Technical Performance Of System Research Articles

Prediction of geomagnetic storms associated with interplanetary coronal mass ejections

Geomagnetic storms have a significant impact on the performance of technical systems both in space and on Earth. The sources of strong geomagnetic storms are most often interplanetary coronal mass ejections (ICMEs), generated by coronal mass ejections (CMEs) in the solar corona. The ICME forecast is based on regular optical observations of the Sun, which make it possible to detect CMEs at the formation stage. It is known that the intensity of geomagnetic storms correlates with the magnitude of the southern component of the magnetic field (Bz) of the ICME. However, it is not possible yet to predict the sign and magnitude ofBzfrom solar observations for the operational forecast of an arbitrary CME. Under these conditions, a preliminary forecast of the magnetic storm probability can be obtained under the assumption that the strength of the storm is related to the magnitude of the magnetic flux from the eruption region, observed as dimming. In this paper we examine the relationship between the integral magnetic flux from the dimming region and the probability that CMEs associated with them will cause geomagnetic storms, using a series of 37 eruptive events in 2010–2012. It is shown that there is a general trend toward an increase in the ICMEs geoefficiency with an increase in the magnitude of the magnetic flux from the dimming region. It has been demonstrated that the frequency of moderate and severe storms observation increases in cases of complex events associated with the interaction of CMEs with other solar wind streams in the heliosphere.

Forecasting the parameters of performance monitoring of complex technical systems

The problem of monitoring the performance of technical systems is considered, corresponding to the stage of final control during the production of a product, as well as the stage of testing the product before its use. Based on the generalization and development of the existing approaches, models and methods for monitoring the performance of complex technical systems were developed, and models for predicting the parameters of their control were proposed. Methods of optimizing the number of tests of units of technical systems when monitoring their performance were developed. Methods for estimating the optimal level of the total defect rate are proposed. The efficiency of the proposed approaches is illustrated using a specific numerical example. The methods and models presented in the article can be useful for engineering and technical workers of design bureaus, research institutes, research and production associations and enterprises in ensuring the reliability of products and technical systems.

Leveraging water utility customer reporting for resilient operations and management

Water utilities collect information from various sources to gain continuous insights into the state of drinking water systems. Among the available data types, service problems that customers report are critical sources of information—especially during emergencies—which allow utilities to gage the impact of system operations on the resulting level of service. While some utilities increasingly collect and analyze customer reporting data to track key performance indicators (e.g., total complaints, response times), this information remains largely underutilized in research and practice. Further, little is known about spatial variations in the quantity or types of problems reported, which can indicate disparities in level of service and customer engagement. Here, we identify and compare spatial patterns in customer reporting against technical system performance and evaluate how trends change during emergency events (e.g., natural disasters). Our analysis demonstrates tightly coupled sociotechnical interdependencies between end user populations and drinking water systems. For instance, results reveal the prevalence of service problems in certain areas and show that several sociodemographic characteristics were statistically different in areas with higher or lower reporting levels. Finally, we offer recommendations for incorporating customer data into operational decision making and outreach efforts.

Technical and economic modeling of a trigeneration system with EF7 engine as a prime mover

In this paper, a comprehensive technical and economic modeling of a trigeneraion system based on a gas engine named EF7 is presented. The innovation is presenting a differential model with high accuracy which considers the effects of spark timing in half-load and full-load modes on the system technical performance, including specific fuel consumption, and the economic performance of the system, including fuel cost savings, investment payback period, net present value and internal rate of return.From economic viewpoint, at half-load condition and optimal spark timing (18° CA BTDC), the system will reach profitability after 8 years. From technical viewpoint, at half-load condition, the spark timing should be more advanced (24° CA BTDC) and the overall specific fuel consumption is 103.24 gr/kWh.But, at full-load mode and optimum ignition timing (18° CA BTDC), the economic performance has improved and with 10% inflation rate, the system can reach profitability after 4 years. Also, after 7 and 10 years, the profit values are $42,300 and $80,500, respectively and internal rate of return values of 22 and 26%, respectively. Also, from technical viewpoint, at full-load condition and optimal spark timing (22° CA BTDC) the minimum amount of overall specific fuel consumption is 110.42 gr/kWh.

A Model-Based Engineering Approach for Evaluating Software-Defined Radio Architecture

In product development, important specification and design decisions must be made at various stages of the lifecycle that include design, manufacturing, operations, and support. However, making these decisions becomes more complex when a multi-disciplinary team of stakeholders is involved in system-level or subsystem-level architecture and design decisions. Model-Based Engineering (MBE) approaches are enabling a digital thread of connected data and models. This work demonstrates a novel MBE approach that incorporates a model-based systems engineering (MBSE) method and a multi-criteria decision-making (MCDM) method to determine the best architecture solution that aligns with stakeholder needs and objectives over multiple domains. This approach demonstrates the connection of a system descriptive model, modeled using the systems modeling language (SysML), to underlying physics-based engineering models for the purpose of better predicting the technical performance of systems during the architecture development phase. This approach is demonstrated for a common aerospace communications application, a software-defined radio. This novel MBE approach supports digital transformation at organizations and allows for earlier design validation, enabling designers to test and select the best system architecture from many candidates and validate that the design meets stakeholder needs.

Review Models and Methods for Determining and Predicting the Reliability of Technical Systems and Transport

Modern power and transportation systems are subject to high requirements for reliability and performance in performing their specified functions. At the same time, these requirements are constantly increasing with the increasing complexity of technology and the introduction of electronics and computer technology into its structure. This is fully applicable to energy and transportation infrastructure, including electric vehicles. The complexity of the systems and increasing requirements for them have led to the fact that the problem of increasing their operational reliability has acquired great importance. The article presents a review of methods and justification of ensuring a high level of reliability and serviceability of technical systems as one of the most important tasks in the creation and operation of complex systems, such as modern energy and transportation systems. It is shown that a significant reserve in solving the problem of increasing the reliability and performance of technical systems is the information on failures and malfunctions of these systems obtained from the field of operation. The methodology of collection and processing of statistical information on failures of vehicles described by different distribution laws is outlined.

Cross Sectional Analysis of Impact of Seasonal Changes on Excimer Laser Ablation Performance on Polymethyl Methacrylate (PMMA).

Seasonal changes and varying degree of corneal hydration has been linked to excimer laser corneal ablation rates. The use of PMMA as a calibration material in refractive lasers is well established. However, PMMA ablation may be equally affected by seasonal variations in temperature and humidity, in turn affecting the calibration process. The aim of this work is to analyze the effect of seasonal changes in PMMA performance using SCHWIND AMARIS laser system. PET and PMMA ablations conducted in climate-controlled environment with 826 consecutive AMARIS systems manufactured over 6 years were retrospectively analyzed. Lasers were stratified depending on seasons and months of the year. Metrics like single laser pulse fluence, nominal number of laser pulses, mean performance, standard deviation, and technical performance of system were compared to global average values. Cyclic winter-summer variation was confirmed with seasons winter and summer showing statistically significant variations with respect to global values. Metric technical performance showed deeper PMMA ablation performance in summertime, with maximum seasonal deviation of 6%. Results were consistently confirmed in seasonal as well as monthly analyses. These findings could help minimize variance among laser systems by implementing compensation factors depending on seasons such that laser systems installed worldwide follow the same trend line of variation.

Comprehensive exergetic performance assessment and techno-financial optimization of off-grid hybrid renewable configurations with various dispatch strategies and solar tracking systems

The suitable selection of a dispatch strategy in a hybrid renewable configuration is essential in determining optimum scenarios. In this study, to determine the most reliable and economical way to meet the electricity demand of remote areas, an off-grid hybrid renewable configuration comprised of PV panels, wind turbines, a battery bank, and a biogas generator (as backup) is proposed. To this end, exergy and environmental analyses and techno-economic optimization are applied to four dispatch strategies including cycle charging, load following, combined dispatch, and HOMER predictive over a remote off-grid village located in South Khorasan province as a case study. The results of the exergy analysis signposted that for all dispatch modes, the highest share in overall exergy destruction was pertinent to PV modules, and accordingly, the inauguration of three solar tracking systems was examined. To investigate the cost-effectiveness of different configurations and dispatch strategies, a cost-effective index was defined and in all dispatch strategies, the highest belonged to the vertical tracker. On these grounds, the vertical tracking mode was the most cost-effective option to enhance the hybrid system's technical performance. The results indicated that upon forecasting the future load, the HOMER predictive dispatch strategy was performant in terms of employing the storage system and minimizing excess electricity, while the Combined Dispatch elicited the lowest rate of application and appropriate use of the battery. On the economic side, the cycle charging strategy had a cost of energy of 0.128 $/kWh and a net prest cost of $ 152258 and was found as the most affordable scenario with vertical tracking mode. Afterward, sensitivity analyses concerning the financial factors, exergetic parameters, and renewable resources were implemented for generalizing the findings of the investigation to other operating conditions. Eventually, the time series of electrical energy consumption and production, and the frequency of SOC for the battery bank for all dispatch strategies are explored.

Performance assessment of a distribution system by simultaneous optimal positioning of electric vehicle charging stations and distributed generators

Extensive penetration of Renewable Energy based Distributed Generator (REDG) units in a Distribution System necessitates its efficient and optimal applicability. Plug-in Electric Vehicles (PEV) is currently gaining importance steadily in a distribution system due to its environmental compatibility. However, suitable positioning of PEV is a mandate as it increases the overall demand of the system and has appreciable impact on the system's technical performance in terms of losses, voltage profile, penetration level, to name a few. This paper proposes a simple apparent power loss driven technique of Electric Vehicle Charging Station (EVCS) placement along with a REDG unit in a distribution system taking time-driven load models into consideration. The initial State of Charge of the PEV is reformulated taking traffic and weather conditions, proportional distance covered by the electric vehicle and non-availability of EVCS into consideration using Dynamic Fault Tree Analysis and Bayesian optimization techniques. An optimum combination of different sets of PEV with proportional distance coverage is considered. Results are validated on the basis of computation of three REDG assessment indices in comparison with an arbitrary slot of positioning of the above elements.

Optimal sizing of an integrated CHP and desalination system as a polygeneration plant for supplying rural demands

Simultaneous production of electricity, heat, and water is a global challenge for rural residential areas. In the present study, techno-economic optimization of a system including PV, wind turbine, generator, battery, and CHP system alongside brackish water reverse osmosis desalination system is investigated. The proposed polygeneration hybrid system provides the required loads of a village and health clinic in a rural area with a warm climate. This study aims to find the optimum energy cost of essential rural needs, including required electricity, heat, and water demands to improve remote areas' life quality. While previous studies often considered only one or two of these needs. Several sensitivity analyses based on the different economic and climate conditions are carried out. The grid breakeven distance, environmental aspects, and the developed hybrid energy system's technical performance are analyzed. The results demonstrate that the optimum system, including PV/WT/DG/CHP/Bat and reverse osmosis desalination unit has COE and NPC equal to 0.236 $/kWh and 428,246 $, respectively. Also, the CHP unit decreased the annual fuel consumption by about 224 m3/yr. Furthermore, the proposed hybrid system has a 58.4% lower CO2 emission than conventional natural gas-fired plants and less than 27 km of grid breakeven distance.

ANALYSIS OF ACTUAL, TYPICAL AND NORMATIVE CLIMATE DATA IN THE CONTEXT OF BUILDINGS ENERGY MODELING

This article analyses the actual, normative monthly and typical detailed climatic data for the city of Kyiv. Data on actual outdoor air temperatures during 2014-2021 were compared with indicators in accordance with Ukrainian regulations and the most common typical hourly climate files used for building energy modeling: International Weather for Energy Calculations (IWEC), Meteonorm, Typical Meteorological Year (TMY) from PVGIS tool and Onebuilding web-site. The values for outside air temperatures were compared on an average monthly basis and using the number of hours of outside air temperature duration. The latter approach allows to more accurately assess the energy efficiency indicators and energy consumption of heat supply systems with heat pumps. As the buildings energy need and energy consumption for heating values are significantly affected by heat gains due to solar radiation, a comparison of the normative value of global radiation on the horizontal surface with the values from the most common typical climatic data was also performed based on an average monthly basis. Taking into account the set of analysed climatic factors using monthly indicators for outside air temperatures and number of hours of outside air temperature duration, it is decided to use Meteonorm hourly data for Kyiv for further dynamic energy modeling of building with heat supply system based on different types of heat pumps, including the air-to-water and water(brine)-to-water ones. Also, climatic data used in RETScreen program show similar figures as normative values and therefore this program will be used for further technical and economic analysis as well and the results will be compared to the specialised program for heat pumps calculations GeoT*SOL, which also provides the detailed calculation of heat pumps system technical performance and economic calculations. In addition, possible deviations in the values of energy need for heating of the building when using different climatic data were estimated using the DesignBuilder / EnergyPlus software product. The potential deviation of energy need for heating results can be around -10…+6.5%.

Multi-criteria evaluation of professional qualities of railway dispatching personnel using computer simulations

Purpose. Development of a formal method to evaluate professional training of operating and dispatching personnel of railway stations. Methodology. Simulation approaches to generate performance indicators of a human dispatcher under the specified operational conditions are selected as well as techniques of cluster and discriminant analysis to evaluate the obtained results. Findings human factor is one of the main factors determining the performance of technical systems in general and the efficiency of a railway transportation system in particular. Analysis of the transport accident causes demonstrates that from 63 to 95 % of them are related to some extent to a human factor. In this regard, a problem of objective assessment of dispatching staff training quality and its effect on the indices of railway transportation functioning, including the operation safety is reflected in this article. Based on investigations carried out and the results obtained the operator training simulator of railway station was developed. Originality. A simulator is improved of the railway station functioning while using deterministic finite automat formalizing the procedures. The proposed approach helps simulate processes taking place at the railway stations and resulting from the correct actions by operators as well as the incorrect ones. In addition, the paper proposes the improved method to evaluate professional training of station operators based upon the cluster and discriminant analysis providing HF impact minimization in the process of the problem solving. Practical value. The approaches have been proposed to apply while developing training equipment for station operators. On the one hand, formal methods of cluster and discriminant analysis help provide human participation in the evaluation of professional training of station operators at the stage of training sample formation to be analysed. On the other hand, they make it possible to identify the trainee affiliation with a group of the defined training level and prevent from HF impact while evaluating training results of certain applicants.

Techno-economic analysis of the transition towards the large-scale hybrid wind-tidal supported coastal zero-energy communities

In the current academic fields of zero-energy community, there is still limited knowledge on the integration of a coastal community with hybrid ocean-related energy systems. This study investigates the feasibility of a coastal community to reach zero-energy with the support of a hybrid offshore wind and tidal stream energy generation system, as well as an ocean and solar thermal energy supported district cooling and heating system. TRNSYS simulation was performed to demonstrate a proposed community that comprises 8 high-rise residential buildings and 2 mid-rise office buildings with a 9.86 MW community peak power demand. This study considered 21 hybrid renewable energy cases and investigated their performance in 2 scenarios – scenario 1 without battery and scenario 2 with battery. The system performance is assessed from the technical, economic, and emission perspectives by analysing the system load matching, net present value, discounted payback period, and equivalent CO2 emission. In scenario 1, the hybrid renewable energy case 5 with 6 offshore wind turbines (12 MW) and 117 tidal stream converters (29.25 MW) has the best annual load matching (56.68% “onsite energy matching” and 57.84% “onsite energy fraction”) mainly due to their complementary generation pattern during specific periods. In scenario 2, the community-scale electricity storage significantly increases the system technical performance by raising the “onsite energy matching” and “onsite energy fraction” of case 5 to 75.25% and 74.75%, respectively. In addition, the techno-economic analysis reveals the market competitiveness of the 21 RE cases and demonstrates the significant economic impact of the FiT policy. The comparison between scenario 1 and scenario 2 indicates that the community-scale battery diminishes the operation-cycle profits but reduces the equivalent CO2 emission. Furthermore, with the current price settings, tidal stream energy generation is considered less profitable than offshore wind energy generation. This study could provide important insights into the development of coastal zero-energy communities with hybrid offshore wind and tidal stream energy generation at other locations worldwide, especially densely populated coastal cities.

Application of the generic variation operator in the model of PGE – product generation engineering onto the element types of properties and functions of technical systems

In analogy to the research field of epigenetics in biology, engineering research in the Model of PGE – Product Generation Engineering according to Albers is concerned with the detection of phenomena of variation that can be observed not only in physical embodiment, but also in other system elements such as properties and functions. Based on the gathered findings and insights of the structuring of elements of a new product generation or the reference system and an understanding of the set of elements, the generic variation operator in the Model of PGE is applied onto the properties and functions of technical systems. The application of the generic variation operator supports the product developer in identifying the alterations of the system elements. In addition, linking the variation types of properties, functions, and physical elements initially reveals preliminary patterns of “element-spanning” variation. Further research should focus on systematically linking the carry -over and new development shares of properties, functions and physical elements, whereby insights on the innovation potential of a product generation and the underlying development risk may be evaluated.

Analysis of the variation of the element types of properties and functions of technical systems in product development practice

In product development practice, it appears that engineering activities very often focus on the variation of the physical embodiment, as this is where the greatest and most obvious implications for the product seem to be perceived. Nevertheless, an empirical study revealed that variation in physical embodiment affects many other dimensions of a product, such as properties and functions. Within the scope of product specification, this requires a stronger differentiation of various dimensions of system elements. For this purpose, initial challenges and solution approaches in automotive product development practice are analyzed to gain a deeper understanding of the interrelationships of the variation of different types of system elements. The gathered findings and insights are then synthesized in a comprehensive systematic consisting of the structuring of elements of a new product generation or the reference system and an understanding of the set of elements in the Model of PGE – Product Generation Engineering. In summary, the differentiation of the variation types of the element types “property” and “function” is confirmed via the conducted case study. Further research should focus on supporting the product developer in identifying the alterations of the system elements by deriving the generic variation operator specifically onto the system elements of properties and functions of technical systems.

Design, specifications, and first beam measurements of the compact linear accelerator for research and applications front end

The compact linear accelerator for research and applications (CLARA) is an ultrabright electron beam test facility being developed at STFC Daresbury Laboratory. The ultimate aim of CLARA is to test advanced free electron laser (FEL) schemes that can later be implemented on existing and future short-wavelength FELs. In addition, CLARA is a unique facility to provide a high-quality electron beam to test novel concepts and ideas in a wide range of disciplines and to function as a technology demonstrator for a future United Kingdom x-ray FEL facility. CLARA is being built in three phases; the first phase, or front end (FE), comprises an S-band rf photoinjector, a linac, and an S-bend merging with the existing versatile electron linear accelerator beam line; the second phase will complete the acceleration to full beam energy of 250 MeV and also incorporate a separate beam line for use of electrons at 250 MeV; and the third phase will include the FEL section. The CLARA FE was commissioned during 2018, and the facility was later made available for user experiments. Significant advancements have been made in developing high-level software and a simulation framework for start-to-end simulations. The high-level software has been successfully used for unmanned rf conditioning and for characterization of the electron beam. This paper describes the design of the CLARA FE, performance of technical systems, high-level software developments, preliminary results of measured beam parameters, and plans for improvements and upgrades. © 2020 authors. Published by the American Physical Society.

Multiplexed enrichment and genomic profiling of peripheral blood cells reveal subset-specific immune signatures.

Specialized immune cell subsets are involved in autoimmune disease, cancer immunity, and infectious disease through a diverse range of functions mediated by overlapping pathways and signals. However, subset-specific responses may not be detectable in analyses of whole blood samples, and no efficient approach for profiling cell subsets at high throughput from small samples is available. We present a low-input microfluidic system for sorting immune cells into subsets and profiling their gene expression. We validate the system's technical performance against standard subset isolation and library construction protocols and demonstrate the importance of subset-specific profiling through in vitro stimulation experiments. We show the ability of this integrated platform to identify subset-specific disease signatures by profiling four immune cell subsets in blood from patients with systemic lupus erythematosus (SLE) and matched control subjects. The platform has the potential to make multiplexed subset-specific analysis routine in many research laboratories and clinical settings.

Integrity and lifetime in extreme environment of Arctic regions

The Integrity means not only the structural strength and performance of technical systems. The Integrity here is consolidating of the engineers and scientist in many research areas. The extreme environment has a significant influence on infrastructures and living beings during the development and service life in or close to the Arctic regions. Russia has a large boundary to Arctic and has a huge territory classified as a frigid zone. So the extreme environment contains conditions that are hard to survive even for steel structures due to extreme temperature, corrosion, inappropriate service and repair. Many problem should by discussed therefor including the structural integrity as the strength and mechanical properties and behavior of steel, polymer and composite structures, the phase transition processes, inhomogeneity of materials and thermal physics. The transport problem is a very important in Extreme environment, also the energy supply and mining technology. So it is an exigency to discussing and conferencing for the integrity and lifetime in extreme conditions.

Functional survivability analysis of structurally complex technical systems

Aim. The paper analyzes the functional survivability of structurally complex technical systems. This approach is the evolution of the structural survivability paradigm, when the system/element failure criterion is binary. The paper shows that given a wide variety of probabilistic scenarios of adverse effects (AE) on a system, an invariant model kernel is identified that is responsible for the interpretation of functional redundancy. The aim is to identify the proportion of retained operable states within the acceptable computational time, when the fixed number u of elements is disabled as the result of AE. In this case the analysis of survival law is conducted at the confluence of functional redundancy analysis and probabilistic AE models of arbitrarily wide variety. Methods . A technical system is considered a controllable cybernetic system equipped with specialized survival facilities (SF). System survivability analysis uses logic and probabilistic methods, as well as the results of the combinatorial theory of random allocation. It is assumed that: a) AE are localized and single (one effect affects exactly one element); b) each of the system’s elements has a binary logic (operability – failure) and zero resilience, i.e. destruction after one effect is guaranteed. Subsequently this assumption is generalized for the case of r-fold AE and L-resilient element. Results. The paper reconstructs a number of variants of the destruction law and survivability functions of technical systems. It is identified that those distributions are based on prime and generalized Morgan numbers, as well as Stirling numbers of the second kind that can be recovered using the simplest recurrence formulas. While the assumptions of the mathematical model are generalized for the case of nr-fold AE and L-resilient elements, the generalized Morgan numbers involved in the estimation of the destruction law are identified using the random allocation theory by means of n-fold differentiation of the generating polynomial. In this case it does not appear to be possible to establish a recursive relation between the generalized Morgan numbers. It is shown that under homogeneous assumptions regarding the survivability model (equally resilient system elements, equally probable AEs) in the correlation kernel for the system survivability function, regardless of the destruction law, is the functional redundancy vector F(u, e ), where u is the number of affected elements, e is the system’s limiting efficiency criterion, below which its functional failure is diagnosed, F(u, e ) is the number of system states operable in terms of e under u failures (destructions) of its elements. Conclusions. Point models of survivability are an excellent tool of express analysis of structurally complex systems and tentative estimation of survivability functions. The most simple assumptions of structural survivability can be generalized in cases when the system’s operability logic is not binary, yet is associated with the level of system operation efficiency. In this case we must speak of functional survivability. The PNP computational complexity of the survivability evaluation problem does not allow solving it by means of a simple enumeration of the system states and AE variants. Ways must be found of avoiding simple enumeration, e.g. by using conversion of the system operability function and its decomposition by means of generalized logical and probabilistic methods.

Improving the operation quality of technical systems using information theory models

Improving the operation quality of the technical system performance while designing and operating is considered through the application of information theory models. The models are based on the mathematical description of the probabilistic state of system elements and the possibility of determining the information entropy. To implement the model, the role of the stochastic behavior of a technical object is emphasized. This role determines its probability state. The basis for the determining of the entropy of object state based on a series of scientific and conceptual positions, developments of well-known scientists in connection with the problems of realization of physical processes. A mathematical model is proposed, that allows using the classical methods to determine the amount of information entropy and to use it to solve several problems: to choose the first preference structure with less uncertainty; to evaluate the behavior ("aging") of a system; to identify the problem areas of structures for the purpose of timely execution of equipment preventative maintenance; to construct the optimal system structure.