scholarly journals Complexity in Economic and Social Systems: Cryptocurrency Market at around COVID-19

Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 1043 ◽  
Author(s):  
Stanisław Drożdż ◽  
Jarosław Kwapień ◽  
Paweł Oświęcimka ◽  
Tomasz Stanisz ◽  
Marcin Wątorek

Social systems are characterized by an enormous network of connections and factors that can influence the structure and dynamics of these systems. Among them the whole economical sphere of human activity seems to be the most interrelated and complex. All financial markets, including the youngest one, the cryptocurrency market, belong to this sphere. The complexity of the cryptocurrency market can be studied from different perspectives. First, the dynamics of the cryptocurrency exchange rates to other cryptocurrencies and fiat currencies can be studied and quantified by means of multifractal formalism. Second, coupling and decoupling of the cryptocurrencies and the conventional assets can be investigated with the advanced cross-correlation analyses based on fractal analysis. Third, an internal structure of the cryptocurrency market can also be a subject of analysis that exploits, for example, a network representation of the market. In this work, we approach the subject from all three perspectives based on data from a recent time interval between January 2019 and June 2020. This period includes the peculiar time of the Covid-19 pandemic; therefore, we pay particular attention to this event and investigate how strong its impact on the structure and dynamics of the market was. Besides, the studied data covers a few other significant events like double bull and bear phases in 2019. We show that, throughout the considered interval, the exchange rate returns were multifractal with intermittent signatures of bifractality that can be associated with the most volatile periods of the market dynamics like a bull market onset in April 2019 and the Covid-19 outburst in March 2020. The topology of a minimal spanning tree representation of the market also used to alter during these events from a distributed type without any dominant node to a highly centralized type with a dominating hub of USDT. However, the MST topology during the pandemic differs in some details from other volatile periods.

1981 ◽  
Vol 20 (03) ◽  
pp. 169-173
Author(s):  
J. Wagner ◽  
G. Pfurtscheixer

The shape, latency and amplitude of changes in electrical brain activity related to a stimulus (Evoked Potential) depend both on the stimulus parameters and on the background EEG at the time of stimulation. An adaptive, learnable stimulation system is introduced, whereby the subject is stimulated (e.g. with light), whenever the EEG power is subthreshold and minimal. Additionally, the system is conceived in such a way that a certain number of stimuli could be given within a particular time interval. Related to this time criterion, the threshold specific for each subject is calculated at the beginning of the experiment (preprocessing) and adapted to the EEG power during the processing mode because of long-time fluctuations and trends in the EEG. The process of adaptation is directed by a table which contains the necessary correction numbers for the threshold. Experiences of the stimulation system are reflected in an automatic correction of this table. Because the corrected and improved table is stored after each experiment and is used as the starting table for the next experiment, the system >learns<. The system introduced here can be used both for evoked response studies and for alpha-feedback experiments.


2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Akram Alizadeh

AbstractThe Urmia Lake Basin is located between the West and East Azerbaijan provinces in the northwest of Iran. Lake Urmia is the twentieth largest lake and second largest hypersaline lake in the world. Stratigraphic columns have been constructed, using published information, to compare the sedimentary units deposited from the Permian to the Neogene on the east and west sides of the lake, and to use these to quantity subsidence and uplift. East of the lake, the sedimentary section is more complete and has been the subject of detailed stratigraphic studies, including the compilation of measured sections for some units. West of the lake, the section is incomplete and less work has been done; three columns illustrate variations in the preserved stratigraphy for the time interval. In all cases, the columns are capped by the Oligocene–Miocene Qom Formation, which was deposited during a post-orogenic marine transgression and unconformably overlies units ranging from Precambrian to Cretaceous. Permian to Cretaceous stratigraphy is used to measure subsidence in the Lake Urmia basin up to the end of the Cretaceous, and then, the subsequent orogenic uplift, which was followed by further subsidence recorded by the deposition of the Qom Formation in the Oligocene–Miocene.


2021 ◽  
Vol 62 (1) ◽  
pp. 43-80
Author(s):  
Wolfgang S. Heinz

Abstract: This article approaches the matter of institutional reform of the United Nations Human Rights Council from an international relations perspective. A well-known tension exists between State representatives acting for their governments in international organisations, but whose decisions are presented as UN policies. The latter should be guided primarily by the UN Charter and public international law. However, in reality, different worldviews and foreign policy considerations play a more significant role. In a comprehensive stock-take, the article looks at four major dimensions of the Council, starting with structure and dynamics and major trends, followed by its country and thematic activities, and the role of key actors. Council reform proposals from both States and civil society are explored. Whilst the intergovernmental body remains the most important authority responsible for the protection of human rights in the international sphere, it has also been the subject of considerable criticism. Although it has made considerable progress towards enlarging its coverage and taking on more challenging human rights crises, among some of its major weaknesses are the election of human rights-unfriendly countries into its ranks, the failure to apply stronger sanctions on large, politically influential countries in the South and North, and lack of influence on human rights crises and chronic human rights problems in certain countries. Whilst various reform proposals have emerged from States and NGOs, other more far reaching propositions are under sometimes difficult negotiations. In the mid- to long-term, the UN human rights machinery can only have a stronger and more lasting impact if support from national/local actors and coalitions in politics and society can be strengthened.


2013 ◽  
Vol 20 (5) ◽  
pp. 899-919 ◽  
Author(s):  
A. V. Artemyev ◽  
A. I. Neishtadt ◽  
L. M. Zelenyi

Abstract. We investigate dynamics of charged particles in current sheets with the sheared magnetic field. In our previouspaper (Artemyev et al., 2013) we studied the particle motion in such magnetic field configurations on the basis of the quasi-adiabatic theory and conservation of the quasi-adiabatic invariant. In this paper we concentrate on violation of the adiabaticity due to jumps of this invariant and the corresponding effects of stochastization of a particle motion. We compare effects of geometrical and dynamical jumps, which occur due to the presence of the separatrix in the phase plane of charged particle motion. We show that due to the presence of the magnetic field shear, the average value of dynamical jumps is not equal to zero. This effect results in the decrease of the time interval necessary for stochastization of trapped particle motion. We investigate also the effect of the magnetic field shear on transient trajectories, which cross the current sheet boundaries. Presence of the magnetic field shear leads to the asymmetry of reflection and transition of particles in the current sheet. We discuss the possible influence of single-particle effects revealed in this paper on the current sheet structure and dynamics.


2021 ◽  

The yearbook "West-East-Russia" 2020 presents the most significant events, processes and trends of the past year in the relations of the countries of the Center, Periphery and Semi-Periphery, including the positions and interests of Russia in this interaction. The main theme of the panorama of 2020 was the COVID-19 pandemic, the analysis of its damage to the world economy, the study of the experience of countering it in various countries and regions (China, India, Southeast Asia, Africa, Latin America). On this background, the problems of the BRICS and the post-Soviet space are considered. Attention is paid to the situation in Syria, Libya and other hot spots. These and other topics are presented in both global and regional dimensions (Middle East, East and Southeast Asia, Latin America, etc.). There are sections on ecology and scientific life, as well as reviews of new books on the subject of the yearbook.


2021 ◽  
Vol 16 (1(21)) ◽  
pp. 22-31
Author(s):  
David Bidzinashvili

The new Corona-virus and the contagious disease which it causes, the so called COVID 19, put forward the serious challenges for many countries all over the world and for Georgia among them. Almost the whole world is facing very serious obstacles on the international and national levels. Too many problems emerged in the world countries. To resist against the new disease has become the main priority for each country. The global processes caused by the pandemics have influenced the audit service as well. The uncertainty and unpredictability caused the new risks of deficiencies and activated already existed ones in the new environment. The situation became more complicated due to the fact that it can happen that the auditors do not consider the mentioned risks in the process of planning for audits or the risks may be considered mistakenly. The firms and other economical institutions in which the audit is carried out are obliged to adopt the new rules and changing environments in which their businesses function; they should change the rules of fulfilling the operation, preparing the financial accounts, the processes of their representing the information processes, safety of information shown in the financial accounts, the rules of their preparing; they also evaluate the possibilities of keeping on their activities in the nearest future. The qualified performing of the audit implies the basical elemenst which helps to create such environment where the possibility of the high level audit will be at the maximum. Implementing the quality control implies that such system will include two stages; each of them is directed towards providing the audit processes according the international standards There are several types of the quality improvement system. In all of them the main variable value represents the amount of costs for the proper system. All countries choose the system which provides benefits taking the costs into consideration. There are four main stages in the process of implementation the system which will ensure the high quality audit. Here are four main stages shown in the process of implementation:  The first stage: to carry out diagnostic observation;  The second stage: stating the view;  The third sage: working out the system;  The fourth stage: implementation of the system. The firms and other economical institutions where the audit is carried out are obliged to be reliable with their activities in the changing situation in which their businesses function. The subjects change the rules of carrying out the usual operations, change the open information given in the financial accounts, and estimate the possibilities of maintaining the existing possibilities for the nearest future. It is important to revise some standards out of Audit International Standards and to make them fit for revealing and assessing the risks of essential mistakes and discrepencies. The controlled variation of the standard regulates such issues as the newly corrected risks caused by influences of COVID-19 pandemic on the planned approaches to the audit and also, evaluation of the risks already defined and making changes in them taking into consideration the influence of the errors in the risk evaluations and influence made upon the planned evaluations and audits the changes of which will influence the evaluations of the risks in the inner control of the subject on the previously made imagination of the control environment, in order to define the measures to be taken in order to change the reactions to the mistakes using different measures in order to reach the trustful mechanisms to rely on. International standards of audit– answering to the assessed risks, the checked variation of the standard implies that it maybecome necessary to change the measures of reaction to the changes in the circumstances in order to obtain enough reliable measures and activities to control the situation by means of enough auditory evidences. The auditor has responsibilities to take into consideration that largening the deadlines will cause growth of the period and the risks of the dates of events which will happen in the time interval between accountability date and the date of the conclusion made by audit, the audit is also responsible for any event taking place later in relation to the Covid-19 situation. He is responsible also for evaluation of the fact about financial information. The enterprise functioning within nowadays complex environment taking into consideration the situation of COVID 19, should consider such priority issues as the uncertainty accompanying the Covid situation, related covenants, and others which accompany the pandemic period, among them the region, the financial state of customers and dealers, liquidating and paying capacity. During the process of the risk assessments it should considered that Covid 19 pandemic greatly influenced the global economics and the separate branches such as hotels business, retail sail, tourism and others. As a result of pandemic, it is possible that the number of audit considerations and thee circumstances can modify them which can be conditioned by different circumstances and the audit will state if there are incorrectable improper conditioned due to the circumstances. The audit will make it certain there are unimprovable mistakes which apart and together are essential for the financial accountability and the auditor will conclude that they cannot acquire the proper conditioned which apart or together could be essential financial accounts or the audit will conclude that they are not able to the essential accountability. Important researches were led to assess the appeared situation and it was concluded that the COVID 19 pandemic had influenced the financial situation which showed that the specific actions and procedures became complicated.


2020 ◽  
Vol 2020 (1) ◽  
pp. 81-103
Author(s):  
Aleksandr Babkin ◽  
Diana Burkaltseva ◽  
Andrej Tyulin ◽  
Pulod Azimov ◽  
Oleg Blazhevich

In conditions of financial institutions' development it is crucial to examine the transformation in the form of a collective investment institution under the influence of digitalization and, in particular, the emergence of cryptocurrencies. The subject of the research refers to the features of ICO functioning as a transformation of a financial institution for collective investment. The goal is to explore the ICO as a new form of collective investment. The results of the research are achieved through a comprehensive comparative analysis of ICO and IPO as a basic tool of financial institutions. The paper highlights the advantages and disadvantages, identifies the factors, analyzes the institutional regulation of ICO and proposes development vectors from three angles: for project creators, investors, regulators. The results can be used in policymaking, the functioning of joint investment platforms, in training specialists in the field of digital economy and financial markets.


2013 ◽  
Vol 11 (1) ◽  
pp. 117-123 ◽  
Author(s):  
Fernando Garcia-Trejo ◽  
Silvia Laura Hurtado-Gonzalez ◽  
Genaro Soto-Zarazua ◽  
Oscar Alatorre-Jacome ◽  
Enrique Rico-Garcia ◽  
...  

Studies on the biological aspects of fish typically focus on species that currently have commercial value, causing species that lack such market value to be ignored. This is the case of several freshwater fish, specifically of several members of the Goodeidae family. In the State of Querétaro there are several species of this family characterized for being viviparous and having distinctive sexual dimorphism that may have commercial potential. The subject of this study is Girardinichthys multiradiatus, a viviparous fish endemic to the upper-half of the Lerma River basin. The lack of knowledge regarding its biology and ecology has prevented the development of guidelines to manage its habitat and to preserve its population. The objective was to determine the ecophysiological responses of G. multiradiatus to its environmental management. From the sampling (24 hours every two months) population structure and dynamics were analyzed throughout a hydrological cycle using meristic data (standard length). Trophic and ecophysiological responses to fluctuations in environmental factors were also identified. Although the mexcalpique is a polytrophic species, results show that it prefers feeding on Diptera or Cladocera, while detritus is the third substance frequently found in their stomachs. Environmentally, the water regime is responsible for fluctuations in the population dynamics of the species, while temperature changes are the most influence its energy balance. These results can guide efforts to conserve this species and its habitat.


2019 ◽  
Vol 11 (6) ◽  
pp. 703 ◽  
Author(s):  
Andrea Barone ◽  
Maurizio Fedi ◽  
Pietro Tizzani ◽  
Raffaele Castaldo

Uturuncu volcano (southwestern Bolivia) is localized within one of the largest updoming volcanic zones, the Altiplano Puna Volcanic Complex (APVC). In several geodetic studies the observed uplift phenomenon is analyzed and modeled by considering a deep source, related to the Altiplano Puna Magma Body (APMB). In this framework, we perform a multiscale analysis on the 2003–2010 ENVISAT satellite data to investigate the existence of a multi-source scenario for this region. The proposed analysis is based on Cross-correlation and Multiridge method, pointing out the spatial and temporal multiscale properties of the deformation field. In particular, we analyze the vertical component of ground deformation during two time interval: within the 2005–2008 time interval an inflating source at 18.7 km depth beneath the central zone of the APVC is retrieved; this result is in good agreement with those proposed by several authors for the APMB. Between August 2006 and February 2007, we identify a further inflating source at 4.5 km depth, beneath Uturuncu volcano; the existence of this latter, located just below the 2009–2010 seismic swarm, is supported by petrological, geochemical, and geophysical evidence, indicating as a possible interpretative scenario the action of shallow, temporarily trapped fluids.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Christina Sul ◽  
Sherif M. Badawy

In-flight medical emergencies (IMEs) are acute onboard events of illnesses or injuries with potential immediate risk to a passenger’s short- or long-term health, or life. IMEs are significant events that are related to public safety concerns. With the increasing amount of annual air travel every year, it is expected that the number of encountered IMEs will continue to grow. Thus, it will be critical to develop and implement appropriate measures to manage IMEs with the best possible outcome. Despite the fact that most IMEs are self-limited with no serious adverse events, serious IME can lead to death, disability, or other unfavorable health outcomes, particularly as a result of suboptimal medical care. In this article, we systematically reviewed the published up-to-date evidence on the subject of in-flight emergencies with a specific focus on pediatric population.


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