In reality, failure data are often collected under diffract operational conditions (covariates), leading to heterogeneity among the data. Heterogeneity can be classified as observed and unobserved heterogeneity. Un-observed heterogeneity is the effect of unknown, unrecorded, or missing covariates. In most reliability studies, the effect of unobserved covariates is neglected. This may lead to inaccurate ...

Oil and gas (O&G) industry is expanding its activities into Arctic offshore, where is characterised with severe operating conditions and less-developed infrastructure. Such conditions affect the reliability, availability, and maintainability (RAM) of offshore O&G plants, operations, and activities through different scenarios. Plant RAM analysis provides key information for decision-making on, for ...

Seafaring is one of the oldest documented human activities, with a rich heritage created by generations of seamen. The first boats were developed several thousand years ago, based on primitive principles, and they were probably not suitable for other than simple purposes. Analyzing the history of boat building shows a gradual change in designs. These design changes were most likely due to improvements, ...

Disasters differ markedly in their speed of manifestation, which in turn greatly affects how researchers as well as authorities interpret and respond to them. In theory, disasters with a gradual and creeping onset are easier to manage than sudden and unexpected ones. However, the unfortunate reality is that hazards with a slow-onset are often ignored, left smouldering in the background, while their ...

New designs of high-resolution ultrasonic imaging systems that operate in the 30–100MHz region, for example, those based on linear transducer systems, are currently being investigated for medical purposes. Acoustic waves with frequencies in this range can detect microscopic structures in human tissue but will typically only penetrate a few mm because of large attenuation. However, this is sufficient ...

The paper analyses the economic and political history of the Ross Sea, where exploration, science, commercial exploitation, politics and adventure became highly interlinked and interwoven. Expedition accounts and the extensive literature on Antarctic history and politics inform the contextual aspects. The archives of the Norwegian whaling company A/S Rosshavet, established in 1923, and the ...

Autonomous navigation will play an important role in the future of the shipping industry. Hence, this study illustrates several concepts that should support the navigation side in relation to the collision avoidance of autonomous ships. The concept of system intelligence, i.e., cloned by human navigators, as the digital helmsman to navigate future vessels is discussed in the first part of this study. ...

To meet the availability target and reduce system downtime, effective maintenance have a great importance. However, maintenance performance is greatly affected in complex ways by human factors. Hence, to have an effective maintenance operation, these factors needs to be assessed and quantified. To avoid the inadequacies of traditional human error assessment (HEA) approaches, the application of ...

One of the mining industry's main concerns is the management of waste rock and tailings generated by sulfide ore extraction. Upon exposure of atmospheric oxygen, iron sulfides oxidize generating acidity. Infiltrating water form a metal-rich acidic leachate called acid mine drainage (AMD), that can cause serious environmental problems. Green liquor dregs (GLD) is a material that resists the passage ...