Nippon Telegraph and Telephone Corporation

Sachi Tsujimura

Hidenobu Hirota

Naotsugu Ambe

Hiroyuki Iida

Takui Uematsu

Yasuhiro Maehara

Jun Onishi

An object is to provide a determination device that determines a state of a terminal end portion of a coated optical fiber at any location of the coated optical fiber. Reflection of test light varies in a reflection amount at each wavelength depending on a situation of the terminal end portion of the coated optical fiber. In other words, if the magnitude of the reflection amount at each wavelength can be known, the situation of the terminal end portion of the coated optical fiber can be estimated. The determination device according to the present invention is configured to make test light having a plurality of wavelengths incident from the optical fiber side and determine the test light based on a light intensity ratio of each reflected light beams reflected at the terminal end. In addition, reflection of test light varies in return loss at each wavelength depending on a situation of the terminal end portion of the coated optical fiber. If Rayleigh backscattered light can also be measured when measuring a reflection amount, the return loss can be known for each wavelength, and the situation of the terminal end portion of the coated optical fiber can be estimated from the result. The determination device according to the present invention is configured to make test light having a plurality of wavelengths incident from the optical fiber side and determine the test light based on a return loss at the terminal end.

Judgment device and judgment method

The purpose of the present invention is to provide a hazard prediction method that can perform hazard prediction activities so as to prevent accidents, regardless of skills and personalities of workers. A hazard prediction method according to the present invention includes: photographing an outdoor facility along with environment to capture an image; collating the image with accident data including photos of outdoor facilities along with environment and accidents occurred at open-air facilities in the photos to detect, when a photo similar to the image is found, an accident occurred at an open-air facility in the photo from the accident data; extracting, from a safety measure list describing accidents, hazardous spots related to the accidents, and safety measures for prevention of the accidents, hazard information on a hazardous spot and a safety measure corresponding to the detected accident; receiving input information that is a safety measure devised by a worker for the hazardous spot; and comparing the input information with the hazard information to check that the input information and the hazard information match each other.

Danger prediction method and danger prediction device

Growing community of inventors

Musashino, Japan

Sachi Tsujimura