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.

Dynamic syslog mining for network failure monitoring

Abstract: Syslog monitoring technologies have recently received vast attentions in the areas of network management and network monitoring They are used to address a wide range of important issues including network failure symptom detection and event correlation discovery Syslogs are intrinsically dynamic in the sense that they form a time series and that their behavior may change over time This paper proposes a new methodology of dynamic syslog mining in order to detect failure symptoms with higher confidence and to discover sequential alarm patterns among computer devices The key ideas of dynamic syslog mining are 1) to represent syslog behavior using a mixture of Hidden Markov Models, 2) to adaptively learn the model using an on-line discounting learning algorithm in combination with dynamic selection of the optimal number of mixture components, and 3) to give anomaly scores using universal test statistics with a dynamically optimized threshold Using real syslog data we demonstrate the validity of our methodology in the scenarios of failure symptom detection, emerging pattern identification, and correlation discovery

Characteristics and Design of Power Hardware-in-the-Loop Simulations for Electrical Power Systems

Abstract: This paper presents a compendious summary of power hardware-in-the-loop (PHIL) simulations that are used for designing, analyzing, and testing of electrical power system components. PHIL simulations are an advanced application of real-time simulations that represent novel methods, which conjoin software and hardware testing. This contribution outlines necessary requirements for the implementation of PHIL simulations, which are defined by the nature of the digital real-time simulator, the power amplifier, and the power interface (PI). Fundamental characteristics, such as the input/output systems, PI, interface algorithm, and system stability considerations, are discussed for PHIL setups, in order to illustrate both flexibility and complexity of this compound simulation method. The objective of this work is to elaborate an understandable overview of PHIL simulation for electrical power systems and to constitute a contemporary state-of-the-art status of this research area.

Longitudinal spin Seebeck effect: from fundamentals to applications

Abstract: The spin Seebeck effect refers to the generation of spin voltage as a result of a temperature gradient in ferromagnetic or ferrimagnetic materials. When a conductor is attached to a magnet under a temperature gradient, the thermally generated spin voltage in the magnet injects a spin current into the conductor, which in turn produces electric voltage owing to the spin-orbit interaction. The spin Seebeck effect is of increasing importance in spintronics, since it enables direct generation of a spin current from heat and appears in a variety of magnets ranging from metals and semiconductors to insulators. Recent studies on the spin Seebeck effect have been conducted mainly in paramagnetic metal/ferrimagnetic insulator junction systems in the longitudinal configuration in which a spin current flowing parallel to the temperature gradient is measured. This 'longitudinal spin Seebeck effect' (LSSE) has been observed in various sample systems and exclusively established by separating the spin-current contribution from extrinsic artefacts, such as conventional thermoelectric and magnetic proximity effects. The LSSE in insulators also provides a novel and versatile pathway to thermoelectric generation in combination of the inverse spin-Hall effects. In this paper, we review basic experiments on the LSSE and discuss its potential thermoelectric applications with several demonstrations.

Device for recording video signals and device for displaying electronic program guide

Abstract: A video recorder for recording content signals including audio and video signals, comprises a module for receiving program information signals designating a program identifier, starting and ending time of a program, a first storage device (103), a first recording module for continuously recording the content signals at least one channel in the first storage device, and a module for deleting the content signals of the oldest program recorded in the first storage device in reference with the program information signals.

Method and apparatus for cataloging and displaying e-mail using a classification rule preparing means and providing cataloging a piece of e-mail into multiple categories or classification types based on e-mail object information

Abstract: An electronic mail cataloging and retrieving system comprises an electronic mail communication unit, an electronic mail storage unit for storing electronic mails, a tray information storage unit for storing information on classification types used for classification of electronic mails and a format for relating electronic mails to said classification types, an electronic mail object storage unit for storing an electronic mail object related to each electronic mail stored in the electronic mail storage unit, a header information display control unit for showing header information and electronic mail attribute information on a prescribed electronic mail in the form of an at-a-glance guide, a tray display control unit showing tray information which shows that a prescribed electronic mail is classified into a prescribed classification type, and an electronic mail editing means for showing and editing the content of an electronic mail.