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Enhancing the Robustness of Visual Object Tracking via Style Transfer

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Computers, Materials & Continua 2022年第1期70卷 981-997页

作者： abdollah Amirkhani Amir Hossein Barshooi Amir Ebrahimi School of Automotive Engineering Iran University of Science and TechnologyTehran16846-13114Iran School of Electrical Engineering and Computing The University of NewcastleCallaghan2308Australia

The performance and accuracy of computer vision systems are affected by noise in different forms.Although numerous solutions and algorithms have been presented for dealing with every type of noise,a comprehensive technique that can cover all the diverse noises and mitigate their damaging effects on the performance and precision of various systems is still missing.In this paper,we have focused on the stability and robustness of one computer vision branch(i.e.,visual object tracking).We have demonstrated that,without imposing a heavy computational load on a model or changing its algorithms,the drop in the performance and accuracy of a system when it is exposed to an unseen noise-laden test dataset can be prevented by simply applying the style transfer technique on the train dataset and training the model with a combination of these and the original untrained data.To verify our proposed approach,it is applied on a generic object tracker by using regression networks.This method’s validity is confirmed by testing it on an exclusive benchmark comprising 50 image sequences,with each sequence containing 15 types of noise at five different intensity levels.The OPE curves obtained show a 40%increase in the robustness of the proposed object tracker against noise,compared to the other trackers considered.

关键词： Style transfer visual object tracking robustness corruption

The Impact of the Covid-19 Pandemic on Iranian Oil and Gas Industry Planning:A Survey of Business Continuity Challenges

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International Journal of Disaster Risk Science 2022年第3期13卷 391-400页

作者： Seyyed abdollah Razavi Ali Asgary Marjan Khaleghi Department of Energy Economics and Management Tehran Faculty of PetroleumPetroleum University of Technology***TehranIran Disaster&Emergency Management School of Administrative StudiesFaculty of Liberal Arts&Professional StudiesYork UniversityTorontoONM3J 1P3Canada Department of Industrial Engineering Abadan Faculty of PetroleumPetroleum University of Technology***AbadanKhuzestanIran

The Covid-19 pandemic has severely affected various aspects of life,and its compounding and cascading impacts have been observed in most industries and firms.The oil and gas(O&G)industry was among the first to experience the impacts as the pandemic began due to the global economic recession and a sharp decline in demand for oil.The pandemic revealed major risk management and business continuity challenges and uncovered some of the vulnerabilities of the O&G industry and its major companies during a prolonged global disaster.Examining and understanding how the Covid-19 pandemic impacted the O&G sector in different countries,considering their unique circumstances,can provide important lessons for managing the current and future similar events.This study investigated various impacts of the Covid-19 pandemic on the O&G industry using Iran's Pars Oil and Gas Company(POGC)as a case study.Data were collected through indepth interviews with key managers of the company.Qualitative methods,specifically thematic analysis,were used to analyze the data.Findings of this study provide further insights into how the pandemic impacted the operations,risks,and business continuity of the POCG.The results show that the pandemic caused significant operational,financial,and legal impacts by disrupting routine maintenance,reducing the availability of human resources under the public health measures and mobility restrictions,increasing processing and delivery times,increasing costs and decreasing revenues,and delaying contractual obligations.

关键词： Business continuity Covid-19 pandemic Global disaster Iran Oil and gas industry Pars Oil and Gas Company

Experimental investigation and flow analysis of clear-water scour around pier and abutment in proximity

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Water Science and Engineering 2023年第1期16卷 94-105页

作者： Mohammad Saeed Fakhimjoo abdollah Ardeshir Kourosh Behzadian Hojat Karami Department of Civil and Environmental Engineering Amirkabir University of TechnologyTehran 15875-4413Iran School of Computing and Engineering University of West LondonLondon W55RFUK Department of Civil Engineering Semnan UniversitySemnan 35131-19111Iran

Local scour around bridge piers and abutments is one of the most significant causes of bridge failure.Despite a plethora of studies on scour around individual bridge piers or abutments,few studies have focused on the joint impact of a pier and an abutment in proximity to one another on scour.This study conducted laboratory experiments and flow analyses to examine the interaction of piers and abutments and their effect on clear-water scour.The experiments were conducted in a rectangular laboratory flume.They included 18 main tests(with a combination of different types of piers and abutments)and five control tests(with individual piers or abutments).Three pier types(a rectangular pier with a rounded edge,a group of three cylindrical piers,and a single cylindrical pier)and two abutment types(a wingewall abutment and a semicircular abutment)were used.An acoustic Doppler velocimeter was used to measure the three-dimensional flow velocity for analyses of streamline,velocity magnitude,vertical velocity,and bed shear stress.The results showed that the velocity near the pier and abutment increased by up to 80%.The maximum scour depth around the abutment increased by up to 19%.In contrast,the maximum scour depth around the pier increased significantly by up to l71%.The presence of the pier in the vicinity of the abutment led to an increase in the scour hole volume by up to 87%relative to the case with a solitary abutment.Empirical equations were also derived to accurately estimate the maximum scour depth at the pier adjacent to the abutment.

关键词： Abutment ADV Bridge scour Laboratory experiment Maximum scour depth Pier

Microstructure and Corrosion Properties of CP-Ti Processed by Laser Powder Bed Fusion under Similar Energy Densities

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Acta Metallurgica Sinica(English Letters) 2022年第9期35卷 1453-1464页

作者： Mohammad Hossein Mosallanejad Saber Sanaei Masoud Atapour Behzad Niroumand Luca Iuliano abdollah Saboori Department of Materials Engineering Isfahan University of Technology84156-83111IsfahanIran Department of Applied Science and Technology Politecnico di TorinoCorso Duca Degli Abruzzi 2410129TorinoItaly Department of Management and Production Engineering Politecnico di TorinoCorso Duca Degli Abruzzi 2410129TorinoItaly

In this work, two types of CP Ti cubes with similar volumetric energy densities(VED) but diff erent process parameters were produced using laser powder bed fusion(LPBF) method. The corrosion behavior of the fabricated specimens was investigated by conducting electrochemical impedance spectroscopy(EIS) and polarization experiments in simulated body fl uid(SBF) solution at 37 °C. The results indicated that the microstructure and porosities, which are of great importance for biomedical applications, can be controlled by changing the process parameters even under constant energy densities. The sample produced with a lower laser power(E1) was featured with a higher level of porosity and thinner alpha laths, as compared with the sample fabricated with a higher laser power(E2). Moreover, results obtained from the bioactivity tests revealed that the sample produced with a higher laser power conferred a slight improvement in the bioactivity due to the higher amount of porosity. Lower laser power and hence higher porosity level promoted the formation of bone-like apatite on the surface of the printed specimens. The potentiodynamic polarization tests revealed inferior corrosion resistance for the fabricated sample with higher porosity. Moreover, the EIS results after diff erent immersion times indicated that a stable oxide film was formed on the surface of samples for all immersion times. After 1 and 3 days of immersion, superior passivation behavior was observed for the sample fabricated with lower laser power. However, very similar impedance and phase values were observed for all the samples after 14 days of immersion.

关键词： Additive manufacturing Laser powder bed fusion Energy density Corrosion Microstructure CP Titanium

Tribological behaviour of AZ31 magnesium alloy reinforced by bimodal size B_(4)C after precipitation hardening

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Journal of Magnesium and Alloys 2022年第11期10卷 3267-3280页

作者： Seyed Kiomars Moheimani Azadeh Keshtgar Saeed Khademzadeh Morteza Tayebi Ali Rajaee abdollah Saboori Advanced Materials Research Center Department of Materials EngineeringNajafabad BranchIslamic Azad UniversityNajafabadIran Department of Research and Development Nejat Darya CompanyBoushehrIran Center for Risk and Reliability University of MarylandCollege ParkMD 20742United States Department of Industrial Engineering University of Padova35131 PadovaItaly Young Researchers and Elites Club Science and Research BranchIslamic Azad UniversityTehranIran Department of Materials and Polymer Engineering Hakim Sabzevari UniversitySabzevarIran Integrated Additive Manufacturing Center(IAM) Department of Management and Production Engineering(DIGEP)Politecnico di TorinoCorso Duca Degli Abruzzi2410129TorinoItaly

This study investigated dry sliding wear properties of AZ31 magnesium alloy and B_(4)C-reinforced AZ31 composites containing 5, 10, and 20 wt.% B_(4)C with bimodal sizes under different loadings(10-80 N) at various sliding speeds(0.1-1 m/s) via the pin-on-disc configuration.Microhardness evaluations showed that when the distribution of B_(4)C particles was uniform the hardness of the composites increased by enhancing the reinforcement content. The unreinforced alloy and the composite samples were examined to determine the wear mechanism maps and identify the dominant wear mechanisms in each wear condition and reinforcement content. For this purpose, wear rates and friction coefficients were recorded during the wear tests and worn surfaces were characterized by scanning electron microscopy and energy dispersive X-ray spectrometry analyses. The determined wear mechanisms were abrasion, oxidation, delamination, adhesion, and plastic deformation as a result of thermal softening and melting. The wear evaluations revealed that the composites containing 5 and 10 wt.% B_(4)C had a significantly higher wear resistance in all the conditions. However, 20 wt.% B_(4)C/AZ31 composite had a lower resistance at high sliding speeds(0.5-1 m/s) and high loadings(40-80 N) in comparison with the unreinforced alloy. The highest wear resistance was obtained at high sliding speeds and low loadings with the domination of oxidative wear.

关键词： B_(4)C AZ31 alloy Metal matrix composite Wear mechanism Bimodal

Application of biocementation technique using Bacillus sphaericus for stabilization of soil surface and dust storm control

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Journal of Arid Land 2022年第5期14卷 537-549页

作者： Davood NAMDAR-KHOJASTEH Masoud BAZGIR Seyed abdollah HASHEMI BABAHEIDARI Akwasi B ASUMADU-SAKYI Department of Soil Science Faculty of AgricultureShahed UniversityTehran ***Iran Department of Soil and Water Engineering Faculty of AgricultureIlam UniversityIlam ***Iran Department of Plant Protection Faculty of AgricultureShahed UniversityTehran ***Iran International Laboratory for Air Quality and Health School of ChemistryPhysics and Mechanical EngineeringQueensland University of TechnologyBrisbaneQueensland 4000Australia

Dust emission and wind erosion are widespread phenomena in arid and semi-arid regions,which have far-reaching harmful effects to the environment.This study aimed to use microbial induced carbonate precipitation(MICP)method with Bacillus sphaericus to reduce soil losses that occur in a dust-producing area due to wind erosion in the Ilam Province,Iran.Soil samples at the 0-30 cm depth were used and sterilized in an autoclave for 2 h at 121℃ and 103 kPa.Approximately 3 kg soils were weighed and poured in the 35 cm×35 cm×3 cm trays.Different treatments included two levels of B.sphaericus(0.0 and 0.5 OD),three levels of suspension volume(123,264,and 369 mL),two levels of urea-chloride cementation solution(0.0 and 0.5 M),and two levels of bacterial spray(once and twice spray).After 28 d,soil properties such as soil mass loss,penetration resistance,and aggregate stability were measured.The results showed a low soil mass loss(1 g)in F_(14)formulation(twice bacterial spray+264 mL suspension volume+without cementation solution)and a high soil mass loss(246 g)in F_(5) formulation(without bacteria+264 mL suspension volume+0.5 M cementation solution).The highest(42.55%)and the lowest(19.47%)aggregate stabilities were observed in F_(16)and F_(7)formulations,respectively,and the highest penetration resistance(3.328 kg/cm^(2))was observed in F_(18) formulation.According to the final results,we recommended the formulation with twice bacterial spray,0.5 M cementation solution,and 269 mL suspension volume as the best combination for soil surface stabilization.Furthermore,this method is environmentally friendly because it has no adverse effects on soil,water,and plants,thus,it would be an efficient approach to stabilize soil surface.

关键词： soil stabilization microbial cementation calcium carbonate bacteria penetration resistance

A new solution to estimate the time delay on the topographic site using time domain 3D boundary element method

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Earthquake Engineering and Engineering Vibration 2020年第3期19卷 611-623页

作者： Reza Tarinejad Mohsen Isari abdollah Sohrabi-Bidar Faculty of Civil Engineering University of TabrizTabrizIran School of Geology College of ScienceUniversity of TehranTehranIran

This study focuses on investigating spatial variation of ground motion that has great influence on the dynamic behavior of the large structures located on the surface topography.One of the most effective parameters on the spatial variation of ground motion is the difference between the arrival time of seismic waves in different points located on the abutments.In this research,a three-dimensional model of the Pacoima Dam site is prepared.The time domain 3 D boundary element method is used to apply non-uniform excitation at the dam supports.This model is subjected to vertically propagating incident SH and P waves.The time delay can be characterized by calculating the value of the time delay for which the cross-correlation between two records is maximized.Finally,to obtain the time delay in a topographic site,a function considering effective parameters such as the height from the canyon base,wave velocity and predominant frequency,is presented.Furthermore,a code was developed for generating the spatially variation of seismic ground motions.The results show that the proposed functions have an acceptable accuracy in estimating the time delay to generate non-uniform ground motion.

关键词： delay boundary element

Effects of Mn and Cu on the Mechanical Properties of a High Strength Low Alloy NiCrMoV Steel

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Journal of Materials Science & Technology 2005年第4期21卷 470-474页

作者： A.abdollah-zadeh M.Belbasy Department of Materials Engineering Tarbiat Modarres University P.O. Box 14115-143 Tehran IranDepartment of Materials Engineering Tarbiat Modarres University P.O. Box 14115-143 Tehran Iran

The present study focuses on the effects of Mn and Cu on the mechanical properties, in particular, strength and toughness of a low alloy steel containing Ni, Cr, Mo and V. Specimens with different amounts of Mn （0.23%-0.85%）and Cu （0.15%-0.45%） were cast and forged, and then austenitized at 870℃ for 1h, followed by oil quenching. All specimens were tempered at 650℃ for 1h. The results show that as the amounts of Mn and Cu increase respectively from 0.35% to 0.85% and from 0.15% to 0.45%, the yield and tensile strength increase. The highest impact energies were observed in the specimen with 0.35% Mn and in the specimen with 0.25% Cu. The impact energy decreases with increasing the Mn and Cu from 0.35% to 0.85% and from 0.25% to 0.45%, respectively. Furthermore, the variation of Mn and Cu does not cause a considerable change in the tempered martensite microstructure. The optimum strength and toughness is observed in 0.35% Mn containing steel and in the 0.25% Cu containing steel.

关键词： NiCrMoV steel Cu Mn Tensile strength Impact energy

A Stable Analytical Solution Method for Car-Like Robot Trajectory Tracking and Optimization

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IEEE/CAA Journal of Automatica Sinica 2020年第1期7卷 39-47页

作者： Keyvan Majd Mohammad Razeghi-Jahromi abdollah Homaifar School of Computing Informaticsand Decision Systems EngineeringArizona State UniversityTempeAZ 85281 USA ABB Corporate Research Center RaleighNC 27606 USA Department of Electrical and Computer Engineering North Carolina A&T State UniversityGreensboroNC 27403 USA

In this paper, the car-like robot kinematic model trajectory tracking and control problem is revisited by exploring an optimal analytical solution which guarantees the global exponential stability of the tracking error. The problem is formulated in the form of tracking error optimization in which the quadratic errors of the position, velocity, and acceleration are minimized subject to the rear-wheel car-like robot kinematic model. The input-output linearization technique is employed to transform the nonlinear problem into a linear formulation. By using the variational approach, the analytical solution is obtained, which is guaranteed to be globally exponentially stable and is also appropriate for real-time applications. The simulation results demonstrate the validity of the proposed mechanism in generating an optimal trajectory and control inputs by evaluating the proposed method in an eight-shape tracking scenario.

关键词： Index Terms—Global asymptotic stability input-output linearization,optimal control trajectory tracking.