Journal articles: 'Sensitivity to Uncertain Threat'

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Phan, Liem G., Charles A. Manzler, and Stephanie M. Gorka. "Neural and self-report indices of cognitive reappraisal moderate the association between sensitivity to uncertain threat and problem alcohol use." International Journal of Psychophysiology 175 (May 2022): 54–60. http://dx.doi.org/10.1016/j.ijpsycho.2022.03.002.

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Lan, Qin-ying, Ke Xia, Xiao-feng Wang, Jun-wei Liu, Jin Zhao, and Yun-hong Tan. "Seed storage behaviour of 101 woody species from the tropical rainforest of southern China: a test of the seed-coat ratio–seed mass (SCR–SM) model for determination of desiccation sensitivity." Australian Journal of Botany 62, no. 4 (2014): 305. http://dx.doi.org/10.1071/bt14037.

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The Xishuangbanna tropical rainforest in Yunnan Province is the greatest biodiversity hotspot in China. However, the biodiversity of this region is under threat, making seed conservation through seed and/or germplasm banking particularly urgent and crucial. Seed desiccation sensitivity limits the possibility of seed banking of 47% of tropical rainforest species. Thus, knowing if a species has desiccation-sensitive seeds is an important first step in seed banking; however, often resources are limited, making it difficult to determine storage behaviour for all the species in a region. Prediction of seed sensitivity using the SCR–SM model based on seed-coat ratio (SCR) and seed dry mass (SM) might be an alternative for determining desiccation sensitivity of seeds of each species. Here, seed-desiccation sensitivity of 101 woody species from the Xishuangbanna tropical forest were analysed using this model, and physiological determinations were made for a total of 25 species. Seed storage behaviour for 59 species was used for model validation, and storage behaviour of 88% of these species was successfully predicted. Seed storage behaviour of 83% of the 59 species was successfully predicted using the 1000-seed weigth–moisture content (TSW–MC) criteria, which include seeds with 1000-seed weight >500 g and seed moisture content at shedding of 30 –70%. The two predictive methods were subsequently used to predict seed desiccation sensitivity for another 42 species from Xishuangbanna whose storage behaviour was uncertain. Our results indicated that ~50% of the species in Xishuangbanna are likely to have desiccation-sensitive seeds.

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Savchenko, Olena. "THE MODEL OF PERSONAL PSYCHOLOGICAL SECURITY AS A COMPLEX PHENOMENON." PSYCHOLOGICAL JOURNAL 6, no. 12 (December 30, 2020): 66–79. http://dx.doi.org/10.31108/1.2020.6.12.7.

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Increasing number and frequency of threatening factors that occur in the world raises the issue of the necessity to study psychological security as a complex phenomenon that combines a number of components, determines human behavior in uncertain and threatening situations. The article analyzes the main approaches to the study of personality`s psychological security as a separate psychological phenomenon: 1) the study of the behavior of the safe type of personality; 2) the analysis of security as a characteristic of the environment where an individual grows and interacts; 3) axiological approach broadcasting of the safe living values; 4) a comprehensive psychological approach. The authors propose to consider the personality`s psychological security as a complex personal formation that combines motivational, cognitive, emotional and behavioral components that ensure the resilience of an individual to environmental factors, the optimal level of their functioning and the integrated type of interaction with the world, other individuals, themselves. The purpose of the study is to develop a model of personality`s psychological security, to analyze its internal structure. The methodological basis of the study is a systematic approach. The following diagnostic methods were used in the study: the method "Diagnosis of the degree of basis needs satisfaction" (V. Skvorczov, modification by I. Akindinova), "Scale of basic beliefs" (R. Janoff-Bulman, adaptation by O. Kravczova), test-questionnaire "Sensitivity to threats" (V. Maralov, E. Maly`sheva, O. Nifontova, E. Perchenko, I. Tabunov), test-questionnaire "Identifying of the ways of responding to situations of danger" (V. Maralov, E. Maly`sheva, O. Smirnova, E. Perchenko, I. Tabunov). The study has been conducted on the sample of 43 university students in Kyiv (Ukraine). A proposed conceptual model of personality`s psychological security combines 4 components: 1) the need for security (motivational component); 2) beliefs about the security of the world and one's own ability to interact constructively with others (cognitive component); 3) experiencing one's own security (emotional component); 4) readiness to activate self-defense tactics in the threatening situation (behavioral component). The use of factor analysis (Principal components method, Varimax normalized rotation procedure) has allowed to identify 3 independent factors that explain 68.6% of the total variance. The following components have been identified: motivational-cognitive, emotional-behavioral (constructive), destructive behavioral component that confirms the importance of behavioral aspects of psychological security, which reflect the means of human interaction with the world and other people in situations of real or imagined threat. The results of the application of correlation analysis have revealed the independence of the three components of personality`s psychological security. A general indicator that reflects the development level of psychological security as a complex phenomenon has been introduced. Students who demonstrate a high level of psychological security have the following characteristics: adequate satisfaction of the need for security, positive beliefs about the goodness of the world and the reliability of others, high sensitivity to threats, they often use adequate or uncertain means of responding to threats, try to avoid the anxious and ignoring behavioral strategies in threatening situations.

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Sosna, Matthew M. G., Colin R. Twomey, Joseph Bak-Coleman, Winnie Poel, Bryan C. Daniels, Pawel Romanczuk, and Iain D. Couzin. "Individual and collective encoding of risk in animal groups." Proceedings of the National Academy of Sciences 116, no. 41 (September 23, 2019): 20556–61. http://dx.doi.org/10.1073/pnas.1905585116.

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The need to make fast decisions under risky and uncertain conditions is a widespread problem in the natural world. While there has been extensive work on how individual organisms dynamically modify their behavior to respond appropriately to changing environmental conditions (and how this is encoded in the brain), we know remarkably little about the corresponding aspects of collective information processing in animal groups. For example, many groups appear to show increased “sensitivity” in the presence of perceived threat, as evidenced by the increased frequency and magnitude of repeated cascading waves of behavioral change often observed in fish schools and bird flocks under such circumstances. How such context-dependent changes in collective sensitivity are mediated, however, is unknown. Here we address this question using schooling fish as a model system, focusing on 2 nonexclusive hypotheses: 1) that changes in collective responsiveness result from changes in how individuals respond to social cues (i.e., changes to the properties of the “nodes” in the social network), and 2) that they result from changes made to the structural connectivity of the network itself (i.e., the computation is encoded in the “edges” of the network). We find that despite the fact that perceived risk increases the probability for individuals to initiate an alarm, the context-dependent change in collective sensitivity predominantly results not from changes in how individuals respond to social cues, but instead from how individuals modify the spatial structure, and correspondingly the topology of the network of interactions, within the group. Risk is thus encoded as a collective property, emphasizing that in group-living species individual fitness can depend strongly on coupling between scales of behavioral organization.

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Bardsley, Tim, Andrew Wood, Mike Hobbins, Tracie Kirkham, Laura Briefer, Jeff Niermeyer, and Steven Burian. "Planning for an Uncertain Future: Climate Change Sensitivity Assessment toward Adaptation Planning for Public Water Supply." Earth Interactions 17, no. 23 (October 1, 2013): 1–26. http://dx.doi.org/10.1175/2012ei000501.1.

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Abstract Assessing climate change risk to municipal water supplies is often conducted by hydrologic modeling specific to local watersheds and infrastructure to ensure that outputs are compatible with existing planning frameworks and processes. This study leverages the modeling capacity of an operational National Weather Service River Forecast Center to explore the potential impacts of future climate-driven hydrologic changes on factors important to planning at the Salt Lake City Department of Public Utilities (SLC). Hydrologic modeling results for the study area align with prior research in showing that temperature changes alone will lead to earlier runoff and reduced runoff volume. The sensitivity of average annual flow to temperature varies significantly between watersheds, averaging −3.8% °F−1 and ranging from −1.8% to −6.5% flow reduction per degree Fahrenheit of warming. The largest flow reductions occur during the high water demand months of May–September. Precipitation drives hydrologic response more strongly than temperature, with each 1% precipitation change producing an average 1.9% runoff change of the same sign. This paper explores the consequences of climate change for the reliability of SLC's water supply system using scenarios that include hydrologic changes in average conditions, severe drought scenarios, and future water demand test cases. The most significant water management impacts will be earlier and reduced runoff volume, which threaten the system's ability to maintain adequate streamflow and storage to meet late-summer water demands.

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Sjölander, Arvid, and Ola Hössjer. "Novel bounds for causal effects based on sensitivity parameters on the risk difference scale." Journal of Causal Inference 9, no. 1 (January 1, 2021): 190–210. http://dx.doi.org/10.1515/jci-2021-0024.

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Abstract Unmeasured confounding is an important threat to the validity of observational studies. A common way to deal with unmeasured confounding is to compute bounds for the causal effect of interest, that is, a range of values that is guaranteed to include the true effect, given the observed data. Recently, bounds have been proposed that are based on sensitivity parameters, which quantify the degree of unmeasured confounding on the risk ratio scale. These bounds can be used to compute an E-value, that is, the degree of confounding required to explain away an observed association, on the risk ratio scale. We complement and extend this previous work by deriving analogous bounds, based on sensitivity parameters on the risk difference scale. We show that our bounds can also be used to compute an E-value, on the risk difference scale. We compare our novel bounds with previous bounds through a real data example and a simulation study.

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Chisolm, Rachel E., and Daene C. McKinney. "Dynamics of avalanche-generated impulse waves: three-dimensional hydrodynamic simulations and sensitivity analysis." Natural Hazards and Earth System Sciences 18, no. 5 (May 17, 2018): 1373–93. http://dx.doi.org/10.5194/nhess-18-1373-2018.

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Abstract. This paper studies the lake dynamics for avalanche-triggered glacial lake outburst floods (GLOFs) in the Cordillera Blanca mountain range in Ancash, Peru. As new glacial lakes emerge and existing lakes continue to grow, they pose an increasing threat of GLOFs that can be catastrophic to the communities living downstream. In this work, the dynamics of displacement waves produced from avalanches are studied through three-dimensional hydrodynamic simulations of Lake Palcacocha, Peru, with an emphasis on the sensitivity of the lake model to input parameters and boundary conditions. This type of avalanche-generated wave is an important link in the GLOF process chain because there is a high potential for overtopping and erosion of the lake-damming moraine. The lake model was evaluated for sensitivity to turbulence model and grid resolution, and the uncertainty due to these model parameters is significantly less than that due to avalanche boundary condition characteristics. Wave generation from avalanche impact was simulated using two different boundary condition methods. Representation of an avalanche as water flowing into the lake generally resulted in higher peak flows and overtopping volumes than simulating the avalanche impact as mass–momentum inflow at the lake boundary. Three different scenarios of avalanche size were simulated for the current lake conditions, and all resulted in significant overtopping of the lake-damming moraine. Although the lake model introduces significant uncertainty, the avalanche portion of the GLOF process chain is likely to be the greatest source of uncertainty. To aid in evaluation of hazard mitigation alternatives, two scenarios of lake lowering were investigated. While large avalanches produced significant overtopping waves for all lake-lowering scenarios, simulations suggest that it may be possible to contain waves generated from smaller avalanches if the surface of the lake is lowered.

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Coe, Michael T., Toby R. Marthews, Marcos Heil Costa, David R. Galbraith, Nora L. Greenglass, Hewlley M. A. Imbuzeiro, Naomi M. Levine, et al. "Deforestation and climate feedbacks threaten the ecological integrity of south–southeastern Amazonia." Philosophical Transactions of the Royal Society B: Biological Sciences 368, no. 1619 (June 5, 2013): 20120155. http://dx.doi.org/10.1098/rstb.2012.0155.

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A mosaic of protected areas, including indigenous lands, sustainable-use production forests and reserves and strictly protected forests is the cornerstone of conservation in the Amazon, with almost 50 per cent of the region now protected. However, recent research indicates that isolation from direct deforestation or degradation may not be sufficient to maintain the ecological integrity of Amazon forests over the next several decades. Large-scale changes in fire and drought regimes occurring as a result of deforestation and greenhouse gas increases may result in forest degradation, regardless of protected status. How severe or widespread these feedbacks will be is uncertain, but the arc of deforestation in south–southeastern Amazonia appears to be particularly vulnerable owing to high current deforestation rates and ecological sensitivity to climate change. Maintaining forest ecosystem integrity may require significant strengthening of forest conservation on private property, which can in part be accomplished by leveraging existing policy mechanisms.

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Lai, Christopher K. C., Zigui Chen, Grace Lui, Lowell Ling, Timothy Li, Martin C. S. Wong, Rita W. Y. Ng, et al. "Prospective Study Comparing Deep Throat Saliva With Other Respiratory Tract Specimens in the Diagnosis of Novel Coronavirus Disease 2019." Journal of Infectious Diseases 222, no. 10 (August 1, 2020): 1612–19. http://dx.doi.org/10.1093/infdis/jiaa487.

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Abstract Background Self-collected specimens have been advocated to avoid infectious exposure to healthcare workers. Self-induced sputum in those with a productive cough and saliva in those without a productive cough have been proposed, but sensitivity remains uncertain. Methods We performed a prospective study in 2 regional hospitals in Hong Kong. Results We prospectively examined 563 serial samples collected during the virus shedding periods of 50 patients: 150 deep throat saliva (DTS), 309 pooled-nasopharyngeal (NP) and throat swabs, and 104 sputum. Deep throat saliva had the lowest overall reverse-transcriptase polymerase chain reaction (RT-PCR)-positive rate (68.7% vs 89.4% [sputum] and 80.9% [pooled NP and throat swabs]) and the lowest viral ribonucleic acid (RNA) concentration (mean log copy/mL 3.54 vs 5.03 [sputum] and 4.63 [pooled NP and throat swabs]). Analyses with respect to time from symptom onset and severity also revealed similar results. Virus yields of DTS correlated with that of sputum (Pearson correlation index 0.76; 95% confidence interval, 0.62–0.86). We estimated that the overall false-negative rate of DTS could be as high as 31.3% and increased 2.7 times among patients without sputum. Conclusions Deep throat saliva produced the lowest viral RNA concentration and RT-PCR-positive rate compared with conventional respiratory specimens in all phases of illness. Self-collected sputum should be the choice for patients with sputum.

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Ibne Hossain, Niamat Ullah, Morteza Nagahi, Raed Jaradat, Chiranjibi Shah, Randy Buchanan, and Michael Hamilton. "Modeling and assessing cyber resilience of smart grid using Bayesian network-based approach: a system of systems problem." Journal of Computational Design and Engineering 7, no. 3 (April 4, 2020): 352–66. http://dx.doi.org/10.1093/jcde/qwaa029.

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Abstract Due to the widespread of new technologies, the modern electric power system has become much more complex and uncertain. The Integration of technologies in the electric power system has increased the exposure of cyber threats and correlative susceptibilities from malicious cyber-attacks. To better address these cyber risks and minimize the effects of the power system outage, this research identifies the potential causes and mitigation techniques for the smart grid (SG) and assesses the overall cyber resilience of smart grid systems using a Bayesian network approach. Bayesian network is a powerful analytical tool predominantly used in risk, reliability, and resilience assessment under uncertainty. The quantification of the model is examined, and the results are analyzed through different advanced techniques such as predictive inference reasoning and sensitivity analysis. Different scenarios have been developed and analyzed to identify critical variables that are susceptible to the cyber resilience of a smart grid system of systems. Insight drawn from these analyses suggests that overall cyber resilience of the SG system of systems is dependent upon the status of identified factors, and more attention should be directed towards developing the countermeasures against access domain vulnerability. The research also shows the efficacy of a Bayesian network to assess and enhance the overall cyber resilience of the smart grid system of systems.

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Sinha, Gunjan. "Uncertain Threat." Scientific American 290, no. 1 (January 2004): 18–20. http://dx.doi.org/10.1038/scientificamerican0104-18.

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Kumar, Vikram, and Sumit Sen. "Assessment of Spring Potential for Sustainable Agriculture: A Case Study in Lesser Himalayas." Applied Engineering in Agriculture 36, no. 1 (2020): 11–24. http://dx.doi.org/10.13031/aea.13520.

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HighlightsSpring flows are the primary source of water for rural Himalayan communities.An attempt was made to understand the potential of spring discharge as an alternative irrigation source.Improved management of resources is vital to account for agricultural water use.Managing water resources is a collective endeavor for achieving water security.Abstract.With increasing population and restricted water and land resources, there is a growing concern for better planning of the available water and land resources. In the mountainous regions or mountains, there is limited land with uncertain water availability as the rainfall patterns pose a major threat to the livelihood of the people. Therefore, it becomes necessary to quantify and manage the available water resources in a sustainable way. People in the Himalayas are mainly dependent on the springs for drinking water, but not much attention has been dedicated to the development and conservation of these springs. A spring in the Tehri-Garhwal district of Uttarakhand state of India, has been continuously monitored to quantify the available water for domestic use and agriculture. In this study, an attempt is made to understand the potential of a spring for agricultural water use by evaluating the crop water requirement and potential improved strategies to increase the water productivity. Analysis proves that crop evapotranspiration is higher (946-1062 mm) for crops with extended duration (165-180 days) as compared to evapotranspiration (92.91 mm) of short duration (60 days) crops. The total water requirement for major crops in the area is 6411.35 mm and the monitored spring has the potential to supplement this water requirement. Adopting the system of rice intensification to increase the rice yield (by 49%), increases the water productivity. The sensitivity analysis of benefit to cost suggests that, an increase in the crop yield by 30% can increase the revenue in the study area by Rs.3687197, which is 217% more than the input costs. Therefore, it is essential to optimize the available water and area for irrigation to achieve the global water security for increasing population. Further, utilizing springs as potential irrigation sources will support rural community in meeting domestic water requirement and achieving environmental sustainability. Findings of this study will help in planning and implementing management strategies that are resilient in the face of future changes and improve the economic condition of farmers. Keywords: Crop evapotranspiration, Himalaya, Optimization, Sensitivity analysis, Spring.

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Meunier, Félicien, Wim Verbruggen, Hans Verbeeck, and Marc Peaucelle. "Low sensitivity of three terrestrial biosphere models to soil texture over the South American tropics." Geoscientific Model Development 15, no. 20 (October 19, 2022): 7573–91. http://dx.doi.org/10.5194/gmd-15-7573-2022.

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Abstract. Drought stress is an increasing threat for vegetation in tropical regions, within the context of human-induced increase of drought frequency and severity observed over South American forests. Drought stress is induced when a plant's water demand is not met with its water supply through root water uptake. The latter depends on root and soil properties, including soil texture (i.e. the soil clay and sand fractions) that determines the soil water availability and its hydraulic properties. Hence, soil clay content is responsible for a significant fraction of the spatial variability in forest structure and productivity. Soil-textural properties largely vary at the spatial resolution used by Terrestrial Biosphere Models (TBMs) and it is currently unclear how this variability affects the outputs of these models used to predict the response of vegetation ecosystems to future climate change scenarios. In this study, we assessed the sensitivity of the carbon cycle of three state-of-the-art TBMs, i.e. ORganizing Carbon and Hydrology in Dynamic EcosystEms (ORCHIDEEv2.2), Ecosystem Demography model version 2 (ED2), and Lund–Potsdam–Jena General Ecosystem Simulator (LPJ-GUESS) to soil-textural properties at the regional level over the South American tropics using model default pedotransfer functions. For all three TBMs, the model outputs, including gross primary productivity (GPP), aboveground biomass (AGB), soil carbon content and drought stress, were shown to be mostly insensitive to soil-texture changes representative of the spatial variability in soil properties, except for a small region characterised by very low water availability in ORCHIDEEv2.2 and ED2. We argue that generic pedotransfer and simple drought stress functions, as currently implemented in TBMs, should be reconsidered to better capture the role of soil texture and its coupling to plant processes. Similarly, we suggest that better estimates of the soil-texture uncertainty resulting from soil-texture data aggregate should be considered in the future. Those steps forward are critical to properly account for future increasing drought stress conditions in tropical regions.

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van Rees, Charles B., and J. Michael Reed. "Predicted effects of landscape change, sea level rise, and habitat management on the extirpation risk of the Hawaiian common gallinule (Gallinula galeata sandvicensis) on the island of O‘ahu." PeerJ 6 (June 22, 2018): e4990. http://dx.doi.org/10.7717/peerj.4990.

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We conducted a spatially explicit, stochastic, individually based population viability analysis for the Hawaiian common gallinule (Gallinula galeata sandvicensis), an endangered subspecies of waterbird endemic to fragmented coastal wetlands in Hawai‘i. This subspecies persists on two islands, with no apparent movement between them. We assessed extirpation risk for birds on O‘ahu, where the resident gallinule population is made up of several fragmented subpopulations. Data on genetic differentiation were used to delineate subpopulations and estimate dispersal rates between them. We used sensitivity analyses to gauge the impact of current uncertainty of vital rate parameters on population projections, to ascertain the relative importance of gallinule vital rates to population persistence, and to compare the efficacy of potential management strategies. We used available sea level rise projections to examine the relative vulnerability of O‘ahu’s gallinule population to habitat loss arising from this threat. Our model predicted persistence of the island’s gallinule population at 160 years (∼40 generations), but with high probabilities of extirpation for small subpopulations. Sensitivity analyses highlighted the importance of juvenile and adult mortality to population persistence in Hawaiian gallinules, justifying current predator control efforts and suggesting the need for additional research on chick and fledgling survival. Subpopulation connectivity from dispersal had little effect on the persistence of the island-wide population, but strong effects on the persistence of smaller subpopulations. Our model also predicted island-wide population persistence under predicted sea level rise scenarios, but with O‘ahu’s largest gallinule populations losing >40% of current carrying capacity.

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Zhu, Rongchen, Xiaofeng Hu, Xin Li, Han Ye, and Nan Jia. "Modeling and Risk Analysis of Chemical Terrorist Attacks: A Bayesian Network Method." International Journal of Environmental Research and Public Health 17, no. 6 (March 19, 2020): 2051. http://dx.doi.org/10.3390/ijerph17062051.

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The chemical terrorist attack is an unconventional form of terrorism with vast scope of influence, strong concealment, high technical means and severe consequences. Chemical terrorism risk refers to the uncertainty of the effects of terrorist organisations using toxic industrial chemicals/drugs and classic chemical weapons to attack the population. There are multiple risk factors infecting chemical terrorism risk, such as the threat degree of terrorist organisations, attraction of targets, city emergency response capabilities, and police defense capabilities. We have constructed a Bayesian network of chemical terrorist attacks to conduct risk analysis. The scenario analysis and sensitivity analysis are applied to validate the model and analyse the impact of the vital factor on the risk of chemical terrorist attacks. The results show that the model can be used for simulation and risk analysis of chemical terrorist attacks. In terms of controlling the risk of chemical terrorist attack, patrol and surveillance are less critical than security checks and police investigations. Security check is the most effective approach to decrease the probability of successful attacks. Different terrorist organisations have different degrees of threat, but the impacts of which are limited to the success of the attack. Weapon types and doses are sensitive to casualties, but it is the level of emergency response capabilities that dominates the changes in casualties. Due to the limited number of defensive resources, to get the best consequence, the priority of the deployment of defensive sources should be firstly given to governmental buildings, followed by commercial areas. These findings may provide the theoretical basis and method support for the combat of the public security department and the safety prevention decision of the risk management department.

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Johnson, Stephanie S., Katelin C. Jackson, Matthew S. Mietchen, Samir Sbai, Elissa J. Schwartz, and Eric T. Lofgren. "Excess Risk of COVID-19 to University Populations Resulting from In-Person Sporting Events." International Journal of Environmental Research and Public Health 18, no. 16 (August 4, 2021): 8260. http://dx.doi.org/10.3390/ijerph18168260.

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Background: One of the consequences of COVID-19 has been the cancelation of collegiate sporting events. We explore the impact of sports on COVID-19 transmission on a college campus. Methods: Using a compartmental model representing the university, we model the impact of influxes of 10,000 visitors attending events and ancillary activities (dining out, visiting family, shopping, etc.) on 20,000 students. We vary the extent visitors interact with the campus, the number of infectious visitors, and the extent to which the campus has controlled COVID-19 absent events. We also conduct a global sensitivity analysis. Results: Events caused an increase in the number of cases ranging from a 25% increase when the campus already had an uncontrolled COVID-19 outbreak and visitors had a low prevalence of COVID-19 and mixed lightly with the campus community to an 822% increase where the campus had controlled their COVID-19 outbreak and visitors had both a high prevalence of COVID-19 and mixed heavily with the campus community. The model was insensitive to parameter uncertainty, save for the duration a symptomatic individual was infectious. Conclusion: Sporting events represent a threat to the health of the campus community. This is the case even in circumstances where COVID-19 seems controlled both on-campus and among the general population.

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Regehr, Eric V., Kristin L. Laidre, H. Resit Akçakaya, Steven C. Amstrup, Todd C. Atwood, Nicholas J. Lunn, Martyn Obbard, Harry Stern, Gregory W. Thiemann, and Øystein Wiig. "Conservation status of polar bears ( Ursus maritimus ) in relation to projected sea-ice declines." Biology Letters 12, no. 12 (December 2016): 20160556. http://dx.doi.org/10.1098/rsbl.2016.0556.

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Loss of Arctic sea ice owing to climate change is the primary threat to polar bears throughout their range. We evaluated the potential response of polar bears to sea-ice declines by (i) calculating generation length (GL) for the species, which determines the timeframe for conservation assessments; (ii) developing a standardized sea-ice metric representing important habitat; and (iii) using statistical models and computer simulation to project changes in the global population under three approaches relating polar bear abundance to sea ice. Mean GL was 11.5 years. Ice-covered days declined in all subpopulation areas during 1979–2014 (median −1.26 days year −1 ). The estimated probabilities that reductions in the mean global population size of polar bears will be greater than 30%, 50% and 80% over three generations (35–41 years) were 0.71 (range 0.20–0.95), 0.07 (range 0–0.35) and less than 0.01 (range 0–0.02), respectively. According to IUCN Red List reduction thresholds, which provide a common measure of extinction risk across taxa, these results are consistent with listing the species as vulnerable. Our findings support the potential for large declines in polar bear numbers owing to sea-ice loss, and highlight near-term uncertainty in statistical projections as well as the sensitivity of projections to different plausible assumptions.

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Garay, Osvaldo Ulises, Gonzalo Guiñazú, Wanda Cornistein, Javier Farina, Ricardo Valentini, and Gabriel Levy Hara. "Budget impact analysis of using procalcitonin to optimize antimicrobial treatment for patients with suspected sepsis in the intensive care unit and hospitalized lower respiratory tract infections in Argentina." PLOS ONE 16, no. 4 (April 30, 2021): e0250711. http://dx.doi.org/10.1371/journal.pone.0250711.

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Background Inappropriate antibiotic use represents a major global threat. Sepsis and bacterial lower respiratory tract infections (LRTIs) have been linked to antimicrobial resistance, carrying important consequences for patients and health systems. Procalcitonin-guided algorithms may represent helpful tools to reduce antibiotic overuse but the financial burden is unclear. The aim of this study was to estimate the healthcare and budget impact in Argentina of using procalcitonin-guided algorithms to guide antibiotic prescription. Methods A decision tree was used to model health and cost outcomes for the Argentinean health system, over a one-year duration. Patients with suspected sepsis in the intensive care unit and hospitalized patients with LRTI were included. Model parameters were obtained from a focused, non-systematic, local and international bibliographic search, and validated by a panel of local experts. Deterministic and probabilistic sensitivity analyses were performed to analyze the uncertainty of parameters. Results The model predicted that using procalcitonin-guided algorithms would result in 734.5 [95% confidence interval (CI): 1,105.2;438.8] thousand fewer antibiotic treatment days, 7.9 [95% CI: 18.5;8.5] thousand antibiotic-resistant cases avoided, and 5.1 [95% CI: 6.7;4.2] thousand fewer Clostridioides difficile cases. In total, this would save $422.4 US dollars (USD) [95% CI: $935;$267] per patient per year, meaning cost savings of $83.0 [95% CI: $183.6;$57.7] million USD for the entire health system and $0.4 [95% CI: $0.9;$0.3] million USD for a healthcare provider with 1,000 cases per year of sepsis and LRTI patients. The sensitivity analysis showed that the probability of cost-saving for the sepsis patient group was lower than for the LRTI patient group (85% vs. 100%). Conclusions Healthcare and financial benefits can be obtained by implementing procalcitonin-guided algorithms in Argentina. Although we found results to be robust on an aggregate level, some caution must be used when focusing only on sepsis patients in the intensive care unit.

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Trivedi, Ishita, Jason Hou, Giacomo Grasso, Kostadin Ivanov, and Fausto Franceschini. "Nuclear Data Uncertainty Quantification and Propagation for Safety Analysis of Lead-Cooled Fast Reactors." Science and Technology of Nuclear Installations 2020 (August 12, 2020): 1–14. http://dx.doi.org/10.1155/2020/3961095.

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In this study, the Best Estimate Plus Uncertainty (BEPU) approach is developed for the systematic quantification and propagation of uncertainties in the modelling and simulation of lead-cooled fast reactors (LFRs) and applied to the demonstration LFR (DLFR) initially investigated by Westinghouse. The impact of nuclear data uncertainties based on ENDF/B-VII.0 covariances is quantified on lattice level using the generalized perturbation theory implemented with the Monte Carlo code Serpent and the deterministic code PERSENT of the Argonne Reactor Computational (ARC) suite. The quantities of interest are the main eigenvalue and selected reactivity coefficients such as Doppler, radial expansion, and fuel/clad/coolant density coefficients. These uncertainties are then propagated through safety analysis, carried out using the MiniSAS code, following the stochastic sampling approach in DAKOTA. An unprotected transient overpower (UTOP) scenario is considered to assess the effect of input uncertainties on safety parameters such as peak fuel and clad temperatures. It is found that in steady state, the multiplication factor shows the most sensitivity to perturbations in 235U fission, 235U ν, and 238U capture cross sections. The uncertainties of 239Pu and 238U capture cross sections become more significant as the fuel is irradiated. The covariance of various reactivity feedback coefficients is constructed by tracing back to common uncertainty contributors (i.e., nuclide-reaction pairs), including 238U inelastic, 238U capture, and 239Pu capture cross sections. It is also observed that nuclear data uncertainty propagates to uncertainty on peak clad and fuel temperatures of 28.5 K and 70.0 K, respectively. Such uncertainties do not impose per se threat to the integrity of the fuel rod; however, they sum to other sources of uncertainties in verifying the compliance of the assumed safety margins, suggesting the developed BEPU method necessary to provide one of the required insights on the impact of uncertainties on core safety characteristics.

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Deyglun, C. "Testing and performances of Spectroscopic Radiation Portal Monitor for homeland security." EPJ Web of Conferences 225 (2020): 07008. http://dx.doi.org/10.1051/epjconf/202022507008.

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Each year States report to IAEA loss, theft or out of regulatory control radioactive materials. Most incidents are minor, but material is potentially available for criminal acts. Measures to reduce the radiological and nuclear threat are many-faceted. An important component is the ability to detect illicit transport of radioactive material. Spectroscopic Radiation Portal Monitors are deployed around the world to detect illegal radioactive material traffic. A combination of experimental data collected during testing campaigns and simulations is a good way to study the performance of Spectroscopic Radiation Portal Monitors in realistic conditions. The paper presents a process to evaluate the performances of a portal, based on a combination of experimental data and MCNP simulations to calculate the detection probability and the false alarm rate. IRSN developed platforms for testing Spectroscopic Radiation Portal Monitors for pedestrian control. Experimental data were collected from an available commercial Spectroscopic Radiation Portal Monitor, tested in the framework of the Illicit Trafficking Radiation Assessment Program phase II Round Robin Test. Many scenarios were tested with different sources using realistic setups and many experimental data were collected. The tested equipment was then simulated with MCNP only based on the data provided in the user manual and the standards found in the industry. To get a realistic idea of the uncertainty, all the variables inherent in the measurement were considered, their relative contributions were identified and quantified, then propagated to predict an overall uncertainty. The combination of experimental data, numerical simulations and uncertainty evaluation showed good agreement with experimental assays. The results were used to test the sensitivity of a Spectroscopic Radiation Portal Monitor to special nuclear materials for different alarm thresholds. This process applied to different scenarios according to defined targets should help in the selection of operating characteristics of the portal.

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Rebecca Dresser. "Neuroscience's Uncertain Threat to Criminal Law." Hastings Center Report 38, no. 6 (2008): 9–10. http://dx.doi.org/10.1353/hcr.0.0076.

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Deng, Yong. "A Threat Assessment Model under Uncertain Environment." Mathematical Problems in Engineering 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/878024.

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Threat evaluation is extremely important to decision makers in many situations, such as military application and physical protection systems. In this paper, a new threat assessment model based on interval number to deal with the intrinsic uncertainty and imprecision in combat environment is proposed. Both objective and subjective factors are taken into consideration in the proposed model. For the objective factors, the genetic algorithm (GA) is used to search out an optimal interval number representing all the attribute values of each object. In addition, for the subjective factors, the interval Analytic Hierarchy Process (AHP) is adopted to determine each object’s threat weight according to the experience of commanders/experts. Then a discounting method is proposed to integrate the objective and subjective factors. At last, the ideal of Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is applied to obtain the threat ranking of all the objects. A real application is used to illustrate the effectiveness of the proposed model.

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Okada, Kenji, and Robert E. Skelton. "Sensitivity controller for uncertain systems." Journal of Guidance, Control, and Dynamics 13, no. 2 (March 1990): 321–29. http://dx.doi.org/10.2514/3.20552.

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Kambouropoulos, Nicolas, Sarah Egan, Elodie J. O’Connor, and Petra K. Staiger. "Escaping Threat." Journal of Individual Differences 35, no. 1 (March 1, 2014): 47–53. http://dx.doi.org/10.1027/1614-0001/a000126.

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Individuals with a hypersensitivity to threatening stimuli in the environment may be more likely to experience a higher level of social anxiety. According to Reinforcement Sensitivity Theory (RST), there are two important aspects of threat stimuli that influence subsequent emotional and behavioral responses. Specifically, perceptions pertaining to defensive direction and distance are considered critical factors in understanding threat responses. This paper aimed to determine whether threat perceptions mediate the relationship between threat sensitivity and social anxiety. Self-report measures of sensitivity to threat, social anxiety, and a vignette designed to assess threat perceptions were administered to a sample of 218 participants (73% female; M age = 33.75, SD age = 11.52). Data indicated a mediational influence of perceived escapability on the relationship between sensitivity to threat and social anxiety. Overall, these findings highlight the role of perceived escapability of threat in understanding the relationship between threat sensitivity and social anxiety.

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Tanaka, Makoto. "The Effects of Uncertain Divestiture as Regulatory Threat." Journal of Industry, Competition and Trade 11, no. 4 (October 27, 2010): 385–97. http://dx.doi.org/10.1007/s10842-010-0089-7.

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Muhtadie, Luma, and Sheri L. Johnson. "Threat sensitivity in bipolar disorder." Journal of Abnormal Psychology 124, no. 1 (February 2015): 93–101. http://dx.doi.org/10.1037/a0038065.

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Tiunova, M. G. "THE IMPACT OF EXTERNAL SHOCKS ON THE RUSSIAN ECONOMY." Finance: Theory and Practice 22, no. 4 (October 3, 2018): 146–70. http://dx.doi.org/10.26794/2587-5671-2018-22-4-146-170.

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The article is devoted to the study of the degree of sensitivity of the Russian economy to exogenous shocks from the external environment. Indicators of the dynamics of foreign markets are changes in the global market of raw materials, financial markets of developed countries, and the propensity of foreign investors to risk. The topic of our study is relevant against the background of the current key risks for the world economy and financial system: uncertainty of the global energy market prospects due to the growth of oil production in the united States; normalization of monetary policy by developed countries, which in the future can provoke capital outflow from emerging markets; the threat of global protectionism. The article describes the potential consequences of these events for the world economy and financial system. The study uses statistical data on the real and financial sectors of the Russian economy, as well as foreign markets for the period 2002–2018. The parameters of external market conditions are world trade conditions, the volatility of the global stock and currency markets, the level of business activity in the Eurozone region, and the degree of risk and uncertainty in emerging markets. The research methodology is based on Bayesian structural vector autoregressions. The graphs of the impulse response function allow us to determine the direction of the key parameters of the Russian economy (industry, inflation, exchange rate, and sovereign risk premium) in response to changes in external environment. The contribution of external shocks to the dynamics of macroeconomic indicators is determined on the basis of the decomposition of the error variance of the model endogenous variables forecast. Our analysis confirmed the significant dependence between the dynamics of the key indicators of the Russian economy and the external markets. The author concludes that the inflation targeting regime and the policy of budget rules have a positive impact on the protection of the Russian economy from global risks.

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Fan, X., C. X. Tang, C. J. van Westen, and D. Alkema. "Simulating dam-breach flood scenarios of the Tangjiashan landslide dam induced by the Wenchuan Earthquake." Natural Hazards and Earth System Sciences 12, no. 10 (October 2, 2012): 3031–44. http://dx.doi.org/10.5194/nhess-12-3031-2012.

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Abstract. Floods from failures of landslide dams can pose a hazard to people and property downstream, which have to be rapidly assessed and mitigated in order to reduce the potential risk. The Tangjiashan landslide dam induced by the Mw = 7.9 2008 Wenchuan earthquake had impounded the largest lake in the earthquake affected area with an estimated volume of 3 × 108 m3, and the potential catastrophic dam breach posed a serious threat to more than 2.5 million people in downstream towns and Mianyang city, located 85 km downstream. Chinese authorities had to evacuate parts of the city until the Tangjiashan landslide dam was artificially breached by a spillway, and the lake was drained. We propose an integrated approach to simulate the dam-breach floods for a number of possible scenarios, to evaluate the severity of the threat to Mianyang city. Firstly, the physically-based BREACH model was applied to predict the flood hydrographs at the dam location, which were calibrated with observational data of the flood resulting from the artificial breaching. The output hydrographs from this model were inputted into the 1-D–2-D SOBEK hydrodynamic model to simulate the spatial variations in flood parameters. The simulated flood hydrograph, peak discharge and peak arrival time at the downstream towns fit the observations. Thus this approach is capable of providing reliable predictions for the decision makers to determine the mitigation plans. The sensitivity analysis of the BREACH model input parameters reveals that the average grain size, the unit weight and porosity of the dam materials are the most sensitive parameters. The variability of the dam material properties causes a large uncertainty in the estimation of the peak flood discharge and peak arrival time, but has little influence on the flood inundation area and flood depth downstream. The effect of cascading breaches of smaller dams downstream of the Tangjiashan dam was insignificant, due to their rather small volumes, which were only 2% of the volume of the Tangjiashan lake. The construction of the spillway was proven to have played a crucial role in reducing the dam-breach flood, because all the other natural breach scenarios would have caused the flooding of the downstream towns and parts of Mianyang city. However, in retrospect improvements on the spillway design and the evacuation planning would have been possible. The dam-break flood risk will be better controlled by reducing the spillway channel gradient and the porosity of the coating of the channel bottom. The experience and lessons we learned from the Tangjiashan case will contribute to improving the hazard mitigation and risk management planning of similar events in future.

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Gorka, S. M., D. Hee, L. Lieberman, V. A. Mittal, K. L. Phan, and S. A. Shankman. "Reactivity to uncertain threat as a familial vulnerability factor for alcohol use disorder." Psychological Medicine 46, no. 16 (September 14, 2016): 3349–58. http://dx.doi.org/10.1017/s0033291716002415.

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BackgroundWhen sober, problematic drinkers display exaggerated reactivity to threats that are uncertain (U-threat). Since this aversive affective state can be alleviated via acute alcohol intoxication, it has been posited that individuals who exhibit heightened reactivity to U-threat at baseline are motivated to use alcohol as a means of avoidance-based coping, setting the stage for excessive drinking. To date, however, no study has attempted to characterize the dispositional nature of exaggerated reactivity to U-threat and test whether it is a vulnerability factor or exclusively a disease marker of problematic alcohol use.MethodThe current investigation utilized a family study design to address these gaps by examining whether (1) reactivity to U-threat is associated with risk for problematic alcohol use, defined by family history of alcohol use disorder (AUD) and (2) reactivity to U-threat is correlated amongst adult biological siblings. A total of 157 families, and 458 individuals, participated in the study and two biological siblings completed a threat-of-shock task designed to probe reactivity to U-threat and predictable threat (P-threat). Startle potentiation was collected as an index of aversive responding.ResultsWithin biological siblings, startle potentiation to U-threat [intraclass correlation (ICC) = 0.35] and P-threat (ICC = 0.63) was significantly correlated. In addition, independent of an individuals’ own AUD status, startle potentiation to U-threat, but not P-threat, was positively associated with risk for AUD (i.e. AUD family history).ConclusionThis suggests that heightened reactivity to U-threat may be a familial vulnerability factor for problematic drinking and a novel prevention target for AUD.

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Carver, Charles S. "Threat Sensitivity, Incentive Sensitivity, and the Experience of Relief." Journal of Personality 77, no. 1 (February 2009): 125–38. http://dx.doi.org/10.1111/j.1467-6494.2008.00540.x.

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Alavalapati, Janaki R. R., Shibu Jose, George A. Stainback, Jagannadha R. Matta, and Douglas R. Carter. "Economics of Cogongrass Control in Slash Pine Forests." Journal of Agricultural and Applied Economics 39, s1 (October 2007): 61–68. http://dx.doi.org/10.1017/s1074070800028947.

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Cogongrass (Imperata cylindrica), an invasive weed, is a threat to slash pine forests. Using a dynamic optimization model, we estimated the impact of cogongrass on the profitability of slash pine forestry under four scenarios: no threat of cogongrass infestation; infestation is uncertain, and no control measures are taken; infestation is uncertain, but control measures are undertaken by one landowner but not the neighbors; and infestation is uncertain, and control measures are undertaken by everyone. Results indicate that annual net returns per acre under each scenario, respectively, are $25.30, $16.97, $13.89, and $17.38. Results suggest fostering a cooperative behavior among landowners is desirable.

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Kashou, Anthony H., Demilade A. Adedinsewo, and Peter A. Noseworthy. "Subclinical Atrial Fibrillation: A Silent Threat with Uncertain Implications." Annual Review of Medicine 73, no. 1 (January 27, 2022): 355–62. http://dx.doi.org/10.1146/annurev-med-042420-105906.

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Atrial fibrillation (AF) is one of the most common cardiac arrhythmias. Implantable and wearable cardiac devices have enabled the detection of asymptomatic AF episodes—termed subclinical AF (SCAF). SCAF, the prevalence of which is likely significantly underestimated, is associated with increased cardiovascular and all-cause mortality and a significant stroke risk. Recent advances in machine learning, namely artificial intelligence–enabled ECG (AI-ECG), have enabled identification of patients at higher likelihood of SCAF. Leveraging the capabilities of AI-ECG algorithms to drive screening protocols could eventually allow for earlier detection and treatment and help reduce the burden associated with AF.

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Oglesby, Mary E., Amanda M. Raines, Nicole A. Short, Daniel W. Capron, and Norman B. Schmidt. "Interpretation bias for uncertain threat: A replication and extension." Journal of Behavior Therapy and Experimental Psychiatry 51 (June 2016): 35–42. http://dx.doi.org/10.1016/j.jbtep.2015.12.006.

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Hur, Juyoen, Jason F. Smith, Kathryn A. DeYoung, Allegra S. Anderson, Jinyi Kuang, Hyung Cho Kim, Rachael M. Tillman, Manuel Kuhn, Andrew S. Fox, and Alexander J. Shackman. "Anxiety and the Neurobiology of Temporally Uncertain Threat Anticipation." Journal of Neuroscience 40, no. 41 (September 21, 2020): 7949–64. http://dx.doi.org/10.1523/jneurosci.0704-20.2020.

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Hur, Juyoen, Jason F. Smith, Kathryn A. DeYoung, Jinyi Kuang, Allegra A. Anderson, Rachael M. Tillman, Hyung Cho Kim, and Alexander J. Shackman. "S23. The Neurobiological Substrates of Uncertain and Certain Threat." Biological Psychiatry 85, no. 10 (May 2019): S305. http://dx.doi.org/10.1016/j.biopsych.2019.03.774.

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Jung, Jiin, Michael A. Hogg, Andrew G. Livingstone, and Hoon‐Seok Choi. "From uncertain boundaries to uncertain identity: Effects of entitativity threat on identity–uncertainty and emigration." Journal of Applied Social Psychology 49, no. 10 (August 7, 2019): 623–33. http://dx.doi.org/10.1111/jasp.12622.

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Greegar, G., and C. S. Manohar. "Global response sensitivity analysis of uncertain structures." Structural Safety 58 (January 2016): 94–104. http://dx.doi.org/10.1016/j.strusafe.2015.09.006.

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Pritchard, Joselyn I., Howard M. Adelman, and Jaroslaw Sobieszczanski-Sobieski. "Optimization for minimum sensitivity to uncertain parameters." AIAA Journal 34, no. 7 (July 1996): 1501–4. http://dx.doi.org/10.2514/3.13259.

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Niedbala, Elizabeth M., and Zachary P. Hohman. "Retaliation against the outgroup: The role of self-uncertainty." Group Processes & Intergroup Relations 22, no. 5 (May 9, 2018): 708–23. http://dx.doi.org/10.1177/1368430218767027.

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Outgroups who threaten the core aspects of one’s identity, such as one’s social group and its values, may make group members feel self-uncertain. Because past research associates uncertainty with defensive behavior, we propose that self-uncertainty will drive aggressive retaliation against a threatening outgroup. Two experiments tested the role of self-uncertainty in retaliation motivation. In Experiment 1, university students were threatened by their school rival and then reported self-uncertainty and willingness to retaliate. The threat evoked anger and caused male group members to feel significantly more self-uncertain, which was associated with significantly greater retaliation motivation. In Experiment 2, we manipulated Americans’ feelings of self-uncertainty and threat from a terrorist group, ISIS. Uncertain males were significantly more willing to retaliate against ISIS after threats that caused anger and fear. For male group members, outgroup threat increases self-uncertainty, which then motivates them to be more willing to violently retaliate.

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Goel, Sanjay, and Eitel J. M. Lauría. "Quantification, Optimization and Uncertainty Modeling in Information Security Risks." Information Resources Management Journal 23, no. 2 (April 2010): 33–52. http://dx.doi.org/10.4018/irmj.2010040103.

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In this paper, the authors present a quantitative model for estimating security risk exposure for a firm. The model includes a formulation for the optimization of controls as well as determining sensitivity of the exposure of assets to different threats. The model uses a series of matrices to organize the data as groups of assets, vulnerabilities, threats, and controls. The matrices are then linked such that data is aggregated in each matrix and cascaded across the other matrices. The computations are reversible and transparent allowing analysts to answer what-if questions on the data. The exposure formulation is based on the Annualized Loss Expectancy (ALE) model, and uncertainties in the data are captured via Monte Carlo simulation. A mock case study based on a government agency is used to illustrate this methodology.

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Zhu, Jing Yao, Qi Fang He, Tie Zhu Wang, and Zu Tong Wang. "Multiobjective Mission Planning for UAV under Uncertain Environment." Applied Mechanics and Materials 556-562 (May 2014): 4435–38. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.4435.

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The combat environment of Unmanned Aerial Vehicles (UAVs) is filled with uncertain factors, which is complex and dynamic. This paper is devoted to the UAV mission planning problem under uncertain environment with three optimization objectives, such as flight time, fuel usage and threat imposed by enemy. Based on the uncertainty theory and multiobjective programming method, the UAV uncertain multiobjective mission plaaning model is built and solved.

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Hefner, Kathryn R., Christine A. Moberg, Laura Y. Hachiya, and John J. Curtin. "Alcohol stress response dampening during imminent versus distal, uncertain threat." Journal of Abnormal Psychology 122, no. 3 (2013): 756–69. http://dx.doi.org/10.1037/a0033407.

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Belegundu, A. D., and Shenghua Zhang. "Robustness of Design Through Minimum Sensitivity." Journal of Mechanical Design 114, no. 2 (June 1, 1992): 213–17. http://dx.doi.org/10.1115/1.2916933.

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The problem of designing mechanical systems or components under uncertainty is considered. The basic idea is to ensure quality control at the design stage by minimizing sensitivity of the response to uncertain variables by proper selection of design variables. The formulation does not involve probability distributions. It is proved, however, that when the response is linear in the uncertain variable, reduction in sensitivity implies lesser probability of failure. The proof is generalized to the non-linear case under certain restrictions. In one example, the design of a three-bar truss is considered. The length of one of the bars is considered to be the uncertain variable while cross-sectional areas are the design variables. The sensitivity of the x-displacement is minimized. The constrained optimization problem is solved using a nonlinear programming code. A criterion which can help identify some of the problems where robustness in design is critical is discussed.

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Liu, Y., W. C. Guo, R. Cao, Z. Chen, and L. Wang. "Dynamic performance and sensitivity of grid-connected hydropower station under uncertain disturbance." IOP Conference Series: Earth and Environmental Science 1079, no. 1 (September 1, 2022): 012113. http://dx.doi.org/10.1088/1755-1315/1079/1/012113.

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Abstract The grid-connected operating condition of hydropower station is a common operation mode to provide electric energy for the load side. This paper investigates the dynamic performance and sensitivity of grid-connected hydropower station (GCHS) under uncertain disturbance. Firstly, the nonlinear uncertain model of GCHS under uncertain disturbance is established. Then, the dynamic performance of GCHS is studied when the governor parameters change under certain step disturbance, periodic disturbance and uncertain random disturbance, respectively. Finally, based on the sensitivity index of the uncertain output obtained from the extended Fourier amplitude sensitivity test method, the sensitivity of the uncertain random disturbance at different input positions is studied. The results indicate that the GCHS under periodic disturbances or random disturbances have more complex dynamic performance than that under certain step disturbance. Under periodic disturbance, the forced oscillations and high frequency resonances are generated in dynamic response of GCHS. Under the uncertain random disturbance, the system of GCHS always presents random oscillation. The state variables q H , z, qP, y, x s , x t , and δ of GCHS are the most sensitive to uncertain disturbances, which are introduced at the generator or surge tank. The uncertain disturbances have significant interaction on the dynamic response of GCHS.

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Yao, Min, and Min Zhao. "Unmanned aerial vehicle dynamic path planning in an uncertain environment." Robotica 33, no. 3 (March 5, 2014): 611–21. http://dx.doi.org/10.1017/s0263574714000514.

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SUMMARYAn unmanned aerial vehicle (UAV) dynamic path planning method is proposed to avoid not only static threats but also mobile threats. The path of a UAV is planned or modified by the potential trajectory of the mobile threat, which is predicted by its current position, velocity, and direction angle, because the positions of the UAV and mobile threat are dynamically changing. In each UAV planning path, the UAV incurs some costs, including control costs to change the direction angle, route costs to bypass the threats, and threat costs to acquire some probability to be destroyed by threats. The model predictive control (MPC) algorithm is used to determine the optimal or sub-optimal path with minimum overall costs. The MPC algorithm is a rolling-optimization feedback algorithm. It is used to plan the UAV path in several steps online instead of one-time offline to avoid sudden and mobile threats dynamically. Lastly, solution implementation is described along with several simulation results that demonstrate the effectiveness of the proposed method.

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Aliee, Maryam, Matt J. Keeling, and Kat S. Rock. "Modelling to explore the potential impact of asymptomatic human infections on transmission and dynamics of African sleeping sickness." PLOS Computational Biology 17, no. 9 (September 13, 2021): e1009367. http://dx.doi.org/10.1371/journal.pcbi.1009367.

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Gambiense human African trypanosomiasis (gHAT, sleeping sickness) is one of several neglected tropical diseases (NTDs) where there is evidence of asymptomatic human infection but there is uncertainty of the role it plays in transmission and maintenance. To explore possible consequences of asymptomatic infections, particularly in the context of elimination of transmission—a goal set to be achieved by 2030—we propose a novel dynamic transmission model to account for the asymptomatic population. This extends an established framework, basing infection progression on a number of experimental and observation gHAT studies. Asymptomatic gHAT infections include those in people with blood-dwelling trypanosomes, but no discernible symptoms, or those with parasites only detectable in skin. Given current protocols, asymptomatic infection with blood parasites may be diagnosed and treated, based on observable parasitaemia, in contrast to many other diseases for which treatment (and/or diagnosis) may be based on symptomatic infection. We construct a model in which exposed people can either progress to either asymptomatic skin-only parasite infection, which would not be diagnosed through active screening algorithms, or blood-parasite infection, which is likely to be diagnosed if tested. We add extra parameters to the baseline model including different self-cure, recovery, transmission and detection rates for skin-only or blood infections. Performing sensitivity analysis suggests all the new parameters introduced in the asymptomatic model can impact the infection dynamics substantially. Among them, the proportion of exposures resulting in initial skin or blood infection appears the most influential parameter. For some plausible parameterisations, an initial fall in infection prevalence due to interventions could subsequently stagnate even under continued screening due to the formation of a new, lower endemic equilibrium. Excluding this scenario, our results still highlight the possibility for asymptomatic infection to slow down progress towards elimination of transmission. Location-specific model fitting will be needed to determine if and where this could pose a threat.

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McNally, Richard J., Christopher D. Hornig, Emily C. Hoffman, and Edmund M. Han. "Anxiety sensitivity and cognitive biases for threat." Behavior Therapy 30, no. 1 (1999): 51–61. http://dx.doi.org/10.1016/s0005-7894(99)80045-8.

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Ugrinovskii, Valery A. "Risk-sensitivity Conditions for Stochastic Uncertain Model Validation." IFAC Proceedings Volumes 41, no. 2 (2008): 15309–14. http://dx.doi.org/10.3182/20080706-5-kr-1001.02589.

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WAKASA, Yuji, Tetsuzo TANINO, and Tohru KATAYAMA. "Sensitivity Analysis of Uncertain Systems via Semidefinite Programming." Transactions of the Society of Instrument and Control Engineers 32, no. 8 (1996): 1212–18. http://dx.doi.org/10.9746/sicetr1965.32.1212.

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Fang, Sheng-En, Qiu-Hu Zhang, Bao Zhang, and Xiao-Hua Zhang. "Probabilistic and Nonprobabilistic Sensitivity Analyses of Uncertain Parameters." Mathematical Problems in Engineering 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/236304.

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Parameter sensitivity analyses have been widely applied to industrial problems for evaluating parameter significance, effects on responses, uncertainty influence, and so forth. In the interest of simple implementation and computational efficiency, this study has developed two sensitivity analysis methods corresponding to the situations with or without sufficient probability information. The probabilistic method is established with the aid of the stochastic response surface and the mathematical derivation proves that the coefficients of first-order items embody the parameter main effects on the response. Simultaneously, a nonprobabilistic interval analysis based method is brought forward for the circumstance when the parameter probability distributions are unknown. The two methods have been verified against a numerical beam example with their accuracy compared to that of a traditional variance-based method. The analysis results have demonstrated the reliability and accuracy of the developed methods. And their suitability for different situations has also been discussed.

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Journal articles on the topic 'Sensitivity to Uncertain Threat'

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