scholarly journals PERFORMANCE EVALUATION OF COMPUTING SYSTEM AND NETWORK OBJECTS AT DIFFERENT LEVELS OF SURVIVABILITY

Author(s):  
Andrey V. Vertemyagin ◽  
◽  
Vasiliy G. Litvin ◽  
Yuriy V. Litvin ◽  
◽  
...  

The article discusses an approach to calculating the performance of objects exposed to adverse effects (AE), based on Markov models of queuing theory operating in a random environment. Three types of models of service queuing systems with an unlimited and a limited queue are investigated differing from each other in the message processing modes performed in the recovery process after AE: (1) incoming messages continue to be executed with a different performance compared to the normal mode; (2) in the process of recovery, incoming messages are accumulated, and processing is blocked; (3) in the process of restoration, no messages are received and no processing of messages already in the queue is carried out. The modes of operation of objects change as a result of random influences of the external environment (cyberattacks, influences of the external environment or object failures). The models are considered under the simplest assumptions about the distributions of the input flows of messages arriving at the object, their service time, the distributions of the time of occurrence of the AE and the recovery time of the object after that (Poisson flows and exponential time of the considered time intervals). The developed models make it possible to evaluate the design decisions taken from the performance point of view on the organization of message service for a given survivability under stationary assumptions. Numerical examples illustrate the use of models for assessing performance indicators and some indicators of survivability of the objects under study.

2013 ◽  
Vol 347-350 ◽  
pp. 1467-1472
Author(s):  
Wen Wei Huang ◽  
Gang Yao ◽  
Xiao Yan Qiu ◽  
Nian Liu ◽  
Guang Tang Chen

Optimization of restoration paths of power system after blackout is a multi-stage, multi-target, multi-variable combinatorial problem in the power system restoration. This paper presents a reasonable model and effectually method. The proposed model is considered as a typical partial minimum spanning tree problem from the mathematical point of view which considering all kinds of constraints. Improved data envelopment analysis (DEA) was used to get the weight which considering line charging reactive power, weather conditions, operation time and betweenness of transmission lines. The improved genetic algorithm method is employed to solve this problem. Finally, an example is given which proves the strategy of the line restoration can effectively handle the uncertainty of the system recovery process, to guarantee the system successfully restored after the catastrophic accidents.


2021 ◽  
Vol 1 (1) ◽  
pp. 111-123
Author(s):  
Anton Effendi ◽  
◽  
Bambang Hadi Prabowo

This article aims to investigate and analyze the potential of the hospitality industry by comparing the potential occupancy rates and hotel revenues of foreign and domestic tourists. This investigation uses an investigation of company data obtained from reports from hotel companies throughout Indonesia which are listed on the Indonesia Stock Exchange and secondary data obtained from world banks and other reliable data. This study uses behavioral data analysis using Threshold Autoregressive from 2000 to 2019. It was found that domestic tourists are a new hope that needs to be considered in surviving and restoring the hospitality industry after being exposed to the COVID-19 pandemic which has led hotel companies. temporarily closed operations and part of the hotel went bankrupt. Optimization of domestic tourists allowed the hotel industry to develop rapidly after the Covid-19 pandemic ended.


Author(s):  
Mykhailo Prodanchuk

Purpose. Problems of the existing theory, methodology and organization of accounting need to be solved taking into account practical requirements of modern management. In turn, this provides an opportunity to expand the functionality of accounting to make informed decisions, focused on achieving the efficiency of business operations and maximize the value of business, which contributes to the increased importance of accounting in management. This testifies to the relevance of the chosen topic , which determined the directions of the research, which requires in-depth scientific research, its scientific-methodological and practical importance. Purpose. The purpose of the article is to systematize existing approaches and to improve the classification of accounting functions in accordance with the requirements of the management system. Methods. In the process of researching the growth of accounting functionality in the management of agrarian business used general scientific methods of knowledge of reality, including: structural-logical and semantic analysis - to clarify and streamline the terminology in the conceptual apparatus; induction and deduction - for parameterization of accounting functionality in management; grouping and classification - to develop methodological principles and systematize the classification features of accounting functions. The research is based on general and specific methods of studying the economic processes, facts and phenomena of management requests for increasing the functionality of accounting for agricultural business management. The scientific base of the research was scientific works of domestic and foreign scientists on accounting functions in the management system, materials of international scientific-practical conferences and seminars, results of personal experience and observations. Results. Accounting as an information system, which is designed to make operational and strategic management decisions, needs to expand its functionality and increase its tasks. These categories have become one of the main ones in accounting, but also in management, as indispensable tools of managerial relations in business. Today, accounting is facing a scientific problem that needs theoretical and methodological justifications and practical solutions. It is necessary to expand the functionality of accounting in agrarian enterprises in order to meet management requests focused on achieving the strategic goal of the enterprise and maximize the value of business. The analysis of the evolution of information requests of the branch management and the priority of accounting functions in the development of agrarian business makes it possible to conclude that the priority task characterizes the process of information support for customers and consumers. According to the results of studying the classifications of functions, we have concluded that most often the scientists indicate the information function, the second most important is the control, and then the analytical and evaluation. Considering different approaches of scientists to classification of accounting functions and summarizing the results of the research, we concluded that the existing set of accounting functions does not allow to fully fulfill the tasks set before it. Therefore, in the current conditions of development of the global economy, the solution of this problem requires both theoretical and methodological justifications. That is why an important component of increasing the importance of accounting in the management of agrarian business is the expansion of its functionality, in particular by isolating new objectively formed functions. Given the priority of accounting functions in the development of agrarian business, they should be classified according to the information requests of the management system, as a result of which we propose to introduce a cost-oriented function and the function of saving capital and economic security of business. The capital saving function is a tool through which the formation of equity, regulation of property relations and business management, which provides a legal platform for completeness of payments with owners and guarantees the economic security of the enterprise. This function will facilitate the management of capital formation and its use. The value-oriented function is based on creating the market value of the business or providing the assets with the characteristics of the most valuable investments. It reflects the change in the value of the property of the enterprise from the point of view of transformation of its value in the external environment and allows to better understand the alternative advantages of investment sources. The proposed functions are aimed at identifying the degree of participation of owners in the management of the business entity, completeness of payments with them and determining the market value of agricultural businesses, increasing the investment attractiveness of Ukrainian agricultural enterprises. Discussion. Further scientific research in the direction of increasing the functionality of accounting in the management of agricultural business, it is advisable to carry out on the basis of domestic and foreign experience where the basis is the assertion that is built on the basis that accounting becomes the main function of management, which will facilitate the implementation of all functions of the management system. This will allow you to determine the place of accounting functions in achieving the goal of the management system, which will help in the formation of feedbacks between management and accounting. In-depth study of accounting functions will create the basis for improving the theoretical and methodological level of its development and will enhance functionality in the management system of agricultural business. Functional approach will allow to study the object of accounting not from the point of view of internal structure, set of interrelations of elements of its system, but on the other hand - interrelations with the external environment.


Author(s):  
В. Б. Швайченко ◽  
О. П. Гребінь ◽  
Н. Ф. Левенець

Improving the quality of the restored information in the process of restoration and restoration of phonograms.Synthesis of the system model on the basis of analysis of the processes of restoration and restoration of phonograms from media of various types and computer processing. The characteristics of the conceptual model of the restoration and restoration of the phonogram are determined. The structure of the system model of the information recovery process is developed. A lot of concepts and connections between concepts are defined. The structure of the system modeling restoration and restoration of phonograms is defined. A conceptual model of the restoration and restoration process is proposed. The distribution of artifacts over the playback and processing modes of a phonogram is justified. Details of the type of content with features of the effect on the state of the phonogram.The solutions obtained are the basis of the methodology for carrying out the process of restoration and restoration of phonograms by the criterion of sound quality.


2018 ◽  
Vol 2 (3) ◽  
pp. 153 ◽  
Author(s):  
Jeronimo Guilherme Remigio MONTEIRO

Aim: In this paper we are looking at the seaports (in India called ‘major ports’) from the context of its trade and India’s strategic importance in trade world after the initiation of economic reforms in 1991. It empirically estimates the levels of productivity and efficiency of seaports in India. This paper applies DEA technique to assess productivity and efficiency of seaports in India. Design/Research methods: DEA technique is extensively used in the literature of economics to provide measures of firms’ technical efficiency. These measures rank the firms by looking at their apparent performances over a period of time. DEA is a frontier model which is non-parametric since no functional specification or form is required to be mentioned. Conclusions/Findings: The DEA results as discussed and reported in the paper have shown how Indian ports are performing over the years. This investigation alone is not sufficient to develop a benchmark in the port system of India. Rather it will do well to have a closer look at the Indian ports from the physical and financial performance point of view. This study made use of data envelopment analysis (DEA) to generate what we call an efficiency benchmarks and assessment of the Indian ports sector. With this modest attempt to investigate the port sector of India several issues are in the open one can further analyze and come to desired conclusions. Originality/value of the paper: The main role of a port is to transfer goods between two transport modes. As far as Indian ports are concerned, there are few studies with regard to productivity and efficiency of the port sector. Since, there is an attempt in recent years to overhaul the infrastructure sectors of the Indian economy and especially seaports. There is a need to look at issues in port sector as well. Productivity and efficiency concerns should be the main aspect of the benchmarking of the performance of today’s Indian ports. Limitations of the research: Second stage DEA, distance function approach, Bayesian techniques, Carlo Monte techniques, can be alternatively used.  


2019 ◽  
Vol 17 (1) ◽  
pp. 370-379
Author(s):  
Oksana Korolovych ◽  
Olha Chabaniuk ◽  
Natalia Ostapiuk ◽  
Yurii Kotviakovskyi ◽  
Nelia Gut

The conditions for doing business at this stage are often similar in a game in which you need to calculate your actions a few steps ahead. At the same time, it is important to highlight several possible current options and make the necessary decision at the control moment. Moreover, each of the options formed should be justified, understandable and take into account the risk factors and available resources.Today, the main problem of assessing and minimizing the risk of “unfriendly takeover” is due to the fact that in most cases the raider is a player who acts quite legitimately and relies on the loopholes of the current legislative framework. Therefore, it is easier to identify possible actions of the raider and to avoid them within the limits of the reverse game than to deal with the consequences.The purpose of the research is to study the specificity of the individualized assessment and minimization of the risk of “unfriendly takeover” by using elements of game theory.It has been taken into account that the effect of individualization in assessing the risk of unfriendly takeover of enterprises can possibly be achieved on the basis of the application of game theory, the elements of which provide simulation of the unfriendly takeover process within the mathematical description of the inherent combinations of attack/defence as if they actually occurred in time both within one state of the external environment and for their given set.The results allowed forming mathematical decision-making models based on the elements of the antagonistic game “raider-target enterprise” and “raider games with the external environment”, which proved the possibility to: 1) identify possible functions of wins/losses; 2) combinations of attacks that can be neglected (that is, from the point of view of the rationality of decisions, will be rejected by the raider); 3) the ranking of the raider’s “attack combinations” for the reliability of their use during “unfriendly takeover”. Under such conditions, the target company can provide not only a detailed assessment, but also an effective minimization of the risk of “unfriendly takeover” and allocate the best combination of protection.


2020 ◽  
Vol 144 ◽  
pp. 126-135
Author(s):  
Anna A. Voloshinskaya ◽  

There is no generally accepted definition of a territory’s mission either in Russia or abroad. So is it worth including a mission in the strategy of socio-economic development of a territory and what definition of the mission is better to choose? To answer these questions, a content analysis of Russian and foreign definitions of the territory's mission has been carried out, from which common units of meaning were identified. It was established that a number of semantic units in definitions of the territory's mission and the mission of organization coincide. However, from the point of view of the mission statement, there are a number of significant differences between a territory and an organization, which makes some definitions of the territory’s mission hardly applicable in practice. Conclusion is made: it is better to define the territory's mission through its role in the external environment, functions and unique features of the territory. The article examines advantages and disadvantages of alternative options: not to develop a mission at all or to develop it in a purely formal way. Practical recommendations on developing a territory mission, examples from Russian and foreign experience are given.


Author(s):  
Hui-min Qin ◽  
Chang-qi Yan ◽  
Meng Wang ◽  
Shi-jing He

Steam generator is one of the key equipments in the pressurized water reactor, from the performance point of view, it is necessary to apply optimization techniques to the design of the steam generator. In this work, the optimal designs of a U-tube steam generator (UTSG), taking minimization of the total volume and net weight as objective respectively, are carried out by considering thermohydraulic and geometric constraints using a complex-genetic algorithm (CGA). And the sensitivities of some parameters which influence the total volume and net weight of UTSG are also analyzed. Under the condition of constant secondary thermalhydraulic parameters of the steam generator, the optimal design indicates an obvious effect taking either the overall volume or the total weight of the steam generator as the objective. The optimization results show that the proposed optimal method is feasible and effective. And the results of optimal designs and sensitivity analysis would provide guidance in the engineering design of UTSG.


Author(s):  
Manoj K. Gupta ◽  
Thomas A. Soulas ◽  
Dara W. Childs

Improved rotordynamic stability is desired by end users, and centrifugal compressor manufacturers are expected to meet, if not exceed, this expectation. Compressor manufacturers are required to design and build machines that are rotordynamically stable on the test stand and in the field. Confidence has been established in predicting the excitation forces from seals and bearings, but impeller aerodynamic excitation forces continue to be a challenge. While much attention is paid to impellers from an aerodynamic performance point of view, more efforts are needed from a rotordynamic standpoint. A high-pressure, reinjection centrifugal compressor is analyzed in order to predict rotordynamic stability using the best available resources for seals and bearings. Impeller shroud forces are predicted using the bulk-flow model developed by Gupta and Childs (Gupta, M., and Childs, D., Proc. of ASME Turbo Expo 2000, Power for Land, Sea, and Air). Each impeller stage is analyzed and an attempt is made to improve the estimation of impeller aerodynamic excitation forces. Logarithmic decrement (log dec) predictions for the full rotor model consisting of all the stages and seals are compared to the full-load full-pressure test measured values using a magnetic bearing exciter. A good correlation is obtained between the measured test results and analytical predictions.


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