2,249 research outputs found

    From computer-aided to intelligent machining: Recent advances in computer numerical control machining research

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    The aim of this paper is to provide an introduction and overview of recent advances in the key technologies and the supporting computerized systems, and to indicate the trend of research and development in the area of computational numerical control machining. Three main themes of recent research in CNC machining are simulation, optimization and automation, which form the key aspects of intelligent manufacturing in the digital and knowledge based manufacturing era. As the information and knowledge carrier, feature is the efficacious way to achieve intelligent manufacturing. From the regular shaped feature to freeform surface feature, the feature technology has been used in manufacturing of complex parts, such as aircraft structural parts. The authors’ latest research in intelligent machining is presented through a new concept of multi-perspective dynamic feature (MpDF), for future discussion and communication with readers of this special issue. The MpDF concept has been implemented and tested in real examples from the aerospace industry, and has the potential to make promising impact on the future research in the new paradigm of intelligent machining. The authors of this paper are the guest editors of this special issue on computational numerical control machining. The guest editors have extensive and complementary experiences in both academia and industry, gained in China, USA and UK

    A framework for developing engineering design ontologies within the aerospace industry

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    This paper presents a framework for developing engineering design ontologies within the aerospace industry. The aim of this approach is to strengthen the modularity and reuse of engineering design ontologies to support knowledge management initiatives within the aerospace industry. Successful development and effective utilisation of engineering ontologies strongly depends on the method/framework used to develop them. Ensuring modularity in ontology design is essential for engineering design activities due to the complexity of knowledge that is required to be brought together to support the product design decision-making process. The proposed approach adopts best practices from previous ontology development methods, but focuses on encouraging modular architectural ontology design. The framework is comprised of three phases namely: (1) Ontology design and development; (2) Ontology validation and (3) Implementation of ontology structure. A qualitative research methodology is employed which is composed of four phases. The first phase defines the capture of knowledge required for the framework development, followed by the ontology framework development, iterative refinement of engineering ontologies and ontology validation through case studies and experts’ opinion. The ontology-based framework is applied in the combustor and casing aerospace engineering domain. The modular ontologies developed as a result of applying the framework and are used in a case study to restructure and improve the accessibility of information on a product design information-sharing platform. Additionally, domain experts within the aerospace industry validated the strengths, benefits and limitations of the framework. Due to the modular nature of the developed ontologies, they were also employed to support other project initiatives within the case study company such as role-based computing (RBC), IT modernisation activity and knowledge management implementation across the sponsoring organisation. The major benefit of this approach is in the reduction of man-hours required for maintaining engineering design ontologies. Furthermore, this approach strengthens reuse of ontology knowledge and encourages modularity in the design and development of engineering ontologies

    Model-Based Environmental Visual Perception for Humanoid Robots

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    The visual perception of a robot should answer two fundamental questions: What? and Where? In order to properly and efficiently reply to these questions, it is essential to establish a bidirectional coupling between the external stimuli and the internal representations. This coupling links the physical world with the inner abstraction models by sensor transformation, recognition, matching and optimization algorithms. The objective of this PhD is to establish this sensor-model coupling

    BIM communication waste

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    Developments in Information and Communication Technology can bring about significant improvements in the efficiency of the Architecture, Engineering and Construction and Facilities Management industry. Building Information Modelling (BIM), is a term which encompasses a type of software but more importantly a set of processes which, at their core, support an approach for integrated project delivery enabled by interoperable software systems. The last three years have seen intensified and coordinated adoption of BIM in the UK mainly as a result of the mandate of the UK government. One facet of these developments is the growing need for BIM collaboration tools which can interoperate effectively with the various BIM software systems, support the required standards and codes of practice and provide for requirements of construction project information production and management such as model-based workflows, model-based communication, model-based procurement, role-based data access and role-based privileges. The pre-requisites for collaboration can be broadly divided into two categories: (1) coordination of information and responsibilities, and (2) communication. This research recognizes the strong focus of recent and ongoing efforts to provide for coordination and aims to support the communication aspect. Additionally, successful collaborative practice results from (1) the "softer" or "human-aspect" issues: collaborative culture, software training and adherence to protocols as well as from (2) the provision of appropriate, intuitive and configurable collaboration tools and, more generally, digital collaboration environments. This research focuses on the latter. Despite efforts from a variety of software-as-a-service (SaaS) collaboration tool vendors to achieve dominance in the market, there is still uncertainty as to what type of solutions would best support BIM collaboration. Additionally, there is considerable variation in software configurations and a lack of a universally applicable method for evaluating the communication capabilities of BIM collaboration tools in a meaningful way. Vendors lack a robust conceptual framework to guide the long-term development of their tools and evaluate them. The process of requirements engineering, which in this context involves a diversity of stakeholders and involves projects at different BIM maturity levels would benefit significantly from a robust, context-specific conceptual model-ontology. The aim of this research is to produce a context-specific conceptual model-ontology which can support the discourse of requirements engineering and provide a robust and widely applicable framework for evaluating the communication capabilities of BIM collaboration tools. It is anticipated that this would help reduce BIM communication waste . To meet this aim, BIM collaboration tools were studied from five perspectives: 1.Users: their opinions, requirements and requests were collected through an online questionnaire survey. 2.Vendor: their perspective was captured through semi-structured interviews. 3.Schemata for interoperability: effectiveness of tools and schemata was evaluated through analysis of software by data fidelity study and scenario-based testing. 4.Tool use: patterns of digitally-enabled communication were explored through an analysis of communication data and meta-data collected from a collaboration tool. 5.Tool improvement: a successful approach in improving a collaboration tool was examined through the development of a context-specific requirements engineering process. This process was evaluated through semi-structured interviews with collaboration tool implementation consultants. Each perspective helped produce more specific requirements from the model as well as elements of the model itself. The end result was the Model for communication waste in BIM process interactions (WIMBIM). WIMBIM has the BIM process transmission as the fundamental unit of analysis and focuses on BIM communication waste and how it results from sub-optimal collaboration tools and schemata. The ultimate purpose of WIMBIM is to support the development of technology which would reduce this waste. This model was converted into a communicable format and was related to BIM standards to aid contextualization and gap identification. To evaluate the validity and utility of this model, interviews with BIM experts were conducted, and the proposed model was found to be a valid approach to address aspects of BIM waste, which is not usually examined and could potentially complement the existing model for BIM maturity. Additionally, the model provides a useful lens for further academic research into BIM collaboration tools

    Recombinant design : leveraging process capture for collective creativity

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    Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 123-126).Design is omnipresent and fundamental to the modern world, yet so little of the rich semantic information of the design evolution is preserved. If we are to gain the greatest knowledge and utility from a creative work, we must understand and preserve the process by which it was designed. To pursue this understanding, I have designed and implemented two electronic media-based process capture frameworks that automatically capture and share process as well as provide process reviewing tools. The first system, Chronicler, is a universal capture framework which captures fine-grained process information at an action resolution, demonstrated through the example of a painting program. The second system, Artwork Genealogy, a component of the OPENSTUDIO project, uses versions embedded with process metadata to document the evolution of artwork in an open collaborative community. This web-based system was launched to users in February 2006 and continues to collect art processes from an active and growing community. Through simple, friendly user interfaces, these two systems encourage designers to donate to a repository of shared, searchable design information from which design rationale, the explanations for design decisions, can be inferred.(cont.) The comparison of these two systems, through data mining and user analysis, shows the effectiveness of these methods for collaborative process capture and combinatorial process reuse. In particular, I demonstrate the ability of process capture systems to give rise to emergent behaviors, uncover process regularities, and to empower designers through five key areas: learning from past work, reusing ideas and work, expression, attribution, and evaluation.by Annie Ding.M.Eng

    Information Preserving Processing of Noisy Handwritten Document Images

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    Many pre-processing techniques that normalize artifacts and clean noise induce anomalies due to discretization of the document image. Important information that could be used at later stages may be lost. A proposed composite-model framework takes into account pre-printed information, user-added data, and digitization characteristics. Its benefits are demonstrated by experiments with statistically significant results. Separating pre-printed ruling lines from user-added handwriting shows how ruling lines impact people\u27s handwriting and how they can be exploited for identifying writers. Ruling line detection based on multi-line linear regression reduces the mean error of counting them from 0.10 to 0.03, 6.70 to 0.06, and 0.13 to 0.02, com- pared to an HMM-based approach on three standard test datasets, thereby reducing human correction time by 50%, 83%, and 72% on average. On 61 page images from 16 rule-form templates, the precision and recall of form cell recognition are increased by 2.7% and 3.7%, compared to a cross-matrix approach. Compensating for and exploiting ruling lines during feature extraction rather than pre-processing raises the writer identification accuracy from 61.2% to 67.7% on a 61-writer noisy Arabic dataset. Similarly, counteracting page-wise skew by subtracting it or transforming contours in a continuous coordinate system during feature extraction improves the writer identification accuracy. An implementation study of contour-hinge features reveals that utilizing the full probabilistic probability distribution function matrix improves the writer identification accuracy from 74.9% to 79.5%
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