Hitachi, Ltd.

Tatsuki Inuduka

Tsunenori Yamamoto

Hiromichi Yamada

Makoto Tsumura

Yasutaka Toyoda

Takashi Hotta

Yasuhiro Nakatsuka

Kotaro Shimamura

Takanaga Yamazaki

Dai Fujii

Masayuki Miyazaki

Kenichiro Yamane

Jun Yamazaki

Osamu Tomobe

Masahiro Yatsu

Yasutaka Serizawa

Sumito Tobe

Ryo Nakano

Satoru Harada

The present invention monitors an electric power system using a time-series measurement value including abnormality. An electric power system monitoring device is provided with: a storage unit that stores facility information indicating a position relationship of a plurality of measurement sites in an electric power system; a reception unit that receives time-series measurement information measured by a measurement device disposed at each of the plurality of measurement sites; and a computation unit that acquires an electrical distance between the plurality of measurement sites on the basis of the facility information, classifies the plurality of measurement sites into at least one measurement site group on the basis of the electrical distance, extracts, with respect to each of the measurement sites in the measurement site group, a frequency component of electric power fluctuation from the measurement information, selects, with respect to a first frequency component which is a frequency component of a first measurement site in the measurement site group, a second frequency component which is a frequency component of a second measurement site in the measurement site group, and calculates a similarity between the first frequency component and the second frequency component.

Electric power system monitoring device and electric power system monitoring system

In a multi-hop radio communication network including a base station (a radio station connected to a management server), each radio station in the network is given a data transmission opportunity in turn according to a predetermined transmission order, and transmits data via broadcast or multicast upon occurrence of transmission timing. The radio station having received the data adds data of the radio station to the received data and then forwards the packet via broadcast or multicast when it is the radio station's turn for transmission.

Multi-hop radio communication method

An image display device includes a pair of transparent substrates, a liquid crystal composition and at least two types of color filters disposed between the pair of substrates, at least two types of light sources, and a light source controller. Each of the light sources generating peak wavelengths of at least two colors, wherein the peak wavelengths are different from one another. The light source controller switches on and off the light sources in time sequence within one frame period.

Image display device

An image formation apparatus includes an aperiodic data generating unit for generating aperiodic data between pixel areas having a neighboring relation every pixel area comprising a plurality of pixels having an interlocking relation of the image data, a threshold value deciding unit for converting the aperiodic data into a plurality of threshold data for forming a systematic dot array in the pixel area, and a gradation conversion processing unit for performing a gradation converting process by comparing the image data with the threshold data, thereby reducing a signal processing amount as compared with that in case of performing the propagating process on a pixel unit basis.

Image formation apparatus

A multi-color display system operates to suppress deterioration in resolution and increase in power consumption or deterioration in brightness. The multi-color display system includes n types of spectrum selecting means; m types of light sources each having a different spectral distribution; light source controlling means for controlling, on a time-division basis, emissions from the m types of light sources; color light sources controlled by the light source controlling means and the n types of spectrum selecting means, the number of the color light sources being not less than n+1, but not more than n&#xd7;m; and a light valve for controlling transmittance or reflectance of light in accordance with image information.

A micro-controller includes a dictionary memory for storing instruction codes which appear in a program, and a compressed code memory for storing compressed codes each converted from each of the instruction codes included in the program. Each compressed code has a word length sufficiently long to identify all instruction codes included in the program. Each compressed code has a value indicative of an address in the dictionary memory at which an associated instruction code is stored. The micro-controller is responsive to an instruction code read request which specifies an address of a compressed code to read the compressed code stored in the specified address in the compressed code memory, and to subsequently read an instruction code stored in an address indicated by the compressed code in the dictionary memory.

Micro-controller for reading out compressed instruction code and program memory for compressing instruction code and storing therein

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Tokyo, Japan

Tatsuki Inuduka