Loading...
Search for:
cost-benefit-analysis
0.008 seconds
Total 181 records
Using sensitivity analysis and gradual evaluation of ignition delay error to produce accurate low-cost skeletal mechanisms for oxidation of hydrocarbon fuels under high-temperature conditions
, Article Energy and Fuels ; Volume 31, Issue 10 , 2017 , Pages 11234-11252 ; 08870624 (ISSN) ; Mazaheri, K ; Owliya, M ; Sharif University of Technology
Abstract
Three-dimensional thermo-hydrodynamic analysis of gas turbine combustion chambers is of great importance in the power generation industry to achieve higher efficiency and reduced emissions. However, it is prohibitive to use a comprehensive full-detailed mechanism in their simulation algorithms because of the huge CPU time and memory space requirements. Many reduction approaches are available in the literature to remedy this problem. Here a new approach is presented to reduce large detailed or skeletal mechanisms of oxidation of hydrocarbon fuels to a low-cost skeletal mechanism. The method involves an integrated procedure including a Sensitivity Analysis (SA) and a procedure of Gradual...
High-efficiency low-cost AC/AC buck converter with stability analysis
, Article IET Power Electronics ; Volume 10, Issue 7 , 2017 , Pages 802-807 ; 17554535 (ISSN) ; Mokhtari, H ; Sharif University of Technology
Abstract
The commutation issue is the most important limiting factor of expanding AC chopper applications, which in most cases are solved by employing snubber circuits, implementing sensor-based selective switching patterns and utilising resonant circuits. To overcome the commutation problem, this study proposes a novel non-resonant AC/AC buck converter with no snubber circuits and no sensor-based switching patterns. The introduced hardware configuration and the proposed control strategy provide a path for an inductive load current in all switching states. This converter offers higher reliability and efficiency as well as lower cost compared to the AC choppers with snubber circuits or voltage and...
Optimal acceptance sampling policy considering Bayesian risks
, Article Communications in Statistics - Theory and Methods ; Volume 46, Issue 11 , 2017 , Pages 5228-5237 ; 03610926 (ISSN) ; Fallah Nezhad, M. S ; Jafari, R ; Sharif University of Technology
Taylor and Francis Inc
2017
Abstract
In this paper, we propose a sampling policy considering Bayesian risks. Various definitions of producer's risk and consumer's risk have been made. Bayesian risks for both producer and consumer are proven to give better information to decision-makers than classical definitions of the risks. So considering the Bayesian risk constraints, we seek to find optimal acceptance sampling policy by minimizing total cost, including the cost of rejecting the batch, the cost of inspection, and the cost of defective items detected during the operation. Proper distributions to construct the objective function of the model are specified. In order to demonstrate the application of the proposed model, we...
Customer choice of reliability in spinning reserve procurement and cost allocation using well-being analysis
, Article Electric Power Systems Research ; Volume 79, Issue 10 , 2009 , Pages 1431-1440 ; 03787796 (ISSN) ; Fotuhi Firuzabad, M ; Goel, L ; Sharif University of Technology
2009
Abstract
A novel pool-based market-clearing algorithm for spinning reserve (SR) procurement and the cost allocation associated with provision of spinning reserve among customers (DisCos) is developed in this paper. Rational buyer market model is used to clear energy and spinning reserve markets in the proposed algorithm. This market model gives DisCos the opportunity to declare their own energy requirement together with their desired reliability levels to the ISO and also they can participate in the SR market as a interruptible load. The DisCos' desired reliability levels are selected from a hybrid deterministic/probabilistic framework designated as the system well-being model. Using the demand of...
Task scheduling mechanisms in cloud computing: A systematic review
, Article International Journal of Communication Systems ; Volume 33, Issue 6 , 2020 ; Movaghar, A ; Rahmani, A. M ; Sharif University of Technology
John Wiley and Sons Ltd
2020
Abstract
Today, cloud computing has developed as one of the important emergent technologies in communication and Internet. It offers on demand, pay per use access to infrastructure, platforms, and applications. Due to the increase in its popularity, the huge number of requests need to be handled in an efficient manner. Task scheduling as one of the challenges in the cloud computing supports the requests for assigning a particular resource so as to perform effectively. In the resource management, task scheduling is performed where there is the dependency between tasks. Many approaches and case studies have been developed for the scheduling of these tasks. Up to now, a systematic literature review...
Statistical evaluation of using the new generation of wind turbines in South Africa
, Article Energy Reports ; Volume 6 , November , 2020 , Pages 2816-2827 ; Jahangiri, M ; Haghani, A ; Hosseini Dehshiri, S. J ; Hosseini Dehshiri, S. S ; Sedaghat, A ; Saghaei, H ; Akinlabi, E. T ; Sichilalu, S. M ; Chowdhury, S ; Techato, K ; Issakhov, A
Elsevier Ltd
2020
Abstract
In the view of the latest status and the potential of developing wind energy in South Africa, the present study aims to perform technical–economic–environmental analysis on a wind turbine system with HOMER software using the 20-years average data of the wind speed obtained from NASA's database, for providing the electricity to residential buildings. The results showed that the Port Elizabeth station, had the lowest levelized cost of electricity (LCOE) with the value of -0.363 $/kWh when using the EOLO wind turbine, and the Bloemfontein station had the highest LCOE with the value of 1.601 $/kWh when using the Turby wind turbine. The results from the step-wise assessment ratio analysis...
Cyber-Physical technologies in freight operations and sustainability: A case study of smart GPS technology in trucking
, Article Sustainable Cities and Society ; Volume 55 , 2020 ; Baroud, H ; Abkowitz, M ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
With the growing rate of urbanization, freight transportation systems have become critical in supporting economic and social needs in the United States. In order to achieve efficient and effective operations, freight transportation systems are recognizing the value of using Cyber-Physical (CP) technologies. This research provides a scenario-based assessment of CP technology penetration to improve sustainability in freight transportation systems with a focus on the use of smart GPS technologies by the trucking industry in Tennessee. Based on the case study, CP technologies can result in significant benefits to the economy, environment, and society. A cost-benefit analysis shows that benefits...
Simultaneous congestion management and cost allocation in a short-run market model
, Article Iranian Journal of Science and Technology, Transaction B: Engineering ; Volume 31, Issue 6 , December , 2007 , Pages 617-628 ; 10286284 (ISSN) ; Barati, H ; Ehsan, M ; Sharif University of Technology
2007
Abstract
This paper proposes a simultaneous approach to manage congestion, evaluate congestion cost, and to allocate this cost among consumers in a short-run market model. The proposed method consists of an iterative algorithm to search and apply a sequence of the best feasible bilateral power exchange among the generators that would optimally reduce and completely remove the congestion. The best exchanges are selected using sensitivity analysis and the AC load flow is used to apply the selected exchange on the system. Congestion cost is calculated using the change in generation cost and divided among the overloaded lines regarding the change in power flow of these lines, after applying the selected...
Internalizing the social cost of noise pollution in the cost analysis of electricity generated by wind turbines
, Article Wind Engineering ; Volume 30, Issue 6 , 2006 , Pages 521-529 ; 0309524X (ISSN) ; Bahadori, M. N ; Sharif University of Technology
2006
Abstract
The Social Cost of nuisance noise from a wind turbine is defined here as the additional cost to reduce the noise level at a receptor to an exceptable, non-nuisance value, i.e. to mitigate this cost. This acceptable sound level is considered to be 35 dB. Our example is a 10-kW (nominal power) wind turbine considered to supply the electrical energy needs of a 3-storey residential building in Tehran and Manjil. The turbine generates sound at 75 dB. To reduce the sound level at the third floor of the building to 35 dB, it was necessary to increase the height of the turbine from 24 m to 48 m. The initial installed cost of the turbine thereby increased from US$45.000 to US$55,000. The cost of...
Integrated water resources management in Polrud irrigation system
, Article Water Resources Management ; Volume 20, Issue 2 , 2006 , Pages 215-225 ; 09204741 (ISSN) ; Sharif University of Technology
2006
Abstract
Water is needed in all aspects of life and is vital to its social, economical and environmental dimensions. Having a key role in sustainable development, water management requires an integrated approach. Irrigation Water shortage promotes the development of innovative management and supply enhancement models. Effective water management requires a comprehensive consideration of all related aspects, e.g., technical, social, environmental, institutional, political and financial. Then the conventional methods of cost-benefit analysis and single-objective models have changed to multi-objective models. The rising of population in Iran puts significant pressure on authorities and infrastructures to...
Network and application-aware cloud service selection in peer-assisted environments
, Article IEEE Transactions on Cloud Computing ; Volume 9, Issue 1 , 2021 , Pages 258-271 ; 21687161 (ISSN) ; Malekimajd, M ; Movaghar, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
There are a vast number of cloud service providers, which offer virtual machines (VMs) with different configurations. From the companies perspective, an appropriate selection of VMs is an important issue, as the proper service selection leads to improved productivity, higher efficiency, and lower cost. An effective service selection cannot be done without a systematic approach due to the modularity of requests, the conflicts between requirements, and the impact of network parameters. In this paper, we introduce an innovative framework, called PCA, to solve service selection problem in the hybrid environment of peer-assisted, public, and private clouds. PCA detects the conflicts between the...
Comparison of mechanical properties in interference screw fixation technique and organic anterior cruciate ligament reconstruction method: a biomechanical study
, Article BMC Musculoskeletal Disorders ; Volume 22, Issue 1 , 2021 ; 14712474 (ISSN) ; Nourani, A ; Moeinnia, H ; Mohseni, M ; Korani, H ; Ghias, N ; Chizari, M ; Sharif University of Technology
BioMed Central Ltd
2021
Abstract
Background: Bone and Site Hold Tendon Inside (BASHTI) technique is an organic implant-less technique for anterior cruciate ligament (ACL) reconstruction with some clinical advantages, such as speeding up the healing process, over implantable techniques. The study aims to compare the mechanical properties of BASHTI technique with the conventional interference screw technique. Methods: To investigate the mechanical properties, 20 in-vitro experimental tests were conducted. Synthetic dummy bone, along with fresh digital bovine tendons, as a graft, were used for experiments. Three loading steps were applied to all specimens, including a preconditioning, a main cyclic, and a pull-out loading....
Time series analysis framework for forecasting the construction labor costs
, Article KSCE Journal of Civil Engineering ; Volume 25, Issue 8 , 2021 , Pages 2809-2823 ; 12267988 (ISSN) ; Gholipour, Y ; Kashani, H ; Sharif University of Technology
Springer Verlag
2021
Abstract
This manuscript presents a framework to develop vector error correction (VEC) models applicable to forecasting the short- and long-run movements of the average hourly earnings of construction labor, which is an essential predictor of the construction labor costs. These models characterize the relationship between average hourly earnings and a set of explanatory variables. The framework is applied to develop VEC forecasting models for the average hourly earnings of construction labor in the USA based on the identified variables that govern its movements, such as Global Energy Price Index, Gross Domestic Product, and Personal Consumption Expenditures. More than 150 candidate VEC models were...
A reliability cost/worth approach to determine optimum switching placement in distribution systems
, Article 2005 IEEE/PES Transmission and DistributionConference and Exhibition - Asia and Pacific, Dalian, 15 August 2005 through 18 August 2005 ; Volume 2005 , 2005 , Pages 1-5 ; 0780391144 (ISBN); 9780780391147 (ISBN) ; Fotuhi Firuzabad, M ; Rashidi Nejad, M ; Sharif University of Technology
2005
Abstract
Nowadays automation in distribution systems is growing largely. Automated and remote controlled switches play prominent rules in automated distribution systems. By opening and closing these remote controlled switches in emergency states when a fault has been occurred we can manage fault and restoration process in order to minimize interruption time and costs. In the normal states feeder load management and power loss minimization can be controlled by these remote controlled switches. Finding optimum numbers and optimum locations for installing these switches is the main concern in this between. Up to now a number of algorithms have been developed for optimum switch placement. In this paper a...
Impacts of power wheeling on composite system adequacy enhancement
, Article 2005 IEEE/PES Transmission and DistributionConference and Exhibition - Asia and Pacific, Dalian, 15 August 2005 through 18 August 2005 ; Volume 2005 , 2005 , Pages 1-5 ; 0780391144 (ISBN); 9780780391147 (ISBN) ; Gharagozloo, H ; Haghifam, M. R ; Sharif University of Technology
2005
Abstract
Considerable attention has been devoted to demonstrate reliability enhancement of power systems with power wheeling transactions. The impacts of power wheeling on power systems depends on various factors such as direction, amount of power/energy wheeled, system topology and sink or source nodes of power system. The effects on Iran Composite Power System (ICPS) reliability of wheeling energy from Azerbaijan to Turkmenistan are presented in this paper. This transaction is done through the transmission facilities on north part of ICPS. The sensitivity of ICPS to the direction and amount of power wheeling is attended. Finally, the optimum value for power wheeling is determined and the associated...
HFOS L : hyper scale fast optical switch-based data center network with L-level sub-network
, Article Telecommunication Systems ; Volume 80, Issue 3 , 2022 , Pages 397-411 ; 10184864 (ISSN) ; Hessabi, S ; Koohi, S ; Yan, F ; Calabretta, N ; Sharif University of Technology
Springer
2022
Abstract
The ever-expanding growth of internet traffic enforces deployment of massive Data Center Networks (DCNs) supporting high performance communications. Optical switching is being studied as a promising approach to fulfill the surging requirements of large scale data centers. The tree-based optical topology limits the scalability of the interconnected network due to the limitations in the port count of optical switches and the lack of optical buffers. Alternatively, buffer-less Fast Optical Switch (FOS) was proposed to realize the nanosecond switching of optical DCNs. Although FOSs provide nanosecond optical switching, they still suffer from port count limitations to scale the DCN. To address...
Exergy cost analysis of soil-plant system
, Article International Journal of Exergy ; Volume 38, Issue 3 , 2022 , Pages 293-319 ; 17428297 (ISSN) ; Saboohi, Y ; Valero, A ; Azamian, S ; Sharif University of Technology
Inderscience Publishers
2022
Abstract
In this paper, inspired by a gas turbine power plant, the interaction between plant-soil processes has been simulated. It is aimed to indicate that solar energy in the photosynthesis process is equivalent to the fuel in combustion chambers. In the glucose production process, when solar exergy is considered as a fuel, 99.4% of total exergy cost is supplied by solar exergy and only 0.6% of the exergy cost is provided by nutrients’ content. In general, 30% of the total exergy entering the Calvin cycle is consumed in glucose production and the remaining 70% is related to biomass generation (as flue gas in the gas turbine). Moreover, 98% of the total exergy cost of the soil box is related to...
Coordination of process integration and exergoeconomic methodology for analysis and optimization of a pulp and paper mill
, Article Scientia Iranica ; Volume 16, Issue 4 B , 2009 , Pages 301-312 ; 10263098 (ISSN) ; Mozafari, A. A ; Farhanieh, B ; Sharif University of Technology
2009
Abstract
By simultaneously applying pinch technology and the exergoeconomic method to a complex process system, beneficial and energy-efficient measures are identified. The "three-link-model" exergoeconomic methodology optimizes the design and operability of a system. In this work, contrary to traditional exergoeconomic methods, a reversed method is used. The approach proposed for the optimization of such a complex system is to iteratively optimize subsystems. Since the reversed exergoeconomic method is used, assumptions considered by Tsatsaronis (based on four assumptions for calculating the cost-optimal exergetic efficiency and relative cost difference) are not applicable and new assumptions are to...
Multiple interactive pollutants in water quality trading
, Article Environmental Management ; Volume 42, Issue 4 , 2008 , Pages 620-646 ; 0364152X (ISSN) ; Lence, B. J ; Shamsai, A ; Sharif University of Technology
2008
Abstract
Efficient environmental management calls for the consideration of multiple pollutants, for which two main types of transferable discharge permit (TDP) program have been described: separate permits that manage each pollutant individually in separate markets, with each permit based on the quantity of the pollutant or its environmental effects, and weighted-sum permits that aggregate several pollutants as a single commodity to be traded in a single market. In this paper, we perform a mathematical analysis of TDP programs for multiple pollutants that jointly affect the environment (i.e., interactive pollutants) and demonstrate the practicality of this approach for cost-efficient maintenance of...
Determination of the Desired and Economical Reliability Level in Electric Power Distribution Systems Considering Network Condition
, M.Sc. Thesis Sharif University of Technology ; Safdarian, Amir (Supervisor) ; Fotuhi Firuzabad, Mahmud (Co-Supervisor)
Abstract
Electric energy distribution system (DS) reliability has a great impact on the quality of service provided to customers. On the other hand, improving the reliability performance in a DS is an expensive task. So, determining an efficient and economical target for the reliability of DSs is imperative. This thesis aims to determine efficient and economical reliability targets for reliability indices of DS based on data envelopment analysis (DEA) considering distribution feeders as the decision-making units (DMUs). For this sake, using the fuzzy c-mean (FCM) method, feeders are clustered and the membership degrees are determined so that the target associated with each feeder gets greater impact...