Forensic Construction Investigation of Reconstructed Premises

The article addresses solving the issue of the possibility of preserving reconstructed premises or carrying out proposed reconstruction works in the course of in the course of construction forensic investigation. The significance of the problem attributes to the volume of the stock of residential and public buildings which are older than 40 years (according to statistics, the housing stock of Russia in 1980 was 1,861 million m2 , in 2015 – 3,581 million m2 ), outdated layouts of premises, and the evolved consumers’ idea of comfort.A construction expert’s task is to determine if there is a possibility to change the layout, the function of premises to improve living conditions, or reconstruction poses a threat to the state of the object, its further proper operation, the integrity of the installed engineering systems, the appearance of the facades, nearby buildings and structures. Using regulatory material, the authors consider the criteria for solving this problem, present the procedure for conducting studies of buildings or structures, building materials, structures, and relevant documents in this line of forensic construction examination. Finally, the article gives specific examples of the redevelopment of apartments, a proposed reconstruction of the kindergarten premises.It is noted that the reliability of experts’ opinions is based on a comprehensive, unbiased analysis of all the technical and economic characteristics of construction objects, verification of documentation, an inspection of structures for compliance with the requirements of federal laws, rules, and regulations.

Operation Analysis of Selected Domestic Appliances Supplied with Mixture of Nitrogen-Rich Natural Gas with Hydrogen

This article presents the results of the testing of the addition of a hydrogen-to-nitrogen-rich natural gas of the Lw group and its influence on the operation of selected gas-fired domestic appliances. The tests were performed on appliances used for the preparation of meals and hot water production for hygienic and heating purposes. The characteristics of the tested gas appliances are also presented. The burners and their controllers, with which the tested appliances were equipped, were adapted for the combustion of Lw natural gas. The tested appliances reflected the most popular designs for domestic gas appliances in their group, used both in Poland and in other European countries. The tested appliances were supplied with nitrogen-rich natural gas of the Lw group, and a mixture of this gas with hydrogen at 13.2% content. The article presents the approximate percentage compositions of the gases used during the tests and their energy parameters. The research was focused on checking the following operating parameters and the safety of the tested appliances: the rated heat input, thermal efficiency, combustion quality, ignition, flame stability, and transfer. The article contains an analysis of the test results, referring, in detail, to the issue of decreasing the heat input of the appliances by lowering the energy parameters of the nitrogen-rich natural gas of the Lw group mixture with a hydrogen addition, and how it influenced the thermal efficiency achieved by the appliances. The conclusions contain an explanation regarding, among other things, how the design of an appliance influences the thermal efficiency achieved by it in relation to the heat input decrease. In the conclusions, on the basis of the research results, answers have been provided to the following questions: (1) Whether the hydrogen addition to the nitrogen-rich natural gas of the Lw group will influence the safe and proper operation of domestic gas appliances; (2) What hydrogen percentage can be added to the nitrogen-rich natural gas of the Lw group in order for the appliances adapted for combusting it to operate safely and effectively, without the need for modifying them?

Polarization control algorithm for QKD systems

The crucial task for polarization-encoding fiber QKD is to compensate polarization drift occurring in a quantum channel. To solve this problem, the receiver usually uses a polarization controller. For proper operation, this device must be efficiently managed in real-time. In this work, a gradient-descent-based algorithm is proposed to solve this problem. The algorithm was implemented and tested on a QRate commercial QKD fiber system, that utilizes BB84-protocol. Low and stable QBER has been obtained during a day of continuous operation.

Lithium-Titanate As Electrode Material for Aprotic Systems

This article briefly describes experiments which investigate the mutual compatibility of aprotic solvents with higher fire safety and Lithium Titanate Oxide (LTO) as the negative electrode material for lithium-ion batteries. The work follows the current trend of enhancing fire safety by using new kinds of aprotic solvents along with a new generation of electrode materials which fulfil the intended using of lithium-ion batteries for high power applications, e.g. electric vehicle propulsion. In our work, the examiner of using sulfolane electrolyte (SL) and Li4Ti5O12 (LTO) under various ambient temperatures. The influence of electrolyte on the proper operation and stability of negative electrode material was considered. The measurements were performed in the temperature range from 25 °C up to 80 °C with half-cell connection. Our main objective of these experiments was to prove and investigate a proper operation of an aprotic electrolyte with higher fire safety together with LTO negative material under high ambient temperatures.

Identifying Influential SLD Authoritative Name Servers on the Internet

DNS plays an important role on the Internet. The addressing of most applications depends on the proper operation of DNS. The root servers and the top-level domain servers are relied upon by many domains on the Internet, and their security affects the whole Internet. As a result, more attention has been paid to the security of servers at these two levels. However, the security of second-level domains and their servers also needs to be brought to the forefront. This paper focuses on showing the complex resolving dependencies and identifying influential name servers for second-level domains. We start by detecting domain name resolution paths and building up a name dependency graph. Then we construct domain name resolution networks of different numbers and sizes, which are connected by a certain number of domain name resolution graphs. On this basis, the network is analyzed from the perspective of complex network analysis, and a multi-indicators node importance evaluation method based on partial order is proposed to identify the influential name servers of the network. Once these name servers are not properly configured and fail or are compromised by DDoS attacks, it will cause resolution failure for a wide range of domain names.

Reliability and Availability Study of a Gas Turbine based on usual Approaches with a Failure Mode Analysis

The rotating machines like gas turbine types are highly valuable in the gas transportation industry. They are often strategic and have a major impact on the proper operation of gas transport and compression facilities. In this context, the aim of this work is to increase efficiency and production by developing an approach for this kind of installations using real data collected from the operation of the gas turbine. The objective is to provide a database relating to the reliability, availability, and maintenance of gas turbines while using standard reliability approaches. In addition, ensuring maximum availability of this type of rotating machine by preventing its failures and reducing emissions, and by minimizing start-up sequences, which reduces emissions when starting this machine. Also, the proper operation of these gas turbine installations with the reliability approaches developed in this work makes it possible to model the effects of failures in order to predict optimal operating performance and increase the life of their components. This, therefore, ensures a reliable and safe operation of the gas turbine in a compression station for economically profitable gas recovery.

Improve PBFT Based on Hash Ring

Aiming at the problems of practical Byzantine fault tolerance (PBFT) algorithm, such as high communication complexity, frequent switching views because of Byzantine node become primary nodes and random selection of primary node, HR-PBFT algorithm is proposed. First, the HR-PBFT algorithm uses a hash ring to group nodes, which ensures the randomness and fairness of the grouping. Then, a dual-view mechanism is used in the consensus process, where the first layer node maintains the primary view and the second layer node maintains the secondary view to ensure the proper operation of the algorithm. Finally, the Byzantine node determination mechanism is introduced to evaluate the node status according to the node behavior in the consensus process, improve the reliability of primary node selection, and reduce the frequency of view changes. The experimental results show that the optimized HR-PBFT algorithm can effectively improve the problem of the sharp increase in the number of communications caused by the increase in the number of nodes in the network and prevent frequent view changes.

The Concept of Implementation of Multifrequency RFID System Industrial Involvement in Laboratory Conditions

People have been dealing with the correct identification of objects for a long time. In industry, we cannot avoid this area, whether it is to identify people, semi-finished products or final products. Therefore, this article deals with the design of a multifrequency RFID system for industry 4.0. The idea of the article is to implement one type of identification technology for tracking objects using the radio frequency spectrum at different wavelengths. We have based our design on the built industrial-assembly line in the SmartTechLab laboratory, where we have implemented LF, HF and UHF systems connected by an industrial PLC into a complex system. In this article, we gradually focus on the selection of RFID systems, their cooperation and the design of connection to one portable box. Using an RFID box, we can monitor different types of objects and verify RFID reading using a single reading device or by creating portal RFID gateways. The implemented system consists of four middleware and four independent antennas that can cooperate. For proper operation, there is necessary implement not only hardware but also necessary software. The system can identify RFID tags in the range of 1 cm to several meters. Also, the advantage of the design is that it identifies all types of tags (industry, label, ceramic, laundry, paper). One of the main benefits of the design is modularity, mobility and the creation of a robust design that can be used for measurements in companies and also for educating students in laboratory conditions. The whole system is designed to meet the requirements of Industry 4.0 and improve the competitiveness of businesses.

Low-orbit satellite grouping of the system for monitoring geodesic parameters of the Earth and the direction of its development

Спутниковые миссии наряду с наземными геодезическими сетями различных космических технологий являются второй важной составляющей российского сегмента системы контроля геодезических параметров Земли (ГПЗ). Спутники имеют неоспоримое преимущество в том, что они непрерывно собирают однородные данные над большими частями земной поверхности. Они позволяют сбор данных, которые не могут быть зарегистрированы на поверхности Земли. Такие спутники в наше время оборудованы множеством датчиков, контролирующих поверхности суши, океана и льда, а также гравитационное поле Земли и его временные изменения. Потенциал и влияние спутниковых миссий для наблюдений Земли значительно возрастут в связи с тем, что: (1) будут запускаться все больше и больше спутниковых созвездий, вместо отдельных спутников, увеличивая тем самым временное и пространственное разрешение получаемых данных; (2) спутники будут летать в «формированиях», образуя большие наблюдательные приборы, состоящие из датчиков, расположенных на нескольких спутниках. В работе автор, с учетом рекомендаций международного геодезического сообщества, предлагает набор низкоорбитальных спутниковых миссий различных направлений, необходимых для полноценного функционирования системы контроля ГПЗ, и рассматривает направления развития данных миссий. Satellite missions, along with ground-based geodesic networks of various space technologies, will be the second important component of the Russian segment of the system for monitoring geodesic parameters of the Earth (GPE). Satellites have the undeniable advantage of continuously collecting uniform data over large parts of the Earth’s surface. They allow the collection of data that cannot be registered on the Earth’s surface. Such satellites are now equipped with a variety of sensors that monitor the surface of land, ocean and ice, as well as the Earth’s gravitational field and its temporal changes. The potential and impact of satellite missions for Earth observations will increase significantly as: (1) more and more satellite constellations will be launched, instead of individual satellites, thereby increasing the temporal and spatial resolution of the data received; (2) satellites will fly in “formations”, forming large observation instruments consisting of sensors located on several satellites. In this article the author taking into account the international geodetic community recommendations proposes a set of low-orbit satellite missions to various areas, necessary for proper operation of the system for monitoring GPE, and the directions of development of these missions are considered.

Passive Fault-Tolerant Control of a 2-DOF Robotic Helicopter

The presence of faults in dynamic systems causes the potential loss of some of the control objectives. For that reason, a fault-tolerant controller is required to ensure a proper operation, as well as to reduce the risk of accidents. The present work proposes a passive fault-tolerant controller that is based on robust techniques, which are utilized to adjust a proportional-derivative scheme through a linear matrix inequality. In addition, a nonlinear term is included to improve the accuracy of the control task. The proposed methodology is implemented in the control of a two degrees of a freedom robotic helicopter in a simulation environment, where abrupt faults in the actuators are considered. Finally, the proposed scheme is also tested experimentally in the Quanser® 2-DOF Helicopter, highlighting the effectiveness of the proposed controller.