无形资本VS有形资本：创意产业新企业生存能力的影响因素分析

通过分析金融资本、关系资本和先前经验这三类重要的创业资源对创意产业新企业生存能力的影响,比较了无形资本与有形资本对新企业生存能力影响程度的大小。结果表明,创业者拥有的有形资本对创意产业新企业的生存更加重要,尤其是在新企业成立的初期,避免新企业创立初期现金流局限可能造成的关键员工信心丧失和人员流失,才能保证附着于其上的关系资本和先前经验等无形资本发挥重要作用。

Parallelized Implementation of the Finite Particle Method for Explicit Dynamics in GPU

As a novel kind of particle method for explicit dynamics,the finite particle method(FPM)does not require the formation or solution of global matrices,and the evaluations of the element equivalent forces and particle displacements are decoupled in nature,thus making this method suitable for parallelization.The FPM also requires an acceleration strategy to overcome the heavy computational burden of its explicit framework for time-dependent dynamic analysis.To this end,a GPU-accelerated parallel strategy for the FPM is proposed in this paper.By taking advantage of the independence of each step of the FPM workflow,a generic parallelized computational framework for multiple types of analysis is established.Using the Compute Unified Device Architecture(CUDA),the GPU implementations of the main tasks of the FPM,such as evaluating and assembling the element equivalent forces and solving the kinematic equations for particles,are elaborated through careful thread management and memory optimization.Performance tests show that speedup ratios of 8,25 and 48 are achieved for beams,hexahedral solids and triangular shells,respectively.For examples consisting of explicit dynamic analyses of shells and solids,comparisons with Abaqus using 1 to 8 CPU cores validate the accuracy of the results and demonstrate a maximum speed improvement of a factor of 11.2.

A GPU-Based Parallel Algorithm for 2D Large Deformation Contact Problems Using the Finite Particle Method

Large deformation contact problems generally involve highly nonlinear behaviors,which are very time-consuming and may lead to convergence issues.The finite particle method(FPM)effectively separates pure deformation from total motion in large deformation problems.In addition,the decoupled procedures of the FPM make it suitable for parallel computing,which may provide an approach to solve time-consuming issues.In this study,a graphics processing unit(GPU)-based parallel algorithm is proposed for two-dimensional large deformation contact problems.The fundamentals of the FPM for planar solids are first briefly introduced,including the equations of motion of particles and the internal forces of quadrilateral elements.Subsequently,a linked-list data structure suitable for parallel processing is built,and parallel global and local search algorithms are presented for contact detection.The contact forces are then derived and directly exerted on particles.The proposed method is implemented with main solution procedures executed in parallel on a GPU.Two verification problems comprising large deformation frictional contacts are presented,and the accuracy of the proposed algorithm is validated.Furthermore,the algorithm’s performance is investigated via a large-scale contact problem,and the maximum speedups of total computational time and contact calculation reach 28.5 and 77.4,respectively,relative to commercial finite element software Abaqus/Explicit running on a single-core central processing unit(CPU).The contact calculation time percentage of the total calculation time is only 18%with the FPM,much smaller than that(50%)with Abaqus/Explicit,demonstrating the efficiency of the proposed method.

GPU-accelerated vector-form particle-element method for 3D elastoplastic contact of structures

A graphics processing unit(GPU)-accelerated vector-form particle-element method,i.e.,the finite particle method(FPM),is proposed for 3D elastoplastic contact of structures involving strong nonlinearities and computationally expensive contact calculations.A hexahedral FPM element with reduced integration and anti-hourglass is developed to model structural elastoplastic behaviors.The 3D space containing contact surfaces is decomposed into cubic cells and the contact search is performed between adjacent cells to improve search efficiency.A connected list data structure is used for storing contact particles to facilitate the parallel contact search procedure.The contact constraints are enforced by explicitly applying normal and tangential contact forces to the contact particles.The proposed method is fully accelerated by GPU-based parallel computing.After verification,the performance of the proposed method is compared with the serial finite element code Abaqus/Explicit by testing two large-scale contact examples.The maximum speedup of the proposed method over Abaqus/Explicit is approximately 80 for the overall computation and 340 for contact calculations.Therefore,the proposed method is shown to be effective and efficient.

Review of transcutaneous electrical acupoint stimulation and related devices

A review was undertaken of the operation process and development of transcutaneous electrical acupoint stimulation(TEAS)and related devices for TEAS,with the aim to offer a reference for developing an international standard for the basic safety and essential performance of the devices.The articles related to TEAS and instruction of devices for TEAS were searched using the EMBASE,MEDLINE,and Web of Science databases with the time period from inception to July 18,2023.In the absence of a parameter description of the stimulators,a multimeter was used to measure the output voltage,resistance,and current.Thirty-two related devices for TEAS were obtained.The safety parameters ofmost devices were neither clearly defined,nor standardized,and in some cases weremissing.There was a noticeable disparity in the upper safety limits of the output current among the devices.The sizes of the skin electrode pads as well as the lengths of the electrode connecting wires of most devices were not clearly indicated.Acupoints on different parts of the human body,including the upper limbs,head,auricle,chest,abdomen,trunk,and lower limbs,required different maximum tolerable current intensities and current densities.It is important to indicate comprehensive output/safety parameters and essential performance for devices for TEAS to meet the need of global distribution,achieve precise stimulation parameters at different acupoints across the human body,and allay any safety concern of national therapeutic device authorities,the regulators,manufacturers,and end users.