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41.
42.
Dwight Read 《Computational & Mathematical Organization Theory》2010,16(4):329-347
The promise of agent-based for explicating properties of social systems has not yet been fully realized. Agent models sometimes
provide only a veneer of, rather than substantive engagement with, social behavior. The problem will be illustrated with Axelrod’s
model for evolution of ethnocentrism (a biological model) versus Schelling’s model for spatial segregation based on preferences
(a cultural model). The examples show the need to incorporate both the biological and cultural basis for behavior through
a schema that includes behavior based on cultural/cognitive processing of information and behavior based on biological/cognitive
processing of information. An example of an agent-based model that implements decision making in this manner is discussed.
The model accounts for heterogeneity in behavior outcomes and leads to two main predictions: (1) small scale, hunter-gatherer
societies in resource scarce environments will have stable adaptations less affected by variation in resource abundance in
comparison to groups in resource rich regions where inter-group conflict is more likely and (2) the relationship between community
size, population size and administrative complexity will have two distinct patterns, one for patrilineally organized societies
and the other for matrilineally organized societies. Both predictions have been verified empirically. 相似文献
43.
Ronald C. Read 《Aequationes Mathematicae》1986,31(1):47-63
A class of plane multigraphs having a series-parallel structure is defined and enumerated. The enumeration is carried out both for the rooted graphs as originally defined, and also for those where no distinctions are made between the vertices. Some other related problems are also discussed. 相似文献
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46.
O'Brien L Petit D Lewis ER Cowburn RP Read DE Sampaio J Zeng HT Jausovec AV 《Physical review letters》2011,106(8):087204
Domain wall (DW) pinning in ferromagnetic nanowires is in general a complex process. Distortions of the DW shape make quantitative agreement between modeling and experiment difficult. Here we demonstrate pinning using nanometer scale localized stray fields. This type of interaction gives well-characterized, tailorable potential landscapes that do not appreciably distort the DW. Our experimental results are in excellent quantitative agreement with an Arrhenius-Néel model of depinning--a result only possible when the modeled potential profile agrees fully with that experienced by the DW. 相似文献
47.
R. A. Ranga Prabodanie John F. Raffensperger E. Grant Read Mark W. Milke 《Annals of Operations Research》2014,220(1):87-109
Nitrate discharges from diffuse agricultural sources significantly contribute to groundwater and surface water pollution. Tradable permit programs have been proposed as a means of controlling nitrate emissions efficiently, but trading is complicated by the dispersed and delayed effects of the diffuse pollution. Hence, markets in nitrate discharge permits should be carefully designed to account for the underlying spatial and temporal interactions. Nitrate permit markets can be designed similar to the modern electricity markets which use LPs to find the equilibrium prices because the two trading problems have close analogy. In this paper, we propose alternative LP models to find efficient permit prices for year-ahead markets. The model structure varies depending on the catchment hydro-geology and long-term goals of the community. We show how the market price structures are driven by the constraint structure under different environmental conditions. We discuss the physical and economic conditions required to assure consistent prices, the modeling of essential and optional constraints in an LP, and the problem of balancing resource allocation over time among delayed-response discharge units. We then extend the LP model to balance resource allocation over time and to improve the market performance. 相似文献
48.
We continue our study of operator algebras with contractive approximate identities (cais) by presenting a couple of interesting examples of operator algebras with cais, which in particular answer questions raised in previous papers in this series, for example about whether, roughly speaking, ‘weak compactness’ of an operator algebra, or the lack of it, can be seen in the spectra of its elements. 相似文献
49.
Dwight R. Stoll 《Analytical and bioanalytical chemistry》2010,397(3):979-986
Comprehensive two-dimensional HPLC (2DLC) has been used very successfully in proteomics applications for over a decade. Increasingly
we are seeing online, comprehensive 2DLC used for non-proteomic applications. This article gives an overview of the state
of the art of this technique, with emphasis on current trends in theory and practice that are exciting and hold the most promise
for advancing the performance of 2DLC. Specifically, the recently commercialized small, superficially porous packing materials
are very well suited to use in the second dimension of online 2DLC where analysis speed is critical and largely dictates the
performance of the 2DLC system. Further, the recent development of optimization schemes and associated software that support
the use of different second-dimension elution modes in a single 2DLC analysis will improve the flexibility and effectiveness
of 2DLC separations. Excluding separations of peptides, proteins, and polymers, 2DLC systems utilizing reversed-phase separation
in one dimension, and either normal phase or reversed-phase in the other dimension continue to be the most popular. Although
these systems have been applied mostly to complex biological materials, we are beginning to see applications in the analysis
of pharmaceutical materials for ingredient purity and degradation profiling. The general lack of robust, easy-to-use commercially
available software is arguably the greatest impediment to wider application of 2DLC methods. This situation is improving slowly,
however, and at least two commercially available software packages have been described in the peer-reviewed literature. This
is an exciting time in the development of online 2DLC. 相似文献
50.
Parthasarathy R Bykhovski A Gelmont B Globus T Swami N Woolard D 《Physical review letters》2007,98(15):153906
In this work, a theoretical study of the coupling of TM polarized subterahertz (THz) radiation with periodic semiconductor rectangular slot arrays was conducted, using InSb as an example. Simulation results showed that the structure with 4-12 microm thickness provides over a 20-30-fold increase in the electric field at slot edges in a nanosize region ( approximately 500 nm). The enhancement of the THz electromagnetic field extends across the slots and reaches peak values at the edges due to discontinuity effects. Because of the strong local electromagnetic field enhancement, the structure can potentially be used for the development of novel biophotonic sensors, leading to improved detection sensitivity. 相似文献