56 research outputs found
Can the evolution of music be analyzed in a quantitative manner?
We propose a methodology to study music development by applying multivariate
statistics on composers characteristics. Seven representative composers were
considered in terms of eight main musical features. Grades were assigned to
each characteristic and their correlations were analyzed. A bootstrap method
was applied to simulate hundreds of artificial composers influenced by the
seven representatives chosen. Afterwards we quantify non-numeric relations like
dialectics, opposition and innovation. Composers differences on style and
technique were represented as geometrical distances in the feature space,
making it possible to quantify, for example, how much Bach and Stockhausen
differ from other composers or how much Beethoven influenced Brahms. In
addition, we compared the results with a prior investigation on philosophy.
Opposition, strong on philosophy, was not remarkable on music. Supporting an
observation already considered by music theorists, strong influences were
identified between composers by the quantification of dialectics, implying
inheritance and suggesting a stronger master-disciple evolution when compared
to the philosophy analysis.Comment: 8 pages, 6 figures, added references for sections 1 and 4.C, better
mathematical description on section 2. New values and interpretation, now
considering a bootstrap metho
UrbanFoodplus – African-German Partnership to enhance resource use efficiency in urban and peri-urban agriculture for improved food security in West African cities
Food security in West Africa not only depends on productivity increases in marginal rural areas, but also on enhanced use of intensively farmed agricultural “niche” lands such as the urban and peri-urban spaces. They are characterised by easy market access and input availability which allows self-reinforcing processes of agricultural intensification. However, too little is known about resource use efficiencies, matter flows and negative externalities in these systems. Starting from general assessments (status quo analyses), the African-German UrbanFoodPlus (UFP) network develops and tests site-specific, farmer-tailored innovations. These directly address the above mentioned knowledge gaps in the fourWest African cities of Ouagadougou (Burkina Faso), Tamale (Ghana), Bamako (Mali), and Bamenda (Cameroon). At all locations farmers attempt to cope with increasing land pressure by cultivating along electrical power lines, on public property, and on undeveloped private land
Demand-Orientated Power Production from Biogas: Modeling and Simulations under Swedish Conditions
The total share of intermittent renewable electricity is increasing, intensifying the need for power balancing in future electricity systems. Demand-orientated combined heat and power (CHP) production from biogas has potential for this purpose. An agricultural biogas plant, using cattle manure and sugar beet for biogas and CHP production, was analyzed here. The model Dynamic Biogas plant Model (DyBiM) was developed and connected to the Anaerobic Digestion Model No. 1 (ADM1). Flexible scenarios were simulated and compared against a reference scenario with continuous production, to evaluate the technical requirements and economic implications of demand-orientated production. The study was set in Swedish conditions regarding electricity and heat price, and the flexibility approaches assessed were increased CHP and gas storage capacity and feeding management. The results showed that larger gas storage capacity was needed for demand-orientated CHP production but that feeding management reduced the storage requirement because of fast biogas production response to feeding. Income from electricity increased by 10%, applying simple electricity production strategies to a doubled CHP capacity. However, as a result of the currently low Swedish diurnal electricity price variation and lack of subsidies for demand-orientated electricity production, the increase in income was too low to cover the investment costs. Nevertheless, DyBiM proved to be a useful modeling tool for assessing the economic outcome of different flexibility scenarios for demand-orientated CHP production
Demand-Orientated Power Production from Biogas: Modeling and Simulations under Swedish Conditions
Rate Regulation, Capital Structure and the Sharing of Interest Rate Risk in the Electric Utility Industry.
Comparison of alveolar and arterial concentrations of 85Kr and 133Xe infused intravenously in man
Measuring catastrophic events on operating viability of firms: hurricane hugo and hospitals
Combining the unrestricted estimators into a single estimator and a simulation study on the unrestricted estimators
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