Time substitution and network effects with an application to nanobiotechnology policy for US universities

We present a dynamic network model of the knowledge production process for nanobiotechnology research at 25 US universities during 1990–2005. Universities produce knowledge outputs in nanobiotechnology consisting of Ph.D. graduates, research publications, and patents. Inputs include the university’s spending on R&D in engineering and the life sciences, and the university’s own stock of knowledge measured by past publications in nanobiotechnology. In addition, universities take advantage of the stock of knowledge produced by other universities in previous periods. We simulate the effect of the National Science Foundation being able to optimally allocate research funds for nanobiotechnology research between universities and across time so as to maximize the aggregate amounts of the three knowledge outputs produced by the universities.     

Enhancing SMED: Changeover Out of Machine Evaluation Technique to implement the duplication strategy

The present paper introduces an integrated approach to support the process engineers during the implementation of the conventional Single Minute Exchange of Dies. In particular, the proposed approach grounds on the new concept of ‘duplication strategy’, and takes advantage of an implementation tool here presented. It follows a top-down functional decomposition of machines, which helps practitioners identifying all those items impacting on the changeover process, and to propose appropriate intervention strategies. It aims at verifying the possibility of replicating entire parts of machines, fixtures and/or equipment, in order to externalise as many tasks as possible, yet carefully evaluating the cost-benefit ratio and any operational issue of the intervention. To show this novel approach, an actual implementation is hereby fully described. Finally, the results of the study are commented and proposals for future possible developments are suggested.     

考虑政府补贴的排放依赖型生产优化

政府在追求经济增长的同时还兼顾环境效益。为探讨政府的现金补贴政策对排放依赖型生产商的决策以及对环境效益的影响作用,构建政府的现金补贴函数。结果表明:（1）排放依赖型生产商会根据政府的补贴程度在3种排放权获取渠道（政府分配的配额、自身的排放处理或市场购买）间进行选择;（2）随着现金补贴政策的推出,环境效益得到明显提升,且提升空间与政府可调控的补贴参数紧密相关。通过数值分析进一步说明了模型的应用。     

高标准基本农田建设政策对粮食产能的影响

高标准基本农田建设既是国家制度安排,也是一种技术革新,体现在要素上的技术进步是高标准基本农田建设的本质。构建“制度+技术——粮食产能”的理论分析框架,采用连续型DID模型分析高标准基本农田建设政策实施对粮食产能的影响及作用机制。研究发现：其一,实施高标准基本农田建设政策显著提升了粮食产能,并且通过一系列稳健性检验结果依然显著。其二,异质性分析表明,相对于粮食主产区和平原地区,高标准基本农田建设政策实施对非粮食主产区和山地地区的粮食产能提升具有更高的边际贡献;政策实施对粮食数量和粮食质量均有提升作用,对粮食质量促进效果更明显;政策实施促进粮食主产区的粮食数量增加和非粮食主产区的粮食质量提升以及促进平原地区的粮食数量增加和山地地区的粮食数量、粮食质量双提升。其三,机制分析表明,高标准基本农田建设政策实施通过优化生产要素配置和促进农业规模经营从而提升粮食产能。     

水土资源约束下灌溉和机械投入对水稻生产效率的影响

立足水土资源禀赋,分析灌溉和机械投入对水稻生产效率的区域差异影响,对优化资源配置具有重要意义。根据长江中下游和东北地区859份调研数据,运用SFA方法进行分析,结果表明：①在长江中下游地区,灌溉投入对水稻生产效率无显著影响,机械投入影响为正且与人均耕地规模相互促进;②在东北地区,灌溉和机械投入均具有正向影响,且灌溉投入与水资源条件存在替代作用,耕地细碎化削弱机械投入的影响,机械投入与人均耕地规模表现出互补作用;③关于技术非效率,灌溉条件对长江中下游和东北地区的影响分别为正向和负向,且长江中下游地区受人均耕地规模影响,东北地区受耕地细碎化影响。因此,差异化投入灌溉和机械要素是提高水稻供给能力的重要途径。     

互联网使用、农业生产效率与乡村振兴的内涵式发展

推进农业智能化建设,提高农业生产效率,是实现乡村振兴的有效途径。基于2010年、2014年、2016年和2018年中国家庭追踪调查（CFPS）数据,实证分析互联网使用对农业生产效率的影响和内在机制,最后讨论提升农业生产效率对乡村振兴内涵式发展的重要意义。研究发现：（1）互联网使用能够显著提高农业生产效率,这一结论在经过一系列稳健性检验与内生性处理后仍然成立。（2）机制分析表明农户使用互联网可以加速推广应用农业新兴技术、优化土地资源配置效率和强化社会网络关系,进而提升农业生产效率。（3）异质性分析发现在农村地区、连片特困地区和胡焕庸线以西地区提高农户互联网使用率对农业生产效率的提升作用更显著。（4）进一步分析发现,提高农业生产效率有助于巩固脱贫成果、增加农业家庭收入、助力农民需求升级和提升农民幸福感,从而加快实现乡村振兴的内涵式发展。     

Implementation of S-DBR in four manufacturing SMEs: a research case study

Production planning and control systems (PPCs) are tools that have a major effect on the performance of manufacturing companies. An inappropriate determination of the applicability of PPCs could seriously jeopardise the ability to achieve competitive priorities. This mistake can be expensive for any company, but proper implementation is particularly critical for small and medium enterprises (SMEs), which are characterised by limited access to financial resources. Simplified Drum–Buffer–Rope (S-DBR) is a PPC control approach that is characterised by minimum detail in the planning stage and a primary emphasis on the control of execution. Therefore, this approach is a suitable choice for the highly variable context of SMEs. This study aims to explore the practical issues related to S-DBR implementation in four Ecuadorian SMEs through case study research. The case analysis within this study first identifies the choices made in the implementation process design within the four companies according to process and product characteristics. We then conduct a cross-case analysis to explore the effects of the S-DBR implementation process designs on a group of performance measures. Our research findings provide new insights into the S-DBR implementation process in the context of SMEs, and the effects of this approach on performance measures.     

Integrating Kanban principles in a pharmaceutical campaign production system

Centralised planned campaign production is the predominant production system in process industries. In this study, we investigate whether a decentralised Kanban control system, which has proven to offer advantages in other industries, can be successfully integrated in a campaign production environment. The used research methodology combines model-based and case-study-based elements. Using the example of a pharmaceutical internal five-stage supply chain, we conceive a Kanban concept that integrates campaign formation, develop a discrete-event simulation model and conduct a range of explorative simulation experiments. We find that a Kanban campaign production system is not merely feasible but would also be favourable: throughput times can be reduced without increasing customer lead times. Sensitivity analysis shows that the system’s performance is relatively robust to changes in Kanban key configuration parameters such as number of Kanban cards or campaign size. We conclude by discussing our findings and formulating three propositions that might stimulate future research.     

The use of period batch control (PBC) in the implosive industries

Period batch control (PBC) is a just-in-time (JIT) production control system of the flow control, single cycle type. It was developed in the UK before the Second World War, by the late R. J. Gigli, who installed it in 30 different factories and used it to regulate the manufacture of Spitfire fighter aircraft for the Battle of Britain. Implosive industries are those—such as foundries, glass works, spinning mills and potteries, among others—which produce a wide variety of different products from a very small number of material items. The paper shows how PBC is used in implosive industries, and explains why it is normally the best method to adopt in such factories.     

Manufacturing feature-based cost management system: a case study in Brazil

Feature costing is a topic of recent discussion related to cost management systems (CMSs) aimed at understanding how product features influence production process costs. It raises as a key issue in mass customisation environments where a single product model can present hundreds of menu options. In this study, we explore the concept of feature costing beyond the use of activity-based costing (ABC). We propose a CMS based on features and common elements as costing objects instead of products. In our model, we use the unit of production effort method to organise the direct manufacturing costs, ABC method to address the indirect cost and the standard methods to compute raw materials costs. We illustrate the method in the production of bus seats in a Brazilian manufacturing company. This study gives different perspectives to the international academic community on the use of a different CMS used by many Brazilian companies.