154 research outputs found
The application of the theory of dynamical systems in conceptual models of enrivonmental physics
Opportunity or threat? The impact of digitalization on co-producing and co-creating public services.
Planning and scheduling in the digital factory
Production planning and scheduling with the aid of software tools in today’s
manufacturing industries have become a common practice which is indispensable
for providing high level customer service, and at the same time to utilize the
production resources, like workforce, machine tools, raw materials, energy, etc.,
efficiently. To meet the new requirements, problem modeling tools, optimization
techniques, and visualization of data and results have become part of the software
packages. In this chapter some recent developments in problem modeling and optimization
techniques applied to important and challenging industrial planning and
scheduling problems are presented. We will focus on new problem areas which are
still at the edge of current theoretical research, but they are motivated by practical
needs. On the one hand, we will discuss project based production planning, and on
the other hand, we will tackle a resource leveling problems in a machine environment.
We will present the problems, some modeling and solution approaches, and
various extensions and applications
Inhomogeneities and caustics in the sedimentation of noninertial particles in incompressible flows
In an incompressible flow, fluid density remains invariant along fluid
element trajectories. This implies that the spatial distribution of
non-interacting noninertial particles in such flows cannot develop density
inhomogeneities beyond those that are already introduced in the initial
condition. However, in certain practical situations, density is measured or
accumulated on (hyper-) surfaces of dimensionality lower than the full
dimensionality of the flow in which the particles move. An example is the
observation of particle distributions sedimented on the floor of the ocean. In
such cases, even if the initial distribution of noninertial particles is
uniform within a finite support in an incompressible flow, advection in the
flow will give rise to inhomogeneities in the observed density. In this paper
we analytically derive, in the framework of an initially homogeneous particle
sheet sedimenting towards a bottom surface, the relationship between the
geometry of the flow and the emerging distribution. From a physical point of
view, we identify the two processes that generate inhomogeneities to be the
stretching within the sheet, and the projection of the deformed sheet onto the
target surface. We point out that an extreme form of inhomogeneity, caustics,
can develop for sheets. We exemplify our geometrical results with simulations
of particle advection in a simple kinematic flow, study the dependence on
various parameters involved, and illustrate that the basic mechanisms work
similarly if the initial (homogeneous) distribution occupies a more general
region of finite extension rather than a sheet.Comment: 56 pages, 17 figure
A vállalati informatika szerepe a versenykĂ©pessĂ©g alakĂtásában a pĂ©nzĂĽgyi Ă©s gazdasági válság idĹ‘szakában (Corporate IT in shaping the competitiveness of the Hungarian enterprises in the financial and economic crisis)
A cikk az informatika Ă©s a versenykĂ©pessĂ©g kapcsolatát vizsgálja. A Budapesti Corvinus Egyetem VersenykĂ©pessĂ©g Kutatási Programjának korábbi felmĂ©rĂ©sei Ăłta számos Ăşj technolĂłgia bukkant fel, illetve hazánkat is elĂ©rte a világmĂ©retű pĂ©nzĂĽgyi Ă©s gazdasági válság hatása. E kihĂvások tĂĽkrĂ©ben Ă©rdemesnek tűnt Ăşjra megvizsgálni az informáciĂłtechnolĂłgia (IT) szerepĂ©t a versenykĂ©pessĂ©g alakĂtásában. / === / In this paper the relationship between information technology (IT) and competitiveness is tackled. Since the authors’ previous surveys within their Competitiveness Research Program several new technologies have emerged, and the influence of the word wide financial and economic crisis has reached Hungary as well. In the face of these challenges it is worth reexamining the role of IT in shaping the competitive position of companies. The structure of the paper is as follows. A brief theoretical introduction is provided before their research questionsare presented. After that, the paper contains an analysis on selected fields of the corporate IT function, namely IT infrastructure, IT applications, IT management and IT strategy. Based on this, conclusions are made both at the end of the main parts, and in the final section of the paper. As far as the final conclusions are concerned, the majority of respondents do not regard IT today as a source of sustainable or contestable competitive advantage, though the dominant opinion underlines that IT is a strategic necessity. Besides this, their research results suggest a kind of association between corporate performance and the maturity level of the IT function. However, even the best performing companies are not prepared yet to effectively respond to their own prediction that forecasts the strengthening role of IT as a competitive factor
A társadalmi tekintĂ©ly szerepe az ĂtĂ©lkezĂ©sben – tradicionális keresztĂ©ny egyházak jogai Ă©s Ă©rdekei a magyar bĂrĂłságok elĹ‘tt
Car Sequencing with respect to Regular Expressions and Linear Bounds
In this paper we introduce a new model and a computational approach for sequencing
assembly lines with two types of constraints: (i) patterns described by regular expressions and
(ii) linear bounds on the number of certain products that may occur in pre-specified intervals.
If we restrict the problem to the second type of constraints only we obtain a generalization
of the familiar car sequencing problem, whereas constraints of type (i) may be useful to add
extra structure. Constraints of both types may have priorities and can be violated, and a Pareto
optimal solution is sought minimizing the violation of constraints in the given priority order. We
describe a computational method based on mathematical programming and genetic algorithms
for finding suboptimal solutions
Vállalati közösségi média – A személyközi hálózatok motorja
Napjainkban a szervezetek és személyek hálózatos összekapcsolódása a nemzetközi vezetéstudományi szakirodalom egyik legmeghatározóbb témája. A vállalati közösségi média – mint a hálózatosodást támogató technológia – meglehetősen
gyorsan vált nĂ©pszerűvĂ©, noha pontos tartalma mĂ©g formálĂłdik, Ă©s szervezeti hatásairĂłl is keveset tudunk. A szerzĹ‘k ismertetik a vállalati közössĂ©gi mĂ©dia fontosabb meghatározásait, majd áttekintik az elmĂşlt Ă©vek tĂ©mával foglalkozĂł nemzetközi szakirodalmát. Tanulmányukban a vállalati közössĂ©gi mĂ©diát a szemĂ©lyközi hálĂłzatok motorjakĂ©nt Ă©rtelmezik, amelynek működĂ©sĂ©t összevetik az offline tĂ©r hálĂłzataival. A szerzĹ‘k saját kvalitatĂv kutatásuk alapján ismertetik egy hazai tudásintenzĂv iparágban működĹ‘ szervezet vállalati közössĂ©gimĂ©dia-használatának legfontosabb szervezeti funkciĂłit
Scheduling of inventory releasing jobs to minimize a regular objective function of delivery times
In this note we provide new complexity and algorithmic results for scheduling inventory releasing jobs, a new class of single machine scheduling problems proposed recently by Boysen et al. We focus on tardiness related criteria, while known results are concerned with inventory levels between fixed delivery points. Our interest is motivated by the fact that deciding whether a feasible schedule exists is NP-hard in the strong sense, provided that all delivery deadlines are fixed, and there are no restrictions on the amount of products released by the jobs, nor on the job processing times. We will establish NP-hardness results, or provide polynomial or pseudo-polynomial time algorithms for various special cases, and describe a fully polynomial approximation scheme for one of the variants with the maximum tardiness criterion. © 2012 Springer Science+Business Media New York
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