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Sustainable human exploitation of living marine resources stems from a delicate balance between yield stability and population persistence to achieve socioeconomic and conservation goals. But our imperfect knowledge of how oceanic oscillations regulate temporal variation in an exploited species can obscure the risk of missing management targets. We illustrate how applying a management policy to suppress fluctuations in fishery yield in variable environments (prey density and regional climate) can present unintended outcomes in harvested predators and the sustainability of harvesting. Using Atlantic cod (Gadus morhua, an apex predatory fish) in the Barents Sea as a case study we simulate age‐structured population and harvest dynamics through time‐varying, density‐dependent and density‐independent processes with a stochastic, process‐based model informed by 27‐year monitoring data. In this model, capelin (Mallotus villosus, a pelagic forage fish), a primary prey of cod, fluctuations modulate the strength of density‐dependent regulation primarily through cannibalistic pressure on juvenile cod survival; sea temperature fluctuations modulate thermal regulation of cod feeding, growth, maturation, and reproduction. We first explore how capelin and temperature fluctuations filtered through cod intrinsic dynamics modify catch stability and then evaluate how management to suppress short‐term variability in catch targets alters overharvest risk. Analyses revealed that suppressing year‐to‐year catch variability impedes management responses to adjust fishing pressure, which becomes progressively out of sync with variations in cod abundance. This asynchrony becomes amplified in fluctuating environments, magnifying the amplitudes of both fishing pressure and cod abundance and then intensifying the density‐dependent regulation of juvenile survival through cannibalism. Although these transient dynamics theoretically give higher average catches, emergent, quasicyclic behaviors of the population would increase long‐term yield variability and elevate overharvest risk. Management strategies that overlook the interplay of extrinsic (fishing and environment) and intrinsic (life history and demography) fluctuations thus can inadvertently destabilize fish stocks, thereby jeopardizing the sustainability of harvesting. These policy implications underscore the value of ecosystem approaches to designing management measures to sustainably harvest ecologically connected resources while achieving socioeconomic security. [ABSTRACT FROM AUTHOR]

A kinetic sensitivity analysis of almost any combustion observable will highlight pressure-dependent reactions important to predictions. Third-body efficiencies play a critical role in pressure-dependent reactions, serving as a species-specific multiplier on the rate constant of the reference collider (M). When third-body efficiencies are specified, the typical convention is to specify third-body efficiencies for a handful of common species relative to nitrogen, argon, or helium as the reference (in large part due to insufficient data for most other species). Species without explicit specification of a third-body efficiency are implicitly assumed to have a value of 1.0 – i.e. the same as the reference collider. While the impact of values used for third-body efficiencies for commonly specified species like water or carbon dioxide is well recognized, the impact of unspecified or "missing" third-body colliders is considerably less known. Naturally, the lack of specification of third-body efficiencies for some species could conceivably yield significant prediction errors. Their impact could be especially pronounced given that many unspecified third bodies, which are likely to have more rovibrational degrees of freedom or have permanent dipole moments, may be more effective in inducing energy transfer than the monatomic or diatomic gases used as a reference. Here, we present a screening procedure to estimate the potential impact of unspecified third-body efficiencies; outline key results across an array of models, fuels, and initial conditions; and explore implications for model development, optimization, and validation. In general, we find that the impact of unspecified third-body efficiencies can be substantial – large enough to potentially contaminate parameter inference in optimization studies in some cases and resolve factor-of-three differences between models and experimental data in other cases. These results therefore have further implications for the list of relevant colliders to be considered in both future modeling and energy transfer studies. [ABSTRACT FROM AUTHOR]

As a consequence of the complexity of ecosystems and context-dependence of species interactions, structural uncertainty is pervasive in ecological modeling. This is particularly problematic when ecological models are used to make conservation and management plans whose outcomes may depend strongly on model formulation. Nonlinear time series approaches allow us to circumvent this issue by using the observed dynamics of the system to guide policy development. However, these methods typically require long time series from stationary systems, which are rarely available in ecological settings. Here we present a Bayesian approach to nonlinear forecasting based on Gaussian processes that readily integrates information from several short time series and allows for nonstationary dynamics. We demonstrate the utility of our modeling methods on simulated from a wide range of ecological scenarios. We expect that these models will extend the range of ecological systems to which nonlinear forecasting methods can be usefully applied. [ABSTRACT FROM AUTHOR]

Identifying appropriate strategies for sustainable harvest is a challenge for many terrestrial vertebrate species because of uncertain system dynamics, limited data to inform population models, and potentially conflicting objectives that seek to harvest and maintain populations at desirable levels. The absence of monitoring and assessment infrastructure needed to regularly estimate abundance accentuates this challenge for many species, and limits application of rigorous state-dependent frameworks for decision making that are commonly advocated in natural resource management. Reference points, which define management targets or triggers for changing management, are often used to guide decision-making, but suffer from ambiguity when developed without explicit consideration of uncertainty or trade-offs among competing objectives. We describe an approach for developing unambiguous target reference points for assessment-limited species using structured decision making, and demonstrate the approach to develop target harvest rates for management of fall Wild Turkey ( Meleagris gallopavo) harvests in the face of uncertain population and harvest dynamics. We use simulation and decision analyses to identify harvest rates that are optimal for accomplishing explicit management objectives in the face of uncertainty, and harvest rates with robust performance over broad regions of the demographic and harvest model parameter space. We demonstrate that population and harvest parameters commonly uncertain to wildlife managers interact to determine appropriate target harvest rates for Wild Turkeys, and that formally acknowledging a range of plausible values for structurally uncertain parameters results in more conservative target reference points than suggested by previously published studies. The structured decision making framework described here provides a natural conceptual and quantitative framework for extending our approach to develop unambiguous harvest targets for other assessment-limited wildlife populations while formally acknowledging structural uncertainty in system dynamics. [ABSTRACT FROM AUTHOR]

In this study, the effect of active and semi-active Fuzzy Logic Controllers (FLC) on the damage imposed on steel structures, considering structural uncertainties, are investigated. Two FLCs are designed for controlling the actuators and controllable viscous dampers as active and semi-active devices, respectively. Fragility curves are used to show the probability of damage imposed on uncontrolled and controlled structures. They are developed in consideration with three performance levels specified in FEMA 356, including Immediate Occupancy (IO), Life Safety (LS), and Collapse Prevention (CP). Considering deterministic and probabilistic parameters for the structure, fragility curves are generated separately to investigate the effect of structural uncertainties on the damage. To simulate the structure including the probabilistic parameters, Latin hypercube sampling is employed. Effectiveness of the controllers is illustrated and verified using the simulated response of a 3-story nonlinear benchmark building excited by several ground motions. To compare the performance of fuzzy controllers, fragility curves are also generated for the structure controlled by LQG and clipped-optimal controllers. Results show that FLCs can reduce the probability of damage significantly. Moreover, it is observed that the uncertainty in mass and yield strength has the greatest effect on the maximum drift of structure. [ABSTRACT FROM AUTHOR]

The article focuses on the valuation of forward-looking strategic patents under structural uncertainty of competitive advantage in the high-technology industry. It examines possible approaches, such as simple numerical method, pay-off method and rolling valuation, to the valuation of these patent portfolios. It also suggests that the methods are flexible tools that enable further analysis and decision-making in valuation of these portfolios.

Sustainability of socio-economic-ecological systems always implies a structural uncertainty coming mainly from the diversity of social values involved in the decision making processes required to manage the system. Such uncertainty cannot be reduced in any way, but needs to be managed if sustainability is to be pursued in its 'strong' meaning. This work proposes a methodology to manage structural uncertainty based upon the integration of elements from ecological economics, sociology and biology. This integration provides an approach to the strong sustainability of systems that is based on human consciousness from the perspective of the biology of knowledge and provides for a more holistic perspective for understanding and managing sustainability. [ABSTRACT FROM AUTHOR]

Based on robust control Lyapunov functions (RCLF), an equivalent condition for a function to be an RCLF is given and then a sufficient condition for the robust stabilization, robust practical stabilization and robust asymptotical stabilization is deduced. In addition, the continuous state feedback control law about the pointwise minimum norm is designed to globally asymptotically stabilize the equilibrium of the closed -- loop system. The simulation result shows the effectiveness of the method. [ABSTRACT FROM AUTHOR]

Finite element methods have often been used for structural analyses of various mechanical problems. When finite element analyses are utilized to resolve mechanical systems, numerical uncertainties in the initial data such as structural parameters and loading conditions may result in uncertainties in the structural responses. Therefore the initial data have to be as accurate as possible in order to obtain reliable structural analysis results. The typical finite element method may not properly represent discrete systems when using uncertain data, since all input data of material properties and applied loads are defined by nominal values. An interval finite element analysis, which uses the interval arithmetic as introduced by Moore (1966) is proposed as a non-stochastic method in this study and serves a new numerical tool for evaluating the uncertainties of the initial data in structural analyses. According to this method, the element stiffness matrix includes interval terms of the lower and upper bounds of the structural parameters, and interval change functions are devised. Numerical uncertainties in the initial data are described as a tolerance error and tree graphs of uncertain data are constructed by numerical uncertainty combinations of each parameter. The structural responses calculated by all uncertainty cases can be easily estimated so that structural safety can be included in the design. Numerical applications of truss and frame structures demonstrate the efficiency of the present method with respect to numerical analyses of structural uncertainties. [ABSTRACT FROM AUTHOR]

The article examines the bird-landscape relations in Chihuahuan Desert along Texas-Mexico border and their interannual consistency. It describes ways to cope with uncertainties undermining confidence in using the relations in conservation decision processes. It explains the influence of early spring rainfall differences to bird abundance. It also demonstrates the factors of bird-landscape relations consistency including plant succession, exotic species invasion, and habitat occupancy patterns.