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Structural Problems (structural + problem)
Selected AbstractsWOMEN IN DEVELOPING COUNTRIES AND BENEFIT SHARINGDEVELOPING WORLD BIOETHICS, Issue 3 2006FATIMA ALVAREZ-CASTILLO ABSTRACT The aim of this paper is to show that any process of benefit sharing that does not guarantee the representation and participation of women in the decision-making process, as well as in the distribution of benefits, contravenes a central demand of social justice. It is argued that women, particularly in developing countries, can be excluded from benefits derived from genetic research because of existing social structures that promote and maintain discrimination. The paper describes how the structural problem of gender-based inequity can impact on benefit sharing processes. At the same time, examples are given of poor women's ability to organise themselves and to achieve social benefits for entire communities. Relevant international guidelines (e.g. the Convention on Biodiversity) recognise the importance of women's contributions to the protection of biodiversity and thereby, implicitly, their right to a share of the benefits, but no mechanism is outlined on how to bring this about. The authors make a clear recommendation to ensure women's participation in benefit sharing negotiations by demanding seats at the negotiation table. [source] Münch, morphology, microfluidics , our structural problem with the phloemPLANT CELL & ENVIRONMENT, Issue 9 2010MICHAEL KNOBLAUCH ABSTRACT The sieve tubes of the phloem are enigmatic structures. Their role as channels for the distribution of assimilates was established in the 19th century, but their sensitivity to disturbations has hampered the elucidation of their transport mechanisms and its regulation ever since. Ernst Münch's classical monograph of 1930 is generally regarded as the first coherent theory of phloem transport, but the ,Münchian' pressure flow mechanism had been discussed already before the turn of the century. Münch's impact rather rested on his simple physical models of the phloem that visualized pressure flow in an intuitive way, and we argue that the downscaling of such models to realistic, low-Reynolds-number sizes will boost our understanding of phloem transport in this century just as Münch's models did in the previous one. However, biologically meaningful physical models that could be used to test predictions of the many existing mathematical models would have to be designed in analogy with natural phloem structures. Unfortunately, the study of phloem anatomy seems in decline, and we still lack basic quantitative data required for evaluating the plausibility of our theoretical deductions. In this review, we provide a subjective overview of unresolved problems in angiosperm phloem structure research within a functional context. [source] Near-atomic resolution structures of urate oxidase complexed with its substrate and analogues: the protonation state of the ligandACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2010Laure Gabison Urate oxidase (uricase; EC 1.7.3.3; UOX) from Aspergillus flavus catalyzes the oxidation of uric acid in the presence of molecular oxygen to 5-hydroxyisourate in the degradation cascade of purines; intriguingly, catalysis proceeds using neither a metal ion (Fe, Cu etc.) nor a redox cofactor. UOX is a tetrameric enzyme with four active sites located at the interface of two subunits; its structure was refined at atomic resolution (1,Å) using new crystal data in the presence of xanthine and at near-atomic resolution (1.3,1.7,Å) in complexes with the natural substrate (urate) and two inhibitors: 8-nitroxanthine and 8-thiouric acid. Three new features of the structural and mechanistic behaviour of the enzyme were addressed. Firstly, the high resolution of the UOX,xanthine structure allowed the solution of an old structural problem at a contact zone within the tetramer; secondly, the protonation state of the substrate was determined from both a halochromic inhibitor complex (UOX,8-nitroxanthine) and from the H-atom distribution in the active site, using the structures of the UOX,xanthine and the UOX,uric acid complexes; and thirdly, it was possible to extend the general base system, characterized by the conserved catalytic triad Thr,Lys,His, to a large water network that is able to buffer and shuttle protons back and forth between the substrate and the peroxo hole along the reaction pathway. [source] Integration of General Sparse Matrix and Parallel Computing Technologies for Large,Scale Structural AnalysisCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 6 2002Hsien Hsieh, Shang Both general sparse matrix and parallel computing technologies are integrated in this study as a finite element solution of large,scale structural problems in a PC cluster environment. The general sparse matrix technique is first employed to reduce execution time and storage requirements for solving the simultaneous equilibrium equations in finite element analysis. To further reduce the time required for large,scale structural analyses, two parallel processing approaches for sharing computational workloads among collaborating processors are then investigated. One approach adopts a publicly available parallel equation solver, called SPOOLES, to directly solve the sparse finite element equations, while the other employs a parallel substructure method for the finite element solution. This work focuses more on integrating the general sparse matrix technique and the parallel substructure method for large,scale finite element solutions. Additionally, numerical studies have been conducted on several large,scale structural analyses using a PC cluster to investigate the effectiveness of the general sparse matrix and parallel computing technologies in reducing time and storage requirements in large,scale finite element structural analyses. [source] Visualizing massively multithreaded applications with ThreadScopeCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 1 2010Kyle B. Wheeler Abstract As highly parallel multicore machines become commonplace, programs must exhibit more concurrency to exploit the available hardware. Many multithreaded programming models already encourage programmers to create hundreds or thousands of short-lived threads that interact in complex ways. Programmers need to be able to analyze, tune, and troubleshoot these large-scale multithreaded programs. To address this problem, we present ThreadScope: a tool for tracing, visualizing, and analyzing massively multithreaded programs. ThreadScope extracts the machine-independent program structure from execution trace data from a variety of tracing tools and displays it as a graph of dependent execution blocks and memory objects, enabling identification of synchronization and structural problems, even if they did not occur in the traced run. It also uses graph-based analysis to identify potential problems. We demonstrate the use of ThreadScope to view program structure, memory access patterns, and synchronization problems in three programming environments and seven applications. Copyright © 2009 John Wiley & Sons, Ltd. [source] Prediction of the maximum credible ground motion in Singapore due to a great Sumatran subduction earthquake: the worst-case scenarioEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 8 2002Kusnowidjaja Megawati Abstract Although Singapore is located in a low-seismicity region, huge but infrequent Sumatran subduction earthquakes might pose structural problems to medium- and high-rise buildings in the city. Based on a series of ground motion simulations of potential earthquakes that may affect Singapore, the 1833 Sumatran subduction earthquake (Mw=9.0) has been identified to be the worst-case scenario earthquake. Bedrock motions in Singapore due to the hypothesized earthquake are simulated using an extended reflectivity method, taking into account uncertainties in source rupture process. Random rupture models, considering the uncertainties in rupture directivity, slip distribution, presence of asperities, rupture velocity and dislocation rise time, are made based on a range of seismologically possible models. The simulated bedrock motions have a very long duration of about 250 s with a predominant period between 1.8 and 2.5 s, which coincides with the natural periods of medium- and high-rise buildings widely found in Singapore. The 90-percentile horizontal peak ground acceleration is estimated to be 33 gal and the 90-percentile horizontal spectral acceleration with 5% damping ratio is 100 gal within the predominant period range. The 90-percentile bedrock motion would generate base shear force higher than that required by the current design code, where seismic design has yet to be considered. This has not taken into account effects of local soil response that might further amplify the bedrock motion. Copyright © 2002 John Wiley & Sons, Ltd. [source] How sustainable is the Japanese recovery?ECONOMIC OUTLOOK, Issue 4 2004Article first published online: 14 OCT 200 For nearly two years the Japanese economy has grown significantly faster than commentators expected, raising the question of whether the country has finally broken out of its long economic malaise. This article by Simon Knapp examines recent developments to see whether this recovery is sustainable. It argues that over the last year the recovery has broadened out beyond merely the export sector, although there are good reasons to believe that growth as measured by GDP has been overstated and that many serious structural problems remain. Business investment has surged on the back of rising profitability and an improved labour market has helped lift consumer confidence. At the same time the paper recognises the importance of China's boom in stimulating the Japanese economy over the last two years, and estimates that this factor may have boosted the level of GDP by between 1 to 2%. With Chinese growth now moderating to more sustainable levels, export growth will slow over the next year or so. However, domestic demand should now be strong enough, in the absence of major external shocks, to generate GDP growth of around 1.5 to 2% per annum in the medium term; a respectable figure given the country's falling population. [source] The Reign of James VI and I: the Birth of BritainHISTORY COMPASS (ELECTRONIC), Issue 1 2003Pauline Croft This article considers recent work over the past twenty-five years on the reign of James VI and I. The author argues that the multiple monarchy created by James VI of Scotland's accession to the English throne in 1603 was one of the greatest formative moments in the history of the British Isles, creating a political unit that endured until 1922, with the emergence of the Irish Free State. However, the structural problems of that multiple monarchy were also the major underlying cause of the ,British' civil war , fought out in Scotland and Ireland as well as England , that broke out in 1642. [source] Automatic energy conserving space,time refinement for linear dynamic structural problemsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 3 2005P. Cavin Abstract In this paper a local space,time automatic refinement method (STAR method) is developed to efficiently solve time-dependent problems using FEM techniques. The automatic process is driven by an energy or a displacement error indicator which controls the precision of the result. The STAR method solves the numerical problem on grids with different mesh size. For the Newmark schemes, a general demonstration, using the energy method, gives the interface conditions between two successive grids which is compatible with the stability of the scheme. Finally, using a linear one-dimensional example, the convergence of the method and the precision of the results are discussed. Copyright © 2005 John Wiley & Sons, Ltd. [source] Moving least-square interpolants in the hybrid particle methodINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 4 2005H. Huang Abstract The hybrid particle method (HPM) is a particle-based method for the solution of high-speed dynamic structural problems. In the current formulation of the HPM, a moving least-squares (MLS) interpolant is used to compute the derivatives of stress and velocity components. Compared with the use of the MLS interpolant at interior particles, the boundary particles require two additional treatments in order to compute the derivatives accurately. These are the rotation of the local co-ordinate system and the imposition of boundary constraints, respectively. In this paper, it is first shown that the derivatives found by the MLS interpolant based on a complete polynomial are indifferent to the orientation of the co-ordinate system. Secondly, it is shown that imposing boundary constraints is equivalent to employing ghost particles with proper values assigned at these particles. The latter can further be viewed as placing the boundary particle in the centre of a neighbourhood that is formed jointly by the original neighbouring particles and the ghost particles. The benefit of providing a symmetric or a full circle of neighbouring points is revealed by examining the error terms generated in approximating the derivatives of a Taylor polynomial by using a linear-polynomial-based MLS interpolant. Symmetric boundaries have mostly been treated by using ghost particles in various versions of the available particle methods that are based on the strong form of the conservation equations. In light of the equivalence of the respective treatments of imposing boundary constraints and adding ghost particles, an alternative treatment for symmetry boundaries is proposed that involves imposing only the symmetry boundary constraints for the HPM. Numerical results are presented to demonstrate the validity of the proposed approach for symmetric boundaries in an axisymmetric impact problem. Copyright © 2005 John Wiley & Sons, Ltd. [source] Elastoplastic dynamic analysis with hybrid stress elementsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 3 2002J. A. Teixeira de Freitas Abstract The stress model of the hybrid finite element formulation is applied to the solution of dynamic elastoplastic structural problems. The stress field is approximated in the domain of the elements and the displacements on its boundary. The displacement, velocity and acceleration approximations in the domain of the element are implicit, in the sense that they result from a combination of the stress estimate with the time integration procedure that ensures that the equilibrium condition is locally satisfied. The finite elements are subdivided in plastic cells where a gradient dependent model is implemented using a hybrid formulation based on the approximation of the plastic parameter and the plastic radiation fields in the domain and on the boundary of the plastic cells, respectively. Generalized variables associated with orthogonal and naturally hierarchical bases are used. The resulting solving systems are symmetric, sparse, p -adaptive and well suited to parallel processing. The performance of the element is assessed using a representative set of testing problems. Copyright © 2001 John Wiley & Sons, Ltd. [source] The p -version of the finite element method for three-dimensional curved thin walled structuresINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 7 2001A. Düster Abstract In this paper we present an implementation of a three-dimensional p -version for structural problems of solids with almost arbitrarily curved surfaces. Applying the blending function method, complex structures can often be modelled by a few p -elements, being the basis for a higher order approximation. Numerical examples will demonstrate, that the p -version with anisotropic Ansatz spaces allows to predict the structural behaviour of three-dimensional plates and shells with approximately the same amount of degrees of freedom as in the two-dimensional case, yet significantly more accurate due to the three-dimensional model. Furthermore, it is advantageous to compute complex structures exclusively with three-dimensional discretizations as no special elements are needed to model the transition from dimensionally reduced formulations like plates or shells to fully three-dimensional solid elements. Using the p -version with anisotropic Ansatz spaces the whole structure can be efficiently discretized with solid elements, even if the aspect ratio of the elements becomes very large. Copyright © 2001 John Wiley Sons, Ltd. [source] Foundational Value of Statistics Education for Management CurriculumINTERNATIONAL STATISTICAL REVIEW, Issue 3 2007Hirokuni Tamura Traitement humain de l'information; Education/Enseignement; Prise de décision; Prévision; Modèles statistiques Summary The purpose of this paper is to propose a unique and distinct value of statistics education for management. The 1986 inaugural conference on Making Statistics More Effective in Schools of Business (MSMESB) proposed valuable guidelines for reforming statistics education in schools of business. However, a survey conducted by McAlevey & Everett (2001) identified that their impact has been minimal, and argued that structural problems many business schools have are the potential cause. We argue these structural problems exist because the value of the body of statistical tools for management is ambiguous and has not been made explicit. The unique and distinct value of statistics for management can be identified as the body of tools necessary to meet the inherent needs of a manager charged with making predictive judgments facing data. The need arises because human information-processing capacity is quite limited, as the findings of researchers in cognitive psychology testify. These findings also affirm that the basic statistical concepts needed for processing data cannot be learned from management experiences. The model of a manager faced with data, while considering the evidence of inherent limitations of human information-processing capacity, establishes the foundational value of statistics training in the management curriculum. Statistics education in business schools will be made more effective when management educators recognize such value of the discipline, lend their support and reward the ownership commitment for continuous improvement and innovations of the business statistics curriculum. Résumé Le but de cet article est de proposer une valeur unique et particulière de l'enseignement des statistiques dans le domaine de la gestion. La conférence inaugurale de 1986 traitant des moyens d'améliorer l'efficacité de cet enseignement dans les écoles de gestion a proposé des lignes directrices valables pour la réforme de l'enseignement des statistiques dans les écoles de gestion. Néanmoins, un sondage effectué par McAlevey & Everett (2001), a identifié leur impact comme étant minimal et en attribue la cause probable aux problèmes structurels des écoles de gestion. Nous considérons que ces problèmes existent parce que la valeur du corpus statistique de gestion est ambigüe et n'a pas été mise en lumière. La valeur unique et distincte des statistiques de gestion peut être identifiée comme un corpus d'outils nécessaires pour répondre aux besoins inhérents d'un gestionnaire chargé de faire des prévisions au moyen d'informations brutes. Ce besoin vient du fait que la capacité humaine de traitement de l'information est limitée ainsi qu'en témoignent les recherches en psychologie cognitive. Ces résultats affirment également que les concepts statistiques basiques nécessaires pour le traitement de l'information ne peuvent être acquis par l'expérience de la gestion. Le modèle du gestionnaire confronté de l'information, une fois l'évidence des limites des capacités humaines en matière de traitement de l'information est prise en compte, établi la valeur fondatrice de l'entrainement aux statistiques dans un curriculum de gestion. L'enseignement des statistiques dans les écoles de commerce sera plus efficace quand les responsables de l'éducation reconnaitront cette valeur de la discipline, y apporteront leur soutien et récompenseront les actions visant à l'amélioration et l'innovation constante au sein du curriculum statistique de gestion. [source] On Doing Being a Stranger: The Practical Constitution of Civil InattentionJOURNAL FOR THE THEORY OF SOCIAL BEHAVIOUR, Issue 1 2005STEFAN HIRSCHAUER ABSTRACT:The article takes on a less developed aspect of the sociology of the stranger: the normalized non-relations people in urban settings establish in their effort to stay strangers for one another. How is their "civil inattention"accomplished in practice? What is the social orderliness of "asocial" relations? In order to answer these questions the article uses the elevator as a sociological research instrument allowing for a highly detailed investigation in structural problems of public encounters: bodily navigation, contact avoidance, feigned preoccupation, and the blocking of the automatism by which co-present bodies start interactions. The setting used for the investigation also raises questions about how the artifact and the bodies present are integrated into the interaction order. The "heteromobile" of the elevator offers specific sociotechnical scripts for interaction. While the human actors work hard at doing nothing, their bodies seem to take over their agency. The specific challenge of elevator riding for the enactment of indifference is the vanishing of actors: undoing presence. [source] Intertemporal analysis of employment decisions on agricultural holdings in SloveniaAGRICULTURAL ECONOMICS, Issue 2 2005Luka Juvan Employment decisions; Mobility of labor supply; Off-farm employment; Probit model Abstract The article attempts to quantify determinants influencing the dynamics of employment decisions on agricultural holdings in Slovenia and to test specific aspects of labor reallocation during the transition period by the application of an agricultural household model. Through the use of a 1991,2000 longitudinal data set for 22,055 farm households, quantitative analysis of intertemporal employment decisions by farm holders is carried out using probit techniques. The determinants tested relate to the personal characteristics of farm holders (gender, age, education level, and potential off-farm income), household characteristics (size, structure), characteristics of the agricultural holding (economic size, labor intensity), and local labor market conditions. The model results generally confirm existing empirical evidence on asymmetrical and irreversible participation of holders on the labor market. Despite intensive restructuring of agriculture and profound changes in the nonfarm labor market in the analyzed period, labor supply of farm holders remains rigid. The mobility of labor supply is lower than expected, which can be attributed to the importance of structural problems constraining intersectoral mobility. Low labor mobility reduces the efficiency of labor allocation on agricultural holdings in Slovenia. Elements of this problem emerge on both supply (e.g., low level of educational and professional attainment of reference persons) and demand sides of the labor market (e.g., unfavorable local labor market conditions). A marked tendency toward maintaining the same employment status is more distinct in the case of holders employed on-farm only. [source] Updating the Foreign Language AgendaMODERN LANGUAGE JOURNAL, Issue 3 2001Richard D. Lambert At the founding of the National Foreign Language Center in 1987, several major structural problems facing the field of foreign language (FL) instruction were identified in an editorial in The Modern Language Journal. These broad architectural issues are part of a national agenda for change, both here and abroad, and have been the focus of the NFLC's activities since its establishment. The agenda issues identified in the article are: evaluating language competency; articulating instruction across educational levels and the different contexts in which FLs are taught; increasing the range of languages taught and studied; achieving higher levels of language skills; promoting language competency and use among adults; expanding research and maximizing its impact on FL teaching and learning; and assessing and diffusing new technologies in instructional practice, with particular attention to Internet communication, machine translation, and distance education. The article briefly indicates the nature of these challenges and notes the progress that has been made. [source] LIMITS TO COMPETITION AND REGULATION IN PRIVATIZED ELECTRICITY MARKETSANNALS OF PUBLIC AND COOPERATIVE ECONOMICS, Issue 4 2009Hulya Dagdeviren ABSTRACT,:,Privatization of electricity has been extensive both in the developed and the developing world. Failures in various areas have led to the emergence of a new consensus which regards competitive pressures and regulation as crucial for utility privatizations to work. This review paper presents a critical evaluation of this newly found wisdom with reference to the developing economies. The experience in the developed world, especially in the USA and the UK, has been used to draw conclusions for the developing economies. Overall, the paper highlights the problems associated with the ,competitive model' both in the developed and developing world and points to the potential instability in private competitive power supply systems. It also examines the degree to which regulation can be a panacea for market failures and structural problems under private provision. [source] China and the Global Financial Crisis: Assessing the Impacts and Policy ResponsesCHINA AND WORLD ECONOMY, Issue 3 2010Yan Liang F40; O11; O53 Abstract The present paper explores the role of China in the creation of the current global financial crisis and the impacts of the crisis on its economy. It argues against the view that the "saving glut" in China (along with other Asian emerging economies) played a significant causal role in the crisis. The global financial crisis did not engender much damage in China's financial structure, thanks to the relatively closed, bank-centered financial system. However, the impacts on the "real" side of the Chinese economy were hard felt. Growth and employment have fallen, largely due to the decline in exports and foreign direct investment. The crisis reveals the vulnerability of the export-dependent growth pattern. Policy responses of the Chinese Government, including monetary, fiscal and social policies, have helped to stem the downfall of the economy in the immediate term, but some of the policies have not addressed the structural problems of the Chinese economy and might well aggravate such problems over time. The present paper proposes a tentative reform blueprint to rebalance the economy and to sustain long-term growth. [source] China as a Net Creditor: An Indication of Strength or Weaknesses?CHINA AND WORLD ECONOMY, Issue 6 2007Xin Wang E44; F21; F31; F41 Abstract China's international investment position is characterized by large net foreign assets, a dominance of low-return foreign exchange reserves and costly foreign direct investment in foreign assets and foreign liabilities. In addition, China's foreign investment positions are facing potentially large exchange risks. These features reflect entrenched institutional and structural problems in China, including underdeveloped capital markets, biased resource allocation and a defective social security system. China's net creditor status might actually be an indication of weakness rather than strength. To improve its international investment position, China must speed up economic reforms and allow the market to play a fundamental role in resource allocation. [source] | |||||||||||||||||||