A practical index for approximate dictionary matching with few mismatches

Approximate dictionary matching is a classic string matching problem (checking if a query string occurs in a collection of strings) with applications in, e.g., spellchecking, online catalogs, geolocation, and web searchers. We present a surprisingly simple solution called a split index, which is based on the Dirichlet principle, for matching a keyword with few mismatches, and experimentally show that it offers competitive space-time tradeoffs. Our implementation in the C++ language is focused mostly on data compaction, which is beneficial for the search speed (e.g., by being cache friendly). We compare our solution with other algorithms and we show that it performs better for the Hamming distance. Query times in the order of 1 microsecond were reported for one mismatch for the dictionary size of a few megabytes on a medium-end PC. We also demonstrate that a basic compression technique consisting in $q$-gram substitution can significantly reduce the index size (up to 50% of the input text size for the DNA), while still keeping the query time relatively low

Lightweight Fingerprints for Fast Approximate Keyword Matching Using Bitwise Operations

We aim to speed up approximate keyword matching with the use of a lightweight, fixed-size block of data for each string, called a fingerprint. These work in a similar way to hash values; however, they can be also used for matching with errors. They store information regarding symbol occurrences using individual bits, and they can be compared against each other with a constant number of bitwise operations. In this way, certain strings can be deduced to be at least within the distance k from each other (using Hamming or Levenshtein distance) without performing an explicit verification. We show experimentally that for a preprocessed collection of strings, fingerprints can provide substantial speedups for k = 1, namely over 2.5 times for the Hamming distance and over 30 times for the Levenshtein distance. Tests were conducted on synthetic and real-world English and URL data

Catheter-directed therapy to treat intermediate- and high-risk pulmonary embolism: Personal experience and review of the literature

Pulmonary embolism (PE) is the third leading cause of cardiovascular death in the western world. Prompt recognition, risk stratification, and individualized treatment are crucial to improve outcomes in patients with PE. Anticoagulation alone is a sufficient therapeutic option in low-risk patients, whereas primary reperfusion with systemic thrombolysis (ST) is usually chosen in high-risk patients. The choice of treatment in intermediate-risk patients is complex and depends on the clinical presentation. Catheter-directed therapy (CDTh) includes all therapies delivered via a catheter placed in the branches of the pulmonary arteries directly into the thrombus. Because ST bears a high risk of major bleeding and numerous patients have contraindications to ST, CDTh is an alternative to ST in intermediate- and high-risk PE patients. CDTh includes local thrombolysis using low-dose alteplase, ultrasound-assisted thrombolysis, and mechanical fragmentation and aspiration of the thrombi, as well as their combinations. In this review article, we have summarized devices and technical details for CDTh, discussed the efficacy and safety of CDTh in comparison to ST in previous clinical trials, and outlined future research directions regarding CDTh, both based on the literature and our personal experience from the local PE Response Team of the Center for the Management of Pulmonary Embolism (CELZAT) in Warsaw

Electron-topological, energetic and π-electron delocalization analysis of ketoenamine-enolimine tautomeric equilibrium

The ketoenamine-enolimine tautometic equilibrium has been studied by the analysis of aromaticity and electron-topological parameters. The influence of substituents on the energy of the transition state and of the tautomeric forms has been investigated for different positions of chelate chain. The quantum theory of atoms in molecules method (QTAIM) has been applied to study changes in the electron-topological parameters of the molecule with respect to the tautomeric equilibrium in intramolecular hydrogen bond. Dependencies of the HOMA aromaticity index and electron density at the critical points defining aromaticity and electronic state of the chelate chain on the transition state (TS), OH and HN tautomeric forms have been obtained

RECENT RESEARCH IN VLSI, MEMS AND POWER DEVICES WITH PRACTICAL APPLICATION TO THE ITER AND DREAM PROJECTS

Several MEMS (Micro Electro-Mechanical Systems) devices have been analysed and simulated. The new proposed model of SiC MPS (Merged PIN-Schottky) diodes is in full agreement with the real MPS devices. The real size DLL (Dynamic Lattice Liquid) simulator as well as the research on modelling and simulation of modern VLSI devices with practical applications have been presented. In the basis of experience in the field of ATCA (Advanced Telecommunications Computing Architecture) based systems a proof-of-concept DAQ (data acquisition) system for ITER (International Thermonuclear Experimental Reactor) have been proposed

3D DEM simulations of basic geotechnical tests with early detection of shear localization

This paper deals with elementary geotechnical tests: triaxial and direct shear of cohesionless sand using the discrete element method (DEM). The capabilities of the numerical DEM code are shown, with a special focus on the early phenomena appearance in localization zones. The numerical tests were performed in 3D conditions with spherical grains. Contact moments law was introduced due to simulate not perfectly round sand grains. The influence of different physical parameters was studied, e.g. initial density or confining pressure. The sieve curve corresponded to the Karlsruhe sand [1]; however, in some tests, it was linearly scaled. Special attention was laid on the behaviour of the sand grains inside localization, e.g. rotation, porosity, fluctuations, etc. and forces redistribution. Emphasis was given on the pre-failure regime and early localization predictors

3D DEM simulations of basic geotechnical tests with early detection of shear localization

This paper deals with elementary geotechnical tests: triaxial and direct shear of cohesionless sand using the discrete element method (DEM). The capabilities of the numerical DEM code are shown, with a special focus on the early phenomena appearance in localization zones. The numerical tests were performed in 3D conditions with spherical grains. Contact moments law was introduced due to simulate not perfectly round sand grains. The influence of different physical parameters was studied, e.g. initial density or confining pressure. The sieve curve corresponded to the Karlsruhe sand [1]; however, in some tests, it was linearly scaled. Special attention was laid on the behaviour of the sand grains inside localization, e.g. rotation, porosity, fluctuations, etc. and forces redistribution. Emphasis was given on the pre-failure regime and early localization predictors