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SERGE GALAM 《国际通用系统杂志》2013,42(3):191-200
The use of majority rule voting is believed to be instrumental to establish democratic operating of political organizations. However in this work it is shown that, while applied to hierarchical systems, it leads to political paradoxes. To substantiate these findings a model to construct self-directed pyramidal structures from bottom up to the top is presented. Using majority rules it is shown that a minority and even a majority can be systematically self-eliminated from top leadership, provided the hierarchy has a minimal number of levels. In some cases, 70% of the population is found to have zero representation after 6 hierarchical levels. Results are discussed with respect to internal operating of political organizations. 相似文献
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SERGE A. POMMIER 《Journal of food science》1991,56(5):1455-1456
Ninety-five Holstein bull calves raised on milk replacer were used to study the development of meat color during storage. Luminous reflectivity (Y) of the pectoralis profundus muscle increased an average of 22 lux units after a 3-day aging period. Forty-five-minute color measurements correlated with 3-day color measurements (r = 0.69) and pre-slaughter hemoglobin (r = 0.53), which also correlated with 3-day color measurements (r = 0.65). Meat color at 45 min and pre-slaughter hemoglobin concentration contributed significantly to predict 3-day Y values (R2= 0.59). However, this procedure was not accurate to predict color of meat at 3 days after slaughter. 相似文献
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Several approaches have been developed for the spectral analysis of nonstationary processes in the literature. Otherwise, it has been shown recently that, as in the stationary case, the partial autocorrelation function characterizes, like the autocovariance function, the second-order properties of the process. Our main result is the introduction of a new time-dependent power spectrum clearly related to this function. At each time, this spectrum describes a stationary situation in which the present is correlated with the past in the same way as our nonstationary process at this time. The properties of this spectrum are analysed. In particular, it is defined for all nonstationary processes and is in a one-to-one correspondence with the autocovariance function. Unfortunately, no spectral representation of the process is actually associated with it. This spectrum is also compared with two similar other spectra. Some examples of theoretical spectra and an estimated spectrum are considered for illustration. 相似文献
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Since the works of Kalman (1963) and Tou (1964) it is known that an nth-order sampled-data system needs n control signals to reach equilibrium if taken in an arbitrary initial state. These control signals may be applied either in open loop, through linear feedback channels when all the state variables are accessible or with a digital compensator if only the output is available. A computational procedure for solving this problem is described. This method uses the analogue simulation of the process in order to form a linear system which is then solved on a digital computer giving directly the open-loop control signals. Then, with the open-loop control signals one sees how the feedback coefficients or the digital compensator can be found in a very simple way in order to get dead-beet response. The method has the advantage of keeping all the tedious work (matrix integration and matrix multiplication) to a minimum by using the analogue computer, the digital computer only having to solve two linear systems. The method may be applied to scalar systems or to multi-input systems. The authors think that the design of dead-beat compensators is thus greatly simplified mid two examples are displayed with numerical results. 相似文献
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SERGE BÉROT SYLVIE GAUTIER MICHEL NICOLAS BERNARD GODON YVES POPINEAU 《International Journal of Food Science & Technology》1994,29(5):489-502
Commercial wheat gluten was fractionated on a pilot plant scale to produce gliadin-and glutenin-rich fractions. Acetic acid solutions (0.01–0.05 M) were blended with dry gluten (16, 10 or 7 volumes unit-1 of dry gluten ratio) and the slurry was separated by continuous centrifugation to yield a gliadin-rich supernatant, which was then concentrated by ultrafiltration and spray-dried. the pellet obtained was optionally rinsed by water or acetic acid and separated in a second stage. the second supernatant was treated as the first one, and the final residue, insoluble and glutenin-rich, was then dispersed in ammonia and spray-dried. the protein distributions in supernatants and residues depended on pH and ranged from 20/80 to 40/60 for the first stage, and from 40/60 to 80/20 for the sum of the two stages. the compositions of the fractions were measured by solubility tests and size exclusion high performance liquid chromatography (SE-HPLC) profiles. A [-1, +1] selectivity scale was created: each fraction was compared to pure gliadins (-1), gluten (0) and pure glutenins (+1). the best combination between yields of soluble and insoluble fractions (40/60 distribution) and selectivities for gliadins and glutenins (-0.32 and +0.26 respectively) was obtained at ratio 16 and a 0.01 M molarity. Though the selectivities were limited because gliadins and medium-size glutenin polymers have similar solubilities in acid solutions, this process permits preparation of fractions which differ widely from gluten in contents of high molecular weight glutenin polymers. 相似文献
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The usual approach for obtaining the optimal control For a linear time-delay system with a quadratic cost consists of first deriving a set of necessary conditions for optimality and then using conventional iterative numerical methods to find a control satisfying those conditions. The burden of computation in this approach is enormous. The iterative scheme proposed in this paper does not proceed along these lines. Instead, the delay term is treated liko an extra perturbing input. A linear non-delay system is optimized at each stage, and the resulting sequence of control functions converges rapidly to the sub-optimal control for the original problem, as illustrated by two numerical examples. 相似文献
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Co-operation between human operators and autonomous machines in dynamic (not fully controlled) situations implies a need for dynamic allocation of activities between the agents, in order to adapt the human-machine system to unexpected circumstances. Dynamic allocation is a way, for example, to avoid human workload peaks. Depending on whether tasks or functions are allocated, the demands made on human-machine co-operation design are different. Task and subtask allocation assume that both the human operator and the machine (or its designer) share the same decomposition of the overall task into subtasks. Function delegation is less demanding, provided that the human operator delegates functions to the machine explicitly, and within the context of a task representation transmitted by the human. This paper discusses these principles on the basis of experimental results taken from a series of studies on human-machine cooperation in air traffic control. 相似文献
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