10 research outputs found

    Morphometric and meristic study of Garra rufa populations in Tigris and Persian Gulf Basins

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    This study was conducted to determine morphometric and meristic characteristics of Garra rufa in 13 stations of Tigris and Persian Gulf basins. We caught 310 specimens during the year 2007-2008 using electro-shocker and sachok. Univariate analysis of variance (ANOVA) and principal component analysis were conducted and the ANOVA revealed significant differences in 28 morphometric and 9 meristic factors (P<0.05). Factor analysis showed that G. rufa of thirteen stations had 48.855% changes in 3 factors of the first morphometric characters (pectoral fin length, ventral fin length, depth of anal fin) and 71/611% changes in 3 factors of the first meristic characters (lateral line scales , circum peduncle scales, predorsal scales). Plotting the first and second principal component morphometric and meristic characters showed that the Mond River population was separated from the others but the other populations were overlapping with each other in the characteristics studied

    ESTIMATING AND FUSING OPTICAL FLOW, GEOSTROPHIC CURRENTS AND SEA SURFACE WIND IN THE WATERS AROUND KISH ISLAND

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    The aim of this study is calculation of sea surface currents (SSCs) which are estimated from satellite data sets and processed with the variance component estimation (VCE) algorithm to check role of each data set, in fused surface currents (FSCs). The satellite data used in this study are sea surface temperature (SST), satellite altimetry data and sea surface wind (SSW) that plays the important role to make the SSCs and is measured by Ascat satellite. We use optical flow (OF) method (Horn-Schunck algorithm) to extract sea surface movements from sequential SST imageries; in addition, geostrophic currents (GCs) are estimated by satellite altimetry data like sea surface height (SSH). Combining these data sets, has its pros and cons, the OF results are so dense and precise due to high spatial resolution of MODIS data (SST), but sometimes cloud covering over the sea, does not allow the MODIS sensor to measure the SST. In contrast the SST data, the altimetry data have poor spatial resolution and the GCs are not able to determine small scale SSCs. The VCE algorithm shows variances of our data sets and it can be shown their correlations with themselves and with the FSCs. We also calculate angular differences between FSCs and OF, GCs and SSW, and plot distributions of these angular differences. We discover that, the OF and SSW are homolographic, but OF and GCs are accordant to each other

    Investigation of Optical Flow Techniques for Extracting Non-Rigid Sea Surface Currents

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    This paper is about performance evaluation of two optical flow (OF) methods for extracting sea surface curved motions like eddies. By incorporating a simple matrix and its rotation in programming procedure, curved motion can be obtained. These two OF methods are Horn/Schunk and Lucas/Kanade. The Horn/Schunk method depends on a smoothness parameter (α) and when it changes, smoothness and reality change too. The Lucas/Kanade method is more complex than previous one. It depends on two parameters, smoothness parameter (Sigma) and window size (Win). Different values for Win and Sigma change smoothness and reality of the flows. Sea surface currents are extracted from two sequential sea surface temperature (SST) images by using OF methods. By using these methods and selecting the appropriate parameters like smoothness (for Horn/Schunk) and window size and smoothness (for Lucas/Kanade) extracting real flows or smooth flows are possible and investigated in this paper

    Human erroranalysis among petrochemical plant control room operators with human errorassessment and reduction technique

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    Background and aims Control room is a palpitating heart of a system, and any error in operator`s duties have irreparable consequences. Nowadays, in many work places such as nuclear industry, military and chemical parts human error can cause catastrophic event that led many events around the world, so the purpose of this study is analyzing human error in a utility unit control room of a Petrochemical Company using HEART method.MethodsData collection was done by direct observation methods, interview with "Bordman", senior shift, boss of Fuel vapor, related experts and analysis of previous incidents that occur. Then job analysis and human error identified respectively by HTA and TRACEr technique. Additionally, the error probability determined with HEARTtechniques which is a one of the tools of human reliability assessment.ResultsThe most important factors in incidence of human error at the control room operators were: fatigue, experience, consciousness, complexity of information, focus error and Error producing conditions were diagnosed: mental stress, High work load, focus, clear guidelines, lack of training and the task adaptation,. The most calculated likely error in the duties: reload bugs, boiler commissioning, control of production, maintenance, warning signs control.Conclusionthe results can be acknowledged that supervisor duties "Nobatkar" control room because of a high sensitivity range of error likely to have occurred and solutions must be proposed. This technique for this group should be priorited

    An FCM-based dynamic modeling of operability and maintainability barriers in road projects

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    Building a new road infrastructure in the country leads to economic and industrial growth. A massive amount of money is paid by governments to build them; however, they fail due to many reasons related to operability and maintainability (O&M) issues. They are not also completed within the expected budget, time, and quality; so they are not justifiable. As these factors have a strong impact on projects, to reduce the final cost and other mentioned problems, it is necessary to identify the existing O&M barriers, their interrelationships, and their effects on the three mentioned factors. An in-depth literature review is conducted to identify the barriers. The fuzzy cognitive mapping (FCM) technique is used to model O&M barriers using real case data analyses. The findings reveal that managerial factors have more significanct impacts on the project’s success compared to other factors such as organizational, human resource, technology, and project management. Therefore, management methods are very important in developing integration in the project. Identifying, classifying, and determining the effects of barriers to entry of O&M contractors on the cost, time, and quality of road infrastructure projects show the signifcance of conducting this research, which is necessary to deal with the existing barriers. All these ultimately increase quality and reduce time and cost in road infrastructure projects
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