Miracle-dz/UniFAR-FTUs huggingface dataset:
Existence and location of internal resonance of two-mode nonlinear conservative oscillators

Internal resonances can be widely observed in nonlinear systems; even a simple nonlinear system can exhibit intricate internal resonances when vibrating at large amplitudes. In this study, the existence and locations of internal resonances of a general two-mode system with an arbitrary eigenfrequency ratio are considered. This is achieved by first considering the symmetric case, where the internal resonances are found to be approximately captured by the Mathieu equation. It is shown that the bifurcations can exist in pairs; and, for each pair, the bifurcated solution branches capture modal interactions with the same commensurate frequency relationship but different phase relationships. To determine the existence and locations of internal resonances, the divergence and convergence for correlated bifurcation pairs are then considered. Lastly, the internal resonances in asymmetric cases are analytically derived, where the asymmetry induced bifurcation splitting is captured by a non-homogeneous extended Mathieu equation. This work explores the mechanism underpinning internal resonances, and explains their topological features, such as which internal resonances are observed as amplitude increases. A graphical method is also proposed for efficient determination of the existence and locations of internal resonances.
The megaherbivore gap after the non-avian dinosaur extinctions modified trait evolution and diversification of tropical palms

The Cretaceous–Palaeogene (K-Pg) extinction of the non-avian dinosaurs (66 Ma) led to a 25 million year gap of megaherbivores (>1000 kg) before the evolution of megaherbivorous mammals in the Late Eocene (40 Ma). The botanical consequences of this ‘Palaeocene megaherbivore gap’ (PMHG) remain poorly explored. We hypothesize that the absence of megaherbivores should result in changes in the diversification and trait evolution of associated plant lineages. We used phylogenetic time- and trait-dependent diversification models with palms (Arecaceae) and show that the PMHG was characterized by speciation slowdowns, decreased evolution of armature and increased evolution of megafaunal (≥4 cm) fruits. This suggests that the absence of browsing by megaherbivores during the PMHG may have led to a loss of defence traits, but the absence of megaherbivorous seed dispersers did not lead to a loss of megafaunal fruits. Instead, increases in PMHG fruit sizes may be explained by simultaneously rising temperatures, rainforest expansion, and the subsequent radiation of seed-dispersing birds and mammals. We show that the profound impact of the PMHG on plant diversification can be detected even with the overwriting of adaptations by the subsequent Late Eocene opening up of megaherbivore-associated ecological opportunities. Our study provides a quantitative, comparative framework to assess diversification and adaptation during one of the most enigmatic periods in angiosperm history.
Warwick-Monash Economics Student

This paper addresses two issues: the underinvestment in education and the poverty trap that ensues for poor households. In a setting where the end outcome is binary, an investing agent faces two levels of risk, one in the intermediate outcome - how much human capital she obtains for a given amount of investment, and one inherent in the end outcome - whether she gets the high-paid job. We show that when human capital is inheritable, risk-averse agents are deterred from investing because their parents are not suﬀiciently educated. Moreover, the U-shaped expected utility means the optimal investment occurs at either corners. If this investment or underinvestment is sustained through generations, a separating equilibrium such that poor households do not invest while wealthier ones do emerges. The divergence in educational attainment translates into a divergence in wealth between those who invest and those who do not. A simple calibration employing data from the NLSY97 demonstrates the existence of these equilibria at different levels of risk-aversion.
Inversion of Control in Employee–Employer Relation: Multiple Case Study of Generational Cohorts from State Government Sector

The article embarks upon its investigation with the help of multiple case analysis to benefit some perspectives on organisational control. It studies certain generational cohorts of employees who engage with organisations that do not represent the usual spectrum of economic interests namely government organisations. The cases belong to generations that temporally lie closer to each other and the employees have retired from service. The case analyses the perception of evolving nature of control on employees. Direction, evaluation and discipline being the three areas that are increasingly discussed in control literature, the case particularly concentrates on revelations under these focal points as it journeys through their work lives. The article unearths a curious inversion of relationship between the employee and employer on account of increasing strengthening of knowledge of the employee. It also explains the apparent hesitation/delay in adopting new and upbeat technologies largely by the government structure.
On the ambivalence of preferences for income redistribution: A research note

Increased income inequality, and policies that can limit its further growth, are an important issue for citizens, politicians and the media. Numerous empirical studies have measured political support for redistributive policies by asking whether the government should equalize gaps between rich and poor. They try to discover whether ‘redistributive’ policies are supported by public opinion and are therefore politically feasible. This research note argues that the standard instrument measures diffuse support for more equality, but gives rather vague hints if this support is transformed into a political mandate for redistributive programmes. With regard to the way in which the political demand for state redistribution to reduce income inequality has been raised so far, methodological critique and innovation is largely lacking. This article therefore tests the validity of the standard item. It argues that the conventional measurement only captures a general ‘inclination’ towards the idea of equality. However, since the item phrasing is unspecific, other orientations confound the answers, so that ultimately the predictive power in terms of political behaviour is low. The standard item measures egalitarian preferences with inconsistence. This limits its reliability, so that hardly any conclusions can be drawn regarding voting for left parties or support for redistributive programmes.
Design of a Path Tracking Scheme and Collision Avoidance Controller for Autonomous Vehicles

Abstract This paper presents an obstacle avoidance scheme for autonomous vehicles as an active safety procedure in unknown environments. The obstacle avoidance problem is treated using a nonlinear model predictive framework in which simplified dynamics are used to predict the state of the actual vehicle over the look-ahead horizon. Due to the slight dissimilarity between the simplified model used for trajectory generation and the actual vehicle trajectory, a separate tracking controller is designed to track the generated trajectory. The longitudinal dynamics of the vehicle is controlled using the inverse dynamics of the vehicle power-train model and the lateral controller is designed based on the linear quadratic regulator. In the nonlinear model predictive framework, the threat of local obstacles is augmented into the performance index using a parallax-based method. The simulation results show that the presented model-predictive-control-based trajectory generation and tracking controller, together, give satisfactory performance in terms of obstacle avoidance when applied to the full nonlinear vehicle model.
On the Effect of Flexibility on the Dynamics of a Suspended Payload Carried by a Quadrotor

: Unmanned aerial vehicles (UAVs) have been gaining increased importance due to their variety of applications. In some speciﬁc tasks, UAVs require the addition of payloads and onboard components, including sensors, which require great stability to provide safe and reliable responses (related to the payload characteristics, such as the temperature, pressure, vibrations and many other factors). In contrast with the suspended payloads carried by a quadrotor aircraft with a rigid attachment, an elastic attachment is designed to assess the inﬂuence of the vibration characteristics on the quadrotor and its payload. Since the payload dynamics can alter the ﬂight performance, sensor measurement accuracy and payload integrity, an adapted sliding mode control is used to guide the quadrotor on its desired trajectory and to compensate for the payload dynamics. To reduce the need for position sensors, a reduced-dimension observer is designed to estimate the payload trajectory, as well as the external disturbance behavior. Numerical simulations are performed to demon-strate that the ﬂexibility inﬂuences the quadrotor’s dynamics and can create residual oscillation on its payload.
Beyond facts - a survey and conceptualisation of claims in online discourse analysis

Analyzing statements of facts and claims in online discourse is subject of a multitude of research areas. Methods from natural language processing and computational linguistics help investigate issues such as the spread of biased narratives and falsehoods on the Web. Related tasks include fact-checking, stance detection and argumentation mining. Knowledge-based approaches, in particular works in knowledge base construction and augmentation, are concerned with mining, verifying and representing factual knowledge. While all these fields are concerned with strongly related notions, such as claims, facts and evidence, terminology and conceptualisations used across and within communities vary heavily, making it hard to assess commonalities and relations of related works and how research in one field may contribute to address problems in another. We survey the state-of-the-art from a range of fields in this interdisciplinary area across a range of research tasks. We assess varying definitions and propose a conceptual model – Open Claims – for claims and related notions that takes into consideration their inherent complexity, distinguishing between their meaning, linguistic representation and context. We also introduce an implementation of this model by using established vocabularies and discuss applications across various tasks related to online discourse analysis.
Polymorphic dynamics of ribosomal proteins gene expression during somatic cell reprogramming and their differentiation in to specialized cells-types

Factor induced pluripotent stem cells (iPSCs) offer great promise in regenerative medicine. However, accumulating evidence suggests that iPSCs are heterogeneous in comparison with embryonic stem cells (ESCs), and that is attributed to various genetic and epigenetic states of donor cells. In the light of the discovery of cell-type specialized ribosomal protein composition, its role as the cells transit through different stages of reprogramming and when iPSCs differentiate into specialized cell-types has not been explored to understand its influence in the reprogramming and differentiation process and outcome. By re-analyzing the publicly available gene expression datasets among ESCs, various sources of iPSCs and somatic cells and by studying the ribosomal protein gene expression during different stages of reprogramming of somatic cells and different passages of established iPSCs we found distinct patterns of their expression across multiple cell-types. We experimentally validated these results on the cells undergoing reprogramming from human dermal fibroblasts. Finally, by comparing publicly available data from iPSCs, iPSCs derived specialized cells and it’s in vivo counterparts, we show alterations in ribosomal gene expression during differentiation of specialized cells from iPSCs which may have Implications in the context of ribosomopathies. Our results provide an informatics framework for researchers in efficient generation of iPSCs that are equivalent to ESCs.
Polyfunctional IL-17A+ MAIT cells are expanded in the peripheral blood of patients with HLA-B27+ axial spondyloarthritis

Objectives Studies in axial spondyloarthritis (axSpA) have yielded conflicting results regarding the identity of the major IL-17A-producing lymphocyte populations. The goal of this study was to comprehensively assess the production of IL-17A and related cytokines by peripheral blood lymphocytes in axSpA. Methods Peripheral blood mononuclear cells were isolated from patients with axSpA and healthy controls matched for age, sex and HLA-B27 status. Unstimulated cells and cells activated with PMA/Ionomycin were analyzed by 25-parameter fluorescent flow cytometry. Data were analyzed by hierarchical gating, UMAP and SPICE. Results Except for a reduced frequency of mucosal-associated invariant T (MAIT) cells and natural killer (NK) cells, there were no other significant differences in abundance of major lymphocyte populations in axSpA patients compared with controls. Increased IL-17A production in axSpA was observed in total non-B lymphocytes and in MAIT cells. The fraction of MAIT cells expressing the tissue residency markers CD69 and CD103 was increased in axSpA. CD103 positive MAIT cells were enriched for IL-17A producers. axSpA patients demonstrated an expansion of MAIT cell subsets producing IL-17A, IL-17F, GM-CSF and TNF. This expansion was only observed in HLA-B27+ patients. Conclusions We document an expansion of polyfunctional IL-17A+ MAIT cells in the peripheral blood of HLA-B27+ patients with axSpA. These results are consistent with the implied role of intestinal dysbiosis or inflammation in axSpA pathogenesis. Key messages What is already known about this subject? Various IL-17A-producing lymphocyte populations have been implicated in the pathogenesis of axSpA. What does this study add? Polyfunctional MAIT cells capable of producing IL-17A, IL-17F, GM-CSF and TNF are expanded in the peripheral blood of HLA-B27+ patients with axSpA. How might this impact on clinical practice or future developments? Overproduction of IL-17A by MAIT cells is the most consistent finding of peripheral blood lymphocyte studies in axSpA. Our data support the pathogenetic link between intestinal and axial inflammation in axSpA.
Online tests yield robust thresholds with the right auditory hygiene

Most human auditory psychophysics research has been conducted with extreme ‘auditory hygiene’ in carefully controlled environments, with calibrated audio equipment, and potentially hours of repetitive testing with expert, well-characterized listeners. The incompatibility of web-based platforms with such experimental regimes would seem to preclude online auditory psychophysical paradigms, where success may hinge on absolute sound presentation level, reliably estimated perceptual thresholds, and sustained motivation, attention, and vigilance. Here, we introduce and validate a set of procedures that aim to address these challenges and facilitate successful online auditory psychophysics research. First, we establish a simple means of setting sound presentation levels where online participants serve as their own sound level meter. Across a set of three experiments conducted in person, we demonstrate the stability and robustness of this volume setting procedure both ‘in the wild’ and in controlled settings. Second, we test participants' tone-in-noise thresholds using widely adopted online experiment platforms, and demonstrate that reliable threshold estimates can be derived in approximately one minute of testing. Third, using these sound level setting and thresholding procedures to establish participant-specific stimulus conditions, we show that frequency-selective attention can be reliably demonstrated in individual participants with an online implementation of the classic, yet challenging, probe signal psychophysics paradigm. Finally, we show how threshold and attentional measures relate to well-validated assays of online participant fatigue, task confidence, and apathy acquired at multiple timepoints across the task. In all, this demonstrates the promise of asking new questions in auditory neuroscience with classic, yet challenging, online psychophysics paradigms. The code to duplicate our results is publicly available in JavaScript, through both Pavlovia (pavlovia.org) and Gorilla (gorilla.sc).
A case-study using the COSMIC-FFP measurement method for assessing real-time systems specifications

The success of a system development project largely depends on the nonambiguity of its system-level requirements specification document, where the requirements are described at the system level rather than at the software and hardware level. There may be missing details about the allocation of functions between hardware and software, both for the developers who will have to implement such requirements later on, and for the software measurers who have to immediately attempt to measure the software functional size of such requirements. The result of different interpretations of the specification problem would lead to different software being built, and of different functional size. The research described in this paper is concerned with the challenges inherent in understanding the initial system requirements in textual form and assessing the codesign decisions using the functional size measurement. This paper aimed at understanding the applicability of the COSMIC-FFP functional size measurement method in assessing the hardware-software requirements allocation, and illustrates the approach on a Steam Boiler Controller case study.
A Power/Area Optimal Approach to VLSI Signal Processing

A Power/Area Optimal Approach to VLSI Signal ProcessingbyDejan Marko Markovi´cEng. (University of Belgrade, Yugoslavia) 1998M.S. (University of California, Berkeley) 2000A dissertation submitted in partial satisfaction of therequirements for the degree ofDoctor of PhilosophyinEngineering – Electrical Engineering and Computer Sciencesin theGRADUATE DIVISIONof theUNIVERSITY OF CALIFORNIA, BERKELEYCommittee in charge:Professor Robert W. Brodersen, Co-chairProfessor Borivoje Nikoli´c, Co-chairProfessor Jan M. RabaeyProfessor Paul K. WrightSpring 2006
An integrated security scheme with resource-awareness for wireless ad hoc networks

Wireless ad hoc networks have emerged as a new information-transmission paradigm based on collaborative efforts of multiple self-organized mobile nodes. Without the support from any fixed infrastructure, this type of network provides an extremely flexible method for establishing communications in situations where geographical or terrestrial constraints demand totally distributed network system. While the inherent characteristics of an ad hoc network make it useful for many applications, they also bring in a lot of research challenges. One of the important issues is the security, since conventional security approaches adopted for traditional networks are not directly applicable to ad hoc networks. Secure ad hoc network is critical to the development of any real application of wireless ad hoc networks. In this dissertation, we attempt to develop an integrated and distributed security scheme with resource-awareness to enhance the security of ad hoc networks. Our scheme can be logically divided into two parts. An efficient intrusion prevention mechanism is developed to prevent the various attacks from external intruders, and an intrusion detection mechanism is used to provide a second line of defense for the misbehaviors of internal intruders. In the intrusion prevention mechanism, the identity-based cryptography, bivariate polynomial-based pairwise key and one way hash chain techniques are used to provide various security goals, such as availability, integrity, confidentiality, authentication and non-repudiation. Considering the self-organizing property of ad hoc networks, the intrusion detection is implemented in a distributed fashion, in which the behavior of each node is monitored and analyzed using cooperative functions involved in the network. The intrusion detection scheme can detect both the internal and external attacks, but it pays more attention on the attacks that cannot handled by the intrusion prevention approach, and the result of intrusion detection would further guide and help the intrusion prevention mechanism to efficiently isolate the malicious nodes. The proposed security scheme can be incorporated into the existing routing protocols to enhance the overall security, at the same time keep a minimal overhead to the routing protocols.
DRAFT: SINGLE AND MULTIPLE CIRCUMFERENTIAL CASING GROOVE FOR STALL MARGIN IMPROVEMENT IN A TRANSONIC AXIAL COMPRESSOR

The stability limit of a tip-stalling axial compressor is sensitive to the magnitude of the near casing blockage. In transonic compressors, the presence of the passage shock could be a major cause for the blockage. Identification and elimination of this blockage could be key to improving the stability limit of the compressor. In this paper, using numerical simulation, the near casing blockage within the transonic rotor, NASA Rotor 37, is quantified using a blockage parameter. For a smooth casing, the blockage at conditions near stall has been found to be maximum at about 20% of the tip axial chord downstream of the tip leading edge. This maximum blockage location is found to be consistent with the location of the passage shock-tip leakage vortex interaction. A datum single casing groove design that minimises the peak blockage is found through an optimisation approach. The stall margin improvement of the datum casing groove is about 0.6% with negligible efficiency penalty. Furthermore, the location of the casing groove is varied upstream and downstream of the datum location. It is shown that the stability limit of the compressor is best improved when the blockage is reduced upstream of the peak blockage location. The paper also discusses the prospects of a multi-groove casing configuration.
AN EFFICIENT ALGORITHM FOR SLIDING WINDOW BASED INCREMENTAL PRINCIPAL COMPONENTS ANALYSIS

It is computationally expensive to compute principal components from scratch at every update or downdate when new data arrive and existing data are truncated from the data matrix frequently. To overcome this limitations, incremental principal component analysis is considered. Speciﬁcally, we present a sliding window based eﬃcient incremental principal component computation from a covariance matrix which comprises of two procedures; simultaneous update and downdate of principal components, followed by the rank-one matrix update. Additionally we track the accurate decomposition error and the adaptive numerical rank. Experiments show that the proposed algorithm enables a faster execution speed and no-meaningful decomposition error diﬀerences compared to typical incremental principal component analysis algorithms, thereby maintaining a good approximation for the principal components.