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Semi-automated carotid lumen segmentation in computed tomography angiography images

The Journal of Biomedical Research 2017年第6期31卷 548-558页

作者： hamid reza hemmati Mahdi Alizadeh Alireza Kamali-Asl Shapour Shirani Radiation Medicine Engineering Department Shahid Beheshti UniversityTehran ***Iran Department of Neurosurgery Thomas Jefferson University HospitalPhiladelphiaPAl9107USA Department of Radiology Thomas Jefferson University HospitalPhiladelphiaPA 19107USA Department of Imaging Tehran University of Medical ScienceTehran ***Iran

Carotid artery stenosis causes narrowing of carotid lumens and may lead to brain infarction. The purpose of this study was to develop a semi-automated method of segmenting vessel walls, surrounding tissues, and more importantly, the carotid artery lumen by contrast computed tomography angiography（CTA） images and to define the severity of stenosis and present a three-dimensional model of the carotid for visual inspection. In vivo contrast CTA images of 14 patients（7 normal subjects and 7 patients undergoing endarterectomy） were analyzed using a multi-step segmentation algorithm. This method uses graph cut followed by watershed and Hessian based shortest path method in order to extract lumen boundary correctly without being corrupted in the presence of surrounding *** measurements of the proposed method were compared with those of manual delineation by independent board-certified radiologists. The results were quantitatively evaluated using spatial overlap surface distance indices. A slightly strong match was shown in terms of dice similarity coefficient（DSC） = 0.87±0.08; mean surface distance（Dmsd）= 0.32±0.32; root mean squared surface distance（Drmssd） = 0.49±0.54 and maximum surface distance（Dmax）=2.14±2.08 between manual and automated segmentation of common, internal and external carotid arteries, carotid bifurcation and stenotic artery, respectively. Quantitative measurements showed that the proposed method has high potential to segment the carotid lumen and is robust to the changes of the lumen diameter and the shape of the stenosis area at the bifurcation site. The proposed method for CTA images provides a fast and reliable tool to quantify the severity of carotid artery stenosis.

关键词： computed tomography angiography carotid atherosclerosis centerline extraction segmentation

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Stochastic Linear Programming for Optimal Planning of Battery Storage Systems Under Unbalanced-uncertain Conditions

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Journal of Modern Power Systems and Clean Energy 2020年第5期8卷 971-980页

作者： reza hemmati Hasan Mehrjerdi Department of Electrical Engineering Kermanshah University of TechnologyKermanshahIran Qatar University DohaQatar

Battery energy storage system(BESS)has already been studied to deal with uncertain parameters of the electrical systems such as loads and renewable ***,the BESS have not been properly studied under unbalanced operation of power *** paper aims to study the modelling and operation of BESS under unbalanced-uncertain conditions in the power *** proposed model manages the BESS to optimize energy cost,deal with load uncertainties,and settle the unbalanced loading at the same *** three-phase unbalanced-uncertain loads are modelled and the BESSs are utilized to produce separate charging/discharging pattern on each phase to remove the unbalanced *** IEEE 69-bus grid is considered as case *** load uncertainty is developed by Gaussian probability function and the stochastic programming is adopted to tackle the *** model is formulated as mixed-integer linear programming and solved by GAMS/*** results demonstrate that the model is able to deal with the unbalanced-uncertain conditions at the same *** model also minimizes the operation cost and satisfies all security constraints of power grid.

关键词： Battery energy storage system(BESS) singlephase storage planning unbalanced loading uncertainty

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Resilence Control of DC Microgrid Integrated with Multi-Nanogrids Considering Connected-Islanded States

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 786-796页

作者： Hossien Faraji reza hemmati Pierluigi Siano Department of Electrical Engineering Amirkabir University of TechnologyTehranIran Department of Electrical Engineering Kermanshah University of TechnologyKermanshahIran Department of Management&Innovation Systems University of Salernoand also with the Department of Electrical and Electronic Engineering ScienceUniversity of JohannesburgJohannesburg 2006South Africa

In this paper, a DC microgrid (DCMG) integrated with a set of nano-grids (NG) is studied. DCMG exchanges predetermined active and reactive power with the upstream network. DCMG and NGs are coordinately controlled and managed in such a way the exchanged P-Q power with external grid are kept on scheduled level following all events and operating conditions. The proposed control system, in addition to the ability of mutual support between DCMG and NGs, makes NGs support each other in critical situations. On the other hand, in all operating conditions, DCMG not only feeds three-phase loads with time-varying active and reactive power on the grid side but also injects constant active power into the grid. During events, NGs support each other, NGs support DCMG, and DCMG supports NGs. Such control strategies are realized by the proposed control method to increase resilience of the system. For these purposes, all resources and loads in DCMG and NGs are equipped with individual controllers. Then, a central control unit analyzes, monitors, and regularizes performance of individual controllers in DCMG and NGs. Nonlinear simulations show the proposed model can effectively control DCMG and NGs under normal and critical conditions.

关键词： Control system DC microgrid nanogrid resilience

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Application of consistent geometric decomposition theorem to dynamic finite element of 3D composite beam based on experimental and numerical analyses

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Frontiers of Structural and Civil Engineering 2020年第3期14卷 675-689页

作者： Iman FATTAHI hamid reza MIRDAMADI hamid ABDOLLAHI Department of Mechanical Engineering Isfahan University of TechnologyIsfahan ***Iran

Analyzing static and dynamic problems including composite structures has been of high significance in research efforts and industrial *** this article,equivalent single layer approach is utilized for dynamic finite element procedures of 3D composite beam as the building block of numerous composite *** this model,both displacement and strain fields are decomposed into cross-sectional and longitudinal components,called consistent geometric decomposition ***,the model is discretized using finite clement *** local coordinate systems and a global one are defined to decouple mechanical degrees of ***,from the viewpoint of consistent geometric decomposition theorem,the transformation and element mass matrices for those systems are introduced here for the first *** same decomposition idea can be used for developing element stiffiness ***,comprehensive validations are conducted for the theory against experimental and numerical results in two case studies and for various conditions.

关键词： composite beam dynamic finite element degrees of freedom coupling experimental validation numerical validation

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A multi-functional dynamic state estimator for error validation:measurement and parameter errors and sudden load changes

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Frontiers of Information Technology & Electronic Engineering 2016年第11期17卷 1218-1227页

作者： Mehdi AHMADI JIRDEHI reza hemmati Vahid ABBASI Hedayat SABOORI Department of Electrical Engineering Kermanshah University of Technology

We propose a new and efficient algorithm to detect, identify, and correct measurement errors and branch parameter errors of power systems. A dynamic state estimation algorithm is used based on the Kalman filter theory. The proposed algorithm also successfully detects and identifies sudden load changes in power systems. The method uses three normalized vectors to process errors at each sampling time: normalized measurement residual, normalized Lagrange multiplier, and normalized innovation vector. An IEEE 14-bus test system was used to verify and demonstrate the effectiveness of the proposed method. Numerical results are presented and discussed to show the accuracy of the method.

关键词： Dynamic state estimation Kalman filter Measurement errors Branch parameter errors Sudden load changes

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Introducing a Novel Approach for Oil-Oil Correlation based on Asphaltene Structure: X-ray Diffraction

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Acta Geologica Sinica(English Edition) 2021年第6期95卷 2100-2119页

作者： Zahra SADEGHTABAGHI Ahmad reza RABBANI Abdolhossein hemmati-SARAPARDEH Department of Petroleum Engineering Amirkabir University of TechnologyTehranIran Department of Petroleum Engineering Shahid Bahonar University of KermanKermanIran Institute of Research and Development Duy Tan UniversityDa Nang 550000Vietnam Faculty of Environmental and Chemical Engineering Duy Tan UniversityDa Nang 550000Vietnam

Asphaltenes have always been an attractive subject for ***,the application of this fraction of the geochemical field has only been studied in a limited *** other words,despite many studies on asphaltene structure,the application of asphaltene structures in organic geochemistry has not so far been ***-oil correlation is a wellknown concept in geochemical studies and plays a vital role in basin modeling and the reconstruction of the burial history of basin sediments,as well as accurate characterization of the relevant petroleum *** study aims to propose the Xray diffraction(XRD)technique as a novel method for oil-oil correlation and investigate its reliability and accuracy for different crude *** this end,13 crude oil samples from the Iranian sector of the Persian Gulf region,which had previously been correlated by traditional geochemical tools such as biomarker ratios and isotope values,in four distinct genetic groups,were selected and their asphaltene fractions analyzed by two prevalent methods of XRD and Fouriertransform infrared spectroscopy(FTIR).For oil-oil correlation assessment,various cross-plots,as well as principal component analysis(PCA),were conducted,based on the structural parameters of the studied *** results indicate that asphaltene structural parameters can also be used for oil-oil correlation purposes,their results being completely in accord with the previous *** average values of distance between saturated portions(d_(r))and the distance between two aromatic layers(d_(m))of asphaltene molecules belonging to the studied oil samples are 4.69Aand 3.54A,***,the average diameter of the aromatic sheets(L_(a)),the height of the clusters(L_(c)),the number of carbons per aromatic unit(C_(au)),the number of aromatic rings per layer(R_(a)),the number of sheets in the cluster(M_(e))and aromaticity(f_(a))values of these asphaltene samples are 10.09A,34.04A,17.42A,3.78A,10.6

关键词： oil-oil correlation petroleum characterization X-ray diffraction Fourier-transform infrared spectroscopy decision tree classification

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Numerical and experimental study of an innovative pipeline design in a granular pneumatic-conveying system

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Particuology 2018年第3期16卷 196-203页

作者： Hasan Ghafori hamid reza Ebrahimi Department of Mechanical Engineering MaJlesi Branch Islamic Azad University lsfilhan Iran Department of Chemical Engineering Majlesi Branch Islamic Azad University lsfahan Iran

During gas-solid mixture conveying in a dense phase, material is conveyed in dunes on the bottom of the pipeline, or as a pulsating moving bed. This phenomenon increases the pressure drop and power consumption. We introduce a new technique to reduce the pressure drop, which is termed the perforated double tube. To validate this new model, the gas-solid flow pattern and pressure drop were studied numerically and experimentally. The power consumption was also studied experimentally. Numerical studies were performed by the Eulerian-Lagrangian approach to predict gas and particle movement in the pipeline, Comparisons between the numerical predictions and the experimental results for the gas-solid flow patterns and pressure drop show good agreement.

关键词： Computational fluid dynamics Power consumption Perforated double tube Pneumatic conveying

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Preparation of La-Mo-V mixed-oxide systems and their application in the direct synthesis of acetic acid

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Journal of Natural Gas Chemistry 2008年第3期17卷 213-224页

作者： hamid reza Arandiyan Matin Parvari Chemical Engineering Department Iran University of Science and Technology

In this study, mixed metal oxides developed with a perovskite-type structure that show great potential for use in catalysis. Perovskite oxide catalysts with the composition LaMoxV1-xOn （x = 0.1, 0.3, 0.5, 0.7, and 0.9） have been synthesized by the sol-gel method and then used in the ethane dry reforming reaction for the direct synthesis of acetic acid. The influence of the nature of the metallic source （metal, nitrate, acetylacetonate, and ammonium） on gel formation has been studied by Fourier-transform infrared spectroscopy （FT-IR） and thermogravimetric analysis （TGA-DTA）. After calcination, the obtained perovskites were characterized by X-ray diffraction （XRD） and energy-dispersive X-ray spectrometry （EDS） coupled with scanning electron microscopy （SEM）. The catalysts were then subjected to thermo-programmed reduction （TPR）. The surface area （BET） was found to increase from 2.6 m^2/g （x = 0.1） to 5.1 m2/g （x = 1.0） with increasing molybdenum content following calcinations at 750 °C, and pure LaMoxV1-xOn perovskite was obtained with good homogeneity. The catalysts have been characterized by XRD, SEM, EDS, and carbon analysis （CA）. The results indicate that through this synthesis it is possible to obtain highly crystalline, homogeneous and pure solids, with well-defined structures. The direct synthesis of acetic acid from ethane over the perovskite catalysts was studied at temperatures between 450 and 850 °C and elevated pressures between 1 and 8 bar. It was found that the yield of acetic acid and the selectivity of its formation could be increased by incorporating more molybdenum into the perovskite structure. The experimental studies have shown that the calcination temperature and the molybdenum content have a significant influence on the catalytic activity. Amongst the catalysts tested, LaMo0.7V0.3O4.2 exhibited the best activity and stability.

关键词： acetic acid catalyst perovskite activity LaMoxV1-xOn

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Generating one-,two-,three-and four-scroll attractors from a novel four-dimensional smooth autonomous chaotic system

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Chinese Physics B 2010年第6期19卷 106-114页

作者： Sara Dadras hamid reza Momeni Automation and Instruments Lab Electrical Engineering DepartmentTarbiat Modares UniversityP.O.Box 14115-143TehranIran

A new four-dimensional quadratic smooth autonomous chaotic system is presented in this paper, which can exhibit periodic orbit and chaos under the conditions on the system parameters. Importantly, the system can generate one-, two-, three- and four-scroll chaotic attractors with appropriate choices of parameters. Interestingly, all the attractors are generated only by changing a single parameter. The dynamic analysis approach in the paper involves time series, phase portraits, Poincare maps, a bifurcation diagram, and Lyapunov exponents, to investigate some basic dynamical behaviours of the proposed four-dimensional system.

关键词： new smooth autonomous four-dimensional chaotic system multi-scroll chaotic attractor Poincare mapping bifurcation Lyapunov exponent

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Aircraft robust multidisciplinary design optimization methodology based on fuzzy preference function

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Chinese Journal of Aeronautics 2018年第12期31卷 2248-2259页

作者： Ali reza BABAEI Mohammad reza SETAYANDEH hamid FARROKHFAL Department of Mechanical and Aerospace Engineering Malek-Ashtar University of Technology

This paper presents a Fuzzy Preference Function-based Robust Multidisciplinary Design Optimization(FPF-RMDO) methodology. This method is an effective approach to multidisciplinary systems, which can be used to designer experiences during the design optimization process by fuzzy preference functions. In this study, two optimizations are done for Predator MQ-1 Unmanned Aerial Vehicle(UAV):(A) deterministic optimization and(B) robust optimization. In both problems, minimization of takeoff weight and drag is considered as objective functions, which have been optimized using Non-dominated Sorting Genetic Algorithm(NSGA). In the robust design optimization, cruise altitude and velocity are considered as uncertainties that are modeled by the Monte Carlo Simulation(MCS) method. Aerodynamics, stability and control, mass properties, performance, and center of gravity are used for multidisciplinary analysis. Robust design optimization results show 46% and 42% robustness improvement for takeoff weight and cruise drag relative to optimal design respectively.

关键词： Fuzzy logic Multidisciplinary design optimization Preference function Robust design Unmanned Aerial Vehicle(UAV)

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