Showing papers by "Université Paris-Saclay published in 1991"

A computation model for executable higher-order algebraic specification languages

Abstract: The combination of polymorphically typed lambda-calculi with first-order as well as higher-order rewrite rules is considered. The need of such a combination for exploiting the benefits of algebraically defined data types within functional programming is demonstrated. A general modularity result, which allows as particular cases primitive recursive functionals of higher types, transfinite recursion of higher types, and inheritance for all types, is proved. The class of languages considered is first defined, and it is shown how to reduce the Church-Rosser and termination properties of an algebraic functional language to a so-called principal lemma whose proof depends on the property to be proved and on the language considered. The proof of the principal lemma is then sketched for various languages. The results allow higher order rules defining the higher-order constants by a certain generalization of primitive recursion. A prototype of such primitive recursive definitions if provided by the definition of the map function for lists. >

Prognostic factors in 951 nonmetastatic rhabdomyosarcoma in children : a report from the international rhabdomyosarcoma workshop

Abstract: A total of 951 newly diagnosed patients with nonmetastatic rhabdomyosarcoma (RMS) under 21 years of age from four different cooperative study groups were analyzed to identify the most important pretreatment tumor characteristics in predicting survival. The patient characteristics considered were tumor invasiveness (T), tumor size, status of locoregional lymph nodes, and primary site. The cooperative groups and studies analyzed were: SIOP [RMS-75 (1975-1984)], the Intergroup Rhabdomyosarcoma Study [IRS-II (1978-1982)], Federal Republic of Germany [CWS-81 (1981-1986)] and Italy [RMS-79 (1979-1986), each study involving a different therapeutic protocol. Patient characteristics identified as having a significant relationship to survival by univariate analysis were (favorable features given in brackets): tumor invasiveness [T1], tumor size [less than or equal to 5 cm], status of locoregional lymph nodes [clinically negative], and primary site [orbit and genitourinary non-bladder prostate (GU-non-BP) sites]. T2 tumors tended to have large size (greater than 5 cm), to be associated with positive nodes, and to have a different distribution by primary site than T1 tumors. A multivariate Cox regression analysis of the pooled data identified tumor invasiveness (T), primary site, and the interaction between T and primary site as significant predictive factors for survival. The prognosis of orbital tumors was consistently favorable regardless of T status, whereas the prognosis for "other sites" was consistently unfavorable. International cooperation in this study has permitted the identification of good and poor risk patient subgroups, permitting the focusing of therapeutic protocols to particular risk groups and setting the stage for common future therapeutic protocols for rare subgroups of patients.

Highly photoactive chemically modified thin films of chloroaluminum (and bromoaluminum) phthalocyanines probed by NEXAFS and UPS: Determination of the electronic structure and the molecular orientation

Abstract: Near edge x-ray absorption fine structure (NEXAFS) at the C and N K edges and UV photoelectron spectroscopy (UPS) at variable excitation energy (21.2 and 120 eV) have been used to characterize the electronic structure and the molecular orientation of chloroaluminum phthalocyanine (ClAlPc) thin films deposited on glass or SnO{sub 2} substrates and subjected to chemical transformations. Transformation H occurs when the films are soaked in an aqueous acidic solution, while transformation I is observed if I{sub 3}{sup {minus}}/I{sup {minus}} is added to the solution. It is demonstrated that the protonation of the aza nitrogen atoms of ClAlPc happens during both transformations. It modifies the valence band of the compound but has no effect on the unoccupied levels of the material. Besides the protonation, the uptake of I{sub 3}{sup {minus}} in the phthalocyanine film during transformation I leads to the formation of a charge-transfer complex between the phthalocyanine and the iodine species with a modification of both the occupied and unoccupied levels of the material. The band gap is reduced by 0.3 eV and 1.5 eV for transformations H and I, respectively. No orientation-dependent effect is observed when the chloroaluminum phthalocyanine is deposited on SnO{sub 2}. On the contrary, strongmore » polarization effects are observed in the NEXAFS spectra of phthalocyanine deposited on a float glass substrate.« less

Cracks Interacting with Particles or Fibers in Composite Materials

Abstract: Micromechanics analysis of damage in heterogeneous media and composites cannot ignore the interactions among cracks as well as between cracks and inclusions or voids. Previous investigators can to this conclusion upon finding that states of distributed (diffuse) cracking (damage) cannot be mathematically represented merely as crack systems in a homogeneous medium, even though stable states with distributed damage have been experimentally observed in heterogeneous materials such as concrete. This paper presents a method for modeling interactions between a crack and many inclusions. Based on the Duhamel‐Neuman analogy, the effect of the inclusions is equivalent to unbalanced forces acting on the contour of each inclusion in an infinite homogeneous solid. The problem is solved by superposition; it is decomposed into several standard problems of elasticity for which well‐known solutions are available. The problem is finally reduced to a system of linear algebraic equations similar to those obtained by Kachano...

Measurement of the branching ratio of the decay KL0

Abstract: Using the complete Fermilab E371 data set, we find {Gamma}({ital K}{sub {ital L}}{r arrow}{pi}{sup 0}{gamma}{gamma},+{ital m}{sub {gamma}{gamma}}{ge}0.280 GeV)/{Gamma}({ital K}{sub {ital L}}{r arrow}all) =(1.86{plus minus}0.60{plus minus}0.60){times}10{sup {minus}6}, in good agreement with a recent report of the first observation of this decay. For the low {gamma}{gamma} mass region we find {Gamma}({ital K}{sub {ital L}}{r arrow}{pi}{sup 0}{gamma}{gamma},{ital m}{sub {gamma}{gamma}}{lt}0.264 GeV)/{Gamma}({ital K}{sub {ital L}}{r arrow}all){lt} 5.1{times}10{sup {minus}6} (90% confidence).

Temperature dependence of barrier heights in spin glasses

Abstract: One of the characteristics of spin glasses (SG) below the glass temperature T g is aging. It is a direct consequence of the ‘‘rugged’’ and highly degenerate nature of the free‐energy landscape in configuration space. We have determined the temperature dependence of the height of a given barrier Δ(T) in the ‘‘canonical’’ spin glass AgMn2.6%. Our results show that the rate of change, ‖δΔ/δT‖, increases linearly with increasing Δ in the range of Δ we explore experimentally.