Principles and typical computational limitations of sparse speaker separation based on deterministic speech features

The separation of mixed auditory signals into their sources is an eminent neuroscience and engineering challenge. We reveal the principles underlying a deterministic, neural network-like solution to this problem. This approach is orthogonal to ICA/PCA that views the signal constituents as independent realizations of random processes. We demonstrate exemplarily that in the absence of salient frequency modulations, the decomposition of speech signals into local cosine packets allows for a sparse, noise-robust speaker separation. As the main result, we present analytical limitations inherent in the approach, where we propose strategies of how to deal with this situation. Our results offer new perspectives toward efficient noise cleaning and auditory signal separation and provide a new perspective of how the brain might achieve these tasks.     

Dynamic Programming for Minimum Steiner Trees

We present a new dynamic programming algorithm that solves the minimum Steiner tree problem on graphs with k terminals in time O^*(c^k) for any c > 2. This improves the running time of the previously fastest parameterized algorithm by Dreyfus-Wagner of order O^*(3^k) and the so-called "full set dynamic programming" algorithm solving rectilinear instances in time O^*(2.38^k).     

IT outsourcing as strategic partnering: the case of the UK Inland Revenue

The information systems (IS) literature, and the industry sectors confronted with information technology (IT) outsourcing, are beginning to perceive IT outsourcing as more than just a necessary organizational resource-acquisition venture. Instead organizations have begun to consider vendors as their partners, causing many companies to enter into more intricate deals that include both contractual and informal issues. In light of these developments, a growing concern with forming closer client–vendor relationships has evolved for both vendors and clients. This paper explores, in the context of a case study, three critical dimensions emerging from previous studies. These are: what is outsourced; the contract; and the relationship dimension. We also explore the process and management issues underlying these dimensions. The investigation is enabled through two analytical frameworks, one proven in previous research, one exploratory, but both specifically developed for IT outsourcing arrangements.     

Machine learning in continuous casting of steel: a state-of-the-art survey

Journal of Intelligent Manufacturing - Continuous casting is the most important route for the production of steel today. Due to the physical, mechanical, and chemical components involved in the...     

Thermal and Electrical Conductivity of Amorphous and Graphitized Carbide‐Derived Carbon Monoliths

The influence of graphitization and composition of carbide‐derived carbon (CDC) monoliths on the electrical and thermal conductivity was investigated. Carbon monoliths with varying porosities were synthesized employing biomorphous macroporous TiC and SiC as precursors. Graphitization was carried out in situ during high‐temperature chlorination with and without addition of nickel, iron, and cobalt chloride to the carbide. The graphitized monoliths showed improved properties. The results demonstrate that despite graphitic carbon also glass‐like carbon, stemming from the carbide synthesis, increases the thermal and electrical conductivity significantly.     

Yield estimation and forecasting for winter wheat in Hungary using time series of MODIS data

Wheat is one of the most important crops in Hungary, which represents approximately 20% of the entire agricultural area of the country, and about 40% of cereals. A robust yield method has been improved for estimating and forecasting wheat yield in Hungary in the period of 2003–2015 using normalized difference vegetation index (NDVI) derived from the data of the Moderate Resolution Imaging Spectroradiometer. Estimation was made at the end of June – it is generally the beginning of harvest of winter wheat in Hungary – while the forecasts were performed 1–7 weeks earlier. General yield unified robust reference index (GYURRI) vegetation index was calculated each year using different curve-fitting methods to the NDVI time series. The correlation between GYURRI and country level yield data gave correlation coefficient (r) of 0.985 for the examined 13 years in the case of estimation. Simulating a quasi-operative yield estimation process, 10 years’ (2006–2015) yield data was estimated. The differences between the estimated and actual yield data provided by the Hungarian Central Statistical Office were less than 5%, the average difference was 2.5%. In the case of forecasting, these average differences calculated approximately 2 and 4 weeks before the beginning of harvest season were 4.5% and 6.8%, respectively. We also tested the yield estimation procedure for smaller areas, for the 19 counties (Nomenclature of Territorial Units for Statistics-3 level) of Hungary. We found that, the relationship between GYURRI and the county level yield data had r of 0.894 for the years 2003–2014, and by simulating the quasi-operative forecast for 2015, the resulting 19 county average yield values differed from the actual yield as much as 8.7% in average.     

Testing Einstein's faux formula: fast computers+slow humans=creative brilliance

An experiment was designed for the purpose of testing the proposition that creative decision-making can be greatly improved by making use of the personal computer to solve a set of word anagrams serving as hints to a surprise phrase. The authors hypothesised that the experimental condition of students using various unscramble word jumble websites would significantly outperform the control group of students who attempted to unscramble the words and solve the surprise answer by hand. Results were mixed and the authors conclude that certain types of creative problem solving exercises might benefit more from the innate abilities and talents of the participants rather than the speed and accuracy of the computer.     

Production of fungal lipases using wheat bran and soybean bran and incorporation of sugarcane bagasse as a co-substrate in solid-state fermentation

Fungal strains were screened for lipase producing activities and 10 strains were classified as good producers. Aspergillus sp., Fusarium sp., and Penicillium sp. exhibited the highest activities when fermented in wheat bran (WB) and soybean bran (SB). No fungal growth was observed using sugarcane bagasse (CB). An experimental design was applied to incorporate CB into the fermentation process for lipase production by Aspergillus sp. and Penicillium sp., and to evaluate the best moisture content for the substrate. Strains studied achieved maximum lipase activities with 25% CB combined with 75% WB or SB at 40% moisture content. The highest lipase activities were observed for WB and SB, and for SB combined with CB using Aspergillus sp. Fermentation of 96 h was the optimum period for enzyme production.