A seismic sensor includes a measurement unit configured to measure acceleration; an earthquake determination unit configured to determine whether or not an earthquake has occurred based on the acceleration measured in a predetermined determination period; an index calculator configured to calculate an index value indicating a scale of an earthquake in an earthquake processing period after the predetermined determination period, when the earthquake determination unit determines that an earthquake has occurred; a continuous earthquake determination unit configured to determine whether or not an earthquake has occurred, based on the acceleration measured in the earthquake processing period; and a shut-off determination unit configured to inhibit output of the shut-off signal regardless of the index value when the continuous earthquake determination unit determines that no earthquake has occurred.

Described herein is method for the detection of seismic activity using a network of lights, and in particular, street lights (43) arranged over a number of streets (42). Each light includes a control module having the facility for both long- and short-distance communication, the control modules being grouped with other control modules and associated with a group controller to create a short-distance or mesh network. Each control module includes a sensor which is capable of detecting seismic activity and data relating to such activity may be transmitted to a central server via its group controller using long-distance communication. Even if the sensors are relatively inaccurate, the high number of such sensors present in the network makes it possible to detect and analyse the activity using geocoordinate information provided by the control modules at the server. Information relating to an epicentre of an earthquake can be determined and distributed to control modules in the vicinity of the detected seismic activity (50) to provide warning light signals for the population in that vicinity.

The present disclosure generally relates to infrastructure health condition estimation. There is provided a computer-implemented method for characterising behaviours of working events of components of an infrastructure (110), the working events comprising previous working events. The method comprises obtaining historical data representing the previous working events of the components (112) of the infrastructure (110); and determining, based on the historical data, values of parameters of a stochastic process model to characterise the behaviours of the working events, wherein the stochastic process model comprises a set of Hawkes processes that characterise occurrences of the working events and a Bayesian nonparametric process that characterises dependency of the working events.

A communication device includes a memory and a processor coupled to the memory and configured to, when a first vibration is detected in the communication device, set a certain state that protects information stored in the memory, and cancel the certain state based on receiving from another communication device a notification indicating that the other communication device detected a second vibration.

It is possible to accurately convey information relevant to a long period ground motion to a person staying on each floor of a building. A system 1 for communicating information relating to a long period ground motion acquires information indicating a floor on which a user stays in a building at which the user stays, information relevant to a position and a structure of the building, and information relevant to a state of an earthquake that occurs, and calculates a state of shaking that occurs on the floor of the building at which the user stays due to the long period ground motion to be communicated to the user through a user terminal 3, and thus, information relevant to the long period ground motion can be obtained through the user terminal 3 that the user has.

A system for collecting and managing seismic data via an external communications network comprises one or more seismic stations, each including a seismic measurement apparatus producing seismic signals, a station processor converting the signals to seismic data, a station memory securely storing the seismic data on site and a station communication interface transmitting the seismic data onto an external network. The system further comprises one or more data servers, each including a server computing device, a server communication interface receiving the seismic data from the seismic stations and a server memory storing the received seismic data. The data server can determine if the received seismic data satisfies predetermined conditions for certification and/or triggering a payout in accordance with a contract, and can thereafter transmit the appropriate data signals to another location on the external communications network.

A computer-implemented method for seismic event localization includes: generating, with at least one processor, a vectorized snapshot matrix representing wave propagation data at a series of snapshots in time for a subterranean formation; computing a reduced orthonormal column basis matrix based on the vectorized snapshot matrix; constructing a reduced order wave propagation model based on the reduced orthonormal column basis matrix; receiving seismic data collected from a plurality of receivers at the subterranean formation; generating a time-domain coefficient matrix based on back propagation of the received seismic data and the reduced order wave propagation model; reconstructing time-reversed wavefield data based on the time-domain coefficient vector; and generating signals for outputting wavefield or seismic event location information based on the time-reversed wavefield data.

A prediction portion predicts states including a water level of the wave at a prediction subject location. In a case in which inputs of the flow velocity in a line-of-sight direction of the wave at each observation location have been received, an estimation portion estimates states of waves including the water level thereof at the prediction subject location. The estimation of the states is based on a difference between the flow velocity in a line-of-sight direction of the wave at each input observation location, and the flow velocity in a line-of-sight direction of the wave at each input observation location obtained by converting states of the wave using an observation matrix. A determination portion causes the predictions of the states and the estimation of the states to be repeated until predetermined conditions have been satisfied.

A network of motion sensors employs sensitive accelerometers to issue time-domain measurements of building movement from multiple locations within and between buildings and other structures. The time-domain measurements from the various motion sensors are synchronized and converted into frequency-domain measurements of building movement. Individual motion sensors can be equipped with the requisite processor and memory to synchronize and covert the time-domain measurements. The motions sensors can classify detected events into various event types, such as earthquakes, wind events, or bipedal locomotion. The sensors can also communicate with one another or other resources to calculate event probabilities. A motion sensor may, for example, receive an earthquake-verification signal responsive to an earthquake-verification request. The network of motion sensors can calculate local soil stiffness and financial loss estimations responsive to their individual or collective frequency-domain measurements.

A device can receive sensor data from a plurality of sensor devices. The sensor data can include information relating to vibrations detected by the plurality of sensor devices. The device can determine, based on the information relating to vibrations, whether the vibrations are likely to be associated with one or more primary waves of a seismic event. The device can predict, based on determining that the vibrations are likely to be associated with the one or more primary waves, a geographic area that is likely to be impacted by one or more secondary waves of the seismic event. The device can transmit, based on predicting the geographic area, and to one or more of a plurality of user equipments, one or more of a notification providing information relating to the seismic event or instructions to perform one or more actions.