3,529 research outputs found
Is the debt crisis history? Recent private capital inflows to developing countries
Get PDFThe outlook for economic development for an important group of middle-income countries has again been buoyed by substantial private capital inflows in the 1990s. As in the 1970s, this development has been met with cautious optimism. It is generally accepted that these countries need resource transfers from the rest of the world to support capital formation and growth. It is also generally accepted that these private capital flows make the allocation of resources more efficient. But there is concern that a rapid reversal of market sentiment could impose considerable adjustment costs on these same economies. The authors try to quantify what many consider to be the main reasons debtor countries have access to capital markets again: (a) Domestic policy reform in the debtor countries. (b) Debt and debt service reduction, usually associated with Brady Plan restructuring. (c) Changes in the external market, such as changes in interest rates in industrial countries. They argue that a useful barometer for access to new loans is the market value of existing sovereign debt. It follows that a quantitative analysis of the factors that caused the market value of sovereign debts to rise rapidly after 1989 would also improve understanding of the forces behind the renewed access to international capital. Empirical historical evidence suggests that fiscal reform, privatization, and debt reduction are useful in explaining relative improvements in the standing of debtor countries in international credit markets. Debtor countries with strong reform programs, in other words, are better prepared to withstand deterioration in the external environment. But the reduction in dollar interest rates since 1989 appears to be the chief factor in the debtor countries'renewed access to international loans. The authors estimate the effect of increases in dollar interest rates and conclude that the typical debtor country remains vulnerable to increases in interest rates that are well within the range of recent experience.Economic Theory&Research,Environmental Economics&Policies,Banks&Banking Reform,Strategic Debt Management,Financial Intermediation
Scan and paint: theory and practice of a sound field visualization method
Get PDFSound visualization techniques have played a key role in the development of acoustics throughout history. The development of measurement apparatus and techniques for displaying sound and vibration phenomena has provided excellent tools for building understanding about specific problems. Traditional methods, such as step-by-step measurements or simultaneous multichannel systems, have a strong tradeoff between time requirements, flexibility, and cost. However, if the sound field can be assumed time stationary, scanning methods allow us to assess variations across space with a single transducer, as long as the position of the sensor is known. The proposed technique, Scan and Paint, is based on the acquisition of sound pressure and particle velocity by manually moving a P-U probe (pressure-particle velocity sensors) across a sound field whilst filming the event with a camera. The sensor position is extracted by applying automatic color tracking to each frame of the recorded video. It is then possible to visualize sound variations across the space in terms of sound pressure, particle velocity, or acoustic intensity. In this paper, not only the theoretical foundations of the method, but also its practical applications are explored such as scanning transfer path analysis, source radiation characterization, operational deflection shapes, virtual phased arrays, material characterization, and acoustic intensity vector field mapping
Mathematics
No full text"Inservice education"--Final (unnumbered) p. of each document.; Includes bibliographical references.T. Teaching mathematics : elementary & middle grades / prepared by Steven P. Meiring (19 p.) -- K. Kindergarten mathematics / principal authors, James B. Wesson, Steven P. Meiring (18 p.) -- 1. First grade mathematics (18 p.) ; 2. Second grade mathematics (15 p.) ; 3. Third grade mathematics (18 p.) / principal author, C. Winston Smith, Jr. -- 4. Fourth grade mathematics (21 p.) ; 5. Fifth grade mathematics (19 p.) / principal author, James B. Wesson -- 6. Sixth grade mathematics (19 p.) ; 7. Seventh grade mathematics (23 p.) / principal author, William R. Speer -- 8. Eighth grade mathematics (19 p.) ; 8E. Eighth grade enrichment mathematics / principal author, James E. Schultz.A series of eleven monographs describing mathematics learning in the elementary and middle grades. These documents identify appropriate outcomes for each grade level and discuss teaching methods for helping students achieve those outcomes
Syntactic negation in three medieval Aragonese histories of Juan Fernandez de Heredia (c. 1310-1396).
No full textThis study is an analysis of the syntax of negation in three texts of the Aragonese historiographer and compiler, Juan Fernandez de Heredia (c. 1310-1396). The three texts analyzed are: (1) Libro delos fechos et conquistas del principado de la Morea; (2) Cronica Troyana; (3) Historia contra los paganos. The focus of this work is both descriptive and comparative in nature. The descriptive portion of this study comprises an analysis of the various negative structures found in the texts. The comparative portion seeks to gather evidence in favor of an east-west split in the systems of negation in the Romance dialects of the Iberian peninsula. Chapter 1 consists of an exploration of the various textual problems that the Heredian corpus presents. Issues such as scribal interference, a rather passive textual mediation process, and the bilingualism of both the compiler and literary public must be confronted in any study of the Heredian texts. The parameters of syntactic negation are set in Chapter 2, along with a discussion of the most relevant literature. Chapter 3 comprises an investigation of simple negation in the Heredian texts. A complete analysis of the various functions of the negative marker (=NEG), non, is given. In this chapter, I discuss the role of negative scoping and the use of non in subordinate clauses introduced by comparatives, verbs of doubt, fear and prohibition, and certain conjunctions. Chapter 3 concludes with a study of the negative emphatic element pas. Chapter 4 treats the syntactic manifestations of negative polarity terms (=NPT). Negative deletion, the loss of NEG when a NPT is moved to the preverbal position, is discussed. Arguing against external motives for this phenomenon, I posit that, unlike in Castilian, retention of NEG is pragmatically conditioned in Aragonese and Catalan, hence the possibility of an east-west split in negation in the Iberian peninsula. Chapter 5 concludes this investigation and explores the linguistic classification of the Heredian texts based on the data presented in this study.PhDRomance Languages and Literatures: Romance LinguisticsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/103472/1/9034418.pdfDescription of 9034418.pdf : Restricted to UM users only
Ruthenium-catalysed decomposition of formic acid : fuel cell and catalytic applications
No full textThe decomposition of formic acid into H-2 and CO2 was successfully performed using a ruthenium hydride catalyst, without any concomitant CO evolution. The reaction mechanism is investigated by means of density functional theory calculations (DFT). The generated H-2 was further exploited in a fuel cell to produce electricity. The catalytic hydrogenation of conjugated olefins, using this dihydrogen generation procedure, is also reported. (C) 2017 Elsevier B.V. All rights reserved
Survival of Salmonella typhimurium, Listeria monocytogenes and indicator bacteria on cooked uncured turkey loaf stored under vacuum at 3°C
No full textSterile slices of cooked uncured turkey loaf were inoculated with 106 CFU of either Salmonella typhimurium, Listeria monocytogenes, Escherichia coli, Enterococcus faecalis, Citrobacter freundii, Klebsiella pneumoniae, or Enterobacter cloacae. Inoculated samples were vacuum‐packaged and stored at 3 ± 1°C. Microorganisms were enumerated at 0, 3, 6, 9, 12, and 15 days on nonselective media. K. pneumoniae exhibited the least cold‐tolerance with a log10 1.70 decrease in numbers. The coliforms E. cloacae, E. coli, and C. freundii had a survival pattern similar to that of S. typhimurium, with population decreases of log10 0.65, 0.82, 1.13, and 0.79, respectively. E. faecalis and L. monocytogenes were significantly more cold‐resistant, with a decrease of log10 0.20 and no significant change in numbers, respectively. Survival of E. faecalis was not significantly (p < 0.01) different than that of L. monocytogenes, suggesting the use of enterococci as indicators of L. monocytogenes contamination of processed meats.Peer reviewedfinal article publishe
From olefin metathesis to organoruthenium homogeneous catalysis : synthesis, applications and mechanistic understanding
No full textOlefin metathesis is a valuable synthetic tool, widely used in several fields of science. Due to the importance of this transformation several contributions have been made in this field in order to understand mechanistic aspects, reactivity and applicability of this process.
In this topic, ruthenium indenylidene complexes have shown great activity and stability in metathesis, making them very valuable pre-catalysts. However, several aspects of these pre-catalysts have not been evaluated yet. For example, even though reports of active second generation ruthenium indenylidene complexes bearing bulky N-heterocyclic carbenes are present in the literature, no studies have been done to understand how steric hindrance affects the process. For these reasons, [RuCl₂(IPr*)(PPh₃)(3-phenylindenylidene)] (IPr*-PPh₃) and [RuCl₂(IPr*)(Py)(3-phenylindenylidene)] (IPr*-Py), bearing the very bulky ligand, IPr* have been synthesised and compared with [RuCl₂(IPr)(PPh₃)(3-phenylindenylidene)] (IPr-PPh₃) and the new [RuCl₂(IPr)(Py)(3-phenylindenylidene)] (IPr-Py).
Another important aspect, presented in this thesis, is the investigation of the stability of indenylidene pre-catalysts in alcohol solvents. Surprisingly, several different decomposition processes occur depending on the starting complex and the alcohol used. Mechanistic investigation into this decomposition, allowed us to develop a better understanding of this process, and to predict the decomposition product based on the environment. In particular, this study revealed that [RuCl(η⁵-3-phenylindenyl)(PPh₃)₂] (Eta-5) is accessed from [RuCl₂(3-phenylindenylidene)(PPh₃)₂] (M₁₀) via a novel indenylidene to η⁵-indenyl rearrangement. This formal decomposition product has been found to be active in at least 20 different catalytic transformations, rendering it a versatile catalytic tool
Revisiting the learning curve (once again)
No full textThe vast majority of published work in the field of associative learning seeks to test the adequacy of various theoretical accounts of the learning process using average data. Of course, averaging hides important information, but individual departures from the average are usually designated "error" and largely ignored. However, from the perspective of an individual differences approach, this error is the data of interest; and when associative models are applied to individual learning curves the error is substantial. To some extent individual differences can be reasonably understood in terms of parametric variations of the underlying model. Unfortunately, in many cases, the data cannot be accomodated in this way and the applicability of the underlying model can be called into question. Indeed several authors have proposed alternatives to associative models because of the poor fits between data and associative model. In the current paper a novel associative approach to the analysis of individual learning curves is presented. The Memory Environment Cue Array Model (MECAM) is described and applied to two human predictive learning datasets. The MECAM is predicated on the assumption that participants do not parse the trial sequences to which they are exposed into independent episodes as is often assumed when learning curves are modelled. Instead, the MECAM assumes that learning and responding on a trial may also be influenced by the events of the previous trial. Incorporating non-local information the MECAM produced better approximations to individual learning curves than did the Rescorla-Wagner Model (RWM) suggesting that further exploration of the approach is warranted
Unified mathematical treatment of complex cascaded bipartite networks: The case of collections of journal papers
Get PDFIn this study, a mathematical treatment is proposed for analysis of entities and relations among entities in
complex networks consisting of cascaded bipartite networks. This treatment is applied to the case of
collections of journal papers. In this case, entities are distinguishable objects and concepts, such as papers,
references, paper authors, reference authors, paper journals, reference journals, institutions, terms, and term
definitions. Relations are associations between entity-types such as papers and the references they cite, or
paper authors and the papers they write. An entity-relationship model is introduced that explicitly shows
direct links between entity-types and possible useful indirect relations. From this a matrix formulation and
generalized matrix arithmetic are introduced that allow easy expression of relations between entities and
calculation of weights of indirect links and co-occurrence links. Occurrence matrices, equivalence
matrices, membership matrices and co-occurrence matrices are described. A dynamic model of growth
describes recursive relations in occurrence and co-occurrence matrices as papers are added to the paper
collection. Graph theoretic matrices are introduced to allow information flow studies of networks of papers
linked by their citations. Similarity calculations and similarity fusion are explained. Derivation of feature
vectors for pattern recognition techniques is presented. The relation of the proposed mathematical
treatment to seriation, clustering, multidimensional scaling, and visualization techniques is discussed. It is
shown that most existing bibliometric analysis techniques for dealing with collections of journal papers are
easily expressed in terms of the proposed mathematical treatment: co-citation analysis, bibliographic
coupling analysis, author co-citation analysis, journal co-citation analysis, Braam-Moed-vanRaan (BMV)
co-citation/co-word analysis, latent semantic analysis, hubs and authorities, and multidimensional scaling.
This report discusses an extensive software toolkit that was developed for this research for analyzing and
visualizing entities and links in a collection of journal papers. Additionally, an extensive case study is
presented, analyzing and visualizing 60 years of anthrax research through a collection of journal papers.
When dealing with complex networks that consist of cascaded bipartite networks, the treatment presented
here provides a general mathematical framework for all aspects of analysis of static network structure and
network dynamic growth. As such, it provides a basic paradigm for thinking about and modeling such
networks: computing direct and indirect links, expressing and analyzing statistical distributions of network
characteristics, describing network growth, deriving feature vectors, clustering, and visualizing network
structure and growth
Provenance-based trust for grid computing: Position Paper
No full textCurrent evolutions of Internet technology such as Web Services, ebXML, peer-to-peer and Grid computing all point to the development of large-scale open networks of diverse computing systems interacting with one another to perform tasks. Grid systems (and Web Services) are exemplary in this respect and are perhaps some of the first large-scale open computing systems to see widespread use - making them an important testing ground for problems in trust management which are likely to arise. From this perspective, today's grid architectures suffer from limitations, such as lack of a mechanism to trace results and lack of infrastructure to build up trust networks. These are important concerns in open grids, in which "community resources" are owned and managed by multiple stakeholders, and are dynamically organised in virtual organisations. Provenance enables users to trace how a particular result has been arrived at by identifying the individual services and the aggregation of services that produced such a particular output. Against this background, we present a research agenda to design, conceive and implement an industrial-strength open provenance architecture for grid systems. We motivate its use with three complex grid applications, namely aerospace engineering, organ transplant management and bioinformatics. Industrial-strength provenance support includes a scalable and secure architecture, an open proposal for standardising the protocols and data structures, a set of tools for configuring and using the provenance architecture, an open source reference implementation, and a deployment and validation in industrial context. The provision of such facilities will enrich grid capabilities by including new functionalities required for solving complex problems such as provenance data to provide complete audit trails of process execution and third-party analysis and auditing. As a result, we anticipate that a larger uptake of grid technology is likely to occur, since unprecedented possibilities will be offered to users and will give them a competitive edge
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