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1.
本文在现有多活性代理复杂信息系统理论及其方法的研究基础上,进一步阐述了多活性代理理论体系的基本概念、活性代理的内涵;提出了活性度的概念、特性以及表征;基于活性度的研究,讨论了通过代理活性保持、协商协调增强信息系统的活性方法.首先,从组成复杂信息系统的集合、空间等概念出发,明确了多活性代理复杂信息系统理论体系所涉及的基本概念,以及这些基本概念之间的关系;其次,根据复杂信息系统功能层次上特点与活性自组织机理,提出了代理活性度的概念,并详细探讨了代理活性度的特性、表征及应用实例;同时,从活性的丧失、感知、调整以及判断决策等几个方面给出了多活性代理复杂信息系统活性保持策略;最后,本文详细探讨了多活性代理功能保持的协商协调机理、方法.上述研究成果进一步完善了多活性代理理论体系,并初步给出了代理活性和系统活性的定量表征表示方法,为进一步开展多活性代理复杂信息系统的理论和应用研究奠定了基础.  相似文献   

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Developments in the application of quantum mechanics to the understanding of the chemical bond are traced with a view to examining the evolving conception of the covalent bond. Beginning with the first quantum mechanical resolution of the apparent paradox in Lewis’s conception of a shared electron pair bond by Heitler and London, the ensuing account takes up the challenge molecular orbital theory seemed to pose to the classical conception of the bond. We will see that the threat of delocalisation can be overstated, although it is questionable whether this should be seen as reinstating the issue of the existence of the chemical bond. More salient are some recent developments in a longstanding discussion of how to understand the causal aspects of the bonding interaction—the nature of the force involved in the covalent link—which are taken up in the latter part of the paper.  相似文献   

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为了对煤矿井下瓦斯涌出量进行预测,采用粗糙集与改进极限学习机相结合的方法,在样本数据的筛选上吸取粗糙集数据约简的优点,充分利用极限学习机训练速度快、具有良好泛化性能的特点,并结合遗传算法选择最优的输入权值矩阵和隐含层偏差,避免随机产生所造成的误差。利用编写程序确定隐含层神经元个数,比依靠经验更为准确。在实际应用中选取煤层瓦斯含量、煤层埋藏深度、煤层厚度、煤层间距、工作面日产量五个因素作为预测的影响参数。研究结果表明:该预测模型预测的最大相对误差为5687 1%,最小相对误差为0,平均相对误差为2582 7%,相比改进前的预测模型具有更强的泛化能力和更高的预测精度。  相似文献   

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This paper advocates the reduction of the inference of common cause to that of common origins. It distinguishes and subjects to critical analysis thirteen interpretations of “the inference of common cause” whose conclusions do not follow from their assumptions. Instead, I introduce six types of inferences of common origins of information signals from their receivers to reduce, in the sense of supersede and replace, the thirteen inferences of common causes. I show how the paradigmatic examples of inferences of common cause, as well as a broader scope of inferences in the historical sciences, are better explained by inferences of origins.Inferences of origins from information rich coherences between receivers of information signals both fit more closely and explain better the range of examples that have traditionally been associated with inferences of common causes, as well as a broader scope of examples from the historical sciences. Shannon's concept of information as reduction in uncertainty, rather than physicalist concepts of information that relate it to entropy or waves, simplifies the inferences, preempts objections, and avoids the underdetermination of conclusions that challenge models of inferences of common causes.In the second part of the paper I model inferences of common origins from information preserved in their receivers. I distinguish information poor inferences that there were some common origins of receivers from the information richer inferences of ranges of possible common origins and the information transmission channels by which they transmitted signals to receivers. Lastly and most information rich, I distinguish the inference of the defining properties of common origins. The information transmission model from origins to receivers allows the reconceptualization of the concepts of "independence" as absence of intersections between information channels and "reliability" as the preservation of information from origins in receivers. Finally, I show how inferences of origins form the epistemic basis of the historical sciences.  相似文献   

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传统的工作流技术局限于当时的业务需求和技术水平,已不能满足当今业务过程管理的需要。企业运营过程中重要的合同审核业务流程仍由合同管理人员操作完成,浪费人力物力的同时易造成信息传递不及时、不准确,极大影响了企业运作。本文利用面向服务工作流技术解决传统工作流的局限性,并将面向服务的工作流技术应用在合同审核业务中,规范了合同审核的过程,避免了人为干预,实现了合同审核在各系统间的自动传递。  相似文献   

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运用第一性原理方法,计算研究了在0~40GPa压强范围内硝基甲烷键长的变化研究和固态硝基甲烷结构性席随属强的变化。研究发现,在低于20GPa时所有的键变化都比较小,在2~30GPa时被压缩,在30-40GPa时又被拉伸。在40GPa高压下,几乎所有的键都处于拉伸状态,只剩下部分N-O键被压缩。此外,C—H键在压强下的拉伸与甲基的转动和原予闯电荷的转移有关。在30GPa时H原子的电荷转移到C和N原予,而甲基的转动使得分子间的距离变小。逮使得C—H键较弱而容易拉伸。  相似文献   

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Our study relates to the development of the membrane relief of the blastomeres of the trout egg from the stage before their division up to gastrulation. The surface of the blastoderm shows first a more or less dense system of crests which by the time of gastrulation are replaced by microvilli distributed over the whole surface of the enveloping layer. The deep blastomeres, loosely connected to each other by lamellipodes and filopodes produce only a few projections of their membranes and these are only semispherical bodies. Possible roles of the microvillosities in the respiratory exchange of the egg and in the motility of the enveloping layer, are considered.  相似文献   

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The reception process of Aristotle's Mechanical Questions during the early modern period began with the publication of the corpus aristotelicum between 1495 and 1498. Between 1581 and 1627, two of the thirty-five arguments discussed in the text, namely Question XIV concerning the resistance to fracture and Question XVI concerning the deformation of objects such as timbers, became central to the work of the commentators. The commentaries of Bernardino Baldi (1581–1582), Giovanni de Benedetti (1585), Giuseppe Biancani (1615) and Giovanni di Guevara (1627) gradually approached the doctrine of proportions of the Renaissance architects, some aspects of which deal with the strength of materials according to the Vitruvian conception of scalar building. These aspects of the doctrine of proportions were integrated into the Aristotelian arguments so that a theory of linear proportionality concerned with the strength of materials could be formulated. This very first theory of strength of materials is the theory to which Galileo critically referred in his Discorsi where he published his own theory of strength of materials. Economic and military constraints are determined as the fundamental reasons for the commentators’ commitment to developing a theory of strength of materials that later linked Galileo's work to the practical knowledge of the architects and machine-builders of his time.  相似文献   

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在任意弯曲多驱动输送机的方案设计中,利用黑箱法建立了方案组合模型,用功能分解法建立了方案组合评价的寻优模型,并且利用动态规划方法确定了最佳的结构方案组合,有效解决了方案设计中因信息缺乏而难以量化评价的问题。结果证明该方法确定的几组最优方案正确全面且符合实际。  相似文献   

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Postural changes associated with voluntary movements of the arm as observed during a positioning task, were studied on subjects standing upright on a force platform. Subjects performed the movements with either a normal visual field or without peripheral vision (tubular vision). Data analysis comprised the EMG activity of soleus and tibialis anterior and the displacement of the vertical component of the force applied to the platform. Average data of EMG indicate that the masking of the extrofoveal receptors increases the desactivation of soleus before the onset of the movement and provokes a burst of activity in the soleus 80 to 100 ms after the onset of the movement.  相似文献   

13.
R D Myers 《Experientia》1989,45(5):436-443
Two classes of amine-aldehyde adducts, the tetrahydroisoquinoline (TIQ) and beta-carboline (THBC) compounds, have been implicated in the mechanism in the brain underlying the addictive drinking of alcohol. One part of this review focuses on the large amount of evidence unequivocally demonstrating not only the corporeal synthesis of the TIQs and THBCs but their sequestration in brain tissue as well. Experimental studies published recently have revealed that exposure to alcohol enhances markedly the endogenous formation of condensation products. Apart from their multiple neuropharmacological actions, certain adducts when delivered directly into the brain of either the rat or monkey, to circumvent the brain's blood-barrier system, can evoke an intense and dose-dependent increase in the voluntary drinking of solutions of alcohol even in noxious concentrations. That the abnormal intake of alcohol is related functionally to opioid receptors in the brain is likely on the basis of several distinct lines of evidence which include: the attenuation of alcohol drinking by opioid receptor antagonists; binding of a TIQ to opiate receptors in the brain; and marked differences in enkephalin values in animals genetically predisposed to the ingestion of alcohol. Finally, it is proposed that the dopaminergic reward pathways which traverse the meso-limbic-forebrain systems of the brain more than likely constitute an integrative anatomical substrate for the adduct-opioid cascade of neuronal events which promote and sustain the aberrant drinking of alcohol.  相似文献   

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This paper situates the metaphysical antinomy between chance and determinism in the historical context of some of the earliest developments in the mathematical theory of probability. Since Hacking's seminal work on the subject, it has been a widely held view that the classical theorists of probability were guilty of an unwitting equivocation between a subjective, or epistemic, interpretation of probability, on the one hand, and an objective, or statistical, interpretation, on the other. While there is some truth to this account, I argue that the tension at the heart of the classical theory of probability is not best understood in terms of the duality between subjective and objective interpretations of probability. Rather, the apparent paradox of chance and determinism, when viewed through the lens of the classical theory of probability, manifests itself in a much deeper ambivalence on the part of the classical probabilists as to the rational commensurability of causal and probabilistic reasoning.  相似文献   

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Summary Experimental results of different authors show that the attractive stimulus of the germinal epithelium for the germ cells in the chick embryo lasts less long than the reactivity of these cells to the same stimulus. However, both of them (stimulus and reactivity) last far longer than the period of the incorporation of germ cells into the primordia of the gonads. Each of them disappears when an important phase of differentiation is about to start in the group of cells concerned.  相似文献   

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针对黄金坪水电站1号泄洪洞原设计方案有压出口渐变段顶板存在负压,在工作闸门小开度运行时工作闸门室底板出现大范围负压,容易引起空蚀等问题,根据水力学模型试验,提出通过增加有压渐变段长度、改变工作闸门室底板连接形式,对有压出口渐变段及闸门室体型进行优化。试验实测结果表明,优化后的有压段出口项板及闸门室底板在各种运行工况下均没有出现负压,闸门室底板水流空化数显著增加,提高了泄洪洞安全运行的可靠性。  相似文献   

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Summary The production of acetylmethylcarbinol by various strains of actinomycetes was established. The biosynthesis of acetylmethylcarbinol depends largely on the composition of the fermentation medium and on the presence of arsenite, which regulates the metabolism of pyruvic acid. In the case ofStreptomyces aureofaciens the stimulating effect of phosphate on the production of acetylmethylcarbinol gives a partial explanation of the well-known negative effect of phosphate on the biosynthesis of chlortetracycline.  相似文献   

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Despite deserving a place amongst the historic milestones of the philosophy of disciplines, the system of the sciences put forward by Whewell has so far received little interest. Yet his ideas had a significant impact on the researches subsequently carried out on the topic, exerting in particular a decisive influence on Peirce and Spencer. The present paper aims to display the innovatory nature of the philosophical foundations of the Whewellian classification of the sciences. In this respect, we will argue that the most striking feature of his disciplinary system lies in a heuristic categorization of the sciences according to their “methods of discovery”. This represents a double departure from both the Aristotelian and the Baconian disciplinary paradigms, which are instead underpinned by ontological and epistemological criteria, respectively. Next, we will explore the pivotal role of Whewell's classification of the sciences for his overall project of a philosophy of scientific discovery.  相似文献   

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Geodesy—the determination of the size and shape of the earth—has often been the science operating at the frontier of precision in the measurement of length. Its contribution to the technologies and standards of length measurement has, however, been underestimated in the literature. That, instead, places emphasis on the on the creation and international acceptance of the metric system as a whole. By new research into the standards-in-use of the community of geodesists, I rediscover the original purpose of the Metre Convention of 1875, and show for the first time the significant influence of geodesy on the standardisation of length measurement thereafter. I emphasise the role of the coherence of the web of measurement in the context of change and improvement in standards.  相似文献   

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