1,511 research outputs found
Non-local conservation laws and flow equations for supersymmetric integrable hierarchies
An infinite series of Grassmann-odd and Grassmann-even flow equations is
defined for a class of supersymmetric integrable hierarchies associated with
loop superalgebras. All these flows commute with the mutually commuting bosonic
ones originally considered to define these hierarchies and, hence, provide
extra fermionic and bosonic symmetries that include the built-in N=1
supersymmetry transformation. The corresponding non-local conserved quantities
are also constructed. As an example, the particular case of the principal
supersymmetric hierarchies associated with the affine superalgebras with a
fermionic simple root system is discussed in detail.Comment: 36 pages, LaTeX fil
Developing Competences Designed to Create Customer Value
This paper focuses on how small, specialized suppliers can gain competitive advantage by acting as a potential for their scale intensive producing customers in achieving competitive advantage. Of special interest is how a shared under-standing of ‘value’ for the customer is obtained, transferred and implemented in the specialized supplier’s production of process equipment. The study draws on theory on networks and specialized suppliers as well as interviews with key in-formants in three specialized supplier companies for the aluminum industry. An important finding is that the constellation of the specialized supplier’s network changes as the project moves from planning to production. With these changes, the role of specialized suppliers in the value creation process also changes. It seems to be an important competence for small, specialized supplier to be able to draw on and manage this network in their value creation process.
Performance of an Occam/transputer implementation of interval arithmetic
Rounded interval arithmetic is very easy to implement by means of directed rounding arithmetic operators. Such operators are available in the IEEE floating point arithmetic of the transputer. When a few small pieces of assembly language code are used to access the directed rounding operators, the four basic rounded interval arithmetic operators can easily be expressed in the programming language Occam.The performance of this implementation is assessed and it is shown that the time consuming part of the calculation are not the directed rounding floating point operations as one might have expected. Most of the time is spent with transport of operands to and from the on-chip floating point unit and the procedure call/parameter passing overhead. Based on this experience the implementation is improved. This implementation runs with 0.15 MIOPS (Million Interval Operations Per Second) or 0.30 MFLOPS on an example interval calculation proposed by Moore. Furthermore, it is demonstrated that an advanced interval language compiler may provide a performance of 0.30 MIOPS or 0.59 MFLOPS on this example calculation
The AAU Smart Production Laboratory for Teaching and Research in Emerging Digital Manufacturing Technologies
A Plug and Produce Framework for Industrial Collaborative Robots
Collaborative robots are today ever more interesting in response to the increasing need for agile manufacturing equipment. Contrary to traditional industrial robots, collaborative robots are intended for working in dynamic environments alongside the production staff. To cope with the dynamic environment and workflow, new configuration and control methods are needed compared to those of traditional industrial robots. The new methods should enable shop floor operators to reconfigure the robot. This article presents a plug and produce framework for industrial collaborative robots. The article focuses on the control framework enabling quick and easy exchange of hardware modules as an approach to achieving plug and produce. To solve this, an agent-based system is proposed building on top of the robot operating system. The framework enables robot operating system packages to be adapted into agents and thus supports the software sharing of the robot operating system community. A clear separation of the hardware agents and the higher level task control is achieved through standardization of the functional interface, a standardization maintaining the possibility of specialized function features. A feasibility study demonstrates the validity of the framework through a series of reconfigurations performed on a modular collaborative robot. </jats:p
An open boundary condition for application in numerical coastal models
Open boundaries (OBs) are usually unavoidable in numerical coastal circulation simulations. At OBs, appropriate open boundary conditions (OBCs) are required and a good OBC should be able to let outgoing waves freely pass to the exterior of a computational domain without creating reflections at the OBs. In the present study, a methodology has been developed to predict two parameters, phase speed c_r and decay time T_f, in a standard OBC formulation, so that the OBC is significantly improved compared to commonly used existing OBCs with specified c_r and T_f. For the conditions where wave period is unknown, the OBC with approximated c_r and T_f may be applied and a test reveals that this OBC is able to yield good results in typical coastal flow conditions. In addition, a Swing-Door Boundary Condition (SDBC) is proposed and tested for application at an offshore open boundary where both incoming and outgoing waves exist.Singapore-MIT Alliance for Research and Technology Cente
On the choice of random wave simulation in the surf zone processes
In this paper, the two common approaches to account for wave randomness, the spectral approach and the wave-by-wave approach, are compared through numerical experiments conducted with the coupling of a surf zone hydrodynamic model and a bedload sediment transport model. Special attention is paid to the wave nonlinearity and net cross-shore bedload transport predictions. The two approaches are found to have negligible difference in their predictions of certain average hydrodynamics, such as wave heights, set-up and undertow. However, the wave-by-wave approach outperforms the spectral approach in the wave nonlinearity prediction, and the two approaches differ significantly in their predictions of wave-induced net cross-shore bedload transport which strongly depends on wave nonlinearity. This suggests the necessity of using the wave-by-wave approach. The computational efficiency of the wave-by-wave approach is also discussed.Singapore-MIT Alliance. Center for Environmental Sensing and Monitorin
Whistleblowing and neoliberalism: Political resistance in late capitalist economy
The reigning global market ideology, frequently referred to as neoliberalism, inherently strives for fewer economic regulations in order to create greater wealth for humanity. Whistleblowing, on the other hand, is an action that aims at preserving the conditions and values of the greater common good. Therefore, economic considerations, and human and ethical considerations sometimes collide. In the present globalised economy where neoliberalism endeavours for fewer regulations, workers that oppose wrongdoing at work (i.e. whistleblowers) seem to hold a unique position inbetween governmental interference
and singularaction. Whistleblowers are neither sole state regulators nor grass root activists but attempt to effect change from within the organisation. This paper discusses ways in
which neoliberalism can influence the act of whistleblowing
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