Macro Approach Research Articles

The Need for a Multi-Disciplinary Approach

Like any science focusing on man (either as an individual or as part of a group), demography is faced with the need to develop a systematic approach: its units of observation (individual or collective) are multidimensional systems, whose many components define a single entity, which takes decisions, experiences events and influences its environment. The various disciplines as we currently know them are simply different points of view from which we observe these units. Economics, sociology, epidemiology and medicine, the disciplines closest to demography from a thematic perspective, all face the same dilemma: in order to explain the behaviour of the unit studied, all dimensions of that unit must be taken into account, and no single dimension considered as exclusive (or more important than the others).The need for a multidisciplinary (or, more precisely, systematic) approach is not, therefore, unique to demography. It is, perhaps, simply more apparent, more acute in this discipline, for two reasons that can be seen as constraints, but also as opportunities, in that they strengthen the imperative to move beyond the classical approach. The first reason is the need to take both micro and macro dimensions into account. Demography, which is based upon a macro approach to the study of populations, has only recently begun to concern itself with micro (individual) and meso (family) units. Bringing these strands together is quite clearly vital (although moves to do so were late in coming, as indeed was the micro approach itself, if one considers the history of the discipline).The second reason arises out of the fact that with time, the events of specific interest to the demographer have lost much of their essentially biological nature and are increasingly matters of individual choice. They are, however, events of great significance in the life of an individual - birth of a child, migration, family formation, death - which are not the result of merely circumstantial choices (or situations), but rather milestones on a long decision path (or life course). Many different elements come into play (individual and collective, economic and social, cultural and biological, etc.), and it is often impossible - perhaps also ill-advised - to attempt to determine the specific part played by each.A multidisciplinary approach is thus vital to progress in demography, just as the advent of longitudinal methods has proven to be in recent years for the reconstruction of processes whose unfolding, on an individual timescale, as on a historical timescale, leads to certain demographic choices and events. The same applies today for the simultaneous consideration of micro and macro (and/or meso) levels when interpreting demographic behaviour.A further constraint - or opportunity - is the relative inadequacy of the theoretical corpus of demography, which favours an approach based on empirical observation. Such an approach does not, of course, allow one to dispense with a conceptual framework for analysing a phenomenon. On the contrary, a clear and well-structured theoretical framework with which to organize the system of relations governing the phenomenon is absolutely essential, even when collecting the initial statistics that will subsequently serve to describe its evolution and properties. What is often lacking is the grouping of sectorial hypotheses and theories into one coherent ensemble to be expressly adopted by those undertaking and initiating research. In one respect, the caution with which demographers have always approached the construction of theories reflects the realism of a discipline that, to build bridges between social and biological sciences, has always needed to be wary of partial approaches and the inadequacy of simple theories to resolve the complexity of the object of study. But this circumspection is liable to become a growing hindrance, as it quite clearly runs counter to the process of theory testing-appraisal-refutation that has been a driving force for progress in other fields, thanks notably to the passionate debates it has sparked (though such debate has not always been free from ideology and prejudice) (Popper, 1999)(1). …

Multiscale simulation of viscoelastic free surface flows

A micro–macro approach based on combining the Brownian configuration fields (BCF) method [M.A. Hulsen, A.P.G. van Heel, B.H.A.A. van den Brule, Simulation of viscoelastic flow using Brownian configuration fields, J. Non-Newtonian Fluid Mech. 70 (1997) 79–101] with an Arbitrary Lagrangian–Eulerian (ALE) Galerkin finite element method, using elliptic mesh generation equations coupled with time-dependent conservation equations, is applied to study slot coating flows of polymer solutions. The polymer molecules are represented by dumbbells with both linear and non-linear springs; hydrodynamic interactions between beads are incorporated. Calculations with infinitely extensible (Hookean) and pre-averaged finitely extensible (FENE-P) dumbbell models are performed and compared with equivalent closed-form macroscopic models in a conformation tensor based formulation [M. Pasquali, L.E. Scriven, Free surface flows of polymer solutions with models based on the conformation tensor, J. Non-Newtonian Fluid Mech. 108 (2002) 363–409]. The BCF equation for linear dumbbell models is solved using a fully implicit time integration scheme which is found to be more stable than the explicit Euler scheme used previously to compute complex flows. We find excellent agreement between the results of the BCF based formulation and the macroscopic conformation tensor based formulation. The computations using the BCF approach are stable at much higher Weissenberg numbers, W i = λ γ ˙ (where λ is the characteristic relaxation time of polymer, and γ ˙ is the characteristic rate of strain) compared to the purely macroscopic conformation tensor based approach, which fail beyond a maximum Wi. A novel computational algorithm is introduced to compute complex flows with non-linear microscopic constitutive models (i.e. non-linear FENE dumbbells and dumbbells with hydrodynamic interactions) for which no closed-form constitutive equations exist. This algorithm is fast and computationally efficient when compared to both an explicit scheme and a fully implicit scheme involving the solution of the non-linear equations with Newton’s method for each configuration field.

Analysis of SMA composite laminates using a multiscale modelling technique

AbstractThe present work deals with the analysis of smart laminates, obtained as stacking sequence of fibre‐reinforced composite laminae and composite shape memory alloy (SMA) layers. The behaviour of composite SMA (CSMA) laminate is studied developing a full micro–macro approach. In fact, a non‐linear 4‐node mixed interpolation of tensorial components (MITC4) laminate finite element, based on the first‐order shear deformation theory, is developed. The SMA layer constitutive relationship is determined solving a non‐linear homogenization problem at each non‐linear iteration of each time step for each integration Gauss point. Some numerical applications are developed in order to investigate the influence of the CSMA on the buckling behaviour of plates and on the transversal displacement control of plates subjected to different loading conditions. Copyright © 2006 John Wiley & Sons, Ltd.

The workplace politics of U.S. accounting: Race, class and gender discrimination at Baruch College

Abstract There are significant differences between the U.S. and European academic workplaces (and therefore the way struggles against class and race discrimination are waged) however there are also important commonalities and convergences. This shared experience may be accentuated in the U.K. as a post-research assessment exercise (RAE) era approaches. This paper offers an account of U.S. workplace politics at a macro and micro level. We introduce our paper through a macro approach providing context for our analysis via a brief overview of a progressive research journal assessment exercise, designed to assist critical accounting faculty in promotion, tenure, hiring, and firing struggles. We then report our findings from our survey of progressive academics’ views on journal assessment and the implications of for higher education staff and students and potential students alike. Through our micro focus we present an in-house expose of the anatomy of discriminatory practices at the largest accountancy department, and the largest business, in the U.S.: Baruch College at the City University of New York (CUNY). There are specificities that are unique to the U.S. (and even between Baruch and other U.S. schools) however these differences should not be overstated. Nor should we minimize the possibility of distilling some broad lessons: the systematic subordination of education and research to capital accumulation processes and market pressures that evoke similarities that span academic workplaces across the U.S., Europe, Asia, and Australasia.

One Europe, One Product, Two Prices - The Price Disparity in the EU

This article examines the price dispersion in the European Union in the last fifteen years (1990-2005). The analysis of price convergence is examined on aggregate and disaggregate levels. The macro approach is based on Comparative Price Level index calculated as the ratio between PPPs and exchange rate. The disaggregate analysis utilizes actual prices of 148 individual products sold in the 15 capital cities of the EU. The calculations comprise of sigma and beta convergence adopted from the real growth literature. The different results of the speed of convergence are obtained according to the different econometric methods. Moreover the gravity model is tested to measure the contribution of different factors in explaining the observed convergence pattern.

Theoretical and Experimental Analysis of GFRP Bridge Deck under Temperature Gradient

The temperature difference between the top and bottom of a glass fiber reinforced polymer (GFRP) composite deck, ∼65°C (∼122°F) , is nearly three times that of conventional concrete decks ∼23°C (∼41°F) . Such a large temperature difference is attributed to the relatively lower thermal conductivity of GFRP material. In this study, laboratory tests were conducted on two GFRP bridge deck modules (10.2 and 20.3 cm deep decks) by heating and cooling the top surface of the GFRP deck, while maintaining ambient (room) temperature at the deck bottom. Deflections and strains were recorded on the deck under thermal loads. Theoretical results (using macro approach, Navier-Levy, and FEM) were compared with the laboratory test data. The test data indicated that the GFRP deck exhibited hogging under a positive temperature difference (i.e., Ttop > Tbottom , heating test; Ttop and Tbottom are temperatures at top and bottom of the deck, respectively) and sagging under a negative temperature difference (i.e., Ttop < Tbottom...

New venture creation: evidence from an investigation into Chinese entrepreneurship

PurposeThis study aims to use the Timmons model to identify the pattern of entrepreneurial activity at micro‐level in China.Design/methodology/approachThe paper employs a self‐administered questionnaire survey approach, involving a sample of MBA students and general public in China.FindingsThe analysis suggests that personality characteristics, cultural environment and economic environment are external factors influencing new venture creation.Practical implicationsThe findings of this study suggest that supportive cultural environment and economic environment is more important for MBA entrepreneurs than for general public to encourage the former to start new businesses as they bear higher entrepreneurial opportunity cost.Originality/valueThe paper extends the macro approach of the GEM China Report to examine entrepreneurial activity in China at micro‐level.

A new integrated micro–macro approach to damage and fracture of composites

The element-failure method (EFM) is a novel finite element-based method for the modeling of damage, fracture and delamination in fibre-reinforced composite laminates. The nature of damage in composite laminates is generally diffused and complex, characterized by multiple matrix cracks, fibre pullout, fibre breakage and delaminations. It is usually not possible to model or identify crack tips in the conventional fashion of fracture mechanics. The central idea of the EFM, on the other hand, is to model the damaged portions with partially failed elements, whose nodal forces have been modified to take into account the local damage modes. This has the additional benefit of unconditional computational stability compared to other methods such as material property degradation (MPD) models. Here, we present the application of EFM with a recently-proposed failure criterion called the strain invariant failure theory (SIFT) in the prediction of complex damage progression in open-hole tension (OHT) composite laminates, and show that the damage patterns and predicted final failure loads are in very good agreement with experiments.

On Essence and Measurement of Changes in Competitiveness of the Accession Countries; Critical Review of Literature

Although competitiveness is a world very often used in literature it is seldom to be found in economic textbook which prefer the term comparative advantage much narrowly defining formula describing international specialization. As Porter underlines comparative advantage and competitiveness (competitive advantage) do not overlap because competitiveness is much wider concept. Competitiveness is an ambiguous notion. In literature there are many approaches to competitiveness and many ways of defining and measuring it. Partly it is a result of the lack of general theory of competitiveness and the fact that this category is of business rather than theoretical origins. Paper systematizes and presents results of analysis on competitiveness of the accession countries which are based on three approaches to competitiveness: macro, micro and trade approach.

Coupled modeling of damage growth and permeability variation in brittle rocks

This paper presents a coupled model for anisotropic damage and permeability evolution by using a micro–macro approach. The damage state is represented by a second order tensor. The evolution of damage is determined from a crack propagation criterion. The free enthalpy function of cracked material is obtained by using micromechanical considerations. It is assumed that cracks exhibit normal aperture which is coupled with the crack growth due to asperities of crack faces. By using Darcy’s law for macroscopic fluid flow and assuming laminar flow in microcracks, the overall permeability of the RVE is obtained by a volume averaging procedure taking into account crack aperture in each orientation.

Landscape of Immigration in Europe

The Politics of Migration and Immigration in Europe. By Andrew Geddes. London: Sage 2003. 232 pp., $93.95 cloth (ISBN: 0-7619-5668-9), $38.95 paper (ISBN: 0-7619-5669-7). With the failure of its constitution, the European Union (EU) sits at a cross-roads, conflicted about which direction integration should and will take in the coming decades. At the same time, the threat of transnational terrorism, changing labor markets, and major demographic shifts—amplified by the admission of 10 new member states in 2004—mean that migration has become one of the most salient issues in European politics today. It is likely to remain crucial for decades to come. How these developments will intersect and play out is a key question for scholars examining immigration policy both within member states and for the EU as a whole. To understand how these issues may evolve, one must have a good understanding of the historical and contemporary foundations of immigration, both into and within Europe. Policymakers and scholars need descriptive information about migration policies in member states as well as analytic insights into what is happening at the EU institutional level. And, they need some good conceptual tools to make sense of it all. Andrew Geddes seeks to provide some of these products in his wide ranging Politics of Migration and Immigration in Europe . In writing about this topic, he joins plenty of company. There is a veritable plethora of work on migration in the international relations literature. The work can be roughly divided into three wide areas: those scholars who take a macro or global approach (for example, Sassen 1999; Castels and Miller 2003), those who use a comparative perspective (for example, Brubaker 1989; Cornelius, Martin, and Holifield 1994; Andreas and Synder 2000); and those who focus on particular states or regions, …

Sacrificed at the Alamo: Tragedy and Triumph in the Texas Revolution

Fans of Bruce Winders now have another book to place on their shelves, one that certainly matches, in quality and clarity, other works by the noted historian and curator of the Alamo. Unlike most studies of the famous siege and capture of the Alamo in 1836, Winders spends little time or effort in detailing who exactly was in the fort, where they were when the final assault took place, what their last words must have been, and whether they fell fighting or fleeing. Not that these are not interesting and worthy issues to many, but this author attempts a macro history to explain what brought a small Mexican army and a still smaller Texas one fatefully to San Antonio in February and March of 1836. In doing so, Winders enriches our understanding of the Alamo in dozens of ways.The author first looks at the meaning of republicanism as an ideology, in order to explain how the Anglo-Texans thought war was to be fought. If ever Jacksonian democracy ran amok, it was among these Anglo-Texans attempting to organize a government, pick civilian and military leaders, craft the war’s objectives, and raise an army of military equals. It did not work, which explains much about the strange indecisiveness of those who defended the Alamo. At the same time, the conduct of the Mexican army under Santa Anna sprang from a different historical environment—one that allowed it to move much faster and more decisively than its northern opponents.No nineteenth-century war among those of European descent was complete with-out homage to Napoleon’s shade. Winders finds the Corsican’s influence everywhere in the Texas revolt, with deference to the unique Gulf Coast environment of flat, hot land sloping toward the ocean. Line and column, volley and bayonet, infantry versus cavalry, and traditional tactics for assaulting a fortified stronghold were common subjects in the training of all military officers, and Texas events followed standard military practices hammered out and honed in the long European wars of the first decades of the century.Winders’s macro approach considers many other topics; among the most interesting is that of the Mexican civil war between centralists and federalists. Regardless of what some Texans might have thought, they were very much a part of this. Sacrificed at the Alamo demonstrates that what happened in San Antonio was merely a smaller version of what had happened to defeated federalists in the north a year earlier, in the so-called Rape of Zacatecas. If Mexican military leadership was consistent about anything, it was in its consensus on proper treatment toward defeated rebels. Giving quarter to traitors never seemed to produce the right results.No historical work on the Alamo will escape criticism, and Winders’s book will certainly receive some. His treatment of Santa Anna, for example, still has elements of an older view of the Mexican leader as a bombastic, inept Latin American caudillo. While acknowledging grave and tragic flaws in his character, modern scholarship has moved toward a more charitable view of the Mexican general, one that finds consistency in his political actions, patriotism in his approach to national problems, and decisiveness in pressing a military campaign. For a good and provocative read about the most famous event in Texas War of the 1830s, scholars on both side of the Rio will find Winders’s book well worth the time.

A micro–macro approach to rubber-like materials. Part II: The micro-sphere model of finite rubber viscoelasticity

A micromechanically based non-affine network model for finite rubber elasticity incorporating topological constraints was discussed in Part I (2004. J. Mech. Phys. Solids 52, 2617–2660) of this work. In this follow-up contribution we extend the non-affine micro-sphere model towards the description of time-dependent viscoelastic effects. The viscoelastic network model is constructed by an additive split of the overall response into elastic equilibrium-stress and viscoelastic overstress contributions. The equilibrium response of the network is understood to be related to results obtained from an infinite relaxation process and modeled by our above mentioned elasticity formulation. Inspired by (2004. J. Mech. Phys. Solids 52, 2617–2660), the rate-dependent overstress response is assumed to be driven by two micro-kinematical mechanisms related to the stretch and the area contraction of a tube containing a prototype chain. Firstly, a retraction of fictitiously unconstrained dangling chains is explained by diffusive reptile motions. Secondly, a release of constraint effects due to surrounding chains is modeled by a time-dependence of a tube cross-section area. The latter contribution is considered to be a result of the retraction of forest chains. We outline a distinct micromechanical model for the viscous overstress in terms of the above outlined two micro-kinematic mechanisms and discuss its numerical implementation in context of an affine homogenization procedure of space orientations. The characteristics and modeling capabilities of the proposed micro-sphere model of finite rubber viscoelasticity are reported for a broad spectrum of experimentally-based benchmark simulations. They demonstrate an excellent performance of the model in simulating rate and hystereses effects of rubbery polymers.

A micro–macro approach to rubber-like materials. Part III: The micro-sphere model of anisotropic Mullins-type damage

A micromechanically based non-affine network model for finite rubber elasticity and viscoelasticity was discussed in Parts I and II [Miehe, C., Göktepe, S., Lulei, F., 2004. A micro–macro approach to rubber-like materials. Part I: The non-affine micro-sphere model of rubber elasticity. J. Mech. Phys. Solids 52, 2617–2660; Miehe, C., Göktepe, S., 2005. A micro–macro approach to rubber-like materials. Part II: Viscoelasticity model for polymer networks. J. Mech. Phys. Solids, published on-line, doi: 10.1016/j.jmps.2005.04.006.] of this work. In this follow-up contribution, we further extend the micro-sphere network model such that it incorporates a deformation-induced softening commonly referred to as the Mullins effect. To this end, a continuum formulation is constructed by a superimposed modeling of a crosslink-to-crosslink (CC) and a particle-to-particle (PP) network. The former is described by the non-affine elastic network model proposed in Part I. The Mullins-type damage phenomenon is embedded into the PP network and micromechanically motivated by a breakdown of bonds between chains and filler particles. Key idea of the constitutive approach is a two-step procedure that includes (i) the set up of micromechanically based constitutive models for a single chain orientation and (ii) the definition of the macroscopic stress response by a directly evaluated homogenization of state variables defined on a micro-sphere of space orientations. In contrast to previous works on the Mullins effect, our formulation inherently describes a deformation-induced anisotropy of the damage as observed in experiments. We show that the experimentally observed permanent set in stress–strain diagrams is achieved by our model in a natural way as an anisotropy effect. The performance of the model is demonstrated by means of several numerical experiments including the solution of boundary-value problems.

05/01406 Coal cleaning: A viable strategy for reducedcarbon emissions and improved environment in China?: Glomsrød, S. and Taoyuan, W. Energy Policy, 2005, 33, (4), 525–542

China is a dominant energy consumer in a global context and current energy forecasts emphasise that China's future energy consumption also will rely heavily on coal. The coal use is the major source of the greenhouse gas CO2 and particles causing serious health damage. This paper looks into the question if coal washing might work as low cost strategy for both CO2 and particle emission reductions. Coal washing removes dirt and rock from raw coal, resulting in a coal product with higher thermal energy and less air pollutants. Coal cleaning capacity has so far not been developed in line with the market potential. In this paper an emerging market for cleaned coal is studied within a CGE model for China. The macro approach catches the repercussions of coal cleaning through increased energy efficiency, lower coal transportation costs and crowding out effect of investments in coal washing plants. Coal cleaning stimulates economic growth and reduces particle emissions, but total energy use, coal use and CO2 emissions increase through a rebound effect supported by the vast reserve of underemployed labourers. A carbon tax on fossil fuel combustion has a limited effect on total emissions. The reason is a coal leakage to tax exempted processing industries.

A Macro Approach to Detection and Prevention of Corporate Insolvency

The application of financial analysis tools such as current, quick, and fixed assets ratios, creditors cover and liquidity index among others have not helped in stemming the rising rate of insolvency and business liquidation owing mainly to the fact that these tools are inadequately equipped to highlight futuristic financial problem spots. A normative research carried out on moribund business organizations in Nigeria aimed at finding the reasons for their inability to detect futuristic financial problem spots and proffering solutions thereon reveal that there are factors other than immediate liquidity considerations which also affect the going concern position of a business in the long run. It also revealed that every business has its operational point of perfection, which stands as its financial homeostasis and that three main variables (product mark-up ratio, technical efficiency level, and the cost of operating a production cycle) are necessary for proper estimation of working capital adequacy. The study made use of the experimental and survey research methods for internal and external validity tests respectively. It recommends the application of an advanced working capital formula derived from this study for estimating the most appropriate level for a firm's working capital base, as well as predict organizational life-span and evaluate future projects more objectively.

A Macro Approach to the Asset Price for Principles

Perhaps because of the prolonged stock market boom of the 1990's most macro principles textbooks have increased their coverage of the stock market, but there is very little analysis of how the economy affects the stock market. The present paper suggests a demand-side approach to predicting asset prices, which treats changes in GDP, the price level, money supply, and many other parameters, as comparative static exercises. The major conclusions are that (1) changes in asset prices may substitute for changes in GDP when the economy experiences shocks, (2) many Monday morning quarterback analyses of stock price trends are flawed because they assume an effect that works through GDP, and (3) normally asset prices increase because GDP increases.

Hierarchy Theory in Sociology, Ecology, and Resource Management: A Conceptual Model for Natural Resource or Environmental Sociology and Socioecological Systems

ABSTRACT This article argues that hierarchy theory can be used as a conceptual bridge to facilitate analysis of socioecological systems (SES). An SES model is proposed based on a synthesis of structuration theory in sociology and hierarchy theory in ecology. The model is process rather than component based by relating institutional processes with ecological processes at multiple scales. The model also offers a means to conceptually integrate the divide between micro and macro approaches in the fields of environmental and natural resource (E&NR) sociology.

Micro–macro analysis of shape memory alloy composites

The aim of the paper is to develop a micro–macro approach for the analysis of the mechanical behavior of composites obtained embedding long fibers of Shape Memory Alloys (SMA) into an elastic matrix. In order to determine the overall constitutive response of the SMA composites, two homogenization techniques are proposed: one is based on the self-consistent method while the other on the analysis of a periodic composite. The overall response of the SMA composites is strongly influenced by the pseudo-elastic and shape memory effects occurring in the SMA material. In particular, it is assumed that the phase transformations in the SMA are governed by the wire temperature and by the average stress tensor acting in the fiber. A possible prestrain of the fibers is taken into account in the model. Numerical applications are developed in order to analyze the thermo-mechanical behavior of the SMA composite. The results obtained by the proposed procedures are compared with the ones determined through a micromechanical analysis of a periodic composite performed using suitable finite elements. Then, in order to study the macromechanical response of structural elements made of SMA composites, a three-dimensional finite element is developed implementing at each Gauss point the overall constitutive laws of the SMA composite obtained by the proposed homogenization procedures. Some numerical applications are developed in order to assess the efficiency of the proposed micro–macro model.

A formulation for electrostatic-mechanical contact and its numerical solution

The progress in advanced technology fields requires more and more sophisticated formulations to consider contact problems properly. This paper is devoted to the development of a new constitutive model for electrostatic-mechanical contacts, based on a micro–macro approach to describe the contact behaviour. The electric-mechanical contact constitutive law is obtained considering the real microscopic shape of the contacting surfaces, the microscopic behaviour of force transmission and current flow. Some thermo-mechanical macroscopic models based on microscopic characterizations have already been developed to compute the normal and tangential contact stiffness and the thermal contact resistance. On the basis of such macroscopic models, a similar model, suitable for the electric-mechanical field, is developed. With reference to the thermal constriction resistance the electric contact resistance is studied, assuming a flux tube around each contacting asperity, and choosing a suitable geometry for its narrowing at the contact zone. The contact element geometry is based on well known theoretical and experimental micro-mechanical laws, suitably adapted for the FEM formulation. The macroscopic stiffness matrix is calculated on the basis of the microscopic laws and it is continuously updated as a function of the changes in the mechanical and electric significant parameters. A consistent linearization of the set of equations is developed to improve the computational speed, within the framework of implicit methods. Copyright © 2005 John Wiley & Sons, Ltd.