Six schools were randomly assigned to a multilevel bullying intervention or a control condition. Children in Grades 3-6 (N=1,023) completed pre- and posttest surveys of behaviors and beliefs and were rated by teachers. Observers coded playground behavior of a random subsample (n=544). Hierarchical analyses of changes in playground behavior revealed declines in bullying and argumentative behavior among intervention-group children relative to control-group children, increases in agreeable interactions, and a trend toward reduced destructive bystander behavior. Those in the intervention group reported enhanced bystander responsibility, greater perceived adult responsiveness, and less acceptance of bullying/aggression than those in the control group. Self-reported aggression did not differ between the groups. Implications for future research on the development and prevention of bullying are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
Network Function Virtualization (NFV) has been identified to revamp the provisioning of next-generation network services. This new paradigm allows cloud and network/service providers to compose their network services, also known as service function chains (SFCs), in an agile way since the software of the network function is decoupled from the legacy hardware. To reap the benefits of this new technology, there is a need for novel mechanisms that help cloud and network/service providers deploy the increasingly complex virtual network services seamlessly, efficiently, and in a time-efficient way. Existing state-of-the-art techniques often rely on the Integer Linear Programming framework, heuristics/metaheuristics, and greedy methods to deploy the services function chains. However, these techniques although reasonable and acceptable, still suffer from several key limitations: convergence time and scalability. To this end, we propose RAFALE, a suite of solution techniques, to tame this complexity by leveraging the concept of similarity from machine learning and skip-gram modeling framework. To the best of our knowledge, we are the first to tackle these key limitations and propose a suite of solutions to them. RAFALE, a novel approach proposed to find the similarity between the new incoming virtual network service request and all the already-deployed services to learn from the previous experience of deploying techniques and use the same or close similar provisioning techniques. RAFALE is the first and the only method that develops the idea of detecting the similarity between virtual network services. Experimental results show that RAFALE reduces greatly the convergence time needed for provisioning virtual network services and can scale to 100 virtual network functions per virtual network service compared to the state-of-the-art. The Experimental results prove that RAFALE accomplished the NFV promises; decreasing the time and complexity of managing and deploying the virtual services, and providing a solution that is agile, faster, and scalable to deploy the new service requests by skipping one or more service provisioning steps (i.e., detecting and resolving the conflicts among policies, placement, and chaining) while satisfying the validated NFV policies.
Telecommunication satellites were first used as a means for establishing alternative transoceanic routes in competition with existing submarine cables. The use of advanced techniques in conjunction with the multitime-zone coverage makes it possible for transoceanic satellite systems to compete favorably with conventional intercontinental transmission means. This paper concerns itself with methods for economically applying satellite techniques to European conditions in competition with a finely meshed land-based relatively cheap coaxial cable system. Under these conditions every effort must be made to obtain the highest possible efficiency. The national gateways to the international telecommunication network are to see the satellite system as an equivalent trafficcarrying means capable of handling 30-70 percent of the total interEuropean traffic. It is therefore necessary to regard the satellite system, consisting of earth stations and satellite, as if it were a supranational switching center for international traffic. An essential ingredient in such a solution is a system global control. This global control is proposed to be implemented by computer means intercorrelated by means of common signaling channel methods. Principles and means of implementation of the principles are outlined. 相似文献
The gill withdrawal reflex (GWR), an important model system for neural mechanisms of learning, varies in form and amplitude within as well as between preparations and is therefore a heterogeneous collection of action patterns, not a reflex. At least 4 action patterns occur in response to mechanical stimulation of the siphon. It is often impossible to categorize a particular movement unambiguously. All may occur spontaneously. Gill movements may be described as combinations of 10 actions; 4 involving vein movements are described here. All actions and action patterns can occur in preparations lacking the central nervous system (CNS). Some vein movements may generate considerable force without markedly altering gill area. It is suggested that this explains why some early studies failed to identify the important role of the peripheral nervous system in the GWR. Studies based on the assumption that the GWR involves a single type of movement controlled by cells of the parietovisceral ganglion require reevaluation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
Scanning tunneling microscopy (STM) has been used to examine the structures of the skeletal muscle enzymes phosphorylase and phosphorylase kinase. The interaction of these two proteins represents the last step in the process of signal transduction which results in muscle glycogen being converted into metabolic energy for use in muscle contraction. Phosphorylase b has a molecular weight of 97,000 and the dimer is seen by STM to have dimensions of 11 X 5.7 nm. Phosphorylase b has a tendency to form linear arrays of dimers on the graphite surface used as the support for STM imaging. Phosphorylase kinase is imaged as a butterfly-like object with lateral dimensions of 36 X 27 nm. The molecular thicknesses given by scanning tunneling microscopy for these two non-conducting molecules is significantly less than expected. The height measurement in STM is dependent not only on the surface topology of the object being imaged, but also on the electronic work function of the object compared to that of the graphite surface on which it lies. In addition to the individual proteins, a complex between phosphorylase and phosphorylase kinase has been observed by scanning tunneling microscopy. 相似文献
Parabolic rate constants were determined for the formation of wüstite by the solid state reaction between magnetite and iron. The reaction was diffusion controlled and inert marker studies indicated that the mass transport through the wüstite layer was accomplished by means of iron migration. Relationships between rate constants and self-diffusivities are discussed. The transport capacity for iron through dense wüstite layers was found to be sufficient to carry on reduction, even in gaseous reduction processes. 相似文献
This study was a longitudinal extension of a random control trial of the Steps to Respect antibullying program. Students in Grades 3–5 were surveyed (n = 624) and observed on the playground (n = 360). Growth curve models of intervention students showed 2-year declines in playground bullying, victimization, nonbullying aggression, destructive bystander, and argumentative behavior. Grade-equivalent contrasts indicated group differences in all problem behaviors. Problem behaviors in the control group increased or remained stable across grade. Intervention group students reported less difficulty responding assertively to bullying compared with control students. Within both groups, older students perceived themselves to be more aggressive and less frequently victimized than younger students. Methodological issues posed by inconsistencies between self-reported and observed behavior are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献