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2. A full three dimensional Navier-Stokes numerical simulation of flow field inside a power plant Kaplan turbine using some model test turbine hill chart points.
- Author
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Hosseinalipour, S. M., Raja, A., and Hajikhani, S.
- Subjects
- *
NUMERICAL solutions to Navier-Stokes equations , *COMPUTER simulation , *GAS-turbine power-plants , *MATHEMATICAL models , *PERFORMANCE of gas turbines , *PROTOTYPES - Abstract
A full three dimensional Navier - Stokes numerical simulation has been performed for performance analysis of a Kaplan turbine which is installed in one of the Irans south dams. No simplifications have been enforced in the simulation. The numerical results have been evaluated using some integral parameters such as the turbine efficiency via comparing the results with existing experimental data from the prototype Hill chart. In part of this study the numerical simulations were performed in order to calculate the prototype turbine efficiencies in some specific points which comes from the scaling up of the model efficiency that are available in the model experimental Hill chart. The results are very promising which shows the good ability of the numerical techniques for resolving the flow characteristics in these kind of complex geometries. A parametric study regarding the evaluation of turbine performance in three different runner angles of the prototype is also performed and the results are cited in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
3. Developing energy performance label for office buildings in Iran.
- Author
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Bagheri, Farshid, Mokarizadeh, Vahab, and Jabbar, Mohsen
- Subjects
- *
OFFICE building energy consumption , *OFFICE buildings & the environment , *COMPUTER simulation , *BUILDING performance , *CLIMATIC zones , *MATHEMATICAL models - Abstract
Abstract: In this paper, technical procedure for developing energy performance label for office buildings in Iran is presented. According to inappropriate energy consumption indexes of the office buildings in Iran, present research was conducted for this group of buildings. For this purpose, a building energy simulator software tool was developed, validated, and applied to simulate an exhaustive sample society of office buildings. A widespread field activity was conducted to gather the modeling data from 285 office buildings through all the 4 climatic zones in Iran. Moreover, Reference Buildings as the energy efficient buildings were defined and modeled in the software environment. Energy consumption indexes from modeling of sample society and Reference Buildings were applied to conclude the boundaries for grades A–G of the label. Finally, the label appearance was designed and authorized to be applied for both the existent and new buildings. The upper limit for grade A is determined as: 84, 75, 78, and 82 (kWh/Y/m2) and the upper limit of grade G (the failing point) is concluded as: 588, 525, 546, and 574 (kWh/Y/m2) for cold, mild, hot and dry, and hot and wet climatic zones, respectively. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
- View/download PDF
4. Prediction of hepatitis B virus lamivudine resistance based on YMDD sequence data using an artificial neural network model.
- Author
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Ravanshad, Mehrdad, Sabahi, Farzaneh, Falahi, Shahab, kenarkoohi, Azra, Amini-Bavil-Olyaee, Samad, Hosseini, Seyed Younes, Madvar, Hossein Riahi, and Khanizade, Sayad
- Subjects
- *
LAMIVUDINE , *ALGORITHMS , *CHRONIC diseases , *COMPUTER simulation , *DRUG resistance , *GENETIC techniques , *HEPATITIS B , *MATHEMATICAL models , *ARTIFICIAL neural networks , *HEALTH outcome assessment , *PATIENTS , *STATISTICS , *SURGERY , *PHENOTYPES , *THEORY , *MULTIPLE regression analysis , *PREDICTIVE validity , *TREATMENT effectiveness , *THERAPEUTICS - Abstract
Background: Hepatitis B virus (HBV) infection is an important health problem worldwide with critical outcomes. The nucleoside analog lamivudine (LMV) is a potent inhibitor of HBV polymerase and impedes HBV replication in patients with chronic hepatitis B. Treatment with LMV for long periods causes the appearance and reproduction of drug-resistant strains, rising to more than 40% after 2 years and to over 50% and 70% after 3 and 4 years, respectively.Objectives: Artificial neural networks (ANNs) were used to make predictions with regard to resistance phenotypes using biochemical and biophysical features of the YMDD sequence.Patients and Methods: The study population comprised patients who were intended for surgery in various hospitals in Tehran-Iran. An ACRS-PCR method was performed to distinguish mutations in the YMDD motif of HBV polymerase. In the training and testing stages, these parameters were used to identify the most promising optimal network. The ideal values of RMSE and MAE are zero, and a value near zero indicates better performance. The selection was performed using statistical accuracy measures, such as root mean square error (RMSE), coefficient of determination (R2), and mean absolute error (MAE). The main purpose of this paper was to develop a new method based on ANNs to simulate HBV drug resistance using the physiochemical properties of the YMDD motif and compare its results with multiple regression models. Results: The results of the MLP in the training stage were 0.8834, 0.07, and 0.09 and 0.8465, 0.160.04 in the testing stage; for the total data, the values were 0.8549, 0.115, and 0.065, respectively. The MLP model predicts lamivudine resistance in HBV better than the MLR model. Conclusions: The ANN model can be used as an alternative method of predicting the outcome of HBV therapy. In a case study, the proposed model showed vigorous clusterization of predicted and observed drug responses. The current study was designed to develop an algorithm for predicting drug resistance using chemiophysical data with artificially created neural networks. To this end, an intelligent and multidisciplinary program should be developed on the basis of the information to be gained on the essentials of different applications by similar investigations. This program will help design expert neural network architectures for each application automatically. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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