Subsystem Models Research Articles

The use of sound phonons in the development of NVH treatments for light commercial electric vehicles

Light Commercial Electric vehicles (LCEV) are becoming increasingly popular due to their environmental benefits and lower operating costs, making them a sustainable choice for businesses looking to reduce their carbon footprint and save fuel expenses. However, unlike Saloon and SUV electric vehicles LCEV's have to be potentially configured for a wide variety of operating roles including parcel delivery, mini-buses, retail wagons, ambulances and mobile workshops to name just a few. Consequently, when considering their refinement aspects during their development it has become economically restrictive to base this on actual physical prototypes. Acoustic modelling provides a suitable alternative, but any software package must be highly flexible so that multiple configurations can be examined without requiring time consuming re-modelling. This paper describes the use of sound phonons in an interactive GUI for the successful development process of an LCEV from target setting through to final optimised NVH package creation. The project involved full vehicle model creation via donor CAD, of a current ICE LCV, which was morphed into an EV to include an under-floor battery and rear drive system. Sub-system models of areas such as the interior bulkhead, battery pack insulation and EV encapsulation were also integrated during the optimisation process.

Research of methods of modeling of mass service enterprise

Objective. The purpose of the study is to use artificial intelligence tools to optimize and model the automated organization of work at a mass service enterprise. Method. The research is based on the use of a Petri net as a modeling tool, as well as mathematical hardware that makes it possible to implement simulation models of subsystems and conduct additional research on GPSS artificial intelligence models. Result. To process the results of the modeling process, the Petri net modeling method was used and a network activity model graph was developed. The modeling process used with the Petri Net application allows such functions to be described more clearly. The principles of modeling systems based on the GPSS language and Petri nets are considered. Conclusion. It is advisable to use the language devices GPSS and SP, which provide information support for the activities of a mass service enterprise, modeling the structural organization and information flows.

Аналіз даних теплового режиму комутаційного обладнання комп’ютерних мереж на основі відновлення сигналів температурних датчиків

The article considers the task of analyzing distributed data of temperature modes of chips of switching equipment of computer networks. For this, a temperature measurement system using a temperature sensor is used. In the case when the temperature sensor is inside the chip, the speed of the measurement system's response to temperature changes is satisfactory. However, when the sensor is outside the chip, due to the inertness of the thermal contact, the response speed of the measuring system is low. In this situation, the effectiveness of the control system becomes unsatisfactory. To overcome the inertness of temperature sensors, it is proposed to analyze the distributed data that is received in digital form on the data processing server by restoring the distorted signals of nonlinear measuring subsystems «chip – temperature sensor» based on the use of their mathematical models in the form of a partial sum of the Volterra integro-power series. The identification of the mathematical model of the measurement subsystem is carried out on a finite interval of time by conducting a series of experiments using test signals. The method of reducing the number of test signals based on taking into account the specificity of the impact of nonlinearity on the results of experiments is considered. The obtained model is the basis for solving the inverse problem of restoring the signal of temperature influence at the sensor input. Since this problem is incorrect, it is suggested to supplement the model with a regularization parameter and reduce the problem to a correct one. To use the model over an infinite period of time, a computer modeling technique is proposed using restarts of computing processes, which are carried out in several streams with a shift in time. The result of calculations is formed by combining fragments from different streams. To check the reliability of the results obtained by applying the developed method, the solutions of the model problems are given.

Analysis of the Effect of Motor Waste Heat Recovery on the Temperature and Driving Range of Electric Heavy Truck Batteries

In some scenarios, electric heavy-duty trucks with battery swapping mode (ETBSm) are more cost-effective than battery charging mode. The viability of battery swapping stations is contingent upon the operational requirements and range capabilities of the ETBSm. Low temperatures have the effect of reducing the range of the ETBSm, thereby creating difficulties for battery swapping. This article proposes the use of motor waste heat recovery (MWHR) to heat batteries, which would improve range. A number of subsystem models have been established, including the ETBSm, battery, motor, and thermal management system (TMS). The calibration of battery temperature and motor efficiency is achieved with a model error of less than 5%. Comparison of performance, such as temperature, energy consumption, and range, when using only positive temperature coefficient (PTC) heating and when using both PTC heating and motor waste heat. The results indicate a 15% increase in the rate of rise in battery temperature and a 10.64 kW·h reduction in energy consumption under Chinese heavy-duty vehicle commercial vehicle test cycle (CHTC) conditions. Then, the motor waste heat percentage, energy consumption, and range are analyzed at different ambient temperatures. At an ambient temperature of −20 °C, −10 °C, and 0 °C, the percentage of the motor waste heat is 32.1%, 35%, and 40.5%; when 75% of the state of charge (SOC) is consumed, the range is improved by 6.55%, 4.37%, and 4.49%. Additionally, the effect of the PTC heater on temperature characteristics and power consumption is investigated by changing the target temperature of the coolant at the battery inlet. In accordance with the stipulated conditions of an ambient temperature of −20 °C and a target coolant temperature of 40 °C at the battery inlet, the simulation results indicated a battery temperature rise rate of 0.85 °C/min, accompanied by a PTC power consumption of 15.6 kW·h. This study demonstrates that as the ambient temperature increases, the utilization of motor waste heat becomes more effective in reducing PTC heating power consumption. At the lowest ambient temperature tested, the greatest improvement in driving range is observed. It is important to note that while an increase in the target heating temperature of the PTC helps to raise the battery temperature more rapidly, this is accompanied by a higher energy consumption. This article provides a reference for the ETBSm with MWHR.

Study on Multi-Span Tension Coupling Relationship of Gravure Printed Electronic Equipment

To improve the performance of the tension control system in gravure printed electronic equipment, it is necessary to study the tension system model of gravure-printing electronic equipment. This paper focuses on the coupling characteristics of multi-span tension systems. Firstly, based on the single-span tension model, the mathematical model of the printing tension subsystem is established and simplified into a general multi-span tension coupling model. Then, using the relationship between the inputs and outputs of the system, the coupling model is simulated using MATLAB/Simulink and verified through experiments on the gravure printed electronic platform. Finally, the coupling relationship and influence laws among multi-physical quantities of the system are analyzed. The research results show that changes in the input web tension of the multi-span system will affect the steady-state tension values of all subsequent spans. Moreover, the speed change in a roller in the multi-span system will not only affect the steady-state tension value of its own span, but also cause transient tension fluctuations in all subsequent spans. The findings of this paper provide an important theoretical basis for the research of the tension system in gravure printed electronic equipment, contributing to the enhancement of printed electronic product quality.

Integrated solar system for hydrogen production using steam reforming of methane

Integrating renewable technologies has emerged as a promising option in pursuing sustainable and efficient energy solutions. The primary source of industrial hydrogen is steam methane reforming (SMR); however, this process is based on fossil fuels with massive carbon byproduct emissions. The solar thermal tower appears to be a suitable renewable source for powering SMR by providing high temperature heat to drive the process reactions. This approach aims to harness the abundance of solar energy for natural gas reforming to produce hydrogen at minimum environmental impact. This research establishes the viability of combining external central receiver concentrated solar power with SMR integrated with thermal energy storage (TES), revealing general insights into the system energy and exergy performance. The analysis of the current system is performed using the thermodynamic and thermochemical approaches to conduct a parametric study. A 543 MW central receiver is first modeled with a high-temperature molten salt as a working fluid. The SMR process model is then developed, considering both reforming and shift reactions, and solved using Engineering Equation Solver (EES). The subsystem models are validated before being integrated into the overall system model. The performance of the SMR reactor is found to affect the overall system performance considerably. The results also show that when increasing the temperature above 760 ° C, no remarkable improvement in the reforming process is observed. In contrast, the higher the temperature in the water gas shift reactor, the lower the system's performance. Moreover, the impact of wind velocity on the overall system is considered due to the large central receiver surface area. The overall system performance in terms of energy, exergy, and effectiveness is evaluated for one day of operating through charging and discharging operations. In charging mode, the overall energy and exergy efficiencies are 46.5% and 57.2%, respectively, while the overall effectiveness is 61.8%; on the discharging operation, the overall energy efficiency and effectiveness have a similar definition with a value of 82.4% and the overall exergy efficiency achieves a value of 78.7%. Additionally, the amount of hydrogen produced at a central receiver of 543 MWth capacity is about 7.3 kg/s at a 2.1 steam-to-carbon ratio. This integration mitigates a minimum of 12 kg/s of CO2 emissions that would be generated due to methane combustion.

Research on digital twin architecture of ship maneuverability simulation for system model

Abstract With the development of civil and military requirements, ship maneuverability simulation systems tend to be complicated, and the traditional simulation methods are difficult to meet in terms of the development needs of digitalization. The joint simulation technology based on the FMI standard can realize the digital twin of complex system models, which can solve the difficult problem of multidisciplinary and multi-sub-system integration simulation. This paper analyzes the current domestic and foreign research content on joint simulation technology, digital twin technology, and complex system modeling, takes a typical Z-type maneuverability test as an example, establishes a multidisciplinary and cross-platform subsystem model, and designs and develops a ship maneuverability joint simulation algorithm and system software for the complex system model. The simulation results verify the effectiveness of the system modeling technique and the joint simulation technique based on FMI. Based on this system, the whole framework of the ship maneuverability simulation system, which is based on digital twins, is designed. According to the development requirements of ship maneuverability simulation, the main design framework, key technology, and implementation approach of this research method are given, which provides basic methods and ideas for the digital research of ship maneuverability simulation.

Estimation of blocked forces for NVH source characterization of a beam axle using analytical methods

Component-Based Transfer Path Analysis (TPA) has been of growing interest recently because, unlike classical TPA, it enables source characterization independent of the receiver structure. The source energy in component TPA is typically characterized by blocked forces. As part of virtual prototyping, OEMs have interest in building a library of component/subsystem models that may be "plugged" into larger system models. For an OEM supplier, it is imperative to have the capability to provide subsystem models along with source energy characterized in component blocked force prior to availability of physical parts to support virtual validation and optimization efforts for seamless system integration. In this paper, three methods of blocked force calculation are considered: Direct, Free Velocity and In-situ. A Finite Element Analysis (FEA) model is used to Directly calculate the blocked forces exerted by a rear beam axle at the vehicle attachment points, then to simulate how they might be estimated in a dynamometer test stand using the Free Velocity or In-situ methods, with the aim of offering practical guidance for both scenarios. Assumptions regarding input and output boundary conditions, along with three versus six degree-of-freedom (DOF) attachment paths, affecting both the analytical and test-based estimation of blocked forces, are also scrutinized.

Foreign Practices of Intelligent Transport Systems Functioning: Experience of Japan and USA

The article examines the experience of managing the implementation of intelligent transport systems (ITS) in the USA and Japan, analyzes the main forms of interaction between the state, local government and private sector organizations in the implementation of relevant projects. The research used methods of comparative legal and secondary analysis of statistical data. The presented work shows that in the USA and Japan, public authorities played a key role in the process of creating intelligent transport systems, and the private sector acted as a secondary agent. At the same time, the Japanese and American models of ITS implementation management differ significantly from each other. In Japan, the main participants in this process are entities with different social and managerial status, in the United States, equal organizational structures take part in the creation process. The consequence of this is that the financing of projects to create intelligent transportation systems in the United States is carried out by the states, the federation and the private sector, and in Japan only by the state and the private sector. The presented difference leads to the fact that the Japanese model of intelligent transport systems is characterized by a vertically integrated model of various subsystems with subordination. In turn, in the USA, ITS is a network structure. It should be added to the above that both the United States of America and Japan have formed an effective communication system between the main participants in the process of implementing intelligent transport systems, which avoids various dysfunctions and contradictions in their actions. In particular, in these countries, many discussion platforms, interdepartmental commissions, as well as working groups have been organized, within which the positions of the departments involved in the process of creating ITS are coordinated, as well as contradictions that arise during the implementation of the project under consideration are resolved. The experience of advanced countries in implementing ITS can be useful, given that similar projects are actively being implemented in most regions of Russia.

Reduced-order modeling of modular, position-dependent systems with translating interfaces

Many complex mechatronic systems consist of multiple interconnected dynamical subsystems, which are designed, developed, analyzed, and manufactured by multiple independent teams. To support such a design approach, a modular model framework is needed to reduce computational complexity and, at the same time, enable multiple teams to develop and analyze the subsystems in parallel. In such a modular framework, the subsystem models are typically interconnected by means of a static interconnection structure. However, many complex dynamical systems exhibit position-dependent behavior (e.g., induced by translating interfaces) which cannot be captured by such static interconnection models. In this paper, a modular model framework is proposed, which allows to construct an interconnected system model, which captures the position-dependent behavior of systems with translating interfaces, such as linear guide rails, through a position-dependent interconnection structure. Additionally, this framework allows to apply model reduction on subsystem level, enabling a more effective reduction approach, tailored to the specific requirements of each subsystem. Furthermore, we show the effectiveness of this framework on an industrial wire bonder. Here, we show that including a position-dependent model of the interconnection structure (1) enables to accurately model the dynamics of a system over the operating range of the system and, (2) modular model reduction methods can be used to obtain a computationally efficient interconnected system model with guaranteed accuracy specifications.

Development of a Proof-of-Concept Multi-Method Computer Simulation to Support Rural Healthcare Disaster Preparedness Planning

Due to a lack of resources, rural communities often face challenges when planning catastrophic events. This project involved applying systems thinking and model-based systems engineering to develop a proof-of-concept, multi-method computer simulation and then determining whether the simulation could be used to assess the efficacy of disaster planning approaches on health outcomes in rural communities, as a function of primary healthcare. The project focus was a rural or non-urban healthcare system experiencing a natural hazard. Both system dynamics and discrete event models were incorporated to represent subsystem operations, crucial disaster responses, as well as three key response systems: public health, emergency management, and healthcare. The subsystem models included several components: policies/procedures, communications, resources, exercises/drills/training, healthcare space and staff, and the flow of affected people into and through the system. The combined simulation can serve as a first step to a more comprehensive approach to helping rural communities achieve more efficient and effective healthcare planning for disaster responses.

A Reliability Assessment Method for Complex Systems Based on Non-Homogeneous Markov Processes.

The Markov method is a common reliability assessment method. It is often used to describe the dynamic characteristics of a system, such as its repairability, fault sequence and multiple degradation states. However, the "curse of dimensionality", which refers to the exponential growth of the system state space with the increase in system complexity, presents a challenge to reliability assessments for complex systems based on the Markov method. In response to this challenge, a novel reliability assessment method for complex systems based on non-homogeneous Markov processes is proposed. This method entails the decomposition of a complex system into multilevel subsystems, each with a relatively small state space, in accordance with the system function. The homogeneous Markov model or the non-homogeneous Markov model is established for each subsystem/system from bottom to top. In order to utilize the outcomes of the lower-level subsystem models as inputs to the upper-level subsystem model, an algorithm is proposed for converting the unavailability curve of a subsystem into its corresponding 2×2 dynamic state transition probability matrix (STPM). The STPM is then employed as an input to the upper-level system's non-homogeneous Markov model. A case study is presented using the reliability assessment of the Reactor Protection System (RPS) based on the proposed method, which is then compared with the models based on the other two contrast methods. This comparison verifies the effectiveness and accuracy of the proposed method.

Real-Time Multi-Sensor Joint Fault Diagnosis Method for Permanent Magnet Traction Drive Systems Based on Structural Analysis.

Sensor faults are one of the most common faults that cause performance degradation or functional loss in permanent magnet traction drive systems (PMTDSs). To quickly diagnose faulty sensors, this paper proposes a real-time joint diagnosis method for multi-sensor faults based on structural analysis. Firstly, based on limited monitoring signals on board, a structured model of the system was established using the structural analysis method. The isolation and detectability of faulty sensors were analyzed using the Dulmage-Mendelsohn decomposition method. Secondly, the minimum collision set method was used to calculate the minimum overdetermined equation set, transforming the higher-order system model into multiple related subsystem models, thereby reducing modeling complexity and facilitating system implementation. Next, residual vectors were constructed based on multiple subsystem models, and fault detection and isolation strategies were designed using the correlation between each subsystem model and the relevant sensors. The validation results of the physical testing platform based on online fault data recordings showed that the proposed method could achieve rapid fault detection and the localization of multi-sensor faults in PMTDS and had a good application value.

Dynamic modelling of supplemental cooling systems with vapor compression refrigeration units in civil aircrafts

Newly developed airliners have adopted supplemental cooling systems (SCS) to provide for non-cabin cooling requirements. In the present study, dynamic component models for compressor and phase change heat exchangers were developed with dynamic decoupling and explicit solution methods, and pressure zone separation and solution methods are developed based to obtain dynamic pressures as key values. A dynamic VCRU subsystem model is established, and the result under single-unit startup condition shows pressure deviations less than 0.16 %, with a simulation time ratio of 5.65 %, exhibiting good overall performance at both precision and speed. A dynamic SCS system model is developed, and the simulation of a 9000 s flight took 1973.3 s to complete. Result in the cruise phase shows the condensation and evaporation temperatures are in the ranges of 28.39–31.33 °C and −17.93 to −10.71 °C, respectively, meeting their respective designed ranges of 30 ± 5 °C and −15 ± 5 °C. These results reflects good consistency of the model with actual system characteristics. Control optimization is conducted based on the developed model to eliminate temperature fluctuation. The optimization reduced the maximum temperature deviation from 0.4004 K to 0.0019 K after system starting process, proving the feasibility of control method optimization based on the developed dynamic simulation model.

Multi-objective integrated attitude control of large solar power satellite: A distributed incremental predictive approach

This paper addresses the multi-objective integrated attitude control problem of a large solar power satellite (SPS) in the presence of time-varying parameters, disturbances, and actuator saturation. The attitude coupling dynamic model, which could accurately describe the rotational motion of different SPS components, is firstly obtained. The gravity gradient, solar radiation pressure, microwave radiation reflection, and friction torques are investigated to evaluate their influence on attitude control accuracy. The coupling dynamic model is linearized and discretized, which provides a subsystem model for distributed controller design. A distributed incremental predictive controller is designed for each rotation channel to form a distributed system. The augmented system state is defined to solve the complex constraint problem, and the predicted value with feedback correction is introduced to deal with the disturbances. Besides, the stability of the system is analyzed by considering external disturbances and actuator failure. Comparative analysis with centralized methods under the same prediction horizon is provided, and the results demonstrate a tenfold solution performance enhancement while maintaining accuracy. Furthermore, the controller is integrated with feedback correction, which could improve control accuracy by at least one order of magnitude. The proposed controller reduces the adjusting time for attitude stabilization by 56.8 % in the presence of actuator failure. The simulation results demonstrate that the proposed controller has good robustness and fault tolerance, which provides a feasible solution for SPS multiple attitude control missions.

Improving Fault Diagnosis of the Drilling Permanent Magnet Synchronous Motor (DPMSM) in Harsh Environments: A Novel Approach Using Object-Oriented Bayesian Network (OOBN)

The drilling permanent magnet synchronous motor (DPMSM) contains multiple subsystems with identical structures and has a high probability of failure because the downhole working conditions are harsh. Therefore, the quick localization of faults is difficult to determine although the fault type may be identified in time. The system diagnostic model based on the Bayesian network (BN) can be used for fault diagnosis and localization for components in subsystems, but it is difficult to build and modify due to the complex system in practice. New methods are necessary to reduce the difficulty of building and modifying models. In this study, object-oriented ideas are introduced into the BN to establish a system diagnostic model based on an Object-oriented Bayesian network (OOBN) for the DPMSM. First, the fault diagnostic models for subsystems based on BN are established, respectively. Then, submodels of forward and backward based on BN are instantiated as instance nodes. Next, instance nodes are connected through input nodes and output nodes to establish the OOBN-based system diagnosis model. Finally, the system diagnosis model is validated by sensitivity analysis and the effectiveness is discussed in Cases. The system diagnosis model can effectively reduce the difficulties of modeling and modifying.

Модельные технологические решения по обеспечению качества изделий при обработке точением

Model technological solutions for ensuring the quality of products during turning processing are proposed. A study of the workability of materials based on the ISO classification was carried out. To clarify the workability group, the MS code system was used, which allowed not only to clarify the workability group and the terms of delivery of the workpiece, but also to determine the specific cutting force. Based on the classifier-handbook, the parameters of the prefabricated cutting tool were selected and the technological modes for the prescribed processing conditions were determined. Based on the obtained specific cutting force, an algorithm for simplified determination of the cutting force is implemented. A study of the vibrations of the technological machining system was performed, which made it possible to formulate dynamic models for the system as a whole, subsystems of the workpiece and cutting tool. In relation to the dynamic model of the workpiece subsystem. The model has been simplified. A dynamic cutting characteristic was constructed, which made it possible to build an autonomous dynamic model of the technological system. In relation to this model, parameterization was performed, which made it possible to determine the stiffness coefficients of the fixed workpiece, as well as the inertia and dissipation coefficients. In relation to the selected processing conditions, the accuracy and roughness of the treated surface were checked. A study of the stability of the technological system of mechanical processing based on the algebraic Hurwitz criterion is carried out. In the general formulation, the Hurwitz determinant and stability conditions are obtained. The performed complex of calculations showed that the conditions determined by the Hurwitz stability criterion are met. This indicates that when processing in the selected modes, quiet cutting is carried out, which ensures the requirements for the quality of the product. The construction of the stability boundary can be performed in the space of variable technological parameters using the D-partitioning method or based on the R. Loeb algorithm. As a result of constructing the stability boundary in the space of variable parameters, the area of permissible technological modes is highlighted, which is the basis for solving the problem of processing control in accordance with the formed efficiency criteria. The complex of technological solutions presented in the article was deployed and implemented in relation to the turning of coating discs, as well as discs of turbines and compressors of gas turbine engines.

Intraday two-stage hierarchical optimal scheduling model for multiarea AC/DC systems with wind power integration

To make full use of the flexible adjustment capability of DC tie-lines in multiarea AC/DC systems and to coordinate the generation resources and load demand of multiarea AC/DC systems, this paper presents an intraday two-stage hierarchical optimal scheduling model for multiarea AC/DC systems based on analytical target cascading (ATC). To avoid repeated adjustment and overadjustment of DC tie-lines after wind power integration, a two-stage rolling coordinated scheduling model for the area subsystem based on model predictive control (MPC) is proposed. The two-stage rolling coordinated scheduling method takes into consideration the influence of the predicted value in the future finite time domain and the latest measured DC tie-line power on the current scheduling state. Based on the ATC and the area decomposition criterion of the AC/DC grid, an optimal scheduling model for the upper-level system is proposed that takes into consideration the DC tie-line adjustment constraints and the area coupling constraints. The optimal scheduling model for the upper-level system formulates the two-stage DC tie-line plan for the multiarea AC/DC system, and the two-stage rolling coordinated scheduling model of the area subsystem solves the subproblems of the generation plan for each area subsystem in a parallel manner considering the area coupling constraints. The proposed method can achieve intraday two-stage decoupling scheduling of multiarea AC/DC systems and promote the cross-area consumption of large-scale wind power through flexible adjustment of the DC tie line. This approach also reduces the communication burden between the area subsystems and ensures the efficiency of the solution algorithm.

Dynamic analysis and control strategy of ORC coupled ejector expansion refrigeration cycle driven by geothermal water

Organic Rankine cycle combined ejector expansion refrigeration cycle (ORC-EERC) has significant potential for utilizing low-temperature heat. The study on dynamic response of the ORC-EERC combined system plays a particularly important role in optimizing the control strategy for the system, given the instability of the low-temperature heat source. In this paper, the ORC-EERC dynamic models with single and dual condensers are proposed. The simulation results show that the proposed improved model of EERC subsystem presents more accurate results relevant to the experiment system. The impact of the ORC subsystem on the refrigeration subsystem is more pronounced in the ORC-EERC system with a single condenser than in the system with dual condensers. In addition, the phenomenon of chocking in the ejector throat leads to the degradation of system performance when the heat source is disturbed. Therefore, a multi-device cooperative control strategy is proposed to enhance the safety and performance of the system. In the case study of geothermal water mass flow scheduling disturbance, the control strategy increases the cooling capacity of the system by a maximum of 9.29%.

Digital Twin Technologies for Autonomous Environmental Control and Life Support Systems

Environmental control and life support systems will require enhanced self-awareness and self-sufficiency as human spaceflights are designed to reach further destinations. These requirements have led to the development of autonomous technologies and systems to enable more Earth independence, while at the same time relying more heavily on the knowledge contained in their computational models (as opposed to the knowledge of ground control experts). For environmental control and life support systems, these consist of disparate models often tailored to specific subsystems and use cases, such as temperature control and CO2 removal. Therefore, there is a need for technologies supporting the integration of existing models. We propose to extend existing digital twin frameworks to integrate models and serve as a tool for answering onboard queries during operation. Toward this vision, we identify research directions for three types of technologies: i) streamlining the process of merging information models without redundancies by leveraging model-based systems engineering languages; ii) the calibration of simulation models that requires a better understanding of how to encode domain knowledge into a probabilistic representation of subsystem states and model parameters; and iii) automating the query understanding process and constructing a mapping between information and simulation models.