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.

Packet scheduling device

Abstract: In the packet scheduling device, the output class selection part is made to conduct the selective output of priority class, based on the weight count value calculated from a weight value corresponding to minimum guarantee bandwidth for each priority class and the amount of packet accumulated in each queue. The output class selection part operates so that if the weight count value is “0” or more, then the packet length of variable-length packet data to be output is subtracted from the current weight count value to give a renewed weight count value. On the other hand, if the weight count value is less than “0”, until reaching a predetermined repeat count (Cmax−1), the weight value of each priority class is added to the weight count value of all priority classes, and, when reaching the repeat count (Cmax−1), the weight value is added to the weight count value of all priority classes or replaced by half the weight value. Thereby, the weight count value is made to be more than “0”, and the values thus renewed are subject to the rule of round robin so as to select the priority class.

An Analysis of Automatic Equalizers for Orthogonally Multiplexed QAM Systems

Abstract: A simple structure of a per-channel automatic equalizer for an orthogonally multiplexed QAM system is proposed and the performance is analyzed. It is shown that a dual automatic equalizer with T/2 -long tapped delay lines, where T is a period of individual baseband baud, can equalize not only the transmission channel distortions, but the timing deviations and demodulating carrier phase deviations. Despite its high efficiency, the orthogonally multiplexed QAM system has been regarded as overly costly. However, by using the dual automatic equalizer with fairly simple structure, the system is competitive with conventional single channel data transmission systems.

Data classification method and data classification device

Abstract: A separation surface set storage part stores information defining a plurality of separation surfaces which separate a feature space into at least one known class region respectively corresponding to at least one known class and an unknown class region. Each of the at least one known class region is separated from outside region by more than one of the plurality of separation surfaces which do not intersect to each other. A data classification apparatus determine a classification of a classification target data whose inner product in the feature space is calculable by calculating to which region of the at least one known class region and the unknown class region determined by the information stored in the separation surface set storage part the classification target data belongs. A method and apparatus for data classification which can simultaneously perform identification and outlying value classification with high reliability in a same procedure are provided.

Process for purifying, uncapping and chemically modifying carbon nanotubes

Abstract: Disclosed is a process for purifying carbon nanotubes which has steps of 1) mixing carbon nanotubes which accompany carbon impurities with a reagent selected from a group consisting of oxidation agents, nitration agents and sulfonation agents in liquid phase, 2) reacting the carbon nanotubes with the reagent at a predetermined temperature in the liquid phase, wherein the carbon impurities except carbon nanotubes are selectively reacted to dissolve in the liquid phase, and 3) separating carbon nanotubes from which the impurities were released from the liquid phase then washing and drying it. A process for uncapping carbon nanotubes and a process for chemically modifying carbon nanotubes are also disclosed.