4,408 research outputs found
On some new or rare spider species from Lesbos, Greece (Araneae: Agelenidae, Amaurobiidae, Corinnidae, Gnaphosidae, Liocranidae)
In this paper, three new spider species are described from the Greek Aegean island Lesbos: Tegenaria maelfaiti sp. nov. (Agelenidae), Amaurobius lesbius sp. nov. (Amaurobiidae) and Agroeca parva sp. nov. (Liocranidae), as well as the unknown male of Arabelia pheidoleicomes Bosselaers, 2009 (Corinnidae). Diagnostic features and notes on ecology and distribution of these species are given. Two new records for the island are provided, such that currently 300 spider species are known from Lesbos
Inequality and quasi-concavity
We discuss a property of quasi-concavity for inequality measures. Defining income distributions as relative frequency functions, this property says that a convex combination of any two given income distributions is weakly more unequal than the least unequal income distribution of the two. The quasi-concavity property is not essential to the idea of inequality comparisons in the sense of not being implied by the fundamental, i.e., Lorenz type, axioms on their own. However, it is shown that all inequality measures considered in the literature—i.e., the class of decomposable inequality measures and the class of normative inequality measures based on a social welfare function of the rank-dependent expected utility form—satisfy the property and even a stronger version). The quasi-concavity property is then shown to greatly reduce the possible inequality patterns over a much studied type of income growth process.Inequality, Quasi-Concavity, Growth, Rank-Dependent Expected Utility
Laissez-Faire Versus Pareto
Consider two principles for social evaluation. The
first, ‘laissez-faire’, says that mean-preserving redistribution away
from laissez-faire incomes should be regarded as a social worsening.
This principle captures a key aspect of liberal political
philosophy. The second, weak Pareto, states that an increase
in each individual’s disposable income should be regarded as a
social improvement. We show that the combination of the two
principles implies that total disposable income ought be maximized.
Strikingly, the relationship between disposable incomes
and laissez-faire incomes must therefore be ignored, leaving little
room for liberal values
Cracked rotor demonstration
The purpose of this demonstration is to observe the behavior of a rotor with a single crack. This will be presented in oscilloscope orbits, 2X POLAR PLOTS, and spectrum cascade diagrams. Crack detection must be observed in all three formats and monitored over a period of time or start-ups. The change in the 2X behavior pattern provides an early warning that a crack potentially exists and that it is likely propagating toward total rotor fracture
Hydraulic induced instability on a vertical service
The case history contained provides insight toward the mechanical and hydraulic behavior of a vertical pump. It clearly demonstrates the need for measurements on the rotor at or near the impeller area. The results are reported of an analysis on a service water pump. This pump is typical of the water pumps used throughout the power generation industry. Although little is known of the mechanical behavior of vertical pumps because of difficulty in modeling the rotor system, recent developments in the application of submersible proximity transducers have made possible the measurement of pump dynamics under operating conditions. The purpose of this study was to determine the proper selection and installation of vibration-monitoring transducers as well as to measure the effects of imbalance, misalignment, and hydraulics on the performance and reliability of vertical pumps. In addition, the cause of shaft failures on this pump was to be determined
An axiomatic approach to the measurement of envy
We characterize a class of envy-as-inequity measures. There are three key axioms. Decomposability requires that overall envy is the sum of the envy within and between subgroups. The other two axioms deal with the two-individual setting and specify how the envy measure should react to simple changes in the individuals’ commodity bundles. The characterized class measures how much one individual envies another individual by the relative utility difference (using the envious’ utility function) between the bundle of the envied and the bundle of the envious, where the utility function that must be used to represent the ordinal preferences is the ‘ray’ utility function. The class measures overall envy by the sum of these (transformed) relative utility differences. We discuss our results in the light of previous contributions to envy measurement and multidimensional inequality measurement
Description of Cithaeron dippenaarae sp. n. from Morocco (Araneae: Cithaeronidae)
Cithaeron dippenaarae sp. n. is described from both sexes. The species occurs in stony regions in the south
of Morocco
On the spider species described by L. Koch in 1882 from the Balearic Islands (Araneae)
Examination of the L. Koch collection of the Zoological Museum in Berlin allows us to propose the following new synonyms and combinations: Erigone marina L. Koch, 1882 = Oedothorax fuscus (Blackwall, 1834) n. syn.; Theridion elimatum L. Koch, 1882 = Enoplognatha diversa (Blackwall, 1859) n. syn.; Liocranum variabilis Wunderlich, 2008 = Zora inornata L. Koch, 1882 n. syn. = Liocranum inornatum n. comb.; Lycosa perspicax L. Koch, 1882 = Arctosa fulvolineata (Lucas,1846) n. syn.; Alopecosella Roewer, 1960 = Arctosa C. L. Koch, 1847 n. syn.; Lycosa subhirsuta L. Koch, 1882 = Arctosa lacustris (Simon, 1876) n. syn.; Philodromus vegetus L. Koch, 1882 = Thanatus vulgaris Simon, 1870 n. syn.; Ozyptila bicuspis Simon, 1932 = Ozyptila furcula L. Koch, 1882 n. syn.; Haplodrassus maroccanus Denis, 1956 = Drassus parvulus L. Koch, 1882 n. syn. = Haplodrassus parvicorpus (Roewer, 1951) n. comb. (replacement name); Zelotes ruscinensis Simon, 1914 = Zelotes semirufa (L. Koch, 1882) n. syn.; Phlegra simoni L. Koch, 1882 = Phlegra bresnieri Lucas, 1846 n. syn.; Trochosula conspersa (L. Koch, 1882), Lycorma fraisnei (L. Koch, 1882), Lycorma insulana (L. Koch, 1882), Arctosa misella (L. Koch, 1992) and Pirata simplex (L. Koch, 1882) are all retransferred to their original genus Lycosa stat. rev. Cheiracanthium occidentale L. Koch, 1882, Ozyptila furcula L. Koch, 1882 and Zelotes callidus (Simon, 1878) are redescribed
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