Design of a motorised plasma delivery system for ultra-precision large optical fabrication

A unique plasma figuring (PF) process was created and demonstrated at Cranfield University for manufacturing extremely large telescopes. The atmospheric pressure processing is faster and more cost-effective than other finishing processes; thus, providing an important alternative for large optical surfaces. The industrial scale manufacturing of thousands of ultra-precision metre-scale optics requires a robust PF machine: this requirement is achieved by making the plasma delivery system (PDS) performance repeatable. In this study, a dedicated PDS for large optical manufacturing was proposed to meet the industrial requirement. The PDS is based on an L-type radiofrequency (RF) network, a power supply, and an inductively coupled plasma torch. However, the complexities of these technologies require an in depth understanding of the integrated components that from the PDS. A smart control system for the modified PDS was created. This novel control system aims to make the characterization process deterministic: by automating the tuning of critical electrical components in the RF network, which is achieved by the use of in-line metrology. This paper describes the main design aspects. The PDS was tested with a good correlation between capacitance and RF frequencies. The robust PDS design enables a stable discharge of plasma with a low deviation of RF signals during the total 15 hours' te

Total Design in the Design and Development Process of a Remotely Operated Vehicle (ROV) with Particular Consideration of Sensorization

This paper provides a methodological proposal for the design and development process of a remotely operated vehicle (ROV). The design core and product design specifications (PDS) of Pugh’s Total Design model are considered, with a focus on the early stages of the product design and development process. A modularization of the functional groups of an ROV is proposed, focusing attention on the sensor system. The main concepts regarding ROVs are presented, Pugh’s Total Design model is explained, justifying the application interest in technological projects, a methodological proposal adapted to ROV projects is provided, based on Pugh’s Total Design model, with special interest in the early stages of the new product development process (NPD), the suitability of applying our own model of industrial design engineering in an ROV system is analyzed, and the contribution of this study is evaluated, proposing future work and lines of research

Creation of a control system for plasma delivery to increase determinism and robustness while processing using an ICP torch

International audienceThe Cranfield University Precision Engineering Institute team has created a unique plasma figuring capability to correct large optical surfaces at atmospheric pressure. In the context of ever increasing dimensions of optical components, there is a need for improving the robustness and securing the performance of our Plasma Delivery System (PDS). The current PDS is based on an inductive output L type RF circuit, Inductively Coupled Plasma (ICP) torch and computer numerically controlled (CNC) motion system. The combination of optical component surface areas and the nature of the sub-aperture plasma tool lead to significant processing duration. This atmospheric pressure processing environment is more cost-effective than vacuum chamber based ones which are often used by competitors. However it requires deep awareness and fine understanding of technologies used. Based on the knowledge acquired for the past eight years, we have created a smart control system for our unique PDS that equips a machine called Helios1200. This novel control system aims at securing the process determinism and assisting the machine operator by tuning some key electrical components of the RF network and monitoring some processing parameters. Furthermore, specific assistance is provided during the different phases of the plasma processing. This paper describes the main design aspects

Private Data System Enabling Self-Sovereign Storage Managed by Executable Choreographies

With the increased use of Internet, governments and large companies store and share massive amounts of personal data in such a way that leaves no space for transparency. When a user needs to achieve a simple task like applying for college or a driving license, he needs to visit a lot of institutions and organizations, thus leaving a lot of private data in many places. The same happens when using the Internet. These privacy issues raised by the centralized architectures along with the recent developments in the area of serverless applications demand a decentralized private data layer under user control. We introduce the Private Data System (PDS), a distributed approach which enables self-sovereign storage and sharing of private data. The system is composed of nodes spread across the entire Internet managing local key-value databases. The communication between nodes is achieved through executable choreographies, which are capable of preventing information leakage when executing across different organizations with different regulations in place. The user has full control over his private data and is able to share and revoke access to organizations at any time. Even more, the updates are propagated instantly to all the parties which have access to the data thanks to the system design. Specifically, the processing organizations may retrieve and process the shared information, but are not allowed under any circumstances to store it on long term. PDS offers an alternative to systems that aim to ensure self-sovereignty of specific types of data through blockchain inspired techniques but face various problems, such as low performance. Both approaches propose a distributed database, but with different characteristics. While the blockchain-based systems are built to solve consensus problems, PDS's purpose is to solve the self-sovereignty aspects raised by the privacy laws, rules and principles.Comment: DAIS 201

Innovative mechanical design with a case study of pumping systems for low yield tube wells

University of Technology Sydney. Faculty of Engineering.This thesis focuses on combinatorial methods of invention/innovation/design emphasizing the manipulation of form (as distinct from the manipulation of function alone) that help the designer to generate a wide range of good design alternatives. It is based on my case study of a morphological analysis of a ground water pumping system suitable for low volume flow pumping. The first premise of this approach is that the elements and functions of mature technologies such as mechanical machines are well documented and understood. Thus, innovations are more likely to involve new combinations of existing forms than the introduction of new machine elements. The second premise is that valuable information is available about most elements and the more popular sub-systems and machines. That information has evolved, sometimes over time spans ranging to hundreds of years, but it has not usually been systematically documented and categorised, thus leaving opportunities to investigate these areas and discover good design possibilities. Further, some valuable information is available only anecdotally or is tightly held by the managements of the companies that have manufactured the device(s) or own the intellectual rights. In recent years a proposed "design science" has been the subject of much research and many models have been proposed of processes for designers to follow. These typically model the design process in stages, including: clarifying the problem, conceptualising, embodiment selection and detailing. It is widely recognized that industrial invention/innovation/design processes are non-linear, and so complex that, despite extensive research, design science and models are still at an immature stage. The literature confirms that industry is often driven by cost/time constraints and short term thinking, rather than using “design science” methods. My methodology (abbreviated as TREND-MORPH-PDS) is an original contribution to design science. It outlines three stages to be followed by the designer: 1. Start with a general goal(s). Break this down into sub-areas/systems, including: socio-economic, near physical environment, power source, prime mover, gearing/matching, transmission, working sub-system and control system. Research and document historical trends in each of these areas and their possible influences on the design. 2. Apply morphological analysis to each sub-system, using rapid graphical techniques. Move to detail design for specific alternatives as satisficing sub-systems are identified. 3. At all times during these stages, take advantage of design knowledge/tools that are currently available, looking for ideas and opportunities. Work constantly on constructing the Product Design Specification (PDS). The conceptual design is complete when the PDS is finalized. Detail design, which would follow from the PDS is not treated in this thesis. The methods and ideas put forward in this thesis and its case study are an original contribution to design science. They also identify issues and differences between design science models and the design processes seen in industry. Several patentable inventions have resulted from my application of the methodology, and the dissertation is a significant contribution to the knowledge domains of mechanical machine design and the technology of ground water pumping

Accounting for Uncertainties in Strengths of SiC MEMS Parts

A methodology has been devised for accounting for uncertainties in the strengths of silicon carbide structural components of microelectromechanical systems (MEMS). The methodology enables prediction of the probabilistic strengths of complexly shaped MEMS parts using data from tests of simple specimens. This methodology is intended to serve as a part of a rational basis for designing SiC MEMS, supplementing methodologies that have been borrowed from the art of designing macroscopic brittle material structures. The need for this or a similar methodology arises as a consequence of the fundamental nature of MEMS and the brittle silicon-based materials of which they are typically fabricated. When tested to fracture, MEMS and structural components thereof show wide part-to-part scatter in strength. The methodology involves the use of the Ceramics Analysis and Reliability Evaluation of Structures Life (CARES/Life) software in conjunction with the ANSYS Probabilistic Design System (PDS) software to simulate or predict the strength responses of brittle material components while simultaneously accounting for the effects of variability of geometrical features on the strength responses. As such, the methodology involves the use of an extended version of the ANSYS/CARES/PDS software system described in Probabilistic Prediction of Lifetimes of Ceramic Parts (LEW-17682-1/4-1), Software Tech Briefs supplement to NASA Tech Briefs, Vol. 30, No. 9 (September 2006), page 10. The ANSYS PDS software enables the ANSYS finite-element-analysis program to account for uncertainty in the design-and analysis process. The ANSYS PDS software accounts for uncertainty in material properties, dimensions, and loading by assigning probabilistic distributions to user-specified model parameters and performing simulations using various sampling techniques

How pharmacoepidemiology networks can manage distributed analyses to improve replicability and transparency and minimize bias

Several pharmacoepidemiology networks have been developed over the past decade that use a distributed approach, implementing the same analysis at multiple data sites, to preserve privacy and minimize data sharing. Distributed networks are efficient, by interrogating data on very large populations. The structure of these networks can also be leveraged to improve replicability, increase transparency, and reduce bias. We describe some features of distributed networks using, as examples, the Canadian Network for Observational Drug Effect Studies, the Sentinel System in the USA, and the European Research Network of Pharmacovigilance and Pharmacoepidemiology. Common protocols, analysis plans, and data models, with policies on amendments and protocol violations, are key features. These tools ensure that studies can be audited and repeated as necessary. Blinding and strict conflict of interest policies reduce the potential for bias in analyses and interpretation. These developments should improve the timeliness and accuracy of information used to support both clinical and regulatory decisions

Public distribution system reforms and consumption in Chhattisgarh

Chhattisgarh's public distribution system reforms have been lauded as a model for the National Food Security Act, and as one that other states can emulate. Previous research has shown that PDS rice consumption increased in Chhattisgarh following reforms by the Raman Singh government, which began in 2004. However, one-third of PDS rice consumption growth in Chhattisgarh took place before 2004. This finding suggests that the pre-2004 reforms to fair price shop ownership and state procurement by the Ajit Jogi government contributed to PDS consumption growth. Our findings suggest that sustained reforms, when coupled with political and social will, can improve PDS access, and that improvements may not be substantial or sustained in the absence of these factors

Communications-Inspired Projection Design with Application to Compressive Sensing

We consider the recovery of an underlying signal x \in C^m based on projection measurements of the form y=Mx+w, where y \in C^l and w is measurement noise; we are interested in the case l < m. It is assumed that the signal model p(x) is known, and w CN(w;0,S_w), for known S_W. The objective is to design a projection matrix M \in C^(l x m) to maximize key information-theoretic quantities with operational significance, including the mutual information between the signal and the projections I(x;y) or the Renyi entropy of the projections h_a(y) (Shannon entropy is a special case). By capitalizing on explicit characterizations of the gradients of the information measures with respect to the projections matrix, where we also partially extend the well-known results of Palomar and Verdu from the mutual information to the Renyi entropy domain, we unveil the key operations carried out by the optimal projections designs: mode exposure and mode alignment. Experiments are considered for the case of compressive sensing (CS) applied to imagery. In this context, we provide a demonstration of the performance improvement possible through the application of the novel projection designs in relation to conventional ones, as well as justification for a fast online projections design method with which state-of-the-art adaptive CS signal recovery is achieved.Comment: 25 pages, 7 figures, parts of material published in IEEE ICASSP 2012, submitted to SIIM