Response Capability Research Articles

6.I. Round table: Strengthening preparedness for public health emergencies: lessons learned and future perspectives

Abstract In the face of intensifying global health threats, robust health security measures in Europe and worldwide have never been more pressing. The COVID-19 pandemic has underscored the critical need for coordinated action, adaptive strategies, and robust collaborative mechanisms to effectively respond to emerging infectious diseases and other public health emergencies. This workshop serves as a platform to examine the multifaceted landscape of health security actors, focusing on collaborative initiatives and lessons learned from recent crises. By convening experts and stakeholders from across Europe, the workshop aims to achieve several key objectives: i) To provide an overview of collaborative initiatives established to strengthen European and international health security. By showcasing successful models of cooperation, participants will gain insights into effective strategies for fostering collaboration among diverse stakeholders. ii) Emphasize the role of European and international institutions, such as the European Centre for Disease Prevention and Control (ECDC) and the World Health Organization (WHO), in supporting states both in coordinating regional response efforts and in developing the necessary health workforce competencies and capabilities to respond to health emergencies. iii) Drawing on experiences from recent health emergencies, including outbreaks of high-risk pathogens, such as Ebola, the workshop will facilitate a critical examination of lessons learned. Through interactive discussions, participants will identify challenges, best practices, and opportunities for enhancing preparedness and response capacity. iv) By interactive presentations and panel discussions, the workshop will provide a platform for knowledge exchange and networking among participants. By sharing experiences, expertise, and innovative approaches, participants will contribute to a collective understanding of the challenges and opportunities in strengthening health security. This workshop seeks to illuminate key strategies, capacity-building efforts, and real-world lessons learnt that contribute to enhancing response capabilities to public health emergencies. Participants will gain a deeper understanding of emergency participation mechanisms, essential skills required, and available training resources to enhance preparedness. Key messages • Collaboration and adaptive strategies are essential for strengthening international health security in the face of emerging infectious diseases and other public health emergencies. • Lessons learned from recent crises provide valuable insights into effective response strategies and opportunities for enhancing preparedness and response capacity.

Pediatric Allergy Management at ULSNE: Insights into Public Health Implications

Abstract Introduction Pediatric allergies present a complex challenge to public health systems, affecting both policy-making and clinical management. This study explores the management trends and challenges of pediatric allergies at the Unidade Local de Saúde do Nordeste (ULSNE) in Portugal, emphasizing its implications for refining healthcare practices over a seven-year period. Methods A retrospective review of medical records was performed, from children aged 0 to 18 who presented with allergic reactions at ULSNE’s emergency services between 2017 and 2023. The analysis concentrated on demographics, allergen types, reaction severity, and the management strategies deployed. Results The analysis revealed a wide range of allergens, from food to insect stings, with medication being the most prevalent triggers. Significant findings include observing severe allergic reactions across all age groups, highlighting the need for acute emergency interventions. The data underscores a critical demand for early diagnosis and tailored-made management plans to efficiently handle the diverse severity of allergic reactions observed. Conclusions This study demonstrates the complexity of managing pediatric allergies within ULSNE’s public health framework. Standardized, evidence-based management methods should be adopted to strengthen emergency response capabilities, as shown by the frequency of severe responses and the prevalence of various allergens. As an outcome, our results support a comprehensive, interdisciplinary strategy that includes medical personnel, educational institutions, and family involvement to create a supportive community that is supportive of both immediate care and long-term preventive measures. Subsequent efforts should give precedence to educational programs designed to increase consciousness and encourage preventive measures in community environments. Key messages • A rapid response is essential for healthcare systems to have fast, effective strategies ready for children’s severe allergic reactions. • Emphasizes a collective approach involving healthcare workers, schools, and families to prevent and manage children’s allergies, enhancing safety and awareness.

Solvent-adaptive hydrogels with lamellar confinement cellular structure for programmable multimodal locomotion

Biological organisms can perform flexible and controllable multimodal motion under external stimuli owing to the hierarchical assembly of anisotropic structures across multiple length scales. However, artificial soft actuators exhibit the limited response speed, deformation programmability and movement capability especially in harsh environments because of insufficient anisotropic hierarchy and precision in structural design. Here, we report a programmed assembly directed confinement polymerization method for the fabrication of environmentally tolerant and fast responsive hydrogels with lamellar assembly-confined cellular structure interpenetrated with highly aligned nanopillars by the directional freezing-assisted polymerization in the predesigned anisotropic laminar scaffold. The obtained hydrogel exhibits ultrafast responsiveness and anisotropic deformation exposed to temperature/light/solvent stimulation, maintaining highly consistent responsive deformation capability in all-polarity solvents over 100 days of soaking. Moreover, the hydrogels implement photoactive programmable multi-gait locomotion whose amplitude and directionality are precisely regulated by the intrinsic structure, including controlled crawling and rotation in water and non-polar solvents, and 3D self-propulsion floating and swimming in polar solvents. Thus, this hydrogel with hierarchically ordered structure and dexterous locomotion may be suitable for flexible intelligent actuators serving in harsh solvent environments.

Emergency Capability Evaluation of Port-Adjacent Oil Storage and Transportation Bases: An Improved Analytic Hierarchy Process Approach

The large-scale storage and stable supply of oil products are essential for national energy security and economic development. As the economy expands and energy demands rise, centralized storage and supply systems become increasingly vital for ensuring the efficiency and reliability of oil product distribution. However, large oil storage depots present substantial safety risks. In the event of fires, explosions, or other accidents, emergency response efforts face stringent demands and challenges. To enhance the emergency response capabilities of oil storage and transportation bases (OSTBs), this paper proposes an innovative approach that integrates the improved analytic hierarchy process (IAHP) with the Entropy Weight Method (EMW) to determine the combined weights of various indices. This approach reduces the subjective bias associated with the traditional analytic hierarchy process (AHP). The emergency response capabilities of OSTBs are subsequently evaluated through fuzzy comprehensive analysis. An empirical study conducted on an OSTB in the Zhoushan archipelago quantitatively assesses its emergency preparedness. The results show that the base excels in pre-incident prevention, demonstrates robust preparedness and response capabilities, and exhibits moderate recovery abilities after incidents. These findings provide a theoretical foundation for reducing the likelihood of accidents, enhancing emergency response efficiency, and mitigating the severity of consequences. Practical recommendations are also offered based on the results.

Bioinspired Hydro- and Hydrothermally Responsive Tubular Soft Actuators.

Soft actuators made of thermoresponsive polymers have great potential for intelligent robotics and biomedical devices due to their reversible deformation capability in response to temperature fluctuations. However, they are constrained by a predefined phase transition temperature, limited directional deformation, and nonbiocompatible formulations, thereby restricting their practical utility. Herein a new biomimicry approach is presented to overcome these limitations by developing hydro- and hydrothermally responsive soft actuators made of biocompatible and pliable materials i.e. cotton yarn and polyurethane. We mimic the tubular shape of elephant trunks with their unique muscle orientation by embedding a helical cotton yarn within a hydrophilic polyurethane tube, followed by targeted surface patterning. Unlike the narrow-range shape morphing across the phase transition temperature boundary of typical thermoresponsive hydrogel actuators, we harness hydrothermal stiffness variations in polyurethane to obtain consistent morphing capabilities over a much wider temperature range. The developed actuators can perform versatile activities such as linear, bending, curvilinear, and rotating movements, overcoming the unidirectional motion limitations of conventional soft actuators. The cell viability assay on the building block materials also confirms the high biocompatibility of the actuators. The reported facile fabrication strategy provides new insights for designing complex yet free-standing soft actuators from readily available supple materials.

Comprehensive review of recent research trends in dielectric elastomer transducers: applications, materials, and fabrication

Abstract While rigid transducers have led to innovations in industrial automation and control systems,
their rigidity limits them to the controlled environment of the factory. Recently, soft transducers
have become an attractive area of research because their compliant nature presents potential to
be applied to soft-bodied robots operating in uncontrolled environments. Dielectric elastomer
transducers (DETs) demonstrate large electrically-driven deformations, high energy density, fast
response, long lifespans, and self-healing capabilities which makes them a favorable replacement
for rigid transducers. This review first introduces the working principles of DETs, modeling work,
and different transducer designs. Then the applications of DETs to robotics, generators, and
electronics are reviewed. Lastly, the challenges currently faced by DET technology are discussed
and potential approaches are explored.

Injectable and pH-Responsive Metformin-Loaded Hydrogel for Active Inhibition of Posterior Capsular Opacification.

Posterior capsular opacification (PCO) is a common complication following cataract surgery, which can lead to a significant vision loss. This study introduces a facile method for developing a metformin-derived hydrogel (HCM6) stabilized by dynamic covalent bonds among natural polymers. This hydrogel demonstrates antifibrotic properties, on-demand drug release, pH responsiveness, injectability, and self-healing capabilities. Our in vitro experiments confirmed that the HCM6 hydrogel exhibits excellent biocompatibility, inhibiting lens epithelial cell migration, and transforming growth factor-2β (TGFβ2)-induced α-smooth muscle actin (α-SMA) expression in lens epithelial cells. In vivo studies conducted in a rat extracapsular lens extraction (ECLE) model revealed that HCM6 significantly suppressed PCO after 21 days of implantation with no observed pathological effects on surrounding tissues or the optic nerve. According to our experimental results, the inhibitory mechanism of PCO may be attributed to metformin's suppressive effect on lens cell migration, epithelial-mesenchymal transition (EMT), and lens fiber formation. In summary, the long-acting, controllable, and on-demand release characteristics of the HCM6 hydrogel not only provide an effective strategy for preventing PCO but also offer new avenues for treating undesirable proliferative conditions in ophthalmology and beyond.

Knowledge-assisted hybrid optimization strategy of large-scale crude oil scheduling integrated production planning

As modern refinery crude oil scheduling scales up, traditional manual operations and independent optimization methods struggle with complexity and dynamics. This study proposes an empirically assisted integrated planning and scheduling optimization model.The integrated model is solved using a hybrid optimization algorithm combining mathematical programming and particle swarm optimization (MP/PSO). Long-term planning aims to minimize operational and transportation costs while maximizing refinery profits; short-term scheduling, based on initial long-term plans, aims to minimize unit switchovers. In the short-term scheduling phase, heuristic rules based on empirical operational knowledge generate a high-performing initial population to accelerate convergence. This strategy is crucial for enhancing refinery emergency response capabilities, ensuring stable operations, and improving economic benefits. Experimental results show that within a reasonable time frame, MP/PSO performs better than PSO and manual scheduling in large-scale crude oil scheduling scenarios.

Tutoria na Pandemia: os desafios de sempre, os novos e as lições permanentes

University life is full of challenges that add up and the pandemic has shaken social and educational systems, reaffirming existing vulnerabilities and creating new ones. This work, developed on the Mentoring Program of the School of Arts, Sciences and Humanities of the University of São Paulo, set out to think about these challenges, ways to improve tutoring and learning in this context. Among the challenges, we find: lack of institutional support; tutors’ response capabilities; availability of tutors; and adherence to program activities. However, there are many potentialities that extend to both professional and academic as well as personal spheres. So, suggestions for the program were listed, including a calendar of activities, participation in the organization of events and involvement in scientific activities. Permanent lessons include: 1. the virus was not the protagonist in deaths during the pandemic; 2. our risk society demands that we be prepared for anything and everything; 3. human values help us face adversity.

Research on position tracking control of electro-hydraulic actuator system combining feedforward inverse model controller and exponential functional link network adaptive controller

The electro-hydraulic actuator system plays a crucial role in indoor high-frequency simulation experiments. Many components of the system exhibit unavoidable nonlinear characteristics, which reduce its dynamic position response capability. Additionally, most algorithms are unsuitable for practical high-frequency conditions due to either local instability or high computational complexity. To improve position tracking accuracy under high-frequency control, a novel combined control strategy is proposed, integrating an appropriate feedforward inverse model controller (FFIMC) with an exponential functional link network adaptive controller (EFLNAC). Initially, the system has reached a stable state under the action of the PID controller. Subsequently, the FFIMC estimates both the model and the inverse model of the PID system by applying the AIC technique developed through the DCT-VSSNLMS adaptive algorithm, which extends the system’s bandwidth. Following this, the EFLNAC, as the outermost loop, acquires the inverse model of the FFIMC system and updates internal parameters in real-time, thereby enhancing the system’s resistance to nonlinear disturbances. Finally, the combined controller is validated through simulations and experiments under various working conditions. The results show a significant increase in the PID system’s bandwidth and demonstrate that the tracking error of the signal is maintained within 0.079 mm. Therefore, the combined controller proves to be an effective solution for high-precision, high-frequency displacement tracking, offering the advantages of low computational complexity, high accuracy, and strong effectiveness.

Two-component heterojunction-based ambipolar field effect transistors for improved sensitivity of ammonia sensor

To improve the sensing response of ammonia (NH3) sensors, a two-dimensional configuration molecule 5,11-di-naphthalen-2-yl-6,12-dihydro-indolocarbazole (ICZ-NA) was designed and synthesized as the p-channel organic semiconductor material. Bilayer organic field-effect transistor (OFET) was constructed with ICZ-NA and N,N’-bis(n-octyl)-2,6-dicyanonaphthalene-1,4,5,8-bis(dicarboximide (NDI-8CN2) as p-type and n-type active semiconductor materials respectively, and the two-component devices exhibits excellent ambipolar FET performance. The thin film transistors based on single-component and two-component were further used as sensors for ammonia detection. Compared with the sensors based on NDI-8CN2, the sensitivity and selectivity of ammonia detection based on two-component sensors have been greatly improved, and the ratio of current change can still be maintained over 3.65 %, when the gas concentration lower to 10 ppb level. The higher sensing response and low limit of detection demonstrate that the two-component ambipolar configuration is a highly effective method for improving sensing response capability.

The Impact of Deployment of National Police Reservists on the Overall Security Incidents in Elgeyo Marakwet County, Kenya

The use of police reservists has been recognized as a key strategy in enhancing security, especially in conflict-prone regions like Elgeyo Marakwet County, Kenya. Their unique advantage lies in their proximity to the local community, quick response capabilities, and familiarity with both the terrain and the people they serve. These traits, combined with their role in community policing, have proven vital in addressing resource-based conflicts and cattle rustling. Despite challenges such as limited personnel and the presence of firearms, reservists have significantly contributed to reducing violence and fostering better relations between law enforcement and local communities. The data used in this paper was part of a study that examined the relationship between the deployment of National Police Reservists and security incidents in Elgeyo Marakwet County, Kenya. Through a cross-sectional survey, data was collected from community members through a questionnaire (n = 362), interviews (the County Commander, Subcounty Commanders, Officer Commanding Police Stations and administrative Chiefs; n = 7) and FGDs (n = 7 police reservists). The Friedman Test was conducted to evaluate whether the deployment of NPRs led to reduction in the frequency of security incidents. Qualitative data, was analysed thematically. The study established that the deployment of National Police Reservists (NPRs) had a significant impact on crime reduction (χ²(4) = 11.800, p = .019). The community considered the police reservists as effective in maintaining peace and security, with residents reporting increased safety and expressing strong trust in their abilities. There was a high level of trust in the reservists' ability to protect the community. The potential challenges in the deployment of National Police Reservists include logistical constraints, inadequate communication infrastructure, limited training and resource shortages. The study recommends the continued deployment of NPRs while monitoring and evaluating their impact regularly. In addition, there is need to build on the strong community trust in NPRs by enhancing community engagement and communication. There is need to invest to increase resource allocation to the NPRs as well as address the logistical constraints faced by reservists.

An affordable operational oil spill monitoring system in action: A diachronic multiplatform analysis of recent incidents in the southern Gulf of Mexico

The coexistence of marine sensitive areas with the oil industry requires robust preparedness and rapid response capabilities for monitoring and mitigating oil spill events. Scientifically proven satellite-based methods for the visual detection of oil spills are widely recognized as effective, low-cost, transferable, scalable, and operational solutions, particularly in developing economies. Following meticulous design and implementation, we adopted and executed a relatively low-cost operational monitoring and alert system for oil spill detection over the ocean surface and alert issuance. We analyzed over 1500 satellite images, issuing over 70 warning reports on oil slicks and spills in the southern Gulf of Mexico. To assess the system’s efficiency and performance, we leveraged data from three major oil spill incidents in the study region during June and July of 2023 in the study region, covering a maximum area of 669 km2 and tracked for 12 to 24 days. We documented the evolution of these oil spills by integrating satellite sensing data with on-site Lagrangian drifting buoys, a network of high-frequency radars, and citizen reports to validate the outcomes of this system. We generated timely technical information on the spill’s evolution, informing decision-makers and local community leaders to strengthen their mitigation response capabilities. Additionally, we developed a robust database with spectral and spatiotemporal features of satellite-detected oil, thereby contributing to advancing the scientific understanding of sea surface dynamics related to natural and anthropogenic oil sources. This study also highlights immediate-, medium-, and long-term research agendas and establishes a reference for a sustained, transferable, and operational oil spill monitoring system.

We need to aim at the top: Factors associated with cybersecurity awareness of cyber and information security decision-makers.

Cyberattacks pose a significant business risk to organizations. Although there is ample literature focusing on why people pose a major risk to organizational cybersecurity and how to deal with it, there is surprisingly little we know about cyber and information security decision-makers who are essentially the people in charge of setting up and maintaining organizational cybersecurity. In this paper, we study cybersecurity awareness of cyber and information security decision-makers, and investigate factors associated with it. We conducted an online survey among Slovenian cyber and information security decision-makers (N = 283) to (1) determine whether their cybersecurity awareness is associated with adoption of antimalware solutions in their organizations, and (2) explore which organizational factors and personal characteristics are associated with their cybersecurity awareness. Our findings indicate that awareness of well-known threats and solutions seems to be quite low for individuals in decision-making roles. They also provide insights into which threats (e.g., distributed denial-of-service (DDoS) attacks, botnets, industrial espionage, and phishing) and solutions (e.g., security operation center (SOC), advanced antimalware solutions with endpoint detection and response (EDR)/extended detection and response (XDR) capabilities, organizational critical infrastructure access control, centralized device management, multi-factor authentication, centralized management of software updates, and remote data deletion on lost or stolen devices) are cyber and information security decision-makers the least aware of. We uncovered that awareness of certain threats and solutions is positively associated with either adoption of advanced antimalware solutions with EDR/XDR capabilities or adoption of SOC. Additionally, we identified significant organizational factors (organizational role type) and personal characteristics (gender, age, experience with information security and experience with information technology (IT)) related to cybersecurity awareness of cyber and information security decision-makers. Organization size and formal education were not significant. These results offer insights that can be leveraged in targeted cybersecurity training tailored to the needs of groups of cyber and information security decision-makers based on these key factors.

The prevention and response to infectious diseases in long-term care facilities in Korea: a nationwide survey.

Long-term care facilities (LTCFs) are communal environments for patients with chronic diseases or older adults, making them particularly susceptible to significant harm during infectious disease outbreaks. Nonetheless, LTCFs have historically been subject to less stringent infection prevention and control (IPC) mandates. This study aimed to assess the current state of LTCFs and to develop an IPC system tailored for these facilities following the coronavirus disease 2019 (COVID-19) pandemic. We conducted an online survey of 11,366 LTCFs in Korea from December 30, 2022 to January 20, 2023, to evaluate the components of IPC in LTCFs. The infectious diseases targeted for IPC included COVID-19, influenza, and scabies. Additionally, we compared institution-based and home-based long-term care insurance facilities. Overall, 3,537 (31.1%) LTCFs responded to the survey, comprising 1,819 (51.4%) institution-based and 1,718 (48.6%) home-based facilities. A majority (87.4%, 2,376/2,720) of these facilities experienced COVID-19 outbreaks. However, only 42% of home-based facilities, in contrast to 90.6% of institution-based facilities, were equipped to manage concurrent COVID-19 cases. Similarly, while 92.1% of institution-based facilities were capable of managing influenza, only 50.5% of home-based facilities could do the same. The incidence of scabies was significantly higher in institution-based facilities than in home-based ones (26.1% vs. 4.3%). Additionally, 88.7% of institution-based facilities managed scabies cases effectively, compared to only 42.1% of home-based facilities. Approximately half of the LTCFs had a basic capacity to respond to infectious diseases. However, there were differences in response capabilities between institution-based facilities and home-based facilities.

International Air Cargo Volume Forecasting based on the Stacking Fusion Model

Accurate forecasting of international air cargo volumes is crucial for air cargo carriers, which optimizes operational efficiency and profitability and strengthens market competitiveness and risk response capabilities. This study focuses on the open-source cargo data of over 100 international airlines in India from January 2015 to March 2017. Firstly, the missing data must be dealt with. Then, histograms and probability density plots are used to depict the distribution of the cargo volume and analyze the dynamics of the cargo volume of each company at annual and quarterly levels. Subsequently, key factors affecting cargo volumes are analyzed, with a special focus on the cargo performance of the Top 5 airlines, which is visualized in box plots. Given the time-series nature of cargo data, this study adopts the data sequential partitioning method. It innovatively utilizes the Stacking ensemble learning framework, integrating regression models such as Random Forest, Decision Tree, Extreme Gradient Boosting, and K-Nearest Neighbor as the base learners. The meta-learner is constructed to integrate the outputs of each base model, and the hyperparameters of the model are optimized by grid search and cross-validation. Comparison results show that the Stacking model has a higher R² value and lower MSE than any single base learners, indicating that it is more effective in international air cargo volume prediction. The prediction model based on stacking ensemble learning provides an effective strategy for improving air cargo prediction accuracy.

Programmed BRD9 Degradation and Hedgehog Signaling Activation via Silk-Based Core-Shell Microneedles Promote Diabetic Wound Healing.

Wound healing impairment in diabetes mellitus is associated with an excessive inflammatory response and defective regeneration capability with suppressed Hedgehog (Hh) signaling. The bromodomain protein BRD9, a subunit of the non-canonical BAF chromatin-remodeling complex, is critical for macrophage inflammatory response. However, whether the epigenetic drug BRD9 degrader can attenuate the sustained inflammatory state of wounds in diabetes remains unclear. Without a bona fide immune microenvironment, Hh signaling activation fails to effectively rescue the suppressed proliferative ability of dermal fibroblasts and the vascularization of endothelial cells. Therefore, a silk-based core-shell microneedle (MN) patch is proposed to dynamically modulate the wound immune microenvironment and the regeneration process. Specifically, the BRD9 degrader released from the shell of the MNs mitigated the excessive inflammatory response in the early phase. Subsequently, the positively charged Hh signaling agonist is released from the negatively charged core of the silk fibroin nanofibers and promotes the phase transition from inflammation to regeneration, including re-epithelialization, collagen deposition, and angiogenesis. These findings suggest that the programmed silk-based core-shell MN patch is an ideal therapeutic strategy for effective skin regeneration in diabetic wounds.

Energy management strategy and operation strategy of hybrid energy storage system to improve AGC performance of thermal power units

With the continuous increase of the renewable energy power generation penetration, the intermittency and fluctuation of renewable energy power generation make the traditional thermal power units (TPU) which play the main role of regulation need to undertake more frequent and more severe regulation tasks. In order to improve the automatic generation control (AGC) command response capability of TPU, an operation strategy of hybrid energy storage system (HESS) is proposed in this paper. While assisting TPU to complete the regulation tasks, it gives full play to the advantages of power-type and energy-type energy storage. Moreover, an energy management strategy of energy storage array (ESA) is proposed to improve the overall operation efficiency of ESA while making the state of charge (SOC) of all energy storage subunits consistent. Finally, the effectiveness of the proposed strategy is verified by simulation experiments. The results show that after using HESS to assist TPU operation, the comprehensive regulation performance index of TPU increased from 4.0198 to 7.8112, which significantly improved the operational flexibility of TPU. Meanwhile, the strategy proposed in this paper makes different types of energy storage systems in HESS operate in a relatively healthy SOC range, and the SOC of the flywheel energy storage system (FESS) reaches the limitation value decrease from 6 times to once, ensuring the overall charge and discharge capacity of HESS.

Current Stress Minimization Based on Particle Swarm Optimization for Dual Active Bridge DC–DC Converter

Under extended-phase-shift (ESP) control, the current stress of the dual active bridge converter (DAB) is relatively high, which reduces the efficiency of the converter. To solve this problem, a particle swarm optimization (PSO) algorithm based on minimizing the current stress is proposed in this paper. The optimal phase-shift ratio of the DAB converter with ESP control is obtained by using the algorithm’s optimization characteristic. This approach ensures that the converter achieves minimal current stress, thereby enhancing the steady-state performance of the DAB converter. Moreover, in terms of dynamic performance, traditional PI control has poor dynamic response ability when there are sudden changes in load and input voltage. To solve this problem, the voltage dynamic matrix control (DMC) algorithm is introduced to combine with the PSO algorithm to minimize the current stress of the DAB converter under EPS control while enhancing the dynamic response capability of the DAB converter. A simulation model was constructed for comparative validation on MATLAB/Simulink 2019, demonstrating the correctness and effectiveness of the improved control method.

Research on safety risk factors of metro shield tunnel construction in China based on social network analysis

PurposeDuring metro construction using the shield method, the construction process's complexity, the construction environment's variability, and other factors can easily lead to tunnel construction accidents. This paper aims to explore the interconnections between risk factors and related accident types, as well as the risk chain formed between risk factors, and to analyze the key risk factors and vulnerabilities in shield tunnel construction through empirical data.Design/methodology/approachBased on the social network analysis theory, the connection of various risk factors in subway shield tunnel construction is explored, and the mechanism of multiple risk factors is studied. Through literature analysis, articles on safety risk factors in metro shield tunnel construction are organized and studied, and the identified safety risk factors can comprehensively reflect the significant risks that need to be concerned in metro shield tunnel construction.FindingsThe results show that a small world characterizes the SNA network of safety risk factors for metro shield tunnel construction: The frequency of association between the five risk factors “unsafe behavior,” “site management,” “safety supervision and inspection,” “safety education system” and “safety protection” is higher than that of other factors. Only a few risks, such as “site management,” “safety supervision and inspection,” and “rapid response capability,” directly lead to accidents. In addition, risk factors such as the “safety education system” and “safety protection” will indirectly cause unsafe behaviors of construction personnel.Research limitations/implicationsDuring construction, the probability of occurrence of risk factors may vary with the construction phase and area and is not considered in this paper. In addition, although this paper identifies, determines and analyzes the risk factors affecting the safety of metro shield tunnel construction, including the importance of each risk factor and the connection between them, more detailed information before and after the accident could not be obtained based on the accident investigation report alone. Therefore, future research can collect the same accident case from more sources to obtain more information.Practical implicationsThe theory of accident causation has been improved at the theoretical level. The identified safety risk factors can comprehensively reflect the significant risks that need to be paid attention to in metro shield tunnel construction. From a practical point of view, the results of the study provide a basis for the rational control of the risk factors in the construction of subway shield tunnels, which can help guide practitioners to do a good job of risk prevention before the construction of metro shield tunnels and reduce the probability of related accidents.Originality/valueThis study expands the application of social network analysis in the field of subway tunnel construction risk, quantitatively analyzes the key risk factors and vulnerabilities in shield method tunnel construction and proposes policy recommendations for future metro tunnel construction safety management.