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排序方式: 共有434条查询结果,搜索用时 15 毫秒
161.
Ari‐Pekka Hameri Mikael Puittinen Mikko Syrjlahti 《International Journal of Communication Systems》2002,15(7):607-619
Research on complex adaptive systems has generated several conceptual parables to explain systems with emergent behaviour. One prominent use for terms such as self‐organization, evolutionary trajectories, co‐evolution and punctuated equilibrium has been in understanding human organizations. In such systems, emergent behaviour is demonstrated in novel structures, processes and spin‐offs that cannot be explained just by studying single components of the organization and the intelligence embedded in them. Instead of solely exploiting the qualitative explanatory power of the evolutionary concepts, this paper focuses also on quantitative methods to track emergent behaviour in a globally distributed, constantly fluctuating and highly networked project organization. The underlying case is that of CERN (CERN, the European Laboratory for Particle Physics, has its headquarters in Geneva. At present, its Member States are Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Netherlands, Norway, Poland, Portugal, the Slovak Republic, Spain, Sweden, Switzerland and the United Kingdom. Israel, the Russian Federation, Turkey, Yugoslavia (status suspended after the UN embargo, June 1992), the European Commission and UNESCO have observer status.) and its decade long accelerator project, which strongly relies on electronic communication and networking to achieve its major objectives due to be accomplished by the year 2006. By using time series and self‐organizing maps to analyse the global interaction among project groups and individuals the paper provides new insight to the understanding of emergent behaviour in human organizations. The key result of the study concerns the rigid deep structure of each case organization that seems to remain intact for the duration of the whole project. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
162.
Shapiro Ari D.; Janik Vincent M.; Slater Peter J. B. 《Canadian Metallurgical Quarterly》2003,117(4):355
A gray seal (Halichoerus grypus) was trained to touch a target on its left or right by responding to pointing signals. The authors then tested whether the seal would be able to generalize spontaneously to altered signals. It responded correctly to center pointing and head turning, center upper body turning, and off-center pointing but not to head turning and eye movements alone. The seal also responded correctly to brief ipsilateral and contralateral points from center and lateral positions. Pointing gestures did not cause the seal to select an object placed centrally behind it. Like many animals in similar studies, this gray seal probably did not understand the referential character of these gestures but rather used signal generalization and experience from initial operant conditioning to solve these tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
163.
Ari Jaaksi 《Software》1995,25(3):271-289
This paper presents an object-oriented approach for the implementation of interactive systems. This approach applies the model-view-controller (MVC) paradigm, which is modified for the C++ environment. The modified paradigm is called MVC++. In this approach the design of interactive applications starts by constructing an object model that represents the key concepts of the problem domain. This object model does not contain any user interface elements. According to the MVC++ approach, the object model is called the model part of the application. Only after the model part has been created, is the user interface designed. A collection of user interface classes is called the view. The classes that connect the model and the view form the controller, which is designed to communicate with both the model and the view. The approach presented in this paper provides a number of benefits. Advantages of the original MVC approach are obtained in a standard C++ environment, the structure of applications becomes clear and stable, and reusability as well as readability of the classes increases. Reusability is achieved by employing a mechanism called ‘abstract partners’. The approach presented in this paper is being applied in the development of a large network management system with over one million lines of C++ code running in the XII environment. 相似文献
164.
165.
Binary heterogeneous nucleation of water and sulphuric acid vapours has been investigated using the hydrates interaction model in atmospheric conditions. The effect of the contact angle as well as the effect of the size of the condensation nucleus are studied. The number of adsorbed molecules on the condensation nucleus is considered. Hydration is found to decrease the nucleation rate by several orders of magnitude depending on contact angle, temperature, water and acid activity. 相似文献
166.
PID controller design is considered where optimal controller parameters are found with constraint on maximum sensitivity and robustness with regard to a cone bounded static nonlinearity acting in feedback with part of the plant. The design procedure has been successfully applied in the synthesis of a controller for an Anti‐lock Braking System (ABS). 相似文献
167.
The kinetic parameters of the Mehl-Johnson-Avrami rate equation for disperse order (DO) formation in a-CuAl alloy were determined
from nonisothermal experiments. Activation energy values of 145 ± 7/155 ± 10/178 ± 14 kJ/mol were obtained from rate dependent
curves for alloys containing, respectively, 19, 13, and 6.5 pct Al. These values are consistent with those for self-diffusion.
Further analysis allowed for the determination of the preexponential factorko and the exponentn (= 1.39 ± 0.2), the latter being found to be insensitive to alloy composition. This indicates a diffusion limited growth
of particles from a nonnegligible size, suggesting that the preexisting short range order acts as nuclei for DO development.
By employing the absolute reaction rate theory, a virtually constant activation free energy, ΔG* = 163 ± 15 kJ/mol, was measured
for the three alloys investigated. These results indicate that the transformation proceeds more rapidly with increasing aluminum
content of the alloy. Values for domain size and concentration, computed by the classical theory for nucleation and growth
processes, are compared with those obtained experimentally. Also, an (α + DO) field is proposed in the Cu-Al equilibrium diagram. 相似文献
168.
V??n?nen Ari; Buunk Bram P.; Kivim?ki Mika; Pentti Jaana; Vahtera Jussi 《Canadian Metallurgical Quarterly》2005,89(2):176
The authors examined esteem enhancement theory and equity theory in explaining the long-term health status of men (n = 178) and women (n = 575). Baseline characteristics were measured in 1990-1993, intimate reciprocity in 1993, and recorded sickness absences for a 9-year period during 1993-2001. Among women, giving more support than receiving in intimate relationships positively affected subsequent health status, as indicated by fewer sickness absences. Among men, receiving more support than giving predicted fewer absences. These effects remained even after significant covariates were included in the model. Thus, women seem to benefit from giving support in intimate relationships, and men seem to benefit from receiving support in intimate relationships. The findings on women are in line with the esteem enhancement theory. No support was obtained for the equity theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
169.
Interpreting top-down mass spectra using spectral alignment 总被引:1,自引:0,他引:1
Recent advances in mass spectrometry instrumentation, such as FTICR and OrbiTrap, have made it possible to generate high-resolution spectra of entire proteins. While these methods offer new opportunities for performing "top-down" studies of proteins, the computational tools for analyzing top-down data are still scarce. In this paper we investigate the application of spectral alignment to the problem of identifying protein forms in top-down mass spectra (i.e., identifying the modifications, mutations, insertions, and deletions). We demonstrate how spectral alignment efficiently discovers protein forms even in the presence of numerous modifications and how the algorithm can be extended to discover positional isomers from spectra of mixtures of isobaric protein forms. 相似文献
170.
Application of raman spectroscopy and sequential injection analysis for pH measurements with water dispersion of polyaniline nanoparticles 总被引:1,自引:0,他引:1
A novel method for pH measurements between pH 7.5 and 10.4 is reported in this paper. The method combines Raman spectroscopy and the automated sequential injection analysis system (SIA) and makes use of the acid-base properties of a commercially available water dispersion of polyaniline (PANI) nanoparticles with a mean particle size of 46 nm. The useful pH range of the PANI nanoparticles is broader than for conventional acid-base indicators, due to the 1:2 reaction stoichiometry of the proton-ligand complex of the nanoparticles. The pH measurements were conducted with the 633-nm laser excitation wavelength by calculating the difference between the Raman intensities of the primary and reference wavenumbers. In this study, the pH-sensitive CH=CH stretching band at 1422 cm-1 and C-H in-plane bending band of the quinoid form at 1163 cm-1 were chosen as the primary wavenumbers. The presented method is fast and allows pH to be measured with a precision of 0.2 pH unit. The advantage of the proposed method is that the hysteresis effect, which is usually observed for PANI films, can be overcome with the PANI nanoparticles, because a fresh nanoparticle solution is used in each measurement. It should be pointed out, that this work is a fundamental study showing the applicability of Raman spectroscopy in combination with the SIA technique for pH measurements in specific applications, where the conventional glass pH electrode cannot be used. 相似文献