpose of this research is to review and evaluate the cross lingual speaker adaptation... 

Surface piercing propellers are particular type of supercavitating propellers that are commonly used for High-speed vessels. Most studies on this type of propellers has been investigating the hydrodynamic forces. But in recent years with increase in SPPs diameter used in vessels, structural analysis of this type of propellers is considered. For this purpose, studies on the stresses exerted on the propeller structures under load is done with the help of Hydro elastic methods. In this type of analysis, structura of propeller is intended to be flexible and Displacements under pressure checked and Tensions resulting from it are studied.
The present Thesis using ANSYS software to analyze a... 

The increasing demand for autonomous vehicles and reliable communication protocols and hardware interfaces, such as CAN bus and USB, underscores the necessity for stable clock sources that maintain a low temperature coefficient (TC) over wide temperature ranges. This demand is particularly emphasized in applications such as wearables, network sensors, downhole devices, WSNs, and IoT, where long-lasting battery life and frequency-stable clock sources over a broad temperature range (e.g. -20 °C to 100 °C) are crucial. Traditionally, variations in frequency caused by temperature have been mitigated by employing off-chip components like crystals or ceramic based oscillators, but this approach... 

Pricing plays an important and essential role in the profit and income of companies. The importance of pricing is not only related to its role in the company's profitability, but it also changes the customer's understanding and loyalty towards the company and can create the company's reputation or destroy it. Determining the right price will increase product sales and increase customer loyalty and create a competitive advantage for the company. One of the most important and influential variables in product pricing is the amount of demand. The main challenge of companies for product pricing is the uncertainty in their demand. In order to deal with this problem, data-driven pricing is used.... 

During the last few years researchers have drawn much attention to HSLA steels because of the application of these steels in many industries. Ferrite-martensite dual phase(DP) steels are one of the most common HSLA steels which are currently used. Combination of these two phases provides good strength along with good ductility. Joining and welding of these steels has always been an important challenge. The aim of this study is to examine applicability of TLP method for joining and dual phase processing of this steels at the same time. Microstructural and mechanical examination of the bonded specimens showed that isothermal solidification occurred during holding for 50 min at the...