Nec Corporation

Taichi Ohtsuji

Kazushi Muraoka

Hiroaki Aminaka

Norio Yamagaki

Takashi Yoshinaga

Dai Kanetomo

Toshiki Takeuchi

Jun Sakai

Masaki Kitsunezuka

Shoji Nishimura

Yasufumi Hirakawa

Kiyohiko Takahashi

Kaoru Kishimoto

Umihiko Ito

Kenji Kouno

Hiroyuki Akiba

A tracking support system includes a position calculating section connected with a plurality of cameras arranged in a predetermined monitoring area to transmit video images imaged by the plurality of cameras and configured to calculate a position of the tracking target based on the video images received from the plurality of cameras; a tracker selecting section configured to select a tracker to be instructed to track the tracking target, based on position information of the terminal received from the terminal and the calculated position of the tracking target; and an information transmitting section configured to transmit information of a distance between the tracking target and the terminal during the tracking of the tracking target to the terminal carried by the selected tracker.

Tracking support apparatus, terminal, tracking support system, tracking support method and program

An abnormality detection apparatus according to an example embodiment includes a reception unit for receiving radio waves, a feature amount extraction unit for extracting a plurality of feature amounts in a predetermined frequency band from the received radio waves, a recording unit for recording the plurality of extracted feature amounts and the frequency band in association with each other, and a processing unit for acquiring a plurality of feature amounts in a predetermined range from the plurality of accumulated feature amounts, determining whether or not the acquired feature amounts fall within a preset normal range, and generating, based on a result of the determination, an abnormality determination mask, threshold values for the plurality of feature amounts, in order to detect an abnormality of the radio waves being set in the abnormality determination mask.

Abnormality detection apparatus, abnormality detection method and non-transitory computer readable medium

A wireless terminal detection system provided with user position information acquisition means for measuring a position of a reception-side wireless terminal; pattern classification means for classifying movement patterns extracted from position history information of the reception-side wireless terminal into ordinary patterns and non-ordinary patterns based on classification results in which the movement patterns are classified in accordance with times and positions; and determination means for determining whether a transmission-side wireless terminal, which is a transmission source of radio waves received by the reception-side wireless terminal, is a suspicious terminal based on a reception history of radio waves from the transmission-side wireless terminal in time intervals classified as the non-ordinary patterns.

Wireless terminal detection system, wireless terminal detection device, wireless terminal detection method, and storage medium having program stored therein

A transmission apparatus recognition apparatus includes a storage unit that stores K sets of template feature groups for estimating K (an integer of 2 or more) kinds of information indicative of a transmission apparatus, a degree-of-similarity calculation unit that generates an i (an integer of 1 to K)-th sample feature from a radio feature, and calculates an i-th degree-of-similarity group, based on the i-th sample feature and an i-th set of the template feature group, a summed degree-of-similarity calculation unit that calculates a summed degree of similarity by summing K degrees of similarity by using an i-th weighting factor with respect to 1 to K of i, and an estimation unit that estimates that K information pieces, which are correlated in advance with calculation sources of K degrees of similarity having the summed degree of similarity that is highest, are information indicative of the transmission apparatus.

Transmission apparatus recognition apparatus, learning apparatus, transmission apparatus recognition method, and, learning method

The present invention improves efficiency of operator's work by automating template registration of an unregistered transmission apparatus. A transmission apparatus recognition apparatus includes a receiving unit, a recognition unit, and a template feature registration unit. The receiving unit receives a signal wirelessly transmitted from a transmission apparatus. The recognition unit calculates a degree of similarity between a sample feature generated from a received signal received by the receiving unit and template features registered in advance, compares the degree of similarity with recognition threshold value, and thereby recognizes the transmission apparatus. The template feature registration unit generates a template feature from a sample feature that failed to be recognized by the recognition unit.

Transmission apparatus recognition apparatus, transmission apparatus recognition system, transmission apparatus recognition method, and computer readable medium

A transmission apparatus recognition apparatus includes a receiver configured to receives a signal wirelessly transmitted from a transmission apparatus, a signal region detector, a feature extractor, and a recognizer. The signal region detector generates a spectrogram from a received signal received by the receiver, and detects a signal region parameter indicating a specific signal region based on the spectrogram. The feature extractor converts the received signal based on a signal conversion parameter according to the signal region parameter, and extracts a feature from the converted signal. The recognizer calculates a degree of similarity based on the extracted feature and a feature stored in advance, and recognizes the transmission apparatus based on the degree of similarity. The transmission apparatus recognition apparatus adjusts the signal region parameter based on a recognition accuracy of the recognizer.

Transmission apparatus recognition apparatus, transmission apparatus recognition method, and non-transitory computer readable medium

A modulation format estimation deviceincludes: a frequency shift correction unitconfigured to estimate the amount of a frequency shift using a baseband signal acquired from a received signal and correct the baseband signal based on an estimation result; a frequency error generation unitconfigured to generate a plurality of frequency errors from a range set based on an error occurring in the estimation of the frequency shift amount; a frequency error introduction unitconfigured to acquire learning baseband signals in which each of a plurality of source signals modulated by different modulation formats is frequency-shifted by each frequency error; and a modulation format estimation unitconfigured to input a corrected baseband signal to a first machine learning model created by machine learning using learning data including the plurality of learning baseband signals and a label, and estimate a modulation format of the received signal.

Modulation format estimation device, and modulation format estimation method

A terminal number estimating system includes: a plurality of receivers that receive a wireless signal transmitted from a plurality of terminal devices by frequency-division multiple access; a Fourier transform unit that performs a discrete Fourier transform on each wireless signal received by the plurality of reception means and outputs a discrete Fourier coefficient; and a terminal number estimation unit that estimates a position of each terminal device by clustering a resource block of each wireless signal based on each discrete Fourier coefficient.

Terminal number estimating system, terminal specifying system, terminal number estimating device, terminal number specifying device, and processing method

A transmission device identification system includes: one or more reception units; a feature output unit that outputs, for each of the one or more reception units, a feature of a reception signal of the reception unit, the feature being corrected based on a receiver characteristic of the reception unit; and an identification unit that identifies a transmission device that is a radio wave transmitting source based on the feature and a transmission radio wave feature, the transmission radio wave feature indicating a feature of a transmission radio wave for each transmission device.

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Tokyo, Japan

Taichi Ohtsuji