scholarly journals Probabilistic Inverse Method for Source Localization Applied to ETEX and the 2017 Case of Ru-106 including Analyses of Sensitivity to Measurement Data

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1567
Author(s):  
Kasper Skjold Tølløse ◽  
Eigil Kaas ◽  
Jens Havskov Sørensen
Keyword(s):  
Source Localization ◽  
Inverse Method ◽  
Bayesian Method ◽  
Measurement Data ◽  
Release Site ◽  
Tracer Experiment ◽  
Sensitivity Analyses ◽  
Southern Ural Region ◽  
Release Area ◽  
Release Location

In recent years, cases of unexplained, elevated levels of radioactive particles have demonstrated an increasing need for efficient and robust source localization methods. In this study, a Bayesian method for source localization is developed and applied to two cases. First, the method is validated against the European tracer experiment (ETEX) and then applied to the still unaccounted for release of Ru-106 in the fall of 2017. The ETEX dataset, however, differs significantly from the Ru-106 dataset with regard to time resolution and the distance from the release site to the nearest measurements. Therefore, sensitivity analyses are conducted in order to test the method’s sensitivity to these parameters. The analyses show that the resulting source localization depends on both the observed temporal resolution and the existence of sampling stations close to the source. However, the method is robust, in the sense that reducing the amount of information in the dataset merely reduces the accuracy, and hence, none of the results are contradictory. When applied to the Ru-106 case, the results indicate that the Southern Ural region is the most plausible release area, and, as hypothesized by other studies, that the Mayak nuclear facility is the most likely release location.

Parasitism of Diamondback Moth (Lepidoptera: Plutellidae) Larvae by Cotesia plutellae (Hymenoptera: Braconidae) and Diadegma insulare (Hymenoptera: Ichneumonidae) in Cabbage Fields after Inundative Releases of C. plutellae2

1999 ◽  
Vol 34 (1) ◽  
pp. 101-112 ◽  
Author(s):  
E. R. Mitchell ◽  
G. Y. Hu ◽  
J. S. Okine ◽  
J. E. Carpenter
Keyword(s):  
Brassica Oleracea ◽  
Diamondback Moth ◽  
Release Site ◽  
Cotesia Plutellae ◽  
Diadegma Insulare ◽  
Cabbage Plant ◽  
Sentinel Plants ◽  
Release Area ◽  
Total Parasitism ◽  
Inundative Releases

Cocoons of Cotesia plutellae (Kurdjumov) were released for nine consecutive wk along the margins of two commercial cabbage (Brassica oleracea var. bravo L.) fields near Bunnell, Flagler Co., FL, in spring 1996. The larval parasitism of diamondback moth, Plutella xylostella (L.), by C. plutellae and by the native parasitoid Diadegma insulare (Cresson) was evaluated in release fields and in nearby cabbage fields using two methods-sentinel collard (Brassica oleracea var. acephala L.) or sentinel cabbage plants and non-sentinel plants. Total parasitism of diamondback moth larvae on sentinel plants in the release and adjacent fields was 35.7%. There were no significant differences in the level of parasitism by C. plutellae among sentinel plant locations within the release fields. In non-release fields, parasitoids spread as far as 1,500 m from the nearest release site during the release period, but parasitism of larvae on sentinel plants decreased as the distance from the release area increased. Parasitism of diamondback moth larvae by D. insulare was 8.3% in C. plutellae release and adjacent fields, but 14.6% in the nearby fields. Sampling of non-sentinel cabbage plants for diamondback moth larvae demonstrated a total of 37.4% larval parasitism by C. plutellae in the release and adjacent fields, similar to that recorded on sentinel plants. However, C. plutellae were detected only as far as 800 m from the release site on non-sentinel cabbage plants, and total parasitism in the dispersal fields also was very low. Diadegma insulare contributed only 1.1% parasitism of larvae sampled from non-sentinel plants in all cabbage fields. Cotesia plutellae was more effective than D. insulare in attacking diamondback moth larvae in this study where field populations of diamondback moth were low (<0.1 larva per cabbage plant).

Can translocations be used to mitigate human - wildlife conflicts?

2010 ◽  
Vol 37 (5) ◽  
pp. 428 ◽  
Author(s):  
Giovanna Massei ◽  
Roger J. Quy ◽  
Joanne Gurney ◽  
Dave P. Cowan
Keyword(s):  
Survival Rates ◽  
Release Site ◽  
Management Options ◽  
Wild Mammals ◽  
Impact On Survival ◽  
Release Area ◽  
Livestock Health ◽  
The Cost ◽  
The Impact ◽  
Detrimental Impact

Growing public concerns about lethal methods to mitigate human–wildlife conflicts place increasing constraints on wildlife management options. Translocations, perceived as humane and non-lethal solutions, are increasingly advocated to resolve these conflicts. The present study summarises the literature on translocations of wild mammals, with particular emphasis on ‘problem’ animals, reviews the impact of translocations on survival, behaviour, animal welfare and potential spread of diseases, and evaluates the feasibility and effectiveness of translocations to mitigate human–wildlife conflicts. Translocations may have a detrimental impact on survival rates and lead to extreme dispersal movements. In some species, stress-related capture results in substantial mortality. In other species, homing causes animals to leave the release area. In addition, some animals resume the nuisance behaviour at the release site. Individuals that survive a translocation may suffer from malnutrition, dehydration, decreased immunocompetence and predation. Supportive measures such as acclimatisation pens and provision of food and shelter can drastically reduce post-release dispersal movements and mortality, although the adoption of these measures increases the cost of translocation. Translocations have the potential to spread diseases to conspecifics, humans, domestic animals and livestock. Health surveillance, seldom implemented, is likely to add significantly to the cost of translocation. Very few studies have reported the costs of translocations or addressed which stakeholders are expected to pay for translocating problem animals. Alternative management options are rarely mentioned. Despite the perceived humaneness of translocations to mitigate human–wildlife conflicts, the fate of translocated animals has been rarely monitored. In addition, very few studies have mentioned whether and for how long the conflict was resolved. We suggest that determining whether the translocation leads to the resolution of the problem should be the main criterion to evaluate the success of the translocation of problem animals. We propose a list of criteria to assist decisions regarding the suitability, effectiveness and humaneness of translocations to manage problems posed by wild mammals.

scholarly journals An inverse method for design and characterisation of acoustic materials

2019 ◽  
Vol 304 ◽  
pp. 02002
Author(s):  
Huina Mao ◽  
Romain Rumpler ◽  
Peter Göransson
Keyword(s):  
Elastic Material ◽  
Material Properties ◽  
Inverse Method ◽  
Measurement Data ◽  
Experimental Tests ◽  
Material Model ◽  
Full Field ◽  
Inverse Estimation ◽  
Anisotropic Elastic ◽  
Anisotropic Elastic Material

This paper presents applications of an inverse method for the design and characterisation of anisotropic elastic material properties of acoustic porous materials. Full field 3D displacements under static surface loads are used as targets in the inverse estimation to fit a material model of an equivalent solid to the measurement data. Test cases of artificial open-cell foams are used, and the accuracy of the results are verified. The method is shown to be able to successfully characterise both isotropic and anisotropic elastic material properties. The paper demonstrates a way to reduce costs by characterising material properties based on the design model without a need for manufacturing and additional experimental tests.

Residency and movement patterns of yellowfin bream (Acanthopagrus australis) released at natural and artificial reef sites

2017 ◽  
Vol 68 (8) ◽  
pp. 1479 ◽  
Author(s):  
Michael Lowry ◽  
Alistair Becker ◽  
Heath Folpp ◽  
James McLeod ◽  
Matthew D. Taylor
Keyword(s):  
Site Fidelity ◽  
Artificial Reef ◽  
Movement Patterns ◽  
Release Site ◽  
Suitable Habitat ◽  
Artificial Habitat ◽  
Natural Reef ◽  
Release Location ◽  
Related Mortality

The present study investigated the long-term (>2 years) site fidelity, residency and movement patterns of Acanthopagrus australis (Sparidae) at artificial (AR) and natural reef (NR) sites. Acoustic telemetry was used to assess movement patterns of 39 fish released at NR and AR locations and other habitat types within the study area. Detection periods ranged from 1 day to a maximum of 912 days, with 36% of fish detected by the array for >1 year and a further 7% detected for >2 years. Results indicate that tagged fish tended to remain associated with the release site; however, AR fish were detected for considerably longer periods with greater numbers of fish identified as resident within the AR system. AR-released fish were also identified more frequently across the entire array, with the majority (90%) of detections between receiver stations located within the AR system. Results were affected by short detection periods (<6 days) of a relatively high proportion of fish released at the NR, possibly indicating differential rates of fishing mortality between locations. Longer range movements of >200km were also detected, but there was no obvious trend with release location. The results of the present study indicate interactions between existing and introduced artificial habitat are more complex than a ‘draw-down’ effect and provide further evidence that AR systems provide suitable habitat for a variety of species, as well as further support for the use of AR systems in fisheries enhancement initiatives. The results also have important implications for understanding the effect of AR systems and indicate that the size of the reef system may be an important factor in controlling for levels of fishing-related mortality.

scholarly journals Heat Source Localization Sensitivity Analyses for an Ultrasonic Sensor Array

2011 ◽  
Author(s):  
M. R. Myers ◽  
A. B. Jorge ◽  
D. G. Walker ◽  
M. J. Mutton
Keyword(s):  
Kalman Filter ◽  
Heat Source ◽  
Extended Kalman Filter ◽  
Source Localization ◽  
Time Of Flight ◽  
Ultrasonic Pulse ◽  
Sensitivity Analyses ◽  
Pulse Time ◽  
Heating Source ◽  
Measurement Models

State estimation procedures using the extended Kalman filter are investigated for a transient heat transfer problem in which a heat source is applied on one side of a thin plate and ultrasonic pulse time of flight is measured between spatially separated transducers on the other side of the plate. This work is an integral part of an effort to develop a system capable of locating the boundary layer transition region on a hypersonic vehicle aeroshell. Results from thermal conduction experiments involving one-way ultrasonic pulse time of flight measurements are presented. Uncertainties in the experiments and sensitivity to heating source location are discussed. Comparisons of heating source localization measurement models are conducted where ultrasonic pulse time of flight readings provide the measurement update to the extended Kalman filter. Two different measurement models are compared: 1) directly using the one-way ultrasonic pulse time of flight as the measurement vector and 2) indirectly obtaining distance from the one-way ultrasonic pulse time of flight and then using these obtained distances as the measurement vector in the extended Kalman filter. For the direct model, the Jacobian required by the extended Kalman filter is obtained numerically using finite differences from the finite element forward conduction solution. For the indirect model, the derivatives of the distances with respect to the state variables are obtained in closed form. Heating source localization results and convergence behavior are compared for the two measurement models. Two areas of sensitivity analyses are presented: 1) heat source location relative to sensor array position, and 2) sensor noise. The direct measurement model produced the best results when considering accuracy of converged solution, ability to converge to the correct solution given different initial guesses, and smoothness of convergence behavior.

scholarly journals Winter release and management of reintroduced migratory Whooping Cranes Grus americana

2009 ◽  
Vol 20 (1) ◽  
pp. 43-54 ◽  
Author(s):  
RICHARD P. URBANEK ◽  
LARA E. A. FONDOW ◽  
SARA E. ZIMORSKI ◽  
MARIANNE A. WELLINGTON ◽  
MARK A. NIPPER
Keyword(s):  
Gulf Coast ◽  
Release Site ◽  
High Survival ◽  
The West ◽  
Grus Americana ◽  
Whooping Cranes ◽  
Release Area ◽  
Males And Females ◽  
Sandhill Cranes ◽  
Substrate Addition

SummaryFrom 2001 to 2005, 71 costume-reared juvenile Whooping Cranes Grus americana were led by ultralight aircraft from Wisconsin to a winter release site on the west-central Gulf Coast of Florida. A strategy was developed and implemented to maximize first winter survival while preventing exposure to non-costumed humans and tame Sandhill Cranes, maximize social bonding between males and females, promote safe roosting and wild behaviour, and minimize harassment by Whooping Cranes from earlier releases. Methods were improved each year; these modifications included enlargement of an open-topped release pen, creation of an artificial roosting substrate, addition of a top-netted pen, and holding birds at a distant pen site until older birds had cleared the release area. These techniques resulted in high survival and successful adaptation to the wild after migration from the winter release site.

Does 'acoustic anchoring' reduce post-translocation dispersal of North Island robins?

2011 ◽  
Vol 38 (1) ◽  
pp. 69 ◽  
Author(s):  
David W. Bradley ◽  
Calum E. Ninnes ◽  
Sandra V. Valderrama ◽  
Joseph R. Waas
Keyword(s):  
Radio Telemetry ◽  
Control Release ◽  
Release Site ◽  
Immediate Release ◽  
Control Site ◽  
Management Tool ◽  
And Control ◽  
Release Location ◽  
The Impact

Context Animal translocations are an important conservation tool; however, post-release dispersal can hinder successful population establishment. Playback of conspecific song attracts dispersing individuals in some species, although its application following animal translocation has yet to be rigorously investigated. Aims To determine whether conspecific song can be used as an ‘acoustic anchor’, we adopted an experimental approach during the translocation of 60 North Island robins (Petroica longipes). Methods At one of two release locations, we broadcast song at natural rates from four speakers (4 h per morning), for 9 days following release; we set the second release location as a control where identical conditions were established but no playback occurred. To assess the impact of playback, we monitored speaker and control locations, surveyed tracks around the release areas, and radio-tracked robins over nine playback days and an additional 9 days. Key results Most robins left both immediate release areas; however, our results showed that (1) more robins (6 birds on 14 of the 18 days), in particular females (3 birds), approached the playback location than the ‘flagged’ control location (3 male birds on 5 of the 18 days), (2) individual robins returned to the playback location repeatedly, unlike those at the control site, and (3) robins also visited the playback location longer after playback than they did silent control locations. In contrast, radio-telemetry data from five robins suggested that general dispersal was not influenced by playback. Two radio-tracked females moved over long distances (some to >3 km from their release location), whereas two radio-tracked males remained relatively close to the release sites. Conclusions We demonstrated a short-term attraction effect of playback over a period of several weeks for some birds, particularly females. In contrast, we detected fewer birds over a shorter period at the silent control release site, where no females were detected. However, long-term monitoring at both sites suggested that the effect of playback on reducing post-release dispersal was transitory. Implications The lack of a clear and lasting effect of acoustic anchoring on dispersal in the present study has provided information on the limited utility of song playback as a conservation management tool for this species. Consideration of the species’ ecology and suitability for ‘acoustic anchoring’ must be made before playback is employed as a conservation measure to reduce excess post-translocation dispersal.

scholarly journals Spherical Reverse Beamforming for Sound Source Localization Based on the Inverse Method

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2618 ◽  
Author(s):  
Chao Sun ◽  
Yuechan Liu
Keyword(s):  
Source Localization ◽  
Sound Source ◽  
Background Noise ◽  
Inverse Method ◽  
Optimization Problem ◽  
Sound Field ◽  
Sound Source Localization ◽  
Sound Sources ◽  
Sound Field Reconstruction ◽  
Array Aperture

A spherical array is not limited to providing an acoustic map in all directions by the azimuth of the array. In this paper, spherical reverse beamforming for sound source localization based on spherical harmonic beamforming and the principle of sound field reconstruction is proposed in order to output a sharper scanning beam. It is assumed that there is an imaginary sound source at each scan point, and the acoustic map of a spherical array to the actual sound source is regarded as the combination of all of the imaginary sound sources. Sound source localization can be realized by calculating the contribution of each imaginary sound source to the sound field. Also in this work, the non-convex constrained optimization problem is established using p-norm. Combined with the norm method, the sparse solution of the imaginary sources is obtained through iterative weighted techniques, and the resolution of sound source localization is improved significantly. The performance of this method is investigated in comparison to conventional spherical beamforming. The numerical results show that the proposed method can achieve higher resolution for the localization of sound sources without being limited by the frequency and array aperture, and has a stronger ability to suppress fluctuations in background noise.

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