关于现代河流生态保护的哲学思考

从矛盾观、自然观、系统观等唯物辩证法的方法论入手,对河流生态保护进行了哲学反恩。必须运用系统的观点来看待河流系统,保护河流系统的完整性和连续性;必须减轻人类活动对河流自然形态的限制,恢复河流的千姿百态;必须深刻认识河流的演化规律,正确处理好人类和河流之间的关系,不断实现人水和谐;必须尊重河流生命,从辩证的角度在河流开发利用与河流保护之间不断寻求折中点,通过最大努力保护和修复河流生态。     

Real and Ideal Institutional Frameworks for Managing the Common Arab-Israeli Water Resources

The Oslo A and B agreements of September 1993 and September 1995 were the beginning of a process aimed at a peaceful resolution of the Arab-Israeli conflict. The Israeli-Jordanian Treaty of 1994 addresses issues of water sharing between the two parties. In 1995, Israel and the Palestinians signed an Agreement on Water and Sewage as part of their Interim Agreement. In February 1996, Israel, Jordan, and the Palestinians agreed to a “Declaration of Principles for Joint Development of Water Resources.” The purpose of this paper is to compare the components of the two Agreements with an “ideal” institution for management of shared water resources. The “ideal” institution was formulated by 23 water experts who were interviewed on this issue. The main finding is that in most respects, expert opinions did not differ significantly from the Israeli-Jordanian Treaty of Peace and the Israeli-Palestinian Interim Agreement.     

Kinematic analysis of 3SPS+1PS bionic parallel test platform for hip joint simulator based on unit quaternion

As a novel parallel hip joint simulator, the 3SPS+1PS bionic parallel test platform with 4 degrees of freedom including three rotations and one translation is proposed. SPS denotes the spherical-prismatic-spherical leg and PS denotes the prismatic-spherical leg where only the prismatic joint is actuated and hence underlined. By means of the unit quaternion method, the formulae for solving the inverse/forward displacement, the inverse/forward velocity and the inverse/forward acceleration kinematics are derived. Using the unit quaternion to represent the position and orientation of a moving platform, singularities caused by Euler angles can be avoided. Combining the topological structure characteristics of the 3SPS+1PS bionic parallel test platform and letting the three-dimensional (3-D) motion of a human hip joint as its output movement, the displacement trajectories of three active legs are constructed based on the inverse displacement kinematics. The forward kinematic tests whose data are recorded by a 3-D orientation capture system are carried out on the developed parallel hip joint simulator. Moreover, the results of the forward kinematic tests prove that the 3SPS+1PS bionic parallel test platform can approximately represent human hip joint motion and provide more reliable experimental data for hip joint prostheses in clinical application.     

A composite likelihood approach for spatially correlated survival data

The aim of this paper is to provide a composite likelihood approach to handle spatially correlated survival data using pairwise joint distributions. With e-commerce data, a recent question of interest in marketing research has been to describe spatially clustered purchasing behavior and to assess whether geographic distance is the appropriate metric to describe purchasing dependence. We present a model for the dependence structure of time-to-event data subject to spatial dependence to characterize purchasing behavior from the motivating example from e-commerce data. We assume the Farlie-Gumbel-Morgenstern (FGM) distribution and then model the dependence parameter as a function of geographic and demographic pairwise distances. For estimation of the dependence parameters, we present pairwise composite likelihood equations. We prove that the resulting estimators exhibit key properties of consistency and asymptotic normality under certain regularity conditions in the increasing-domain framework of spatial asymptotic theory.     

多单播模型下的网络编码研究

每个信源-信宿对之间只有一个商品流(Commodity)唯一地表示从信源到信宿的流量,该模型称为多单播模型.由于无线网络、P2P等应用均可看作基于多单播模型,所以如何在多单播模型下提升网络的性能成为研究的重点.网络编码近年来作为能有效提升网络性能的方法之一,其应用于多单播模型下的各种科学问题成为研究热点.本文研究多单播模型下的网络编码关键理论,主要内容包括网络容量区域、编码构造算法和联合编码等方面,最后讨论基于多单播模型下网络编码的研究前景.     

基于CORBA实现电网联合反事故演习

联合反事故演习是保证电网安全稳定运行的关键。随着电力系统仿真技术的发展,文中提出利用分布式仿真技术来实现电网联合反事故演习。在此方案中基于CORBA的分布式面向对象的体系结构,提出一种多层的C/S的数据服务模型,从而提高了分布式仿真系统中数据的可用性和实时性,并且大大地减少了网络传输中的冗余信息。     

浅析浅城市轨道交通高架车站的空调选型

通过对城市轨道交通高架车站几种空调选型的分析，得出VRV多联空调系统是针对高架站最适合的空调方式。     

一种最佳空间滤波器在圆柱型基阵上的实现

根据最佳空间滤波器的数学表述,在圆柱型基阵上实现了最佳空间滤波器。研究了目标附近数个干扰源存在情况下弱信号检测及干扰的抑制效果。表明在圆柱型基阵上最佳空间滤波器能够有效抑制多个干扰、完成弱信号检测。设计的最佳空间滤波器实现方法可以方便地在圆柱型基阵上实现。     

Ni元素对Al-Si-Cu基真空钎焊料接头性能的影响

研究了添加Ni的Al-Si-Cu基钎料真空钎焊LF21铝合金接头的力学性能、微观组织形貌.结果表明,采用添加Ni元素的真空钎料,可提高钎焊接头的剪切强度,其机制在于Ni元素能够改善LF21铝合金真空钎焊接头焊缝及其基体组织的分布.但随着Ni元素含量的增加,其钎料的熔点也有所提高.