Complicated Technical Systems Research Articles

Overheating and Air Velocities in Modern Office Buildings During Heating Season

Proper design and operation of buildings are expected to result in optimal thermal comfort and energy performance at the same time. If occupants are not satisfied with thermal conditions, corrective actions by building managers and maintenance staff may lead to elevated room temperatures with evident energy penalties. Because of complicated technical systems and control logic, it is worth studying how well the design intent has been realised in new office buildings. In this study, thermal comfort was analysed by measurements of draught, room, and supply air temperature as well as with occupant questionnaire surveys in five modern office buildings. Both short‐ and long‐term measurements were conducted to demonstrate problems in the operation and to find potential solutions for improvement. The results revealed an issue of excessive overheating during the heating season despite generally low air velocities. Radiant ceiling panels had the lowest velocities in both summer and winter, while buildings with active chilled beams showed the potential to meet Category II air velocity and temperature requirements. The building with thermally activated building systems experienced the most overheating during the heating season. Occupants were satisfied with the heating season temperatures of 23°C–25°C that can be attributed to lighter clothing (0.7 clo) instead of the standard 1.0 clo. Ventilation supply air and indoor temperature analyses indicate that elevated setpoints have been used to compensate for draught, resulting in overheating. As a measure of improvement to avoid overheating, we propose control curves for room temperature based on the outdoor running mean temperature and for supply air temperature based on the extract air temperature.

Systems Engineering for the Energy Transition: Potential Contributions and Limitations

Systems engineering finds its origin in analyzing and exploring complicated technical systems. In this positioning paper, we set out to discuss the value and limitations of a Systems Engineering approach in its contribution to societal challenges, notably the energy transition. We conceptualize the energy system as a sociotechnical system. We specifically explore stakeholders and their roles, agency, and acceptance. We illustrate the relevance by a case at the municipal level that shows the relevance of acceptance, pluralism, distributed agency, context, and process aspects. The municipality is still in a phase of exploration and conceptualization. Systems Engineering can be of great value in this phase to explore the problem and solution space. However, to make the most of this requires that Systems Engineering addresses policy making, distributed agency, and complexity. We discuss the challenges this poses for the traditional Systems Engineering approach; we indicate several potential strategies to address these challenges, and we show two fields that can help clarify how to address these challenges: transition studies and sustainability assessment.

Methodical Procedure for Creating a New Methodology for Assessing the Resilience of Transport Infrastructure

An important part of risk assessment is the assessment of resilience. Resilience assessment leads to increased safety of the evaluated element. Resilience can be understood in different ways. In general, resilience is the ability of an element to resist, absorb, and adapt to adverse events. To unify the understanding of the area of resilience, it is appropriate to develop a uniform methodology for the assessment of resilience. Such a methodology can unify input and output information, thus facilitating resilience assessment. Transport and transport infrastructure are complicated technical systems that require a specific approach. This article aims to analyse the appropriate methodologies used in the assessment of resilience and to present a proposal for a uniform methodology for the assessment of resilience specific to the transport sector.

МЕТОДЫ И СРЕДСТВА РАЗРАБОТКИ И ВЕРИФИКАЦИИ UML-МОДЕЛЕЙ КОМПЛЕКСА ТРЕБОВАНИЙ К АВТОМАТИЗИРОВАННЫМ СИСТЕМАМ УПРАВЛЕНИЯ ОРГАНИЗАЦИОННО-ТЕХНИЧЕСКИМИ СИСТЕМАМИ

The article describes the methods and tools for developing and verifying a formal model of a set of requirements to the automated management systems for complicated organizational and technical systems in accordance with the methodology of the model-oriented approach. A classification characteristics quality of a set of requirements is proposed. The methodology and means of automated development of a formal model of a set of requirements, its transformation and loading into the environment of the Neo4j graph database are presented. Methods and means of verification and validation of a set of requirements by creating and executing test tasks and queries in the Cypher language are proposed. Promising areas of further research are identified.

Homogeneous problems of elasticity theory for different boundary conditions in the region of the angular cut of the boundary

Mathematical modeling of structures as complicated technical systems includes development of an experimental calculation method of problem solving for areas having different variants of structural shaping (special lines and points, e.g., reentering angles). The notion of stress concentration in an irregular point of the area boundary is losing its sense. Infinite stress and strain are determined in the area of the angular cut of the boundary as solution of homogeneous boundary problems. The singularity of a problem solution depends upon the type of homogeneous boundary conditions, mechanical specifications of the areas, apex angles of the boundary cut. The studies of power-mode strain and stress get especially vital during studies of the stress of multi-part structures in the areas of conjunction of elements made of materials with different mechanical properties in forced deflected mode with ruptural deformation along the contact line (surface) of the elements. The present paper reports on statements of homogeneous boundary problems for different types of homogeneous boundary conditions for a flat wedge-shaped area. A system determinant for determining of proper values is indicated, as well as proprietary solutions of the problem for different variants of the component areas of the wedge, mechanical properties and the cutout opening of the areas boundary.

Probabilistic pattern of risks in company’s Quality management system

One possible approach for calculation of probabilistic rate of risks in Quality management system (QMS), which is prescribed by requirements of International Standard ISO 9001:2015, is proposed in this article. Aspects of the theory of dependability and Markov techniques are used, which are applied for evaluation of probability of failures in complicated technical systems. Representation of QMS processes as a graph with controlled discrete Markov chains is suggested, which allows to evaluate a probability of customer requirements non-fulfillment as a function of an intensity of mistakes that bring to non-conformities in QMS.

Theoretical Aspects of the Patterns Recognition Statistical Theory Used for Developing the Diagnosis Algorithms for Complicated Technical Systems

In the article, the problem of application of the pattern recognition (a relatively young area of engineering cybernetics) for analysis of complicated technical systems is examined. It is shown that the application of a statistical approach for hard distinguishable situations could be the most effective. The different recognition algorithms are based on Bayes approach, which estimates posteriori probabilities of a certain event and an assumed error. Application of the statistical approach to pattern recognition is possible for solving the problem of technical diagnosis complicated systems and particularly big powered marine diesel engines.

Структурно-аналітичне моделювання та анімація технологічних процесів в інженерно-технічних комплексах

For complex engineering systems (CES), it is typical that the time change of value of influencing parameters (temperature, level, pressure, flow, speed of movement, etc.) takes place. Then the dynamic model of the CES can be represented by a system of linear (nonlinear) differential and algebraic equations, the latter in the case of linear transfer functions. The complicated technical systems and complexes have another feature associated with such concepts as the «condition» and «event» that may have a certain relationship with each other. Mathematical and structural forms of modeled problems situation are the apparatus of Petri nets, where the conditions are positions, and events is junctions. Fig.: 7. Refs: 3 titles.

COMPARATIVE MULTIOBJECTIVE ANALYSIS OF COMPLICATED TECHNICAL AND SOCIAL SYSTEMS IN TERMS OF ECONOMICS AND MANAGEMENT

The article is devoted to the comparative multiobjective analysis of complicated technical and social systems in terms of economics and management. The difficulty of carrying out such comparison is determined by multidimensionality of the target application, diversity and qualitative variety of separate system elements, dissimilarity of technological conditions, under which they are created, and analogues used for the comparison. It is not about choosing the one “best” solution out of several alternatives, how it is required having the traditional optimization task setting, but about the comparison of home object to its analogues. Usually the purpose of such comparison consists in the assessment of its comparative objective efficiency. However, the object compared is the product of the respective technological chain. The resources used to create the object and analogues compared are always different as well as technologies used to transform resources to end products. It is the reason for the new problem to assess the management quality of own object creation as compared to the analogues. Objectives. The purpose is the development of effective approaches to the management quality assessment of complicated technical and social systems creation. Four multiobjective tasks of integral assessment are considered to solve the stated problem: objective efficiency assessment, assessment of all kinds of resources used, applied technology assessment and finally three-objective task to assess the management quality of object creation with assessed objective efficiency by using stated resources and technologies. The last task implies achievement of the highest objective efficiency with the use of less resource and less sophisticated technology that points at the higher management level. The stated task pertains to the class of multiobjective decision making where alternatives are distinguished by partial criteria and depend on the range of uncertain factors. Methods. The methodology of solving this problem relies on the use of confident judgment method that allows making decision simply and on a reasonable basis taking into account only natural judgments. The stated method does not use artificial procedures, intended to formalize the task by means of searching the unique appropriate way to consider uncertainty, but takes into account the whole variety of such ways. Indeed the method allows identifying the rating of the required solution that represents the rate of uncertainty consideration ways whereby this solution is the best compared to other ones. Results. Test approval of the proposed method application are illustrated through the management quality comparative analysis while creation of Global Navigation Satellite Systems (GNSS). Russian Global Navigation Satellite System (GLONASS) is compared to similar systems of the USA (GPS), Europe (Galileo) and China (Kompas/Beidou). Conclusions and Relevance. The proposed approach has powerful capabilities and can be used in complex comparison to the existing analogues of complicated technical and social systems both being created and already in place. The method gives the possibility to acquire useful information about the quality and the efficiency of such systems and to elaborate recommendations regarding further development.

Statistical modelling of team training in a microworld study

A command and control environment is a dynamic and complex setting with complicated technical systems where teams of operators interact to reach shared goals. This study presents an experiment in which we, by means of Structural Equation Modeling (SEM), explain the relations between basic concepts of command and control environments: mental workload, frustration, situational awareness, and performance. This paper reports a LISREL analysis of the Baroutsi, Berggren, Nählinder, & Johansson (2013) data. From that data, a new latent variable “Frustration” emerges, which now can be included in the model.

Utilization of the International Space Station for education and popularization of space research

Providing aerospace industry with highly qualified workforce is an international problem. There are multiple science and educational programs which are currently being developed aimed at training specialists capable of solving tasks related to the development, creation, testing and utilization of complicated technical systems. Some portion of these programs is being conducted with the support of national space agencies.Currently, the task of using International Space Station as modern innovative element in the system of aerospace education of students is pending. Recently the YouTube and Lenovo manufacturer of laptop computers have offered to students to develop scientific experiments, the best of which are to be conducted on board of International Space Station. The project was supported by various space agencies – USA (NASA), Europe (ESA) and Japan (JAXA) – and by Space Adventures company, which specializes in space tourism.Actual start of implementing educational technologies from space platform took place during the flight of orbital complex “Mir” (1987–2001). Russian cosmonauts, headed by flight engineer Alexander Serebrov, conducted a series of lessons from space, demonstrating various experiments in the condition of weightlessness and illustrating the laws of nature by unique tests. As a result of such lessons, several educational videos – in Russian and in English – have been created with the topics in physics, hydrodynamics, mechanics, liquids in space, and others.Currently, in order to utilize the educational capabilities of Russian segment of International Space Station, a scientific-educational program of space experiments has been developed as part of Russia׳s Federal Space Agency program of space experiments. The program creates conditions for attracting the youth to independent scientific-research activity under the supervision of leading experts from space companies. The main advantage of the program is possibility to conduct dialog by high-school and university students with the crews of International Space Station using amateur radio channels. Some of such lessons may be viewed at WWW.RS0ISS.RU. Use of amateur radio frequencies allows communication with the station and experiments at schools and universities in live mode.This article demonstrates the results of Russian and International space experiments – “RadioScaf”, “MAI-75”, “About Gagarin from Space”, “Shadow-beacon”, “Great Beginning” – and outlines the plans for new projects, such as experiment to study the deployment of frame-less thin-film structure from the extra-small-size spacecraft “Sail-BMSTU” and others.Utilization of International Space Station as modern innovative element in the system of space education of youth allows popularizing the achievements of space exploration, improving the quality of education and increasing the popularity of space activity.

CORRECTION OF FUNCTIONAL STATE IN OPERATOR’S OF COMPLICATED TECHNICAL SYSTEMS BY MEANS OF XENON-OXIGEN GAS MIXTURE

The supporting optimal functional state and efficiency of operators of complicated technical systems during or after the long-lasting working cycle at the marine ships is one of the most important problem of the marine medicine. It is known that the errors of operators during controlling complicated technical systems are the reasons in 50% of accidents in the navy. Usually operator’s errors appear at the state of increasing of exhaustion and decreasing of working efficiency. Application of xenon-oxygen gas mixture inhalations makes possible to restore the working efficiency of operators in more short period of time.

Dynamic Measures for Performance Assessment in Complex Environments

The command and control environment is a dynamic and complex setting with complicated technical systems where teams of operators interact to reach shared goals. This paper presents a study where a quasi-dynamic evaluation technique was used to assess performance. Nine operators from the Swedish Air Force participated in a peace support operation scenario in an operational setting. Data was collected by a repeated measurement technique to measure performance, workload, situation awareness, complexity, team coordination and sharing of information. A causal model was derived from the data which shows the relations between mental workload, individual performance and team performance. An efficiency index was calculated showing that the operators performed better over time, even though complexity increased. The use of the repeated measurement technique proved to be successful for measuring complex and dynamic events.

The potential damage zone concept and risk analysis for complicated technical systems

It is shown that the following tasks have to be handled in devising models, computational techniques, and a database for risk analysis for complicated technical systems (CTS): the description of CTS from the viewpoint of integrity and hierarchic structure; formulation of the data support to risk analysis; choice of risk criterion and the setting up of risk analysis techniques with given adjustable parameters. Developments in CTS risk analysis require advances in the mechanics of deformation and failure and also in computational technologies and engineering.

Methodology of Complicated System Hazard Analysis by the Use of Sharp and Fuzzy Sets

Algorithms are given for risk calculation and classification for complicated technical systems, including linguistic evaluation of the parameters (levels of possible undesirable event initiation, damaging factors, risk exposure), fuzziness level, and gradations (classification) of fuzziness. Risk calculation on the basis of fuzzy sets terminates with classification, as in the case of sharp sets.

THE SOLUTION OF CUSTOMS POSTS MANAGEMENT PROBLEMS AT RAILWAY BORDER STATIONS

The Identification and solution of transportation problems related to customs posts at railway border stations enable successful functioning of international freight transport, thus guaranteeing its reliability, punctuality and high quality. Perfection of the complex work is necessary in order to meet the requirements as well as to preserve goods during their transportation process. For the solution of the problems at the stations it is important to analyse fundamental principles, to assess an environmental impact, to formulate and evaluate the issues of wagon management by means of complicated technical systems, and to optimise the process of problems on the basis of research methods.

The solution of customs posts management problems at railway border stations

Abstract The Identification and solution of transportation problems related to customs posts at railway border stations enable successful functioning of international freight transport, thus guaranteeing its reliability, punctuality and high quality. Perfection of the complex work is necessary in order to meet the requirements as well as to preserve goods during their transportation process. For the solution of the problems at the stations it is important to analyse fundamental principles, to assess an environmental impact, to formulate and evaluate the issues of wagon management by means of complicated technical systems, and to optimise the process of problems on the basis of research methods.

Operational Planning of Verification of Measuring Instruments of Complicated Technical Systems

The effectiveness of operational planning of measuring instrument verification is assessed, using the example of the ARM-2 automated work station in a mobile measuring technique laboratory. An operational planning algorithm for measuring instrument verification is presented.

“Probabalistic Expert-Advisory System” Program Package for Probabalistic Analysis of Complex Technical Systems

In connection with the possible catastrophic consequences of failures and incidents in the operation of complicated technical systems, systems operational efficiency, and reliability assessment at the stage of design and selection of the basic technical solutions and during operation is one of the priorities when investigating public and environmental safety. To solve the problem, a method of probabilistic assessment of complex technical systems has been developed. This method is implemented in the program package “Probabilistic Expert-Advisory System” (PEAS). A characteristic feature of the method is a switch from point to integral probabilistic assessments and representation of the temporal characteristics of the process in the form of interval assessments.

Intelligent control of multivariate signal analysis

Multivariate signal analysis is a tool which can be used to study the behaviour of complicated technical systems in amplitude, time and frequency domains. Tools and means to do meaningful analysis using a priori knowledge, and to master the large amount of information generated, are presented. The usefulness of the analysis method in explaining the transfer paths of various phenomena is illustrated by a case application.