Generating significant subassemblies from 3D assembly models for design reuse

Significant subassemblies are defined as the reusable regions of pre-existing 3D assembly models. A significant subassembly has great significances for design reuse as it aggregates abundant knowledge in a vivid 3D CAD model and enables designers to reuse existing mature designs from a high-level perspective. Consequently, this paper contributes to significant subassembly generation from pre-existing 3D assembly models for design reuse. The paper first gives an explicit definition of significant subassemblies and further explores the multilevel knowledge embedded in these significant subassemblies. Based on the above definition and multilevel knowledge, a knowledge-based approach is then proposed for significant subassembly generation, which includes three phases: (1) identifying candidate subassemblies with high cohesion inside and low coupling outside using the Markov clustering process; (2) removing normal candidate subassemblies with low reusability and less information, and generating filtered subassemblies using the proposed assembly frequency – inverse mean subassembly frequency based scheme; and (3) determining significant subassemblies by measuring the complexity of the filtered subassemblies. Finally, a computer numerical control honing machine model is taken as an application example to demonstrate the effectiveness of the proposed approach.     

Light-activated nanotube-porphyrin conjugates as effective antiviral agents

Porphyrins have been used for photodynamic therapy (PDT) against a wide range of targets like bacteria, viruses and tumor cells. In this work, we report porphyrin-conjugated multi-walled carbon nanotubes (NT-P) as potent antiviral agents. Specifically, we used Protoporphyrin IX (PPIX), which we attached to acid-functionalized multi-walled carbon nanotubes (MWNTs). We decided to use carbon nanotubes as scaffolds because of their ease of recovery from a solution through filtration. In the presence of visible light, NT-P was found to significantly reduce the ability of Influenza A virus to infect mammalian cells. NT-P may be used effectively against influenza viruses with little or no chance of them developing resistance to the treatment. Furthermore, NT-P can be easily recovered through filtration which offers a facile strategy to reuse the active porphyrin moiety to its fullest extent. Thus NT-P conjugates represent a new approach for preparing ex?vivo reusable antiviral agents.     

Supply chain resilience: definition,review and theoretical foundations for further study

There has been considerable academic interest in recent years in supply chain resilience (SCRES). This paper presents a timely review of the available literature on SCRES based on a three-stage systematic search that identified 91 articles/sources. We provide a comprehensive definition of SCRES before strategies proposed for improving resilience are identified and the contributions to the literature are critiqued, e.g. in terms of research method and use of theory. We take stock of the field and identify the most important future research directions. A wide range of strategies for improving resilience are identified, but most attention has been on increasing flexibility, creating redundancy, forming collaborative supply chain relationships and improving supply chain agility. We also find that only limited research has been conducted into choosing and implementing an appropriate set of strategies for improving SCRES. Much of the literature is conceptual, theoretical and normative; the few available empirical studies are mainly cross-sectional and confined to a large firm, developed country context; and, there has been limited use of theory frames to improve understanding. We propose Complex Adaptive Systems (CAS) theory as an appropriate lens for studying SCRES. We demonstrate that SCRES mirrors many characteristics of a CAS – including adaptation and coevolution, non-linearity, self-organisation and emergence – with implications for the direction of both future research and practice.     

Self-citations,co-authorships and keywords: A new approach to scientists’ field mobility?

This paper introduces a new approach to detecting scientists’ field mobility by focusing on an author’s self-citation network, and the co-authorships and keywords in self-citing articles. Contrary to much previous literature on self-citations, we will show that author’s self-citation patterns reveal important information on the development and emergence of new research topics over time. More specifically, we will discuss self-citations as a means to detect scientists’ field mobility. We introduce a network based definition of field mobility, using the Optimal Percolation Method (Lambiotte & Ausloos, 2005; 2006). The results of the study can be extended to selfcitation networks of groups of authors and, generally also for other types of networks.     

Environmental effects of physical life span of a reusable unit following functional and physical failures in a remanufacturing system

Reuse of product components is an effective way to conserve natural resources. Likewise, remanufacturing is a new trend in the field of environmentally friendly products. A product undergoes functional failure or physical failure in a remanufacturing environment, where the former failure is equivalent to the state in which the product cannot be used because of functional insufficiency or obsolescence and the latter failure is equivalent to the state of malfunction or breakdown of a product. A unit intended for reuse should be designed to be durable for a period equal to at least two functional lives through remanufacturing. Utilization of excess materials-for example, for improvement of unit strength-can enable a reusable unit to endure over a period equal to at least two functional lives. However, if the environmental impact of such excessive use of materials is taken into account, a strong doubt arises as to whether such a method truly reduces the environmental load from the viewpoint of lifecycle design. In order to analyse this issue, the present study examines the optimal physical life span of a reusable unit and its effect on the environment. A mathematical model of a remanufacturing system is constructed, taking into account functional and physical failures of a product. A minimization problem of the incurred total environmental impact per unit time for a reusable unit is formulated under the decision variables of a design parameter vector of the unit and the maximum number of times of reuse. The design parameter vector is closely related with physical life span. The maximum number of times of reuse can cause environmental loss if a product has a long residual physical life span brought on by the small number of times of reuse. The effects of physical life span of a reusable unit on environmental impact are analysed to show the potential value of the developed model by means of varying stochastic characteristics and the parameters of the remanufacturing environment.     

Complex problem-solving: a field in search of a definition?

Complex problem-solving (CPS) is as an area of cognitive science that has received a good amount of attention, but theories in the field have not progressed accordingly. The reasons could be the lack of good definitions and classifications of the tasks (taxonomies). Although complexity is a term used pervasively in psychology and is operationalized in different ways, there are no psychological theories of complexity. The definition of problem-solving has been changed in the past to reflect the varied interests of the researchers and has lost its initial concreteness. These two facts together make it difficult to define CPS or make clear if CPS should reuse the theory and methods of classical problem-solving or on the contrary should build a theoretical structure starting from scratch. A taxonomy is offered of tasks using both formal features and psychological features that are theory-independent that could help compare the CPS tasks used in the literature. The adequateness is also reviewed of the most extended definitions of CPS and conclude that they are in serious need of review, since they cover tasks that are not considered problem-solving by their own authors or are not complex, but ignore others that should clearly be included.     

What is negative refraction?

We review various published definitions associated with the phenomenon of negative phase velocity propagation of electromagnetic waves in meta-media, as observed through negative refraction. For the principal definition, based on the Poynting vector and the wave vector having negative scalar product, we summarise the various material constraints that have been derived. The distinction between criteria based on the Poynting vector and the group velocity are considered, both in respect of causality, and in the context of moving media. Instances where a fully covariant definition is necessary are also identified, and compared with other results from the extant literature. Satisfaction of the NPV propagation criterion is also considered for surface plasmons.     

Termination of narrowing via termination of rewriting

Narrowing extends rewriting with logic capabilities by allowing logic variables in terms and by replacing matching with unification. Narrowing has been widely used in different contexts, ranging from theorem proving (e.g., protocol verification) to language design (e.g., it forms the basis of functional logic languages). Surprisingly, the termination of narrowing has been mostly overlooked. In this work, we present a novel approach for analyzing the termination of narrowing in left-linear constructor systems—a widely accepted class of systems—that allows us to reuse existing methods in the literature on termination of rewriting.     

Leveraging Values in Global Organizations: Premises,Paradoxes and Progress

In this focused issue on the theme of “Leveraging Values in Global Organizations”, we highlight several prevalent themes on national, organizational and individual values in the literature. We argue that many premises in the literature have been accepted as fact; yet there are still many avenues open to exploration. We present several paradoxes that are often overlooked or lead to inconsistencies in the literature on values. The five articles in this focused issue address these premises and paradoxes, presenting new challenges and opportunities, providing progress and paving the way for future research on leveraging values in global organizations. The selected articles explore values with respect to international alliances and subsidiaries of multinational organizations at the organizational level, among global managers at the group level, and among employees and inpatriates at the individual level of analysis. We trust that readers of this issue will agree that the articles provide novel insights into key issues in the established, yet dynamic, field of research on values in the context of global organizations.     

Effective visualisation of design versions: visual storytelling for design reuse

Improving and supporting the process of design knowledge reuse can increase productivity, improve the quality of designs and lead to corporate competitive advantage. Whereas internal knowledge reuse (reusing knowledge from one’s personal memory or experiences) is very effective, external knowledge reuse (reusing knowledge from an external digital or paper archive) often fails. This paper studies the value of the storytelling paradigm in supporting reuse from an external repository. Based on a formalisation of the internal reuse process from ethnographic studies, a prototype system, Corporate Memory (CoMem) is presented, which supports the reuse process, specifically the steps of finding and understanding reusable items. This paper focuses on the ability of designers to understand designs that are found in corporate repositories. It is argued that in order to understand and reuse a found design, the designer needs to see the evolution of that design during the original design process. An Evolution History Explorer module of the CoMem system is presented that uses a storytelling metaphor and lays out versions visually side-by-side. A formal user evaluation of CoMem supports the hypotheses that (1) exploring the evolution of a design improves the reuse process, and (2) that visual storytelling is an effective paradigm for supporting that exploration.     

The strategy of resources reuse and its selection of customized products based on genetic北大核心CSCD

The degree of product design resources reuse is the key factor that influences the enterprise's response time on market demand and the costs of design. The characterization way of customized products gene was defined based on the relationship between customized products and resource reuse. Three kinds of the strategy of resources reuse which included genetic reuse, variation reuse, and mutation reuse were obtained based on genetic and the development process of customized product. For the convenience of the choice to the strategy, the availability of resources was evaluated based on the similarity analysis, the similarity between existing product gene with customized product gene was calculated by Euclidean distance, and the similarity threshold was set based on Weber's law to determine the resource reuse strategy. Finally, the strategy was verified by a design example of customized reusable small agricultural machinery.     

A collective and abridged lexical query for delineation of nanotechnology publications

In order to monitor articles/patents in nanotechnology, there is little agreement on a universal lexical query or even an explicit definition of nanotechnology. Here in the light of a proposed definition, a set of case studies has been conducted to remove keywords which are not exclusive to nanotechnology. This resulted in a collective and abridged lexical query (CALQ) for nanotechnology delineation. Through bibliometric quantification of already-proposed as well as the novel keywords, it was shown that all keywords included in CALQ have considerable exclusive retrieval and precision, while the removed keywords do not satisfy either of these numerical thresholds. This approach may also be applied for the future updating of CALQ.     

基于基因遗传的定制化产品资源重用策略及其选择

产品设计资源重用程度是影响企业响应市场需求时间和设计成本的关键因素.在明确定制化产品与资源重用关系基础上对定制化产品基因的表征方式进行界定,基于基因传导机理和定制化产品开发过程得出的产品资源重用策略分为复制重用、变异重用和突变重用三类策略.为方便人们选用策略,基于相似度分析对资源可用性进行评价,用欧氏距离法计算现有产品与定制产品基因体之间的相似度,并依据韦伯定律来设定相似度阈值以确定资源合理重用策略.最后以定制化可重构小型农业作业机的设计为实例验证该策略的可行性.     

Quantitative approaches for the integration of production and distribution planning in the supply chain: a systematic literature review

Production and distribution are the two primary internal elements of the supply chain. This paper presents a systematic literature review (SLR) of quantitative approaches for the integration of production and distribution planning (IPDP) in the supply chain. We provide a classification framework with eight dimensions and give a brief overview of the quantitative approaches such as modelling approaches and solution approaches for the IPDP problem in the supply chain. The SLR has been carried out using two basic search databases Scopus and Web of Science. In all, we identify relevant articles in the period from 2000 to 2019. We also highlight certain research opportunities, suggestions, and research gaps for possible future research by assessing the current knowledge on the quantitative approaches for IPDP problems in the supply chain.     

基于配置的可复用工作流设计方法与关键技术研究

提高工作流的重复利用程度,是快速建立工作流模型的关键。提出了基于配置的可复用工作流设计方法。该方法的基础是通过对工作流进行保留目标的多途径分解,以建立其非精确模型。在实际执行时,根据配置的范围与参数不同,采用相应的配置方法得到其精确模型。将工作流模型中结构相同的部分作为“复用元”以提高工作流的设计效率。讨论了从“重复有用性”、“复用粒度”以及“复用成本”等几个方面进行工作流可复用性综合评价的方法。最后给出了应用实例。     

An empirical investigation of the influence of collaboration in Finance on article impact

We investigate the impact of collaborative research in academic Finance literature to find out whether and to what extent collaboration leads to higher impact articles (6,667 articles across 2001–2007 extracted from the Web of Science). Using the top 5 % as ranked by the 4-year citation counts following publication, we also follow related secondary research questions such as the relationships between article impact and author impact; collaboration and average author impact of an article; and, the nature of geographic collaboration. Key findings indicate: collaboration does lead to articles of higher impact but there is no significant marginal value for collaboration beyond three authors; high impact articles are not monopolized by high impact authors; collaboration and the average author impact of high-impact articles are positively associated, where collaborative articles have a higher mean author impact in comparison to single-author articles; and collaboration among the authors of high impact articles is mostly cross-institutional.     

A comparative life cycle assessment of single‐use fibre drums versus reusable steel drums

This paper deals with a comparative analysis of two different packaging and transport scenarios, which exemplifies the implications of choosing between single‐use and reusable packaging. In particular, transport of a batch of chemicals by means of disposable fibre drums versus reusable steel drums is investigated from a life cycle perspective, and the associated environmental impact in terms of global warming potential, acidification potential, gross energy requirement and solid waste generation is assessed. Results prove beyond reasonable doubt that even in the case of durable packaging containers requiring the use of comparatively energy‐intensive materials for their production, the reuse scenario is characterized by lower environmental impact indicators across the board, and as such is the most advisable and environmentally sound option. Copyright © 2009 John Wiley & Sons, Ltd.     

VPP虚拟仪器元件库的实现框架

 可视化编程平台(VPP)是快速组建虚拟仪器系统的集成可视化环境,而虚拟仪器元件库是其组建系统的
基本构造块的集合,是VPP体系结构的基础．但是,当前版本VPP虚拟仪器元件库的设计与实现存在复用性和扩
展性差等问题． 通过对虚拟仪器元件的概念模型分析和形式化描述,不仅提出了虚拟仪器元件的对象模型和动态
模型,而且运用设计模式给出了虚拟仪器元件的核心框架,并使用UML对它们进行了描述,从而形成了VPP虚拟
仪器元件库的一个可复用、可扩展的面向对象框架． 基于该框架可以快速地实现虚拟仪器元件库的开发．