Software Platform Evaluation - Verifiable Fuel Cycle Simulation (VISION) Model

This paper addresses the usability of mathematical models for simulation of sediment pattern in the River Nile. Therefore, CCHE2D as a two-dimensional model was used for mathematical simulation in this work. Velocity distribution is one of the major parameters affecting sediment process in open channels and reservoirs. Since it is very difficult to simulate analytically the sediment process in channels and reservoirs, simulation models are mostly used. Accurate results from models simulating sediment process depends greatly on the accuracy of the simulation of the velocity components. This paper is focuses on calibrating CCHE-2D simulation model in order to be able to predict accurately the 2-D transverse velocity distribution and bed morphology along the River Nile. Measured field velocity data collected by Nile Research Institute were used in the calibration of the model. The calibrated and verified simulation model (CCHE-2D) was used to predict the velocity distribution at four sections along the Nile at certain locations. The selected sections are located within a length of 1.53 km. A drinking water pump station is located at the middle of the selected reach. The selected reach covers locations from km 7.78 to km 9.31 downstream El-Roda gauging stations (km 934.785 to the km 936.31 from Aswan dam). Statistical measures indicated that the model results are accurate enough for all practical purposes and hence the model could be used to predict the morphological changes in the River Nile

Technology development and deployment decisions are justified by weighing their costs against the expected benefits. Multiple nuclear fuel cycle (NFC) simulation models have been devised, some with the aim of quantifying cyclewide sensitivities to variations from base-case scenarios. Base-case sensitivity studies often perturb only one parameter at a time and only in the region around the initial value. This paper details a sensitivity study methodology that applies entropy-based statistical methods of information theory to describe outcomes produced by an NFC model. This supersedes past efforts at sensitivity and uncertainty analysis by allowing a much larger space to be explored. Here, 30 independent fuel cycle parameters for a fast reactor-light water reactor hybrid scenario are varied simultaneously and stochastically. This fuel cycle schema was chosen as a well-known, sufficiently complex model; the underlying statistical methods could be applied to any cycle. This study uses the uncertainty coefficient computed from contingency tables (CTs) to represent the sensitivity of a technology-defining input to the response. The response of interest here was taken to be the deep geologic repository capacity for a given realization of fuel cycle inputs. After computing the uncertainty coefficients, the inputs themselves are sorted based on decreasing sensitivities. Fast reactor used fuel plutonium separations were found to be most important to the cycle. Furthermore, to represent input covariances (the effect of one input on the sensitivity of a second input to the response), a new measure is defined on three-dimensional CTs. This metric is the coefficient of the variation of uncertainty coefficient of two-dimensional slices of the original table. Sorting by this sensitivity of sensitivity metric, the input pair of fast reactor americium separations together with high-level-waste storage time was found to have the largest joint effect on the repository capacity.

High fidelity aircraft simulations can dramatically reduce training and proficiency-related expenses, and can also reduce overall design and development costs by revealing problems early in the design process. However, developing, updating, and verifying simulation models is currently very expensive. Tremendous savings could result from innovative software tools that provide an objective and somewhat automated process for developing and verifying simulation aerodynamic models. The mathematical properties of wavelets appear to be a good match for the properties needed in a software tool capable of automatically developing and conducting verification and validation of simulation models. The primary reason for selecting wavelets over other methods is that wavelets are capable of performing localized analysis of a signal. Wavelets capture details in a signal at different resolutions at the same time. This paper addresses the feasibility of using wavelets to quickly and consistently detect irregularities in a large set of aerodynamic data. Two examples are presented. For demonstrative purposes, the cubic B-spline wavelet was used to smooth a noisy signal while obtaining 95% compression and retaining desired properties in the signal. Additionally, the linear wavelet was used to detect trends and irregularities in wind tunnel data consisting of seventeen separate data sets.

If advanced fuel cycles are to include a large number of fast reactors (FRs), what should be the transuranic (TRU) conversion ratio (CR)? The nuclear energy era started with the assumption that they should be breeder reactors (CR > 1), but the full range of possible CRs eventually received attention. For example, during the recent U.S. Global Nuclear Energy Partnership program, the proposal was burner reactors (CR < 1). Yet, more recently, Massachusetts Institute of Technology’s “Future of the Nuclear Fuel Cycle” proposed CR [approximately] 1. Meanwhile, the French company EDF remains focused on breeders. At least one of the reasons for the differences of approach is different fuel cycle objectives. To clarify matters, this paper analyzes the impact of TRU CR on many parameters relevant to fuel cycle systems and therefore spans a broad range of topic areas.The analyses are based on a FR physics parameter scan of TRU CR from 0 to [approximately]1.8 in a sodium-cooled metal-fueled FR (SMFR), in which the fuel from uranium-oxide-fueled light water reactors (LWRs) is recycled directly to FRs and FRs displace LWRs in the fleet. In this instance, the FRs are sodium cooled and metal fueled. Generally, it is assumed that all TRU elements are recycled, which maximizes uranium ore utilization for a given TRU CR and waste radiotoxicity reduction and is consistent with the assumption of used metal fuel separated by electrochemical means. In these analyses, the fuel burnup was constrained by imposing a neutron fluence limit to fuel cladding to the same constant value. This paper first presents static, time-independent measures of performance for the LWR [right arrow] FR fuel cycle, including mass, heat, gamma emission, radiotoxicity, and the two figures of merit for materials for weapon attractiveness developed by C. Bathke et al.No new fuel cycle will achieve a static equilibrium in the foreseeable future. Therefore, additional analyses are shown with dynamic, time-dependent measures of performance including uranium usage, TRU inventory, and radiotoxicity to evaluate the complex impacts of transition from the current uranium-fueled LWR system, and other more realistic impacts that may not be intuited from the time-independent steady-state conditions of the end-state fuel cycle. These analyses were performed using the Verifiable Fuel Cycle Simulation Model VISION.Compared with static calculations, dynamic results paint a different picture of option space and the urgency of starting a FR fleet. For example, in a static analysis, there is a sharp increase in uranium utilization as CR exceeds 1.0 (burner versus breeder). However, in dynamic analyses that examine uranium use over the next 1 to 2 centuries, behavior as CR crosses the 1.0 threshold is smooth, and other parameters such as the time required outside of reactors to recycle fuel become important.Overall, we find that there is no unambiguously superior value of TRU CR; preferences depend on the relative importance of different fuel cycle system objectives.

Reliability of non-destructive techniques (NDT) is traditionally quantified by experimental determined probability of detection (POD). Such multi-parameter variability studies require a significant amount of experiments for each application verified, making them extremely costly. Reducing the need of experimental data by simulations requires both a verified simulation model and a procedure for effective computer experiments. Here synthetic POD curves for ultrasonic phased array testing have been generated using simSUNDT for signal amplitude simulations and a procedure to emulate response variability by predictive (meta) modeling and Monte Carlo simulations.

In this investigation, the influences of voids on the crack initiation of the solder joints of high-power LED applications were studied. For the experimental analysis, power cycling tests with and without superimposed temperature cycling have been carried out. By using nondestructive test method of computed tomography (CT), the initiation and development of the cracks and failures during the aging tests were documented. In order to evaluate the different sizes, numbers and distributions of voids and their impact on the crack initiation in the solder joints, simulation approach with finite element method (FEM) has been applied. Based on the verified simulation model, further evaluations showed that the thickness of the solder joint had the strongest influence on the crack initiation, followed by the number of the voids. Critical areas of the solder joints in terms of crack formation have also been identified.

The pressure gain of hydraulic servovalves is caused by an internal leakage. The leakage flow occurs because of the spool construction and finite radial clearance of the spool. The internal leakage results in unwanted properties such as crawling of a loaded actuator in open loop systems and position error of a P-controlled loaded actuator. On the other hand system damping increases. This paper presents a robust model for internal leakage that can be identified according to known pressure gain. The importance of the valve’s pressure gain on steady state and dynamic behaviour is studied by a well verified simulation model.

For bearings, radiation noise was an important evaluation index for mechanical property, in particularly mute machinery. Environmental pollution caused by bearing noise has always been the focus in bearing industry. In this paper, slippage of the rolling bearing and its own variable stiffness excitation were considered to accomplish the vibration coupling between the bearing and bearing seat as well as the coupling between bearing vibration and noise by means of combination of dynamic model, FEA model and boundary element method. A perfect coupled vibro-acoustic model of the bearing was built, and its results were compared with the experimental results to verify the reliability of the proposed method. Based on the verified simulation model, the improved design was carried out for the low-noise rolling bearings. Finally, in order to further verify the superiority of the proposed method in this paper, the designed rolling bearing was compared with that of the traditional design method. The results showed that the proposed design method was reliable.

Fast nucleic acid analyzer has developed rapidly recently due to the spread of COVID-19 virus. In order to calibrate the temperature parameters of fast nucleic acid analyzer, it is necessary to study its temperature field distribution and temperature change curve, so as to put forward a scientific and accurate temperature field simulation model. This article studies the heat transfer mechanism of the heating module of the fast nucleic acid analyzer based on the finite element method by using CATIA three-dimensional modeling software and ANSYS Meshing platform, and the dynamic simulation model of the temperature field is obtained by studying two typical types of fast nucleic acid analyzers. Thus, this article provides a basis for the research on the calibration device of the fast nucleic acid analyzer, and the simulation model can be used to verify the reliability of the calibration device.

The United States Department of Energy (DOE), Office of Nuclear Energy (NE) has embarked on a long-term program to significantly advance the science and technology of nuclear energy. This is in response to the overall national plan for accelerated development of domestic energy resources on several fronts, punctuated by recent dramatic events that have emphasized the need for the US to reduce its dependence on foreign petroleum supplies. Key aspects of the DOE-NE agenda are embodied in the Generation-IV (Gen-IV) advanced nuclear energy systems development program and in the Advanced Fuel Cycle (AFC) program. The planned efforts involve near-term and intermediate-term improvements in fuel utilization and recycling in current nuclear power reactor systems as well as the longer-term development of new nuclear energy systems that offer much improved fuel utilization and proliferation resistance, along with continued advances in operational safety. The success of the overall NE effort will depend not only on sophisticated system development and engineering, but also on the advances in the supporting sciences and technologies. Of these, one of the most important is the improvement of the relevant fundamental nuclear science data bases, especially the evaluated neutron interaction cross section files that serve as the foundation of all reactor system designs, operating strategies, and fuel cycle engineering activities. The new concepts for reactors and fuel cycles involve the use of transuranic nuclides that were previously of little interest, and where experimentally measured information is lacking. The current state of the cross section database for some of these nuclides is such that design computations for advanced fast-spectrum reactor systems and fuel cycles that incorporate such materials in significant quantities are meaningful only for approximate conceptual applications. No actual system could reliably be designed according to currently accepted standards, nor could such a system be safely and efficiently operated, with the limited nuclear data and related information now available.

In this paper, a simulation model and practical testbed for green Internet of Things (IoT) edge devices are proposed based on solar harvester with constant voltage-maximum power point tracking (CV-MPPT) technique. Billions of connected edge devices represent the essential part of the IoT through the IP-enabled sensor networks based on IPv6 over Low power Wireless Personal Area Network (6LoWPAN). In traditional IoT edge devices, the stored energy in the non-rechargeable battery determines the node lifetime while it is being depleted with time. Therefore, purchasing billions of such batteries is costly and must be disposed of efficiently. This paper is aimed at simulating and implementing a new class of green IoT edge devices that can report data wirelessly and powered perpetually using clean energy. The developed edge device utilizes solar energy harvesting mechanism through photovoltaic (PV) module, this approach will avoid periodical battery replacement and hence, the energy supplied to the sensor mode is not limited anymore. The implemented testbed is based on open-source hardware and software platforms while the simulation environment is based on MATLAB/SIMULINK 2019a. The effects of temperature and solar irradiance on the performance of the developed approach are examined in order to confirm the leverage of the proposed methodology scheme. The lifetime of the developed green IoT device is predicted based on the device’s activities, current consumption, and energy storage capacity. The obtained results showed that the battery lifetime is extended by 38-49% when the edge device runs on an independent power source.

A universal synchrophasor based test platform is developed in this paper. This software platform can transform simulation data from the time-domain simulation software to synchrophasor data format specified by IEEE standards. It can serve as a test platform for various synchrophasor application algorithms, and provide validation for power system simulation models. In this paper, its validation function for power system simulation models is the main focus. Four case studies are conducted using the developed test platform in order to validate a power grid simulation model, where the output of the test platform are compared with the field recorded synchrophasor data from installed Phasor Measurement Units (PMUs) in this power grid. These case studies show that the test platform can play an important role in improving accuracy of a power system simulation model.

This paper presents an object-oriented simulation model that can be used to evaluate the perfor mance of MAC (Multiple ACcess) protocols. It is intended for satellite communication networks in which the propagation delay plays a major role on the performance of the communication channel. The model has been used to evaluate the perfor mance of multiple access protocols for NASA's Mars Regional Network in the Martian environ ment with some specific requirements. These re quirements include protocol robustness, stringent use of power and buffer memory, channel stabil ity, and low complexity of the control algorithm. The simulation model can accommodate different classes of MAC protocols including fixed assign ments, demand assignments, random access, hy brid of random access, and adaptive protocols. While the simulation model has been developed to evaluate the MAC protocols for the Martian envi ronment, it is intended to accommodate other multiple access protocols with different require ments.

Pedestrian choice behavior analysis and simulation of ticket gate machine in rail transit station

The Underwater Internet of Things (UW-IoT) is a novel class of Internet of Things (IoT) that enables extend the terrestrial internet to the marine environment. However, as the underwater acoustic channel poses extremely challenging difficulties for underwater IoT communication and networking, the performance of the underwater IoT networks lags far behind the terrestrial internet. Due to the expense of conducting experiments in real underwater systems many researches have been endowed with only simulation model and analysis. This paper presents the design and implementation of an underwater IoT network test platform in order to evaluate and analyze the performance of underwater communication and network protocol in physical shallow water environment. The design of this IoT network platform considers the application background of environment parameter acquisition in marine environment stereoscopic monitoring. The software and hardware implementation of the IoT platform are introduced. Sea test result shows that the platform is effective in evaluating the performance of underwater IoT network.