Search

Automated Driving Systems (ADSs) bring many benefits, however their safety assurance poses challenges. Scenario-based testing has been proposed. To provide strong safety evidence for their safety assurance, the scenario-based testing process needs to consider the Operational Design Domain (ODD) of the systems, ODD combined with the behavioural elements can provide a foundation for the scenario generation workflow due to common domain elements between ODDs and scenarios. Based on such background, this paper introduces a novel framework to generate scenarios specifically target on testing the system’s claimed ODD. It includes the process going from the system’s ODD and behaviour competency, to logical scenarios generation utilising scenario construct rule sets, and to the concretisation of the logical scenarios into concrete scenarios. This paper also draws link towards the part II of the paper series, which illustrates a novel approach for scenario coverage analysis.

The interaction between the structural response and hydrodynamic loading (hydroelasticity) must be considered for design and operation purposes of high-speed planing craft made of composites that are prone to frequent water impact (slamming). A computational approach was proposed to study the hydroelastic slamming of a flexible wedge. The computational approach is a loose two-way coupling between a Wagnerbased hydrodynamic solution and a linear finite element plate model. Verification and validation (V&V) was performed on this coupled model. It was found that the model overpredicts rigid-body/spray root kinematics by <15% and hydrodynamic loading/ structural response by <26%. [ABSTRACT FROM AUTHOR]

Modern highly automated and autonomous traffic systems and sub-systems require new approaches to test their functional safety in the context of validation and verification. One approach that has taken a leading role in current research is scenario-based testing. For various reasons, simulation is considered to be the most practicable solution for a wide range of test scenarios. However, this is where many existing simulation systems in research reach their limits. In order to be able to integrate the widest possible range of systems to be tested into the simulation, the use of co-simulation has proven to be particularly useful. In this work, the High-Level Architecture defined in the IEEE 1516-2010 standard is specifically addressed, and a concept is developed that establishes the foundation for the feasible use of scenario-based distributed co-simulation on its basis. The main challenge identified and addressed is the resolution of the double-sided dependency between scenario and simulation models. The solution was to fully automate the generation and instantiation of the simulation environment on the basis of a scenario instance. Finally, the developed concept was implemented as a prototype, and the resulting process for its use is presented here using an example scenario. Based on the experience gained during the creation of the concept and the prototype, the next steps for future work are outlined in conclusion. [ABSTRACT FROM AUTHOR]

The CUPID code was developed and is continuously updated in KAERI. Verification and validation (V&V) is mainly done for light water reactors (LWRs). This paper describes a benchmarking of the detailed mesh level compared with sub-channel level for application to pressurized heavy water reactors (PHWRs), even though component scale comparison for the PHWR moderator system was done once before. We completed a sub-channel level comparison between the CUPID code and the ASSERT code and a CUPID code analysis. Because the ASSERT code has already been validated with numerous experiments, benchmarking with the ASSERT code will offer us more trust on the CUPID code. The target channel has high power and thus high pressure deformation. The high power channel tends to have a high possibility of critical heat flux (CHF), because a high void fraction and quality in channel exit region appear. In this research, after determining the reference grid and T/H model, we compared the sub-channel level results of the CUPID code with those of the ASSERT code.

Constant rise in industrial usage of robots for commercial applications has led to the need for rapid, efficient, and reliable robotic system development processes. The idea of collaborative modeling and simulation provides different views to the stakeholders, enhancing the decision‐making process towards design, development, and deployment. This paper 1) applies Model‐Based Systems Engineering (MBSE) principles to a robot grasping system performing a simple pick and place task, 2) integrates Cameo Systems Modeler (CSM), CoppeliaSim robot simulator, and Gurobi Optimizer to facilitate and accelerate the system design process, and 3) describes a simulation‐based Verification & Validation (V&V) framework and performs design space exploration. This is an effort to integrate tools to reduce the burden on system design, integration, and deployment of dexterous grasping and manipulation systems. [ABSTRACT FROM AUTHOR]

The use of Monte-Carlo (MC) simulations for neutronic reactor core physics has been of high interest since long. Resulting MC models would be relevant, e.g., for high-resolution assessments of the local neutron flux and power gradients, generally beyond the modeling capabilities of engineering deterministic codes for regular full core simulations. Such MC simulations would be of particular importance for the advancement of reactor operation and safety assessments or, for example, to support designing new materials testing experimental programs at operational reactors, designing advanced reactor cores, etc. Nevertheless, MC-based core-follow burnup calculations are still challenging for routine applications. Therefore, the Laboratory for Reactor Physics and Thermal-Hydraulics (LRT) has developed in recent years a "cycle-check-up" (CHUP) concept. It allows to transfer the operating conditions (coolant and fuel temperatures, density of moderator, boron concentration, position of control rods) and burned fuel isotopic compositions from validated reference core-follow models, based on the state-of-the-art deterministic codes CASMO5/SIMULATE5/SNF, to MC codes, such as Serpent 2.2 or MCNP6®. This article presents recent work performed on the optimization of the methodology. This optimization is based on a newly developed adaptive fuel materials clustering to maximize the accuracy of the simulations while keeping the memory consumption of simulations constant. In addition, thanks to the availability of the validated deterministic core-follow models and access to additional reference data for Swiss power plants, such as start-up tests at PWRs, there is a valuable opportunity to extend the validation database for Burnup Credit applications using Swiss reactors data. This paper presents the ongoing work towards the verification and validation (V&V) of MC full core simulations for burned configurations against results of the validated deterministic models. The radial power distribution of the MC full core model using pin-wise composition was verified, yielding relative deviations in the [-9, 6]% range against the validated nodal solver. Additionally, using the developed MC models for hot zero power (HZP) conditions, the analysis of the start-up reactor measurements showed a −100 ± 2 pcm deviation from criticality, which is considered as an excellent agreement. [ABSTRACT FROM AUTHOR]

Codes and methods are subjected to a continuous update process for answering the regulatory requirements concerning the long-term operation of existing reactors and new concept deployment. In this continuous improvement process, new generation codes are developed for supporting industrial applications and the long-term strategy. In this paper, attention is devoted to selecting codes under development in France for lattice and core steady-state and transient calculations. These codes, APOLLO3® and CATHARE3, have been selected for carrying out the activities of the H2020 CAMIVVER Project oriented to the 3D-multiphysics couplings improvements. Multiscale and multiphysics solutions are key topics to keep competitiveness and answer to newer industrial needs in plant operations, licensing, and safe operating envelope requirements. The paper presents an overview of the activities performed by Framatome to support the definition of benchmarks exercises proposed in the CAMIVVER Project. Small core configurations subjected to a Reactivity Insertion Accident (RIA) are presented with associated preliminary results. To open the discussions toward the development of Best-Estimate Plus Uncertainties (BEPU) solutions, the URANIE statistical platform was used for sensitivity analysis over different configurations. These preliminary results are also presented. [ABSTRACT FROM AUTHOR]

Copyright of Oil Drilling & Production Technology / Shiyou Zuancai Gongyi is the property of Shiyou Zuancai Gongyi Bianjibu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Codes and methods are subjected to a continuous update process for answering the regulatory requirements concerning the long-term operation of existing reactors and new concept deployment. In this continuous improvement process, new generation codes are developed for supporting industrial applications and the long-term strategy. In this paper, attention is devoted to selecting codes under development in France for lattice and core steady-state and transient calculations. These codes, APOLLO3® and CATHARE3, have been selected for carrying out the activities of the H2020 CAMIVVER Project oriented to the 3D-multiphysics couplings improvements. Multiscale and multiphysics solutions are key topics to keep competitiveness and answer to newer industrial needs in plant operations, licensing, and safe operating envelope requirements. The paper presents an overview of the activities performed by Framatome to support the definition of benchmarks exercises proposed in the CAMIVVER Project. Small core configurations subjected to a Reactivity Insertion Accident (RIA) are presented with associated preliminary results. To open the discussions toward the development of Best-Estimate Plus Uncertainties (BEPU) solutions, the URANIE statistical platform was used for sensitivity analysis over different configurations. These preliminary results are also presented.

Finite element analysis (FEA), introduced more than half a century ago, requires a (qualified) analyst to generate the necessary input data, verify the output and post process the analysis results for a meaningful conclusion. The required expertise and labor efforts have precluded the use of FEA in daily medical practice by orthopedic surgeons for example. Patient-specific analyses of the mechanical response of human bones may have a tremendous impact in clinical practice should they be easily accessible by orthopedic surgeons. Recent scientific advancements such as low dose CT scans, machine learning, and high order FEA which facilitates an inherent methodology for assessing numerical accuracy allow a fully autonomous process for assessing bone strength and fracture risk. This autonomous process, that we shall refer to here as "Autonomous Finite Element" (AFE) analysis, introduces a paradigm shift in the use of FEA. We shall describe herein a novel process that utilizes AFE to produce a patient-specific assessment of bone strength. The process consists of an automatic segmentation of femurs from CT-scans by convolution neural networks, an automatic mesh generation and application of boundary conditions based on anatomical points, a high-order FE analysis with numerical error control, and finally an automatic report with a clear assessment of bone fracture risk. One specific application of AFE is the determination of the risk of fracture for patients with tumors of the femur and whether a prophylactic surgery is needed. To the best of our knowledge this is the first CE accredited AFE application being used by orthopedic surgeons in clinical practice. [ABSTRACT FROM AUTHOR]

Sodium fire is one of key issues in sodium-cooled fast reactor (SFR) plants. JAEA has developed sodium fire analysis codes, a zone model code SPHINCS and a field model code AQUA-SF, to evaluate the consequence of sodium fire events. This paper describes a PIRT (Phenomena Identification and Ranking Table) process for sodium fire events. Ranking table for important phenomena and an assessment matrix are completed. Because a sodium fire event in an SFR plant involves complex phenomena, the ranking table has been established through both element- and sequence-based phenomena analyses in addition to the engineering judgement. The assessment matrix confirms sufficiency of experimental data for validation of models corresponding to the identified important phenomena in the sodium fire analysis codes. As a part of comprehensive validation based on the assessment matrix, an experimental analysis for a large-scale sodium spray fire experiment Run-E1 is conducted by using the SPHINCS and AQUA-SF codes. The analytical results of the both codes show good agreements with the experimental data of gas pressure transient. Difference from the experimental result of the maximum pressure are about 5% smaller in the SPHINCS code and about 10% larger in the AQUA-SF code. General validity for the codes would be confirmed through the comprehensive validation based on the assessment matrix.

The integrated communication infrastructure is the core of the Smart Grid architecture. Its two-way communication and information flow provides this network with all needed resources in order to control and manage all connected components from the utility to the customer side. This latter, named the Home Area Network or HAN, is a dedicated network connecting smart devices inside the customer home, and using different solutions. In order to avoid problems and anomalies along the process life cycle of developing a new solution for HAN network, the modeling and validation is one of the most powerful tools to achieve this goal. This paper presents a practical case study of such validation. It intends to validate a HAN SDL model, described in a previous work, using model checking techniques. It introduces a method to translate the SDL model to a Promela model using an intermediate format IF. After the generation of the Promela model, verification is performed to ensure that some functional properties are satisfied. The desired properties are defined in Linear Temporal Logic (LTL), and DTSPIN (an extension of SPIN with discrete time) model checker is used to verify the correctness of the model. [ABSTRACT FROM AUTHOR]

• Verification and validation for the accuracy of FASYS is performed. • Basic requirements of FASYS and PIRT in CEFR are established. • Bottom-up, top-down and uncertainty assessment are conducted. • Results indicate FASYS can simulate the accident processes of fast reactor. The fast reactor system analysis code FASYS is developed by CIAE for transient accident analysis in CEFR. By referring to the application scope of FASYS, the basic requirements of FASYS and PIRT in CEFR are established. A comprehensive verification and validation for the accuracy of FASYS is performed, which consist of bottom-up assessment, top-down assessment and uncertainty assessment. The bottom-up assessment applies the static analysis and dynamic analysis to verify the basic function of FASYS. The separate effect tests and integral effect tests are employed in the top-down assessment to validate the availability to simulate model and system. The calculated results confirms that the basic function and model in FASYS are reasonable and credible. The uncertainty assessment results show that FASYS can still calculate IET under the reasonable uncertainty of input parameters, indicating that the FASYS can simulate and analyze the transient accident processes of sodium-cooled fast reactor. [ABSTRACT FROM AUTHOR]

Results of the project "Comprehensive Verification of the FALCON Code for Calculation of Nuclear Fuel Temperature", relating to thermal fuel behaviour under steady-state (SST) irradiation and slow power ramps are presented. Two groups of irradiation experiments carried out in the Halden Boiling Water Reactor (HBWR) are analyzed. Improvement of the prediction capability with respect to fuel temperature under SST irradiation after the earlier calibration of the selected models is confirmed. The data from the on-line measurement of fuel temperature are interpreted in consideration of the effects of Fuel Thermal Conductivity (FTC) degradation with burnup, Fission Gas Release (FGR), reduction of FTC due to development of gaseous fuel porosity, and Pellet-Cladding Mechanical Interaction (PCMI). Relevance of the analyzed data to current new concepts of Advanced Technology Fuel (ATF) is noted. [ABSTRACT FROM AUTHOR]

Business processes are usually defined by business experts who require intuitive and informal graphical notations such as BPMN (Business Process Management Notation) for documenting and communicating their organization activities and behavior. However, BPMN has not been provided with a formal semantics, which limits the analysis of BPMN models to using solely informal techniques such as simulation. In order to address this limitation and use formal verification, it is necessary to define a certain “mapping” between BPMN and a formal language such as Concurrent Sequential Processes (CSP) and Petri Nets (PN). This paper proposes a method for the verification of BPMN models by defining formal semantics of BPMN in terms of a mapping to Time Petri Nets (TPN), which are equipped with very efficient analytical techniques. After the translation of BPMN models to TPN, verification is done to ensure that some functional properties are satisfied by the model under investigation, namely liveness and reachability properties. The main advantage of our approach over existing ones is that it takes into account the time components in modeling Business process models. An example is used throughout the paper to illustrate the proposed method.

Sodium fire is one of risk factors for containment failure in a sodium-cooled fast reactor in case of sodium spray from the top of a reactor vessel due to a power excursion during a severe accident. Modifications of multi-dimensional sodium fire analysis code AQUA-SF have been carried out so as to investigate the sodium fire under the severe accident condition inside a reactor containment. The GGDH (Generalized Gradient Diffusion Hypothesis) turbulence model and a radiation model for sodium droplets were newly implemented to the AQUA-SF code. A validation study has been conducted through a benchmark analysis of an upward spray combustion experiment. This paper describes detailed influencing factors in the benchmark analysis. Reasonable temperature distribution is obtained in turbulence analyses although a laminar analysis shows an upward high temperature jet which was not observed in the experiment. The temperature distributions are almost the same between the analyses with the previous and GGDH turbulence models because there is no significant difference in the balance of production and dissipation of turbulence energy between them. The radiation model for sodium droplet increases heat transfer to structure and hence gas temperature and pressure decrease. Consequently, it has been confirmed that the experimental results is simulated reasonably by the newly introduced models in the AQUA-SF code. This means the improved AQUA-SF code is applicable for investigation of sodium fire under the severe accident condition. In addition, because the improved models on turbulence and radiation are applicable for various sodium fire events, general validity for various cases would be confirmed by additional validation activities.

The Fluoride Salt Cooled High Temperature Reactor (FHR) is a liquid salt-cooled reactor utilizing TRISO-based fuel. Its low operating pressure and large thermal margin offer attractive safety. However, its complex core design, in particular the double heterogeneity introduced by TRISO particles, as well as the presence of several moderating materials, require careful verification and validation (V&V) of the core physics modeling and simulation (M&S) methods. Due to their ability to accurately simulate complex geometries and utilize continuous-energy nuclear data, Monte Carlo methods are used in this study to evaluate core physics phenomena and provide reference solutions for verification of lower fidelity methods. This work is focused on the FHR design with hexagonal fuel elements consisting of fuel plates (“planks”), i.e., the Advanced High-Temperature Reactor (AHTR) developed by ORNL. The pebble-bed FHR design, PB-FHR, is not directly considered in this work, although the results of this study are relevant for PB-FHR as well. The SERPENT Monte Carlo code is selected and utilized to perform core physics analyses of an FHR fuel assembly. The issues investigated include detailed fission distribution, quantification of certain approximations, study of neutron spectra in different material regions, and impact of graphite density, temperature, and scattering matrix data. This study contributes to V&V of modeling and simulation methods for FHR. [ABSTRACT FROM AUTHOR]

This paper presents a Very High Temperature Gas-Cooled Reactor (VHTR) core analysis of the McCARD and DeCART-2D with High Temperature Engineering Test Reactor (HTTR) benchmark problem. The numerical results of the HTTR benchmark problem are demonstrated, the capability for VHTR core analysis of McCARD is validated by using the experiment data, and that of DeCART-2D is verified by comparing the numerical results with those of McCARD. The detail HTTR benchmark problem and specification of core geometry and material are also described. Also, a method of approximation for the complex geometry of the VHTR core is described for modelling in computational code. In terms of the multiplication factor and temperature coefficient, the numerical results of McCARD are easily compared with the HTTR experiment data. Because the DeCART-2D can solve 2-dimensional (2D) geometry, the simulation of 2D HTTR fuel rod, block, and core problem is performed with DeCART-2D and McCARD. The numerical results between them are around 200–400 pcm, meaning that DeCART-2D can be used to analyze VHTR core. [ABSTRACT FROM AUTHOR]

In this paper, the verification of two low-Reynolds-number turbulence models in an open source environment is reported. The two models are the Spalart-Allmaras model without the ft2 term and the k - ω SST model using vorticity in production estimation. Grid convergence is achieved in all verification cases, while reasonable agreements with other codes are found. The two turbulence models are also validated through comparison with some well-known validation cases, the results of which show good agreement with experimental data. The differences between the results obtained from incompressible and compressible codes are also discussed. The impact of wall distance estimation on the performance of turbulence modelling is also evaluated through grid convergence studies. Within the realm of search algorithms for wall distance estimation, a three-level search approach is found to be necessary in order to achieve correct and converged results, especially for skewed meshes. It is shown, through a 2D bump flow grid convergence study, that the use of a one-level search approach can not only lead to a maximum friction coefficient deviation of 3.8%, but also cause an inconsistent convergence behaviour. [ABSTRACT FROM AUTHOR]

WebRTC (Web Real-Time Communication) is a Web real-time audio and video communication technology, which is natively supported by the browser and is not dependent on third-party plug-ins. In order to establish a WebRTC session, there is a need for a signaling protocol to help different parties to agree on parameters such as codecs, types of media, transport addresses, etc. The paper presents a formal model and validation for a complete signaling exchange between two WebRTC communicating browsers. The formal model is built using SDL (Specification and Description Language) to describe the structure, the data, and the behaviour of the system, while the validation of the resulting model is done using the reachability analysis technique. The ultimate objective of the validation is to show that the system model is free of design errors so that it can be analyzed first and then used to generate code automatically for WebRTC solutions. [ABSTRACT FROM AUTHOR]

During a nuclear reactors design phase many possible accidents are postulated. The main accident that could occur in an open pool reactor, such as the Brazilian Multipurpose Reactor (RMB) is the Loss-Of-Coolant Accident (LOCA). This type of accident occurs when the primary cooling piping breaks and the pressure gradient induces the refrigerant (water) to flow through this pipe by siphon effect, draining the pool. This accident can be avoided with a siphon breaking mechanism, which could consist of an orifice in the coolant pipe at a level above the minimum required water level in the pool. If the pipe breaks, air will enter through this orifice, interrupting the siphon flow. However, tests have shown that the mechanism in most cases does not stop the water flow immediately, causing a reduced water level. The siphon break phenomenon is a complex two-phase transient flow. Experimental studies of the siphon break are very expensive and time-consuming tasks. In this case, it would be appropriate to make a Computational Fluid Dynamics (CFD) analysis of this phenomenon, allowing a detailed evaluation of the flow characteristics in a simpler and cheaper way than an experiment. However, the complexity of this phenomenon imposes difficulties to its computer modeling and its accuracy must be assessed. In this study, a methodology is proposed for the simulation of orifice type siphon breaker for research reactors. In order to properly evaluate the numerical methodology, an experimental model available in the literature was simulated and a Verification and Validation (V&V) procedure was performed based on the Grid Convergence Index ( GCI ) method. Numerical uncertainties due to mesh were evaluated and estimated for other simulations with different siphon breaker orifice diameters to assess the applicability of the proposed methodology. Results showed good agreement with experimental results with reasonable uncertainty range. The proposed simple numerical uncertainty estimation procedure aims to encourage the discussion towards an uncertainty quantification culture in the CFD community. [ABSTRACT FROM AUTHOR]

In this paper, we present recent advances on PWR core calculations schemes with the most advanced features of the new deterministic neutronic transport code APOLLO3®. We focus mostly on reactivity effects of control rod sub-assemblies representation. Two kinds of representation are being studied: a representation in which the control rod sub-assembly is surrounded by standard sub-assemblies, calculated using 2D TDT-MOC solver associated with the fine structure self-shielding method in 281 groups at the Lattice calculation level; and a semi-heterogeneous modeling (3 × 3 zones) of the control rod sub-assembly at the Core calculation level. Taking advantage of the possibility of subdividing a sub-assembly with the MINARET core solver which uses an unstructured conforming triangular spatial mesh (Discontinuous Galerkin Finite Elements), the core calculation represents much better the control rod shadowing effects within the control rod sub-assembly. Tests to demonstrate the ability of such a calculation scheme have been carried out on an UOX fueled PWR reactor. The accuracy of the new APOLLO3® scheme has been tested against TRIPOLI-4® and has been found extremely accurate without requiring any equivalency method. This calculation scheme lays down the foundations for a new upgrading approach for deterministic calculations to study PWR cores. [ABSTRACT FROM AUTHOR]

The main challenge facing simulation-based hydrodynamic design of naval ships comes from the complexity of the salient physics involved around ships, which is further compounded by the multidisciplinary nature of ship applications. Simulation of the flow physics using “first principles” is computationally very expensive and time-consuming. Other challenges largely pertain to software engineering, ranging from software architecture, verification and validation (V & V), and quality assurance. This article presents a computational fluid dynamics (CFD) framework called NavyFOAM that has been built around OpenFOAM, an open source CFD library written in C that heavily draws upon object-oriented programming. In the article, the design philosophy, features, and capabilities of the software framework, and computational approaches underlying NavyFOAM are described, followed by a description of the V&V effort and application examples selected from Navy’s recent R&D and acquisition programs. [ABSTRACT FROM AUTHOR]

Changing from physical prototype–based product design to computational (virtual) prototype–based product design requires more than leading edge computational engineering codes, joint R&D efforts with a Department of Energy Laboratory, brilliant and dedicated researchers, and meticulous verification, validation, and uncertainty quantification. For the most difficult engineering design problems, most of these are necessary but not sufficient. In every case, the designers, engineers, scientists, and their management must also believe that the benefits in time savings and more creative new products justify the cost and risk of conversion. In the extreme case, an impending crisis may force conversion even in the face of strong resistance. The Goodyear Tire & Rubber Company’s experience illustrates a successful, crisis-driven transition to virtual prototype–based product design. [ABSTRACT FROM AUTHOR]

With a shift in technology to digital systems as the result of analog obsolescence and digital functional advantages, existing plants have begun to replace some current analog instrument and control (I&C) systems, while new plant designs fully incorporate digital systems. The requirements for dynamic site testing of digital distributed I&C system (DCS) come with the transitions from analog to digital technology because DCS have more complex structure (hardware/software/firmware), employ more complicated logic algorithms and have more dynamic interactions than the analog one. Further, the requirements are enhanced by the fact that there are several NPPs under construction each year in China, but a shortage of expert engineers and an urgency for continued construction. However, the dynamic testing methods developed for the design V&V or the factory testing cannot be applied directly in site testing because of the constraints of the conditions at site. In this paper, we generalized on-line virtual testing (OLVT) methods for site testing and expanded the application scope of OLVT to test a universal DCS system based on our experience and knowledge of site testing. An implementation scheme for OLVT is introduced to support flexible DCS-testing applications, including a structure design of OLVT, development of the DCS-testing platform and connection ways. [ABSTRACT FROM AUTHOR]

Although engineering simulators were used for the V&V of NPP DCS, there has been no systematic evaluation of its use for site testing. This study summarizes on-line virtual testing (OLVT) methods for DCS site testing to guide the on-site V&V activities. DCS-testing methods for different types of systems are described in detail. We classified OLVT into four types according to the mode of implementation way: 1) hard wiring closed-loop test, 2) network connection closed-loop test, 3) signal injection open-loop test, and 4) integrated automatic comparison open-loop test. Each of the testing methods is illustrated in detail with a typical application. These four kinds of testing methods differ in their characteristics, but flexible application of them should be performed based on the specific conditions and requirements of site testing. Following the guide lines present here, OLVT can be applied to generalized DCS systems in site testing. [ABSTRACT FROM AUTHOR]

Hoy en día es complicado para una Pyme desarrolladora de Software aplicar los Modelos de Calidad y Pruebas propuestos, tales como: CMMI, CMM, MOPROSOFT, COMPETISOFT, TMMi, TMap que hacen referencia al proceso de Verificación y Validación (V&V), principalmente por: 1) el grado de complejidad, la mayoría han sido estructurados para ser aplicados en empresas grandes; 2) las restricciones de costo de las Pymes; o 3) por el desconocimiento que se tiene sobre los beneficios que se obtendrían. El presente trabajo tiene como principal objetivo elaborar un Marco Metodológico del Proceso de V&V ajustado a la realidad socio económico de las Pymes, el trabajo incluye una guía metodológica, los roles y competencias del equipo de trabajo, plantillas/listas de verificación base y las principales métricas. El Marco fue aplicado al Sistema de Control de Inventarios de la empresa QBOSS SAC, que es una Pyme peruana, obteniéndose mejoras en la calidad del software.

Business processes are usually defined by business experts who require intuitive and informal graphical notations such as BPMN (Business Process Management Notation) for documenting and communicating their organization activities and behavior. However, BPMN has not been provided with a formal semantics, which limits the analysis of BPMN models to using solely informal techniques such as simulation. In order to address this limitation and use formal verification, it is necessary to define a certain "mapping" between BPMN and a formal language such as Concurrent Sequential Processes (CSP) and Petri Nets (PN). This paper proposes a method for the verification of BPMN models by defining formal semantics of BPMN in terms of a mapping to Time Petri Nets (TPN), which are equipped with very efficient analytical techniques. After the translation of BPMN models to TPN, verification is done to ensure that some functional properties are satisfied by the model under investigation, namely liveness and reachability properties. The main advantage of our approach over existing ones is that it takes into account the time components in modeling Business process models. An example is used throughout the paper to illustrate the proposed method. [ABSTRACT FROM AUTHOR]

Multiscale analysis of a semi-periodically perforated plate based on a homogenization theory is experimentally validated both macroscopically and microscopically, using a full-field strain measurement. To do this, a plate-fin-type perforated plate with a misaligned microstructure is considered as a semi-periodically perforated plate. Then, a homogenization theory that can analyze macroscopic behavior and microscopic stress and strain distributions of the perforated plate is presented. To validate the theory, a tensile test of a plate-fin-type semi-periodically perforated plate made of epoxy resin is conducted. During the test, the microscopic deformation of the specimen is observed with a digital image correlation (DIC) full-field measurement system, from which microscopic strain distribution of the specimen is calculated. It is shown that the obtained strain distribution satisfies the unit-cell periodicity except at edges of the periodic structure, and that the strain distribution is in good agreement with the result of analysis using the homogenization theory. It is also shown that the macroscopic stress–strain relationships obtained by the experiment and analysis agree well, supporting the macroscopic and microscopic validity of the multiscale analysis using the homogenization theory. [ABSTRACT FROM AUTHOR]

A successful fielding of computation-based engineering (CBE) software requires quality assurance to be built into the fabric of capability development and deployment processes. Good software quality is an emergent property of the healthy interplay among CBE software development teams, testing teams, user support, and training teams, with the vital notion of continual feedback to improve the user experience. This article describes how the HPCMP CREATE Air Vehicles (AV) project addresses these topics through the functions performed by its quality assurance group. Industry quality standards are discussed and their strengths and weaknesses within the CREATE-AV framework addressed. The article concludes with lessons and best practices learned over the course of an extended (seven+ year) effort to field next-generation multiphysics aviation design tools to the DoD community. [ABSTRACT FROM PUBLISHER]

As one of the six Generation-IV reactors, SFR (sodium-cooled fast reactor) is attracting more and more attention in recent years. To evaluate the SFR safety characteristics, the Shutdown Heat Removal Tests (SHRT) conducted by Argonne National Laboratory (ANL) were performed in Experimental Breeder Reactor-II (EBR-II) to verify inhere safety characteristics. To find the inaccuracies in the exist models and improve the simulating level for SFR, SHRT-17 and SHRT-45R have been chosen as the benchmark problems for the IAEA coordinated research project (CRP), which we have participated in. THACS (the Transient Thermal-Hydraulic Code for Analysis of Sodium Cooled Fast Reactor) developed by XJTU was used in our work. THACS has finished preliminary with completion of all the models of primary loop originally intended for simulating accidents in SFRs. THACS is a multi-channel, multi-phase, multi-component transient and universal code coupled with the point reactor kinetics model. In this paper the models of THACS were introduced in detail and SHRT scenario simulation work of EBR-II has been performed. THACS was verified with the simulation results of flowrate and temperatures in core and instrumented subassembly XX09. After the verification, the peak coolant, cladding and fuel temperatures were estimated which is under the safety limits. Results show that EBR-II is effective in protecting the reactor against the severe loss-of-flow accidents. The three-layer model for cold pool coupled with THACS was used and the predicted results in a better agreement with the measurements. [ABSTRACT FROM AUTHOR]

To better utilize the potential of system simulation models and simulators, industrially applicable methods for Verification, Validation and Uncertainty Quantification (VV&UQ) are crucial. This paper presents an exploratory case study of VV&UQ techniques applied on models integrated in aircraft system simulators at Saab Aeronautics and in driving simulators at the Swedish National Road and Transport Research Institute (VTI). Results show that a large number of Verification and Validation (V&V) techniques are applied, some of which are promising for further development and use in simulator credibility assessment. Regarding the application of UQ, a large gap between academia and this part of industry has been identified, and simplified methods are needed. The applicability of the NASA Credibility Assessment Scale (CAS) at the studied organizations is also evaluated and it can be concluded that the CAS is considered to be a usable tool for achieving a uniform level of V&V for all models included in a simulator, although its implementation at the studied organizations requires tailoring and coordination. [ABSTRACT FROM AUTHOR]

Construction of an expert system involves the acquisition of domain knowledge, and then performing the process of verification and validation of the encoded knowledge. The article discusses the process of verifying the completeness of the medical knowledge base created to develop the expert system that supports decisionmaking in cardiac surgery. Due to the special character of knowledge sources in this domain, studying completeness plays a crucial role. The author proposes the twostage verification of the knowledge base, treating the stage of the initial assessment of completeness and indeterminism as an essential element supporting the codification of knowledge. During realization of the mentioned tasks the author used her own program, performing the static verification of the completeness of the knowledge base. [ABSTRACT FROM AUTHOR]

With an annual budget of nearly US600 billion, the US Department of Defense (DoD) is tasked with protecting the US and its allies and interests abroad against potential adversaries. It must accomplish these tasks in a globalized and highly interconnected world where the pace of technology is moving faster than the current time-consuming DoD acquisition systems can keep up with. Moving forward, the DoD must change these time-consuming paradigms and accelerate the pace of innovation. One way to do this is to shift to a virtual prototyping environment where the benefits of high-performance supercomputing and complex physics-based engineering software can expand the decision space and enable the DoD to field better systems faster, cheaper, and at less risk than previous methods. This is the goal of the Computational Research and Engineering Acquisition Tools and Environments (CREATE) program. This issue of CiSE provides the third installment of articles relating to the history, formation, and ongoing work of the High Performance Computing Modernization Program (HPCMP) CREATE program. [ABSTRACT FROM AUTHOR]