bluuebunny/crossref_metadata_2025 huggingface dataset:
Parental Reflective Functioning in First-Time Parents and Associations with Infant Socioemotional Development
Authors: Madsen Eva B. , Væver Mette S. , Egmose Ida , Krogh Marianne T. , Haase Tina W. , de Moor Marleen H. M. , Karstoft Karen-Inge
Published: March 2023

Parental reflective functioning (PRF) refers to parents’ capacity to reflect on mental states such as their own and their child’s feelings, thoughts, and intentions. Studies suggest that PRF is an important factor in parental behavior; however, only a few studies have examined the effect of early PRF on infant socioemotional development. The Parental Reflective Functioning Questionnaire (PRFQ) was developed as a brief, multidimensional measure to assess PRF. Recently, a modified version, the PRFQ-I, was suggested as a more accurate measure of PRF in an at-risk sample of mothers of infants. The study aims were to examine the factor structure and factorial invariance across parental gender of the PRFQ-I in a community sample, to compare PRF dimensions across mothers and fathers, and to investigate the association between PRF dimensions and infant socioemotional development. We examined this within a longitudinal design in a community sample of 1243 first-time mothers and 512 fathers. The results supported the expected factor structure of PRFQ-I and invariance across parental gender. Significant differences between mothers and fathers were found on the three PRF dimensions comprised by the questionnaire. The PRF dimensions of pre-mentalizing and certainty about mental states significantly predicted infant socioemotional development. Findings show that the PRFQ-I is a valid measure in parents of infants and suggest that PRF in early parenthood is an important factor in infant socioemotional development. Identification of first-time parents with limited PRF enables early intervention and may thus prevent limited PRF from having potentially adverse effects on infant socioemotional development.
Co-creation and decision-making with students about teaching and learning: a systematic literature review
Authors: Geurts Esther M. A. , Reijs Rianne P. , Leenders Hélène H. M. , Jansen Maria W. J. , Hoebe Christian J. P. A.
Published: March 2023

Involving students in shaping their own education allows for more suitable, acceptable and effective education. We focus on how student voice is embodied in the context of teaching and learning as well as relevant factors for implementation and the impact of student voice activities on students' personal development and school connectedness. This systematic literature review provides an overview of qualitative studies which focus on involving 12–20 year-old students in co-creation and decision-making in the context of teaching and learning. The 15 included studies indicate that students were involved in various phases and were assigned multiple roles and responsibilities. There was a tendency to include students as advisors in planning, as co-researchers in acting/observing and as reviewers in reflecting. Relevant factors for implementation were knowledge, skills, beliefs about capabilities, optimism, emotions, social/professional role and identity, and social influences. Those students who participated increased their skills, confidence and ownership. Ongoing challenges remain with granting students various opportunities for taking diverse roles in each research phase. Future research is needed in more diverse school contexts and which assesses the long-term impact on students’ development and their health, well-being and social position.
Expert Consensus on the Resource Needs of Autistic Children and Young People in Ireland During the Early Months of the COVID-19 Pandemic
Authors: Egan Cillian , McLaughlin Nadine , McGarrell Maria , Gurrin Cathal , Devlin Sarah , Smyth Sinéad
Published: March 2023

The COVID-19 pandemic has brought significant changes across society. This Delphi study aimed to gain expert consensus on challenges faced and resource needs for autistic children during the COVID-19 pandemic. Round 1 of the Delphi method employed semi-structured interviews with experts (N = 24) which were thematically analysed in order to identify needs, resource targets and resource development. In a follow-up Round 2 survey participants rated emergent need and resource in order of priority. Round 2 provided consensus on challenges faced with anxiety, routine and wellbeing ranked most important. Direction on resource design was also obtained. Consensus on the challenges and resources was achieved and is being integrated into a needs-based transition resources toolkit. Future studies could make use of the Delphi method to quickly gain consensus on focus of needs in other contexts and communities.
Associations Between Dog Breed and Clinical Features of Mammary Epithelial Neoplasia in Bitches: an Epidemiological Study of Submissions to a Single Diagnostic Pathology Centre Between 2008–2021
Authors: Edmunds Grace , Beck Sam , Kale Kedar Umakant , Spasic Irena , O’Neill Dan , Brodbelt David , Smalley Matthew J.
Published: March 2023

Mammary cancer is one of the most common neoplasms of dogs, primarily bitches. While studies have been carried out identifying differing risk of mammary neoplasia in different dog breeds, few studies have reported associations between dog breeds and clinical features such as number of neoplastic lesions found in an individual case or the likelihood of lesions being benign or malignant. Such epidemiological studies are essential as a foundation for exploring potential genetic drivers of mammary tumour behaviour. Here, we have examined associations between breed, age and neuter status and the odds of a diagnosis of a mammary epithelial-origin neoplastic lesion (as opposed to any other histopathological diagnosis from a biopsied lesion) as well as the odds of a bitch presenting with either a single mammary lesion or multiple lesions, and the odds that those lesions are benign or malignant. The study population consisted of 129,258 samples from bitches, including 13,401 mammary epithelial neoplasms, submitted for histological assessment to a single histopathology laboratory between 2008 and 2021.

In multivariable analysis, breed, age and neuter status were all significantly associated with the odds of a diagnosis of a mammary epithelial-origin neoplastic lesion. Smaller breeds were more likely to receive such a diagnosis. In cases diagnosed with a mammary epithelial neoplasm, these three factors were also significantly associated with the odds of diagnosis with a malignant lesion and of diagnosis with multiple lesions. Notably, while neutered animals were less likely to have a mammary epithelial neoplasm diagnosed, and were less likely to have multiple neoplasms, they were more likely to have malignant disease. Exploration of the patterns of risk of developing malignant disease, or multiple lesions, across individual breeds showed no breed with increased odds of both outcomes. Breeds with altered odds compared to the Crossbreed baseline were either at increased risk of malignant disease and decreased risk of multiple lesions, or vice versa, or they were at significantly altered odds of one outcome with no change in the other outcome. Our analysis supports the hypothesis that age, neuter status and intrinsic biological and genetic factors all combine to influence the biological heterogeneity of canine mammary neoplasia.
A dynamic dendritic connectivity assessment tool for the planning and design of barrier mitigation strategies in river networks
Authors: King Myron , van Zyll de Jong Michael , Cowx Ian G.
Published: March 2023

Context

Increasing fragmentation of rivers caused by barriers continues to impact watersheds, especially disruption of fish migration patterns and loss of access to spawning and nursery habitats. Infrastructure expansion and ageing installations exacerbate the problem, reducing effectiveness of management in addressing barriers. Reduction in watershed connectivity requires effective tools capable of guiding river managers in remediation actions.

Objectives

Our objective was to develop a watershed dynamic connectivity assessment tool (D-CAT), a customizable geospatial tool capable of river analyses at varying watershed scales. The tool uses proven watershed connectivity modelling combined with an effective evaluation approach to provide measurable change model outcomes.

Methods

Three different barrier encounter scenarios were examined using the D-CAT tool to study watershed connectivity. The tool was tested on a watershed area of the River Derwent, a major tributary of the River Trent system in the United Kingdom.

Results

For each barrier scenario tested, the D-CAT tool indicated which barriers could be removed or modified to provide the greatest watershed connectivity improvement. The tool provided a prioritized list of barriers for each scenario under varying choices for the number of barriers to remove, demonstrating the utility of the D-CAT tool to planning and design.

Conclusions

The D-CAT tool is built to handle geographical data and variable user input, allowing in-depth watershed connectivity analysis. The tool forecasts the cumulative effects of alternative change scenarios for watershed connectivity, providing prioritization and optimization of removal strategies. The D-CAT tool offers significant support for landscape management towards better barrier removal/remediation decisions.
Is it Still Ok to be Ok? Mental Health Labels as a Campus Technology
Authors: Armstrong Neil , Beswick Laura , Vega Marta Ortega
Published: March 2023

This article uses ethnography and coproduced ethnography to investigate mental health labels amongst university students in the UK. We find that although labels can still be a source of stigma, they are also both necessary and useful. Students use labels as ‘campus technologies’ to achieve various ends. This includes interaction with academics and administrators, but labels can do more than make student distress bureaucratically legible. Mental health labels extend across the whole student social world, as a pliable means of negotiating social interaction, as a tool of self-discovery, and through the ‘soft-boy’ online archetype, they can be a means of promoting sexual capital and of finessing romantic encounters. Labels emerge as flexible, fluid and contextual. We thus follow Eli Clare in attending to the varying degrees of sincerity, authenticity and pragmatism in dealing with labels. Our findings give pause to two sets of enquiry that are sometimes seen as opposed. Quantitative mental health research relies on what appear to be questionable assumptions about labels embedded in questionnaires. But concerns about the dialogical power of labels to medicalise students also appears undermined.
Video question answering supported by a multi-task learning objective
Authors: Falcon Alex , Serra Giuseppe , Lanz Oswald
Published: March 2023

Video Question Answering (VideoQA) concerns the realization of models able to analyze a video, and produce a meaningful answer to visual content-related questions. To encode the given question, word embedding techniques are used to compute a representation of the tokens suitable for neural networks. Yet almost all the works in the literature use the same technique, although recent advancements in NLP brought better solutions. This lack of analysis is a major shortcoming. To address it, in this paper we present a twofold contribution about this inquiry and its relation with question encoding. First of all, we integrate four of the most popular word embedding techniques in three recent VideoQA architectures, and investigate how they influence the performance on two public datasets: EgoVQA and PororoQA. Thanks to the learning process, we show that embeddings carry question type-dependent characteristics. Secondly, to leverage this result, we propose a simple yet effective multi-task learning protocol which uses an auxiliary task defined on the question types. By using the proposed learning strategy, significant improvements are observed in most of the combinations of network architecture and embedding under analysis.
Group agents, moral competence and duty-bearers: the update argument
Authors: de Haan Niels
Published: March 2023

According to some collectivists, purposive groups that lack decision-making procedures such as riot mobs, friends walking together, or the pro-life lobby can be morally responsible and have moral duties. I focus on plural subject- and we-mode-collectivism. I argue that purposive groups do not qualify as duty-bearers even if they qualify as agents on either view. To qualify as a duty-bearer, an agent must be morally competent. I develop the Update Argument. An agent is morally competent only if the agent has sufficient positive and negative control over updating their goal-seeking states. Positive control involves the general ability to update one’s goal-seeking states, whereas negative control involves the absence of other agents with the capacity to arbitrarily interfere with updating one’s goal-seeking states. I argue that even if purposive groups qualify as plural subjects or we-mode group agents, these groups necessarily lack negative control over updating their goal-seeking states. This creates a cut-off point for groups as duty-bearers: Organized groups may qualify as duty-bearers, whereas purposive groupscannotqualify as duty-bearers.
A composite measure for patient-reported outcomes in orthopedic care: design principles and validity checks
Authors: Schöner Lukas , Kuklinski David , Geissler Alexander , Busse Reinhard , Pross Christoph
Published: March 2023

Background

The complex, multidimensional nature of healthcare quality makes provider and treatment decisions based on quality difficult. Patient-reported outcome (PRO) measures can enhance patient centricity and involvement. The proliferation of PRO measures, however, requires a simplification to improve comprehensibility. Composite measures can simplify complex data without sacrificing the underlying information.

Objective and methods

We propose a five-step development approach to combine different PRO into one composite measure (PRO-CM): (i) theoretical framework and metric selection, (ii) initial data analysis, (iii) rescaling, (iv) weighting and aggregation, and (v) sensitivity and uncertainty analysis. We evaluate different rescaling, weighting, and aggregation methods by utilizing data of 3145 hip and 2605 knee replacement patients, to identify the most advantageous development approach for a PRO-CM that reflects quality variations from a patient perspective.

Results

The comparison of different methods within steps (iii) and (iv) reveals the following methods as most advantageous: (iii) rescaling via z-score standardization and (iv) applying differential weights and additive aggregation. The resulting PRO-CM is most sensitive to variations in physical health. Changing weighting schemes impacts the PRO-CM most directly, while it proves more robust towards different rescaling and aggregation approaches.

Conclusion

Combining multiple PRO provides a holistic picture of patients’ health improvement. The PRO-CM can enhance patient understanding and simplify reporting and monitoring of PRO. However, the development methodology of a PRO-CM needs to be justified and transparent to ensure that it is comprehensible and replicable. This is essential to address the well-known problems associated with composites, such as misinterpretation and lack of trust.
Is the maximum entropy production just a heuristic principle? Metaphysics on natural determination
Authors: Sánchez-Cañizares Javier
Published: March 2023

The Maximum Entropy Production Principle (MEPP) stands out as an overarching principle that rules life phenomena in Nature. However, its explanatory power beyond heuristics remains controversial. On the one hand, the MEPP has been successfully applied principally to non-living systems far from thermodynamic equilibrium. On the other hand, the underlying assumptions to lay the MEPP’s theoretical foundations and range of applicability increase the possibilities of conflicting interpretations. More interestingly, from a metaphysical stance, the MEPP’s philosophical status is hotly debated: does the MEPP passively translate physical information into macroscopic predictions or actively select the physical solution in multistable systems, granting the connection between scientific models and reality? This paper deals directly with this dilemma by discussing natural determination from three angles: (1) Heuristics help natural philosophers to build an ontology. (2) The MEPP’s ontological status may stem from its selection of new forms of causation beyond physicalism. (3) The MEPP’s ontology ultimately depends on the much-discussed question of the ontology of probabilities in an information-theoretic approach and the ontology of macrostates according to the Boltzmannian definition of entropy.
Phylogenetic divergence associated with climate oscillations and topology illustrates the dispersal history of Formosan sambar deer (Rusa unicolor swinhoii) in Taiwan
Authors: Li Kuan-Yi , Hsiao Chen , Yen Shih-Ching , Hung Chien-Yi , Lin You-Zhu , Jheng Sheng-Wun , Yu Pei-Ju , Hwang Mei-Hsiu , Weng Guo-Jing , Chen Ku-Lin , Lin Shu-Fen , Chang Shih-Wei , Wang Ying , Ju Yu-Ten
Published: March 2023

The island of Taiwan represents an ideal context for studying the effects of climatic oscillations and topographic variation on large herbivores due to its varied tropical to sub-tropical climate zones at different elevational ranges. We explored the phylogenetics of Formosan sambar deer (Rusa unicolor swinhoii) using the control region of the mitochondrial genome. We detected 18 haplotypes among 454 sequences across the island and grouped them into six regions based on SAMOVA, with 68.78% variance among regions. A Bayesian phylogenetic dendrogram revealed two spatially segregated genetic clades. Neutrality tests and Bayesian skyline plots uncovered different demographic expansion histories for the two clades. We further tested divergence times and chronology to propose potential phylogenetic scenarios, which were examined using approximate Bayesian computation. Finally, we present a credible hypothesis for a glacial refugium in the northern part of the Central Mountain Range. Subsequent secondary contact between the two clades during interglacial periods has led to the extant genetic structure of Formosan sambar deer.
From ultra-low friction to superlubricity state of black phosphorus: Enabled by the critical oxidation and load
Authors: Li Qiang , Su Fenghua , Chen Yanjun , Sun Jianfang
Published: March 2023

Based on the density functional theory (DFT), we investigate the friction properties of inevitable oxidized black phosphorus (o-BP). o-BP with the weaker interlayer adhesion exhibits their great potential as a solid lubricant. At the zero load, the friction property of o-BP is adjusted by its oxidation degree. Expressly, ultra-low friction of P4O2 (50% oxidation, O : P = 2 : 4 = 50%) is obtained, which is attributed to the upper O atoms with lower sliding resistance in the O channel formed by lower layer O atoms. More attractive, we observe superlubricity behavior of o-BP at the critical load/distance due to the flattening potential energy surface (PES). The flattening PES is controlled by the electrostatic role for the high-load (P4O3, O : P = 3 : 4 = 75%), and by the electrostatic and dispersion roles for the low-load (P4O2). Distinctly, the transform from ultra-low friction to superlubricity state of black phosphorus (BP) can be achieved by critical oxidation and load, which shows an important significance in engineering application. In addition, negative friction behavior of o-BP is a general phenomenon (Z > Zmin, Zmin is the interlayer distances between the outermost P atoms of minimum load.), while its surface-surface model is different from the fold mechanism of the tip-surface model (Z0 < Z < Zmin, Z0 is the interlayer distances between the outermost P atoms of equilibrium state.). Thus, this phenomenon cannot be captured due to the jump effect with instability of the atomic force microscopy (AFM) (Z > Zmin). In summary, o-BP improves the friction performance and reduces the application limitation, comparing to graphene (Gr), MoS2, and their oxides.
Influence of aging treatment on mechanical properties and wear resistance of medium manganese steel reinforced with Ti(C,N) particles
Authors: Cai Zhihui , Wang Shangkun , Zhou Yanjun , Dong Jiayi , Ma Lifeng , Liu Shilong
Published: March 2023

In this study, the hot rolled medium manganese steel containing titanium was solution treated at 1,000 °C and followed by aging treatment at 500, 550, and 600 °C. The influence of aging treatment on mechanical properties and wear resistance of medium manganese steel reinforced with Ti(C,N) particles was investigated. It was found that the matrix of medium manganese steel was austenite. The austenite grain size was refined, and Ti(C,N) particles were precipitated after aging treatment. Compared to that of the as-hot rolled sample, the initial hardness of 500 °C aged sample increased by 9.5% to 312.86 HV, whose impact energy was more than doubled to 148.5 J. As the aging temperature raised to 600 °C, the initial hardness changed slightly. However, the impact energy dropped significantly to 8 J due to the aggregation of Mn at the grain boundaries. In addition, the main wear mechanisms of the samples were fatigue wear and abrasive wear. It was worth noting that 500 °C aged sample exhibited the best wear resistance under a 300 N applied load, whose wear loss was just half of the as-hot rolled sample. The relationship between wear loss and mechanical properties indicated that the wear resistance of medium manganese steel was independent of the initial hardness. The large difference in the wear resistance was predominately due to the outstanding work hardening ability of 500 °C aged sample, whose strengthening mechanisms were contributed from transformation induced plasticity (TRIP) effect, dislocation strengthening, twinning induced plasticity (TWIP) effect, and precipitation strengthening.
Applying surface tension as pressure boundary condition in free surface flow analysis by moving particle simulation method
Authors: Tsujimura Hiroki , Kubota Kenichi , Sato Tetsuya
Published: March 2023

A model that introduces surface tension as a pressure boundary condition, named the surface tension as pressure (STP) model, was developed for free surface flow analyses by the moving particle simulation (MPS) method. The STP model assigns to surface particles the liquid pressure of Laplace’s formula. The model is an alternative to previous models that apply surface tension as volume force such as the continuum surface force model. Problems that appeared when using the volume force models, such as the dependencies of calculation results on particle resolution and pressure gradient accuracy, were solved by using the STP model. Calculations predicted the theoretical values of the internal pressure of a 3D spherical droplet and the oscillation period of a 2D elliptic droplet over a wide range of surface tension coefficients and droplet sizes with errors less than 10%. Since the STP model is easy to implement, does not increase computation cost from previous models, and does not require surface reconstruction or additional marker particles, the model is suitable for practical and large-scale free surface flow problems that involve violent deformation of the liquid surface such as liquid atomization.
No Compelling Evidence that Self-Reported Personality Traits Explain Basal Testosterone and Cortisol’s Associations with Status-Relevant Behavior
Authors: Casto Kathleen V. , Prasad Smrithi , Josephs Robert A. , Zilioli Samuele , Welker Keith , Maslov Alexander , Jones Amanda C. , Mehta Pranjal H.
Published: March 2023

Objective

A goal of behavioral neuroendocrinology is to understand how basal hormone levels relate to behavior. Studies of human participants sometimes measure self-reported personality traits, in addition to or instead of direct behavioral observation. Although personality traits often predict their respective behaviors, whether personality explains hormone-behavior relationships remains unclear.

Methods

We obtained data from eight previous studies (total N = 985) that examined baseline testosterone and cortisol as predictors of status-relevant behavior (competitiveness, dominance, risk-taking, aggression, affiliation, and social status). We tested whether the previously reported hormone-behavior relationships are mediated by self-reported personality traits (e.g., trait dominance, prestige, extraversion). As a secondary research question, we also tested whether trait dominance moderated the testosterone-behavior relationships.

Results

As expected, self-reported personality traits often predicted status-relevant behaviors, but there was little evidence that traits also correlated with basal testosterone or the testosterone × cortisol interaction. Across all eight studies, personality traits did not significantly mediate hormone-behavior relationships. Indeed, the effect sizes of the hormone-behavior relationships were robust to the inclusion of personality traits as covariates. Further, we did not find strong or consistent evidence that trait dominance moderates the testosterone-behavior association.

Conclusion

Results suggest that basal testosterone and cortisol predict status-related behavior independent of self-reported personality. We discuss how these results may have broader implications for the physiological mechanisms by which testosterone and cortisol influence behavior, a process that could be unconscious and automatic. We also discuss alternative explanations, limitations, and future directions.
Lyapunov exponents and entropy for divergence-free Lipschitz vector fields
Authors: Bessa Mário
Published: March 2023

Let $$\mathfrak {X}^{0,1}_\nu (M)$$

X

ν

0
,
1

(
M
)

be the subset of divergence-free Lipschitz vector fields defined on a closed Riemannian manifold M endowed with the Lipschitz topology $$\Vert \,{\cdot }\,\Vert _{0,1}$$

‖

·

‖

0
,
1

where $$\nu $$
ν
is the volume measure. Let $$\mathfrak {X}^{0,1}_{\nu ,\ell }(M)\subset \mathfrak {X}^{0,1}_\nu (M)$$

X

ν
,
ℓ

0
,
1

(
M
)

⊂

X

ν

0
,
1

(
M
)

be the subset of vector fields satisfying the $$\ell $$
ℓ
-property, a property that implies $$C^1$$

C
1

-regularity $$\nu $$
ν
-almost everywhere. We prove that there exists a residual subset "Equation missing" with respect to $$\Vert \,{\cdot }\,\Vert _{0,1}$$

‖

·

‖

0
,
1

such that Pesin’s entropy formula holds, i.e. for any "Equation missing" the metric entropy equals the integral, with respect to $$\nu $$
ν
, of the sum of the positive Lyapunov exponents.
Uncovering the Link Between the Theoretical and Probabilistic Models of the Global Production Function: A Copula Approach
Authors: Sánchez-Vargas Armando , Márquez-Estrada José Manuel , Hernández-Ramírez Eric
Published: March 2023

We provide micro foundations for the global production function (GPF) based on the standard microeconomic model, and we develop a parallel probabilistic model with similar properties. The theoretical and probabilistic models of the GPF are integrated in the context of a technology choice problem. We construct a primitive, named the augmented transformation function, to obtain a GPF and its associated joint distribution that includes the output and labor-saving and capital-saving technological innovations. This type of primitive allows us not only to derive the theoretical GPF but also to consistently build a link between the substitutability microparameters (elasticities) and the probabilistic parameters (correlations). We find that the shape of the GPF is determined by all the relations among technological innovations and output and the way they are combined.
Two-stage multi-sensor fusion positioning system with seamless switching for cooperative mobile robot and manipulator system
Authors: Yang Manman , Yang Erfu
Published: March 2023

The stoppage of a mobile platform is generally scheduled to feed parts for machines on production lines, such as fenced industrial robotic manipulators. A non-stop mobile robotic part feeding system can contribute to production efficiency and flexibility but contains several challenging tasks. For example, the industrial robotic manipulator needs to perceive the positions of the mobile robot accurately and robustly before grasping the supplies when the mobile robot moves around. Thus, based on the relative distance between the two robots, an interaction mode of the integrated robotic system consisting of a fixed robotic manipulator and a mobile robot is developed for robotic interaction. In order to accurately and robustly perceive the positions of a mobile robot, two different positioning approaches for the robotic manipulator positioning mobile robot in an indoor environment are utilised. One approach is ultrasonic sensors fused with inertia measurement units (IMU) by extended Kalman filter (EKF). Furthermore, an outlier rejection mechanism is implemented to escape outliers from ultrasonic measurement. Another positioning approach is achieved by detecting an ArUco marker with visual sensor. Lastly, a positioning switching strategy according to the visual sensor state allows the robotic manipulator to reposition the mobile robot seamlessly. According to the static experiments, EKF-based positioning approach fusing IMU with ultrasonic sensor can export high-accuracy (the root mean square error is 0.04 m) and high-precision (the standard deviation is 0.0033 m) in positioning while keeping a high update frequency of 181.9 HZ in static positioning. Evaluations through dynamic experiments demonstrate that the proposed positioning system can suppress the positioning drifts over time in comparison with wheel encoder-based positioning method. The two-stage repositioning strategy can support the robotic manipulator to identify the positions of the mobile robot robustly, even in the case when the visual sensor is occluded.
Fast Columnar Physics Analyses of Terabyte-Scale LHC Data on a Cache-Aware Dask Cluster
Authors: Eich Niclas , Erdmann Martin , Fackeldey Peter , Fischer Benjamin , Noll Dennis , Rath Yannik
Published: March 2023

The development of an LHC physics analysis involves numerous investigations that require the repeated processing of terabytes of data. Thus, a rapid completion of each of these analysis cycles is central to mastering the science project. We present a solution to efficiently handle and accelerate physics analyses on small-size institute clusters. Our solution uses three key concepts: vectorized processing of collision events, the “MapReduce” paradigm for scaling out on computing clusters, and efficiently utilized SSD caching to reduce latencies in IO operations. This work focuses on the latter key concept, its underlying mechanism, and its implementation. Using simulations from a Higgs pair production physics analysis as an example, we achieve an improvement factor of 6.3 in the runtime for reading all input data after one cycle and even an overall speedup of a factor of 14.9 after 10 cycles, reducing the runtime from hours to minutes.
Classification method of shale gas analytic stages and its application
Authors: Keying Zhao , Kai Mu
Published: March 2023

China is rich in shale gas resources, and improving the oil recovery of shale gas wells is one of the hot issues in the current research. The production of shale gas wells releases shale gas by reducing formation pressure by repeated fracturing. In this paper, the curvature of shale desorption efficiency curve is analyzed to study the pressure suitable for formation shale gas release. According to the inflection point and stagnation point of the curvature curve, the starting pressure, sensitive pressure and turning pressure are obtained. the curvature curve can be divided into four stages: sensitive desorption, rapid desorption, slow desorption and inefficient desorption. In actual exploitation, shale desorption cannot go through all four desorption stages, and can be determined according to the ratio of $$V_{L} /P_{L}$$

V
L

/

P
L

. When the ratio is greater than 2.59, there are four integral stages in shale desorption, and the larger the ratio is, the longer the sensitive desorption stage is. At 1.0–2.59, there are three stages of desorption; at 0.54–1, there are only two stages; below 0.54, there are only low efficiency stage. The isothermal adsorption study on the core samples of the Upper Paleozoic in Yulin area of Ordos Basin shows that the shale of the Upper Paleozoic in the study area has more starting pressure and turning pressure, and less sensitive pressure, and the ratio of $$V_{L} /P_{L}$$

V
L

/

P
L

is between 0.5 and 2.0. Generally, the isotherm adsorption curve can be divided into three stages: fast desorption, slow desorption and low efficiency desorption. The low efficiency desorption stage contributes the most to the productivity of Upper Paleozoic shale in this area, and the slow desorption is supplementary. According to the desorption stage and pressure node in shale mining, the formation pressure can be appropriately reduced to improve shale gas recovery efficiency.
A network-based discrete choice model for decision-based design
Authors: Sha Zhenghui , Cui Yaxin , Xiao Yinshuang , Stathopoulos Amanda , Contractor Noshir , Fu Yan , Chen Wei
Published: March 2023

Customer preference modelling has been widely used to aid engineering design decisions on the selection and configuration of design attributes. Recently, network analysis approaches, such as the exponential random graph model (ERGM), have been increasingly used in this field. While the ERGM-based approach has the new capability of modelling the effects of interactions and interdependencies (e.g., social relationships among customers) on customers’ decisions via network structures (e.g., using triangles to model peer influence), existing research can only model customers’ consideration decisions, and it cannot predict individual customer’s choices, as what the traditional utility-based discrete choice models (DCMs) do. However, the ability to make choice predictions is essential to predicting market demand, which forms the basis of decision-based design (DBD). This paper fills this gap by developing a novel ERGM-based approach for choice prediction. This is the first time that a network-based model can explicitly compute the probability of an alternative being chosen from a choice set. Using a large-scale customer-revealed choice database, this research studies the customer preferences estimated from the ERGM-based choice models with and without network structures and evaluates their predictive performance of market demand, benchmarking the multinomial logit (MNL) model, a traditional DCM. The results show that the proposed ERGM-based choice modelling achieves higher accuracy in predicting both individual choice behaviours and market share ranking than the MNL model, which is mathematically equivalent to ERGM when no network structures are included. The insights obtained from this study further extend the DBD framework by allowing explicit modelling of interactions among entities (i.e., customers and products) using network representations.
Boundary effects on ideal fluid forces and Kelvin's minimum energy theorem
Authors: McKee Kyle I.
Published: March 2023

The electrostatic force on a charge above a neutral conductor is generally attractive. Surprisingly, that force becomes repulsive in certain geometries (Levin & Johnson, Am. J. Phys., vol. 79, issue 8, 2011, pp. 843–849), a result that follows from an energy theorem in electrostatics. Based on the analogous minimum energy theorem of Kelvin (Camb. Dublin Math. J., vol. 4, 1849, pp. 107–112), valid in the theory of ideal fluids, we show corresponding effects on steady and unsteady fluid forces in the presence of boundaries. Two main results are presented regarding the unsteady force. First, the added mass is proven to always increase in the presence of boundaries. Second, in a model of a body approaching a boundary, where the unsteady force is typically repulsive (Lamb, Hydrodynamics, 1975, § 137, University Press), we present a geometry where the force can be attractive. As for the steady force, there is one main result: in a model of a Bernoulli suction gripper, for which the steady force is typically attractive, we show that the force becomes repulsive in some geometries. Both the unsteady and steady forces are shown to reverse sign when boundaries approximate flow streamlines, at energy minima predicted by Kelvin's theorem.
On the stability of a dirigible body
Authors: Rath P. C. , Sharma S. M.
Published: March 2023

When the Magnus effects are completely absent the oscillatory motion of a dirigible body is said to be plane-yawing. Such bodies are stabilised by attaching fins or control vanes at their rear ends. Initial choice of the fin-size is made, depending on a static stability condition: JM < O, where JM is the normalised overturning aerodynamic moment coefficient. A proper fin-size requirement should normally be found from an appropriate dynamic stability condition. Under the very severe aerodynamic restriction stipulated above, one would expect, if the static stability condition is liberally satisfied by attaching over calibre fins, perhaps dynamic stability requirements could be met. This, however, may considerably reduce the ballistic range of the body. One would, therefore, need some sort of an upper majorant for JM consistent with the dynamic stability of the body and this should be a function of the other associated aerodynamic forces. In the present note a suitable majorant function for JM has been worked out. For this purpose, the aerodynamic coefficients are assumed to be slowly ranging functions of the path length as is usually stipulated. The stability problem has been solved using certain known results in the oscillation theory of differential equations.
European industry and civil air transport
Authors: Lecomte Pierre
Published: March 2023

When you heard the title of my paper you were probably disappointed. Indeed, other lecturers have already discussed very similar subjects on this same occasion. To recall the most recent:

I. G. Bloch in 1963: “The Aeronautical Industry in the Europe of Tomorrow”

Mr. Handel Davies in 1968: “Some Thoughts about the Future of European Aeronautics”.

M. Louis Giusta in 1969: “European Co-operation in the Aviation Industry and its Future Development”.

On reading again these three papers, I was struck by the pertinence of most of the points which were made. In that case, one may ask, why refer to them again? The reason is that many predictions have failed to materialise and many warnings do not seem to have been sufficiently heeded.
High speed flight tests with the Bo. 105
Authors: Teleki Adam
Published: March 2023

In giving this paper, my aim is to give an outline of the practical aspects of flight tests performed with a Bo. 105 helicopter, in the speed range of 100 kt to 220 kt, rather than to dwell on theoretical explanations for the results obtained, which have been dealt with in Refs. 1 and 2. In a short paper of this nature it is not possible to deal in detail with all aspects of such a test programme, so I have selected some results which I hope will be of interest. A number of similar investigations have of course been performed with other helicopters during the past, albeit not with this type of main rotor system, and to those who are familiar with these flight programmes I must apologise for not bringing any startling new discoveries.
Closed-form analysis of a class of damped systems
Authors: Kumar K. , Modi V. J.
Published: March 2023

This note attempts to obtain an approximate solution for a class of second-order systems represented by

where the well-known procedures, such as perturbation, variation of parameters, the WKBJ analysis, etc, may prove to be inadequate. The approach is illustrated through an example related to the planar librations (satellite oscillations about its mass centre) of gravity gradient cylindrical satellites in circular orbit, subjected to the solar radiation pressure damping (Fig. 1).
Coefficient of linear thermal expansion as a function of temperature
Authors: Holland M.
Published: March 2023

In many branches of engineering there is an increasing demand for light materials which will operate in conditions of elevated temperature and /or under severe temperature gradients. Magnesium alloys have found extensive use in the field of aviation, due to their lightness and retention of structural strength at elevated temperatures. When this type of structure is subjected to service conditions, it is likely that the general temperature level will change, in addition to the establishment of temperature gradients. A detailed analysis of the structural displacement, loading and stress under such conditions would undoubtedly be aided by a knowledge of the mathematical “law” describing the coefficient of linear thermal expansion as a function of temperature. A single integration of this equation over the limits of temperature will give the displacement per unit length. Integration of the product of this equation and Young's modulus of elasticity, ie integration of the thermal modulus, provides an accurate determination of the thermal stresses promoted by internal restraint, resulting from temperature gradients in the structure.
Initial buckling of lipped channel struts
Authors: Williams F. W.
Published: March 2023

Several recent theoretical advances have been incorporated in computer programs which find the initial buckling loads of prismatic assemblies of thin plates “exactly”. Any such assembly of plates which are connected together and/or supported along their longitudinal edges, while being simply supported at their ends, can be analysed. Furthermore, curved plates and anistropic materials are allowed. Thus plate assemblies with many practically important types of cross-section can be analysed. Consequently, published results mainly relate to a few crosssections of each of several possible types. However, the designer needs comprehensive design curves, like those in the Structures Data Sheets of the Royal Aeronautical Society, for as many common cross-section types as possible. Unfortunately, production of such curves using the programs mentioned is unlikely to be achieved for all desired types of cross-section, at least for some time, because each type involves plotting curves as several parameters are varied. Nevertheless, a range of results for one type of cross-section is obviously valuable. Thus the lipped channel strut made from isotropic material is considered in this Note (see Fig. 1).
The international angle
Authors: Browne Secor D.
Published: March 2023

Transatlantic travel has entered a new era, the era of mass tourism. Low cost, newly available air charter services have made it possible. Their far-reaching benefits, economic, cultural, and educational, are now widely recognised and enjoyed on both sides of the Atlantic.

For more and more people lower travel costs are awakening a latent demand. For those who have tasted the benefits of low cost travel there can be no turning back. Low cost charter availability is taking on the character of a right which governments are increasingly being expected to protect and promote.
The management of the MRCA
Authors: Stewart W.
Published: March 2023

It is an honour and privilege to present this further memorial tribute to those early pioneers in the aeronautical world, William Samuel Henson and John Stringfellow. It is a very long way from their pioneering achievements in the aeronautical field and their model flying activities of the 1840s to the subject of the management of the MRCA project, an international collaborative development of an advanced technology aircraft. However, it is not devoid of associations. The fact that the Memorial Lecture is dedicated to Henson and Stringfellow is in itself a recognition of collaborative venture in aeronautics. The First Memorial Lecture was also a unique occasion in the collaboration in its preparation between the current secretary and the past secretary of the Royal Aeronautical Society.

I would like to take one quotation from the First Memorial Lecture'11, where it is recorded that String-fellow wrote to Henson on 25th July 1845 as follows:

“I received two notes from Marriott: in the one received this morning there was a proposition which I give you under and to which I believe Columbine is agreeable, that is to divide the patent interests into 12 as follows, Henson 4/12, Columbine 4/12, Marriott 2/12, String-fellow 2/12—this Marriott thinks equable and just.
Space shuttle and post Apollo
Authors: Farrar D. J.
Published: March 2023

In the 18th Mitchell Memorial Lecture given to the Southampton Branch of the Society on 3rd February 1971, Val Cleaver discussed the outlook for astronautics after Apollo.

In the light of participation in the rapidly evolving programme since that date, I shall discuss, in this lecture, the history of the Apollo project, its relation to the evolving objectives of the NASA space programme as a whole, the origins of ideas which led to the post Apollo system, the history of negotiations between the Americans and Europe on European participation in the programme, the current studies, and factors underlying possible European involvement.

The first American satellite weighed 30 lb and was launched in 1958. Since then the Americans have launched several million pounds of payload into low earth orbit and, in the Apollo programme, individual payloads into low earth orbit have a weight of 300 000 lb. NASA astronauts have spent more than 6000 hrs in space, safely flying more than 100 million miles. Eighteen American astronauts have orbited the moon, eight have left their footprints on the lunar surface.
Characteristic overpressure of a supersonic transport of given length in a homogeneous atmosphere
Authors: Jones L B.
Published: March 2023

In recent years many investigations have been made into ways of reducing the pressure jumps across the shock waves resulting from supersonic transports. Lately Warren has stated that a quantity which typifies a sonic bang and in particular with regard to its effect on structures is the characteristic overpressure. The characteristic overpressure is the ratio of four times the running integral of the overpressure to the time interval between the first and last shock in the signature. The work on the pressure jumps across the shock waves and the resulting lower bound values have to be modified when the characteristic overpressure is considered. This note describes a preliminary investigation into methods of obtaining the lower bound values for the characteristic overpressure.
Note on an Aerodynamic Seal
Authors: Klomp E. D.
Published: March 2023

Figure 1 is a sketch of an “aerodynamic seal”. This type seal has potential application where it is necessary to control leakage of fluid through a clearance space bounded by one moving wall. For mechanical reasons it is necessary to maintain a clearance, in this case equal to the throat width t, between the inner wall I and the outer wall O. To prevent flow from the high pressure chamber H from passing into the low pressure chamber L, pump P supercharges fluid from H and forces it through nozzle J. The resulting fluid jet, which may be aided in following the curved surface by the Coanda effect, passes through the throat t and into diffuser D which recovers part of the entering velocity head. In the ideal case, with no losses and one-dimensional flow, the per cent recovery of inlet velocity head may be made as near to 100% as desired, since the diffuser recovery coefficient becomes asymptotic to 1-0 with increasing area ratio. Conversely, the dumping loss may be made as near to zero as desired. The attractiveness of this proposal hinges on diffuser performance. The pump is necessary to make up for the velocity head lost at the diffuser exit and for flow losses in the system. The pressure at the diffuser throat should be approximately that of the low pressure chamber for optimum performance. For large pressure ratios it may be necessary to stage two or more seals in series.