Implementation and experimental studies of an adaptive self-optimizing power system stabilizer

This paper describes the implementation and experimental studies of an adaptive self-optimizing pole shifting power system stabilizer. Using an Intel iSBC386/21 single-board computer, the adaptive power system stabilizer has been tested on a physical model of a single-machine infinite-bus power system. Under different operating conditions and disturbances, the behavior of the proposed adaptive stabilizer was investigated. Comparison has also been made to a digital-type conventional fixed-parameter power system stabilizer. Results of the experimental studies show that the proposed adaptive stabilizer outperforms the conventional stabilizer.     

Results of the ASTM field test of tristimulus weighting functions

In 1993, the American Society for Testing and Materials carried out a field test of newly calculated tristimulus weighting factors. These weighting factors had been calculated by a method proposed by Venable. the test also included a method of correction for bandpass dependence put forth by Stearns. the purpose of the trial was to assess the possible reduction in bandpass dependence introduced by each of these sets of weights. A large number of sets of spectral data were gathered from the cooperators in the field test. Results of integration by the various sets of tristimulus weighting factors were calculated. A total of 15 120 color differences were calculated and statistics were derived to test the probable error resulting from each method of correction. Errors attributable to bandpass dependence were on the order of a few tenths to as much as one CIELAB unit when uncorrected weight sets were used. These errors could be reduced to a few hundreths of a CIELAB unit, and in some cases to a few thousandths of a unit, by employing one correcting strategy or the other. an overall mix of strategies was ultimately chosen to minimize the bandpass dependence over the entire range of weight sets. Utilizing this mixed strategy, the median error introduced into 10-nm integration by bandpass dependence was only 0.004 CIELAB units. © 1995 John Wiley & Sons, Inc.     

分析卤化银微晶的EDS方法探讨

本文探讨了用Ｘ射线能谱仪（ＥＤＳ）分析卤化银微晶的空间分辨率和吸收修正问题。对ＳＥＭ－ＥＤＳ和ＳＴＥＭ－ＥＤＳ两种不同分析模式的空间分辨率进行计算，表明ＳＴＥＭ－ＥＤＳ是研究单个卤化银微晶内碘的含量及分布的有效方法。并对定量分析数据和吸收修正参数进行了讨论，结果证明微晶不同区域厚度的差异，对碘含量的定量测定的影响可以忽略。     

野外观测系统的检验与校正

在地震资料处理中常常发现野外观测系统不准,其后果极为严重。为了避免重复施工,改善处理效果,笔者在IBM3081系统上编制了利用初至波对野外观测系统进行检验和校正的程序。文中介绍了两种校正方法:其一是只作炮检距校正。根据工区的小折射、井口时间、反射记录等资料提供一条或几条比较准确的初至时距曲线,作为标准曲线,然后将从实际共炮点道集中拾取的初至曲线与标准初至时距曲线相比较,确定出实际初至曲线所对应的炮检距,并对各个地震道的空间属性进行修改。对某三维工区的处理结果表明,该方法的效果良好。其二是先用迭代方法加误差约束条件计算炮点和检波点的坐标,然后计算炮检距,再进行校正。这种校正处理的效果也是明显的。但实验表明,对于观测系统误差较大的数据,不宜作坐标计算,只作炮检距校正尚可完成部分校正。处理中要根据数据的性质选取校正方法。     

Synthesizing Energy-Efficient Embedded Systems with LOPOCOS

In this paper, we introduce the LOPOCOS (Low Power Co-synthesis) system, a prototype CAD tool for system level co-design. LOPOCOS targets the design of energy-efficient embedded systems implemented as heterogeneous distributed architectures. In particular, it is designed to solve the specific problems involved in architectures that include dynamic voltage scalable (DVS) processors. The aim of this paper is to demonstrate how LOPOCOS can support the system designer in identifying energy-efficient hardware/software implementations for the desired embedded systems. Hence, highlighting the necessary optimization steps during design space exploration for DVS enable architectures. The optimization steps carried out in LOPOCOS involve component allocation and task/communication mapping as well as scheduling and dynamic voltage scaling. LOPOCOS has the following key features, which contribute to this energy efficiency. During the voltage scaling valuable power profile information of task execution is taken into account, hence, the accuracy of the energy estimation is improved. A combined optimization for scheduling and communication mapping based on genetic algorithm, optimizes simultaneously execution order and communication mapping towards the utilization of the DVS processors and timing behaviour. Furthermore, a separation of task and communication mapping allows a more effective implementation of both task and communication mapping optimizationsteps. Extensive experiments are conducted to demonstrate the efficiency of LOPOCOS. We report up to 38% higher energy reductions compared to previous co-synthesis techniques for DVS systems. The investigations include a real-life example of an optical flow detection algorithm.     

叠前地震数据的规则化

本文通过对动校正前积分法DMO原理的探讨，在借鉴Canning(1996)提出的利用DMO实现三维数据规则化的方法和Biondi(1998)提出的三维叠前地震数据方位角校正方法的基础上，从方位角校正的角度入手，利用DMO和DMO^-1相结合的处理流程对地震数据进行规则化，以得到新的规则的观测系统下具有所需特定方位角的观测数据。此方法可用于解决叠前地震数据道插值、陆上地震勘探中不规则观测数据的规则化和海上地震勘探中的羽状现象校正等问题，可将已有地震观测数据转变为特定观测系统的叠前地震数据，以便于某些处理方法的应用。此方法原理简单并具有广泛的适用性。     

用COEFGN程序实现Eclips系统对RFT仪器的温度校正

Eclips测井系统对阿特拉斯生产的FMT仪器进行温度校正的20个主刻度数据都是浮点数据，利用COEFGEN程序产生的浮点校正数据输入到Eclips测井系统中对RFT进行温度校正，把RFT仪器的温度压力关系的十进制主刻度数据转换成Eclips测井系统对FMT仪器进行温度压力校正的浮点数据，对RFT仪器所测的泥浆柱压力值和地层压力值进行了实时测井校正，并分析了校正前后的误差。     

数字放大器—3G无线基站的助推器

为了构筑第三代无线网络,人们需要对现有基础设施进行彻底改造,包括网络的发射基站。配置在无线基站中的新型数字控制功率放大器能够改善频谱利用率和功率效率,从而提高系统容量。PMC-Sierra公司的数字控制功率放大器采用了数字校正信号处理器(DCSP)以及自适应控制处理器和补偿估值器(ACPCE),该放大器可改善无线基础设施的可靠性,同时降低系统成本、规模及复杂性。     

实时中间件的研究与实现

解决分布式应用日益增多的实时问题需要实时中间件.实时中间件是分布式实时应用的支撑平台,它为应用提供表达实时约束的手段,并提供调度请求的机制和多种控制资源的方法,从而为分布式应用实现执行时间的可预测性提供方法.本文给出了实时中间件的概念体系,在分析中间件的体系结构模型的基础上,提出了一个多级线程池实时中间件体系结构,该模型不仅具有较强的并发处理能力,而且可以控制网络和请求使用的各种资源,能够提高系统的时间可预测性.采用该体系结构,我们实现了一个遵循实时CORBA规范的实时ORB,并通过详细的对比测试验证了多级线程池实时中间件模型的有效性.     

基于DSP的图像灰度校正

本文介绍了一个在用户视频环境下，采用典型非线性因子2.2进行非线性校正的公式；进而给出采用TMS320C2000进行图像灰度校正的软件设计方法。