967 resultados para Personal Time
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Information of crop phenology is essential for evaluating crop productivity. In a previous work, we determined phenological stages with remote sensing data using a dynamic system framework and an extended Kalman filter (EKF) approach. In this paper, we demonstrate that the particle filter is a more reliable method to infer any phenological stage compared to the EKF. The improvements achieved with this approach are discussed. In addition, this methodology enables the estimation of key cultivation dates, thus providing a practical product for many applications. The dates of some important stages, as the sowing date and the day when the crop reaches the panicle initiation stage, have been chosen to show the potential of this technique.
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This paper deals with the estimation of a time-invariant channel spectrum from its own nonuniform samples, assuming there is a bound on the channel’s delay spread. Except for this last assumption, this is the basic estimation problem in systems providing channel spectral samples. However, as shown in the paper, the delay spread bound leads us to view the spectrum as a band-limited signal, rather than the Fourier transform of a tapped delay line (TDL). Using this alternative model, a linear estimator is presented that approximately minimizes the expected root-mean-square (RMS) error for a deterministic channel. Its main advantage over the TDL is that it takes into account the spectrum’s smoothness (time width), thus providing a performance improvement. The proposed estimator is compared numerically with the maximum likelihood (ML) estimator based on a TDL model in pilot-assisted channel estimation (PACE) for OFDM.
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In this paper, a novel approach for exploiting multitemporal remote sensing data focused on real-time monitoring of agricultural crops is presented. The methodology is defined in a dynamical system context using state-space techniques, which enables the possibility of merging past temporal information with an update for each new acquisition. The dynamic system context allows us to exploit classical tools in this domain to perform the estimation of relevant variables. A general methodology is proposed, and a particular instance is defined in this study based on polarimetric radar data to track the phenological stages of a set of crops. A model generation from empirical data through principal component analysis is presented, and an extended Kalman filter is adapted to perform phenological stage estimation. Results employing quad-pol Radarsat-2 data over three different cereals are analyzed. The potential of this methodology to retrieve vegetation variables in real time is shown.
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In this study, a methodology based in a dynamical framework is proposed to incorporate additional sources of information to normalized difference vegetation index (NDVI) time series of agricultural observations for a phenological state estimation application. The proposed implementation is based on the particle filter (PF) scheme that is able to integrate multiple sources of data. Moreover, the dynamics-led design is able to conduct real-time (online) estimations, i.e., without requiring to wait until the end of the campaign. The evaluation of the algorithm is performed by estimating the phenological states over a set of rice fields in Seville (SW, Spain). A Landsat-5/7 NDVI series of images is complemented with two distinct sources of information: SAR images from the TerraSAR-X satellite and air temperature information from a ground-based station. An improvement in the overall estimation accuracy is obtained, especially when the time series of NDVI data is incomplete. Evaluations on the sensitivity to different development intervals and on the mitigation of discontinuities of the time series are also addressed in this work, demonstrating the benefits of this data fusion approach based on the dynamic systems.
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Competition law seeks to protect competition on the market as a means of enhancing consumer welfare and of ensuring an efficient allocation of resources. In order to be successful, therefore, competition authorities should be adequately equipped and have at their disposal all necessary enforcement tools. However, at the EU level the current enforcement system of competition rules allows only for the imposition of administrative fines by the European Commission to liable undertakings. The main objectives, in turn, of an enforcement policy based on financial penalties are two fold: to impose sanctions on infringing undertakings which reflect the seriousness of the violation, and to ensure that the risk of penalties will deter both the infringing undertakings (often referred to as 'specific deterrence') and other undertakings that may be considering anti-competitive activities from engaging in them (often referred to as 'general deterrence'). In all circumstances, it is important to ensure that pecuniary sanctions imposed on infringing undertakings are proportionate and not excessive. Although pecuniary sanctions against infringing undertakings are a crucial part of the arsenal needed to deter competition law violations, they may not be sufficient. One alternative option in that regard is the strategic use of sanctions against the individuals involved in, or responsible for, the infringements. Sanctions against individuals are documented to focus the minds of directors and employees to comply with competition rules as they themselves, in addition to the undertakings in which they are employed, are at risk of infringements. Individual criminal penalties, including custodial sanctions, have been in fact adopted by almost half of the EU Member States. This is a powerful tool but is also limited in scope and hard to implement in practice mostly due to the high standards of proof required and the political consensus that needs first to be built. Administrative sanctions for individuals, on the other hand, promise to deliver up to a certain extent the same beneficial results as criminal sanctions whilst at the same time their adoption is not likely to meet strong opposition and their implementation in practice can be both efficient and effective. Directors’ disqualification, in particular, provides a strong individual incentive for each member, or prospective member, of the Board as well as other senior executives, to take compliance with competition law seriously. It is a flexible and promising tool that if added to the arsenal of the European Commission could bring balance to the current sanctioning system and that, in turn, would in all likelihood make the enforcement of EU competition rules more effective. Therefore, it is submitted that a competition law regime in order to be effective should be able to deliver policy objectives through a variety of tools, not simply by imposing significant pecuniary sanctions to infringing undertakings. It is also clear that individual sanctions, mostly of an administrative nature, are likely to play an increasingly important role as they focus the minds of those in business who might otherwise be inclined to regard infringing the law as a matter of corporate risk rather than of personal risk. At the EU level, in particular, the adoption of directors’ disqualification promises to deliver more effective compliance and greater overall economic impact.
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Federal Highway Administration, Washington, D.C.
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Federal Highway Administration, Washington, D.C.
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Reprint. Originally published: New York : G.W. Carleton, 1867.
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Mode of access: Internet.
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Reprint. Originally published: Ionia, Mich. : Sentinel Print. Co., 1908.
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Reprint. Originally published: Philadelphia : Lippincott, 1888.
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A new United States (U.S.) self-supporting low-profile bednet was designed by Walter Reed Army Institute of Research in collaboration with Breakthrough Technologies. The bednet incorporated permethrin-impregnated screening into a frame that erected automatically when removed from its bag. The new U.S. bednet was compared with the current Australian Defense Force (ADF) mosquito bednet at Buka Island, North Solomons Province, Papua New Guinea, in March 1999. At the time of the test, Anopheles farauti Laveran was the most abundant biting mosquito. Both bednet types provided > 97.8% protection compared with an unprotected collector. The untreated U.S. Army prototype bednet provided better protection than the untreated ADF bednet against mosquitoes entering the bednet during the night.
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Supervision provides benefits for school counsellors and career counsellors such as support, an opportunity to gain new ideas and strategies, and personal and professional development. Despite this, studies have also shown that school counsellors perceive that the amount of time they participate in supervision is inadequate. In career counselling, there is little evidence that supervision has even been established as a mainstream professional practice. The reasons for this curious situation, whereby little time is spent on a potentially beneficial activity, are uncertain. The present study investigated the supervisory experiences of a group of school counsellors and career counsellors for a six month period following their completion of an intensive supervision training program. Participants recorded their supervisory experiences in a structured diary. Even though the participants were well informed about supervision, the findings of the present study are consistent with those of previous studies. This history of repeatedly similar findings suggests that it may be timely to ask some fundamental questions about supervision in these two professions. Such questions in turn suggest possible new research directions.
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Purpose - This paper aims to demonstrate the need for an improved understanding of the opportunities offered by privacy online. This is contextualized in the case of supermarket purchases of food in particular, often described as an intimate and personal choice. In the case of grocery shopping, the "intimacy" may be at the household level between members or/and between e-grocers' food offerings, and their other "non-food" related services Design/methodology/approach - This paper draws upon social practice theory research, retailing and consumer behaviour in order to develop a conceptual framework for understanding the value of positive privacy. The research uses 39 in-depth interviews of e-grocery shoppers in the area of Portsmouth (UK). Findings - This paper suggests a framework for embedded elements of positive privacy into retailing strategy as a driver for growth in the e-grocery sector. Three meta-themes requiring different approaches to privacy are uncovered. Positive privacy is dynamic and contextual at the consumer/household levels as well as for product/e-grocery brands. Research limitations/implications - This paper advocates the building of long-term sustainable relationship through sharing, offering, and exchange of information rather than pure technological chasing of data. Originality/value - A consumer centred bottom-up approach is employed demonstrating the value of two-way dialogues with consumers on sensitive issues. E-grocery is used as an illustration that involves regular re-purchase of a basket of staple goods over a long period of time where privacy becomes a latent long-term concern. © Emerald Group Publishing Limited.
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This thesis is concerned with the optimising of hearing protector selection. A computer model was used to estimate the reduction in noise exposure and risk of occupational deafness provided by the wearing of hearing protectors in industrial noise spectra. The model was used to show that low attenuation hearing protectors con provide greater protection than high attenuation protectors if the high attenuation protectors ore not worn for the total duration of noise exposure; or not used by a small proportion of the population. The model was also used to show that high attenuation protectors will not necessarily provide significantly greater reduction in risk than low attenuation protectors if the population has been exposed to the noise for many years prior to the provision of hearing protectors. The effects of earplugs and earmuffs on the localisation of sounds were studied to determine whether high attenuation earmuffs are likely to have greater potential than the lower attenuation earplugs for affecting personal safety. Laboratory studies and experiments at a foundry with normal-hearing office employees and noise-exposed foundrymen who had some experience of wearing hearing protectors showed that although earplugs reduced the ability of the wearer to determine the direction of warning sounds, earmuffs produced more total angular error and more confusions between left and right. !t is concluded from the research findings that the key to the selection of hearing protectors is to be found in the provision of hearing protectors that can be worn for a very high percentage of the exposure time by a high percentage of the exposed population with the minimum effect on the personal safety of the wearers - the attenuation provided by the protection should be adequate but not a maximum value.