Search results for " Applications"
showing 10 items of 4541 documents
Turbulence model effect on heat exchange characteristics through the neutron beam window for European spallation source
2011
PurposeThe purpose of this paper is to compare k‐ω shear‐stress transport (SST) and large eddy simulation (LES) turbulence model application effect on numerical computation of flow pattern and heat exchange characteristics through the neutron beam window region for European spallation source setup model.Design/methodology/approachTransient hydrodynamic and thermal calculations with appropriate heat sources are performed using both turbulence models and typical discrepancies in flow and thermal patterns are discussed, as well as, simulation results are qualitatively compared with experimental data for heat transfer coefficient distribution α at the window surface.FindingsContribution of grea…
Semiactive vibration control of nonlinear structures through adaptive backstepping techniques withH∞performance
2011
This article presents a new approach to the vibration mitigation problem in structures subject to seismic motions. These kinds of structures are characterised by the uncertainties of the parameters that describe their dynamics, such as stiffness and damping coefficients. Moreover, the dampers used to mitigate the vibrations caused by earthquakes are usually nonlinear devices with frictional or hysteretic dynamics. We propose an adaptive backstepping controller to account for the uncertainties and the nonlinearities. The controller is formulated in such a way that it satisfies an H∞ performance. It is designed for a 10-storey building whose base is isolated with a frictional damper (passive …
Past, Present and Future of Process Control at Xstrata Nikkelverk
2009
MIC celebrates its 30th anniversary in 2009 and Xstrata Nikkelverk celebrates its 100th anniversary in 2010. Both anniversaries are certainly worth celebrating and with this article Xstrata Nikkelverk salutes MIC at this special occasion. This article is about process control developments at Xstrata Nikkelverk during the last 40 years. We also give an overview of the current status and a view on the current and future trends of process control at the Nikkelverk renery.
daptive Backstepping Control of Nonlinear Hydraulic-Mechanical System Including Valve Dynamics
2010
Published version of an article from the journal: Modeling Identification and Control. Also available from publisher: http://dx.doi.org/10.4173/mic.2010.1.3 The main contribution of the paper is the development of an adaptive backstepping controller for a nonlinear hydraulic-mechanical system considering valve dynamics. The paper also compares the performance of two variants of an adaptive backstepping tracking controller with a simple PI controller. The results show that the backstepping controller considering valve dynamics achieves significantly better tracking performance than the PI controller, while handling uncertain parameters related to internal leakage, friction, the orifice equat…
A novel fuel cell-based power system modeling approach
2013
Nowadays, fuel cells are the most promising source of energy for stationary applications. Unfortunately, the power density of fuel cells is not adequate for modern applications. A fuel cell - based hybrid power supply is required. The fuel cell is coupled with a high-energy density power source to improve performances of the composite power source. A power management stage is introduced between the two basic sources to control the power flow path from the fuel cell to the auxiliary source and the load. In order to avoid effects of a limited power density of the fuel cell on the whole power supply, sophisticated power management algorithms are implemented. Accurate modeling is required to te…
Robust energy-to-peak sideslip angle estimation with applications to ground vehicles
2015
Abstract In this paper, the observer design problem for the sideslip angle of ground vehicles is investigated. The sideslip angle is an important signal for the vehicle lateral stability, which is not measurable by using an affordable physical sensor. Therefore, we aim to estimate the sideslip angle with the yaw rate measurements by employing the vehicle dynamics. The nonlinear lateral dynamics is modeled firstly. As the tyre model is nonlinear and the road adhesive coefficient is subject to a large variation, the nonlinear lateral dynamics is transformed into an uncertain model. Considering the variation of longitudinal velocity, an uncertain linear-parameter-varying (LPV) system is obtain…
Lean design improves both health-care facilities and processes: a literature review
2014
This article presents a literature review of the challenges and possibilities for Lean design in modern health-care facilities. Many of today's health-care facilities are in dire need of renovation since limited financial resources among health-care demand improved work process efficiency, safety and employee well-being. Lean philosophy has been successfully implemented into hospitals with up-and-running hospital processes, but has not been thoroughly tested as a design methodology. The principles of Lean do not contradict with user-centric, participatory or ergonomic design approaches and thus the possibilities of using Lean as a complementary design methodology to the aforementioned appro…
Reconfigurable control of robotized manufacturing cells
2007
This paper investigates the field of manufacturing system control. The addressed subject is indeed very fascinating, due to the importance that it has reached in the last decades both at research and industrial level. On the other hand, it seems to the author that most of the complexity intrinsic to the subject itself relies on the different meanings or levels of abstraction that both the terms ''manufacturing system'' and ''control'' may symbolize. The presented research aims to face the topic in a concrete fashion, i.e., by developing a control software system for a specific, although easy to be generalized, robotized manufacturing cell. Two different development methodologies, from the c…
In Search of Evidence for Model-Driven Development Claims: An Experiment on Quality, Effort, Productivity and Satisfaction
2015
Context: Model-Driven Development (MDD) is a paradigm that prescribes building conceptual models that abstractly represent the system and generating code from these models through transformation rules. The literature is rife with claims about the benefits of MDD, but they are hardly supported by evidences. Objective: This experimental investigation aims to verify some of the most cited benefits of MDD. Method: We run an experiment on a small set of classes using student subjects to compare the quality, effort, productivity and satisfaction of traditional development and MDD. The experiment participants built two web applications from scratch, one where the developers implement the code by h…
The harp: a vehicle crash test apparatus for full-scale crash test experiments
2012
Published version of an article in the journal: The International Journal of Advanced Manufacturing Technology. Also available from the publisher at: http://dx.doi.org/10.1007/s00170-012-3960-3 The current paper describes an apparatus for full-scale vehicle crash test experimentation. This apparatus is referred to as the harp. In brief, the harp may either accelerate a trolley which is impacted into a test vehicle or the test vehicle itself may be accelerated and impacted into an object such as a barrier, a pole, or another vehicle. If a trolley is accelerated, it is equipped with load cells to record the axial crushing force. If a test vehicle is accelerated, it is equipped with a three-ax…