Design Of Simulation Model Research Articles

Similarity Criteria of Water Drive Physical Simulation of Pressure-Sensitive Fractured Reservoirs

A mathematical equation of water drive physical simulation of pressure-sensitive fractured reservoirs was established based on previous research results. In this study, the similarity criteria of water drive physical simulation of pressure-sensitive fractured reservoirs were derived according to the similarity theory. First of all, based on the three-dimensional differential equation of rock mechanics, a dimensionless analysis was conducted to determine the similarity relationship between the displacement of oil by water of pressure-sensitive fractured reservoirs, the similarity criterion was obtained, and the similarity criteria were formed. Secondly, according to the similarity criterion, the similar relationship between the stress-strain fields of the real object and the simulated object was worked out. Thirdly, the finite element software COMSOL Multiphysics was applied to model and calculate the multifield coupling process in the percolation of pressure-sensitive fractured reservoirs, verifying the correctness of the established similarity criteria and similarity relationship. The verifying results shows that the similarity between the physical model and the actual model can be realized by magnifying the geometric size N times in a certain direction and adjusting the load and boundary conditions according to the similarity principle, which can be used for the design of the pressure-sensitive fractured reservoir simulation model for a physical indoor test.

Energy harvesting effect on prolonging low-power lossy networks lifespan

Low-power lossy networks performance relies heavily on the wireless node battery status. Furthermore, Routing Protocol for Low-Power and Lossy Network routing protocol was not optimally designed with sustainable energy consumption in mind to suit these networks. Prolonging the lifespan of these networks is of utmost priority. This article introduces a solar energy harvesting module to power energy-constrained network devices and quantifies the effect of using harvested energy on prolonging their network lifetime when Routing Protocol for Low-Power and Lossy Network routing protocol is used. Simulation of the new developed module is conducted in three different scenarios using Contiki Cooja simulator sporting Zolertia Z1 motes. Furthermore, the harvested energy used was fed from a Cooja-based Simulation model of actual PV supercapacitor circuit design. All battery levels were set to 1% of their total capacity for all nodes in the network to speed up observing the energy harvesting effect. The performance evaluation results showed that the network with no-energy harvesting operated for time duration of 4:08:04 time units (i.e. hour:minute:second) with a dramatic decrease in connection between nodes in the network. However, the same network, when using the harvested energy to back up the battery operation, lasted for 6:40:01 in time units with improved connectivity, a total extended network lifetime of 2:31:97-time units. Furthermore, for the Routing Protocol for Low-Power and Lossy Network routing metrics, OF0 outperformed ETX in term of throughput, packet delivery ratio, energy consumption, and network connectivity. Results indicate that the developed harvested energy module fits perfectly for any Cooja-based simulation and mimics actual photovoltaic-based supercapacitor battery. It should also help researchers introduce and quantify accurately new energy consumption-based routing metrics for Routing Protocol for Low-Power and Lossy Network.

Функциональные возможности среды Wolfram Mathematica для визуализации кривых линий и поверхностей

The paper states that the current conditions in which the education system is located, and the rapid development of IT require constant improvement of methodological materials, taking into account the full capacity of the current software. Examples of programs necessary for preparation of methodological materials for high-quality classes are given. The purpose of the paper was to identify the Wolfram Mathematica didactic potential when conducting classes in the disciplines of the geometric and graphic profile at a technical high educational institution. In this paper has been performed analysis of literature sources both domestic and foreign ones on the Wolfram Mathematica system application in science and teaching of various disciplines. It has been shown that the program use scope is very wide, in fact, it is comprehensive and requires additional and in-depth study. Examples of Wolfram Mathematica using in mathematics, physics, chemistry, geometry, robotics, virology, and the humanities are given. In the paper have been provided examples for pedagogical design of simulation models for an electronic course on descriptive geometry in the Moodle system. An example of code written in the Wolfram Mathematica is provided. Interactive models developed during the design are presented, which allow the user to change the constructed curves and surfaces’ parameters. Have been defined some functional capabilities of the system, and has been revealed the Wolfram Mathematica didactic potential for teaching geometric and graphic disciplines. Have been considered other authors’ similar models, which can be used in the educational process to increase the clarity of the material presented in the classroom. In conclusion it is pointed out that interactive visualization in the "Descriptive Geometry" discipline, together with classical working practices, significantly enriches the content of geometric education.

Функциональные возможности среды Wolfram Mathematica для визуализации кривых линий и поверхностей

The paper states that the current conditions in which the education system is located, and the rapid development of IT require constant improvement of methodological materials, taking into account the full capacity of the current software. Examples of programs necessary for preparation of methodological materials for high-quality classes are given. The purpose of the paper was to identify the Wolfram Mathematica didactic potential when conducting classes in the disciplines of the geometric and graphic profile at a technical high educational institution. In this paper has been performed analysis of literature sources both domestic and foreign ones on the Wolfram Mathematica system application in science and teaching of various disciplines. It has been shown that the program use scope is very wide, in fact, it is comprehensive and requires additional and in-depth study. Examples of Wolfram Mathematica using in mathematics, physics, chemistry, geometry, robotics, virology, and the humanities are given. In the paper have been provided examples for pedagogical design of simulation models for an electronic course on descriptive geometry in the Moodle system. An example of code written in the Wolfram Mathematica is provided. Interactive models developed during the design are presented, which allow the user to change the constructed curves and surfaces’ parameters. Have been defined some functional capabilities of the system, and has been revealed the Wolfram Mathematica didactic potential for teaching geometric and graphic disciplines. Have been considered other authors’ similar models, which can be used in the educational process to increase the clarity of the material presented in the classroom. In conclusion it is pointed out that interactive visualization in the "Descriptive Geometry" discipline, together with classical working practices, significantly enriches the content of geometric education.

An Investigation of a Novel Dural Repair Device for Intraoperative Incidental Durotomy Repair.

Incidental durotomies, or dural tears, can be very difficult and time consuming to repair properly when they are encountered in confined spaces. A novel dural repair device was developed to address these situations. In this paper, the novel device was assessed against the use of traditional tools and techniques for dural repairs in two independent studies using an intricate clinical simulation model. The aim was to examine the results of the two assessments and link the outcomes to the clinical use of the novel device in the operating room. The novel device outperformed conventional techniques as measured by dural repair time, CSF leak pressure and nerve root avoidance in the simulation. The results were generally replicable clinically, however, numerous additional clinical scenarios were also encountered that the simulation model was unable to capture due to various inherent limitations. The simulation model design, potential contributors to watertightness, clinical experiences, and limitation are discussed.

Design and Implementation of General Target Aircraft Maneuver Simulation Model Based on JSBSim

Design and Implementation of General Target Aircraft Maneuver Simulation Model Based on JSBSim

Harnessing the Power of Data

Research capacity is the basic currency of a sentencing commission, and the gold standard is data, with its capability of being transformed into meaningful information to support policy development and guide sentencing decisions. This paper investigates the science of best practices in Pennsylvania and the roles of the Pennsylvania Commission on Sentencing in collecting, preparing, and disseminating sentencing and resentencing data; in collaborating with other agencies to integrate justice-related data; and in establishing partnerships to expand the research capacity of the Commission to use these data. The application of evidence-based practices—of harnessing the power of data to develop policy and support decision making—will be demonstrated through a discussion of four Commission projects: construction and validation of a sentence risk assessment instrument; comprehensive review of the use of criminal history in the Pennsylvania Sentencing Guidelines; establishment of state parole guidelines; and design of a modular population projection simulation model.

Eye Protection in ENT Practice During the COVID-19 Pandemic.

ObjectivesThere is a lack of evidence-based guidelines with regard to eye protection for aerosol-generating procedures in otolaryngology practice. In addition, some recommended personal protective equipment (PPE) is not compatible with commonly used ENT equipment. This study aims to investigate the degree of eye protection that commonly used PPE gives.Study DesignSimulation model.SettingSimulation laboratory.MethodsA custom-built setup was utilized to simulate the clinical scenario of a patient cough in proximity of a health care worker. A system that sprays a xanthan-fluorescein mixture was set up and calibrated to simulate a human cough. A mannequin with cellulose paper placed on its forehead, eyes, and mouth was fitted with various PPE combinations and exposed to the simulated cough. The degree of contamination on the cellulose papers was quantified with a fluorescent microscope able to detect aerosols ≥10 µm.ResultsWhen no eye protection was worn, 278 droplets/aerosols reached the eye area. The use of the surgical mask with an attached upward-facing shield alone resulted in only 2 droplets/aerosols reaching the eye area. In this experiment, safety glasses and goggles performed equally, as the addition of either brought the number of droplets/aerosols reaching the eye down to 0.ConclusionWhen used with an upward-facing face shield, there was no difference in the eye protection rendered by safety goggles or glasses in this study. Safety glasses may be considered a viable alternative to safety goggles in aerosol-generating procedures.

Three-Dimensional Electro-Thermal Analysis of a New Type Current Transformer Design for Power Distribution Networks

In recent years, the new type design of current transformer with bushing structure has been widely used in the distribution network system due to its advantages of miniaturization, high mechanical strength, maintenance-free, safety and environmental protection. The internal temperature field distribution is an important characteristic parameter to characterize the thermal insulation and aging performance of the transformer, and the internal temperature field distribution is mainly derived from the joule heat generated by the primary side guide rod after flowing through the current. Since the electric environment is a transient field and the thermal environment changes slowly with time as a steady field under the actual conditions, it is more complex and necessary to study the electrothermal coupling field of current transformer (CT). In this paper, a 3D simulation model of a new type design of current transformer for distribution network based on electric-thermal coupling is established by using finite element method (FEM) software. Considering that the actual thermal conduction process of CT is mainly by conduction, convection and radiation, three different kinds of boundary conditions such as solid heat transfer boundary condition, heat convection boundary condition and surface radiation boundary condition are applied to the CT. Through the model created above, the temperature rise process and the distribution characteristics of temperature gradient of the inner conductor under different current, different ambient temperatures and different core diameters conditions are studied. Meanwhile, the hottest temperature and the maximum temperature gradient difference are calculated. According to this, the position of weak insulation of the transformer is determined. The research results can provide a reference for the factory production of new type design of current transformer.

Performance Evaluation of WDM Channel Transmission for Probabilistic Shaping With Partial Multilevel Coding

We propose partial multilevel coding (MLC) for optical communications with probabilistic shaping (PS), which improves the signal-to-noise ratio performance and makes information rates more adaptable, while reducing the power consumed by forward error correction. We designed simulation models of partial-MLC and bit-interleaved coded modulation (BICM) implementing the same low-density parity-check code to have almost the same transmission performance in an additive white Gaussian noise channel. The estimated power consumption of the partial-MLC model was about 38~39% lower than that of the BICM model. Next, we evaluated the effect of nonlinearity on fiber wavelength division multiplexing (WDM) channels in numerical simulations. The results showed that both models behaved similarly regardless of nonlinear noise, illustrating the usefulness of MLC with PS for optical transmissions on WDM channels.

Analysis three dispersion compensation techniques using DCF

Abstract Dispersion is one of the very important parameters that effect on the performance of optical fiber communication systems. It causes pulse broadening, limiting of transmission distance and low bit rate. Dispersion compensation fiber (DCF) is widespread used in the dispersion compensation scheme. In this paper, the suggested DCF included (pre–post-symmetrical) schemes with various bit rates (10–60 Gbit/s), and the positive dispersion accumulated over the length of the fiber at 100 km of optical fiber with 21.25 km of DCF. Optisystem software version 7 is used to design simulation model. The performances have been compared on the basis of parameters such as Q factor, bit error rate (BER) and eye height which used to evaluate the performance analysis of the system. We concluded that the symmetrical compensation techniques are better than the other compensation schemes when the Q factor is 14.9536 and BER is 1.759842.10−0.22, these at 60 Gbit/s and the input cw laser frequency equal 193.1 THz.

Design of precise simulation model of power converter of energy storage system located within micro-grids

In this paper, the modeling procedure of the bidirectional power converter for energy storage systems located within microgrids is being described. The aim was to develop simulation model with accurate behavior compared to experimental sample, due to implementation of the model within system-level simulations of complex microgrid systems. Simulations have been performed with PLECS circuit simulator. Also experimental sample similar to circuit topology of simulation model was realized within reduced power ration of the target application (1:10). Simulation models have been optimized based on laboratory findings to obtain the maximum degree of operating property precision possible. As a result of this approach, high-accuracy simulation models of DC microgrid systems can be created, allowing any operating scenario to be investigated at the appropriate power delivery.

Design and assessment of a penile fracture simulation model

Design and assessment of a penile fracture simulation model

Design and Study of Simulation Model for Organization of the VHF Station Network

A scientific and reasonable construction of the organizational simulation model of the VHF station is based on executing the simulation evaluation of the organization and effectiveness of the VHF station network. First, we analyzed in detail the requirements of the VHF station network organization simulation model construction from the perspective of organization. Secondly, the entity-oriented modeling method is adopted to design the model composition of the simulation entity, the relationship between the entity models, and the entity model behavior. Eventually, the UML modeling language is employed to create a connection between entity model behavior and information interaction. The simulation model constructed in this paper can provide core model resources for the design and implementation of the simulation system for VHF station network organization. Moreover, it can also provide reference for constructing organization simulation models of the other communication network.

Application of multigraph sampling method in network traffic design of simulation model of integrated telecommunication and computer network

Designing an integrated telecommunications and computer network using a simulation model requires defining all the network and communication elements that make up the network and network communication. The accuracy, quality, and usability of the simulation results depend on the accuracy and the way of defining the network traffic as a timed event between the source and the destination in the network. In this paper, the method for a more accurate definition of network traffic required for the development of a simulation model using the software tool OPNET is proposed. Network traffic can be represented using a multigraph associated with an appropriate matrix of network traffic over time. Time definition of network traffic is enabled by applying the method of sampling multigraphs with the mathematical derivation of the corresponding statistical distribution function. Predicted or existing communication in the network describes using the derived function of network traffic distribution and precisely defines the OPNET simulation model.

Industrial plants investment projects efficiency estimation based on simulation and artificial intelligence methods

Methods and software enabling the estimation of efficiency and the comparisons of alternative designs of industrial plants are discussed. Problem of efficiency estimation for investment projects of industrial plants is formulated in the terms of decision theory. Presented approach is based on the reduction of multicriterion problem of investment project estimating to one-criterion problem. Application of simulation and artificial intelligence (AI) methods for estimation of technological and structural decisions, is the central feature of presented approach. Designed simulation model refers to discrete-event class. Object-oriented approach was applied for designing of the model and programming language C++ for its implementation. After it’s successful implementation this model was improved, in order to obtain robust, adaptive, re-configurable and responsive system. That was done with self-organization, self-learning, self-adaptation, self-optimization. This approach is based on application of AI methods (multi-agent systems (MAS), in particular) for simulation model development. MAS is a bio-inspired paradigm that allows to design systems based on autonomous and cooperative agents, exhibiting modularity, robustness, flexibility, adaptability and re-configurability. Presented methodology is tried-and-true method which applies on the phase of designing and engineering of industrial plant. This approach is discussed on the example of foundry plant with moulding line.

Theoretical and methodological features of creating reservoir models of hydrocarbon fields

To increase the efficiency of appraisal and development of hydrocarbon fields, the most effective technology is the integration of geological and field information into modern software systems for reservoir simulation, starting from the input of seismic data to field development planning based on a reservoir models. Building a three-dimensional geocellular models is an integral part of hydrocarbon reservoir management. After all, the reservoir model built to solve the main tasks of reservoir management such as: achieve the highest recovery and maximum economic effect. The modern level of software and the advances in computer processing power and graphics allows you to operate with big data, provides an opportunity for its systematization, statistical processing and detecting the basic laws between them. The availability of reliable data plays important role in the creation of a database for reservoir models. The input data for reservoir modelling of the fields, which were discovered in the 1960s, are the results of complex studies, characterized by insufficient accuracy and low quality. Lack of reliable and high-quality data brings significant uncertainty in all stages of modelling from volumetric estimation to the history match and forecasting. The necessity of using available geological and field information has led to the development of new methodological principles and approaches to reservoir modelling in conditions of limited initial information. According to the results of numerous studies, a significant number of methods have been developed, which are successfully used in the design of simulation models of hydrocarbon reservoirs of JSC “Ukrgazvydobuvannya”. Thanks to the use of new approaches to the building of 3D-models, high accuracy and reliability of the simulation results under such conditions is achieved.

A Coupled Effect Model of Two-Position Local Geometric Deviations on Subsonic Blade Aerodynamic Performance

The coupled aerodynamic performance influence of multiple deviations in the blade profile is a complex phenomena. In this paper, a high-pressure compressor rotor blade mid-span profile is studied with the design of experiments (DOE), numerical simulation and surrogate model to analyze the influence of the deviations on the blade aerodynamic performance. The purpose of this work is to provide a new rapid evaluation approach for the blade aerodynamic performance under multiple geometric deviations influence. First, the Hicks-Henne function was used to model the local geometric deviations of the blade profile, and the blade aerodynamic performance was calculated by using the computational fluid dynamics tools. By analyzing the calculation results, the momentum thickness of the boundary layer, the deviations height and the distance between the deviations are combined into a coupled effect model. Then, the coupled effect model was used to rapidly evaluate the blade aerodynamic performance when the two-position local geometric deviations exist on the blade surface. Finally, the evaluated performance were compared with the results predicted by a high-precision surrogate model, which verifies the high accuracy of the coupled effect model in evaluating the positive incidence range of the blade profile.

A PDF-based performance shift approach for reliability-based design optimization

A probability density function (PDF)-based performance shift approach (PPSA) is proposed for sequential reliability-based design optimization (RBDO) in this paper, which provides an effective tool for complex engineering design with consideration of uncertainties associated with design variables and simulation models. It converts the double-loop probabilistic optimization into a serial of cycles of reliability assessment and deterministic optimization through a performance shift strategy. The approach further proceeds by calculating the performance shift scalar and then solving a deterministic design optimization at each cycle, and eventually converges to the optimum design solution. The novelty of the proposed approach lies in two main aspects. First, the shift scalar is deducted for each probabilistic constraint in the response space, rather than in the design variable space, through which the violated constraints are moved towards the reliable region and the design solutions are improved progressively. Second, reliability analysis methods that calculate the moments or probability density functions, rather than most probable points or reliability indexes, are able to be integrated in the sequential RBDO framework, through which we could enhance the performance of existing sequential RBDO methods, especially the computational efficiency. Three numerical examples are investigated to demonstrate the effectiveness of the proposed approach, and the proposed approach is further utilized to perform crashworthiness design of a vehicle side impact problem.

A Visual transformation method of SysML model to Modelica model

The core idea of Model based systems engineering (MBSE) is to model all the information related to the system design starting from the beginning of the system development in the integrated form, and serve as a central system model throughout the product system life cycle. In view of the lack of executable capability of the standard system modeling language (SysML) within MBSE, the system design-simulation model transformation method was studied. Visualizing the transformation process based on SysML could contribute to the low complexity of the transformation. Finally, an example of 3D printer is used to verify the proposed method.