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Search Results: 1 - 10 of 1280 matches for " Mayer "
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Measuring Criticality of Raw Materials: An Empirical Approach Assessing the Supply Risk Dimension of Commodity Criticality  [PDF]
Herbert Mayer, Benedikt Gleich
Natural Resources (NR) , 2015, DOI: 10.4236/nr.2015.61007
Abstract: Providing a sustainable and reliable supply of raw materials at economic prices has become essential to industrialized economies. Therefore, the need for both economical and sustainable methods and strategies for the management of raw materials has been postulated to enable companies and economies to counteract dramatic effects of supply disruptions, or at least to provide early warnings. The relevant studies assign generic weights to different driving factors and therefrom derive criticality indexes. However, it often remains open how to interpret the resulting measures and how to apply them practically. Here we show that based on current commodity key figures, it is possible to empirically determine the risk for future price increases and fluctuations. Thus, we can identify future supply risks and incorporate their patterns into an empirically calibrated criticality measurement. To this end, we apply the well-known compounding framework used by many companies for their financial planning, calculating net present values and volatility from the predicted future price development. To calibrate each resource specific model, we perform extended regression analyses on our compounded criticality index from time series of 42 (out of about 60 industrially relevant) chemical elements. The analysis thereby covers 9 driving factors for criticality and a 40-year time span. Our results suggest a fundamental modification of current practices for criticality assessment, in particular by scaling the criticality measure to correspond with the net present value of future commodity expenses and future volatility.
Measuring Criticality of Raw Materials: An Empirical Approach Assessing the Supply Risk Dimension of Commodity Criticality  [PDF]
Herbert Mayer, Benedikt Gleich
Natural Resources (NR) , 2015, DOI: 10.4236/nr.2015.61007
Abstract: Providing a sustainable and reliable supply of raw materials at economic prices has become essential to industrialized economies. Therefore, the need for both economical and sustainable methods and strategies for the management of raw materials has been postulated to enable companies and economies to counteract dramatic effects of supply disruptions, or at least to provide early warnings. The relevant studies assign generic weights to different driving factors and therefrom derive criticality indexes. However, it often remains open how to interpret the resulting measures and how to apply them practically. Here we show that based on current commodity key figures, it is possible to empirically determine the risk for future price increases and fluctuations. Thus, we can identify future supply risks and incorporate their patterns into an empirically calibrated criticality measurement. To this end, we apply the well-known compounding framework used by many companies for their financial planning, calculating net present values and volatility from the predicted future price development. To calibrate each resource specific model, we perform extended regression analyses on our compounded criticality index from time series of 42 (out of about 60 industrially relevant) chemical elements. The analysis thereby covers 9 driving factors for criticality and a 40-year time span. Our results suggest a fundamental modification of current practices for criticality assessment, in particular by scaling the criticality measure to correspond with the net present value of future commodity expenses and future volatility.
Periodic Bifurcations in Descendant Trees of Finite p-Groups  [PDF]
Daniel C. Mayer
Advances in Pure Mathematics (APM) , 2015, DOI: 10.4236/apm.2015.54020
Abstract: Theoretical background and an implementation of the p-group generation algorithm by Newman and O’Brien are used to provide computational evidence of a new type of periodically repeating patterns in pruned descendant trees of finite p-groups.
Index-p Abelianization Data of p-Class Tower Groups  [PDF]
Daniel C. Mayer
Advances in Pure Mathematics (APM) , 2015, DOI: 10.4236/apm.2015.55029
Abstract:

Given a fixed prime number p, the multiplet of abelian type invariants of the p-class groups of all unramified cyclic degree p extensions of a number field K is called its IPAD (index-p abeliani- zation data). These invariants have proved to be a valuable information for determining the Galois group \"\" of the second Hilbert p-class field and the p-capitulation type of K. For p=3 and a number field K with elementary p-class group of rank two, all possible IPADs are given in the complete form of several infinite sequences.

Periodic Sequences of p-Class Tower Groups  [PDF]
Daniel C. Mayer
Journal of Applied Mathematics and Physics (JAMP) , 2015, DOI: 10.4236/jamp.2015.37090
Abstract:

Recent examples of periodic bifurcations in descendant trees of finite p-groups with \"\" ?are used to show that the possible p-class tower groups G of certain multiquadratic fields K with p- class group of type (2,2,2), resp. (3,3), form periodic sequences in the descendant tree of the elementary Abelian root \"\"

Environmental Mechanisms Shaping the Nature of Dwarf Spheroidal Galaxies: The View of Computer Simulations
Lucio Mayer
Advances in Astronomy , 2010, DOI: 10.1155/2010/278434
Abstract: We review numerical works carried out over the last decade on the role of environmental mechanisms in shaping nature of the faintest galaxies known, dwarf spheroidals (dSphs). The combination of tidally induced morphological transformation, termed tidal stirring, with mass loss due to tidal and ram-pressure stripping aided by heating due to the cosmic ionizing background can turn late-type dwarfs resembling present-day dIrrs into classic dSphs. The time of infall into the primary halo is shown to be a key parameter. Dwarfs accreting at when the cosmic ultraviolet ionizing flux was much higher than today, and was thus able to keep the gas in the dwarfs warm and diffuse, were rapidly stripped of their baryons via ram pressure and tidal forces, producing very dark-matter-dominated objects with truncated star-formation histories, such as the Draco dSph. The low star-formation efficiency expected in such low-metallicity objects prior to their infall was crucial for keeping their disks gas dominated until stripping took over. Therefore gas stripping along with inefficient star-formation provides a new feedback mechanism, alternative to photoevaporation or supernovae feedback, playing a crucial role in dwarf galaxy formation and evolution. We also discuss how the ultra-faint dSphs belong to a different population of lower-mass dwarf satellites that were mostly shaped by reionization rather than by environmental mechanisms (“reionization fossils”). Finally, we scrutinize the various caveats in the current understanding of environmental effects as well as other recent ideas on the origin of Local Group dSphs. 1. Introduction Dwarf spheroidals (dSphs) in the Local Group are the faintest galaxies known. Including the ultrafaint dwarf spheroidals discovered in the last few years, they span luminosities in the range . They are gas poor and have pressure supported stellar components [1]. Among them, some stopped forming stars about 10?Gyr ago and others have extended star-formation histories [2–4]. They are typically clustered around the largest galaxy in a group, although a few of them are found also at significantly larger distances from the primary galaxy [1]. These properties of dSphs, while best studied and known in the Local Group due to its proximity, are also typical of this class of galaxies in nearby groups and clusters. Chiboucas, Karachentsev, and Tully [5] have recently uncovered a population of dSphs in the M81 group having a range of luminosities comparable to the LG dwarfs and which share with the latter the same scaling relations between fundamental
Assessing Local Turbulence Strength from a Time Series
Mayer Humi
Mathematical Problems in Engineering , 2010, DOI: 10.1155/2010/316841
Abstract: We study the possible link between “local turbulence strength” in a flow which is represented by a finite time series and a “chaotic invariant”, namely, the leading Lyaponuv exponent that characterizes this series. To validate a conjecture about this link, we analyze several time series of measurements taken by a plane flying at constant height in the upper troposphere. For each of these time series we estimate the leading Lyaponuv exponent which we then correlate with the structure constants for the temperature. In addition, we introduce a quantitative technique to educe the scale contents of the flow and a methodology to validate its spectrum.
When Clinical Trials Are Compromised: A Perspective from a Patient Advocate
Musa Mayer
PLOS Medicine , 2005, DOI: 10.1371/journal.pmed.0020358
Abstract:
Inequality of maximum a posteriori estimators with equivalent sire and animal models for threshold traits
M Mayer
Genetics Selection Evolution , 1995, DOI: 10.1186/1297-9686-27-5-423
Abstract:
A gramática da a??o de trabalhadores em cooperativas de produ??o no sul do Brasil
Mayer, Ricardo;
Caderno CRH , 2011, DOI: 10.1590/S0103-49792011000300011
Abstract: this paper seeks investigating the grammar of action of workers in production co-operative established in the core of the processes of economical restructuring that took place in brazil in the 1990s. based upon a sociology of experiment, we split up logic of actions from the workers engaged in the formation of two production co-operative where we aimed to investigate: a) the solidarity relationships, b) logic of the strategic actions in each work group, c) the subjective processes expressed in the identity construction workers of the co-operative investigated. investigating two production co-operative in the metropolitan area of porto alegre, it was verified a process of subjectivity marked by an ambivalent attitude between the commitment to the project of building the co-operative and an approach guided by certain pragmatic characterised by a field of possibilities, limited regarded to alternative of social reintegration.
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