siEDM: an efficient string index and search algorithm for edit distance with moves

Although several self-indexes for highly repetitive text collections exist, developing an index and search algorithm with editing operations remains a challenge. Edit distance with moves (EDM) is a string-to-string distance measure that includes substring moves in addition to ordinal editing operations to turn one string into another. Although the problem of computing EDM is intractable, it has a wide range of potential applications, especially in approximate string retrieval. Despite the importance of computing EDM, there has been no efficient method for indexing and searching large text collections based on the EDM measure. We propose the first algorithm, named string index for edit distance with moves (siEDM), for indexing and searching strings with EDM. The siEDM algorithm builds an index structure by leveraging the idea behind the edit sensitive parsing (ESP), an efficient algorithm enabling approximately computing EDM with guarantees of upper and lower bounds for the exact EDM. siEDM efficiently prunes the space for searching query strings by the proposed method, which enables fast query searches with the same guarantee as ESP. We experimentally tested the ability of siEDM to index and search strings on benchmark datasets, and we showed siEDM's efficiency.Comment: 23 page

A Space-Optimal Grammar Compression

A grammar compression is a context-free grammar (CFG) deriving a single string deterministically. For an input string of length N over an alphabet of size sigma, the smallest CFG is O(log N)-approximable in the offline setting and O(log N log^* N)-approximable in the online setting. In addition, an information-theoretic lower bound for representing a CFG in Chomsky normal form of n variables is log (n!/n^sigma) + n + o(n) bits. Although there is an online grammar compression algorithm that directly computes the succinct encoding of its output CFG with O(log N log^* N) approximation guarantee, the problem of optimizing its working space has remained open. We propose a fully-online algorithm that requires the fewest bits of working space asymptotically equal to the lower bound in O(N log log n) compression time. In addition we propose several techniques to boost grammar compression and show their efficiency by computational experiments

Preparation and characterization of activated carbons produced from oil palm empty fruit bunches

Activated carbons were prepared by activating oil palm empty fruit bunches (EFB) using various chemicals including H3PO4, KOH or ZnCl2 and were characterized by elemental analysis, nitrogen and methylene blue adsorption. The effect of the pre-treatment of EFB by NaOH was also investigated. Among all samples, EFB pre-washed with NaOH and then activated with ZnCl2 showed the greatest maximum adsorption capacity (357 mg/g) and BET specific surface area (1265 m2/g). The experimental data of all adsorbents were well fitted to the Langmuir isotherm model and pseudo-second-order kinetics model. This study demonstrated that ZnCl2 activation was the best way to obtain an activated carbon, and that NaOH pre-washing was effective as well for developing mesopores in EFB activated by H3PO4 and ZnCl2

ミズノコイワ カラ ハッケン サレタ ビゼンヤキ

The sintering process of a broken piece of Bizen-yaki vase discovered in Mizunoko-iwa and its components were studied by means of X-ray diffraction and electron microscopy. The components of the sample discovered in Mizunoko-iwa were mainly mullite, cristobalite, quartz and feldspar. Quartz and feldspar were much contained in it, compared with Bizen-yaki of recent days. It is considered that the sintering process was similar to the process now in current. As a result of electron microscopy, the needle-shaped and thin crystal were observed in the sample above mentioned. The formation of needle-shaped crystal was considered to be due to the reaction with the sea water. The Bizen-yaki vases in Mizunoko-iwa were generally porous and raw materials were comparatively rough

Two Distinct Mechanisms Underlying γδ T Cell-Mediated Regulation of Collagen Type I in Lung Fibroblasts

Idiopathic pulmonary fibrosis is a chronic intractable lung disease, leading to　respiratory failure and death. Although anti-fibrotic agents delay disease progression, they are not considered curative treatments, and alternative modalities have attracted attention. We examined the effect of human γδ T cells on collagen type I in lung fibroblasts. Collagen type I was markedly reduced in a γδ T cell number-dependent manner following treatment with γδ T cells expanded with tetrakis-pivaloxymethyl 2-(thiazole-2-ylamino) ethylidene-1,1-bisphosphonate (PTA) and interleukin-2. Collagen type I levels remained unchanged on addition of γδ T cells to the culture system through a trans-well culture membrane, suggesting that cell–cell contact is essential for reducing its levels in lung fibroblasts. Re-stimulating γδ T cells with (E)-4-hydroxy-3-methylbut-2-enyl diphosphate (HMBPP) reduced collagen type I levels without cell–cell contact, indicating the existence of HMBPP-induced soluble anti-fibrotic factors in γδ T cells. Adding anti-interferon-γ (IFN-γ)-neutralizing mAb restored collagen type I levels, demonstrating that human γδ T cell-derived IFN-γ reduces collagen type I levels. Conversely, interleukin-18 augmented γδ T cell-induced suppression of collagen type I. Therefore, human γδ T cells reduce collagen levels in lung fibroblasts via two distinct mechanisms; adoptive γδ T cell transfer is potentially a new therapeutic candidate