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  • biological control  (3)
  • global optimization  (3)
  • Springer  (6)
  • American Physical Society
  • Blackwell Science Ltd
  • International Union of Crystallography
  • 2000-2004
  • 1990-1994  (6)
Collection
Keywords
Publisher
  • Springer  (6)
  • American Physical Society
  • Blackwell Science Ltd
  • International Union of Crystallography
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Interval Newton/generalized bisection when there are singularities near roots (1990)
    Springer
    Annals of operations research 25 (1990), S. 181-196 
    Details
    ISSN: 1572-9338
    Keywords: Nonlinear algebraic systems ; Newton's method ; interval arithmetic ; Gauss-Seidel method ; global optimization ; singularities
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Economics
    Notes: Abstract Interval Newton methods in conjunction with generalized bisection are important elemetns of algorithms which find theglobal optimum within a specified box X ⊂ ℝn of an objective function ϕ whose critical points are solutions to the system of nonlinear equationsF(X)=0with mathematical certainty, even in finite presision arithmetic. The overall efficiency of such a scheme depends on the power of the interval Newton method to reduce the widths of the coordinate intervals of the box. Thus, though the generalized bisection method will still converge in a box which contains a critical point at which the Jacobian matrix is singular, the process is much more costly in that case. Here, we propose modifications which make the generalized bisection method isolate singular solutions more efficiently. These modifications are based on an observation about the verification property of interval Newton methods and on techniques for detecting the singularity and removing the region containing it. The modifications assume no special structure forF. Additionally, one of the observations should also make the algorithm more efficient when finding nonsingular solutions. We present results of computational experiments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02283694
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  • 2
    Electronic Resource
    Electronic Resource
    Integration of Pythium nunn and Trichoderma harzianum isolate T-95 for the biological control of Pythium damping-off of cucumber (1990)
    Springer
    Plant and soil 121 (1990), S. 243-250 
    Details
    ISSN: 1573-5036
    Keywords: biological control ; cucumber ; Cucumis sativus ; Pythium damping-off ; Pythium nunn ; Pythium ultimum ; Trichoderma harzianum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two biological control agents, Pythium nunn and Trichoderma harzianum isolate T-95, were combined to reduce Pythium damping-off of cucumber in greenhouse experiments lasting 3–4 weeks. T. harzianum T-95, a rhizosphere competent mutant, was applied to seeds and P. nunn was applied to pasteurized and raw soils naturally and artificially infested with Pythium ultimum. Some treatments were also amended with bean leaves to enhance the activity of P. nunn. The biological control of Pythium damping-off was evaluated in a Colorado soil (Nunn sandy loam) and an Oregon soil mix, which were replanted twice after 2 and 3 months. Interactions between P. nunn and T-95 were detected in the Colorado but not the Oregon soil. No consistent evidence of antagonism between P. nunn and T. harzianum was seen, and significant interactions were detected in the Colorado, but not the Oregon soil. In the first planting of some treatments, the combination of P. nunn and T. harzianum gave greater control of damping-off than either applied alone. P. nunn was most effective in soils that were pasteurized or amended with bean leaves. T. harzianum controlled Pythium damping-off in the Colorado, but not the Oregon soil. In both soils, disease declined over time in treatments amended with bean leaves but without P. nunn or T. harzianum added. This suppression was greater in the Colorado soil, which contained an indigenous population of P. nunn. This work demonstrates that two compatible biological control agents can be combined to give additional control of a soil-borne plant pathogen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00012318
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  • 3
    Electronic Resource
    Electronic Resource
    Integration ofPythium nunn andTrichoderma harzianum isolate T-95 for the biological control of Pythium damping-off of cucumber (1990)
    Springer
    Plant and soil 122 (1990), S. 243-250 
    Details
    ISSN: 1573-5036
    Keywords: biological control ; cucumber ; Cucumis sativus ; Pythium damping-off ; Pythium nunn ; Pythium ultimum ; Trichoderma harzianum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two biological control agents,Pythium nunn andTrichoderma harzianum isolate T-95, were combined to reduce Pythium damping-off of cucumber in greenhouse experiments lasting 3–4 weeks.T. harzianum T-95, a rhizosphere competent mutant, was applied to seeds andP. nunn was applied to pasteurized and raw soils naturally and artificially infested withPythium ultimum. Some treatments were also amended with bean leaves to enhance the activity ofP. nunn. The biological control of Pythium damping-off was evaluated in a Colorado soil (Nunn sandy loam) and an Oregon soil mix, which were replanted twice after 2 and 3 months. Interactions betweenP. nunn and T-95 were detected in the Colorado but not the Oregon soil. No consistent evidence of antagonism betweenP. nunn andT. harzianum was seen, and significant interactions were detected in the Colorado, but not the Oregon soil. In the first planting of some treatments, the combination ofP. nunn andT. harzianum gave greater control of damping-off than either applied alone.P. nunn was most effective in soils that were pasteurized or amended with bean leaves.T. harzianum controlled Pythium damping-off in the Colorado, but not the Oregon soil. In both soils, disease declined over time in treatments amended with bean leaves but withoutP. nunn orT. harzianum added. This suppression was greater in the Colorado soil, which contained an indigenous population ofP. nunn. This work demonstrates that two compatible biological control agents can be combined to give additional control of a soil-borne plant pathogen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02444239
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  • 4
    Electronic Resource
    Electronic Resource
    An interval branch and bound algorithm for bound constrained optimization problems (1992)
    Springer
    Journal of global optimization 2 (1992), S. 259-280 
    Details
    ISSN: 1573-2916
    Keywords: Primary: 65K10 ; Secondary: 65G10 ; Nonlinear algebraic systems ; Newton's method ; interval arithmetic ; Gauss-Seidel method ; global optimization ; singularities
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract In this paper, we propose modifications to a prototypical branch and bound algorithm for nonlinear optimization so that the algorithm efficiently handles constrained problems with constant bound constraints. The modifications involve treating subregions of the boundary identically to interior regions during the branch and bound process, but using reduced gradients for the interval Newton method. The modifications also involve preconditioners for the interval Gauss-Seidel method which are optimal in the sense that their application selectively gives a coordinate bound of minimum width, a coordinate bound whose left endpoint is as large as possible, or a coordinate bound whose right endpoint is as small as possible. We give experimental results on a selection of problems with different properties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00171829
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  • 5
    Electronic Resource
    Electronic Resource
    The cluster problem in multivariate global optimization (1994)
    Springer
    Journal of global optimization 5 (1994), S. 253-265 
    Details
    ISSN: 1573-2916
    Keywords: Branch and bound principle ; inclusion function ; interval extensions ; midpoint test ; global optimization ; order of an interval extension ; nonconvex optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract We consider branch and bound methods for enclosing all unconstrained global minimizers of a nonconvex nonlinear twice-continuously differentiable objective function. In particular, we consider bounds obtained with interval arithmetic, with the “midpoint test,” but no acceleration procedures. Unless the lower bound is exact, the algorithm without acceleration procedures in general gives an undesirable cluster of boxes around each minimizer. In a previous paper, we analyzed this problem for univariate objective functions. In this paper, we generalize that analysis to multi-dimensional objective functions. As in the univariate case, the results show that the problem is highly related to the behavior of the objective function near the global minimizers and to the order of the corresponding interval extension.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01096455
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  • 6
    Electronic Resource
    Electronic Resource
    Life histories ofPsyllaephagus yaseeni (Hym., Encyrtidae) andTamarixia leucaenae (Hym., Eulophidae), parasitoids of the leucaena psyllidHeteropsylla cubana (1993)
    Springer
    BioControl 38 (1993), S. 565-577 
    Details
    ISSN: 1573-8248
    Keywords: Psyllaephagus ; Tamarixia ; Heteropsylla ; biological control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Résumé La fécondité en fonction de l'âge de deux parasitoïdes du psylleHeteropsylla cubana, Psyllaephagus yaseeni etTamarixia leucaenae a été étudiée en condition de laboratoire. A 25 °C,P. yaseeni présente une fécondité plus élevée (R0=192,9) queT. leucaenae (R0=71,2);T. leucaenae montre cependant une sex ratio plus faible (environ 99 % de femelles) queP. yaseeni (environ 50 %). Le taux d'accroissement potentiel (rm=0,236) deT. leucaenae était plus élevé que celui deP. yaseeni (rm=0,188). Les vitesses de développement des parasitoïdes ont été examinées à des températures constantes et fluctuantes et les équations de la vitesse de développement en fonction de la température ont été calculées. A 25 °C, la durée moyenne des générations était respectivement de 28,0 et 18,1 jours pourP. yaseeni etT. leucaenae. Aux températures de 21,5, 25 et 30 °C la durée totale de développement (de l'œuf à l'adulte) était de 28,5, 21,9 et 14,7 jours chezP. yaseeni et 19,2, 12,6 et 9,5 jours chezT. leucaenae. Le taux de parasitisme était faible et la mortalité nymphale était élevée à la température la plus basse, 21,5 °C, pour les deux parasitoïdes. Tous deux présentaient une survie faible à 100 % de HR;P. yaseeni survivait particulièrement bien à une température de 21 °C et à 44 ou 76% d'HR. P. yaseeni attribuait environ 58 % de femelles aux larves de premier stade de développement mais seulement 12 % aux larves de second stade. Environ 99 % de toutes les éclosions deT. leucaenae était constituée de femelles. La taille des femelles issues des larves de 5e stade étaient significativement supérieure à la taille de celles qui émergeaient des larves de 3e ou 4e stade.
    Notes: Abstract Age specific fecundity of two parasitoids,P. yaseeni andT. leucaenae, of the leucaena psyllidH. cubana, were studied under laboratory conditions. At 25 °C,P. yaseeni had a greater fecundity (R0=192.9)_thanT. leucaenae (R0=71.2);T. leucaenae however had a lower sex ratio (about 99 % females) thanP. yaseeni (about 50 % females). Innate capacity for increase (rm=0.236) ofT. leucaenae was higher thanP. yaseeni (rm=0.188). Developmental rates of the parasitoids were examined at constant and fluctuating temperatures and equations of the rate of development against temperature were calculated. At 25 °C, mean generation times were 28.0 and 18.1 days forP. yaeseeni andT. leucaenae respectively. At temperatures of 21.5, 25, and 30 °C total development times (egg to adult) were 28.5, 21.9, and 14.7 days inP. yaseeni and 19.2, 12.6, and 9.5 days inT. leucaenae respectively. The level of parasitism was low and pupal mortality was high at the lower temperature of 21.5 °C for both parasitoids. Both parasitoids showed poor survivorship at 100 % RH,P. yaseeni survived particularly well (32 days) at a temperature of 21.5 °C and 44 or 76 % RH. P. yaseeni allocated about 58 % females to first instar psyllid nymphs but only 12 % females to second instars. About 99 % of allT. leucaenae births were females. Significantly largerT. leucaenae females emerged from fifth instar parasitized nymphs than third or fourth instars.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02373091
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