Operation Of Complex Systems Research Articles

Contribution Assessment Approach for Command and Control System Based on Force-Sparsed Stacked-Auto Encoding Neural Networks

Aiming at the difficulty of feature extraction and related generation mechanism analysis for Command and Control (C2) System using traditional data mining method, a novel contribution assessment approach based on Force-Sparsed Stacked-Auto Encoding Neural Networks (FS-SAE) is proposed. Combined with big data and complex networks technology, the contribution assessment model to operational system of system (SoS) is built. The emergence relations between the capacity indices of C2 system are formalized. The derivation results show that formalized presentation for the emergence process of performance indices of C2 system based on the proposed model not only reflects the complexity characteristics of non-linear and uncertainty in emergence process, but also gives general-defined meaning for indices structure of C2 system. It provides a feasible method for the commanders to deeply understand, manage and control the complex operation system.

On the similarity of shear deformation of a granular massif and a fragmented medium in the seismically active area

In recent research, the dynamics of the medium located in the seismic region at the boundary of tectonic plates is considered as the behavior of a complex open system that is in a state of self-organized criticality. Such an approach results from the very laws of earthquake generation and the complex structure of these areas. The network of faults and cracks makes seismic zones significantly heterogeneous and fragmented. Therefore, discrete models are increasingly used to model the dynamics of these media. The basis for comparing the model and the full-scale object serves the statistical regularities of their dynamic deformation. Relying on this concept, in the paper it is modeled the shear dynamics of a granular massif composed of identical cubic granules and is compared system’s statistical characteristics with the similar characteristics obtained for the earthquake generation zone. Shear deformation is carried out by means of the box consisting of two parts — movable and immovable ones. The movable part possesses the cover which receives kinetic energy from the granular massif in the process of shear deformation. For numerical simulations of the shear dynamics, the discrete element method is applied. The numerical calculations result in the distribution of cover’s kinetic energy jumps simulating the perturbations transmitted from the granular system to an external medium. It turned out that the distribution for these perturbations is the power dependence with an exponent that is inherent in earthquakes (Gutenberg-Richter law). Before and after large perturbations it is observed the swarms of smaller perturbations which are the analogues of foreshocks and aftershocks. The distributions of element’s velocity fluctuations and the correlation of velocity fluctuations are calculated as well. It is revealed the similarity of distributions for velocity fluctuations in the model massif and in the seismically active region of California, which includes the San Andreas fault. Moreover, the similarity of corresponding correlation functions is shown. They both are the functions of the stretched exponent. The obtained result indicates that shear processes in granular massifs and natural seismic processes in the San Andreas Fault are statistically similar.

Forecasting the production of gross output in agricultural sector of the Ryazan oblast

Gross agricultural output is a generalised physical output indicator in an industry that includes hundreds of different types of products, as well as the result of the interaction of production factors. This study provides a comparative analysis of methods based on "Gradient boosting of regression trees" in the Python programming language to identify the optimal values of the model parameters with the subsequent construction of a predictive model based on indicators that affect the production of gross agricultural output. The purpose of this study is to build a regression model for predicting gross agricultural output at actual prices for 2020. To achieve this goal, the methods of regression analysis, forecasting, gradient boosting, etc., were used. The gradient boosting of regression trees was solved for the conditions of the Ryazan Oblast. 4 models were created, 2 of which were based on the preliminary data processing. As a result of the construction of all models, the optimal values of the parameters were found and the results of the correctness on the model on the test set were obtained. It was found that the gradient boosting of regression trees gives adequate regression models for predicting the target variable, in particular, the indicator of gross agricultural output. The investigated indicator is a complex result of the interaction of many factors that are common for agricultural production. Thus, the gradient boosting of trees is most suitable for forecasting complex open systems. Such a method can be used to forecast the production of gross agricultural output not only of individual regions but also of the state as a whole. Based on the "test_score" model, which showed the correctness of 99% (0.994) on the test set, the gross agricultural output in all categories of farms in 2020 amounted to RUB 19187.84 million.

Fast Synergetic Control for Chaotic Oscillation in the Power System Based on Input-Output Feedback Linearization

This paper presents a fast synergetic control scheme for chaotic oscillation in a three-bus power system model. First, the coupling dynamic model of a controlled power system with the current source converter-based STATCOM device and energy storage device is established. Then, the input-output linearization process for the controlled power system is derived step by step, the control problem for the complex nonlinear power system model is completely transformed into the control of linear systems, and a fast synergetic control scheme is proposed for these linear systems. Since the designed control inputs contain complex system functions which are very difficult to obtain and reduce the engineering practicability of the designed controllers, the assumption that system functions are bounded is introduced into the controller design process, and the controllers are redesigned. The remarkable advantages of the proposed control method are that it improves the rapidity of traditional synergetic control and avoids complex system functions in control inputs. Finally, the effectiveness and the superiority of the control scheme are verified by simulation results.

OPTIMIZATION OF PREVENTIVE THRESHOLD FOR CONDITIONBASED MAINTENANCE OF RADIO ELECTRONIC EQUIPMENT

Context. Operation costs throughout the life cycle of radio electronic equipment are very significant, which value far exceeds the initial cost of the equipment. Therefore, the up-to-date scientific and technical problem is to minimize operation costs. One of the ways to solve this problem is the introduction of statistical data processing technologies in the operation systems of radio electronic equipment.
 Objective. The goal of the paper is to improve the efficiency of thecondition-based maintenance with the determining parameters monitoring, which is widely used in civil aviation.
 Method. The solution of this problem is based on finding the functional dependence of the efficiency indicator in the form of specific operation costs on the basic parameters of radio electronic equipment and its operation system. To determine this dependence, the probability-event model is used,as well as methods of probability theory and mathematical statistics, in particular methods of statistical classification of sample sets and functional transformations of random variables. To determine the optimal level of the preventive threshold by the criterion of minimizing operation costs, the method of statistical simulation of Monte-Carlo is used.
 Results. Maintenance strategy with the determining parameters monitoring based on additional statistical data processing and technology of the optimal preventive threshold calculation are improved.
 Conclusions. The obtained results can be used during the development and modernization of operation systems of radio electronic equipment in terms of application of statistical data processing procedures. A comparative analysis of the two maintenance strategies showed that the use of additional statistical data processing might reduce specific operation costs. The proposed technology for determining the optimal preventive threshold can be extended to use during the operation of complex technical systems, in particular for those whose technical condition is associated with the values of the determining parameters.

Temperature and Voltage Dynamic Control of PEMFC Stack Using MPC Method

Proton Exchange Membrane Fuel Cell (PEMFC) is a multi-parameter and strongly coupled complex system, efficient and smooth operation is beneficial to the efficiency and stability of PEMFC. In this paper, aiming at improve the temperature and voltage management in PEMFC, a stack model is established, and a PEMFC temperature and voltage dynamic management controller based on Model Predict Control method (MPC) is proposed. The working temperature and output voltage are controlled by the mass flow rates of cooling water and hydrogen gas, respectively. The performances of PEMFC under different controller including MPC and traditional PID controllers are analyzed. The results show that the MPC controller can remarkably reduce the response time and overshoots of temperature and voltage. The temperature overshoot of MPC controller is lower than 1.1 K, and the response time is less than traditional PID controllers. Moreover, with step current change, voltage overshoot of MPC controller is less than 0.6V which is better than other controllers.

Ports and climate uncertainty: An economic imperative for India

ABSTRACT Seaports are an indispensable asset in interconnected and interdependent global supply chains. Their complex infrastructural and operational systems and critical foreland and hinterland networks make ports a vital nodal point in the economic progress of nations at large, and the coastal urban agglomerations in particular. These critical maritime assets are currently under threat from the disruptive impacts of anthropogenic climate change, such as sea-level rise and intensifying extreme weather events. The economic losses from these impacts will span a wide range, from hard infrastructural damages to operational delays in supply chain management. Incorporating climate resilience in existing and new port infrastructure remains a complex challenge that will require port authorities to confront the problem of climate uncertainty and its socio-economic implications. This article focuses on seaports in the Indian context to highlight the complex threats of climate change. It examines the main debates on climate uncertainty and policymaking, path dependencies in port planning, global best practices, knowledge gaps and strategies that will be critical for Indian ports to better confront climate change induced disruptions in the near future.

Degenerated Liouvillians and steady-state reduced density matrices

Symmetries in an open quantum system lead to degenerated Liouvillians that physically imply the existence of multiple steady states. In such cases, obtaining the initial condition independent steady states is highly nontrivial since any linear combination of the true asymptotic states, which may not necessarily be a density matrix, is also a valid asymptote for the Liouvillian. Thus, in this work, we consider different approaches to obtain the true steady states of a degenerated Liouvillian. In the ideal scenario, when the open system symmetry operators are known, we show how these can be used to obtain the invariant subspaces of the Liouvillian and hence the steady states. We then discuss two other approaches that do not require any knowledge of the symmetry operators. These could be powerful numerical tools to deal with quantum many-body complex open systems. The first approach that is based on Gram–Schmidt orthonormalization of density matrices allows us to obtain all the steady states, whereas the second one based on large deviations allows us to obtain the non-degenerated maximum and minimum current carrying states. We discuss the symmetry-decomposition and the orthonormalization methods with the help of an open para-benzene ring and examine interesting scenarios such as the dynamical restoration of Hamiltonian symmetries in the long-time limit and apply the method to study the eigenspacing statistics of the nonequilibrium steady state.

Prognostics and Health Management in Nuclear Power Plants: An Updated Method-Centric Review With Special Focus on Data-Driven Methods

In a carbon-constrained world, future uses of nuclear power technologies can contribute to climate change mitigation as the installed electricity generating capacity and range of applications could be much greater and more diverse than with the current plants. To preserve the nuclear industry competitiveness in the global energy market, prognostics and health management (PHM) of plant assets is expected to be important for supporting and sustaining improvements in the economics associated with operating nuclear power plants (NPPs) while maintaining their high availability. Of interest are long-term operation of the legacy fleet to 80 years through subsequent license renewals and economic operation of new builds of either light water reactors or advanced reactor designs. Recent advances in data-driven analysis methods—largely represented by those in artificial intelligence and machine learning—have enhanced applications ranging from robust anomaly detection to automated control and autonomous operation of complex systems. The NPP equipment PHM is one area where the application of these algorithmic advances can significantly improve the ability to perform asset management. This paper provides an updated method-centric review of the full PHM suite in NPPs focusing on data-driven methods and advances since the last major survey article was published in 2015. The main approaches and the state of practice are described, including those for the tasks of data acquisition, condition monitoring, diagnostics, prognostics, and planning and decision-making. Research advances in non-nuclear power applications are also included to assess findings that may be applicable to the nuclear industry, along with the opportunities and challenges when adapting these developments to NPPs. Finally, this paper identifies key research needs in regard to data availability and quality, verification and validation, and uncertainty quantification.

Tracking Ultrafast Structural Dynamics by Time-Domain Raman Spectroscopy.

In traditional Raman spectroscopy, narrow-band light is irradiated on a sample, and its inelastic scattering, i.e., Raman scattering, is detected. The energy difference between the Raman scattering and the incident light corresponds to the vibrational energy of the molecule, providing the Raman spectrum that contains rich information about the molecular-level properties of the materials. On the other hand, by using ultrashort optical pulses, it is possible to induce Raman-active coherent nuclear motion of the molecule and to observe the molecular vibration in real time. Moreover, this time-domain Raman measurement can be combined with femtosecond photoexcitation, triggering chemical changes, which enables tracking ultrafast structural dynamics in a form of “time-resolved” time-domain Raman spectroscopy, also known as time-resolved impulsive stimulated Raman spectroscopy. With the advent of stable, ultrashort laser pulse sources, time-resolved impulsive stimulated Raman spectroscopy now realizes high sensitivity and a wide detection frequency window from THz to 3000 cm–1, and has seen success in unveiling the molecular mechanisms underlying the efficient functions of complex molecular systems. In this Perspective, we overview the present status of time-domain Raman spectroscopy, particularly focusing on its application to the study of femtosecond structural dynamics. We first explain the principle and a brief history of time-domain Raman spectroscopy and then describe the apparatus and recent applications to the femtosecond dynamics of complex molecular systems, including proteins, molecular assemblies, and functional materials. We also discuss future directions for time-domain Raman spectroscopy, which has reached a status allowing a wide range of applications.

Moving Target Defense for SDN-Based Cloud Datacenter Network Protection

The significant advance of software Defined Networking (SDN) technology has enabled several complex system operations to be highly dynamic, flexible and robust; particularly in terms of programmability and controllability with the help of SDN controllers. Accordingly, many security operations have utilized this capability to be optimally deployed in a complex network using the SDN functionalities. Moving target defense (MTD) has emerged as an adaptive and proactive defense mechanism aiming to thwart a potential attacker. The key underlying idea of MTD is to increase uncertainty and confusion for attackers by changing attack surface (i.e., system or network configurations) that can invalidate the intelligence collected by the attackers and interrupt attack execution; ultimately leading to attack failure. In this research, by leveraging the advanced SDN technology, the model of MTD using SDN-based system framework design is proposed. The model uses a runtime model that allows the proposed framework to infer the current state of the system. Based on the obtained information, the MTD mechanism using SDN can provide proactive, adaptive and affordable defense services for the exploitable aspects of the cloud datacenter network to increase uncertainty and complexityto the attackers and reduce the likelihood of an attack and minimize cloud security risk. The research also validates the outperformance of the proposed MTD technique in attack success rate via simulation on SDN-based cloud datacenter network experiments in a virtualized environment

Embodied instrumentation in learning mathematics as the genesis of a body-artifact functional system

Recent developments in cognitive and educational science highlight the role of the body in learning. Novel digital technologies increasingly facilitate bodily interaction. Aiming for understanding of the body’s role in learning mathematics with technology, we reconsider the instrumental approach from a radical embodied cognitive science perspective. We highlight the complexity of any action regulation, which is performed by a complex dynamic functional system of the body and brain in perception-action loops driven by multilevel intentionality. Unlike mental schemes, functional systems are decentralized and can be extended by artifacts. We introduce the notion of a body-artifact functional system, pointing to the fact that artifacts are included in the perception-action loops of instrumented actions. The theoretical statements of this radical embodied reconsideration of the instrumental approach are illustrated by an empirical example, in which embodied activities led a student to the development of instrumented actions with a unit circle as an instrument to construct a sine graph. Supplementing videography of the student’s embodied actions and gestures with eye-tracking data, we show how new functional systems can be formed. Educational means to facilitate the development of body-artifact functional systems are discussed.

Development, fabrication and evaluation of passive interface gloves

Previously, glove-integrated communication based on gestures, hand movement and finger touch had a complex operating system and an active power source was needed. This paper introduces batteryless and maintenance-free interface gloves. Our solution is based on passive ultra-high frequency (UHF) radio frequency identification (RFID) technology, comprising four electro-textile antenna parts and three RFID microchips (each with a unique ID). The three RFID microchips have unique IDs, which can be activated by the gentle touch of the human finger and used to control the surrounding technology. The aim is to evaluate the reliability of different conductive materials and microchip attachment methods. The antennas are fabricated from two different materials: a stretchable and a non-stretchable commercial electro-textile. Further, two types of microchip attachment methods are used with both antenna materials: a conductive silver epoxy and embroidery with conductive multifilament silver-plated thread. The developed interface gloves are tested by six users in a home and in an office environment, where they achieve 93–100% success rates. Especially those glove interfaces with the antennas fabricated from the non-stretchable electro-textile and the antenna-microchip interconnections embroidered with conductive thread showed good read ranges (80–110 cm). The gloves also show practical functionality, when tested with a mobile reader in practical identification and access control application. These results are very encouraging, especially when considering that the interface glove, being maintenance-free and cost-effective, promises versatile and interesting applications for customizing user-friendly augmentative and alternative communication solutions, easy controlling of ambient assisted-living applications, and providing simple identification and access control for increased safety and comfort.

Guest Editors’ Introduction: Special Issue on Latest Developments for Security Management of Networks and Services

As the backbone of communications amongst objects, humans, companies, and administrations, the Internet has become a great integration platform capable of efficiently interconnecting billions of entities, from RFID chips to data centers. This platform provides access to multiple hardware and virtualized resources (servers, networking, storage, applications, connected objects) coming from cloud computing and Internet-of-Things (IoT) infrastructures. From these resources that may be hosted and distributed amongst different providers and tenants, the building and operation of complex and value-added networked systems is enabled.

Evolution of the Unix System Architecture: An Exploratory Case Study

Unix has evolved for almost five decades, shaping modern operating systems, key software technologies, and development practices. Studying the evolution of this remarkable system from an architectural perspective can provide insights on how to manage the growth of large, complex, and long-lived software systems. Along main Unix releases leading to the FreeBSD lineage we examine core architectural design decisions, the number of features, and code complexity, based on the analysis of source code, reference documentation, and related publications. We report that the growth in size has been uniform, with some notable outliers, while cyclomatic complexity has been religiously safeguarded. A large number of Unix-defining design decisions were implemented right from the very early beginning, with most of them still playing a major role. Unix continues to evolve from an architectural perspective, but the rate of architectural innovation has slowed down over the system's lifetime. Architectural technical debt has accrued in the forms of functionality duplication and unused facilities, but in terms of cyclomatic complexity it is systematically being paid back through what appears to be a self-correcting process. Some unsung architectural forces that shaped Unix are the emphasis on conventions over rigid enforcement, the drive for portability, a sophisticated ecosystem of other operating systems and development organizations, and the emergence of a federated architecture, often through the adoption of third-party subsystems. These findings have led us to form an initial theory on the architecture evolution of large, complex operating system software.

Highly Sensitive and Multiplexed In Situ RNA Profiling with Cleavable Fluorescent Tyramide.

Understanding the composition, regulation, and function of complex biological systems requires tools that quantify multiple transcripts at their native cellular locations. However, the current multiplexed RNA imaging technologies are limited by their relatively low sensitivity or specificity, which hinders their applications in studying highly autofluorescent tissues, such as formalin-fixed paraffin-embedded (FFPE) tissues. To address this issue, here we develop a multiplexed in situ RNA profiling approach with a high sensitivity and specificity. In this approach, transcripts are first hybridized by target-specific oligonucleotide probes in pairs. Only when these two independent probes hybridize to the target in tandem will the subsequent signal amplification by oligonucleotide hybridization occur. Afterwards, horseradish peroxidase (HRP) is applied to further amplify the signal and stain the target with cleavable fluorescent tyramide (CFT). After imaging, the fluorophores are chemically cleaved and the hybridized probes are stripped by DNase and formamide. Through cycles of RNA staining, fluorescence imaging, signal cleavage, and probe stripping, many different RNA species can be profiled at the optical resolution. In applying this approach, we demonstrated that multiplexed in situ RNA analysis can be successfully achieved in both fixed, frozen, and FFPE tissues.

Modelling and presentation of cyber-physical systems on the morphological approach basis

The article discussed cyber-physical systems are considered as a logical evolutionary stage in the development of system theory and system analysis. Cyber-Physical systems are a complex of interacting computational and physical components, with a constant exchange of information with the environment. The computational component can be easily changed and adapted to changing environmental conditions. At the same time, the re-construction of physical elements causes certain difficulties and already at the stage of conceptual design, they should be able to adapt to changes in the environment. Their use will allow you to achieve many advantages in the creation, management and operation of complex systems. These systems are highly adaptable in response to environmental changes, which leads to increased efficiency, are adaptable and transformative, and contribute to increased efficiency. The aim of the research was to find the position of cyber-physical systems in the general theory of systems. Morphological analysis was used for justification and selection, and it is proposed to use agglomerative clustering. The morphological representation made it possible to clearly determine the place of cyber-physical systems and to obtain a morphological set of possible variants. The creation of a classification morphological matrix will increase the accuracy of identification of these systems. For the first time, a morphological classification of cyber-physical systems as subsets of complex systems is given.

A Column Study on The Efficiency and Reusability of Kapok Fibre as Car Wash Wastewater Treatment

The car washing industry which consumes large amount of water produces Car Wash Wastewater (CWW) which were likely to exceeds the standard set in both Malaysia’s and Singapore’s regulation. Kapok Fibre (KF) is a natural adsorbing material which have large lumen and low density is believed to be able to act as an adsorbent to manage the CWW. This study was done to determine the characteristic of KF and CWW and investigate the efficiency of KF in treating CWW along with the reusability of KF through a column study with Organic Loading Rate (OLR) of 12.41g COD/L.day. The CWW contains a certain concentration of Chemical Oxygen Demand (COD, Oil and Grease (O&G), and Anionic Surfactant (AS) though the interaction between KF and AS is novel. KF found out to has the capability in removing COD, O&G, and AS up to 88.37%, 100%, and 83.8% respectively. However, in reusability experiment there is limitation to KF in which by exceeding the operation time to 600 minutes of treatment, the efficiency in removing COD, O&G, and AS were found to drop to 62.02%, 75%, and 55% respectively. This shows that KF could be an avant-garde, low-cost sustainable treatment to treat CWW instead of the conventional high cost and complex operating system.

SAT and SMT-Based Verification of Security Protocols Including Time Aspects.

For many years various types of devices equipped with sensors have guaranteed proper work in a huge amount of machines and systems. For the proper operation of sensors, devices, and complex systems, we need secure communication. Security protocols (SP) in this case, guarantee the achievement of security goals. However, the design of SP is not an easy process. Sometimes SP cannot realise their security goals because of errors in their constructions and need to be investigated and verified in the case of their correctness. Now SP uses often time primitives due to the necessity of security dependence on the passing of time. In this work, we propose and investigate the SAT-and SMT-based formal verification methods of SP used in communication between devices equipped with sensors. For this, we use a formal model based on networks of communicating timed automata. Using this, we show how the security property of SP dedicated to the sensors world can be verified. In our work, we investigate such timed properties as delays in the network and lifetimes. The delay in the network is the lower time constraint related to sending the message. Lifetime is an upper constraint related to the validity of the timestamps generated for the transmitted messages.

Analysis of experience of the smart cities’ organization and substantiation of their development conception

The article analyzes the advantages and disadvantages of modern smart cities, as well as outlines their development conception.Goal. Experience in the design, construction, and operation of smart cities, both completely new and implemented in the form of particular technologies, provides a large amount of data for systematic analysis of their advantages and disadvantages. In turn, the results of such an analysis should be taken into account in the scientific substantiation of the concept of the development of smart cities. The purpose of the publication is to present the results of a systematic analysis of the smart city organization experience and substantiation of the smart city development conception.Methodology. The study was conducted based on a systematic approach in several stages. To determine the strengths and weaknesses of smart cities concerning internal and external factors, the method of SWOT-analysis is used, the results of which are used to substantiate the conception of smart city development. This conception is based on the idea that ​​the city is a complex open dynamic system, formalized from the standpoint of the theory of self-organization of complex systems, as well as bionic analogies of the functioning of the city and living beings.Results. The data characterizing the parameters of smart cities are analyzed. Their advantages and disadvantages are revealed. It is established that they have a systemic nature and are manifested at all levels of organization of the urban environment. The conception of the development of smart cities is sustained. The conception is formulated in the form of five general provisions, principles of organization and coordination of levels of the urban environment, as well as two additional provisions relating to methods of assessment and optimization of the environment.Scientific novelty. Based on the system approach and the theory of self-organization of complex systems the conception of smart city development is sustained for the first time.Practical significance. The data collected on smart cities can be used in a variety of analytical, marketing, and statistical research. The results of the SWOT-analysis can be used to substantiate the conceptions and strategies for the introduction of smart technologies both in the traditional urban environment and in the construction of completely new smart cities.The proposed conception of smart city development can be used in determining the feasibility and purpose of building such a city (district, street, etc.), the introduction of certain technologies, prevention and correction of errors, evaluation, and optimization of the urban environment.