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.

146λ × 6 × 19-Gbaud Wavelength-and Mode-Division Multiplexed Transmission Over 10 × 50-km Spans of Few-Mode Fiber With a Gain-Equalized Few-Mode EDFA

Abstract: We demonstrate wavelength- and mode-division multiplexed transmission over a fiber re-circulating loop comprising 50-km of low-DMGD few-mode fiber, and an optimized few-mode EDFA with reduced wavelength-dependent gain and mode-dependent gain. We characterize the channel matrix in terms of its singular value spread, and investigate its long-term stability.

Multipoint communication system having polling and reservation schemes

Abstract: In a multipoint communication system, first polling signals are sequentially and respectively transmitted to terminal stations on a broadcast channel from a central station, asking a request for reservation without waiting for a reply from the terminal stations. A reservation signal is transmitted on a multiple access channel from a terminal station requesting the reservation to the central station in response to the first polling signal addressed to it. A second polling signal is then transmitted on the broadcast channel in response to the reservation signal and the multiple access channel is reserved for a period of time variable in accordance with the reservation signal. A data signal is transmitted from the terminal station requesting the reservation on the reserved multiple access channel in response to the second polling signal.

Generalizing case frames using a thesaurus and the MDL principle

Abstract: A new method for automatically acquiring case frame patterns from large corpora is proposed. In particular, the problem of generalizing values of a case frame slot for a verb is viewed as that of estimating a conditional probability distribution over a partition of words, and a new generalization method based on the Minimum Description Length (MDL) principle is proposed. In order to assist with efficiency, the proposed method makes use of an existing thesaurus and restricts its attention to those partitions that are present as "cuts" in the thesaurus tree, thus reducing the generalization problem to that of estimating a "tree cut model" of the thesaurus tree. An efficient algorithm is given, which provably obtains the optimal tree cut model for the given frequency data of a case slot, in the sense of MDL. Case frame patterns obtained by the method were used to resolve PP-attachment ambiguity. Experimental results indicate that the proposed method improves upon or is at least comparable with existing methods.

\textnormal{\textsc{TWINE}}: A Lightweight Block Cipher for Multiple Platforms

Abstract: This paper presents a 64-bit lightweight block cipher \(\textnormal{\textsc{TWINE}}\) supporting 80 and 128-bit keys. \(\textnormal{\textsc{TWINE}}\) realizes quite small hardware implementation similar to the previous lightweight block cipher proposals, yet enables efficient software implementations on various CPUs, from micro-controllers to high-end CPUs. This characteristic is obtained by the use of generalized Feistel combined with an improved block shuffle, introduced at FSE 2010.

Graphic user interface for managing a server system

Abstract: A graphical user interface provides a navigation model in the form of a hierarchical tree structure which is representative of a server system a user selected to manage. The hierarchical tree structure is populated or built to include a number of icons representative of different classes or categories of major components and their associated subcomponents contained in the selected server system and their logical relationships. In response to user icon selections, the navigation model expands and collapses the tree structure in a predetermined manner so as to enable the user to easily navigate through the different levels of components and subcomponents of the server with a minimum amount of information and determine status in addition to setting threshold values for items to be managed within the server system.