Electrical conductivity in iodine-doped ethyl cellulose

The electrical conductivity of solution-grown ethyl cellulose (EC) films, 5–30 μm thick, has been studied in the sandwich configuration (metal–EC–metal) as a function of iodine concentration from 0.5 to 5.0 wt% ratio. The studies were conducted in the temperature range 333–383 K, while the field was varied over the range (3.0–5.5) × 10⁴V/cm. Aluminium was used as the lower electrode, while the upper electrode was of Al, Ag, Cu, Au or Sn. Certain transient effects such as a large burst of current immediately after the application of field were observed. An attempt was made to identify the nature of the current by comparing the observed dependence on electric field, electrode material and temperature with the respective characteristic features of the existing theories of electrical conduction. The results show that the electrical conduction follows Ohm's law at lower fields, while at higher fields, space-charge limited current (SCLC) was observed. It was also found that Richardson–Schottky emission was responsible, to some extent, for the transport of charge carriers in the polymer. The conductivity of the films increased on doping with iodine. The dopant molecules are considered to act as additional trapping centes and provide links between the polymer molecules in the amorphous region, thus resulting in the formation of charge transfer complexes.     

一种适合协同工作系统的安全认证方案

针对网络化协同工作系统的安全认证需求，综合应用Kerberos协议、X．509证书和口令认证技术，借鉴PKI的思想，设计了一种适合网络化协同工作系统的灵活而易于扩展的安全认证方案。这个方案能够保证证书的安全分发，满足网络化协同工作系统对分散、动态的用户安全身份认证的要求。     

示例学习的扩张矩阵理论

本文提出示例学习的一种计算理论,扩张矩阵论.根据这个理论,示例学习中一些主要最优化问题被证明是NP难题,并给出这些难题的近似解法及下界的估计.     

基于熵权的料场方案模糊多属性优选研究

砂石料场方案选择中存在着许多难以精确度量的模糊性因素，常规的平衡法、系统分析法很难对此进行有效的处理。将模糊数学理论应用于砂石料场的方案选择，提出了熵权与模糊理论相结合的砂石料场方案优选方法，重点对标准化属性矩阵的产生、主客观权重结合得到综合权重及相对接近度的计算等几个方面进行了说明，并通过实例验证了该方法的可行性与实用性。     

渐变填充的性质和算法

本文着重研究了Jordan数字流形上的渐变填充,设计了紧缩渐变填充算法和分裂渐变填充算法;并证明:如果D是离散网格空间上的Jordan凸集,那么存在O(|D||D|)时间的紧缩算法去做渐变填充.最后,我们对Jordan正方形区域、三角域和圆盘,分别给出了它们各自的O(|D|log_2|D|)时间的分裂渐变填充算法.     

Optimization Design for Digital Binoculars

In order to develop competitive and high performance/cost ratio of digital binoculars, design scheme should be optimized in term of technical capacity, economic benefit, product performance, risk management, etc. The common optimization method is limited in qualitative analysis, and the parameter optimization method is limited in obtaining optimal parameter only from technical side. Each method has its limitation. Based on the analysis of digital binoculars parameters, optional design schemes are laid down.Analytic hierarchy process combined the qualitative analysis with the quantitative analysis together. The design schemes are optimized, and result is worked out.     

Modified CIELAB formula tested using a textile pass/fail data set

The proposed new color-difference formula of CIE TC 129, which is a modified version of CIELAB, was tested with a recently published data set of textile pass/fail judgments. Goodness of fit is improved, if the parameter of lightness is set near 2, and if, additionally, a weight function for lightness is defined that reduces the weight of a lightness difference with lightness level in relation to chroma or hue scaling. © 1994 John Wiley & Sons, Inc.     

基于模糊度测度和改进遗传算法的图像分割

为了利用模糊集理论进行图像分割,本文提出了一种模糊度测度函数,它衡量了背景模糊集和某一个二值图像的相似性:模糊度越小,这种相似程度越大;并且对模糊度的计算只需要进行简单的比较运算和加法运算,便于硬件实现。本文利用遗传算法求取最佳阈值,针对遗传算法的某些不足之处.我们利用精英策略和模拟退火的思想,对其做了一些修正。实验结果表明:相对于Shannon熵方法和模糊熵方法,本文方法取得了较好的分割结果,并且具有较强的抗噪声能力。     

地震属性神经网络油气模式识别技术及其在东海的应用

神经网络油气模式识别技术是综合利用地震属性进行油气预测的技术之一 ,它首先通过计算获得多种地震属性 ,综合分析找出对储层油气比较敏感的地震属性组合 ;然后收集油气井与非油气井的井旁道地震属性 ,组成学习样本并进行神经网络学习 ;最后利用学习结果对储层进行油气预测。该技术在东海某工区的应用结果表明 ,振幅统计类和复数道统计类地震属性是对该地区储层油气最敏感的地震属性组合。神经网络油气模式识别技术可以作为东海地区储层油气预测的一种手段。     

A Two-Level Spreading-despreading CDMA System and Its Performance Evaluation

1　IntroductionHowtosuppresstheinterferenceintheCDMAsystems,includingtheSelfInterference(SI) ,Mul tipleAccessInterference(MAI)andtheAdjacentCellInterference(ACI) ,isthekeypointinimprov ingthesystemperformanceandcapacity .Insteadofthecomplicatedspecializedsignalprocessingtech niquesusedbefore[1～ 4] ,spreadingsequenceswithgoodcorrelationpropertiescanimprovethesystemperformanceradically[5] .InRef.[6～ 9],theconceptofZeroCorrelationZone (ZCZ) ,whichisequivalenttothegeneralizedothogonal…