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An mTSP model for multiple telescope short-term scheduling
No full textPulsar observation scheduling is a highly dynamic problem with uncertainty caused by scintillation and environmental interference. In the scheduling systems used by observatories today, this uncertainty is usually accounted for by using a short-term scheduling process. In order to observe as many pulsars as possible within a certain period of time, it becomes imperative for multiple telescopes or sub-arrays to observe multiple targets at the same time. However, there is little research on the speed improvement and cost-efficiency improvement of such “parallel" observation with multiple telescopes. In this work, we have designed a multiple telescope short-term scheduling simulation system, based on extending previously proposed scheduling heuristics using a single telescope pulsar scheduling simulator. Additionally, we propose a more complex multiple telescope short-term scheduling policy based on the multiple travelling salesperson problem (mTSP). Realistic datasets within the simulation environment are used to evaluate the proposed algorithms with multiple telescopes. The results show that multiple telescopes can significantly reduce the time to observe a set of pulsars. The previous single telescope heuristics adapt surprisingly well to the multiple telescope scenario and the novel mTSP policy is competitive, with potential for future improvements
Design Foundations of Graph Databases
No full textThe property graph model and graph database management systems such as Neo4j
have become increasingly popular. Naturally, questions around graph data modelling
best practices arise. Graph databases are perceived as very intuitive and our
research will provide evidence to showcase their benefits. One of our main contributions
is formalising the observation that hierarchical property graphs provide
a graph semantics to the Entity-Relationship model (E/R model) and vice versa
Entity-Relationship diagrams (E/R diagrams) impart a schema framework to hierarchical
property graphs. While the E/R model is well-established with comprehensive
research that spans more than 40 years, surprisingly this observation has not
been stated or formalised so far. Moreover, hierarchical property graphs constitute
a natural graph semantics for E/R diagrams, namely in the form of homomorphisms
on E/R diagrams. We will call such property graphs E/R graphs. This outlines how
graphs unify conceptual and logical data modelling which showcases an opportunity
to overcome shortcomings of the relational data model for integrity management.
One fundamental goal in database design is to eliminate redundancy, yet even Inclusion
Dependency Normal Form relies on attribute duplication introduced through
foreign keys to establish referential integrity. Interestingly, edges in property graphs
can avoid such attribute redundancy completely. Furthermore, we introduce E/R
keys, an expressive yet efficient subclass of the previously proposed PG-Keys and
demonstrate how they improve entity and referential integrity management. Another
major contribution is the first ever establishment of a normalisation framework
that accommodates any interpretation of missing data in response to the data
variety dimension graph databases are expected to handle as No-SQL databases. To
this end, we introduce redundancy-causing graph functional dependencies that are
transformed into graph uniqueness constraints that avoid redundancy. These dependencies
strike a great balance between expressiveness and tractability as required
for a normalisation framework. Despite the major challenge of property graphs not
necessarily having a schema, our functional dependencies and uniqueness constraints
also enable us to extend the entire classical relational normalisation framework of
Boyce-Codd and Third Normal Forms to property graphs
Repetitive key audit matters and audit effort
No full text
Purpose
This study aims to examine the determinants of disclosing repetitive year-to-year key audit matters (KAMs) content by auditors for a client and whether repetitive KAMs content is indicative of lower audit effort.
Design/methodology/approach
The authors use a sample of publicly listed firms from New Zealand between 2016 and 2020. Multivariate regression models are used to test the determinants of the extent of repetitive content in the KAMs section of the audit report. The authors compare the KAMs disclosed in the current period to those disclosed in prior period(s) to determine the level of recurring items and repetitive textual content.
Findings
The authors find evidence of repetitive KAMs content being disclosed at the client level since the reporting requirement was introduced. In multivariate analyses, the authors find that client business risk and auditor reputation are negatively associated with auditors’ reporting of repetitive KAMs. Furthermore, the authors find that auditors exert lower effort on audits for which they report a higher level of repetitive content in KAMs.
Originality/value
The study provides novel findings that contribute to the literature on auditors’ voluntary reporting of KAMs and provide important practical implications for investors and regulators.
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Touching superdiversity: migrants’ experiences of transcultural tactility in recreational dance
No full textAs a multi-sensorial recreational activity, dance provides a significant means of contributing to transcultural competence within super-diverse urban environments. Creative, physical interactions can involve subtle and yet deeply significant sensual encounters between strangers, and advance cultural democracy. Amongst dynamic and evolving population groups, the formation of new cultural understandings through such collaborative activity can enable an ongoing diversification of diversity, in ways that often transcend more prescribed and codified aspects of culture, such as language. This study therefore focuses on tactile encounters within recreational dance, to explore how super-diversity may be sensed and responded to within leisure activities. We ask: how can touch within recreational dances prompt cultural conceptualisations, transformations and collaborations? Our Interpretive Phenomenological Analysis engages 12 migrants from Asia, the Pacific, Europe and South America to critically reflect on how haptic encounters influence attitudes towards superdiversity. Their reflective narratives present diverse experiences of touch in recreational classes in ballroom, tango, contemporary dance, ballet and contact improvisation in Auckland, a super-diverse city in the South Pacific undergoing rapid demographic shifts. This establishes a theoretical platform for further investigations into haptic interactions within recreational activities, as a significant dimension worthy of further consideration within the societal development of cultural democracy
Cardiac muscle contracts more efficiently at lower contraction frequencies
No full textThis study investigated how contraction frequency impacts the mechano-energetics of cardiac muscle performing mechanical work. Left-ventricular trabeculae were isolated from rat hearts and mounted in our work-loop calorimeter to assess their function at physiological temperature (37°C) across three stimulation frequencies, 2 Hz, 3.5 Hz and 5 Hz, in a randomised sequence. Each trabecula was subjected to two experimental protocols: work-loop contractions under a range of afterloads and isometric contractions under a range of muscle lengths. Two contraction protocols allowed the partition of the various components of energy expenditure during cardiac contraction. By simultaneously measuring force-length work and heat output, mechanical efficiency was calculated over a range of afterloads to determine the peak value. Our findings revealed that force production, activation heat (energy associated with Ca2+ cycling) and cross-bridge heat were unaffected by stimulation frequency. Trabeculae produced greater work output per twitch at 2 Hz and 3.5 Hz than at 5 Hz. Positive correlations among work output, shortening extent and mechanical efficiency were detected. From these findings it was concluded that the higher work output at lower frequencies is associated with greater extent of shortening, which correlates to greater mechanical efficiency. This study highlights the mechano-energetic advantage of ventricular trabeculae in terms of increased work output and energy efficiency gained from operating at lower contraction frequencies, supporting the notion that heart rate reduction produces direct benefits on cardiac energetics
Undaria pinnatifida: Biogeography in Auckland and DNA Extraction Methodologies
No full textThis study aimed to improve molecular sampling methods for the invasive species Undaria pinnatifida (Harvey) Suringar, 1873 and to explore its population genetic structure in the Auckland region of New Zealand.
Molecular tools can be used to infer patterns of population connectivity. However, due to the well-known presence of polysaccharides and polyphenols in macroalgae, the quality of extracted DNA is often compromised. A more suitable DNA extraction method for large algae like U. pinnatifida has become crucial. A better method for the extraction of DNA from macroalgae such as U. pinnatifida is therefore necessary.
Our results show that the sorbitol pretreatment solution strongly enhances DNA yield and quality and is thus appropriate for field samples. This provides a new interesting method for the extraction of DNA from macroalgae as a whole.
Our results support the historical status of U. pinnatifida in Auckland. We performed Sanger sequencing of three molecular markers (cox3, tatC–tLeu, and ITS1). The genetic diversity within Auckland populations was very low as indicated by the results. This is consistent with a model of “single introduction followed by human-mediated dispersal” of invasion, and the presence of substantial gene flow between local populations.
Even though there is little diversity in the isolates, the mutations at certain nucleotides of some sequences in comparison with the sequences available in the literature imply that these genes are still undergoing micro-evolution.
In this work, our findings from molecular analysis provide preliminary insight into the invasion dynamics of U. pinnatifida and highlight the necessity for further high-resolution genetic study with long-term monitoring
Answers to questions about medial layer graphs of self-dual regular and chiral polytopes
No full textAn abstract n-polytope P is a partially-ordered set which captures important properties of a geometric polytope, for any dimension n. For even n≥2, the incidences between elements in the middle two layers of the Hasse diagram of P give rise to the medial layer graph of P, denoted by G=G(P). If n=4, and P is both highly symmetric and self-dual of type {p,q,p}, then a Cayley graph C covering G can be constructed on a group of polarities of P. In this paper we address some open questions about the relationship between G and C that were raised in a 2008 paper by Monson and Weiss, and describe some interesting examples of these graphs. In particular, we give the first known examples of improperly self-dual chiral polytopes of type {3,q,3}, which are also among the very few known examples of highly symmetric self-dual finite polytopes that do not admit a polarity. Also we show that if p=3 then C cannot have a higher degree of s-arc-transitivity than G, and we present a family of regular 4-polytopes of type {6,q,6} for which the vertex-stabilisers in the automorphism group of C are larger than those for G
Problematic cats in urban reserves: Implications for native biodiversity and urban cat management
No full textPredation by domestic cats (Felis catus) contributes to the extinction and decline of native species worldwide. Managing these cats is challenging in urban environments because they are valued as companion animals. We quantified cat behaviour in six urban reserves with high biodiversity values across the three largest New Zealand cities using camera traps, in an effort to understand cat impacts on urban biodiversity. Individual cats were identified and their detection rates and diel activity patterns analysed. To assess cat impacts on ground nesting birds, we also monitored the nests of the endangered northern New Zealand dotterel (Charadrius obscurus aquilonius). The minimum number of cats intruding into the reserves was high (ranging from 7 cats in 8 ha to 98 cats in 70 ha), and cats were active both day and night. Behaviour varied greatly among individual cats. Some cats intruded much more frequently than others, and these were the only individuals preying on native birds. One cat visited dotterel nests every night. Hatching or fledging failed at all the nests that were visited by this cat, even though the nests were not depredated. Our study shows that some cats impact native species more than others, and that identifying and targeted management of these problematic cats could be an effective approach if management of the general population is not feasible. The densities of domestic cats that allow native wildlife to thrive in urban environments is a significant knowledge gap that needs to be addressed
Exploring sexism with Chinese women in Aotearoa New Zealand
No full textThis project explores the experiences of sexism among Chinese women in Aotearoa New Zealand through the lens of ambivalent sexism theory and culturally specific frameworks. The present study focuses on examining how Chinese women navigate, negotiate, and resist gendered expectations shaped by both Confucian-influenced values and sociocultural influences.
A culturally responsive and sensitive methodological approach to qualitative research was developed and utilised. Liáo tiān facilitates open, culturally mindful, and meaningful discussions with Chinese participants. Liáo tiān with 15 Chinese women in Aotearoa NZ provided insight into the ways sexism is embedded within familial, social, and institutional structures, as well as how cultural values, such as miànzi (face), rénqíng (interpersonal obligations), guānxi (social networks), and wǔlún (hierarchical relationships), shape Chinese women’s experiences of sexism and gender inequality. The findings illustrate how Confucian ideals, which historically emphasise social harmony and order, contribute to deeply ingrained gender norms that persist across generations, even as societal shifts challenge these expectations.
This study demonstrates that sexism within Chinese communities is not universally oppressive. Instead, Chinese women actively negotiate their roles within intersecting cultural and societal frameworks. While benevolent sexism is often framed as care and protection, it also reinforces restrictive gender norms, limiting women's autonomy. Additionally, social stigma surrounding emotional expression and mental health can further minimise the psychological impact of sexism. This study found that enduring Confucian values continue to indirectly shape gender hierarchies and norms, even though participants often did not hold such values themselves, but were in an environment where Confucian ideologies were valued. Many participants discussed how their families became more open to progressive views and ideologies after migrating to Aotearoa New Zealand, reflecting how exposure to a new environment and different cultural values can significantly reshape perspectives and facilitate shifts in long-held beliefs. Participants discussed how missed opportunities in professional and academic settings became a significant contributor to psychological distress and a loss of autonomy. Participants also showed their resilience when navigating sexism, often finding strength in community groups.
By integrating AST with a culturally specific approach, this research contributes to a more nuanced understanding of sexism beyond Western paradigms. It challenges deficit-based perspectives on Chinese culture, instead highlighting the complexities of cultural transmission and adaptation. The findings have implications for future research, policy, and advocacy, emphasising the need for intersectional and culturally attuned approaches to addressing gender inequality
Trajectory Recovery using Mixture of Experts and a Graph Representation Framework
No full textWith the development of GPS devices and other positioning technologies, the collection
of trajectory data has become increasingly accessible. However, the quality of such
data remains uncertain. Due to device limitations, business requirements, and user privacy
protection, trajectory data often exhibit sparsity, irregularity, or low sampling rates,
making it challenging to accurately reconstruct complete user trajectories. The rise of
artificial intelligence technologies, such as deep learning, offers new solutions to the recovery
of trajectory. The mixture of experts (MoE) model is a machine learning model
composed of multiple submodels (experts), where each expert contributes to the final
output based on the characteristics of the input data. MoE adapts to complex data patterns,
improving model performance and generalization. However, no existing research
has applied MoE to trajectory recovery. Therefore, this study integrates MoE with existing
trajectory recovery methods. MoE selects appropriate candidate edge weights based
on trajectory features and returns these weights to a graph-based Seq2Seq framework,
generating high-quality trajectories. This approach enables automatic weight selection
in complex scenarios, allowing machine learning methods to uncover hidden factors and
generate more accurate trajectories with optimized weights. Experimental results demonstrate
that MoE improves the accuracy of Seq2Seq-based trajectory recovery, particularly
in cases with sparse trajectory data