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Systems engineering (SE) andmodel-based development (MBD) attract attention from manufacturers to producemore complex products with less rework in order to satisfy higher demands. However, concrete methodology is not defined well. This paper proposes a methodology of target assignment with respect to a special functional cascading for integrated atchitectural products. This paper also proposes "abstracted energy model" for assignment in top layer in the cascade. An example for air conditioner development demonstrates the efficiency of this methodology. [ABSTRACT FROM AUTHOR]

This study explores practical experiences of model-based development and implementation, focusing on 'lessons identified.' The study draws on experience from several case studies in the Swedish Defence domain using semistructured interviews as the major source of information. The study identifies several conditions as being crucial for successful implementation of model-based development work, including an increased focus on the planning and premodeling phase, a need for interorganizational or across-project collaboration, scalability, change management, and documentation and reuse of experiences. It was also found that most of the challenges identified in the model-based development and implementation processes are common organizational and system development related problems such as change management, the issue of user participation, and how to carry out requirements engineering based on the models. Therefore, future research in the area should aim for a more integrative perspective, for instance, bridging the gap between information collection, models, user needs, and organizational and system requirements. © 2012 Wiley Periodicals, Inc. Syst Eng 15 [ABSTRACT FROM AUTHOR]

The protein streptavidin (SAV) is applied in a large variety of molecular methods due to an extraordinarily strong binding to the vitamin biotin (BIO). The protein structure is homotetrameric, characterized by one binding site for BIO per subunit. Therefore, one of the major criteria to determine the quality of SAV isolates is the proportion of BIO-blocked binding sites per tetramer. A rapid analysis of BIO-free binding sites is achieved by fluorescence quenching of biotin-4-fluorescein (B4F). However, BIO-blocked binding sites can only be determined by costly and laborious procedures such as ELISA-based methods or radioactive labeling. This study describes the systematic, model-supported development of a method for the quick and simple detection of BIO-blocked binding sites, based on a short-term heat incubation of the sample in the presence of B4F. Kinetic modeling and parameter estimation yielded dissociation constants of 1.22 ± 0.27 × 10−11 M for the complex SAV-BIO and 5.16 ± 0.70 × 10−13 M for SAV-B4F at 70°C, allowing a displacement of SAV-bound BIO by B4F. This method allows the rapid monitoring of BIO-blocked binding sites in fermentation processes, independent from the chain length of SAV and the concentration of contaminating proteins, e.g. when optimizing the BIO concentration in cultivation media. [ABSTRACT FROM AUTHOR]

A model-based approach was implemented for the development of the proliferator-activated receptor gamma (PPARγ?) agonist rivoglitazone. Population pharmacokinetic and pharmacodynamic models were developed using data collected from 2 phase I and 2 phase II studies in healthy volunteers and participants with type 2 diabetes mellitus. A 2-compartment model with first-order absorption and elimination and an absorption time lag best described rivoglitazone pharmacokinetics. Modified indirect-response models were used to characterize changes in fasting plasma glucose, HbA1c, and hemodilution as a function of rivoglitazone plasma concentrations. In addition, differences in hemodilution among participants correlated with the incidence of edema. Current use of oral antidiabetic medication was a significant covariate for the fasting plasma glucose-HbA1c exposure-response model. Using a learn-and-confirm process, models developed prior to the second phase II study were able to make valid predictions for exposures and response variables in that study. In future studies, seamless designs can be supported by models such as those developed here. [ABSTRACT FROM AUTHOR]

As the transition to model-based drug development continues, pharmacometric analysis will have an increasingly important role across the entire life cycle of drug discovery, development, regulatory approval, and commercialization. For this reason, pharmacometrics can—and should—have an integrating function in the transformation to model-based development. This essay describes an approach for formalizing the pharmacometrics process using the disciplines encompassed by enterprise engineering.Clinical Pharmacology & Therapeutics (2007) 82, 137–142. doi:10.1038/sj.clpt.6100270 [ABSTRACT FROM AUTHOR]

Many real-time systems are safety-and security-critical systems and, as a result, tools and techniques for verifying them are extremely important. Simulation and testing such systems can be exceedingly time-consuming and these techniques provide only probabilistic measures of correctness. There are a number of model-checking tools for real-time systems. Although they provide formal verification for models, we still need to implement these models. To increase the confidence in real-time programs written in real-time Java, this paper proposes a model-based approach to the development of such programs. First, models can be mechanically verified, to check whether they satisfy particular properties, by using current real-time model-checking tools. Then, programs can be derived from the model by following a systematic approach. We introduce a timed automata to RTSJ Tool (TART), a prototype tool to automatically generate real-time Java code from the model. Finally, we show the applicability of our approach by means of four examples: a gear controller, an audio/video protocol, a producer/consumer and the Fischer protocol. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

It has recently been shown that the oxygen content of a three-way catalyst can be observed directly by a microwave-assisted technique. In this contribution, several control strategies based on this microwave measurement approach are proposed. In the first step, the lambda probe downstream of the catalyst is replaced by the microwave-based state observer. In the second step, the microwave-based state observer replaces both lambda probes, upstream and downstream of the catalyst. A model-based rapid control prototyping approach is used to test the selected control schemes and to compare their performance to the conventional air-fuel ratio control. This comparison is completed using a complex catalyst model and measured data for a realistic driving cycle. It is shown that under idealized conditions the new microwave-based control strategies can outperform the conventional lambda control based on two lambda probes. One important result is that improving the time resolution of the current microwave measurement system is essential to use the full potential of the new approach. [ABSTRACT FROM AUTHOR]

D1244 in operation – first data and results on the way to controlled adaptation Global construction is responsible for about 50 % of the world's CO2‐emissions and resource consumption. For a sustainable future, a drastic reduction is required, which, however, is in contradiction to the worldwide demographics characterized by population increase and urbanization. One possible approach are adaptive load‐bearing structures equipped with distributed actuators and sensors that can manipulate deformations and stress distributions under loads through geometric adaptation. For high‐rise buildings, this technology enables a reduction of resource consumption by about 50 %, for example. The world's first prototype was inaugurated at the end of 2021 on the campus of the University of Stuttgart. With twelve floors on a base area of 5 m × 5 m, the D1244 is 36 m high and has 24 hydraulic actuators, 128 strain gauges, and an optical measurement system that uses two cameras to measure deformations at 16 points on the structure in a plane parallel to the camera sensor with submillimeter precision. This paper illustrates the steps within the model‐based development chain for automation and control of D1244 that have been accomplished and the results that have been achieved on this high‐rise building. The experimental model identification and the subsequent model‐based controller and observer design are discussed. Finally, the algorithms used for fault detection and diagnosis are presented and their basic functionality is demonstrated on the basis of initial validation measurements. [ABSTRACT FROM AUTHOR]

Current requirements for the reduction of CO2 emissions, as well as for the improvement of durability and reliability of sociotechnical systems such as passenger cars, lead to an increase in development effort in order to increase efficiency and system lifetime. Tribological systems play an essential role in the development of sociotechnical systems, but have proved to be particularly complex. The development of tribological systems, as part of the overall system under development, is an interdisciplinary effort. Involvement of solid mechanics, fluid mechanics, rheology, and many more scientific disciplines is essential to cope with the high number of nonlinear relationships, which often cause unpredictable system behavior. This paper contributes to the scientific field of tribology by introducing concepts of model‐based systems engineering for the specific case of elastohydrodynamic lubrication states. The elastohydrodynamic lubrication state of tribological system has been chosen as example to show how system models can be used to better describe the behavior of a system by connecting several specific models. In order to gain an overview of the models used in tribological system development, a system cube was used to structure the models. The system cube enabled gaps and overlapping model zones to be identified. Finally, the role of system models in development and the benefit of using system models to solve problems that cannot be solved by a single technical discipline but only in an interdisciplinary effort are discussed. An approach to connect models and methods to describe a system in an elastohydrodynamic lubrication state is presented. [ABSTRACT FROM AUTHOR]

In product development, rarely a product is developed from scratch. In many cases, a product is developed from a prior design or several prior designs. The associated development cost is actually a switching cost (or some called reuse cost), representing the cost incurred from developing the product from prior designs. So far, no proven works in switching cost estimation were found for products developed using MBSE (Model‐Based Systems Engineering). Today, MBSE is being widely adopted. It is important to develop switching cost estimation methods that leverage models and support model‐based development needs. This paper, per the best of our knowledge, is among the firsts that developed switching cost methods for MBSE. Our work identifies different use case scenarios/phases in an MBSE development cycle, and provides corresponding switching cost estimation methods, laying down the fundamental methodology for the model‐based switching cost estimations. Using SysML, an example use case of derivative airplane electrical power system is used to demonstrate the effectiveness of our methods. [ABSTRACT FROM AUTHOR]

Model‐based development and implementation of the digital building file – BIM from construction to operation The use of BIM in bridge construction is currently limited to the design and construction phases, but BIM can be particularly useful for the operation of structures. The basis for the use of BIM in the operation life cycle phase is the transfer of relevant information from the planning and construction life cycle phases to operation. The creation of a model‐based digital building file enables the transfer of relevant information for operation. The article classifies the creation and use of model‐based digital construction files both in the scientific context and in the current working methodology with analog construction files and construction files. It also includes the practical implementation of a specific project. Furthermore, the reference to the standardized use cases 190 "Project and building documentation" and 200 "Use for operation and maintenance" is presented. The implementation of the model‐based digital construction file is demonstrated using the example of the Cologne Heumar highway interchange. The objectives and principles associated with the use of BIM, the project development and the background are discussed. The implementation and handover of the model‐based digital construction file is described in detail for the practical example. [ABSTRACT FROM AUTHOR]

Presents abstract of the study "Model based development of a direct factor Xa inhibitor," by S. Rohatagi and colleagues.

Model-based development is a popular development approach in which software is implemented and verified based on a model of the required system. Finite state machines (FSMs) are widely used as models for systems in several domains. Validating that a model accurately represents the required behaviour involves the generation and execution of a large number of input sequences, which is often an expensive and time-consuming process. In this paper, we speed up the execution of input sequences for FSM validation, by leveraging the high degree of parallelism of modern graphics processing units (GPUs) for the automatic execution of FSM input sequences in parallel on the GPU threads. We expand our existing work by providing techniques that improve the performance and scalability of this approach. We conduct extensive empirical evaluation using 15 large FSMs from the networking domain and measure GPU speed-up over a 16-core CPU, taking into account total GPU time, which includes both data transfer and kernel execution time. We found that GPUs execute FSM input sequences up to 9.28x faster than a 16-core CPU, with an average speed-up of 4.53x across all subjects. Our optimizations achieve an average improvement over existing work of 58.95% for speed-up and scalability to large FSMs with over 2K states and 500K transitions. We also found that techniques aimed at reducing the number of required input sequences for large FSMs with high density were ineffective when applied to all-transition pair coverage, thus emphasizing the need for approaches like ours that speed up input execution. [ABSTRACT FROM AUTHOR]

Summary: Model‐based development (MBD) holds the promise to capture potential timing problems in embedded software during the early phases of the development, securing the production of bug‐free embedded software. For most MBD approaches, the source code is just an intermediate artifact that can be generated automatically from the models. This assumption clashes with an undeniable fact: a large share of the commercial embedded software exploits existing libraries or is developed using C/C++ natively. A way to reconcile the ambitions of MBD with the use of a programming language is by offering new language constructs and an innovative compilation tool‐chain that prevents model error and timing problems "by construction." However, the persistent popularity of C/C++ among embedded programmers and the limited availability of tools have severely limited the uptake of alternative programming languages for embedded software. Therefore, we propose an original route. Our language proposal, named Tice, has been shaped as a C++ active library. Tice retains full compatibility with existing C++ code, which can be integrated easily into new Tice‐based projects. The enforcement of Tice syntax and semantics can be made by a standard C++ compiler, forgoing the need for new tools. In this article, we describe Tice's syntax, semantics, and model of computation and communication. We demonstrate Tice's practical applicability on an industrial scale use‐case and give ample evidence for Tice's efficient compilation using off‐the‐shelf C++ compilers. Finally, we show Tice's code generation process. [ABSTRACT FROM AUTHOR]

A discrete‐time full‐order sensorless control strategy for high‐speed interior permanent magnet synchronous motor (IPMSM) used in electric vehicle (EV) traction system is designed in this paper. While most speed and position observer (SPO) methods are developed in the continuous‐time domain, the presence of a unit‐time‐delay block existed in feedback loop and discretisation of the algorithm can lead to performance degradation during digital implementation. In this work, speed and angle are observed using the discrete‐time four‐order IPMSM model. A quadrature phase‐locked loop model with compensation is introduced, and its stability condition is established for the first time. Furthermore, to address the potential for sudden speed changes in vehicle applications, the parameter range is further refined to keep the estimation error within a specified range. The sliding mode observer is discretised and its stability is analysed using discrete Lyapunov theory. Additionally, the time sequence of interactive signals between SPO and field‐oriented control is thoroughly examined to ensure accurate time cycle. Finally, the proposed control strategy is validated and demonstrated through bench tests and real EV (LS6 of IM Motors) tests with a 190 kW IPMSM, which can improve the accuracy by 0.3 radians at 8000 rpm compared to traditional methods, and achieve stable control at 15,000 rpm on the test bench and at 120 kph with the EV. [ABSTRACT FROM AUTHOR]

Next‐generation genome sequencing machines and Point‐of‐Care (PoC) in vitro diagnostics devices are precursors of an emerging class of Cyber‐Physical Systems (CPS), one that harnesses biomolecular‐scale mechanisms to enable novel "wet‐technology" applications in medicine, biotechnology, and environmental science. Although many such applications exist, testifying the importance of innovative life‐sciences instrumentation, recent events have highlighted the difficulties that designing organizations face in their attempt to guarantee safety, reliability, and performance of this special class of CPS. New regulations and increasing competition pressure innovators to rethink their design and engineering practices, and to better address the above challenges. The pace of innovation will be determined by how organizations manage to ensure the satisfaction of aforementioned constraints while also streamlining product development, maintaining high cost‐efficiency and shortening time‐to‐market. Model‐Based Systems Engineering provides a valuable framework for addressing these challenges. In this paper, we demonstrate that existing and readily available model‐based development frameworks can be adopted early in the life‐sciences instrumentation design process. Such frameworks are specifically helpful in describing and characterizing CPS including elements of a biological nature both at the architectural and performance level. We present the SysML model of a smartphone‐based PoC diagnostics system designed for detecting a particular molecular marker. By modeling components and behaviors spanning across the biological, physical‐nonbiological, and computational domains, we were able to characterize the important systemic relations involved in the specification of our system's Limit of Detection. Our results illustrate the suitability of such an approach and call for further work toward formalisms enabling the formal verification of systems including biomolecular components. [ABSTRACT FROM AUTHOR]

Summary: Development of distributed software systems is complex due to the distribution of resources, which complicates validation of system‐wide functionality. Such systems include various facets like functionality and distribution, each of which must be validated and integrated in the final software solution. Model‐based techniques advocate various abstraction approaches to cope with such challenges. To enhance model‐based development, this paper proposes (1) guidelines for development of distributed systems, where the different facets are introduced gradually through systematic modeling extensions, (2) code generation capabilities supporting technology specific realizations, and (3) demonstration of the applicability of our approach using an industrial case study involving the development of a harvest planning system, where the communication infrastructure paradigm changed late in the project. When developing this system, we spent most time validating system‐wide functionality. The model extensions allowed an easier change of the underlying communication paradigm and code generation supported realization of the different system representations. [ABSTRACT FROM AUTHOR]

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In industrial process control, the proportional–integral–derivative (PID) control scheme is well‐recognized and widely utilized. However, due to the distinctive characteristics of real systems, their control design primarily aims at achieving optimal production performance, constrained by uncertainty and variations. This paper initially discusses a database‐driven PID (DD‐PID) control scheme that was previously proposed. This scheme combines the DD‐PID with the cerebellar model articulation control to minimise computational and memory requirements for industrial application. Subsequently, a hydraulic system is introduced, detailing its characteristics and control necessities. Furthermore, both the DD‐PID and the proposed cerebellar model articulation control memory‐based DD‐PID control schemes are implemented and evaluated through experimental examples on a hydraulic system. Lastly, as a practical validation of the theoretical approach, a quantitative assessment compares the two methods, discussing the practicality and efficacy of the proposed scheme in reducing computation and memory consumption. [ABSTRACT FROM AUTHOR]

In order to claim conformance with a Java Specification Request, a Java implementation has to pass all tests in an associated Technology Compatibility Kit. This paper presents a model-based development of a Technology Compatibility Kit test suite and a test execution tool for the draft safety-critical Java profile specification. The Java Modeling Language is used to model conformance constraints for the profile. Java Modeling Language annotations define contracts for classes and interfaces. The annotations are translated by a tool into runtime assertion checks. Hereby, the design and elaboration of the concrete test cases are simplified, because the expected results are derived from contracts and thus do not need to be provided explicitly. Bottom-up testing is applied for testing methods of the safety-critical Java classes, whereas top-down testing is applied for testing global properties, such as protocols, memory management, and real-time properties, including scheduling. The tests are executed using a simplified version of JUnit, which makes the test suite executable on resource-constrained platforms. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper discusses the applicability of agile methods to aircraft embedded software development. It presents the main results of an experiment that combines agile practices from Scrum with model-based development and distributed development. The experiment consists of the development of an aircraft cockpit display system divided in five distributed teams. Three features are analysed and quantified, using the output artefacts of each team: the artefacts' quality, the adherence to agile methods, and the adherence to standard DO-178C. The main conclusion of the experiment is that there is a high correlation between the adherence to agile methods and the artefacts' quality, motivating the use of agile methods in aircraft industry. Also, the experiment evinced that agile methods does not specifically address the integration of distributed teams and the hardware/software integration. This lacuna affects the artefacts' quality. The results of the experiment emphasize the importance of concentrating future work in the proposal of specific agile practices for these activities. [ABSTRACT FROM AUTHOR]

This study proposes an optimal energy management strategy for dual‐source fuel cell hybrid electric vehicles (FCHEV) utilizing the support vector machine (SVM) classifier. The goal is to optimize power distribution between fuel cells and batteries to enhance vehicle's performance and efficiency. The SVM classifier is trained using a dataset of driving conditions and corresponding optimal power distribution (OPD) values obtained through simulation. The trained classifier predicts real‐time OPD based on driving conditions. In comparison to existing literature, this study conducts a comparative analysis of energy management control strategies like model predictive control (MPC), fuzzy, equivalent consumption minimization strategy (ECMS), proportional‐integral (PI) control, and state machine control (SMC) strategy for FCHEVs using the MATLAB/SIMULINK platform and real‐world driving dataset. The proposed strategy is then tested in a real‐time EV simulator to verify its efficacy. Additionally, this study introduces the SVM classifier technique for selecting the optimal energy management strategy for FCHEVs. Performance analysis using SVM reveals that the MPC control strategy offers the highest efficiency compared to other techniques based on selected features, achieving an average performance of 95% through cross‐validation. This analysis demonstrates the most cost‐effective and fuel‐efficient utilization of electricity flow in a modern energy‐efficient environment. [ABSTRACT FROM AUTHOR]

Current methods of dose determination have contributed to suboptimal and inequitable health outcomes in underrepresented patient populations. The persistent demand to individualise patient treatment, alongside increasing technological feasibility, is leading to a growing adoption of model-informed precision dosing (MIPD) at point of care. Population pharmacokinetic (popPK) modelling is a technique that supports treatment personalisation by characterising drug exposure in diverse patient groups. This publication addresses this important shift in clinical approach, by collating and summarising recommendations from literature. It seeks to provide standardised guidelines on best practices for the development of popPK models and their use in MIPD software tools, ensuring the safeguarding and optimisation of patient outcomes. Moreover, it consolidates guidance from key regulatory and advisory bodies on MIPD software deployment, as well as technical requirements for electronic health record integration. It also considers the future application and clinical impact of machine learning algorithms in popPK and MIPD. Ultimately, this publication aims to facilitate the incorporation of high-quality precision-dosing solutions into standard clinical workflows, thereby enhancing the effectiveness of individualised dose selection at point of care., (© 2024 VESYNTA LTD and The Author(s). British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Compared to conventional actuators, the soft ionic polymer–metal composite (IPMC) actuator has significant advantages in specific applications, and the mathematical model of IPMC actuators is essential to comprehending and applying IPMCs. Due to the inherent characteristics of IPMCs and the impact of the manufacturing and measurement processes, it is challenging to developa reliable model. This article provides a comprehensive overview of the developments in IPMC actuator modeling. In particular, three types of models are examined and contrasted: the nonphysical identification model, the partial‐physical model, and the physical‐based model. In order to comprehend the current state of numerous IPMC actuator models, the characteristics, evolution, and functions of each type of model are discussed. Afterward, the evolution of the IPMC actuators' applications is discussed. Finally, promising research directions for IPMC actuator models are identified that can more effectively facilitate the development of IPMC‐based devices. [ABSTRACT FROM AUTHOR]

SUMMARY Ensuring models' consistency is a key concern when using a model-based development approach. Therefore, model inconsistency detection has received significant attention over the last years. To be useful, inconsistency detection has to be sound, efficient, and scalable. Incremental detection is one way to achieve efficiency in the presence of large models. In most of the existing approaches, incrementalization is carried out at the expense of the memory consumption that becomes proportional to the model size and the number of consistency rules. In this paper, we propose a new incremental inconsistency detection approach that only consumes a small and model size-independent amount of memory. It will therefore scale better to projects using large models and many consistency rules. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

SUMMARY The development of software-based systems for vehicles in compliance with the new standard ISO 26262 - functional safety for road vehicles - requires a common understanding between the two domains. In this paper, we consider the impact of the ISO 26262 to the concept phase of the vehicle development, especially the model-based development of electric/electronic architectures. To found a formal basis for the electric/electronic architecture modeling, located in the development process and addressed by ISO 26262, we introduce a meta-model, combining the major concepts and relations of electric/electronic architectures and ISO 26262. Safety analysis can be supported by data available in the electric/electronic architecture model. In this paper, we present a methodology to facilitate and accumulate context-based information from electric/electronic architecture models to use them as input information for safety analysis. We also demonstrate how to perform the safety analysis method, that is, failure mode and effect analysis, based on the same architecture description language as the electric/electronic architecture model and also within the same modeling tool. We also present a methodology for the modeling and consideration of safety aspects and requirements crossing different system perimeters. This facilitates the consistent description and analysis of systems of systems, such as contemporary vehicles. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The paper overviews the long‐term cooperation between the Bauhaus University, Weimar and the Budapest University of Technology and Economics on computational modelling of structures. The cooperation consists of diverse elements of research activities, experimental and numerical model‐based development of design methods for innovative structural details of industrial halls, bilateral education of students at different levels (BSc, MSc and PhD), cooperative supervision of PhD researches and review of PhD theses. The fruitful cooperation is closely linked to the friendly relationship between Prof. Frank Werner and Prof. László Dunai, who jointly organized and managed the main part of the common research and educational activities. The common research results significantly extended the state‐of‐the‐art knowledge of the design of light‐gauge roof systems for industrial halls, of the design of shear connectors in cold‐formed composite slabs and of the modelling of cyclic plasticity. Hungarian students had the opportunity to study at the Bauhaus University, Weimar during Summer Schools organized by Prof. Werner. He also hosted two Hungarian PhD Students in Weimar, and a German PhD student had a research stay in Budapest under the guidance of Prof. Dunai. The current paper gives a summary of the most important activities and results of this two‐decade long cooperation, which are all linked to the computational modelling of steel and composite structures. The paper also congratulates Prof. Frank Werner on his 70th birthday. [ABSTRACT FROM AUTHOR]

Pharmacokinetic (PK) and exposure-response modeling of a selective sphingosine 1-phosphate receptor-1 modulator (CS-0777) was conducted in an iterative process to guide early clinical development decisions. A model based on preclinical data from monkeys was extrapolated to humans to support a single ascending dose (SAD) study. The model was updated after each cohort, providing guidance on both maximal inhibition and time to recovery for lymphocyte counts. A 2-compartment PK model with firstorder absorption and elimination was found to describe the monkey and human datasets. The relationship between lymphocyte counts and active metabolite (M-1) concentrations was modeled via an indirect response model, whereby M-1 inhibited the reentry of lymphocytes to the circulation. The indirect-response model based on SAD data had an I[submax] of approximately 85% and an IC[sub50] of 0.24 ng/mL. Additionally, based on SAD data, similar models were developed for lymphocyte subsets, including CD4 cells. Subsequently, simulations were utilized to design a multiple ascending dose study with adaptive dosing regimens that would meet targeted pharmacodynamic (PD) response thresholds (eg, minimum 40% reduction in lymphocytes) while maintaining CD4 counts above a reasonable safety threshold. In conclusion, model-based development and use of adaptive designs for dose optimization can reduce the time and number of subjects needed in early clinical development. [ABSTRACT FROM AUTHOR]

The exploration of Systems of Systems (SoS) modeling using Model‐Based Systems Engineering (MBSE) is an ongoing area of research, wherein researchers are actively investigating various frameworks and languages suitable for initiating SoS modeling. Urban Air Mobility (UAM) represents a novel approach to urban transportation, integrating multiple systems and stakeholders to enable on‐demand, environment friendly, efficient, and sustainable air travel within cities. International organizations have dedicated significant efforts to develop a comprehensive Concept of Operation (ConOps) for UAM, aiming to define the UAM ecosystem and identify the supporting systems. While previous research was focused on defining the Urban Air System (UAS) using Systems Modeling Language (SysML), there remains a gap in capturing the ConOps for UAM as a System of Systems (SoS) using SysML. This study seeks to address this gap by utilizing the MagicGrid Framework for SoS modeling. [ABSTRACT FROM AUTHOR]

Since the last decade, the automotive industry has undergone a significant transformation, moving from traditional document‐based systems engineering to a more architecture‐focused and model‐based systems engineering (MBSE) approach. This shift is driven by the rapidly increasing complexity and the difficulties in managing system descriptions using conventional document‐based methods. The paper investigates how MBSE can support this transformation using an architecture framework developed at Continental. As a response, the authors propose an architecture‐centric Systems Engineering approach based on viewpoints. The focus on architecture‐centricity and using models enables a more efficient and effective way of analyzing, developing, and designing complex systems. The authors use an automotive example to demonstrate how this approach can be practically implemented within a development workflow. The article highlights the architecture‐centric model‐based systems engineering application through an in‐house architecture framework used at Continental. [ABSTRACT FROM AUTHOR]

There is ongoing digital transformation in many industrial contexts including non‐digital hardware‐intensive domains such as heavy construction equipment machinery. This transformation is augmented by the latest technologies, increasing sustainability regulations, as well as integrated customer needs. This paradigm shift is causing transformation of current product‐centric business models towards complex business models enabled by so‐called Product Service Systems (PSS) offering advanced "capabilities" and "services". However, the development of PSSs requires a holistic approach to unify underlying solution domains such as mechatronic systems, embedded software control as well as information systems. In this paper, we describe a holistic "unified" architecture description methodology towards aligning the underlying domain‐specific design and development contexts. The framework, developed in construction domain, consists of two main parts: a minimalistic reference model as the "common language" for cross‐functional stakeholder communication; a modeling methodology based on existing standard modeling frameworks. We illustrate the methodology using examples from the construction equipment domain. [ABSTRACT FROM AUTHOR]

Summary: Model‐based test design is increasingly being applied in practice and studied in research. Model‐based testing (MBT) exploits abstract models of the software behaviour to generate abstract tests, which are then transformed into concrete tests ready to run on the code. Given that abstract tests are designed to cover models but are run on code (after transformation), the effectiveness of MBT is dependent on whether model coverage also ensures coverage of key functional code. In this article, we investigate how MBT approaches generate tests from model specifications and how the coverage of tests designed strictly based on the model translates to code coverage. We used snowballing to conduct a systematic literature review. We started with three primary studies, which we refer to as the initial seeds. At the end of our search iterations, we analysed 30 studies that helped answer our research questions. More specifically, this article characterizes how test sets generated at the model level are mapped and applied to the source code level, discusses how tests are generated from the model specifications, analyses how the test coverage of models relates to the test coverage of the code when the same test set is executed and identifies the technologies and software development tasks that are on focus in the selected studies. Finally, we identify common characteristics and limitations that impact the research and practice of MBT: (i) some studies did not fully describe how tools transform abstract tests into concrete tests, (ii) some studies overlooked the computational cost of model‐based approaches and (iii) some studies found evidence that bears out a robust correlation between decision coverage at the model level and branch coverage at the code level. We also noted that most primary studies omitted essential details about the experiments. [ABSTRACT FROM AUTHOR]

In recent years, Model‐Based Systems Engineering (MBSE) practices have been applied in various industries to design, simulate and verify complex systems. The verification and validation (V&V) of such systems engineering models are crucial to develop high‐quality systems. However, this is a challenging problem due to the complexity of the models and semantic differences in how different tools interpret the models, which can undermine the validity of the obtained results if they go undiscovered. To address these issues, we propose (i) a subset of the SysML language for which the practical semantic integrity of tools can be achieved and (ii) a cloud‐based V&V framework for this subset, lifting verification to an industrial scale. We demonstrate the feasibility of our approach on an industrial‐scale model from the aerospace domain and summarize the lessons learned during transitioning formal verification tools to an industrial context. [ABSTRACT FROM AUTHOR]

Abstract: Model‐based systems engineering (MBSE) is an emerging technique widely used in current industry. It is a leading way expected to become a next generation standard practice in the systems engineering. Fundamental principles of systems engineering can be supported by a model‐based approach to minimize design risks and avoid design changes in late development stages. The models can be used to formalize, analyze, design, optimize, verify and validate target products integrating engineering developments, organizations and products across domains. Though model‐based development is well established in specific domains, such as software, mechanical system, electric systems, its role in integrated development from a system perspective is still a big challenge for current Chinese industry. In this paper, a survey from volunteers related with MBSE is taken by using questionnaires. The purpose of this survey is to highlight the usage and status of MBSE in current Chinese industry and address the rough understandings of MBSE concepts among system developers in China based on the answers about usages, advantages, barriers, concerns, trends of MBSE, particularly the perspective of tool‐chain development. [ABSTRACT FROM AUTHOR]

Abstract: Anacetrapib is a cholesteryl ester transfer protein (CETP) inhibitor being developed for the treatment of mixed dyslipidemia. The aim of the study was to evaluate the pharmacokinetic, pharmacodynamic, and safety characteristics of anacetrapib following single doses in healthy, young Japanese men. In a double‐blind, randomized, placebo‐controlled, 3‐panel, single‐rising‐dose study, 6 healthy young Japanese male or white male subjects (aged 19 to 44 years) received single oral doses of 5 to 500 mg anacetrapib, and 2 received placebo. Plasma and urine drug concentrations were measured 0–168 hours postdose, and plasma CETP inhibition was measured 0–24 hours postdose. Urinary anacetrapib levels were all below quantitation limits. Plasma concentrations of anacetrapib increased approximately less than dose‐proportionally. Consumption of a traditional Japanese breakfast prior to dosing increased the plasma pharmacokinetics of anacetrapib in Japanese subjects compared with fasted conditions, to a similar extent as in white subjects. CETP activity measured over 0–24 hours postdose resulted in significant inhibition. Anacetrapib was generally well tolerated, and there were no serious adverse experiences. No clinically meaningful differences in PK and CETP inhibition parameters were found between Japanese and white subjects. [ABSTRACT FROM AUTHOR]

Control systems are typically tightly embedded into their environment to enable adaptation to environmental effects. As the complexity of such adaptive systems is rapidly increasing, there is a strong need for coherent tool‐centric approaches to aid their systematic development. This paper proposes an end‐to‐end component‐based specification, design and verification approach for adaptive systems based on the integration of a high‐level scenario language (sequence chart variant) and an adaptation definition language (statechart extension) in the open source Gamma tool. The scenario language supports high‐level constructs for specifying contracts and the adaptation definition language supports the flexible activation and deactivation of static contracts and managed elements (state‐based components) based on internal changes (e.g., faults), environmental changes (e.g., varying context) or interactions. The approach supports linking managed elements to static contracts to formally verify their adherence to the specified behavior at design time using integrated model checkers. Implementation can be derived from the adaptation model automatically, which can be tested using automated test generation and verified at runtime by contract‐based monitors. [ABSTRACT FROM AUTHOR]

An intelligent video surveillance system is crucial to enhance public safety, crime prevention, traffic, and crowd management in a smart city milieu. Situational awareness is an essential aspect of these surveillance systems and it is inferred through underlying context aware frameworks. However, these systems may not possess the ability to proactively disseminate the real‐time context among its sensor nodes. Moreover, in the specific conditions of occurrence of related or repeated events, these systems may also perform inefficiently through afresh context processing and disseminate cycles, without learning from the relevant context that has already been occurred and processed by the system. It leads to deteriorated performance, especially delay in reaction, overwhelmed processing, and energy expenditures. Therefore, to counter such issues, this research work proposes an energy efficient situational aware framework deployed in visual sensors network that is incorporated with context associative learning. System observes currently occurring context at each instance of an event. Overtime, context is refined and stored in context database. Such mechanism empowers the system to learn from previous experiences and develop relationship among the subsequent events that is embedded through this associative (adaptive) learning. Eventually, each event is processed through intelligent resource allocation, supported through mechanism of context learning that further illustrates the independent functions of reduced processing and improved (rapid) decision making resulting in evolution of energy efficient computing paradigm. Ultimately, the capability of learned reflex‐action is induced through introspectively evolved context of the system in entirety and against specific condition of recurred situation depicting minimum energy expenditure. [ABSTRACT FROM AUTHOR]

Cybersecurity has become one of the most crucial challenges in the automotive development lifecycle. The upcoming ISO/SAE 21434 standard provides only a generic framework that is insufficient to derive concrete design methods. This article proposes an actionable cybersecurity development lifecycle model that provides concrete action and work product guidance aligned with the ISO/SAE 21434 and Automotive SPICE® extension for cybersecurity. The model has been inspired by action research in "next" industry practice pilot projects, which ensures that it is actionable. It has been augmented by insights gained from literature research in cybersecurity development for embedded systems. The proposed lifecycle model complements the ISO/SAE 21434 standard and provides the basis for the company‐specific process and practice specifications. It has been validated through the integration of cybersecurity‐related aspects in an electric power steering system. A core characteristic of the model is the central role of threat modeling, vulnerability analyses, and cybersecurity requirements derivation on both system and subsystem levels. Without concrete practice guidelines, the ISO/SAE 21434 is very difficult to understand and apply at this stage. This contribution aims to fill this gap through a model inspired by cutting‐edge embedded cybersecurity practices interpreted for the current and near‐future automotive electronic architectures. [ABSTRACT FROM AUTHOR]

The primary objective of this research is to determine if the dynamic version of an averaged sub‐gradient (ASG) integral siding mode (ISM) controller can effectively handle the end‐effector acceleration tracking problem for a two‐link robotic arm avoiding singularity conditions. The proposed scheme solves a nonlinear extremum seeking problem that minimizes a non‐strictly convex function that depends on the acceleration tracking error defined by the difference between the desired acceleration trajectory and the cueing end‐effector acceleration of a two‐link robotic arm in a 2D‐plane. A second‐order differential equation drives the proposed dynamic ASG with nonlinear coefficients and a discontinuous right‐hand side term, which allows for the achievement of the necessary ISM regime in the presence of considerable errors in the mathematical model description. A special switch between modes allows the controller to track accelerations even in extreme positions (near to the active boundaries of the joint articulations) effectively. [ABSTRACT FROM AUTHOR]

This paper describes concepts to support the application of descriptive functions using artificial intelligence technologies. Descriptive functions are typically used in the system design phase to describe and specify the system behavior. In a model‐based systems engineering approach the system functions, their dependencies, and the allocation to the technical solution are typically documented in system models. Descriptive functions have a fuzziness that is beneficial in the solution finding process but also challenging in terms of development efficiency. To support development teams in formulation and working with descriptive functions in system design, and verification and validation phase several concepts with the use of artificial intelligence technologies are discussed. [ABSTRACT FROM AUTHOR]

The automotive industry is currently experiencing a major transition towards a revolutionary vehicle architecture concept known as Server‐Zone architecture. As a result, complexity increases exponentially and, in order to better deal with it, new development approaches like Model Based Systems Engineering (MBSE) are required. This paper focuses on how MBSE can support the migration towards a server‐zone vehicle architecture, using a real‐life example from Continental. Along with this example, the authors provide modeling insights into the application of Continental's MBSE framework. [ABSTRACT FROM AUTHOR]

This paper presents an approach to link heterogeneous and domain‐specific models. The background of this research is the complete investigation and comparison of cabin system variants, where many different aspects have to be represented. These include functional requirements, safety regulations, and geometric properties (e.g. installation space). However, these cannot always be validated or represented with just one model, as different levels of detail are required. Therefore, different discipline models have to be created, which in turn increases the complexity as a whole. Furthermore, the system to be represented by the models, such as the aircraft cabin, is already complex in itself. The many dependencies among each other and subsystems make it difficult to integrate new variants or technologies (e.g. liquid hydrogen) into the existing system architecture. The approach presented here therefore shows how the data and models of the different disciplines can interact with each other in order to be able to investigate variants holistically. This is demonstrated using the design of hatrack variants for a commercial aircraft. [ABSTRACT FROM AUTHOR]

Model‐Based Product Line Engineering (MBPLE) and Variability Management are key enablers of Model‐Based Systems Engineering (MBSE). A MBSE Architecture Framework based on the SysML language has been developed at Airbus Group Level: R‐MOFLT ‐ Requirements, Mission, Operational, Functional, Logical, Technical Analysis. MBPLE4MOFLT is a feature‐based product line engineering framework based on the ISO 26580 (2021) standard, extending R‐MOFLT. This paper defines the methodological foundations of the Airbus MBPLE4MOFLT framework and provides insights into its application in practice. [ABSTRACT FROM AUTHOR]

In the development of complex mechatronic systems, interdisciplinary cooperation requires an exchange between stakeholders in order to ensure fulfillment of requirements and related functions. The cooperation of the stakeholders from different disciplines must be well coordinated to address systems changes. The system model as an essential aspect of model‐based systems engineering, has to be linked to specific models of involved disciplines (mechanical, electrical/electronical and software) to enable a basis for automatic identification e.g., of affected subsystems and functions. This contribution discusses the potential of model linking from the perspective of change scenarios by considering published approaches to link system models and computer‐aided design (CAD). A methodical approach on how descriptive system models can be used as base for computer‐aided design is presented. This approach is analyzed by reviewing a use case for a design change scenario of an automotive eAxle. [ABSTRACT FROM AUTHOR]

When developing cyber‐physical systems (CPS), the context is of vital importance. CPS interact with the world not only through sensing the environment and acting upon it (like embedded systems) but also by communicating with other CPS (like systems in the Internet of Things [IoT]). This means that the context interactions CPS must deal with are much greater than regular embedded or IoT systems: On the one hand, external systems and human users constrain the specific interaction among them. On the other hand, properties of these external systems, human users, and laws, regulations, or standards constrain the way the CPS must be developed. In this paper, we propose a comprehensive, ontologically grounded context modeling framework to systematically explore the problem space in which a CPS under development will operate. This allows for the systematic elicitation of requirements for the CPS, early validation and verification of its properties, and safety assessment of its context interactions at runtime. [ABSTRACT FROM AUTHOR]

Model‐based systems engineering is a powerful methodology to develop safety‐critical systems. The use of the system model as a single source of truth for risk and dependability analysis results in a consistent and complete assessment. Besides, representation and logging of the assessment within the model result in a complete and up‐to‐date single source of information that can be used during the device certification as well. This paper aims to provide a comprehensive risk management SysML profile that includes interconnected safety analysis [functional hazard assessment (FHA), fault tree, and failure mode and effect analysis (FTA, FMEA)], control measure, and evaluation model elements in compliance with the medical standards. Model‐based risk assessment of a point‐of‐care diagnostic device for sepsis has been shown as a case study to show the implementation of the profile. This device is a standalone unit and the test results obtained directly affect the patient. Therefore, both the top‐down (FHA and FTA) and bottom‐up (FMEA) safety assessment methods have been used. Another objective of the study is to define a systematic and holistic method to perform fault tree analysis, not only from the system architecture models but also from the functional, activity, and sequence diagrams of the system model. [ABSTRACT FROM AUTHOR]

Abstract: Various tools, tutorials and examples exist about the idea of doing development based on models of information (MBSE) as apposed to the traditional document driven approach. Yet, the practical examples of achieving this are still relatively few. An unguided modelling approach can easily lead to “modelling for modelling's sake”, paying for expensive management tools – and creating diagrams that makes the project more complex instead of simpler. This paper is a case study on the efforts to move to a model based development for a large complex system by looking at early conceptual and preliminary design stages of the Telescope Manager project – particularly taking into consideration how it transforms from a functional to a physical design. The aim is to see if general principles and concepts can be derived upon which future Systems Engineers can make use, of before embarking on a similar venture. The study will define the problem area and scope of modelling required for the Telescope manager. Then the study will give a critical examination of various strategies and actions undertook regarding the use of MBSE for the Telescope Manager. The study will conclude with a derived set of concepts and principles based on the evaluation results that may be used in the future. Lastly the study will comment on what the future looks like for MBSE and give some recommendations in terms of preparing for what comes next. [ABSTRACT FROM AUTHOR]

Software product line engineering emerged as an effective approach for the development of families of software‐intensive systems in several industries. Although its use has been widely discussed and researched, there are still several open challenges for its industrial adoption and application. One of these is how to efficiently develop and reuse shared software artifacts, which have dependencies on the underlying electrical and hardware systems of products in a family. In this work, we report on our experience in tackling such a challenge in the railway industry and present a model‐based approach for the automatic generation of test scripts for product variants in software product lines. The proposed approach is the result of an effort leveraging the experiences and results from the technology transfer activities with our industrial partner Alstom SA in Sweden. We applied and evaluated the proposed approach on the Aventra software product line from Alstom SA. The evaluation showed that the proposed approach mitigates the development effort, development time, and consistency drawbacks associated with the traditional, manual creation of test scripts. We performed an online survey involving 37 engineers from Alstom SA for collecting feedback on the approach. The result of the survey further confirms the aforementioned benefits. [ABSTRACT FROM AUTHOR]

The software of systems of elevators needs constant maintenance to deal with new functionality, bug fixes, or legislation changes. To automatically validate the software of these systems, a typical approach in industry is to use regression oracles, which execute test inputs both in the software version under test and in a previous software version. However, these practices require a long test execution time and cannot be re‐used at different test phases. To deal with these issues, we propose Dispatching AlgoRIthm Oracle (DARIO), a test oracle that relies on regression machine‐learning algorithms to detect both functional and non‐functional problems of the system. The machine‐learning algorithms of this oracle are trained by using data from previously tested versions to predict reference functional and non‐functional performance values of the new versions. An empirical evaluation with an industrial case study demonstrates the feasibility of using our approach. A total of five regression learning algorithms were validated by using mutation testing techniques. For the context of functional bugs, the accuracy when predicting verdicts by DARIO ranged between 95% and 98%, across the different scenarios proposed. For the context of non‐functional bugs, were competitive too, having an accuracy when predicting verdicts by DARIO ranged between 83% and 87%. [ABSTRACT FROM AUTHOR]

The User Interface Transition Diagram (UITD) is a simplified modeling notation to describe the transitions between the UIs of a software system. It is designed to be used for customer‐developer s improving the models. This study investigates (i) which concepts of the UITD language are easy to understand and which ones require more effort to be understood and (ii) to what extent UITD comprehensibility depends on the user's programming skill level. A questionnaire was applied to a group of 334 non‐developers after they received a very brief explanation of the UITD concepts. The results were analyzed using statistical methods. The overall average score of the group was 70.42%, which is quite acceptable considering the briefness of the explanation. We observed a very low correlation between the subjects' programming skill level and their scores. This suggests that, even for people who have little or no programming skills, the entirety of the UITD symbols and concepts should quickly be understood with little further training. [ABSTRACT FROM AUTHOR]