Tokyo, Japan

The Nippon Telegraph and Telephone Corporation , commonly known as NTT, is a Japanese telecommunications company headquartered in Tokyo, Japan. Ranked 29th in Fortune Global 500, NTT is the largest telecommunications company in the world in terms of revenue.The company is incorporated pursuant to the NTT Law . The purpose of the company defined by the Law is to own all the shares issued by Nippon Telegraph and Telephone East Corporation and Nippon Telegraph and Telephone West Corporation and to ensure proper and stable provision of telecommunications services all over Japan including remote rural areas by these companies as well as to conduct research relating to the telecommunications technologies that will form the foundation for telecommunications.While NTT is listed on Tokyo, Osaka, New York, and London stock exchanges, the Japanese government still owns roughly one-third of NTT's shares, regulated by the NTT Law. Wikipedia.


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Patent
Fujikura Ltd, Nippon Telegraph, Telephone and Osaka Prefecture University | Date: 2016-08-15

An amplification optical fiber operable to propagate light beams in a plurality of modes in a predetermined wavelength range through a core doped with a rare earth element, wherein Expression (1) is satisfied, where a cutoff wavelength of a propagated highest mode light beam is defined as max, under conditions in which the cutoff wavelength of the highest mode light beam is defined as c, a shortest wavelength of the wavelength range is defined as min, and a cutoff wavelength of a second-highest mode light beam to the highest mode light beam is min. c>0.5 min+0.5 max(1)


Patent
Nippon Telegraph, Telephone and NTT Electronics | Date: 2016-08-29

A video coding apparatus comprises a motion prediction unit configured to perform motion prediction for a plurality of coding unit sizes of an original image serving as the picture of an input video signal and evaluate results obtained by the motion prediction for the coding unit sizes so as to supply a first evaluation value; a merge mode evaluation unit configured to evaluate each of merge candidates on a coding unit of the merge size determined by a merge size determination unit so as to supply a second evaluation value of each of the merge candidates; and an inter-prediction mode determination unit configured to determine a mode used for coding on the basis of the second evaluation value obtained by the merge mode evaluation unit and the first evaluation value of the coding unit sizes.


At the time of setting authority, a management apparatus stores a database in which authority information corresponding to authority to physically drive a drive apparatus, which is a tangible object, using a terminal apparatus, and registration identification information corresponding to a subject that is given the authority are associated, and outputs information representing any of the registration identification information; and a permission apparatus receives and stores the information. At the time of exercising the authority, the terminal apparatus outputs information representing identification information, and the permission apparatus receives the information and, when the identification information corresponds to registration identification information comprised in setting information, outputs information representing authority exercise information required to exercise the authority. The terminal apparatus receives the information representing the authority exercise information and outputs a drive signal corresponding to the authority exercise information. By this drive signal, a drive apparatus, which is a tangible object, is physically driven.


Patent
Nippon Telegraph and Telephone | Date: 2017-01-11

Polarization rotators of conventional techniques require forming a silicon nitride layer, which is not employed in usual fabrication of a silicon waveguide circuit. In order to employ a polarization rotator function in an optical integrated circuit, a process of forming a silicon nitride layer is added just for that purpose. This increases the fabrication time and complicates the fabrication equipment. In a polarization rotator of the present invention, the waveguide width of a center core portion of a polarization converter (104) is made small. Thus, the intensity of an optical wave does not concentrate only at the center core portion and is more influenced by structural asymmetry. With the configuration of the polarization rotator of the present invention, it is possible to efficiently cause polarization conversion with a structure including only a silicon waveguide and no silicon nitride layer or the like formed thereon.


The receiving device of the present invention is provided with a means that receives, as a received signal, a signal that has been transmitted a transmitting device by dividing by N the spectrum of a signal to be transmitted and performing spectrum editing to reduce its occupied bands; a means that generates a first decoded signal by error-correcting and decoding this received signal in the bandwidth of the signal to be transmitted; a means that generates a transmission replica signal from this first decoded signal and divides by N the spectrum of this transmission replica signal to generate N sub-replicas; a means that generates a compensated received signal by restoring the spectrum of the signal to be transmitted from the transmitting device using the N sub-replicas and the received signal; and a means that decodes this compensated received signal to generate a second decoded signal.


An encoder and a decoder are provided that are capable of reproducing a frequency-domain envelope sequence that provides high approximation accuracy around peaks caused by the pitch period of an audio signal by using a small amount of code. An encoder of the present invention comprises a periodic-combined-envelope generating part and a variable-length coding part. The periodic-combined-envelope generating part generates a periodic combined envelope sequence which is a frequency-domain sequence based on a spectral envelope sequence which is a frequency-domain sequence corresponding to a linear predictive coefficient code obtained from an input audio signal and on a frequency-domain period. The variable-length coding part encodes a frequency-domain sequence derived from the input audio signal. A decoder of the present invention comprises a periodic-combined-envelope generating part and a variable-length decoding part. The periodic-combined-envelope generating part generates a periodic combined envelope sequence which is a frequency-domain sequence based on a spectral envelope sequence which is a frequency-domain sequence corresponding to a linear predictive coefficient code and on a frequency-domain period. The variable-length decoding part decodes a variable-length code to obtain a frequency-domain sequence.


A video is superimposed on an object in order that the object will be perceived as if the object were given a motion. This video is a video including a luminance motion component corresponding to a motion given to the object.


A browser emulator (25) is caused to emulate a client environment that is arbitrary values of types and versions of an OS, a browser, and a plugin. Further, the browser emulator (25) monitors execution of a script or a plugin. A browser emulator manager (23) then causes the browser emulator (25) to patrol a predetermined Web site, and accumulates, in an analysis information database (24), results of access to the Web site in association with information on client environments emulated upon the access to the Web site. The browser emulator manager (23) then refers to the accumulated results of access, and identifies a Web site that causes a difference between results of access according to a difference between client environments.


Patent
Nippon Telegraph and Telephone | Date: 2017-04-12

In encoding, a frequency-domain sample sequence derived from an acoustic signal is divided by a weighted envelope and is then divided by a gain, the result obtained is quantized, and each sample is variable-length encoded. The error between the sample before quantization and the sample after quantization is quantized with information saved in this variable-length encoding. This quantization is performed under a rule that specifies, according to the number of saved bits, samples whose errors are to be quantized. In decoding, variable-length codes in an input sequence of codes are decoded to obtain a frequency-domain sample sequence; an error signal is further decoded under a rule that depends on the number of bits of the variable-length codes; and from the obtained sample sequence, the original sample sequence is obtained according to supplementary information.


Notomi M.,Nippon Telegraph and Telephone
Reports on Progress in Physics | Year: 2010

Recently, strongly modulated photonic crystals, fabricated by the state-of-the-art semiconductor nanofabrication process, have realized various novel optical properties. This paper describes the way in which they differ from other optical media, and clarifies what they can do. In particular, three important issues are considered: light confinement, frequency dispersion and spatial dispersion. First, I describe the latest status and impact of ultra-strong light confinement in a wavelength-cubic volume achieved in photonic crystals. Second, the extreme reduction in the speed of light is reported, which was achieved as a result of frequency dispersion management. Third, strange negative refraction in photonic crystals is introduced, which results from their unique spatial dispersion, and it is clarified how this leads to perfect imaging. The last two sections are devoted to applications of these novel properties. First, I report the fact that strong light confinement and huge light-matter interaction enhancement make strongly modulated photonic crystals promising for on-chip all-optical processing, and present several examples including all-optical switches/memories and optical logics. As a second application, it is shown that the strong light confinement and slow light in strongly modulated photonic crystals enable the adiabatic tuning of light, which leads to various novel ways of controlling light, such as adiabatic frequency conversion, efficient optomechanics systems, photon memories and photons pinning. © 2010 IOP Publishing Ltd.

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