Sharif Digital Repository

Local scouring at the downstream of sluice gates in the erosive beds is one of the main concerns of hydraulic engineers because of the significant damage that it can cause to the hydraulic structures. It is important to control the local scour depth at downstream of hydraulic structures to ensure safety operation of these systems. Many researchers have conducted various studies to predict the maximum depth and diameter of scour hole and develop new methods in order to control this phenomenon. One way to overcome this problem is the use of apron, or non-erosive bed. In order to shorten the apron length or decrease the effect of the... 

In this thesis, the satellite constellation orbit design for regional coverage is investigated. The orbits of satellites in a constellation for Earth observation missions play a crucial role in performance and characteristics of the mission; for example the image resolution, the area of coverage, and the coverage interval. In this thesis the problem is to find the optimal initial orbital elements for meeting the earth observation mission objectives for one or several sites. The cost functions are the total coverage time, the maximum gap time, time average gap, altitude, and number of satellites. The problem is solved in a multi-objective manner for different combination of two of the above... 

Many embedded multicore systems can benefit from a memory hierarchy to bridge the processor/memory speed gap. Embedded systems usually utilize a cacheless architecture to avoid the unpredictable behavior. Unlike caches, scratchpad memories (SPM) are software controlled and hence the execution time of applications on such systems can be accurately predicted. Scheduling the tasks of an embedded multicore application and partitioning the available SPM budget among these cores are two critical issues in such systems. Often, these are considered separately, such a decoupled approach may miss better quality schedules. In this paper, we present an integrated approach to task scheduling and SPM... 

Nowadays marine-tourism industry, especially under water tourism, has become very attractive. Thus, numerous under water vehicles are designed and constructed. The primary objective of the present study is to design an underwater vehicle capable of carrying ten passengers. Tow system is proposed as propulsion system. Due to the high costs, noise and vibrations of existing propulsion systems in medium size vehicles which contradicts the goal of calm atmosphere for passenger, the proposing system seems suitable and pragmatic. Two-part tow system is utilized to enhance the stability of the under water vehicle named Towfish. In this study the structure of towfish is being designed. Then,... 

This paper provides and empirical investigation of individual labor supply of Iranian spouses in a collective framework in which gender ratio and plays a central role in the decision process in household. The data set is taken from the socioeconomic characteristics of panel survey over 2001-2004 and ten yearly headcount of Iran. We have conducted the parameters estimation and hypothesis testing by Semykina, A. and Wooldridge, J.M., (2005) generalized procedure of sample selection in panel data model. Our findings explore that females’ labor supply is affected significantly and strongly by the gender ratio, (total number of males over the females in provinces, both in urban and rural areas).... 

The Swaⅿpⅼanⅾ prograⅿ was ⅾeveⅼopeⅾ to ⅽonstrain the effeⅽtive fieⅼⅾ theories that ⅽan be ⅽoⅿpatibⅼe with quantuⅿ gravity. Our ⅾissertation foⅽuses on one of the ⅽonjeⅽtures of this prograⅿ، whiⅽh is known as the Ⅾark Ⅾiⅿension، that preⅾiⅽts the existenⅽe of a ⅿesosⅽopiⅽ fifth ⅾiⅿension of the orⅾer of (mev)−1 . Before exaⅿining the ⅾark ⅾi− ⅿension، however، we introⅾuⅽe soⅿe reⅼateⅾ ⅽonjeⅽtures. Our priⅿary goaⅼ is to stuⅾy the ⅾynaⅿiⅽs of the ⅾark ⅾiⅿension through ⅽosⅿoⅼogiⅽaⅼ observations. To this enⅾ، we begin by proviⅾing a brief overview of 5−ⅾiⅿensionaⅼ fieⅼⅾ theory anⅾ the resuⅼting speⅽ− truⅿ after ⅽoⅿpaⅽtifiⅽation. Next، we ⅾerive the Frieⅾⅿan equations for spaⅽes with ⅿore than... 

Lateral confinement is a proven method of increasing strength, stiffness and ductility of concrete columns. This is attributed to a created tri-axial stress state in the concrete core due to the confinement resulting in a higher level of endurable deviatoric stress. Plastic pipes are able to create such a confining medium in concrete-filled UPVC tube (CFUT) columns and therefore they can provide the concrete with some benefits of concrete filled steel tube (CFST) column system. Besides, these pipes are cheap, light and they are also easy to handle. Furthermore, they are resistant to corrosion or other forms of deterioration and recyclable and in this aspect, they are... 

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... 

Unmanned aerial vehicles (UAVs), particularly hexacopters, are increasingly used in agricultural spraying due to their high payload capacity and stable flight performance. However, changes in liquid mass during spraying alter flight dynamics, and fluid sloshing within the tank introduces internal disturbances that may affect stability. This study presents an Active Disturbance Rejection Control (ADRC) for velocity control of spraying hexacopters to maintain performance under varying mass and internal/external disturbances. A real tank was used to analyze variations in the fluid’s center of mass under different conditions, revealing a nearly spherical distribution. Based on this, a... 

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... 

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.... 

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... 

The increasing demand for communication bandwidth and limited spectrum availability have heightened the complexity of radio front-end circuits in IoT applications. Achieving spectral efficiency is a key challenge, particularly for IoT devices operating at specific frequency bands such as 315 MHz, 433 MHz, 868 MHz, and 915 MHz.Due to the limited linearity of the transmit path, harmonic distortion components, known as counter intermodulation (CIM) products, are generated. These CIM products can directly fall into the receiver (RX) band or enter it via cross-modulation, thereby degrading the frequency division performance. Additionally, CIM products can interfere with protected bands, violating...