摇块机构节能运动规律设计

在工程实践中,摇块机构传统运动规律存在大量的无用能量消耗。针对这一弊端本文介绍了应用高等数学知识完成摇块机构节能运动规律设计的方法,并通过数字泵控制进入油缸的流量来实现该运动规律,从而减少能量消耗,优化了设计结果。

两位“猪先生”的代言——从美国“理财能力”和“节约能源”运动看卡通代言在公益传播中的运用

现代社会公益事业的发展状况和水平是衡量一个国家或地区民众文化、道德水准和社会文明的重要标志。由于社会地位的独特性,起用代言人可以帮助推动公益事业的传播,但运用真人代言有时会出现许多问题,而运用卡通形象代言则可从一定程度上对这些问题进行规避。本文以由美国AC组织开展的两个公益运动(Financial Literacy and Energy Efficiency)传播中的两位"猪先生"的正反形象代言为例,分析卡通代言在公益事业传播中起到的作用,从而为我国公益事业传播效果最大化提出建设性意见。

Alignment Techniques in Total Knee Arthroplasty:Where do We Stand Today?

Achieving optimal alignment in total knee arthroplasty(TKA) is a critical factor in ensuring optimal outcomes and long-term implant survival. Traditionally, mechanical alignment has been favored to achieve neutral postoperative joint alignment. However, contemporary approaches, such as kinematic alignments and hybrid techniques including adjusted mechanical, restricted kinematic, inverse kinematic, and functional alignments, are gaining attention for their ability to restore native joint kinematics and anatomical alignment, potentially leading to enhanced functional outcomes and greater patient satisfaction. The ongoing debate on optimal alignment strategies considers the following factors: long-term implant durability, functional improvement, and resolution of individual anatomical variations. Furthermore, advancements of computer-navigated and robotic-assisted surgery have augmented the precision in implant positioning and objective measurements of soft tissue balance. Despite ongoing debates on balancing implant longevity and functional outcomes, there is an increasing advocacy for personalized alignment strategies that are tailored to individual anatomical variations. This review evaluates the spectrum of various alignment techniques in TKA, including mechanical alignment, patient-specific kinematic approaches, and emerging hybrid methods. Each technique is scrutinized based on its fundamental principles, procedural techniques, inherent advantages, and potential limitations, while identifying significant clinical gaps that underscore the need for further investigation.

印尼：骑马上班为省油

连日来，印度尼西亚政府发布了总统令，要求各级政府部门采取措施节约能源，积极参与节能运动。为此，印尼的13家国营电视台响应号召，每天停播4个小时的电视节目。梭罗市市长呼吁所有公务员骑车上班；贝克西市政府决定关闭办公场所的电视机；中苏拉威西省农业厅厅长甚至每天骑马上班。他说：

On Energy Efficient Design for Dynamic CoMP Transmission in K-Tier Heterogeneous Cellular Networks

Motivated by the objective of pursuing revenue, improvement in coverage and reduction in energy cost for wireless communication networks have been of great significance for mobile operators. Therefore, heterogeneous cellular networks(HCNs) and Coordinated Multipoint(Co MP) transmission are considered as promising solutions to enhance the performances of wireless communication systems. This paper analyzed the K-tier HCNs with a dynamic downlink Co MP scheme, in which the flexible clusters of cooperative stations are determined by a connecting threshold θ. Using stochastic geometry, the coverage probability(CP) and energy efficiency(EE) of a K-tier HCN operating under this scheme are derived, based on which the trade-off between CP and EE is discovered and discussed. Simulation results show the validity of our derivations. The proposed schememay significantly reduce energy consumption sacrificing a small amount of CP, and outperforms the fixed scheme as well. The CP-EE trade-off are also revealed, whichsuggests suitable trade-off points between CP and EE that will deliver the maximum economic profitability. Tendencies discovered in this paper may provide the operators with opportunities for further optimization in pursuit of economic profitability.

Effect of turf on the cutting movement of female football players

Purpose： The globalisation of artificial turf and the increase in player participation has driven the need to examine injury risk in the sport of football. The purpose of this study was to investigate the surface--player interaction in female football players between natural and artificial turf. Methods： Eight university level female football players performed an unanticipated cutting manoeuvre at an angle of 30° and 60°, on a regulation natural grass pitch （NT） and a 3G artificial turf pitch （AT）. An automated active maker system （CodaSport CXS System, 200 Hz） quantified 3D joint angles at the ankle and knee during the early deceleration phase of the cutting, defined from foot strike to weight acceptance at 20% of the stance phase. Differences were statistically examined using a two-way （cutting angle, surface） ANOVA, with an α level of p 〈 0.05 and Cohen＇s d effect size reported. Results： A trend was observed on the AT, with a reduction in knee valgus and internal rotation, suggesting a reduced risk of knee injury. This findings highlight that AT is no worse than NT and may have the potential to reduce the risk of knee injury. The ankle joint during foot strike showed large effects for an increase dorsiflexion and inversion on AT. A large effect for an increase during weight acceptance was observed for ankle inversion and external rotation on AT. Conclusion： These findings provide some support for the use of AT in female football, with no evidence to suggests that there is an increased risk of injury when performing on an artificial turf. The ankle response was less clear and further research is warranted. This initial study provides a platform for more detailed analysis, and highlights the importance of exploring the biomechanical changes in performance and injury risk with the introduction of AT.

异构多目标差分-动态窗口算法及其在移动机器人中的应用

为了实现在多移动机器人和多窄通道的复杂动态环境中机器人的节能运动规划,提出异构多目标差分-动态窗口法(heterogeneous multi-objective differential evolution-dynamic window algorithm,HMODE-DWA).首先,建立行驶时间、执行器作用力和平滑度的3目标优化模型,设计具有碰撞约束的异构多目标差分进化算法来获得3个目标函数的最优解,进而在已知的静态环境中获得帕累托前沿,利用平均隶属度函数获得起点与终点间最优的全局路径;其次,定义基于环境缓冲区域的模糊动态窗口法使机器人完成动态复杂环境中避障,利用所提出的HMODE-DWA算法动态避障的同时实现节能规划.仿真和实验结果表明,所提出的混合路径规划控制策略能够有效降低移动机器人动态避障过程中的能耗.