5,900 research outputs found

    The Euclidean Algorithm for Generalized Minimum Distance Decoding of Reed-Solomon Codes

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    This paper presents a method to merge Generalized Minimum Distance decoding of Reed-Solomon codes with the extended Euclidean algorithm. By merge, we mean that the steps taken to perform the Generalized Minimum Distance decoding are similar to those performed by the extended Euclidean algorithm. The resulting algorithm has a complexity of O(n^2)

    Revisiting leadership development:the participant perspective

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    Purpose – The purpose of this paper is to address limitations of prevailing approaches to leadership development programmes and make suggestions as to how these might be overcome. These limitations are an outcome of the dominant rational functional approach to leadership development programmes. Based on empirical research, and underpinned by organisational theory, the paper suggests a shift towards a socio-constructivist perspective on design and implementation of leadership development programmes. The explorative study proposes that context and participant differences need to be recognised as factors impacting on the effectiveness of leadership development initiatives. Design/methodology/approach – The paper is based on a review of relevant literature and qualitative data collected using the case study method. The study presented is explorative. Findings – The paper finds that participant interaction with leadership development programmes varies depending on individual and/or contextual factors. Current design logic neither recognises nor utilises such situatedness as programmes develop their linear and unidirectional logic. Designers of programmes underestimate the extent to which programme participants create a context-specific understanding of leadership learning as they interact with the programme. Their personal and organisational context shapes this interaction. A socio-constructivist perspective can provide theoretical foundation for the argument that leadership development programmes can become more effective if context-specific dimensions are recognised as shaping and constraining factors impacting on programme participants. Originality/value – The paper argues that it is time to move away from offering leadership development programmes which emphasise input over interaction. The paper encourages commissioners and designers of leadership programmes to recognise that an overly didactic approach may limit the effectiveness of such programmes

    Empirical Regularities in Distributions of Individual Consumption Expenditure

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    We empirically investigate distributions of individual consumption expenditure f or four commodity categories conditional on fixed income levels. The data stems from the Family Expenditure Survey carried out annually in the United Kingdom. W e use graphical techniques to test for normality and lognormality of these distributions. While mainstream economic theory does not predict any structure for these distributions, we find that in at least three commodity categories individual consumption expenditure conditional on a fixed income level is lognormally distributed.Comment: 9 pages including figures; for Int. J. Mod. Phys. C 13, No.

    Auswirkungen der Einbringung von Buche (Fagus sylvatica L.) auf die ArtendiversitÀt und NaturnÀhe von NadelholzbestÀnden in Niedersachsen

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    The promotion and extension of continuous cover mixed stands with a simultaneous reduction of conifer-monocultures play a major role in current silvicultural practices in Central Europe. It is assumed that the admixture of the natural dominant beech (Fagus sylvatica) in pure non site-specific conifer stands automatically indicates better conditions in terms of nature conservation and forest management. To test this hypothesis three different conifer-beech-comparisons of pure and mixed stands in Lower Saxony are studied, analyzing plant species diversity and naturalness of understory vegetation as one important indicator for the ecological status of forests. Each comparison includes pure coniferous stands (Picea abies, Pinus sylvestris, Pseudotsuga menziesii), mixed coniferous-beech-stands, and pure beech stands on similar acidic mineral soils where the potential natural vegetation will be an oligotrophic beech forest (L u z u l o - Fa g e t um). The age of stands varies between 50 and 150 years. To specify tree species influence on site conditions and vegetation, the study also includes light climate and soil data of the stands. It is observed that, with regard to all comparisons, the admixture of beech reduces plant species diversity but increases naturalness of the stands. The intensity of beech admixture effects differs. While in Scots pine stands the impact of admixed beech is very noticeable, with the mixed stands being nearly identical with pure beech stands, the species change in Douglas-fir and Norway spruce stands proceeds more slowly. Assuming that the status in nature conservation and forest management is improving with increasing plant species diversity and increasing naturalness, the results of this study show a contrary development on a stand scale, as the potential natural vegetation of the L u z u l o - F a g e t u m is in its self very species poor on vascular plants.Die Förderung und Ausweitung von MischwĂ€ldern bei gleichzeitiger Reduktion reiner Nadelholz-BestĂ€nde spielt aktuell eine große Rolle im mitteleuropĂ€ischen Waldbau. Gemeinhin wird angenommen, dass die Beimischung der standortsgemĂ€ĂŸen Buche (Fagus sylvatica) in standortsfremden Nadelholz Monokulturen die Bedingungen im Sinne des Naturschutzes und der Forstwirtschaft verbessert. Diese Hypothese wird auf der Grundlage von drei unterschiedlichen Nadelholz- Buchen-Versuchsreihen geprĂŒft. Im Mittelpunkt steht dabei die Bodenvegetation als wichtiger und sensitiver Indikator fĂŒr den ökologischen Zustand von WĂ€ldern. Jede Versuchsreihe umfasst reine Nadelholz-BestĂ€nde (Picea abies, Pinus sylvestris, Pseudotsuga menziesii), Nadelholz-Buchen- MischbestĂ€nde und reine Buchen-BestĂ€nde auf sauren Mineralböden, auf denen von Natur aus nĂ€hrstoffarme BuchenwĂ€lder (L u z u l o - Fa g e t um) vorherrschen wĂŒrden. Das Alter der BestĂ€nde variiert zwischen 50 und 150 Jahren. Schwerpunkte der Analyse sind die Artenvielfalt und NaturnĂ€he der Bodenvegetation. Um den Einfluss der Baumarten auf den Standort und die Vegetation zu bewerten, werden die Licht- und BodenverhĂ€ltnisse der BestĂ€nde charakterisiert. Es zeigt sich, dass mit der Beimischung der Buche in allen Versuchsreihen die Pflanzenartenvielfalt abnimmt und die NaturnĂ€he zunimmt. Unterschiedlich ist dabei die IntensitĂ€t der VerĂ€nderungen. Zwischen den Kiefern-Buchen-MischbestĂ€nden und den Kiefern-ReinbestĂ€nden bestehen sehr deutliche Unterschiede im Aufbau der Bodenvegetation, so dass die MischbestĂ€nde den Buchen-ReinbestĂ€nden bereits sehr Ă€hnlich sind. In den Douglasien- und Fichten-Versuchsreihen vollzieht sich der Artenwechsel vergleichsweise unauffĂ€llig und kontinuierlich. Wenn man davon ausgeht, dass der naturschutzfachliche und waldbauliche Status sich sowohl mit zunehmender PhytodiversitĂ€t als auch bei zunehmender NaturnĂ€he verbessert, so zeigen diese Ergebnisse auf Bestandesebene eine gegenlĂ€ufige Entwicklung, da das in der Region der potenziell natĂŒrlichen Vegetation entsprechende L u z u l o - Fa g e tum von Natur aus sehr artenarm an GefĂ€ĂŸpflanzen ist

    A Percolation-Based Model Explaining Delayed Take-Off in New-Product Diffusion

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    A model of new-product diffusion is proposed in which a site-percolation dynamics represents socially-driven diffusion of knowledge about the product's characteristics in a population of potential buyers. A consumer buys the new product if her valuation of it is not below the price of the product announced by the firm in a given period. Our model attributes the empirical finding of a delayed ``take-off'' of a new product to a drift of the percolation dynamics from a non-percolating regime to a percolating regime. This drift is caused by learning-effects lowering the price of the product, or by network-effects increasing its valuation by consumers, with an increasing number of buyers.new-product diffusion, innovation adoption, spatial stochastic processes, percolation
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