Subtractive Categories and Extended Subtractions

We introduce a notion of an extended operation which should serve as a new tool for the study of categories like Mal’tsev, unital, strongly unital and subtractive categories. However, in the present paper we are only concerned with subtractive categories, and accordingly, most of the time we will deal with extended subtractions, which are particular instances of extended operations. We show that these extended subtractions provide new conceptual characterizations of subtractive categories and moreover, they give an enlarged “algebraic tool” for working in a subtractive category—we demonstrate this by using them to describe the construction of associated abelian objects in regular subtractive categories with finite colimits. Also, the definition and some basic properties of abelian objects in a general subtractive category is given for the first time in the present paper. The second author acknowledges the support of Claude Leon Foundation, INTAS (06-1000017-8609) and Georgian National Science Foundation (GNSF/ST06/3-004).     

单源模糊数及其运算

本文首先指出模糊数的运算存在模糊源问题，然后定义了单源模糊数的一些基本概念，并建立了单源模糊数的运算方法，最后给出了单源模糊数线性方程组的求解方法。     

X射线通信系统的误码率分析

基于栅极控制脉冲发射X射线源与单光子探测技术的X射线通信语音方案已经在实验室实现, 为探索未来X射线深空通信应用打下了坚实的基础. 实验室X射线语音通信演示系统实现后, 迫切需要测试X射线通信系统的误码率性能. 在泊松噪声模型下对X射线通信演示系统的理论分析的基础上, 使用基于现场可编程门阵列的误码率测量方法对开关键控调制方式下X 射线通信误码率进行测量. 通过实验测量发现, 要实现语音通信, 系统误码率应该达到10^-4 量级; 分析、测量了现有系统在开关键控调制方式下不同速率对应的误码率, 论证了泊松噪声模型理论分析现有X射线通信系统的合理性; 分析提出了限制现有实验室条件下X 射线通信误码率性能的主要因素.     

Tight upper bound on the quantum value of Svetlichny operators under local filtering and hidden genuine nonlocality

Nonlocal quantum correlations among the quantum subsystems play essential roles in quantum science. The violation of the Svetlichny inequality provides sufficient conditions of genuine tripartite nonlocality. We provide tight upper bounds on the maximal quantum value of the Svetlichny operators under local filtering operations, and present a qualitative analytical analysis on the hidden genuine nonlocality for three-qubit systems. We investigate in detail two classes of three-qubit states whose hidden genuine nonlocalities can be revealed by local filtering.     

数据包络分析在信用评估中的应用

提出了一种基于拒绝案例集的数据包络分析模型和边界为分段线性分离超平面的分类方法，探讨了在只掌握单方面信息(信用差的单位)的情况下，如何对新单位进行信用评估的问题，并给出了评价决策单元信用状况的具体方法，应用实例表明所提出的模型和方法是可行的。     

成本最小问题与(弱)DEA有效性

在文[1]的基础上,本文证明了在一定条件下对所给的决策单元、其弱DEA有效性或DEA有效性能由成本最小问题的最优解来判断.     

A dynamic programming approach for the airport capacity allocation problem

In most of the optimization models developed to manage airportsoperations, arrivals and departures capacities are treated asindependent variables: that is the number of flights allowedto take off does not affect the number of landings in any unitof time, and vice versa. This assumption is seldom verifiedin most of the congested airports, where many interactions betweenarrivals and departures take place. In this paper, we face the problem of finding the optimal trade-offbetween the number of arrivals and departures in order to reducea delay function of all the flights, using a more realisticrepresentation of the airport capacity, i.e. the capacity envelope. Under the assumption of piecewise linear convex capacity envelopesand of the exact interpolation of all the Pareto-optimal operationalpoints, we show that the problem can be formulated as a linearprogramming model. For general airport capacity envelopes, wepropose a dynamic programming formulation with a correspondingbackward solution algorithm, which is robust, easy to implementand has a linear computational complexity. The algorithm performancesare evaluated on different realistic scenarios, and the optimalsolutions are compared with those computed by a greedy algorithm,which can be seen as an approximation of the current decisionprocedures. The percentage deviation of the cost of these twosolutions ranges from 3.98 to 35.64%.     

实际QKD系统误码检测的检错比特数研究

在量子密钥分发协议中,需要消耗一定的比特用于误码检测.研究实际QKD系统中用于检测量子误码率的检测比特数,得到了误码率、允许误差、漏检率和最少检测比特数之间的关系;分析了实际QKD系统中所需要的检测比特数.研究结果表明,实际QKD系统中,用于误码检测的检测比特数为2 760时就可以估算量子误码率.     

一种低重频高码率紫外光通信方法和系统

针对低重频光源要实现高码率数据传输的问题,采用紫外激光器作为光源,研究了4-PPM调制解调算法,在FPGA上实时实现该算法,并由此构建了一套基于紫外激光器的紫外光通信系统。外场通信实验表明,在紫外激光器脉冲重复频率为20kHz的条件下,通信系统可实现码率高达40kbit/s的数据传输,误码率优于10-4。