Triple-zero singularity of a Kaldor–Kalecki model of business cycles with delay

In this manuscript, we study triple zero singularity of a Kaldor–Kalecki model of business cycles with delay in both the gross product and the capital stock. By using the frameworks of Campbell–Yuan [1] and Faria–Magalhães [2, 3], the normal form on the center manifold is derived for this singularity and hence the corresponding bifurcation diagrams such as Hopf, BT, zero-Hopf, and homoclinic bifurcations are obtained. An example is given to verify some theoretical results

When Sensitivity is a Function of Age and Time Spent in the Preclinical State in Periodic Cancer Screening

Probability models are extended for periodic cancer screening trials to model sensitivity when it is changing with an individual’s age and time spent in the preclinical state. Wu et al. (2005) showed that sensitivity is monotone increasing with age, but intuitively, sensitivity is also a function of the time one has spent in the preclinical stage. This allows us to infer sensitivity at a late stage, just before symptoms manifest. We developed the probability model and applied Bayesian inference to the HIP study group data. The methodology we developed is also applicable to other kinds of chronic diseases

Normal form of double-Hopf singularity with 1:1 resonance for delayed differential equations

In this manuscript, we provide a framework for the double-Hopf singularity with 1:1 resonance for general delayed differential equations (DDEs). The corresponding normal form up to the third-order terms is derived. As an application of our framework, a double-Hopf singularity with 1:1 resonance for a van der Pol oscillator with delayed feedback is investigated to illustrate the theoretical results

Bifurcation Analysis of a Kaldor-Kalecki Model of Business Cycle with Time Delay

In this paper, we investigate a Kaldor-Kalecki model of business cycle with delay in both the gross product and the capital stock. Stability analysis for the equilibrium point is carried out. We show that Hopf bifurcation occurs and periodic solutions emerge as the delay crosses some critical values. By deriving the normal forms for the system, the direction of the Hopf bifurcation and the stability of the bifurcating periodic solutions are established. Examples are presented to confirm our results

Space and practice: A multifaceted understanding of the designs and uses of “Active Learning Classrooms”

Space is playing an increasingly significant role in modern societies, for “nothing and no one can avoid trial by space” (Lefebvre 1991: 416). Yet, it permeates our everyday life to such a degree that we often take it for granted. The importance of space has for a long time been largely underestimated in social sciences. In light of this, this thesis develops a multifaceted understanding of space, using a primarily social semiotic approach (Kress & Van Leeuwen 2001; Martin & Rose 2007; McMurtrie 2017; Ravelli & McMurtrie 2016; Van Leeuwen 2008a). Instead of focusing on spatial forms in isolation, this thesis highlights spatial practices – the dynamic interaction process between subject and space, a process that necessarily includes the mobile body in internal space and includes time as an inherent dimension. This practice model argues for a dynamic construction of space and shifts the analytical focus from structural elements of space to performative practices, whereby the agentive role of subject and the material entities afforded within space are simultaneously accounted for. A practice model is needed, for it can link different aspects of space together, and is a necessary step towards a complete exposition of the production of space. In particular, this thesis explores the ways in which teachers and students of three film studies lessons utilize so-called “Active Learning Classrooms” in a tertiary setting, in terms of how their movement and writing practices performed within the classroom, and their interaction with classroom designs create meaning together. By foregrounding the tripartite relationship among space, subject and practice, this thesis provides different ways in which space can be conceived of and analyzed. Rather than conceptualizing space as a mere collection of things, this thesis demonstrates that movement and writing practices in space, as a significant social construct, contribute significant elements to the making of the complexity and dynamics of space, and that rhythm can be employed as an integrative principle to encapsulate different practices and engender spatial coherence. This thesis contributes to the recent history of explorations of how and why space matters. Using social semiotic multimodal analyses, it provides a set of concrete frameworks for describing and interpreting the semiotics of embodied practices in space, thus enabling a more nuanced understanding of the interrelations between space, subject, and practice, and the semiotic resources used to structure them. It also provides general semiotic principles in terms of how a specific classroom is used and can be used in different ways, thus enabling an understanding of spatial pedagogy (Lim et al. 2012), whereby interactions of subjects with educative spaces in pedagogic practices enact a specific pedagogy

Investigation of the effects of needling the acupuncture point Houxi (SI 3) on pressure pain threshold, needling sensation and needling pain in healthy participants

University of Technology Sydney. Faculty of Science.: During the past decades, there has been a surge in prescribing opioids for pain related conditions, the “opioid epidemic”. It is critical for researchers and clinicians to explore other non-pharmacological approaches to manage pain instead of relying on opioid analgesics. Acupuncture could be an effective tool to modulate pain. Since 1999, studies on the effect of acupuncture on pressure pain threshold (PPT), at the University of Technology Sydney (UTS), have been conducted. The effects of the acupuncture to the acupoint LI 4 () on PPT, the strength and quality of needling sensation () and the intensity of needling pain have been investigated by researchers from the UTS acupuncture group. However, the effects of another acupoint, Small Intestine 3 (SI 3 - ) a commonly used acupoint for the treatment of various pain-related conditions has not been explored for its effect on PPT and . : The primary aim of this study was to investigate the effects of needling the acupoint SI 3 in healthy people on: 1. Regional PPT at ten sites (SI 11ᴿ, SI 11ᴸ, GV 4, GV 14, HT 7ᴿ, HT 7ᴸ, BL 60ᴿ, BL 60ᴸ, GB 21ᴿ, GB 21ᴸ) following three different interventions - SI3m⁺, SI3m⁻ and SL; 2. The strength and quality of needling sensation () reported by subjects; and 3. The intensity of pain associated with the intervention. : Prior to commencing the study a systematic review was undertaken on the clinical use of acupoint SI 3 and PPT in acupuncture clinical studies. Following the reviews, this prospective study was designed as a randomised, double-blind, three-arm, and cross-over experimental study to investigate the effects of needling SI 3 on regional PPT, and needling pain. : For SI3m⁺ and SI3m⁻ interventions, the post intervention mean % PPT scores were significantly elevated compared with SL (p < 0.001). SI3m⁺ statistically significantly elevated PPT% comparing to SI3m⁻ (p < 0.001). The mean needle sensation and pain scores were similar for the two needling interventions, but both increased when comparing to SL. The subjects’ anxiety and tension levels were not significantly different across the interventions. : Both intervention and site of needling were found to be important contributors to the effects on regional PPT in healthy participants. This study has provided findings that support the belief that obtaining during acupuncture is necessary for eliciting a pain modulating effect. Needling pain had no correlation with PPT

Thermoelectric (TE) Device made using PbTe Nanocrystal Coated Glass Fibers

Around 60 % of the energy produced in the U.S. in 2013 was wasted and most of this was dissipated in the form of heat. Thermoelectric materials could potentially harvest part of the energy being wasted by converting heat energy into electrical energy. Lead telluride nanocrystals are an interesting thermoelectric material particularly for solution-based coating of flexible substrates. The purpose of this project is to develop a working thermoelectric device using p-n pairs of PbTe nanocrystal coated glass fibers. In this project, p- and n- type PbTe nanocrystals are synthesized in solution. Bare glass fibers are sequentially dipped in solutions of PbTe nanocrystals to form a layer of PbTe, diluted aqueous hydrazine to remove organic ligands, and acetonitrile to wash away the hydrazine. The procedure is repeated to achieve a sufficiently thick nanocrystal coating on the glass fibers. The coated glass fibers are then used to make a prototype thermoelectric device with alternating p-type and n-type segments placed electrically in series and thermally in parallel. The device is placed in a temperature gradient and the resistance, current, voltage, and power output are measured. We found that the device has a resistance of approximately 33 MΩ and generates a power output of 5.3 pW in a temperature gradient of 20 Kelvin

Context-sensitive graph representation learning

Graph Convolutional Network (GCN) is a powerful emerging deep learning technique for learning graph data. However, there are still some challenges for GCN. For example, the model is shallow; the performance is poor when labelled nodes are severely scarce. In this paper, we propose a Multi-Semantic Aligned Graph Convolutional Network (MSAGCN), which contains two fundamental operations: multi-angle aggregation and semantic alignment, to resolve two challenges simultaneously. The core of MSAGCN is the aggregation of nodes that belong to the same class from three perspectives: nodes, features, and graph structure, and expects the obtained node features to be mapped nearby. Specifically, multi-angle aggregation is applied to extract features from three angles of the labelled nodes, and semantic alignment is utilised to align the semantics in the extracted features to enhance the similar content from different angles. In this way, the problem of over-smoothing and over-fitting for GCN can be alleviated. We perform the node clustering task on three citation datasets, and the experimental results demonstrate that our method outperforms the state-of-the-art (SOTA) baselines

Simple-Zero and Double-Zero Singularities of a Kaldor-Kalecki Model of Business Cycles with Delay

We study the Kaldor-Kalecki model of business cycles with delay in both the gross product and the capital stock. Simple-zero and double-zero singularities are investigated when bifurcation parameters change near certain critical values. By performing center manifold reduction, the normal forms on the center manifold are derived to obtain the bifurcation diagrams of the model such as Hopf, homoclinic and double limit cycle bifurcations. Some examples are given to confirm the theoretical results