Search for: decision-making
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    A history based semantic aware access control model using logical time

    , Article Proceedings of 11th International Conference on Computer and Information Technology, ICCIT 2008, 25 December 2008 through 27 December 2008, Khulna ; 2008 , Pages 43-50 ; 9781424421367 (ISBN) Noorollahi Ravari, A ; Amini, M ; Jalili, R ; Jafarian, J. H ; Sharif University of Technology
    With the advent of semantic technology' access control cannot be done in a safe way unless the access decision takes into account the semantic relationships among the entities in a semantic-aware environment. The SBAC model (Semantic Based Access Control model) considers this issue in its decision making process. However' time plays a crucial role in new computing environments'which is not supported in SBAC. In this paper' we propose the Temporal Semantic Based Access Control (TSBAC) model' as an extension of SBAC' which enhances the specification of user-defined authorization rules by constraining time interval and temporal expression over users' history of accesses. TSBAC uses logical... 

    A heuristic methodology for multi-criteria evaluation of web-based e-learning systems based on user satisfaction

    , Article Journal of Applied Sciences ; Volume 8, Issue 24 , 2008 , Pages 4603-4609 ; 18125654 (ISSN) Mahdavi, I ; Fazlollahtabar, H ; Heidarzade, A ; Mahdavi Amiri, N ; Rooshan, Y. I ; Sharif University of Technology
    Web-based E-Leaning Systems (WELSs) have emerged as new means of skill training and knowledge acquisition, encouraging both academia and industry to invest resources in the adoption of these systems. Traditionally, most pre- and post-adoption tasks related to evaluation are carried out from the viewpoints of technology. Since users have been widely recognized as being a key group of stakeholders in influencing the adoption of information systems, their attitudes about these systems are considered as pivotal. Therefore, based on the theory of multi-criteria decision making and the research results concerning user satisfaction in the fields of human-computer interaction and information... 

    A fuzzy-stochastic OWA model for robust multi-criteria decision making

    , Article Fuzzy Optimization and Decision Making ; Volume 7, Issue 1 , 2008 , Pages 1-15 ; 15684539 (ISSN) Zarghami, M ; Szidarovszky, F ; Ardakanian, R ; Sharif University of Technology
    All realistic Multi-Criteria Decision Making (MCDM) problems face various kinds of uncertainty. Since the evaluations of alternatives with respect to the criteria are uncertain they will be assumed to have stochastic nature. To obtain the uncertain optimism degree of the decision maker fuzzy linguistic quantifiers will be used. Then a new approach for fuzzy-stochastic modeling of MCDM problems will be introduced by merging the stochastic and fuzzy approaches into the OWA operator. The results of the new approach, entitled FSOWA, give the expected value and the variance of the combined goodness measure for each alternative. Robust decision depends on the combined goodness measures of... 

    A model for investigation of optimal hydrogen pathway, and evaluation of environmental impacts of hydrogen supply system

    , Article International Journal of Hydrogen Energy ; Volume 33, Issue 24 , 2008 , Pages 7314-7325 ; 03603199 (ISSN) Qadrdan, M ; Saboohi, Y ; Shayegan, J ; Sharif University of Technology
    Elsevier Ltd  2008
    In order to achieve a hydrogen economy, developing widespread hydrogen supply systems are vitally important. A large number of technological options exist and are still in development for hydrogen production, storage, distribution., which cause various pathways for supplying hydrogen. Besides the technical factors, there are other effective parameters such as cost, operability, reliability, environmental impacts, safety and social implications that should be considered when assessing the different pathways as optimal and viable long-term alternatives. To aid this decision-making process, we have developed a generic optimization-based model for the long-range energy planning and design of... 

    Integration of simulation and fuzzy multi attribute decision making for modeling and assessment of fuzzy parameters

    , Article Summer Computer Simulation Conference 2007, SCSC 2007, Part of the 2007 Summer Simulation Multiconference, SummerSim 2007, San Diego, CA, 15 July 2007 through 18 July 2007 ; Volume 1 , 2007 , Pages 400-407 ; 9781622763580 (ISBN) Azadeh, A ; Seifoory, M ; Abbasi, M ; Sharif University of Technology
    This paper introduces how to incorporate fuzzy set theory with discrete-event simulation in order to model uncertain activity duration in simulating a real-world system, especially when insufficient or no sample data are available. A case study is developed to apply this method to select a scenario to implement the maintenance program in a constant work in process (CONWIP) system. The maintenance activities directly or indirectly affect on production system performance such as response time production costs and etc. so we used the fuzzy simulation to determine the maintenance affects on the system performance. Finally we used the fuzzy simulation result to develop a fuzzy multi attribute... 

    A decision making framework in production processes using Bayesian inference and stochastic dynamic programming

    , Article Journal of Applied Sciences ; Volume 7, Issue 23 , 2007 , Pages 3618-3627 ; 18125654 (ISSN) Akhavan Niaki, T ; Fallah Nezhad, M. S ; Sharif University of Technology
    Asian Network for Scientific Information  2007
    In order to design a decision-making framework in production environments, in this study, we use both the stochastic dynamic programming and Bayesian inference concepts. Using the posterior probability of the production process to be in state λ (the hazard rate of defective products), first we formulate the problem into a stochastic dynamic programming model. Next, we derive some properties for the optimal value of the objective function. Then, we propose a solution algorithm. At the end, the applications and the performances of the proposed methodology are demonstrated by two numerical examples. © 2007 Asian Network for Scientific Information  

    A stochastic framework for optimal island formation during two-phase natural disasters

    , Article IEEE Systems Journal ; 2021 ; 19328184 (ISSN) Bahrami, M ; Vakilian, M ; Farzin, H ; Lehtonen, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2021
    This article proposes a new three-stage stochastic framework for dealing with predictable two-phase natural disasters in distribution systems. This framework is a multiobjective optimization, in which the amount of curtailed energy, the number of switching actions, and the vulnerability of operational components are selected as the main criteria for decision-making process. The optimization problem is formulated in the form of a stochastic mixed-integer linear programming (MILP) problem. In this article, a windstorm event followed by flooding is analyzed as a two-phase natural disaster. In this regard, the uncertainties associated with gust-wind speed, floodwater depths, and load demands are... 

    Decision-Making tree analysis for industrial load classification in demand response programs

    , Article IEEE Transactions on Industry Applications ; Volume 57, Issue 1 , 2021 , Pages 26-35 ; 00939994 (ISSN) Dehghan Dehnavi, S ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Dehghanian, P ; Wang, F ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2021
    Industrial loads play an important role in the success of demand response programs (DRPs). However, these programs may compromise the consumers' convenience, which can overshadow their real-world practicality. In response, this article provides a two-level decision-making tree approach to effectively determine the participation abilities of different industrial processes in DRPs considering various features and abilities of these customers. The level I of this framework introduces several classifying variables by which a basic criterion is extracted to classify different industrial processes applying the analytic hierarchy process (AHP). A participation factor is then introduced in level II... 

    A new hybrid risk-averse best-worst method and portfolio optimization to select temporary hospital locations for Covid-19 patients

    , Article Journal of the Operational Research Society ; October , 2021 ; 01605682 (ISSN) Kheybari, S ; Ishizaka, A ; Salamirad, A ; Sharif University of Technology
    Taylor and Francis Ltd  2021
    Choosing the right place to set up temporary hospitals is one of the most important and urgent measures for pandemic response. To solve this problem, we propose a new hybrid approach based on two steps. Firstly, since human health is highly sensitive to the impact of decisions about temporary hospital locations and a mistake may pose severe threat to human lives, we propose a new risk-averse multi-criteria decision-making (MCDM) approach. To choose the alternatives with the fewest possible weaknesses, a comprehensive hierarchal structure of relevant criteria categorized into environmental, social, economic, and infrastructural, along with a new risk-averse best-worst method (BWM), are... 

    Task-specific modulation of PFC activity for matching-rule governed decision-making

    , Article Brain Structure and Function ; Volume 226, Issue 2 , 2021 , Pages 443-455 ; 18632653 (ISSN) Parto Dezfouli, M ; Zarei, M ; Constantinidis, C ; Daliri, M. R ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Storing information from incoming stimuli in working memory (WM) is essential for decision-making. The prefrontal cortex (PFC) plays a key role to support this process. Previous studies have characterized different neuronal populations in the PFC for working memory judgements based on whether an originally presented stimulus matches a subsequently presented one (matching-rule decision-making). However, much remains to be understood about this mechanism at the population level of PFC neurons. Here, we hypothesized differences in processing of feature vs. spatial WM within the PFC during a matching-rule decision-making task. To test this hypothesis, the modulation of neural activity within the... 

    Optimal agent framework: a novel, cost-effective model articulation to fill the integration gap between agent-based modeling and decision-making

    , Article Complexity ; Volume 2021 , 2021 ; 10762787 (ISSN) Taghavi, A ; Khaleghparast, S ; Eshghi, K ; Sharif University of Technology
    Hindawi Limited  2021
    Making proper decisions in today's complex world is a challenging task for decision makers. A promising approach that can support decision makers to have a better understanding of complex systems is agent-based modeling (ABM). ABM has been developing during the last few decades as a methodology with many different applications and has enabled a better description of the dynamics of complex systems. However, the prescriptive facet of these applications is rarely portrayed. Adding a prescriptive decision-making (DM) aspect to ABM can support the decision makers in making better or, in some cases, optimized decisions for the complex problems as well as explaining the investigated phenomena. In... 

    Semi-augmented reality, a novel approach to improve customer safety in pre-sale process of under construction buildings

    , Article International Journal of Engineering, Transactions B: Applications ; Volume 34, Issue 10 , 2021 , Pages 2198-22205 ; 1728144X (ISSN) Alvanchi, A ; Didehvar, N ; Jalilehvand, M ; Adami, P ; Shahmir, S ; Sharif University of Technology
    Materials and Energy Research Center  2021
    Effective marketing is quite vital in many building construction projects that depend on the pre-sale cash in-flow. However, the unsafe condition of the under-construction projects postpones in-person customer visits to the completion date and complicates the marketing process. This safety concern is especially critical for the upper floor units. Although virtual tours of the buildings are used to show the project specifications, they do not convey the impression that customers receive in the real ambiance of in-person visits. This research proposes a novel method called semi-augmented reality to address the safety issue of the under-construction projects during the marketing process. In... 

    Emission assessment of alternative dam structure types, a novel approach to consider in new dam projects

    , Article Construction Innovation ; Volume 21, Issue 2 , 2021 , Pages 203-217 ; 14714175 (ISSN) Alvanchi, A ; Bajalan, Z ; Iravani, P ; Sharif University of Technology
    Emerald Group Holdings Ltd  2021
    Purpose: Dams require high-volume of construction materials and operations over the life cycle. This paper aims to select a proper type of dam structure that can significantly contribute to the sustainability of dam projects. Design/methodology/approach: This research proposes a complementary fuel consumption and carbon dioxide (CO2) emission assessment method for the alternate dam structure types to assist decision-makers in selecting sustainable choices. Related equations are developed for two common earthen and rock-fill dam structures types in Iran. These equations are then successfully applied to two real dam project cases where the significance of the achieved results are assessed and... 

    Iteration Control in Design Process

    , Ph.D. Dissertation Sharif University of Technology Soltan Mohammad, Bahram (Author) ; Malaek, Mohammad Bagher (Supervisor)
    The main goal of this research is to reduce aircraft design cycle period, by reducing the necessary number of design cycle iterations. The Design cycle period is one of the main characteristics of the design process and design cycle iterations play a major role in the design cycle period. To achieve the above mentioned goal, we present a mathematical model of iterations for the aircraft design process. This model describes the design coupled tasks as a discrete-linear time invariant dynamic system. This model also helps identify tasks which are the most important for generating iterations. This new method basically helps break information cycles that create iterations among important tasks.... 

    An Analysis of Key Factors Contributing to Residential Property Valuation in Iran

    , M.Sc. Thesis Sharif University of Technology Naderi, Iman (Author) ; Sharbatoghlie, Ahmad (Supervisor)
    It is our purpose in this study to compare and analyze behavioral aspects of residential property valuation in Iran. More specifically, this research aims to explore the attributes that influence the value of residential property from the consumers’ and valuers’ perspective to determine whether valuers account for consumer behavior accurately. Finally, we investigate which variables operate at the lower end of the market, as distinct from those influencing the value of higher priced property. The core methodology underpinning the measurement of buyer and valuer behavior is the use of survey analysis. The identification of variables employing a two stage process forms an initial but critical... 

    Determining Product Portfolio of Petrochemical Plants Using Multi Objective Decision Making Tools (Case study: Jam Petrochemical Plant)

    , M.Sc. Thesis Sharif University of Technology Hejazi Bakhsh, Mahboubeh (Author) ; Akbari Jokar, Mohammad Reza (Supervisor)
    Decision making for planning a petrochemical plant is a difficult task, particularly when decisions are required to be made under constraints and different objectives. Final purpose of current research is to develop a reliable model for selecting limited petrochimal products among all potential alternatives under different constraints, considering two desired objective functions; Maximizing economic gain and minimizing safety risk. The powerful tool of multi objective decision making has been used for solving the proposed model. The developed model has been applied to Jam Petrochemical Company as a case study and the acquired results found to be successful.


    An Evolutionary Decision Model for Solving Road Maintenance Problems

    , M.Sc. Thesis Sharif University of Technology Khalifeh, Vahid (Author) ; Pourzahedi, Hossein (Supervisor)
    Pavement maintenance and rehabilitation is an important problem in road pavement programming. Pavements experience significant distress over its life due to passage of vehicle (particularly heavy trucks), as well as abrupt variation in temperature (freeze and thaw). This would deteriorate pavements and reduces their serviceability. Rise of pavement maintenance costs places higher importance upon the need for maintenance programming. This study employs an evolutionary model to optimize the long-run benefit of the maintenance program. The model is stochastic in nature, and imbeds a Markovian decision procedure in the model to take into account such variabilities. The model is applied on... 

    Passive Islanding Detection for Distributed Generation Using Decision Tree Algorithm

    , M.Sc. Thesis Sharif University of Technology Madani, Sohail (Author) ; Abbaspour Tehrani Fard, Ali (Supervisor) ; Ranjbar, Ali Mohammad (Supervisor)
    The integration of renewable energy sources introduces several issues including islanding operation. Therefore, Islanding phenomenon should be detected by a fast and reliable islanding detection method. In this thesis an intelligent-based approach is proposed to detect islanding state for Photovoltaic (PV) and Doubly Fed Induction Generator (DFIG) units. Decision tree classification algorithm is chosen as weak classifier and by Adaptive Boosting (AdaBoost), detection accuracy is improved. 16 features are employed to construct feature vectors. Because of intermittency of renewable electricity generation, different states for PV and DFIG generation are assumed. Probable events are simulated... 

    Cross layer Design in Cognitive Radio Networks

    , Ph.D. Dissertation Sharif University of Technology Majd, Arash (Author) ; Pakravan, Mohammad Reza (Supervisor)
    In this thesis, the challenges of the PHY and MAC layers in cognitive radio networks are discussed and a plan which considers the cross layer concept between them is presented.In the first part of the thesis, a brief survey on various spectrum sensing techniques is presented. A detector which can improve the network performance is introduced and based on this detector, the important problem of trade-off between spectrum sensing period and the network throughput is considered. For this purpose, first of all, the truncated SPRT detector is presented and for low SNRs the optimal truncation time which leads to maximum network throughput is obtained. In the second part of the thesis,the... 

    Towards a Method to Architectural Decision Making in Collaborative Environments

    , M.Sc. Thesis Sharif University of Technology Samghani Nejad, Marzieh (Author) ; Habibi, Jafar (Supervisor)
    Considering the aggregation of software architecture design decisions, the decision on appropriate from, is important to the success of a software project. Hence, the software architects need reliable and accurate process for correct decision making which seeks to reduce risk and increase productivity. Furthermore, different stakeholders involved in the architectural design process and presence of cooperation between them for architecture decision making indicates the nature of collaborative activities related to architectural design. Effective collaboration among those involved in the design process not only will affect on the quality and accuracy of the architecture, but also accelerates...