适用于应用层多播的建树算法的设计

设计一个新的建树算法,该算法适用于应用层多播。考虑到应用层上两点间代价的不对称性和实时性要求,设计出一种基于源端的多播树建立方法,以保证组内每个成员都能及时收到组内其它任何一个成员发送的报文。多播组的成员通过测量应用层的点到点的瓶颈带宽和往返时延获得链路代价,并分别以自己为根节点建立多播树,以便在报文转发时确定最优路径。     

一个改进的多播路由算法

Multicasting is a communication service that allows an application to efficiently transmit copies of data packets to a set of destination nodes. The problem of finding a minimum cost multicast tree can be formulated as a minimum Steiner tree problem in networks, which is NP-completeness. MPH (minimum path cost heuristic) algorithm is a famous solution to this problem. In this paper,we present a novel solution TPMPH (two phase minimum path cost heuristic) to improve the MPH by generating the nodes and the edges of multicast tree separately. The cost of multicast tree generated by the proposed algorithm with the same time as MPH is no more than that of MPH in the worst case. Extensive simulation results show that TPMPH can effectively improve the performance on MPH, and performs better in large-scale networks and wireless networks.     

Algorithm for Delay-Constrained Minimal Cost Group Multicasting

Group multicast routing algorithms satisfying quality of service requirements of real-time applications are essential for high-speed networks. A heuristic algorithm was presented for group multicast routing with bandwidth and delay constrained. A new metric was designed as a function of available bandwidth and delay of link, And source-specific routing trees for each member were generated in the algorithm by using the metric, which satisfy member＇s bandwidth and end-to-end delay requirements. Simulations over random network were carried out to compare the performance of the proposed algorithm with that from literature. Experimental results show that the algorithm performs better in terms of network cost and ability in constructing feasible multicast trees for group members. Moreover,the algorithm can avoid link blocking and enhance the network behavior efficiently.     

The study on the core concepts of contemporary sociology of education and its theoretical construction

Within the sphere of contemporary social sciences, the terms “modernity,” “post-modernity” and “globalization” have penetrated, as the core concepts, into various fields of social sciences in a logical way. In constituting the concept of “modernity,” sociology of education develops the educational theory, as sociological theory does, into a “grand narrative” and “foundationalist” theory; the contribution of post-modernity is pluralism and self-examination in an attempt to transcend modernity. Globalization, a kind of expanded modernity, makes education sociologists broaden their perspective from single and traditional “nationality,” “society” and “nation” to an international society and even to the global society, which has broken through the research paradigm of modernity with ethnocentrism, anthropocentrism and Euro-centrism. These changes have required urgent constitution of the conceptions and theoretical frameworks of sociology of education to be applied on a global level. __________ Translated from Peking University Education Review, 2006 (1)     

Solution of an inverse problem for ＂fixed-fixed＂ and ＂fixed-free＂ spring-mass systems

The tridiagonal coefficient matrix for the ＂fixed-fixed＂ spring-mass system was obtained by changing spring length. And then a new algorithm of the inverse problem was designed to construct the masses and the spring constants from the natural frequencies of the ＂fixed-fixed＂ and ＂fixed-fres＂ spring-mass systems. An example was given to illustrate the results.     

English phonological specificity predicts early French reading difficulty in emerging bilingual children

The purpose of the present study was to examine the predictive value of a dynamic test of English and French lexical specificity on at-risk reading classification in 13 at-risk and 44 not at-risk emerging English (L1)–French (L2) bilingual Grade 1 children (M = 75.87 months, SD = 3.18) enrolled in an early French immersion program in Canada. Lexical specificity was assessed with a computerized word learning game in which children were taught new English (e.g., “foal” and “sole”) and French (e.g., bac “bin” and bague “ring”) word pairs contrasted by minimal phonological differences. The results indicated that the dynamic test of lexical specificity in English contributed significantly to the prediction of children’s French at-risk reading status at the end of Grade 1 after controlling for French phonological awareness and nonverbal reasoning skills. However, French lexical specificity did not predict children’s reading risk classification in French after controlling for French phonological awareness. Thus, it may be feasible to identify at-risk status in emerging bilinguals using dynamic measures in their stronger language.     

Quality of life and cost-effectiveness of combined therapy for reflux esophagitis

Objective: To evaluate clinical, Quality of Life (QoL) and medical cost outcomes in patients with symptomatic reflux esophagitis (RE) receiving different ″triple combination therapy″. Methods: A multicenter medical effectiveness trial conducted in 10 hospitals of 5 regions in Zhejiang Province. 248 patient-volunteers were assigned to 8 weeks of ″ triple combination therapy″ with Lansoprazole plus Cisapride and Sucralfate or Ranitidine plus Cisapride and Sucralfate. Main outcomes assessment included symptoms scale scores, RE severity, QoL at baseline and 8 weeks. Medical cost data were collected with cost analysis questionnaire. Results: (1)More Lansoprazole group patients noted RE symptoms resolution than Ranitidine group(92.3% vs 78.4%, P<0.01). There was no striking difference between two groups in RE healing rate (90.8% vs 82.9%, P>0.05). (2)RE significantly impaired QoL of patients(P<0.001).Compared with Ranitidine group, QoL in Lansoprazole group had significant improvement (rate of ″good″ QoL 64.5% vs 45.6%, P<0.01). (3)There was close correlation between symptomic effectiveness and QoL rating scale in both the Lansoprazole and Ranitidine group(P<0.01, r=0.235 and 0.353 respectively). There were no statistical difference of medical cost between the two groups (P>0.05). Conclusion: RE significantly impaired QoL of patients. ″Triple combination therapies″ can significantly improve RE symptoms and QoL. Lansoprazole combination therapy was more cost-effective than Ranitidine combination group.     

An analysis of reform in administrative system of Chinese higher education

After the founding of the People’s Republic of China, the administrative system of higher education then was characterized as “centralized”, “Tiao and Kuai” were segmented (some higher education institutions were directly administered by provincial governments, and some were affiliated to the relative administrative departments of the state) and higher education institutions (HEIs) were government-run. The reform in the administrative system of higher education launched in the 1980s broke down the segmentation of “Tiao and Kuai”, and changed it into a new administrative system emphasizing the role of the provincial governments (“Kuai-oriented mode”). Thus, HEIs gained more autonomy and tremendous changes have taken place in the relation between HEIs and the government. However, weakening the government’s administrative control over HEIs and readjusting government-HEIs relations are still the main concerns in reforming the administrative system of Chinese higher education. __________ Translated from Journal of Nanjing Normal University (Social Science), 2005 (4)     

Metamorphosis in Two Novels by Melvin Burgess: Denying and Disguising ‘Deviant’ Desire

Melvin Burgess has gained a reputation as an enfant terrible, whose writing tackles topics and presents attitudes which are controversial in literature for adolescents. Kimberley Reynolds cites him as an author whose work demonstrates that “writing about sex, sexuality and relationships between the sexes [is] one of the most radically changed areas in contemporary children’s literature.” Reynolds argues that novels depicting teenage sexuality no longer focus on socialising teenagers into adult-approved behaviours. Yet changes in literature are never fully “radical”; they always build on established traditions. This article examines the ways in which Burgess uses the motif of animal transformation in Tiger Tiger and Lady: My Life as a Bitch to maintain the prevailing view of adolescent carnality as a deviant variation of “proper,” adult sexuality, whilst celebrating early sexual experiences.     

Bandwidth allocation algorithm for aggregated tree in optical networks

Wavelength and bandwidth allocation is important for multicast communication in optical networks. In this paper, a new method based on scheduling theory is proposed. The proposed method formulates wavelength bandwidth capacity as a large rectangle and these multicast stream bandwidth requirements as small rectangles. It treats the wavelength and bandwidth allocation question as a rectangle packing problem. The proposed algorithm solves the problem by taking quasi-human strategy with Euclidian distance. It is an effective heuristic algorithm to quickly solve multicast stream bandwidth allocation problem in optical networks by theoretic analysis. Further simulation experiments show the bandwidth allocation algorithm can increase network utilization and have a good fairness performance for unicast stream and multicast stream in optical networks. The results indicate the effectiveness of the algorithm.     

The Talking Drawings Strategy: Using Primary Children’s Illustrations and Oral Language to Improve Comprehension of Expository Text

Listening and reading comprehension can be assessed by analyzing children’s visual, verbal, and written representations of their understandings. “Talking Drawings” (McConnell, S. (1993). Talking drawings: A strategy for assisting learners. Journal of Reading, 36(4), 260–269 is one strategy that enables children to combine their prior knowledge with the new information derived from an expository text and “translate” those newly-acquired understandings into other symbol systems, including an oral discussion with a partner, a more detailed drawing, and written labels for the drawing. The Talking Drawings strategy begins by inviting children to create pre-learning drawings. These initial drawings are a way of taking inventory of a child’s current content knowledge about a particular topic. After pre-learning drawings are created and shared, children listen to or read an expository text (e.g., information book, passage from a textbook) on the same topic as their drawing. Pairs of students discuss the information and either modify their pre-learning drawings to be more detailed or create completely new drawings that reflect the recently-acquired information. Students are encouraged to label their drawings with words in a diagram or schematic fashion. By evaluating the “before” and “after” artwork, educators can identify advances in students’ reading and listening comprehension of the terminology, facts, and principles on a particular topic.     

基于自由树的中心的MAODV改进算法

MAODV路由协议是应用于移动Ad Hoc网络的一个组播路由协议,协议中的组长选取具有较大的随机性。本文分析了协议中组长的位置选取的相关特征,并在此基础上提出了基于自由树的中心的MAODV改进,改进算法避免了MAODV路由协议中组长处于组播共享树叶子结点的位置,减少了数据分组的传输次数,降低了网络传输的延迟。     

The “System of Chymists” and the “Newtonian dream” in Greek-speaking Communities in the 17th–18th Centuries

The acceptance of new chemical ideas, before the Chemical Revolution of Lavoisier, in Greek-speaking communities in the 17th and 18th centuries did not create a discourse of chemical philosophy, as it did in Europe, but rather a “philosophy” of chemistry as it was formed through the evolution of didactic traditions of Chemistry. This “philosophical” chemistry was not based on the existence of any academic institutions, it was focused on the ontology of principles and forces governing the analysis/synthesis of matter and formulated two didactic traditions. The one, named “the system of chymists”, close to the Boylean/Cartesian tradition, accepted, contrary to Aristotelianism, the five “chymical” principles and also the analytical ideal, but the “chymical” principles were not under a conceptual and experimental investigation, as they were in Europe. Also, a crucial issue for this tradition remained the “mechanical” principles which were under the influence of the metaphysical nature of the Aristotelian principles. The other, close to the Boylean/Newtonian tradition, was the integrated presentation of the Newtonian “dream”, which maintained a discursive attitude with reference to the “chemical attractions”–“chemical affinities” and actualised the mathematical atomism of Boscovich, according to which the elementary texture of matter could be causally explained within this complex architecture of mathematical “punkta”. In this tradition also coexisted, in a discursive synthesis, the “chemical element” of Lavoisier and the arguments of the new theory and its opposition to the phlogiston theory, but the “chemical affinities” were under the realm of the “physical element” as “metaphysical point”.     

小生境伪并行遗传算法在全自主移动机器人路径规划中的应用

1IntroductionPath planning of autonomous mobile robot is pivotaltechnique for machine intelligence,which ai ms to finda non-collision path frominitial position to objectiveposition according to evaluation functions in anobstacle space[1].It can be described as travelersalesman problem(TSP),a typical combinationopti mization problem,which belongs to the well-known NP-hard opti mization[2].The mathematicaldefinition can be regarded as a mapG=(V,E),where eachlinee∈Ehas a nonnegative powerω(…     

Ready...Fire...Aim! Toward meaningful technology standards for educators and students

Conclusion I applaud ISTE, AASL, AECT, and the other organizations involved for tackling the “messy work” of developing standards for the use of technology and information resources in schools. And, at the same time, I call for a “second generation” of standards that define realistic expectations for teachers based on the subjects and levels they are called upon to teach. I propose that professional organizations from each subject work with ISTE and AECT to complete this huge task, and I propose that we consider as a “next step” the creation of a set of on-line learning experiences through which teachers can gain the identified skills and knowledge by using the very technologies we’re hoping they’ll embrace in their own teaching. There’s an old saying, “If you don’t know where you’re going, any road will do.” As far as educational technologies are concerned, this is also true. For many, the goal seems to have been simply to “get more computers into the schools,” without much thought about purpose. To return to Phil Schlechty’s metaphor, It’s generally been a brief and misguided “Ready” stage (occupied with questions like “How many do we need?” “What type?” “Where?” and “How shall we connect them?”), followed by “Fire!” (the acquisition and installation of equipment). What we need is: “Ready” (the creation of appropriate teams of people who will combine their insights to plan for the district)... “Aim” (a series of discussions about what technologies can accomplish for schools and the students they serve)... “Fire” (acquisition, installation, and professional development according to plan)... “Aim” (an assessment of how well the technologies and related programs met the intended goals, and a new planning effort designed to close the gap)... “Fire” (acquisition and implementation designed to eliminate the gap)... “Aim” (another gap assessment)... “Fire” (another attempt to close gaps)..., And so on.     

Individuals and Leadership in an Australian Secondary Science Department: A Qualitative Study

In this article, we consider the complex and dynamic inter-relationships between individual science teachers, the social space of their work and their dispositions towards teacher leadership. Research into the representation of school science departments through individual science teachers is scarce. We explore the representations of four individual teachers to the assertions of teacher leadership proposed by Silva et al. (Teach Coll Rec, 102(4):779–804, 2000). These representations, expressed during regular science department meetings, occur in the social space of Bourdieu’s “field” and are a reflection of the “game” of science education being played within the department. This departmentally centred space suggests an important implication when considering the relationship between subject departments and their schools. The development of an individual’s representation of teacher leadership and the wider “field” of science education appears to shape the individual towards promoting their own sense of identity as a teacher of science, rather than as a teacher within a school. Our work suggests that for these individuals, the important “game” is science education, not school improvement. Consequently, the subject department may be a missing link between efforts to improve schools and current organizational practices.     

Construction of life-practice moral education based on traditional Chinese morality with life connotation

The actual effect is a big problem in current school moral education. By analyzing the problems in the theory and practice of the current school moral education, the author points out that the reason is that, for a long time, the meaning of morality has been dissimilated, and moral education is considered as a kind of knowledge input and neglecting it is the life-style of human beings. By exploring the meaning of morality in the traditional Chinese culture, the author fully affirmed the rich life connotation both in the dynamic conversion between Tao and virtue and in the Taoist saying “Great virtue is growth”. In the article, the author suggests that nowadays, we should reconsider and understand the moral connotation in traditional culture and explain the traditional morals in a modern way. It is also necessary to construct a new moral education system such as a “life-practice” model. __________ Translated from Journal of Educational Studies, 2005 (5)     

Adaptive ant-based routing in wireless sensor networks using Energy*Delay metrics

To find the optimal routing is always an important topic in wireless sensor networks （WSNs）. Considering a WSN where the nodes have limited energy, we propose a novel Energy^＊Delay model based on ant algorithms （＂E＆D ANTS＂ for short） to minimize the time delay in transferring a fixed number of data packets in an energy-constrained manner in one round. Our goal is not only to maximize the lifetime of the network but also to provide real-time data transmission services. However, because of the tradeoff of energy and delay in wireless network systems, the reinforcement learning （RL） algorithm is introduced to train the model. In this survey, the paradigm of E＆D ANTS is explicated and compared to other ant-based routing algorithms like AntNet and AntChain about the issues of routing information, routing overhead and adaptation. Simulation results show that our method performs about seven times better than AntNet and also outperforms AntChain by more than 150% in terms of energy cost and delay per round.     

A Festschrift for Andy Hargreaves

Recent social policy reforms have sought to overcome the limitations of “First Way” strategies emphasizing the welfare state and “Second Way” approaches advocating markets. Scholars and policymakers instead have begun to explore optimal synthesis of the public and private sector in a new “Third Way” of leadership and change. According to one line of interpretation advanced by Andy Hargreaves and Dennis Shirley, however, the Third Way as developed in education has ushered in a new orthodoxy of testing, accountability, and data-driven decision making. This new orthodoxy is said to distract educators from their true moral purposes. Hence, Hargreaves and Shirley have called for a new “Fourth Way” of change that draws upon international best practices in education. In this interpretive essay for a Festschrift issue of the Journal of Educational Change celebrating Andy Hargreaves’ 60th birthday, Dennis Shirley revisits Fourth Way change architecture to inquire after the appropriate role of new technologies in classrooms and schools. He retrieves the concept of mindful teaching and learning from the Fourth Way change model and illustrates how it can be used as a lens to adjudicate various interpretations of the appropriate role of new technologies in schools.     

Hutchins’s University of Utopia: Institutional Independence,Academic Freedom,and Radical Restructuring

In a crisis-plagued world looking to higher education for knowledge, wisdom, and solutions, higher education itself is stumbling. Its transformational thinking has frozen up like an overstressed computer program; and we need, in effect, to “push the reset button.” In 1953, the renowned and controversial president of the University of Chicago, Robert M. Hutchins, authored a refreshing and provocative work, The University of Utopia, containing ideas that still challenge today’s paradigms. He argued for institutional independence over “accountability,” “outcomes,” and “stakeholders.” He indicted educational evils he called “industrialization,” “specialization,” “philosophical diversity,” and “social and political conformity” and suggested ways to defeat them. Although his 56-year-old thoughts on reconceptualizing the multiversity are not a panacea, they could help higher education make a fresh start. This essay reintroduces the modern reader to Hutchins’s iconoclastic and stimulating ideas in the hope of restarting the stalled agenda for educational reform.