Sharif Digital Repository

Nowadays, air pollution has become one of the biggest problem of large cities and has numerous negative effects on the environment and people's health. The present research examines how various types of pollutants are distributed in an urban environment, depending on the type of arrangement in different places. Razaviyeh town (including nine 15-story buildings) in the 9th phase of Pardis new city in Tehran has been studied three-dimensionally here. The dimensions of each building in this complex are 12 x 13.5 meters and their height is about 45 meters. Thus, the dimensions of the computational domain used are estimated to be less than 0.02 square kilometers. In this research, computational... 

This project evaluates the feasibility of using waste salmon fish bones as the reusable and low cost solid catalyst support for synthesis of biodiesel from waste sunflower oil via transestrification method. Calcinated waste fish bone derived hydroxyapatite (HAP) was employed as the supporter for KOH & K2CO3 to prepare an efficient solid base catalyst for biodiesel production. The catalyst were characterized by SEM-EDS, XRD, FTIR, BET, TGA, ICP. The effects of catalyst preparation conditions (such as fish bone and KOH or K2CO3 calcination temperature, loading of KOH or K2CO3 on the support), reaction conditions (such as reaction time, methanol/oil molar ratio, reaction temperature and... 

There are different kinds of ownership structures. In every economy special kinds of these structures are common. These structures include Pyramidal ownership, cross-ownership, etc. These structures empower shareholders to make a gap between their cash flow right and ownership right in a special firm so they could control more firms with the same capital. These structures have their pros and cons, like the internal capital market and tunneling. Of important factors affecting these structures are Legal protection of minor shareholders, shareholder concentration, and largest shareholder. In this research, we find that, unlike most countries, there is a negative relationship between a firm's... 

Despite adoption of HR analytics and the recognition of its importance by senior managers, its effective implementation in organizations remains a challenge. Given the benefits of HR analytics for organizations and the relative readiness of organizational structures to leverage it, this study seeks to answer the question: “How can HR analytics processes be effectively implemented in organizations?” Establishing an empirical foundation for improving existing theoretical models can significantly contribute to advancing this field. Using a single-case study approach, this research investigates the implementation of an employee engagement system through Officevibe software in a startup operating... 

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...