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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Iranian Journal of Medical Physics
- نوع مقاله: Journal Article
- کلمات کلیدی: γ –index,Cubic Spline,Dose Calculation
- چکیده:
- چکیده انگلیسی: Introduction
Relative dose computation is a necessary step in radiation treatment planning. Therefore, finding an approach that is both fast and accurate seems to be necessary. The purpose of this work was to investigate the feasibility of natural cubic spline to reconstruct dose maps for linear accelerator radiation treatment fields in comparison with those of the simulation.
Materials and Methods
A natural cubic spline algorithm was used to reproduce dose calculations of linac radiation treatment fields resulting from GEANT4 application for tomographic emission (GATE) simulation. The spline algorithm was used to compute percent depth dose of radiation therapy fields for 6 MV X-rays, which were calculated by simulation of Elekta Compact Linac. It reconstructed 2-dimensional dose maps and created isodose distributions. This dose maps were evaluated and compared with the simulation, where the γ -index was used.
Results
A good agreement was found between the doses calculated from the simulation and the spline. In particular, an average γ-index passing rate of 0.24 was obtained for sample percent depth dose distributions, and an average γ -index passing rate of 0.20 was observed for sample dose profiles.
Conclusion
Natural cubic spline has been established to calculate dose maps from field characteristics. The feasibility and possibility of natural cubic spline to calculate dose maps for linac radiation therapy fields in a homogeneous phantom has been demonstrated.- انتشار مقاله: 11-04-1392
- نویسندگان: Hamid-Reza Sadoughi,Shahrokh Nasseri,Mahdi Momennezhad,Hadi Sadoghi-Yazdi,Mohammad-Hossein Zare,Mohammad-Hossein Bahreyni-Toosi
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Finance and Managerial Accounting
- نوع مقاله: Journal Article
- کلمات کلیدی: Accounting Information System,Maturity of accounting information system,Maturity indices of accounting information system
- چکیده:
- چکیده انگلیسی: Management accounting highlights the use of accounting information for decision making and optimal control and management of executives in organizations. Accounting information is provided comprehensively by the accounting information system (AIS). To develop the AIS, the maturity of the system should be determined. In this regard, the first step is to identify and categorize maturity factors and indices. This research study aimed to identify and categorize the factors and indices effective in measuring the AIS maturity in the large manufacturing industries located at Markazi province. The research method was descriptive and library method and field studies were also used to collect data. The statistical population encompassed two groups: AIS experts whose scientific comments were applied in the selection of indices, and the employees in experienced AIS who determined the impact of the factors. Using Factor Analysis, the factors and indices used to measure the AIS maturity were categorized and 36 effective indices in nine factors were selected. Then their impact was calculated using structural equations. Finally, the factors with effective indices were categorized and the findings and recommendations were provided to the major industries of Markazi province, as special beneficiaries, and other industries.
- انتشار مقاله: 18-10-1398
- نویسندگان: Hadi Yazdi,Mehrdad Ghanbari,Babak Jamshidinavid,Habiballah Javanmard
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Mathematical Finance and Application
- نوع مقاله: Journal Article
- کلمات کلیدی: Stock Returns,speculative bubbles,market downswing
- چکیده:
- چکیده انگلیسی: Recent studies show that individual investors tend to speculate on stock markets and hold shares with a lottery-like return. For this speculation of people have a significant impact on stock returns, individual investors must trade the same shares with the same time. The purpose of this study was to investigate the effect of the speculative bubble on the stock returns of companies in Iran. Following the design of the speculative bubble specification indexes, the transaction information was collected from the stock market in the five-year period from 2011 to 2015 and a sample of 106 companies was selected by systematic elimination method, which totaled 530
year-company. In this research, linear regression and correlation analysis were used to analyze the hypotheses of the research. To analyze the data and test the hypotheses, Eviews software was used. What can be said in the summing-up and conclusion of the general test of research hypotheses is that there is a speculative bubble in the Tehran Stock Exchange index. In addition, the speculative bubble has an impact on stock returns, and this effect has been confirmed in conditions of market boom and downswing. The results obtained in this study are consistent with the documents referred to in the theoretical framework of the research and financial literature.- انتشار مقاله: 11-08-1396
- نویسندگان: Soheil Ali,Hadi Yazdi
- مشاهده