格理论和存在句

格理论是Chomsky生成语法中的一个重要理论,对句子的生成以及句中名词短语的句法分布起着重要作用.但格理论对存在句的解释却不尽人意,虽然先后有过几种解决方案,但仍然是众说纷纭,意见不一.以格理论为指导,结合格传递说和LF词缀说对存在句的一致问题和名词短语的确指问题进行再探讨,解释存在句的主谓一致受制于there和其后的NP,其后的NP大部分情况下是不确指的NP,但有时也有确指的NP.     

城市交通流诱导系统与交通控制系统集成中的信息处理

分析了诱导和控制集成下的实时交通信息采集和信息传输过程,描述了城市交通流诱导系统与交通控制系统集成中的信息处理理论模型,建议采用基于出行者出行行为的动态交通分配模型,并在此基础上给出了全局最优路径的动态交通分配模型。此外还提出系统集成中的网络通信采用计算机支持的协同网络,并给出了一种基于Multicast通信的数据通信方式。     

An Ant-Based Approach for Dynamic RWA in Optical WDM Networks

In this paper, we propose a new ant-based algorithm for the dynamic routing and wavelength assignment (RWA) problem in optical WDM networks under the wavelength continuity constraint. Unlike conventional approaches, which usually require centralized global network information, our new RWA algorithm constructs the routing solution in a distributed manner by means of cooperative ants. To facilitate the ants’ foraging task, we adopt in our algorithm a probabilistic routing table structure for route selection. The new algorithm is highly adaptive in that it always keeps a suitable number of ants in the network to cooperatively explore the network states and continuously update the routing tables, so that the route for a connection request can be determined promptly by the current states of routing tables with only a small setup delay. Some new schemes for path scoring and path searching are also proposed to enhance the performance of our ant-based algorithm. Extensive simulation results upon three typical network topologies indicate that the proposed algorithm has a very good adaptability to traffic variations and it outperforms both the fixed routing algorithm and the promising fixed–alternate routing algorithm in terms of blocking probability. The ability to guarantee both a low blocking probability and a small setup delay makes the new ant-based routing algorithm very attractive for both the optical circuit switching networks and future optical burst switching networks     

Link-State-Based Algorithms for Dynamic Routing in All-Optical Networks with Ring Topologies

The increased usage of large bandwidth in optical networks raises the problems of efficient routing to allow these networks to deliver fast data transmission with low blocking probabilities. Due to limited optical buffering in optical switches and constraints of high switching speeds, data transmitted over optical networks must be routed without waiting queues along a path from source to destination. Moreover, in optical networks deprived of wavelength converters, it is necessary for each established path to transfer data from source to destination by using only one wavelength. To solve this NP-hard problem, many algorithms have been proposed for dynamic optical routing like Fixed-Paths Least Congested (FPLC) routing or Least Loaded Path Routing (LLR). This paper proposes two heuristic algorithms based on former algorithms to improve network throughput and reduce blocking probabilities of data transmitted in all-optical networks with regard to connection costs. We also introduce new criteria to estimate network congestion and choose better routing paths. Experimental results in ring networks show that both new algorithms achieve promising performance.     

Eigenstructure assignment in a class of second-order dynamic systems

Eigenstructure assignment using the proportional-plus-derivative feedback controller in a class of second-order dynamic system is investigated. Simple, general, complete parametric expressions for both the closed-loop eigenvector matrix and the feedback gains are established based on two simple Smith form reductions. The approach utilizes directly the original system data and involves manipulations only on n-dimensional matrices. Furthermore, it reveals all the degrees of freedom which can be further utilized to achieve additional system specifications. An example shows the effect of the proposed approach.     

Hybrid procedure to determine optimal workforce without noise hazard exposure

Hearing loss is a major occupational health problem among industrial workers. Repetitive exposure to loud noise increases the risk of hearing loss. An administrative noise control such as job rotation can help to reduce workers’ daily noise exposures. In a case where noise levels are excessively high, it is often necessary to assign additional workers to the current workforce to alleviate daily noise exposures that individual workers receive. This paper presents four solution algorithms (three approximations and one exact) to determine a minimum number of workers and their work assignments to attend noisy workstations without noise hazard exposure (that is, daily noise exposure does not exceed 90 dBA). Then, a hybrid procedure which utilizes the four algorithms successively is proposed to improve the solution procedure. Based on a computational experiment on 300 test problems, it is found that the hybrid procedure outperforms all four algorithms (when utilized separately) and is able to find an optimal solution for 88% of the test problems.     

高校工资分配体制改革的探索

本文主旨意在阐明现行的工资分配体制已不适应社会主义市场经济的发展和需要。随着改革的深入发展,我们应该转变观念,克服平均主义的影响,依据“效率优先,兼顾公平”的原则,建立符合高校教师劳动特点的工资分配制度。     

用自适应的多种群蚁群算法求解频率分配问题

提出一种自适应的多种群蚁群算法求解移动通信中的频率分配问题。该算法改变了传统蚁群算法只有一个蚂蚁群体的做法,使用多个蚂蚁子群体同时进行优化处理。为每个蚂蚁子群体定义一个收敛系数,根据收敛系数来决定子群体内部的路径选择和信息量更新、子群体间的信息交流策略,同时采用自适应的信息更新策略以取得各蚂蚁子群体中解的多样性和收敛性之间的动态平衡。通过对固定频率分配和最小跨度频率分配问题进行仿真的实验,表明此算法不仅具有较强的全局收敛性,而且有更快的寻优速度。     

Models and Approximation Algorithms for Channel Assignment in Radio Networks

We consider the frequency assignment (broadcast scheduling) problem for packet radio networks. Such networks are naturally modeled by graphs with a certain geometric structure. The problem of broadcast scheduling can be cast as a variant of the vertex coloring problem (called the distance-2 coloring problem) on the graph that models a given packet radio network. We present efficient approximation algorithms for the distance-2 coloring problem for various geometric graphs including those that naturally model a large class of packet radio networks. The class of graphs considered include (r,s)-civilized graphs, planar graphs, graphs with bounded genus, etc.     

一种多跳无线网扩频码分配算法

在多跳分组无线网中使用码分多址(CDMA)技术可以明显地降低隐终端问题对网络造成的影响.码分配是多跳无线网中使用CDMA的基本问题.码分配的目的在于提高扩频码的空间重用、降低分组冲突以及反映网络的动态变化.本文提出了一种多跳无线网扩频码分配算法,证明了其正确性并与其它算法比较了复杂度.与以往的算法追求降低码的数目不同,本算法是假设扩频码的数目有一定的冗余,寻求算法的方便、快捷和低通信开销.