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Evaluating innovation ecosystem resiliency using agent-based modeling and systems dynamics

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Journal of Safety Science and Resilience 2024年第2期5卷 204-221页

作者： Soheila Abdi Mehdi yazdani esmaeil Najafi Department of Industrial Engineering Science and Research BranchIslamic Azad UniversityTehranIran Department of Industrial Engineering Qazvin BranchIslamic Azad UniversityQazvinIran

Evaluating the resilience of the innovation ecosystem to maintain its performance,in the sense of resistance to disruption and recovery after it,has recently received more *** studies have been conducted to model different ecosystems and evaluate their ***,modeling the innovation ecosystem from a holistic perspective and performing a quantitative assessment of its resilience have received less *** paper models the innovation ecosystem holistically and evaluates its resilience index using a quantitative approach through five main *** the first step,a case study related to the innovation ecosystem of Iran's Ministry of Energy,called the Power Innovation Ecosystem,is modeled by combining system dynamics and agent-based *** validating the model in the second step,the disruption of the loss of experts is investigated in the third step,and all possible actions to recover each actor are *** the fourth step,the performance of the ecosystem is simulated before and after the disruption using the data gathered in the previous ***,resilience is calculated in two different ways in the fifth *** improvement solutions are also suggested when considering that the resilience index of the innovation ecosystem is at a medium *** research may assist policymakers in observing the resilience level of the innovation ecosystem based on the proposed *** applying strategic changes to this model,they can determine the effects of their policies and make the most appropriate decisions to increase the resilience of the innovation ecosystem.

关键词： Resilience index innovation ecosystem System dynamics Agent-based modeling

Short circuit analysis of a fault-tolerant current-limiting high temperature superconducting transformer in a power system in presence of distributed generations

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Superconductivity 2024年第1期9卷 74-86页

作者： Alireza Sadeghi Shahin Alipour Bonab Wenjuan Song Mohammad yazdani-Asrami Propulsion Electrification&Superconductivity GroupAutonomous Systems&Connectivity DivisionJames Watt School of EngineeringUniversity of GlasgowGlasgow G128QQUnited Kingdom

Power transformers are key elements for the safe and reliable delivery of electrical energy generated by renewable energy resources to consumers via transmission ***‐tolerant current‐limiting High Temperature Superconducting(FTCL HTS)transformers are type of superconducting transformers that tolerate fault for seconds and limit the fault current without the threat of burnout or delamination of tapes and deformation of *** this paper,the fault performance of a FTCL HTS transformer in a standard IEEE power system is *** studied transformer is a 50 MVA 132 kV/13.8 kV transformer where both windings are made up of HTS *** understudied power system consists of two microgrids with distributed *** of the power in microgrids is supplied by the upstream grid which is connected to the microgrids through the HTS *** fault scenarios have been considered in this power system,in each one of these scenarios,a fault happens in one of the *** considered fault scenarios have an approximate fault current of 18x to 23x of the rated current in the secondary *** showed that insulated windings in FTCL HTS transformers could substantially reduce the peak temperature of the HTS windings,compared to bare ***,post‐fault loading is imposed on the HTS windings,to observe their performance against the current increase after fault *** this case,for the first scenario of the faults,the FTCL HTS transformer could tolerate 192%of post‐fault overloading,while this number for the second fault scenario is 170%.Finally,the impact of post‐fault loading on the full recovery time was discussed.

关键词： Fault Energy Heat dissipation Heat transfer Insulation Recovery Time Temperature rise

Shear behavior and dilatancy of an artificial hard-matrix bimrock: An experimental study focusing on the role of blocky structure

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Rock Mechanics Bulletin

Rock Mechanics Bulletin 2024年第4期3卷 83-101页

作者： Amir yazdani Saeed Karimi-Nasab Hossein Jalalifar Department of Mining Engineering Isfahan University of TechnologyIsfahanIran Department of Mining Engineering Shahid Bahonar University of KermanKermanIran Department of Petroleum Engineering Shahid Bahonar University of KermanKermanIran

Bimrocks are characterized by their geotechnically significant blocky structure,presenting complex shear *** study investigates the shear behavior and dilatancy of bimrocks featuring a rock-like matrix,such as *** study addresses a gap in current research,which has predominantly examined the shear behavior of soil-matrix bimrocks(bimsoils).Laboratory direct shear tests were performed on idealized models with varying volumetric block proportions(VBPs).The results highlight that blocks exert both positive and negative effects on shear strength,dilation,and block breakage factor(BF),depending on *** indicate 40%and 60%as critical VBPs,revealing distinct shear strength trends within this range,contrary to the dominant downward *** positively impact dilation and BF between 20%and 50%VBP,while negatively affecting them beyond this *** skeleton inherently promotes stable dilatancy under normal stress increments and intensifies stress dependency of shear *** in dilation angle concerning normal stress and VBP suggest the potential for characterizing this factor using equivalent strength and roughness,akin to rockfill *** assessments of equivalent strength revealed positive effects of blocks when VBP was between 30%and 70%.Lastly,the findings indicate that blocks notably impact pre-and post-peak behaviors by reducing shear stiffness and inducing local hardening *** study also discusses the similarities and distinctions in the function of blocks within soil-like and rock-like *** offers new insights into the exact role of blocks in bimrock shear behavior beyond the traditional interpretation through the variation of friction and cohesion.

关键词： Bimrock Rock-like matrix Shear behavior Shear strength Shear dilation Block breakage

Modeling metallurgical responses of coal Tri-Flo separators by a novel BNN:a"Conscious-Lab"development

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International Journal of Coal Science & Technology 2021年第6期8卷 1436-1446页

作者： Mehdi Alidokht Samaneh yazdani esmaeil Hadavandi Saeed Chehreh Chelgani Tabas Parvardeh Coal Company(TPCCO) BirjandIran Department of Electrical and Computer Engineering Islamic Azad UniversityNorth Tehran BranchTehranIran Department of Industrial Engineering Birjand University of TechnologyBirjandIran Minerals and Metallurgical Engineering Department of CivilEnvironmental and Natural Resources EngineeringLulea University of Technology97187 LuleaSweden

Tri-flo cyclone,as a dense-medium separation device,is one of the most typical environmentally friendly industrial techniques in the coal washery ***,no detailed investigation has been conducted to explore the effectiveness of tri-flo cyclone operating parameters on their representative metallurgical responses(yield and recovery).To fill this gap,this work for the first time in the coal processing sector is going to introduce a type of advanced intelligent method(boosted-neural network"BNN")which is able to linearly and nonlinearly assess multivariable correlations among all variables,rank them based on their effectiveness and model their produced *** assessments and modeling were considered a new concept called"Conscious Laboratory(CL)".CL can markedly decrease the number of laboratory experiments,reduce cost,save time,remove scaling up risks,expand maintaining processes,and significantly improve our knowledge about the modeled *** this study,a robust monitoring database from the Tabas coal plant was prepared to cover various conditions for building a CL for coal tri-flo ***-known machine learning methods,random forest,and support vector regression were developed to validate BNN *** comparisons indicated the accuracy and strength of BNN over the examined traditional modeling *** a sentence,generating a novel BNN within the CL concept can apply in various energy and coal processing areas,fill gaps in our knowledge about possible interactions,and open a new window for plants’fully automotive process.

关键词： Conscious laboratory BNN Tri-flo Random forest Support vector regression

Applying the spectral stochastic finite element method in multiple-random field RC structures

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Frontiers of Structural and Civil Engineering 2022年第4期16卷 434-447页

作者： Abbas yazdani Civil Engineering Department University of Sistan and BaluchestanZahedan 98167-45845Iran

This paper uses the spectral stochastic finite element method(SSFEM)for analyzing reinforced concrete(RC)beam/slab *** doing so,it presents a new framework to study how the correlation length of a random field(RF)with uncertain parameters will affect modeling uncertainties and reliability *** considers:1)different correlation lengths for uncertainty parameters,and 2)dead and live loads as well as the elasticity moduli of concrete and steel as a multi-dimensional RF in concrete *** show the SSFEM’s efficiency in the study of concrete structures and to evaluate the sensitivity of the correlation length effects in evaluating the reliability,two examples of RC beams and slabs have been *** to the results,the RF correlation length is effective in modeling uncertainties and evaluating reliabilities;the longer the correlation length,the greater the dispersion range of the structure response and the higher the failure probability.

关键词： uncertainty spectral stochastic finite element method correlation length reliability assessment reinforced concrete beam/slab

Studies on mass attenuation coefficients for some body tissues with different medical sources and their validation using Monte Carlo codes

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Nuclear Science and Techniques 2020年第12期31卷 50-64页

作者： Sepideh yazdani Darki Sajad Keshavarz Department of Physics University of YazdYazdIran Department of Medical Radiation Engineering University of Science and Research Branch TehranTehranIran

The mass attenuation coefficients of the breasts,lungs,kidneys,pancreas,liver,eye lenses,thyroid,brain,ovary,heart,large intestines,blood,skin,spleen,muscle,and cortical bone were measured at different sources(i.e.,0.021,0.029,0.03,0.14,0.218,0.38,0.412,0.663,0.83,and 1.25 MeV)using various methods including the Monte Carlo N-particle transport code(MCNP),the geometry and tracking code(GEANT4),and theoretical approach described in this *** attenuation coefficients were also compared with the values from the national institute of standards and technology(NIST-XCOM).The values obtained were similar to those obtained using *** results show that the theoretical method is quite convenient in comparison with GEANT4 and MCNP in the calculation of the mass attenuation coefficients of the human body samples applied when compared with the NIST values and demonstrated an acceptable difference.

关键词： Mass attenuation coefficient MCNP Geant4 XCOM Human organs

Delay-Constrained Optimized Packet Aggregation in High-Speed Wireless Networks

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Journal of Computer Science & Technology 2013年第3期28卷 525-539页

作者： Peyman Teymoori Nasser yazdani School of Electrical and Computer Engineering University College of Engineering University of Tehran School of Computer Science Institute for Research in Fundamental Sciences

High-speed wireless networks such as IEEE 802.11n have been introduced based on IEEE 802.11 to meet the growing demand for high-throughput and multimedia applications. It is known that the medium access control （MAC） efficiency of IEEE 802.11 decreases with increasing the physical rate. To improve efficiency, few solutions have been proposed such as Aggregation to concatenate a number of packets into a larger frame and send it at once to reduce the protocol overhead. Since transmitting larger frames eventuates to dramatic delay and jitter increase in other nodes, bounding the maxi- mum aggregated frame size is important to satisfy delay requirements of especially multimedia applications. In this paper, we propose a scheme called Optimized Packet Aggregation （OPA） which models the network by constrained convex optimization to obtain the optimal aggregation size of each node regarding to delay constraints of other nodes. OPA attains proportionally fair sharing of the channel while satisfying delay constrains. Furthermore, reaching the optimal point is guaranteed in OPA with low complexity. Simulation results show that OPA can successfully bound delay and meet the requirements of nodes with only an insignificant throughput penalty due to limiting the aggregation size even in dynamic conditions.

关键词： high-speed wireless network delay requirement aggregation convex optimization

The Energy Distribution of a Noncommutative Reissner–Nordström Black Hole

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Chinese Physics Letters 2013年第9期30卷 25-28页

作者： Kourosh Nozari A.yazdani Center for Excellence in Astronomy and Astrophysics(CEAAI-RIAAM)-Maragha P.O.Box55134-441MaraghaIran Department of Physics Faculty of Basic SciencesUniversity of MazandaranP.O.Box 47416-95447BabolsarIran

We study the energy distribution of a noncommutative Reissner–Nordström black *** consider both Ein-stein and Møller prescriptions,and compare our results with the corresponding results obtained recently for a Schwar... 详细信息

关键词： Reissner commutative black

Effect of earth reinforcement,soil properties and wall properties on bridge MSE walls

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Frontiers of Structural and Civil Engineering 2021年第5期15卷 1209-1221页

作者： Zaid MOMANI Eyosias BENEBERU Nur yazdani Department of Civil Engineering Al-Ahliyya Amman UniversityAmman 19328Jordan Bridgefarmer&Associates DallasTX 75234USA Department of Civil Engineering University of Texas at ArlingtonArlingtonTX 76019USA

Mechanically stabilized earth(MSE)retaining walls are popular for highway bridge *** have precast concrete panels attached to earth *** panels are designed to have some lateral ***,in some cases,excessive movement and even complete dislocation of the panels have been *** this study,3-D numerical modeling involving an existing MSE wall was undertaken to investigate various wall *** effects of pore pressure,soil cohesion,earth reinforcement type and length,breakage/slippage of reinforcement and concrete strength,were *** showed that the wall movement is affected by soil pore pressure and reinforcement integrity and length,and unaffected by concrete *** cohesion has a minor effect,while the movement increased by 13–20 mm for flexible geogrid reinforced walls compared with the steel grid *** steel grid stresses were below yielding,while the geogrid experienced significant stresses without *** reinforcement may be used taking account of slippage resistance and wall *** steel grid is used,non-cohesive soil is recommended to minimize *** soil drainage is important for control of pore pressure.

关键词： mechanically stabilized earth walls precast concrete panels backfill soil finite element modeling earth reinforcement