A polychromatic sets approach to the conceptual design of machine tools

Currently very few computer-aided conceptual design systems are available to support the initial development of a machine tool and its structure (concept, calculation, design) and the verification of the prototype. In recent years, polychromatic sets have emerged as a promising approach for mathematical modelling. The theory, techniques, and approaches of polychromatic sets are capable of playing an important role in the conceptual design of a variety of products including machine tools. In this paper, the concept of polychromatic sets is introduced, and a polychromatic sets approach for the conceptual design of machine tools is proposed. The usefulness of the proposed method is illustrated by a conceptual design example of a machining centre of drilling, milling, and boring. Applying the proposed approach to machine tools helps to make right decisions in the conceptual design stage. Due to its powerful mathematical modelling capability, the polychromatic sets technique proposed in this paper may possibly be extended and applied to design evaluation problems encountered in other design tasks in manufacturing systems including process planning.     

A pilot framework developed as a common platform integrating diverse elements of computer aided fixture design

In the present study, an integrated computer-aided engineering platform has been developed for fixture design. Different computer aids needed for an automated fixture design system include geometrical modelling, finite element analysis, specialised mathematical tools, such as screw theory, and also artificial intelligence routines. It has been illustrated through several examples that the Python environment is a capable candidate to be employed for developing an integrated platform capable of providing these computer-aided tools. For this purpose, different specialised modules were developed, including a CAD system for geometrical modelling of workpiece, a mathematical analysis module for designing the locating system by using the screw theory, a FEM module being employed for support system design and an expert fixture planning module. The developed platform has also been examined for its capability to be interfaced with existing commercial CAD, FEM and expert system programmes.     

A multi-level modelling system for the design of flexible machining installations

Modern flexible manufacturing facilities can be highly complex, consisting of the latest developments in machine tool technology, automated material handling systems and sophisticated cell controllers. The design and management of such systems requires a large number of decisions and choices with regard to production mix, assignment of fixtures and cutting tools. A large number of commercial computer modelling packages are now available in the market place. Although these allow valuable assistance in the analysis of a manufacturing facility, they usually take significant amounts of time to build models and require a large amount of training, and can be constraining in their application. This paper establishes a research prototype for a multi-level approach for the realization of a three-phase design and modelling system for flexible machining facilities. It portrays the view of an integrated fully data-driven solution underpinned by a machining cell database, and outlines three major areas of work within the structure, i.e. the 'Cell Configurator', 'Evaluator' and 'Emulator'. The approach is demonstrated and supported throughout the paper by an industrial case study of a modern three-machine flexible machining cell, illustrating the use of the underlying methodology behind the approach and typical inputs/outputs at each phase. The final part of the paper provides a discussion of the approach adopted based on user comments and in relation to commercial simulation tools available.     

Advanced machine service support using Internet-enabled three-dimensional-based virtual engineering

In the era of globalization, one of the key factors for manufacturing machine builders/suppliers to remain competitive is their capability to provide cost-effective and comprehensive machine service and maintenance for their clients at anytime, anywhere. Previous research has highlighted the role of virtual engineering tools in the design and development life cycle of manufacturing machinery systems. Virtual engineering models created during the development phase can potentially be used to provide valuable functions for many other tasks during the operational phase, including service and maintenance support. This paper introduces an innovative Internet-enabled three-dimensional-based virtual engineering framework that can be used for such purposes. Specifically, it addresses a system architecture that is designed to facilitate the tight integration between virtual engineering tools and a set of Internet-based reconfigurable modular maintenance supporting tools. This system architecture has been verified by implementations using different toolsets atop of various Internet technologies (e.g. XML Web services and LabView's Datasocket). Implementation details and successful industrial-based test cases are also provided in this paper.     

Heterogeneous modelling tools for integrated production systems

The general instability in the environment of enterprises is the main reason for their quest for more and more reactivity, in order to adapt their products in time to market. The consequences of this are changes in products, processes, and the organization of companies. Development of the 'information system' within manufacturing departments makes the efficiency of methods to manage this system a critical point. Our aim here is to develop this efficiency, making possible integrated use of several modelling tools within a single project. We provide a classification of links that are possible between modelling tools. This classification is partially applied to links between IDEF0 and CIM-OSA.     

An intelligent feature-based process planning system for prismatic parts

Today, feature-based design has become a core technology for solid product modelling primarily because it can capture the designer's intent and provide the capability to satisfy the informational needs of the down-line application tasks for CAD/CAM integration. This paper reports the development of an intelligent environment, IFPP (Intelligent Feature-based Process Planning), for the feature-based design synthesis and process planning of prismatic parts to be produced on CNC machining centres. IFPP consists of two functional modules, namely Feature Based Modeller (FBM) and Automatic process Planner (AutoPlan). The FBM provides a graphical environment for the feature-based synthesis, validation and representation of the solid model of the part to be produced. AutoPlan maps this feature information to the corresponding machining processes to generate the operation plan and corresponding CNC code. This CNC code is unique in that it is functionally encapsulated with the feature data to provide a 'Variant' strategy utilizing the special parametric programming facilities provided on the controller. IFPP thus demonstrates an integrated part-process environment that enables quick turnaround from design to manufacture.     

Progress in and prospects for fluvial flood modelling

Recent floods in the UK have raised public and political awareness of flood risk. There is an increasing recognition that flood management and land-use planning are linked, and that decision-support modelling tools are required to address issues of climate and land-use change for integrated catchment management. In this paper, the scientific context for fluvial flood modelling is discussed, current modelling capability is considered and research challenges are identified. Priorities include (i) appropriate representation of spatial precipitation, including scenarios of climate change; (ii) development of a national capability for continuous hydrological simulation of ungauged catchments; (iii) improved scientific understanding of impacts of agricultural land-use and land-management change, and the development of new modelling approaches to represent those impacts; (iv) improved representation of urban flooding, at both local and catchment scale; (v) appropriate parametrizations for hydraulic simulation of in-channel and flood-plain flows, assimilating available ground observations and remotely sensed data; and (vi) a flexible decision-support modelling framework, incorporating developments in computing, data availability, data assimilation and uncertainty analysis.     

Supply chain management practices as a mediator of the relationship between operations capability and firm performance

The current study uses mediated regression analysis and structural equation modelling to test the proposition that supply chain management practices mediate the relationship between operations capability and firm performance. Operations capability is defined in terms of a firm's new product design and development, total quality management and just-in-time capabilities. Results support the research model and also suggest the existence of a direct relationship between operations capability and performance.     

Visualization support to better comprehend and improve decision tree classification modelling process: a survey and appraisal

Data mining (DM) can be defined as the non-trivial process of identifying valid, novel, potentially useful and ultimately understandable patterns in data. Modelling is the crucial step where DM algorithms are applied in order to extract data patterns. In order for domain experts, who play significant roles in DM process, to make the most efficient and effective use of DM tools, these tools must incorporate appropriate visualization to facilitate the process of modelling. Yet, unfortunately, study of how visualization should be designed, particularly what components should be included and how to present them, has been rather limited. This paper surveys the current state of art in application of visualization techniques to better comprehend and improve the decision trees modelling process in three modes: visualization of tree models, visualization of model evaluation and visual interactive tree construction. A number of issues that have been overlooked and areas that need to be improved are identified through reviewing a collection of related research and examining six current DM softwares in terms of their design of a few important features in each mode of the visualization support to decision trees classification modelling. Although this article focuses on decision trees classification modelling, guidelines derived from this study can be beneficial to other modelling techniques as well. At the end of the paper, a desirable design of visualization support to DM modelling is proposed with a conceptual model.     

Reliability improvement via taguchi's robust design

Taguchi's robust design strategy, whose aim is to make processes and products insensitive to factors which are hard or impossible to control (termed noise factors), is an important paradigm for improving products and processes. We present an overview of the strategy and tactics for robust design and demonstrate its usefulness for reliability improvement. Two important components of robust design are a criterion for assessing the effect of the noise factors and experimentation according to specialized experimental plans. Recent criticism of Taguchi's criterion and his analysis of its estimates has led to an alternative approach of modelling the response directly. We give additional reasons for using this response-model approach in the context of reliability improvement. Using the model for the response, appropriate criteria for assessing the effect of the noise factors can then be evaluated. We consider an actual experiment and reanalyse its data to illustrate these ideas and method.     

Systems engineering medicine: engineering the inflammation response to infectious and traumatic challenges

The complexity of the systemic inflammatory response and the lack of a treatment breakthrough in the treatment of pathogenic infection demand that advanced tools be brought to bear in the treatment of severe sepsis and trauma. Systems medicine, the translational science counterpart to basic science''s systems biology, is the interface at which these tools may be constructed. Rapid initial strides in improving sepsis treatment are possible through the use of phenomenological modelling and optimization tools for process understanding and device design. Higher impact, and more generalizable, treatment designs are based on mechanistic understanding developed through the use of physiologically based models, characterization of population variability, and the use of control-theoretic systems engineering concepts. In this review we introduce acute inflammation and sepsis as an example of just one area that is currently underserved by the systems medicine community, and, therefore, an area in which contributions of all types can be made.     

Bridging WebML to model-driven engineering: from document type definitions to meta object facility

Meta-models are a prerequisite for model-driven engineering (MDE) in general and consequently for model-driven web engineering in particular. Various web modelling languages, however, are not based on meta-models and standards, like object management group's prominent meta object facility (MOF). Instead they define proprietary languages rather focused on notational aspects. Thus, MDE techniques and tools cannot be deployed for such languages preventing to exploit the full potential of MDE in terms of standardised storage, exchange and transformation of models. The WebML web modelling language is one example that does not yet rely on an explicit meta-model in the sense of MDE. Instead, it is defined in terms of a document type definition (DTD), and implicitly within the accompanying tool. Code generation then has to rely on model-to-code transformations based of extensible stylesheet language transformations (XSLT). We propose a meta-model for WebML to bridge WebML to MDE. To establish such a meta-model, instead of remodelling WebML's meta-model from scratch, a semi-automatic approach is provided that allows generating MOF-based meta-models on the basis of DTDs. The meta-model for WebML accomplishes the following aims: first, it represents an initial step towards a transition to employ MDE techniques within the WebML design methodology. Second, the provision of a MOF-based meta-model ensures interoperability with other MDE tools. Third, it represents an important step towards a common meta-model for Web modelling in future.     

Evaluation by simulation to optimise information systems’ personalisation quality in logistics

Personalised information systems (PISs), related to different fields (travelling and mobility, production, logistics and so on), represent an object of many research and development perspectives. Using PISs, it becomes possible to supply the user only with the pertinent information that suits their preferences. Indeed, thanks to personalisation, the user may feel that a particular PIS is developed for them. This system adaptation becomes a necessity for the user's satisfaction. In this context, many studies were orientated toward the user modelling, the design methods of PIS and the personalisation algorithms, etc. but, the evaluation of these systems is neglected. Difficulties concerning context-centred evaluation appear. This paper is focused on the evaluation of the personalised information systems in order to optimise the personalisation quality according to several criteria. For such systems, it is important to envisage new adapted evaluation methods. An evaluation method using a PIS simulation model, called MetSim (Method evaluation per Simulation), is proposed. MetSim is also based on the case-based reasoning system to identify problems. This evaluation approach has been validated by applying it to assess PISs in the logistics field.     

Implementation of an object-oriented tool for the simulation of manufacturing systems and its application to study the effects of flexibility

Although there is a reasonable number of currently available modelling tools for the analysis and evaluation of flexible manufacturing systems, these models, in general, neglect flexibility. They do not consider that in a flexible manufacturing system there is the possibility of different operation sequences. As a consequence, while flexibility in manufacturing is much 'in vogue', the development of models that are able to improve the understanding and consequences of having flexibility is still incipient in the literature. This paper presents work to develop a tool to support the analysis of flexible automation. The tool described is an objectoriented discrete-event simulator, called OOSimFlex, capable of modelling different alternative systems design and analysing a manufacturing system using multiple performance measures under different manufacturing flexibility levels. The paper describes the major theoretical concepts employed for the development of a highly flexible and interactive simulation model environment.     

基于多属性决策模型的传统长柄农具改良设计方法

目的 提出一种多属性决策模型,进行以人为本的传统长柄农具改良设计研究,旨在改善农民在从事农业生产活动中的使用体验,减轻身体负担,提升工作效率。方法 首先,以农民用户为中心,以JACK人机仿真数据为依据提出具体需求,利用层次分析法对需求权重进行计算,明确设计目标和亟需解决的设计问题;其次运用TRIZ工具中的物场模型分析问题,根据对应的标准解决设计问题,以此为依据完成改良设计方案,最后通过JACK仿真软件验证该方法的合理性。结论 构建了融合层次分析法、TRIZ理论、JACK仿真评估的多属性决策模型,完成了传统长柄农具改良方法研究,并且以铁锨为例进行了设计验证,为传统长柄农具的改良设计提供了一条有效路径和实施策略。     

Using ensemble and metaheuristics learning principles with artificial neural networks to improve due date prediction performance

One of the common and important problems in production scheduling is to quote an attractive but attainable due date for an arriving customer order. Among a wide variety of prediction methods proposed to improve due date quotation (DDQ) accuracy, artificial neural networks (ANN) are considered the most effective because of their flexible non-linear and interaction effects modelling capability. In spite of this growing use of ANNs in a DDQ context, ANNs have several intrinsic shortcomings such as instability, bias and variance problems that undermine their accuracy. In this paper, we develop an enhanced ANN-based DDQ model using machine learning, evolutionary and metaheuristics learning concepts. Computational experiments suggest that the proposed model outperforms the conventional ANN-based DDQ method under different shop environments and different training data sizes.     

Top management Team's cognitive diversity and the Firm's ambidextrous innovation capability: The mediating role of ambivalent interpretation

The top management team (TMT) diversity has received considerable attention in literature, especially due to its influence on an organization's innovation strategy. While previous studies have considered diversity in terms of education, experience, skills, functionality, and gender, little is known about the TMT's cognitive diversity. We contribute to the literature by examining the influence of the TMT's cognitive diversity on an organization's ambidextrous innovation capability; i.e., its incremental and radical innovation capability. Results from 50 TMTs involved in the electronics industry support our hypothesized mediating role of ambivalent interpretation; that the TMT cogitative diversity positively influences ambivalent interpretation, and this, in turn, positively influences both radical and incremental innovation capability. These findings have important implications for how a firm's decision makers (i.e., the TMT) with their diverse cognitive styles support building the firm's ambidextrous capability through ambivalent interpretation.     

AGV controlled FMS

One of the key factors that prevent the implementation of Flexible Manufacturing Systems (FMS) is the elaborate cost associated with the control software. In a FMS there is often a wide range of equipment, such as personal computers, Programmable Logical Controllers (PLCs), CNC Machines or robots, each of these having their own 'intelligence' and library of data. Providing a means of communication between these individual controllers has traditionally been achieved using a Local Area Network (LAN). This proves more expensive when traditional manual operated machines have to be integrated into the system. The model described in this paper provides an alternative to the conventional use of a LAN in a FMS environment. In the design solution, an Automatically Guided Vehicle (AGV) is used as both the materials handling unit and the communications line linking each station to the host controller. Communications between the AGV and peripheral equipment is achieved using a standard infrared data link, eliminating hard-wiring and network protocols. A simulation model has been developed to demonstrate the feasibility of such a system, using industrial data. The software package Witness is used to develop the simulation model. The objective from developing this simulation model is to test whether an AGV is capable of meeting the demands of such a scenario. The research undertaken aims to test this by modelling an existing factory layout. Using this layout and captured machining times and part routes, from the factory database, the feasibility of such AGV controlled production system is established. The model shows that such a system is plausible in a scenario where machine times are high and the distance between machines is large.     

Large-Eddy-Simulation-based analysis of complex flow structures within the volute of a vaneless centrifugal pump

Centrifugal pumps are very common in many fluid handling industrial applications, such as petrochemicals, oil and gas, etc. Although the design practices for centrifugal pumps are well established, efforts are directed towards optimising such systems for better operational efficiencies. In order to optimally design centrifugal pumps, it is beneficial to first understand the complex flow phenomena within different sections of the pump for a variety of operating conditions. This is normally achieved through the use of modern techniques, such as Computational Fluid Dynamics (CFD), where the flow within centrifugal pumps can be numerically modelled and important flow features can be analysed for better understanding of interactions amongst different process variables. CFD offers different turbulence modelling techniques with an aim to predict realistic flow approximations. Large Eddy Simulation (LES) offers a more accurate solution to this, in which the larger eddies are resolved while smaller eddies are modelled; hence predictions using LES are more realistic. Further, in turbulence modelling within centrifugal pumps, it is also important to model the complete interaction amongst different variables rather than a simplistic single blade passage flow analysis. In the present work, the complex blade–tongue interactions and their consequent effects on the pressure fluctuations within the volute have been evaluated. It is seen that the secondary flow features in the near-tongue regions due to blade interactions with the tongue affect the flow characteristics within the volute considerably.     

The role of control in mechatronics

This paper discusses some design issues of mechatronic systems. New tools for the design of controllers are needed to apply more advanced control algorithms in an industrial environment. In addition, modelling and simulation tools can play an important role in evaluating designs at an early stage and in supporting design decisions. Re-use of models and controller code can help reduce the time to market of new mechatronic products