公开(公告)号：US12217587B2

公开(公告)日：2025-02-04

申请号：US17625412

申请日：2020-07-10

Applicant: NEC Corporation

Inventor： Jun Sakai ,  Masaki Kitsunezuka ,  Toshiki Takeuchi ,  Taichi Ohtsuji ,  Shoji Nishimura ,  Yasufumi Hirakawa

IPC: G08B21/02 ,  G08B25/10 ,  H04W4/029 ,  H04W4/38

Abstract: 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.

公开(公告)号：US11757548B2

公开(公告)日：2023-09-12

申请号：US17316844

申请日：2021-05-11

Applicant: NEC Corporation

Inventor： Taichi Ohtsuji ,  Jun Sakai

IPC: H04B17/391 ,  H04W16/18

CPC classification number: H04B17/391 ,  H04W16/18

Abstract: 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.

公开(公告)号：US11249009B2

公开(公告)日：2022-02-15

申请号：US16079627

申请日：2017-03-03

Applicant: NEC Corporation

Inventor： Jun Sakai

IPC: G01N19/08 ,  F17D5/02

Abstract: Provided are a diagnostic device and the like for easily diagnosing the condition of the interior of a pipeline. This diagnostic device is provided with: a frictional loss calculating unit which, on the basis of the pressure of a fluid in the pipeline, finds a pressure frictional loss; and a diagnosing unit which diagnoses the condition of the inner surface of the pipeline on the basis of the frictional loss.

公开(公告)号：US11560698B2

公开(公告)日：2023-01-24

申请号：US16636982

申请日：2018-08-02

Applicant: NEC CORPORATION

Inventor： Masatake Takahashi ,  Manabu Kusumoto ,  Jun Sakai

IPC: E03B7/07

Abstract: A state analysis device is capable of determining a state of the interior of piping with high precision, and includes: an index calculation means for deriving an index indicating the state of the piping, based on a flow speed of fluid flowing out of the piping, and a fluid pressure of the interior of the piping at two or more locations of the piping; and a determination means for determining the state of the piping, based on the index.

公开(公告)号：US20210359775A1

公开(公告)日：2021-11-18

申请号：US17316844

申请日：2021-05-11

Applicant: NEC Corporation

Inventor： Taichi Ohtsuji ,  Jun Sakai

IPC: H04B17/391 ,  H04W16/18

Abstract: 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.