32 research outputs found

    Anticipation in entrepreneurship

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    Entrepreneurship is a forward looking activity that embodies implicit imaginaries. If we remove the notion of a future from the field of entrepreneurship, field would cease to exist as its whole rationale is prospective. Entrepreneurship creates future value (Schumpeter 1934) through creative destruction; in uncertain contexts (Knight 1923) and with ‘alertness’ to opportunity (Kirzner 1982). Entrepreneurial opportunity em-braces anticipation as imaginative reason, strategically employed and motivated by aspiration. Entrepreneurial effectuation is concerned with the controllable aspects of an unpredictable future. Entrepreneuring is a process (Steyaert 2007) producing ontological emergence. Entrepreneurship is expressed in action and produces change. Nadin observes that anticipation relates to the perception of change (Nadin 2010) and is always expressed in action (Nadin 2015). Entrepreneurial identity is sig-nificant and the models embodied in an anticipatory system are what comprise its individuality; what distinguish it uniquely from other sys-tems. A change in these models is a change of identity (Rosen et al. 2012, p370). Entrepreneurship is relational and is coupled with other ac-tors in the environment, generating a sense of shared anticipation, or anticipatory coupling. Anticipatory coupling as a social phenomenon seems ripe for further research. Being emplaced, entrepreneuring practice involve sensing and anticipation (Antonacopoulou and Fuller 2019). Although anticipation is a natural activity, the effectiveness of anticipation can be improved through greater awareness in each of these sets of processes, among others. We suggest that the dynamics of emergence require anticipations of multiple forms of value. Seeing entrepreneurship from an anticipatory standpoint brings more to the fore the nature of values in practice. Further research can help reveal the anticipatory work is done in entrepreneurship to maintain the anticipatory capacity of the enterprise and of the interdependent relationships that maintain the enterprise

    Digital RFI suppression in DMT-based VDSL systems

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    In this paper, we propose a method for suppressing radio frequency interference (RFI) in discrete multitone (DMT) based very high bit rate digital subscriber line (VDSL) systems. The method operates in the frequency domain of a DMT system. First, we derive a model of how an unknown narrow-band RF signal is mapped onto the DMT carriers. Then, by measuring the RFI on a few unused DMT carriers we are able to subtract RFI estimates from every modulated subcarrier. Simulation results show. that this method, applied to an RFI signal with the same average power as the VDSL signal, suppresses the RFI with 40-50 dB, which reduces the average SNR loss from about 20 to less than 0.3 dB

    General packet induced queueing schemes for reducing packet delays in ADSL routers with peer-to-peer file sharing applications

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    [[abstract]]This paper proposes a class of queueing schemes named general packet induced queueing schemes (GPIQS) in ADSL routers to reduce the queueing delays of non-P2P packets. The objective of the proposed queueing schemes is to send out the general packets first as well as P2P packets are able to be sent in a bounded queueing delay. The proposed queueing schemes use the general packet to induce the transmission of P2P packets which are from the same client and arrived at the ADSL router before the general packet. The outbound order of the packets transmitted from a specific client is not altered in the proposed schemes. Two queueing schemes named general packet induced queueing scheme with single P2P queue (GPIQS-SQ) and general packet induced queueing scheme with multiple P2P queues (GPIQS-MQ) are proposed. The two proposed queueing schemes differ in the number of P2P queues. In order to prevent the unlimited waiting time of P2P packets, we introduced a variable called the largest number of preempting packets to send out the P2P packets in a bounded time. Simulation results show that the proposed queueing schemes may send out the packets from ADSL router efficiently and the average queueing delay is smaller than the common used first-come first-served algorithm. Specifically, the GPIQS-MQ performs better than the GPIQS-SQ method in terms of average queueing delay of non-P2P packets. We also found that the increased average queueing delay of P2P packets is small. Finally, the values of the largest number of preempting packets are discussed.[[notice]]補正完

    Error Sign Feedback as an Alternative to Pilots for the Tracking of FEXT Transfer Functions in Downstream VDSL

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    <p/> <p>With increasing bandwidths and decreasing loop lengths, crosstalk becomes the main impairment in VDSL systems. For downstream communication, crosstalk precompensation techniques have been designed to cope with this issue by using the collocation of the transmitters. These techniques naturally need an accurate estimation of the crosstalk channel impulse responses. We investigate the issue of tracking these channels. Due to the lack of coordination between the receivers, and because the amplitude levels of the remaining interference from crosstalk after precompensation are very low, blind estimation schemes are inefficient in this case. So some part of the upstream or downstream bit rate needs to be used to help the estimation. In this paper, we design a new algorithm to try to limit the bandwidth used for the estimation purpose by exploiting the collocation at the transmitter side. The principle is to use feedback from the receiver to the transmitter instead of using pilots in the downstream signal. It is justified by computing the Cramer-Rao lower bound on the estimation error variance and showing that, for the levels of power in consideration, and for a given bit rate used to help the estimation, this bound is effectively lower for the proposed scheme. A simple algorithm based on the maximum likelihood is proposed. Its performance is analyzed in detail and is compared to a classical scheme using pilot symbols. Finally, an improved but more complex version is proposed to approach the performance bound.</p
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