993 resultados para Theory of Natural Selection


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The basic premise of transaction-cost theory is that the decision to outsource, rather than to undertake work in-house, is determined by the relative costs incurred in each of these forms of economic organization. In construction the "make or buy" decision invariably leads to a contract. Reducing the costs of entering into a contractual relationship (transaction costs) raises the value of production and is therefore desirable. Commonly applied methods of contractor selection may not minimise the costs of contracting. Research evidence suggests that although competitive tendering typically results in the lowest bidder winning the contract this may not represent the lowest project cost after completion. Multi-parameter and quantitative models for contractor selection have been developed to identify the best (or least risky) among bidders. A major area in which research is still needed is in investigating the impact of different methods of contractor selection on the costs of entering into a contract and the decision to outsource.

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Supplier selection has a great impact on supply chain management. The quality of supplier selection also affects profitability of organisations which work in the supply chain. As suppliers can provide variety of services and customers demand higher quality of service provision, the organisation is facing challenges for making the right choice of supplier for the right needs. The existing methods for supplier selection, such as data envelopment analysis (DEA) and analytical hierarchy process (AHP) can automatically perform selection of competitive suppliers and further decide winning supplier(s). However, these methods are not capable of determining the right selection criteria which should be derived from the business strategy. An ontology model described in this paper integrates the strengths of DEA and AHP with new mechanisms which ensure the right supplier to be selected by the right criteria for the right customer's needs.

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A research has been conducted over methodological issues concerning the Theory of Planned Behaviour (TPB) by determining an appropriate measurement (direct and indirect) of constructs and selection of a plausible scaling techniques (unipolar and bipolar) of constructs: attitude, subjective norm, perceived behavioural control and intention that are important in explaining farm level tree planting in Pakistan. Unipolar scoring of beliefs showed higher correlation among the constructs of TPB than bipolar scaling technique. Both direct and indirect methods yielded significant results in explaining intention to perform farm forestry except the belief based measure of perceived behavioural control, which were analysed as statistically non-significant. A need to examine more carefully the scoring of perceived behavioural control (PBC) has been expressed

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This article reassesses 'Natural Selection as affecting Civilised Nations': a thirteen-page section in the first volume of The Descent of Man (1871) often assumed to be problematic for those who wish to emphasize Darwin's liberal credentials. For hismost virulent critics the section connects Darwin to eugenics and the Nazi Holocaust. Even his admirers tend to view it as symptomatic of Darwin succumbing to a more conservative politics. This article demonstrates, through a delineation of the intellectual context and a close reading of key passages, that in fact 'Natural Selection as affecting Civilised Nations' confirmed, rather than abandoned, Darwin's liberalism.

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Knowledge spillover theory of entrepreneurship and the prevailing theory of economic growth treat opportunities as endogenous and generally focus on opportunity recognition by entrepreneurs. New knowledge created endogenously results in knowledge spillovers enabling inventors and entrepreneurs to commercialize it. This article discusses that knowledge spillover entrepreneurship depends not only on ordinary human capital, but more importantly also on creativity embodied in creative individuals and diverse urban environments that attract creative classes. This might result in self-selection of creative individuals into entrepreneurship or enable entrepreneurs to recognize creativity and commercialize it. This creativity theory of knowledge spillover entrepreneurship is tested utilizing data on European cities.

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A highly performing natural rubber/silica (NR/SiO2) nanocomposite with a SiO2 loading of 2 wt% was prepared by combining similar dissolve mutually theory with latex compounding techniques. Before polymerization, double bonds were introduced onto the surface of the SiO2 particles with the silane-coupling agent. The core-shell structure silica-poly(methyl methacrylate), SiO2-PMMA, nanoparticles were formed by grafting polymerization of MMA on the surface of the modified SiO2 particles via in situ emulsion, and then NR/SiO2 nanocomposite was prepared by blending SiO2-PMMA and PMMA-modified NR (NR-PMMA). The Fourier transform infrared spectroscopy results show that PMMA has been successfully introduced onto the surface of SiO2, which can be well dispersed in NR matrix and present good interfacial adhesion with NR phase. Compared with those of pure NR, the thermal resistance and tensile properties of NR/SiO2 nanocomposite are significantly improved.

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The practical, normative dimension of planning is a plausible source of the ‘family resemblances’ noted by a number of legal theorists between Scott Shapiro’s Planning Theory and natural law jurisprudence. Foremost among these resemblances is Shapiro’s contention that the law, necessarily, has a moral aim. The moral aim thesis is at first glance surprising given Shapiro’s intention to defend exclusive legal positivism and unequivocal rejection of what he takes to be the core commitments of natural law theory. Shapiro’s claim, however, is that although the law necessarily has a moral aim, this does not entail that it is successful in satisfying that aim. In order to assess this thesis, it is helpful to compare the Planning Theory with contemporary natural law approaches. Bringing Shapiro’s Planning Theory into dialogue with contemporary natural law theories can demonstrate some of the Planning Theory’s weaknesses as an alternative explanation of the ultimate grounds of the authoritativeness of legal norms. Some of these weaknesses, moreover, are instructive beyond the specific contours of the Planning Theory insofar as they generalise to other legal positivist approaches. In section one I consider Shapiro’s treatment of the so-called ‘Possibility Puzzle’ regarding the grounding relation between authoritative norms and legal authority. Shapiro’s denial of the capacity of earlier jurisprudential theories to resolve this puzzle overlooks what is – I suggest – a plausible solution developed by John Finnis on the basis of Joseph Raz’s theory of practical reason and norms. Section two then demonstrates why Shapiro’s attempt to combine a robust construal of the social facts thesis with a commitment to the thesis that law necessarily has a moral aim is ultimately unsuccessful.

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For migratory birds, the earlier arrival of males to breeding grounds is often expected to have fitness benefits. However, the selection differential on male arrival time has rarely been decomposed into the direct effect of male arrival and potential indirect effects through female traits. We measured the directional selection differential on male arrival time in the pied flycatcher (Ficedula hypoleuca) using data from 6 years and annual number of fledglings as the fitness proxy. Using structural equation modeling, we were able to take into account the temporal structure of the breeding cycle and the hierarchy between the examined traits. We found directional selection differentials for earlier male arrival date and earlier female laying date, as well as strong selection differential for larger clutch size. These selection differentials were due to direct selection only as indirect selection for these traits was nonsignificant. When decomposing the direct selection for earlier male arrival into direct and indirect effects, we discovered that it was almost exclusively due to the direct effect of male arrival date on fitness and not due to its indirect effects via female traits. In other words, we showed for the first time that there is a direct effect of male arrival date on fitness while accounting for those effects that are mediated by effects of the social partner. Our study thus indicates that natural selection directly favored earlier male arrival in this flycatcher population.

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The destruction of Indigenous rock art sites in the Pilbara district in Western Australia has become a natural sight within the mining landscape of the area. Whilst much of the destruction is explained as acts of vandalism and as a result of the industrial activities that are propelling the Australian economy, I claim that a new theory of iconoclasm is needed to explain fully this disastrous example of heritage conservation. Henceforth, in order to explain the destruction of the Murujuga/Burrup Peninsula petroglyphs, the largest archaeological site in the world, this paper develops the theory of landscape iconoclasm. This theory states that the destruction of Indigenous landscapes can be compared to the destruction of religious images, by analysing the inherent symbolic functions of iconoclasm, together with those of heritage, the better to elucidate the state of affairs in the Murujuga/Burrup Peninsula. Furthermore, by drawing from Aboriginal mythology and art-historical and anthropological theories, the theory of landscape iconoclasm is able to explain the destruction of archaeological sites within a framework that falls outside prevalent discourses of heritage.

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When job applicants lie in job interviews, they can deprive a more honest candidate of a job and deprive an organisation of the best employees. To better understand job interview faking, the present study examined the effect of general dispositions and domain-specific beliefs on the intention to fake job interviews. A community sample of 313 participants completed measures of personality (i.e., extraversion, neuroticism, conscientiousness) and self-monitoring, and a domain-specific measure of beliefs about faking job interviews based on the theory of planned behaviour, which measured attitudes, subjective norms, and perceived behavioural control. Results indicated that the measure of attitudes was the strongest predictor of intention to fake. In line with the compatibility principle, the domain-specific measures based on the theory of planned behaviour correlated much more strongly with intentions to fake job interviews than did the general measures of personality or self-monitoring. Of the dispositional measures, lower conscientiousness, higher neuroticism, and higher self-monitoring was associated with greater intention to fake job interviews. The findings support a model whereby the effect of personality on intentions is partially mediated by domain-specific beliefs.

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The use of natural fibers as reinforcement in polymeric composites for technical applications has been a research subject of scientists during the last decade. There is a great interest in the application of sisal fiber as substitutes for glass fibers, motivated by potential advantages of weight saving, lower raw material price, and ecological advantages of using green resources which are renewable and biodegradable.Castor oil, a triglyceride vegetable that has hydroxyl groups, was reacted with 4,4' diphenylmethane diisocyanate (MDI) to produce the polyurethane matrix. Woven sisal fibers were used untreated and thermal treated at 60 C for 72h, and the composites were processed by compression molding.The present work study tensile behavior at four composites: dry sisal/polyurethane, humid sisal/polyurethane, dry sisal/phenolic and humid sisal/phenolic resin. The moisture content influences of sisal fibers on the mechanical behaviors were analyzed.Experimental results showed a higher tensile strength for the sisal/phenolic composites followed by sisal/polyurethane, respectively. In this research, sisal composites were also characterized by scanning electron microscopy. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of ICM11

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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In the present work, we propose a model for the statistical distribution of people versus number of steps acquired by them in a learning process, based on competition, learning and natural selection. We consider that learning ability is normally distributed. We found that the number of people versus step acquired by them in a learning process is given through a power law. As competition, learning and selection is also at the core of all economical and social systems, we consider that power-law scaling is a quantitative description of this process in social systems. This gives an alternative thinking in holistic properties of complex systems. (C) 2004 Elsevier B.V. All rights reserved.

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This work considers a problem of interest in several technological applications such as the thermal control of electronic equipment. It is also important to study the heat transfer performance of these components under off-normal conditions, such as during failure of cooling fans. The effect of natural convection on the flow and heat transfer in a cavity with two flush mounted heat sources on the left vertical wall, simulating electronic components, is studied numerically and experimentally. The influence of the power distribution, spacing between the heat sources and cavity aspect ratio have been investigated. An analysis of the average Nusselt number of the two heat sources was performed to investigate the behavior of the heat transfer coefficients. The results obtained numerically and experimentally, after an error analysis, showed a good agreement.

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Pós-graduação em Zootecnia - FCAV