10 resultados para CHALLENGES
em Greenwich Academic Literature Archive - UK
Resumo:
Today most of the IC and board designs are undertaken using two-dimensional graphics tools and rule checks. System-in-package is driving three-dimensional design concepts and this is posing a number of challenges for electronic design automation (EDA) software vendors. System-in-package requires three-dimensional EDA tools and design collaboration systems with appropriate manufacturing and assembly rules for these expanding technologies. Simulation and Analysis tools today focus on one aspect of the design requirement, for example, thermal, electrical or mechanical. System-in-Package requires analysis and simulation tools that can easily capture the complex three dimensional structures and provided integrated fast solutions to issues such as thermal management, reliability, electromagnetic interference, etc. This paper discusses some of the challenges faced by the design and analysis community in providing appropriate tools to engineers for System-in-Package design
Resumo:
Accurate representation of the coupled effects between turbulent fluid flow with a free surface, heat transfer, solidification, and mold deformation has been shown to be necessary for the realistic prediction of several defects in castings and also for determining the final crystalline structure. A core component of the computational modeling of casting processes involves mold filling, which is the most computationally intensive aspect of casting simulation at the continuum level. Considering the complex geometries involved in shape casting, the evolution of the free surface, gas entrapment, and the entrainment of oxide layers into the casting make this a very challenging task in every respect. Despite well over 30 years of effort in developing algorithms, this is by no means a closed subject. In this article, we will review the full range of computational methods used, from unstructured finite-element (FE) and finite-volume (FV) methods through fully structured and block-structured approaches utilizing the cut-cell family of techniques to capture the geometric complexity inherent in shape casting. This discussion will include the challenges of generating rapid solutions on high-performance parallel cluster technology and how mold filling links in with the full spectrum of physics involved in shape casting. Finally, some indications as to novel techniques emerging now that can address genuinely arbitrarily complex geometries are briefly outlined and their advantages and disadvantages are discussed.
Resumo:
Purpose – To present key challenges associated with the evolution of system-in-package technologies and present technical work in reliability modeling and embedded test that contributes to these challenges. Design/methodology/approach – Key challenges have been identified from the electronics and integrated MEMS industrial sectors. Solutions to optimising the reliability of a typical assembly process and reducing the cost of production test have been studied through simulation and modelling studies based on technology data released by NXP and in collaboration with EDA tool vendors Coventor and Flomerics. Findings – Characterised models that deliver special and material dependent reliability data that can be used to optimize robustness of SiP assemblies together with results that indicate relative contributions of various structural variables. An initial analytical model for solder ball reliability and a solution for embedding a low cost test for a capacitive RF-MEMS switch identified as an SiP component presenting a key test challenge. Research limitations/implications – Results will contribute to the further development of NXP wafer level system-in-package technology. Limitations are that feedback on the implementation of recommendations and the physical characterisation of the embedded test solution. Originality/value – Both the methodology and associated studies on the structural reliability of an industrial SiP technology are unique. The analytical model for solder ball life is new as is the embedded test solution for the RF-MEMS switch.
Resumo:
At present the vast majority of Computer-Aided- Engineering (CAE) analysis calculations for microelectronic and microsystems technologies are undertaken using software tools that focus on single aspects of the physics taking place. For example, the design engineer may use one code to predict the airflow and thermal behavior of an electronic package, then another code to predict the stress in solder joints, and then yet another code to predict electromagnetic radiation throughout the system. The reason for this focus of mesh-based codes on separate parts of the governing physics is essentially due to the numerical technologies used to solve the partial differential equations, combined with the subsequent heritage structure in the software codes. Using different software tools, that each requires model build and meshing, leads to a large investment in time, and hence cost, to undertake each of the simulations. During the last ten years there has been significant developments in the modelling community around multi- physics analysis. These developments are being followed by many of the code vendors who are now providing multi-physics capabilities in their software tools. This paper illustrates current capabilities of multi-physics technology and highlights some of the future challenges
Resumo:
While E-learning technologies are continuously developing, there are number of emerging issues and challenges that have significant impact on e-learning research and design. These include educational, technological, sociological, and psychological viewpoints. The extant literature points out that a large number of existing E-learning systems have problems with offering reusable, personalized and learner-centric content. While developers are placing emphasis on the technology aspects of e-learning, critical conceptual and pedagogical issues are often ignored. This paper will reports on our research in design and development of personalised e-learning systems and some of the challenges and issues faced.
Resumo:
This paper presents the challenges encountered in modelling biofluids in microchannels. In particular blood separation implemented in a T-microchannel device is analysed. Microfluids behave different from the counterparts in the microscale and a different approach has been adopted here to model them, which emphasize the roles of viscous forces, high shear rate performance and particle interaction in microscope. A T-microchannel design is numerically analysed by means of computational fluid dynamics (CFD) to investigate the effectiveness of blood separation based on the bifurcation law and other bio-physical effects. The simulation shows that the device can separate blood cells from plasma.
Resumo:
Future analysis tools that predict the behavior of electronic components, both during qualification testing and in-service lifetime assessment, will be very important in predicting product reliability and identifying when to undertake maintenance. This paper will discuss some of these techniques and illustrate these with examples. The paper will also discuss future challenges for these techniques.
Resumo:
Food insecurity, chronic hunger, starvation and malnutrition continue to affect millions of individuals throughout the developing world, especially Sub-Saharan Africa. Various initiatives by African governments and International Agencies such as the UN, the industrial nations, the International Monetary Fund, the World Bank and the World Trade Organisation to boost economic development, have failed to provide the much-needed solution to these challenges. The impact of these economic shifts and the failures of structural adjustment programmes on the nutritional well-being and health of the most vulnerable members of poor communities cannot be over-emphasised. The use of ad hoc measures as an adjunct to community-based rural integrated projects have provided little success and will be unsustainable unless they are linked to harnessing available local resources. The present paper therefore focuses on exploring alternative ways of harnessing the scant agricultural resources by employing a scientific approach to food-related problem-solving. The food multimix (FMM) concept offers a scientific contribution alongside other attempts currently in use by the World Food Programme, WHO and FAO to meet the food insecurity challenges that confront most of the developing world in the twenty-first century. It is an innovative approach that makes better use of traditional food sources as a tool for meeting community nutritional needs. The FMM concept employs a food-based approach using traditional methods of food preparation and locally-available, cheap and affordable staples (fruits, pulses, vegetables and legumes) in the formulation of nutrient-enriched multimixes. Developed recipes can provide >= 40% of the daily nutritional requirements of vulnerable groups, including patients with HIV/AIDS and children undergoing nutrition rehabilitation. The FMM approach can also be used as a medium- to long-term adjunct to community-based rural integration projects aimed at health improvement and economic empowerment in Sub-Saharan Africa.
Resumo:
Product knowledge support needs are compared in two companies with different production volumes and product complexity. Knowledge support requirements identified include: function, performance data, requirements data, common parts, regulatory guidelines and layout data. A process based data driven knowledge reuse method is evaluated in light of the identified product knowledge needs. The evaluation takes place through developing a pilot case with each company. It is found that the method provides more benefit to the high complexity design domain, in which a significant amount of work takes place at the conceptual design stages, relying on a conceptual product representation. There is not such a clear value proposition in a design environment whose main challenge is layout design and the application of standard parts and features. The method supports the requirement for conceptual product representation but does not fully support a standard parts library.
Resumo:
Investment treaties, and possibly the EU Treaty itself, are being used by multinational companies Penta and Eureko to try and force the Slovak government to pay compensation for reversing health privatisation and liberalisation policies. Similar action has been used against the Polish government by Eureko to win compensation worth nearly 2 billion Euros and a policy commitment to further privatisation.