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101.
Shahram Golzari Mojtaba Shabani Haji Abdullah Khalili 《Computational Intelligence》2020,36(3):1140-1160
Predicting the delay in servicing incoming ships to ports is crucial for maritime transportation. In this study, we use support vector regression (SVR) in order to accurately predict this delay for ships arriving to the terminal No. 1 of Shahid Rajaee's port in Bandar Abbas. To achieve this goal, a combination of Clonal Selection and Grey Wolf Optimization algorithms (named as CLOGWO) is used for two purposes: (i) selecting the most important features among the features that affect prediction of this delay and (ii) optimizing SVR parameters for a more accurate prediction. Performance of the proposed method was compared with Genetic Algorithm (GA), Clonal Selection (CS), Grey Wolf Optimization (GWO), and Particle Swarm Optimization (PSO) algorithms on the following metrics: correlation, rate of feature reduction, root mean square error (RMSE), and normalized RMSE (NRMSE). Evaluations on Shahid Rajaee dataset showed that the mean value of these metrics in 10 independent runs of the proposed method were 0.867, 74.45%, 0.080, and 9.02, respectively. These results and evaluations on standard datasets indicate that the proposed method provides competitive results with other evolutionary algorithms. 相似文献
102.
Mingfei Xiao Aditya Sadhanala Mojtaba Abdi-Jalebi Tudor H. Thomas Xinglong Ren Tao Zhang Hu Chen Remington L. Carey Qijing Wang Satyaprasad P. Senanayak Cameron Jellett Ada Onwubiko Maximilian Moser Hailiang Liao Wan Yue Iain McCulloch Mark Nikolka Henning Sirringhaus 《Advanced functional materials》2021,31(7):2007359
The measurement of the mechanical properties of conjugated polymers can reveal highly relevant information linking optoelectronic properties to underlying microstructures and the knowledge of the glass transition temperature (Tg) is paramount for informing the choice of processing conditions and for interpreting the thermal stability of devices. In this work, we use dynamical mechanical analysis to determine the Tg of a range of state-of-the-art conjugated polymers with different degrees of crystallinity that are widely studied for applications in organic field-effect transistors. We compare our measured values for Tg to the theoretical value predicted by a recent work based on the concept of effective mobility ζ. The comparison shows that for conjugated polymers with a modest length of the monomer units, the Tg values agree well with theoretically predictions. However, for the near-amorphous, indacenodithiophene–benzothiadiazole family of polymers with more extended backbone units, values for Tg appear to be significantly higher, predicted by theory. However, values for Tg are correlated with the sub-bandgap optical absorption suggesting the possible role of the interchain short contacts within materials’ amorphous domains. 相似文献
103.
Many water resources optimization problems involve conflicting objectives which the main goal is to find a set of optimal solutions on, or near to, Pareto front. In this study a multi-objective water allocation model was developed for optimization of conjunctive use of surface water and groundwater resources to achieve sustainable supply of agricultural water. Here, the water resource allocation model is based on simulation-optimization (SO) modeling approach. Two surrogate models, namely an Artificial Neural Network model for groundwater level simulation and a Genetic Programming model for TDS concentration prediction were coupled with NSGA-II. The objective functions involved: 1) minimizing water shortage relative to the water demand, 2) minimizing the drawdown of groundwater level, and 3) minimizing the groundwater quality changes. According to the MSE and R2 criteria, the results showed that the surrogate models for prediction of groundwater level and TDS concentration performed favorably in comparison to the measured values at the number of observation wells. In Najaf Abad plain case study, the average drawdown was limited to 0.18 m and the average TDS concentration also decreased from 1257 mg/lit to 1229 mg/lit under optimal conditions. 相似文献
104.
Morteza Ghaderi Aram Mojtaba Dehmollaian Ali Khaleghi 《Sensing and Imaging: An International Journal》2017,18(1):19
A wide variety of qualitative methods have been proposed for microwave imaging. It is difficult to select only one of these methods based on a priori information and measurement equipment to achieve a reliable reconstruction. Various arrangements for antennas to be used in, for instance, have been proposed which have direct impacts on the complexity of inverse methods as well as the quality of output images. In this study, four qualitative methods of the linear sampling method (LSM), time reversal (TR), diffraction tomography (DT), and back-projection (BP) have been reviewed in a 2D scenario; the performance of the methods is compared within the same framework of a multi-static configuration. The goal is to compare their resolutions and determine their advantages and drawbacks. It is shown that LSM provides the best azimuth resolution but the worst range resolution. It is almost invariant to dielectric contrast and is appropriate for a wide range of dielectric contrasts and relatively large objects. It is also shown that at relatively low dielectric contrasts, TR images are most similar to the true object, show fewer artifacts, and offer high immunity to noise. While suffering from more artifacts due to the presence of some ghost images, DT offers the best range resolution. The results also show that BP has the worst azimuth resolution when reconstructing deeply-buried targets, although its implementation is straightforward and not computationally complex. 相似文献
105.
A sizing formulation, containing compatible and incompatible silane coupling agents with epoxy resin in conjunction with nanoscale colloidal silica, was used to modify the surface of glass fabric. The modified glass fabric/epoxy resin composite panels were fabricated and characterised by flexural test, Charpy impact test and scanning electron microscope (SEM). By combining nano silica with silane blend in the fabric sizing, more energy was consumed under bending and impacting, which resulted in an improvement of the toughness in composites. The flexural strength, bending stain and Charpy impact strength of the epoxy composite/glass fabric treated with 1?wt-% nano silica and silane blend were ~42, ~22 and 35%, respectively, higher than those of silane blend coated glass fabric-reinforced composites (without nano silica). Furthermore, the change of the brittle fracture of the composite into ductile fracture was investigated by SEM micrographs. A possible toughening mechanism was also proposed. 相似文献
106.
Thyristor Controlled Series Capacitor (TCSC) as a dynamic system, besides its capability in increasing power transfer in transmission lines, can be used to enhance different power system issues. In this paper, the effect of TCSC on voltage sag following transformer inrush current is investigated. It is shown that excessive transient inrush current occurring during transformer energizing can be mitigated by TCSC. Hence, voltage sag as one of the key components of the power quality is alleviated for the sensitive loads that are connected to the same bus which the power transformer is energized from. During a fault, TCSC can improve the voltage sag by limiting the current and help to keep the voltage as high as possible. Moreover, the inrush currents and the associated voltage sags that usually occur after clearing heavy single- or multistage faults are mitigated by the presence of TCSC. The model used for simulating inrush current is based on the characteristics of the major hysteresis loop out of which the internal trajectories are defined using the translation principal and a linear compensation to generate closed loops. An arctangent relation between the flux and the exciting current is defined. The expression parameters are deduced by curve fitting empirical data defining the major loop or the single-valued saturation characteristic. 相似文献
107.
Hard- and soft-modeling approaches for resolution of complex formation of Co2+ and Ni2+ with glycine
Principal component analysis (PCA) was used to obtain information about the number of components in the complex formation equilibria of Co(2+) and Ni(2+) with glycine (Gly). In order to obtain a clearer insight into these complex formation systems, multivariate curve resolution-alternating least squares (MCR-ALS) was used. Using MCR-ALS as a soft-modeling method, well-defined concentration and spectral profiles were obtained under unimodality, non-negativity, and closure constraints. Based on the obtained results, an equilibrium model was proposed and subsequently, a hard-modeling method was used to resolve the complex formation equilibria completely. Due to the presence of multiple equilibria, the resolution of such systems is very difficult. The Co-Gly system was best described by a model consisting of M(GlyH), M(Gly), M(Gly)(2), M(Gly)(2)H, and M(Gly)(3) (M = Co(2+)) with the overall stability constants determined to be 7.10 ± 0.011, 5.14 ± 0.006, 9.28 ± 0.009, 13.75 ± 0.016, and 11.10 ± 0.010, respectively. On the other hand, the system of Ni-Gly was best fitted by a model containing M(GlyH), M(Gly), M(Gly)(2), M(Gly)(3), and M(Gly)(2)(OH) (M = Ni(2+)) with overall stability constants of 10.95 ± 0.04, 6.41 ± 0.03, 11.31 ± 0.03, 15.39 ± 0.06, and 14.32 ± 0.02, respectively. 相似文献
108.
Maryam Sadat Marashi Jalil Vahdati KhakiSeyed Mojtaba Zebarjad 《International Journal of Refractory Metals and Hard Materials》2012,30(1):177-179
In this research, the possibility of mechanochemical decomposition of ammonium paratungstate (APT) has been studied, and compared with thermal decomposition method. For this purpose, APT powders were milled using a planetary ball mill up to 36 h and under air atmosphere. For thermal decomposition, APT powders were heated for 30 minutes at 300 and 450 °C in air atmosphere. X-ray diffraction (XRD), differential scanning calorimeter (DSC), and thermo gravimetric analyzer (TGA) were used to study the decomposition progress, and products. The XRD results showed that APT completely decomposed to WO3 by thermal decomposition, while the final product of mechanochemical decomposition was WO3 (H2O)0.5. According to DSC and TGA results, during thermal decomposition, ammonia and water released in four steps, and leaved WO3. By mechanochemical decomposition crystal water and ammonia liberated from APT structure, but structural water of APT remained. In both methods, an X-ray amorphous phase was the intermediate product of APT decomposition. 相似文献
109.
110.
Morteza Khalilian Mahdi Navidbakhsh Mojtaba Rezazadeh Valojerdi Mahmoud Chizari Poopak Eftekhari Yazdi 《Journal of the Royal Society Interface》2010,7(45):687-694
The zona pellucida (ZP) is the spherical layer that surrounds the mammalian oocyte. The physical hardness of this layer plays a crucial role in fertilization and is largely unknown because of the lack of appropriate measuring and modelling methods. The aim of this study is to measure the biomechanical properties of the ZP of human/mouse ovum and to test the hypothesis that Young''s modulus of the ZP varies with fertilization. Young''s moduli of ZP are determined before and after fertilization by using the micropipette aspiration technique, coupled with theoretical models of the oocyte as an elastic incompressible half-space (half-space model), an elastic compressible bilayer (layered model) or an elastic compressible shell (shell model). Comparison of the models shows that incorporation of the layered geometry of the ovum and the compressibility of the ZP in the layered and shell models may provide a means of more accurately characterizing ZP elasticity. Evaluation of results shows that although the results of the models are different, all confirm that the hardening of ZP will increase following fertilization. As can be seen, different choices of models and experimental parameters can affect the interpretation of experimental data and lead to differing mechanical properties. 相似文献