Sharif Digital Repository

Noise or noise pollution, is defined as an unwanted sound, produced mostly by motor vehicles in urban areas. If the noise exceeds its limit, adverse effects on users and citizens are expected. Thus the assessment of the noise level and its comparison with allowable values is mandatory. Traffic induced noise depends upon different factors such as traffic, weather, and, sound barriers. Noise pollution study has a long history all over the world. Many studies, mostly representing the outdoor noise pollution models, have been done in recent years. This paper presents an assessment of traffic-induced noise in a heavily traveled tunnel, locally referred to as Resalat tunnel, which is located in... 

Data collected from street networks show that travel time in urban street networks is a stochastic variable, whose range of variation increases with the congestion level. Work and school trips comprise the major part of morning peak volumes, whose common characteristic is that they need to be made on time. For this reason, these travelers are pessimistic in their route choice, and try to choose routes which are more reliable. Travel time standard deviation is one of the common measures for estimating travel time reliability that is related to properties of day-to-day travel time distribution on a particular route. Based on the empirical data collected from Tehran street network, this paper... 

With the advancement of automotive industry, the number of electronic systems that need to communicate with each other has increased. An effective strategy to meet these growing demands is using bus-based protocols, which can establish safe communication among numerous nodes with reasonable cost, weight, and space requirements. The objective of this thesis is the design and implementation of a transceiver based on the FlexRay protocol. The significance of this protocol lies in its ability to provide higher data transmission rates compared to other protocols like CAN and LIN, and its role as the foundational communication medium among various domains in modern vehicle architectures. In this... 

In this thesis, we introduce a novel Artificial Intelligence (AI) system inspired by the philosophical and psychoanalytical concept of imagination as a ``Re-construction of Experiences". Our AI system is equipped with an imagination-inspired module that bridges the gap between textual inputs and other modalities, enriching the derived information based on previously learned experiences. A unique feature of our system is its ability to formulate independent perceptions of inputs. This leads to unique interpretations of a concept that may differ from human interpretations but are equally valid, a phenomenon we term as ``Interpretable Misunderstanding". We employ large-scale models,... 

Quantum entanglement is an essential resource in quantum information processing, such as quantum communication and quantum computing. Although entanglement is critical for practical implementations in these fields, creating and transmitting entanglement without altering the states is challenging. External noise may destroy or weaken the entanglement. Consequently, there is a need for methods to improve entanglement. Entanglement distillation is an effort to address this issue. It is a process where, probabilistically, a smaller number of strongly entangled states are created from a fixed number of noisy entangled states. This process is carried out using only local operations and classical... 

In line with developments in the technology of integrated circuits, transistors are implemented in silicon. Although the price is reduced; design is more complicated, which causes the efficiency and power consumption to face some difficulties in such design. The reason why modern GDI-based circuit is the focus of attention is that in designing a digital circuit, less power is required while more efficiency is obtained. Lowering the complexity of the logic circuit can bring about reduction of power consumption and propagation delay and decrease the circuit space. GDI-based integrated circuits resemble MOSFET transistors but have fewer transistors and higher performance capability. This study... 

Optimization of heat transfer in vehicle's underhood which contains radiator, cylidir block, cylinder head and … with minimum pressure loss on engine is one of the most important problems of the car companies in all over the world.To design some cooling parts like simple radiators which doesn’t have a effective cooling effect, we can use equations.but for more complicated geometries which is morte efficient we have many complicated solutions.So in this condition computationl analysis and laboratories play an important role.in this condition we should consider that producing a sample and the process of verifying the result of test is too expensive.So recently the car companies prefare... 

The growth of high voltage dc-dc switching power supplies in various applications such as medical, industrial and laboratory research is undeniable. Design of these power supplies, respect to their expectation have some restrictions. Among the main characteristics, appropriate output voltage regulation, high efficiency, fast dynamic response and low EMI problems, are expected. Transformers constraints as one of the key components of high voltage dc-dc switching power supplies, plays essential role in the selection of converter topology and its control algorithm. In this thesis, first, with regard to issues of high frequency and high voltage transformers, provides a good approximation model... 

This research aims to design and evaluate a generalized algorithm for predicting knee joint angle during gait. To achieve this, electromyography (EMG) sensors were attached to muscles involved in knee joint motion to record their activity. By analyzing and extracting features from these signals, a machine learning model was developed to establish a relationship between the EMG signals as input and the knee joint angle as output. The study prioritizes a model that can be quickly adapted to new users with minimal data, making meta-learning the core approach. This method shares similarities with transfer learning and was trained using two datasets, each containing data from over 10 subjects.... 

In this research, non-isothermal annealing process at temperatures ranging between 400°C to 830 °C was investigated in warm and cold-rolled austenitic stainless steel 304L. First, the wide variety of austenitic to martensitic structure was produced by the multi-pass rolling process at room temperature -8 °C, 200 °C, and 280°C. The n exponent in Olson-Cohen equation was governed 2.83 after non-linear curve fitting to assess the fraction of deformation-induced martensite as a function of strain. Afterward, Abaqus/Explicit method was utilized to achieve the stored energy and plastic strains distribution through the thickness. Then, Cellular automata and Galerkin-finite element models were... 

Raising number of vehicles and increasing tendency of people to possess their own cars have posed a lot of expenses on users. One of the most significant of them is the time it takes to travel between origin and destination. Several researches have been conducted so far in order to evenly distribute travel times among transportation network users. A variable that has been neglected in many of these studies is travel time variability. Users, obviously, need to know not only the travel time, but also the probability of varying this time. In this research, an analytical model has been developed on a geometrical basis that includes both traffic conditions and intersection characteristics to... 

The huge jam complex unit in assaluye (tenth olefin plan) with the capacity of 1320000 tons of ethylene and 306 thousand tons of propylene is considered as one of the biggest olefin units of all world. It is found that the bottleneck of increasing the capacity is the demethanizer unit. In this thesis, after simulation of the demethanizer towers, capacity enhancement is accomplished along with comparing the outlet stream with PFD data in terms of mass fractions, temperature and pressure. in addition, the hydrolic treat ment of towers is checked. This is continued till a problem occures in each of towers. In the bottleneck capacity , a solution and some changes have been offered. Thereafter... 

During the past two decades, laminated composite structures have been used for many engineering applications, including aerospace, automotive, sport equipment and pressure vessels.
In spite of the excellent properties of strength to weight ratio, composite structures are vulnerable to failure when subjected to impact and vibration. It is well known that impact damage may severely degrade the strength and stability of laminated composite structures. For this reason the effect of impact on composites has been a subject of extensive research.
There are several ways of decreasing the vibration energy of structures, such as diminishing the source energy, designing structures...