Search results for "Computer-aided"
showing 10 items of 416 documents
On-Line Control of Single Point Incremental Forming Operations through Punch Force Monitoring
2006
Abstract Among the innovative sheet metal forming processes, Single Point Incremental Forming (SPIF) represents the simplest and the cheapest one. Despite its relevant advantages, up to now no specific CAE tools for SPIF were developed and the tool trajectory is generally defined utilizing CAD/CAM software developed for machining applications. In the paper an innovative monitoring and control approach, aimed to define and in-process update the most relevant process parameters during an industrial SPIF operation, is proposed. The strategy utilizes as monitoring variable the punch force trend: a set of preliminary tests demonstrated, in fact, its suitability as “spy variable” of the process m…
Computer-assisted orientation and drawing of archaeological pottery.
2018
Archaeologists spend considerable time orienting and drawing ceramic fragments by hand for documentation, to infer their manufacture, the nature of the discovery site and its chronology, and to develop hypotheses about commercial and cultural exchanges, social organisation, resource exploitation, and taphonomic processes. This study presents a survey of existing solutions to the time-consuming problem of orienting and drawing pottery fragments. Orientation is based on the 3D geometry of pottery models, which can now be acquired in minutes with low-cost 3D scanners. Several methods are presented: they are based on normal vectors, or circle fittings, or profile fittings. All these methods see…
Intelligent robotic cell for Trencad/spl inodot//spl acute/s mosaics manufacturing
2005
The purpose of this paper is the description of an application for the complete automation of a mosaics manufacturing process with irregular random pieces, so called trencad/spl inodot//spl acute/s. An intelligent robotic cell has been implemented by using intelligent methods and pattern recognition techniques to assemble unpredictable objects in an autonomous manner.
On the impact of within-die process variation in GALS-Based NoC Performance
2012
[EN] Current integration scales allow designing chip multiprocessors (CMP), where cores are interconnected by means of a network-on-chip (NoC). Unfortunately, the small feature size of current integration scales causes some unpredictability in manufactured devices because of process variation. In NoCs, variability may affect links and routers causing them not to match the parameters established at design time. In this paper, we first analyze the way that manufacturing deviations affect the components of a NoC by applying a new comprehensive and detailed within-die variability model to 200 instances of an 8¿8 mesh NoC synthesized using 45 nm technology. Later, we show that GALS-based NoCs pr…
Multi-objective optimization of nitinol stent design.
2017
Nitinol stents continuously experience loadings due to pulsatile pressure, thus a given stent design should possess an adequate fatigue strength and, at the same time, it should guarantee a sufficient vessel scaffolding. The present study proposes an optimization framework aiming at increasing the fatigue life reducing the maximum strut strain along the structure through a local modification of the strut profile.The adopted computational framework relies on nonlinear structural finite element analysis combined with a Multi Objective Genetic Algorithm, based on Kriging response surfaces. In particular, such an approach is used to investigate the design optimization of planar stent cell.The r…
THE METAMODEL: A STARTING POINT FOR DESIGN PROCESSES CONSTRUCTION
2010
The construction of ad-hoc design processes following the Situational Method Engineering (SME) paradigm is currently carried out by adopting a set of phases for which, until now, no well defined techniques and guidelines have been established. The consequence is that organizations are very dependent on method designers' skills. In this paper, we propose an approach based on SME for constructing customized agent oriented design processes. Our approach adopts the metamodel as the most important factor leading to the selection and assembly of method fragments and an algorithm for establishing the instantiation order of metamodel elements. The algorithm makes the proposed approach repeatable a…
Computer assisted techniques for the incremental forming technology
2013
The Asymmetric single point incremental forming (ASPIF) is a manufacturing technology with a high degree of novelty. Even if there are a significant number of research results reported in the literature, the industry has not been very enthusiastic to adopt and implement it on large scale. One of the main reasons for that is the lack of specific computer aided techniques and tools, which could be used to design and optimize the ASPIF process. The paper presents some methods to overcome this drawback, either by using some general purpose computer assisted tools or by developing new simple, yet effective methods. The proposed methods can be used in the preparation stage of computer automated m…
Innovative sheet metal forming processes: numerical simulations and experimental tests
2004
Abstract In this paper, computer aided engineering of some innovative sheet metal forming processes is reviewed. In particular, tube hydroforming processes and spinning processes are examined. Advanced numerical tools are utilized with the aim to design proper forming operations able to produce sound components. Furthermore, as far as the spinning process is concerned, experimental verifications are carried out to confirm the effectiveness of the numerical predictions.
Policy-based channel access mechanism selection for QoS provision in IEEE 802.11e
2007
The appearance of the 802.11e standard made the 802.11 wireless local area networks (WLANs) capable of providing different levels of quality of service (QoS). This standard defines two new channel access mechanisms (CAMs), namely the enhanced distributed channel access (EDCA) and the HCF controlled channel access (HCCA). The introduction of two CAMs increases the complexity of traffic management, since now not only the available resources have to be distributed, but also the optimal CAM for each data flow has to be selected. However, the best CAM selection algorithm is still not clear. This paper presents and analyses different CAM selection policies in order to derive the best-suited strat…
A comparative review of CASE shells: A preliminary framework and research outcomes
1993
Abstract Because of rigidity and weak support of the user's native methods and methodologies in existing CASE tools, there is a growing need for customizable CASE tools (CASE shells). The nature of CASE shells is different from ordinary CASE tools supporting a fixed set of methods. With CASE shells, organizations can define tools to support their own methods, instead of choosing a tool that supports them. Existing CASE shells have different features and architectural principles that make them appropriate for different tasks. Obviously, a framework for comparing them is needed. In this paper we develop one such framework. It takes into account different tasks in customization and the effecti…