842 resultados para Input-output model
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Napjainkban már köztudott tény az, hogy az antropogén szén-dioxid kibocsátás nagymértékben hozzájárul a klímaváltozáshoz. Ahhoz, hogy ténylegesen értékelni tudjuk a kibocsátás környezeti hatását, szükség van egy olyan indikátorra, ami figyelembe veszi a természeti erőforrások és a természet megújuló-képessége által szabott korlátokat. A karbon lábnyom, ilyen módon egy releváns indikátor erre, és segítségével kimutatható, hogy mennyire felel meg egy ország termelése, életmódja, fogyasztási szerkezete a fenntarthatóság kritériumainak. Ennek a tanulmánynak a célja, hogy megvizsgálja a magyarországi fogyasztás környezetterhelésének szerkezetét a karbon lábnyom indikátorának segítségével, középpontba helyezve a nemzetközi kereskedelem hazai hatásainak vizsgálatát. A nemzetközi kereskedelemben elfoglalt pozíció, nemcsak egy ország gazdasági szerkezetét és versenyképességét határozza meg, hanem erőteljes hatással van a fogyasztói szokásokra és a fogyasztás környezetterhelésére is. A karbon lábnyom tartalmazza annak a környezetterhelésnek az értékeit is, amely az importált termékek és szolgáltatások elfogyasztásából származik. Fontos megvizsgálni azt, hogy mely szektorokban van nagy jelentősége az importált termékek környezetterhelésének és ez hogyan járul hozzá a hazai fogyasztási mintákhoz. A tanulmány a fogyasztás környezetterhelését a fogyasztói felelősségi elvet alkalmazva vizsgálja. A karbon lábnyom fogyasztói szempontból való vizsgálata azért jelentős, mert ezáltal képes felhívni a döntéshozók figyelmét, hogy mely szektorokban és fogyasztási kategóriákban jelenik meg nem fenntartható fogyasztás. Így, felszínre kerülnek azok a területek, ahol erőteljes beavatkozásra van szükség a kibocsátások csökkentése érdekében, mindez nemcsak a termelői oldal, hanem a fogyasztói magatartás befolyásolása, jobb informálása, oktatása által. A tanulmány módszertanában kombináltan alkalmazza az ökológiai lábnyom számításból származó karbon lábnyom számítás módszertanát, kiegészítve az ágazati kapcsolatok mérlegének (input-output táblázatok) módszertanával. Ez a kombinált módszertan, a szoros ágazati összefüggéseket és kölcsönhatásokat is kezelni tudja, megjelenítve mind a direkt és indirekt környezeti hatásokat is.
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In recent years there has been a growing concern about the emission trade balance of countries. It is due to the fact that countries with an open economy are active players in the international trade, though trade is not only a major factor in forging a country’s economic structure anymore, but it does contribute to the movement of embodied emissions beyond the country borders. This issue is especially relevant from the carbon accounting policy’s point of view, as it is known that the production-based principle is in effect now in the Kyoto agreement. The study aims at revealing the interdependence of countries on international trade and its environmental impacts, and how the carbon accounting method plays a crucial role in evaluating a country’s environmental performance and its role in the climate mitigation processes. The input-output models are used in the methodology, as they provide an appropriate framework for this kind of environmental accounting; the analysis shows an international comparison of four European countries (Germany, the United Kingdom, the Netherlands, and Hungary) with extended trading activities and carbon emissions. Moving from the production-based approach in the climate policy, to the consumptionperspective principle and allocation [15], it would also help increasing the efficiency of emission reduction targets and the evaluation of the sustainability dimension and its impacts of international trade. The results of the study have shown that there is an importance of distinction between the two emission allocation approaches, both from global and local level point of view.
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There is a need for a proper indicator in order to assess the environmental impact of international trade, therefore using the carbon footprint as an indicator can be relevant and useful. The aim of this study is to show from a methodological perspective how the carbon footprint, combined with input- output models can be used for analysing the impacts of international trade on the sustainable use of national resources in a country. The use of the input-output approach has the essential advantage of being able to track the transformation of goods through the economy. The study examines the environmental impact of consumption related to international trade, using the consumer responsibility principle. In this study the use of the carbon footprint and input-output methodology is shown on the example of the Hungarian consumption and the impact of international trade. Moving from a production- based approach in climate policy to a consumption-perspective principle and allocation, would also help to increase the efficiency of emission reduction targets and the evaluation of the ecological impacts of international trade.
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In recent years there has been growing concern about the emission trade balances of countries. This is due to the fact that countries with an open economy are active players in international trade. Trade is not only a major factor in forging a country’s economic structure, but contributes to the movement of embodied emissions beyond country borders. This issue is especially relevant from the carbon accounting policy and domestic production perspective, as it is known that the production-based principle is employed in the Kyoto agreement. The research described herein was designed to reveal the interdependence of countries on international trade and the corresponding embodied emissions both on national and on sectoral level and to illustrate the significance of the consumption-based emission accounting. It is presented here to what extent a consumption-based accounting would change the present system based on production-based accounting and allocation. The relationship of CO2 emission embodied in exports and embodied in imports is analysed here. International trade can blur the responsibility for the ecological effects of production and consumption and it can lengthen the link between consumption and its consequences. Input-output models are used in the methodology as they provide an appropriate framework for climate change accounting. The analysis comprises an international comparative study of four European countries (Germany, the United Kingdom, the Netherlands, and Hungary) with extended trading activities and carbon emissions. Moving from a production-based approach in climate policy to a consumption-based principle and allocation approach would help to increase the efficiency of emission reductions and would force countries to rethink their trading activities in order to decrease the environmental load of production activities. The results of this study show that it is important to distinguish between the two emission accounting approaches, both on the global and the local level.
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Small errors proved catastrophic. Our purpose to remark that a very small cause which escapes our notice determined a considerable effect that we cannot fail to see, and then we say that the effect is due to chance. Small differences in the initial conditions produce very great ones in the final phenomena. A small error in the former will produce an enormous error in the latter. When dealing with any kind of electrical device specification, it is important to note that there exists a pair of test conditions that define a test: the forcing function and the limit. Forcing functions define the external operating constraints placed upon the device tested. The actual test defines how well the device responds to these constraints. Forcing inputs to threshold for example, represents the most difficult testing because this put those inputs as close as possible to the actual switching critical points and guarantees that the device will meet the Input-Output specifications. ^ Prediction becomes impossible by classical analytical analysis bounded by Newton and Euclides. We have found that non linear dynamics characteristics is the natural state of being in all circuits and devices. Opportunities exist for effective error detection in a nonlinear dynamics and chaos environment. ^ Nowadays there are a set of linear limits established around every aspect of a digital or analog circuits out of which devices are consider bad after failing the test. Deterministic chaos circuit is a fact not a possibility as it has been revived by our Ph.D. research. In practice for linear standard informational methodologies, this chaotic data product is usually undesirable and we are educated to be interested in obtaining a more regular stream of output data. ^ This Ph.D. research explored the possibilities of taking the foundation of a very well known simulation and modeling methodology, introducing nonlinear dynamics and chaos precepts, to produce a new error detector instrument able to put together streams of data scattered in space and time. Therefore, mastering deterministic chaos and changing the bad reputation of chaotic data as a potential risk for practical system status determination. ^
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If we classify variables in a program into various security levels, then a secure information flow analysis aims to verify statically that information in a program can flow only in ways consistent with the specified security levels. One well-studied approach is to formulate the rules of the secure information flow analysis as a type system. A major trend of recent research focuses on how to accommodate various sophisticated modern language features. However, this approach often leads to overly complicated and restrictive type systems, making them unfit for practical use. Also, problems essential to practical use, such as type inference and error reporting, have received little attention. This dissertation identified and solved major theoretical and practical hurdles to the application of secure information flow. ^ We adopted a minimalist approach to designing our language to ensure a simple lenient type system. We started out with a small simple imperative language and only added features that we deemed most important for practical use. One language feature we addressed is arrays. Due to the various leaking channels associated with array operations, arrays have received complicated and restrictive typing rules in other secure languages. We presented a novel approach for lenient array operations, which lead to simple and lenient typing of arrays. ^ Type inference is necessary because usually a user is only concerned with the security types for input/output variables of a program and would like to have all types for auxiliary variables inferred automatically. We presented a type inference algorithm B and proved its soundness and completeness. Moreover, algorithm B stays close to the program and the type system and therefore facilitates informative error reporting that is generated in a cascading fashion. Algorithm B and error reporting have been implemented and tested. ^ Lastly, we presented a novel framework for developing applications that ensure user information privacy. In this framework, core computations are defined as code modules that involve input/output data from multiple parties. Incrementally, secure flow policies are refined based on feedback from the type checking/inference. Core computations only interact with code modules from involved parties through well-defined interfaces. All code modules are digitally signed to ensure their authenticity and integrity. ^
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This dissertation comprises three individual chapters in an effort to examine different explanatory variables that affect firm performance. Chapter Two proposes an additional determinant of firm survival. Based on a detailed examination of firm survival in the British automobile industry between 1895 and 1970, we conclude that a firm's selection of submarket (defined by quality level) influenced survival. In contrast to findings for the US automobile industry, there is no evidence of first-mover advantage in the market as a whole. However, we do find evidence of first-mover advantage after conditioning on submarket choice. Chapter Three examines the effects of product line expansion on firm performance in terms of survival time. Based on a detailed examination of firm survival time in the British automobile industry between 1895 and 1970, we find that diversification exerts a positive effect on firm survival. Furthermore, our findings support the literature with respect to the impacts of submarket types, pre-entry experience, and timing of entry on firm survival time. Chapter Four examines corporate diversification in U.S. manufacturing and service firms. We develop measures of how related a firm's diverse activities are using input-output data and the NAILS classification to construct indexes of "vertical relatedness" and "complementarity". Strong relationships between these two measures are found. We utilize profitability and excess value as the measure for firm performance. Econometric analysis reveals that there is no relationship between the degree of relatedness of diversification and firm performance for the study period.
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Typically, hermetic feedthroughs for implantable devices, such as pacemakers, use a alumina ceramic insulator brazed to a platinum wire pin. This combination of material has a long history in implantable devices and has been approved by the FDA for implantable hermetic feedthroughs. The growing demand for increased input/output (I/O) hermetic feedthroughs for implantable neural stimulator applications could be addressed by developing a new, cofired platinum/alumina multilayer ceramic technology in a configuration that supports 300 plus I/Os, which is not commercially available. Seven platinum powders with different particle sizes were used to develop different conductive cofire inks to control the densification mismatch between platinum and alumina. Firing profile (ramp rate, burn- out and holding times) and firing atmosphere and concentrations (hydrogen (wet/dry), air, neutral, vacuum) were also optimized. Platinum and alumina exhibit the alloy formation reaction in a reduced atmosphere. Formation of any compound can increase the bonding of the metal/ceramic interface, resulting in enhanced hermeticity. The feedthrough fabricated in a reduced atmosphere demonstrated significantly superior performance than that of other atmospheres. A composite structure of tungsten/platinum ratios graded thru the via structure (pure W, 50/50 W/Pt, 80/20 Pt/W and pure Pt) exhibited the best performance in comparison to the performance of other materials used for ink metallization. Studies on the high temperature reaction of platinum and alumina, previously unreported, showed that, at low temperatures in reduced atmosphere, Pt 3Al or Pt8Al21 with a tetragonal structure would be formed. Cubic Pt3Al is formed upon heating the sample to temperatures above 1350 °C. This cubic structure is the equilibrium state of Pt-Al alloy at high temperatures. The alumina dissolves into the platinum ink and is redeposited as a surface coating. This was observed on both cofired samples and pure platinum thin films coated on a 99.6 Wt% alumina and fired at 1550 °C. Different mechanisms are proposed to describe this behavior based on the size of the platinum particle
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The demand side growth accounting studies the demand aggregate component contributions in the Gross Domestic Product (GDP). Traditionally, international and national organizations that uses the traditional method for calculating such contributions. However, this method does not take into account the effect the induction of imports by the various components of aggregate demand on the calculation of these. As an alternative to this method are presented others studies that consider this effect, as the alternative method proposed by Lara (2013), the attribution method, proposed by Kranendonk and Verbruggen (2005) and Hoekstra and van der Helm (2010), and the method the sraffian supermultiplier, by Freitas and Dweck (2013). Was made a summary of these methods, demonstrating the similarities and differences between them. Also, in the aim to contribute to the study of the subject was developed the “method of distribution of imports” that aims to distribute imports for the various components of aggregate demand, through the information set forth in the input-output matrices and tables of resources and uses. Were accounted the contributions to the growth of macroeconomic aggregates for Brazil from 2001 to 2009 using the method of distribution, and realized comparison with the traditional method, understanding the reasons for the differences in contributions. Later was done comparisons with all the methods presented in this work, between the calculated contributions to the growth of the components of aggregate demand and the domestic and external sectors. Was verified that the methods that exist in the literature was not enough to deal with this question, and given the alternatives for contributions to the growth presented throughout this work, it is believed that the method of distribution provides the best estimates for the account of contributions by aggregate demand sector. In particular, the main advantage of this method to the others is the breakdown of the contribution of imports, separated by aggregate demand component, which allows the analysis of contribution of each component to GDP growth. Thus, this type of analysis helps to study the pattern of growth of the Brazilian economy, not just the theoretical point of view, but also empirical and basis for the decision to economic policies
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Peer reviewed
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Peer reviewed
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We study a small circuit of coupled nonlinear elements to investigate general features of signal transmission through networks. The small circuit itself is perceived as building block for larger networks. Individual dynamics and coupling are motivated by neuronal systems: We consider two types of dynamical modes for an individual element, regular spiking and chattering and each individual element can receive excitatory and/or inhibitory inputs and is subjected to different feedback types (excitatory and inhibitory; forward and recurrent). Both, deterministic and stochastic simulations are carried out to study the input-output relationships of these networks. Major results for regular spiking elements include frequency locking, spike rate amplification for strong synaptic coupling, and inhibition-induced spike rate control which can be interpreted as a output frequency rectification. For chattering elements, spike rate amplification for low frequencies and silencing for large frequencies is characteristic
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An assessment of the sustainability of the Irish economy has been carried out using three methodologies, enabling comparison and evaluation of the advantages and disadvantages of each, and potential synergies among them. The three measures chosen were economy-wide Material Flow Analysis (MFA), environmentally extended input-output (EE-IO) analysis and the Ecological Footprint (EF). The research aims to assess the sustainability of the Irish economy using these methods and to draw conclusions on their effectiveness in policy making both individually and in combination. A theoretical description discusses the methods and their respective advantages and disadvantages and sets out a rationale for their combined application. The application of the methods in combination has provided insights into measuring the sustainability of a national economy and generated new knowledge on the collective application of these methods. The limitations of the research are acknowledged and opportunities to address these and build on and extend the research are identified. Building on previous research, it is concluded that a complete picture of sustainability cannot be provided by a single method and/or indicator.
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Over the past decade, the diminishing Arctic sea ice has impacted the wave field, which depends on the ice-free ocean and wind. This study characterizes the wave climate in the Arctic spanning 1992–2014 from a merged altimeter data set and a wave hindcast that uses CFSR winds and ice concentrations from satellites as input. The model performs well, verified by the altimeters, and is relatively consistent for climate studies. The wave seasonality and extremes are linked to the ice coverage, wind strength, and wind direction, creating distinct features in the wind seas and swells. The altimeters and model show that the reduction of sea ice coverage causes increasing wave heights instead of the wind. However, trends are convoluted by interannual climate oscillations like the North Atlantic Oscillation (NAO) and Pacific Decadal Oscillation. In the Nordic Greenland Sea the NAO influences the decreasing wind speeds and wave heights. Swells are becoming more prevalent and wind-sea steepness is declining. The satellite data show the sea ice minimum occurs later in fall when the wind speeds increase. This creates more favorable conditions for wave development. Therefore we expect the ice freeze-up in fall to be the most critical season in the Arctic and small changes in ice cover, wind speeds, and wave heights can have large impacts to the evolution of the sea ice throughout the year. It is inconclusive how important wave–ice processes are within the climate system, but selected events suggest the importance of waves within the marginal ice zone.
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Uno de los grandes retos de la HPC (High Performance Computing) consiste en optimizar el subsistema de Entrada/Salida, (E/S), o I/O (Input/Output). Ken Batcher resume este hecho en la siguiente frase: "Un supercomputador es un dispositivo que convierte los problemas limitados por la potencia de cálculo en problemas limitados por la E/S" ("A Supercomputer is a device for turning compute-bound problems into I/O-bound problems") . En otras palabras, el cuello de botella ya no reside tanto en el procesamiento de los datos como en la disponibilidad de los mismos. Además, este problema se exacerbará con la llegada del Exascale y la popularización de las aplicaciones Big Data. En este contexto, esta tesis contribuye a mejorar el rendimiento y la facilidad de uso del subsistema de E/S de los sistemas de supercomputación. Principalmente se proponen dos contribuciones al respecto: i) una interfaz de E/S desarrollada para el lenguaje Chapel que mejora la productividad del programador a la hora de codificar las operaciones de E/S; y ii) una implementación optimizada del almacenamiento de datos de secuencias genéticas. Con más detalle, la primera contribución estudia y analiza distintas optimizaciones de la E/S en Chapel, al tiempo que provee a los usuarios de una interfaz simple para el acceso paralelo y distribuido a los datos contenidos en ficheros. Por tanto, contribuimos tanto a aumentar la productividad de los desarrolladores, como a que la implementación sea lo más óptima posible. La segunda contribución también se enmarca dentro de los problemas de E/S, pero en este caso se centra en mejorar el almacenamiento de los datos de secuencias genéticas, incluyendo su compresión, y en permitir un uso eficiente de esos datos por parte de las aplicaciones existentes, permitiendo una recuperación eficiente tanto de forma secuencial como aleatoria. Adicionalmente, proponemos una implementación paralela basada en Chapel.