NEC

About: NEC is a company organization based out in Tokyo, Japan. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 33269 authors who have published 57670 publications receiving 835952 citations. The organization is also known as: NEC Corporation & NEC Electronics Corporation.

BEACON: an adaptive set-membership filtering technique with sparse updates

Abstract: This paper deals with adaptive solutions to the so-called set-membership filtering (SMF) problem. The SMF methodology involves designing filters by imposing a deterministic constraint on the output error sequence. A set-membership decision feedback equalizer (SM-DFE) for equalization of a communications channel is derived, and connections with the minimum mean square error (MMSE) DFE are established. Further, an adaptive solution to the general SMF problem via a novel optimal bounding ellipsoid (OBE) algorithm called BEACON is presented. This algorithm features sparse updating, wherein it uses about 5-10% of the data to update the parameter estimates without any loss in mean-squared error performance, in comparison with the conventional recursive least-squares (RLS) algorithm. It is shown that the BEACON algorithm can also be derived as a solution to a certain constrained least-squares problem. Simulation results are presented for various adaptive signal processing examples, including estimation of a real communication channel. Further, it is shown that the algorithm can accurately track fast time variations in a nonstationary environment. This improvement is a result of incorporating an explicit test to check if an update is needed at every time instant as well as an optimal data-dependent assignment to the updating weights whenever an update is required.

Semiconductor device with schottky electrode having high schottky barrier

Abstract: A carrier travel layer is formed on the substrate of a semiconductor device with a buffer layer interposed, and a spacer layer and carrier supply layer are then formed on this carrier travel layer. On the carrier supply layer are provided a source electrode and a drain electrode, and a gate electrode is provided on an interposed Schottky layer. The carrier supply layer is composed of AlGaN and has tensile strain. The Schottky layer is composed of InGaN and has compressive strain. A negative piezoelectric charge is induced on the carrier supply layer side of the Schottky layer, and a positive piezoelectric charge is induced on the opposite side of the Schottky layer, whereby a sufficient Schottky barrier height is obtained and leakage current is suppressed.

Name resolution server and packet transfer device

Abstract: The DNS server according to the present invention includes a user information identification unit which identifies an attribute of a user who has transmitted a DNS query message through a user information obtaining unit and handing over an identification result to a response generation unit, a user information obtaining unit for referring to a user information database to obtain user attribute information of a user who has transmitted a DNS query message, and a response generation unit for searching a response database for a name resolution method relevant to user attribute information handed over from the user information identification unit to conduct name resolution according to the found name resolution method, thereby enabling name resolution to be minutely customized for each attribute of a user.

Fingerprint input device

Abstract: A fingerprint input device capable of obtaining a fingerprint image presenting sufficient contrast is provided. The fingerprint input device includes: a two-dimensional image sensor for picking up a fingerprint image from a fingerprint measured portion of a measurement target finger; and a transparent solid film mounted on an image pickup surface of the two-dimensional image sensor, the fingerprint measured portion being mounted on the transparent solid film when the two-dimensional image sensor picks up the fingerprint image, wherein the fingerprint input device picks up an image of a fingerprint ridgeline portion in the fingerprint measured portion as a light portion, and picks up an image of a fingerprint valley portion in the fingerprint measured portion as a dark portion through an air layer, and a refractive index of the transparent solid film satisfies that contrast of the image is more than a given value.

Active matrix organic el display device and method of forming the same

Abstract: The present invention provides an active matrix organic electroluminescence display device including: a transparent substrate; a plurality of pixels aligned over the transparent substrate, wherein each of the pixels further includes: a luminescent region which exhibits a luminescence upon application of an electric field; a circuitry region including at least a circuitry; and an optical shielding structure provided between the luminescent region and the circuitry region for shielding the circuitry region from the luminescence from the luminescent region.