基于代码检测的软件故障定位方法

针对现有软件故障定位方法的缺陷，提出了一种基于代码检测的软件故障定位方法，用嵌入式模块获取软件发生故障时的模块运行序列，分析出软件故障可疑模块集及其故障系数，在此基础上对故障模块进行代码的分类检测，根据上述过程中得到的结果进行综合分析运算，得出软件故障的可疑代码集和故障系数，采用代码分析辅助工具进行排查，定位故障。该方法已成功应用于软件密集型系统的故障诊断，能快速有效地实现软件故障定位。     

七大案例 解决CPU常见故障

电脑用久了，难免会出现这样那样的故障。在众多电脑故障中，板卡类出现机率最大。CPU虽然是电脑中重要的配件，但出现故障的机率相当少，常见的CPU故障大致有以下几种：散热故障、重启故障、黑屏故障及超频故障。由于CPU本身出现故障的几率非常小，所以大部分故障都是因为用户粗心大意造成的。[编者按]     

微机系统板故障的诊断

微机的系统板故障可分为关键性故障和非关键性故障。关键性故障措CPU无法执行预定的程序——ROMBIOS，或无法进行正常的操作，或无法实现必需的功能。绝大多数关键性故障都表现为黑屏、无任何显示或死机。非关键性故障是指系统板的某些非关键的功能失常，但不影响微机基本功能的实现。绝大多数非关键性故障都可由屏幕显示故障部位，放本文对此不作展开，主要介绍关键性故障的诊断。关键性故障可分为总线故障和功能模块故障。下面分别予以介绍。总线故障所谓总线故障，是指系统板上的地址总线、数据总线和控制总线出现故障，从而无法完…     

基于GPS-PTK技术的变电站故障高精度定位方法

为了提高变电站故障高精度定位能力，提出基于GPS-PTK技术的变电站故障高精度定位方法。构建变电站故障高精度特征分布式融合模型，结合对变电站故障稳态信息采集样结果，提取变电站故障特征分布的谱信息分量，考虑涌流的衰减过程，实现变电站故障的属性类别辨识；通过对变电站故障分布的涌流波形状态分布，采用GPS-PTK技术进行变电站故障特征聚类，根据特征聚类结果，实现对变电站故障高精度定位。仿真结果表明，采用该方法进行变电站故障定位的效率较高，检测定位性能误差率较低，提高了变电站故障的准确识别和诊断能力。     

基于FCA的物理层故障定位方法

提出了一种基于故障关联算法（FCA）的物理层故障定位模型，依据故障之间的关联关系，运用图论和故障矩阵的方法求出根故障集，确定故障源，有效地起到故障过滤和定位的功能。     

基于FPGA的铁路电力行波故障定位装置设计

针对铁路运输系统中输电线路故障测距和定位效果不佳的问题，提出基于FPGA的铁路电力行波故障定位系统装置。首先，基于暂态行波方法进行故障性质判断，并采用行波信号采集装置进行信号采集；然后利用模极大值算法进行故障特征提取，并通过模量波速时差分段法求出故障距离，从而实现电力行波故障准确定位。仿真结果表明，在铁路线路长度为60 km的状况下，本方法的绝对误差和相对误差分别控制在100 m和0.12%范围内，适应性极强；故障初相角仿真模拟中，故障初相角测距中的绝对误差始终低于80 m,测距误差较小。在不同故障类型测试中，提出故障测距方法的距离误差控制在100 m范围内，测距精度较高。最后在不同故障类型、故障距离和时间差的条件下，本装置的故障距离绝对误差均稳定在200 m范围内。由此可知，设计的故障测距定位装置具备操作性和稳定性，核心故障测距算法提高了电力行波故障定位精度，满足系统设计需求。     

基于近似熵的小电流接地系统故障区段定位

在分析小电流接地系统单相接地故障暂态零序电流特征基础上，提出将近似熵法应用于故障区段定位中。首先主站进行线路不同区域发生故障和线路不发生故障情况模拟，计算出所有情况下的不同故障指示器零序电流近似熵值和相邻检测点近似熵值比，分别设定首段故障阈值和区内故障阈值。求取故障线路所有检测点零序电流近似熵值和熵值比，将熵值比和熵值分别与设定的区内故障阈值和首尾故障阈值比较，进行故障区段定位。最后通过MATLAB/Simulink搭建10kV小电流接地系统单相接地故障仿真模型进行验证。仿真结果证明，上述方法能够有效进行故障区段定位，且不易受接地电阻、故障初相角等复杂因素的影响。     

微机适配卡故障的诊断

上一期中我们介绍了微机系统板故障的诊断，本文我们介绍微机外围适配卡故障的诊断。微机的外围适配卡包括：显示适配卡、打印适配卡、异步通信适配卡、软硬盘适配卡等。这类卡的故障分为总线故障和功能故障两种。总线故障由于外围适配卡是插在系统板的总线扩展槽上进行工作的，其总线发生故障特别是击穿性故障，不但会使外围适配卡本身无法工作，还会使系统板出现故障，无法进行自检，出现死机的现象。对于这类故障，一般的诊断方法是贴胶布法，就是将发生故障的外围适配卡的插槽引脚逐个或分批地用胶布隔离，来观察故障现象是否改变，从而…     

Novell常见故障处理与维护

计算机网络在日常运作中遇到的故障可分为三方面故障：服务器、传输介质、工作部．1服务器故障服务器故障可分为便讲故障和软件故障，本文又讨论软件故障．无论是硬件教障还是软件故障，均会导致整个网络瘫痪，使入网的工作站不能正常工作，每台工作站都不能登录上网使用服务器     

500kV主变夹件接地故障的分析与处理

介绍了一起500kV主变夹件接地故障的分析与现场处理。当主变夹件接地故障后，在不具备彻底消除故障的情况下，通过对故障性质及故障原因的综合分析，应采取串入电阻的方法来限制接地电流。反之，应彻底消除故障。     

Interannual covariability between actual evapotranspiration and PAL and GIMMS NDVIs of northern Asia

This study examined the covariability between interannual changes in the normalized difference vegetation index (NDVI) and actual evapotranspiration (ET). To reduce possible uncertainty in the NDVI time series, two NDVI datasets derived from Pathfinder AVHRR Land (PAL) data and the Global Inventory Monitoring and Modeling Studies (GIMMS) group were used. Analyses were conducted using data over northern Asia from 1982 to 2000. Interannual changes over 19 years in the PAL-NDVI and GIMMS-NDVI were compared with interannual changes in ET estimated from model-assimilated atmospheric data and gridded precipitation data. For both NDVI datasets, the annual maximum correlation with ET occurred in June, which is the beginning of the vegetation growing season. The PAL and GIMMS datasets showed a significant, positive correlation between interannual changes in the NDVI and ET over most of the vegetated land area in June. These results suggest that interannual changes in vegetation activity predominantly control interannual changes in ET in June. Based on analyses of interannual changes in temperature, precipitation, and the NDVI in June, the study area can be roughly divided into two regions, the warmth-dominated northernmost region and the wetness-dominated southern region, indicating that interannual changes in vegetation and the resultant interannual changes in ET are controlled by warmth and wetness in these two regions, respectively.     

Methods of system development in Finland

Interest in the use of different methodologies, methods and tools for information systems analysis and design has been increasing for the last decade in Finland. This has resulted in the founding of a special interest group in systems analysis and design within the Finnish Data Procesing Association and in its making a survey of the methods and tools in use in Finland in 1980. This survey was in the form of a questionnaire mailed to the company members of the association. The results of the survey show a wide use of different tools in the design and implementation of information systems. In the analysis phase, there seems to be a need for more and better methods and tools. In 1980 several companies began to use new methodologies, methods and tools in the field; the most common are: the Swedish ISAC, Jackson's JSP, and the data dictionary.     

关联规则挖掘技术研究进展*

为帮助人们深入研究关联规则挖掘技术,总结了关联规则的分类方法、评价方法以及相关技术的最新进展,特别是对关联规则的主要算法进行了详细的介绍,并探讨未来的发展方向。该研究比较系统全面,对将来进一步深入分析关联规则挖掘技术具有指导意义。     

Organisational computer supported collaborative learning: the affect of context

The purpose of this introduction is to provide a brief overview of the articles in this special issue and also a framework for understanding, designing and evaluating strategies for co-operative learning in the workplace and in educational environments. The special edition is divided into two parts—Issue 1: Computer Supported Collaborative Learning in Formal Education, and Issue 2: Computer Supported Team and Organisational Learning in Workplaces. In general, Issue 1 focuses on collaborative learning in primary and secondary schools and in the University setting. Issue 2 is meant to focus on learning in complex and often highly stressful work situations which mostly require intensive communication in groups or teams and in each case allow for learning in the wider organisation. This introduction outlines a set of themes that can be found in the following papers and traces briefly how each paper fits within each discussion.     

基于Visual FoxPro环境AeCESS数据库操作的实现

在Visual FoxPro中使用ACCESS数据库,能够克服其自奄存在的数据库、数据表与索引文件分离、数据表安全性不高等不利因素,较好地发挥二者在数据库管理与编程方酗的优势。鉴于这方面的资料较少,系统地阐述Visual FoxPm环境下ACCESS数据库的操作方法,实现在Visual FoxPro中ACCESS数据库的建立、压缩与修复;数据表的建立、结构与记录的维护;Visual FoxPro数据库与ACCESS数据库的相互转换、Visual FaxPro中通用字段与ACCESS中OLE字段的数据转换等方法是很多用户的客观需求。用Visual FoxPro编程方式全面操纵ACCESS数据库具有重要的理论与应用价值。     

Ecosystem functioning of protected and altered Mediterranean environments: A remote sensing classification in Doñana, Spain

Spatial heterogeneity in ecosystem functioning is a key component of ecological variability requiring special attention in the context of global change. A large history of human use has produced high physiognomic heterogeneity in Mediterranean ecosystems. However, the consequences for ecosystem functioning remain insufficiently understood. We analyzed spectral indicators of matter and energy fluxes in the land surface to classify the functional ecosystem heterogeneity in a Mediterranean region covering different management histories and protection types. We specifically analyzed the spatial variability in seasonal and annual patterns in the Normalized Difference Vegetation Index (NDVI), surface temperature (T_s) and albedo from five Landsat ETM images. Then we classified numerically this variability into ecosystem functional types (EFTs) and explored their seasonal dynamics in terms of photosynthetic radiation absorption and evapotranspiration. We identified eight main EFTs with ecologically relevant differences including contrasting dynamics in fPAR seasonality, great variation in incoming radiation reflection and differing evapotranspiration rates, particularly during the water-limitation period. Functional variability in natural vegetation mostly consisted in dissimilar annual rates of NDVI and albedo, whereas differences in seasonality were more evident in transformed areas. Similarly, the spatial distribution of EFTs was partly associated to protection, with two EFTs exclusive of protected areas and comparatively higher functional diversity in humanized areas. Landform effects on water availability in protected areas and human activities under different ecological settings were seemingly responsible for the large functional diversity of the region. We advocate for the explicit incorporation of multifunctional ecosystem heterogeneity in ecosystem management and monitoring designs.     

Combined effects of fabric air permeability and moisture absorption on clothing microclimate and subjective sensation during intermittent exercise at 27 degrees C

The present paper aimed at determining the combined effects of two different levels of air permeability and moisture absorption, in terms of clothing microclimate and subjective sensation, in resting and exercising subjects at an ambient temperature of 27 °C, a relative humidity of 50% and an air velocity of 0.14 m s^-1. Three kinds of clothing ensemble were investigated: (1) polyester clothing with low moisture absorption and low air permeability (A), (2) polyester clothing with low moisture absorption and high air permeability (B), and (3) cotton clothing with high moisture absorption and high air permeability (C). The subjects exercised for 10 min on a cycle ergometer at an intensity of 30% maximal oxygen uptake and then had a 10 min rest. This sequence was repeated four times. The main findings are summarized as follows: (1) The clothing microclimate humidity in the back area was significantly higher in A than in B, and in C than in B. (2) The clothing microclimate temperature in the chest area was significantly higher in B than in A, and in B than in C. (3) The clothing microclimate temperature in the back area was significantly higher in C than in B. (4) The clothing surface temperature was significantly higher in C than in B. (5) Although the positive relationships between the microclimate humidity and forearm sweat rate was significantly confirmed in all three kinds of clothing, the microclimate humidity at chest for the same sweat rate was lower in C than in A and B. (6) Although the positive relationships between subjective sensation and forearm sweat rates were significantly confirmed in all three kinds of clothing, the subjective discomfort seemed to be reduced more effectively in C than in A and B for the same sweat rate. These results were discussed in terms of thermal physiology and combined effects of air permeability and moisture absorbency of the fabrics.     

古典青铜器设计中科学性与艺术性的统一

本文主要对于古典青铜器中科学技术的运用从其设计上科学性与艺术性的统一上进行了分析和研究。希望通过本文让大家对古典青铜器设计中科学性与艺术性的统一有一个了解和认识,以便日后更好地运用到现代的产品设计中。     

Spatio-temporal distribution of rice phenology and cropping systems in the Mekong Delta with special reference to the seasonal water flow of the Mekong and Bassac rivers

Multi-temporal Moderate Resolution Imaging Spectroradiometer (MODIS) data was used to estimate the spatial distribution of heading date and rice-cropping system employed in the Mekong Delta relative to seasonal changes in water resources in 2002 and 2003. We improved a Wavelet-based Filter for determining Crop Phenology (WFCP) and developed a Wavelet-based Filter for evaluating the spatial distribution of Cropping Systems (WFCS) to the interpretation of MODIS time-series data to determine the spatial distribution of rice phenology and various rice-cropping systems from the seasonal Enhanced Vegetation Index (EVI) data. The findings correspond well the physical characteristics of the cropping system in the Mekong Delta, which have changed over time in response to localized and seasonal changes in water resources. One such example is the double-irrigated rice-cropping system commonly employed in the upper Mekong Delta in the dry season to avoid damage due to the subsequent floods. The shortage of suitable irrigation water and intrusion of saline water in the coastal regions during the dry season has constrained the practice dry-season cropping and has meant that the double- and single-rainfed rice-cropping systems are employed in the rainy season. A triple-irrigated rice-cropping system is used in the central part of the Mekong Delta which is located midway between the flood-prone and salinity intrusion areas. Analysis of annual changes in the rice cropping systems between 2002 and 2003 showed that the triple-cropped rice expanded to the flood- and salinity-intrusion areas. This expansion indicates that the implementation of measures to limit the extent of flooding and salinity intrusion by improved farming technologies and improvements in land management. The heading dates in the upper Mekong Delta in 2003 were earlier than in 2002 by approximately 20 to 30 days. The reasons for this would be due to decreased flood runoff in 2002 compared to 2001, and implementation of government policies regarding early sowing of dry-season crops. Subsequent analysis of the MODIS data confirmed that the spatial distribution of rice-cropping systems was closely related to seasonal changes in river runoff regime in the Mekong Delta.     

基于机器学习的设备预测性维护方法综述

机器学习算法能够处理高维和多变量数据,并在复杂和动态环境中提取数据中的隐藏关系,在预测性维护技术中具有很好的应用前景。然而,预测性维护系统的性能取决于机器学习算法的选择,对目前应用与预测性维护中的机器学习算法进行综述,详细比较了几种机器学习算法的优缺点,并对机器学习在预测性维护研究中的应用进行了展望。