Sharif Digital Repository

A new approach for optimal reserve determination and cost allocation in the pool-based and disaggregated market model using a well-being framework is presented in this paper. In the proposed method, customers have the chance to specify the risk level which they are willing to accept. Firstly, the energy market is cleared, and afterwards the reserve market is cleared such that the required risk levels of different customers are satisfied. Then, according to the required risk levels and the provided reserve, the cost of reserve is allocated between the different customers with different reliability requirements. For fairly managing the shortage between different customers in the real time... 

This study presents a cost-benefit analysis of energy saving strategies for the commercial sector inTehran City. The article includes a discussion of the estimated energy demand for various energy saving scenarios. The cost-benefit analysis was performed separately for seven energy-saving scenarios based on the energy demand and supply forecasting model. According to which, energy demand of the commercial sector was considered as final consumption, which is a function of different parameters such as number of commercial units, number of electric vehicles, volume of commercial activities, labor force, etc. The research findings indicated that all of the proposed scenarios are economically... 

In this paper, the interaction between various window specifications and different climate conditions is investigated. For this purpose, simultaneous effects of several aspects including glazing system, glass type, filling gas, glass thickness, window frame fraction, and interior shading are considered under three different climatic conditions. To evaluate the energy performance of various considered alternatives, the energy simulation of a base case building is evaluated in a computer environment. Using the validated model, the energy analysis is quantitatively performed, and cost-benefit analyses from the viewpoints of both residents and government are carried out based on the domestic and... 

The total cost of earthquakes is in this paper modeled as a continuous random variable that includes the cost of damage and the cost of construction to prevent damage. Realizations of this variable are obtained by evaluating an array of probabilistic models that take many basic random variables as input. Consequently, analyses can be conducted to determine the mean cost, as well as cost exceedance probabilities and other measures of seismic risk. Such results are employed to address the underlying decision problem, namely to minimize the total cost of earthquakes when that cost is a continuous random variable. Applicable decision theories are outlined and several risk measures are... 

Environmental considerations have imposed new restrictions in the planning and management of energy systems. This research aims at describing the necessity and application of a new concept in environmental responsibility accounting. The method is based on physical quantities to overcome the weaknesses of already developed allocation approaches, and to internalize the external environmental damages using the exergy concept. The proposed method is a modification of the exergoenvironmental analysis in order to take into account the effect of non-energy streams in a macro-level energy system. In the proposed method, environmental responsibilities are to be calculated based on the exergy... 

Role Based Access Control (RBAC) model is naturally suitable to organizations where users are assigned organizational roles with well-defined privileges. Nowadays, many organizations and enterprises such as banks, insurance industry and utility companies, provide online services to their veiy large number of users. This shows that assigning users to roles is a intolerable task and maintaining user-role assignment up-to-date is costly and error-prone. Also, with the increasing number of users, RBAC may have problems in prohibiting cheat and changing roles of users. To overcome these problems, user-role assignment decision can be made based on how much we trust him/her. In this paper, we... 

In this paper we consider a newsvendor problem in which the suppliers offer quantity discounts. We assume that the initial inventory at the beginning of the period is a random variable. This assumption, among other applications, may apply to the case where the decision about the order quantity must be made at a time long before the start of the period and the available inventory may decrease due to several factors, such as deterioration, consumption, etc. up to the start of the period. In this paper, we obtain the optimal order quantity that maximizes the total profit for this model  

In recent years, the emission of various pollutants has caused many problems for human life and the ecosystem. The prioritization between different air pollution control scenarios is a challenge between scientists and policy-makers. This study develops an integrated method for sustainable energy planning considering the energy-pollution-health nexus. The paper investigates three main pollutants (i.e., PM2.5, SO2, and NOx) of different emission sources (i.e., industrial, residential, and intra-city and suburban transportations) in twelve scenarios. The American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) is applied to model the air pollution dispersion,... 

Background/Purpose: To prevent falling, a common incident with debilitating health consequences among stroke survivors, it is important to identify significant fall risk factors (FRFs) towards developing and implementing predictive and preventive strategies and guidelines. This review provides a systematic approach for identifying the relevant FRFs and shedding light on future directions of research. Methods: A systematic search was conducted in 5 popular research databases. Studies investigating the FRFs in the stroke community were evaluated to identify the commonality and trend of FRFs in the relevant literature. Results: twenty-seven relevant articles were reviewed and analyzed spanning... 

Cost estimation plays an essential role in the development of aerospace systems that are perhaps the most complex, time- and labor-consuming ones. Regarding this matter, it is unavoidable to take a systematic approach to build a realistic model through a deliberative, heuristical and easy-to-do process in the early stages of design. In the current study, complexity index theory is utilized to develop a heuristic complexity-based method to estimate various costs of aerospace systems. This method promises to be logically and practically more reliable and accurate than classical parametric methods. Logically, manipulating a group of parameters, instead of only one or two, reduces the... 

This paper considers a repair-replacement strategy for a special class of discretely degrading and repairable products under renewing free replacement warranty. Each product may experience N different working states with different exponential hazard functions, before the warranty contract expires. Once the item enters working state i (i = 1,2, ⋯ ,N), it can either fail or move to any of the subsequent working states with different probabilities, given that a transition has been made. In the former case, the best rectification action, replacement or minimal repair, regarding the failure status, i.e., the product degradation level at the failure time and the remaining warranty time, should be... 

The inclusion of smart grid features such as demand response (DR) and network automation for capacity planning of substation transformers may provide substantial monetary savings. This paper proposes an optimization model for quantification of the savings in capacity management of substation transformers over long-run. The proposed model incorporates the DR as a resource to decrease the outage cost during contingencies while considering existing switching types for load transfer between substations. The model provides optimal selection and scheduling of multistage transformer installations and their refurbishments by considering all the costs associated with them including investment,... 

in recent decades, DEP due to its high efficiency has been exploited widely in separation and manipulation of bioparticles. In the present work a simple, low-cost, and efficient procedure for fabrication of microfluidic chips applied in medicine and biochemistry has been presented. In this method, electrodes are not in direct contact with biological samples which results in elimination of conventional systems' cons. Efficacy of the designed system has been evaluated by injecting samples containing yeast and Ecoli cells into the system and analyzing their trajectory. Experimental results demonstrate that precise adjustment of voltage and frequency can lead to the desired separation in this... 

Large technology-intensive enterprises and companies face a constant challenge: How can a set of selected high-tech projects get done in a manner that would minimize the total cost across all projects? In majority of cases, projects are assumed independent, leading to a separate cost evaluation. This assumption often does not hold for real-world project portfolios, frequently sharing overlapping technologies. In this paper, we show how the order of the execution of the projects can directly affect the total cost of the portfolio, due to shared dependencies. Modeling the problems in this area can be achieved by combining two main fields: graph theory and technology mining. A novel method is... 

A rescheduling method for new order arrival is presented based on the concept of dynamic pegging in multi-level production. Upon the arrival of new, unplanned orders, dynamic pegging enables the re-assignment of the Work-In-Progress (WIP) to the existing or newly arrived orders in such a way that the cost of rescheduling is minimized. A simple yet inspiring Mixed Integer Programming (MIP) model is proposed that combines dynamic pegging with rescheduling. The resulting schedules are compared with the ones obtained from two other basic rescheduling approaches. Analysis of the comparisons confirm the superiority of the proposed method in terms of total rescheduling costs. © 2019  

We consider a demand response program in which a block of apartments receive a discount from their electricity supplier if they ensure that their aggregate load from air conditioning does not exceed a predetermined threshold. The goal of the participants is to obtain the discount, while ensuring that their individual temperature preferences are also satisfied. As such, the apartments need to collectively optimise their use of air conditioning so as to satisfy these constraints and minimise their costs. Given an optimal cooling profile that secures the discount, the problem that the apartments face then is to divide the total discounted cost in a fair way. To achieve this, we take a... 

In this paper, an approach for optimal determining reserve capacity in the electricity market is presented. This paper describes a method for setting the optimum value of reserve capacity based on the cost of its provision and the benefit derived from its availability. Reduction of customer outage cost is interpreted as the benefit of reserve capacity. In the proposed method, reserve is procured up to the point where the marginal cost of procuring reserve is equal to the marginal value of this reserve capacity. The proposed method can be formulated as a mixed-integer linear program (MILP) and solved with large-scale commercial solvers. The proposed method is applied to the IEEE reliability...