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Force rebalance-type accelerometers are mainly used in inertial navigation systems of aircraft, and the characterization of the resulting squeeze film damping (SFD) is essential for estimating dynamic response characteristics of these accelerometers. In this study, a methodology for modeling SFD and experimentally verifying this model for force rebalance-type accelerometers is presented. Modeling of the SFD effect involves determining an effective damping coefficient as a function of pendulum displacement. Damping force and pressure distribution due to SFD are obtained for a range of pendulum displacements via finite element analysis (FEA). The accelerometer is modeled as both an open- and closed-loop system, where an identified damping model for SFD is also used. The open-loop model is verified by comparing the step response of the system, and the closed-loop model is verified by comparing the frequency and shock responses of the system via simulations and experiments. Simulation and test results of both open- and closed-loop systems show close agreement. The presented results indicate that in systems with similar dimensions and material properties, damping due to SFD in a force rebalance accelerometer can be accurately modeled as a function of pendulum displacement using the method described in this research study.

Land surface models have an increasing scope. Initially designed to capture the feedbacks between the land and the atmosphere as part of weather and climate prediction, they are now used as a critical tool in the urgent need to inform policy about land-use and water-use management in a world that is changing physically and economically. This paper outlines the way that models have evolved through this change of purpose and what might the future hold. It highlights the importance of distinguishing between advances in the science within the modelling components, with the advances of how to represent their interaction. This latter aspect of modelling is often overlooked but will increasingly manifest as an issue as the complexity of the system, the time and space scales of the system being modelled increase. These increases are due to technology, data availability and the urgency and range of the problems being studied.

The complex relationship between water, energy, food, and ecological systems, known as the WEFE nexus, has emerged as a major topic in the debate about sustainable economic development and resource management. This subject is of special interest in Mediterranean coastal areas as rapid economic expansion driven by population growth, higher influx of tourists, and intensification of agriculture is leading to structural water scarcity conditions. However, addressing the diverse range of issues associated with the nexus is a difficult task due to the existence of intricate interconnections, interdependencies, and nonlinearities within and across its various components. Accordingly, this case study applies a combination of participatory systems modeling and network analysis tools to yield insights into the complexity of this nexus in Axarquia, a region with features that make it an example of water-stressed jurisdictions in the Mediterranean. Overall, our results provide a strong foundation to understand the dynamics that govern this nexus in regions where the availability of freshwater resources is a significant concern. Furthermore, they lay the groundwork for the development of models and scenarios to simulate the impact of various policies and interventions on the overall system.

Cities are adopting energy planning strategies and emission reduction targets in line with national decarbonization targets. Modeling and scenario assessments are used to support energy planning. City energy systems are complex systems including interactions and interdependencies, as well as the specifics of the local city context. To investigate the representation of city-specific system complexities in existing case studies, a systematic literature review methodology is applied, and model applications are analyzed using a comparative analysis framework. Additionally, research objective themes used to define the specific aims are explored. Key modeling characteristics include scale aspects, method description, system definition, scenario formulation, and case-specific model inputs. The findings of this study suggest that city case studies have a diverse representation of modeling approaches. However, the analysis of model characteristics shows a limited representation of modeling features, such as stakeholder participation and local air pollution impacts that are unique to the urban context. In terms of research objective themes behind the model application, four research themes are identified. Studies aimed at identifying pathways to future low-carbon energy systems and evaluating policy impacts on the city energy systems are the most stated research objective themes for modeling city energy systems.

Background Suicide remains a leading cause of death for young Australians. We need robust analytical tools to help us understand and respond to the dynamic complexity underlying suicide and suicidal behaviour. Participatory systems modelling leverages empirical data together with the experiential knowledge of stakeholders to inform model building, evaluation, and implementation. Efforts to evaluate collaborative deliberative processes such as participatory system modelling remain sparse. The aim of this study was to evaluate the feasibility, value and impact of adopting a participatory systems modelling approach for developing a youth suicide prevention system dynamics model in North-West Melbourne, Australia. Methods Three participatory workshops were conducted with an expert stakeholder group including young people with lived and living experience of self-harm/suicidal behaviour, family members, healthcare professionals, and policy-makers. Data collection was informed by an evaluation framework, including (i) briefing questionnaires, (ii) workshop recordings and field notes and (iii) evaluation questionnaires. Data from each source were analysed separately, using codebook and reflexive thematic analysis, and synthesized to identify patterns in meaning and broad concepts under the evaluation categories of feasibility, value and impact. Results We found that the feasibility of undertaking an inclusive and accessible participatory systems modelling project was influenced by stakeholder cultural diversity, meaningful involvement of those with lived and living experience, accessibility of technical aspects of modelling and managing group dynamics. The value of adopting a participatory approach in developing a complex systems model was demonstrated in the collaborative learning that took place between the expert stakeholder group and the research team. Central to this was the experiential knowledge of young people who helped shape our understanding of the contextual drivers of self-harm and suicidal behaviour. Stakeholders’ knowledge of the regional health system informed the structure, logic and assumptions of the systems model. Conclusions This is one of very few evaluations of a participatory systems modelling project involving young people with lived and living experience of self-harm/suicidal behaviour and bereaved families. Our study offers novel theoretical and practical insights into the processes adopted to ensure the safe and inclusive involvement of diverse perspectives in developing a youth suicide prevention system dynamics model.

The youth mental health sector is persistently challenged by issues such as service fragmentation and inefficient resource allocation. Systems modelling and simulation, particularly utilizing participatory approaches, is offering promise in supporting evidence-informed decision making with limited resources by testing alternative strategies in safe virtual environments before implementing them in the real world. However, improved evaluation efforts are needed to understand the critical elements involved in and to improve methods for implementing participatory modelling for youth mental health system and service delivery. An evaluation protocol is described to evaluate the feasibility, value, impact, and sustainability of participatory systems modelling in delivering advanced decision support capabilities for youth mental health. This study applies a comprehensive multi-scale evaluation framework, drawing on participatory action research principles as well as formative, summative, process, and outcome evaluation techniques. Novel data collection procedures are presented, including online surveys that incorporate gamification to enable social network analysis and patient journey mapping. The evaluation approach also explores the experiences of diverse stakeholders, including young people with lived (or living) experience of mental illness. Social and technical opportunities will be uncovered, as well as challenges implementing these interdisciplinary methods in complex settings to improve youth mental health policy, planning, and outcomes. This study protocol can also be adapted for broader international applications, disciplines, and contexts.

Purpose of Review Assessment of the impact of ocean resolution in Earth System models on the mean state, variability, and future projections and discussion of prospects for improved parameterisations to represent the ocean mesoscale. Recent Findings The majority of centres participating in CMIP6 employ ocean components with resolutions of about 1 degree in their full Earth System models (eddy-parameterising models). In contrast, there are also models submitted to CMIP6 (both DECK and HighResMIP) that employ ocean components of approximately 1/4 degree and 1/10 degree (eddy-present and eddy-rich models). Evidence to date suggests that whether the ocean mesoscale is explicitly represented or parameterised affects not only the mean state of the ocean but also the climate variability and the future climate response, particularly in terms of the Atlantic meridional overturning circulation (AMOC) and the Southern Ocean. Recent developments in scale-aware parameterisations of the mesoscale are being developed and will be included in future Earth System models. Summary Although the choice of ocean resolution in Earth System models will always be limited by computational considerations, for the foreseeable future, this choice is likely to affect projections of climate variability and change as well as other aspects of the Earth System. Future Earth System models will be able to choose increased ocean resolution and/or improved parameterisation of processes to capture physical processes with greater fidelity.

Purpose of Review As we transition to highly renewable energy systems, island energy systems face challenges different from those well-understood for continents. This paper reviews these challenges to guide energy systems modelling for islands. Recent Findings Only a single energy system model is found to be developed especially for islands. Challenges like land scarcity, climate risks, high seasonality of demand, isolation and remoteness, data scarcity, social and political vulnerability, and scarce funding are identified in recent literature. Notably, isolation and remoteness, social and political factors, and insufficient island funding are underrepresented in studies reviewed in this work. Summary This review identifies the specific challenges of island energy systems and compiles the methods employed by researchers to tackle them. We discuss these challenges in detail, highlight gaps, and provide suggestions to improve island energy systems modelling in the future.

Complex systems modeling has wide applications in theory and practice. A new approach is proposed by recognizing data credibility (DC) using multiple machine learning (ML) approaches, named DCML. There are two major components and theoretical contributions of the proposed approach: first, identifying less-credible data with a single ML approach, and second, cross-identifying these less-credible data with multiple ML approaches. A practical case of capability evaluation of the Unmanned Aerial Vehicle (UAV) is studied for validating the effectiveness of DCML. Case study results show that (1) The proposed DCML approach demonstrates a proficient ability to identify less credible data, (2) The validations with various ML methods prove effective, but the efficacy of the method is not necessarily proportional to the number of methods employed, (3) The combination of backpropagation neural network (BPNN) and gaussian process regression (GPR) yields the most favorable outcomes.

The social and emotional wellbeing of young Aboriginal and Torres Strait Islander peoples should be supported through an Indigenous-led and community empowering approach. Applying systems thinking via participatory approaches is aligned with Aboriginal and Torres Strait Islander research paradigms and can be an effective method to deliver a decision support tool for mental health systems planning for Indigenous communities. Evaluations are necessary to understand the effectiveness and value of such methods, uncover protective and healing factors of social and emotional wellbeing, as well as to promote Aboriginal and Torres Strait Islander self-determination over allocation of funding and resources. This paper presents modifications to a published evaluation protocol for participatory systems modelling to align with critical Aboriginal and Torres Strait Islander guidelines and recommendations to support the social and emotional wellbeing of young people. This paper also presents a culturally relevant participatory systems modelling evaluation framework. Recognizing the reciprocity, strengths, and expertise Aboriginal and Torres Strait Islander methodologies can offer to broader research and evaluation practices, the amended framework presented in this paper facilitates empowering evaluation practices that should be adopted when working with Aboriginal and Torres Strait Islander peoples as well as when working with other diverse, non-Indigenous communities.