Fault Diagnosis of a Variable-Speed Wind Turbine via Support Vector Machines

In recent years, wind energy is considered as the most practical substitute energy to replace the fossil fuels. Wind turbines are massive and installed in locations, where a non-planned maintenance is very costly. Therefore, a fault-tolerant control system that is able to maintain the wind turbine connected after the occurrence of certain faults can avoid major economic losses. To keep the wind turbine operational or at least safe, in severe cases, a reliable fault diagnosis methodology has to be exploited. It must detect, in the required time, any deviation of the system behaviour from its ordinary case, identify the location and type of the fault and reconfigure the control system to accommodate the so-called discrepancy. To achieve the above goals, a vast number of methods have been suggested by many researchers all around the world. In this thesis, the promising classification framework of the Support Vector Machines is applied to fault detection for variable speed turbines, highlighting its features. In this regard, different fault scenarios are imposed on a benchmark model of a horizontal-axis wind turbine to check the functionality of the mentioned fault detector and the control reconfiguration module

Surveying relationship between biorhythm and making error in buying stock in Tehran stock exchange

Biorhythm is defined as any repeated pattern of physical, emotional, and intellectual activities which some believe to affect human's behavior. This article studies relationship between Biorhythm, 3 dimensions of Biorhythm (Emotional, Physical and Intellectual) and making error in buying stock in Tehran stock exchange. Statistical population of the present study includes all stock buyers in stock exchange at 2014 that of these 312 buyers selected randomly as sample. This research is applicable in terms of goal and descriptive from solidarity category in terms of methodology and is survey in terms of collecting data. For research hypothesis test, Phi & Cramer's test was used because both of indexes are nominal. Results show there is a meaningful relationship between critical manners in Biorhythm (Emotional, Physical and Intellectual) and error in buying stock (the one that should not be bought) in Tehran stock exchange

Investigating the factors affecting the competitiveness of small and medium companies in Sanandaj

The present study is conducted to investigate the factors affecting the competitiveness of small and medium companies in Sanandaj city, Iran. 177 small and medium companies were investigated and 130 questionnaires were prepared by using stratified random sampling and 121 experts and administrators have responded to the questionnaire. According to the theoretical principles, samples are provided that the research findings confirmed the model and result of path analysis showed the direct effect of variables of industry and specialized environment on companies' competitiveness. In the present study in order to analyze the data obtained from the questionnaires, due to the statistical needs the social sciences statistical software, structural equation of partial least squares model methods were used in form of descriptive and correlations statistics. Finally, these factors were prioritized by using the Friedman test. According to the obtained results from this research, the mean of the existing competitors' rate was 4.41 which has the lowest rate in affecting the competitiveness of small and medium companies. But we can see the highest rates of influencing the competitiveness of small and medium companies in the management dimension with the mean rate of 7.70. Therefore, the highest and lowest influencing rate can be seen in both industry and specialized environment sectors by comparing the mean of rates

Investigating the factors affecting the competitiveness of small and medium companies in Sanandaj

The present study is conducted to investigate the factors affecting the competitiveness of small and medium companies in Sanandaj city, Iran. 177 small and medium companies were investigated and 130 questionnaires were prepared by using stratified random sampling and 121 experts and administrators have responded to the questionnaire. According to the theoretical principles, samples are provided that the research findings confirmed the model and result of path analysis showed the direct effect of variables of industry and specialized environment on companies' competitiveness. In the present study in order to analyze the data obtained from the questionnaires, due to the statistical needs the social sciences statistical software, structural equation of partial least squares model methods were used in form of descriptive and correlations statistics. Finally, these factors were prioritized by using the Friedman test. According to the obtained results from this research, the mean of the existing competitors' rate was 4.41 which has the lowest rate in affecting the competitiveness of small and medium companies. But we can see the highest rates of influencing the competitiveness of small and medium companies in the management dimension with the mean rate of 7.70. Therefore, the highest and lowest influencing rate can be seen in both industry and specialized environment sectors by comparing the mean of rates

Top Management Support Fuzzy Set Analysis Finding TMS the Most Important

This paper builds on the work of Young and Jordan (2008) and Poon et al. (2011) to provide stronger empirical evidence that TMS is the most important factor for project success. It adds to the evidence that current practice emphasizing project methodologies may be misdirecting effort. The contribution of this research may be to provide enough evidence to influence top managers and practitioners to re-evaluate the conventional wisdom of the past 40-50 years. Researchers and practitioners, using the fuzzy-set analytical approach are introduced to a method to compare all their project experiences and determine conclusively the most important critical success factors for project success. There are significant implications for board, senior management and project management practice and academia

The effect of dividend policy on stock price volatility and investment decisions

The allocation of a part of the profit as the dividends considered as one of the significant issues in financial management. Through applying this policy, the main purpose is the capital maximization of stockholders by receiving the dividend and increasing the stock price. The purpose of the present research is to assess the effect of dividend policy on stock price volatility and investment decisions. The statistical community of the present research includes the admitted firms into the Tehran Stock Exchange of which only 65 firms have been selected after the application of the considered criteria. The time of the research is three years from 2007 to 2012 and correlation analysis method and multiple regressions were used in order to analyze the data and test the hypotheses. The research results indicate that the dividend policy has a significant effect on stock price volatility in a short time. However, the dividend policy does not have a significant effect on stock price volatility in a long time. Moreover, the dividend policy does not have a significant effect on investment decisions in terms of cash and accrual

Convective Heat Transfer and Pumping Power Analysis of MWCNT + Fe3O4/Water Hybrid Nanofluid in a Helical Coiled Heat Exchanger with Orthogonal Rib Turbulators

Utilizing nanofluids in heat exchangers can lead to improved thermal performance. Nanofluids with suspended carbon nanotubes are specifically desirable in thermal systems because of their unique capabilities. In this study, convective heat transfer and required pumping power are studied simultaneously for a helical coiled heat exchanger with laminar water flow while incorporating 0.1 and 0.3 percent volume fraction of the hybrid nanofluid MWCNT + Fe3O4/water. Two different geometries of bare and ribbed tubes are used for the heat exchanger part. The ribs are chosen to be orthogonal, i.e., 90° with respect to the inclined ones. Three different Reynolds numbers are selected for investigation, all in laminar flow regime based on the non-dimensional M number defined in coiled tubes. Computational fluid dynamics is used to study thermal and fluid behavior of the problem. The convective heat transfer coefficient can serve as a criterion to measure the effectiveness of utilizing nanofluids in heat exchangers by taking the pressure drop and pumping power of the system into consideration. Finally, the artificial neural network curve fitting tool of MATLAB is used to make a good fit in the data range of the problem. It is shown that for most cases of the study, the pumping power ratio is less than 1 that can be considered appropriate from energy consumption viewpoint.publishedVersio

The effect of dividend policy on stock price volatility and investment decisions

The allocation of a part of the profit as the dividends considered as one of the significant issues in financial management. Through applying this policy, the main purpose is the capital maximization of stockholders by receiving the dividend and increasing the stock price. The purpose of the present research is to assess the effect of dividend policy on stock price volatility and investment decisions. The statistical community of the present research includes the admitted firms into the Tehran Stock Exchange of which only 65 firms have been selected after the application of the considered criteria. The time of the research is three years from 2007 to 2012 and correlation analysis method and multiple regressions were used in order to analyze the data and test the hypotheses. The research results indicate that the dividend policy has a significant effect on stock price volatility in a short time. However, the dividend policy does not have a significant effect on stock price volatility in a long time. Moreover, the dividend policy does not have a significant effect on investment decisions in terms of cash and accrual

RE-ASSESSING THE IMPORTANCE OF NECESSARY OR SUFFICIENT CONDITIONS OF CRITICAL SUCCESS FACTORS IN IT PROJECT SUCCESS: A FUZZY SETTHEORETIC APPROACH

Despite more than fifty years of intensive effort, the issue of IT project failure remains unresolved. It has been suggested that conventional approaches may be misdirecting project management effort and moreover research shows top management support to be of critical importance (e.g. Young and Jordan 2008; Tichy and Bascom 2008). However, existing empirical evidence may have a strong reliance on selective exemplary cases of top management support and they do not account for counterexamples and counterfactuals. This paper lays the foundation for further research to resolve this issue by reassessing the original research using a more systematic approach: fuzzy-set analysis. The main contribution of the paper is methodological. In overcoming the numerical limitation of multiple case study research it provides a standard approach to compare large numbers of case studies. Researchers and practitioners are provided with an approach to compare and reconcile diverse project experiences and unambiguously determine the critical success factors that are the most important for project success

The effect of dividend policy on stock price volatility and investment decisions

The allocation of a part of the profit as the dividends considered as one of the significant issues in financial management. Through applying this policy, the main purpose is the capital maximization of stockholders by receiving the dividend and increasing the stock price. The purpose of the present research is to assess the effect of dividend policy on stock price volatility and investment decisions. The statistical community of the present research includes the admitted firms into the Tehran Stock Exchange of which only 65 firms have been selected after the application of the considered criteria. The time of the research is three years from 2007 to 2012 and correlation analysis method and multiple regressions were used in order to analyze the data and test the hypotheses. The research results indicate that the dividend policy has a significant effect on stock price volatility in a short time. However, the dividend policy does not have a significant effect on stock price volatility in a long time. Moreover, the dividend policy does not have a significant effect on investment decisions in terms of cash and accrual