Roles of GARCH and ARCH effects on the stability in stock market crash

We theoretically stochastic simulate and empirically analyze the escape process of stock market price nonequilibrium dynamics under the influence of GARCH and ARCH effects, and explore the impact of ARCH and GARCH effects on stock market stability. Based on the nonlinear GARCH model of econophysics, and combined with GARCH and ARCH effects of volatility, we propose a delay stochastic monostable potential model. We use the mean escape time, or mean hitting time, as an indicator for measuring price stability, as first introduced in Ref. [1]. Based on the comparative analysis of actual Chinese A-share data, the theoretical and empirical findings of this paper are as follows} (1) The theoretical simulation results and actual data are consistent. (2) There exist optimal GARCH and ARCH effects maximally enhancing stock market stability.

Playing with time to escape time and space: Slow Music Improvisation in an online space for Mindfulness

This article is an exegetical look at a series of improvisational concert/performance/co-creations that started in the lockdown of March 2020 in New Zealand. This informal series of livestream concerts has continued to develop since that time, with a range of collaborative performers. This article serves to unpick some of the creative practice and conceptual framework that outline this series from the point of view of individual creative reflection and mindfulness. This series of events were designed to provide space for shared improvisation as a tool for mindfulness in uncertain times. It was also designed to provide some collective moments of reflection through a shared remote experience. But at the core, this series is in exploring ideas of slow improvisation. Working in a purely online context utilising the limitations of video and sound sharing technology to create specific new performative experiences. As a part of this process we as performers are places into a situation that works between individual awareness (as you are in a space by yourself) and collective experience (as you perform together online). This experience is very intuitive and the participants are forced to embrace the uncertainty of the environment and technology, and recognise the spontaneity of improvisational experiences that are mediated through the experience of shifting time, and the disembodied nature of Zoom to create music that has a sense of release and connection.

The interaction between neural populations: Additive versus diffusive coupling

Models of networks of populations of neurons commonly assume that the interactions between neural populations are via additive or diffusive coupling. When using the additive coupling, a population's activity is affected by the sum of the activities of neighbouring populations. In contrast, when using the diffusive coupling a neural population is affected by the sum of the differences between its activity and the activity of its neighbours. These two coupling functions have been used interchangeably for similar applications. Here, we show that the choice of coupling can lead to strikingly different brain network dynamics. We focus on a model of seizure transitions that has been used both with additive and diffusive coupling in the literature. We consider networks with two and three nodes, and large random and scale-free networks with 64 nodes. We further assess functional networks inferred from magnetoencephalography (MEG) from people with epilepsy and healthy controls. To characterize the seizure dynamics on these networks, we use the escape time, the brain network ictogenicity (BNI) and the node ictogenicity (NI), which are measures of the network's global and local ability to generate seizures. Our main result is that the level of ictogenicity of a network is strongly dependent on the coupling function. We find that people with epilepsy have higher additive BNI than controls, as hypothesized, while the diffusive BNI provides the opposite result. Moreover, individual nodes that are more likely to drive seizures with one type of coupling are more likely to prevent seizures with the other coupling function. Our results on the MEG networks and evidence from the literature suggest that the additive coupling may be a better modelling choice than the diffusive coupling, at least for BNI and NI studies. Thus, we highlight the need to motivate and validate the choice of coupling in future studies.

Post-Eurocentric grand narratives in critical international theory

Critical international theory is confronted with a fundamental ‘problem of orientation’, whose answer defines its capacity to critically analyse world politics. This problem derives from how the capacity for critique is inherently connected with the need to, at least partially, escape time- and space-bound points of view and attain a more cosmopolitan perspective that permits an assessment of the regressive/progressive tendencies of the human past, present and possible futures. The search for this cosmopolitan standpoint of orientation has frequently led to a reliance on grand narratives of human development from the perspective of which critical orientation can be disclosed. However, grand narratives themselves have frequently relied on metaphysical categories and stadial conceptions of history that reproduce forms of Eurocentrism that ultimately undermine their adequacy as means of orientation. A fundamental suspicion of grand narratives and need for ‘reflexivity’ that discloses forms of exclusion embedded in theoretical perspectives have thus become common topics in the field. However, this growing concern with reflexivity is also associated with a tendency for greater philosophical abstraction and a growing gap between theory and practice. This article considers the role of grand narratives in critical international theory and explores the possibility of post-Eurocentric and post-philosophical grand narratives that provide an alternative answer to the problem of orientation and recover the link between theory and practice. With reference to recent developments in the field, namely, the work of Richard Devetak and Andrew Linklater, the article considers the possibility of a historical–sociological approach to grand narratives.

Experimental Study on the Evaluation and Influencing Factors on Individual’s Emergency Escape Capability in Subway Fire

Studying an individual’s emergency escape capability and its influencing factors is of great practical significance for evacuation and escape in subway emergencies. Taking Zhengzhou Zijing Mountain Subway station as the prototype, and using VR technology, a virtual subway fire escape scene was built. Combined with the total escape time, the total contact time with fire, and the total contact time with smoke, it proposed a calculation formula on emergency escape capability. A total of 34 participants with equal gender distribution were recruited to carry out the virtual subway fire escape experiment, and participants’ physiological data (heart rate variability, skin conductance) were real-time recorded by ErgoLAB V3.0 throughout the whole experiment. The emergency escape capability of each participant was evaluated quantitatively, and the related influencing factors were analyzed. The results show that for the age ranges (19–22 years old) in the experiment, the emergency escape capability of women is significantly lower than that of men (p < 0.05); although there is no significance in emergency escape capability in DISC personality types (p > 0.05), the mean emergency escape capability of people with influence personality type is the worst, and that of people with compliance type is the best; during virtual fire escape vs. baseline, Mean_SC and Mean_HR both increased very significantly (all p < 0.01), and participants were under stress during their virtual fire escape. There is a significant negative correlation between emergency escape capability and LF_increase_rate (p < 0.05), and a remarkably significant negative correlation between emergency escape capability and LF/HF_increase_rate (p < 0.01); the greater the increase rate of LF or LF/HF, the smaller the emergency escape capability, with excessive stress probably not being conducive to emergency escape. There is a very significant negative correlation between an individual’s emergency escape capability and the degree of familiarity with the Zijing Mountain subway station (p < 0.01). The findings provide references and suggestions on the emergency management and emergency evacuation for government and subway departments.

Effectiveness of travel time during evacuation in high-rise residential buildings: a case study in Selangor, Malaysia

PurposeIn recent years, the number of high-rise buildings in Malaysia has been increasing. Therefore, it is essential to take evacuation into consideration especially for emergency conditions such as fire, explosion and natural disasters. This research aims to evaluate the effectiveness of the escape time in typical Malaysian high-rise residential buildings.Design/methodology/approachThis work comprises simulation on three buildings around the Selangor area in Malaysia. Quantitative methodology is adopted using Pathfinder software to simulate the evacuation process and time of the three typical Malaysian high-rise residential buildings. Four parameters were studied namely, the occupant load density, walking speed of first and last occupants, average of evacuation time per floor for the three buildings and effect of placement of emergency staircase on travel time.FindingsFindings show that 12 m2 which is double the allowable occupants' density in Malaysia increases evacuation time by 67.9% while the placement of the emergency staircase on the left and middle section of a building significantly affects the evacuation time by 21.2%. In conclusion, from the simulation studies, it is recognized that a higher occupant's density affects the evacuation time.Originality/valueThis work could provide information on escape time for future construction of high-rise buildings in Malaysia. Hence, the specification and design of buildings could be reviewed based on the results obtained from this simulation. This information could be beneficial to the building regulators and developers thus enhancing the knowledge of building constructor and possible issues in the design of staircases, corridors and height of buildings.

Ameliorating Effect on Aβ-Induced Alzheimer’s Mice by Litsea cubeba Persoon Powder

Alzheimer’s disease (AD) is caused by excessive oxidative damage and aging. The objective of this study was to investigate the anti-dementia effect of LCP fruit powder on amyloid β (Aβ)-induced Alzheimer’s mice. The composition of LCP essential oil was determined by gas chromatography/mass spectrometry. In addition, the water maze was used to evaluate the learning and memorizing abilities of the mice. The concentrations of malondialdehyde (MDA), protein carbonyl, phosphorylated τ-protein, and the deposition of Aβ plaques in mouse brains were also assessed. The results showed that the main components of essential oils in LCP and d-limonene, neral, and geranial contents were 14.15%, 30.94%, and 31.74%, respectively. Furthermore, oral administration with different dosages of LCP significantly decreased the escape time (21.25~33.62 s) and distance (3.23~5.07 m) in the reference memory test, and increased the duration time (26.14~28.90 s) and crossing frequency (7.00~7.88 times) in the target zone of probe test (p < 0.05). LCP also inhibited the contents of MDA and the phosphor-τ-protein from oxidative stress, reduced the brain atrophy by about 3~8%, and decreased the percentage of Aβ plaques from 0.44 to 0.05%. Finally, it was observed that the minimum dosage of LCP fruit powder (LLCP, 30.2 mg/day) could prevent oxidative stress induced by Aβ and subsequently facilitate memory and learning deficits in Aβ-induced neurotoxicity and cognitively impaired mice.

A general theory of polymer ejection tested in a quasi two-dimensional space

A general ejection theory of polymer is developed in a two- and three-dimensional space. A polymer is confined initially in a cavity and ejects spontaneously to the outer space through a nanopore channel without the help of any external stimulus. A reflective wall boundary is set at the pore entrance to prevent the falling of the head monomer of chain into the cavity. Three stages are distinguished in a process: (1) an entering stage, in which the head monomer enters the pore to search for a way to traverse the pore channel, (2) a main ejection stage, in which the chain body is transported from the cavity to the outer space, (3) a leaving stage, in which the tail monomer passes through and leaves the pore channel. Depending on the number of the monomers remaining in the cavity, the main ejection stage can be divided into the confined and the non-confined stages. The non-confined stage can be further split into the thermal escape and the entropic pulling stages. The Onsager’s variational principle is applied to derive the kinetics equation of ejection. The escape time is calculated from the corresponding Kramers’ escape problem. Extensive molecular dynamics simulations are then performed in a quasi two-dimensional space to verify the theory. The variation of the ejection speed is carefully examined. The decreasing behavior of the number of monomers in the cavity is studied in details. The scaling properties of the spending time at each processing stage are investigated systematically by varying the chain length, the cavity diameter, and the initial volume fraction of chain. The results of simulation support firmly the predictions of the theory, cross-checked in the studies of various topics. In combining with the previous investigations in the three-dimensional space, the generalized theory is very robust, able to explain the two seemly different phenomena, polymer ejection and polymer translocation, together under the same theoretical framework in the two space dimensions.