32,576 research outputs found

    Computer-Aided Design in Subtractive and Additive Prototyping

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    This paper concerns the use of a commercially available computer-aided design software in designing and manipulating the complex-shaped models for subtractive and additive prototyping processes. In the subtractive prototyping approach, the computer-aided design software was used to create surface models. The models were section-cut into multiple cross sectional layers. Then, the section-cut models were converted from graphic files into non-graphic files (neutral format files). In the additive prototyping approach, the computer-aided design software was used to create solid models with internal cavities (parent model). Multiple smaller diameter solid models were then derived from the parent mode!. The various diameter solid models were converted into surface models. The surface models were then section-cut and later changed into neutral format files. The computer-aided design software used in the project was AutoSurf, a commercially available product of Autodesk, Inc. The hardware which was used ;n the above processes were a four degrees of freedom precision robotic manipulator (for manipulating raw material), a ball-nosed end milling device (in subtractive prototyping) and a semi-liquid deposition tool (for additive prototyping). This study revealed the possibility of using cheap and general computer-aided design software to accomplish the complex-shaped model design and manipulation work in the prototyping processes instead of using expensive rapid prototyping software

    The characteristics of the CAT to CAD to rapid prototyping system

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    ThesisComputer Aided Design (CAD), Rapid Prototyping (RP) and Computer Aided Tomography (CAT) technologies were researched. The project entails a unique combination of the abovementioned technologies, which had to be mastered by the author, on local and international terms. Nine software packages were evaluated to determine the modus operandi, required input and final output results. Fifty Rapid Prototyping systems were investigated to determine the strong and weak areas of the various systems, which showed that prototype materials, machine cost and growing time play an essential role. Thirty Reverse Engineering systems were also researched. Six different RE methods were recorded with several commercial systems available. Nineteen case studies were completed by using several different Computer Aided Tomography (CAT) and Magnetic Resonance Imaging (MRI) centers. Each scanning centre has different apparatus and is discussed in detail in the various case studies. The focus of this project is the data transfer of two dimensional CAT scanning data to threedimensional prototypes by using Reverse Engineering (RE) and Rapid Prototyping (RP). It is therefore of cardinal importance that one is familiar and understands the various fields of interest namely Reverse Engineering, Computer Aided Tomography and Rapid Prototyping. Each of these fields will be discussed in detail, with the latest developments in these fields covered as well. Case studies and research performed in the medical field should gain the medical industry's confidence. Constant marketing and publications will ensure that the technology is applied and transferred to the industry. Commercialisation of the technology is of utmost importanc

    A conceptual level design of a Design Database for the Computer-Aided Prototyping System

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    Vast amounts of evolving data are created in the design of hard real-time software systems. This data must be managed so that it can be stored and retrieved according to the needs of design engineers. In the Computer-Aided Prototyping System (CAPS), a Design Database (DDB) must manage the storage and retrieval of the entire Prototype System Description Language (PSDL) program. This thesis presents a conceptual design and initial implementation of a Design Database (DDB) for the Computer-Aided Prototyping System (CAPS).http://archive.org/details/aconceptuallevel1094524279Lieutenant, United States NavyApproved for public release; distribution is unlimited

    Software Evolution Approach for the Development of Command and Control Systems

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    2000 Command and Control Research and Technology Symposium (CCRTS), June 11-13, 2000, Naval Postgraduate School, Monterey, CAThis paper addresses the problem of how to produce reliable software that is also flexible and cost effective for the DoD distributed software domain. DoD software systems fall into two categories: information systems and war fighter systems. Both types of systems can be distributed, heterogeneous and network-based, consisting of a set of components running on different platforms and working together via multiple communication links and protocols. We propose to tackle the problem using prototyping and a “wrapper and glue” technology for interoperability and integration. This paper describes a distributed development environment, CAPS (Computer- Aided Prototyping System), to support rapid prototyping and automatic generation of wrapper and glue software based on designer specifications. The CAPS system uses a fifth-generation prototyping language to model the communication structure, timing constraints, I/O control, and data buffering that comprise the requirements for an embedded software system. The language supports the specification of hard real-time systems with reusable components from domain specific component libraries. CAPS has been used successfully as a research tool in prototyping large war-fighter control systems (e.g. the command-and-control station, cruise missile flight control system, missile defense systems) and demonstrated its capability to support the development of large complex embedded software.This research was supported in part by the U. S. Army Research Office under contract/grant number 35037-MA and 40473-MA

    Development of compact circular polarized antenna for WLAN application

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    Matching the polarization in both the transmitter and receiver antennas is important in terms of decreasing transmission losses. The use of circularly polarized antennas presents an attractive solution to achieve this polarization match which allows for more flexibility in the angle between transmitting and receiving antennas, reduces the effect of multipath reflections, enhances weather penetration and allows for the mobility of both the transmitter and the receiver. Compact circularly polarized microstrip antenna with Circular Polarization (CP) property for wireless communication system at 2.45 GHz is presented. Microstrip patch antennas being popular because of light weight, low volume, thin profile configuration which can be made conformal. Wireless communication systems applications circular polarization antenna is placing vital role. In this study it was applied DGS to produce circular polarization. The single fed circular polarized microstrip antenna is etched on a FR4 with dielectric substrate of 4.3 with the height of 1.6 mm. The axial ratio of approximate 2.1 dB and the radiation pattern results prove that the designed antenna meets the CP criteria. The simulated and measured results show a good agreement and the proposed antenna is suitable for WLAN applications

    From 3D Models to 3D Prints: an Overview of the Processing Pipeline

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    Due to the wide diffusion of 3D printing technologies, geometric algorithms for Additive Manufacturing are being invented at an impressive speed. Each single step, in particular along the Process Planning pipeline, can now count on dozens of methods that prepare the 3D model for fabrication, while analysing and optimizing geometry and machine instructions for various objectives. This report provides a classification of this huge state of the art, and elicits the relation between each single algorithm and a list of desirable objectives during Process Planning. The objectives themselves are listed and discussed, along with possible needs for tradeoffs. Additive Manufacturing technologies are broadly categorized to explicitly relate classes of devices and supported features. Finally, this report offers an analysis of the state of the art while discussing open and challenging problems from both an academic and an industrial perspective.Comment: European Union (EU); Horizon 2020; H2020-FoF-2015; RIA - Research and Innovation action; Grant agreement N. 68044

    Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): Guidelines for medical 3D printing and appropriateness for clinical scenarios

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    Este número da revista Cadernos de Estudos Sociais estava em organização quando fomos colhidos pela morte do sociólogo Ernesto Laclau. Seu falecimento em 13 de abril de 2014 surpreendeu a todos, e particularmente ao editor Joanildo Burity, que foi seu orientando de doutorado na University of Essex, Inglaterra, e que recentemente o trouxe à Fundação Joaquim Nabuco para uma palestra, permitindo que muitos pudessem dialogar com um dos grandes intelectuais latinoamericanos contemporâneos. Assim, buscamos fazer uma homenagem ao sociólogo argentino publicando uma entrevista inédita concedida durante a sua passagem pelo Recife, em 2013, encerrando essa revista com uma sessão especial sobre a sua trajetória
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