1,601 research outputs found
Negotiation as a Learning Process
This paper presents a discussion of the role of adapting expectations in the bargaining process. Negotiators are charactenzed as persons who choose bargaining strategies in their attempt to optimize their payoffs from the situation. These strategies are contingent on each party's perception of the strategy of his opponent, and if these perceptions contain errors, expectations will change and this will lead in turn to a modification of each party's strategy choice. The payoff demands and manipulative moves which charactenze the bargaining process are seen as combinations of actions which are specified in the original bargaining plans of the parties and of changes in the plans themselves. The influence of the learnmg process on the settlement point is described as well as some empirical implications of the theory in general.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66945/2/10.1177_002200277702100403.pd
Electron collisions in Mercury Vapor - The 9.8 Volt Loss
Magnetic analysis of electrons which have passed through mercury vapor has shown the energy losses corresponding to the principle levels of the normal atom. A very prominent energy loss of 11.1 volts (and so greater than the ionization potential) is not accounted for. It is now shown that the energy loss of 9.8 volts is not due to a double 4.9 excitation
Frequency precision of two-dimensional lattices of coupled oscillators with spiral patterns
Two-dimensional lattices of N synchronized oscillators with reactive coupling are considered as high-precision frequency sources in the case where a spiral pattern is formed. The improvement of the frequency precision is shown to be independent of N for large N, unlike the case of purely dissipative coupling where the improvement is proportional to N, but instead depends on just those oscillators in the core of the spiral that acts as the source region of the waves. Our conclusions are based on numerical simulations of up to N = 29 929 oscillators and analytic results for a continuum approximation to the lattice in an infinite system. We derive an expression for the dependence of the frequency precision on the reactive component of the coupling constant, depending on a single parameter given by fitting the frequency of the spiral waves to the numerical simulations
Domain wall propagation and nucleation in a metastable two-level system
We present a dynamical description and analysis of non-equilibrium
transitions in the noisy one-dimensional Ginzburg-Landau equation for an
extensive system based on a weak noise canonical phase space formulation of the
Freidlin-Wentzel or Martin-Siggia-Rose methods. We derive propagating nonlinear
domain wall or soliton solutions of the resulting canonical field equations
with superimposed diffusive modes. The transition pathways are characterized by
the nucleations and subsequent propagation of domain walls. We discuss the
general switching scenario in terms of a dilute gas of propagating domain walls
and evaluate the Arrhenius factor in terms of the associated action. We find
excellent agreement with recent numerical optimization studies.Comment: 28 pages, 16 figures, revtex styl
Building better oscillators using nonlinear dynamics and pattern formation
Frequency and time references play an essential role in modern technology and in living systems. The precision of self-sustained oscillations is limited by the effects of noise, which becomes evermore important as the sizes of the devices become smaller. In this paper, we review our recent theoretical results on using nonlinear dynamics and pattern formation to reduce the effects of noise and improve the frequency precision of oscillators, with particular reference to ongoing experiments on oscillators based on nanomechanical resonators. We discuss using resonator nonlinearity, novel oscillator architectures and the synchronization of arrays of oscillators, to improve the frequency precision
Genetic Population Structure of Mule Deer Odocoileus Hemionus Across Montana
We conducted a genetic assessment of mule deer (Odocoileus hemionus) population structure across Montana in an effort to understand dispersal routes across the landscape. To assess genetic structure we genotyped 14 microsatellite loci in 359 individuals sampled primarily within Montana. Smaller samples were included from Wyoming, Colorado and Utah in order to provide a regional context for the levels of population structure observed within Montana. Additionally, we sequenced the control region of the mitochondrial genome of 76 individuals subsampled from our original samples across Montana. To avoid potential influences of a priori population designations, individual based analyses were used to test relatedness across the landscape. Weak isolation by distance characterized mule deer individuals across this region. In addition, we did not detect any evidence of spatial autocorrelation in discrete distance classes as small as 10 km. Female mule deer had higher average individual pairwise genetic distances than males, indicating the presence of a contemporary male bias in dispersal rates. Mitochondrial DNA indicated the potential for either reduced overall or female-specific dispersal between a subset of the sampling regions within Montana. Finally, we were unable to detect a genetic signature of past translocations of mule deer across Montana. Taken together these results indicate that within this landscape mule deer populations are characterized by high levels of connectivity and experience few, if any, barriers to dispersal
Frequency precision of two-dimensional lattices of coupled oscillators with spiral patterns
Continuum-type stability balloon in oscillated granular layers
The stability of convection rolls in a fluid heated from below is limited by
secondary instabilities, including the skew-varicose and crossroll
instabilities. We observe a stability boundary defined by the same
instabilities in stripe patterns in a vertically oscillated granular layer.
Molecular dynamics simulations show that the mechanism of the skew-varicose
instability in granular patterns is similar to that in convection. These
results suggest that pattern formation in granular media can be described by
continuum models analogous to those used in fluid systems.Comment: 4 pages, 6 ps figs, submitted to PR
Geo-Statistical Methods for Detecting Elk Parturition Sites from GPS Collar Data
There is an increasing awareness of the importance of juvenile survival in ungulate population dynamics, and the accurate prediction of parturition habitat may allow for more effective management. Detecting birth sites in a statistically rigorous way, however, often requires intensive field efforts that may not be possible for all studies. We developed a hierarchical two-stage clustering analysis for identifying elk parturition locations, which can be conducted retrospectively using only GPS location data. We validated our approach using a dataset of 59 adult female elk ( Cervus elaphus) fitted with both a Global Positioning System (GPS) collar (30-minute sampling interval) and vaginal implant transmitter (VIT) For the top parameter set, approximately 80% of estimable parturition sites were within 1 km of their respective VIT location. Roughly 10 % of our predicted birthing locations were over 2 km away from the VIT location, but many of these events could be filtered from the analyses due to their clustering attributes. Designed to minimize Type II errors this filtering also removes a subset of birthing sites that close to VIT locations, and magnitude of this effect varied across parameter sets. Sub-sampling of the GPS dataset from 30 min to 1, 2, 3, and 6 hour intervals resulted in modest reductions in the efficacy of our approach. With the use of GPS collars in ungulate studies on the rise, our approach provides managers with additional information on birth site locations at no additional cost over and above a typical GPS study
Direct observation of yield in films by flat punch indentation
In regular indentation many strain states are simultaneously present in the indented region, so measured parameters such as hardness and modulus are average values over a wide range of strains. Testing of structures such as pillars, levers or film bulges enables determination of yield point and modulus with uniform strains in the sample, but requires specialised sample preparation and can be significantly affected by surface condition.
Here we show how in-situ indentation with a flat punch allows direct observation of a discrete yield point in soft films on more rigid substrates. The yield point is clearly observable from the load displacement behaviour and from post indent AFM imaging. The film is in uniform uniaxial strain. Finite element simulations show that effective self-confinement by surrounding film material leads to uniformity throughout the film material down to surprisingly low aspect ratios around 4:1. This occurs for a significant range of stresses above the yield point. Eventually at even higher stresses the film material is extruded laterally.
The characteristics of the yield event will be described as a function of temperature and film thickness for thin to ultrathin films. At higher aspect ratio and with sufficient stiffness of punch and substrate, quantitative, in-situ measurement of intrinsic stress vs. strain to well beyond the elastic limit becomes possible for thin films. The extent to which full constitutive relations for polymer films can be determied will be discussed, along with limitations of the technique
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