Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.

Pattern Recognition and Machine Learning

Data Mining Practical Machine Learning Tools and Techniques

Unlike conventional materials removal methods, additive manufacturing (AM) is based on a novel materials incremental manufacturing philosophy. Additive manufacturing implies layer by layer shaping and consolidation of powder feedstock to arbitrary configurations, normally using a computer controlled laser. The current development focus of AM is to produce complex shaped functional metallic components, including metals, alloys and metal matrix composites (MMCs), to meet demanding requirements from aerospace, defence, automotive and biomedical industries. Laser sintering (LS), laser melting (LM) and laser metal deposition (LMD) are presently regarded as the three most versatile AM processes. Laser based AM processes generally have a complex non-equilibrium physical and chemical metallurgical nature, which is material and process dependent. The influence of material characteristics and processing conditions on metallurgical mechanisms and resultant microstructural and mechanical properties of AM proc...

Laser additive manufacturing of metallic components: materials, processes and mechanisms

Additive manufacturing (AM) is poised to bring about a revolution in the way products are designed, manufactured, and distributed to end users. This technology has gained significant academic as well as industry interest due to its ability to create complex geometries with customizable material properties. AM has also inspired the development of the maker movement by democratizing design and manufacturing. Due to the rapid proliferation of a wide variety of technologies associated with AM, there is a lack of a comprehensive set of design principles, manufacturing guidelines, and standardization of best practices. These challenges are compounded by the fact that advancements in multiple technologies (for example materials processing, topology optimization) generate a "positive feedback loop" effect in advancing AM. In order to advance research interest and investment in AM technologies, some fundamental questions and trends about the dependencies existing in these avenues need highlighting. The goal of our review paper is to organize this body of knowledge surrounding AM, and present current barriers, findings, and future trends significantly to the researchers. We also discuss fundamental attributes of AM processes, evolution of the AM industry, and the affordances enabled by the emergence of AM in a variety of areas such as geometry processing, material design, and education. We conclude our paper by pointing out future directions such as the "print-it-all" paradigm, that have the potential to re-imagine current research and spawn completely new avenues for exploration. The fundamental attributes and challenges/barriers of Additive Manufacturing (AM).The evolution of research on AM with a focus on engineering capabilities.The affordances enabled by AM such as geometry, material and tools design.The developments in industry, intellectual property, and education-related aspects.The important future trends of AM technologies.

The status, challenges, and future of additive manufacturing in engineering

Thirty years into its development, additive manufacturing has become a mainstream manufacturing process. Additive manufacturing build up parts by adding materials one layer at a time based on a computerized 3D solid model. It does not require the use of fixtures, cutting tools, coolants, and other auxiliary resources. It allows design optimization and the producing of customized parts on-demand. Its advantages over conventional manufacturing have captivated the imagination of the public, reflected in recent mainstream publications that call additive manufacturing “the third industrial revolution.” This paper reviews the societal impact of additive manufacturing from a technical perspective. Abundance of evidences were found to support the promises of additive manufacturing in the following areas: (1) customized healthcare products to improve population health and quality of life, (2) reduced environmental impact for manufacturing sustainability, and (3) simplified supply chain to increase efficiency and responsiveness in demand fulfillment. In the mean time, the review also identified the need for further research in the areas of life-cycle energy consumption evaluation and potential occupation hazard assessment for additive manufacturing.

Additive manufacturing and its societal impact: a literature review

Closed loop direct metal deposition : art to part

Layered manufacturing (LM) is emerging as a new manufacturing technology that can enhance the scope of manufacturing. One of the essential tasks in LM is process planning. This paper defines, conceptualizes and reviews the literature in this emerging area. The paper concludes with future projections on the possible directions of research in this area.

A review of process planning techniques in layered manufacturing

As more choices of materials and build processes become available in layered manufacturing (LM), it is increasingly important to identify fundamental problems that underlie the entire field. Determination of best build orientation and minimizing build cost of a part are two such issues that must be considered in any LM process. By decoupling the solution to these problems from a specific LM technology, not only can the solution be applied to a variety of processes, but more realistic cost comparisons of parts built on different machines become possible.

Part orientation and build cost determination in layered manufacturing

Improving the geometric accuracy of layer manufactured parts has assumed greater significance as these processes are being integrated into manufacturing, instead of just being used for look-and-feel prototyping. In this paper, we describe two factors associated with the slicing procedures used in layered manufacturing processes that introduce geometric inaccuracy, and suggest solutions for their redressal. Implemented examples are included to explain the procedure.

An accurate slicing procedure for layered manufacturing

An increasing trend toward product development in a collaborative environment has resulted in the use of various software tools to enhance the product design. This requires a meaningful representation and exchange of product data semantics across different application domains. This paper proposes an ontology-based framework to enable such semantic interoperability. A standards-based approach is used to develop a Product Semantic Representation Language (PSRL). Formal description logic (DAML+OIL) is used to encode the PSRL. Mathematical logic and corresponding reasoning is used to determine semantic equivalences between an application ontology and the PSRL. The semantic equivalence matrix enables resolution of ambiguities created due to differences in syntaxes and meanings associated with terminologies in different application domains. Successful semantic interoperability will form the basis of seamless communication and thereby enable better integration of product development systems. Note to Practitioners-Semantic interoperability of product information refers to automating the exchange of meaning associated with the data, among information resources throughout the product development. This research is motivated by the problems in enabling such semantic interoperability. First, product information is formalized into an explicit, extensible, and comprehensive product semantics representation language (PSRL). The PSRL is open and based on standard W3C constructs. Next, in order to enable semantic translation, the paper describes a procedure to semi-automatically determine mappings between exactly equivalent concepts across representations of the interacting applications. The paper demonstrates that this approach to translation is feasible, but it has not yet been implemented commercially. Current limitations and the directions for further research are discussed. Future research addresses the determination of semantic similarities (not exact equivalences) between the interacting information resources.

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Debasish Dutta

Papers

Closed loop direct metal deposition : art to part

A review of process planning techniques in layered manufacturing

Part orientation and build cost determination in layered manufacturing

An accurate slicing procedure for layered manufacturing

Ontology-based exchange of product data semantics