855 research outputs found

    An empirical look at software patents

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    U.S. legal changes have made it easier to obtain patents on inventions that use software. Software patents have grown rapidly and now comprise 15 percent of all patents. They are acquired primarily by large manufacturing firms in industries known for strategic patenting; only 5 percent belong to software publishers. The very large increase in software patent propensity over time is not adequately explained by changes in R&D investments, employment of computer programmers, or productivity growth. The residual increase in patent propensity is consistent with a sizeable rise in the cost effectiveness of software patents during the 1990s. We find evidence that software patents substitute for R&D at the firm level; they are associated with lower R&D intensity. This result occurs primarily in industries known for strategic patenting and is difficult to reconcile with the traditional incentive theory of patentsPatents

    Calcium control of waveform in isolated flagellar axonemes of chlamydomonas

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    The effect of Ca(++) on the waveform of reactivated, isolated axonemes of chlamydomonas flagella was investigated. Flagella were detached and isolated by the dibucaine procedure and demembranated by treatment with the detergent Nonidet; the resulting axomenes lack the flagellar membrane and basal bodies. In Ca(++)-buffered reactivation solutions containing 10(-6) M or less free Ca(++), the axonemes beat with a highly asymmetrical, predominantly planar waveform that closely resembled that of in situ flagella of forward swimming cells. In solutions containing 10(-4) M Ca(++), the axonemes beat with a symmetrical waveform that was very similar to that of in situ flagella during backward swimming. In 10(-5) M Ca(++), the axonemes were predominantly quiescent, a state that appears to be closely associated with changes in axomenal waveform or direction of beat in many organisms. Experiments in which the concentrations of free Ca(++), not CaATP(--) complex were independently varied suggested that free Ca(++), not CaATP(--), was responsible for the observed changes. Analysis of the flagellar ATPases associated with the isolated axonemes and the nonidet- soluble membrane-matrix fraction obtained during preparation of the axonemes showed that the axonemes lacked the 3.0S Ca(++)-activated ATPase, almost all of which was recovered in the membrane-matrix fraction. These results indicate that free Ca(++) binds directly to an axonemal component to alter flagellar waveform, and that neither the 3.0S CaATPase nor the basal bodies are directly involved in this change

    The Software Patent Experiment

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    Over the past two decades, the scope of technologies that can be patented has been expanded to include many items previously thought unsuitable for patenting, for example, computer software. Today, the U.S. Patent and Trademark Office grants 20,000 or more software patents a year. Conventional wisdom holds that extending patent protection to computer programs will stimulate research and development and, thus, increase the rate of innovation. In this article, Bob Hunt and Jim Bessen investigate whether this has, in fact, happened. They describe the spectacular growth in software patenting, who obtains patents, and the relationship between a sharp focus on software patenting and firms\u27 investment in R&D

    An Empirical Look at Software Patents

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    U.S. legal changes have made it easier to obtain patents on inventions that use software. Software patents have grown rapidly and now comprise 15 percent of all patents. They are acquired primarily by large manufacturing firms in industries known for strategic patenting; only 5 percent belong to software publishers. The very large increase in software patent propensity over time is not adequately explained by changes in R&D investments, employment of computer programmers, or productivity growth. The residual increase in patent propensity is consistent with a sizeable rise in the cost effectiveness of software patents during the 1990s. We find evidence that software patents substitute for R&D at the firm level; they are associated with lower R&D intensity. This result occurs primarily in industries known for strategic patenting and is difficult to reconcile with the traditional incentive theory of patents

    A Lower Bound for Quantum Phase Estimation

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    We obtain a query lower bound for quantum algorithms solving the phase estimation problem. Our analysis generalizes existing lower bound approaches to the case where the oracle Q is given by controlled powers Q^p of Q, as it is for example in Shor's order finding algorithm. In this setting we will prove a log (1/epsilon) lower bound for the number of applications of Q^p1, Q^p2, ... This bound is tight due to a matching upper bound. We obtain the lower bound using a new technique based on frequency analysis.Comment: 7 pages, 1 figur

    How to measure patent thickets – a novel approach

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    The existing literature identifies patent thickets indirectly. In this paper we propose a novel measure based on patent citations which allows us to measure the density of patent thickets directly. We discuss the algorithm which generates the measure and present descriptive results validating it. Moreover, we identify technology areas which are particularly impacted by patent thickets
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