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Human echolocation using click trains and continuous noise

Blind people may detect objects from the information in reflected sounds, echolocation. Detection as a function of the number of clicks compared to a continuous noise was tested by presenting clicks of 5 ms with rates from 1 to 64 clicks during a 500 ms period and a 500-ms continuous white noise. The sounds were recorded in an ordinary room through an artificial binaural head. The reflecting objec

Optimal and Adaptive Microphone Arrays for Speech Input in Automobiles

In this chapter, speech enhancement and echo cancellation for hands-free mobile telephony are discussed. A number of microphone array methods have been tested and results from car measurements are given. Traditional methods such as linearly constrained beamforming and generalized sidelobe cancelers are discussed as well as array gain optimization methods. An in situ calibrated method which gives a

Adaptive Microphone Array Employing Spatial Quadratic Soft Constraints and Spectral Shaping

The convenience and the ease of use provided by hands-free operation of speech communication devices mean that speech enhancement schemes are becoming indispensable. In this chapter, two subband adaptive microphone array schemes are presented, which aim to provide good speech enhancement capability in poor signal to noise ratio situations. The basic commonality of the adaptive microphone array sch

Location-Aware Services Using Android Mobile Operating Platform for Safety, Emergency and Health Applications

The introduction of smart phones has redefined the usage of mobile phones in the communications world. Smart phones are now equipped with various sophisticated features such as Wi-Fi, Global Positioning System (GPS) navigation capability, high-resolution camera, touch screen, and broadband access which helps the mobile phone users to stay connected and updated. Many of these features are primarily

Signal extraction

The invention relates to an adaptive method of extracting at least of des ired electro magnetic wave signals, sound wave signals (40, 42), and any oth er signals from a mixture of signals (40, 42, 44, 46) and suppressing noise and interfering signals to produce enhanced signals (50) corresponding to de sired (10) signals, and an apparatus (70) therefore. It relies on the concep t of at least one o

Endogenous processes of Colonial Settlement : The success and failure of European settler farming in sub-Saharan Africa*

This paper comments on studies that aim to quantify the long-term economic effects of historical European settlement across the globe. We argue for the need to properly conceptualise «colonial settlement» as an endogenous development process shaped by the interaction between prospective settlers and indigenous peoples. We conduct three comparative case studies in West, East and Southern Africa, sh

Transition from HCCI to PPC : The Sensitivity of Combustion Phasing to the Intake Temperature and the Injection Timing with and without EGR

An experiment was conducted to investigate the effect of charge stratification on the combustion phasing in a single cylinder, heavy duty (HD) compression ignition (CI) engine. To do this the start of injection (SOI) was changed from -180° after top dead centre (ATDC) to near top dead centre (TDC) during which CA50 (the crank angle at which 50% of the fuel energy is released) was kept constant by

Nanohybrid polymer brushes on silica for bioseparation

Boronic acid based affinity materials are of great importance for effective enrichment of biomolecules containing a cis-diol structure, for example glycoproteins. In this work, we developed a new pH- and temperature-responsive boronate affinity material for effective separation of glycoproteins. A nanohybrid material composed of silica cores and flexible polymer brushes, denoted as Si@poly(NIPAm-c

Cryptography in an all encrypted world

Ensuring that communication is secure, including the ability to encrypt sensitive traffic, has always been a fundamental pillar of the telecom industry. Users expect their right to privacy to be respected, and operators expect to be able to protect themselves and their customers from various kinds of attacks. But the world is changing. Encryption technologies are advancing, regulations are changin

Theoretical and Experimental Investigations of Polyelectrolyte Adsorption Dependence on Molecular Weight

This work focuses on adsorption of polyions onto oppositely charged surfaces and on responses to the addition of a simple monovalent salt as well as to the polyion length (degree of polymerization). We also discuss possible mechanisms underlying observed differences, of the adsorbed amount on silica surfaces at high pH, between seemingly similar polyions. This involves theoretical modeling, utiliz

Why companies change privacy policies : A principal-agent perspective

Companies often update their privacy policies, but it is unclear whether these updates strengthen or weaken user privacy. Using a principal-agent theoretical lens, we analyze over 200 changes to privacy policies of five prominent Internet companies over a period of fifteen years. We find that over time, privacy policy updates are more likely to weaken, rather than strengthen, user privacy on the I

A de Novo Designed Coiled-Coil Peptide with a Reversible pH-Induced Oligomerization Switch

Protein conformational switches have many useful applications but are difficult to design rationally. Here we demonstrate how the isoenergetic energy landscape of higher-order coiled coils can enable the formation of an oligomerization switch by insertion of a single destabilizing element into an otherwise stable computationally designed scaffold. We describe a de novo designed peptide that was di

Populism, extremism and media : Mapping an uncertain terrain

Aiming to critically review key research on populism, extremism and media, this article examines some definition aspects of populism as a concept, its relation to ‘the people’ and points to future directions for research in mainstream – and social media – the terrain where so much of the political is played out. An individualisation of civic cultures has emerged in tandem with the growth of mediat

BRCA2 gene mutations and coagulation-associated biomarkers

Thromboembolic events are the second cause of death in cancer patients, although the mechanisms underlying this increased thromboembolic risk remain unclear. The aims of this study were to examine whether BRCA2 gene mutations may modify the circulating levels of thrombocoagulation biomarkers and whether breast cancer development may influence changes in such circulating biomarkers. The study was p

Genetic risk factors for type 1 diabetes

Type 1 diabetes is diagnosed at the end of a prodrome of β-cell autoimmunity. The disease is most likely triggered at an early age by autoantibodies primarily directed against insulin or glutamic acid decarboxylase, or both, but rarely against islet antigen-2. After the initial appearance of one of these autoantibody biomarkers, a second, third, or fourth autoantibody against either islet antigen-

Holography-guided ptychography with soft X-rays

Ptychography is a lensless imaging technique that aims to reconstruct an object from a set of coherent diffraction patterns originating from different and partially overlapping sample illumination areas. For a successful convergence of the iterative algorithms used, the sample scan positions have to be known with very high accuracy. Here, we present a method that allows to directly encode this inf

A method for 3D direction of arrival estimation for general arrays using multiple frequencies

We develop a novel high-resolution method for the estimation of the direction of incidence of energy emitted by sources in 3D space from wideband measurements collected by a planar array of sensors. We make use of recent generalizations of Kronecker's theorem and formulate the direction of arrival estimation problem as an optimization problem in the space of sequences generating so called general