Non-negative mixtures

This is the author's accepted pre-print of the article, first published as M. D. Plumbley, A. Cichocki and R. Bro. Non-negative mixtures. In P. Comon and C. Jutten (Ed), Handbook of Blind Source Separation: Independent Component Analysis and Applications. Chapter 13, pp. 515-547. Academic Press, Feb 2010. ISBN 978-0-12-374726-6 DOI: 10.1016/B978-0-12-374726-6.00018-7file: Proof:p\PlumbleyCichockiBro10-non-negative.pdf:PDF owner: markp timestamp: 2011.04.26file: Proof:p\PlumbleyCichockiBro10-non-negative.pdf:PDF owner: markp timestamp: 2011.04.2

Truthful approximations to range voting

We consider the fundamental mechanism design problem of approximate social welfare maximization under general cardinal preferences on a finite number of alternatives and without money. The well-known range voting scheme can be thought of as a non-truthful mechanism for exact social welfare maximization in this setting. With m being the number of alternatives, we exhibit a randomized truthful-in-expectation ordinal mechanism implementing an outcome whose expected social welfare is at least an Omega(m^{-3/4}) fraction of the social welfare of the socially optimal alternative. On the other hand, we show that for sufficiently many agents and any truthful-in-expectation ordinal mechanism, there is a valuation profile where the mechanism achieves at most an O(m^{-{2/3}) fraction of the optimal social welfare in expectation. We get tighter bounds for the natural special case of m = 3, and in that case furthermore obtain separation results concerning the approximation ratios achievable by natural restricted classes of truthful-in-expectation mechanisms. In particular, we show that for m = 3 and a sufficiently large number of agents, the best mechanism that is ordinal as well as mixed-unilateral has an approximation ratio between 0.610 and 0.611, the best ordinal mechanism has an approximation ratio between 0.616 and 0.641, while the best mixed-unilateral mechanism has an approximation ratio bigger than 0.660. In particular, the best mixed-unilateral non-ordinal (i.e., cardinal) mechanism strictly outperforms all ordinal ones, even the non-mixed-unilateral ordinal ones

FDM Machine Learning: An investigation into the utility of neural networks as a predictive analytic tool for go around decision making

Loss-of-control events during the approach-to-landing phase of flight account for a large share of fatalities in general aviation. During this critical transition towards the runway it is essential that an aircraft is stabilized. Pilot discretion and judgment is used to determine if an aircraft is suited to either land or go-around, based on an assessment of approach conditions. Many landing incidents and accidents could be prevented with improved go-around decisions. The purpose of this research is to investigate the utility of neural networks in modeling those decisions using historic aircraft flight data. Data collected from nearly 2,000 hours of training flights is used to create a snapshot of an aircraft’s flight parameters at 200’ above ground level on approach. Each approach is then categorized as a landing event or go-around; using this data set a neural network is trained to predict approach outcomes. The network is then tested with an unfamiliar data set. Low error rates with testing data indicate the success of the network in predicting go-around events

Democratization of Large Bureaucratic Organizations Having a Vertical Power Structure and an Authoritarian Leadership

This paper discusses how grass-root workers in large bureaucratic organizations can organize and thereby force democratic changes in the workplace when it has a vertical power structure and an authoritarian leadership. The kinds of organizations we are considering are large factories and similar organizations where a majority of the members are manual or low skilled workers. When we discuss leaders, we are primarily considering the management leadership, but under some circumstances also top-leaders when it is relevant. The paper will first define and discuss the relationship between democracy, bureaucracy, power, leadership, vertical power, and authoritarian leadership. Second, we will discuss how workers can organize and force democratic changes within the workplace; thereby reduce leaders\u27 power sources and power bases that permit leaders to manipulate the behavior of workers. In this context, we will closely examine how democratic changes forced by grass-root workers influence each power source and power base controlled by leaders. Third, we will discuss the consequences the democratization process has on grass-root workers\u27 job situation and the organization (workplace) as a whole; including the bureaucratic structure, the authoritarian leadership style and the vertical power system. Forth, we end with a short conclusion