جستجوی مقالات مرتبط با کلیدواژه « fuzzy topsis » در نشریات گروه « فنی و مهندسی »

Today, quality is one of the most important factors in attracting customer satisfaction and loyalty to service organizations. Therefore, one of the main concerns of managers is to improve the quality of services. With the development of the Internet and the world of communications, a concept called cloud computing has expanded in the world of communications, which provides a new model for the supply, consumption and delivery of computing services. The purpose of this study is to make the optimal decision in choosing the appropriate cloud service according to the conditions of users so that they achieve the highest satisfaction. Fuzzy Delphi method, fuzzy hierarchical analysis method, fuzzy TOPSIS method and finally multi-criteria decision making method are the methods used in this research. The results of the fuzzy Delphi method show that the indicators of transparency, accessibility and reliability should be eliminated. The results of fuzzy hierarchical analysis identified the cost index as the most important index and the support index during demand as the least important index. According to the results of fuzzy TOPSIS based on the weights obtained from fuzzy hierarchical analysis, SAAS, IAAS and PAAS cloud services were ranked first to third, respectively. Using the SAAS service provides numerous benefits to employees and companies, such as reducing time and money spent on time-consuming tasks such as installing, managing, and upgrading software.

In recent decades, the percentage of residential areas has increased due to the expansion of urbanization. This has led to an increase in the percentage of impermeable areas, thus increasing surface runoff in cities. Therefore, it is necessary to control surface runoff values using strategies such as low-impact development (LID) methods in cities. In this study, 6 LID methods have been used, namely permeable pavement, rain barrel, infiltration trench, bio-retention system, impermeable pavement-infiltration trench, and rain barrel-bio-retention system. These methods have been evaluated by 4 criteria which are: reduction of runoff volume, reduction of peak discharge of runoff, economic and social criteria. The SWMM model has been used to determine the values of hydrological criteria. To determine the values of the economic criteria (cost), the price analysis list, and the social criteria, a questionnaire has been used by experts in the field. To prioritize LID methods, the Fuzzy TOPSIS and TOPSIS multi-character decision-making criteria have been used, in terms of the weighted entropy of the fuzzy Shannon for the Fuzzy TOPSIS method and terms of the weighted entropy, equal, emphasis on hydrological criteria and emphasis on economic criteria, for TOPSIS method. The results showed that in the TOPSIS method in terms of the weighted equal, emphasis on economic criterion and emphasis on hydrological criterion, bio-retention system & rain barrel and, in terms of the weighted entropy, rain barrel, selected as the best scenario. In the Fuzzy TOPSIS method, the rain barrel scenario was selected as the most efficient scenario and ranked first in the study area.

Rework is one of the common problems in the construction industry. Despite the many studies that have taken place in the world, the lack of a comprehensive examination of the rework causes in Iran is evident. In addition, there is a need to provide an efficient and effective way to improve the rework issues. Therefore, in this study, using the survey method through the questionnaire, the main factors of rework in Iran were identified and ranked according to the criteria of cost, time, quality, safety and satisfaction of the project team by Fuzzy-TOPSIS method. Then, lean construction techniques were considered as a strategy to prevent rework, and the impact of these techniques on the importance of the rework factors was tested. The results of 52 questionnaires showed that the factors related to the client, the construction phase and the design phase were three main factors of the rework in Iran. Factors for insufficient turnover and commissioning resourcing, late client changes, delaying financing and contract delivery, insufficient skill levels, and ineffective management of project team are also the most important sub-factors, respectively. On the other hand, the lean construction measuring of the projects was examined through the Lean Project Rating System (LPRS) with 14 factors. The results showed that some of the lean construction factors considered in this study (including focus on communication and collaboration status, the use of IT and RFI, and the use of BIM) significantly alter rework and the importance of the its causes.

The purpose of this study was to evaluate the environmental risks of Alborz Dam on Bababrood River in Babol city, using multi-criteria decision making methods. Initially, environmental identification of the study area was carried out, Then a list of environmental risks identified in the construction and exploitation phase was prepared and presented to environmental experts familiar with the Alborz dam area in the form of a questionnaire. environmental risks scored by environmental experts based on three indicators, Severity of occurrence, Probability of occurrence, Then environmental risks ranking was performed using TOPSIS and Fuzzy TOPSIS methods. The most important risks of Alborz dam using TOPSIS method in the construction phase, respectively: Was Obtained, Destruction of forest within the dam with a score of 0.926, Displacement of reservoir residents with a score of 0.837 And in the phase of operation: Thermal stratification of dam reservoir with a score of 0.847, Landslide with a score of 0.751. Also, the most important risks of the Alborz dam using the Fuzzy Topsis method in the construction phase, respectively: Was Obtained, Displacement of reservoir residents with a score of 0.682, Demolition of forest within the dam with a score of 0.677, And in the phase of operation, respectively: Thermal stratification of dam reservoir with a score of 0.645, Landslide with a score of 0.630. Finally, one method of integration (average rating method) was used to resolve the conflict between the results.

The main objectives of supply chain management are reducing the risk of supply chain and production cost, increase the income, improve the customer services, optimizing the achievement level, and business processes which would increase ability, competency, customer satisfaction, and profitability. Further, the process of selecting the appropriate supplier capable of providing buyerchr('39')s requirements in terms of quality products with suitable price and at a suitable time and size is one of the most essential activities to create an efficient supply chain. Consequently, false decisions in the context of supplier selection would lead to negative effects. Usually, suitable supplier selection methods have been multi-criteria or attribute, so finding the optimal solution for supplier selection is demanding. The customary methods in this field have struggled with quantitative criteria however there are a wide range of qualitative criteria in supplier selection. this article has used interval valued intuitionistic fuzzy sets for selecting the appropriate suppliers, which reflect ambiguity and uncertainty far better than other methods. In this article, trapezoidal fuzzy membership function is used for lingual qualitative values. Goal programming satisfaction function (GPSF) is a kind of technique that helps decision makers in solving problems involving conflicting and competing criteria and objectives. Due to the importance of the issue, in this paper, hybrid approach with a group decision-making in Multiple Criteria Decision Making (MCDM) in the context of a range of interval-valued intuitionistic fuzzy sets is implemented to solve the supplier selection problem. In this model in phase 1, decision makers express their opinion about each alternative based on different attribute qualitatively, and after creating interval valued intuitionistic fuzzy membership, a new variable is defined that via its help, interval-valued intuitionistic fuzzy amounts are calculated for each alternative. because of Having capabilities and comprehensiveness in their inside, not only they are better than other fuzzy sets but also they are the best for tracing the real condition and environment in order to select suppliers. Thereafter, for each alternative upper and lower bonds are calculated based on interval-valued intuitionistic fuzzy amounts. In phase 2, Operator Weighted Average (OWA) algorithm is used to reach a collective consensus. After computing the degree of consensus, closeness coefficients is evaluated within the help of TOPSIS method, which is in fact one of the most practicable methods between multi-criteria decision-making methods, such as SAW, AHP, CP, VIKOR. With regard to closeness coefficient, the amount of closeness between individual and collective’s agreement is accounted. The main aim of this article is optimizing the closeness coefficient. The alternative with maximum closeness coefficient is closer to the ideal solution. The final goal of proposed model is ranking the suppliers, meaning that satisfy the main factors of decision making, which is why GPSF model is used. After giving goal and restrict functions, GPSF model will be solved and rank alternatives.

Mechanized excavation of the large cross section tunnels in rock condition has some hazards. Machine purchasing costs, fault zones, water inflows, squeezing, face instability, and etc. are some of the hazards which may cause excavation stop for a long time. In addition to mechanized excavation advantages, machine inflexibility in the complex geological conditions, high investment costs, technical, geometrical and political risks are the major disadvantages. Due to the high investment costs in this method, assessment and ranking the mentioned hazards are of a great importance. In this study, the tunneling risks of Alborz Western Tunnel (AWT) has been investigated using the fuzzy multi criteria decision making methods. The AWT in Tehran Shomal Highway is one of the major country project that considered to be excavated by an EPB shield machine. By analyzing geological condition and survey of some specialist's point of view, in this study, 17 possible hazards have been identified, and assessed by fuzzy TOPSIS and ELECTRE methods. Results shown that insufficient experience in mechanized tunneling of the large diameter tunnel and gas emission in the tunnel and investment and purchasing the machine are the most important risks in the project.

Large and complex infrastructural projects, especially water and wastewater projects always exposed to various internal and external risks. Given the increasing volume and complexity of rural water and wastewater projects, the constraints on funding and resources required their success in identifying, assessing, prioritizing and managing these risks. In this research, using research literature, checklist, experts, and expert opinions, the risks in rural and rural sewage projects in Gilan identified based on the 10 areas of the project management knowledge standard. The ranking indexes in this study include two parts of the primary and secondary indices: 16 effective risk factors among 60 risks, using the initial indicators based on the probability of occurrence and the degree of risk impact on the initial indexes of the project (time, cost, quality, performance) Determined. In the next step, based on additional indicators, the amount of exposure to risk, the level of manageability, the proximity of the occurrence of risk, the socio-economic effects and the environmental impacts (which are proportional to the climate and geographical area studied), are used by two methods of fuzzy topsization and hierarchical analysis Fuzzy has been evaluated for project risks. Finally, by integrating the results with simple averaging, the final ranking of the risks specified. The result of the research showed that the risk of insufficient funding at the due time chosed as the most important risk. In addition, the risk of non-payment of time claims of contractors and work force with a mean score of 2 and the risk of not using feedback results in quality control and implementation with a mean score of 3.5 were in the next priorities. The results of the research show that the rural water and Wastewater Company of Guilan should be adopt special measures for the required budget in order to manage the identified risks, and to conduct more detailed studies of validation in various projects in the preparatory phases. . It also pledges to pay in due time claims and analysis in control and quality and implementation.