Operational Situations Research Articles

Experimental study of the influence of external factors on the functionality of a regenerative decentralized ventilation unit

The article presents an experimental field study of the influence of environmental factors on the functionality of a commercial decentralized ventilation device for regenerative utilization of heat from the exhaust air, intended for installation in an external wall of buildings. The experiments included measurements during the winter and summer seasons. Real operating situations with two regenerative heat exchange matrices are presented and tested. The results of the experiments show that the functionality of the ventilation and heat recovery device does not meet the characteristics that the device shows under standard laboratory conditions.

Improvement of a Centrifugal Compressor Test Bench to Incorporate Variable Impeller-Inducer Bleed Air System as an Active Surge Control

Centrifugal compressors are widely used throughout various industrial applications, including many safety-critical fields like aircraft engines. Thus, the enhancement of stable operational range is essential, which often requires active surge control methods. This includes state-of-the-art digital electronic measurement system to detect the onset of surge, which is a phenomenon that arises under extreme operational conditions and can lead to either negatively influenced behaviour or even the destruction of the compressor hardware in the case of uncontrolled conditions. Therefore, a strong emphasis must be given to observe impending surge and, if possible, to include an active system that can prevent undesired operational situations. Amongst many passive and active possibilities of surge control, Blade Load Distribution Control (BLDC) can be considered as a method, which creates acceptable influence on instabilities with a minor efficiency loss, consequently, could be applied as an active surge suppression system. The aim of this paper is to investigate feasible solutions on an existing centrifugal compressor test bench, which would enable to examine the theoretical solutions for blade load distribution control.

АНАЛІЗ НАЯВНИХ МЕТОДИК ОЦІНЮВАННЯ ЕФЕКТИВНОСТІ ВЕДЕННЯ НАДВОДНИМИ КОРАБЛЯМИ БОЙОВИХ ДІЙ ЗІ ЗНИЩЕННЯ НАДВОДНИХ КОРАБЛІВ ПРОТИВНИКА

The article analyzes the existing methods for assessing the effectiveness of surface ships’ combat operations to destroy enemy surface ships in the Naval Forces of the Armed Forces of Ukraine, namely, the widely known among naval specialists methodology of Matviychuk F.O. and the temporary methodology for calculations in planning operations (combat operations) using cruise missiles, developed by the Naval Forces of the Armed Forces of Ukraine in 2020. However, the above-mentioned methods allow to obtain the results of the study of the constituent stages of naval combat statically (or discretely), but do not consider its development in dynamics and do not fully take into account the probabilistic nature of events. To simplify and make these methods and individual mathematical calculations closer to the process of combat confrontation in a real sea battle, several restrictions are imposed on them, that is, the limits of application are indicated in the form of hypotheses and assumptions. The article considers modern methods used by the armed forces of NATO member countries: the Relative Combat Power Analysis method, the model Correlation of Forces and the distribution of troops by tasks. It was noted that the processes inherent in the models relate to individual specific operational situations, so they cannot give a detailed and universal picture of the need for forces. These processes are helpful in narrowly defined contexts, mainly for planning land operations. The study determines that the Planning Considerations Method RCPA is used in planning of maritime operations in NATO countries. It is found that using this method, less attention is focused on mathematical ratios of forces and more on the subjective comparison of friendly and hostile tangible and intangible factors, identifying relevant information that must be considered when action plans will be being developed.

“They look at us, former officers, as material that, having used it, can be thrown away...”. An unknown letter from a Soviet military specialist about the betrayal of the headquarters of the 14th army in June 1919

The material is a publication of an unknown letter from a Soviet military specialist, former Captain B.F. Chernihovsky-Sokol, to his classmate at the Military Academy G.I. Teodori about the events of the summer of 1919 in Ukraine. At that time, the situation at the front was unfavorable for the Reds: the Whites have captured the Donbass and launched an offensive in the Kharkov and Yekaterinoslav directions. The 2nd Ukrainian Soviet Army was reorganized into the 14th Army, but the name change and reorganization changed little. The army consisted of partisan units of Makhno and Grigoriev, and the troops lacked weapons and ammunition, since the Whites cut off supplies by rail. As a result of the defeat of the Soviet troops, Yekaterinoslav was abandoned by the Red Army units, and a group of employees of the headquarters of the 14th Soviet Army defected to the Whites. The letter details the circumstances of the surrender of Yekaterinoslav by the Reds. The author outlined the dramatic circumstances of the defense of the city, the confusion and lack of centralization in the management of troops, poor leadership on the part of the commander of the 14th Army K.E. Voroshilov, whose location was unknown, abuse of commissars who took staff cars for personal use, as well as ignorance of the operational situation by the headquarters. Of particular interest are the personal experiences of the author of the letter, who wrote about the plight of the military specialists of the Red Army, the inattention of the command to them, the danger for former officers to be captured by the Whites and other moments. The document is stored in the Central Archive of the Federal Security Service and is being introduced into scientific circulation for the first time.

Организация оказания помощи раненым офтальмологического профиля в современных вооруженных конфликтах: состояние и перспективы

The main feature of modern armed conflicts is the use of new weapons and, as a result, changes in the nature and structure of eye injuries. This feature, on the one hand, and the rapid progress of medical science, on the other hand, require a rapid response to the changing operational situation using the resources of modern ophthalmology in order to provide care to wounded and injured ophthalmic patients efficiently and rationally. There are some differences in approaches to pre-hospital self- and mutual aid to the wounded with ophtalmic injuries on the battlefield in different schools of military medical training and tactical medicine. Some use a binocular bandage, while others use a rigid eye shield. The complexity and variety of visual injuries require good practical skills and experience in order to perform high-quality surgical treatment of perforated corneal and scleral wounds in open eye trauma. This necessitates a thorough training of specialists with practical skills. The issue of medical supply of units providing specialized care at the stages of medical evacuation, which includes a military ophthalmologist, is particularly significant. The problem of reasonable and rational update of the ophthalmological equipment at the stages of medical evacuation requires active discussion. There is still the question of the use of effective protective equipment for the eye during combat operations, which, without limiting visual function, could prevent combat eye injuries, most often caused by small fragments and secondary wounding projectiles.

Деятельность территориальных органов НКВД Дальнего Востока по обеспечению безопасности дорожного движения в 1941–1945 гг.

The publication is devoted to a little–studied aspect of the activities of the internal affairs bodies of the Far East during the Great Patriotic War - providing road safety. The basis of the work is unpublished sources related to the official and party documentation of the regional departments of the NKVD of the Khabarovsk and Primorsky Territories. The methodological basis of the research is the principles of historicism and consistency, as well as general scientific historical and logical methods. The article describes the situation in the field of road safety in the Far East during the period under study, analyzes the causes and conditions of its deterioration, the measures taken by the internal affairs bodies to normalize the operational situation.

Influence of Monitor Current on Electrical Performance of Photovoltaic Module (PERC/HJT/Topcon) in Thermal Cycle Test

IEC 61215-2: 2016 is an international standard about testing photovoltaic (PV) module reliability, in which the thermal cycle (TC) test item mainly has focused on thermal stress interaction of PV modules between different materials. At TC testing different stages, except for high working current (Imp), low current (Max. 1 %*Imp) has been turned on continuously as monitor current in order to evaluate the field operation situation of photovoltaic modules. In this paper, the test programme are designed meticulously and I-V data&EL pictures test results are discussed according to the influence level of monitor current on PERC, HJT and TOPCon modules. Three types of PV modules have performed the respective I-V characteristics and thus the values of Isc, Voc and Pmp have appeared different trends.

PLL-Less Active/Reactive Power Control of Photovoltaic Energy Source with Applying pq-Theory in Single-Phase Grid System

Converter systems are applied to manage active/reactive power control of photovoltaic (PV) source during integration with the electric grid system. The control algorithm of the conventional converter system consists of a reference generation unit, a dc-link voltage control loop, two power control loops and a phase lock loop (PLL) system. PLL unit is used to lock in phase angle of the electric grid, and to perform the coordinate transformation for calculations of the active/reactive powers. However, the control algorithm has a slow dynamic response because of utilisation of a PLL structure. In addition, additional complex mathematical computations are required with the use of a PLL algorithm. Furthermore, the interaction of the PLL and the power control loops may lead power oscillation problems under weak grid, and also result in instability of the PV system. In this study, to avoid the aforementioned issues and to enhance the power flow capability of the grid-connected PV panels, a PLL-less control algorithm in pq-theory is studied for the active/reactive power management and the grid synchronization. In addition, the mathematical formulations of the current control algorithm are presented in detail. To show the effectiveness of the PLL-less controller, a PV system model with using real PV panel groups is designed and constructed in a simulation environment. The proposed control method is tested under various operation cases such as dynamic environmental conditions, reactive power support and voltage variations. The proposed method shows efficient performance under applications of the different operation situations.

Improvement of the method of parametric control of the state of the control object based on the improved firefly algorithm

The problem that is solved in the study is to increase the efficiency of decision-making regarding the state of the control object while ensuring a given reliability, regardless of the object's hierarchy. The object of the study is decision support systems. The subject of the study is the process of assessment and parametric control of the state of the control object using the firefly algorithm. The hypothesis of the study is an increase in the efficiency of assessing the state of the control object with a given reliability. In the course of the study, an improved method of parametric control of the control object based on the improved firefly algorithm was proposed. General provisions of artificial intelligence theory were used for solving the problem of object state analysis and subsequent parametric control in intelligent decision support systems. The essence of improvement is to use the following procedures: − taking into account the type of uncertainty about the state of the control object (complete uncertainty, partial uncertainty and complete awareness); − taking into account the noise of data on the state of the control object. Data noise refers to the degree of information distortion created by the enemy's electronic and cyber warfare; − using the improved firefly algorithm to find the path metric while assessing the state of the control object; − deep learning of the synthesized ants using evolving artificial neural networks. The application of the proposed method is presented on the example of assessing the state of the operational situation of a group of troops (forces). The specified example showed a 17–20 % increase in the efficiency of data processing using additional improved procedures

Improving the method for increasing the efficiency of decision-making based on bio-inspired algorithms

The problem that is solved in the research is to increase the efficiency of assessing the state of the monitoring object while ensuring the given reliability, regardless of the hierarchy of the monitoring object. The object of research is decision support systems. The subject of the research is the process of evaluating the monitoring object using bio-inspired algorithms. The hypothesis of the research is the need to increase the efficiency of the assessment of the state of the monitoring object with the given reliability. In the course of the research, an improved method of increasing the efficiency of decision-making based on bio-inspired algorithms was proposed. General provisions of artificial intelligence theory were used to solve the problem of analyzing the object state in intelligent decision support systems. The essence of improvement is to use the following procedures: − taking into account the type of uncertainty about the state of the monitoring object (full uncertainty, partial uncertainty and full awareness); − taking into account the degree of noise in the data on the state of the monitoring object. Noise refers to the degree of information distortion created by the enemy’s means of electronic and cyber warfare; − using the ant colony optimization algorithm and the genetic algorithm to find the path metric while assessing the state of the monitoring object; − deep learning of synthesized ants using evolving artificial neural networks. An example of using the proposed method in assessing the state of the operational situation of a group of troops (forces) is presented. The specified example showed a 15−22 % increase in the efficiency of data processing using additional improved procedures

THE EFFECTS OF ACCOUNTING MEASUREMENT OF COVID-19 PANDEMIC ON THE BUSINESS INDUSTRIES: EMPIRICAL REVIEW

The Covid-19 global pandemic has affected most companies financially as it has led to massive uncertainties across all sectors and industries. In such situation it requires the refined, and highly integrated accounting information to measure and reflect the economic operation situation and provide early warning to decision makers. The study uses online empirical recourses by the name of Covid-19 pandemic impact on the industries and accounting measurement of the business industries in different online database sources such as Google Scholars, Springer Link, Wiley, Science Direct, JSTOR, Emerald full text, Scopus, and EBSCO HOST. The review findings show that there are different accounting measurement used to measure the impact of Covid-19 on various business industries. The findings of the study also identified that different industries react differently to Covid-19, thus the study findings could be used to draw policy guideline for the industries which were significantly affected by the epidemic.

Problems of functioning of public administration mechanisms concerning the operational monitoring of the state of potentially dangerous objects

The problems concerning functioning of the modern Unified State Civil Protection System were studied, namely: the problems of functioning of a single information environment for the prompt supply of data on monitoring the state of potentially dangerous objects, only partial automation of processes concerning organization of the “dispatcher-applicant” dialogue during regulation passing information in the system of emergency assistance to the population using the single telephone number 112. An analysis of the mechanism of information flow in the system of emergency assistance to the population using the single telephone number 112 was carried out. It was shown that currently only part of the processes related to the organization of the “dispatcher-applicant” dialogue and the display of the operational situation on the electrified plan are automated. It has been proved that the territorial and functional subsystems of the Unified State Civil Protection System currently do not provide proper daily collection, processing, transmission and analysis of information about the probability of emergencies of man-made and natural nature and the development of preventive measures and proposals for their implementation. The need to improve the information mechanism of public administration of monitoring the state of potentially dangerous objects through the development of software complexes based on the functioning of intelligent systems, which are focused on processing unstructured data using Sentiment Analysis methods, has been confirmed.

Techno-economic analysis for the effects of electricity pricing system on the market competitiveness of cogeneration model

In this study, the actual operation status of the cogeneration model was investigated to examine the difference between the theoretical evaluation and the field operation situation. The adequacy of the installed capacity of the cogeneration system was assessed by using in-house developed diagnostic analysis simulation tool, and the effects of operational strategy on securing operational cost benefit under the progressive electricity rate system was also examined with event-based operating characteristic analysis. The installed prime mover was found to be designed excessively by an average of 47%, and the relative primary energy savings showed a large deviation in the range of 3–22% for each case. As a result of analyzing the effect of the rapid expansion of renewable energy on the operational performance, it was found that when the renewable power distribution ratio was increased to 30%, the relative primary energy savings effect fell to less than 5%. As an alternative, a hybrid cogeneration model integrated with heat pump was proposed, and it was confirmed that it could have the effect of mitigating the effect of expanding renewable energy.

Maritime information sharing environment deployment using the advanced multilayered Data Lake capabilities

Establishing an efficient information sharing network among national agencies in maritime domain is of essential importance in enhancing the operational performance, increasing the situational awareness and enabling interoperability among all involved maritime surveillance assets. Based on various data-driven technologies and sources, the EU initiative of Common Information Sharing Environment (CISE), enables the networked participants to timely exchange information concerning vessel traffic, joint SAR & operational missions, emergency situations and other events at sea. In order to host and process vast amounts of vessels and related maritime data consumed from heterogeneous sources (e.g. SAT-AIS, UAV, radar, METOC), the deployment of big data repositories in the form of Data Lakes is of great added value. The different layers in the Data Lakes with capabilities for aggregating, fusing, routing and harmonizing data are assisted by decision support tools with combined reasoning modules with semantics aiming at providing a more accurate Common Operational Picture (COP) among maritime agencies. Based on these technologies, the aim of this paper is to present an end-to-end interoperability framework for maritime situational awareness in strategic and tactical operations at sea, developed in EFFECTOR EU-funded project, focusing on the multilayered Data Lake capabilities. Specifically, a case study presents the important sources and processing blocks, such as the SAT-AIS, CMEMS, UAV components, enabling maritime information exchange in CISE format and communication patterns. Finally, the technical solution is validated in the project’s recently implemented maritime operational trials and the respective results are documented.

An innovative Hardware-In-the-Loop rig for linear PTO testing

This paper describes the activities related to the design, manufacturing and commissioning of an innovative Hardware-In-the-Loop test rig for linear Power Take-Off testing. The rig is characterised by a fully coupled architecture in which three electro-mechanical units integrating a ballscrew and an electrical machine can actuate on a linear axis, either as motor or generator. A preliminary mechanical design of the test rig was carried out by identifying the most demanding conditions. The electrical and mechanical designs were assessed through a de-risking simulation of the overall test rig set-up, considering faults between the motors and respective power converters. The resulting rig setup includes a structure that embeds the three units, an electrical control panel and a control system. The use of electro-mechanical units increases the flexibility of the setup and simplifies the test of extreme conditions such as maximum output power or actuation force. Moreover, it allows reusing the power produced by the generating devices, thus reducing operational costs of the tests. The control system integrates a real-time hardware-in-the-loop simulation platform, a supervisory control and data acquisition systems. Those offer not only the possibility of easily tuning parameters but also testing new control strategies, operational situations, and failures of a power-take-off system in very realistic conditions.

Train Formation Management. Part 1

Long-term regulatory and technological documents related to train formation are often so far from the changing actual operational situation that more trains are being formed than can be provided with locomotives and sent from the station in a timely manner, sections are oversaturated with trains, stations operate with an excess of car fleet, etc. Such unpredictable situations result in unproductive delays of trains, increase the goods delivery time, reduce the use of transit, transportation, and processing capacity of railways. At the same time, reducing the time of validity of regulatory and technological documents can significantly increase the efficiency of operational management of the transportation process. The purpose of the article is to show how the operational management of train formation instead of the passive uncontrolled process of accumulation of trains at marshalling yards expands the possibilities of the train formation plan, eliminates uncertainty and creates optimal conditions for train, marshalling and freight operations.Changes in management of train formation, which are put forward on the basis of generalisation of a number of results of earlier author’s studies and publications and newly formulated proposals for discussion, will make it possible to manage the transportation process in a fundamentally new way: to form such a number of trains that will be provided in a timely manner with locomotives and «threads» of the train schedule; send such a number of trains from the train assembling stations that will not lead to oversaturation of sections with trains; to ensure the arrival of such a number of trains at marshalling yards that will allow them to work in the optimal mode; to ensure the parity of arrivals of even and odd trains at locomotive change stations; to help in a timely manner with the selection of wagons cars in case of difficulties in the work of freight stations, etc. [1].

ВОПРОСЫ БЕЗОПАСНОСТИ В ИСПРАВИТЕЛЬНЫХ УЧРЕЖДЕНИЯХ

The article deals with the issues of security in correctional institutions, consisting of ensuring the safety of correctional officers and the safety of the convicts themselves. Ensuring security depends on the ability and ability of correctional personnel to prevent crime and criminal behavior of subjects in places of deprivation of liberty. In order to effectively prevent crimes and ensure the safety of convicts, constant monitoring of the operational situation in the institution is necessary.

A Comparative Study of LSTM Variants in Prediction for Tesla’s Stock Price

Long short-term memory (LSTM) is widely used in the stock market to train the prediction model and forecast future stock prices. Applying the LSTM method to research may incur some problems and facilitate the improvement of the method. Therefore, many LSTM variants are put forward under different circumstances. This paper surveys four LSTM variants, including Vanilla, Stacked, Bi-directional, and CNN LSTM on two different data sets regarding Tesla's stock price. Two data sets mentioned in this paper represent different stock types. To be more specific, data set 1 refers to stocks with a single long-term trend, while data set 2 can be seen as an example of stocks with more complexity. The result shows that the Vanilla LSTM reaches the highest prediction accuracy on the data set without any irregular shift in the long-term trend. CNN LSTM also provides decent predictions for the stock price. Otherwise, the Stacked LSTM performs the best for stock prediction. Bi-LSTM and CNN LSTM are also suitable for stock forecasting in more complicated situations. The change in preference for model selection proves that a company's operation situation and market circumstances also influence the prediction performance of LSTM variants.

The Prospects and Risks of Artificial Intelligence Industry

Nowadays, with the rapid development of scientific and technological information, artificial intelligence has gradually penetrated into people's lives and become an indispensable part. The purpose of this article is to understand and analyze the artificial intelligence industry, and further make suggestions and improvements on its potential risks and prospects. This paper mainly studies the prospects and risks in the field of artificial intelligence, and analyzes them from different perspectives by analyzing the leading enterprises in three fields of artificial intelligence. This paper adopts PEST analysis method to understand the macro trend of artificial intelligence by analyzing the industry, and then analyzes the financial reports of these three companies to comprehensively understand the operation situation and potential risks of these three companies by analyzing four financial indicators. According to the overall analysis of the article, Iflytek and Topband have a better prospect, while TRS and Iflytek are riskier. Topband had the lowest liquidity risk, followed by TRS and finally Iflytek.

Development of force and communication management methodology using resource optimization methods in military (force) operations

The most characteristic features of the construction of communication systems of groups of troops (forces) during the conduct of hostilities (operations) are a high level of a priori uncertainty regarding the operational situation and a small amount of initial data for communication planning. In such conditions, it is important to correctly choose the apparatus for evaluating the made management decisions, which will allow the officials of the points of the control system of the communication system of the groups of troops (forces) to be confident in the made decisions. That is why the issue of increasing the effectiveness of the management of forces and devices of communication of groups of troops (forces) during operations is an important and urgent issue. The object of the research is the communication system of the group of troops (forces). The subject of the research is the effectiveness of the communication system of the grouping of troops (forces) in accordance with the purpose of the operation. The research developed a method for managing forces and devices of communication using methods of resource optimization in the operations of troops (forces). The novelty of the proposed method consists in taking into account the type of uncertainty regarding the operational situation in the operational space. Also, taking into account the number of members of the grouping (consumers of communication services) of groups of troops (forces) in operations. The novelty of the developed method consists in taking into account the duration of the operation (fighting) and the calculation of the labor costs necessary to meet the needs of the communication services of groups of troops (forces) while planning measures for the distribution and use of forces and devices of communication. The specified method is proposed to be implemented: – in planning documents during planning the deployment and operation of forces and devices of communication; – in the software during operational management of the communication system of troop groups.