Helsinki University of Technology

About: Helsinki University of Technology is a based out in . It is known for research contribution in the topics: Thin film & Vortex. The organization has 8962 authors who have published 20136 publications receiving 723787 citations. The organization is also known as: TKK & Teknillinen korkeakoulu.

Discrete-time modelling of musical instruments

Abstract: This article describes physical modelling techniques that can be used for simulating musical instruments. The methods are closely related to digital signal processing. They discretize the system with respect to time, because the aim is to run the simulation using a computer. The physics-based modelling methods can be classified as mass–spring, modal, wave digital, finite difference, digital waveguide and source–filter models. We present the basic theory and a discussion on possible extensions for each modelling technique. For some methods, a simple model example is chosen from the existing literature demonstrating a typical use of the method. For instance, in the case of the digital waveguide modelling technique a vibrating string model is discussed, and in the case of the wave digital filter technique we present a classical piano hammer model. We tackle some nonlinear and time-varying models and include new results on the digital waveguide modelling of a nonlinear string. Current trends and future directions in physical modelling of musical instruments are discussed.

Corporate Venture Capitalists and Independent Venture Capitalists: What do they know, Who do They Know and Should Entrepreneurs Care?

Abstract: There is an established body of research that has examined the value-added provided by venture capitalists for their portfolio companies. More recent work has started to look at the comparable activities of corporate venture capitalists. However, to date, the value-added provided by these two types of investors for their portfolio companies has not been compared systematically. This study undertakes such an evaluation by comparing the social capital-based and knowledge-based forms of value-added provided by independent and corporate venture capitalists to their portfolio firms. Primary data from US technology-based new firms that had received both corporate venture capital and independent venture capital funding is analysed. This study demonstrates that the value-adding contributions of corporate venture capital and independent venture capital investors are different both in their origins and in their consequences. Independent VCs add value in helping raise additional finance, recruiting key employees and...

Comparing Self-Organizing Maps

Abstract: In exploratory analysis of high-dimensional data the self-organizing map can be used to illustrate relations between the data items. We have developed two measures for comparing how different maps represent these relations. The other combines an index of discontinuities in the mapping from the input data set to the map grid with an index of the accuracy with which the map represents the data set. This measure can be used for determining the goodness of single maps. The other measure has been used to directly compare how similarly two maps represent relations between data items. Such a measure of the dissimilarity of maps is useful, e.g., for analyzing the sensitivity of maps to variations in their inputs or in the learning process. Also the similarity of two data sets can be compared indirectly by comparing the maps that represent them.

Mixed and sensory nerve stimulations activate different cytoarchitectonic areas in the human primary somatosensory cortex SI. Neuromagnetic recordings and statistical considerations.

Abstract: Magnetic responses evoked by stimulation of the mixed median nerve at the wrist and its cutaneous branches on the glabrous skin of the index and middle fingers were studied. The first responses to mixed nerve stimulation peaked at 19-24 ms, and those to cutaneous nerve stimulation about 4 ms later. The responses, up to a latency of 150 ms, reversed in polarity between the upper and lower parts of the rolandic fissure. Equivalent dipoles for the mixed nerve stimulation were stronger and they lay statistically significantly deeper from the scalp than those activated by the cutaneous nerve stimulation. It is suggested that mixed nerve stimulation activates areas 3a and 3b whereas cutaneous stimulation activates mainly area 3b at the human primary somatosensory cortex. Statistical procedures were developed for comparison of different field patterns and for determining confidence limits of source model parameters. For these purposes the quality and quantity of the noise were studied. The error caused by inaccuracies in the positioning of the magnetometer was found to be minimal in comparison with the signal noise which was estimated from the standard deviation of the averaged response.

The role of social networks in students' learning experiences

Abstract: The aim of this research is to investigate the role of social networks in computer science education. The Internet shows great potential for enhancing collaboration between people and the role of social software has become increasingly relevant in recent years. This research focuses on analyzing the role that social networks play in students' learning experiences. The construction of students' social networks, the evolution of these networks, and their effects on the students' learning experience in a university environment are examined.