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found 2009 results

Research papers, University of Canterbury Library

High-quality ground motion records are required for engineering applications including response history analysis, seismic hazard development, and validation of physics-based ground motion simulations. However, the determination of whether a ground motion record is high-quality is poorly handled by automation with mathematical functions and can become prohibitive if done manually. Machine learning applications are well-suited to this problem, and a previous feed-forward neural network was developed (Bellagamba et al. 2019) to determine high-quality records from small crustal events in the Canterbury and Wellington regions for simulation validation. This prior work was however limited by the omission of moderate-to-large magnitude events and those from other tectonic environments, as well as a lack of explicit determination of the minimum usable frequency of the ground motion. To address these shortcomings, an updated neural network was developed to predict the quality of ground motion records for all magnitudes and all tectonic sources—active shallow crustal, subduction intraslab, and subduction interface—in New Zealand. The predictive performance of the previous feed-forward neural network was matched by the neural network in the domain of small crustal records, and this level of predictive performance is now extended to all source magnitudes and types in New Zealand making the neural network applicable to global ground motion databases. Furthermore, the neural network provides quality and minimum usable frequency predictions for each of the three orthogonal components of a record which may then be mapped into a binary quality decision or otherwise applied as desired. This framework provides flexibility for the end user to predict high-quality records with various acceptability thresholds allowing for this neural network to be used in a range of applications.

Audio, Radio New Zealand

We have a leaked report which details critical earthquake faults in a new high rise building in Christchurch. A review finds bullies in Parliament but doesn't say who they are. And a Muslim community advocate welcomes the laying of terrorism charges against the Christchurch gunman.

Images, UC QuakeStudies

A photograph of earthquake-damaged buildings down Manchester Street. Crowds have gathered at the intersection with High Street in the distance, after evacuating their buildings during the 22 February 2011 earthquake. Rubble from the building to the left covers the road.

Audio, Radio New Zealand

It's 10 years since an earthquake killed 185 people in Christchurch. Ports of Auckland workers the latest people to be vaccinated against Covid-19. And Papatoetoe High students are back to school following three community Covid cases at the college. Nicola Wright has the news.

Images, UC QuakeStudies

A photograph submitted by Anonymous to the QuakeStories website. The description reads, "The demolition of our preschool opposite Cranmer Square. All children and teachers were evacuated safely with the help of builders working on the old Girl’s High building in front.".

Images, UC QuakeStudies

A view down High Street, looking north-west through the cordon fence near the Tuam Street intersection. On the left a line of shipping containers support the facade of a damaged building. Rubble from demolished buildings can be seen in the distance.

Images, UC QuakeStudies

People cast flowers into the Avon River during the River of Flowers event held in Riccarton Bush, commemorating the second anniversary of the 22 February earthquake. In the background is the string quartet from Christchurch Girls High School which played before the event.

Images, UC QuakeStudies

A woman casts flowers into the Avon River during the River of Flowers event held in Riccarton Bush, commemorating the second anniversary of the 22 February earthquake. In the background is the string quartet from Christchurch Girls High School which played before the event.

Images, UC QuakeStudies

People cast flowers into the Avon River during the River of Flowers event held in Riccarton Bush, commemorating the second anniversary of the 22 February earthquake. In the background is the string quartet from Christchurch Girls High School which played before the event.

Images, UC QuakeStudies

A view down High Street, looking north-west through the cordon fence near the Tuam Street intersection. On the left a line of shipping containers support the facade of a damaged building. Rubble from demolished buildings can be seen in the distance.

Images, UC QuakeStudies

A photograph of a cleared building site on High Street. Three shipping containers are stacked against the remaining facade of the Excelsior Hotel building on the left. The badly-damaged McKenzie & Lewis building on Tuam Street can be seen in the distance.