Flexible Capacity Research Articles

Glucose‐Responsive Microneedle Patch With Variable Crosslinking Density and Flexible Core–Shell Structure for Insulin Delivery

AbstractDeveloping glucose‐responsive microneedle patches with features of simple preparation, high insulin loading, and safety has a great contribution to the treatment of diabetic patients. In this work, a novel glucose‐responsive core–shell microneedle patch is prepared from biocompatible materials by a facile process. The exterior glucose‐responsive shell is composed of polyvinyl alcohol (PVA) and ɛ‐polylysine modified with phenylboronic acid , and the inner flexible core is prepared by pure PVA loaded with insulin. The shell shows superior glucose‐induced swelling and controlled insulin release ability due to the decomposition of borate ester bonds under the synergistic effect of glucose and water. The microneedle patch also features flexibility and high insulin loading capacity (36 IU cm−2). It shows high puncture efficiency (92%) and maintains a relatively complete morphology after being removed, enabling to reduce material residues in the skin. Moreover, the microneedle patch reveals a good hypoglycemic effect in diabetic rats, achieves a hypoglycemic rate similar to that of direct injection after swelling, and works effectively to prevent excess insulin transmission. The high glucose‐responsive ability, simple preparation, high loading capacity, rapid hypoglycemic speed, high conformability to skin, and low component dissolution make this microneedle patch a suitable candidate for diabetic treatment.

Human and Machine: The Impact of Machine Input on Decision Making Under Cognitive Limitations

The rapid adoption of artificial intelligence (AI) technologies by many organizations has recently raised concerns that AI may eventually replace humans in certain tasks. In fact, when used in collaboration, machines can significantly enhance the complementary strengths of humans. Indeed, because of their immense computing power, machines can perform specific tasks with incredible accuracy. In contrast, human decision makers (DMs) are flexible and adaptive but constrained by their limited cognitive capacity. This paper investigates how machine-based predictions may affect the decision process and outcomes of a human DM. We study the impact of these predictions on decision accuracy, the propensity and nature of decision errors, and the DM’s cognitive efforts. To account for both flexibility and limited cognitive capacity, we model the human decision-making process in a rational inattention framework. In this setup, the machine provides the DM with accurate but sometimes incomplete information at no cognitive cost. We fully characterize the impact of machine input on the human decision process in this framework. We show that machine input always improves the overall accuracy of human decisions but may nonetheless increase the propensity of certain types of errors (such as false positives). The machine can also induce the human to exert more cognitive efforts, although its input is highly accurate. Interestingly, this happens when the DM is most cognitively constrained, for instance, because of time pressure or multitasking. Synthesizing these results, we pinpoint the decision environments in which human-machine collaboration is likely to be most beneficial. This paper was accepted by Jeannette Song, operations management. Supplemental Material: The data files and online appendices are available at https://doi.org/10.1287/mnsc.2023.4744 .

Light Weight Deflectometer Evaluation of Low-Volume Road Structural Deterioration under Rapidly Increased Traffic Patterns

When evaluating low-volume road (LVR) condition, there is not a tremendous emphasis on structural capacity, since deterioration is typically caused by environmental factors. However, in cases where LVRs experience rapidly increased traffic loading, structural condition becomes important. The research objective was to determine whether the light weight deflectometer (LWD) can be used as a structural evaluation tool for LVRs. This study explored three major factors that affect measurement of flexible pavement structural capacity: load-induced deterioration (e.g., rutting and cracking), soil moisture, and asphalt temperature. Four full-scale flexible pavement test items were constructed with varying base-course materials and layer thickness typical of LVR. Instrumentation was installed during construction to monitor moisture content, temperature, and ambient weather conditions. Accelerated traffic was applied with a 4-axle military truck. A total of 10,000 cumulative vehicle passes were completed. Falling weight deflectometer (FWD) and LWD testing equipment were utilized to measure pavement structural condition at selected traffic intervals. The LWD was shown applicable for LVRs experiencing accelerated traffic. The LWD is portable and is more efficient for LVRs when high rut depths are permitted. The LWD tracked trends of the FWD; therefore, the LWD, based on these experiments, can be recommended for use in lieu of FWD to assess structural condition in some LVR conditions.

Flexible Hyperspectral Anomaly Detection Using Weighted Nuclear Norm

It has been demonstrated that nuclear-norm-based low-rank representation is capable of modeling cluttered backgrounds in hyperspectral images (HSIs) for robust anomaly detection. However, minimizing the nuclear norm regularizes each singular value equally during rank reduction, which restricts the capacity and flexibility of modeling the major structures of the background. To address this problem, we propose detection of anomaly pixels in HSIs using the weighted nuclear norm, which can preserve the major singular values during rank reduction. We present a down-up sampling scheme to remove plausible anomaly pixels from the image as much as possible and learn a robust principal component analysis (PCA) background dictionary. From a dictionary, we develop a weighted nuclear-norm minimization model to represent the background with a low-rank coefficients matrix that can be effectively optimized using the standard alternating direction method of multipliers (ADMM). Due to the flexible modeling capacity using the weighted nuclear norm, anomaly pixels can be distinguished from the background with the reconstruction error. The experimental results on two real HSIs datasets demonstrate the effectiveness of the proposed method for anomaly detection.

Graphene-Related Nanomaterials for Biomedical Applications

This paper builds on the context and recent progress on the control, reproducibility, and limitations of using graphene and graphene-related materials (GRMs) in biomedical applications. The review describes the human hazard assessment of GRMs in in vitro and in vivo studies, highlights the composition-structure-activity relationships that cause toxicity for these substances, and identifies the key parameters that determine the activation of their biological effects. GRMs are designed to offer the advantage of facilitating unique biomedical applications that impact different techniques in medicine, especially in neuroscience. Due to the increasing utilization of GRMs, there is a need to comprehensively assess the potential impact of these materials on human health. Various outcomes associated with GRMs, including biocompatibility, biodegradability, beneficial effects on cell proliferation, differentiation rates, apoptosis, necrosis, autophagy, oxidative stress, physical destruction, DNA damage, and inflammatory responses, have led to an increasing interest in these regenerative nanostructured materials. Considering the existence of graphene-related nanomaterials with different physicochemical properties, the materials are expected to exhibit unique modes of interactions with biomolecules, cells, and tissues depending on their size, chemical composition, and hydrophil-to-hydrophobe ratio. Understanding such interactions is crucial from two perspectives, namely, from the perspectives of their toxicity and biological uses. The main aim of this study is to assess and tune the diverse properties that must be considered when planning biomedical applications. These properties include flexibility, transparency, surface chemistry (hydrophil-hydrophobe ratio), thermoelectrical conductibility, loading and release capacity, and biocompatibility.

A Novel Distal Hybrid Pneumatic/Cable‐Driven Continuum Joint with Variable Stiffness Capacity for Flexible Gastrointestinal Endoscopy

The robot‐assisted flexible access surgery represented by the emerging robot‐assisted flexible endoscopy (FE) and natural orifice transluminal endoscopic surgery demands flexible and continuum manipulators instead of the rigid and straight instruments in the traditional minimally invasive surgery (MIS). These flexible manipulators are required to advance through the tortuous and narrow anatomic paths via natural orifices for dexterous diagnostic examination and therapeutic operations. Therefore, developing flexible endoscopic manipulators with the capacity of snake‐like movements for flexible access and variable stiffness regulation for operations to address these flexible access surgical difficulties is demanding but remains challenging. To address such challenges, herein, it is proposed that a novel distal continuum joint based on the hybrid pneumatic and cable‐driven approach achieves variable stiffness capacity, excellent bending characteristics in both flexible and rigid states, satisfactory motion consistency and shape‐locking ability during the rigid‐flexible transition, and relatively high loading capacity for flexible gastrointestinal endoscopic robots. Characterization experiments validate these performances, and phantom and ex vivo experiments have been performed to demonstrate the feasibility and effectiveness for FE. The presented method demonstrates an effective and practical approach to enabling continuum robots with both flexible access and tunable stiffness capacity and supports a convenient extension for MIS applications.

The Impact of Covid-19 Social Isolation on Mental Health and Physical Activity of Older Adults

Background: The ongoing COVID-19 pandemic tends to affect older adults more severely, raising the need for social isolation in this age population. Social isolation is likely to impact older adults’ social ties and quality of life, as well as the risk for illness and health. Objective: This study is a narrative literature review to evaluate the potential effects of social isolation on the mental health and well-being of older adults. Methods: A literature search performed between January 1, 2020, and January 13, 2021, comprised an electronic search on different online databases in PubMed and ScienceDirect using the keywords COVID-19 followed by generic terms older adults or older people or aging population or elderly. Excluding duplicates, a total of 376 articles were screened, of which 21 studies were included in the final review. Results: Many older people could be mentally well-equipped to deal with social isolation, but some experience a negative impact on mental health. Stress, anxiety, and depression symptoms were reported during the self-isolation period. Physical activity also has declined among older adults amid COVID-19. Some elderly who are not moving much may lose significant muscle strength, flexibility, and aerobic capacity. Conclusion: If social isolation continues, policy responses such as proactively identifying and addressing COVID-19 for the elderly who are experiencing negative consequences. An effective solution such as “distance connectivity” and creating safe physical activity such as home exercise is recommended.

Grocery omnichannel perishable inventories: performance measures and influencing factors

PurposePerishable inventory management for the grocery sector has become more challenging with extended omnichannel activities and emerging consumer expectations. This paper aims to identify and formalize key performance measures of omnichannel perishable inventory management (OCPI) and explore the influence of operational and market-related factors on these measures.Design/methodology/approachThe inductive approach of this research synthesizes three performance measures (product waste, lost sales and freshness) and four influencing factors (channel effect, demand variability, product perishability and shelf life visibility) for OCPI, through industry investigation, expert interviews and a systematic literature review. Treating OCPI as a complex adaptive system and considering its transaction costs, this paper formalizes the OCPI performance measures and their influencing factors in two statements and four propositions, which are then tested through numerical analysis with simulation.FindingsProduct waste, lost sales and freshness are identified as distinctive OCPI performance measures, which are influenced by product perishability, shelf life visibility, demand variability and channel effects. The OCPI sensitivity to those influencing factors is diverse, whereas those factors are found to moderate each other's effects.Practical implicationsTo manage perishables more effectively, with less waste and lost sales for the business and fresher products for the consumer, omnichannel firms need to consider store and online channel requirements and strive to reduce demand variability, extend product shelf life and facilitate item-level shelf life visibility. While flexible logistics capacity and dynamic pricing can mitigate demand variability, the product shelf life extension needs modifications in product design, production, or storage conditions. OCPI executives can also increase the product shelf life visibility through advanced stock monitoring/tracking technologies (e.g. smart tags or more comprehensive barcodes), particularly for the online channel which demands fresher products.Originality/valueThis paper provides a novel theoretical view on perishables in omnichannel systems. It specifies the OCPI performance, beyond typical inventory policies for cost minimization, while discussing its sensitivity to operations and market factors.

Divergent foraging strategies between populations of sympatric matrilineal killer whales.

In cooperative species, human-induced rapid environmental change may threaten cost-benefit tradeoffs of group behavioral strategies that evolved in past environments. Capacity for behavioral flexibility can increase population viability in novel environments. Whether the partitioning of individual responsibilities within social groups is fixed or flexible across populations is poorly understood, despite its relevance for predicting responses to global change at the population and species levels and designing successful conservation programs. We leveraged bio-logging data from two populations of fish-eating killer whales (Orcinus orca) to quantify patterns of fine-scale foraging movements and their relationships with demography. We reveal striking interpopulation differences in patterns of individual foraging behavior. Females from the endangered Southern Resident (SRKW) population captured less prey and spent less time pursuing prey than SRKW males or Northern Resident (NRKW) females, whereas NRKW females captured more prey than NRKW males. The presence of a calf (≤3 years) reduced the number of prey captured by adult females from both populations, but disproportionately so for SRKW. SRKW adult males with a living mother captured more prey than those whose mother had died, whereas the opposite was true for NRKW adult males. Across populations, males foraged in deeper areas than females, and SRKW captured prey deeper than NRKW. These population-level differences in patterns of individual foraging behavior challenge the existing paradigm that females are the disproportionate foragers in gregarious resident killer whales, and demonstrate considerable variation in the foraging strategies across populations of an apex marine predator experiencing different environmental stressors.

Structural changes in Ukraine’s electricity generation and their impact on the reduction of CO2 emissions

The purpose of the study is to assess the state of and structural changes in Ukraine’s electricity generation and their impact on the reduction of carbon dioxide (CO2) emissions. For the investigation, data from the International Energy Agency and the National Power Company Ukrenergo were used. The study analyzes the trends in Ukraine CO2 emissions by economic sector, the trends in the country’s electricity generation and electricity generation capacities, the structure of electricity generation capacities by type of flexibility and presents the calculations of the integral coefficients of structural changes in the electricity generation capacities and electricity generation by type of flexibility. The study also examines how the structure of the energy sector of Ukraine has changed in terms of electricity generation. For this purpose, the structure of the Ukrainian electricity generation capacities and electricity generation by generation type is considered and the integral coefficients of structural changes in the electricity capacities and electricity production by generation type are calculated. Based on the study results, it is determined that, over the considered period, the decrease in Ukraine’s electricity generation was more significant than the decrease in its generation capacities, which has led to a corresponding reduction in CO2 emissions in the country; the structural changes in the electric power industry of Ukraine were not adequate to the structural changes in the country’s economy, which has led to a shortage in flexible capacities but also resulted in the reduction of CO2 emissions due to a decline in electricity generation.

Placing a value on increased flexible vaccine manufacturing capacity for future pandemics.

Placing a value on increased flexible vaccine manufacturing capacity for future pandemics.

Level of flexibility and coordination in elementary school students

Basic motor skills, as well as flexibility and coordination, are of paramount importance to develop at school age, as these are prerequisites to achieve adequate techniques and tactics in sports. The objective of this study is to improve flexibility and coordination in middle school students, in Physical Education classes through playful activities, at the Daniel Muñoz Serrano School. This research is of a descriptive cross-sectional type and with a quantitative approach. The population under study is made up of 180 students, the results show the capacity for flexibility and coordination are at a bad and very bad level, in terms of coordination, an inefficiency in its development has been evidenced. It is concluded that it is necessary to emphasize alternatives for the development of these capacities, for which activities that contribute to the improvement of these capacities are proposed respectively.

Day-Ahead Optimal Scheduling of Resources in a Distribution System in Joint Energy, Regulation and Ramp Markets

The increasing trend of integrating Renewable Energy Sources (RESs) into power systems could cause operational challenges in the system from flexibility and reliability perspectives. Respectively, utilities would be relied on local flexible resources to address the flexibility requirements in power systems. In this respect, local resources in distribution systems could participate in ancillary markets along with the wholesale energy markets to address the flexibility capacity shortage in the system. Consequently, this paper aims to provide a framework to optimize the scheduling of resources in distribution networks while participating in energy, regulation, and ramp markets. Correspondingly, this approach would maximize the profits of the local resources in distribution systems whereas providing Flexible Ramp Product (FRP) and regulation reserve for the system operators. Respectively, an optimized bidding strategy is developed to maximize the profits of the local resources, while modeling the operational constraints of the distribution grids and power losses to improve the accuracy of the proposed scheme. Furthermore, the chance constrained concept is taken into account in the proposed scheme to model the uncertainty of RESs. Finally, the model is applied on the IEEE-37-bus-test-system and the sensitivity analysis is employed to investigate its effectiveness in the management of the system.

Order controllable enhanced stimulated Brillouin scattering utilizing cascaded diamond Raman conversion

We report on the design and operation of a laser, which outputs wavelengths in the 1.2 and 1.5 μm ranges by leveraging two non-linear processes of stimulated Raman scattering and stimulated Brillouin scattering in diamond. By precisely controlling characteristics of the laser resonator formed around the diamond crystal, we are able to selectively control the onset of each non-linear process so as to tailor laser output characteristics both in way of wavelength and output power. This work demonstrates the high degree of flexibility and power-handling capacity of diamond for wavelength conversion of common laser wavelengths (such as 1064 nm as used in this work) and the generation of a span of discrete wavelengths (with up to eight cascaded orders being demonstrated in this work).

Simulation and optimum control of a two-stage compression air source heat pump system: A comparison of two kinds of variable volume approaches

Two-stage vapor compression technology can effectively improve the performance of an air source heat pump, and a staged compression system with two separate compressors has a highly flexible modulation capacity. However, the effect of different volume modulation approaches on the heating COP requires further analysis. In this study, a Modelica-based dynamic simulation model of a two-stage air-source heat pump was developed and verified with experimental data. A numerical optimization method was used to obtain the optimum frequencies and low- or high-stage cylinder volumes of the compressors that maximize the COP. The results show that the three optimization approaches have different effects. At lower ambient temperatures, varying the high-stage compressor cylinder volume can yield the maximum COP among the three optimization methods, followed by varying the low-stage compressor cylinder volume and compressor frequencies. At higher ambient temperatures, varying low-stage cylinder volume can yield the maximum COP, followed by varying the compressor frequencies and high-stage cylinder volume. The further the working condition deviates from the design point, the greater the improvement in the COP. The maximum improvements in the COP achieved with optimization in this study were 8.23%, 6.39% and 5.39% by varying the high-stage cylinder volume, low-stage cylinder volume, and frequencies, respectively.

A novel integrated system of hydrogen liquefaction process and liquid air energy storage (LAES): Energy, exergy, and economic analysis

With the global positive response to environmental issues, cleaner energy will attract widespread attention. To improve the flexible consumption capacity of renewable energy and consider the urgent need to optimize the energy consumption and cost of the hydrogen liquefaction process, a novel system integrating the hydrogen liquefaction process and liquid air energy storage (HLP–LAES) is proposed. The operating strategy of the system ensures that it can produce liquid hydrogen and has the function of energy storage and power generation. A 3E study (energy, exergy, and economics) is carried out to evaluate the techno-economic performance of the proposed energy-intensive process. After optimization of key parameters, when the daily output of liquid hydrogen is 50 tons, the maximum daily power generation can reach 131.3 MWh, accounting for 1.21% of the daily electricity consumption of urban and rural residents in Qinghai Province, China. The round-trip efficiency of the proposed process is 58.9%, the specific energy consumption of liquid hydrogen is 7.25 kWh/kgLH2, and the total exergy efficiency is 53.2%. The payback period will be reduced to 1.7 years when the liquid hydrogen is sold at 7.0 $/kgLH2. If the proposed process is retrofitted from a stand-alone hydrogen liquefaction plant, the shortest retrofitting payback period is 9.2 years. The charging and discharging processes of the LAES are innovatively redesigned to better match the hydrogen liquefaction process, while achieving deep coupling and good synergy between the systems. This work aims to provide a reference for the efficient consumption of renewable energy, grid load balancing, and commercialization of the combination of liquid air energy storage and hydrogen liquefaction plants.

End-to-End Real-Time Service Provisioning Over a SDN-Controllable Analog mmWave Fiber -Wireless 5G X-Haul Network

The current work presents the first experimental demonstration of real-time Ethernet (ETH) trial services and 4K-Ultra High Definition (UHD) video application transmission over a 2λ Wavelength Division Multiplexing (WDM) analog Fiber-Wireless (FiWi) mmWave X-haul network, supporting dynamic flexible capacity allocation through an integrated silicon photonic Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> Reconfigurable Optical Add Drop Multiplexer (ROADM) and 60 GHz wireless transmission across a 7 m V-band link distance, while controlled by a Software Defined Network (SDN) controller based on Open Daylight. Analog X-haul transport of the radio signals is based on an Intermediate Frequency over Fiber (IFoF) scheme centered at 1.5 GHz using an Orthogonal Frequency Division Multiplexing (OFDM) radio-waveform with a bandwidth of 204 MHz, generated by a Field Programmable Gated Array (FPGA)-based RF System-on-Chip (SoC) processor that converts on-the-fly the real-time ETH downlink traffic to analog radio and vice-versa for the uplink. Dynamic allocation of the X-haul traffic capacity is handled through the use of the 802.1Q Virtual Local Area Network (VLAN) tag-mechanism, which controls the forwarding operation to the proper DAC and InP EML for optical modulation using Intensity Modulation/Direct Detection (IM/DD) schemes, while the wavelength routing operation is handled by the low-loss four-port Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> ROADM featuring only 2.5 dB fiber-to-fiber losses based on a cascaded MZI-interleaver design on the TriPleX platform, routing the real-time traffic to a second mmWave antenna site. Detailed measurements and traffic statistics indicate end-to-end latency of less than 260 μs and a packet loss less than 0.0054% across a dynamic range of at least 6.5 dB in the optical domain, while the high user bandwidth and signal quality are validated by an uninterrupted 4K-UHD video transmission across the FiWi X-haul mmWave transport network. The current work aims to shape a complete technology roadmap for Point-to-Multipoint FiWi transport network architectures with high spectral efficiency X-haul transport for dense areas and 5G/6G hotspots of future mmWave Centralized Radio Access Networks (C-RANs).

Lessons for Oral Bioavailability: How Conformationally Flexible Cyclic Peptides Enter and Cross Lipid Membranes.

Cyclic peptides extend the druggable target space due to their size, flexibility, and hydrogen-bonding capacity. However, these properties impact also their passive membrane permeability. As the "journey" through membranes cannot be monitored experimentally, little is known about the underlying process, which hinders rational design. Here, we use molecular simulations to uncover how cyclic peptides permeate a membrane. We show that side chains can act as "molecular anchors", establishing the first contact with the membrane and enabling insertion. Once inside, the peptides are positioned between headgroups and lipid tails─a unique polar/apolar interface. Only one of two distinct orientations at this interface allows for the formation of the permeable "closed" conformation. In the closed conformation, the peptide crosses to the lower leaflet via another "anchoring" and flipping mechanism. Our findings provide atomistic insights into the permeation process of flexible cyclic peptides and reveal design considerations for each step of the process.

Study of CIM Modeling for a PV Grid-Connected System

To conduct the research on voltage stability online-monitoring simulation system in the photovoltaic (PV) power gird-connected system, a classic 3-bus power system containing a PV power station with a flexible setting capacity (including distributed PV, relatively large-scale and large-scale PV, and super large-scale PV base, etc.) is taken as the test example. According to the IEC 61970 Standard Part 301 (Common Information Model, CIM), CIM modeling method for the PV grid-connected 3-bus system is studied by using the Rational Rose software and the unified modeling language UML, and the PV grid-connected system’s network connection model, each load model, measurement model and topological model are established; meanwhile, the PV power is treated as a load model to simplify the modeling process. On the basis of the established CIM model of the PV grid-connected system, the method of mapping the common information model to the relational database is studied and an applied mapping diagram is set up. Then the database technology is used to deposit the established CIM model into the created database for the use of Energy Manage System (EMS) and each utility software such as the voltage stability online-monitoring software in the PV grid-connected system. Then, the database is technically connected to the voltage stability online-monitoring software of the PV grid-connected system, and the communication between the station terminal and the monitoring terminal can be realized.

Assessing Thai Hospitals’ Evacuation Preparedness Using the Flexible Surge Capacity Concept and Its Collaborative Tool

According to the concept of “flexible surge capacity,” hospitals may need to be evacuated on two occasions: (1) when they are exposed to danger, such as in war; and (2) when they are contaminated, such as during the Covid-19 pandemic. In the former, the entire hospital must be evacuated, while in the latter, the hospital becomes a pandemic center necessitating the transfer of its non-contaminated staff, patients, and routine activities to other facilities. Such occasions involve several degrees of evacuation—partial or total—yet all require deliberate surge planning and collaboration with diverse authorities. This study aimed to investigate the extent of hospital evacuation preparedness in Thailand, using the main elements of the flexible surge capacity concept. A mixed method cross-sectional study was conducted using a hospital evacuation questionnaire from a previously published multinational hospital evacuation study. The tool contained questions regarding evacuation preparedness encompassing surge capacity and collaborative elements and an open-ended inquiry to grasp potential perspectives. All 143 secondary care, tertiary care, and university hospitals received the questionnaire; 43 hospitals provided responses. The findings indicate glitches in evacuation protocols, particularly triage systems, the inadequacies of surge planning and multiagency collaboration, and knowledge limitations in community capabilities. In conclusion, the applications of the essential components of flexible surge capacity allow the assessment of hospital preparedness and facilitate the evaluation of guidelines and instructions through scenario-based training exercises.