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81.
Local and Global Interactions in an Evolutionary Resource Game 总被引:2,自引:0,他引:2
Conditions for the emergence of cooperation in a spatial common-pool resource game are studied. This combines in a unique
way local and global interactions. A fixed number of harvesters are located on a spatial grid. Harvesters choose among three
strategies: defection, cooperation, and enforcement. Individual payoffs are affected by both global factors, namely, aggregate
harvest and resource stock level, and local factors, such as the imposition of sanctions on neighbors by enforcers. The evolution
of strategies in the population is driven by social learning through imitation, based on local interaction or locally available
information. Numerous types of equilibria exist in these settings. An important new finding is that clusters of cooperators
and enforcers can survive among large groups of defectors. We discuss how the results contrast with the non-spatial, but otherwise
similar, game of Sethi and Somanathan (American Economic Review 86(4):766–789, 1996).
相似文献
82.
M. G. Potters X. Bombois M. Mansoori Paul M. J. Van den Hof 《International journal of control》2016,89(8):1533-1553
Estimation of physical parameters in dynamical systems driven by linear partial differential equations is an important problem. In this paper, we introduce the least costly experiment design framework for these systems. It enables parameter estimation with an accuracy that is specified by the experimenter prior to the identification experiment, while at the same time minimising the cost of the experiment. We show how to adapt the classical framework for these systems and take into account scaling and stability issues. We also introduce a progressive subdivision algorithm that further generalises the experiment design framework in the sense that it returns the lowest cost by finding the optimal input signal, and optimal sensor and actuator locations. Our methodology is then applied to a relevant problem in heat transfer studies: estimation of conductivity and diffusivity parameters in front-face experiments. We find good correspondence between numerical and theoretical results. 相似文献
83.
84.
Rita A. RibeiroAuthor Vitae Ana M. MoreiraAuthor VitaePim van den BroekAuthor Vitae Afonso PimentelAuthor Vitae 《Decision Support Systems》2011,51(1):208-219
During software development, many decisions need to be made to guarantee the satisfaction of the stakeholders' requirements and goals. The full satisfaction of all of these requirements and goals may not be possible, requiring decisions over conflicting human interests as well as technological alternatives, with an impact on the quality and cost of the final solution. This work aims at assessing the suitability of multi-criteria decision making (MCDM) methods to support software engineers' decisions. To fulfil this aim, a HAM (Hybrid Assessment Method) is proposed, which gives its user the ability to perceive the influence different decisions may have on the final result. HAM is a simple and efficient method that combines one single pairwise comparison decision matrix (to determine the weights of criteria) with one classical weighted decision matrix (to prioritize the alternatives). To avoid consistency problems regarding the scale and the prioritization method, HAM uses a geometric scale for assessing the criteria and the geometric mean for determining the alternative ratings. 相似文献
85.
Rusu C. van't Oever R. de Boer M.J. Jansen H.V. Berenschot J.W. Bennink M.L. Kanger J.S. de Grooth B.G. Elwenspoek M. Greve J. Brugger J. van den Berg A. 《Journal of microelectromechanical systems》2001,10(2):238-246
We have developed a micromachined flow cell consisting of a flow channel integrated with micropipettes. The flow cell is used in combination with an optical trap setup (optical tweezers) to study mechanical and structural properties of λ-DNA molecules. The flow cell was realized using silicon micromachining including the so-called buried channel technology to fabricate the micropipettes, the wet etching of glass to create the flow channel, and the powder blasting of glass to make the fluid connections. The volume of the flow cell is 2 μl. The pipettes have a length of 130 μm, a width of 5-10 μm, a round opening of 1 μm and can be processed with different shapes. Using this flow cell we stretched single molecules (λ-DNA) showing typical force-extension curves also found with conventional techniques. These pipettes can be also used for drug delivery, for injection of small gas bubbles into a liquid flow to monitor the streamlines, and for the mixing of liquids to study diffusion effects. The paper describes the design, the fabrication and testing of the flow cell 相似文献
86.
Wilfried M. Post Mirjam A. A. Huis in ’t Veld Sylvia A. A. van den Boogaard 《Personal and Ubiquitous Computing》2008,12(3):223-235
Many attempts are underway for developing meeting support tools, but less attention is paid to the evaluation of meetingware.
This article describes the development and testing of an instrument for evaluating meeting tools. First, we specified the
object of evaluation—meetings—by means of a set of input, process, and outcome factors. Then, we designed the process of evaluation,
consisting of, first, the generation of meeting behavior in the form of a controlled series of meetings within the context
of a project and, second, the measurement of the identified meeting factors. To measure these factors, a rating scale, questionnaires,
and information flow analysis were used. Next, the instrument was tested, and the factors for successful meetings were determined
in 13 projects in which four participants had to meet four times. The evaluation instrument proved to be a reliable and useful
aid for the development and improvement of meeting tools. 相似文献
87.
Abstract The Virtual Constructing Tool (VCT) was developed at the Nijmegen School of Management in 1998. The VCT is intended to facilitate the process of writing group papers through the use of construction and communication tools and is based completely on the Internet. The VCT allows a paper to be structured by means of hyperlinking and cooperation between students. Students are allowed to divide tasks, but they are held responsible for the quality of the arguments in the paper as a whole. They are invited to spend time in dealing with validity claims and in building a valid train of thought. Producing a group paper includes four interrelated working processes: exploring the subject, exchanging information, arguing and discussing and editing. Hyperlinking offers a contribution in each of these processes which varies from associative linking of pieces of information to strengthening linear structuring. Therefore, a different perspective has been taken to that of those authors who consider hyperlinking as a tool par excellence for the nonlinear production of information. 相似文献
88.
In this paper we survey our research on smart meeting rooms and its relevance for augmented reality meeting support and virtual
reality generation of meetings in real time or off-line. The research reported here forms part of the European 5th and 6th
framework programme projects multi-modal meeting manager (M4) and augmented multi-party interaction (AMI). Both projects aim
at building a smart meeting environment that is able to collect multimodal captures of the activities and discussions in a
meeting room, with the aim to use this information as input to tools that allow real-time support, browsing, retrieval and
summarization of meetings. Our aim is to research (semantic) representations of what takes place during meetings in order
to allow generation, e.g. in virtual reality, of meeting activities (discussions, presentations, voting, etc.). Being able
to do so also allows us to look at tools that provide support during a meeting and at tools that allow those not able to be
physically present during a meeting to take part in a virtual way. This may lead to situations where the differences between
real meeting participants, human-controlled virtual participants and (semi-) autonomous virtual participants disappear.
相似文献
Dirk HeylenEmail: |
89.
C van den Bogaard HJ van den Hoogen FJ Huygen C van Weel 《Canadian Metallurgical Quarterly》1993,25(7):471-475
BACKGROUND: Previous studies reported that breast-feeding protects children against a variety of diseases, but these studies were generally conducted on "high-risk" or hospitalized children. This paper describes the results of our study on the effects of breast-feeding on rate of illness in normal children with a family history of atopy. METHODS: A historic cohort approach of 794 children with a family history of atopy was used to assess the effects of breast-feeding on illness rates. Family history of atopy was based on allergic diseases in family members as registered by the family physician. Illness data from birth onwards were available from the Continuous Morbidity Registration of the Department of Family Medicine. Information on breast-feeding was collected by postal questionnaire. We then compared rates of illness between children with a family history of atopy who were and who were not breast-fed. RESULTS: Breast-feeding was related to lower levels of childhood illness both in the first and the first three years of life. In the first year of life they had fewer episodes of gastroenteritis, lower respiratory tract infections, and digestive tract disorders. Over the next three years of life they had fewer respiratory tract infections and skin infections. CONCLUSIONS: Our results suggest a protective effect of breast-feeding among children with a family history of atopy that is not confined to the period of breast-feeding but continues during the first three years of life. Breast-feeding should be promoted in children with a family history of atopy. 相似文献
90.
van den Brink Dani?lle; Brown Colin M.; Hagoort Peter 《Canadian Metallurgical Quarterly》2006,32(2):364
An event-related brain potential experiment was carried out to investigate the temporal relationship between lexical selection and the semantic integration in auditory sentence processing. Participants were presented with spoken sentences that ended with a word that was either semantically congruent or anomalous. Information about the moment in which a sentence-final word could uniquely be identified, its isolation point (IP), was compared with the onset of the elicited N400 congruity effect, reflecting semantic integration processing. The results revealed that the onset of the N400 effect occurred prior to the IP of the sentence-final words. Moreover, the factor early or late IP did not affect the onset of the N400. These findings indicate that lexical selection and semantic integration are cascading processes, in that semantic integration processing can start before the acoustic information allows the selection of a unique candidate and seems to be attempted in parallel for multiple candidates that are still compatible with the bottom-up acoustic input. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献