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  • 1
    Electronic Resource
    Electronic Resource
    Convexity preserving interpolation with exponential splines (1986)
    Springer
    Computing 36 (1986), S. 335-342 
    Details
    ISSN: 1436-5057
    Keywords: 65D07 ; 41A15 ; 90C20 ; Convexity conditions ; weakly coupled system of inequalities ; numerical algorithms ; quadratic programming ; unconstrained dual program with tridiagonal Hessian
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Während die Aufgabe der konvexen Interpolation im Falle kubischer Splines im allgemeineen nicht lösbar ist, kann jetzt gezeigt werden, daß sie bei Verwendung von Exponentialsplines Lösungen besitzt sofern die vorkommenden Parameter hinreichend roß sind, und es werden konkrete hinreichende und notwendige Lösbarkeitsbedingungen hergeleitet. Da eindeutige Lösbarkeit in der Regel nicht vorliegt, wird eine Auswahlfunktion eingeführt und das entstehende quadratische Optimierungsproblem nach Dualisierung numerisch behandelt.
    Notes: Abstract Sufficient and necessary conditions are derived under which interpolating splines are convex if the data set is in convex position. In order to select one of the interpolants, by means of a well-known objective function a quadratic optimization problem is stated which can be solved effectively by passing to a dual program.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02240208
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  • 2
    Electronic Resource
    Electronic Resource
    An unconstrained dual program for computing convexC 1-spline approximants (1987)
    Springer
    Computing 39 (1987), S. 133-140 
    Details
    ISSN: 1436-5057
    Keywords: 65D10 ; 41A15 ; 90C20 ; Specially structured optimization problem ; Fenchel dualization ; return-formula
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Es wird die Aufgabe betrachtet, eine vorgegebene Datenmenge durch konvexe kubischeC 1-Splines zu approximieren. Zu diesem Problem wird eine zugehörige duale Optimierungsaufgabe konstruiert, welche den Vorteil hat, daß keine Nebenbedingungen auftreten, und welche sich daher effektiver als das Ausgangsproblem numerisch behandeln läßt.
    Notes: Abstract In the present paper the problem of approximating given data sets by convex cubicC 1-splines is considered. To this programming problem a dual program is constructed which is unconstrained. Therefore an efficient computational treatment is possible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02310102
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  • 3
    Electronic Resource
    Electronic Resource
    Convex spline interpolants with minimal curvature (1985)
    Springer
    Computing 35 (1985), S. 219-229 
    Details
    ISSN: 1436-5057
    Keywords: 65K05 ; 65D07 ; 90C20 ; 41A15 ; Existence conditions ; quadratic programming ; dual optimization problem ; tridiagonal Hessian ; Newton's method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Das Problem, konvexe Interpolationssplines mit minimaler mittlerer Krümmung zu ermitteln, führt auf eine speziell strukturierte quadratische Optimierungsaufgabe. In der vorliegenden Note wird eine zugehörige duale Aufgabe aufgestellt, die ohne Nebenbedingungen auskommt, deren Zielfunktion stückweise quadratisch ist und die daher eine effektive numerische Behandlung erlaubt.
    Notes: Abstract The problem of finding convex spline interpolants with minimal mean curvature leads to a quadratic optimization problem of special structure. In the present note a corresponding dual problem without constraints is derived. Its objective function is piecewise quadratic and therefore admits an effective numerical treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02260507
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  • 4
    Electronic Resource
    Electronic Resource
    Volatiles from mandibular glands of male beewolves (Hymenoptera: Sphecidae,Philanthus) and their possible roles (1985)
    Springer
    Journal of chemical ecology 11 (1985), S. 895-901 
    Details
    ISSN: 1573-1561
    Keywords: Philantus ; beewolf ; Sphecidae ; Hymenoptera ; pheromones ; scentmarking ; tridecanone ; pentadecanone ; heptadecanone ; hexadecanoic acid ; ethyl hexadecanoate ; octadecanoic acid ; ethyl octadecanoate ; mandibular glands ; wasps
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Observations of wasp behavior indicate that male beewolves,Philanthus basilaris andP. bicinctus apply a “marking pheromone” to the leaves and stems of plants within their territories. We now provide direct evidence for the presence of volatile chemicals in the paired mandibular glands of the males, provide preliminary identification of these volatiles, and show that all of the volatile chemicals in the mandibular glands are present on freshly marked plant surfaces but are absent from unmarked plants. Pyrazines, which have been reported in other species of aculeate wasps including the EuropeanPhilanthus triangulum, were not found inP. basilaris orP. bicinctus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01012076
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  • 5
    Electronic Resource
    Electronic Resource
    Chemistry of male mandibular gland secretions ofPhilanthus basilaris cresson andPhilanthus bicinctus (Mickel) (Hymenoptera: Sphecidae) (1987)
    Springer
    Journal of chemical ecology 13 (1987), S. 227-235 
    Details
    ISSN: 1573-1561
    Keywords: Philanthus ; Hymenoptera ; Sphecidae ; pheromone ; scent-marking ; 2-alkanones ; fatty acids ; ethyl esters ; alkenals ; N,N-dimethylhy-drazine ; methyl esters ; EI-MS ; CI-MS ; methoxymercuration ; methylthiolation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Detailed chemical characterizations are provided for the species-specific mixtures of marking pheromones utilized by the male beewolvesPhilanthus basilaris andP. bicinctus. Successful analysis of these complex mixtures of 2-ketones, fatty acids, ethyl esters, and aldehydes was facilitated by the treatment of the crude extracts with 1,1-dimethylhydrazine and direct analysis of the resulting hydrazones, methyl esters, and starting ethyl esters by GC-MS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01025883
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  • 6
    Electronic Resource
    Electronic Resource
    Mandibular gland secretions of the male beewolvesPhilanthus crabroniformis, P. barbatus, andP. pulcher (Hymenoptera: Sphecidae) (1992)
    Springer
    Journal of chemical ecology 18 (1992), S. 27-37 
    Details
    ISSN: 1573-1561
    Keywords: Philanthus crabroniformis ; Philanthus barbatus ; Philanthus pulcher ; Hymenoptera ; Sphecidae ; beewolf ; mandibular glands ; pheromones ; semiochemicals ; mass spectrometry ; infrared spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The composition of the territorial marking pheromones from mandibular glands of males of the beewolvesPhilanthus crabroniformis, P. barbatus, andP. pulcher have been determined. The structures of the components were elucidated by gas chromatography-mass spectrometry and gas chromatography-Fourier transform infrared spectroscopy. The major compound ofP. crabroniformis is isopropyl tetradecanoate, with somewhat lesser amounts of 2-tridecanone, 3-methyl-3-butenyl tetradecanoate, and 92∶8 (Z)∶(E)-11-eicosen-1-ol. The major compounds ofP. barbatus are ethyl tetradecanoate and hexadecanal, which are present in approximately a 60∶40 ratio. These two compounds comprise over 95% of the neutral lipids. Also present in lesser amounts are ethyl dodecanoate, tetradecanal, hexadecan-1-ol, a Δ x -octadecen-1-ol, and octadecan-1-ol. The major compounds ofP. pulcher are ethyl (Z)-7-hexadecenoate and geranylgeraniol acetate, which comprise nearly 90% of the neutral lipid fraction, with smaller amounts of tetradecanal, pentadecanal, and ethyl hexadecanoate; trace amounts of Δ x hexadecenal, hexadecanal, and octadecanal are also present.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00997162
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  • 7
    Electronic Resource
    Electronic Resource
    Chemistry of male mandibular gland secretions ofPhilanthus triangulum (1990)
    Springer
    Journal of chemical ecology 16 (1990), S. 2135-2143 
    Details
    ISSN: 1573-1561
    Keywords: Philanthus triangulum ; Hymenoptera ; Sphecidae ; Philanthinae ; beewolf ; (Z)-11-eicosen-1-ol ; 10-nonadecen-2-one ; nonadecenal ; eicosenal ; pheromone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Males of the European and African beewolf,Philanthus triangulum, possess a sex specific mandibular gland secretion that is used for marking plant stems in mating territories. The secretion is composed of 90% (Z)-11-eicosen-1-ol plus small amounts of 10-nonadecen-2-one, nonadecenal, octadecanoic and octadecenoic acids, and eicosenal. The chemistry of this secretion differs markedly from the secretions of North AmericanPhilanthus, which consist of a larger number of components that possess different chemical functionalities and are more volatile. We postulate that the chemical differences betweenP. triangulum and its New World relatives reflect phylogenetic differences plus a possible reduced necessity for species isolating mechanisms inP. triangulum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01026925
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    Paper (German National Licenses)
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