Comparison between artificial neural networks and mathematical models for estimating equilibrium moisture content in raisin

Empirical models and Artificial Neural Networks (ANNs) were utilized for the prediction of Equilibrium Moisture Content (EMC) in raisin.  Six empirical models including GAB, Smith, Henderson, Oswin, Halsey and D’Arsy-watt were applied for this estimation.  Two types of Multi Layer Perceptron (MLP) neural networks entitled Feed Forward Back Propagation (FFBP) and Cascade Forward Back Propagation (CFBP) were used.  In order to train the input patterns, two training algorithms consist of Levenberg-Marquardt (LM) and Bayesian regularization (BR) were used.  Thermal and relative humidity limits were 30-80℃ and 10.51%-83.62%, respectively.  The best result for mathematical models belonged to D’Arsy-Watt with R2 and the mean relative error of 0.9943% and 10.84%, respectively.  The best outcome for the use of ANN also appertained to FFBP network with LM training algorithm, topology of 2-3-3-1 and threshold function order of TANSIG-TANSIG-PURELIN.  With this optimized network, R2 and the mean relative error was 0.9969% and 8.32%, respectively.  These results show the supremacy of ANN, in comparison with empirical models.  In order to predict the EMC in raisins, empirical models can therefore be replaced with the ANN.Keywords: ANN, back propagation, sorption isotherm, EMC, Iran Citation: Chayjan R. Amiri, and M. Esna-Ashari.  Comparison between artificial neural networks and mathematical models for estimating equilibrium moisture content in raisin.  Agric Eng Int: CIGR Journal, 2010, 12(1): 158-166

Comparison of Soil Classification Methods Using CPT Results

A series of cone penetration test were conducted in the southeast of Tehran to assess the liquefaction potential in this area. At the same time, after sounding of each cone penetration test, soil samples were also taken from different depths of boreholes to visually verify the soil classification. Seventy four samples from twenty boreholes were taken and their soil characteristics were obtained. To classify the soil layers, using recorded data, two various soil behaviour classification charts proposed by Robertson and Wride (1988), and Marr (1981) were examined which for some cases different results were obtained. In this paper validity of these procedures are investigated and discussed in details. These soil classification methods in some cases give a good results but there is a different between those charts and observed soil classification, particularly when the soil contain fines and therefore some modification must be applied

Optimal Input Design for Subspace-Based Fault Detection and Identification

This study focuses on input design for subspace based fault detection and identification methods and investigates its possible advantages over using noise inputs. In several real applications the noise available in environment is the only input to the system and in some cases produce low quality output data for subspace identification and fault detection purposes. Therefore, model order may be underestimated. Due to the nature of subspace based methods, some modes of the system may not appear in the response as the input is not strong enough to excite these modes. In order to improve the result, a method is suggested in literature, that is to use "rotated" input. The rotated input design is proposed in several papers to apply to "ill conditioned systems" in which the vector of different outputs are typically close to collinearity if a white noise is used. In this report, we use this technique to verify possible improvement of subspace-based identification method including output-only, and input-output approaches. Then, for the first time we investigate the possible impacts of the rotated input on subspace base fault detection method. Simulations on a high-purity distillation column shows that this auxiliary input can improve subspace-based fault detection and identification

Contribution of ultramafic rocks in central Sanandaj-Sirjan zone to the characterizing of physio-chemical condition during initiation of subduction

In the central part of the Sanandaj-Sirjan zone, there is an ultramafic rock exposure (hornblendite and pyroxenite) adjacent to Molataleb felsic complex completely located between Azna and Aligoodarz towns. The ultramafic rocks are actually cumulates derived from boninitic magma. During Upper Triassic-Lower Jurassic time the boninitic magma has been originated from mantle wedge as the result of initiation of Neo-Tethys subduction. Later, when subduction was proceeding, the felsic rocks crystallized in Middle Jurassic. Major elements composition of olivine, pyroxene, amphibole and minor plagioclase from the ultramafic rocks reveals crystallization from a sub-alkaline to calc-alkaline magma in a subduction zone setting. Primary minerals have chemical characteristics typical of those derived from a magma with low oxygen fugacity. Different methods for minerals thermobarometry indicate that amphiboles crystallized in relatively low temperature (880°C) but crystallization condition of other minerals corresponds to higher temperatures (1000-1200°c). They were crystallized at pressure condition equal to 5.85 kbar corresponding to the depth of ~17 km. It is not common that a mantle wedge at the depth of ~17 km to be affected by such high thermal gradient during the normal subduction process. Asthenospheric flow around the subducting slab edge during subduction initiation can explain high thermal gradient prevailed the infant mantle wedge. This mechanism corresponds to the boninitic nature of the ultramafic rocks

Evaluation of the pulse pressure index at the peak of exercise before and after cardiac rehabilitation

Background and Objectives: As a new supplementary therapeutic option, cardiac rehabilitation (CR) is getting more attention each day. Several studies have proved the positive impact on qualitative criteria but few studies have been done on quantitative criteria.The purpose of the survey in this study is to evaluate the impact of CR on non-invasive estimated maximum cardiac output by Pulse Pressure index (PPI) at the  peak of exercise.Methods: This is a nonrandomized prospective cohort study conducted in Hamadan, Iran in 2015.100 eligible patients who underwent coronary artery bypass surgery, based on cardiologist permission and an informed consent, participated in our study. The PPI was measured at the peak of exercise before and after standard CR program.Result: In overall, mean of PPI was not significantly different before and after CR. PPI was noticeably increased in patients younger than 60 years old (p = 0.022). In contrast to hypertensive patients, PPI in non-hypertensive patients increased significantly after CR (p=0.002). PPI considerably increased in non-diabetic patients after CR (p=0.046), but not in diabetic individuals. Other variables had not any significant effect on PPI in response to CR.Conclusion: it is clear that PPI is associated with vascular atherosclerosis, as well as cardiac output; Positive effects of CR diminish in older, diabetic and hypertensive patients with more progressive atherosclerosis