Development Of Large Systems Research Articles

АВТОМАТИЗАЦІЯ ПРОТИАВАРІЙНОГО КЕРУВАННЯ ЕНЕРГОСИСТЕМОЮ НА ОСНОВІ ЛОГІКО-ІМОВІРНІСНОГО МОДЕЛЮВАННЯ НАДІЙНОСТІ ПРОДУКЦІЙНИМИ МЕРЕЖАМИ ПЕТРІ

The paper presents the results of research on methods for constructing knowledge bases of decision support systems for dispatch control of power supply systems in crisis situations. Models of products based on Petri nets are proposed for assessing the parameters of reliability of power supply systems. An algorithm for calculating the reliability parameters of the electrical network using analytical matrix equations of Petri nets has been implemented. The work is devoted to the topical problem of intellectualization of power supply systems and means of automation of control of large power systems. The relevance of research in the field of building intelligent power systems is grounded. The basic requirements for the reliability of modern power supply systems are formulated. The concept of intellectualization of power systems and management of their reliability is a stable trend in the development of large energy systems and automated dispatch control systems. The solution to the problem lies in the implementation of intelligent decision support systems. The main task of the work is to model the reliability of the power supply system in order to build an effective knowledge base about the parameters of the reliability of the power supply system. For this purpose, we use a probabilistic approach to assessing reliability. This approach is based on the concepts of the probability of failure-free operation and the probability of failure, which are expressed in terms of the failure rate. On the basis of the obtained models, the construction of intelligent software systems for dispatching can be carried out taking into account the reliability indicators of the components of power supply systems. As a mechanism for formalizing failure circuits in power supply circuits, the production approach of knowledge representation is applied, which implements conjunctive-disjunctive connections of statements associated with failures. The outlined approach is invariant in relation to subject areas, which makes it possible to build effective decision support systems in the field of operational emergency control of the energy system.

Modelling Software Architecture for Visual Simultaneous Localization and Mapping

Visual simultaneous localization and mapping (VSLAM) is an essential technique used in areas such as robotics and augmented reality for pose estimation and 3D mapping. Research on VSLAM using both monocular and stereo cameras has grown significantly over the last two decades. There is, therefore, a need for emphasis on a comprehensive review of the evolving architecture of such algorithms in the literature. Although VSLAM algorithm pipelines share similar mathematical backbones, their implementations are individualized and the ad hoc nature of the interfacing between different modules of VSLAM pipelines complicates code reuseability and maintenance. This paper presents a software model for core components of VSLAM implementations and interfaces that govern data flow between them while also attempting to preserve the elements that offer performance improvements over the evolution of VSLAM architectures. The framework presented in this paper employs principles from model-driven engineering (MDE), which are used extensively in the development of large and complicated software systems. The presented VSLAM framework will assist researchers in improving the performance of individual modules of VSLAM while not having to spend time on system integration of those modules into VSLAM pipelines.

РАЗРАБОТКА ЭКОНОМИЧЕСКИХ МОДЕЛЕЙ РАЗВИТИЯ ТЕХНИЧЕСКИХ СИСТЕМ ПО ЭТАПАМ ЖИЗНЕННОГО ЦИКЛА

Introduction: when forecasting and simultaneously supporting the planned development of a set of large technical systems, it is required to develop an integrated mechanism for accounting for the state and costs of resources. The approaches known for these purposes are characterized by high complexity of implementation and fragmentation over the stages of the system cycle. Purpose: to develop a complex of interrelated economic models for the analysis and development of large technical systems. Results: on the basis of scientific directions of economic analysis, aspects of the development of economic models were considered and on their basis, modeling of complex composite technical systems by stages of their life cycle was carried out in the interests of the subsequent formation and adoption of managerial decisions both in the selection and implementation of such systems, and in support of their development. The set of economic models is combined into a generalized model of systems development in the interests of a comprehensive assessment of current and future costs, further forecasting and, based on the results of simulation and calculations, making effective decisions. Since a feature of the production of large technical systems is their serial nature of products, then the integrated model evaluates the costs both for individual systems and for the stages of their life cycle, and for the entire complex of systems as a whole. Modeling of various modes of financing the development of one system or their complex is predicted, the features for each stage of development are taken into account. The possibility of assessing the structural restructuring of the relationship of enterprises participating in the production process and changing the possible sequence of technological processes for the production of samples has been obtained. Practical relevance: the proposed model (s) for batch or piece production of products is recommended in specific science-intensive areas of mechanical engineering and is applicable, for example, in aviation, space, shipbuilding, mining, and other industries. Its application is especially important in the design, development and manufacture of products for government orders. Discussion: the presented solution is proposed to be formalized with a software package and to create an automated control system for the development, production, operation and disposal of large technical systems with the functions of a decision support system.

Applying an MDA-based approach for enhancing the validation of business process models

Abstract Business process modeling is a key activity during the development of complex and large information systems, such as enterprise management systems. These systems deal with a wide number of business processes; thus, the modeling and validation of processes becomes a challenging task. This entails dealing with issues such as the precedence between tasks and activities within a process, as well as resources, roles and enterprise assets involved. Moreover, undetected mistakes in this phase will be propagated to the system design phase and consequently will have a negative effect in the final system quality. On the other hand, the scientific literature advocates the suitability of formal models to address some issues during the process modeling. However, the adoption of formal models leads to new problems because formal languages are difficult to understand and process stakeholders usually lack of knowledge about them. In that direction, the Model-Driven Architecture (MDA) paradigm includes specifications that may alleviate some difficulties in the adoption of formal languages. Hence, in this paper we introduce an approach which combines MDA-specifications and ontologies to support process modeling. These technologies have great acceptance between both software researchers and developers. The use of ontologies permits to semantically validate the models. Furthermore, the application of MDA-guidelines could facilitate the integration of BPMN, a graphical notation for describing business process models widely accepted among business analysts, with a formal language to automate the analysis of business process models.

БАЗОВЫЕ НАУЧНЫЕ КАТЕГОРИИ ПОНЯТИЙНО-КАТЕГОРИАЛЬНОЙ ПЛАТФОРМЫ ИССЛЕДОВАНИЙ ПРОСТРАНСТВЕННОГО РАЗВИТИЯ РОССИИ И ЕЕ РЕГИОНОВ (ЧАСТЬ 1)

The article presents the results of justification of the most important, in the authors’ opinion, basic scientific categories of the conceptual and categorical platform for research on the spatial development of large socio-economic systems. Among them, scientific categories such as the global hierarchy of socio-economic systems, the trinity of structural elements, the internal environment of systems and the economic space are highlighted. The role and place of these categories in modern studies of spatial transformations are substantiated. Particular attention is paid to such a relatively new category as the internal environment of socio-economic systems. t is shown that the internal environment is essentially the only tool for governing bodies to influence socium in order to initiate the spatial development of Russia and its regions. It has been argued that economic space has a dual manifestation. It is a property of material systems on the one hand and an immaterial object on the other. It is not correct to treat it as a management object. The proposed axiological and methodological framework can be a starting set for a future conceptual and categorical platform.

Key Operational Issues on the Integration of Large-Scale Solar Power Generation—A Literature Review

Solar photovoltaic (PV) power generation has strong intermittency and volatility due to its high dependence on solar radiation and other meteorological factors. Therefore, the negative impact of grid-connected PV on power systems has become one of the constraints in the development of large scale PV systems. Accurate forecasting of solar power generation and flexible planning and operational measures are of great significance to ensure safe, stable, and economical operation of a system with high penetration of solar generation at transmission and distribution levels. In this paper, studies on the following aspects are reviewed: (1) this paper comprehensively expounds the research on forecasting techniques of PV power generation output. (2) In view of the new challenge brought by the integration of high proportion solar generation to the frequency stability of power grid, this paper analyzes the mechanisms of influence between them and introduces the current technical route of PV power generation participating in system frequency regulation. (3) This section reviews the feasible measures that facilitate the inter-regional and wide-area consumption of intermittent solar power generation. At the end of this paper, combined with the actual demand of the development of power grid and PV power generation, the problems that need further attention in the future are prospected.

Enabling consistency in view-based system development — The Vitruvius approach

During the development of large software-intensive systems, developers use several modeling languages and tools to describe a system from different viewpoints. Model-driven and view-based technologies have made it easier to define domain-specific languages and transformations.Nevertheless, using several languages leads to fragmentation of information, to redundancies in the system description, and eventually to inconsistencies. Inconsistencies have negative impacts on the system’s quality and are costly to fix. Often, there is no support for consistency management across multiple languages. Using a single language is no practicable solution either, as it is overly complex to define, use, and evolve such a language. View-based development is a suitable approach to deal with complex systems, and is widely used in other engineering disciplines. Still, we need to cope with the problems of fragmentation and consistency.In this paper, we present the Vitruvius approach for consistency in view-based modeling. We describe the approach by formalizing the notion of consistency, presenting languages for consistency preservation, and defining a model-driven development process. Furthermore, we show how existing models can be integrated. We have evaluated our approach at two case studies from component-based and embedded automotive software development, using our prototypical implementation based on the Eclipse Modeling Framework.

Large-scale machine learning systems in real-world industrial settings: A review of challenges and solutions

Background: Developing and maintaining large scale machine learning (ML) based software systems in an industrial setting is challenging. There are no well-established development guidelines, but the literature contains reports on how companies develop and maintain deployed ML-based software systems. Objective: This study aims to survey the literature related to development and maintenance of large scale ML-based systems in industrial settings in order to provide a synthesis of the challenges that practitioners face. In addition, we identify solutions used to address some of these challenges. Method: A systematic literature review was conducted and we identified 72 papers related to development and maintenance of large scale ML-based software systems in industrial settings. The selected articles were qualitatively analyzed by extracting challenges and solutions. The challenges and solutions were thematically synthesized into four quality attributes: adaptability, scalability, safety and privacy. The analysis was done in relation to ML workflow, i.e. data acquisition, training, evaluation, and deployment. Results: We identified a total of 23 challenges and 8 solutions related to development and maintenance of large scale ML-based software systems in industrial settings including six different domains. Challenges were most often reported in relation to adaptability and scalability. Safety and privacy challenges had the least reported solutions. Conclusion: The development and maintenance on large-scale ML-based systems in industrial settings introduce new challenges specific for ML, and for the known challenges characteristic for these types of systems, require new methods in overcoming the challenges. The identified challenges highlight important concerns in ML system development practice and the lack of solutions point to directions for future research.

Ship systems synthesis and analysis using holistic design approach: The QFD-AD method

Design complexity is generally experienced in the design development and production of large and complex systems. It is viewed as the key element that would determine the design development cycle and quality. In this context, a study was conducted to demonstrate the ROPAX ship design and development processes applying the QFD-AD method. It is proposed to synthesise and analyse the ship systems design and configurations at the early design phase. This study explored the method applicability to facilitate concurrent design and decision-making, alternative to the conventional ship design spiral model. Moreover, it presented the potential method to support holistic design approach in exploring ship design as large and complex systems.

A Grid of Microgrids: Is it the Right Answer? [Point of View

The rapid and worldwide rise in distributed generation capacity, especially photovoltaic, has raised the issue on whether the development and operation of large interconnected systems on a national or continental level will vanish. The usual question is: will the large electric energy systems of today, planned and operated in either a centralized or decentralized way, be replaced by various independent smart-city systems, all with self-healing and other eye-catching characteristics, forming “a grid of microgrids?”

Experimental analysis of encapsulated CaO/Ca(OH)2 granules as thermochemical storage in a novel moving bed reactor

The advantages of Ca(OH)2 such as low cost and high energy density make it a promising material for thermal energy storage. However, the development of cost efficient large scale storage systems remains challenging. One reason is that the low thermal conductivity and cohesiveness of the powder bulk material impede the reliable operation of moving bed reactors. One approach to address these drawbacks is the macro encapsulation of pre-granulated storage material.In this work, a newly moving bed reactor was developed and the performance of two encapsulated storage materials was investigated in lab scale and under application relevant boundary conditions. The two tested material samples were ceramic encapsulated CaO granules (sample 5D1F) and Ca(OH)2 granules coated with Al2O3 nanostructured particles (sample Al2O3). The reaction performance, cycling stability and ability to flow were experimentally examined and the operation of the moving bed reactor was successfully demonstrated. It was found that both encapsulated materials retained their shape after sixfold cycling. After the experiment series, the sample 5D1F flowed freely out of the reactor while the sample Al2O3 clogged the reactor tubes due to the volume expansion during hydration. Further, the experiments revealed that the reaction performance of the sample 5D1F is reduced, while the performance of the sample Al2O3 is comparable to unmodified Ca(OH)2 granules. Overall, this study shows that encapsulated granules are stable under operation in larger reactors and the granules further facilitate the reactor design and operation. Additionally, the volumetric energy density of compacted granules is higher compared to the loose powder bulk. In particular, the encapsulation with Al2O3 nanostructured particles showed promising performance for the cost efficient development of a scalable thermochemical energy storage system and therefore needs to be further investigated.

Trusting Infrastructure: The Emergence of Computer Security Incident Response, 1989-2005.

Historians have tended to analyze maintenance as an intrinsically local activity, something very unlike the development of large technological systems. This article challenges this historiographic dichotomy by examining efforts to construct a global infrastructure for maintaining computer security. In the mid-1990s, as the internet rapidly grew, commercialized, and internationalized, a small community of computer security incident responders sought to scale up their system of coordination, which had been based on interpersonal trust, by developing trusted infrastructure that could facilitate the worldwide coordination of incident response work. This entailed developing not only professional standards, but also institutions for embodying and maintaining those standards in working infrastructure. While some elements of this infrastructure became truly global, others remained regionally bounded. We argue that this boundedness resulted not from the intrinsically local nature of maintenance, but from the historical process of infrastructure development, which was shaped by regionally based trust networks, institutions, and needs.

A Novel Method for Wide Range Electric Current Measurement in Gas-Insulated Switchgears With Shielded Magnetic Measurements

Magnetic field (MF) sensing and interpretation remains an active area of research for source current reconstruction and measurement applications. One such area is large current measurement for power system components with contact less MF sensing. The output of recently made available magnetic sensors is favorable for large current measurement applications. This stimulates development of a noncontact magnetic sensor-based large electric current measurement system for fixed conductors to be employed in power systems. However, the presence of strong magnetic noise from near equipment imposes restriction on the use of sensitive magnetic sensor in open air where magnetic noise sources operating at the same frequency may distort the sensor output. The novelty of this paper is the application of MF sensor inside magnetic shielding layers for large current measurement. High-permeability Mu-metal is employed and arranged in three arc-shaped layers for designing a semicircular special shielding arrangement. The application of the method and design is demonstrated for large current carrying conductor arranged inside a gas-insulated switchgear. The measurement system is first validated by the finite-element analysis method and then tested with a comprehensive experimental setup in the presence of strong magnetic noise stimulus of 0.28 T generated by a strong neodymium magnet. The resultant apparatus is tested for current of up to 1000 A with a resolution of 0.01% and error less than 3% in the worst case scenario. The prototype demonstrated excellent linearity during experimental validation of current measurement of 100–1000 A in the presence of magnetic noise stimuli at different positions where the standard deviation between slopes value for sensor response to input current (100–1000 A) curve for six different test cases remains only 0.83%.

Development of an effective protocol for in vitro multiplication of peppermint (Mentha piperita)

Mentha piperita is a completely sterile hybrid due to the fact that male organs of flower fail to develop. The stamens remain abnormally short, sometimes degenerate and wither from bud. As a result it is not amenable to improvement by sexual crosses. Ruthless exploitation of peppermint due to growing interest in the commercialization of plant based medicines has lead to drastic decrease of natural resource base which will result in extinction. In order to meet pharmaceutical needs and to provent the plants from extinction, development of rapid large scale propagation systems is a necessity. In vitro multiplication was carried out for mass production of disease free planting material without seasonal constraints ensuring germplasm conservation and sustainable use of the medicinal crop.

On the area scalability of valence-change memristors for neuromorphic computing

The ability to vary the conductance of a valence-change memristor in a continuous manner makes it a prime choice as an artificial synapse in neuromorphic systems. Because synapses are the most numerous components in the brain, exceeding the neurons by several orders of magnitude, the scalability of artificial synapses is crucial to the development of large scale neuromorphic systems but is an issue which is seldom investigated. Leveraging on the conductive atomic force microscopy method, we found that the conductance switching of nanoscale memristors (∼25 nm2) is abrupt in a majority of the cases examined. This behavior is contrary to the analoglike conductance modulation or plasticity typically observed in larger area memristors. The result therefore implies that plasticity may be lost when the device dimension is scaled down. The contributing factor behind the plasticity behavior of a large-area memristor was investigated by current mapping, and may be ascribed to the disruption of the plurality of conductive filaments happening at different voltages, thus yielding an apparent continuous change in conductance with voltage. The loss of plasticity in scaled memristors may pose a serious constraint to the development of large scale neuromorphic systems.

Mantle plumes, triple junctions and transforms: A reinterpretation of Pacific Cretaceous – Tertiary LIPs and the Laramide connection

The Shatsky and Hess Rises, the Mid-Pacific Mountains and the Line Islands large igneous provinces (LIPs) present different challenges to conventional plume models. Resolving the genesis of these LIPs is important not only for a more complete understanding of mantle plumes and plume-generated magmatism, but also for establishing the role of subducted LIP conjugates in the evolution of the Laramide orogeny and other circum-Pacific orogenic events, which are related to the development of large porphyry systems. Given past difficulties in developing consistent geodynamic models for these LIPs, it is useful to consider whether viable alternative geodynamic scenarios may be provided by recent concepts such as melt channel networks and channel-associated lineaments, along with the “two mode” model of melt generation, where a deeply-sourced channel network is superimposed on the plume, evolving and adapting over millions of years. A plume may also interact with transform faults in close proximity to a mid ocean ridge, with the resultant bathymetric character strongly affected by the relative age difference of lithosphere across the fault.Our results suggest that the new two-mode melt models resolve key persistent issues associated with the Shatsky Rise and other LIPs and provide evidence for the existence of a conduit system within plumes that feed deeply-sourced material to the plume head, with flow maintained over considerable distances. The conduit system eventually breaks down during plume – ridge separation and may do so prior to the plume head being freed from the triple junction or spreading ridge. There is evidence for not only plume head capture by a triple junction but also for substantial deformation of the plume stem as the distance between the stem and anchored plume head increases. The evidence suggests that young transforms can serve as pathways for plume material migration, at least in certain plume head – transform configurations. A fortuitous similarity between the path of the Shatsky and Sio plumes, with respect to young spreading ridges and transforms, helps to clarify previously problematic bathymetric features that were not readily ascribed to fixed plumes alone. The Line Island Chain, which has been the subject of a vast number of models, is related mainly to several plumes that passed beneath the same region of oceanic crust, a relatively rare event that has resulted in LIP formation rather than a regular seamount track.Our findings have important implications for the timing and mechanism for the Laramide Orogeny in North America, demonstrating that the Hess Rise conjugate may be much smaller than traditionally thought. The Mid Pacific Mountains conjugate may not exist at all, given large parts of these LIPs were formed at an ‘off-ridge’ site. This needs to be taken into account while considering the effects of conjugate collision on mineralization and orogenic events.

Test case prioritization and distributed testing of object-oriented program

Software systems have increased in size and complexity. As a result, object-oriented programming (OOP) is increasingly being used in the development of such large and complex systems. Traditional procedural programming requires a design method that follows a sequential flow of control, which is difficult to follow in the case of large systems design. Thinking in terms of real-life objects and their interactions makes design easier in the case of OOP. However, OOP comes with its own set of disadvantages and testing is one of them. Testing of such systems requires much more effort and time. In our approach the program is analyzed to build a system dependence graph-based model. This model is analyzed for test script generation and to find state-save points within the program where the state of the program can be saved and reused for executing another test case. The test cases are prioritized looking at the structural complexity of the program. The distributed testing presented here is different from traditional distributed testing, where they address testing of web and distributed applications. The distributed architecture developed in this work enables testing of OOP in an efficient manner. The concept is implemented for Java programs as there is support for continuation.

Interactive design and multidisciplinary optimization of geostationary communication satellite

Currently, the design of large geostationary communication satellites is becoming more and more complex systems. On the one hand, customers are demanding high performance communications systems and this for 15–20 years orbital lifetimes. And the other hand, given the large volume and mass of communications satellites, an added constraint that resides in the volume under the launcher fairing which is sometimes represents a great handicap for the technological development of large space systems due to the technological limitation of launchers at the time. Increasing the performance and reliability of communication satellites, tools and methods are needed; the multidisciplinary design optimization methods (MDO) can be useful for this type of complex system. In geostationary communication satellite systems design, there are usually more than one design objectives, which a design team should take into account. These objectives involve system performance measures like mass, size, cost, reliability, power efficiency and system robustness. In a good design procedure, the tradeoffs between competing objectives should be incorporated so that the design team can make an informed decision. In this paper the generic geostationary communication satellite MDO problem is formulated to minimize the total mass of the satellite system under a number of practical constraints including launch vibration and acoustic disciplines. In this paper a gravitational search algorithm based on the law of gravity and mass interactions is introduced. In the proposed algorithm, the searcher agents are a collection of masses which interact with each other based on the Newtonian gravity and the laws of motion. From the results obtained in this paper and after optimization, the total mass of the studied GEO communication satellite is decreased by 185.3 kg (i.e., 7.3% of the total mass). In the case of the presence of two disciplines, acoustics and vibration, we notice that the mass becomes 3470 kg, which means the increase of the total mass of the system in about 124.2 kg and this in order to compensate the effects of these two disciplines.

Design and Development of Large Electric Curtain Control System for Time Controlled

Design and Development of Large Electric Curtain Control System for Time Controlled

Analysis and further development of large telephone systems

The purpose of the article is the analysis and further development of large telephone systems from the disciplines of the department of specialized computer systems. The relevance of the material described in the article is due to the need for analysis of outdated technologies of automatic telephone exchanges in Ukraine and the suggestion of ways to improve them. The development of large telephone systems in our day consists of the creation and improvement of hardware and software systems. To implement the Internet telephone protocol we use the special program Cisco Packet Tracer. When creating telephony we use two types of automatic telephone exchanges. Hardware automatic telephone stations of the Internet protocol are usually supplied in the form of specialized equipment with installed software. In this particular project, we use the Yeastar S300 Internet hardware-based automatic telephone exchange, which has many advantages to reach our goal, namely support for more than 300 people, built-in voicemail functions with internal storage for messages, as well as the possibility of its expansion. A fairly easy installation and upgrade procedure.To meet the needs of a large variety of users, the station is equipped with a large number of built-in features ranging from auto attendant and ending with calls from the site or GSM numbers of mobile operators. As a result of the work, data analysis was carried out on large telephone systems and it was determined that in 2011 the subscriber base was about 11 million subscribers and gradually decreased from 3 to 5% each year. In 2017 In Ukraine, the subscriber base accounted for about 9 million users. These circumstances were conditioned by the gradual development and gaining popularity of mobile communication, as well as Internet protocol telephony. The development of automatic telephone stations of the Internet protocol is due to the fact that unlike the old telephone systems, new Internet protocol stations allow you to use a large number of additional features, and it is not difficult to switch from outdated coordinate telephone systems. To facilitate the use of the new system by subscribers, a portable Internet Protocol telephony program was developed. It is software that will be enough to download to your computer and go through a complicated registration. After that, you will only need to pass authentication and the user will be able to use all its capabilities. The results of this project work can be used to create Internet telephony protocols.