An epistemic analysis of the Harsanyi transformation

Harsanyi (1967–68) proposed a method for transforming uncertainty over the strategy sets of players into uncertainty over their payoffs. The transformation appears to rely on an assumption that the players are rational, or, indeed, that they are rational and that there is common belief of rationality. Such an assumption would be awkward from the perspective of the epistemic program, which is often interested in the implications of irrationality or a lack of common belief of rationality. This paper shows that without common belief of rationality, such implications are not necessarily maintained under a Harsanyi transformation. The paper then shows how, with the belief-system model of Aumann and Brandenburger (1995), such implications can be maintained in the absence of common belief of rationality. Received: December 2000/Revised: February 2002     

Stahl und Eisen

Ohne Zusammenfassung     

Random-order bin packing

The average-case analysis of algorithms usually assumes independent, identical distributions for the inputs. In [C. Kenyon, Best-fit bin-packing with random order, in: Proc. of the Seventh Annual ACM-SIAM Symposium on Discrete Algorithms, SIAM, 1996, pp. 359–364] Kenyon introduced the random-order ratio, a new average-case performance metric for bin packing heuristics, and gave upper and lower bounds for it for the Best Fit heuristics. We introduce an alternative definition of the random-order ratio and show that the two definitions give the same result for Next Fit. We also show that the random-order ratio of Next Fit equals to its asymptotic worst-case, i.e., it is 2.     

The effects of monophenol chain terminators on the structure–property relationships of controlled epoxy networks

Five families of new controlled epoxy thermosets (CENs) using three monophenol chain terminators were prepared to study systematic changes in the structure and amount of the monophenol and the initial molecular weight between crosslinks (M_c,i) on the properties of epoxy thermosets. Glass transition temperature (T_g) decreases with monophenol mole fraction (χ) in proportion to both the concentration and flexibility of the chain terminator. Distinct serial relations for T_g depression were observed for the three M_c,i families. Dynamic mechanical analysis (DMA) shows significant perturbations of the relaxation behavior with added terminator as evidenced by decrease in peak tan δ and in post T_g damping. The rubbery coefficients of thermal expansion (CTE) increases with monophenol concentration only at χ > 0.05 and shows distinct curvature versus temperature, but is largely invariant with monophenol flexibility. The thermal stability of terminated CENs decreases only slightly with χ and little difference was found with monophenol structure. Most surprisingly, fracture toughness decreases markedly and discontinuously with χ depending on M_c,i. The values of the critical monophenol concentration at which fracture toughness markedly decreases (χ_c) are inversely proportional to M_c,i but are independent of monophenol flexibility. No correlation of χ_c with any of the calculated network structure parameters was apparent. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1632–1640, 2008     

In situ activation analysis of marine sediments with252Cf

A seabed nuclear probe has been developed which permits the measurement of up to 33 elements at the parts per thousand to parts per million levels in continental shelf areas. The probe consists of a neutron irradiation source,²⁵²Cf, which neutron activates the elements in the minerals of interest. These resulting radioactive elements emit characteristic gamma radiation which is analyzed in situ in 2- to 10 min counting intervals with a Ge(Li) detector system. Details of the irradiation source, the Ge(Li) detector, and spectra taken in situ in a marine environment are discussed with respect to the detection of the minerals at concentrations of economic interest.     

Conformational analysis of substituted 1-cycloheptene-5,6- and 1-cycloheptene-6,7-diols from ir,raman, and pmr spectra

Conclusions For a number of substituted vic-cycloheptenediols the chair conformation with a transdiequatorial orientation of hydroxyl groups is suggested by the data of PMR in CDCl₃. The data of IR and Raman spectra of dilute solutions of these compounds in CCl₄, indicate the possibility of multiple conformations due to the different orientation of OH groups forming intramolecular hydrogen bonds or, depending on the nature of substitution, in twist boat forms.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1980–1984, September, 1987.The authors wish to thank A. V, Il'yasov for discussing the work.     

Interference of210Bi in the determination of99Mo from a uranium assembly

Low level radioactive determinations of spontaneous fission produced⁹⁹Mo were attempted on 0.77 kg of natural uranium. The radioactivity observed in these samples indicated higher equilibrium values than reported earlier. Because these activities are extremely low, it is possible that the 66.7 h⁹⁹Mo activity with a long-lived component can be confused with²¹⁰Bi/²¹⁰Po activity contamination from the uranium series.