scholarly journals Adaptive Sampling for Spatial Capture-Recapture: An efficient sampling scheme for rare or patchily distributed species

2018 ◽  
Author(s):  
Alec Wong ◽  
Angela Fuller ◽  
J. Andrew Royle
Keyword(s):  
Adaptive Sampling ◽  
A Priori ◽  
Local Population ◽  
Analytical Framework ◽  
Simple Random Sample ◽  
Parameter Estimates ◽  
Probabilistic Sampling ◽  
Standard Scr ◽  
Capture Recapture ◽  
Scr Model

AbstractRare species present challenges to data collection, particularly when the species is spatially clustered over large areas, such that the encounter frequency of the organism is low. Sampling where the organism is absent consumes resources, and offers relatively low-quality information which are often difficult to model using standard statistical methods. In adaptive sampling, a probabilistic sampling method is employed first, and additional effort is allocated in the vicinity of sites where some measured index variable - assumed to be proportional to local population size - exceeds an a priori threshold. We applied this principle to the spatial capture-recapture (SCR) analytical framework in a Bayesian hierarchical model incorporating capture-recapture (CR) and index information from unsampled sites to estimate density. We assessed the adaptively sampled SCR model (AS-SCR) by simulating CR data and compared performance with a standard SCR baseline (F-SCR), adaptive SCR discarding index information (AS-SCR–), and standard SCR applied at a simple random sample of sites. Under AS-SCR, we observed minimal bias and comparable variance with respect to parameter estimates provided by the standard F-SCR model and sampling implementation, but with substantially reduced effort and significant cost saving potential. This represents the first application of adaptive sampling to SCR.

Generalised DOPs with Consideration of the Influence Function of Signal-in-Space Errors

2011 ◽  
Vol 64 (S1) ◽  
pp. S3-S18 ◽  
Author(s):  
Yuanxi Yang ◽  
Jinlong Li ◽  
Junyi Xu ◽  
Jing Tang
Keyword(s):  
Least Squares ◽  
Stochastic Models ◽  
Influence Function ◽  
A Priori ◽  
Functional Model ◽  
Global Navigation Satellite Systems ◽  
Parameter Estimates ◽  
Model Parameters ◽  
Integrated Navigation ◽  
Satellite Systems

Integrated navigation using multiple Global Navigation Satellite Systems (GNSS) is beneficial to increase the number of observable satellites, alleviate the effects of systematic errors and improve the accuracy of positioning, navigation and timing (PNT). When multiple constellations and multiple frequency measurements are employed, the functional and stochastic models as well as the estimation principle for PNT may be different. Therefore, the commonly used definition of “dilution of precision (DOP)” based on the least squares (LS) estimation and unified functional and stochastic models will be not applicable anymore. In this paper, three types of generalised DOPs are defined. The first type of generalised DOP is based on the error influence function (IF) of pseudo-ranges that reflects the geometry strength of the measurements, error magnitude and the estimation risk criteria. When the least squares estimation is used, the first type of generalised DOP is identical to the one commonly used. In order to define the first type of generalised DOP, an IF of signal–in-space (SIS) errors on the parameter estimates of PNT is derived. The second type of generalised DOP is defined based on the functional model with additional systematic parameters induced by the compatibility and interoperability problems among different GNSS systems. The third type of generalised DOP is defined based on Bayesian estimation in which the a priori information of the model parameters is taken into account. This is suitable for evaluating the precision of kinematic positioning or navigation. Different types of generalised DOPs are suitable for different PNT scenarios and an example for the calculation of these DOPs for multi-GNSS systems including GPS, GLONASS, Compass and Galileo is given. New observation equations of Compass and GLONASS that may contain additional parameters for interoperability are specifically investigated. It shows that if the interoperability of multi-GNSS is not fulfilled, the increased number of satellites will not significantly reduce the generalised DOP value. Furthermore, the outlying measurements will not change the original DOP, but will change the first type of generalised DOP which includes a robust error IF. A priori information of the model parameters will also reduce the DOP.

On Adaptive Sampling for Single and Multi-Response Bayesian Surrogate Models

2006 ◽  
Author(s):  
David A. Romero ◽  
Cristina H. Amon ◽  
Susan Finger
Keyword(s):  
Experimental Design ◽  
Adaptive Sampling ◽  
Design Space Exploration ◽  
A Priori ◽  
Computer Experiments ◽  
Latin Hypercube Sampling ◽  
Surrogate Models ◽  
Sampling Techniques ◽  
Design And Optimization ◽  
Sampling Points

In order to reduce the time and resources devoted to design-space exploration during simulation-based design and optimization, the use of surrogate models, or metamodels, has been proposed in the literature. Key to the success of metamodeling efforts are the experimental design techniques used to generate the combinations of input variables at which the computer experiments are conducted. Several adaptive sampling techniques have been proposed to tailor the experimental designs to the specific application at hand, using the already-acquired data to guide further exploration of the input space, instead of using a fixed sampling scheme defined a priori. Though mixed results have been reported, it has been argued that adaptive sampling techniques can be more efficient, yielding better surrogate models with less sampling points. In this paper, we address the problem of adaptive sampling for single and multi-response metamodels, with a focus on Multi-stage Multi-response Bayesian Surrogate Models (MMBSM). We compare distance-optimal latin hypercube sampling, an entropy-based criterion and the maximum cross-validation variance criterion, originally proposed for one-dimensional output spaces and implemented in this paper for multi-dimensional output spaces. Our results indicate that, both for single and multi-response surrogate models, the entropy-based adaptive sampling approach leads to models that are more robust to the initial experimental design and at least as accurate (or better) when compared with other sampling techniques using the same number of sampling points.

scholarly journals Robustness of Eco-Epidemiological Capture-Recapture Parameter Estimates to Variation in Infection State Uncertainty

2018 ◽  
Vol 5 ◽  
Author(s):  
Sarah Benhaiem ◽  
Lucile Marescot ◽  
Heribert Hofer ◽  
Marion L. East ◽  
Jean-Dominique Lebreton ◽  
...  
Keyword(s):  
Parameter Estimates ◽  
State Uncertainty ◽  
Capture Recapture

Simultaneous Bayesian calibration and engineering design with an application to a vibration isolation system

2021 ◽  
Author(s):  
Carl Ehrett ◽  
D. Andrew Brown ◽  
Christopher Kitchens ◽  
Xinyue Xu ◽  
Roland Platz ◽  
...  
Keyword(s):  
Computer Model ◽  
Adaptive Sampling ◽  
Model Calibration ◽  
Vibration Isolation ◽  
Traditional Approach ◽  
Design Procedure ◽  
Parameter Estimates ◽  
Computationally Efficient ◽  
Isolation System ◽  
Vibration Isolation System

Abstract Calibration of computer models and the use of those models for design are two activities traditionally carried out separately. This paper generalizes existing Bayesian inverse analysis approaches for computer model calibration to present a methodology combining calibration and design in a unified Bayesian framework. This provides a computationally efficient means to undertake both tasks while quantifying all relevant sources of uncertainty. Specifically, compared with the traditional approach of design using parameter estimates from previously completed model calibration, this generalized framework inherently includes uncertainty from the calibration process in the design procedure. We demonstrate our approach on the design of a vibration isolation system. We also demonstrate how, when adaptive sampling of the phenomenon of interest is possible, the proposed framework may select new sampling locations using both available real observations and the computer model. This is especially useful when a misspecified model fails to reflect that the calibration parameter is functionally dependent upon the design inputs to be optimized.

scholarly journals Breeding transients in capture–recapture modeling and their consequences for local population dynamics

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Daniel Oro ◽  
Daniel F. Doak
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Population Growth ◽  
Population Growth Rate ◽  
Local Population ◽  
Environmental Stochasticity ◽  
Adult Survival ◽  
Local Survival ◽  
First Reproduction ◽  
Capture Recapture

Abstract Standard procedures for capture–mark–recapture modelling (CMR) for the study of animal demography include running goodness-of-fit tests on a general starting model. A frequent reason for poor model fit is heterogeneity in local survival among individuals captured for the first time and those already captured or seen on previous occasions. This deviation is technically termed a transience effect. In specific cases, simple, uni-state CMR modeling showing transients may allow researchers to assess the role of these transients on population dynamics. Transient individuals nearly always have a lower local survival probability, which may appear for a number of reasons. In most cases, transients arise due to permanent dispersal, higher mortality, or a combination of both. In the case of higher mortality, transients may be symptomatic of a cost of first reproduction. A few studies working at large spatial scales actually show that transients more often correspond to survival costs of first reproduction rather than to permanent dispersal, bolstering the interpretation of transience as a measure of costs of reproduction, since initial detections are often associated with first breeding attempts. Regardless of their cause, the loss of transients from a local population should lower population growth rate. We review almost 1000 papers using CMR modeling and find that almost 40% of studies fitting the searching criteria (N = 115) detected transients. Nevertheless, few researchers have considered the ecological or evolutionary meaning of the transient phenomenon. Only three studies from the reviewed papers considered transients to be a cost of first reproduction. We also analyze a long-term individual monitoring dataset (1988–2012) on a long-lived bird to quantify transients, and we use a life table response experiment (LTRE) to measure the consequences of transients at a population level. As expected, population growth rate decreased when the environment became harsher while the proportion of transients increased. LTRE analysis showed that population growth can be substantially affected by changes in traits that are variable under environmental stochasticity and deterministic perturbations, such as recruitment, fecundity of experienced individuals, and transient probabilities. This occurred even though sensitivities and elasticities of these parameters were much lower than those for adult survival. The proportion of transients also increased with the strength of density-dependence. These results have implications for ecological and evolutionary studies and may stimulate other researchers to explore the ecological processes behind the occurrence of transients in capture–recapture studies. In population models, the inclusion of a specific state for transients may help to make more reliable predictions for endangered and harvested species.

scholarly journals Complementary Currencies: An Analysis of the Creation Process Based on Sustainable Local Development Principles

2020 ◽  
Vol 12 (14) ◽  
pp. 5672 ◽  
Author(s):  
Francisco Javier García-Corral ◽  
Jaime de de Pablo-Valenciano ◽  
Juan Milán-García ◽  
José Antonio Cordero-García
Keyword(s):  
Success Factors ◽  
Swot Analysis ◽  
Local Development ◽  
A Priori ◽  
Local Population ◽  
City Council ◽  
Main Concern ◽  
Complementary Currencies ◽  
Almost All ◽  
Varied Work

Complementary currencies are a reality and are being applied both globally and locally. The aim of this article is to explain the viability of this type of currency and its application in local development, in this case, in a rural mountain municipality in the province of Almería (Spain) called Almócita. The Plus, Minus, Interesting (PMI); “Flying Balloon”; and Strength, Weakness, Opportunity (SWOT) analysis methodologies will be used to carry out the study. Finally, a ranking of success factors will be carried out with a brainstorming exercise. As to the results, there are, a priori, more advantages than disadvantages of implementing these currencies, but the local population has clarified that their main concern is depopulation along with a lack of varied work. As a counterpart to this and strengths or advantages, almost all the participants mention the support from the Almócita city council and the initiatives that are constantly being promoted.

scholarly journals Areal parameter estimates from multiple datasets

2019 ◽  
Vol 475 (2231) ◽  
pp. 20190352 ◽  
Author(s):  
B. L. N. Kennett
Keyword(s):  
Significant Contribution ◽  
A Priori ◽  
Relative Weight ◽  
Parameter Estimates ◽  
Multiple Datasets ◽  
Wide Range ◽  
Spatially Distributed ◽  
Data Points ◽  
Spatial Terms ◽  
Weighted Combination

A wide range of methods exist for interpolation between spatially distributed points drawn from a single population. Yet often multiple datasets are available with differing distribution, character and reliability. A simple scheme is introduced to allow the fusion of multiple datasets. Each dataset is assigned an a priori spatial influence zone around each point and a relative weight based on its physical character. The composite result at a specific location is a weighted combination of the spatial terms for all the available data points that make a significant contribution. The combination of multiple datasets is illustrated with the construction of a unified Moho surface in part of southern Australia from results exploiting a variety of different styles of analysis.

Spatial Flows and Spatial Patterns

1984 ◽  
Vol 16 (4) ◽  
pp. 529-543 ◽  
Author(s):  
A S Fotheringham
Keyword(s):  
Spatial Structure ◽  
Spatial Patterns ◽  
Spatial Interaction ◽  
A Priori ◽  
Parameter Estimates ◽  
Spatial Interaction Models ◽  
Significant Bias ◽  
Spatial System ◽  
Decay Parameters ◽  
Spatial Flows

The misspecification of gravity spatial interaction models has recently been described by the author. The bias in parameter estimates that results from such misspecification appears to produce the ‘map pattern effect’ or ‘spatial structure bias’ in estimated distance-decay parameters. A further aspect of the misspecification bias in gravity parameter estimates is explored here. The severity of the bias is shown to vary in a predictable manner with variations in spatial structure. In particular, the bias is shown to be dependent upon the pattern of accessibility that exists within a spatial system. The relevant aspects of this pattern are discussed for intraurban and interurban (or interregional) flow matrices. It is shown that from an examination of the spatial structure of centres in a spatial system it is possible, a priori, to identify whether significant bias will arise in the calibration of a gravity model. Certain configurations of centres are shown theoretically to produce maximal bias. The author thus answers the question, “why do gravity parameter estimates appear to be biased in some systems but not in others?”

scholarly journals “Critical Ecosystems” as a Concept in Political Ecology - Developing a Comprehensive Analytical Framework

2020 ◽  
Vol 27 (1) ◽  
pp. 190-212
Author(s):  
Michael Acheampong
Keyword(s):  
Ecosystem Services ◽  
Political Ecology ◽  
Power Relations ◽  
Local Population ◽  
Analytical Framework ◽  
Population Based ◽  
Resource Exploitation ◽  
Ecological Processes ◽  
Symbiotic Relationships ◽  
Political Dimensions

Political ecology is supposed to be a field of two parts of equal importance – "politics" and "ecology." However, critics have pointed to the fact that it dwells on the politics, while rendering ecology secondary in its focus. Political ecologists have hardly used the structure that the concept of ecosystem services brought to the field of ecology, and this lends credence to this critique. In this article, I introduce the concept of "critical ecosystems" that reinforces understanding of the science of "ecology", as an important dimension of political ecology. I use components of the framework of ecosystem services in context of unequal power relations. Some local people who have symbiotic relationships with their environment owe their existence – both their livelihoods and culture – to specific natural resources whose decline has proximate and tangible consequences for them. However, they often lose these "critical ecosystems" in times of natural resource exploitation due to their relative powerlessness. I argue that it is important that political ecologists utilize the framework of ecosystem services in our inquiries, to prioritize those ecosystems that are intricately connected to the survival of the local population. Based on this, I introduce the "critical ecosystems" model, and how it can be modified to fit specific cases and can reconcile the sociological and political dimensions of political ecology, with biophysical understanding of ecological processes. This holistic inquiry, I argue, will make political ecology worthy of its name.  Keywords: Political ecology; ecosystem services; unequal power relations; Millennium Ecosystems Assessment; Ghana

scholarly journals Globality in Teaching Art and Architectural History: A Case Study of the Glossary Assignment

2021 ◽  
Vol 20 ◽  
pp. 109
Author(s):  
Pat Seeumpornroj
Keyword(s):  
A Priori ◽  
Research Problem ◽  
Analytical Framework ◽  
Cross Cultural ◽  
Still Life ◽  
Western Art ◽  
Cultural Comparisons ◽  
Visual Impact ◽  
Art And Architecture ◽  
Architecture History

In consideration of the research problem associated with the need for globality and inclusive vision in art and architecture history pedagogy, this research proposes an alternative research framework that entails the globality and inclusion of non-Western content in studying and teaching art and architecture history, as well as the use of interpretive-historical research methodology in conducting cross-cultural and comparative studies for a glossary assignment. This research provides a glossary assignment in which students conduct cross-cultural and comparative investigations of Western and non-Western art and architecture. The study approaches, tactics, and themes employed by students to do cross-cultural comparisons are systematically examined. Common glossary terms from conventional Western art and architecture history, namely, composite image, ziggurat, contrapposto, and still life, are critically used to demonstrate that they are universal and also existent in Southeast Asian art and architecture. Inductive rather than a priori analytical framework reveals new themes derived from cross-cultural comparisons. By juxtaposing original redrawn images of art and architecture from Western traditions and non-Western contexts, this research creates a significant visual impact on the usage of illustrations as tactics that transcend conventional maps and timelines. Application of the alternative study framework reveals the universality of the human desire to create art and architecture that transcends chronology and cultural boundaries.

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