Islamic Azad University at Khorasgan

www.khuisf.ac.ir
Esfahan, Iran
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Ahmadi I.,Islamic Azad University at Khorasgan
Soil and Tillage Research | Year: 2017

The theoretical understanding of the working mechanism of a machine, prepares an opportunity to re-design it without performing the re-fabrication process. In this study, a thorough mechanical model for a rotary tiller is developed that contains both kinematics and kinetics viewpoints of its operation. Specifically, the main aim of this model is to develop a theoretical calculator concerning the torque and power requirement of this active tillage machine. To perform the required calculations simply, and automatically, the derived equations were entered into an Excel spreadsheet, and the results was presented as the torque and power of a rotary tiller. The developed formulas were verified by comparing the results of the model with the acquired results of other studies. The average errors of the calculated specific work of a rotary tiller compared with the results obtained in the studies of Asl and Singh (2009) and Bernacki et al., (1972) were 16% and 14%, respectively. The average error of the calculated power by comparison with the results of Perdok and Burema (1977) was 21%. The average error of the calculated fetch ratio in comparison with the results of the study of Thakur and Godwin (1989) was 9%. Finally, the average error of the calculated torque in comparison to the study of Chertkiattipol and Niyamapa (2010), was 5%. Therefore, good estimates are expected to be obtained when using the developed calculator. © 2016 Elsevier B.V.


Eghbalsaied S.,Islamic Azad University at Khorasgan
Tropical Animal Health and Production | Year: 2011

This study was aimed to assess genetic parameters for 13 traits in heifers and first-parity Holstein dairy cows. Data consisted of calving and insemination dates of 14,707 Holstein dairy cows in Isfahan province of Iran. Reproductive traits included age at first service (AFS), first service to conception (FSTC), gestation length (GL), age at first calving (AFC), calving to first service (CTFS), days open (DO), calving interval (CI), number of services per conception (NS), and non-return rate at 56 days (NRR). Model equations were optimized using GLM procedure in SAS package following genetic analysis using animal models in ASREML software. Minimum and maximum departure from normal distribution for phenotypic records belonged to AFS, NRR, GL, DO, CI and AFC, NS, FSTC, CTFS, respectively. Estimated heritability varied from 0.002 (NRR) to 0.184 (GL) in heifers and from 0.003 (NRR) to 0.153 (GL) in first-parity cows. AFS, CTFS, and GL were noticeably heritable compared to other assessed traits. Estimated absolute additive genetic correlations were in the range of 0.01 (NRR and AFS) and 0.99 (NRR and NS) in heifers and 0.07 (GL and CI) to 1 (FSTC and CI) in cows. Additive genetic correlations were antagonistic between AFS and other traits, except AFC. Interestingly, NRR which has been included in sire catalogs had the highest average absolute genetic associations with other traits. © 2010 Springer Science+Business Media B.V.


Hadi-Vencheh A.,Islamic Azad University at Khorasgan | Mohamadghasemi A.,Islamic Azad University
Expert Systems with Applications | Year: 2011

In order to efficiently control the inventory items and determine the suitable ordering policies for them, multi-criteria ABC inventory classification, which is one of the most common techniques of production and inventory control, is used. In this classification, other criteria in addition to annual dollar usage are taken into account and then the items are classified in three classes with different ordering policies, based on their priority. In this paper, we propose an integrated fuzzy analytic hierarchy process-data envelopment analysis (FAHP-DEA) for multiple criteria ABC inventory classification. The proposed FAHP-DEA methodology uses the FAHP to determine the weights of criteria, linguistic terms such as Very High, High, Medium, Low and Very Low to assess each item under each criterion, the data envelopment analysis (DEA) method to determine the values of the linguistic terms, and the simple additive weighting (SAW) method to aggregate item scores under different criteria into an overall score for each item. The integrated FAHP-DEA methodology is illustrated using a real case study. © 2010 Elsevier Ltd. All rights reserved.


Hadi-Vencheh A.,Islamic Azad University at Khorasgan | Mirjaberi M.,Islamic Azad University at Khorasgan
IEEE Transactions on Fuzzy Systems | Year: 2011

This paper incorporates the basic concepts of subjectivity with the objective of decision theory to develop a method which intellectualizes ambiguity into multiple-criteria decision-making (MCDM) problems. An outranking intensity is introduced to determine the degree of overall outranking between competing alternatives, which are represented by fuzzy numbers. The comparison of these degrees is made through the concept of overall existence ranking index. Comparative examples, as well as a case study, are given to illustrate the approach. © 2010 IEEE.


Hadi-Vencheh A.,Islamic Azad University at Khorasgan
International Journal of Computer Integrated Manufacturing | Year: 2011

Supplier evaluation and selection problem has been studied extensively. Various decision-making approaches have been proposed to tackle the problem. In contemporary supply chain management, the performance of potential suppliers is evaluated against multiple criteria rather than considering a single factor-cost. This article proposes a new weighted nonlinear model to solve the multiple criteria supplier-selection problem. The proposed model not only incorporates multiple criteria for supplier selection but also maintains the effects of weights in the final solution. An illustrative example is presented to compare the proposed model and those in the literature. © 2011 Taylor & Francis.


Ahmadi I.,Islamic Azad University at Khorasgan
Turkish Journal of Agriculture and Forestry | Year: 2013

To examine the effects of different geometries and mass specifications of a tractor operating across irregular sloping grounds on the lateral stability of this machine, a dynamic model was developed. In the proposed model, overturn and skid instabilities were studied and the tractor stability indexes were formulated (i.e. TSIoverturn and TSIskid). Using a modified Excel spreadsheet package employing the parameters of the model, the TSIs were then determined. Finally, the effects of variation in the parameters of the model on TSIs were evaluated. The results of the analyses indicate that changing the tractor mass moment of inertias about the x- and y-axes had no influence on TSIskid, whereas increasing the tractor mass moment of inertias about the x-axis by 71% led to a 2.5% reduction of TSIoverturn and increasing the tractor mass moment of inertias about the y-axis by 71% led to a 1.8% reduction of TSIoverturn. However, increasing the wheel-ground coefficient of friction from 0.34 to 0.84 improved TSI by up to 27%. Moreover, the effect of tractor wheel track width and the height of its center of gravity on TSIoverturn was greater than the effect of the tractor wheel base on this stability index. Therefore, the best strategy for stabilizing a tractor against overturn is to lower the tractor's center of gravity and increase the tractor's wheel track width simultaneously. © TÜBİTAK.


Mokhtarian M.N.,Islamic Azad University at Tehran | Hadi-Vencheh A.,Islamic Azad University at Khorasgan
Applied Soft Computing Journal | Year: 2012

The selection of a facility location among alternative locations is a multiple criteria decision making (MCDM) problem including both quantitative and qualitative criteria. In more cases, in real word situations, determining the exact values for MCDM problems and especially for facility location selection problems is difficult or impossible. So, the values of alternatives with respect to the criteria or/and the values of criteria weights, are considered as fuzzy values (fuzzy numbers) so that the conventional crisp approaches for solving facility location selection problems and other MCDM problems tend to be less effective for dealing with the imprecise or vagueness nature of the linguistic assessments. In such conditions, the fuzzy MCDM methods are applied for solving facility location selection problem and other fuzzy MCDM problems. In this paper, we propose a new fuzzy TOPSIS method based on left and right scores for solving fuzzy MCDM problems. We apply the proposed method for solving three numerical examples. The first two numerical examples are proposed for the purpose of comparison. The third numerical example is a real application in which the selection is an industrial zone among several industrial zones for constructing dairy products factory. As a result, we found that the proposed method is practical for solving facility location selection problem and other fuzzy MCDM problems. Moreover, it seems that the proposed fuzzy TOPSIS method is flexible and easy to use and has acceptable accurate. © 2012 Elsevier B.V.


Hadi-Vencheh A.,Islamic Azad University at Khorasgan | Mirjaberi M.,Islamic Azad University at Khorasgan
Information Sciences | Year: 2014

Multiple attribute decision making forms an important part of the decision process for both small (individual) and large (organization) problems. When available information is precise, many methods exist to solve this problem. But the uncertainty and fuzziness inherent in the structure of information make rigorous mathematical models inappropriate for solving this type of problems. This paper incorporates the fuzzy set theory and the basic nature of subjectivity due to the ambiguity to achieve a flexible decision approach suitable for uncertain and fuzzy environment. The proposed method can take both real and fuzzy inputs. An outranking intensity is introduced to determine the degree of overall outranking between competing alternatives, which are represented by fuzzy numbers. Numerical examples finally illustrate the approach.


Ahmadi I.,Islamic Azad University at Khorasgan
Journal of Terramechanics | Year: 2011

In order to investigate the effects of forward speed, ground slope and wheel-ground friction coefficient on lateral stability of tractor at the presence of position disturbances, a tractor dynamic model was developed. In this model two types of instability were considered: instability due to overturn and skid and for each case the stability index was determined. Different geometries and mass specifications of tractor MITSUBISHI-2501D were used to examine the model. According to the results of this model forward speed and ground slope had a reverse effect on all stability indexes. Moreover stability of this tractor was more affected by tractor skidding than overturning. Therefore to improve the overall stability of this tractor, preference should be on increasing the tractor stability index derived from skid dynamics of tractor. © 2011 ISTVS. Published by Elsevier Ltd. All rights reserved.


Modaresi M.,Islamic Azad University at Khorasgan
Journal of Animal and Veterinary Advances | Year: 2012

The herbs garlic, elderberry, black seed have acknowledged therapeutic use in traditional medicine. With their immune-effective compounds, they are of much application in the traditional treatment of infections, the present study attempts a comparative investigation of the roles of the aforementioned herbs in the immune system and blood proteins. In this study, the mice of the Balb/C genus were divided into four groups: control, 1, 2 and 3. Each of these received 50, 100, 200 mg kg -1 of garlic, elderberry and black seed extracts, respectively. The extract was injected using the Inner Peritoneum (IP) Method every other day for 20 days. At the end of the experiments, blood samples were taken to conduct a count of white blood cells and an electrophoresis of blood proteins. The results were evaluated through SPSS at a p<0.05 level. The analysis indicates that black seed and garlic extract were able to increase the number of white blood cells. While black seed gave rise to the amount of white blood cells and also caused the albumin, alpha 1 and 2 proteins and the A/G ratio to increase, garlic was effective in raising alpha 1 and gamma globulin levels. This is in contrast with elderberry which plays a significant role in decreasing the gamma protein's density. The two herbs, garlic and black seed, impressed the immune system through changing the density of such blood proteins albumin, alpha 1 and 2 and altering the number of white blood cells whereas the result suggest no significant effect in the case of elderberry. © Medwell Journals, 2012.

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