959 resultados para Process capability index


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In the absence of market frictions, the cost-of-carry model of stock index futures pricing predicts that returns on the underlying stock index and the associated stock index futures contract will be perfectly contemporaneously correlated. Evidence suggests, however, that this prediction is violated with clear evidence that the stock index futures market leads the stock market. It is argued that traditional tests, which assume that the underlying data generating process is constant, might be prone to overstate the lead-lag relationship. Using a new test for lead-lag relationships based on cross correlations and cross bicorrelations it is found that, contrary to results from using the traditional methodology, periods where the futures market leads the cash market are few and far between and when any lead-lag relationship is detected, it does not last long. Overall, the results are consistent with the prediction of the standard cost-of-carry model and market efficiency.

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There is ongoing work on conceptual modelling of such busi- ness notions as Affordance and Capability. We have found that such business notions as Affordance and Capability are constructively defned using elements and properties of exe- cutable behaviour models. In this paper, we clarify the def- initions of Affordance and Capability using Coloured Petri Nets and Protocol models.The illustrating case is the process of drug injection. We show that different behaviour modelling techniques provide different precision for definition of Affordance and Capability and clarify the conceptual models of these notions. We generalise that the behaviour models can be used to improve the precision of conceptualization.

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Research on invention has focused on business invention and little work has been conducted on the process and capability required for the individual inventor or the capabilities required for an advice to be considered an invention. This paper synthesises the results of an empirical survey of ten inventor case studies with current research on invention and recent capability affordance research to develop an integrated capability process model of human capabilities for invention and specific capabilities of an invented device. We identify eight necessary human effectivities required for individual invention capability and six functional key activities using these effectivities, to deliver the functional capability of invention. We also identified key differences between invention and general problem solving processes. Results suggest that inventive step capability relies on a unique application of principles that relate to a new combination of affordance chain with a new mechanism and or space time (affordance) path representing the novel way the device works, in conjunction with defined critical affordance operating factors that are the subject of the patent claims.

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In Mediterranean areas, conventional tillage increases soil organic matter losses, reduces soil quality, and contributes to climate change due to increased CO2 emissions. CO2 sequestration rates in soil may be enhanced by appropriate agricultural soil management and increasing soil organic matter content. This study analyzes the stratification ratio (SR) index of soil organic carbon (SOC), nitrogen (N) and C:N ratio under different management practices in an olive grove (OG) in Mediterranean areas (Andalusia, southern Spain). Management practices considered in this study are conventional tillage (CT) and no tillage (NT). In the first case, CT treatments included addition of alperujo (A) and olive leaves (L). A control plot with no addition of olive mill waste was considered (CP). In the second case, NT treatments included addition of chipped pruned branches (NT1) and chipped pruned branches and weeds (NT2). The SRs of SOC increased with depth for all treatments. The SR of SOC was always higher in NT compared to CT treatments, with the highest SR of SOC observed under NT2. The SR of N increased with depth in all cases, ranging between 0.89 (L-SR1) and 39.11 (L-SR3 and L-SR4).The SR of C:N ratio was characterized by low values, ranging from 0.08 (L-SR3) to 1.58 (NT1-SR2) and generally showing higher values in SR1 and SR2 compared to those obtained in SR3 and SR4. This study has evaluated several limitations to the SR index such as the fact that it is descriptive but does not analyze the behavior of the variable over time. In addition, basing the assessment of soil quality on a single variable could lead to an oversimplification of the assessment. Some of these limitations were experienced in the assessment of L, where SR1 of SOC was the lowest of the studied soils. In this case, the higher content in the second depth interval compared to the first was caused by the intrinsic characteristics of this soil's formation process rather than by degradation. Despite the limitations obtained SRs demonstrate that NT with the addition of organic material improves soil quality.

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The intermetallic compound InPd (CsCl type of crystal structure with a broad compositional range) is considered as a candidate catalyst for the steam reforming of methanol. Single crystals of this phase have been grown to study the structure of its three low-index surfaces under ultra-high vacuum conditions, using low energy electron diffraction (LEED), X-ray photoemission spectroscopy (XPS), and scanning tunneling microscopy (STM). During surface preparation, preferential sputtering leads to a depletion of In within the top few layers for all three surfaces. The near-surface regions remain slightly Pd-rich until annealing to ∼580 K. A transition occurs between 580 and 660 K where In segregates towards the surface and the near-surface regions become slightly In-rich above ∼660 K. This transition is accompanied by a sharpening of LEED patterns and formation of flat step-terrace morphology, as observed by STM. Several superstructures have been identified for the different surfaces associated with this process. Annealing to higher temperatures (≥750 K) leads to faceting via thermal etching as shown for the (110) surface, with a bulk In composition close to the In-rich limit of the existence domain of the cubic phase. The Pd-rich InPd(111) is found to be consistent with a Pd-terminated bulk truncation model as shown by dynamical LEED analysis while, after annealing at higher temperature, the In-rich InPd(111) is consistent with an In-terminated bulk truncation, in agreement with density functional theory (DFT) calculations of the relative surface energies. More complex surface structures are observed for the (100) surface. Additionally, individual grains of a polycrystalline sample are characterized by micro-spot XPS and LEED as well as low-energy electron microscopy. Results from both individual grains and “global” measurements are interpreted based on comparison to our single crystals findings, DFT calculations and previous literature.

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The resource based view of strategy suggests that competitiveness in part derives from a firms ability to collaborate with a subset of its supply network to co-create highly valued products and services. This relational capability relies on a foundational intra and inter-organisational architecture, the manifestation of strategic, people, and process decisions facilitating the interface between the firm and its strategic suppliers. Using covariance-based structural equation modelling we examine the relationships between internal and external features of relational architecture, and their relationship with relational capability and relational quality. This is undertaken on data collected by mail survey. We find significant relationships between both internal and external relational architecture and relational capability and between relational capability and relational quality. Novel constructs for internal and external elements of relational architecture are specified to demonstrate their positive influence on relational capability and relationship quality.

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P>Vegetable oils can be extracted using ethanol as solvent. The main goal of this work was to evaluate the ethanol performance on the extraction process of rice bran oil. The influence of process variables, solvent hydration and temperature was evaluated using the response surface methodology, aiming to maximise the soluble substances and gamma-oryzanol transfer and minimise the free fatty acids extraction and the liquid content in the underflow solid. It can be noted that oil solubility in ethanol was highly affected by the water content. The free fatty acids extraction is improved by increasing the moisture content in the solvent. Regarding the gamma-oryzanol, it can be observed that its extraction is affected by temperature when low level of water is added to ethanol. On the other hand, the influence of temperature is minimised with high levels of water in the ethanol.

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In this work, a sol-gel route was used to prepare Y(0.9)Er(0.1)Al(3)(BO(3))(4) glassy thin films by spin-coating technique looking for the preparation and optimization of planar waveguides for integrated optics. The films were deposited on silica and silicon substrates using stable sols synthesized by the sol-gel process. Deposits with thicknesses ranging between 520 and 720 nm were prepared by a multi-layer process involving heat treatments at different temperatures from glass transition to the film crystallization and using heating rates of 2 degrees C/min. The structural characterization of the layers was performed by using grazing incidence X-ray diffraction and Raman spectroscopy as a function of the heat treatment. Microstructural evolution in terms of annealing temperatures was followed by high resolution scanning electron microscopy and atomic force microscopy. Optical transmission spectra were used to determine the refractive index and the film thicknesses through the envelope method. The optical and guiding properties of the films were studied by m-line spectroscopy. The best films were monomode with 620 nm thickness and a refractive index around 1.664 at 980 nm wavelength. They showed good waveguiding properties with high light-coupling efficiency and low propagation loss at 632.8 and 1550 nm of about 0.88 dB/cm. (C) 2009 Elsevier B.V. All rights reserved.

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This work aims at combining the Chaos theory postulates and Artificial Neural Networks classification and predictive capability, in the field of financial time series prediction. Chaos theory, provides valuable qualitative and quantitative tools to decide on the predictability of a chaotic system. Quantitative measurements based on Chaos theory, are used, to decide a-priori whether a time series, or a portion of a time series is predictable, while Chaos theory based qualitative tools are used to provide further observations and analysis on the predictability, in cases where measurements provide negative answers. Phase space reconstruction is achieved by time delay embedding resulting in multiple embedded vectors. The cognitive approach suggested, is inspired by the capability of some chartists to predict the direction of an index by looking at the price time series. Thus, in this work, the calculation of the embedding dimension and the separation, in Takens‘ embedding theorem for phase space reconstruction, is not limited to False Nearest Neighbor, Differential Entropy or other specific method, rather, this work is interested in all embedding dimensions and separations that are regarded as different ways of looking at a time series by different chartists, based on their expectations. Prior to the prediction, the embedded vectors of the phase space are classified with Fuzzy-ART, then, for each class a back propagation Neural Network is trained to predict the last element of each vector, whereas all previous elements of a vector are used as features.

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Apesar de o CMMI (Capability Maturity Model Integration) prover uma cobertura mais detalhada do ciclo de vida dos produtos que o uso isolado de outros processos de melhoria, ainda assim não pode ser visto como uma metodologia pronta para ser utilizada pelas organizações. Cada organização deve mapear as áreas de processo do nível CMMI desejado (caso a opção seja a representação por estágios, como veremos adiante) à sua metodologia, aos seus métodos e técnicas de desenvolvimento de produtos e sistemas, levando também em consideração os objetivos de negócio da organização. Tanto o CMMI como as demais normas e modelos de qualidade, dizem “o que” e não “como” fazer. Determinar este “como” é um trabalho adicional bastante grande que as organizações devem realizar quando da adoção destas normas. Para isto, normalmente as organizações buscam no mercado empresas de consultoria que possuem experiência na área. Essas consultorias são bastante indicadas porque aumentam significativamente a qualidade e a velocidade dos resultados. Este trabalho pretende facilitar as organizações interessadas na implementação de um modelo de qualidade, fornecendo descrições sobre alguns dos modelos de qualidade mais utilizados atualmente, bem como modelos de processos, guias e formulários que podem ser utilizados diretamente ou como uma base para a implementação do modelo desejado. Embora se aplique à implementação de qualquer modelo de qualidade, mais especificamente, este trabalho destina-se a auxiliar organizações que visem implementar o modelo CMMI nível 2 (doravante usaremos também a abreviação CMMI-N2). Para tanto, descreve de forma mais detalhada este modelo e fornece um caminho para a implementação do mesmo, incluindo a descrição de um processo mínimo de desenvolvimento de software, com base no RUP (Rational Unified Process) e o uso de um modelo de ciclo de vida de melhoria de processos, o IDEAL. Neste trabalho, propõe-se que seja utilizado o modelo IDEAL para a implementação do modelo de qualidade devido ao fato de este modelo ter sido concebido originalmente como um modelo de ciclo de vida para melhoria de processos de software com base no SW-CMM (Capability Maturity Model for Software). Associado a esse modelo, é sugerido que se utilize algumas técnicas e processos de gerência de projetos para cada área de processo do CMMI-N2, visando implantar cada área de processo através de um projeto. Para a implementação são propostos guias, modelos (formulários) de implementação e uma tabela que mapeia todas as áreas de processo do CMMI-N2, seus objetivos, práticas, produtos de trabalho e as ferramentas associadas.

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This paper performs a thorough statistical examination of the time-series properties of the daily market volatility index (VIX) from the Chicago Board Options Exchange (CBOE). The motivation lies not only on the widespread consensus that the VIX is a barometer of the overall market sentiment as to what concerns investors' risk appetite, but also on the fact that there are many trading strategies that rely on the VIX index for hedging and speculative purposes. Preliminary analysis suggests that the VIX index displays long-range dependence. This is well in line with the strong empirical evidence in the literature supporting long memory in both options-implied and realized variances. We thus resort to both parametric and semiparametric heterogeneous autoregressive (HAR) processes for modeling and forecasting purposes. Our main ndings are as follows. First, we con rm the evidence in the literature that there is a negative relationship between the VIX index and the S&P 500 index return as well as a positive contemporaneous link with the volume of the S&P 500 index. Second, the term spread has a slightly negative long-run impact in the VIX index, when possible multicollinearity and endogeneity are controlled for. Finally, we cannot reject the linearity of the above relationships, neither in sample nor out of sample. As for the latter, we actually show that it is pretty hard to beat the pure HAR process because of the very persistent nature of the VIX index.

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In the past decade, indicators have been created to assess the sustainability performance of companies listed in stock exchange markets. Academics and practitioners expect companies to benefit from being listed in such indexes, but evidence of value creation is still scarce. Since virtually all studies about the Corporate Sustainability Index (ISE) of the S~ ao Paulo Stock Exchange (Brazil) e the object of the present study e focused on the value of shares, we initially looked for answers in the finance theory. We collected secondary data about the financial and economic performance of companies forming the ISE's ‘theoretical portfolio’, as these kinds of indexes are also known. In a second stage, we sought additional motivations for companies to make efforts to be listed in the index. We collected additional data and interviewed representatives of key companies listed in the ISE, as well as industry leaders who chose not to participate in the selection process. The results support the main propositions of the institutional theory, as well as the ‘pays to be green’ literature e that the intangible value created by voluntary environmental initiatives, such as access to knowledge, new capabilities and reputational gain, better explain the efforts companies make to be listed in the ISE index

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Many factors such as the sunlight, intensity of radiation, temperature, and moisture may influence the degradation process of geosynthetics. UV stabilizers are used especially in polyolefin geomembrane to prevent the degradation process. In these geomembranes the service lifetime is initially governed by the consumption of antioxidants. Tests like MFI and OIT are a alternative to detect the oxidative degradation in polyolefins. This article evaluates HDPE geomembrane degradation after UV exposure through the results of MFI and OIT tests. Two kinds of geomembranes were evaluated: a black and smooth (0.8, 1.0, 1.5, 2.5 mm) and a white and textured (1.0 mm). MFI test showed some levels of superficial degradation (crosslink) in HDPE geomembrane.

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Global society and technology have changed the relationships of the market. Quality and cost are not the main aspects of any industrial product. On the other hand, design, innovation and sustainability became significant requirements to company’s competitiveness. In this context, the design approach has shown evolutions, integrating social and environmental aspects beside traditional aspects such as technical and economic. Still, design has been becoming a strategic opportunity for companies, improving their competitiveness and increasing their market share. Thus, this research has analyzed the integration of both the Sustainable Design and Strategic Design Coaching (SDC) method in the making decision activities of companies. A cement company (BQMIL) was assigned as case study, in which the previous results have pointed out the significant hole of those concepts to generate Eco-innovation and Eco-Brand to increase its market share, corroborating the expectative of the design team

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