Індекс рубрикатора НБУВ: З965.3 я431(0)

Рубрики:

Електричні системи автоматики

Шифр НБУВ: ВА868561 Пошук видання у каталогах НБУВ 

Шифр НБУВ: Ж25371 Пошук видання у каталогах НБУВ 

Розглянуто одну з важливих проблем сучасної реології полімерних матеріалів - можливість опису деформації аморфних полімерів у межах лінійних реологічних співвідношень між відносною деформацією та деформуючим напруженням або необхідність використання нелінійних реологічних рівнянь. Обговорено також критерії розмежування цих підходів - визначення відповідних критичних значень макро- та мікрофізичних характеристик матеріалу та умов проведення механічних випробувань. Зокрема, відмічено різницю між впливами кінетичних і термодинамічних нелінійних ефектів на закономірності процесів деформації аморфних полімерів у теплому та замороженому станах. Проаналізовано вплив нелінійних ефектів на загальний вигляд і характеристики окремих стадій діаграми "відносна деформація - деформуюче напруження" при деформуванні зразків полімера з заданими значеннями швидкості деформації та температури. Результати теоретичного аналізу використано для фізичної інтерпретації загальної форми й особливостей окремих стадій діаграм розтягу аморфних плівок полііміду (V. D. Natsik, Y. V. Rusakova, S. V. Lubenets, V. A. Lototskaya, and L. F. Yakovenko, Fiz. Nyzk. Temp. 49, 569 (2023) [Low Temp. Phys. 49, 521 (2023)], одержано емпіричні оцінки для реологічних характеристик цього полімера.

This study modelled an electric vehicle fire on the example of a Tesla Model S (USA) in a closed car park. Such fires pose an increased danger due to their rapid spread, the presence of a large number of vehicles, the release of toxic combustion products and heavy smoke. In fact, the rapid spread of a fire in a closed car park is caused by unreasonably small distances between vehicles. Thus, the purpose of the study was to determine the minimum fire protection distances due to an electric vehicle fire in a closed car park using the example of Tesla Model 3. For this purpose, the objects and their physical characteristics were described, input and environmental parameters were set, and a mathematical model of the dynamics of fire development was formed. This made it possible to establish the minimum fire protection distance during the free development time of 610 s for an electric vehicle fire in a closed car park, which is 10 m along the flank and 6 m along the front. The difference in fire protection distances on the flank and front is explained by the design features of the electric vehicle. That is, the flank area of the flame will be larger than the front of the burning electric vehicle, and therefore the heat radiation power will also be greater. The actual heat radiation power is the key factor affecting fire protection distances. The results of the study can be used in the design of various types of car parks and the safe placement of vehicles in them. Fire protection distances between cars in enclosed car parks can be taken into account by insurance companies when assessing the risk of damage to cars due to fires. And also by fire and rescue units involved in extinguishing such fires, to ensure the safety of rescuers.

By applying the probabilistic method and optimization synthesis of flexible technological lines, topological models have been built of safety-oriented management of human flows and evacuation time using the "Arena Lviv" stadium as an example. They are necessary to calculate the time of evacuation of people to a safe zone. When people leave the stadium sectors on the promenade, their flow is significantly modified. Therefore, the calculation of the time of evacuation of people requires the use of different procedures depending on the type of human flow in order to obtain more accurate results. There may be several such cases on one evacuation route and significantly more during the evacuation of people from all sectors and premises of the stadium administrative building as a whole. Thus, a lot of time is spent on choosing the right procedure and initial data for calculation if we use existing classical verbal models, which is their disadvantage. Verbal models have a large volume, they need to be repeatedly re-read in order to determine the numerical values of factors affecting the flow of people while topological models are much more compact. Topological models make it possible to visually present more complete information about the evacuation process, and this makes it possible to quickly select the initial data for calculating the time of evacuation of people at the next evacuation site. The time of evacuation of people from the "Arena Lviv" stadium was calculated; the evacuation system happened to not comply with the accepted standards. In particular, the time of evacuation of people from the structure exceeded eight minutes. Using the critical path method, bottlenecks of the stadium evacuation system were identified, and human flows were redistributed, which made it possible to reduce the total evacuation time to acceptable indicators.

Research of the impact of information technology on the environment, analysis of ways to solve ecological problems by Green Computing, consideration of the largest IT companies' participation in the implementation of "green technologies". Methods of analysis of literature sources on the issue, scientific articles and publications were used during researching the problem of the impact of information technologies on the environment. A list of Green Computing areas that have a significant impact on reducing energy consumption and environmental pollution through the spread of information technologies has been defined. The conducted research demonstrates that today, companies, which produce computer equipment, pay a lot of attention to reducing environmental pollution by recycling components with completed life cycle. Minimization of emissions into the environment, decreasing energy consumption and implementing virtualization and cloud technologies in workflows. It has been determined that significant carbon emissions into the atmosphere occur due to the manufacturing computing equipment and the production of the energy required for the functionality of data centers. The technological cycle of computer production causes the problem of toxic waste electrical and electronic equipment, which deteriorates the hydro-sphere and lithosphere. Green Computing is responsible for the design, manufacture, use and disposal of computers, servers and their hardware to consume energy efficiently with minimal environmental impact. Modern IT corporations introduce new methods of computer equipment development, which improve ecological security and increase manufactory productivity. Green Computing includes virtualization and cloud computing. Throughout the analysis of the participation of IT corporations in the implementation of "green technologies", the achievements of Facebook, Google and Microsoft in setting up data centers in different parts of the world and even underwater were considered. Apple, Intel, AMD companies are to improve the environmental friendliness of products and production.

Purpose. To determine the correlation between adhesion tightness of filtering half-masks and anthropometric indices of employees' faces. Methodology. To study tightness of the half-mask adhesion to a user's face, a coefficient of NaCl aerosol test was determined in accordance with the requirements by DSTU EN 149:2017 (EN 149:2001 + A1:2009, IDT). Volunteers took part in the testing selected in keeping with the parametric table divided into 12 settings along the face length and across its width. The tests were carried out using Respi and Standart respirators produced in lots by SPE Standart ltd. Findings. It has been identified that the tested filtering half-masks correspond to the standards by DSTU EN 149:2017 (EN 149:2001 + A1:2009, IDT) and provide adequate protection of respiratory organs of users against harmful aerosols. It has been demonstrated that the required half-mask adhesion to a face depends upon the obturator design, half-mask geometry, and stretching force of a headband. It has been proved that employees with small faces require the instrumental verification of the preferred half-mask while selecting respiratory protective equipment. In turn, for users with large faces quality control is quite sufficient by means of any suitable method described by DSTU EN 529:2006 (EN 529:2005, IDT). Individuals with large faces have demonstrated the greatest values of the tightness coefficient of filtering half-mask adhesion. Originality. It is represented by the scientific substantiation of the tightness coefficient of filtering half-mask adhesion upon the length and width of users' faces. Practical value. Mathematical expressions have been derived making it possible to calculate the tightness coefficient of the half-mask adhesion relying upon the face size. The abovementioned will help assess preliminarily protective characteristics of respirators without specific laboratory equipment.

Індекс рубрикатора НБУВ: З970.632

Рубрики:

Комп'ютерне оброблення зображень

Шифр НБУВ: Ж24320 Пошук видання у каталогах НБУВ 

Street lighting is very important now-days especially at dangerous areas and highways but it consume a lot of power and it became challenging for many researchers in the past few years. Enormous efforts have been placed on the issue of reducing power consumption in illuminating cities and streets, researchers had various approaches and methods in tackling this challenging matter, till now there is no ideal system that has been developed to reduce the electricity usage. In this paper intelligent controller based on deep learning proposed to control the light at the street from sunset to sunrise, the system will decrease the light used to illuminate the streets in the absence of movements, the network trained based on deep learning with several image of different objects to help the system detecting any moving objects in the street to provide the street with the exact amount of light needed in order to reduce the waste of electrical energy resulting from street lighting and to help reduce accidents hence high percentage of criminal activity and life threatening conditions occur in the absence of light. The system was trained with a vast and diverse dataset to assure the accuracy and efficiency of the proposed system, the trained system showed a result of 90 precision of detecting moving objects, the proposed system was tested with a new dataset to assure the reliability and dependency of the system and reducing the errors to the minimum, the system shows promising results in detecting movements and objects, after the detection being complete, the system will send a pulse width modulation causing a 20 % light dimming, leading to enormous reduction in the power consumption, adding to that the proposed system is easy to use.

The survey explores the potential for the creation of sun oriented cells from Kazakhstani p-type semiconductors, filtered by a metallurgical strategy utilizing the benefits of the mono-like innovation. As per the exploratory information, it tends to be seen that the successful lifetime shows low markers on the solar element taken from the upper piece of the ingots before the gettering system. This applies to multi-glasslike silicon cells. After phosphorus dispersion, an expansion in complete viability should be visible, which doesn't rely upon the material under study. Generally speaking, a decrease in the effective lifetime of charge carriers in silicon can happen because of the presence of a lot of metal impurities, which can create formations in the form of deposits in crystal defects or dissolve in silicon. It is shown that silicon developed by the mono-like innovation has a more drawn out transporter lifetime contrasted with standard mc-Si. Likewise, it was shown that during the time spent making a solar element, the lifetime of charge transporters builds because of the gettering impact without extra refinement processes. The benefits of the created innovation were seen at the degree of sunlight based cells, appeared in an expansion in proficiency and a reduction in the conveyance of effectiveness along the ingot level. All in all, it is shown that a solar cell made of mono-like silicon has a fairly low corruption of productivity when presented to light. Mono-like silicon sooner rather than later may turn into a forward leap in the photovoltaic business because of the great potential for the development of sunlight-based cells with high proficiency and a critical decrease in expenses.

Болгарський туризм робить значний внесок у економіку країни. У зв'язку з цим азартні ігри як потреба сучасної людини мають власне важливе місце в регіональному секторі туризму та розваг, як і в інших розвинених країнах. Справляння податків і зборів є для країн основним шляхом поповнення державного бюджету, і болгарський сектор азартних ігор не є винятком. Постановка проблеми. Лотерея займає ключовий сегмент грального бізнесу. Створення та розвиток Національної лотереї було фінансово мотивованим. Уряд побачив шанс зібрати значні кошти до державної скарбниці та інвестувати їх у нові проекти. Однак державні гроші, що надходять із грального бізнесу, повинні спрямовуватися також і на благодійні потреби. Аналіз останніх досліджень та публікацій. Більшість матеріалів та досліджень, що стосуються сектору лотерей та азартних ігор, було опубліковано в останні десятиліття науковцями з провідних країн. Дослідженню підлягали такі питання, як певні категорії, що стосуються інтересів соціальних структур, задіяних в секторі азартних ігор; деякі визначення, пов'язані з азартними іграми, їхніми елементами та мотивами. Деякі проблеми, ідеї та рішення обговорювались у низці доповідей та на наукових конференціях, що проводились різними установами та організаціями. Це дослідження має на меті коротко висвітлити та представити наукову перспективу щодо елементарної логіки, принципів та важливих фінансових причин генезису лотерейного бізнесу та розвитку букмекерського бізнесу. Метод або методологія проведення дослідження. У цьому дослідженні використовуються дані та джерела, відібрані на основі різних методів та підходів, таких як спостереження, аналіз, синтез, систематизація та узагальнення інформації; професійні дослідження; вивчення об'єктів і цілей; аналіз тенденцій; статистичний аналіз різних баз даних; статистика та джерела даних. В дослідженні порівнюється досвід та практика провідних європейських ринків лотерейного бізнесу із умовами, що склалися в Болгарії. Крім того, предметом аналізу є деякі економічні та фінансові проблеми, що постають перед сектором. У 2019 році валовий дохід загального європейського ринку азартних ігор (лише для країн ЄС-27 та Великобританії) склав 98,6 млрд. євро, у т.ч. від онлайн-ігор - 24,5 млрд. євро. Частка ринку азартних ігор в інтернеті стабільно зростає і, як очікується, до 2025 року в Європі вона досягне 33,6 % валового доходу від азартних ігор. Висновки: дохід від податку на азартні ігри та букмекерську діяльність разом із доходом від Національної лотереї, широко відомим як "безболісний податок" (через його добровільність), є величезним фінансовим ресурсом, що надходить до державних бюджетів від цих ефективно регульованих ринків. Відповідно до керівних принципів ОЕСР, регулювання конкурентного середовища не повинно надмірно дискримінувати державні підприємства порівняно з їхніми ринковими конкурентами. Проте в результаті "доопрацювання" законодавства у лютому 2020 р. ситуація в болгарському лотерейному бізнесі зазнала певних змін, що відбилося на монопольному становищі компанії "BSL" на ринку лотерейних та миттєвих лотерейних ігор.

This research addressed the issue of improving the quality of service for the control system of mobile radio networks. The analysis of the forecasting sphere concerning the methods of service quality of mobile radio networks for special purposes, in particular, forecasting the time of congestion of data transmission routes is carried out. It is found that these methods are used in wired and computer networks operating at the network and data link levels. The basic parameters of the protocols of the channel and network layers of mobile radio networks are highlighted. Forecasting methods are analyzed: temporal extrapolation, causality, expert, and the main disadvantages are indicated. A model of a control system for mobile radio networks with a forecasting subsystem is shown. The features of mobile radio networks, which form the requirements for routing methods, are described. A lot of requirements have been put forward for the model of a control system for mobile radio networks. The structure of a model of a control system for mobile radio networks with an improved forecasting subsystem is proposed. On the basis of genetic algorithms, the tasks that arise in the process of identification, training and forecasting in the forecasting subsystem are solved. The operation of the processes consists in building a base of rules aimed at identifying significant dependencies in a time series based on the use of a genetic algorithm. It is based on the use of evolutionary principles to find the optimal solution. Application of the proposed model will allow real-time identification and will significantly improve the quality of service for mobile radio networks. It will increase the speed and volume of data processed during training, improve the quality and reliability of predicting changes in data transmission routes.

Індекс рубрикатора НБУВ: Л288.56

Рубрики:

Сполуки ванадію

Шифр НБУВ: Ж100357 Пошук видання у каталогах НБУВ 

Multifruit juicers are designed, constructed and improved to be able to process pineapples, oranges and watermelons efficiently. Little juice manufacturers need both a small and efficient device for juice extraction for being economically concurrent compared to big corporations. The authors of the represented paper aim to present the experimental device for juice extraction, its effectiveness, and functional. This device was created using the compressive and compressive shear forces conveyed by an auger conveyor system as a working power. The juicer consists of a hopper, a screw conveyor shaft, a filter screen, a juice outlet, gearbox housing, and a motor. The analysis of the component design enabled the authors to use the data in order to identify the sizes, manufacture and assemble the machine. The authors have made a lot of tests to detect the efficiency and functionality of the presented device. Tests of the device productivity were carried out using watermelons loaded into the device both peeled and unpeeled. Percentage of juice yield, juice extraction efficiency and extraction losses were used as performance indicators. Productivity analysis results revealed that a fruit type and peel condition reliably influenced productivity indicators at the value of 1 %. The percentage of juice yield from peeled and unpeeled water-melons constituted 89,5 % and 89,7 %, respectively. Extraction efficiency constituted 96,6 % for peeled watermelons and 97,1 % for unpeeled ones. Extraction losses amounted to 2,9 % and 2,6 % correspondingly. The proposed device is easy to use and maintain, therefore, it will perfectly suit the needs of small fruit juice manufacturers and can help to get economic efficiency to the small manufacture

Purpose. Feasibility of completely dispensing with solar collectors (SCs) that are used in heat pump (HP) systems for hot water in cold areas. Methodology. Since the temperature of gearbox oil is relatively high, lots of heat can be exploited. Therefore, the recovery of this unutilized heat from gearbox oil temperature of a wind turbine shows a promising solution in improving heat pump (HP) efficiency for hot water especially in cold environment or the district that is located in the north of our planet where the solar energy is very low. This investigation focuses on the feasibility of direct conversion of mechanical energy harvested from the wind speed into thermal energy by exploiting only the friction phenomenon inside the gearbox of the wind turbine by completely dispensing with solar collectors (SCs) that are used in combined solar assisted heat pump (SAHP) because the SCs have various problems, such as large heat loss, low efficiency, freezing and tube-burst, which may limit their applications. Findings. Results show that the wind turbine can provide the power required for HP during the winter season due to high wind speed in Xuzhou city, Jiangsu, China particularly in January. At best, coefficient of performance (COP) may reach 4,08 without SCs, thus the suggested system ensures high COP in addition to decrease in the fuel consumption by 23,25 %. Originality. Wind power driven HPs have been suggested in many pervious papers as a sustainable measure to provide heat to a house; however, to improve COP of HP system, we suggest using a wind turbine to directly drive the HP and exploit gearbox oil temperature in an assistant heat exchanger installed after the HP evaporator for providing additional thermal energy to refrigerant R12 and cooling the gearbox oil. Practical value. The coefficient of performance (COP) of HP has reached 4,08 without SCs, so the suggested system demonstrates high COP in addition to the reduced fuel consumption. Approximately 23,25 % of energy could be saved using this novel system compared to a fuel water heater for DHW.

A Software-Defined Network (SDN) on a Wide Area Network (WAN) is a computer network that is controlled and created by software. SD-WAN is an emerging research area that has received a lot of attention from industry and government. This technology offers tremendous opportunities to support the creation of consolidated data centers and secure networks. This is an innovation that allows the network to be monitored and programmed so that it can respond to network events caused by security breaches. This solution provides network security, offers a single network management console, and provides complete control over the network architecture. Also controls security in the cloud software-defined infrastructure (SDI), such as dynamically changing the network configuration when forwarding packets, blocking, redirecting, changing Media Access Control (MAC) or Internet Protocol (IP) addresses, limiting the packet flow rate etc. Using SD-WAN technology, it is possible to reduce the cost of dedicated bandwidth channels, achieve a high-quality Virtual Private Network (VPN), and the ability to automatically select a channel for certain channels. The main advantages of SD-WAN are the management of an unlimited number of devices from a single center, reducing the cost of deploying branch infrastructure. According to the results of the survey, 7 % of respondents use SD-WAN for security solutions, 14 % at the piloting stage. As a result of the research, it was revealed that by 2024, to increase the flexibility and support of cloud applications, more than 60 % of SD-WAN customers will implement the SASE (Secure Access Service Edge) architecture, which is 30 % more than in 2020 and the main concept - application security and cloud functions.

Індекс рубрикатора НБУВ: К663.6-18 + З361-04

Рубрики:

Інші види покриттів металів

Парові котли.Котлобудування

Шифр НБУВ: Ж24320 Пошук видання у каталогах НБУВ 

Обґрунтовано теоретичні, методичні та методологічні засади статистичного оцінювання національного ринку логістичних послуг. У ході дослідження уточнено зміст понять "логістична послуга" та "логістичний потік". Виявлено особливості структурування ринку логістичних послуг на основі виділення переліку видів економічної діяльності, що належать до сфери надання логістичних послуг. Ідентифіковано систему статистичних показників дослідження ринку логістичних послуг, висвітлено результати статистичного оцінювання цього ринку в Україні. Окреслено cегментацію ринку логістичних послуг, перспективи та визначено економічний ефект від упровадження інформаційних технологій, таких як loT-технології для національного ринку логістичних послуг. Запропоновано оцінювати ефективність регіональної логістики в Україні з використанням розробленої анкети, гармонізованої з анкетою оцінки індексу ефективності логістики. Здійснено багатовимірне групування регіонів України за рівнем та потенціалом розвитку ринку логістичних послуг. Виявлено ключові фактори розвитку ринку логістичних послуг в Україні на основі побудованої моделі головних компонент, а також виконано моделювання та прогнозування ключових статистичних показників розвитку ринку логістичних послуг.

The study of the metrological risks of the car cables' production is provided in the current issue. It is proposed to develop several different sampling methods to form lots for the study. Their capabilities are evaluated according to selected criteria based on the available technology. The advantages of the dynamic method according to the possibilities of operative metrological workshops are shown. Certain advantageous factors of the method (e.g. percentage of cables to be measured; the lot's waiting time, etc.) have been identified.

One of the key processes in software development and information security management is the evaluation of vulnerability risks. Analysis and evaluation of vulnerabilities are considered a resource-intensive process that requires high qualifications and a lot of technical information. The main opportunities and drawbacks of existing systems for evaluation of vulnerability risks in software, which include the lack of consideration of the impact of trends and the degree of popularity of vulnerability on the final evaluation, were analyzed. During the study, the following information was analyzed in the structured form: the vector of the general system of vulnerability evaluation, the threat type, the attack vector, the existence of the original code with patches, exploitation programs, and trends. The obtained result made it possible to determine the main independent characteristics, the existence of a correlation between the parameters, the order, and schemes of the relationships between the basic magnitudes that affect the final value of evaluation of vulnerability impact on a system. A dataset with formalized characteristics, as well as expert evaluation for further construction of a mathematical model, was generated. Analysis of various approaches and methods for machine learning for construction of a target model of dynamic risk evaluation was carried out: neuro-fuzzy logic, regression analysis algorithms, neuro-network modeling. A mathematical model of dynamic evaluation of vulnerability risk in software, based on the dynamics of spreading information about a vulnerability in open sources and a multidimensional model with an accuracy of 88,9 %, was developed. Using the obtained model makes it possible to reduce the analysis time from several hours to several minutes and to make a more effective decision regarding the establishment of the order of patch prioritization, to unify the actions of experts, to reduce the cost of managing information security risks.