Extended Hyperbolic Model for Sand-to-Concrete Interfaces

A relatively simple, four-parameter extended hyperbolic model for interfaces was developed for use in soil-structure interaction analyses. The model accommodates arbitrary stress path directions and includes three important elements: (1) development of a yield surface during interface shear; (2) a formulation for yield-inducing shear stiffness that is applicable to any stress path orientation; and (3) a formulation for unloading-reloading shear stiffness. The model was evaluated against the results of shear tests performed at the interface between three different types of sand and a concrete surface under a variety of stress paths. Comparisons between measured and calculated interface response indicate that the model provides accurate estimates of the response of sand-to-concrete interfaces.     

Faculty and Student Attitudes Toward Community Service: A Comparative Analysis

The Humanitarian Engineering initiative, sponsored by the William and Flora Hewlett Foundation, at the Colorado School of Mines, is creating a program that will support engineering students in understanding their responsibility for solving community development problems that exist throughout the world. As part of this effort, data has been collected on faculty and student attitudes using the ‘Community Service Attitudes Scale,” developed and validated by Shiarella, McCarthy, and Tucker. During the fall 2004, 78 students and 34 faculty members responded to this instrument. Statistically significant differences were found between the attitudes of students and faculty, males and females, and among different age groupings with respect to service activities. A general finding was that faculty displayed better attitudes toward community service than the students.     

一种网络服务自动部署方法

为满足网络服务使用者对网络服务部署的功能性和非功能性需求,运用Petri网的方法进行了互联网动态多变环境下的网络服务自动部署的研究,建立了一种基于Petri网的网络服务部署网模型,从形式化的角度描述了网络服务功能的部署情况,提出了一种按照服务质量来选择最优网络服务部署的算法。仿真的结果表明,与目前常用的固定部署算法和随机部署算法相比,按照该方法得到的网络服务部署能最好地满足服务使用者对服务的非功能性方面的需求。     

Hydrodynamic interaction and coalescence of two droplets under large step shear strains

We observed change in distance between two droplets in each step after application of large multi-step shear strains. Experiments were performed using a sliding plate apparatus. Large step shear strains were applied to two polyisobutylene droplets in poly(dimethyl siloxane) matrix in the same plane between the plates. The distance between the two droplets decreases with increasing the total shear strain, which is given by the product of the step strain magnitude and the number of application of the step strains. The two droplets coalesce when the distance becomes less than the diameter of the droplets. The slope for plots of the distance versus the total strain is independent of the step strain magnitude. This indicates that the effect per unit strain on the distance is the same, irrespective of the strain magnitude. It is suggested that a stronger hydrodynamic interaction between the droplets is the main cause for the droplet approach.     

Name‐Based Autoconfiguration for Mobile Ad hoc Networks

In a mobile ad hoc network, difficulties exist in supporting address autoconfiguration and naming resolution due to the lack of centralized servers. This letter presents a novel approach, called name‐based autoconfiguration (NBA), which uses host names to determine IP addresses and provides address autoconfiguration and name resolution as a single protocol.     

Assimilation for Affiliation and Contrast for Control: Complementary Self-Construals.

People have knowledge about relationships (i.e., relational schemas) that is based on their experiences. Because most people have experience with complementary behavior (interaction partners behaving similarly in terms of affiliation but oppositely in terms of control), they expect complementary behavior in their relationships. Like other beliefs about relationships, expectations of complementarity affect self-construal. The authors provide evidence for complementary self-construal; people assimilate to relevant relationship partners on the affiliation dimension and contrast on the control dimension. Consistent with the proposed role of relationship knowledge in these effects, complementary self-construal was moderated by the familiarity of the target, whether people focused on their relationship with or the appearance of the target, and whether the context was relevant for the interpersonal dimension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characterizing navigation maps for web applications with the NMM approach

This paper presents the Navigation Maps Modeling approach (NMM), which provides platform independent models for characterizing navigation maps of web applications. The NMM approach is conceived to obtain a trade off between high and low-level design notations. As high-level design notations, NMM models permit architectural details that may hinder the overall understanding of the web application to be left out. As low-level design notations, NMM models can easily be transformed into detailed architectural designs, which are very valuable at coding and maintenance stages.     

Impact of QOS requirements on video coding for ATM networks

The broadband integrated services digital networks (B-ISDN) based on asynchronous transfer mode (ATM) technology can support a wide range of applications such as voice, video, still images, and data. Compression techniques increase the effective bandwidth utilization, but the bursty and asynchronous nature of the traffic can still lead to congestion in the network, and degradation of image quality and quality of service (QOS). Some of the features to provide better coding schemes for ATM networks are layered coding, resynchronization, buffering, interleaved schemes, constrained bit rate due to buffers, encapsulation with the RTP or AAL1 for clock recovery, lapped transforms, motion compensation, and optimal bit allocation for coders based on wavelet transforms. We review various techniques forimage and video coding such as transforms, motion compensation, vector quantization, and subband coding. We outline the impact of the cell loss ratio (CLR), delay and cell delay variation (CDV) on video coding: blocking effects, loss of frame synchronization, motion vectors, and vector quantization codewords. The open problems include tuning coding parameters to the available QOS provided by the network.     

话音ATM交换的实现─—ATM论坛电路仿真系列建议

近年来，随着ATM主干网络的建设和发展，研究ATM对现有通信业务的支持方式和适配技术是目前ATM技术研究的热点之一。话音ATM交换在降低话音通信成本和简化网络操作环境等方面提供了大量的技术手段，并且支持在单一网络环境中的多种综合业务传输。ATM论坛制定了电路仿真系列建议，话音ATM交换的技术已经基本成熟。文章通过对话音ATM交换在实现和优化方面的技术进行分析，并提出一种基于NativeModeATM的话音通信方式。