Functional Safety Research Articles

Safety-Critical Model Reference Adaptive Control of Switched Nonlinear Systems With Unsafe Subsystems: A State-Dependent Switching Approach.

In this article, a novel safety-critical model reference adaptive control approach is established to solve the safety control problem of switched uncertain nonlinear systems, where the safety of subsystems is unnecessary. The considered switched reference model consists of submodels possessing safe system behaviors that are governed by switching signals to achieve satisfactory performances. A state-dependent switching control technique based on the time-varying safe sets is proposed by utilizing the multiple Lyapunov functions method, which guarantees the state of the subsystem is within the corresponding safe set when the subsystem is activated. To deal with uncertainties, a switched adaptive controller with different update laws is constructed by resorting to the projection operator, which reduces the conservatism caused by the common update law adopted in all subsystems. Moreover, a sufficient condition is obtained by structuring a switched time-varying safety function, which ensures the safety of switched systems and the boundedness of error systems in the presence of uncertainties. As a special case, the safety control problem under arbitrary switching is considered and a corollary is deduced. Finally, a numerical example and a wing rock dynamics model are provided to verify the effectiveness of the developed approach.

북한 치안체제의 역할과 기능에 관한 연구

The purpose of this study is to understand the social control system of the Kim Jong-un government by examining the roles and functions of the North Korean Kim Jong-un government's security system.
 From the inauguration of the Kim Jong-un government in 2012 to 2022, the role and function of national policy, public security policy, and the Ministry of Social Security, which constitute the security apparatus, were analyzed in detail. The outline of the detailed research is as follows: First, in order to analyze the role and function of the security policy in North Korea, theoretical discussions for the analysis of the security system were developed, and the theory of political system analysis and political system approach were introduced. The research analysis framework was constructed through the Narrow-Gauge theory, which emphasizes the distinctiveness of the political system, and the Super Mixed Mode Dictatorship approach.
 Through this, the study was conducted by dividing the Kim Jong-un government into the 1st power hereditary period, 2nd period of power building, 3rd period of power stabilization, and 4th period of power instability.
 Second, the ruling ideology and national policy of the Kim Jong-un government were examined. Third, the role and function of the public security system of the Kim Jong-un government were examined.
 North Korea's Ministry of Social Security is based on protecting Chairman Kim Jong-un and the Workers' Party of North Korea, and monitoring and controlling counterrevolutionary activities that threaten the dictatorship, rather than what is stipulated in the People's Security Control Act.
 In particular, Chairman Kim Jong-un operates the Defense Security Bureau, the Ministry of State Security, Ministry of Social Security, and Ministry of National Defense as direct agencies, strengthening the one-man rule system.
 The main role of Ministry of Social Security is, first, the enforced propagation of the ruling ideology, and second, the implementation of intricate social control policies.
 The primary functions of social safety encompass maintaining public order, engaging in crime prevention activities, identifying and apprehending criminals, conducting sanitary inspections, managing resident registrations, overseeing overseas diplomatic missions, and supervising prison facilities. Notably, it is responsible for conducting extrajudicial house searches, inspecting lodgings, carrying out involuntary examinations, making arrests, and managing detention functions.
 As for future research tasks, it is necessary to more organically analyze the roles and functions of the Kim Jong-un administration's three major social control agencies, such as the Ministy of Social Security, the Ministry of National Security, and the Defense Security Bureau. This is because these institutions are key pillars supporting the Kim Jong-un Government.

Occupational Safety and Health (OSH) Awareness at the Higher Institution: Does it Matter to the Staff?

Maintaining awareness of occupational safety and health (OSH) is crucial in reducing occupational risks. This study aimed to assess the level of OSH awareness among staff at UiTM Cawangan Terengganu Kampus Bukit Besi (UiTMCTKBB), particularly those directly involved with high-risk equipment, machines, and substances in the School of Mechanical Engineering, School of Chemical Engineering, and Faculty of Applied Sciences. The findings indicate that UiTMCTKBB staff showed a high level of OSH awareness, with an overall mean score of 4.67 out of 5. Among the six factors used to evaluate the level of OSH awareness among respondents, standard operating procedures achieved the highest mean score (4.83), while the lowest mean score was for the safety and health committee (4.31). Although an independent sample t-test found no significant difference in OSH awareness based on job classification, the study's findings showed that non-academic staff members possess a higher level of OSH awareness in comparison to academic staff. The university management needs to proactively highlight the significance of the safety and health committee's function, as it plays a pivotal role in cultivating a culture of workplace safety. Consistent implementation of OSH initiatives, campaigns, training sessions, informative materials, safety discussions, and ongoing activities is essential to nurturing a secure and protected working atmosphere.

Simulation of a shell-tube heat exchanger in the oil and gas industry

From the analysis of available literary sources, it follows that the most effective way of introducing heat exchangers into production processes is by using computational fluid dynamics (CFD) modeling. This method also involves fine-tuning the components from which the model is formed. Energy efficiency, safety, and stable functionality of units are key aspects of production activities. CFD modeling provides ample opportunities for studying heat exchange processes in thermal installations, such as tubular heat exchangers. Optimizing the operation of such systems implies careful adjustments, including creating a three-dimensiona l model taking into account real dimensions, and flexible adjustment of various flow regimes and thermal conditions. 
 Process flow heating and cooling processes are standard practice in various industries. These operations are often performed in heat exchangers where the fluid flows through tubes in laminar conditions. Heat transfer mechanisms in such conditions are complex and not yet fully explored, as they include both forced and natural convection. This creates difficulties in accurately predicting the design of the heat exchanger. The use of simplified geometric models and limited information about oil refining processes in computer simulations significantly affects the analysis and optimization possibilities. This approach can significantly accelerate the development of new types of heat exchangers. Current research emphasizes design changes to improve heat transfer and other performance. 
 Previous studies note a lack of specific recommendations for design improvement, incomplete investigation of the causes of inaccurate results, and insufficient detail of important parameters. This study presents the model setup steps with emphasis on the important details of the heat exchanger. The grid adjustment process and the properties of the incoming oil are described. The impact of turbulence on crude oil and steam temperature changes is considered. The influence of speed on the heat exchange coefficient was also analyzed in detail, and prospects for further optimization were determined. The application of computer modeling in the oil and gas industry is important. It is a key tool for improving the efficiency, security, and sustainability of operations in the industry. 
 Computer modeling allows you to predict and optimize processes, create accurate virtual models of objects, analyze their security, and research new technologies. It also facilitates economic analysis, staff training, and innovation. As a result, computer simulation improves decisions, reduces risks, and promotes the development of the entire oil and gas industry. It is one of the effective methods of studying physical systems. Often, computer models are easier and more convenient to study, they allow conducting computational experiments, the real setting of which is difficult or can give an unpredictable result. All these aspects together are aimed at a deeper and more detailed understanding of heat exchange processes, which reveals the potential for improving this process in the future. 
 The main focus in this context is on the fundamental aspects of developing simulation models when using specialized software. The obtained results of the analysis and adjustment allow a deeper understanding of the model configuration process and the prospects for its further optimization. Increasing the flow rate promotes more efficient heat exchange due to the higher velocity of the medium. A linear dependence of the heat distribution along the length of the pipe and the heat transfer coefficient is obtained in the process of modeling.

Stereotactic Radiotherapy or Whole Brain Radiotherapy Combined with Pyrotinib and Capecitabine in HER2-Positive Advanced Breast Cancer Patients with Brain Metastases (BROPTIMA): A Prospective, Phase Ib/II Single-Arm Clinical Study

Approximately half of patients with advanced HER2-positive breast cancer (BC) will develop brain metastases (BM) over time. Local therapy including stereotactic radiotherapy (SRT) and whole brain radiotherapy (WBRT) is the main initial treatment in malignant tumor patients with BM. However, more than 50% patients after radiotherapy in one year suffered intracranial recurrence. Pyrotinib, a small molecule, irreversible, pan-ErbB receptor tyrosine kinase inhibitor (TKI), has a high potency for controlling BM and reducing the occurrence of brain metastases in advanced HER2-positive BC patients. We hypothesized that SRT or WBRT combined with pyrotinib and capecitabine could decrease intracranial progression in HER2 positive BC with newly diagnosed BM. In this prospective single-arm phase Ib/II trial (NCT04582968), eligible patients were assigned to either fractionated stereotactic radiotherapy (FSRT) or whole-brain radiation therapy (WBRT), combined with pyrotinib and capecitabine. The primary endpoint was one-year CNS progression-free survival (PFS) rate. Secondary endpoints included intracranial objective response rate (IC-ORR) according to RANO-BM criteria, progression-free survival (PFS), overall survival (OS) and evaluation of safety and neurocognitive function. From January 2020 to August 2022, 40 patients were enrolled. Twenty-nine patients were treated with FSRT in 8 Gy per fraction with 3 to 5 fractions and 11 were treated with WBRT in 3 Gy per fraction with 10 fractions, and then received chemotherapy in a time frame starting from 0 to 7 days after radiotherapy. At a median follow-up of 17.3 months, 1-year CNS-PFS rate was 74.9% (95% CI 61.9-90.7%) and median CNS-PFS was 18 months (95% CI, 15.5 to NA months). One-year PFS rate was 66.9% (53.1-84.2%) and median PFS time was 17.6 months (95% CI 12.8-34.1 months). The best intracranial response rate (IC-ORR: complete response and partial response) was 92.5% (37/40). The most common grade 3 or worse toxicity was diarrhea (7.5%) and asymptomatic radiation necrosis was detected in 4 of 67(6.0%) lesions treated with FSRT. No differences of neurocognitive function evaluated by MMSE (Mini-Mental State Exam) were observed between different groups at any time point. Radiotherapy combined with pyrotinib and capecitabine resulted in a promising efficacy that crossed the pre-specified boundary in patients with HER2-positive advanced breast cancer with brain metastases. This is the first prospective study showing the efficacy and safety of CNS radiotherapy concurrent with pyrotinib and capecitabine in patients with BM from HER2-positive breast cancer. Further investigation in a randomized controlled study is warranted.

A Modeling and Verification Method of Cyber-Physical Systems Based on AADL and Process Algebra

Cyber-Physical Systems (CPS) are the next generation of intelligent systems that integrate information control devices with physical resources. With increasingly close connections between CPS components and frequent interactions, potential defects grow exponentially, rendering the operating environment of CPS unreliable. Therefore, research on methods and theories to ensure the correctness, safety and reliability of CPS is not only an important research topic but also an inevitable challenge. In this paper, we propose a CPS modeling and verification method based on Architecture Analysis & Design Language (AADL) and process algebra to address this challenge. Due to the continuous, time-constrained, stochastic, uncertain and concurrent characteristics of CPS, this paper considers both flexibility and rigor in the modeling process. We first extend the ability of AADL to describe the multiple characteristics of CPS and propose Hybrid Probability-AADL (HP-AADL). Second, this paper introduces conditional execution, conditional interruption and probability operators into Temporal Calculus of Communication Systems (TCCS) and designs a new formal modeling language Hybrid Probability-Temporal Calculus of Communication Systems (HP-TCCS). However, HP-AADL is a semi-formal modeling language that cannot be directly used for formal verification, it cannot strictly guarantee the quality of the established CPS models, including its functional correctness and safety. Therefore, this paper proposes transformation rules from HP-AADL to HP-TCCS, which enables model checking of CPS models described in HP-AADL within HP-TCCS. Additionally, this paper designs a new formal specification language HPAT-Spatial Temporal Logic (HPAT-STL) based on Probabilistic Computation Tree Logic (PCTL) and Spatial Logic, which characterizes the temporal, probabilistic and spatial properties of CPS model. To achieve formal verification of HP-TCCS model and HPAT-STL formulas, this paper proposes a model checking algorithm HPAT-Model Checking Algorithm (HPAT-MCA). Finally, we discuss a typical CPS example to demonstrate the effectiveness of our proposed method in ensuring correct, safe and reliable CPS.

Low-Cost Solution for Adding Safety Functions to Programmable Logic Controllers (PLCs)

Increasing requirements in automation and production make control systems more complex and vulnerable to failure. Breakdowns can cause delays in production, material damage, and above all, work-related accidents. For this reason, directives and legislation have been created at the country, European Union, and global levels that define the essential safety and requirements of industrial equipment. Guidelines must be observed by those involved in the design, supply, purchase, or use of industrial equipment in the European Union and several countries outside the European Union. Some guidelines (CAT, SIL) are created to ensure their safe operation in case of failure of both the hardware and the software. For a reliable operation of a fail safety system together with a system operating at SIL2 or SIL3, it must have Safety hardware and software. Industrial equipment manufacturers are incorporating security features into a variety of devices. Depending on the Safety Integrity Level (SIL) requirements, these features can be used during the design phase to increase safety in the event of failures or malfunctions. With proper design, the process as well as its environment (including people) can be protected by entering a controlled safe state. Manufacturers have approached this problem in a number of ways, including adding redundant Central Processing Units (CPUs), using special hardware to interface input and output signals, and developing secure network protocols for communication. Unfortunately, these features cannot be added to existing machines, at least without upgrading some hardware. As the associated costs lead to slower adoption, manufacturers rely on previous work to support certain security features, notably CPU debugging. This is implemented in the form of software libraries that operate at a low level (logic gate), designed to run on older hardware (PLC) so that they can offer an increased level of security. This study analyzes the required guidelines and legislation that must be followed for the safe operation of a production unit. It describes the mechanisms that basic and specialized PLC systems utilize to ensure the safety of an automation system. The authors have developed algorithms to record behavior measurements of electronic equipment. By further analyzing the results, it is concluded that basic equipment can be reused in these systems to provide safety functions, at the same time conserving both cost and time.

High frequency radar transmittance in bumper and exterior trim parts molded from thermoplastic olefins (TPOs): Part I TPO base resin

AbstractAn extensive investigation of the interaction of thermoplastic olefin (TPO) compounds with high frequency radar wave has been conducted to understand how TPO materials affect radar sensor efficiency, an important function for vehicle safety and especially the advancement of autonomous vehicles. In this article, the effect of major ingredients of a TPO on its dielectric properties was studied, and then a wide range of TPO compounds were evaluated for their radar transmittance or attenuation. It was demonstrated that the characteristics of polypropylene (PP) resin and rubber have little impact on the dielectric properties of a TPO, thus minimal influence on TPO's radar transparency, while increasing the talc loading in the compound increases the dielectric constant of the TPO. The TPO materials containing talc from 7% up to 34% were found to have dielectric constants ranging from 2.30 to 2.70 and nearly zero dielectric loss. Experiments confirmed that parts molded with these materials are transparent to high frequency radar wave at optimized thicknesses. Some pigments for coloring the materials also affect dielectric properties of TPOs, thus radar transmittance, with metal pigments showing the most impact. Finally, commercial TPO products are shown to have great batch to batch consistency in radar transmittance at a selected part thickness.

ELSMOR – towards European Licensing of Small Modular Reactors: Methodology recommendations for light-water small modular reactors safety assessment

Decarbonization of energy production is key in today’s societies and nuclear energy holds an essential place in this prospect. Besides heavy-duty electricity production, other industrial and communal needs could be served by integrating novel nuclear energy production systems, among which are low-power nuclear devices, like small modular reactors (SMRs). The ELSMOR (towards European Licensing of Small Modular Reactors) European project addresses this topic as an answer to the Horizon 2020 Euratom NFRP-2018-3 call. The consortium includes 15 partners from eight European countries, involving research institutes, major European nuclear companies and technical support organizations. The 3.5-year project, launched in September 2019, investigates selected safety features of light-water (LW) SMRs with focus on licensing aspects. Providing a comprehensive compliance framework that regulators can adopt and operate, the licensing process of such SMRs could be optimized, helping their deployment. In this prospect, as a result of ELSMOR’s work, this article gives an overview of the specific issues that LW-SMRs may bring about in the different domains of nuclear safety, in terms of: Methodological standpoints: safety goals, safety requirements, safety principles (defence-in-depth implementation);Main safety functions of reactivity control, decay heat removal and confinement management;Severe accident management;Other safety issues particular to SMRs: use of shared systems; performing of multi-unit probabilistic safety assessment (PSA); refuelling, spent fuel management, transport and disposal management. In this article, adequate methodologies are developed to deal with these issues and to help assess the safety of LW-SMRs. This work gives a precious synthesis of the safety assessment issues of LW-SMRs and of the associated methodologies developed in the context of the ELSMOR European project.

Sparsentan: A First-in-Class Dual Endothelin and Angiotensin II Receptor Antagonist.

To provide an overview of the guidelines on the management of immunoglobulin A nephropathy (IgAN) and focal segmental glomerulosclerosis (FSGS), review the evidence for sparsentan, and discuss its place in therapy. A literature search was conducted using MEDLINE, EMBASE, and clinicaltrials.gov using the search terms "sparsentan" and "RE-021" up to the end of Jun 2023. English studies were included if they evaluated the pharmacology, pharmacokinetics, efficacy, and safety of sparsentan in human subjects. Information from the Food and Drug Administration (FDA) and manufacturer's monograph were also extracted. In comparison with irbesartan, sparsentan reduced urine protein-to-creatinine ratio (UPCR) in both IgAN (-49.8% vs -15.1% at interim 36 weeks) and FSGS (-44.8% vs -18.5% at 8 weeks). Hypotension and edema were the most common adverse events in the sparsentan groups. Hepatotoxicity appears to be comparable between sparsentan and irbesartan in short-term results. Sparsentan provides a new option for patients with IgAN who are otherwise at high risk of progressive kidney disease. Continued FDA approval is dependent on long-term study results on renal function decline and safety. Sparsentan reduces proteinuria in IgAN and FSGS, and has expedited approval by the FDA for IgAN in patients at risk of rapid disease progression, generally at urine protein-to-creatinine ratio (UPCR) ≥1.5 g/g. Interim results from PROTECT and results from DUET showed promise for improving proteinuria in IgAN and FSGS. Long-term renal function benefit and safety data are pending.

Time-Sensitive Networking to Improve the Performance of Distributed Functional Safety Systems Implemented over Wi-Fi.

Industry 4.0 has significantly improved the industrial manufacturing scenario in recent years. The Industrial Internet of Things (IIoT) enables the creation of globally interconnected smart factories, where constituent elements seamlessly exchange information. Industry 5.0 has further complemented these achievements, as it focuses on a human-centric approach where humans become part of this network of things, leading to a robust human-machine interaction. In this distributed, dynamic, and highly interconnected environment, functional safety is essential for adequately protecting people and machinery. The increasing availability of wireless networks makes it possible to implement distributed and flexible functional safety systems. However, such networks are known for introducing unwanted delays that can lead to safety performance degradation due to their inherent uncertainty. In this context, the Time-Sensitive Networking (TSN) standards present an attractive prospect for enhancing and ensuring acceptable behaviors. The research presented in this paper deals with the introduction of TSN to implement functional safety protocols for wireless networks. Among the available solutions, we selected Wi-Fi since it is a widespread network, often considered and deployed for industrial applications. The introduction of a reference functional safety protocol is detailed, along with an analysis of how TSN can enhance its behavior by evaluating relevant performance indexes. The evaluation pertains to a standard case study of an industrial warehouse, tested through practical simulations. The results demonstrate that TSN provides notable advantages, but it requires meticulous coordination with the Wi-Fi MAC layer protocol to guarantee improved performance.

The black swans of nuclear repositories – an overview of external events with a potentially serious impact on the long-term operation and safety

Abstract. For Germany, the time until completion and final closure of a repository is estimated to be up to 150 years. So far, it has been implicitly assumed that external political, economic, and infrastructural functions that are necessary for the construction, operation, and closure of such facilities will be fully in place throughout the entire operating period. These include, for example, power supply, presence of well-trained staff, and effective oversight. Event sequences initiated by natural disasters or human-made crises may lead to unintentional long-lasting disruptions of these external safety functions. They are currently only partly considered in safety assessments. To make repository concepts robust against such scenarios, a forward-looking risk analysis is required that creates the basis for a holistic comparative risk assessment of different repository concepts. It provides a starting point for the development of additional resilient structures, management processes, and safety functions. A risk analysis includes an assessment of event-specific vulnerabilities as well as potential consequences of unintended external hazards for various disposal concepts. The first step of this process would be a hazard analysis – a summary and evaluation of external event sequences that have the potential to compromise essential safety elements of a repository within the predicted operation period. These can be divided into political–economic crises and event sequences following transnational natural disasters. A look at the political development of the past 150 years shows that even if only the present territory of Germany is considered, there have been profound disruptions, such as three wars, several major economic depressions, revolutionary government changes, and attempted military coups. This summary shows that political and economic stability as well as a continuous orderly operation cannot be taken for granted. Historic as well as present experiences from the country where the repository is planned as well as the neighbouring regions should be considered when assessing the potential consequences of such events. Local natural disasters are already taken into account in site selection, e.g. risk of flooding, volcanism, or earthquakes. Less attention is typically given to the indirect effects of transnational disastrous events. These include climatic extremes (e.g. droughts), cosmic and geological disasters (e.g. geomagnetic storms) and their climatic consequences (e.g. volcanic winter), and pandemics. Such natural disasters may cause economic depressions and subsequently contribute to political turmoil (e.g. the drought of 1788 as one of the causes of the French Revolution in 1789). At the stage of concept design, additional safety elements, measures, and processes should be included that help to manage situations of external stress and to avoid irreversible processes that challenge the safety architecture of the repository.

Preliminary architecture of the DTT remote handling test and training facility

The realization of a specific REMote HAndling Test and Training Facility (REMHAT) is necessary for the development and optimization of the Remote Handling (RH) system, to demonstrate the fulfilment of all its design requirements, for testing and validation of the RH maintenance procedures, for the qualification and acceptance testing of RH equipment and tooling. Furthermore, it provides training and certification to the RH maintenance operators, by making available to operators the knowledge, instructions and experiencing of the Virtual Simulator platform, the control room devices, the robots and tooling to be used for RH tasks. In this work, the preliminary architecture of the DTT REMHAT facility is described, with a focus on the added value of the adoption of Virtual Reality (VR) technologies enabling real-time alignment of virtual robots’ configuration with the real ones (Digital Twin). A first approach to the facility design is proposed, starting from the technical requirements: Environmental, Design, Physical, Functional, Operational, Human Factors and Product assurance and safety. The proposed logical architecture consists of four Sub-Systems (S/S): building and auxiliaries, mock-ups, robots and Control Room. In the present work, a particular attention is paid on the last one. The idea is to create a digital twin of the RH equipment mock-ups to be coupled with software of real-time structural simulation, in order to have at disposition and show in VR environment real-time additional information about the real environment, like robots’ deflections and/or vibrations, clearances and possible collisions detection. These data could be crucial for the operator’s decision-making process about a sudden intervention on the RH system, further to their employment for future studies and optimization. Therefore, for each subsystem of the facility, the components identification and a description of the software and hardware aspects are provided. In conclusion, an overview of the critical issues of such complex system is presented, in order to prepare the ground for future research works.

Safety, biocompatibility, and potential functionality of a new accommodative intraocular lens: An experimental study in rabbits

This study aims to evaluate the safety, biocompatibility, and functionality of a new accommodative intraocular lens (IOL) (LUZ, patent PCT/ES2016/070,813) after implantation in rabbit eyes. LUZ (Study) and EyeCee® plus a capsular ring (Control) were implanted in rabbits (n = 8 each) after phacoemulsification. Intraoperative follow-up, long-term clinical follow-up, and functional IOL studies were carried out periodically for up to 180 days. A macroscopic examination of the eyeballs to reveal abnormalities and determine the implant centering and a microscopic examination to semi-quantify cell and tissue response were performed. Statistical analysis of the collected data was finally achieved. During follow-up, no significant changes in the general condition nor the clinical evaluation were observed between both groups. However, Study IOL remained centered throughout the study and did not present severe complications as observed in the Control group. Functional studies did not reveal significant differences between both materials. Study showed better centering, fewer adhesions, and maintenance of an opening capsular bag compared to the Control. Local biological effects caused by Study implantation are minimal and comparable to the Control. Therefore, LUZ showed no clinical signs or histological response of adverse reaction to the implanted material, according to UNE-EN ISO 11979-5 and 10993-6. Functionality must be confirmed in another animal species with greater lens accommodation capacity than the rabbit. LUZ keeps the capsular bag open, favoring its centering and avoiding fibrosis and adherence to the bag; this allows potential accommodation of this IOL and theoretically enables the patient to focus dynamically.

Propellant Influence on Electromagnetic Environment Generated by Stationary Plasma Thrusters

Possible aspects of violation of the functional safety of spacecraft in terms of electromagnetic compatibility with electric rocket thrusters in their work on alternative working substances are considered. The procedure of experimental determination of spectral–time characteristics of own electromagnetic radiation of laboratory model of stationary plasma thruster SPT-70 developed by the Research Institute of Applied Mechanics and Electrodynamics of the Moscow Aviation Institute is described. Measurements of noise emissions were carried out on a vacuum installation with a “radiotransparent” compartment and a shielded echo-free camera in the frequency range of 1–12 GHz for typical discharge capacities (600, 800, and 1000 W), vertical and horizontal polarization, and various working substances used (krypton and xenon). The conducted studies have allowed obtaining new comparative results of the assessment of spectral characteristics of SPT-70 radiation for standard modes and prospective working bodies within the orthogonal polarization bases. The new results should include information about the radiation characteristics of SPT-70 in the time area. It is shown that the transition from xenon to krypton retains the pulsed nature of the radiation of a stationary plasma thruster, leading not only to an increase in the amplitude of pulses, but also to an increase in the frequency of repetition of “bursts” and an increase in their duration, which requires additional measures to ensure electromagnetic compatibility in order to preserve the functional safety of the spacecraft.

IMPACT OF LONGSHORE SEDIMENT TRANSPORT ON THE DESIGN AND MAINTENANCE OF LOW-ENERGY, NON-TIDAL SANDY BEACHES

When low-energy, non-tidal lake beaches have a flood safety function, such as at the Houtribdijk, the Netherlands, sediment losses can directly affect the functioning of the beach (fig. 1). Detailed understanding of morphodynamic processes is needed to enable reliable predictions of the morphological development and the design of efficient maintenance strategies. Ton et al. (2021) showed that the development of these beaches is driven by both cross-shore and longshore processes. Wave action causes a distinct cross-shore profile shape to develop, with a steep beach face and a gently sloped platform around the depth of closure. However, on top of that, the combined effect of large-scale horizontal flow circulations (caused by gradients in storm surge level across the lake, Ton et al., submitted) and wave-induced sediment stirring was found to be an important driver of sediment losses along the beaches. In this work, we research how longshore transport (LST) can best be determined for low-energy lake beaches and classify and quantify the uncertainties related to this method.

Agent-Based Product-Social-Impact-Modeling: A Systematic Literature Review and Modeling Process

Abstract A key part of an engineer’s purpose is to create products and services that benefit society, or, in other words, to create products with a positive social impact. While engineers have many predictive models to aid in making design decisions about the functional performance or safety of a product, very few models exist for estimating or planning for the wide range of social impacts an engineered product can have. To model social impact, a model must contain representations of both the product and society. Agent-based modeling is a tool that can model society and incorporate social impact factors. In this paper, we investigate factors that have historically limited the usefulness of product adoption agent-based models and predictive social impact models through a systematic literature review. Common themes of limiting factors are identified, steps are presented to improve the usefulness of agent-based product adoption models and predictive social impact models, and a general process for the creation of agent-based social impact models is presented. Improving the usefulness of these predictive models can aid engineers in making better design decisions. Predictive social impact models can help identify areas in the design space to improve the social impact of products. When coupled with existing design methods, agent-based predictive social impact models can help increase the probability that a product achieves positive social impact.

Clinical efficacy of total laparoscopic splenectomy for portal hypertension and its influence on hepatic hemodynamics and liver function.

The liver hemodynamic changes caused by portal hypertension (PH) are closely related to various complications such as gastroesophageal varices and portosys-temic shunts, which may lead to adverse clinical outcomes in these patients, so it is of great clinical significance to find treatment strategies with favorable clinical efficacy and low risk of complications. To study the clinical efficacy of total laparoscopic splenectomy (TLS) for PH and its influence on hepatic hemodynamics and liver function. Among the 199 PH patients selected from October 2016 to October 2020, 100 patients [observation group (OG)] were treated with TLS, while the remaining 99 [reference group (RG)] were treated with open splenectomy (OS). We observed and compared the clinical efficacy, operation indexes [operative time (OT) and intraoperative bleeding volume], safety (intraperitoneal hemorrhage, ascitic fluid infection, eating disorders, liver insufficiency, and perioperative death), hepatic hemodynamics (diameter, velocity, and flow volume of the portal vein system), and liver function [serum alanine aminotransferase (ALT), serum aspartate aminotransferase (AST), and serum total bilirubin (TBil)] of the two groups. The OT was significantly longer and intraoperative bleeding volume was significantly lesser in the OG than in the RG. Additionally, the overall response rate, postoperative complications rate, and liver function indexes (ALT, AST, and TBil) did not differ significantly between the OG and RG. The hepatic hemodynamics statistics showed that the pre- and postoperative blood vessel diameters in the two cohorts did not differ statistically. Although the postoperative blood velocity and flow volume reduced significantly when compared with the preoperative values, there were no significant inter-group differences. TLS contributes to comparable clinical efficacy, safety, hepatic hemodynamics, and liver function as those of OS in treating PH, with a longer OT but lesser intraoperative blood loss.

General provisions of the substantiation of functional safety of intelligent systems in railway transportation

Aim. The paper aims to solve the problem of objective and confident functional safety (FS) evaluation of intelligent control systems (ICS). As regards ICS, the conventional methods, due to their particular features, do not allow for a sufficiently confident estimation of the actual state of FS. The above features include primarily the nondistinct architecture of ICS and the changing connections between the system elements.Methods. Substantiating ICS FS requires using the complete arsenal of known methods and means recommended in GOST 33432-2015 [1], including managerial measures defined by the requirements for the safety policy, program and case. The authors have analysed the capability to prove ICS FS using experimental, expert, analytical, technological, and simulation-based methods. The limitations of some methods as regards ICS FS substantiation have been established.Results. The authors suggest a heuristic graph-based semi-Markov (Markov) method of proving system FS. For the purpose of substantiating ICS FS, it is recommended using the heuristic graph-based method combined with the technological method defined in GOST R IEC 61508 [2–4]. They don’t only allow confidently evaluating the FS of intelligent systems, but developing recommendations for achieving acceptable safety levels of such systems.

Pedestrian safety in an automated driving environment: Calibrating and evaluating the responsibility-sensitive safety model

The severity of vehicle–pedestrian crashes has prompted authorities worldwide to concentrate on improving pedestrian safety. The situation has only become more urgent with the approach of automated driving scenarios. The Responsibility-Sensitive Safety (RSS) model, introduced by Mobileye®, is a rigorous mathematical model developed to facilitate the safe operation of automated vehicles. The RSS model has been calibrated for several vehicle conflict scenarios; however, it has not yet been tested for pedestrian safety. Therefore, this study calibrates and evaluates the RSS model for pedestrian safety using data from the Shanghai Naturalistic Driving Study. Nearly 400 vehicle–pedestrian conflicts were extracted from 8,000 trips by the threshold and manual check method, and then divided into 16 basic scenarios in three categories. Because crossing conflicts were the most serious and frequent, they were reproduced in MATLAB’s Simulink with each vehicle replaced with a virtual automated vehicle loaded with the RSS controller module. With the objectives of maximizing safety and minimizing conservativeness, the non-dominated sorting genetic algorithm II was applied to calibrate the RSS model for vehicle–pedestrian conflicts. The safety performance of the RSS model was then compared with that of the commonly used active safety function, autonomous emergency braking (AEB), and with human driving. Findings verified that the RSS model was safer in vehicle–pedestrian conflicts than both the AEB model and human driving. Its performance also yielded the best test results in producing smooth and stable driving. This study provides a reliable reference for the safe control of automated vehicles with respect to pedestrians.