15,115 research outputs found

    The evolution of patent functions: New trends, main challenges and implications for firm strategy

    Get PDF
    Recent publications in the field of Intellectual Property (IP) have shown that the previous literature did not grasp how complex patents are. The goal of this paper is to present an overview of all identified functions of patents and of the main strategic implications of such a complex picture. We first survey the main patent functions : innovation protection, functions related to trade and finance, defensive roles, and patent as an input in the innovation process. We then define each function and analyse their main evolution trends in relation with the current environment. We finally identify the strategic implications of each function. We focus on the implications of the newly identified functions and on the interaction between the different functions.Patent ; Intellectual Property ; Strategic Management ; Functions ; Motives to patent

    Existence of Solutions in Continuous-time Optimal Growth Models

    Get PDF
    This paper studies the existence of solutions in continuous time optimization problems. It provides a theorem whose conditions can be easily checked in most models of the optimal growth theory, including those with increasing returns and multi-sector economies.optimization;continuous time;optimal growth

    Exact renormalization group and applications to disordered problems: part I

    Full text link
    We develop a systematic multi-local expansion of the Polchinski-Wilson exact renormalization group (ERG) equation. Integrating out explicitly the non local interactions, we reduce the ERG equation obeyed by the full interaction functional to a flow equation for a function, its local part. This is done perturbatively around fixed points, but exactly to any given order in the local part. It is thus controlled, at variance with projection methods, e.g. derivative expansions or local potential approximations. Our method is well-suited to problems such as the pinning of disordered elastic systems, previously described via functional renormalization group (FRG) approach based on a hard cutoff scheme. Since it involves arbitrary cutoff functions, we explicitly verify universality to O(ϵ=4D){\cal O} (\epsilon =4-D), both of the T=0 FRG equation and of correlations. Extension to finite temperature TT yields the finite size (LL) susceptibility fluctuations characterizing mesoscopic behaviour (Δχ)2ˉLθ/T\bar{(\Delta \chi)^2} \sim L^\theta/T, where θ\theta is the energy exponent. Finally, we obtain the universal scaling function to O(ϵ1/3){\cal O}(\epsilon^{1/3}) which describes the ground state of a domain wall in a random field confined by a field gradient, compare with exact results and variational method. Explicit two loop exact RG equations are derived and the application to the FRG problem is sketched.Comment: 43 pages, 6 figures, LaTe

    Practical identification key for 14 Rubiaceae weed species of western and central Africa

    Full text link
    Des adventices de la famille des rubiacées ont été identifiées en Afrique de l'Ouest et du Centre. Une clé de détermination comprend 8 caractères de l'appareil végétatif. Le tableau de ces critères, la démarche de la clé sont présentés, sans faire appel à une description complète des plante

    AFROweeds: a collaborative and participative online network to enhance weed capacities in Africa

    Full text link
    Weed competition cause high yield losses in African crop production systems. Conservative estimates show that even for rice alone weeds cost economies of sub-Saharan Africa (SSA) already a near $1.5 billion per year. For subsistence farmers in SSA there is only a limited range of affordable and effective control strategies. Due to the diversity of weed species, the complexity of crop – weed ecology and associated environmental and management interactions, as well as the socio-economic constraints of subsistence farming in Africa, few effective weed control strategies are developed so far. Moreover, even the limited number of control strategies, or component technologies currently available face limited dissemination and adoption among the (rice) farmer communities in SSA. The above described situation is largely the result of the sub-optimal capacities of agricultural research and development (R&D) organizations in SSA. The region has an extremely low ratio of trained weed scientists per farmer. Conversely, in the absence of weed scientists, students, R&D professionals or farmers looking for information on weeds, reliable, comprehensive and comprehensible sources are scant and scattered. The EU-ACP funded Afroweeds is an initiative of CIRAD and Africa Rice Center (AfricaRice) to link European and African botanists and weed scientists with the objective to enhance the regional capacities in these fields of expertise. Afroweeds is a network for professionals and students aimed at sharing knowledge on rice weeds. The modes operandi of Afroweeds is an open-access website (http://www.afroweeds.org/network). This online platform enables members to exchange information, discuss relevant issues and to access an increasingly extensive library of information and photos on weed species and management. The most eye-catching features of the Afroweeds collaborative platform are the extremely user-friendly weed species identification tools. They encompass image recognition software and a multiple-choice program (called 'plant robot') using schematic drawings of plant organs (e.g. leaves, flowers). Identification results can be cross-checked with a rich gallery of photos of fieldgrowing or herbarium specimen and information on ecology and biology, while the Afroweeds data base can also be consulted for effective management options. The strength of the Afroweeds collaborative site further lies in the fact that information and concerns can easily be shared with the other members of community for feed-back. By facilitating such exchange between actors who are otherwise isolated from each other, Afroweeds contributes towards spreading and enhancing knowledge on rice weeds and best weed management practices to improve the productivity of African rice-based cropping systems. (Texte intégral

    Atollscape: Simulating freshwater management in Pacific Atolls. Spatial processes and time dependence issues

    Full text link
    Groundwater has long been ranked as a high priority research area by small island nations in the Pacific. It is the major source of freshwater on the atoll of Tarawa (Rep.of Kiribati) and its availability, quality, management and allocation are central to the atoll¿s sustainable development and poverty alleviation. From a modeling perspective, simulating freshwater lens behavior represents a challenge, as it requires sophisticated numerical models. Such models can hardly fit within an integrated management framework taking into account spatially distributed water use (e.g. wells, trees) and social interactions. Simple analytical solutions exist but they apply for steady-state conditions, verified only on an annual basis. Recent advances in the field of Distributed Artificial Intelligence have permitted the development of a Multi Agent System (MAS) approach, closely related to the problem of complexity. AtollScape uses MAS techniques to simulate water management and freshwater lens behavior on the Tarawa atoll. A distributed and nested structure is used to represent local inputs and uptakes, along with freshwater lens adjustments on a 10 day time steps. (Résumé d'auteur
    corecore