Efficient parameterized string matching

In parameterized string matching the pattern P matches a substring t of the text T if there exist a bijective mapping from the symbols of P to the symbols of t. We give simple and practical algorithms for finding all such pattern occurrences in sublinear time on average. The algorithms work for a single and multiple patterns.     

Diagnosing diabetic nephropathy by 1H NMR metabonomics of serum

Object: The most severe complication of type 1 diabetes (T1DM) is diabetic nephropathy. It is associated with a high risk of cardiovascular complications and premature death and requires early detection to be efficiently treated. The clinical practice to diagnose diabetic nephropathy is also a non-optimal and tedious set up based on albumin excretion rate in multiple overnight or 24h urine samples. Conversely, in this study, these independent diagnostic data are used to provide a realistic testing case for applying ¹H NMR metabonomics of serum in a diagnostic fashion. Materials and Methods: 182 T1DM and 21 non-diabetic (non-T1DM) individuals were studied. The ¹H NMR of serum at 500 MHz was targeted at two molecular windows: lipoprotein lipids and low-molecular-weight metabolites. Results: T1DM and non-T1DM individuals were exclusively separated by ¹H NMR. For diabetic nephropathy diagnosis in the T1DM patients, ¹H NMR data (and clinical biochemistry data) gave a sensitivity of 87.1% (83.9%) and a specificity of 87.7% (95.9%). The predictive values of positive and negative tests were 89.0% (95.5%) and 83.6% (79.2%), respectively. Conclusions: ¹H NMR metabonomics clearly distinguishes metabolic characteristics of T1DM and appears approximately as good a means to diagnose diabetic nephropathy from serum as an advanced set of biochemical variables.     

An industry experiment on the effects of test-driven development on external quality and productivity

Existing empirical studies on test-driven development (TDD) report different conclusions about its effects on quality and productivity. Very few of those studies are experiments conducted with software professionals in industry. We aim to analyse the effects of TDD on the external quality of the work done and the productivity of developers in an industrial setting. We conducted an experiment with 24 professionals from three different sites of a software organization. We chose a repeated-measures design, and asked subjects to implement TDD and incremental test last development (ITLD) in two simple tasks and a realistic application close to real-life complexity. To analyse our findings, we applied a repeated-measures general linear model procedure and a linear mixed effects procedure. We did not observe a statistical difference between the quality of the work done by subjects in both treatments. We observed that the subjects are more productive when they implement TDD on a simple task compared to ITLD, but the productivity drops significantly when applying TDD to a complex brownfield task. So, the task complexity significantly obscured the effect of TDD. Further evidence is necessary to conclude whether TDD is better or worse than ITLD in terms of external quality and productivity in an industrial setting. We found that experimental factors such as selection of tasks could dominate the findings in TDD studies.     

Computing Equilibria in Discounted 2 × 2 Supergames

This article examines the subgame perfect pure strategy equilibrium paths and payoff sets of discounted supergames with perfect monitoring. The main contribution is to provide methods for computing and tools for analyzing the equilibrium paths and payoffs in repeated games. We introduce the concept of a first-action feasible path, which simplifies the computation of equilibria. These paths can be composed into a directed multigraph, which is a useful representation for the equilibrium paths. We examine how the payoffs, discount factors and the properties of the multigraph affect the possible payoffs, their Hausdorff dimension, and the complexity of the equilibrium paths. The computational methods are applied to the 12 symmetric strictly ordinal 2 × 2 games. We find that these games can be classified into three groups based on the complexity of the equilibrium paths.     

Preparation of Mono‐, Di‐ and Hemicalcium Ferrite Phases via Melt for Reduction Kinetics Investigations

Iron ore concentrates that are used in the iron production are usually agglomerated into sinter or pellets in order to improve their properties in the blast furnace. The main minerals in the magnetite base sinters are hematite, magnetite and Si and Al containing calcium ferrites of which the latter can exist as either monocalcium ferrite, dicalcium ferrite or hemicalcium ferrite depending on the conditions and on the material's iron/calcium‐ratio. In order to study the reduction behaviour of the sinter in the iron production, samples of monocalcium ferrite, dicalcium ferrite and hemicalcium ferrite were prepared by melting different proportions of pure calcium and iron oxides. After melting the samples were cast and cooled. Samples of hemicalcium ferrite were also heated at a certain temperature before the actual reduction experiments in order to ensure the wanted phase composition of the samples. The mineral compositions of the samples were verified using scanning electron microscopy (SEM‐EDS) as well as X‐ray diffraction (XRD). The verification showed that it was possible to produce the samples of calcium ferrites via melting. The conditions needed to reduce the calcium ferrites were estimated with thermodynamic calculations.     

Optimization of the metakaolin geopolymer preparation for maximized ammonium adsorption capacity

Geopolymers are functional materials that can be used in various environmental applications such as adsorbents in pollutant removal from wastewaters. Metakaolin geopolymer (MK-GP) has been proven to be especially suitable for ammonium (NH₄ ⁺) removal. In this research, the optimal reagent and raw material ratios in the preparation of MK-GP in terms of NH₄ ⁺ adsorption capacity were investigated. The response surface methodology based on the face-centered central composite design was used to optimize the levels of three factors: the amounts of hydroxide, silicate, and metakaolin. In addition, the effect of Na or K as the charge-balancing cation was studied. Empirical models were fitted to the experimental data using multiple linear regression. The significance of the models was confirmed by means of analysis of variance. Optimal NH₄ ⁺ removal efficiency was achieved when the amounts of hydroxide and silicate were maximized, the amount of metakaolin was minimized, and Na-based reagents were used. These trends are most likely a result of optimized conversion of metakaolin into MK-GP.     

Volume integral equations in non-linear 3-D magnetostatics

In this paper a discussion of volume integral formulations in three-dimensional non-linear magnetostatics is presented. Integral formulations are examined in connection with Whitney's elements in order to find new approaches. A numerical algorithm based on a formulation implying properly the continuity conditions of magnetic field strength H, i.e. an h-type formulation, is introduced. Results of demanding application problems are shown demonstrating the characteristics of this kind of volume integral approach. In addition, a discussion of the parallelized version of the numerical code based on the h-type approach is presented appended with numerical results illustrating the advantages of combining integral formulations with concurrent computing.     

High frequency one-step gene replacement in Trichoderma reesei. II. Effects of deletions of individual cellulase genes

Four cellulase genes of Trichoderma reesei, cbh1, cbh2, egl1 and egl2, have been replaced by the amdS marker gene. When linear DNA fragments and flanking regions of the corresponding cellulase locus of more than 1 kb were used, the replacement frequencies were high, ranging from 32 to 52%. Deletion of the major cellobiohydrolase 1 gene led to a 2-fold increase in the production of cellobiohydrolase II; however, replacement of the cbh2 gene did not affect the final cellulase levels and deletion of egl1 or egl2 slightly increased production of both cellobiohydrolases. Based on our results, endoglucanase II accounts for most of the endoglucanase activity produced by the hypercellulolytic host strain. Furthermore, loss of the egl2 gene causes a significant drop in the filter paper-hydrolysing activity, indicating that endoglucanase II has an important role in the total hydrolysis of cellulose.     

Experimental verification of a method for estimating energy for domestic hot water production in a 2-stage district heating substation

In this paper we compare our estimate of energy consumption for domestic hot water production in a building with the measured value. The energy consumption for hot water production is estimated from the measured total power consumption. The estimation method was developed using computer simulations, and it is based on the assumption that hot water production causes rapid and detectable changes in power consumption. A comparison of our estimates with measurements indicates that the uncertainty in estimation of hot water energy consumption is ±10%. Thus, the estimate is comparable to class 3 energy meter measurements, which have an uncertainty of ±2-10%.     

Development of an Efficient Acid Digestion Procedure Utilizing High-Pressure Asher Technique for the Determination of Iodine and Metallic Elements in Milk Powder

An effective wet digestion procedure for the determination of total iodine contents in milk powder samples was developed utilizing a high-pressure asher technique. The optimized method based on a two-stage digestion procedure. In the first stage, 500 mg samples were digested at 300 °C for 2 h using 15.2 mol L^?1 HNO₃ (5 mL) and 30 % H₂O₂ (3 mL). After the first digestion stage, digestion vessels were allowed to cool down and 1.2 mL of 20 % (w/v) Na₂S₂O₈ solution was added as an additional oxidizing agent to the samples. After that, the vessels were closed, and they were heated at 100 °C for 30 min, resulting in clear and colorless sample solutions. Iodine concentrations in the digested samples were measured with inductively coupled plasma mass spectrometry. The accuracy of the optimized method was confirmed by analyzing milk powder reference material (BCR-151, milk powder). The obtained value for iodine (5.29?±?0.37 mg kg^?1, n?=?6) was in good agreement with the certified value (5.35?±?0.14 mg kg^?1). Furthermore, the results obtained for reference material showed that the developed method can be applied also for the determination of other elements, e.g., copper, iron, and lead in the digested milk powder samples.