Black swans or dragon kings? A simple test for deviations from the power law

We develop a simple test for deviations from power law tails, which is based on the asymptotic properties of the empirical distribution function. We use this test to answer the question whether great natural disasters, financial crashes or electricity price spikes should be classified as dragon kings or 'only' as black swans

Phase Transitions in Operational Risk

In this paper we explore the functional correlation approach to operational risk. We consider networks with heterogeneous a-priori conditional and unconditional failure probability. In the limit of sparse connectivity, self-consistent expressions for the dynamical evolution of order parameters are obtained. Under equilibrium conditions, expressions for the stationary states are also obtained. The consequences of the analytical theory developed are analyzed using phase diagrams. We find co-existence of operational and non-operational phases, much as in liquid-gas systems. Such systems are susceptible to discontinuous phase transitions from the operational to non-operational phase via catastrophic breakdown. We find this feature to be robust against variation of the microscopic modelling assumptions.Comment: 13 pages, 7 figures. Accepted in Physical Review

Динамические характеристики магнитожидкостных опор

The paper considers a vibro-protective magneto-fluid support that uses elastic properties of magnetic fluid with a free surface in magnetic field.The paper has experimentally revealed that the analyzed structure is characterized by better noise absorbing characteristics.The conducted experiments have made it possible to conclude that there is a possibility to use vibro-protective magneto-fluid supports within the frequency range from 0 to 300 Hz, amplitudes up to 2 mm and unit load up to 2,5 · 10 4 Н/м².Рассмотрена виброзащитная магнитожидкостная опора с использованием упругих свойств магнитной жидкости со свободной поверхностью в магнитном поле.Экспериментально обнаружено, что анализируемая конструкция обладает улучшенными шумопоглощающими характеристиками.Проведенные исследования позволили сделать вывод о возможности использования виброзащитных магнитожидкостных опор в области частот от 0 до 300 Гц, амплитуд до 2 мм и удельных нагрузок до 2,5 · 10 4 (десять в четвертой степени)  Н/м²

WOOL PRODUCTIVITY AND QUALITY OF RUSSIAN MEAT MERINO SHEEP FROM INTRA- AND INTERLINE SELECTION

Line breeding is often used in purebred animal husbandry, although the combination of lines may affect undesirable result. Therefore, it is very important for animal breeders to know which lines of animals can be combined to produce highly productive offspring with high meat and wool properties. This article studies the influence of interline selection of Russian meat merino breed on wool productivity, quality and skin histostructure. We found that the highest clipping was in the animals of group III obtained from ME-50 line rams and AS-30 line ewes. Ewes exceeded their peers of group II from the intraline AC-30 selection and peers of group IV from AS-30 line rams and ME-50 line queens. At the same time, ewes of group III insignificantly exceeded peers of group I from intraline selection of ME-50 line animals by 2.0% (P>0.05). Animals of group III had rather high fleece indices in terms of the wool condition due to the influence of ME-50 rams. Moreover, they had the highest ratio of “fat:sweat” (0.84), which confirms the high technological wool properties of this genotype. The quality of sheepskins depends on the nature of the connection of collagen fibers in the reticular layer. In terms of the thickness of the skin reticular layer young ewes of the group III exceeded their peers in groups I, II and IV by 5.3% (P> 0.05), 21.9% ( P<0.01) and 12.0% (P<0.05) respectively

Effects of salt stress and cooling regimes on the pigment composition of Dunaliella salina cells

Background: Microalgae are able to produce a significant amount of biologically significant substances. In connection with the growing popularity of microalgae, it is important to develop effective methods for storing cultures and creating strain banks. This will not only meet the needs of science and biotechnology for viable and sustainable crops, but will also solve the problem of biodiversity conservation. Objectives: study the effect of salt stress and cooling regimes on the pigment composition of microalgae Dunaliella salina cells in order to increase their safety after freezing-thawing. Materials and methods: The objects of the study were the unicellular green microalgae D. salina. Cultivation was carried out according to the standard method on nutrient media with different amounts of NaCl and trace elements. Adaptation to low temperatures was carried out by exposure of samples in the dark at temperature 4°C for 24 hours. Freezing was performed by placing 1 ml of the cell suspension in a 1.8 ml polypropylene cryogenic vial (Nunc, Sigma-Aldrich), cooled at a rate of 1 deg/min using a Mr. Frosty with following regimes: to -10°С, -40°С, -40°С followed by immersion to liquid nitrogen or direct immersion to liquid nitrogen (-196°С). Thawing was carried out in a water bath (37°С) with continuous shaking for 1–2 min. Microscopic examinations were carried out on an LSM-510 Meta laser scanning microscope (Carl Zeiss, Germany) upon excitation by a diode laser with a wavelength of 405 nm and 573 nm using a Nile Red stain. Results: It has been established that the formation of intracellular lipid globules and the synthesis of carotenoids in D. salina cells contribute to an increase in the concentration and number of motile cells after freezing-thawing. It has been shown that during rapid cooling, adaptive mechanisms do not have time to turn on in cells, and complete destruction of carotene-containing lipid globules occurs. Conclusions: Cryopreservation of D. salina cells should be carried out at a rate of 1 deg/min to -40°C, followed by immersion in liquid nitrogen and a mandatory stage of precultivation at 4°C for 24 hours. This approach allows the cells to adapt to a decrease in temperature, which contributes to the best result after freezing-thawing

PRODUCTIVE AND BIOLOGICAL CHARACTERISTICS OF RUSSIAN MEAT MERINOS SHEEP WITH DIFFERENT LINEAR SELECTION

Line breeding is a difficult but effective zootechnical process in purebred sheep husbandry. Linear sheep consistently transmit their characteristics to offspring in order to increase and identify the most promising genotypes, characterized by high productivity and breeding efficiency, by detecting interline selection. The main purpose of the work was to identify the most suitable options for intra- and interline selection of the Russian meat merino breed. The article studies the early development of animals’ growth and physique, the high rates of animals, live weight in different age periods, slaughter and meat qualities. We established that young animals obtained by mating between the animal lines VK-40 and ME-50 were characterized by more proportional body shapes, better slaughter and meat qualities. The increase in live weight of lambs obtained by mating queens of the VK-40 line and rams of the ME-50 line (group III) was more intense than their peers from the intraline selection of the VK-40 line (I group) and of queens of the line AC- 30 with ME-50 rams (group II). The heaviest carcasses were in lambs obtained from the mating of queens of the VK-40 line and rams of the ME-50 line (13.26 kg), the weight of the carcass was greater, compared with the same indicator of the peers of groups I and II, respectively, by 7.7% and 4.0%, by internal fat mass – by 21.8% and 9.8%, by slaughter weight – by 8.3% and 4.3%

Does insurance fraud in automobile theft insurance fluctuate with the business cycle?

[[abstract]]Financial institutions face various cyclical risks, but very few studies have analyzed the cyclicality of operational risk. External fraud is an important operational risk faced by insurers. In this research, we analyze the empirical relationship between insurance fraud and business cycle and we concentrate our study on two insurance contracts that may create an incentive to defraud. We find that residual insurance fraud exists both in the contract with replacement cost endorsement and the contract with no-deductible endorsement in the Taiwan automobile theft insurance market. These results are consistent with previous literature on the relationship between fraud activity and non-optimal insurance contracting. We also show that the severity of insurance fraud is countercyclical. Fraud is stimulated during periods of recession and mitigated during periods of expansion. Although this last result seems intuitive, our contribution is the first to measure its significance.[[notice]]補正完畢[[incitationindex]]SSCI[[booktype]]紙本[[booktype]]電子

FinTech revolution: the impact of management information systems upon relative firm value and risk

The FinTech or ‘financial technology’ revolution has been gaining increasing interest as technologies are fundamentally changing the business of financial services. Consequently, financial technology is playing an increasingly important role in providing relative performance growth to firms. It is also well known that such relative performance can be observed through pairs trading investment. Therefore pairs trading have implications for understanding financial technology performance, yet the relationships between relative firm value and financial technology are not well understood. In this paper we investigate the impact of financial technology upon relative firm value in the banking sector. Firstly, using pairs trade data we show that financial technologies reveal differences in relative operational performance of firms, providing insight on the value of financial technologies. Secondly, we find that contribution of relative firm value growth from financial technologies is dependent on the specific business characteristics of the technology, such as the business application and activity type. Finally, we show that financial technologies impact the operational risk of firms and so firms need to take into account both the value and risk benefits in implementing new technological innovations. This paper will be of interest to academics and industry professionals