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Prediction of Materials Density according to Number of Scattered Gamma Photons Using Optimum Artificial Neural Network
Gholam Hossein Roshani,Seyed Amir Hossein Feghhi,Farzin Shama,Abolfazl Salehizadeh,Ehsan Nazemi
Journal of Computational Methods in Physics , 2014, DOI: 10.1155/2014/305345
Abstract: Through the study of scattered gamma beam intensity, material density could be obtained. Most important factor in this densitometry method is determining a relation between recorded intensity by detector and target material density. Such situation needs many experiments over materials with different densities. In this paper, using two different artificial neural networks, intensity of scattered gamma is obtained for whole densities. Mean relative error percentage for test data using best method is 1.27% that shows good agreement between the proposed artificial neural network model and experimental results. 1. Introduction The gamma-ray photons lose their energy in a stopping medium by these processes: photoelectric effect, Compton effect, pair production, and photonuclear effect. With the analysis of these interactions, some information about characteristics of materials can be obtained. Compton scattering is strongly dependent on the materials density. Therefore, this method is very good choice for densitometry of unknown materials [1–6]. El Abd [7] has shown that scattering photons are more sensitive than transmitted photons in order to density meter and void fraction prediction. In [7], the void fraction has been predicted without using artificial neural network (ANN); therefore the error is considerable. In this paper, experimental data have been obtained from a density measurement tomography system [8]. These data were used for training the ANN. Set-up of this tomography system was shown in Figure 1. Figure 1: Schematic of tomography structure system. In investigated tomography system [8], a NaI (Tl) scintillation detector in 3 × 3 inch dimensions has been used. The detector records scattered photons from target sample. The source is 137Cs with 8？mci activation. Distances between the sample from the source collimator and the detector are 5.56？cm and 6？cm, respectively. Investigated samples have dimensions and thickness of 1 × 2？cm2 and 1？cm, respectively. The time durations of measurement are 100 seconds. Relative stochastic error has inverse relation with the number of registered counts in detector. In this study because the scattering method is used and the number of counts in this method is less in comparison with the transmission method, therefore the measurement time should be increased in order to decrease the stochastic error. By taking 100-second time duration, the stochastic errors are in the range of 0.5%–1.5% (5000–20000 counts for different materials). The experimental results are shown in Table 1. Table 1: Number of detected photons
Evaluation of Genetic Programming for modeling solute breakthrough curve through the temporal data assignment scenarios
Sepideh Karimi,Ali Ashraf Sdaraddini,Amir Hossein Nazemi,Reza Delear Hasannia
Journal of Civil Engineering and Urbanism , 2013,
Abstract: A modeling procedure was assessed in the present paper to investigate the abilities of GeneExpression Programming (GEP) approach for modeling solute breakthrough curve. The evaluation of theGEP method for modeling solute breakthrough curve was carried out through complete data scanningtechniques. In this way, a complete scan of the possible train and test set configurations was carried outaccording to temporal criteria using ‘leave one out’ procedures. The obtained results reveal that the suitableassessment of the model performance should consider a complete temporal and/or spatial scan of the data setused.
Photonuclear Effect on ITER Operation  [PDF]
Farshid Tabbakh, Amir Hossein Gharashi
Journal of Applied Mathematics and Physics (JAMP) , 2015, DOI: 10.4236/jamp.2015.38130
Abstract:

In this study, neutron and gamma radiation produced during the ITER tokamak operation including the nuclear heating were studied. This is an approach for analyzing the neutron flux by their contributions. The calculations were conducted using Geant4 Monte Carlo method based on the ITER simplified geometry. It was found that for present design of ITER, only 0.1% of neutrons is contributed by photonuclear interaction while, 33% belongs to the (n, xn) reaction. Finally by adding Beryllium element in the coolant leading to the increase in the neutron flux by increasing the rate of (γ, n) reactions was calculated.

Photonuclear Effect on ITER Operation  [PDF]
Farshid Tabbakh, Amir Hossein Gharashi
Journal of Applied Mathematics and Physics (JAMP) , 2015, DOI: 10.4236/jamp.2015.310150
Abstract: In this study, neutron and gamma radiation produced during the ITER tokamak operation including the nuclear heating were studied. This is an approach for analyzing the neutron flux by their contributions. The calculations were conducted using Geant4 Monte Carlo method based on the ITER simplified geometry. It was found that for present design of ITER, only 0.1% of neutrons is contributed by photonuclear interaction while, 33% belongs to the (n, xn) reaction. Finally by adding Beryllium element in the coolant leading to the increase in the neutron flux by increasing the rate of (γ, n) reactions was calculated.
Tree Based Energy and Congestion Aware Routing Protocol for Wireless Sensor Networks  [PDF]
Amir Hossein Mohajerzadeh, Mohammad Hossien Yaghmaee
Wireless Sensor Network (WSN) , 2010, DOI: 10.4236/wsn.2010.22021
Abstract: Wireless Sensor Networks (WSNs) have inherent and unique characteristics rather than traditional networks. They have many different constraints, such as computational power, storage capacity, energy supply and etc; of course the most important issue is their energy constraint. Energy aware routing protocol is very important in WSN, but routing protocol which only considers energy has not efficient performance. Therefore considering other parameters beside energy efficiency is crucial for protocols efficiency. Depending on sensor network application, different parameters can be considered for its protocols. Congestion management can affect routing protocol performance. Congestion occurrence in network nodes leads to increasing packet loss and energy consumption. Another parameter which affects routing protocol efficiency is providing fairness in nodes energy consumption. When fairness is not considered in routing process, network will be partitioned very soon and then the network performance will be decreased. In this paper a Tree based Energy and Congestion Aware Routing Protocol (TECARP) is proposed. The proposed protocol is an energy efficient routing protocol which tries to manage congestion and to provide fairness in network. Simulation results shown in this paper imply that the TECARP has achieved its goals.
Effects of Fillerwire Composition along with Different Pre- and Post-Heat Treatment on Mechanical Properties of AISI 4130 Welded by the GTAW Process  [PDF]
Ali Emamian, Ardalan Emamian, Amir Hossein Kowkabi
Materials Sciences and Applications (MSA) , 2010, DOI: 10.4236/msa.2010.13022
Abstract: This research intends to find out the optimal mechanical properties of AISI 4130 steel welded by the GTAW process. Six test plates were joined by two types of filler wire with similar chemical composition to the base metal, and with lower carbon content and slightly higher alloy elements content compared to the first one. Test plates then exerted three different pre-heat and post-heat treatments on both groups. The three types of heat treatments were alternatively without pre-heat and post-heat, with pre-heat only, and finally with pre-heat and post-heat. Tensile, side bends and impact tests (for weld zone and HAZ) have been conducted. Results show that using low-carbon filler wire along with pre- and post-heat resulted in outstanding mechanical properties.
Predict Edges in Fliker Social Network Using Data Mining Method  [PDF]
Amir Hossein Rasekh, Zeinab Liaghat, Ala Mahdavi
Intelligent Information Management (IIM) , 2012, DOI: 10.4236/iim.2012.43009
Abstract: Using social networking services is becoming more popular day by day. The websites of the social networks like face-book currently are among the most popular internet services just after giant portals such as Yahoo, MSN and search engines like Google. One of the main problems in analyzing these networks is the prediction of relationships between people in the network. The purpose of this paper is to forecast the friendship of a person with a new person using existing data on Flickr website accurately. In this paper, we achieved about 90% percent correct prediction with regards to the results which are obtained by using data mining methods.
Helicobacter pylori microbe and detecting with data mining algorithms  [PDF]
Amir Hossein Rasekh, Zeinab Liaghat, Alireza Tabebordbar
Open Journal of Gastroenterology (OJGas) , 2013, DOI: 10.4236/ojgas.2013.32016
Abstract:

Nowadays medicines believe that the only definite method to diagnose the existence of Helicobacter pylori microbe is performing endoscope, however it’s painful and insufferable for young children. Thus in this paper we used data mining algorithms to diagnose the existence of this microbe and eventually we succeeded in predicting the existence of this bacterium in stomach that guides medicines to perform Endoscopy just in cases where percentage of finding this bacterium is high.

Evaluating of Training and Internship Programs of University Hospitals  [PDF]
Farzianpour Fereshteh, Emami Amir Hossein, Hosseini Shayan
Health (Health) , 2016, DOI: 10.4236/health.2016.87069
Abstract: Objective: This study aimed to assess training and internship programs (courses) of basic and clinical sciences in hospitals based on surveying the students of Tehran University of Medical Sciences. Material and Methods: The present study was a cross-sectional one with survey descriptive designs. The data collection tool was a questionnaire with 14 five-point likert style items. The Research and Development Center of Tehran University of Medical Sciences surveyed all 185 students of training and internship programs, using a questionnaire with the Cronbach’s alpha coefficient of 81%, for the purpose of adjusting the education to the society’s needs and improving its quality. Result: The mean scores of the assessment of training and internship programs were 3.32%, 2.98%, 3.38% and 3.29%, respectively for theoretical classroom training related to practical training, mental, communicational and practical skills courses. The students’ satisfaction rate regarding the quality of educational courses of training and internship programs was 50.2%. Conclusion: Educational authorities have made necessary attempts to implement these programs and use potential resources for realizing the objectives and achieving the educational quality; however, they should make further attempts in this regard.
Mobile Phone Usage and the Risk of Brain Tumors  [PDF]
Naina Sawal, Amir Hossein Mortazavi Entesab
Occupational Diseases and Environmental Medicine (ODEM) , 2016, DOI: 10.4236/odem.2016.43006
Abstract: Purpose: This literature review investigated the possible association between the use of mobile phones and brain tumors. Methods: In brief, 11 publications were retrieved from JSTOR, PubMed, Google Scholar and Summon in order to compare the association between the usage of mobile phones in patients with a brain tumor and those without. Papers published in English, and after 2001 were selected for. There was no limit on age, gender, geographical location and type of brain tumor. Results: For regular mobile phone usage, the combined odds ratios (OR) (95% confidence intervals) for three studies are: 1.5 (1.2 - 1.8), 1.3 (0.95 - 1.9), and 1.1 (0.8 - 1.4), respectively. Furthermore, the odds ratio did not increase, regardless of mobile phone use duration. Additionally, Lonn et al. (2005) observed that the risk also did not significantly increase when assessing the laterality (ipsilateral or contralateral) of the tumor in relation to side of head used for the mobile phone. Kan et al. (2007) observed an OR of 1.22 when comparing analog phone to digital phone use. Conclusion: This review concludes that there is no current association between mobile phone use and the development of brain tumors. Although certain studies speak in favor of an increased risk, many are plagued with either: sampling bias, misclassification bias, or issues concerning risk estimates. Further research needs to be done in order to evaluate the long-term effect of mobile phone usage on the risk of developing a brain tumor.
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