Software Verification for a Custom Instrument using VectorCAST and CodeSonar

The goal of this thesis is to apply a structured verification process to a software package using a set of commercially available verification tools. The software package to be verified is adapted from a project that was developed to monitor an industrial machine at the Oak Ridge National Laboratory and includes two major subsystems. One subsystem, referred to as the Industrial Machine Monitoring Instrument (IMMI), connects to a machine and monitors operating parameters using common industrial sensors. A second subsystem, referred to as the Distributed Control System (DCS), interfaces between the IMMI and a personal computer, which provides a human machine interface using a hyperterminal. Both the IMMI and DCS are built around Freescale’s MC9S12XDP microcontroller using CodeWarrior as the Integrated Development Environment (IDE). The software package subjected to the structured verification process includes the main C code with its header file and the code for its interrupt events for the IMMI as well as the main C code for the DCS and its interrupt events. The software package is exposed to the scrutiny of two verification tools, VectorCAST and CodeSonar. VectorCAST is used to execute test cases and provide results for code coverage based on statement and branch coverage. CodeSonar is used to identify issues with the code at compile time such as allocation/deallocation issues, unsafe functions, and language use problems. The results from both verification tools are evaluated and necessary changes made to the software package. The modified software is then tested again with VectorCAST and CodeSonar. The final verification step is downloading the modified code into the IMMI and DCS microcontrollers and testing the overall system to ensure the expected results are achieved with hardware that is developed to simulate realistic signals

Reducing tower fatigue through blade back twist and active pitch-to-stall control strategy for a semi-submersible floating offshore wind turbine

The necessity of producing more electricity from renewable sources has been driven predominantly by the need to prevent irreversible climate chance. Currently, industry is looking towards floating offshore wind turbine solutions to form part of their future renewable portfolio. However, wind turbine loads are often increased when mounted on a floating rather than fixed platform. Negative damping must also be avoided to prevent tower oscillations. By presenting a turbine actively pitching-to-stall, the impact on the tower fore–aft bending moment of a blade with back twist towards feather as it approaches the tip was explored, utilizing the time domain FAST v8 simulation tool. The turbine was coupled to a floating semisubmersible platform, as this type of floater suffers from increased fore–aft oscillations of the tower, and therefore could benefit from this alternative control approach. Correlation between the responses of the blade’s flapwise bending moment and the tower base’s fore–aft moment was observed with this back-twisted pitch-to-stall blade. Negative damping was also avoided by utilizing a pitch-to-stall control strategy. At 13 and 18 m/s mean turbulent winds, a 20% and 5.8% increase in the tower axial fatigue life was achieved, respectively. Overall, it was shown that the proposed approach seems to be effective in diminishing detrimental oscillations of the power output and in enhancing the tower axial fatigue life

EngD in Renewable Energy Marine Structures

The negative effects of anthropogenic climate change has led to an increase in electricity generated from renewable energy sources. Within this, offshore wind is currently one of the fastest growing markets, and industry is now looking towards the role that floating offshore wind turbines (FOWT) may play in the future. However, FOWT are often subjected to increased tower loads, up to 1.6 times those experienced by their fixed-to-seabed counterparts. Reducing these loads would help to decrease the costs of this fledgling technology, by diminishing the tower strengthening requirements. In the present work, as a possible technological solution to reduce the above mentioned loads, a variable speed, variable pitch-to-stall (VSVP-S) control strategy, is proposed for wind turbines. The 5 MW turbine is applied to both a semi-submersible and a spar floating platform, as these floaters both suffer from increased tower fore-aft oscillations. The VSVP-S control configuration avoids negative damping by design, allowing higher controller gain settings and hence a more regulated power output, than a pitch-to-feather controlled floating scenario. The FOWTs are further altered to incorporate back twisted blades, to decrease the blade bending moment response. This was seen to decrease the tower fore-aft moment range, creating an increase in the turbine tower life expectancy, when compared to their respective feather base models. To predict the overall tower axial fatigue life, the frequency of anticipated wind speeds are required. The likely occurrence of the different wind speed cases was accounted for through a weighted analysis. This took account of the distribution of probability of occurrence at three mean turbulent wind speeds: 8, 13 and 18 m/s. FOWT analysis highlighted trends in terms of back twist angle initiation point and magnitude were similar for both VSVP-S models (i.e. semi-submersible and a spar floating platforms). When a back twist angle to -6° at the tip was imposed, starting at 75% along the blade length, increases in the tower axial fatigue life of 10.2% for the semi-submersible and 18.8% for the spar were achieved, with the VSVP-S controlled turbines, compared to their feather controlled counterparts

Una Mirada Antropológica hacia el Mundo del Artesano del Voqui Fuco en un Contexto de Desarrollo Sostenible: San Juan de la Costa, X Región de Chile

En la comuna de San Juan de la Costa, Décima Región de Chile, los artesanos Mapuche-Huilliches son conocidos por su cestería confeccionada de una forma única y tradicional. Utilizando la fibra vegetal de la enredadera voqui fuco (Berberidopsis corallina), producen cestería tradicional y moderna, la que tiene usos domésticos y ornamentales. La cestería del voqui no sólo tiene una gran importancia sociocultural en la comuna, también tiene un alto valor económico (constituyendo una fuente importante de ingresos para ellos). En este caso, el voqui fuco es un buen ejemplo de la importancia del valor y uso de los productos forestales no madereros recolectados en el bosque nativo de la Cordillera de la Costa. Sin embargo, pese a la importancia del desarrollo de esta actividad para los artesanos y el valor de la artesanía como un patrimonio nacional, el futuro de los conocimientos de su producción y manejo tradicional, como también los lugares de recolección y la propia enredadera, corren serios riesgos de desaparecer. La relevancia antropológica de la presente tesis es introducir al lector al mundo poco conocido de los artesanos mapuche-huilliche especializados en la cestería de voqui fuco a través de un estudio etnográfico que relate su situación actual y analice la sostenibilidad de este oficio artesanal

Assessing female sexual offenders\u27 motivations and cognitions : an exploratory study

Semi-structured interviews eliciting cognitions and motivations were carried out with 15 incarcerated female child sexual abusers (nearly 50% of the current UK female sexual offender prison population). Qualitative analysis indicated that four of the five motivational schemas (implicit theories) suggested by Ward (Ward, 2000; Ward & Keenan, 1999) to underlie male sexual offenders\u27 cognitions could be clearly identified in women, these were: Uncontrollability (UN, identified in 87% of participants), Dangerous world (DW, 53%), Children as sexual objects (CSO, 47%) and Nature of harm (NH, 20%). Entitlement, the final implicit theory (IT), commonly found in males, was not identified in any participants in the sample. Further analysis indicated that there were four main motivational types of offender based on combinations of these ITs. These were: (1) presence of DW/CSO, indicating sexual motivation and cognitions with fear of violence; (2) presence of DW/no CSO, indicating fear of violence with no sexual cognition or motivation; (3) presence of CSO/no DW, indicating sexual motivation and cognition; the NH IT also strongly featured in this group; and (4) presence of UN/no DW or CSO, indicating lack of control, sometimes with sense of protection for the victim. Suggestions are made on how the results can inform theoretical developments in the field as well as policy and practice

Analysis of the effect of a series of back twist blade configurations for an active pitch-to-stall floating offshore wind turbine

For a turbine mounted on a floating platform, extreme induced loads can be increased by up to 1.6 times those experienced by a turbine situated on a fixed base. If these loads cannot be reduced, towers must be strengthened which will result in increased costs and weight. These tower loads would be additionally exasperated for a pitch-to-feather controlled turbine by a phenomenon generally referred to as “negative damping,” if it were not avoided. Preventing negative damping from occurring on a pitch-to-feather controlled floating platform negatively affects rotor speed control and regulated power performance. However, minimizing the blade bending moment response can result in a reduction in the tower fore-aft moment response, which can increase the tower life. A variable-speed, variable pitch-to-stall (VSVP-S) floating semi-submersible wind turbine, which does not suffer from the negative damping and hence provides a more regulated power output, is presented. This incorporates a back twist blade profile such that the blade twist, starting at the root, initially twists toward stall and, at some pre-determined “initiation” point, changes direction to twist back toward feather until the tip. Wind frequency weighting was applied to the tower axial fatigue life trends of different blade profiles and a preferred blade back twist profile was identified. This had a back twist angle of −3 deg and started at 87.5% along the blade length and achieved a 5.1% increase in the tower fatigue life

Virus transcript levels and cell growth rates after naturally occurring HPV16 integration events in basal cervical keratinocytes.

Cervical carcinogenesis is characterized by a clonal selection process in which the high-risk human papillomavirus (HRHPV) genome usually changes from the extra-chromosomal (episomal) state seen in productive infections to DNA that is integrated into host chromosomes. However, it is not clear whether all HRHPV integration events provide cells with a selective growth advantage compared with the episome-containing cells from which they originate. It is also unclear whether selection of cells containing a particular integrant from a mixed population simply reflects the highest levels of virus oncogene expression or has additional determinants. These early events in cervical carcinogenesis cannot readily be addressed by cross-sectional studies of clinical samples. We used the W12 model system to generate a panel of cervical squamous cell clones that were derived from an identical background under non-competitive conditions and differed only by the genomic site of HPV16 integration. Compared with the 'baseline' episome-containing cells from which they were isolated, only 9/17 clones (53%) showed significantly greater growth rates and only 7/17 (41%) showed significantly greater expression of the major virus oncogenes E7/E6. There were significant variations in levels of HPV16 transcription per DNA template, changes that were associated with histone modifications in the integrated virus chromatin. Cell growth rates showed only weak and non-significant associations with protein and mRNA levels for E7, E6, and the mean E7/E6 values. We conclude that HPV16 integration in basal cervical cells does not necessarily lead to increased levels of virus oncogenes, or to a competitive growth advantage, when compared with the initiating episome-containing cells

Circulating microRNAs as biomarkers to assist the management of the malignant germ-cell-tumour subtype choriocarcinoma.

Germ-cell-tumours (GCTs) are heterogeneous and management is complex. The current conventional biomarkers, alpha-fetoprotein and human-chorionic-gonadotropin (HCG), have limited utility for diagnosis/follow-up as secretion is restricted to specific malignant-GCT subtypes and long half-life can make interpretation and clinical decision-making challenging. We sought to identify circulating microRNAs that reflected choriocarcinoma disease activity more accurately than HCG in a metastatic primary mediastinal nonseminomatous-GCT (PMNSGCT) case with elevated diagnostic serum HCG (>250,000U/L), consistent with pure choriocarcinoma. We undertook comprehensive microRNA profiling (n=754 microRNAs) using two 384-well TaqMan Low-Density-Array cards in 16 serum samples; 10 from PMNSGCT diagnosis/follow-up and six controls. Key findings underwent confirmatory qRT-PCR. We identified a serum panel of choriocarcinoma-specific ‘chromosome-19-microRNA-cluster’ (C19MC) microRNAs that were highly elevated at diagnosis but fell rapidly on treatment and normalised before the second full chemotherapy course. We also re-confirmed serum elevation of the previously identified malignant-GCT marker miR-371a-3p at diagnosis. These circulating microRNA markers reflected choriocarcinoma disease activity more accurately than serum HCG and real-time knowledge would have assisted clinical decision-making. With further study, these microRNA markers will facilitate future management of such patients and are likely to result in improved outcomes.Acknowledgment of research support: The authors acknowledge grant funding from the St. Baldrick’s Foundation [reference 358099], the Isaac Newton Trust [reference 15.40f], the Medical Research Council [reference MR/R001146/1] and Addenbrooke’s Charitable Trust [reference 23/17 B (iv)]. We are grateful for support from the Max Williamson Fund and from Christiane and Alan Hodson, in memory of their daughter Olivia. The funders were not involved in study design, data collection or interpretation, or decision to submit for publication

Reimagining Education

In this paper, a Principal and two lead teachers describe the ways their school community has reimagined the learning environment at their NYC urban, public, K-5 elementary school throughout the COVID-19 pandemic. In March 2020 they were forced to immediately switch to fully remote learning, a platform they had never previously experienced.  Since then, they have engaged in hybrid and now fully in person learning through a worldwide pandemic.  The school community, whose focus before the pandemic was on social emotional learning and culturally responsive pedagogy, utilized those practices and the strong relationships between staff, students and families in order to persevere.  The pandemic disporportionately impacted communities of color, like the one this school community is located in.  Other inequalities such as food insecurity, job loss, sickness, financial strain and death impacted the community.  Racial trauma and political unrest that was exacerbated during the pandemic also placed a toll on the school community.  The staff, families and children of the community joined together with a mission to support one another, strengthen relationships, practice self care, address trauma and crisis, tackle unfinished learning, and focus on celebrating the community wherever possible as a way to find joy, survive and thrive.