Detector Characterization and Mitigation of Noise in Ground-Based Gravitational-Wave Interferometers

Since the early stages of operation of ground-based gravitational-wave interferometers, careful monitoring of these detectors has been an important component of their successful operation and observations. Characterization of gravitational-wave detectors blends computational and instrumental methods of investigating the detector performance. These efforts focus both on identifying ways to improve detector sensitivity for future observations and understand the non-idealized features in data that has already been recorded. Alongside a focus on the detectors themselves, detector characterization includes careful studies of how astrophysical analyses are affected by different data quality issues. This article presents an overview of the multifaceted aspects of the characterization of interferometric gravitational-wave detectors, including investigations of instrumental performance, characterization of interferometer data quality, and the identification and mitigation of data quality issues that impact analysis of gravitational-wave events. Looking forward, we discuss efforts to adapt current detector characterization methods to meet the changing needs of gravitational-wave astronomy.

Automated Drilling Data Quality Control Using Application of AI Technologies

Drilling data quality is notoriously a challenge for any analytics application, due to complexity of the real-time data acquisition system which routinely generates: (i) Time related issues caused by irregular sampling, (ii) Channel related issues in terms of non-uniform names and units, missing or wrong values, and (iii) Depth related issues caused block position resets, and depth compensation (for floating rigs). On the other hand, artificial intelligence drilling applications typically require a consistent stream of high-quality data as an input for their algorithms, as well as for visualization. In this work we present an automated workflow enhanced by data driven techniques that resolves complex quality issues, harmonize sensor drilling data, and report the quality of the dataset to be used for advanced analytics. The approach proposes an automated data quality workflow which formalizes the characteristics, requirements and constraints of sensor data within the context of drilling operations. The workflow leverages machine learning algorithms, statistics, signal processing and rule-based engines for detection of data quality issues including error values, outliers, bias, drifts, noise, and missing values. Further, once data quality issues are classified, they are scored and treated on a context specific basis in order to recover the maximum volume of data while avoiding information loss. This results into a data quality and preparation engine that organizes drilling data for further advanced analytics, and reports the quality of the dataset through key performance indicators. This novel data processing workflow allowed to recover more than 90% of a drilling dataset made of 18 offshore wells, that otherwise could not be used for analytics. This was achieved by resolving specific issues including, resampling timeseries with gaps and different sampling rates, smart imputation of wrong/missing data while preserving consistency of dataset across all channels. Additional improvement would include recovering data values that felt outside a meaningful range because of sensor drifting or depth resets. The present work automates the end-to-end workflow for data quality control of drilling sensor data leveraging advanced Artificial Intelligence (AI) algorithms. It allows to detect and classify patterns of wrong/missing data, and to recover them through a context driven approach that prevents information loss. As a result, the maximum amount of data is recovered for artificial intelligence drilling applications. The workflow also enables optimal time synchronization of different sensors streaming data at different frequencies, within discontinuous time intervals.

Craft, Detail & Quality

<p>Over the past decade and even currently within New Zealand there have been quality issues within timber construction. My research proposes to address what these quality issues are both functionally, and aesthetically and how we can create a dialogue between craft, detail and quality. In residential architecture in New Zealand, the most common practice is timber stud framing or otherwise known as traditional platform framing. This construction type results in little variety throughout NZ as the vast majority is dominated by NZS:3604. This common platform framing can also create architecture that barely resembles the timber material. This research creates a framework to what will be a possible solution in exposing the details of timber joints, which in turn may prevent quality issues along with creating a crafted timber design. As a starting point for this research, it seemed appropriate to draw on traditional Japanese, European and Pacific construction techniques. These cultures have mastered the art of craft, and we in New Zealand could learn from this and reflect in contemporary practices in NZ. This could in turn create a solution which highlights the quality issues in construction of New Zealand residential architecture. Typically, in New Zealand platform framing construction, timber joint details are concealed. These concealed details are more prone to failure and so by exposing these, it can lead to improving quality of construction. Quality is, however, an elusive concept and this will become clear through an analysis of interviews with numerous builders, project managers, architects and of course the everyday user. These interviews define what they believe is the most common area of defect, and where quality can be improved. This research will therefore look at what system can be designed between the connections of architectural elements to focus on exposed refined details and joints. As these connection details are explored the definition of “craft” will become more defined, where it currently begins as examples of exposed, visible and readable detail. Taking place in a rural New Zealand environment in Raglan Waikato, the portfolio proposes a boutique hotel, with a scheme that demonstrates this newly proposed construction system as an alternative to platform framing. The role of the hotel design is merely a vehicle to apply and test the research. There are many implications that may be a factor in the conclusion of this research proposal, for example CLT timber accessibility and costs. However further outcomes will result in celebration and awareness of detailing which leads to improving quality of New Zealand timber architecture. This research explores turning traditional methods of construction into contemporary architecture using the technologies and material practices of today.</p>

Craft, Detail & Quality

<p>Over the past decade and even currently within New Zealand there have been quality issues within timber construction. My research proposes to address what these quality issues are both functionally, and aesthetically and how we can create a dialogue between craft, detail and quality. In residential architecture in New Zealand, the most common practice is timber stud framing or otherwise known as traditional platform framing. This construction type results in little variety throughout NZ as the vast majority is dominated by NZS:3604. This common platform framing can also create architecture that barely resembles the timber material. This research creates a framework to what will be a possible solution in exposing the details of timber joints, which in turn may prevent quality issues along with creating a crafted timber design. As a starting point for this research, it seemed appropriate to draw on traditional Japanese, European and Pacific construction techniques. These cultures have mastered the art of craft, and we in New Zealand could learn from this and reflect in contemporary practices in NZ. This could in turn create a solution which highlights the quality issues in construction of New Zealand residential architecture. Typically, in New Zealand platform framing construction, timber joint details are concealed. These concealed details are more prone to failure and so by exposing these, it can lead to improving quality of construction. Quality is, however, an elusive concept and this will become clear through an analysis of interviews with numerous builders, project managers, architects and of course the everyday user. These interviews define what they believe is the most common area of defect, and where quality can be improved. This research will therefore look at what system can be designed between the connections of architectural elements to focus on exposed refined details and joints. As these connection details are explored the definition of “craft” will become more defined, where it currently begins as examples of exposed, visible and readable detail. Taking place in a rural New Zealand environment in Raglan Waikato, the portfolio proposes a boutique hotel, with a scheme that demonstrates this newly proposed construction system as an alternative to platform framing. The role of the hotel design is merely a vehicle to apply and test the research. There are many implications that may be a factor in the conclusion of this research proposal, for example CLT timber accessibility and costs. However further outcomes will result in celebration and awareness of detailing which leads to improving quality of New Zealand timber architecture. This research explores turning traditional methods of construction into contemporary architecture using the technologies and material practices of today.</p>

Signatures of Transient Overvoltages in Low Voltage Power Systems in Tea Factories and Their Implications on Insulation Deterioration and Allied Power Quality Issues

Electrical equipment and supply cables demand a better quality of supply, with the recent advancements in integrated sensitive solid-state controls. Divergently, proliferated heavy inductive motors and some performance additions based on power electronics have introduced power quality issues to the network. Thus, this study mainly investigates the impact of switching transients generated by electromechanical machines in industrial power systems on insulation deterioration while taking transient overvoltages due to capacitor bank switching also to support. Transients with a high rate of rise are likely to catalyze the degradation of the insulation quality and break down the insulating material through ionization. These steeply passing overvoltage stresses let partial discharges ensue, which can attack the insulation over long service. To unveil this danger, 314 common-mode transient waveforms were measured in the electrical machines of five tea factories in Sri Lanka, in a 50 ms measurement window, taken in 55 measuring attempts. Most of the transients observed are in the form of a damped oscillatory waveform tailed by fast exponential collapse. That correlates to insulation degradation having a very steep rise as 30.04 V/ns, the highest at the withering section. When machines are heavily loaded, situations tend to generate transients with high amplitudes. There were transient bursts that spread as 426.3 ms, while 14 ns fast rise times were recorded from withering motors. Unlike electrical resonance and power-frequency overvoltages, electromagnetic switching transients last even less than 100 ms. To underline this, an analysis of the frequency domain of transients was also presented, which proves high density of high-frequency components reaching 107 kHz range. Accepting the fact that frequency and amplitude are always under the influences of innumerable dynamics, the observational evidence of the study endorses that electrical stress built by the transient nature of the factories reduces the life expectancy of electrical insulation.