A review of shape and size considerations in pinch grips

In handgrip-related studies, it has been theorised that modifying the design of object shapes and sizes to accommodate the hand can reduce risks of cumulative trauma disorders (CTDs). However, there appears to be a lack of theoretical groundwork to support this premise in the area of pinch grip research. Therefore, this article aims to provide a review of shape and size considerations in pinch grips. The literature reviews were first conducted individually on shape, size and pinch grip factors, followed by the development of a literature summary based on the theoretical connections among shape, size and pinch grips. Though further studies are still required, this review has provided fundamental knowledge on possible theoretical connections among shape, size and pinch grip factors. These preliminary efforts shed light on potential mechanisms that explain how shape and size can influence pinch grips towards preventing CTDs and maximising the human performance.     

Ultrasonic characterization of tubing pinch welds

Spatially-focused, high-frequency ultrasonic pulses have been used in the evaluation of the quality of stainless steel tubing pinch welds. Experimentally, echoes from the bond plane were generally too weak to observe, except in bond planes with macrocracking. Correlations were therefore sought between bond quality and the amplitude and spectral features of the back-surface echo that has passed through the bond plane twice. Linear scans of the back-surface echo parallel and perpendicular to the tubing axis were made on pinch welds of four classes of bond quality. Trends, with scatter, were observed between the ultrasonic parameters and bond quality. These experimental results were interpreted using the Stanke-Kino theory of ultrasonic attenuation due to grain scattering to relate the microstructural changes caused by the pinch-weld process to the observed ultrasonic signals. The results illustrate the importance of process-related changes in near-bond microstructure in attempts to nondestructively determine bond strength.     

基于夹点技术的修正布雷顿循环优化分析

为提高修正布雷顿循环氦液化系统的液化率及效率,基于夹点技术的优化方法对该系统进行优化分析。通过建立夹点技术的T-H组合曲线图分析系统的夹点所在、利用Fortran模拟计算来定性、定量地分析系统的主要性能指标,如系统压缩机出口压力、膨胀机中间压力等与系统的液化率及效率之间的关系。发现当膨胀机中间压力为600—800 MPa时,系统的液化率和效率最高。     

Optimization of machining techniques — A retrospective and literature review

In this paper an attempt is made to review the literature on optimizing machining parameters in turning processes. Various conventional techniques employed for machining optimization include geometric programming, geometric plus linear programming, goal programming, sequential unconstrained minimization technique, dynamic programming etc. The latest techniques for optimization include fuzzy logic, scatter search technique, genetic algorithm, Taguchi technique and response surface methodology.     

A method to design job rotation schedules to prevent work-related musculoskeletal disorders in repetitive work

Job rotation is an organisational strategy widely used in human-based production lines with the aim of preventing work-related musculoskeletal disorders (WMSDs). These work environments are characterised by the presence of a high repetition of movements, which is a major risk factor associated with WMSDs. This article presents a genetic algorithm to obtain rotation schedules aimed at preventing WMSDs in such environments. To do this, it combines the effectiveness of genetic algorithms optimisation with the ability to evaluate the presence of risk by repeated movements by following the OCRA ergonomic assessment method. The proposed algorithm can design solutions in which workers will switch jobs with high repeatability of movements with other less demanding jobs that support their recovery. In addition, these solutions are able to diversify the tasks performed by workers during the day, consider their disabilities and comply with restrictions arising from the work organisation.     

A review of methods,techniques and tools for project planning and control

The purpose of this article is to provide a brief review of methods and techniques developed for the most commonly studied decision-making problems in project planning and control over the last decade. These problems involve project representation, project scheduling, resource allocation, risk analysis, time and cost performance evaluation, time, cost, and cash flow forecasting, optimal timing of control points, and corrective action decision-making. We also review recent tools developed for project planning and control. The emphasis is on recent contributions, but several older yet important works are also cited. Our analysis shows an increasing attention to the stochastic nature of projects in planning and control decision and processes. Recent attention has also been put at improvements in existing project control techniques as well as developing new methods to automate data collection, process, and generate more integrated project plan. More importantly, our review highlights an important shift in the project planning and control research field, which has been largely dominated by the project scheduling literature in the past, as short term and reactive decision-making bring new challenges and opportunities to project organisations and researchers.     

三维GIS中地层多比例尖灭自动建模技术

利用地质勘察数据导入到三维系统中,运用各种三维空间构模方法,自动进行地层推理与连接,生成三维地层模型。以多数据源自动生成模型,可以方便地使地学领域中的地质工作者从繁重的地质信息获取和地质解释手工劳动中解放出来,提高了三维地层建模的速度和构建质量。     

直接驱动Z箍缩的FLTD型脉冲功率源的发展

介绍了快直线型变压器（FLTD）脉冲源的技术特点;概述了美国圣地亚国家实验室与俄罗斯强流电子学研究所合作研制的FLTD—Z模块的新进展,基于FLTD拟重复频率运行的针对聚变能源（IFE）应用的原理性样机Z—POP装置,以及下一代惯性约束核聚变（ICF）和IFE用的指标为6MV,60MA／90MA和100nsFLTD型直接驱动脉冲源的概念设想;初步分析了FLTD直接驱动源需要研究的关键技术。     

网店从业人员MSDs的职业病研究

旨在研究MSDs职业病在网店从业人群中的分布情况和影响因素,并给出相应改善建议。研究采用肌肉骨骼疾患调查表,发现样本的年患病率高达94.7%,其中以颈部和肩部患病率最高。因此,需从人体工效学角度科学地设计办公间的布局和人机界面,合理调整工作姿势,尽量保持高频率的工间休息,并结合有氧运动、柔韧练习等运动疗法,以缓解和治疗MSDs。     

A means for predicting low-back musculo-skeletal disorders from jolting and jarring of heavy equipment operators

This article presents a step-by-step procedure for predicting the occurrence (or non-occurrence) of lumbar spinal disorders in workers subjected to long-term, whole-body vibration exposure. The procedure consists of relatively simple steps including the use of a biodynamic computer model together with an International Organization for Standardization (ISO) standard. The underlying analysis is based upon Kane's equations and the resulting worker model is validated with experimental data provided by the National Institute for Occupational Safety and Health (NIOSH), Biodynamics Laboratory, University of Vermont, and with published data.     

A review on manufacturing flexibility

Flexibility has become one of the most useful and necessary tool in today’s competitive markets. Manufacturing flexibility is widely recognised as a critical component to achieving a competitive advantage in the market place. It is one of the most sought after properties for manufacturing enterprises and has aroused considerable interest among researchers and professionals. This paper presents a review of various issues related with manufacturing flexibility specifically concept, need, dimensions, measurement, relationship among various dimensions, implementation aspect in a company and management of manufacturing flexibility and its aim to contribute to the conceptual systemisation of the material.     

Design and implementation of ergonomic risk assessment feedback system for improved work posture assessment

Ergonomic risk factors which include force, repetition and awkward postures, can result in Work-Related Musculoskeletal Disorders (WMSDs) among workers. Hence, systems that provide real-time feedback to the worker concerning his current ergonomic behaviours are desirable. This paper presents the design and implementation of a human-machine interface posture assessment feedback system whose conceptual model is developed through a model-driven development perspective using the Unified Modeling Language (UML) and interface flow diagrams. The resulting system provides a shop floor with a simple, cost-effective and automatic tool for real-time display of worker's postures. Testing the system on volunteer participants reveals that it is easy to use, achieves real-time posture assessment and provides easy-to-understand feedback to workers. This system may be useful for reducing the rate of occurrence of awkward postures, one of the contributing factors to risk of WMSDs among workers.     

手工搬举作业的人因工程量化评估与改进研究

针对制造业生产过程中手工搬举作业的人因改善问题,研究了基于复合搬运指数的人因量化评估与改进方法。该方法针对实际搬运作业多任务构成的特点引入了复合搬运指数对其进行人因量化评估,通过复合搬举任务的选取及分析、复合搬举指标的计算、复合搬举任务的优化改进和基于人因仿真的改善方案多方位验证四个步骤可有效完成搬举作业的人因工程量化评估与改进。该方法在汽车公司车轮分装工序人因工程改进中的成功应用验证了其可行性和有效性。     

A systematic literature review of remanufacturing scheduling

This paper studies a vendor–buyer integrated inventory system with buyers’ variable demand and warehouse space limitation where the consignment stock (CS) replenishment operates under a controllable lead time. Within any cycle, the production rate, the number of shipments and the shipping size are all fixed. Based upon the CS policy, the vendor agrees to maintain the buyer’s inventory to be above a safety level and less than the buyer’s space limitation. Due to the uncertainty in the demand, shortages/over stocks are sometimes inevitable. In such cases, penalties are incurred to discourage such occurrence. The holding cost consists of a storage component and a financial component, and the lead time is controlled with an extra investment which is a function of both the shipment size and the reduced time. Two-constraint, five-variable mix-integer optimisation models are established to describe the CS system. Two doubly-hybrid meta-heuristic algorithms are employed to solve the models that are complex and difficult to solve with available techniques. Two numerical examples are used to illustrate the solution procedure and the analysis of the computational results reveals the effects of some important parameters used for the annual joint total expected cost of the integrated system. The computational efficiency and quality of the solutions are evaluated by comparing them with other existing and popular methods. The results founds in all comparative evaluation are very encouraging and competitive.     

A design and modelling review of rotary magnetorheological damper

The trend and progress in rotary magnetorheological (MR) damper development is currently not as extensive as the advancement of linear MR damper, despite the fact that it has several comparative advantages. A rotary MR damper offers substantial weight reduction and design compactness thus requiring smaller space than a linear MR damper for device installation. In addition, a rotary damper also utilizes a smaller quantity of MR fluid, which is a significant contribution for cost reduction. In this paper, an overview of recent advances in rotary MR damper are presented, in terms of different proposed concepts of structural design, magnetic circuit configuration, and modelling techniques. The review separates rotary MR damper design into two categories, namely continuous angle and limited angle dampers. Issues regarding device endurance, ease of manufacturing and maintenance and controllability are particularly highlighted.     

不同粉体制备工艺对铌酸钠钾无铅压电陶瓷性能的影响

铌酸钠钾(KNN)基无铅压电陶瓷性能的提高可通过掺杂、取代和添加烧结助剂等方法来实现,还可通过适当改变陶瓷制备工艺来达到.为了探索可实用化的KNN陶瓷制备工艺,以纯KNN陶瓷的制备为例,考察了3种不同粉体制备工艺(包括传统固相反应法、原料中添加活性炭的固相反应法、以及粉体经分批预烧处理后再混合的固相反应法)对KNN元铅压电陶瓷的晶相、微观结构和电学性能的影响.实验结果表明:采用原料中添加活性炭的固相反应法制得的纯KNN陶瓷,其表面晶粒尺寸相对均一,晶界清晰,样品致密性好;所得的陶瓷样具有较好的介电、压电性能,其中d33=116pC/N,κP=0.37,e=630,tanδ=0.034,Pr=22.40μC/cm2,Ec=0.675kV/mm,Tc=405℃.     

公交司机肌肉骨骼损伤风险的工效学分析

通过问卷调查,结合Ovako工作姿势分析系统(OWAS)对城市公共汽车司机患肌肉骨骼损伤性疾病的风险进行了评估和分析。分析结果显示,公共汽车司机的颈部和背部存在较大的损伤风险,车辆进站、出站和转弯过程中不良姿势的比例较高。研究结果分别从主观和客观两个方面评估了城市公共汽车司机的职业负荷和可能的职业伤害,对城市公共汽车司机职业健康的促进和工作环境的改进具有一定的实践指导意义。     

近代现场吸声测量技术

驻波管法和混响室法是吸声测量技术中常用的方法,用于现场测量时不满足特殊声场环境假设、样品尺寸、频率限制等。脉冲回波方法和声强测量法对测量环境没有严格要求,适用于现场测量。这类方法的共同特点是在频域处理数据,往往需要将反射波与入射波分离,测量步骤较多,不利于在线测量。参数反演方法直接利用测量的声压时间序列获得声学阻抗或吸声系数,是一种时域测量方法,更适用于在线测量。在声学理论指导下,借助于计算机与数字信号处理技术的研究成果,一些新的测量方法不断被提出,但要成为一种成熟的技术,还有大量的研究工作去做。     

A review of slip transfer: applications of mesoscale techniques

In this review article, we present and discuss recent mesoscale modeling studies of slip transmission of dislocations through biphase interfaces. Specific focus is given to fcc/fcc material systems. We first briefly review experimental, atomistic, and continuum-scale work that has helped to shape our understanding of these systems. Then several mesoscale methods are discussed, including Peierls–Nabarro models, discrete dislocation dynamics models, and phase field-based techniques. Recent extensions to the mesoscale mechanics technique called phase field dislocation dynamics are reviewed in detail. Results are compiled and discussed in terms of the proposed guidelines that relate composite properties to the critical stress required for a slip transmission event.     

A review of processing techniques for graphene-reinforced metal matrix composites

In the quest to enhance reinforcement efficiency of graphene in metal matrices, various processing techniques have been devised over recent years. As the advancement in this field nowhere seems to slow down, the processing aspects of graphene-reinforced metal matrix composites are becoming more relevant than ever. In that premise, there lies an imminent need for a critical assessment of existing fabrication routes and their ability to extend a solution for the primary challenges of agglomeration, dispersion, interfacial interaction and structural integrity of graphene in metal matrix composites. This review presents a brief yet a meaningful insight to the processing techniques for graphene-reinforced metal matrix composites, while highlighting the key findings from individual studies, thereby expressing the primitive challenges and strengthens of these techniques. A critical evaluation of state of the art is presented alongside an inclusive review of improvement in mechanical, thermal, and electrical properties of composites fabricated by various processing routes. In the consideration of reviewed literature, it is established that a comprehensive processing strategy with a potential to simultaneously address all of the key processing challenges of graphene, is yet to nurture. Conclusively, future road map and a potential solution encompassing hybrid processing strategies, is opined.