陶瓷基复合材料超声辅助磨削力建模的研究进展

超声辅助磨削技术在加工陶瓷基复合材料时具有磨削力小和加工质量高、精度高、效率高等优势。磨削力是影响材料去除量、加工精度和加工质量的关键要素,准确预测磨削力对优化超声辅助磨削陶瓷基复合材料加工工艺具有重要意义。综述了超声辅助磨削加工陶瓷基复合材料的磨削力预测模型发展现状,详细介绍经验建模法、解析建模法以及有限元分析建模法三种典型磨削力建模方法并分析其优缺点,最后对磨削力的影响因素及未来研究作了讨论、总结和展望。

基于Karnopp模型和数据驱动的虚拟针灸手法力建模

针灸学是一门实践性学科,操作训练的经验对针灸医学生掌握针灸技术十分重要。本文针对传统训练方法准确性和真实感低的问题,基于Touch X和unity搭建了虚拟针灸训练平台,并通过采集针刺猪肉的数据建立提插和捻转手法力模型。针对提插手法可分为刺入力和提插力两部分,在刺入力模型中增加了衰减力建模,使刺入的分层感更加真实;借鉴Karnopp模型建立不同组织层的单位长度阻尼函数,结合刺入力和提插力建立完整的提插手法力模型。针对捻转手法采用数据驱动建模,分为动态捻转和静态衰减两部分,两者测试集准确率分别为0.98508和0.99249。最后通过左右手对比实验和用户使用感受对模型进行评估,结果表明,本文建立的两种针灸手法力模型准确度高,真实性强,可扩展性好。

用于机器人辅助穿刺手术进针策略研究的猪肝进针力建模

为研究机器人辅助肝脏穿刺手术中的进针策略以确保手术安全，基于实验数据建立了猪肝的进针力模型。方法如下：在2个新鲜离体猪肝3个不同区域内共采集了18条进针力曲线数据，根据针尖位置及进针力特征将力曲线划分为“被膜刺破前”、“进入肝脏前”和“进入肝脏后”3个阶段，然后采用已有的力模型分别进行每一阶段的进针力建模，通过对比各阶段的建模效果，确定最优的各阶段进针力模型，最后组合成完整的进针力模型。最终的进针力模型比较表明，相同个体不同区域的力模型差异较小，可以用一个力模型来表示该个体进针力特征，不同个体的进针力特征能否用一个力模型表示还需进一步验证。猪肝进针力模型的建立，可为实现机器人辅助人体肝脏穿刺手术中的进针控制和手术安全提供重要依据。

SiC单晶片切割过程动态切割力建模及PID控制

分析切割过程中不同工艺参数,如线锯速度、工件转速、工件进给量及线锯张紧力对切割力的影响,建立切割力与工艺参数的静态模型并进行简化,获得了进给量与动态切割力的模型,采用PID控制策略设计了切割力控制器。Matlab环境下仿真和试验表明:设计的控制器可良好地控制切割过程的切割力;对比切割完成的晶片表面粗糙度,该控制器可实现切割过程的稳定性,提高切片表面质量。

算力网络中面向业务体验的算力建模

针对算力网络中算力量化的问题,对异构的IT算力资源进行归一化建模,并提出算力的分级标准。同时阐述了为保障业务体验的算力、存储、网络等的联合服务能力,从业务角度归纳了不同类型业务的服务能力需求,旨在形成通用的算力服务,为客户的业务体验提供基础保障。

季节性冻土的水-热-力建模与数值分析

为了防治季节性冻土区由水-热-力相互作用引起的道路病害,对季节性冻土水-热-力耦合问题进行了研究。根据季节性冻土的特点,重点考虑了基质势和压力势与温度的关系,给出了季节性冻土水-热-力三场耦合的数学模型,并将耦合问题归结为求解一个非线性、非稳态温度场微分方程,含水量、应力及蠕变变形都可以在温度求解以后算出。详细推导了该方程的数值解法,包括有限元方程、时间域离散及迭代方法。最后对国道G109橡皮山段季节性冻土区公路路堤进行了数值模拟,对计算值与实测值做了对比。结果表明:采用水泥加固砂砾垫层的对比断面与采用砂砾垫层的原断面相比,其温度更低,含水量及预测的路面变形量更小。

基于模糊集定性比较分析方法改进胜任力建模

基于常规流程和方法胜任力建模会产生一些局限,本文对此进行了分析,并提出使用基于模糊集理的定性比较方法作为改进策略。通过采用该方法考察文化企业经营人才的胜任力与企业能力间的匹配关系,结果发现,无论组织属于何种能力类型,执行能力都是文化类企业经营人才必需的,而创新能力却不是。此外,基于模糊集理的定性比较方法的特点也得到了讨论。

浅析“东数西算”背景下运营商算力网络架构方案

随着国家“东数西算”工程的全面启动,各运营商借助机会加快对算力网络进行布局和建设。算力网络旨在根据业务需求,在云、网、边之间按需分配和灵活调度计算资源、存储资源以及网络资源。通过对算力网络体系架构、关键技术等方面进行详细分析和探讨,并结合运营商实际情况,针对性地提出算力网络建设初期的部署方案。

Gated Neural Network-Based Unsteady Aerodynamic Modeling for Large Angles of Attack

Modeling of unsteady aerodynamic loads at high angles of attack using a small amount of experimental or simulation data to construct predictive models for unknown states can greatly improve the efficiency of aircraft unsteady aerodynamic design and flight dynamics analysis.In this paper,aiming at the problems of poor generalization of traditional aerodynamic models and intelligent models,an intelligent aerodynamic modeling method based on gated neural units is proposed.The time memory characteristics of the gated neural unit is fully utilized,thus the nonlinear flow field characterization ability of the learning and training process is enhanced,and the generalization ability of the whole prediction model is improved.The prediction and verification of the model are carried out under the maneuvering flight condition of NACA0015 airfoil.The results show that the model has good adaptability.In the interpolation prediction,the maximum prediction error of the lift and drag coefficients and the moment coefficient does not exceed 10%,which can basically represent the variation characteristics of the entire flow field.In the construction of extrapolation models,the training model based on the strong nonlinear data has good accuracy for weak nonlinear prediction.Furthermore,the error is larger,even exceeding 20%,which indicates that the extrapolation and generalization capabilities need to be further optimized by integrating physical models.Compared with the conventional state space equation model,the proposed method can improve the extrapolation accuracy and efficiency by 78%and 60%,respectively,which demonstrates the applied potential of this method in aerodynamic modeling.

面向中国式现代化的干部教育培训:基于胜任力的方法

干部教育在推进中国特色社会主义伟大事业和党的建设新的伟大工程中发挥着不可替代的重要作用。党的二十大报告明确指出中国式现代化的五大特征,对干部教育培训工作提出了系统化的新要求。聚焦面向中国式现代化的干部教育培训这一主题,中国式现代化全面推进历程中干部教育培训面临三大现实挑战。以胜任力理论及经典胜任力模型框架为主要理论视角,进一步开发面向中国式现代化干部教育的胜任力模型,提出在这一新情境下,领导干部教育需要特别聚焦面向党性修养与理论素养、面向关键支撑战略、面向核心业务能力三个重要方面,关注基于胜任力的干部教育课程体系优化设计、情境嵌入与参与式学习为代表的干部教育培训方法与技术,以及基于胜任力的干部教育培训效果评估。

算力网络四面三级算力度量技术体系

算力网络要实现广泛的算力互联,就离不开统一的算力度量和算力建模机制。算力度量技术主要解决算力描述的标准化,提供方便的跨厂商互通能力、算力资源协同管控能力。对算力网络中算力度量需求进行分析,并提出四面三级算力度量技术体系,同时还探索了在算力路由决策中,网络按需进行算力信息通告等关键技术,为后续的算力度量研究提供参考。

职业信息网络的框架、特征和应用

传统岗位分析方法在适应环境变化和实施成本等问题上存在不足,职业信息网络(Occupational Information Network,O*NET)的开发可以应对上述问题。O*NET的核心框架是内容模型,它整合了工作和工作者两方面信息。它的主要特征体现在减少描述单元数量,成本有效性和及时性、多层嵌套指标体系、跨职业描述指标等方面。O*NET对个人发展和组织管理都有重要作用。O*NET在研究上的应用主要围绕岗位分析和职业分类两大领域展开,建议未来国内的研究可以在多方面深入。

单刀片镗削加工时的力学建模

介绍镗削加工的力学模型。沿切削刃切屑厚度的分布,被作为刀具刃倾角、刀尖圆弧半径、切削深度和进给量的函数被建模。使用机械的和直角到斜角切削转变两种方法,建立该过程的切削力学模型。

Method of Testing of Dynamic Forces on Digital Jet Elements

Method of testing for dynamic output forces from jet elements is studied, the handwidth is large in testing with this method. By establishing a model of the test system and simulating it, principles of how inherent features of the test system affect the dynamic force test are found out. Thus a theoretical foundation is given for the design and error modification to the actual test system.

Experiments and modeling of double-peak precipitation hardening and strengthening mechanisms in Al-Zn-Mg alloy

The aim of the present work is to develop a model for simulating double-peak precipitation hardening kinetics in Al-Zn-Mg alloy with the simultaneous formation of different types of precipitates at elevated temperatures based on the modified Langer-Schwartz approach. The double aging peaks are present in the long time age-hardening curves of Al-Zn-Mg alloys. The physically-based model, while taking explicitly into account nucleation, growth, coarsening of the new phase precipitations and two strengthening mechanisms associated with particle-dislocation interaction （shearing and bypassing）, was used for the analysis of precipitates evolution and precipitation hardening during aging of Al-Zn-Mg alloy. Model predictions were compared with the measurements of Al-Zn-Mg alloy. The systematic and quantitative results show that the predicted hardness profiles of double peaks via adding a shape dependent parameter in the growth equation for growth and coarsening generally agree well with the measured ones. Two strengthening mechanisms associated with particle-dislocation interaction （shearing and bypassing） were considered operating simultaneously in view of the particle size-distribution. The transition from shearing to bypassing strengthening mechanism was found to occur at rather early stage of the particle growth. The bypassing was found to be the prevailing strengthening mechanism in the investigated alloys.

Comparison of evolution laws of stress and strain fields in hot rolling of titanium alloy large rings with different sizes

For hot rolling of titanium alloy large rings,evolution laws of stress and strain fields in rings with various sizes were explored and compared based on a reliable coupled thermo-mechanical three-dimensional （3D） finite element （FE） model.The results show that for forming processes of different rings,as γ^-（the equivalent distribution ratio of feed amount per revolution of a process） decreases,the final peak Mises stress may transfer from the biting point at the driver roll side to that at the idle roll side,and the final peak equivalent plastic strain may transfer from the outside surface to the inside surface;as L^- （the equivalent deformation zone length of a process） increases,the final peak Mises stress may appear in the middle layer.The final positions of peak Mises stress and equivalent plastic strain are the combined effects of the above two aspects.In the deformation zone of a deformed ring,the surface layers are in the 3D compressive stress state,while the middle layer is in the 1D compressive and 2D tensile stress state or 2D compressive and 1D tensile stress state;the whole ring is in the 1D compressive and 2D tensile strain state.

ROBOTIC DYNAMIC MODEL ON LOAD SWING OF SLEWING CRANE

This paper sets up a robotic manipulator model on slewing crane. The model can synthetically describe the dynamic behavior of the load of slewing crane in rotating, elevating and hoisting motions. The dynamic equations of the system are recursively derived by a Newton Euler method. The dynamic behavior of the load of slewing crane in rotating motion is simulated on a computer. The method of robotic dynamics to derive the dynamic equations of the swing of load is accurate and convenient and it has good regularity. The result of the study provides a base in theory on design of crane and an accurate mathematical model for controlling the swing of load.

金融危机背景下的商业银行培训体系建设

一、经济金融危机对商业银行培训管理体系提出了新的挑战在金融危机的背景下,我国的银行系统也不可避免受到影响和冲击,这不仅冲击着商业银行的业务拓展,也波及着商业银行现行的教育培训管理体系。

Modelling Wave Transmission and Overtopping Based on Energy Balance Equation

Wave transmission and overtopping around nearshore breakwaters can have significant influence on the transmitted wave parameters,which affects wave conditions and sediment transportation and becomes the focus of design in engineering.The objective of this paper is to present a simplified model to estimate these important wave parameters.This paper describes the incorporation of wave transmission and overtopping module into a wave model for multi-directional random wave transformation based on energy balance equation with the consideration of wave shoaling,refraction,diffraction,reflection and breaking.Wen's frequency spectrum and non-linear dispersion relation are also included in this model.The influence of wave parameters of transmitted waves through a smooth submerged breakwater has been considered in this model with an improved description of the transmitted wave spectrum of van der Meer et al.(2000) by Carevic et al.(2013).This improved wave model has been validated through available laboratory experiments.Then the verified model is applied to investigate the effect of wave transmission and overtopping on wave heights behind low-crested breakwaters in a project for nearshore area.Numerical calculations are carried out with and without consideration of the wave transmission and overtopping,and comparison of them indicates that there is a considerable difference in wave height and thus it is important to include wave transmission and overtopping in modelling nearshore wave field with the presence of low-crested breakwaters.Therefore,this model can provide a general estimate of the desired wave field parameters,which is adequate for engineers at the preliminary design stage of low-crested breakwaters.

Activity-based resource capability modeling

To analyse and optimize a enterprise process in a wide scope, an activity-based method of modeling resource capabilities is presented. It models resource capabilities by means of the same structure as an activity, that is, resource capabilities are defined by input objects, actions and output objects. A set of activity-based resource capability modeling hales and matching rules between an activity and a resource are introduced. This method can not only be used to describe capability of manufacturing tools, but also capability of persons and applications, etc. It unifies methods of modeling capability of all kinds of resources in an enterprise and supports the ootimization of the resource allocation of a orocess.