جستجوی مقالات مرتبط با کلیدواژه "ارزیابی عملکرد" در نشریات گروه "مهندسی آب"

Water distribution networks (WDNs) are complicated infrastructures which their construction, operation and maintenance have considerable costs. Since most of the variables effective on the design and operation of WDNs cannot be computed and achieved accurately and definitely, uncertainty subject should be considered as an inseparable issue in the calculation of these networks. In this study, using the fuzzy logic concept and genetic optimization algorithm, the impact of uncertainties of input variables (nodal demands and pipe roughness coefficients) on the results of hydraulic analysis of two sample networks have been examined. In this regard, first, the fuzzy membership functions of input variables have been determined and by considering the simultaneous impacts of these variables' uncertainties, the output variables of hydraulic analysis have been calculated more accurately. Afterwards, variables of pressure, velocity and energy loss have been considered as representers for evaluating the hydraulic performance of network elements (nodal demand and pipes). In order to calculate the hydraulic performance indices of these elements, after analyzing the network based on the pressure driven simulation method, penalty curves defined according to the available standards, have been employed and the obtained results have been compared to the results of the demand driven simulation method. In addition, a new relation for combining the performance indices of network elements and obtaining an index for evaluating the total pipe performance and calculating the total hydraulic performance index of network has been introduced. According to the obtained results, slight uncertainties in the input variables of hydraulic analysis lead to high uncertainties in the outputs of the hydraulic analysis of WDNs. Meanwhile, velocity in pipes more than nodal pressures are affected by the uncertainties of input variables of hydraulic analysis. Also, implementing the pressure driven simulation method in performance evaluation of WDNs in their operation period leads to more reasonable and real results. For instance the total performance of network was 0.56 for 9-loop network and was 0.26 and 0.59 for 2-loop network, respectively, based on demand and pressure driven simulation methods.

Comprehensive evaluation of organization performance is one of the most powerful tools for decision making. It helps managers to gain necessary information about the status of their organization. One of the most widely welcomed models in this regard is the Balanced Scorecard Model which provides comprehensive evaluation for various aspects in the Water and Wastewater Corporation. The present study was a descriptive-applied research in terms of objectives. The objectives included selecting a comprehensive evaluation pattern, recognizing and ranking the indexes and main sub-standards for evaluating the comprehensive performance with BSC model denoting various parts in water and wastewater corporations. The model was used in West Azarbayjan province water and wastewater company as a pilot. Data collection was based on the library and field study via 3 types of questionnaires and interview with staff, financial staff, and by the customers of the given company. Based on the correlation and regression coefficients, the mean variables test and the fuzzy method showed that the BSC fields are in the order of priority in the performance of the mentioned company. These included internal processes, learning and growth, and customer and financial perspective. In the regression dependent variable model, the performance of the company and independent variables included various variables in fields of the balanced scorecards, and the result showed that the most effective factors on the company performance were decreasing the unnecessary costs, increasing and developing new facilities, finding new custumers, providing infrastructures, and organizational resources through learning, increasing customer satisfaction, enhancing the efficiency and quality of the internal processes.

The basic concept of this paper is to establish systematization of performance assessment. To improving a methodology for integrated model on performance assessment of irrigation systems is subjected to uncertainty of natural events and vagueness or fuzziness of management characteristics objectives. It is important to consider the objective of irrigation system as a service to be provided for farmers. The main issue of performance assessment is to provide indicators, based on subjective judgments of management environment. Initial indicators and fuzzy rule are defined as a physical and institutional condition of system and inter relation of indicators respectively.In this model level of water users and irrigation water supply agency is distinguished, linguistic-expression indicators are defined, all indicators are fuzzified, Mamdani fuzzy system is implied, these foresaid is enabled the model to assess each fuzziness condition, and assessment of irrigation management transfer and upgrading management. Results indicated that measured performance indicators for a given design or intended value can be subjected to significant rule that could describe the interrelationship between different parameters of performance. The effects of various types of fuzziness and the assessment of irrigation performance for irrigation water delivery are investigated. Management performance measures from water users and irrigation water supply agency judgments in the pilot were 39% and 58% respectively, adequacy indicator from water users and irrigation water supply agency judgments were 38% and 82% respectively, these two measures shows that unfavorites physical and natural condition is not the main problem of the system. But difference between actual water users needs, and unsufficient plan of water delivery, is the main problem of the system.