Philips

About: Philips is a company organization based out in Vantaa, Finland. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 68260 authors who have published 99663 publications receiving 1882329 citations. The organization is also known as: Koninklijke Philips Electronics N.V. & Royal Philips Electronics.

Practical biometric authentication with template protection

Abstract: In this paper we show the feasibility of template protecting biometric authentication systems In particular, we apply template protection schemes to fingerprint data Therefore we first make a fixed length representation of the fingerprint data by applying Gabor filtering Next we introduce the reliable components scheme In order to make a binary representation of the fingerprint images we extract and then quantize during the enrollment phase the reliable components with the highest signal to noise ratio Finally, error correction coding is applied to the binary representation It is shown that the scheme achieves an EER of approximately 42% with secret length of 40 bits in experiments

Features for audio and music classification

Abstract: Four audio feature sets are evaluated in their ability to classify five general audio classes and seven popular music genres. The feature sets include low-level signal properties, mel-frequency spectral coefficients, and two new sets based on perceptual models of hearing. The temporal behavior of the features is analyzed and parameterized and these parameters are included as additional features. Using a standard Gaussian framework for classification, results show that the temporal behavior of features is important for both music and audio classification. In addition, classification is better, on average, if based on features from models of auditory perception rather than on standard features.

Optimized Spatial Correlations for Broadband Light Trapping Nanopatterns in High Efficiency Ultrathin Film a-Si:H Solar Cells

Abstract: Nanophotonic structures have attracted attention for light trapping in solar cells with the potential to manage and direct light absorption on the nanoscale. While both randomly textured and nanophotonic structures have been investigated, the relationship between photocurrent and the spatial correlations of random or designed surfaces has been unclear. Here we systematically design pseudorandom arrays of nanostructures based on their power spectral density, and correlate the spatial frequencies with measured and simulated photocurrent. The integrated cell design consists of a patterned plasmonic back reflector and a nanostructured semiconductor top interface, which gives broadband and isotropic photocurrent enhancement.

Security Challenges in the IP-based Internet of Things

Abstract: A direct interpretation of the term Internet of Things refers to the use of standard Internet protocols for the human-to-thing or thing-to-thing communication in embedded networks. Although the security needs are well-recognized in this domain, it is still not fully understood how existing IP security protocols and architectures can be deployed. In this paper, we discuss the applicability and limitations of existing Internet protocols and security architectures in the context of the Internet of Things. First, we give an overview of the deployment model and general security needs. We then present challenges and requirements for IP-based security solutions and highlight specific technical limitations of standard IP security protocols.

LED collimation optics with improved performance and reduced size

Abstract: An LED module that includes an LED (light-emitting diode) and a rotationally symmetrical, bowl-shaped collimator lens is provided. The collimator lens has an inner refractive wall, an outer reflective wall, a first surface having an entrance aperture with a recess in which the LED is situated and which collimator lens is also provided with a second surface from which light generated by the LED emerges, the normal to the surface extending substantially parallel to the axis of symmetry of the lens, and the LED module also includes one or more of the following structures: (1) a conic wall portion of the recess of the inner refractive wall at the entrance aperture that includes a curved portion, and an outer reflective wall so configured in accordance with the structure of the inner refractive wall to achieve substantial collimation of a source of light at the entrance aperture; and/or (2) a first surface of the lens that is recessed away from the LED source; and/or (3) two surfaces of said refractive wall between which the refractive function of said refractive wall is divided. The LED module offers an improvement in the performance of the Flat top Tulip Collimator disclosed and claimed in our co-pending application Ser. No. 09/415,833 in terms of reduced size, beam divergence, beam uniformity, and to some degree efficiency. Moreover, it allows a wider variety of choices in optimizing various performance characteristics, and this in turn allows more flexibility in the structure design.