Relations between allometric scalings and fluctuations in complex systems: The case of Japanese firms

To elucidate allometric scaling in complex systems, we investigated the underlying scaling relationships between typical three-scale indicators for approximately 500,000$500\text{,}000$ Japanese firms; namely, annual sales, number of employees, and number of business partners. First, new scaling relations including the distributions of fluctuations were discovered by systematically analyzing conditional statistics. Second, we introduced simple probabilistic models that reproduce all these scaling relations, and we derived relations between scaling exponents and the magnitude of fluctuations.     

Catalyst-controlled asymmetric synthesis of fostriecin and 8-epi-fostriecin

Catalytic asymmetric synthesis of the natural antibiotic fostriecin (CI-920) and its analogue 8-epi-fostriecin and evaluation of their biological activity are described. We used four catalytic asymmetric reactions to construct all of the chiral centers of fostriecin and 8-epi-fostriecin; cyanosilylation of a ketone, Yamamoto allylation, direct aldol reaction, and Noyori reduction, two of which were developed by our group. Catalytic enantioselective cyanosilylation of ketone 13 produced the chiral tetrasubstituted carbon at C-8. Both enantiomers of the product cyanohydrin were obtained with high enantioselectivity by switching the center metal of the catalyst from titanium to gadolinium. Yamamoto allylation constructed the C-5 chiral carbon in the alpha,beta-unsaturated lactone moiety. A direct catalytic asymmetric aldol reaction of an alkynyl ketone using LLB catalyst constructed the chirality at C-9 with the introduction of a synthetically versatile alkyne moiety, which was later converted to cis-vinyl iodide, the substrate for the subsequent Stille coupling for the triene synthesis. Noyori reduction produced the secondary alcohol at C-11 from the acetylene ketone 6 with excellent selectivity. Importantly, all the stereocenters were constructed under catalyst control in this synthesis. This strategy should be useful for rapid synthesis of stereoisomers of fostriecin.     

Adaptively secure revocable hierarchical IBE from k-linear assumption

Designs, Codes and Cryptography - Revocable identity-based encryption (RIBE) is an extension of IBE with an efficient key revocation mechanism. Revocable hierarchical IBE (RHIBE) is its further...     

Study of the parameters controlling the enantio-differentiating ability of asymmetrically modified solid catalysts for the hydrogenation of γ-ketoesters

The enantio-differentiating hydrogenation of γ-ketoesters was carried out over asymmetrically modified solid catalysts. The parameters affecting the enantiomer excess (ee) were investigated and the results were compared with those of the hydrogenation of methyl acetoacetate and 2-octanone reported in the literature. The highest value of enantiomer excess of 51% was attained for the hydrogenation of methyl 4-oxopentanoate over a tartaric acid (TA)-NaBr-modified reduced nickel catalyst prepared from nickel oxide. The amount of NaBr in the modification solution needed to be optimized according to the manufacturers of the nickel oxides. The addition of an appropriate amount of carboxylic acid to the reaction media increased the enantiomer excess of the hydrogenated products.     

New conservative schemes with discrete variational derivatives for nonlinear wave equations

New conservative finite difference schemes for certain classes of nonlinear wave equations are proposed. The key tool there is “discrete variational derivative”, by which discrete conservation property is realized. A similar approach for the target equations was recently proposed by Furihata, but in this paper a different approach is explored, where the target equations are first transformed to the equivalent system representations which are more natural forms to see conservation properties. Applications for the nonlinear Klein–Gordon equation and the so-called “good” Boussinesq equation are presented. Numerical examples reveal the good performance of the new schemes.     

Improvement of a Sinc-collocation method for Fredholm integral equations of the second kind

A Sinc-collocation scheme for Fredholm integral equations of the second kind was proposed by Rashidinia–Zarebnia in 2005. In this paper, two improved versions of the Sinc-collocation scheme are presented. The first version is obtained by improving the scheme so that it becomes more practical, and natural from a theoretical view point. Then it is rigorously proved that the convergence rate of the modified scheme is exponential, as suggested in the literature. In the second version, the variable transformation employed in the original scheme, the “tanh transformation”, is replaced with the “double exponential transformation”. It is proved that the replacement improves the convergence rate drastically. Numerical examples which support the theoretical results are also given.     

Analysis of price diffusion in financial markets using PUCK model

Based on the new type of random walk process called the potentials of unbalanced complex kinetics (PUCK) model, we theoretically show that the price diffusion in large scales is amplified 2(2+b)^-1 times, where b is the coefficient of quadratic term of the potential. In short time scales the price diffusion depends on the size M of the super moving average. Both numerical simulations and real data analysis of Yen-Dollar rates are consistent with theoretical analysis.     

Evaluation of acoustical and non-acoustical properties of sound absorbing materials made of polyester fibres of various cross-sectional shapes

Four types of fibrous material samples made of polyester fibres of various cross-sections, i.e. circle, hollow, flat and triangle, have been prepared. The surface impedance and the non-acoustical parameters of them have been measured.The effect of the variation in the cross-sections on the acoustical properties and the non-acoustical parameters of the polyester fibre samples have been examined. The effects of the ‘circle’ and the ‘hollow’ samples are almost the same. However, for the ‘flat’ and the ‘triangle’ samples, the effects different from the ‘circle’ sample are found in the measured flow resistivity and the two characteristic lengths. This paper also discusses the equivalent diameters of the materials made of non-circular cross-sections.     

Synthesis of the starfish ganglioside AG2 pentasaccharide

This Letter reports the first synthesis of the AG2 pentasaccharide, using silylene-oxazolidinone double-locked sialic acid building blocks. The di-DTBS-protected sialic acid building block was easily prepared and readily activated with NIS and TfOH to provide the sialylated lactose unit in good yield with moderate selectivity. After obtaining the trisaccharide unit, the oxazolidinone-protected C4-OH on the sialic acid residue was readily deprotected by treatment with NaOMe. Coupling with the galactofuranosylβ(1-3)galactopyranosyl fluoride building block produced the desired AG2 pentasaccharide in a highly stereoselective manner. Finally, the desired AG2 pentasaccharide was obtained in good yield following global deprotection.     

Tag-based ABE in prime-order groups via pair encoding

Designs, Codes and Cryptography - Predicate/pair encodings are simple frameworks for designing attribute-based encryption ( $$textsf {ABE}$$ ) for complex predicates, with pair encodings...