Sharif Digital Repository

The rapid deployment of district heating systems in local energy markets and increasing the number of small-scale heat producers along with the expansion of local electricity markets increase the need for a transaction framework to manage the transactions between local participants in both heat and electricity markets. This paper presents a peer-to-peer thermal energy transaction framework to manage the transactions between small-scale heat prosumers. This framework enables small-scale thermal energy producers and consumers to participate in the market as price maker agents. Moreover, the optimal strategy of heat market participants is determined by proposing a linear profit function for... 

Electricity companies have been under a great pressure to improve their technical and financial performances in order to survive and thrive in the deregulated environment. Therefore, these companies are seeking for innovative approaches to take the most out of the restricted resources. These approaches inherently concentrate the available budgets to the most critical components. In this regard, prioritizing the system components and identifying the most critical ones play a vital role in the planning and operation of the system. This paper presents a novel approach to prioritize power transmission system components. In the proposed methodology, a criticality factor is defined and implemented... 

Demand response programs can be regarded as a risk management approach for retailers in electricity market. In case of high wholesale electricity price, implementation of demand response will reduce the economic risk exposure of the retailer. Realization of demand response requires investment in various sectors, and therefore, there is a need for economic valuation in order to determine the economic profit gained. This paper attempts to evaluate the economic value of demand response programs by the use of real option valuation method. In this regard, at first demand response programs are converted to option contracts. Then, the profit of retailer resulting from the demand response is... 

Efficient operation of electricity markets necessitates a penalty mechanism to penalize market participants who do not fulfill their market obligations. However, the traditional penalty mechanisms that have been successfully implemented in wholesale electricity markets may result in unintended consequences in transactive markets where the participants have uncertain supply or demand. In this regard, this letter investigates main challenges of applying traditional penalty mechanisms in transactive energy markets. Some efficient strategies are also proposed to operate the transactive markets in such a way that guarantees its security as well as liquidity. © 1969-2012 IEEE  

Going back and taking a quick glance at the history of developed countries prove that prosperity of any society is tightly intertwined with resiliency and sustainability of its preliminary infrastructures. Surely, in modern societies, electricity is among the most important infrastructures whose resiliency and sustainability are a key driving force toward development of the society. This is verified by the fact that since the industrial revolution, per capita electricity consumption has been taken as a key index showing the level of economic development and standard of living in a country. This paper focuses on the concept of resiliency and sustainability of electric power systems. The... 

Expanding the electricity market into the retail domain calls for inexpensive mass-produced smart devices that enable the small customers to participate in local energy transactions by managing the energy production/consumption and submitting buy/sell bids to the market. In this context, this paper presents a mathematically proven as well as practical approach for bidding of an autonomous smart transactive agent in local energy markets. To reach this goal, behaviors of both riskneutral and risk-averse agents selling energy to the market are modeled taking into account expected profit and risk criteria. Based on this modeling procedure, an optimal multi-step quantity-price bidding strategy is... 

Competition in the electric power industry urges utilities to not only reduce the investment costs, but also to reasonably cut the operation and maintenance expenses as much as possible, while keeping both power quality and reliability requirements met. Reliability-centred maintenance (RCM) has been proven to be in response to this dilemma in power systems and has been yet successfully applied in various engineering contexts. This study introduces a novel approach, as of the first steps of RCM implementation in composite power generation and transmission systems, to identify the critical components for the main sake of a more focused maintenance management. Criticality evaluation is, here,... 

The forecast errors for distributed energy resources (DERs) and hourly demands have contributed to power system uncertainties and additional risks in the day-ahead scheduling of electricity markets. In this paper, a risk-based approach is introduced to determine the stochastic solution of network-constrained unit commitment (NCUC) when additional uncertainties are embedded in the power system scheduling. The historical power market transaction data are used to model nodal injection uncertainties and reserve capacity requirements are considered to assess the solution of the risk-based NCUC. The proposed NCUC problem is formulated as a single-stage second order cone program which is a convex... 

Power systems are stretched across thousands of miles of diverse territories, often in remote locations, to generate and transfer the energy to geographically dispersed customers. The system is therefore subjected to a wide range of natural hazards which could potentially damage critical system components and cause interruption of electricity supply in some areas. To improve system resilience against natural hazards, management frameworks are required to identify hazardous areas and prioritize reinforcement activities in order to take the most out of the limited resources.Landslide is a natural disaster that involves the breakup and downhill flow of rock, mud, water, and anything caught in... 

Modeling and analysis of information system vulnerabilities helps us to predict possible attacks to networks using the network configuration and vulnerabilities information. As a fact, exploiting most of vulnerabilities result in access rights alteration. In this paper, we propose a new vulnerability analysis method based on the Take-Grant protection model. We extend the initial Take-Grant model to address the notion of vulnerabilities and introduce the vulnerabilities rewriting rules to specify how the protection state of the system can be changed by exploiting vulnerabilities. Our analysis is based on a bounded polynomial algorithm, which generates the closure of the Take-Grant graph... 

We study the translocation of stiff polymers through a nanopore, driven by the chemical-potential gradient exerted by binding proteins (chaperones) on the trans side of the pore. Bound chaperones prevent backsliding through the pore and, therefore, partially rectify the polymer passage. We show that the sequence of chain monomers with different binding affinity for the chaperones significantly affects the translocation dynamics. In particular, we investigate the effect of the nearest-neighbor adjacency probability of the two monomer types. Depending on the magnitude of the involved binding energies, the translocation speed may either increase or decrease with the adjacency probability. We... 

Combining the advection-diffusion equation approach with Monte Carlo simulations we study chaperone driven polymer translocation of a stiff polymer through a nanopore. We demonstrate that the probability density function of first passage times across the pore depends solely on the Péclet number, a dimensionless parameter comparing drift strength and diffusivity. Moreover it is shown that the characteristic exponent in the power-law dependence of the translocation time on the chain length, a function of the chaperone-polymer binding energy, the chaperone concentration, and the chain length, is also effectively determined by the Péclet number. We investigate the effect of the chaperone size on... 

The amount of rippling in graphene sheets is related to the interactions with the substrate or with the suspending structure. Here, we report on an irreversibility in the response to forces that act on suspended graphene sheets. This may explain why one always observes a ripple structure on suspended graphene. We show that a compression-relaxation mechanism produces static ripples on graphene sheets and determine a peculiar temperature Tc, such that for T