Sharif Digital Repository

Focusing on developing the EEPS (Energy Electric and Power System) based on the SG (Smart Grid) infrastructure to achieve implementation of EI (Energy Internet) ultimately, in order to analyze and manage the energy/power consumption, requires a robust embedded EMS (Energy Management System) to implement real-time LF (Load Forecasting), prevent the power waste and realize consumption management which eventually leads toward the smart industries/buildings. STLF (Short Term Load Forecasting) is an essential component that an industrial plant requires to manage the power, regarding the load fluctuations during production, and compulsory requirement of cost mitigation. This thesis, in order to... 

Since traffic lights are the only mechanized system at street level, their operation mode affects traffic congestion. Since traffic lights organize vehicles at crossways, the target of traffic light smartification is to reduce waiting time based on the density of traffic flows. There are many topics that work in this field to recognize traffic before making any decision based on traffic. Hence, if it is possible to introduce an algorithm for change static timing and predetermined timing of the traffic lights, it can affect the density of traffic at the large scale. This dissertation introduces an algorithm to reduce traffic congestion using traffic lights and correct timing. In this case,... 

The fundamental goal of communication networks is to transfer messages across the network between the nodes. Often, maximizing the information flow which is limited by connectivity of the network could be interesting. The concept of connectivity is divided into edge and vertex connectivity. If our focus were on the vertex-connectivity, connected dominating sets (CDS) could be a valuable tool. Obtaining (fractionally) vertex-disjoint connected dominating sets which are called fractional CDS packing presents a backbone to get an information flow matching the size of connectivity. In this thesis, we will present a distributed algorithm that is given a communication network with n nodes and... 

Approximate Agreement (AA) is one of the most important issues in distributed networks in which non-faulty processes execute a voting algorithm to reach the values that are very close to each other. AA for Partially Connected Networks (PCNs) is very limited because a node may not have a complete view of the whole network which makes it difficult to reach the convergence. This research proposes a convergent Fuzzy algorithm for synchronous distributed networks in the presence of faulty or Byzantine processes. When each node receives a new value from its neighbors,it runs the convergent Fuzzy algorithm. If the received value is not in the expected range of values, the processor can discard the... 

In a distributed system, each solution for the problem of Byzantine Agreement requires that some of correct processes reach a common decision value from a set of proposed values while Byzantine processes may behave arbitrary. This problem is one of the most fundamental problems in the theory of distributed systems. While the problem has been widely studied in fully-connected fixed networks, few studies have been carried out in the context of self-organizing mobile networks such as Mobile Ad-Hoc Networks.
This research presents a randomized consensus protocol with three additional modules for the case of dynamic networks: Participant Detectors, Failure Detectors and Maintainer. We assume... 

Common Object Request Broker Architecture (CORBA) is a standard for hybrid applications that is designed and supported by Object Management Group (OMG). This standard defines protocols and Relational Data Model Objects / Services which can be connected into heterogeneous software (written in different languages). So we can use CORBA to share the distributed object platform, without worrying about where they are located or who has designed them. CORBA can package the codes (in some programming languages) and add the packaging information, such as the ability to execute the codes and how to implement them. So this package or object code can execute some other programs or CORBA objects that... 

Using energy storage systems has been remarkably improved the energy systems efficiency and reliability indicators of the system and also reduced the operating costs of these systems. Thus using them in an energy system would count as an advantage. Lately, the procedure of implementation of these systems has been studied widely and various motives behind implementing them have been reviewed. For example, the effect of cost optimization in electrical vehicles on reliability indicators from the load management perspective can be addressed. Therefore this thesis has studied the effect of electrical and thermal storage systems on the reliability indicators of an energy hub and the effect of... 

Occurrence of natural disasters such as flood, windstorms, tsunamis and earthquakes has caused striking effects on critical infrastructures like power systems in recent decades. There are some examples of high-impact low-possibility (HILP) events which causes catastrophic effects on power systems. Traditionally, planning and operational studies of power system have been run taking into account some reliability metrics. Although, the reliability indices can represent the ability of a system in confronting with possible failures of components, they are unable to efficiently consider the effects of severe events such as earthquake and other HILP events. Moreover, traditional power systems were... 

The objective of the present research work has been the development of a model of optimal distribution electrical energy which may include distributed generators. Electrical distribution company has the option of receiving electric power from distributed generators owned by customers (Private Companies), DGs belonging to the electrical distribution company and purchase of power from market (high voltage network). The electrical distribution company would alternatively be able to sell surplus of its generation to the power market (high voltage network). The model of distribution system depicts the flow of electricity in each hour interval. The restrictions and bounds are the flows in each... 

Information and communications technologies have affected the human world rapidly, which challenges the facing today’s information society. Extensive use and impact of these technologies in different aspects of human life have led to an information revolution. This revolution, changes in our understanding of the human nature and physical world. The human is an information organism among the other agents which is living in the informational environment, that is called the infosphere. Moreover, the information revolution has caused to emerge of “Bitcoin”; a phenomenon that is changing economic relations. Bitcoin is a “crypto-currency” and “encrypted payment system” that relying on a... 

Motif finding problem in biology is a search for repeated patterns to reveal information about gene expression, one of the most complex subsystems in genomics. ChIP-seq technology abled researchers to investigate location of protein-DNA interactions but analyzing downstream results of such experiments to find actual regulatory signals in genome is challenging. For many years, applications of motif finding had models based on limiting assumption as an exchange for lower computational complexity. Results: AKAGI program is build upon upgraded methods and new general models to investigate statistical and experimental evidences for accurately finding significant patterns among biological... 

Developing distributed systems is always harder than centralized systems, because in distributed systems there are problems like how nodes must collaborate with each other, throughput, latency and so on, that is not concerned in centralized systems. For solving this problem, It's better to have an abstract view of system to show this concerns. one of the coordination languages to have that abstract view of system, is Reo language. Reo language is a coordination language that describe how components of systems, can coordinate with each other. This project is built to decrease the distance between designing and implementing. In this project an abstract view of system which is in Reo language,... 

Verifiable secret sharing (VSS) is one of the basic problems in the theory of distributed cryptography and has important role in secure multi-party computation. In this case, it is tried to share a confidential data as secret, between multiple nodes in a distributed system, in the presence of an active adversary that can destroy a number of nodes, such that the secret can be reconstructed with the participation of certain size of honest nodes. There are two types of active adversary; Static and dynamic which the latter can change it’s corrupted nodes among the protocol. VSS protocols have different types of algorithmic complexity and one of these definitions, is the use of broadcast channel... 

A workflow management system is a software system which manages and coordinates the operational tasks of an organization. Typically, the def­ inition of a workflow involves human and computer resources and tools on various geographic locations, and thus the concerns of distributed systems are one of the main challenges in this domain. Following this,allocating various resources to different tasks of a workflow and schedul­ ing them in a manner which satisfies some predefined constraints is one of the new and fundamental challenges in this field.The main goal of this research is to design an agent-oriented workflow system which utilizes a novel method for resource allocation and schedul­ ing... 

One of the most important characteristics of real-time systems is executing tasks before their specified deadlines. The tasks’ execution may require several resources like processor, I/O ports, and data structures. Some of these resources may be shared between several tasks and their availability is important in executing tasks before the deadlines. Allocating shared resources which are used in mutually exclusive manner often encounteres some problems such as priority inversion and deadlock. Resource access protocols are used to minimize or eliminate these problems. The effect of using these protocols issupporting tasks’ execution before their deadlines. To meet deadlines is of decisive... 

In distributed systems, a huge amount of data is dispersed among different nodes; centralization of this data is infeasible due to communication and storage costs. In addition, Databases with high dimensional data objects are becoming more prevalent is many areas. When the dimensionality increases, the volume of the space increases so fast that the available data becomes sparse. This sparsity is problematic from many aspects. In order to obtain a statistically sound and reliable result, the amount of data needed to support the result often grows exponentially with the dimensionality. Also organizing and searching data often relies on detecting areas where objects form groups with similar... 

This dissertation proposes a new platform and a new software for evaluation of urban Water Distribution Network (WDN) resilience. Resilience is considerd as the ability of an infrastructure to come back to steady state after being affected by any environmental or man-made disturbance. WDN, as an essential infrastructure, has major role on resilience and sustainability of cities and communities. Today, uninterrupted performance of WDN is a basic need of people who live in cities. This uninterrupted performance becomes bolder in face of man-made or natural disasters like earthquake. The uninterrupted performance of a system is dependent on the system’s resilience. Majority of researchers... 

In various industries, particularly in the process industries, computational fluid dynamics (CFD) stands as the predominant method for simulating distributed systems. In these methods, discretization of system geometry and partial differential equations is necessary, resulting in a system of algebraic or ordinary differential equations, or a combination thereof. The significant computational demands arising from the extensive number of equations derived from dynamic system simulations highlight the necessity for substantial processing and computing power. The objective of this project is to reduce the computational load associated with solving these equations. It focuses on utilizing machine... 

In this work, a non-isothermal model of natural gas in pipelines including mass, momentum and energy balance equations are used as model equations for modeling and state estimation in gas pipeline systems. An algorithm is proposed to handle the discontinuities that appear in the dynamic model of a GTN. The states of GTN are estimated using the continuous/discrete form of the extended Kalman filter for two benchmarks and some heuristic rules for sensor placement in a GTN are concluded. Also, a framework for distributed and decentralized state estimation in high-pressure and long-distance gas transmission networks (GTNs) is proposed. Some heuristic rules are suggested for system decomposition... 

Fossil fuel are energy resources in decline. In recent years, fuel cell have become as a source of energy to replace conventional systems .Among the various types of fuel cells, PEMFCs (proton exchange membrane fuel cells) possess a series of highly advantageous features such as a low-operating temperature, sustained operation at high-current density, low weight, compactness, potential for low cost and volume, long stack life, fast start-ups and suitability for discontinuous operation. Water management is one of the most critical and challenging problems. There is a delicate balance between the membrane hydration and avoiding cathode from flooding. Cathode flooding occurs when the water...