A review of digital twin in product design and development

In the era of digitalization, there are many emerging technologies, such as the Internet of Things (IoT), Digital Twin (DT), Cloud Computing and Artificial Intelligence (AI), which are quickly developped and used in product design and development. Among those technologies, DT is one promising technology which has been widely used in different industries, especially manufacturing, to monitor the performance, optimize the progresses, simulate the results and predict the potential errors. DT also plays various roles within the whole product lifecycle from design, manufacturing, delivery, use and end-of-life. With the growing demands of individualized products and implementation of Industry 4.0, DT can provide an effective solution for future product design, development and innovation. This paper aims to figure out the current states of DT research focusing on product design and development through summarizing typical industrial cases. Challenges and potential applications of DT in product design and development are also discussed to inspire future studies.     

财政票据生命周期管理方法的研究与实现

提出了财政票据生命周期的概念。阐述了财政票据生命周期管理的原理，介绍了支持该原理的两项关键技术：实现财政票据生命周期管理的数据表达方法——分布式数据的组织、传输与集成；支持财政票据生命周期管理的业务流和数据流的集成技术——基于模板的财政票据多代理定制技术。实现了财政票据生命周期管理系统，做到了财政票据在收费全过程中的“闭环”管理，进而提高政府财政收费的效率及透明性。     

A trust negotiation system for digital library Web services

A scalable approach to trust negotiation is required in digital library (DL) environments that have large and dynamic user populations. In this paper we introduce Trust-Serv, a model-driven trust negotiation framework for Web services, and show how it can be used to effectively handle trust negotiation in DLs. The framework employs a model for trust negotiation based on state machines, extended with security abstractions. High-level specifications expressed with the state-machine-based model are then translated into formats suitable for automating the trust negotiation process. The proposed framework also supports negotiation policy lifecycle management, an important trait in the dynamic environments that characterize DLs. In particular, we present a set of policy change operations that enable the dynamic evolution of negotiation policies without disrupting ongoing negotiations. The proposed approach has been implemented as a container-centric mechanism that is transparent to the DL and to the developers of DL Web services, simplifying DL development and management as well as enabling scalable deployments.     

移动环境下一种缓存管理策略

移动计算环境中带宽具有非对称性,并且移动设备资源有限,传统的缓存管理策略需要占用大量的设备计算资源和网络带宽,有效的缓存管理技术能够极大提高移动计算的性能。对此提出一系列的针对移动计算的缓存管理策略。首先根据用户访问频率建立对应的具有生命周期的数据项缓存,然后使用自适应一致性维护策略维护缓存的一致性。通过实验分析,提出的管理策略能够很好地降低带宽占用,并且有效地减少对移动客户端的资源需求。     

A comparison of manufacturing and remanufacturing energy intensities with application to diesel engine production

Climate change reports and policies relating to end-of-use products, CO₂ emissions, and energy are causing manufacturers to examine their operations closely. Several reports have touted the economic and environmental benefits of remanufacturing, including claims of significant reductions in terms of energy and CO₂ emissions. However, large-scale remanufacturing of heavy equipment engine components has not been closely examined and no standard procedure exists to quantify the benefits of remanufacturing. A methodology is presented for determining the energy intensity and benefits of remanufacturing as compared to new manufacturing, and this is applied to a diesel engine example. These findings are used to estimate the embodied manufacturing/remanufacturing energy across multiple use cycles.     

Proposal of cause–effect pattern library for realizing sustainable businesses

Sustainable business design has gained growing interest in recent years. However, it is often difficult to clarify which business activities actually contribute to (or violate) the sustainability of the earth due to high complexity of environmental and economical system of our society. In order to help a business to generate sustainable business ideas handling this complexity in a systematic and comprehensive manner, this paper proposes a method to formulate a wide variety of causalities in our society into a cause–effect pattern library and illustrates how to use it for design and planning of sustainable businesses.     

钢铁产品生命周期的铁资源效率研究

我国是铁矿石资源贫乏国家,矿石品位低,开采成本高。特别是近年来随着我国钢铁产能的迅速提升,铁矿石资源的利用问题愈发突出。本文以资源效率作为衡量天然资源节约程度的指标,设计了一张有时间概念的钢铁产品生命周期铁流图,在此基础上研究铁的排放率、大循环率、产量年均变化率和平均使用寿命对铁资源效率的影响规律,以此指导铁矿资源的高效利用。     

Product modularity for life cycle design

Modular design is an important elemental technique in life cycle design for improving, e.g., maintainability, upgradability, reusability, and recyclability. Appropriate modular structure differs according to applied life cycle options; e.g., while the modular structure for recycling should be based on material kinds, the structure for upgrading should be based on functions to be obsolete. This paper proposes a method for determining modular structure by aggregating various attributes related to a product life cycle and evaluating geometric feasibility of modules. This paper also illustrates the prototype system that implements the proposed method and a case study of a printer.     

Analysis of Reusability using ‘Marginal Reuse Rate’

While reuse is an effective lifecycle option in terms of reduction of environmental loads and value of reutilization, reuse has inherent difficulties. Our naive question is why component reuse of home appliances seems impossible while that of photocopiers succeeded. This paper clarifies an essential factor for successful reuse; that is, the balance between supply and demand of reusables, and proposes an index named ‘marginal reuse rate,’ which indicates upper limit of reusability. By using this index, reusability of several products is analyzed. The marginal reuse rate indicates that design of lifecycle, in addition to product design, is indispensable for successful reuse.     

Assessing the impacts of industrial water use in life cycle assessment

Use of freshwater gives rise to important environmental impacts to consider in the sustainability analysis of an industry or a product. Water use impacts are highly dependent on the local or regional conditions, and apart from the quantity that is extracted and used, the impact of the freshwater use also depends on the local sensitivity to freshwater extraction, and the change in the quality from water intake to discharge of the used water. A methodology is presented catering to these characteristics of the water use issue and demonstrated on an industrial case study from the biotech industry.