城市化进程中地铁晚高峰经济出行模式分析

城市交通有早高峰与晚高峰之分,我国城市晚高峰有区别于早高峰的不同特征。因为晚高峰不需要像早高峰一样考虑直接迟到成本,只需要考虑相对晚到成本,如身体上的疲劳,晚间休息活动时间的减少等因素;并且在大城市,会分流一部分人群在回家前参加晚间活动。本文对晚高峰的这些特点进行分析,通过运筹学最优化方法建立实现社会收益最大化的基于地铁多方式经济出行模型并进行求解,对城市地铁出行经济模式和地铁站联合运营自行车及私家车停车场定价给出了参考性意见。     

基于绩效保障模式的可修备件保障系统运营管理策略

基于绩效保障模式,设计了一个由备件仓库和维修车间组成的装备可修部件闭环保障系统,推导了备件库存水平状态的稳态概率分布,计算了可用度等几个保障绩效度量指标,建立了基于可用度约束的保障系统运作优化模型,并通过仿真分析探讨了保障系统运营管理策略问题。     

基于FPGA的紫外光DPIM调制系统设计

为了验证数字脉冲间隔调制（DPIM）在紫外光通信中应用的可行性,设计了基于FPGA的DPIM调制和解调系统。调制过程在锁存器的控制下,将串并转换后的数据输入比较器,并与计数值相比较产生DPIM调制信号;在解调端,利用计数器检测相邻光脉冲间的空时隙数,在锁存器的控制下,恢复得到原始数据。以16-DPIM为例,随机输入一组串行二进制数据,经过调制系统得到了16-DPIM信号;同样随机输入一个16-DPIM调制信号,通过解调系统恢复得到了原始数据。并在此基础上提出了一种新型的双幅度、定长DPIM调制方式,能更好地弥补DPIM符号长度不固定的缺陷。     

小订单优先分配规则对供应链运作的影响

通过理论分析与实验研究相结合,在完全信息和不完全信息两种模式下,探讨供应短缺情景中小订单优先分配规则对零售商订货决策的影响。理论结果表明,小订单优先诱导零售商制定不超过真实市场需求量的订货决策,并且订货量不随运作成本而改变。实验数据表明,完全信息模式下,被试者的订货量高于理论预测值,不同运作成本的订货决策存在显著差异,并且被试者在不断重复决策中存在学习效应;不完全信息模式下,被试者的订货量与理论的预测没有显著偏差。这些研究结论为小订单优先分配规则的实践应用提供了理论和实证依据。     

Geometric Algebra for Subspace Operations

The set theory relations , \,,, and have corollaries in subspace relations. Geometric algebra is introduced as a useful framework to explore these subspace operations. The relations , \, and are easily subsumed by geometric algebra for Euclidean metrics. A short computation shows that the meet () and join () are resolved in a projection operator representation with the aid of one additional product beyond the standard geometric algebra products. The result is that the join can be computed even when the subspaces have a common factor, and the meet can be computed without knowing the join. All of the operations can be defined and computed in any signature (including degenerate signatures) by transforming the problem to an analogous problem in a different algebra through a transformation induced by a linear invertible function (a LIFT to a different algebra). The new results, as well as the techniques by which we reach them, add to the tools available for subspace computations.     

Hardware Implementation of Finite-Field Division

Algorithms for performing divisions over Z _p and GF(p ^m ) are described, the corresponding digital circuits are synthesized and conclusions about their computation times are drawn. The results of their implementation within field-programmable devices are given in the case of the most efficient ones.     

Notes on Th bit ibn Qurra and his rule for amicable numbers

On the basis of the Arabic text, we investigate how Th bit ibn Qurra (ninth century) could have found his rule for amicable numbers.     

A knowledge-based system for tactical situation assessment

To perform tactical situation assessment effectively, a system must be capable of performing tactical information integration, interpretation, and threat evaluation. This paper describes a prototype system for naval surface warfare which incorporates a human operator for integration, an artificial intelligence-based subsystem for interpretation, and an operations research-based system for evaluation. The system provides the operator with an interactive environment for displaying and managing tactical information and tools for interpreting and evaluating it.The opinions expressed in this paper are those of the author, are not official, and do not necessarily reflect the views of the Navy Department.     

LEVELS OF IMPLICATION AND TYPE FREE THEORIES OF CLASSIFICATIONS WITH APPROXIMATION OPERATOR

We investigate a theory of Frege structures extended by the Myhill-Flagg hierarchy of implications. We study its relation to a property theory with an approximation operator and we give a proof theoretical analysis of the basic system involved. MSC: 03F35, 03D60.     

The two-dimensional problem of steady waves on water of finite depth: regimes without waves of small amplitude

The two-dimensional problem of steady waves on water of finite depth is considered without assumptions about periodicity and symmetry of waves. A new form of Bernoulli's equation is derived, and it involves a new bifurcation parameter which is the product of the Froude number μ and the rate of flow ω. The main result obtained from this equation is the absence of waves, having sufficiently small amplitude, provided $|\mu \omega |>1$. To cite this article: V. Kozlov, N. Kuznetsov, C. R. Mecanique 333 (2005).