Drivers and sources of supply flexibility: An exploratory study

Purpose - There has been much research on manufacturing flexibility, but supply chain flexibility is still an under-investigated area. This paper focuses on supply flexibility, the aspects of flexibility related to the upstream supply chain. Our purpose is to investigate why and how firms increase supply flexibility. Methodology/Approach – An exploratory multiple case study was conducted. We analyzed seven Spanish manufacturers from different sectors (automotive, apparel, electronics and electrical equipment). Findings - The results show that there are some major reasons why firms need supply flexibility (manufacturing schedule fluctuations, JIT purchasing, manufacturing slack capacity, low level of parts commonality, demand volatility, demand seasonality and forecast accuracy), and that companies increase this type of flexibility by implementing two main strategies: “to increase suppliers’ responsiveness capability” and “flexible sourcing”. The results also suggest that the supply flexibility strategy selected depends on two factors: the supplier searching and switching costs and the type of uncertainty (mix, volume or delivery). Research limitations - This paper has some limitations common to all case studies, such as the subjectivity of the analysis, and the questionable generalizability of results (since the sample of firms is not statistically significant). Implications - Our study contributes to the existing literature by empirically investigating which are the main reasons for companies needing to increase supply flexibility, how they increase this flexibility, and suggesting some factors that could influence the selection of a particular supply flexibility strategy.Supply flexibility, sourcing, Spain, case study

Non-Abelian Black Holes and Catastrophe Theory II: Charged Type

We reanalyze the gravitating monopole and its black hole solutions in the Einstein-Yang-Mills-Higgs system and we discuss their stabilities from the point of view of catastrophe theory. Although these non-trivial solutions exhibit fine and complicated structures, we find that stability is systematically understood via a swallow tail catastrophe. The Reissner-Nordstr\"{o}m trivial solution becomes unstable from the point where the non-trivial monopole black hole appears. We also find that, within a very small parameter range, the specific heat of a monopole black hole changes its sign .Comment: 23 pages, LaTeX (Figures are available on request as hard copies.) WU-AP/40/9

Wavelet characterizations of weighted Herz spaces

We characterize the homogeneous weighted Herz space ˙K α,p q (w1,w2) and the non-homogeneous weighted Herz space Kα,p q (w1,w2) using wavelets in C1(Rn) with compact support. Applying the characterizations, we prove that the wavelet basis forms an unconditional basis in ˙Kα,p q (w1,w2) and in Kα,p q (w1,w2)

Monitoring environmental liabilities with support of the technology and information system

Este artigo apresenta uma estrutura de software de monitoramento socioambiental para diagnóstico das organizações em termos de sustentabilidade. Este sistema está alicerçado em uma base de dados de indicadores de desenvolvimento socioambiental, concebida como resultado de pesquisa empírica, desenvolvida pelo método da grounded theory. Tais indicadores, além de refletir o estágio de sustentabilidade em que se encontra a empresa analisada, subsidiam o mapeamento socioambiental dos diferentes segmentos econômicos do universo empresarial brasileiro. A arquitetura, estruturada com o suporte dos recentes recursos das tecnologias da informação, possibilitará o desenvolvimento de programas de um sistema informatizado, sob medida, para cada tipo de empresa, para suporte às decisões inerentes à gestão sustentável de sua cadeia produtiva. Como resultados destacam-se a concepção de software para suporte às decisões socioambientais e de um mapa de sustentabilidade das organizações.This manuscript presents a software framework for social and environmental monitoring for diagnosis of organizations in terms of sustainability. This system is based on a database of indicators of social and environmental development, conceived as a result of empirical research, developed by the grounded theory method. These indicators in addition to reflecting the stage of sustainability in which the analyzed company is found, they also signalize the mapping of the different social and environmental economics segments of the Brazilian business. The architecture, structured with the support of the latest features of information technology, allow the development of programs of a computer system, exactly for each type of company to support the decisions taken on the sustainable management of their production chain. As results, we can highlight the development of a design software to support social and environmental decisions and of a company sustainability map

Weighted Sobolev-Lieb-Thirring inequalities

We give a weighted version of the Sobolev-Lieb-Thirring inequality for suborthonormal functions. In the proof of our result we use '-transform of Frazier-Jawerth

Dynamics of Topological Defects and Inflation

We study the dynamics of topological defects in the context of ``topological inflation" proposed by Vilenkin and Linde independently. Analysing the time evolution of planar domain walls and of global monopoles, we find that the defects undergo inflationary expansion if $\eta\stackrel{>}{\sim}0.33m_{Pl}$, where $\eta$ is the vacuum expectation value of the Higgs field and $m_{Pl}$ is the Planck mass. This result confirms the estimates by Vilenkin and Linde. The critical value of $\eta$ is independent of the coupling constant $\lambda$ and the initial size of the defect. Even for defects with an initial size much greater than the horizon scale, inflation does not occur at all if $\eta$ is smaller than the critical value. We also examine the effect of gauge fields for static monopole solutions and find that the spacetime with a gauge monopole has an attractive nature, contrary to the spacetime with a global monopole. It suggests that gauge fields affect the onset of inflation.Comment: 12 pages, revtex, 13 figures, some discussions are modified, to appear in Phys.Rev.

Wavelet bases in the weighted Besov and Triebel-Lizorkin spaces with A^loc_p-weights

The aim of this paper is to obtain the wavelet expansion in the Besov spaces and the Triebel-Lizorkin spaces coming with Aloc p -weights. After characterizing these spaces in terms of wavelet, we shall obtain unconditional bases and greedy bases

Dynamics of Gravitating Magnetic Monopoles

According to previous work on magnetic monopoles, static regular solutions are nonexistent if the vacuum expectation value of the Higgs field $\eta$ is larger than a critical value $\eta_{{\rm cr}}$, which is of the order of the Planck mass. In order to understand the properties of monopoles for $\eta>\eta_{{\rm cr}}$, we investigate their dynamics numerically. If $\eta$ is large enough ($\gg\eta_{{\rm cr}}$), a monopole expands exponentially and a wormhole structure appears around it, regardless of coupling constants and initial configuration. If $\eta$ is around $\eta_{{\rm cr}}$, there are three types of solutions, depending on coupling constants and initial configuration: a monopole either expands as stated above, collapses into a black hole, or comes to take a stable configuration.Comment: 11 pages, revtex, postscript figures; results for various initial conditions are added; to appear in Phys. Rev.

Gravitational Properties of Monopole Spacetimes Near the Black Hole Threshold

Although nonsingular spacetimes and those containing black holes are qualitatively quite different, there are continuous families of configurations that connect the two. In this paper we use self-gravitating monopole solutions as tools for investigating the transition between these two types of spacetimes. We show how causally distinct regions emerge as the black hole limit is achieved, even though the measurements made by an external observer vary continuously. We find that near-critical solutions have a naturally defined entropy, despite the absence of a true horizon, and that this has a clear connection with the Hawking-Bekenstein entropy. We find that certain classes of near-critical solutions display naked black hole behavior, although they are not truly black holes at all. Finally, we present a numerical simulation illustrating how an incident pulse of matter can induce the dynamical collapse of a monopole into an extremal black hole. We discuss the implications of this process for the third law of black hole thermodynamics.Comment: 23 pages, 4 figures RevTe

Cosmic Colored Black Holes

We present spherically symmetric static solutions (a particle-like solution and a black hole solution) in the Einstein-Yang-Mills system with a cosmological constant.Although their gravitational structures are locally similar to those of the Bartnik-McKinnon particles or the colored black holes, the asymptotic behavior becomes quite different because of the existence of a cosmological horizon. We also discuss their stability by means of a catastrophe theory as well as a linear perturbation analysis and find the number of unstable modes.Comment: 12 pages, latex, 4 figures (available upon request