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Conflict-Aware Safe Reinforcement Learning:A Meta-Cognitive Learning Framework

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IEEE/CAA Journal of Automatica Sinica 2022年第3期9卷 466-481页

作者： majid Mazouchi Subramanya Nageshrao Hamidreza Modares Michigan State University East LansingMI 48824 USA Ford Research and Innovation Center Ford Motor CompanyPalo AltoCA 94304 USA IEEE

In this paper,a data-driven conflict-aware safe reinforcement learning(CAS-RL)algorithm is presented for control of autonomous *** safe RL results with predefined performance functions and safe sets can only provide safety and performance guarantees for a single environment or *** contrast,the presented CAS-RL algorithm provides safety and performance guarantees across a variety of circumstances that the system might *** is achieved by utilizing a bilevel learning control architecture:A higher metacognitive layer leverages a data-driven receding-horizon attentional controller(RHAC)to adapt relative attention to different system’s safety and performance requirements,and,a lower-layer RL controller designs control actuation signals for the *** presented RHAC makes its meta decisions based on the reaction curve of the lower-layer RL controller using a metamodel or *** specifically,it leverages a prediction meta-model(PMM)which spans the space of all future meta trajectories using a given finite number of past meta *** will adapt the system’s aspiration towards performance metrics(e.g.,performance weights)as well as safety boundaries to resolve conflicts that arise as mission scenarios *** will guarantee safety and feasibility(i.e.,performance boundness)of the lower-layer RL-based control *** is shown that the interplay between the RHAC and the lower-layer RL controller is a bilevel optimization problem for which the leader(RHAC)operates at a lower rate than the follower(RL-based controller)and its solution guarantees feasibility and safety of the control *** effectiveness of the proposed framework is verified through a simulation example.

关键词： Optimal control receding-horizon attentionalcontroller(RHAC) reinforcement learning(RL)

Relativistic symmetries in the Hulthn scalar-vector-tensor interactions

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Chinese Physics B 2013年第8期22卷 257-263页

作者： majid Hamzavi Ali Akbar Rajabi Department of Science and Engineering Abhar Branch Islamic Azad UniversityAbhar Iran Physics Department Shahrood University of TechnologyShahrood Iran

In the presence of spin and pseudospin （p-spin） symmetries, the approximate analytical bound states of the Dirac equation for scalar-vector-tensor Hulth6n potentials are obtained with any arbitrary spin-orbit coupling number using the Pekeris approximation. The Hulth6n tensor interaction is studied instead of the commonly used Coulomb or linear terms. The generalized parametric Nikiforov-Uvarov （NU） method is used to obtain energy eigenvalues and corresponding wave functions in their closed forms. It is shown that tensor interaction removes degeneracy between spin and p-spin doublets. Some numerical results are also given.

关键词： Dirac equation Hulth6n scalar-vector-tensor potential spin and p-spin symmetry NU method

Undrained seismic bearing capacity of strip footing adjacent to a heterogeneous excavation

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Frontiers of Structural and Civil Engineering 2023年第4期17卷 566-583页

作者： Ramin VALI Saeed KHOSRAVI majid BEYGI Department of Civil Engineering Technical and Vocational UniversityTehran ***Iran Department of Mining Engineering Shahid Bahonar University of KermanKerman ***Iran Department of Civil Engineering Yazd UniversityYazd ***Iran

The analysis of the bearing capacity of strip footings sited near an excavation is critical in *** this study,the effects of the geometrical features of the excavation and the soil strength properties on the seismic bearing capacity of a strip footing resting on an excavation were evaluated using the lower and upper bounds of the finite element limit analysis *** effects of the setback distance ratio(L/B),excavation height ratio(H/B),soil strength heterogeneity(kB/cu),and horizontal earthquake coefficient(kh)were *** charts and tables were produced to clarify the relationship between the undrained seismic bearing capacity and the selected parameters.

关键词： excavation finite element limit analysis heterogeneous soil strip footing undrained bearing capacity

A New Integrable (2+1)-Dimensional Generalized Breaking Soliton Equation:N-Soliton Solutions and Traveling Wave Solutions

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Communications in Theoretical Physics 2016年第10期65卷 385-388页

作者： Abdul-majid Wazwaz Department of Mathematics Saint Xavier University

In this work,we study a new(2+1)-dimensional generalized breaking soliton equation which admits the Painleve property for one special set of *** derive multiple soliton solutions,traveling wave solutions,and periodic ... 详细信息

关键词： breaking soliton equations Hirota bilinear method multiple soliton solutions traveling wave solutions

Innovative mitigation method for buried pipelines crossing faults

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Earthquake Engineering and Engineering Vibration 2022年第4期21卷 1089-1101页

作者： Mahdi Rojhani majid Moradi Ali Derakhshani Department of Civil Engineering Faculty of EngineeringShahed UniversityTehranIran Faculty of Civil Engineering College of EngineeringUniversity of TehranTehranIran

A new remediation technique is proposed to mitigate large deformations imposed on buried pipeline systems subject to permanent ground *** this technique,low-density gravel(LDG)with high porosity,such as pumice,is used as backfill in the trench containing the pipe near an area susceptible to *** countermeasure decreases soil resistance,soil-pipe interaction forces and strain on the pipe as the pipeline deformation mechanism changes to a more desirable *** polystyrene geofoam has been introduced to decrease the density of the pipeline backfill;however,LDG is more efficient regarding workability during construction,environmental effects,durability,fire safety,and cost-effectiveness.A series of centrifuge model experiments in which the pipelines were subjected to reverse faulting was conducted to evaluate the proposed *** faulting,the axial and bending strain and pipe deflection were measured.A comparison of the responses of the remediated pipeline and the pipeline without remediation indicates that the proposed technique substantially mitigates the effects of large deformation.

关键词： pipelines centrifuge modeling faulting mitigation earthquake

The distribution and frequency of damage to roadside trees in low-volume road construction

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Journal of Forestry Research 2018年第1期29卷 221-226页

作者： majid Lotfalian Mehran Nasiri Department of Forestry Faculty of Natural Resources Sari University of Agricultural Sciences and Natural Resources

We investigated the distribution and frequency of damage to tree stands adjacent to low-volume roads according to the type of hillside materials involved（soil or rock） and hillside gradient in mountainous forests of northern Iran. A total of 80 plots were systematically and randomly sampled to record damaged trees（bending,crushing and wounding） by class of hillside gradient and materials at the edge of road. Tree wounding and crushing at rock slopes was significantly greater than at hillsides with a mix of clay soil（p ／ 0.05）. Damage on hillsides with slope gradients[45% were 2, 8.5 and 2.3 times more frequent than on hillsides with slope gradient／15% for bending, crushing and wounding, respectively. The damage distribution varied according by type and the most frequent damage was tree wounding（p ／ 0.05）. The damage distribution was measured at distances of 4, 5 and 8 m from the road fillslope for tree bending, crushing and wounding, respectively. Using hydraulic excavators and physical barriers（wooden obstruction and synthetic holder） during earthworks for road construction could reduce these damage.

关键词： Low-volume road construction Tree damage Hillside materials Gradient Distribution

Handheld diffuse optical breast scanner probe for cross-sectional imaging of breast tissue

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Journal of Innovative Optical Health Sciences 2019年第2期12卷 74-85页

作者： majid Shokoufi Farid Golnaraghi School of Mechatronic Systems Engineering Simon Fraser University 250-13450102nd Avenue SurreyCanadaBC V3T 0A3

Diffuse optical spectroscopy is a relatively new,noninvasive and nonionizing technique for breast cancer *** the present study,we have introduced a novel handheld diffuse optical breast scan(DOB-Scan)probe to measure optical properties of the breast in vivo and create functional and compositional images of the *** addition,the probe gives more information about breast tissue's constituents,which helps distinguish a healthy and cancerous *** symmetrical light sources,each including four different wavelengths,are used to illuminate the breast tissue.A high-resolution linear array detector measures the intensity of the back-scattered photons at different radial destinations from the illumination sources on the surface of the breast tissue,and a unique image reconstruction algorithm is used to create four cross-sectional images for four different *** fromfiber optic-based illumination techniques,the proposed method in this paper integrates multi-wavelength light-emitting diodes to act as pencil beam sources into a scattering medium like breast *** unique design and its compact structure reduce the complexity,size and cost of a potential *** the introduced technique miniaturizes the probe,this study points to the reliability of this technique in the phantom study and clinical breast *** have received ethical approval to test the DOB-Scan probe on patients and we are currently testing the DOB-Scan probe on subjects who are diagnosed with breast cancer.

关键词： Breast cancer diffuse optical spectroscopy image reconstruction techniques medical and biological imaging optical breast phantom

An Alternative Approach to Rank Efficient DMUs in DEA via Cross-Efficiency Evaluation,Gini Coefficient,and Bonferroni Mean

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Journal of the Operations Research Society of China 2022年第4期10卷 763-783页

作者： Zahra Behdani majid Darehmiraki Department of Mathematics and Statistics Behbahan Khatam Alanbia University of TechnologyBehbahanKhouzestanIran

In this paper,we focus on a critical problem in data envelopment analysis(DEA)and propose a simple resolution for *** major problem of the DEA is the existence of several efficient decision-making units(DMUs).To deal with this issue,we introduce a method that involves cross-efficiency evaluation,Gini coefficient,and Bonferroni ***,a cross-efficiency matrix is ***,mixing the Gini coefficient and Bonferroni mean,a Gini–Bonferroni(GB)index is proposed for ranking efficient DMUs,where the DMUs with bigger GB are ranked *** proposed method broke the tie between efficient ***,a numerical example and real application of this method are presented in the ranking of research and development(R&D)investment companies in the pharmaceutical and biotechnology industries.

关键词： Data envelopment analysis Efficiency Gini coefficient Bonferroni mean Cross-efficiency evaluation Ranking Efficient units

A Coprocessor Architecture for 80/112-bit Security Related Applications

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Computers, Materials & Continua 2023年第3期74卷 6849-6865页

作者： Muhammad Rashid majid Alotaibi Department of Computer Engineering Umm Al-Qura UniversityMakkah21955Saudi Arabia

We have proposed a flexible coprocessor key-authentication architecture for 80/112-bit security-related applications over GF(2m)field by employing Elliptic-curve Diffie Hellman(ECDH)*** flexibility,a serial input/output interface is used to load/produce secret,public,and shared keys ***,to reduce the hardware resources and to achieve a reasonable time for cryptographic computations,we have proposed a finite field digit-serial multiplier architecture using combined shift and accumulate ***,two finite-statemachine controllers are used to perform efficient control *** proposed coprocessor architecture over GF(2^(163))and GF(2^(233))is programmed using Verilog and then implemented on Xilinx Virtex-7 FPGA(field-programmable-gate-array)*** GF(2^(163))and GF(2^(233)),the proposed flexible coprocessor use 1351 and 1789 slices,the achieved clock frequency is 250 and 235MHz,time for one public key computation is 40.50 and 79.20μs and time for one shared key generation is 81.00 and 158.40μ***,the consumed power over GF(2^(163))and GF(2^(233))is 0.91 and 1.37mW,*** proposed coprocessor architecture outperforms state-of-the-art ECDH designs in terms of hardware resources.

关键词： Coprocessor design key-authentication wireless sensor nodes RFID ECDH FPGA