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排序方式: 共有1846条查询结果,搜索用时 62 毫秒
71.
区间数的排序方法研究 总被引:26,自引:1,他引:26
指出献^[3-5]所定义的用于区间数排序的可能度存在的不足,分别给出了刻画区间数大小比较的相对优势度的定义和模糊互补矩阵排序的一种新方法。在此基础上,给出了区间数的一种排序方法。 相似文献
72.
73.
基于相对熵的不完全信息群体专家权重的集结 总被引:1,自引:1,他引:1
万树平 《应用数学与计算数学学报》2009,23(1):66-70
针对属性权重信息和属性效用信息都不完全的群体多属性决策问题,运用相对熵理论提出了一种专家权重的确定方法.该方法通过集结各方案的综合评价值向量,客观地得到专家的权重,避免系统聚类方法中由给定相似度水平归类而产生的主观性问题.应用实例表明了方法的有效性和实用性. 相似文献
74.
中医方药量化研究中“相对药量”的数学模型体系 总被引:7,自引:4,他引:7
建立中医方药量华研究的"相对药量"概念模型体系;方法:运用微分方程理论;提出五种情况下,中药常用量范围内相对药量概念的数学模型,分别为直线模型、指数函数模型、对数函数模型、二次函数模型(开口向上和向下两种),并说明该模型体系的和理性与适应性;结论:相对药量概念核心体系的建立,增加了中医方药"相对药量"可比性的全面性,这对进一步研究单位药乃至方剂中各药在性、味、归经等方面的影响程度及其规律性,将起到至关重要的作用. 相似文献
75.
A. Morozov T. Heindl J. Wieser R. Krücken A. Ulrich 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(1):51-57
Continuous and pulsed 12 keV electron beams were used to excite nitrogen
within a gas cell at pressures ranging from 10 to 1400 hPa. The pressure
dependence of the ratio of photon fluxes for emission from vibrational
levels v'=0 and 1 of the C 3Π u state has been studied. The
results confirm the presence of a collisional excitation mechanism
populating v'=0, 1 in addition to electron impact excitation. Rate constants
of (1.27 ±0.04)×10-11 cm3s-1 [ v'=0] and
(2.68 ±0.08)×10-11 cm3s-1 [ v'=1] were measured for
C 3Π u quenching by ground state nitrogen. For electron beam
conditions relative excitation efficiencies of 1:0.59:0.22 for
vibrational levels 0, 1 and 2 were calculated. The recorded flux ratios are
compared with the predictions given by a vibrational relaxation model. 相似文献
76.
Considering a two-level atom interacting with the competing two-mode field, this paper investigates the entanglement between the two-level atom and the two-mode field by using the quantum reduced entropy, and that between the two-mode field by using the quantum relative entropy of entanglement. It shows that the two kinds of entanglement are dependent on the relative coupling strength of atom-field and the atomic distribution, and exhibit the periodical evolution. The maximal atom-field entanglement state can be prepared via the appropriate selection of system parameters and interaction time. 相似文献
77.
WU Jin-Jie HENG Yue-Kun SUN Zhi-Jia WU Chong ZHAO Yu-Da YANG Gui-An JIANG Chun-Hua 《中国物理C(英文版)》2008,32(3)
A new charge measurement method, time over threshold (TOT), has been used in some gas detectors lately. Here TOT is studied for TOF system, made of plastic scintillator counter, which can simplify the electronics of the system. The signal characteristics are measured and analyzed with a high quality oscilloscope, including noise, pedestal, signal amplitude, total charge, rise time and the correlation between them. The TOT and charge are related and can be fitted by some empirical formula. The charge measurement resolution by TOT is given and this will help the design of TOF electronics. 相似文献
78.
We study the spectrum of Hamiltonians of charged multiparticle systems in a homogeneous magnetic field with a fixed sum P
of the pseudomomentum components and without it. We prove that if P
is fixed, then the spectrum of Hamiltonians is independent of the value of P
, while the spectrum without fixation of P
coincides with the spectrum with fixation and differs from the latter only by some additional infinite degeneration (this is a principal difference between problems with a homogeneous magnetic field and problems without any field in which the absence of any fixation of the total angular momentum results in covering the spectrum of the relative motion by a continuous spectrum). We find the continuous spectrum of the Hamiltonians and characterize the spectrum of Hamiltonians of two-cluster mutually noninteracting systems obtained by decomposing the original system in the state with a fixed value of P
. The last result is necessary for the study of the purely point spectrum. 相似文献
79.
We prove some limiting results for a Lévy process X
t
as t0 or t, with a view to their ultimate application in boundary crossing problems for continuous time processes. In the present paper we are mostly concerned with ideas related to relative stability and attraction to the normal distribution on the one hand and divergence to large values of the Lévy process on the other. The aim is to find analytical conditions for these kinds of behaviour which are in terms of the characteristics of the process, rather than its distribution. Some surprising results occur, especially for the case t0; for example, we may have X
t
/t
P
+ (t0) (weak divergence to +), whereas X
t
/t a.s. (t0) is impossible (both are possible when t), and the former can occur when the negative Lévy spectral component dominates the positive, in a certain sense. Almost sure stability of X
t
, i.e., X
t
tending to a nonzero constant a.s. as t or as t0, after normalisation by a non-stochastic measurable function, reduces to the same type of convergence but with normalisation by t, thus is equivalent to strong law behaviour. Boundary crossing problems which are amenable to the methods we develop arise in areas such as sequential analysis and option pricing problems in finance. 相似文献
80.
Marco Buratti 《Designs, Codes and Cryptography》2002,26(1-3):111-125
We prove the existence of a cyclic (4p, 4, 1)-BIBD—and hence, equivalently, that of a cyclic (4, 1)-GDD of type 4
p
—for any prime
such that (p–1)/6 has a prime factor q not greater than 19. This was known only for q=2, i.e., for
. In this case an explicit construction was given for
. Here, such an explicit construction is also realized for
.We also give a strong indication about the existence of a cyclic (4p 4, 1)-BIBD for any prime
, p>7. The existence is guaranteed for p>(2q
3–3q
2+1)2+3q
2 where q is the least prime factor of (p–1)/6.Finally, we prove, giving explicit constructions, the existence of a cyclic (4, 1)-GDD of type 6
p
for any prime p>5 and the existence of a cyclic (4, 1)-GDD of type 8
p
for any prime
. The result on GDD's with group size 6 was already known but our proof is new and very easy.All the above results may be translated in terms of optimal optical orthogonal codes of weight four with =1. 相似文献