Sharif Digital Repository

Safe and efficient pedestrian movement is an important issue of concern in traffic engineering. Evaluation and identification of effective parameters in pedestrians' decision-making process when crossing a street can be beneficial in improving their safety. In this report, two streets in Tehran, Iran were selected to study the pedestrians' crossing. The data from the video films at these locations were used to fit the logit and nested logit models. The results indicate that factors such as arrival time of first nearside vehicle to crosswalk, headway between first and second vehicle approaching the crosswalk, vehicles platoon size and their approaching speed in each lane, pedestrians' age,... 

Zamin, is an Artificial Life ecosystem, suitable for cognitive studies such as evaluation of different thinking and acting methods. Up to now, simple models for decision making, generalization and abstraction, environment perception and pleasure computation is developed and tested in Zamin. In this paper, we have promoted the two layered decision-making system of Zamin creatures, the Aryos, to a three layered emotional decision making mechanism, compared the learning and coping with predators capabilities of the new creatures with the old ones and shown that they can defeat the previous, emotion-less creatures  

In this paper, two basic new call admission control policies in soft-handoff regions in Code-Division Multiple-Access (CDMA) cellular networks are compared. The two policies are Independent Decision Policy (IDP), which is, approximately, equivalent to a directed retry policy proposed for non-CDMA cellular networks and Collective Decision Policy (CDP). The merits in this comparison include the tradeoff between carried traffic and quality loss probability while maintaining other traffic parameters (such as blocking and dropping (handoff failure) probabilities) sufficiently low. Using numerical results, it is deduced that the CDP leads to a better overall performance. Another important issue... 

This study developed a groundwater sustainable management index including components of environmental, social, economic and institutional responsibility. Four significant indicators: integrated groundwater footprint, population density, percentage of groundwater used for agricultural and industrial sectors, and density of observation wells were adopted and executed for 443 of Iran’s aquifers. The results indicated that the groundwater sustainable management for 32% of Iran’s aquifers is poor–very poor, and this index is more sensitive to economic and social indicators. Finally, an inverse correlation was observed between the groundwater sustainable management index values and the coefficient... 

Even though there have been so many articles and studies that focused on the supplier selection problem, a few of them considered the major decisions related to supplier selection. In this paper, the supplier selection problem is studied under a novel fuzzy approach in multiple sourcing conditions to select appropriate supplier in group decision-making environment regarding multiple sources. The use of the model is suitable in evaluating situations that involve subjectivity, vagueness and imprecise information. The group data have been used in multiple criteria decision making with multiple objective supplier selection. Trapezoidal fuzzy numbers are applied to evaluate the weights of... 

One of the basic requirements of the companies to survive in real-world competitive environments is to make their supply chains as efficient as possible. Due to recent governmental regulations, environmental issues, and the development of the concept of social responsibility, the closed-loop supply chain management has been focused by many researchers. A closed-loop supply chain includes both forward and reverse supply chain networks with the purpose of combining environmental considerations with the traditional supply chain network designs through the collection of used products and activities related to their reuse. In this paper, a bi-objective, multi-period, multi-product, closed-loop... 

In this research, we investigate a three-stage supply chain with one supplier, several manufacturers and multiple retailers where the supplier provides a common raw material to each manufacturer, who in turn uses a single stage production facility to convert it into final products that are delivered at fixed lot sizes to retailers. An integrated economic procurement, production, and delivery model is developed whose objective is to find the common production cycle length, production sequences of final products at manufacturers and delivery frequencies of final products to retailers minimizing the total costs of considered supply chain. We propose an analytical solution procedure and an... 

Roadmapping, a tool of strategic planning, visualize where and how an organization will be in the future. Visualization of strategic programs assists people in the organization to understand the strategy which is a key for implementing strategy successfully. A generic roadmap is included of three main layers such as; market, product and technology. Decision making in each layer are done separately because of the nature of each layer. Therefore, decisions in roadmapping can be done with different tools. Whiles, decisions in each layer of the roadmap cannot be done without considering the upper or lower layer decisions. In this study we propose Fuzzy PROMETHEE method for integrating decisions... 

Tow-mode theories explain that risky behaviors in young individuals may be the result of competition between an affective system (e.g., Empathizing system) and a deliberative system (e.g., Systemizing system). We aimed to investigate a total of 134 children aged 7-12. years old on scores of risky decision making and empathizing and systemizing measures. The primary analysis indicated that systemizers showed higher sensitivity to punishment than those in balanced or empathizer classes (F (2,130) = 14.8, p < 0.001). Furthermore empathizers indicated higher level of risk taking than balanced and empathizer children (F (2,130) = 5.027, p = 0.005). Providing further support for two-mode theories... 

Individuals have been regarded as independent decision makers in majority of transportation analysis. However, agents’ behaviors are usually affected by the interactions among the members in a group; and therefore, individual decision-making paradigms may result in unrealistic outcomes and erroneous interpretations of the results. In light of this, the present study develops discrete choice models in individual and group levels and compares their prediction power in predicting the choice of escort pattern in dual-worker households with at least one under-18-year-old student. The main purpose is to reveal the efficiency of each approach in analyzing parent-child joint activities and highlight... 

Although simple additive weighting method (SAW) is the most popular approach for classical multiple attribute decision making (MADM), it is not practical any more if information is fuzzy. The existing methods of Fuzzy Simple Additive Weighting method (FSAW) apply defuzzification which distorts fuzzy numbers. Furthermore, most of the methods usually require lengthy and laborious manipulations. In this paper, we develop a new a fuzzy simple additive weighting method for multiple attribute decision making problems. To avoid defuzzification round off errors caused by multiplication or other arithmetic manipulations, fuzzy numbers are ranked prior to any fuzzy arithmetic in this method. The... 

In maintenance and replacement planning of an industry, the purchasing of new equipment on the market with some kind of technological improvement over existing equipment should be taken into account. Because of operating cost, ordinary and preventive maintenance expenses may be lower, production rate may be higher and the quality of output may be better, etc. The industry to be considered in this paper is the mining industry and the replaced equipment is the mine shovel. It is assumed that, at most, one new shovel can be purchased before the mine is exhausted. It is possible that the mine is given up before exhausted, because of the disadvantage of the expense and loss of the salvage value... 

Hydrogen generation from renewable energy resources is considered as a suitable solution to solve the problems related to the energy sector and the reduction of greenhouse gases. The aim of this study is to provide an integrated framework for identifying suitable areas for the construction of wind farms to produce hydrogen. For this purpose, a combined method of Geographic Information System (GIS) and multi-criteria decision making (MCDM) has been used to locate the power plant in Yazd province. The GIS method in the present study consisted of two parts: constraints and criteria. The constraint section included areas that were unsuitable for the construction of wind farms to produce power... 

One of the most important aspects of a successful space mission is the transition to the correct orbit and maintaining it. As a result, many modern orbit transfer techniques have been developed in space industry in order to accomplish this task in a more reliable and less expensive way. However, when it comes to the design of student satellites, usually there are serious limitations on the financial resources, technical database and satellite industry experts. These limitations may compromise the access to advanced methods and techniques. Therefore, reliability and expenses may no longer be the only criteria to be met in the process of design. As a result, at each step of the design, a... 

Taking account of uncertainty in multicriteria decision making problems is crucial due to the fact that depending on how it is done, ranking of alternatives can be completely different. This paper utilizes linguistic values to evaluate the performance of qualitative criteria and proposes using appropriate shapes of fuzzy numbers to evaluate the performance of quantitative criteria for each problem with respect to its particular conditions. In addition, a process to determine the weights of criteria using fuzzy numbers, which considers their competition to gain greater weights and their influence on each other is described. A new fuzzy methodology is proposed to solve such a problem that... 

In this research work, a modified fuzzy approach referred to as modified fuzzy logic method (MFLM) is proposed to more conveniently solve intricate decision-making problems under uncertainty and data deficiency. The method resolves major drawbacks like inaccuracy, complexity, and a high volume of computational efforts with the existing approaches for the mentioned problems. Here, MFLM is applied to materials selection for a cryogenic storage tank and a gas turbine blade, which are standard engineering problems used for verification by researchers, and the ranking results are compared with the state-of-the-art techniques in the literature, such as the conventional fuzzy logic method.... 

Hydrogen as an energy carrier can play a significant role in reducing environmental emissions if it is produced from renewable energy resources. This research aims to assess hydrogen production from wind energy considering environmental, economic, and technical aspect for the East Azerbaijan province of Iran. The economic assessment is performed by calculation of payback period, levelized cost of hydrogen, and levelized cost of electricity. Since uncertainty in the power output of wind turbines may affect the payback period, all calculations are performed for four different turbine degradation rates. While it is common in the literature to choose the wind turbine based on a single criterion,... 

Line balancing problem plays an important role in the decision making process to increase efficiency and productivity. Recently, U-shaped layout in many production lines has replaced the traditional straight line layout using just-in-time concept. Here, we propose a model, using multi-objective decision making approach to the U-shaped line balancing problem, to offer enhanced decision maker flexibility, by allowing for conflicting goals. The assembly line operation efficiency is the most significant aim in our study, and this efficiency relates to management of resources and the solution of line balancing problem. First, the U-shaped line balancing problem is solved considering the model's... 

This research deals with a model with better efficiency for selection of portfolio making use of cardinal constraints, which are explained in previous sections. Such a method, which is a combination of fuzzy models and MCDM considering the constraints intended by investors, has not been used in previous models. We have considered transactions cost, because they are among factors important for an investor, and their being ignored in a portfolio selection method will result in inefficient portfolio. Sector value constraint is among other constraints considered here. Such a constraint aims to raise investment rate in sectors with higher values. Cardinal constraints (number of shares existing in...