Multicast can improve network performance by eliminating unnecessary duplicated flows in the data center networks. Thus it can significantly save network bandwidth. However, the network multicast blocking may cause the retransmission of a large number of data packets and seriously influence the traffic efficiency in data center networks, especially in the fat-tree DCNs with multirooted tree structure. In this paper, we build a multicast blocking model and apply it to solve the problem of network blocking in the fat-tree DCNs. Furthermore, (...) we propose a novel multicast scheduling strategy. In the scheduling strategy, we select the uplink connecting to available core switch whose remaining bandwidth is close to and greater than the three times of bandwidth multicast requests so as to reduce the operation time of the proposed algorithm. Then the blocking probability of downlink in the next time-slot is calculated in multicast subnetwork by using Markov chains theory. With the obtained probability, we select the optimal downlink based on the available core switch. In addition, theoretical analysis shows that the multicast scheduling algorithm has close to zero network blocking probability as well as lower time complexity. Simulation results verify the effectiveness of our proposed multicast scheduling algorithm. (shrink)

Since the outbreak of the COVID-19 pandemic, there has been countless debate about the virus. The role discourse plays in this pandemic is tightly associated with the impact of pandemic on society....

This thesis investigates two main issues concerning the behavior of rational agents, preference dynamics and agent diversity. -/- We take up two questions left aside by von Wright, and later also the multitude of his successors, in his seminal book Logic of Preference in 1963: reasons for preference, and changes in preference. Various notions of preference are discussed, compared and further correlated in the thesis. In particular, we concentrate on extrinsic preference. Contrary to intrinsic preference, extrinsic preference is reason-based, i.e. (...) one's preference for one option over another has a reason. A logical model is proposed and its properties are determined. Dynamics come in naturally, since reasons for the preferences can change. Logical systems and formal results regarding dynamical preference change are then presented. -/- Preference arises from comparisons between alternatives. A first option is to compare situations. Abstractly speaking, preferences are in this case between propositions, viewed as sets of possible worlds. The reasons can then be based on a `betterness' relation over possible worlds. Propositional preference arises as a lift from this primitive relation. A standard modal logical approach is taken and we use a modality for the betterness relation in the language. We then model preference change by techniques from dynamic epistemic logic (DEL), where a typical action, e.g. a suggestion or a command can change the betterness ordering of the worlds, and thereby the propositional preference. Dynamic reduction axioms are obtained to encode exactly how such a change takes place. We obtain a complete dynamic preference logic. -/- A second option is to compare objects as such. Concretely, properties of the objects often determine the preference over the objects. Properties are now the reasons. Inspired by Optimality Theory (OT), we propose a priority sequence, an ordering of properties. Various ways of getting a preference from the priority sequence are investigated, though we mostly follow the OT approach. We use a fragment of first-order logic to describe the situation. Here, on the dynamic side, it is priority change that leads to preference change. Using the DEL methodology again we propose a complete set of reduction axioms concerning the possible dynamic operations on priority sequences. -/- Not surprisingly, the above two views are closely related. After all, possible worlds can be thought of as objects! On the basis of a systematic comparison of the two views, we develop a two level perspective, in which the models themselves are structured in layers. In particular, correspondence results between the changes at the level of the possible worlds and the changes at the level of the priority sequences are proved. We end up by sketching a two-level preferential predicate logic to describe more complex circumstances in which situations and objects are compared simultaneously. -/- But we do not see this as the whole story. Preference does not live by itself, it is often intermingled with epistemic notions of knowledge and belief. One can have different intuitions about how this entanglement operates. A few options are discussed, and proposals for logical models are presented. When moving to dynamics, we now see a picture of knowledge update, belief revision and preference change taking place symbiotically, often unconsciously as in real life. -/- The resulting picture in the thesis is one of agents that process information and adjust beliefs and preferences in many different ways. There is no logically prescribed unique norm for doing this. The second part of the thesis takes this general phenomenon of diversity of agents as its focus, since it raises many issues for logical systems and the idealized agents which they normally presuppose. In reality, agents can differ across a wide spectrum of cognitive abilities and habits: in their memory capacity, observation power, inferential power, introspective ability, and revision policies when facing new information. -/- Two kinds of agents, perfect recall agents, and memory-free agents are studied thoroughly, in the setting of playing games. We show how current dynamic logics can be `parametrized' to allow for this memory diversity, with new characterizations of agent types resulting in complete dynamic-epistemic logics. The other dimension of the reality of diverse agents is that, however different they are, they often do manage to coordinate with each other successfully. While this theme has been prominent in game theory and multi-agent systems, it has received hardly any attention in logic. We analyze this interaction between different agents by looking at concrete scenarios which model their types explicitly. -/- Finally, we analyze the issue of agent diversity in its generality, discussing what dynamic logics would have to look like to become a full-fledged account of agents of different capacities and tendencies that pursue and sometimes achieve their goals in irreducibly social settings. -/- . (shrink)

While respect for persons is fundamental to many moral and political theories, its nature and ground remain controversial. According to the standard model of respect, respect is primarily a response to certain inherent features of a person or an object. Importantly, it is in virtue of the value, status or authority of those features that respect is justified or owed. This model, however, faces many serious challenges. Drawing on the classical Confucian notion of jing, I develop an alternative model of (...) respect, which construes respect as an expression of agent’s sense of the self and its place in the world. The emphasis is thus on the agent’s own self-conception and the corresponding attitudes and dispositions, as opposed to on inherent features of the objects of respect. To further illustrate this distinction, I contrast the traditional Kantian conception of respect for persons with the Confucian, jing-based, conception along three dimensions: the normative ground, the content, and the distribution of respect. The Kantian respect certainly has its merits, and perhaps is indispensable in some contexts, but there is much more to respect than what Kantians can offer. The Confucian conception of respect, on the other hand, has important theoretical and practical values such that it is essential to an adequate understanding of the role of respect in our moral and political life. (shrink)

The main purpose of this study is to probe into the human capacity of understanding systems and defects in human knowledge of the world. The study addresses the greyness levels and systems levels and explains why the world cannot be perceived as a purely white or black structure. It also clarifies why human knowledge of systems always remains grey. The investigation relies on logical and deductive reasoning and uses the theoretical foundations of systems thinking and Boulding’s systems hierarchy. The most (...) important argument that this study advances is that human knowledge, in any form or under any circumstances, is grey and incomplete and will remain grey. Because the notion of “perfect knowledge” is ambiguous given human epistemic limits, any proportion of knowledge is incomplete and prone to change. Less complexity could lead to more accurate predications, but even in the simplest forms of systems, reaching perfect knowledge seems to be an unwarranted claim. Furthermore, because our perception of past events is incomplete, we cannot predict the future with certainty, as a result of which both the past and the future appear grey to us. The world, as an integrated system, is neither black nor white, but it remains grey, and the systems partially recognized by humans are part of the grey world. Gaining knowledge and increasing discoveries only contribute to the grey systems that are already known. (shrink)

刘大椿(1944- ),江西于都人,中国人民大学哲学系副主任、教授,科学技术哲学专业博士生导师.

孙子一书,即孙子兵法,该书以其睿智而富有思辨性,反映了春秋末期,战国初年社会变革的历史,总结了一套科学,实用的系统军事理论.

《孔子家語》真偽問題，是中國學術史上一個著名公案。作者考鏡源流、旁征博引、推陳出新，着力從公案學的角度，對與王肅偽造《家語》說相關的公案群進行透徹的爬梳與剔抉；對此案產生的諸多取徑，如誤說誤文流傳訛變 、疏證辨偽方法移植錯置、文本內外關系牽強附會等進行認真的推究與歸納；就丁晏所謂王肅偽造眾書之說對康有為的劉歆遍偽群經說之影響進行清晰的提示與論證；對此案所涉《家語》三序的可信性程度、孔安國身世等重要而 又諸說紛紜的史事進行縝密的析說與考證。.

本书以系统辨证思维方式为导向,运用现代系统科学方法论,从“广角镜”式的多维立体视野出发,综合考察了囊括天体、地球、生物、人类在内的广阔世界之现状和未来。.

This paper contains four variations on Duhem's theme about the contrast between the abstract French mind and the concrete British mind. The first variation brings out the real contrast between two types of methods and their results: the A method or models and the C method or models. The second variation gives a critical discussion of the Callender-Cohen deflationary contruel of scientific representation. The third variation discusses Russell's structuralism in connection to the theme. And the fourth variation critically discusses the (...) relationship between models and fiction in connection to the distinction between the A-models and the C-models. A coda maps out without sufficiently detailed arguments the author's view on the nature of the C-models and why they, and only they, can be viewed as fully fictional. (shrink)