Compact directed acyclic word graphs for a sliding window

Suffix trees are a well-known and widely-studied data structure highly useful for string matching. The suffix tree of a string w can be constructed in O(n) time and space, where n denotes the length of w. Larsson achieved an efficient algorithm to maintain suffix trees for a sliding window. It contributes to prediction by partial matching (PPM) style statistical data compression scheme. Compact directed acyclic word graphs (CDAWGs) are a more space-economical data structure for indexing strings. In this paper we propose a linear-time algorithm to maintain CDAWGs for a sliding window.     

Computer simulation for the cooligomerization system

In order to clarify the kinetic features of the styrene (A)–methyl methacrylate (B)–CCl₄(S) cooligomerization system, a computer simulation was carried out. The experimental data on the degree of polymerization and the deviation of the cooligomer composition from the statistical steady-state composition were comparatively well explained by calculations based on the kinetic equations derived from the assumed reaction scheme and the values of the velocity coefficients, although the values of the four velocity coefficients in the initiation step and the velocity coefficient of the termination by the coupling of two solvent radicals were estimated. The results of the calculation of the rate of each component reaction show that the following two reactions are the most important in the initiation and in the transfer and termination steps when the [S]/([A] + [B]) ratio is large: where, A, A*, and P are styrene, polystyryl radical, and the cooligomer, respectively. Moreover, it was concluded that the deviation of the cooligomer composition from the statistical steady-state composition was caused by these two reactions.     

NMR Studies on Solution Structures of Methanol and Ethanol Saturated with CO2

²H and ¹⁷O NMR relaxation times, T ₁(²H) and T ₁(¹⁷O), and ²H NMR chemical shifts, δ(²H), in CO₂-saturated CD₃OD and C₂D₅OD solutions were measured at 313.2 K over the pressure range up to ~6 MPa. The rotational correlation times, τ _r, of the CD and OD axes within CD₃OD and C₂D₅OD molecules and the CO axis within the CO₂ molecule were determined from T ₁(²H) and T ₁(¹⁷O), and the magnetic susceptibility-corrected chemical shifts, δ _corr, were derived from δ(²H). The differences in τ _r and δ _corr observed between the two alcohol systems: τ _r and δ _corr of OD in C₂D₅OD, decreased rapidly with increasing CO₂ concentration, while those of OD in CD₃OD remained almost unchanged at mole fractions of CO₂, \( x_{\text CO_{2}} \) , lower than ~0.25 and then slightly decreased at higher \( x_{\text CO_{2}} \) . The hydrogen bonding structure in C₂D₅OD was found to be gradually broken down by CO₂ dissolution. On the other hand, in CD₃OD, it has been revealed that the hydrogen bonding structure can persist at \( x_{\text CO_{2}} \)  < ~0.25 but then collapses at higher \( x_{\text CO_{2}} \) .     

Interaction and arrangement of nitrogen and carbon atoms in fcc γ-iron

A Mössbauer effect measurement has been done for Fe?N, Fe?Al?C and Fe?Ni?C austenite in order to study the interaction between the interstitial atoms and their distribution among the octahedral sites of the fcc lattice, together with the influence of Al and Ni atoms. The spectra for Fe?N and Fe?Al?C austenite are decomposed into three components; one singlet γ₀, and two sets of doublet γ₁ and γ₂, with different quadrupole splittings, while no γ₂ component is found in the spectrum for Fe?Ni?C. By analyzing the component ratio in each spectrum, it is concluded that, in Fe?N and Fe?Al?C, the interaction between 2nd nearest neighboring nitrogen or carbon atoms is attractive, and is repulsive between 1st nearest for Fe?N, and that the interaction between 2nd nearest atoms is repulsive for Fe?Ni?C. By measuring the spectra of Fe?Ni?C in magnetic field, the sign of EFG for most of the γ₁ component is determined to be negative.     

A Study of the Solvation Structure of l‐Leucine in Alcohol–Water Binary Solvents through Molecular Dynamics Simulations and FTIR and NMR Spectroscopy

The solvation structures of l ‐leucine (Leu) in aliphatic‐alcohol–water and fluorinated‐alcohol–water solvents are elucidated for various alcohol contents by using molecular dynamics (MD) simulations and IR, and ¹H and ¹³C NMR spectroscopy. The aliphatic alcohols included methanol, ethanol, and 2‐propanol, whereas the fluorinated alcohols were 2,2,2‐trifluoroethanol and 1,1,1,3,3,3‐hexafluoro‐2‐propanol. The MD results show that the hydrophobic alkyl moiety of Leu is surrounded by the alkyl or fluoroalkyl groups of the alcohol molecules. In particular, TFE and HFIP significantly solvate the alkyl group of Leu. IR spectra reveal that the Leu C?H stretching vibration blueshifts in fluorinated alcohol solutions with increasing alcohol content, whereas the vibration redshifts in aliphatic alcohol solutions. When the C?H stretching vibration blueshifts in the fluorinated alcohol solutions, the hydrogen and carbon atoms of the Leu alkyl group are magnetically shielded. Consequently, TFE and HFIP molecules may solvate the Leu alkyl group through the blue‐shifting hydrogen bonds.     

Structure of thiotropocin,a new sulfur-containing 7-membered antibiotic

The structure of a new antibiotic thiotropocin is described.     

An analysis of medium noise of Co-Cr double-layer films in perpendicular magnetic recording

The medium noise in perpendicular magnetic recording is discussed. The perpendicular recording mode was expected to prevent zig-zag walls around transitions, and the experimental result of low transition noise in Co-Cr media confirms this. Also, the main origin of the noise is concluded to be irregular clusters of grains in the film.     

The Itô–Nisio theorem,quadratic Wiener functionals,and 1-solitons

Among Professor Kiyosi Itô’s achievements, there is the Itô–Nisio theorem, a completely general theorem relative to the Fourier series decomposition of Brownian motion. In this paper, some of its applications will be reviewed, and new applications to 1-soliton solutions to the Korteweg–de Vries (KdV for short) equation and Eulerian polynomials will be given.