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.

Output level control circuit for use in rf power amplifier

Abstract: An output level control circuit for a high frequency power amplifier for amplifying high frequency signals having the "on" and "off" periods of transmit signals in a fixed recurrent cycle such as in a TDMA radio communication system or a GSM system. The high frequency detecting circuit for the output level control circuit is responsive to part of the output of the high frequency power amplifier and a control signal corresponding to said "on" and "off" periods of transmission power for generating an output level control signal for the high frequency power amplifier. The high frequency detecting circuit has detecting means for detecting the wave height of the high frequency signals and differential voltage generating means for generating, for each of said recurrent cycles, a differential voltage between the detection output during the "on" period and the detection output during the "off" period immediately preceding it. This differential voltage is used as the temperature-compensated output level control signal for the high frequency power amplifier.

Query routing for Web search engines: architectures and experiments

Abstract: General-purpose search engines such as AltaVista and Lycos are notorious for returning irrelevant results in response to user queries. Consequently, thousands of specialized, topic-specific search engines (from VacationSpot.com to KidsHealth.org) have proliferated on the Web. Typically, topic-specific engines return far better results for `on topic' queries as compared with standard Web search engines. However, it is difficult for the casual user to identify the appropriate specialized engine for any given search. It is more natural for a user to issue queries at a particular Web site, and have these queries automatically routed to the appropriate search engine(s). This paper describes an automatic query routing system called Q-Pilot. Q-Pilot has an off-line component that creates an approximate model of each specialized search engine's topic. On line, Q-Pilot attempts to dynamically route each user query to the appropriate specialized search engines. In our experiments, Q-Pilot was able to identify the appropriate query category 70% of the time. In addition, Q-Pilot picked the best search engine for the query, as one of the top three picks out of its repository of 144 engines, about 40% of the time. This paper reports on Q-Pilot's architecture, the query expansion and clustering algorithms it relies on, and the results of our preliminary experiments.

Reconstruction-Based Disentanglement for Pose-Invariant Face Recognition

Abstract: Deep neural networks (DNNs) trained on large-scale datasets have recently achieved impressive improvements in face recognition. But a persistent challenge remains to develop methods capable of handling large pose variations that are relatively under-represented in training data. This paper presents a method for learning a feature representation that is invariant to pose, without requiring extensive pose coverage in training data. We first propose to generate non-frontal views from a single frontal face, in order to increase the diversity of training data while preserving accurate facial details that are critical for identity discrimination. Our next contribution is to seek a rich embedding that encodes identity features, as well as non-identity ones such as pose and landmark locations. Finally, we propose a new feature reconstruction metric learning to explicitly disentangle identity and pose, by demanding alignment between the feature reconstructions through various combinations of identity and pose features, which is obtained from two images of the same subject. Experiments on both controlled and in-the-wild face datasets, such as MultiPIE, 300WLP and the profile view database CFP, show that our method consistently outperforms the state-of-the-art, especially on images with large head pose variations.

Ball-grid-array semiconductor device with protruding terminals

Abstract: There is provided a ball-grid-array semiconductor device. The semiconductor device has a semiconductor element sealed with a resin material. In addition, a lead frame is connected to the semiconductor element in the resin material. The lead frame is provided with terminal portions that protrude through the surface of the resin material.

Power transmission of a desk with a cord-free power supply

Abstract: The battery is an indispensable component of portable electronic equipment, but charging is often inconvenient. A contactless electric power supply, such as the desk-type contactless power station (CLPS) we propose, significantly improves the ease of charging such equipment. In this system, primary coils are embedded into the desk surface to efficiently supply electrical power to portable equipment placed on the desk. Only the primary and the secondary coils facing each other work as a power transmitter. We have confirmed that electric power transmission with efficiency of 85 /spl plusmn/ 5% can be attained anywhere on the desk. This examination reveals the effectiveness of using several primary coils.