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Prediction of lightweight concrete strength by categorized regression, MLR and ANN
S. Tavakkol,F. Alapour,A. Kazemian,A. Hasaninejad,A. Ghanbari,A.A. Ramezanianpour 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.12 No.2
Prediction of concrete properties is an important issue for structural engineers and different methods are developed for this purpose. Most of these methods are based on experimental data and use measured data for parameter estimation. Three typical methods of output estimation are Categorized Linear Regression (CLR), Multiple Linear Regression (MLR) and Artificial Neural Networks (ANN). In this paper a statistical cleansing method based on CLR is introduced. Afterwards, MLR and ANN approaches are also employed to predict the compressive strength of structural lightweight aggregate concrete. The valid input domain is briefly discussed. Finally the results of three prediction methods are compared to determine the most efficient method. The results indicate that despite higher accuracy of ANN, there are some limitations for the method. These limitations include high sensitivity of method to its valid input domain and selection criteria for determining the most efficient network.
A.A. Ramezanianpour,A. Kazemian,E. Radaei,H. AzariJafari,M.A. Moghaddam 사단법인 한국계산역학회 2014 Computers and Concrete, An International Journal Vol.13 No.4
Ground Granulated Blast Furnace Slag (GGBFS) is widely used as an effective partial cement replacement material. GGBFS inclusion has already been proven to improve several performance characteristics of concrete. GGBFS provides enhanced durability, including high resistance to chloride penetration and protection against alkali silica reaction. In this paper results of an experimental research work on influence of low-reactivity GGBFS (which is largely available in Iran) on the properties of mortars and concretes are reported. In the first stage, influence of GGBFS replacement level and fineness on the compressive strength of mortars was investigated using Taguchi method. The analysis of mean (ANOM) statistical approach was also adopted to develop the optimal conditions. Next, based on the obtained results, concrete mixtures were designed and water penetration, capillary absorption, surface resistivity, and compressive strength tests were carried out on high-strength concrete specimens at different ages up to 90 days. The results indicated that 7-day compressive strength is adversely affected by GGBFS inclusion, while the negative effect is less evident at later ages. Also, it was inferred that use of low-reactivity GGBFS (at moderate levels such as 20% and 30%) can enhance the impermeability of high-strength concrete since 28 days age.
Erfan Avazpoor,Amir Hossein Kazemian,Hossein Rahmani 한국섬유공학회 2023 Fibers and polymers Vol.24 No.9
This study was performed with the aim of investigating the Radius of Curvature Influence of glass fiber reinforced epoxy composites under Low Velocity Impact (LVI). Three different curvature radii of 10, 15, and 20 cm, as well as a sample with an infinite curvature radius (flat) of 9-ply laminated composite with woven roving glass fiber were employed for fabricating the specimens. Impact tests were performed using drop-weight impact device at different energy levels of 50, 100, and 150 J. Maximum force, absorbed energy, loading and unloading time, and damage area of the curved and flat composites laminated were evaluated. The results indicate that the absorption of energy increases with decreasing the curvature diameter, so that for sample D20, the amount of absorbed energy has increased on average 20%, for sample D15, 75% and for sample D10, 120% compared to the flat sample. Also the radius of curvature effects on peak load and loading and unloading times. Moreover, the low-velocity impact specifications of specimens were simulated using ABAQUS finite element software, and the results were compared with the experimental data.
Alireza Mohammadkarim,Manijhe Mokhtari-Dizaji,Ali Kazemian,Hazhir Saberi 대한초음파의학회 2018 ULTRASONOGRAPHY Vol.37 No.1
Purpose: The aim of this study was to assess vascular changes and blood flow abnormalities in the common carotid arteries of patients with head and neck cancers after external radiotherapy, using color Doppler ultrasonography. Methods: We studied 24 patients treated with external radiotherapy for various head and neck cancers. In order to study the acute effects of irradiation on common carotid blood flow and arterial diameter changes, color Doppler ultrasonography parameters such as peak systolic velocity, end diastolic velocity, mean velocity, systolic-to-diastolic velocity (S/D) ratio, pulsatility index (PI), resistive index (RI), and instantaneous diameter changes were evaluated before and after external radiotherapy. Additionally, the blood volume flow (VF) values in the peak systolic and end diastolic phases, as well as mean velocity, were evaluated throughout three cardiac cycles using B-mode ultrasonic image processing. Results: The findings showed significant changes in the S/D ratio, PI, and RI of the common carotid arteries before and after external radiotherapy (P<0.05). Moreover, a significant decrease in artery diameter and blood VF was observed after radiotherapy relative to the pretreatment values. A significant correlation was found between the blood VF values estimated using ultrasonic measurements and mathematical methods throughout three cardiac cycles. Conclusion: The hemodynamic parameters of the common carotid arteries changed during radiotherapy. These arterial changes may lead to late adverse effects of radiotherapy, such as ischemic strokes and ischemic attacks.
Alireza Mohammadkarim,Manijhe Mokhtari-Dizaji,Ali Kazemian,Hazhir Saberi,Niloofar Ayoobi Yazdi,Mahbod Esfehani 대한초음파의학회 2022 ULTRASONOGRAPHY Vol.41 No.1
Purpose: The purpose of this study was to investigate the incidence of short-term atherosclerosis in the common carotid arteries following radiotherapy. Methods: The mean radiation dose to the arteries was 49.30±15.83 Gy. A computational ultrasound method was introduced to investigate the elastic modulus. Ultrasonography was performed 2-3 cm inferior to the bifurcation region before and after radiotherapy, and sequential images were extracted from a video of each artery. Instantaneous movement of the arterial wall in the radial and longitudinal directions was extracted by implementing the maximum gradient and block matching algorithms, respectively. Results: There was a significant change in systolic blood pressure after radiotherapy (P=0.008). Irradiated arteries had significantly smaller systolic and end-diastolic diameters than nonirradiated arteries (P<0.001). The shear modulus was significantly different between irradiated and non-irradiated arteries (3.10±2.03 kPa vs. 1.38±0.98 kPa, P<0.001). The shear and Young moduli of radiation-induced arteries were 2.25±1.50 and 1.57±0.59 times higher than those of the pre-irradiation arteries. Conclusion: The arterial shear modulus can be considered as a new biomarker of radiationinduced atherosclerosis in the common carotid artery. Purpose: The purpose of this study was to investigate the incidence of short-term atherosclerosis in the common carotid arteries following radiotherapy.Methods: The mean radiation dose to the arteries was 49.30±15.83 Gy. A computational ultrasound method was introduced to investigate the elastic modulus. Ultrasonography was performed 2-3 cm inferior to the bifurcation region before and after radiotherapy, and sequential images were extracted from a video of each artery. Instantaneous movement of the arterial wall in the radial and longitudinal directions was extracted by implementing the maximum gradient and block matching algorithms, respectively.Results: There was a significant change in systolic blood pressure after radiotherapy (P=0.008). Irradiated arteries had significantly smaller systolic and end-diastolic diameters than non-irradiated arteries (P<0.001). The shear modulus was significantly different between irradiated and non-irradiated arteries (3.10±2.03 kPa vs. 1.38±0.98 kPa, P<0.001). The shear and Young moduli of radiation-induced arteries were 2.25±1.50 and 1.57±0.59 times higher than those of the pre-irradiation arteries.Conclusion: The arterial shear modulus can be considered as a new biomarker of radiationinduced atherosclerosis in the common carotid artery.
Allahbakhshi Maryam,Mosaferi Mohammad,Mahmoodi Niyaz Mohammad,Kazemian Hossein,Aslani Hassan 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.12
MIL-53(Fe) as a three-dimensional MIL was prepared with different precursors-to-solvent ratios and denoted as MIL53B and MIL53C. All as-synthesized samples were modified using 3-amino propyl trimethoxy silane (organosilane) for synthesizing MIL53B/NH2(0.10), MIL53B/NH2(0.20), MIL53B/NH2(0.30), MIL53C/NH2(0.10), MIL53C/NH2(0.20), and MIL53C/NH2(0.30), respectively. The XRD, SEM, EDS, and FTIR techniques were used to characterize materials. The adsorption ability of the materials for the adsorption of dye (Direct Red 23) was studied. The effect of operational parameters was evaluated. The kinetics and isotherm of pollutant removal obeyed pseudo-second-order kinetic and the Langmuir models, respectively. The row and modified MIL53B indicated the adsorption capacity of 1,375 and 4,989 mg/g, respectively. The high pollutant removal ability and fast adsorption rate ascertain that the modified MIL53 could be considered as a dye adsorbent and potentially other organic molecules with similar structures from contaminated water.