393 resultados para Bang-bang Pll
Resumo:
Este artículo se refiere a la formación de acuerdos endógenos de libre comercio en un modelo de competencia imperfecta entre tres países. Teniendo en cuenta que la literatura ha ignorado en ocasiones el requisito de sostenibilidad en las áreas de libre comercio, el artículo propone una estructura para predecir qué acuerdos comerciales se forman cuando la sostenibilidad es explícitamente incluida como una restricción en la formación de acuerdos cooperativos. Se encuentra que la introducción de un requisito de auto-ejecución reduce el alcance general de los acuerdos comerciales y que las áreas comerciales preferenciales pueden ser puntos de apoyo o impedimentos, dependiendo de la demanda relativa entre los países.
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El proyecto parte de la Apropiación Social de la Ciencia y la Tecnología para abordar los conceptos de pertinencia, rigurosidad y crítica alrededor del periodismo científico y la salud. El resultado es la aplicación práctica en www.elestetoscopio.com
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Examina la historia de esta ciencia considerada la más antigua de todas por el interés que desde la antigüedad ha suscitado en los hombres el conocimiento de los complejos movimientos de los objetos celestiales.También, se repasan los orígenes del universo con la violenta explosión ocurrida hace billones de años, llamada Big Bang. Se estudia el sistema solar, formado de planetas, lunas e innumerables cuerpos más pequeños como asteroides y cometas. Se completa con una observación de las estrellas y galaxias en el cielo de la noche, con cartas estelares y perfiles de constelaciones y, por último, se añade una guía con la posición mes a mes de las constelaciones septentrionales y australes.
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Sumario: I. Todos los caminos conducen a Roma. 1.1. La dignidad. 1.2. El derecho subjetivo. 1.3. La capacidad. 1.4. La igualdad. II. Estirar los pies hasta donde alcanza la sábana. 2.1. La dignidad. 2.2. El derecho subjetivo. 2.3. La capacidad. 2.4. La igualdad. III. Caminar alegremente hacia la fuente. 3.1. La relacionalidad. 3.2. La correspondencia. 3.3. La complementariedad. 3.4. El principio de reciprocidad. IV. Del agujero negro al Big Bang. V. Reflexiones finales. VI. Bibliografía.
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Pontryagin's maximum principle from optimal control theory is used to find the optimal allocation of energy between growth and reproduction when lifespan may be finite and the trade-off between growth and reproduction is linear. Analyses of the optimal allocation problem to date have generally yielded bang-bang solutions, i.e. determinate growth: life-histories in which growth is followed by reproduction, with no intermediate phase of simultaneous reproduction and growth. Here we show that an intermediate strategy (indeterminate growth) can be selected for if the rates of production and mortality either both increase or both decrease with increasing body size, this arises as a singular solution to the problem. Our conclusion is that indeterminate growth is optimal in more cases than was previously realized. The relevance of our results to natural situations is discussed.
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Purpose – Today marketers operate in globalised markets, planning new ways to engage with domestic and foreign customers alike. While there is a greater need to understand these two customer groups, few studies examine the impact of customer engagement tactics on the two customer groups, focusing on their perceptual differences. Even less attention is given to customer engagement tactics in a cross-cultural framework. In this research, the authors investigate customers in China and UK, aiming to compare their perceptual differences on the impact of multiple customer engagement tactics. Design/methodology/approach – Using a quantitative approach with 286 usable responses from China and the UK obtained through a combination of person-administered survey and computer-based survey screening process, the authors test a series of hypotheses to distinguish across-cultural differences. Findings – Findings show that the collectivists (Chinese customers) perceive customer engagement tactics differently than the individualists (UK customers). The Chinese customers are more sensitive to price and reputation, whereas the UK customers respond more strongly to service, communication and customisation. Chinese customers’ concerns with extensive price and reputation comparisons may be explained by their awareness towards face (status), increased self-expression and equality. Practical implications – The findings challenge the conventional practice of using similar customer engagement tactics for a specific market place with little concern for multiple cultural backgrounds. The paper proposes strategies for marketers facing challenges in this globalised context. Originality/value – Several contributions have been made to the literatures. First, the study showed the effects of culture on the customers’ perceptual differences. Second, the study provided more information to clarify customers’ different reactions towards customer engagement tactics, highlighted by concerns towards face and status. Third, the study provided empirical evidence to support the use of multiple customer engagement tactics to the across cultural studies.
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Purpose – CRM treats various profiles of customers or individual customers differently, purposively favoring certain customers while deliberately disadvantaging others. This research aims to provide insights into how advantaged (favored) and (non-favored) disadvantaged customers perceive fairness in retailers’ marketing tactics. Design/methodology/approach – A multiple study approach has been adopted, influenced by a three-stage process, which involved exploratory interviews, pilot tests, and the main survey. Findings – The results have provided marketers with a perspective on maintaining and enhancing relationships. Service and marketing communications concern the advantaged customers most, while pricing is the most important aspect for the disadvantaged customers. Practical implications – In terms of handling customers, there are important implications from recognizing how those who are favored and those who are not so advantaged perceive their treatment. Failure to appreciate the pitfalls for visibly treating certain customers more favorably and others demonstrably less so, will have stark consequences for retail management and consumer marketing. Originality/value – Contributions are made to the literatures on CRM and on unfairness, particularly in terms of how to address the inevitable inequities inherent in retailers’ CRM offerings. Identification of the advantaged and disadvantaged customers and their respective views allows marketers to develop more appropriate approaches for handling customers who are sensitive to perceived unfairness.
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Research into the dark side of customer management and marketing is progressively growing. The marketing landscape today is dominated with suspicion and distrust as a result of practices that include hidden fees, deception and information mishandling. In such a pessimistic economy, marketers must reconceptualise the notion of fairness in marketing and customer management, so that the progress of sophisticated customisation schemes and advancements in marketing can flourish, avoiding further control and imposed regulation. In this article, emerging research is drawn to suggest that existing quality measures of marketing activities, including service, relationships and experiences may not be comprehensive in measuring the relevant things in the social and ethically oriented marketing landscape, and on that basis does not measure the fairness which truly is important in such an economy. The paper puts forward the concept of Fairness Quality (FAIRQUAL), which includes as well as extends on existing thinking behind relationship building, experience creation and other types of customer management practices that are believed to predict consumer intentions. It is proposed that a fairness quality measure will aid marketers in this challenging landscape and economy.
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We develop a new measurement scale to assess consumers’ brand likeability in firm-level brands. We present brand likeability as a multidimensional construct. In the context of service experience purchases, we find that increased likeability in brands results in: (1) greater amount of positive association; (2) increased interaction interest; (3) more personified quality; and (4) increased brand contentment. The four-dimensional multiple-item scale demonstrates good psychometric properties, showing strong evidence of reliability as well as convergent, discriminant and nomological validity. Our findings reveal that brand likeability is positively associated with satisfaction and positive word of mouth. The scale extends existing branding research, providing brand managers with a metric so that likeability can be managed strategically. It addresses the need for firms to act more likeably in an interaction-dominated economy. Focusing on likeability acts as a differentiator and encourages likeable brand personality traits. We present theoretical implications and future research directions on the holistic brand likeability concept.
The dark side of brand attachment: a conceptual framework of brand attachment's detrimental outcomes
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Brand attachment recently has received great attention among practitioners and academics alike. Scholars consider brand attachment a key requisite in consumer-brand relationships that create favourable consumer behaviours such as positive brand attitudes and brand loyalty. Few studies, however, examine the detrimental outcomes of brand attachment. In this paper, we develop a conceptual framework that explores how brand attachment may explain detrimental consumer behaviours, such as oppositional brand loyalty and antibrand actions. We investigate consumers' trash-talking and schadenfreude in brand communities and their subsequent outcomes. Our framework reveals that the link between brand attachment and oppositional brand loyalty is driven by consumers' social identity and sense of rivalry. Furthermore, we put forward that brand attachment leads to anti-brand actions when relationships deteriorate. We identify two factors behind the deterioration: (1) companies' opportunism activities, and (2) incongruity between consumers' values and the brand's values. Theoretical and managerial implications are discussed arising from our emerging 'dark side' brand attachment framework.
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The first stars that formed after the Big Bang were probably massive(1), and they provided the Universe with the first elements heavier than helium (`metals`), which were incorporated into low-mass stars that have survived to the present(2,3). Eight stars in the oldest globular cluster in the Galaxy, NGC 6522, were found to have surface abundances consistent with the gas from which they formed being enriched by massive stars(4) (that is, with higher alpha-element/Fe and Eu/Fe ratios than those of the Sun). However, the same stars have anomalously high abundances of Ba and La with respect to Fe(4), which usually arises through nucleosynthesis in low-mass stars(5) (via the slow-neutron-capture process, or s-process). Recent theory suggests that metal-poor fast-rotating massive stars are able to boost the s-process yields by up to four orders of magnitude(6), which might provide a solution to this contradiction. Here we report a reanalysis of the earlier spectra, which reveals that Y and Sr are also over-abundant with respect to Fe, showing a large scatter similar to that observed in extremely metal-poor stars(7), whereas C abundances are not enhanced. This pattern is best explained as originating in metal-poor fast-rotating massive stars, which might point to a common property of the first stellar generations and even of the `first stars`.
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Radiative capture of nucleons at energies of astrophysical interest is one of the most important processes for nucleosynthesis. The nucleon capture can occur either by a compound nucleus reaction or by a direct process. The compound reaction cross sections are usually very small, especially for light nuclei. The direct capture proceeds either via the formation of a single-particle resonance or a non-resonant capture process. In this work we calculate radiative capture cross sections and astrophysical S-factors for nuclei in the mass region A < 20 using single-particle states. We carefully discuss the parameter fitting procedure adopted in the simplified two-body treatment of the capture process. Then we produce a detailed list of cases for which the model works well. Useful quantities, such as spectroscopic factors and asymptotic normalization coefficients, are obtained and compared to published data. (C) 2010 Elsevier Inc. All rights reserved.
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Nuclear collisions recreate conditions in the universe microseconds after the Big Bang. Only a very small fraction of the emitted fragments are light nuclei, but these states are of fundamental interest. We report the observation of antihypertritons-comprising an antiproton, an antineutron, and an antilambda hyperon-produced by colliding gold nuclei at high energy. Our analysis yields 70 +/- 17 antihypertritons (3/Lambda(H) over bar) and 157 +/- 30 hypertritons ((3)(Lambda)H). The measured yields of (3)(Lambda)H (3/Lambda(H) over bar) and (3)He ((3)(He) over bar) are similar, suggesting an equilibrium in coordinate and momentum space populations of up, down, and strange quarks and antiquarks, unlike the pattern observed at lower collision energies. The production and properties of antinuclei, and of nuclei containing strange quarks, have implications spanning nuclear and particle physics, astrophysics, and cosmology.
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High-energy nuclear collisions create an energy density similar to that of the Universe microseconds after the Big Bang(1); in both cases, matter and antimatter are formed with comparable abundance. However, the relatively short-lived expansion in nuclear collisions allows antimatter to decouple quickly from matter, and avoid annihilation. Thus, a high-energy accelerator of heavy nuclei provides an efficient means of producing and studying antimatter. The antimatter helium-4 nucleus ((4)(He) over bar), also known as the anti-alpha ((alpha) over bar), consists of two antiprotons and two antineutrons (baryon number B = -4). It has not been observed previously, although the alpha-particle was identified a century ago by Rutherford and is present in cosmic radiation at the ten per cent level(2). Antimatter nuclei with B -1 have been observed only as rare products of interactions at particle accelerators, where the rate of antinucleus production in high-energy collisions decreases by a factor of about 1,000 with each additional antinucleon(3-5). Here we report the observation of (4)<(He) over bar, the heaviest observed antinucleus to date. In total, 18 (4)(He) over bar counts were detected at the STAR experiment at the Relativistic Heavy Ion Collider (RHIC; ref. 6) in 10(9) recorded gold-on-gold (Au+Au) collisions at centre-of-mass energies of 200 GeV and 62 GeV per nucleon-nucleon pair. The yield is consistent with expectations from thermodynamic(7) and coalescent nucleosynthesis(8) models, providing an indication of the production rate of even heavier antimatter nuclei and a benchmark for possible future observations of (4)(He) over bar in cosmic radiation.
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The bare nucleus S(E) factors for the (2)H(d, p)(3)H and (2)H(d.n)(3)He reactions have been measured for the first time via the Trojan Horse Method off the proton in (3)He from 1.5 MeV down to 2 key. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre-Main-Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the S(E) factors deviate by more than 15% from available direct data with new S(0) values of 57.4 +/- 1.8 MeVb for (3)H + p and 60.1 +/- 1.9 MeV b for (3)He + n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors. (C) 2011 Elsevier By. All rights reserved.