Recent issues on stochastic directional convexity, and new results on the analysis of systems for communication, information, time scales and maintenance

2013 ◽  
Vol 30 (4) ◽  
pp. 479-496 ◽  
Author(s):  
Eva María Ortega ◽  
José Alonso
Keyword(s):  
Time Scales ◽  
Directional Convexity ◽  
Information Time ◽  
Stochastic Directional Convexity

scholarly journals CONVEX COMPARISONS FOR RANDOM SUMS IN RANDOM ENVIRONMENTS AND APPLICATIONS

2008 ◽  
Vol 22 (3) ◽  
pp. 389-413 ◽  
Author(s):  
José María Fernández-Ponce ◽  
Eva María Ortega ◽  
Franco Pellerey
Keyword(s):  
Random Environment ◽  
Environmental Parameters ◽  
Random Environments ◽  
Actuarial Science ◽  
Random Sums ◽  
Convex Order ◽  
Stochastic Comparisons ◽  
Directional Convexity ◽  
Stochastic Directional Convexity ◽  
Directionally Convex Order

Recently, Belzunce, Ortega, Pellerey, and Ruiz [3] have obtained stochastic comparisons in increasing componentwise convex order sense for vectors of random sums when the summands and number of summands depend on a common random environment, which prove how the dependence among the random environmental parameters influences the variability of vectors of random sums. The main results presented here generalize the results in Belzunce et al. [3] by considering vectors of parameters instead of a couple of parameters and the increasing directionally convex order. Results on stochastic directional convexity of families of random sums under appropriate conditions on the families of summands and number of summands are obtained, which lead to the convex comparisons between random sums mentioned earlier. Different applications in actuarial science, reliability, and population growth are also provided to illustrate the main results.

Information time scales for interim analyses of randomized clinical trials

2016 ◽  
Vol 13 (4) ◽  
pp. 391-399 ◽  
Author(s):  
Boris Freidlin ◽  
Megan Othus ◽  
Edward L Korn
Keyword(s):  
Clinical Trials ◽  
Time Scales ◽  
Randomized Clinical Trials ◽  
Interim Analyses ◽  
Information Time

LVSEM: Past Present and Future

1990 ◽  
Vol 48 (1) ◽  
pp. 364-365
Author(s):  
James B. Pawley
Keyword(s):  
Field Emission ◽  
Line Width ◽  
Time Scales ◽  
Silicon Oxide ◽  
Beam Current ◽  
High Brightness ◽  
High Beam ◽  
Fixed Charges ◽  
Beam Voltage ◽  
Deposited Metal

Past: In 1960 Thornley published the first description of SEM studies carried out at low beam voltage (LVSEM, 1-5 kV). The aim was to reduce charging on insulators but increased contrast and difficulties with low beam current and frozen biological specimens were also noted. These disadvantages prevented widespread use of LVSEM except by a few enthusiasts such as Boyde. An exception was its use in connection with studies in which biological specimens were dissected in the SEM as this process destroyed the conducting films and produced charging unless LVSEM was used.In the 1980’s field emission (FE) SEM’s came into more common use. The high brightness and smaller energy spread characteristic of the FE-SEM’s greatly reduced the practical resolution penalty associated with LVSEM and the number of investigators taking advantage of the technique rapidly expanded; led by those studying semiconductors. In semiconductor research, the SEM is used to measure the line-width of the deposited metal conductors and of the features of the photo-resist used to form them. In addition, the SEM is used to measure the surface potentials of operating circuits with sub-micrometer resolution and on pico-second time scales. Because high beam voltages destroy semiconductors by injecting fixed charges into silicon oxide insulators, these studies must be performed using LVSEM where the beam does not penetrate so far.

A Two Time Scales Turbulence Model of Turbulent Bubbly Flows

2013 ◽  
Vol 40 (3) ◽  
pp. 185-203
Author(s):  
Dhahri Maher ◽  
Bellakhel Ghazi ◽  
Chahed Jamel
Keyword(s):  
Time Scales ◽  
Turbulence Model ◽  
Bubbly Flows

Sparsity and Time Scales

1983 ◽  
Author(s):  
Joe H. Chow ◽  
Petar V. Kokotovic
Keyword(s):  
Time Scales

Agent-Based Computational Model

2017 ◽  
Author(s):  
Joshua M. Epstein
Keyword(s):  
Computational Model ◽  
Bounded Rationality ◽  
Time Scales ◽  
Spatially Explicit ◽  
Agent Based ◽  
Affective Component ◽  
Elementary Type ◽  
Social Component ◽  
Different Time Scales

This part describes the agent-based and computational model for Agent_Zero and demonstrates its capacity for generative minimalism. It first explains the replicability of the model before offering an interpretation of the model by imagining a guerilla war like Vietnam, Afghanistan, or Iraq, where events transpire on a 2-D population of contiguous yellow patches. Each patch is occupied by a single stationary indigenous agent, which has two possible states: inactive and active. The discussion then turns to Agent_Zero's affective component and an elementary type of bounded rationality, as well as its social component, with particular emphasis on disposition, action, and pseudocode. Computational parables are then presented, including a parable relating to the slaughter of innocents through dispositional contagion. This part also shows how the model can capture three spatially explicit examples in which affect and probability change on different time scales.

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