CORA
Cork Open Research Archive (CORA) is UCC’s Open Access institutional repository which enables UCC researchers to make their research outputs freely available and accessible.
UCC Research Communities
Recent Submissions
Enabling high baud rate terabit superchannels
(University College Cork, 2025) Canas Estrada, Natalia; Gunning, Fatima; Science Foundation Ireland
Internet service providers rely on optical systems to transmit and receive data through the optical fibre network, supporting applications ranging from video streaming to autonomous driving. To meet growing user demands, optical communication systems have evolved to maximize spectral efficiency and aggregated data rates by transmitting multiple closely-spaced optical carriers within a single fiber. However, opto-electronic components are reaching their performance limits in terms of electro-optic conversion, bandwidth, and frequency response. Innovative solutions are necessary. Superchannel systems offer a promising approach, utilizing off-the-shelf components to achieve high spectral efficiency by transmitting closely-spaced optical carriers that overlap. The optical carriers are treated as a single entity that collectively deliver multiple terabits per second. These systems, if designed for compact architectures, could be well-suited for integration into photonic integrated chips.
A critical component in superchannel systems is the Mach-Zehnder modulator (MZM), used to generate the optical carriers and encode data onto optical carriers through amplitude and phase modulation. However, MZMs are prone to bias drifts, requiring an effective DC bias control for stable operation. This work addresses the challenge of MZM bias drift by first characterizing the behavior of single and nested MZMs to understand their transfer functions. Based on the analysis and results, a simple DC bias monitoring method based on asymmetric dithering signals is proposed. The proposed method allows slope identification when the MZM is biased at quadrature. Time-interleaving is proposed to extend this approach to multiple devices using low-frequency dither signals of varying frequencies to monitor each MZM. This method successfully identifies bias point drifts by analyzing the peak-to-peak and mean power of the low-frequency components of the modulated signal.
The proposed technique was experimentally validated in an NRZ-OOK system transmitting at 10, 12.5, and 20 Gbit/s, demonstrating negligible impact on the bit error rate (BER) performance. Additionally, a DC bias control method based on the perturb-and-observe approach was developed and tested in simulations, effectively correcting bias drifts. These findings demonstrate a simple and feasible solution for stabilizing MZMs, ensuring reliable integration into advanced optical communication systems such as superchannels.
‘When and how will it all end?’ Bishop Daniel Cohalan of Cork: the Irish republican movement, just war theory and evolving perspectives, 1916-1923
(University College Cork, 2024) O'Connell, Therese; Doherty, Gabriel; Bielenberg, Andrew
The research will incorporate this significant period of Daniel Cohalan’s episcopate into a wider examination of his life and career, beginning with his formative years in Kilmichael and the early influences which continued to inspire his thinking throughout his life. His time as both student and professor at St Patrick’s College, Maynooth is also examined, and it is during his tenure as professor that we see insightful glimpses of the character and personality of the future Bishop of Cork. Alongside an examination of his views on Irish republican tactics during the revolutionary period, the study also explores Cohalan’s broader outlook. It considers the initiatives he supported and engaged with as the newly formed Irish Free State worked to define its social, moral, religious, and political identity.
The presence of 'fifty thousand people' lining the two-mile route from the Bons Secours hospital to the North Cathedral on 25 August 1952 — just two hours after Cohalan’s death — arguably indicates how the ordinary people of Cork viewed their late bishop. This thesis analyses Cohalan’s interactions with agents of Irish political and physical force nationalism, international agencies, his peers and lower clergy, and the ordinary people who looked to their church for temporal and spiritual succour. Through this research, a lacuna in the literature of Irish history is narrowed and an enduring imbalance is addressed.
Obstetric blood loss quantification
(University College Cork, 2024) Lutfi, Ahmed; Greene, Richard A.; Higgins, John R.; Stryker
Background
The research undertaken for this thesis focuses on the quantification of obstetric blood loss. Obstetric haemorrhage contributes to rising worldwide maternal morbidity and mortality rates. In Ireland, obstetric haemorrhage is the leading cause of Severe Maternal Morbidity (SMM). Accurate and rapid assessment of maternal bleeding status is essential to the diagnosis of obstetric haemorrhage. Obstetric blood loss quantification needs to be standardised as a varying approach to measuring maternal blood loss may lead to a missed or delayed diagnosis. It is possible that currently utilised quantitative methods, namely volumetry and gravimetry, produce inconsistent measurements of maternal blood loss and that an alternative method may be more reliable. The aim of this research was to identify the limitations of currently utilised quantitative methods and to explore novel blood loss quantifying technology. We also aimed to identify the cost of obstetric haemorrhage to aid in future cost-effectiveness studies on novel blood loss quantifying technology.
Methods
We used a mixed methods approach, utilizing both qualitative and quantitative research methods, to provide a deeper understanding of the cost of obstetric haemorrhage and to study obstetric blood loss quantification. Micro-costing, a research methodology from the social sciences, was used to estimate the cost of obstetric haemorrhage and the cost contribution of blood transfusions used in the management of obstetric haemorrhage in Ireland. In this study, we used a dataset generated from a nationwide cross-sectional study of obstetric haemorrhage from the National Perinatal Epidemiology Centre (NPEC) in Ireland. An observational study of Caesarean births was performed to assess current blood loss quantification practices in Cork University Maternity Hospital (CUMH), which is a tertiary maternity hospital. Through laboratory testing, we compared the blood detecting accuracy of a novel blood loss quantifying device (the Stryker (R) System), developed by Stryker Instruments Innovation Centre, against a reference haematology analyser. In this study, unwanted human whole blood provided by the Irish Blood Transfusion Service was diluted with normal saline to simulate birth waste. We transitioned to clinical testing of the device in Caesarean section patients delivering in CUMH where we compared the device against standard volumetry performed by hospital staff members. The haemoglobin content of the birth waste as measured by a haemoglobinometer was assigned as the standard for the purpose of comparison. Hospital staff feedback of the device was gathered to guide future device modifications and improvements.
Results
A cost-analysis of obstetric haemorrhage in Ireland estimates that obstetric haemorrhage adds an additional 140% to maternity care costs with blood transfusions contributing to one third to half of this additional cost. We identified that assessments of maternal blood loss following Caesarean birth varied with hospital staff members applying both subjective and objective methods (a hybrid approach) in the majority of cases (84%). Patients classified as high risk of haemorrhage had more objective methods utilized (40%) when compared to patients classified as low or medium risk (19% and 7% respectively). A pilot study evaluating the accuracy the Stryker (R) System against a reference haematology analyser showed that the device is accurate in measuring haemoglobin concentrations (g/dL) of fluid mixtures. Bland-Altman analysis in this study demonstrated 95% limits of agreement of –0.96 to 1.03 g/dL. An early feasibility study of the Stryker (R) System’s performance in Caesarean section births showed that the device offered more accurate measurements of maternal blood loss when compared with volumetry done by hospital staff. Bland-Altman analysis produced mean biases of 0.236 +/- 1.213 g/dL and -0.661 +/- 1.458 g/dL for the device and staff measurements respectively when compared against the haemoglobinometer. The width of the limits of agreement at 95% confidence was narrower for device measurements than staff measurements (4.519 g/dL and 5.715 g/dL respectively). The device’s measurements of haemoglobin content correlated more strongly with the haemoglobinometer rather than hospital staff measurements (Spearman correlation coefficients of 0.881 and 0.635 respectively). This suggests that the device is more accurate in determining the blood content of the birth waste than hospital staff volumetric measurements. Lastly, a mean System Usability Scale (SUS) score of 82 +/- 13 suggests that the device is highly usable.
Conclusion
This thesis sheds light on the critical issue of obstetric blood loss quantification. The research highlights the financial burden of obstetric haemorrhage on the healthcare system. Furthermore, it reveals the current inconsistencies and subjectivity in assessing maternal blood loss. This research underscores the necessity for standardized, accurate, and rapid quantification methods to ensure timely diagnosis and management of obstetric haemorrhage. It sets the stage for future advancements in obstetric care, emphasizing the importance of incorporating novel technologies to enhance patient outcomes and mitigate the global affliction of obstetric haemorrhage.
Contested nationhood: Literary Geographies of contemporary Italian Alpine borders
(University College Cork, 2025) Turini, Jacopo; Ross, Silvia; Giuliani, Chiara; Irish Research Council
This thesis examines the articulation of spatial identity, and the sense of nationhood as expressed in Italian literature set in the Alpine border regions from the 1980s to the present. It explores how the presence of the national border, along with its related geopolitical, cultural, and social dynamics, influences Italian-language literary production and the imagined geographies created by it.
Texts provide insights into the geographical spaces they represent, while geography, in turn, influences the textual representation of place and spatial identity. Employing a geo-literary approach developed at the intersection of Literary Geography and Geocriticism, this study investigates how national, regional, and local belonging is expressed in selected works set in three Alpine border regions, in relation to the geo-social transformations that have occurred since the 1980s. These regions are the Piedmontese and Ligurian valleys along the Franco-Italian border, the Canton Ticino in Italian-speaking Switzerland, and the multilingual autonomous Italian region of South Tyrol.
My geo-literary analysis identifies three types of textual geographies, that is, what emerges from the intersection of the places represented in the texts and the geographical contexts in which these texts are produced. Consequently, the thesis is divided into three chapters. Chapter 1, on the Franco-Italian border, focuses on what I term geographies of transgression. Through the analysis of Vento largo (1991) and Le parole la notte (1998) by Francesco Biamonti, Il mangiatore di pietre (2004) by Davide Longo, and Un viaggio che non promettiamo breve (2016) by Wu Ming 1, the chapter explores how representations of the areas’ traditional transnational identity become tools to address geopolitical and environmental issues and challenge the normative geographies of the nation-state. Chapter 2 examines the Canton Ticino in Italian-speaking Switzerland, analysing Adrea Fazioli’s crime fiction novels L’uomo senza casa (2008), La sparizione (2010), Gli svizzeri muoiono felici (2018), and Le strade oscure (2022); Alberto Nessi’s poetry, and his novel Tutti discendono (2000); and Fabio Pusterla’s poetry, beginning with his debut collection Concessione all’inverno (1985). Their representation of the industrialised and globalised border area between Italy and Switzerland delineates geographies of ambivalence, as I have labelled them, which reflect the region’s cultural marginality and, at the same time, express tension between rootedness and displacement. Chapter 3 focuses on South Tyrol through Francesca Melandri’s Eva dorme (2010), Maddalena Fingerle’s Lingua madre (2021), and Luca D’Andrea’s La sostanza del male (2016). The three writers’ relationship with the region is developed through what I have called geographies of detachment, which reflect a deliberate effort to distance themselves and their work from cultural isolationism and ethnonationalist localism, while critiquing the region’s rigid linguistic boundaries.
The Italian Alps represent a complex border zone – sometimes porous and open, at other times closed and isolationist. The findings of this study reveal that the national border is addressed in contemporary Italian literature primarily through local and regional perspectives strongly tied to the experiences of autochthonous communities. Ultimately, this thesis argues that the Alpine borders are a crucial site for examining the tension between change and resistance in the evolution of Italian spatial identities and the sense of cultural and national belonging.
De-anonymization of health data: a survey of practical attacks, vulnerabilities and challenges
(SCITEPRESS, 2025) Aguelal , Hamza; Palmieri, Paolo; Research Ireland
Health data ranks among the most sensitive personal information disclosing serious details about individuals. Although anonymization is used, vulnerabilities persist, leading to de-anonymization and privacy risks highlighted by regulations like the General Data Protection Regulation (GDPR). This survey examines de-anonymization attacks on health datasets, focusing on methodologies employed, data targeted, and the effectiveness of current anonymization practices. Unlike previous surveys that lack consensus on essential empirical questions, we provide a comprehensive summary of practical attacks, offering a more logical perspective on real-world risk. Our investigation systematically categorizes these practical attacks, revealing insights into suc cess rates, generality and reproducibility, new analytics used, and the specific vulnerabilities they exploit. The study covers health-related datasets, including medical records, genomic data, electrocardiograms (ECGs), and neuroimaging, highlighting the need for more robust anonymization. Significant challenges remain in the literature despite existing reviews. We advocate for stronger data safeness by improving anonymization methods and advancing research on de-anonymization and assessment within healthcare.