Scientific visualization: a performance study of CSMA/CD with connected data links-(Hybrid-Ethernet)

Fine-Grained Parallel and Distributed Spatial Stochastic Simulation of Biological Reactions

In this paper the problem of simulation of the dynamics of an electron beam in the small-sized induction accelerators developed in Tomsk Polytechnic University is considered. The description of the computer simulation system intended for automation of designing of the new types small-sized cyclic accelerators is also given. In the described system the numerical models based on the one-particle description of a beam and on the method of super-particles are used. The results of simulation of an electronic beam interaction with a target during all cycle of acceleration are presented. The system of computer simulation was carried out in the C++ Builder environment.

Nowadays, the power system is evolving into a complex cyber physical system with the closely merged physical system, information system, and communication network. It is critical to understand the connections between the power and cyber systems, and the potential impact of cyber vulnerability. In this study, a flexible hardware‐in‐the‐loop (HIL) testbed is proposed for studying the cyber physical power system. By using the flexible interface, various co‐simulation systems for different purposes are generated. Based on this testbed, three sample co‐simulators are built as proofs. First, a HIL power and communication co‐simulator with non‐real‐time synchronisation mechanism is introduced, and a case of false data injection attack on automation voltage control is studied. Then, a real‐time power and communication HIL co‐simulator is introduced, and a case considering the impact of communication bit error on the stability control system is simulated to demonstrate the performance of stability control equipment. Finally, another co‐simulator for simulating the actual cyber‐attack on the stability control system is introduced, and a case of a man‐in‐the‐middle attack on the data link is simulated to demonstrate the impact of cyber‐attack on the stability control system.

Sediments in many parts of the New York and New Jersey estuary system are contaminated with toxic organic and inorganic compounds by different sources. Because of the potential environmental consequences, detailed information on the spatial distribution of sediment contaminants is essential in order to carry out routine shipping channel dredging in an environmentally responsible way, and to remediate hot spots cost-effectively and safely. Scientific visualization and scatter data modeling techniques have been successfully applied in analyzing the sparse sampling data of sediment contaminants in New York and New Jersey estuaries, the underlying spatial characteristics of which are otherwise difficult to comprehend. Continuous realizations of contaminant concentrations in the region were obtained by using a spectral domain-decomposition scattered data model and IBM Data Explorer which is a software package for scientific data visualization.

Physical experiments allow to obtain maximum information on a studied process at minimal cost, ensuring its higher accuracy comparing with data, obtained by mathematical simulation and avoiding risks, which can occur at industrial testing of new technological modes. Results of studies of deformation in the process of pipes production by extrusion presented. The studies were accomplished at laboratory test units, developed by specialists of the laboratory of drawing and extrusion of JSC “RusNITI”. One of the basic problems at pipes production by extrusion is ensuring minimal possible wall non-uniform thickness. It was noted that the relation between plunger die moving speeds during sleeve pressing-out and immediate pipe extrusion has a significant effect on pipe wall non-uniform thickness. Computer simulation of the pipe extrusion process, accomplished by application QForm program shown that minimal values of wall non-uniform thickness corresponded to relation abovementioned speeds as 0.5–0.8. To check the data, a physical simulation of extrusion process of lead cylinder samples, having outside diameter of 18.94 mm and wall thickness 5.19–5.32 mm was accomplished. For the extrusion, a universal servohydraulic system of dynamic test Shimadzu Servopulser was used. Within the physical experiment a dependence was established between pipe wall non-uniform thickness on relation between speeds of pressing-out and extrusion. The revealed regularity was confirmed during pilot production of a pipe lot at the 55 MN force extrusion line. Another physical simulation of extrusion of 10.0×2.0 mm pipe-samples made of C1 grade lead was accomplished with one- and twothread helical ribbing of internal surface. For its accomplishment an experimental module was designed and manufactured. It was established that rotation speed of the extrusion mandrel had no significant effect on extrusion force. Metallographic studies shown that the extrusion mandrel rotation speed contributes to considerable increase of pipes surface hardness and obtaining finer grain comparing with the classic extrusion method. The technical ability of pipes production with internal helical ribbing by hot extrusion method was confirmed. The results of the study became a base for elaboration of a technology of pipes production at Volzhsky pipe plant according to ТУ 14-3Р-157–2018 “Steel seamless hot-extruded pipes with helical ribbing of internal surface for steam boilers”. Results of physical simulation of pipe drawing process at self-adjusting mandrel with application of lubricant materials of various viscosity. The data obtained were used for elaboration of a technology for production of cold-deformed pipes with internal diameter of 6.0–12.0 mm at Sinarsky pipe plant.

The article deals with the problem of future physics specialist preparation in modern conditions of cardinal updating the educational in Ukraine content,which is based on tendencies of globalization, integration, fundamentalization, humanization, continuity, differentiation, individualization, informatization, diversification, multilevel and standardization of modernity and standardization processes. It has been found out that issues that bring the content of education and its forms 1)into perspective directions of socio-economic development of the country; 2) in accordance with international educational requirements and standards, are based on the principles of a competent approach. In this regard, the problem of forming competent university graduates studying in the educational programs "Secondary Education (Physics)", "Physics and Astronomy" and "Applied Physics and Nanomaterials" under new conditions is acute. Methodical approaches to creation and development of innovative educational environment in physics defined by the competence-oriented education paradigm, which is based on the integrated usage of modern methods, techniques, technologies and means of ICT for forming competent graduates of physical specialists are presented. It is determined that special attention needs to be given to strengthening the practical orientation of teaching physics and the applied importance of physical knowledge in the modern conditions of creation and development of innovative educational environment in physics in higher education institutions. It is suggested to use computer modeling of physical phenomena and processes in practical classes in order to form the students’ subject competences (for example, studying the section "Optics" of the general course of physics). The article gives examples of such physical tasks in optics, the results of which can be analyzed and presented in the form of computer models or graphical dependencies, or involve the programming of certain physical dependencies for further studying by a computer model or graphical interpretation. Key words: competency approach, subject competence in physics, computer simulation of physical processes, physical problems, methods of teaching physics at university.

Recently, Digital Twin-based solutions have been proposed as experimentation platforms to study the behaviour of Cyber-Physical Systems (CPS) under attack, and design appropriate detection and mitigation measures. Existing solutions focus on physical process, control logic, or network communication simulation. Unfortunately, none of the Digital Twin solutions currently available provide a realistic and holistic solution to represent all three aspects. In this work, we propose the Digital HydrAuLic SIMulator (DHALSIM), a Digital Twin for water distribution systems that simulates physical, control, and network processes. DHALSIM builds on the integration of the Water Network Tool for Resilience (WNTR) hydraulic simulator and MiniCPS—an industrial network emulator—which are run in a co-simulation environment. Thanks to this integration, DHALSIM is able to simulate the hydraulic processes characterizing a water distribution system as well as full stack emulation of well-known industrial control protocols. The Digital Twin is demonstrated on the benchmark case study of C-Town, where we carry out a number of cyber-attack experiments. To our knowledge, DHALSIM is the first Digital Twin that implements a well known physics simulator with a virtual industrial logic and network emulation environment for water systems. DHALSIM is open source and available to the research community.

For implementation of Cyber-Physical Systems (CPS) simulation, interoperability between physical and cyber system are required. IEEE High Level Architecture (HLA) is standard for distributed simulation interoperability, and ETSI Machine-to-Machine (M2M) is standard for integration between physical machines. In this paper, we propose M2MHLA adaptor to integrate HLA-based simulations and M2M physical machines. M2M-HLA adaptor is located between HLA simulation systems and M2M systems. This adaptor transforms HLA data to M2M data and M2M data to HLA data. We propose sequence structure between M2M-HLA APIs for interconnection, data type definition and transformation method and time management method for design and implementation M2M-HLA adaptor. Because of M2M-HLA adaptor allows interoperability between different cyber systems and physical systems, this would extend the scope of CPS simulation system and increase its utilization.

Many real-life applications of processor-arrays suffer from memory bandwidth limitations. In many cases an unstructured mesh is given (computation on sensor data, simulations of physical systems — PDEs), where the vertices represent computations with dependencies represented by the edges. Utilization of processing elements (PEs) during these computations is mainly depends on the node indexing of the mesh. If the adjacent nodes are stored close to each other in main memory, the reloading of node data can be significantly decreased. In case of FPGA the memory accesses can be fully determined by the designer. The mesh and an ordering of its nodes, define the graph bandwidth, which determines the minimum size of on-chip memory to avoid reloading of the nodes from the off-chip memory. If the required on-chip memory size is higher than the available resources, the mesh must be divided into parts. In this paper a novel geometry-based method is presented, which constructs reordered parts from a given unstructured mesh, where each part meets some predefined constraints on graph bandwidth.

In this paper, an event driven strategy is used to design a distributed simulation system, and a distributed simulation architecture of three-tiers is proposed. Based on the service-oriented design of event-driven distributed simulation system, the hierarchical design of WCF-based simulation hierarchy is completed, and the data transfer and loose coupling between the components of the architecture are realized. Considering the system-level modeling idea based on the design structure matrix, an improved event scheduling method is proposed and the incident management technology is studied. Based on the above research, a simulation system was designed and developed. Taking the multidisciplinary modeling and simulation of the all-electric telecommunication satellite as a case, the simulation application integration and simulation results were analyzed to verify the versatility and correctness of the simulation system.

Discrete dynamic simulation models and technique for complex control systems

Summary form only given. A description of the thermodynamic properties of matter in a wide range of temperatures and pressures is of fundamental as well as practical interests. The equations of state for metals over the range from normal conditions to extremely high energy densities are necessary for hydrodynamic simulations of processes in plasmas under pulsed power influences. In this report, a new semiempirical equations-of-state model, which takes into account melting, evaporation and ionization effects, is proposed. Wide-range equations of state for some metals (aluminum, gold, tungsten and others) are constructed on the basis of model developed. Calculation results are compared with available high-temperature, high-pressure experimental data. Most essential dynamic experiments are described. The equations of state can be used efficiently in numerical simulations of different physical processes in the metals at high energy densities.

In order to improve the control ability of the human body in the process of physical training, it is necessary to carry out the inverse simulation analysis of the physical training process and establish the process control model of the physical training. The complex problem of high-dimensional spatial motion planning involved in physical training is decomposed into a series of sub-problems in low-dimensional space, and the inertial attitude parameter fusion is carried out according to the position and pose state of the human body in the end of the workspace during the process of physical training. The design of sensor node and base station in the system can realize real-time collection of motion parameters of motion collectors. The multi-dimensional control of physical training process is carried out by fuzzy constraint and inverse integral control, and the attitude parameters of human body are adjusted by means of mechanical analysis model and inertial parameter analysis method. The simulation results show that the inversion simulation control has better convergence, higher control quality, and better inverse simulation performance in the process of physical training, which can effectively guide physical training and improve the effect of physical training.

An extended finite volume model for implicit cohesive zone fracture propagation in a poroelastic medium

Software simulation is one of the most common methods to study worm propagation. However, simulation process and software interface, which lack unified description, cause inefficiencies of worm propagation simulation. In order to achieve a unified description for worm propagation simulation process, we propose a Worm Propagation Simulation Description Language (WPSDL), which characterizes the software interfaces and parameters of each module in simulation process in a unified way. Meanwhile, we develop a simulation system of worm propagation oriented our presented language. In this system, we use related commands of the description language as interactive instructions, and then implement worm propagation simulation for different types of network worms. In addition, we conduct a series of experiments to analyse the impacts of worm propagation mechanism and network topology structure. The experiments show that increasing infection ability and scanning rate can improve the propagation scale significantly, and the propagation delay can influence the outbreak time and explosion intensity of worm propagation. The experiments not only provide support for the study of worm propagation mechanisms, but also verify the practicability of the description language and the simulation system.