Magnetic bearingsa new world opens for design engineers.docx

1、Magnetic bearings a new world opens for design engineersComputer Physics Communications, Volume 181, Issue 6, June 2010, Pages 1150-1160Benzhuo Lu, Xiaolin Cheng, Jingfang Huang, J. Andrew McCammonShow preview| Related articles|Related reference work articles Purchase$ 31.50489Service category-to-wa

2、velength selection technique for QoS support in connection-oriented optical packet switchingOriginal Research ArticleComputer Networks, Volume 51, Issue 1, 17 January 2007, Pages 14-30D. Careglio, J. Sol Pareta, S. SpadaroClose preview| Related articles|Related reference work articles AbstractAbstra

3、ct | Figures/TablesFigures/Tables | ReferencesReferences AbstractThis paper considers an optical packet-switched node subject to asynchronous, variable-length packets and connection-oriented operation. We firstly address the problem of setting up the optical virtual connections and properly configur

4、ing the forwarding table at the node. We do not deal with routing aspects, but with the efficient mapping of the virtual connections to the wavelengths of the output ports. In this context, we suggest a wavelength assignment procedure that improves the node performance in comparison with simple rand

5、om or balanced schemes. We then address the QoS provisioning problem. While existing solutions focus on applying some forms of resource reservation on top of the contention resolution algorithm, here we propose a method based on the well-known ATM scheme of defining different service categories. In

6、particular, we define a case study with three OPS service categories, and for each category a specific contention resolution algorithm is applied. With such a strategy the algorithms present the problem of a different performance alignment; we solve it by designing an ad hoc optical buffer architect

7、ure based on non-degenerate delays. The performance of the final node architecture is evaluated by simulation. The results obtained indicate the merits of this method, which opens up interesting future developments for a whole optical network scenario.Article Outline1. Introduction2. The WA problem

8、in connection-oriented OPS 2.1. Problem description2.2. The grouping wavelength assignment (GRP-WA) algorithm2.3. Performance evaluation3. QoS provisioning 3.1. Service category-to-wavelength selection technique3.2. Performance evaluation3.3. Ad hoc optical buffer architecture4. Summary and conclusi

9、onAcknowledgementsAppendix A. Simulation environmentReferencesVitaePurchase$ 31.50490The deployment of artificial reef ecosystem: Modelling, simulation and applicationOriginal Research ArticleSimulation Modelling Practice and Theory, Volume 14, Issue 5, July 2006, Pages 663-675Chun-Hsiung Lan, Che-Y

10、u HsuiClose preview| Related articles|Related reference work articles AbstractAbstract | Figures/TablesFigures/Tables | ReferencesReferences AbstractArtificial reefs (ARs) have been demonstrated to be a potential tool for the restoration of marine habitat and to retard the stress of coral reefs in r

11、ecent decades. For most engineers, the deployment of an artificial reef ecosystem (ARE) is based on their experience, but what is the effective deployment to produce the higher abundance and to enrich biomass under the finite budget is seldom mentioned. In fact, how to deploy artificial reefs into t

12、he selected site and construct an effective ARE is the most challenge to ecological engineers. The main objective of this research is to construct a mathematical model called the deployment of artificial reef communities (DARCs) model, and then to provide a concrete approach for deploying an ARE und

13、er the finite budget. The constructing spirit of DARCs model is based on the observations of biologists that a higher complexity of habitat system will increase the species diversity and biomass. The fractal dimension (FD) is applied as an assessing indicator for the habitat system complexity of ARE

14、 in this study. In addition, a step-by-step algorithm for achieving the maximal fractal dimension of an ARE through the determinations of the number of deployed artificial reef communities (ARCs), the distance of adjacent ARCs, and the spatial configuration of ARCs in an ARE is presented. A computer

15、ized tool written by Fortran program to conduct the design of an ARE as well as perform the simulated analyses is completely proposed, and a case study is followed. The simulation-based analyses of changing budget reveal that the FD of a given region will be constrained regardless of increasing budg

16、et. This phenomenon shows that the more deployment of ARCs may lead to waste capital. Finally, a decision support system called DSSforARE is established for the quick-design of an AR ecosystem under the consideration of conservation policy.Article OutlineNomenclature1. Introduction2. Assumptions3. M

17、odel construction4. A step-by-step algorithm5. A case study6. Simulated analyses7. Decision support system8. ConclusionAcknowledgementsAppendix A. AppendixReferencesPurchase$ 31.50491Non-linear aeroelastic prediction for aircraft applicationsReview ArticleProgress in Aerospace Sciences, Volume 43, I

18、ssues 4-6, May-August 2007, Pages 65-137M.J. de C. Henshaw, K.J. Badcock, G.A. Vio, C.B. Allen, J. Chamberlain, I. Kaynes, G. Dimitriadis, J.E. Cooper, M.A. Woodgate, A.M. Rampurawala, D. Jones, C. Fenwick, A.L. Gaitonde, N.V. Taylor, D.S. Amor, T.A. Eccles, C.J. DenleyClose preview| Related article

19、s|Related reference work articles AbstractAbstract | Figures/TablesFigures/Tables | ReferencesReferences AbstractCurrent industrial practice for the prediction and analysis of flutter relies heavily on linear methods and this has led to overly conservative design and envelope restrictions for aircra

20、ft. Although the methods have served the industry well, it is clear that for a number of reasons the inclusion of non-linearity in the mathematical and computational aeroelastic prediction tools is highly desirable. The increase in available and affordable computational resources, together with majo

21、r advances in algorithms, mean that non-linear aeroelastic tools are now viable within the aircraft design and qualification environment. The Partnership for Unsteady Methods in Aerodynamics (PUMA) Defence and Aerospace Research Partnership (DARP) was sponsored in 2002 to conduct research into non-l

22、inear aeroelastic prediction methods and an academic, industry, and government consortium collaborated to address the following objectives: (1) To develop useable methodologies to model and predict non-linear aeroelastic behaviour of complete aircraft. (2) To evaluate the methodologies on real aircr

23、aft problems. (3) To investigate the effect of non-linearities on aeroelastic behaviour and to determine which have the greatest effect on the flutter qualification process.These aims have been very effectively met during the course of the programme and the research outputs include: (a) New methods

24、available to industry for use in the flutter prediction process, together with the appropriate coaching of industry engineers. (b) Interesting results in both linear and non-linear aeroelastics, with comprehensive comparison of methods and approaches for challenging problems. (c) Additional embryoni

25、c techniques that, with further research, will further improve aeroelastics capability.This paper describes the methods that have been developed and how they are deployable within the industrial environment. We present a thorough review of the PUMA aeroelastics programme together with a comprehensiv

26、e review of the relevant research in this domain. This is set within the context of a generic industrial process and the requirements of UK and US aeroelastic qualification. A range of test cases, from simple small DOF cases to full aircraft, have been used to evaluate and validate the non-linear me

27、thods developed and to make comparison with the linear methods in everyday use. These have focused mainly on aerodynamic non-linearity, although some results for structural non-linearity are also presented. The challenges associated with time domain (coupled computational fluid dynamicscomputational

28、 structural model (CFDCSM) methods have been addressed through the development of grid movement, fluidstructure coupling, and control surface movement technologies. Conclusions regarding the accuracy and computational cost of these are presented. The computational cost of time-domain methods, despit

29、e substantial improvements in efficiency, remains high. However, significant advances have been made in reduced order methods, that allow non-linear behaviour to be modelled, but at a cost comparable with that of the regular linear methods. Of particular note is a method based on Hopf bifurcation th

30、at has reached an appropriate maturity for deployment on real aircraft configurations, though only limited results are presented herein. Results are also presented for dynamically linearised CFD approaches that hold out the possibility of non-linear results at a fraction of the cost of time coupled

31、CFDCSM methods. Local linearisation approaches (higher order harmonic balance and continuation method) are also presented; these have the advantage that no prior assumption of the nature of the aeroelastic instability is required, but currently these methods are limited to low DOF problems and it is

32、 thought that these will not reach a level of maturity appropriate to real aircraft problems for some years to come. Nevertheless, guidance on the most likely approaches has been derived and this forms the basis for ongoing research. It is important to recognise that the aeroelastic design and qualification requires a variety of methods applicable at different stages of the process. The methods reported herein are ma