scholarly journals Multistate modeling of habitat dynamics: factors affecting Florida scrub transition probabilities

Ecology ◽  
2010 ◽  
Vol 91 (11) ◽  
pp. 3354-3364 ◽  
Author(s):  
David R. Breininger ◽  
James D. Nichols ◽  
Brean W. Duncan ◽  
Eric D. Stolen ◽  
Geoffrey M. Carter ◽  
...  
Keyword(s):  
Transition Probabilities ◽  
Florida Scrub ◽  
Factors Affecting ◽  
Habitat Dynamics

Factors affecting Florida scrub-jay nest survival on Ocala National Forest, Florida

2011 ◽  
Vol 75 (5) ◽  
pp. 1040-1050 ◽  
Author(s):  
Kathleen E. Franzreb ◽  
Stanley J. Zarnoch
Keyword(s):  
Nest Survival ◽  
National Forest ◽  
Florida Scrub ◽  
Factors Affecting

A Markov Decision Process for Managing Habitat for Florida Scrub-Jays

2011 ◽  
Vol 2 (2) ◽  
pp. 234-246 ◽  
Author(s):  
Fred A. Johnson ◽  
David R. Breininger ◽  
Brean W. Duncan ◽  
James D. Nichols ◽  
Michael C. Runge ◽  
...  
Keyword(s):  
Transition Probabilities ◽  
Survival Rates ◽  
Monitoring Program ◽  
Optimal Management ◽  
Prescribed Burn ◽  
National Wildlife Refuge ◽  
Florida Scrub ◽  
Wildlife Refuge ◽  
Management Actions ◽  
Optimal Action

Abstract Florida scrub-jays Aphelocoma coerulescens are listed as threatened under the Endangered Species Act due to loss and degradation of scrub habitat. This study concerned the development of an optimal strategy for the restoration and management of scrub habitat at Merritt Island National Wildlife Refuge, which contains one of the few remaining large populations of scrub-jays in Florida. There are documented differences in the reproductive and survival rates of scrub-jays among discrete classes of scrub height (<120 cm or “short”; 120–170 cm or “optimal”; >170 cm or “tall”; and a combination of tall and optimal or “mixed”), and our objective was to calculate a state-dependent management strategy that would maximize the long-term growth rate of the resident scrub-jay population. We used aerial imagery with multistate Markov models to estimate annual transition probabilities among the four scrub-height classes under three possible management actions: scrub restoration (mechanical cutting followed by burning), a prescribed burn, or no intervention. A strategy prescribing the optimal management action for management units exhibiting different proportions of scrub-height classes was derived using dynamic programming. Scrub restoration was the optimal management action only in units dominated by mixed and tall scrub, and burning tended to be the optimal action for intermediate levels of short scrub. The optimal action was to do nothing when the amount of short scrub was greater than 30%, because short scrub mostly transitions to optimal height scrub (i.e., that state with the highest demographic success of scrub-jays) in the absence of intervention. Monte Carlo simulation of the optimal policy suggested that some form of management would be required every year. We note, however, that estimates of scrub-height transition probabilities were subject to several sources of uncertainty, and so we explored the management implications of alternative sets of transition probabilities. Generally, our analysis demonstrated the difficulty of managing for a species that requires midsuccessional habitat, and suggests that innovative management tools may be needed to help ensure the persistence of scrub-jays at Merritt Island National Wildlife Refuge. The development of a tailored monitoring program as a component of adaptive management could help reduce uncertainty about controlled and uncontrolled variation in transition probabilities of scrub-height and thus lead to improved decision making.

THE DEFERRAL OPTION IN LONG-TERM-CARE INSURANCE

2002 ◽  
Vol 16 (1) ◽  
pp. 101-119
Author(s):  
Esther Frostig ◽  
Doron Kliger ◽  
Benny Levikson
Keyword(s):  
Long Term Care ◽  
Transition Probabilities ◽  
Term Care ◽  
Common Assumption ◽  
Factors Affecting ◽  
Insurance Contracts ◽  
Risk Of Death ◽  
Long Term Care Insurance ◽  
The Right

Long-term-care (LTC) insurance contracts provide the insured with different benefits for several nursing care levels, for a limited number of benefit eligibility periods. A common assumption in pricing these LTC contracts is that the insured will exercise the right to claim benefits as soon as the eligibility conditions are satisfied. This assumption, however, may contradict the insured's optimization, as it might be worthwhile not to claim when in low care levels and, by doing so, save the option of claiming higher (more expensive) care levels in the future. We term this option of the insured as the deferral option. The consequence of the traditional pricing (i.e., of ignoring the deferral option) is unexpected losses to the insurer. The factors affecting the deferral option's value are the risk of death, the discount factor, the benefit levels of the different care levels, and the transition probabilities between the different care levels.

Factors Affecting Nutritional Condition of Fledgling Florida Scrub-Jays: A Ptilochronology Approach

The Condor ◽  
1998 ◽  
Vol 100 (4) ◽  
pp. 753-756 ◽  
Author(s):  
Thomas C. Grubb ◽  
Glen E. Woolfenden ◽  
John W. Fitzpatrick
Keyword(s):  
Nutritional Condition ◽  
Florida Scrub ◽  
Factors Affecting

Search for the shortest trajectory of a social engeneering attack between a pair of users in a graph with transition probabilities

2018 ◽  
pp. 74-81 ◽  
Author(s):  
A. O. Khlobystova ◽  
M. V. Abramov ◽  
A. L. Tulupyev ◽  
A. A. Zolotin
Keyword(s):  
Transition Probabilities ◽  
Success Probability ◽  
Social Engineering ◽  
Original Data ◽  
Algorithm Analysis ◽  
Propagation Path ◽  
Factors Affecting ◽  
Calculation Results ◽  
Resource Intensity ◽  
A Chain

Introduction: Social engineering attacks can be divided into two types: direct (one-way) and multi-pass ones, passing through a chain of users. Normally, there are several propagation paths for a multi-pass social engineering attack between two users. Estimates of the probabilities of an attack to spread along different trajectories will differ. Purpose: Identification of the most critical (most probable) trajectory for a multi-pass social engineering attack between two users. Methods: Methods of searching, matching and algorithm analysis are used to identify the most critical trajectory of attack propagation. They apply the information about the intensity of the interaction between employees in companies based on data extracted from social networks. These algorithms are reduced, using a number of transformations of the original data, to the algorithms of finding the shortest path in a graph. The estimates of a multi-path social engineering attack success probability are calculated with the methods of constructing an estimate of a complex event probability. Results: We have proposed an approach to identifying the most critical trajectories, whose estimate of the attack success probability is the highest. In the simplest case, the problem can be reduced to finding a path in the graph with the maximum product of the weights of all the edges involved. The resource intensity of the algorithm when searching for the most critical trajectory on a complete graph with a large number of vertices can be reduced with a specially developed technique. A brief overview of the methods and algorithms providing automated search for the most critical propagation path of a social engineering attack showed that in a general case it can be reduced, with some transformations, to the problem of finding the most critical trajectory using the configuration of Dijkstra and Bellman — Ford algorithms. The chosen algorithm was adapted for the specified context, and an approach was proposed to thin out the graph when searching for the most critical trajectory. The presented methods and algorithms are implemented in software code. Numerical experiments were performed to verify the calculation results. Practical relevance: The developed software based on the method and algorithm proposed in this article complements the functionality of the previous versions of software prototypes for analyzing the protection of information system users against social engineering attacks. It allows you to take into account a wider range of factors affecting the assessment of social engineering attack success probability.

Progress In The Practical Application Of Automated Image Analysis To Tem Negatives

1977 ◽  
Vol 35 ◽  
pp. 214-217
Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly
Keyword(s):  
Image Analysis ◽  
Image Quality ◽  
Exposure Time ◽  
Image Contrast ◽  
Automated Image Analysis ◽  
Practical Application ◽  
Factors Affecting ◽  
High Image Quality ◽  
Qualitative Evidence ◽  
Comprehensive Study

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.

Factors affecting microstructural scale in liquid crystalline polymers

1990 ◽  
Vol 48 (4) ◽  
pp. 220-221
Author(s):  
Christine M. Dannels ◽  
Christopher Viney
Keyword(s):  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Factors Affecting ◽  
Crystalline Polymers ◽  
Thermal Expansion Coefficients ◽  
Low Thermal Expansion ◽  
Lower Viscosity ◽  
Fine Microstructure ◽  
Planar Orientation ◽  
Strength And Stiffness

Processing polymers from the liquid crystalline state offers several advantages compared to processing from conventional fluids. These include: better axial strength and stiffness in fibers, better planar orientation in films, lower viscosity during processing, low solidification shrinkage of injection moldings (thermotropic processing), and low thermal expansion coefficients. However, the compressive strength of the solid is disappointing. Previous efforts to improve this property have focussed on synthesizing stiffer molecules. The effect of microstructural scale has been overlooked, even though its relevance to the mechanical and physical properties of more traditional materials is well established. By analogy with the behavior of metals and ceramics, one would expect a fine microstructure (i..e. a high density of orientational defects) to be desirable.Also, because much microstructural detail in liquid crystalline polymers occurs on a scale close to the wavelength of light, light is scattered on passing through these materials.

EELS white line intensities calculated for the 3d and 4d metals

1989 ◽  
Vol 47 ◽  
pp. 388-389
Author(s):  
C. C. Ahn ◽  
D. H. Pearson ◽  
P. Rez ◽  
B. Fultz
Keyword(s):  
Experimental Data ◽  
Line Intensity ◽  
Transition Probabilities ◽  
Initial Increase ◽  
White Line ◽  
Hartree Fock ◽  
Line Intensities ◽  
Integrated Intensity ◽  
X Ray Absorption ◽  
The Continuum

Previous experimental measurements of the total white line intensities from L2,3 energy loss spectra of 3d transition metals reported a linear dependence of the white line intensity on 3d occupancy. These results are inconsistent, however, with behavior inferred from relativistic one electron Dirac-Fock calculations, which show an initial increase followed by a decrease of total white line intensity across the 3d series. This inconsistency with experimental data is especially puzzling in light of work by Thole, et al., which successfully calculates x-ray absorption spectra of the lanthanide M4,5 white lines by employing a less rigorous Hartree-Fock calculation with relativistic corrections based on the work of Cowan. When restricted to transitions allowed by dipole selection rules, the calculated spectra of the lanthanide M4,5 white lines show a decreasing intensity as a function of Z that was consistent with the available experimental data.Here we report the results of Dirac-Fock calculations of the L2,3 white lines of the 3d and 4d elements, and compare the results to the experimental work of Pearson et al. In a previous study, similar calculations helped to account for the non-statistical behavior of L3/L2 ratios of the 3d metals. We assumed that all metals had a single 4s electron. Because these calculations provide absolute transition probabilities, to compare the calculated white line intensities to the experimental data, we normalized the calculated intensities to the intensity of the continuum above the L3 edges. The continuum intensity was obtained by Hartree-Slater calculations, and the normalization factor for the white line intensities was the integrated intensity in an energy window of fixed width and position above the L3 edge of each element.

Factors affecting dentist participation in a state Medicaid program

1990 ◽  
Vol 54 (11) ◽  
pp. 638-643 ◽  
Author(s):  
PC Damiano ◽  
ER Brown ◽  
JD Johnson ◽  
JP Scheetz
Keyword(s):  
Medicaid Program ◽  
Factors Affecting
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