Causal Algebras on Chain Event Graphs with Informed Missingness for System Failure

Graph-based causal inference has recently been successfully applied to explore system reliability and to predict failures in order to improve systems. One popular causal analysis following Pearl and Spirtes et al. to study causal relationships embedded in a system is to use a Bayesian network (BN). However, certain causal constructions that are particularly pertinent to the study of reliability are difficult to express fully through a BN. Our recent work demonstrated the flexibility of using a Chain Event Graph (CEG) instead to capture causal reasoning embedded within engineers’ reports. We demonstrated that an event tree rather than a BN could provide an alternative framework that could capture most of the causal concepts needed within this domain. In particular, a causal calculus for a specific type of intervention, called a remedial intervention, was devised on this tree-like graph. In this paper, we extend the use of this framework to show that not only remedial maintenance interventions but also interventions associated with routine maintenance can be well-defined using this alternative class of graphical model. We also show that the complexity in making inference about the potential relationships between causes and failures in a missing data situation in the domain of system reliability can be elegantly addressed using this new methodology. Causal modelling using a CEG is illustrated through examples drawn from the study of reliability of an energy distribution network.

The Past, Present, and Future of Tuna at Lake Moāwhitu: Drawing on the two knowledge baskets of Mātauranga Māori and Western Science

<p><b>Knowledge generated through experience and understanding relies on the senses, one of which is listening. This thesis provides an opportunity to hear the diminishing voice of tuna utilizing paleolimnological techniques and our natural senses through traditional Indigenous methodologies in order to track the presence of tuna back in time. </b></p> <p>This study provides historical environmental context of Lake Moāwhitu catchment (Rangitoto ki te Tonga) as a once significant mahinga kai site for manawhenua, Ngāti Koata. The strong connection to place is not lost on Ngāti Koata despite for many their geographic detachment to their turangawaewae. They hear the voice of tuna calling them back to sustain them as they have sustained Māori from the beginning of time. Now considered wāhi tapu due to significant degradation, Moāwhitu is currently undergoing remedial intervention by Ngāti Koata, DoC, Lakes380 and stakeholders to restore the mauri (life force) of the Lake and adjacent wetland ecosystem.</p> <p>Drawing from two distinct knowledge streams of western science and mātauranga Māori, this study draws new (on-site) understandings about the anthropogenic impacts on tuna as well as their status and relationship as tuākana (older sibling) to Māori. Through this journey a ‘te ao Māori’ (Māori worldview) is explored, revealing a historically healthy and abundant tuna population and thriving tuākana-teina relationship up until recent decades. This information complements the environmental reconstruction derived from western science methods applied to a lake Moawhitu sediment core spanning the last 1000 years or so. Through a combination of palynology, hyperspectral scanning and bacterial environmental DNA metabarcoding, it is clear that lake water quality remained high despite various historical land cover and land use changes, until recent decades when deteriorating quality has accompanied a rise in cyanobacteria and toxic algal blooms. These changes appear to coincide with intensified pastoralism accompanying draining of the lake and fringing wetlands since the mid-twentieth century. How tuna have endured these recent human impacts and why their survival and sustainability is important to Aotearoa today is at the heart of this thesis which seeks to explore how two vastly different knowledge streams converge and navigate unchartered waters. The two knowledge baskets (with their respective world views) are held up for the reader to view and consider what an effective collaborative partnership looks like by recognising basic intrinsic values of respect, reciprocity and kindness. The challenge remains to draw out the very best of people (he tangata) as a way to bring about urgent regenerative solutions for our tuākana, tuna, and in turn humanity itself.</p>

The Past, Present, and Future of Tuna at Lake Moāwhitu: Drawing on the two knowledge baskets of Mātauranga Māori and Western Science

<p><b>Knowledge generated through experience and understanding relies on the senses, one of which is listening. This thesis provides an opportunity to hear the diminishing voice of tuna utilizing paleolimnological techniques and our natural senses through traditional Indigenous methodologies in order to track the presence of tuna back in time. </b></p> <p>This study provides historical environmental context of Lake Moāwhitu catchment (Rangitoto ki te Tonga) as a once significant mahinga kai site for manawhenua, Ngāti Koata. The strong connection to place is not lost on Ngāti Koata despite for many their geographic detachment to their turangawaewae. They hear the voice of tuna calling them back to sustain them as they have sustained Māori from the beginning of time. Now considered wāhi tapu due to significant degradation, Moāwhitu is currently undergoing remedial intervention by Ngāti Koata, DoC, Lakes380 and stakeholders to restore the mauri (life force) of the Lake and adjacent wetland ecosystem.</p> <p>Drawing from two distinct knowledge streams of western science and mātauranga Māori, this study draws new (on-site) understandings about the anthropogenic impacts on tuna as well as their status and relationship as tuākana (older sibling) to Māori. Through this journey a ‘te ao Māori’ (Māori worldview) is explored, revealing a historically healthy and abundant tuna population and thriving tuākana-teina relationship up until recent decades. This information complements the environmental reconstruction derived from western science methods applied to a lake Moawhitu sediment core spanning the last 1000 years or so. Through a combination of palynology, hyperspectral scanning and bacterial environmental DNA metabarcoding, it is clear that lake water quality remained high despite various historical land cover and land use changes, until recent decades when deteriorating quality has accompanied a rise in cyanobacteria and toxic algal blooms. These changes appear to coincide with intensified pastoralism accompanying draining of the lake and fringing wetlands since the mid-twentieth century. How tuna have endured these recent human impacts and why their survival and sustainability is important to Aotearoa today is at the heart of this thesis which seeks to explore how two vastly different knowledge streams converge and navigate unchartered waters. The two knowledge baskets (with their respective world views) are held up for the reader to view and consider what an effective collaborative partnership looks like by recognising basic intrinsic values of respect, reciprocity and kindness. The challenge remains to draw out the very best of people (he tangata) as a way to bring about urgent regenerative solutions for our tuākana, tuna, and in turn humanity itself.</p>

Successful Hydraulic Isolation Assessment Saves Rig Utilization Time and Unnecessary Cement Remedial Squeeze Operation - Case Study, Kuwait

While drilling an 8 1/2-incli section of a north Kuwait producer well, severe mud losses were encountered. Hence, it was decided to design a light weight cement for the 7-inch liner section to avoid further losses while pumping the slurry. The main objective was to achieve a hydraulic isolation to avoid any heavy remedial intervention and potential dump flood behind the liner from the high-pressure Lower Burgan (LB) to Shuaiba. Full suite of well integrity logs were ran to properly assess whether enough hydraulic isolation was in place. To evaluate the bonding quality of the cement, two independent measurements were carried out across the 7-inch liner with the ultrasonic and sonic bond logs. A subsequent temperature survey was recorded to determine any geothermal anomaly, which could be indicative of fluid movement behind the casing. Finally, oxygen activation stations were conducted based on the cement log and temperature surveys to assure no water movement behind the casing. The ultrasonic and sonic bond log measurements showed an acceptable bond quality generally. However, the top part of Shuaiba formation up to LB exhibited relatively lower bond quality. The subsequent temperature and oxygen activation logs indicated that the zonal hydraulic isolation was achieved by showing no water movement behind the 7-inch liner. The two complementary surveys helped to take the proper forward decision for this well to go ahead with the planned perforation without cement remedial squeeze, since enough hydraulic isolation was proved to be in place behind the 7-inch liner. Additionally, this saved the rig utilization time and cost by avoiding unnecessary remedial operation. This is usually a heavy-duty operation, which takes time and induces holes in the casing that should be avoided, knowing this type of operation only provides a very marginal gain in terms of isolation. Furthermore, the well is currently producing at 0% water cut after completion. The proper cement design using light weight cement and optimized casing-landing plan were crucial to achieve good cement placement against formation. The use of the right well integrity approach helped to confirm that effective hydraulic isolation was achieved. Hence all these efforts resulted in the saved rig utilization time and cost by avoiding unnecessary squeeze intervention.

"I realized that cops are just regular people" : changing youth attitudes toward the police through community policing programming.

Existing literature examining youth-police relations has consistently found that willingness to engage with the police is directly influenced by youth attitudes toward the police. Research findings suggest that increasing positive attitudes toward the police among adolescent populations will result in a subsequent increase in behaviours supportive of the police and law enforcement. The current study was a mixed-method evaluation (including survey data and qualitative interviews) of a community policing pilot program designed to increase positive contact between at-risk youth and police officers. The program was effective in positively changing youth attitudes toward the police. Interview results provide evidence of a direct mechanism for increasing trust and cooperation with the police. Survey results indicate that positive contact with the police can shift general attitudes toward the police and reduce perceptions of police discrimination. Further, survey findings support the program as a remedial intervention for youth with previous negative police contact.

"I realized that cops are just regular people" : changing youth attitudes toward the police through community policing programming.

Existing literature examining youth-police relations has consistently found that willingness to engage with the police is directly influenced by youth attitudes toward the police. Research findings suggest that increasing positive attitudes toward the police among adolescent populations will result in a subsequent increase in behaviours supportive of the police and law enforcement. The current study was a mixed-method evaluation (including survey data and qualitative interviews) of a community policing pilot program designed to increase positive contact between at-risk youth and police officers. The program was effective in positively changing youth attitudes toward the police. Interview results provide evidence of a direct mechanism for increasing trust and cooperation with the police. Survey results indicate that positive contact with the police can shift general attitudes toward the police and reduce perceptions of police discrimination. Further, survey findings support the program as a remedial intervention for youth with previous negative police contact.

Improved Vision-Based Detection of Strawberry Diseases Using a Deep Neural Network

Detecting plant diseases in the earliest stages, when remedial intervention is most effective, is critical if damage crop quality and farm productivity is to be contained. In this paper, we propose an improved vision-based method of detecting strawberry diseases using a deep neural network (DNN) capable of being incorporated into an automated robot system. In the proposed approach, a backbone feature extractor named PlantNet, pre-trained on the PlantCLEF plant dataset from the LifeCLEF 2017 challenge, is installed in a two-stage cascade disease detection model. PlantNet captures plant domain knowledge so well that it outperforms a pre-trained backbone using an ImageNet-type public dataset by at least 3.2% in mean Average Precision (mAP). The cascade detector also improves accuracy by up to 5.25% mAP. The results indicate that PlantNet is one way to overcome the lack-of-annotated-data problem by applying plant domain knowledge, and that the human-like cascade detection strategy effectively improves the accuracy of automated disease detection methods when applied to strawberry plants.

Simplified Analytical/Mechanical Procedure for Post-earthquake Safety Evaluation and Loss Assessment of Buildings

The crucial need to develop and implement simple and cost-effective repair and retrofit strategies and solutions for existing structures has been once again emphasized, if at all needed, by the recent catastrophic earthquake events. The significant socio-economic impacts of the Canterbury earthquakes sequence in 2010–2011 as well as of the “series” of independent events within few years in Italy (L’Aquila 2009; Emilia 2012; Central Italy 2016) have triggered a stepchange in the high-level approach towards the implementation of seismic risk reduction, introducing either a mandatory enforcement or significant financial incentives for a national-wide program to assess (and reduce by remedial intervention) the seismic vulnerability/capacity of the whole (non-dwelling) building stock, including safety and expected repairing costs (direct economic losses). This chapter provides an overview of the motivations, challenges and (possible) solutions for such a complex and delicate task with the intent to stimulate awareness, discussion and synergetic actions within the wider international community. Particular focus will be given to the development and on-going continuos refinement of a simplified analytical-mechanical methodology—referred to as SLaMA (Simple Lateral Mechanism Analysis) method—as part of a proposed integrated methodology for either pre- and post-earthquake safety evaluation and loss assessment of buildings, in order to support the engineering community and stakeholders through the various steps of the decision making process of risk (assessment and) reduction.