Multi-leveled hierarchical control to optimize workload of a service-oriented platform

Nowadays, one of the directions of development of cloud systems is a creation of open platforms, providing resources for deploying third-party services. Users of such resources may deploy their own services, implemented with a wide range of technologies, receiving guaranteed performance and availability. To provide high availability and optimal utilization of hardware resources such platforms are built with a complex hierarchical infrastructure. As complexity of such systems increased, due to inability of control methods on different levels of hierarchy becoming ineffective, an issue with performance appeared. A complex approach to control is needed. This work is focused on researching the probability of making a hierarchical control system that allows choosing optimal methods and influence different system's elements on different levels, depending on current state of the system. A prediction of a probable workload of the system is also taken into consideration. The testing platform allowed conducting simulation experiments to determine threshold values that will influence system's state and to evaluate cost of control methods at certain levels of hierarchy. The received results show that it is highly probable to use the multi-leveled hierarchical control to achieve optimal performance level

Functional model of a software system with random time horizon

Virtualization technologies are being actively used to design infrastructure of cloud computing systems. In this case applications can be duplicated and hosted in different virtual machines on different physical nodes. That defines various performance of applications which causes the problem of managing performance of the entire heterogeneous system. There are different ways of solving this problem, including queuing theory methods. However research of the threshold discipline in scope of queuing theory is not complete because of difficulty of gathering precise analytic values and building of precise mathematic model of the system. Another feature of heterogeneous systems is the finite random time of system functioning which is defined by random endogenous and exogenous factors. This paper gives an overview on a functional model of the system with two heterogeneous devices with random functioning time and different service disciplines. In scope of simulation statistic experiments for different service disciplines at random time interval an average time needed to process a single request is measured. A comparison of service disciplines is conducted. Authors also provide a working software implementation of the heterogeneous system and experiments with use of service disciplines is performed

Achilles tendon rupture prevention in physical activity and sports: predisposition factors

Objective: to summarize all clinically significant factors determining the Achilles tendon predisposition to rupture.Materials and methods: the basis of this scientific-analytical review was the analysis of data from the electronic portals PubMed-NCBI, Google Academy, and “Scientific electronic e-Library.ru”.Results: the presented literature review indicates that injuries and ruptures of the Achilles tendon can be provoked by numerous factors, among which genetic predisposition, individual anatomico-morphological features of the tendon complex structure, initial connective tissue failure, pathological changes in the Achilles tendon structure itself, foot and ankle deformities are of great importance. Men are more susceptible to this injury. Tendon injuries are most common either in 30–40 years, or in the period from 60 to 80 years. Professional athletes and people who lead sedentary lifestyles and do not exercise properly are at risk of Achilles tendon ruptures. Concomitant metabolic disorders and use of some medications also play an important role in the predisposition to this injury. Local corticosteroid injections pose a particular tendon rupture risk. The combination of several established factors significantly increases the likelihood of this emergency.Conclusions: early detection of predisposition to Achilles tendon rupture will allow timely development of effective measures for its prevention in physical training and sports

Regulation of Intestinal Immune Response by Selective Removal of the Anterior, Posterior, or Entire Pituitary Gland in Trichinella spiralis Infected Golden Hamsters

The influence of anterior pituitary hormones on the gastrointestinal tract of humans and animals has been previously reported. Hypophysectomy (HYPOX) in the rat causes atrophy of the intestinal mucosa, and reduction of gastric secretion and intestinal absorption, as well as increased susceptibility to bacterial and viral infections. However, to our knowledge, no findings have been published concerning the immune response following HYPOX during worm infection, particularly that which is caused by the nematode Trichinella spiralis. The aim of this work was to analyze the effects of total or partial HYPOX on colonization of T. spiralis in the intestinal lumen, together with duodenal and splenic cytokine expression. Our results indicate that 5 days post infection, only neurointermediate pituitary lobectomy (NIL) reduces the number of intestinally recovered T. spiralis larvae. Using semiquantitative inmunofluorescent laser confocal microscopy, we observed that the mean intensity of all tested Th1 cytokines was markedly diminished, even in the duodenum of infected controls. In contrast, a high level of expression of these cytokines was noted in the NIL infected hamsters. Likewise, a significant decrease in the fluorescence intensity of Th2 cytokines (with the exception of IL-4) was apparent in the duodenum of control and sham infected hamsters, compared to animals with NIL surgeries, which showed an increase in the expression of IL-5 and IL-13. Histology of duodenal mucosa from NIL hamsters showed an exacerbated inflammatory infiltrate located along the lamina propria, which was related to the presence of the parasite. We conclude that hormones from each pituitary lobe affect the gastrointestinal immune responses to T. spiralis through various mechanisms

THE REFORM OF THE GOVERNMENTAL COLONY SYSTEM FOR RUSSIAN GERMANS IN THE LATE RUSSIAN EMPIRE: METHODS OF ARCHIVAL TEXT ANALYSIS

This paper considers the methods of historical research applied by the authors to the analysis of the reforms in the late Russian Empire 1860-70es, which completely changed the system of local authorities for Russian Germans. This study also explores the main principles of processing the archival data and represents the most common research strategies of Tsar, Soviet and modern Russian historians, as well as their German, American and French colleagues

TO THE QUESTION OF OPTIMISING THE DYNAMIC CHARACTERISTICS OF A VIBRATIONAL TREE UPROOTING MACHINE

Objectives Following logging operations, tree stumps remain in the site of the former forest.While these may be uprooted by special machines in the course of forestry operations, the use of heavy forestry machines operated repeatedly on the forest sites not only lead to soil erosion, but also to considerable financial expense. Consequently, the development of machines combining cutting (logging) and uprooting operations – that is, uprooting the trees along with their roots – are of a great interest. As research has shown, the main disadvantages of the use of such technology by “conventional” logging or forestry machines are their excessive loading and energy intensity. The aim of the research is to investigate means of eliminating these drawbacks by using vibration.Methods The article deals with theproblem of ensuring the effectiveness of the vibration application – in particular, torsional vibrations, used to stub trees together with their roots. To solve this problem, a mathematical model of the “machine-tree-soil-root system” system was developed, which takes into account the mutual influence of the dynamic characteristics of the machine’s technological equipment and tree and soil-root system, which allows a rational (optimal) frequency range of vibration equipment to be selected by analysing the amplitude-frequency characteristics of a given system. To analyse the amplitude-frequency characteristics of a mechanical system, the Euler-Lagrange equationswere used.Results Based on the mathematical model of the “machine-tree-soil-root system (SRS)” system and an analysis of the amplitude-frequency characteristics of a given system, a rational range of vibration frequencies was determined. As shown by analysis, the work of vibrational equipment in a given frequency range can significantly reduce the dynamic loading of the machine and at the same time create appropriate conditions for the effective destruction of the soil-root system.Conclusion The proposed method allows the rational values of the frequency characteristic of vibration equipment for each calculated tree to be found depending on the soil type and the basic machine

A multi-agent approach to the monitoring of cloud computing system with dynamically changing configuration

Cloud based distributed systems rely on scheduling and resources allocation to function. In complex distributed systems a distribution of many jobs of different types is required. At the same time, a problem of virtual machines migration to physical servers must be solved. Therefore, configuration of a cloud system may be very dynamic, meaning that not only number of existing computational servers but also their location on physical servers might change. Optimal control strategies aimed to solve these problems are effective only when updated information about system's components is available. However, gathering this information from many distributed components of a cloud system, such as physical nodes or virtual machines may significantly decrease overall performance. These problems can be solved by applying different optimization techniques such as multi-agent approach. Agents decide if the information is outdated and needs to be updated by them. This paper describes a cloud system architecture that uses agents of different types. Agents' algorithms and their interaction schemes are defined. Software implementation in form of software environment is presented. Simulation experiments to compare performance of the system when using default monitoring methods and a multi-agent approach were conducted