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Detection method of forward-scatter signal based on Rényi entropy 被引量:1
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作者 ZHENG Yuqing AI Xiaofeng +2 位作者 YANG Yong ZHAO Feng XIAO Shunping 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期865-873,共9页
The application scope of the forward scatter radar(FSR)based on the Global Navigation Satellite System(GNSS)can be expanded by improving the detection capability.Firstly,the forward-scatter signal model when the targe... The application scope of the forward scatter radar(FSR)based on the Global Navigation Satellite System(GNSS)can be expanded by improving the detection capability.Firstly,the forward-scatter signal model when the target crosses the baseline is constructed.Then,the detection method of the for-ward-scatter signal based on the Rényi entropy of time-fre-quency distribution is proposed and the detection performance with different time-frequency distributions is compared.Simula-tion results show that the method based on the smooth pseudo Wigner-Ville distribution(SPWVD)can achieve the best perfor-mance.Next,combined with the geometry of FSR,the influence on detection performance of the relative distance between the target and the baseline is analyzed.Finally,the proposed method is validated by the anechoic chamber measurements and the results show that the detection ability has a 10 dB improvement compared with the common constant false alarm rate(CFAR)detection. 展开更多
关键词 forward scatter radar(FSR) Global Navigation Satellite System(GNSS) time-frequency distribution Rényi entropy signal detection
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Enhancing Data Forwarding Efficiency in SIoT with Multidimensional Social Relations
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作者 Fang Xu Songhao Jiang +3 位作者 Yi Ma Manzoor Ahmed Zenggang Xiong Yuanlin Lyu 《Computers, Materials & Continua》 SCIE EI 2024年第1期1095-1113,共19页
Effective data communication is a crucial aspect of the Social Internet of Things(SIoT)and continues to be a significant research focus.This paper proposes a data forwarding algorithm based on Multidimensional Social ... Effective data communication is a crucial aspect of the Social Internet of Things(SIoT)and continues to be a significant research focus.This paper proposes a data forwarding algorithm based on Multidimensional Social Relations(MSRR)in SIoT to solve this problem.The proposed algorithm separates message forwarding into intra-and cross-community forwarding by analyzing interest traits and social connections among nodes.Three new metrics are defined:the intensity of node social relationships,node activity,and community connectivity.Within the community,messages are sent by determining which node is most similar to the sender by weighing the strength of social connections and node activity.When a node performs cross-community forwarding,the message is forwarded to the most reasonable relay community by measuring the node activity and the connection between communities.The proposed algorithm was compared to three existing routing algorithms in simulation experiments.Results indicate that the proposed algorithmsubstantially improves message delivery efficiency while lessening network overhead and enhancing connectivity and coordination in the SIoT context. 展开更多
关键词 SIoT data forwarding social attributes social relations COMMUNITY
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A fast forward computational method for nuclear measurement using volumetric detection constraints
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作者 Qiong Zhang Lin-Lv Lin 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第2期47-63,共17页
Owing to the complex lithology of unconventional reservoirs,field interpreters usually need to provide a basis for interpretation using logging simulation models.Among the various detection tools that use nuclear sour... Owing to the complex lithology of unconventional reservoirs,field interpreters usually need to provide a basis for interpretation using logging simulation models.Among the various detection tools that use nuclear sources,the detector response can reflect various types of information of the medium.The Monte Carlo method is one of the primary methods used to obtain nuclear detection responses in complex environments.However,this requires a computational process with extensive random sampling,consumes considerable resources,and does not provide real-time response results.Therefore,a novel fast forward computational method(FFCM)for nuclear measurement that uses volumetric detection constraints to rapidly calculate the detector response in various complex environments is proposed.First,the data library required for the FFCM is built by collecting the detection volume,detector counts,and flux sensitivity functions through a Monte Carlo simulation.Then,based on perturbation theory and the Rytov approximation,a model for the detector response is derived using the flux sensitivity function method and a one-group diffusion model.The environmental perturbation is constrained to optimize the model according to the tool structure and the impact of the formation and borehole within the effective detection volume.Finally,the method is applied to a neutron porosity tool for verification.In various complex simulation environments,the maximum relative error between the calculated porosity results of Monte Carlo and FFCM was 6.80%,with a rootmean-square error of 0.62 p.u.In field well applications,the formation porosity model obtained using FFCM was in good agreement with the model obtained by interpreters,which demonstrates the validity and accuracy of the proposed method. 展开更多
关键词 Nuclear measurement Fast forward computation Volumetric constraints
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Estimation of Displacement and Extension due to Reverse Drag of Normal Faults: Forward Method
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作者 Shunshan Xu Angel Francisco Nieto-Samaniego +1 位作者 Huilong Xu Susana Alicia Alaniz-Álvarez 《International Journal of Geosciences》 CAS 2024年第1期25-39,共15页
In the case of reverse drag of normal faulting, the displacement and horizontal extension are determined based on the established equations for the three mechanisms: rigid body, vertical shear and inclined shear. Ther... In the case of reverse drag of normal faulting, the displacement and horizontal extension are determined based on the established equations for the three mechanisms: rigid body, vertical shear and inclined shear. There are three sub-cases of basal detachment for the rigid body model: horizontal detachment, antithetic detachment and synthetic detachment. For the rigid body model, the established equations indicate that the total displacement on the synthetic base (D<sub>t2</sub>) is the largest, that on the horizontal base (D<sub>t1</sub>) is moderate, and that on the antithetic base (D<sub>t3</sub>) is the smallest. On the other hand, the value of (D<sub>t1</sub>) is larger than the displacement for the vertical shear (D<sub>t4</sub>). The value of (D<sub>t1</sub>) is larger than or less than the displacement for the inclined shear (D<sub>t5</sub>) depending on the original fault dip δ<sub>0</sub>, bedding angle θ, and the angle of shear direction β. For all original parameters, the value of D<sub>t5</sub> is less than the value of D<sub>t4</sub>. Also, by comparing three rotation mechanisms, we find that the inclined shear produces largest extension, the rigid body model with horizontal detachment produces the smallest extension, and the vertical shear model produces moderate extension. 展开更多
关键词 Fault Rotation Fault Drag Fault Displacement EXTENSION forward Model
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An efficient method for constructing a random insertional mutant library for forward genetics in Nannochloropsis oceanica
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作者 Zhongyi ZHANG Hang LIU +5 位作者 Xiaohui PAN Yanan ZONG Leili FENG Lixian LIU Li GUO Guanpin YANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第1期216-225,共10页
Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-st... Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-strand breaks of DNA,causing insertional mutation.The random insertional mutant library constructed using this method has become a method of forward genetics for gene cloning.However,the establishment of a random insertional mutant library requires a high transformation efficiency of exogenous genes.Many microalgal species show a low transformation efficiency,making constructing random insertional mutant libraries difficult.In this study,we established a highly efficient transformation method for constructing a random insertional mutant library of Nannochloropsis oceanica,and tentatively tried to isolate its genes to prove the feasibility of the method.A gene that may control the growth rate and cell size was identified.This method will facilitate the genetic studies of N.oceanica,which should also be a reference for other microalgal species. 展开更多
关键词 Nannochloropsis oceanica genetic transformation random insertional mutant library zeocin pretreatment forward genetics
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3D seismic forward modeling from the multiphysical inversion at the Ketzin CO_(2) storage site
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作者 Yi-kang Zheng Chong Wang +2 位作者 Hao-hong Liang Yi-bo Wang Rong-shu Zeng 《Applied Geophysics》 SCIE CSCD 2024年第3期593-605,620,共14页
From June 2008 to August 2013,approximately 67 kt of CO_(2) was injected into a deep saline formation at the Ketzin pilot CO_(2) storage site.During injection,3D seismic surveys have been performed to monitor the migr... From June 2008 to August 2013,approximately 67 kt of CO_(2) was injected into a deep saline formation at the Ketzin pilot CO_(2) storage site.During injection,3D seismic surveys have been performed to monitor the migration of sequestered CO_(2).Seismic monitoring results are limited by the acquisition and signal-to-noise ratio of the acquired data.The multiphysical reservoir simulation provides information regarding the CO_(2) fluid behavior,and the approximated model should be calibrated with the monitoring results.In this work,property models are delivered from the multiphysical model during 3D repeated seismic surveys.The simulated seismic data based on the models are compared with the real data,and the results validate the effectiveness of the multiphysical inversion method.Time-lapse analysis shows the trend of CO_(2) migration during and after injection. 展开更多
关键词 Seismic forward modeling reservoir simulation CO_(2)storage time-lapse analysis
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Temperature and Salinity Dual-parameter Sensing Based on Forward Brillouin Scattering in 1060-XP SMF
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作者 LIU Pengkai ZHANG Wujun LU Yuangang 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2024年第S01期89-95,共7页
A novel temperature and salinity discriminative sensing method based on forward Brillouin scattering(FBS)in 1060-XP single-mode fiber(SMF)is proposed.The measured frequency shifts corresponding to different radial aco... A novel temperature and salinity discriminative sensing method based on forward Brillouin scattering(FBS)in 1060-XP single-mode fiber(SMF)is proposed.The measured frequency shifts corresponding to different radial acoustic modes in 1060-XP SMF show different sensitivities to temperature and salinity.Based on the new phenomenon that different radial acoustic modes have different frequency shift-temperature and frequency shift-salinity coefficients,we propose a novel method for simultaneously measuring temperature and salinity by measuring the frequency shift changes of two FBS scattering peaks.In a proof-of-concept experiment,the temperature and salinity measurement errors are 0.12℃and 0.29%,respectively.The proposed method for simultaneously measuring temperature and salinity has the potential applications such as ocean surveying,food manufacturing and pharmaceutical engineering. 展开更多
关键词 forward Brillouin scattering(FBS) optical fiber sensor salinity sensing temperature sensing
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Time-Domain Higher-Order Boundary Element Method for Simulating High Forward-Speed Ship Motions in Waves
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作者 ZHOU Xiao-guo CHENG Yong PAN Su-yong 《China Ocean Engineering》 SCIE EI CSCD 2024年第5期904-914,共11页
The hydrodynamic performance of a high forward-speed ship in obliquely propagating waves is numerically examined to assess both free motions and wave field in comparison with a low forward-speed ship.This numerical mo... The hydrodynamic performance of a high forward-speed ship in obliquely propagating waves is numerically examined to assess both free motions and wave field in comparison with a low forward-speed ship.This numerical model is based on the time-domain potential flow theory and higher-order boundary element method,where an analytical expression is completely expanded to determine the base-unsteady coupling flow imposed on the moving condition of the ship.The ship in the numerical model may possess different advancing speeds,i.e.stationary,low speed,and high speed.The role of the water depth,wave height,wave period,and incident wave angle is analyzed by means of the accurate numerical model.It is found that the resonant motions of the high forward-speed ship are triggered by comparison with the stationary one.More specifically,a higher forward speed generates a V-shaped wave region with a larger elevation,which induces stronger resonant motions corresponding to larger wave periods.The shoaling effect is adverse to the motion of the low-speed ship,but is beneficial to the resonant motion of the high-speed ship.When waves obliquely propagate toward the ship,the V-shaped wave region would be broken due to the coupling effect between roll and pitch motions.It is also demonstrated that the maximum heave motion occurs in beam seas for stationary cases but occurs in head waves for high speeds.However,the variation of the pitch motion with period is hardly affected by wave incident angles. 展开更多
关键词 high forward speed oblique incident waves ship motion higher-order boundary element method time domain wave field
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Exploring the Relationship Between Patent Forward Citation and Stock Return Rate Using Empirical Data of China Stock Market
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作者 Hong-Wen Tsai Hui-Chung Che 《Management Studies》 2024年第2期67-83,共17页
A novel indicator called price-citation was proposed.Based on the company integrated patent database of China listed companies of common stocks(A-shares)with the stock price and the stock return rate data,more than tw... A novel indicator called price-citation was proposed.Based on the company integrated patent database of China listed companies of common stocks(A-shares)with the stock price and the stock return rate data,more than two thousand of A-shares from 2017 to 2020 were selected.The effect of the traditional patent forward citation and the price-citation for discriminating the stock return rate was thoroughly analyzed via ANOVA.The A-shares of forward citation counts above the average showed higher stock return rate means than the A-shares having patents but receiving no forward citations.The price-citation,combining both the financial and patent attributes,defined as the multiplication of the current stock price and the currently receiving forward citation count,showed its excellence in discriminating the stock return rate.The A-shares of higher price-citation showed significantly higher stock return rate means while the A-shares of lower price-citation showed significantly lowest stock return rate means.The price-citation effect had not been changed by COVID-19 though COVID-19 affected the social and economic environment to a considerable extent in 2020. 展开更多
关键词 China A-share PATENT ANOVA stock return rate forward citation price-citation
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UAV-based transient electromagnetic 3D forward modeling and inversion and analysis of exploration capability
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作者 WEI Laonao LIU Yunhe ZHANG Bo 《Global Geology》 2024年第3期154-166,共13页
Unmanned aerial vehicle transient electromagnetic(UAV-TEM)is a novel airborne exploration method that offers advantages such as low cost,simple operation,high exploration efficiency and suitability for near-surface ex... Unmanned aerial vehicle transient electromagnetic(UAV-TEM)is a novel airborne exploration method that offers advantages such as low cost,simple operation,high exploration efficiency and suitability for near-surface exploration in complex terrain areas.To improve the accuracy of data interpretation in this method,the authors conducted a systematic three-dimensional(3D)forward modeling and inversion of the UAV-TEM.This study utilized the finite element method based on unstructured tetrahedral elements and employed the second-order backward Euler method for time discretization.This allowed for accurate 3D modeling and accounted for the effects of complex terrain.Based on these,the influence characteristics of flight altitudes and the sizes,burial depths,and resistivities of anomalies are compared and analyzed to explore the UAV-TEM systems’exploration capability.Lastly,four typical geoelectrical models of landslides are designed,and the inversion method based on the Gauss-Newton optimization method is used to image the landslide models and analyze the imaging effect of the UAV-TEM method on landslide geohazards.Numerical results showed that UAV-TEM could have better exploration resolution and fine imaging of nearsurface structures,providing important technical support for monitoring,early warning,and preventing landslides and other geological hazards. 展开更多
关键词 UAV 3D forward modeling transient electromagnetic 3D inversion landslide model
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Application Strategy of BIM Technology in the Forward Design of Bridges
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作者 Jianmin He 《Journal of Architectural Research and Development》 2024年第3期14-19,共6页
Bridge engineering is highly specialized and has spatial characteristics,which puts forward higher requirements for design work.The advancement of information technology has provided ample tools to facilitate bridge d... Bridge engineering is highly specialized and has spatial characteristics,which puts forward higher requirements for design work.The advancement of information technology has provided ample tools to facilitate bridge design work,with building information modeling(BIM)technology being one of them.BIM technology ensures the efficiency and quality of the forward design of bridges,while also reducing construction costs.This article starts with defining the concept of BIM technology,followed by a discussion on its advantages in bridge design and application process,which serves as a reference for other bridge designers. 展开更多
关键词 BIM technology BRIDGE forward design Application strategy
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威斯康星大学发展战略规划2020 Forward专项考察
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作者 李歆睿 俞兆达 《高教发展与评估》 CSSCI 北大核心 2023年第3期73-84,I0005,I0006,共14页
基于美国威斯康星大学2020 Forward专项的考察结果显示:实施大学发展战略规划在价值逻辑层面呈现校园文化传统、绩效管理工具和危机应对方案三重意蕴;在行动要素层面有赖于目标体系、主体网络和保障机制的协同增效;在反馈闭环层面应形... 基于美国威斯康星大学2020 Forward专项的考察结果显示:实施大学发展战略规划在价值逻辑层面呈现校园文化传统、绩效管理工具和危机应对方案三重意蕴;在行动要素层面有赖于目标体系、主体网络和保障机制的协同增效;在反馈闭环层面应形成“目标回溯-措施谋划-评价措施-行动成果-评估成效”的系统耦合。威斯康星2020 Forward的实践经验表明,战略思维、目标分解、全员参与和有效评估是大学发展战略规划精准落地、高效实施的四个关键原则。 展开更多
关键词 美国高等教育 威斯康星大学 大学战略规划 2020 forward
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Forward stagewise regression with multilevel memristor for sparse coding
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作者 Chenxu Wu Yibai Xue +6 位作者 Han Bao Ling Yang Jiancong Li Jing Tian Shengguang Ren Yi Li Xiangshui Miao 《Journal of Semiconductors》 EI CAS CSCD 2023年第10期105-113,共9页
Sparse coding is a prevalent method for image inpainting and feature extraction,which can repair corrupted images or improve data processing efficiency,and has numerous applications in computer vision and signal proce... Sparse coding is a prevalent method for image inpainting and feature extraction,which can repair corrupted images or improve data processing efficiency,and has numerous applications in computer vision and signal processing.Recently,sev-eral memristor-based in-memory computing systems have been proposed to enhance the efficiency of sparse coding remark-ably.However,the variations and low precision of the devices will deteriorate the dictionary,causing inevitable degradation in the accuracy and reliability of the application.In this work,a digital-analog hybrid memristive sparse coding system is pro-posed utilizing a multilevel Pt/Al_(2)O_(3)/AlO_(x)/W memristor,which employs the forward stagewise regression algorithm:The approxi-mate cosine distance calculation is conducted in the analog part to speed up the computation,followed by high-precision coeffi-cient updates performed in the digital portion.We determine that four states of the aforementioned memristor are sufficient for the processing of natural images.Furthermore,through dynamic adjustment of the mapping ratio,the precision require-ment for the digit-to-analog converters can be reduced to 4 bits.Compared to the previous system,our system achieves higher image reconstruction quality of the 38 dB peak-signal-to-noise ratio.Moreover,in the context of image inpainting,images containing 50%missing pixels can be restored with a reconstruction error of 0.0424 root-mean-squared error. 展开更多
关键词 forward stagewise regression in-memory computing MEMRISTOR sparse coding
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3D forward modeling and response characteristics of low-resistivity overburden of the CFS-PML absorbing boundary for ground-well transient electromagnetic method
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作者 Lijuan Zhao Mingzhong Gao +3 位作者 Nengzhong Lei Hongfei Duan Weizhong Qiu Zhaoying Chen 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第12期1541-1550,共10页
This study used the stable and convergent Dufort-Frankel method to differentially discretize the diffusion equation of the ground-well transient electromagnetic secondary field.The absorption boundary condition of com... This study used the stable and convergent Dufort-Frankel method to differentially discretize the diffusion equation of the ground-well transient electromagnetic secondary field.The absorption boundary condition of complex frequency-shifted perfectly matched layer(CFS-PML)was used for truncation so that the low-frequency electromagnetic wave can be better absorbed at the model boundary.A typical three-dimensional(3D)homogeneous half-space model was established and a low-resistivity cube model was analyzed under the half-space condition.The response patterns and drivers of the low-resistivity cube model were discussed under the influence of a low-resistivity overburden.The absorption boundary conditions of CFS-PML significantly affected the low-frequency electromagnetic waves.For a low-resistivity cube around the borehole,its response curve exhibited a single-peak,and the extreme point of the curve corresponded to the center of the low-resistivity body.When the low-resistivity cube was directly below the borehole,the response curve showed three extreme values(two high and one low),with the low corresponding to the center of the low-resistivity body.The total field response of the low-resistivity overburden was stronger than that of the uniform half-space model due to the low-resistivity shielding effect of electromagnetic waves.When the receiving-transmitting distance gradually increased,the effect of the low-resistivity overburden was gradually weakened,and the response of the low-resistivity cube was strengthened.It was affected by the ratio of the overburden resistivity to the resistivity of the low-resistivity body. 展开更多
关键词 Ground-well transient electromagnetic method CFS-PML boundary condition 3D forward modeling Low-resistivity overburden
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Entry-Level Forward Surgical Team Training Is Associated with Increased Confidence of Primary Combat Surgeons
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作者 Junnan Wang Jiating Hu +4 位作者 Wang Xi Pengchao Cheng Pei Wang Zhinong Wang Jian Xiao 《Surgical Science》 2023年第5期377-387,共11页
Background: In recent years, we have established an entry-level Forward Surgical Team (FST) training program in a Chinese military medical university for the 5th grade undergraduates, who would be deployed to differen... Background: In recent years, we have established an entry-level Forward Surgical Team (FST) training program in a Chinese military medical university for the 5th grade undergraduates, who would be deployed to different military medical services as primary combat surgeons. This study aimed to assess the role of this pre-service training in improving their confidence with combat medical skills, after several years since they received the training. Methods: We conducted a nationwide survey of 239 primary combat surgeons who have ever participated in an entry-level FST training program before deployment between June 2016 and June 2020, which was for evaluating on a 5-point Likert scale the benefits of entry-level FST training and conventional surgery training in improving their confidence with combat medical skills. The difference in scores was compared using the student t-test. Significance was considered as P Results: The total score was significantly higher for entry-level FST training than that for conventional surgery training (30.76 ± 4.33 vs. 28.95 ± 4.80, P There was no significant difference between the training for surgical skills confidence scores (18.03 ± 8.04 vs. 17.51 ± 8.30, P = 0.098), but for non-technical skills, the score of entry-level FST training was significantly higher than that of conventional surgery training (12.73 ± 5.39 vs. 11.44 ± 5.62, P The distributions of confidence scores were different under various subgroups by demographics. There were no significant differences in scores between the two training in all specific surgical skill sets except “life-saving surgery” (P = 0.011). Scores of all 4 non-technical skill sets were significantly higher for entry-level FST than those for conventional surgery training (P Conclusions: The training should be considered as an essential strategy to improve confidence in combat medical skills, especially life-saving surgery and non-technical skills, for primary combat surgeons. 展开更多
关键词 forward Surgical Team Training Primary Combat Surgeons Combat Medical Skills Increased Confidence
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THE REGULARIZED SOLUTION APPROXIMATION OF FORWARD/BACKWARD PROBLEMS FOR A FRACTIONAL PSEUDO-PARABOLIC EQUATION WITH RANDOM NOISE
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作者 狄华斐 容伟杰 《Acta Mathematica Scientia》 SCIE CSCD 2023年第1期324-348,共25页
This paper deals with the forward and backward problems for the nonlinear fractional pseudo-parabolic equation ut+(-Δ)^(s1)ut+β(-Δ)^(s2)u=F(u,x,t)subject o random Gaussian white noise for initial and final data.Und... This paper deals with the forward and backward problems for the nonlinear fractional pseudo-parabolic equation ut+(-Δ)^(s1)ut+β(-Δ)^(s2)u=F(u,x,t)subject o random Gaussian white noise for initial and final data.Under the suitable assumptions s1,s2andβ,we first show the ill-posedness of mild solutions for forward and backward problems in the sense of Hadamard,which are mainly driven by random noise.Moreover,we propose the Fourier truncation method for stabilizing the above ill-posed problems.We derive an error estimate between the exact solution and its regularized solution in an E‖·‖Hs22norm,and give some numerical examples illustrating the effect of above method. 展开更多
关键词 regularized solution approximation forward/backward problems fractional Laplacian Gaussian white noise Fourier truncation method
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Looking Forward To Oil
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作者 GODFREY OLUKYA 《ChinAfrica》 2023年第1期42-43,共2页
China is playing a major role in Uganda’s oil industry development Although oil in Uganda was first discovered in 1925 during the colonial era,it was not until recently that its exploration and plans to exploit the b... China is playing a major role in Uganda’s oil industry development Although oil in Uganda was first discovered in 1925 during the colonial era,it was not until recently that its exploration and plans to exploit the black gold commercially began in earnest.In November 2022,the country’s Minister of Energy and Mineral Development Ruth Nankabirwa Ssentamu said at a conference in Abu Dhabi,“I hope that by April 2025,we shall see the first oil.” 展开更多
关键词 forward MINISTER PLAYING
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基于区块链的前向安全群签名方案 被引量:1
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作者 胡春强 符云清 +1 位作者 卢俊泽 黄桂林 《西华大学学报(自然科学版)》 CAS 2024年第3期1-7,共7页
针对当前群签名算法的中心化问题和依赖于可信第三方的局限性,提出一种基于区块链的前向安全群签名方案。该方案通过智能合约替代传统的可信第三方角色,旨在解决单点故障和缺乏可信第三方的问题;提出一种群管理员代理签名机制,利用哈希... 针对当前群签名算法的中心化问题和依赖于可信第三方的局限性,提出一种基于区块链的前向安全群签名方案。该方案通过智能合约替代传统的可信第三方角色,旨在解决单点故障和缺乏可信第三方的问题;提出一种群管理员代理签名机制,利用哈希值将原始签名存证于区块链以增强数据的不可篡改性和安全性;通过基础方案、加方案和乘方案设计安全时间为T=2^(k)的前向安全性群签名算法。理论分析和实验验证的结果表明,该方案提高了群签名的安全性和效率。该研究为解决群签名的中心化问题提供了新思路。 展开更多
关键词 群签名 区块链 前向安全
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“携手前进”与推动绿色、数字经济发展--新加坡2023年回顾与2024年展望 被引量:3
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作者 张磊 陈晨 《东南亚纵横》 2024年第1期31-45,共15页
2023年,政治方面,尚达曼当选新加坡第9任总统,新加坡政党多元性得到强化。以副总理兼财政部部长黄循财为核心的第四代领导团体通过《新加坡携手前进》报告,逐步明确新加坡未来发展蓝图。外交方面,新加坡坚持“大国平衡”和立足东盟的外... 2023年,政治方面,尚达曼当选新加坡第9任总统,新加坡政党多元性得到强化。以副总理兼财政部部长黄循财为核心的第四代领导团体通过《新加坡携手前进》报告,逐步明确新加坡未来发展蓝图。外交方面,新加坡坚持“大国平衡”和立足东盟的外交政策,与中国建立了全方位高质量的前瞻性伙伴关系。经济方面,受制造业和货物贸易增长放缓的影响,新加坡经济增速趋缓,仅实现约1%的增长,但旅游业稳健复苏,数字经济和绿色经济的快速发展成为经济发展的新动能;新加坡仍坚持贸易立国,与中国签署《关于进一步升级〈自由贸易协定〉的议定书》,与南方共同市场正式签署《南方共同市场—新加坡自由贸易协定》,进一步织密了自由贸易网络。文化方面,通过《新加坡文化遗产计划2.0》、“年轻变革者文化遗产启动津贴”等实现了文化遗产的创新开发利用,增强了新加坡国民的身份认同。展望2024年,新加坡将稳定推动领导权力的交接,第四代领导团体将继续通过“新加坡携手前进”议程进一步明确未来发展方向,并凝聚共识,助力下一届大选;将继续坚持“大国平衡”和立足东盟的外交政策,积极拓展国际合作空间;经济方面预计将实现1.0%~3.0%的增长。 展开更多
关键词 新加坡 《新加坡携手前进》 绿色经济 数字经济 文化遗产
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基于大语言模型的BIM正向设计问答系统研究 被引量:1
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作者 丁志坤 李金泽 刘明辉 《土木工程与管理学报》 2024年第1期1-7,12,共8页
在正向设计中,设计人员能够通过BIM技术进行设计和管理建筑项目,以支持决策。然而,BIM正向设计过程中的信息处理和知识共享仍面临诸多挑战,尤其是在快速获取和应用复杂建筑规范及设计知识方面。为解决上述问题,本研究基于大语言模型(LLM... 在正向设计中,设计人员能够通过BIM技术进行设计和管理建筑项目,以支持决策。然而,BIM正向设计过程中的信息处理和知识共享仍面临诸多挑战,尤其是在快速获取和应用复杂建筑规范及设计知识方面。为解决上述问题,本研究基于大语言模型(LLM)设计了一套BIM正向设计问答系统,旨在探究LLM在BIM正向设计场景中的实际应用。通过采用基于QLoRA的LLM微调方式提高模型的专业性,并构建本地知识库形成问答系统,最后设计评价指标对系统进行主客观性能评估、专业问答对比分析。实验结果表明,该系统在专业领域性能表现良好,并能根据特定设计场景生成建议和解决方案,验证了本系统的可行性和优越性。 展开更多
关键词 正向设计 BIM 大语言模型 专业问答
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