scispace - formally typeset
Search or ask a question
Institution

NEC

CompanyTokyo, Japan
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.


Papers
More filters
Patent
Stephen Weinstein1, Jun Li1, Junbiao Zhang1, Nan Tu1
30 Jan 2002
TL;DR: The Public Access Mobility LAN (PAMLAN) as mentioned in this paper supports virtual operator LANs representing different network services providers, authorization and accounting mechanism, support of multiple air interfaces, and local IP mobility.
Abstract: Public wireless communications will increasingly extend into wireless LAN (WLAN) environments in order to meet the ubiquitous access, high data rate, and local services demands of future Internet appliances. By relying on IP-level services mechanisms, the Public Access Mobility LAN (PAMLAN) can simultaneously support different air interfaces, franchises for multiple services providers, and a multi-segment LAN environment including handoffs. The PAMLAN supports virtual operator LANs representing different network services providers, authorization and accounting mechanism, support of multiple air interfaces, and local IP mobility. A router associated with each base station realizes this highly distributed IP networking environment, and a QoS-enabled switched Ethernet core supports virtual networks and QoS services.

190 citations

Journal ArticleDOI
TL;DR: In this article, the authors examined the dynamic properties of high-aspect-ratio InAs-quantum-dot (QD) laser at room temperature and found that low chirp in the lasing wavelength under 1-GHz current modulation was found in the quantum dot lasers.
Abstract: We have examined the dynamic properties of high-aspect-ratio InAs-quantum-dot (QD) lasers at room temperature. A novel characteristic of low chirp in the lasing wavelength under 1-GHz current modulation was found in the quantum dot lasers. This is more than one order of magnitude less than the typical chirp (0.2-nm) found in a conventional quantum well laser that we used as a reference. Low chirp was obtained not only in the ground state lasing but in the second level lasing of quantum dots as well.

190 citations

Journal ArticleDOI
TL;DR: A theory of the thermoelectric conversion efficiency of the SSE device is presented, which clarifies the difference between the S SE and conventional thermoelectedric effects and the efficiency limit of theSSE device.
Abstract: The spin Seebeck effect (SSE) refers to the generation of a spin current as a result of a temperature gradient in magnetic materials including insulators. The SSE is applicable to thermoelectric generation because the thermally generated spin current can be converted into a charge current via spin-orbit interaction in conductive materials adjacent to the magnets. The insulator-based SSE device exhibits unconventional characteristics potentially useful for thermoelectric applications, such as simple structure, device-design flexibility, and convenient scaling capability. In this article, we review recent studies on the SSE from the viewpoint of thermoelectric applications. Firstly, we introduce the thermoelectric generation process and measurement configuration of the SSE, followed by showing fundamental characteristics of the SSE device. Secondly, a theory of the thermoelectric conversion efficiency of the SSE device is presented, which clarifies the difference between the SSE and conventional thermoelectric effects and the efficiency limit of the SSE device. Finally, we show preliminary demonstrations of the SSE in various device structures for future thermoelectric applications and discuss prospects of the SSE-based thermoelectric technologies.

190 citations

Journal ArticleDOI
TL;DR: In this paper, a symmetric-Mach-Zehnder (SMZ)-type switch was used to achieve error-free all-optical wavelength conversion at 168 Gb/s, which is the highest repetition rate ever reported.
Abstract: Error-free all-optical wavelength conversion at 168 Gb/s, which is the highest repetition rate ever reported, has been achieved by using a symmetric-Mach-Zehnder (SMZ)-type switch. Low-power-penalty 84-Gb/s operation is also demonstrated. The push-pull switching mechanism of the SMZ switch enables such ultrafast operation based on cross-phase modulation associated with the carrier depletion in a semiconductor optical amplifier. The configuration of the delayed-interference signal-wavelength converter, which is a simplified variant of the SMZ switch, is used in this experiment.

190 citations

Patent
Kosuke Azuma1
23 Jan 2001
TL;DR: In this paper, a semiconductor device having a single semiconductor element and a plurality of segments formed by dividing a conductive plate is described, where some of the segments are electrically coupled with electrodes of the semiconductor elements and constitute lead pad portions as mounting electrodes of semiconductor devices.
Abstract: A semiconductor device having a semiconductor element and a plurality of segments formed by dividing a conductive plate. Some of the segments are electrically coupled with electrodes of said semiconductor element and constitute lead pad portions as mounting electrodes of the semiconductor device. Other segments among the plurality of divided segments constitute die pad portions on which the semiconductor element is mounted. The plurality of divided segments and the semiconductor element are sealed and supported together by a resin material portion. The resin material portion fills the space between the divided segments as the lead pad portions. Semiconductor devices having various package sizes can be fabricated by using standardized common parts.

189 citations


Authors

Showing all 33297 results

NameH-indexPapersCitations
Pulickel M. Ajayan1761223136241
Xiaodong Wang1351573117552
S. Shankar Sastry12285886155
Sumio Iijima106633101834
Thomas W. Ebbesen9930570789
Kishor S. Trivedi9569836816
Sharad Malik9561537258
Shigeo Ohno9130328104
Adrian Perrig8937453367
Jan M. Rabaey8152536523
C. Lee Giles8053625636
Edward A. Lee7846234620
Otto Zhou7432218968
Katsumi Kaneko7458128619
Guido Groeseneken73107426977
Network Information
Related Institutions (5)
Bell Labs
59.8K papers, 3.1M citations

92% related

Hitachi
101.4K papers, 1.4M citations

92% related

Samsung
163.6K papers, 2M citations

91% related

IBM
253.9K papers, 7.4M citations

91% related

Intel
68.8K papers, 1.6M citations

90% related

Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20238
202220
2021234
2020518
2019952
20181,088