3,165 research outputs found
Negative default dependence in supplier networks
No full textThe financial defaults of suppliers in a supplier network are significant risks and causes of uncertainty for buying firms. Hitherto, it has been largely neglected that default probabilities of suppliers in supplier networks are not independent of each other. We aim to overcome this shortcoming by studying negative supplier default dependencies: situations where a surviving supplier may benefit from the default of another supplier, resulting in a lower default probability. We use empirical data from the automotive supplier industry and copula functions, a method of representing joint distribution functions with particular marginals, to capture the default dependency between automotive suppliers and simulate various scenarios with negative default dependency. We also conduct a comparative static analysis illustrating the significant impact of negative default dependence. Our findings should spur managers to analyze their supplier networks with respect to default dependencies, and to take this phenomenon into consideration when making sourcing decisions
Supplier default dependencies: Empirical evidence from the automotive industry
No full textCommon ways to mitigate the detrimental consequences of supplier bankruptcies are to install redundancy and to pursue a multiple-sourcing strategy. This is based on the assumption that the adverse event of one supplier going out of business is largely independent from the default of other suppliers. However, this implicit assumption does not hold in all cases. This study – based on empirical data from automotive suppliers – reveals that default dependencies among suppliers do often exist and can have significant consequences. We use copula functions, a method of representing joint distribution functions with particular marginals, to capture the default dependence between automotive suppliers and to simulate various default dependence scenarios. We also conduct a comparative static analysis illustrating the significant impact of default correlation in a supplier portfolio. Our findings should spur managers to analyze their supplier portfolios with respect to default dependencies, and to take this phenomenon into consideration when making sourcing decisions
A Bijection for the Evolution of B-Trees
Get PDFA B-tree is a type of search tree where every node (except possibly for the root) contains between m and 2m keys for some positive integer m, and all leaves have the same distance to the root. We study sequences of B-trees that can arise from successively inserting keys, and in particular present a bijection between such sequences (which we call histories) and a special type of increasing trees. We describe the set of permutations for the keys that belong to a given history, and also show how to use this bijection to analyse statistics associated with B-trees
Wagner, Stephan (Death, 1873-05-07)
No full textAddress: 324 Liberty St.Pg. 164/1873/116/MW M/Germany/Dr. C. Foertmeyer/Schreiber/Spring GroveOriginal record filed in drawer labeled 'WAGNER-_WALKENHOST'
Il contratto di lavoro tra il progetto italo francese e il corporativismo fascista
No full textIl saggio tematizza il progetto italo-francese delle obbligazioni del 1927 nel contesto della costruzione della concezione corporativa, sotto lo specifico profilo del contratto di lavoro. Il progetto segue di un anno la legge sindacale del 1926 fondata sull'annuncio del corporativismo. Il primo paragrafo delinea vicinanze e distanze tra Italia e Francia nella legislazione lavoristica in tema di contratto di lavoro individuale e collettivo. Nei successivi paragrafi vengono affrontati i nodi concettuali intorno al contratto di lavoro tra locazione e impresa. La concezione comunitaria dell'impresa si collega direttamente al corporativismo nella logica del produttivismo. Nel contesto italiano la dimensione giuslavoristica è sempre più attratta nel corporativismo attraverso il filtro costituito dal concetto di impresa. Emerge dunque un chiaro distacco rispetto all'impianto del progetto del 1927 fondato su una contrattualità introduttiva rispetto alla legislazione sociale
Trichomyia stephani Beran, Doczkal, Pfister & Wagner, 2010, sp. nov
No full textTrichomyia stephani sp. nov Material: 13 (holotype) Germany, Rhineland-Palatinate, Kirchheimbolanden, nature reserve Albertskreuz (coppice management), 400 m a.s.l. 23. May – 7. June 2002, malaise-trap, leg. D. Doczkal; 13 (paratype) 12. July 2007, Germany, Bavaria, Munich, Reitschule [48 °09’ 18 ” N, 11 ° 35 ’ 22 ” E], 511 m, CDC-light trap, leg. B. Beran; 13 (paratype) 19. July 2007, Germany, Bavaria, Munich, Reitschule [48 °09’ 18 ” N, 11 ° 35 ’ 22 ” E], 511 m, CDC-light trap, leg. B. Beran; 1 Ƥ (allotype) (paratype) 12. July 2007, Germany, Bavaria, Munich, Reitschule [48 °09’ 18 ” N, 11 ° 35 ’ 22 ” E], 511 m, CDC-light trap, leg. B. Beran. Derivatio nominis: Dedicated to the grandfather of the senior author, Stephan Beran. Male description: Head with round eyes, no eyes-bridge, as typical of the subfamily. Antenna 15 segmented (broken in all specimens during preparation, fig 1). Scape short, barrel-shaped, pedicel spherical, shorter than scape. Flagellomeres elongate, slightly asymmetric with a pair of elongate simple ascoids, about 1.3 times longer than a flagellomere. Relative size of basal antennal segments: 28 - 24-53 - 46 - 42 - further distal segments missing; scape length 0.1 mm. Palpus 3 -segmented (fig 2) 0.24mm long. Basal segment with a circular pit (vesicle), with sensory rods. Relative length of the palpus segments: 29 - 19-21. Thorax and legs elongate without specific features. Wing venation is typical of the genus with only a single vein (R 4 + 5) between the forks R 2 /R 3 and M 1 /M 2. It is not clear whether sc terminates into costa or into R 1 and what is the cross-vein. Radial fork slightly distal of medial fork, a cross-vein between the stems of M 1 + 2 and M 3 /CuA 1. CuA 2 elongate, with basal cross-vein to basal stem of M 3 /CuA 1, anal vein short. Wing length 1.88 mm (holotype); 1.93, 2.04 mm (paratypes); 2.02 mm (allotype). Male abdomen with tergites 7 and 8 strongly reduced to thin clasps, sternites of usual size. Segment 8 with a torsion of about 90 ° to segment 7, genitalia with another torsion of 90 ° to segment 8 so that the genitalia become inverted (fig 5). Genitalia complicatedly structured; gonocoxite basally with an elongate dorsal apodeme (da); distally with a long prominent ventral process, along its inner margin covered with a row of strong bristles; at about middle height lies a short and broad process with several tips and with strong setae. Above it the slightly bent and flattened simple gonostyle articulates. Aedeagus consists of a laterally flattened strongly sclerotized aedeagus apodeme and a distal, slightly sclerotized portion (figs 4, 5, 6). The distal portion maybe bend ventrally at an about median position, where the lateral ‘arms’ of the aedeagus (la in figures 5 and 6) are markedly thinner. In a basal position of the aedeagus broad distal sclerites are visible (fig 5), in a distal position these are merely visible because they are fold up and appear as if one looks at a blade tip (fig 4). At the end of the basal aedeagus apodeme a pair of sperm ducts opens into a wide chamber, flanked by the faint sclerites. Tergite 9 rectangular, cerci are in a horizontal plane, elongate triangular, quite large and setose, best visible in lateral view. Female description: specimen of similar size and coloration as male, palpus three-segmented, also with a depression and sensory rods on the basal segment. Sternite 8 triangular with a slight basal incision, the tip loosely covered with setae, cerci oval (fig 7). The inner genitalia consist of a broad ventral apodeme, and an elongate slightly sclerotized plate. Above the plate is a thin long apodeme that is probably joined to the plate. Further, two short sperm ducts that evolve from a single opening are visible. They end in a pair of holes with well sclerotized circular entrance. Whether these are openings of spermathecae remains dubious. Further structures cannot be sufficiently interpreted at the moment. Remarks. Six European species of Trichomyia Haliday, 1839 are known so far: T. urbica Haliday (widespread in Europe), T. parvula Szabó (Hungaria, Germany, Great Britain) (Szabó 1960), T. malickyi Wagner (Greece: Islands of Kefallinia and Euböa; Wagner, 1982, Ježek, 1990), T. kostovi Ježek (Bulgaria; Ježek 1990), T. carlestolrai Wagner (Spain: Barcelona; Wagner 2001) and T. minima (England; Withers 2004). Relations to the already described European species appear minor. The construction of the genitalia, especially the male gonostyli is unique among European taxa. It is still unknown whether specific relationships between certain tree species and Trichomyiinae do exist. However it is remarkable that the discovery sites of recently described European species are related to old forests and single old trees and remainder of old trees with slowly decaying trees and traditional careful forest management. Thus we speculate that quite a number of European Trichomyiinae still remains undiscovered. We will find them probably in the minor remnants of old forests with slowly decaying trees and in nature reserves.Published as part of Beran, Bernadett, Doczkal, Dieter, Pfister, Kurt & Wagner, Rüdiger, 2010, Two new species of Psychodidae (subfamilies Trichomyiinae and Psychodinae) from Germany associated with decaying wood, pp. 59-64 in Zootaxa 2386 on pages 60-62, DOI: 10.5281/zenodo.19377
Block Statistics in Subcritical Graph Classes
Get PDFWe study block statistics in subcritical graph classes; these are statistics that can be defined as the sum of a certain weight function over all blocks. Examples include the number of edges, the number of blocks, and the logarithm of the number of spanning trees. The main result of this paper is a central limit theorem for statistics of this kind under fairly mild technical assumptions
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