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Researchers have met the challenge of modeling impact events involving composite targets for a variety of applications in a variety of ways. In this paper, the theory and implementation details of an orthotropic visco-elastic-visco-plastic material model with strain rate dependence are discussed. The model is driven by experimental data from quasi-static as well as high strain rate tests, and the data is used in defining the deformation, damage and failure sub-models. Validation data is generated by shooting a hollow 50 g Al-2024 projectile at different velocities against a flat panel target made of unidirectional composite material in a 16-ply [(0/90/45/-45)2]S layup. Explicit dynamic finite element analyses of four high speed tests involving one contained (projectile rebounded) and three uncontained (projectile penetrated) impact tests show that the developed material model and modeling techniques yield reasonable and acceptable predictions.

A material model which incorporates several key capabilities which have been identified by the aerospace community as lacking in the composite impact models currently available in the commercial transient dynamic finite element code LS-DYNA® has been developed. The material model utilizes experimentally based tabulated input to define the evolution of plasticity and damage as opposed to specifying discrete input parameters (such as modulus and strength. The plasticity portion of the orthotropic, three-dimensional, macroscopic composite constitutive model is based on an extension of the Tsai-Wu composite failure model into a generalized yield function with a non-associative flow rule. The capability to account for the rate and temperature dependent deformation response of composites has also been incorporated into the material model. For the damage model, a strain equivalent formulation is utilized to allow for the uncoupling of the deformation and damage analyses. In the damage model, a diagonal damage tensor is defined to account for the directionally dependent variation of damage. However, the terms in the damage matrix are semi-coupled such that the damage in a particular coordinate direction is a function of the stresses and plastic strains in all of the coordinate directions. For the failure model, a tabulated approach is utilized in which a stress or strain based invariant is defined as a function of the location of the current stress state in stress space to define the initiation of failure, which allows an arbitrarily shaped failure surface to be defined. A systematic series of validation and verification studies, at a variety of length scales ranging from single element simulations to simulations of a flat panel impact test, have been performed to fully exercise and evaluate the capabilities of the developed model.

A new orthotropic elasto-plastic constitutive model has been developed to predict the inelastic response of composite materials under high velocity impact conditions. The model is driven by experimental stress-strain curve data stored as tabular input allowing for a very general material description. The theoretical details of the elasto-plastic deformation part of the material model are briefly summarized. This summary is then followed by details of the numerical implementation of the model as MAT213 (suitable for use with solid elements) into the commercial transient dynamic finite element code, LS-DYNA. The theoretical basis and the numerical implementation of the constitutive model are validated by using two sets of validation tests involving a widely used unidirectional composite, T800/F3900 - composite laminates used in coupon level tests and a low velocity impact test on a flat panel. Results show that the implementation is efficient, robust and accurate.

A simultaneously coupled modeling approach to study the electrochemical and thermal behavior of lithium-ion batteries under large mechanical deformation has been developed. The thermo-electrochemical pseudo-2D (P2D) battery model is coupled with a mechanical material model. Mechanical, thermal, and electrochemical models are implemented as user-defined sub-routines in the commercial multi-physics code LS-DYNA. The mechanical strain experienced by anode, cathode and separator results in thickness and porosity changes in each layer which in turn influences electrochemical behavior. The evolution of concentration profiles and cell potential are studied under different mechanical loading conditions. Internal short-circuits caused by mechanical deformation and corresponding physical behaviors are also elucidated. We discuss the competing effects of improved transport at higher temperature due to the internal short-circuit versus a drop in the effective ionic conductivity and electrolyte diffusivity due to mechanical deformation.

The need for accurate material models to simulate the deformation, damage, and failure of polymer matrix composites under impact conditions is becoming more and more critical, because these...

The need for accurate material models to simulate the deformation, damage and failure of polymer matrix composites under impact conditions is becoming critical as these materials are gaining increased use in the aerospace and automotive communities. The aerospace community has identified several key capabilities which are currently lacking in the available material models in commercial transient dynamic finite element codes. To attempt to improve the predictive capability of composite impact simulations, a next generation material model is being developed for incorporation within the commercial transient dynamic finite element code LS-DYNA. The material model, which incorporates plasticity, damage and failure, utilizes experimentally based tabulated input to define the evolution of plasticity and damage and the initiation of failure as opposed to specifying discrete input parameters such as modulus and strength. The plasticity portion of the orthotropic, three-dimensional, macroscopic composite constitutive model is based on an extension of the Tsai-Wu composite failure model into a generalized yield function with a non-associative flow rule. For the damage model, a strain equivalent formulation is used to allow for the uncoupling of the deformation and damage analyses. For the failure model, a tabulated approach is utilized in which a stress or strain based invariant is defined as a function of the location of the current stress state in stress space to define the initiation of failure. Failure surfaces can be defined with any arbitrary shape, unlike traditional failure models where the mathematical functions used to define the failure surface impose a specific shape on the failure surface. In the current paper, the complete development of the failure model is described and the generation of a tabulated failure surface for a representative composite material is discussed.

Generalized constitutive models, which can be used in explicit finite-element analysis, are being developed to accurately model composite systems under impact conditions. These models requi...

INTRODUCTION Although much effort has been devoted to studying yeast in the past few decades, our understanding of this model organism is still limited. Rapidly developing DNA synthesis techniques have made a “build-to-understand” approach feasible to reengineer on the genome scale. Here, we report on the completion of a 770-kilobase synthetic yeast chromosome II (synII). SynII was characterized using extensive Trans-Omics tests. Despite considerable sequence alterations, synII is virtually indistinguishable from wild type. However, an up-regulation of translational machinery was observed and can be reversed by restoring the transfer RNA (tRNA) gene copy number. RATIONALE Following the “design-build-test-debug” working loop, synII was successfully designed and constructed in vivo. Extensive Trans-Omics tests were conducted, including phenomics, transcriptomics, proteomics, metabolomics, chromosome segregation, and replication analyses. By both complementation assays and SCRaMbLE (synthetic chromosome rearrangement and modification by loxP -mediated evolution), we targeted and debugged the origin of a growth defect at 37°C in glycerol medium. RESULTS To efficiently construct megabase-long chromosomes, we developed an I- Sce I–mediated strategy, which enables parallel integration of synthetic chromosome arms and reduced the overall integration time by 50% for synII. An I- Sce I site is introduced for generating a double-strand break to promote targeted homologous recombination during mitotic growth. Despite hundreds of modifications introduced, there are still regions sharing substantial sequence similarity that might lead to undesirable meiotic recombinations when intercrossing the two semisynthetic chromosome arm strains. Induction of the I- Sce I–mediated double-strand break is otherwise lethal and thus introduced a strong selective pressure for targeted homologous recombination. Since our strategy is designed to generate a markerless synII and leave the URA3 marker on the wild-type chromosome, we observed a tenfold increase in URA3 -deficient colonies upon I- Sce I induction, meaning that our strategy can greatly bias the crossover events toward the designated regions. By incorporating comprehensive phenotyping approaches at multiple levels, we demonstrated that synII was capable of powering the growth of yeast indistinguishably from wild-type cells (see the figure), showing highly consistent biological processes comparable to the native strain. Meanwhile, we also noticed modest but potentially significant up-regulation of the translational machinery. The main alteration underlying this change in expression is the deletion of 13 tRNA genes. A growth defect was observed in one very specific condition—high temperature (37°C) in medium with glycerol as a carbon source—where colony size was reduced significantly. We targeted and debugged this defect by two distinct approaches. The first approach involved phenotype screening of all intermediate strains followed by a complementation assay with wild-type sequences in the synthetic strain. By doing so, we identified a modification resulting from PCRTag recoding in TSC10 , which is involved in regulation of the yeast high-osmolarity glycerol (HOG) response pathway. After replacement with wild-type TSC10 , the defect was greatly mitigated. The other approach, debugging by SCRaMbLE, showed rearrangements in regions containing HOG regulation genes. Both approaches indicated that the defect is related to HOG response dysregulation. Thus, the phenotypic defect can be pinpointed and debugged through multiple alternative routes in the complex cellular interactome network. CONCLUSION We have demonstrated that synII segregates, replicates, and functions in a highly similar fashion compared with its wild-type counterpart. Furthermore, we believe that the iterative “design-build-test-debug” cycle methodology, established here, will facilitate progression of the Sc2.0 project in the face of the increasing synthetic genome complexity. SynII characterization. ( A ) Cell cycle comparison between synII and BY4741 revealed by the percentage of cells with separated CEN2-GFP dots, metaphase spindles, and anaphase spindles. ( B ) Replication profiling of synII (red) and BY4741 (black) expressed as relative copy number by deep sequencing. ( C ) RNA sequencing analysis revealed that the significant up-regulation of translational machinery in synII is induced by the deletion of tRNA genes in synII.

Prediction of failure in metal sheets is an important topic for the sheet forming community, as well as for the automotive crash community. The word 'failure' can have different meaning for different individuals within these communities. Methods for failure prediction within this area can either focus on the prediction of plastic instability (necking), or on the actual fracture phenomenon. The pros and cons of these approaches are discussed in this paper. The current authors have chosen to favour methods for necking prediction. The traditional method for necking prediction is to use a limit curve in the principal strain space (FLD). The great disadvantage of this approach is that it is only applicable for linear strain paths. In fact, the necking phenomenon can be shown to be strongly strain path dependent. In the current report, four different numerical methods for instability prediction are discussed, and compared in applications to some simple problems involving broken strain paths. It is shown that these methods can yield dramatically different results in some particular cases. Based on the findings of this study, the paper concludes with some recommendations for how the failure prediction problem best can be handled in industrial sheet forming and crash simulations.

The need for accurate material models to simulate the deformation, damage, and failure of polymer matrix composites under impact conditions is becoming critical as these materials are gaining increased usage in the aerospace and automotive industries. There are a variety of material models currently available within commercial transient dynamic finite-element codes to analyze the response of composite materials under impact conditions. However, there are several features that are lacking in the currently available models that could improve the predictive capability of the impact simulations. To address these needs, a combined elasto-plastic model with damage suitable for implementation within transient dynamic finite-element codes has been developed. A key feature of the improved material model is the use of tabulated stress-strain data in a variety of coordinate directions to fully define the stress-strain response of the material. Currently, the model development efforts have focused on creating the plasticity portion of the model. A commonly used composite failure model has been generalized and extended to a strain-hardening-based orthotropic yield function with a non-associative flow rule. The coefficients of the yield function are computed based on the input stress-strain curves using the effective plastic strain as the tracking variable. The coefficients of the flow rule are determined in a systematic manner based on the available stress-strain data for the material. The evolution of the yield surface is examined, in detail, for a sample composite. A numerical algorithm based on the classic radial return method is employed to compute the evolution of the effective plastic strain. A specific laminated composite is examined to demonstrate the process of characterizing and analyzing the response of a composite using the developed model. The developed material model is suitable for use within commercial transient dynamic finite-element codes for use in analyzing the nonlinear response of polymer composites.

Metal failure in many applications, such as ballistic impact, containment, shielding, metal forming, and crashworthiness, occurs while the material is in a three-dimensional state of stress. Many previous definitions of triaxiality use two invariants to define the relative stress state in a virtual element, leading to a characterization that can be better thought of as biaxial. In this paper, an additional parameter based upon the third stress invariant is defined, which extends the characterization of the state of stress to three dimensions and to true triaxiality. The relation of the two parameters is explored and limits are found in the failure surface, which is used in defining the critical failure regions. Standard tests are examined to determine if they can provide enough data to construct these regions of interest and new tests are proposed, which envelope the limits and thus define this failure surface.

Modeling the high velocity impact of ice was a requirement in the safety calculations for the return-to-flight of the Space Shuttle on July 26, 2005. Ice, however, is not a common structural material and commercial finite element programs did not have any appropriate models. A phenomenological model with failure was developed to match experimental ballistic tests. The model has a relatively small number of material constants, most of which have been measured experimentally. A description of the model and comparisons of calculations to experiments are presented.

For almost three decades, I have had the privilege of observing the political, economic, social, and cultural changes in Germany. It was a period that was characterized by such terms as Mittelstreckenraketen (medium -ran ge mis- siles), "SS20S," Pershing missiles, and the stationing of nuclear weapons on German soil. All this was accompanied by the NATO debate on the Dop- pelbeschluss, the double-track decision put forward and championed by Hel- mut Schmidt. I was well acquainted with the pioneers of the peace movement and closely associated with the emergence of the pacifist and en- vironmental trends that led to the creation of the Green party in Germany. These are the historical moments that fundamentally shaped and changed the Bonner Republik. Of course all this happened against the backdrop of the Cold War, Ostpolitik, and the normalization of the so-called innerdeutsche Beziehungen, relations between the two German states. In those years, no one could have foreseen the radical outcome of 1989, with the end of the Soviet Union, the reunification of Germany, and the emergence of this reunified country, with Berlin once again its capital. What a road it has been. I count myself lucky to have been able to witness these profound changes, which allowed Germany to reconcile itself with the past and to gradually become a normal country again, an important player on the European and international stage, not only economically but also politically and culturally.The end of this long road is in sight. When I think of the consequences of the Second World War and the Franco-German efforts leading up to the signing of the Elysee treaty by de Gaulle and Adenauer, sealing a friendship crucial for the future of Europe, I cannot help but recognize how the various German governments worked relentlessly to realize the "national dream." Right from the beginning, this dream involved creating ties strong enough to prevent any repeat of the cruel experiences of the 20th century. This desire to be integrated in a larger entity - beyond national borders - gave rise to the European Union, whose roots lie in the European Coal and Steel Community, the 1957 treaty of Rome, and the decisions to consolidate and expand the EU from the six founding countries to the 27 members today. Germany has achieved its "dream" of overcoming its isolation and upheaval to create solid ties with its neighbours, large and small, and to become a country no longer on the eastern margins of the European Community but at the geographical centre of the EU. This dream has been realized peacefully in a reunified Germany and in a continent free of east-west tensions.Does this mean that, its national dream having been realized, Germany no longer has a dream? What I see today is an adjustment of aspirations and an evolution of realities. Globalization obviously plays a significant role here and certainly explains to some extent why Germany has in recent years been increasingly turning its attention to the east, to Russia, a major energy supplier, but also to the emerging markets, in particular China and India. This inevitably has an effect on the transatlantic relationship, which has lost some of its dynamism, or rather common destiny, since the imminent threat posed by the Cold War has evaporated. Yet the transatlantic connection remains particularly important and has, undoubtedly, been underestimated in some areas over the last few years in the wake of September nth. We are bound by our common destiny: Angela Merkel took the right step in launching a transatlantic economic partnership initiative with the US and Canada, with a view to reducing or eliminating the numerous non-tariff trade barriers hindering the expansion of our commercial and economic links, especially in science and technology and investment. …

In the mouse, insulin is produced from two similar but nonallelic genes that encode proinsulins I and II. We have investigated expression of these two genes during mouse embryonic development, using a PCR to detect the two gene transcripts and immunocytochemistry to visualize the two corresponding proteins. At appearance of the dorsal pancreatic anlage at day 9.5 of gestation, both mRNAs could be detected in the embryos, and both proteins were present together in the same cells of the developing pancreas. At days 9.5 and 10.5, when the ventral anlage appears, there were fewer proinsulin II mRNAs than proinsulin I mRNAs. At day 12.5 this ratio was reversed. Proinsulin II mRNA, but not proinsulin I mRNA, could be detected at day 8.5 in the prepancreatic embryo. Proinsulin II mRNA, but not proinsulin I mRNA, was also found in the heads of embryos at day 9.5 and at all later stages studied. These results indicate that the two proinsulin genes are regulated independently, at least in part. They also suggest that insulin might play a role as a growth factor in the developing mouse brain.

The oil field of Rospo Mare is located in the Adriatic Sea, 20 km of the Italian coast. The reservoir lies at a depth j of 1300 m and consists of a paleokarst of Oligocene to Miocene age which developed within cretaceous limestones, now covered by 1200 m of mio-pliocene sequences. The oil column is about 140 m high. The karstic nature of the reservoir was identified through vertical, cored drill holes which allowed the analysis of the various solution features and the sedimentary infilling (spe-leothems, terra rossa, marine clays), as well as their vertical distribution. Erosion morphology at the top of the karst is highly irregular, including more especially paleoval-leys as well as many pit-shaped sinkholes. Observations concerning the upper part of the reservoir were compared to a paléokarst of the same age, outcropping widely, onshore, in quarries located nearby. Detailed knowledge of that morphology through geophysics helped to optimize the development of the field through horizontal drilling. The paléokarst of Rospo Mare is an integral part of the ante miocene paléokarst assemblages of the periphery of the Mediterranean which were formed in tropical conditions., Le gisement pétrolier de Rospo Mare est situé en Adriatique, à 20 km des côtes italiennes. Le réservoir situé à 1300 m de profondeur est constitué par un paléokarst d'âge oligo-miocène développé dans des calcaires crétacés recouverts par 1200 m de couverture mio-pliocène. Il est imprégné sur une hauteur de 140 m. Le réservoir karstique a été caractérisé par des forages verticaux carottés qui ont permis d'analyser les différentes formes de dissolution et de remplissage (concrétions, terra rossa, argile marine) ainsi que leur distribution verticale. La morphologie d'érosion du toit du karst est très irrégulière et comporte notamment des paléovallées et de nombreuses dolines-puits. Les observations concernant la partie supérieure du réservoir ont été comparées à un paléokarst voisin de même âge et affleurant largement en carrière. La connaissance détaillée de cette morphologie à l'aide de la géophysique a permis d'optimiser le développement du champ par puits horizontaux. Le paléokarst de Rospo Mare s'intègre à l'ensemble des paléokarsts anté-miocènes du pourtour méditerranéen qui présentent des caractéristiques de karsts de climats tropicaux., Dubois Paul, Sorriaux P, Soudet Henri- Jean. Rospo Mare (Adriatique) : un paléokarst pétrolier du domaine méditerranéen. In: Karstologia : revue de karstologie et de spéléologie physique, n°21, 1er semestre 1993. pp. 31-42.

The change in catches and mean size of one-year-old perch (Perca fluviatilis) in Lake Geneva was studied between 1957 and 2005, and related to trophic changes and average temperature. The status of Lake Geneva, assessed on the basis of total phosphorus concentrations, switched from being oligotrophic before 1960 to eutrophic, with total phosphorus concentration reaching nearly 90 µ gL −1 in 1976-1979. In response to management measures, the trophic status then returned to mesotrophy in the early 2000s. Zooplankton is the main food consumed by young perch, and quantities present (annual biovolumes of zooplankton) were recorded throughout the study period. The lake water tem- perature was also recorded. Data obtained from perch catches and perch spawns enabled eleven strong cohorts of perch to be identified. Strong cohorts dominated the stock for three years, until they were massively caught by fishermen. Yields have fluctuated widely, increasing rapidly until 1975, and subsequently decreasing, with an exceptional decline between 1976 and 1981. During the period 1977-1981, unfavourable climatic conditions in spring were probably the main cause of this fall in perch yields. For the other periods, perch yields and the mean size of one-year-old perch were significantly correlated with trophic parameters, total phosphorus concentration and zooplankton biovolume. Correla- tions are higher if only strong cohorts are taken into account. As a result of the re-oligotrophication process, perch growth has been progressively reduced, age at first maturity delayed and strong cohorts become less frequent; the mean size of 0+ individuals in strong cohorts is significantly smaller than in the other cohorts, suggesting a population density effect in the context of a limited supply of zooplankton. During the study period, trophic changes in Lake Geneva have had more impact on perch growth and yield than has temperature, since no significant correlation could be detected between water temperature and perch growth.

Identifiant de l'operation archeologique : 9205 Date de l'operation : 2007 (MH) La fouille a ete motivee par une prescription liee aux diagnostics realises en 2003 et 2005 sur cette carriere de sable (BSR, 2003 et 2005). Le site se place sur la rive droite de l’Oise, a moins de 70 m du cours d’eau actuel. Son positionnement sur une butte sableuse le protege des crues de la riviere. Il faut retirer en moyenne 0,40 m de terre vegetale pour observer les creusements anthropiques dans le sedimen...

Paul Dubois : Industrial statistics in progress The recession and the intensity of international competition make it necessary to take decisions on firmer grounds. Good industrial statistics are therefore required. The annual survey of enterprises, the Balance sheets data banks, the exploitation of the "B.I.C (Industrial and Commercial Revenues)", the "S.U.S.E (Enterprise Statistics system)", the E.N.E.I.D.E data bank, represent very important progress made in the last 10 years, by the public statisticians far the understanding of enterprises. It remains to the decision makers to make the best out of it. The product statistics still have to be transformed however. A deep reform of the "branch" surveys should be the major requirement., Paul Dubois : La mutation de la statistique industrielle La crise et la dureté de la concurrence internationale rendent indispensables de fonder plus rigoureusement les décisions industrielles. Pour cela une bonne statistique industrielle est nécessaire. Avec les Enquêtes Annuelles d'Entreprises, les Centrales de Bilans, l'exploitation des"B.I.T.", le système "S.U.S.E." et la Banque de Données "E.N.E.I.D.E."des progrès très importants ont été réalisés par les statisticiens publics, au cours des dix dernières années, dans la connaissance des entreprises. Il appartient aux décideurs d'en tirer le meilleur parti. En revanche une mutation des statistiques sur les produits reste à accomplir. Une réforme profonde des enquêtes de branches doit en être l'élément majeur., Dubois Paul. La mutation de la statistique industrielle. In: Revue d'économie industrielle, vol. 3, 1er trimestre 1978. pp. 14-28.

Breaks in growth and technical progress - 1974 marked a break in french growth, which was accompanied by a break in labor productivity. These breaks, which became more pronouced after 1979, received technological interpretations. In order to appreciate their validity, a detailed quantitative analysis is necessary. The recent evolutions must be relied with the long run ones, and the results got for France compared with thoses available for other developped countries. Conceptual and statistical difficulties bring to adopt a progressive approach, starting from partial productivities of labor and capital, to go to global productivity of factors and then to « technical progress ». Several elements must be taken into account : quality of workers, degree of factors utilization, age of capital, farmers' migrations, supply effects of oil schocks. The conclusions are clear. The rythm of technical progress hardly slew down after 1973, a little more after 1979. This slow down finds no doubt its origin in the end of a quick catching up era of american productivity level. But it can explain only a small part of the slow down of french growth. This slow down results from an upset of regulation mecanisms of french economy and international economy, upset which led to a slackening in the evolution of production factors and of their degree of utilization., L'année 1974 a marqué une rupture dans la croissance française, qui s'est accompagnée d'une rupture dans la productivité du travail. Ces ruptures, qui se sont accentuées après 1979, ont reçu des interprétations technologiques. Pour apprécier leur validité, une analyse quantitative approfondie est nécessaire. Les évolutions récentes doivent être replacées par rapport aux évolutions de long terme, et les résultats obtenus pour la France comparés à ceux disponibles pour les autres pays développés. Les difficultés conceptuelles et statistiques amènent à adopter une démarche progressive, partant des productivités partielles du travail et du capital, pour passer à la productivité globale des facteurs puis au « progrès technique ». De nombreux éléments sont à en prendre en compte : qualité de la main-d'œuvre, taux d'utilisation des facteurs, âge du capital, migrations agricoles, effets d'offre des chocs pétroliers. Les conclusions qui se dégagent sont claires. Le rythme du progrès technique s'est à peine affaibli après 1973, un peu plus après 1979. Cet affaiblissement trouve sans doute son origine dans la fin d'une ère de rattrapage des niveaux de productivité américains. Mais il ne peut expliquer qu'une part réduite du ralentissement de la croissance. Celui-ci résulte d'un dérèglement des mécanismes de régulation internes et internationaux des économies développées, dérèglement qui a entraîné un ajustement à la baisse de l'évolution des facteurs de production et de leur degré d'utilisation., Rupturas de crecimiento y adelantos técnicos - El año 1974 se senaló por una ruptura del crecimiento francés, acompanada con una ruptura de la productividad laboral. Dichas rupturas, las que se fueron acrecentando después de 1979, fueron interpretadas tecnológicamente. Con objeto de apreciar su validez, un análisis cuantitativo profundizado se impone. Las recientes evoluciones deben de volverse a colocar con relación a las evoluciones de largo plazo, y los resultados conseguidos para Francia deben de equipararse con los de que se dispone para los demás países desarrollados. Las dificultades conceptuales y estadísticas encarrilan a adoptar un trámite progresivo, partiendo de las productividades parciales laborales y del capital, para pasar a la productividad global de los factores y finalmente al « desarrollo tecnico ». Debe de tenerse en cuenta numerosos elementos : calidad de la fuerza laboral, tasa de utilización de los factores, edad del capital, migraciones agrícolas, efectos de oferta de los golpes petroleros. Las conclusiones que se desprenden son claras. El ritmo de desarrollo tecnico se fué ralentizando escasamente después de 1973, algo mas después de 1979. Dicha ralentización esta sin duda originada en el final de una era de recuperación de los nivelés de productividad americanos. Mas, tan solo puede explicar una escasa porción de la ralentización del crecimiento. Este resulta de un desajuste de los mecanismos de regulación internos e internacionales de las economías desarrolladas, desajuste que acarreó un ajuste a la baja de la evolución de los factores productivos y de su grado de utilización., Dubois Paul. Ruptures de croissance et progrès technique. In: Economie et statistique, n°181, Octobre 1985. Ruptures de croissance et progrès technique / Les entreprises industrielles en 1984 / Les investissements de la RATP, sous la direction de Daniel Temam. pp. 3-31.

Growth of business investment has been very weak in France, like in other european countries, since 1973. Their pick-up, since 1985 (since 1984 in manufacturing), is faltering. However level of investment was very high in 1973. Therefore the increase of capital remained important a long time. But the capital aged and scraping is high to-day in comparison with new investments. Moreover productivity of capital has strongly dropped in France since 1979. Changes more favorable need nigh rates of return, but also a best allocation and a best use of equipments. These on increasing immaterial investments., La croissance des investissements des entreprises a été très faible en France, comme dans les autres pays européens, depuis 1973. Leur reprise, depuis 1985 (depuis 1984 dans l'industrie), est hésitante. Cependant le niveau des investissements était très élevée en 1973. Aussi la progression du capital est restée longtemps importante. Mais le capital a vieilli et les déclassements d'équipements sont aujourd'hui élevés par rapport aux investissements nouveaux. En outre, la productivité du capital a fortement baissé en France depuis 1979. Des mouvements plus favorables impliquent des taux de profit élevés, mais aussi une meilleure allocation et une meilleure utilisation des équipements. Celles-ci dépendent d'investissements immatériels accrus., Dubois Paul. « L'investissement des entreprises : diagnostic macro-économique ». In: Revue d'économie industrielle, vol. 40-41, 2e trimestre 1987. L'investissement en France. pp. 13-25.

Versa sobre los aspectos macroeconomicos de la planificacion y, mas precisamente, las proyecciones y modelos que permiten esclarecer las estrategias macroeconomicas. Examina los papeles diferentes de las proyecciones macroeconomicas en la planificacion; la utilidad y las limitaciones del empleo de modelos, y las maneras de incorporar la incertidumbre en el empleo de modelos para la planificacion. Se basa en la experiencia francesa en materia de planificacion.

The public system of statistical information regarding firms - Analyzing former times discloses that statistics regarding the productive system is a recent phenomenon; as a matter of fact the first censuses of the large economic sectors were first taken at the beginning of the sixties. INSEE has thus, for the last few years, applied itself to get in position a statistical observation system regarding firms. Consequently, it is convenient to take into account the part taken by each actor face to face : the firms which supply information and the different civil services and professional organizations collecting and processing information (Part 2). The structure of the system comprises four levels : the basic tools (definitions, nomenclatures, directories), the statistical surveys and administrative printed forms, the files amalgamation and, finally, the macroeconomic syntheses (Part 3). Adopting this system is not quite carried into effect for the time being. In the last part of the work, the author lays down the outlines of its future development which is bound to adjust itself to the new requirements called for by economy's evolution., L'analyse du passé montre que le développement des statistiques sur le système productif est? un phénomène récent; les premiers recensements des grands secteurs économiques n'ont eu lieu qu'au début des années soixante. C'est donc à la mise place d'un dispositif d'observation statistique des entreprises que s'attache l'INSEE depuis quelques années. Pour ce faire, il convient de tenir compte du rôle des acteurs en présence : les entreprises qui fournissent l'information et les différentes administrations et organisations professionnelles qui collectent et traitent cette information (2« partie). La structure du système comprend quatre étages. Les instruments de base (définitions, nomenclatures, répertoires), les enquêtes statistiques et les formulaires administratifs, les fusions de fichiers et enfin les synthèses macroéconomiques (3€ partie). La mise en place de ce système n'est pas achevée et, dans la dernière partie, l'auteur trace les grandes lignes de son développement futur qui devra s'adapter aux besoins nouveaux suscités par l'évolution de l'économie., El sistema público de información estadistica relativa a empresas - Al analizar el pasado es factible descubrir que el desarrollo de la estadistica relativa al sistema productivo es un fenómeno de fecha reciente; los primeros censos relativos a los mayores sectores económicos se levantaron tan solo a principios del decenio del sesenta. Por tanto, desde hace unos cuantos anos, el INSEE pone su empeno en mantener un mecanismo de observación estadistica de las empresas. Conviene, a tal efecto, tener presente el papel desempenado por los diversos actores en presencia : las empresas que suministran la información y las diversas administraciones y organizaciones profesionales que recogen y tratan dicha información (Segunda parte). La estructura del sistema consta de tramos, o sea los instrumentes básicos (definiciones, . nomenclaturas, repertorio), las encuestas estadisticas y los formularios administratives, la fusion de ficheros y, por último, las síntesis macroeconómicas (Tercera parte). No esta terminada la instauración de este sistema y en la ultima parte el autor expone los principales rasgos de su futuro desarrollo, el cual tendra que ajustarse a los requerimientospropios de la evolución económica., Dubois Paul. Le système public d'information statistique sur les entreprises. In: Economie et statistique, n°79, Juin 1976. pp. 17-31.

Enorm ous structural adjustm ents are needed in order to emerge from the crisis, and this makes it more vital than ever to think in the medium and long terms. The failure of the policies of the past has largely been due to their negligence vis-a-vis the future: negligence concerning income form ation unfavourable to investm ent and the creation of employment and price stability; negligence concerning deficits resulting in growing indebtedness; negligence concerning the lack of a systematic training and research effort; and negligence concerning the absence of institutions capable of ensuring the maintenance of the kind of intern ational economic order needed in a world in which the interdependence among countries has increased significantly.