توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Watershed planning using MODSIM Simulation Model under Different Management Strategies, A Case Study: Maharlou–Bakhtegan Watershed
نویسنده(ها): ، ،
اطلاعات انتشار: نهمین کنگره بین المللی مهندسی عمران، سال
تعداد صفحات: ۸
With a rapid population growth and consequent increasing in water demands in the last few decades, the management of water resources considering environmental protection issues in a watershed scale is under increasing pressure all over the world. Determination of optimal water resources management strategies is relatively complicated because many parameters and disciplines are dealing with extracting optimal water resources management strategies. In this paper, a scenario–based analysis approach was examined for water resources management and planning of Maharlou–Bakhtegan watershed using MODSIM model as a generic river basin management decision support system (DSS). This approach is used to assess the effects of water and land resources development strategies, climate change, groundwater withdrawal levels and irrigation efficiency on municipal, industrial and agricultural water supply as well as environmental water demand satisfaction. For Evaluation of system performance, performance indices including reliability, resiliency and vulnerability are calculated to evaluate the results of the proposed approach. Results showed that MODSIM model has profound capabilities as a DSS tool in facilitating and evaluating the water resources management strategies in watershed scale<\div>

۲Determining the economic value of agricultural water for developing water management policies: A case study
نویسنده(ها): ،
اطلاعات انتشار: نهمین کنگره بین المللی مهندسی عمران، سال
تعداد صفحات: ۸
Increasing the water demands and decreasing water resources, persuade the goverments to improve the water efficiency. There are several methods to make an equilibrium between demand and supply water.One methods is to increas the water price which can persuade consumers to reduce the water demand andimprove the water efficiency. Another method is to buid the new water capasity for decreasing water scarcity. In this paper the first approach is considered and an optimization model for finding the croppattern configuration and water allocation is develped to calculate the economic value of water foragricultural sector. Genetic Algorithm (GA) method is used to solve the optimization model. The results show that the economic value of water in zayandehrood basin is 0.15 $ per cubic meter<\div>

۳Assessment of climate change impacts on Agricultural water demands
نویسنده(ها): ، ،
اطلاعات انتشار: نهمین کنگره بین المللی مهندسی عمران، سال
تعداد صفحات: ۸
Long–term planning of water resources strongly depends on climate change and its effects on water resources and consumptions. In the past, infrastructures planning and development programs wereintended based on historic data of climate. But in recent decades according to the climate change impactson these planning and programs, moving toward estimation of its effects and finding appropriate strategies to overcome its risks has been interested. One of these effects is impacted on water uses,especially agriculture. In this research the impacts of climate change on water demands of agriculture in the downstream of dam in Zayandehrud river basin for future development of agriculture has been studied. For this purpose we calculate the reference crop evapotranspiration with Penman – Monteithequation and gross water demands of agricultural sectors with AGWAT software. Then the LARS–WG model has been used for down–scaling the parameters of climate change periods. Results show that because of increasing in agriculture water demands, water resources management in the basin will face with big challenges in future. So to reduce this hazard we propose a solution which works with changing in cropping pattern in the basin<\div>

۴Representation of Fuzzy logic Controllers for DC–DC Converters
نویسنده(ها): ،
اطلاعات انتشار: ششمین کنفرانس مهندسی برق و الکترونیک ایران، سال
تعداد صفحات: ۵
In this paper, two distinct topologies–based fuzzy logic controllers for Dc–Dc converters are presented. The fundamentals governing the design, control and performance of the Dc–Dc converters are also illustrated. Two methods for computing the duty cycle are investigated. Simulation results for Buck converter using first topology and second method for computing the duty cycle have been obtained using appropriate scaling factors associated with the input variables of the fuzzy control.<\div>

۵A Study on the Effects of the Frame Modulation Changes in the Seismic Response Parameters of Bundled Tube Structures under Near–Field Records
اطلاعات انتشار: کنفرانس بین المللی عمران، معماری و زیرساخت های شهری، سال
تعداد صفحات: ۱۰
In this article, a study of the effects caused by the changes in the modulation of the frame structure on the performance of the lateral resisting systems with a bundled–tube structure is presented which is based on the assessment of the nonlinear dynamic response under near and far field records. Three different modulations having bundled–tube structures with an orderly plan are chosen for two 10–story and 20–story buildings and are designed according to the Iranian seismic code 2800, fourth edition and also the Iranian National Building Code (Steel Structures – Division 10). Moreover, in this research, the main criterion in choosing near field records for nonlinear time history analyses has been the presence of a singular coherent pulse with a long period and high amplitude accompanied with multiple pulse–like waveforms in the time history of ground motion. The analytical assessment of the results of this research has been done with a major focus on modulation changes in the structure's height and its effect on the fluctuation of seismic response parameters, such as lateral displacement and story drift which are of notable importance in the designing process. It has been observed that subject to near field records contain velocity pulses, the drift response parameter has relatively similar amounts in the 10–story building and its changes become more apparent as the height increases.<\div>

۶A Sensor less MPPT technique for direct–drive PMSG wind turbines
نویسنده(ها): ،
اطلاعات انتشار: کنفرانس بین المللی مهندسی برق، سال
تعداد صفحات: ۱۷
This paper proposes a sensorless maximum power point tracking (MPPT) algorithm for direct–drive permanent magnet synchronous generator (PMSG) wind turbines which are controlled by a space–vector modulation–direct torque control (SVM–DTC) method. The algorithms uses a combination of optimal torque (OT) method and perturb and observe (P&O) to produce an accurate optimal torque reference according to wind speed variations to achieve the MPPT control of the WTG without measuring the wind speed. The effectiveness of the proposed MPPT algorithm is verified by Matlab simulation results on a 1.5–MW direct–drive, low speed, and multipole PMSG wind turbine<\div>
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