震区读者，我们永远心相连

一个月过去了,坚强、乐观、团结的中华民族被暖暖的爱包围着……《电脑爱好者》杂志社时刻关注着震区的救援和灾后重建,同时,我们也积极地捐款捐物,贡献我们的力量。有一个群体,一直在我们的心中牵挂,那就是震区的读者!《电脑爱好者》作为全国发行量最大的IT杂志,在震区的读者覆盖率非常高!不说庞大的邮购读者库,不说最近几项大型读者调查积累的数据库,仅仅是2008年登录爱好者网站显示IP所在地为四川的网友,就达几万人之多。我们把邮件汇总,发去了慰问信,我们还联系了一些读者代表,希望从他们的乐观中,为全国的CFan人寻找力量。     

一种基于蚁群算法的震区环境监测系统设计

针对目前震区生态恢复、环境保护监测的需要,论文提出了一种基于蚁群算法的震区监测系统,利用智能无线传感器网络对光强、温度、湿度等生态环境变量进行监测的方法.该方法解决了传统监测方法中布线复杂、精度有限、能耗高等问题,具有数据采集量大,精度高、低功耗和可靠性高等优点.     

空间散乱点集Delaunay四面体剖分切割算法

提出最大空圆凸多边形和最大空球凸多面体的概念 .在此基础上 ,提出一种空间散乱点集 Delaunay四面体剖分算法 ,即对空间散乱点集首先进行最大空球凸多面体剖分 ,然后在多面体内部作 Delaunay四面体剖分 .这种方法消除了“退化”现象 (平面 3个以上点共圆或空间 4个以上点共球面 )引起的潜在错误 .最后分析了一类常见的 De-launay四面体剖分算法的潜在错误     

基于最大熵与相关性分析的非负矩阵分解

为解决传统非负矩阵分解不考虑潜在因子的相关性与分布特征等缺点，提出一种基于最大熵与相关性分析的非负矩阵分解方法。利用最大熵原理描述非负矩阵分解中的潜在因子分布，以捕捉语义质量的潜在因子特性，并提出一种基于相似性的方法来度量差异性。将自适应加权策略引入因子间的相互关系，使得每个潜在因子能够无监督地获得自适应权重，并对自适应加权的潜在因子进行非线性变换。在多个数据集上的实验结果表明，该方法能够提升传统方法的效果。     

借力本土伙伴IFS克服水土不服融入市场

中国将是未来全球移动通信3G服务潜在的最大市场及全球移动电话最大消费地,走在3G技术应用前列的日本厂家显然看到了这块巨大的奶酪     

空间散点集Delaunay四面体剖分切割算法

提出最大空圆凸多边形和最大空球凸多面体的概念，在此基础上，提出一种空间散乱点集Delaunay四面体剖分算法，即对空间散乱点集首先进行最大空球凸多面体剖分，然后在多面体内部作Delaunay四面体剖分，这种方法消除了“退化”现象（平面3个以上点共圆或空间4个以上点共球面）引起的潜在错误，最后分析了一类常见的Delaunay四面体剖分算法的潜在错误。     

基于AIX操作系统性能优化的研究

本文对基于AIX操作系统性能优化的分析研究,主要以某金融企业应用系统的优化实施为例,通过对该金融企业应用系统中潜在的问题以及完善与解决方案进行分析论述,以提高金融企业应用系统运行的可靠性与稳定性,避免应用系统潜在问题对系统的正常运行造成干扰和损坏,使金融企业的应用系统实现最大可用性。     

基于改进前缀树PStree的最大序列模式挖掘

对现有最大序列模式挖掘算法候选序列模式过多以及可扩展性差的缺点,提出了一种基于序列匹配的最大序列模式挖掘算法CSMS(compare sequence finding maximal sequential pattern).算法首先为所有频繁1序列构建位置信息表;然后利用纵向、横向结合搜索位置信息表的序列扩展匹配方法找到潜在最大序列模式;在进行序列匹配扩展的同时,把每个找到的潜在最大序列模式存储在改进的前缀树PStree(prefix sequential pattern tree)中,树中每个结点链接到索引Hash表,Hash表中保存了结点的位置信息,对于那些重复的序列可以直接从Hash表中找到其位置信息;最后通过对前缀树PStree进行剪枝,得到由最大序列模式组成的前缀树MPStree(maximal sequential pattern tree).实验结果表明算法CSMS具有较好的时间效率和扩展性.     

基于虚拟MIMO子信道的多用户分集资源调度算法

根据多天线(MIMO)信道空间相关特性,提出一种虚拟子信道的分析方法,从子信道角度探讨信道容量在发射端已知信道响应时预期的性能改善;在此基础上,提出一种逼近信道容量上限的波束形成方法,发掘MIMO信道矩阵最大奇异值与波束形成矢量潜在的联系,并从理论角度详细分析了单用户与多用户最大奇异值联合分布特性,实现阵列增益、空间分集和多用户分集充分融合;仿真与分析表明,利用用户间潜在的随机分布特性能有效提高用户的空间分集增益,提高系统资源利用率,对系统性能改善显著.     

最大熵模型的树-栅格最优N解码算法

最大熵模型已被广泛应用于多种自然语言处理任务,但一些现有研究工作在解码算法上存在有待改进的地方.本文提出了一个最大熵模型的树-栅格最优N解码算法,并对算法性能进行了分析和比较.算法的另一优点在于可以在解码过程中检测并控制潜在的标注冲突.     

A fuzzy-probabilistic earthquake risk assessment system

This paper presents an outline of a risk assessment system for evaluating the expected damage of structures and the consequent financial losses and casualties due to a likely earthquake under elevated uncertain conditions; namely where neither the statistical data nor the seismological and engineering knowledge required for such evaluations are sufficient. In such cases, we should consider extra dimensions of uncertainty, in addition to probability that is usually sufficient for expressing the risk of losses and casualties due to an earthquake where such knowledge and data is available. In the present paper, the uncertainties caused by the insufficient knowledge about the interdependency of various parameters have been considered by means of fuzzy relations. Moreover, the uncertainties in eliciting the likelihood of the seismic hazard have been expressed by fuzzy probability in the form of possibility-probability distributions (PPDs). In other words, fuzzy set theory is employed to complement the standard probability theory with a second dimension of uncertainty. By composition of the fuzzy probability of the seismic hazard and fuzzy vulnerability relation of target structure, the fuzzy probability of damage can be derived. The proposed approach has also been compared with an alternative approach for obtaining a PPD of the hazard. As a case study, the risk assessment system has been tested on a sample structure in the Istanbul metropolitan area.     

Use of raster-based data layers to model spatial variation of seismotectonic data in probabilistic seismic hazard assessment

Recent achievements in computer and information technology have provided the necessary tools to extend the application of probabilistic seismic hazard mapping from its traditional engineering use to many other applications. Examples for such applications are risk mitigation, disaster management, post disaster recovery planning and catastrophe loss estimation and risk management. Due to the lack of proper knowledge with regard to factors controlling seismic hazards, there are always uncertainties associated with all steps involved in developing and using seismic hazard models. While some of these uncertainties can be controlled by more accurate and reliable input data, the majority of the data and assumptions used in seismic hazard studies remain with high uncertainties that contribute to the uncertainty of the final results. In this paper a new methodology for the assessment of seismic hazard is described. The proposed approach provides practical facility for better capture of spatial variations of seismological and tectonic characteristics, which allows better treatment of their uncertainties. In the proposed approach, GIS raster-based data models are used in order to model geographical features in a cell-based system. The cell-based source model proposed in this paper provides a framework for implementing many geographically referenced seismotectonic factors into seismic hazard modelling. Examples for such components are seismic source boundaries, rupture geometry, seismic activity rate, focal depth and the choice of attenuation functions. The proposed methodology provides improvements in several aspects of the standard analytical tools currently being used for assessment and mapping of regional seismic hazard. The proposed methodology makes the best use of the recent advancements in computer technology in both software and hardware. The proposed approach is well structured to be implemented using conventional GIS tools.     

Seismic loss assessment for buildings with various-LOD BIM data

Earthquake-induced loss of buildings is a fundamental concern for earthquake-resilient cities. The FEMA P-58 method is a state-of-the-art seismic loss assessment method for buildings. Nevertheless, because the FEMA P-58 method is a refined component-level loss assessment method, it requires highly detailed data as the input. Consequently, the knowledge of building details will affect the seismic loss assessment. In this study, a seismic loss assessment method for buildings combining building information modeling (BIM) with the FEMA P-58 method is proposed. The detailed building data are automatically obtained from the building information model in which the building components may have different levels of development (LODs). The determination of component type and the development of the component vulnerability function when the information is incomplete are proposed. The modeling rules and the information extraction from BIM through the Autodesk Revit application programming interface (API) are also proposed. Finally, to demonstrate the rationality of the proposed method, an office building that is available online is selected, and the seismic loss assessments with various-LOD BIM data are performed as case studies. The results show that, on the one hand, even if the available building information is limited, the proposed method can still produce an acceptable loss assessment; on the other hand, given more information, the accuracy of the assessment can be improved and the uncertainty can be reduced using the proposed method. Consequently, this study provides a useful reference for the automation of the refined seismic loss assessment of buildings.     

地震属性分析系统数据库的设计与研究

文章调查了地震属性分析工作的数据需求。通过归纳属性工作的实际内容抽象出软件系统架构。讨论了属性数据库的标准化。用关系理论进行属性数据建模,实现了表的设计。基于原型系统开发理论提出了地震属性数据库的动态开发策略,建立了一套完备的地震属性分析系统数据库。     

基于复杂网络的历史地震时空分布及异常分析

为了研究地震异常对地震预测及震后引发次生灾害的影响,收集整理1911年之前的历史地震数据,建立中国历史地震数据库。通过对地震及地震异常的关联分析建立复杂网络模型,根据网络模型提出每种地震异常的重要性及每次地震危害度的计算方法,并以此研究地震异常与地震之间的内部关联,最后通过网络模型的数据分析研究历史地震的时空走势。实验结果表明通过复杂网络研究历史地震的可行性,为地震研究提供了新的方法。     

A spatial panel approach to the statistical assessment of seismic impacts and building damages: Case study of Taichung,Taiwan

A set of seismic-related statistical models is developed, using pseudo-data generated by an earthquake-engineering simulation model. The Peak Ground Acceleration (PGA) is the principal measure of seismic hazard, the Peak Ground Displacement (PGD) represents secondary impacts, and land-use patterns characterize urban vulnerability. A PGA model based on earthquake magnitude, epicenter-to-site distances, and source depth is formulated as a spatial lag panel (SLP) model to account for PGA spatial interactions (neighborhood effects). A PGD spatial lag panel model is also specified to account for soil liquefaction effects. Finally, a model of seismic damages to buildings is formulated, relating monetary damages (loss in property values) to seismic hazards (PGA and PGD) and urban vulnerabilities (residential, commercial, industrial, and facility building stocks). Pseudo-data are generated under 22 simulated historical seismic events for the city of Taichung, Taiwan. These data are then used for model estimation. By combining the three models, monetary damages can be estimated as a function of land-use patterns, PGA, PGD, their neighborhood effects, and other seismic characteristics. These models can therefore provide seismic information for policy making and help in allocating land to new activities while minimizing potential seismic damages.     

数据驱动的可靠性评估与寿命预测研究进展:基于协变量的方法

作为保障工业过程可靠性和经济性的重要技术,可靠性评估与寿命预测在过去几十年得到了越来越广泛的关注和长足的发展.在实际应用中,由于难以获取复杂、高可靠性设备失效机理的物理模型,数据驱动的可靠性评估与寿命预测方法成为近年来的主流.同时,自动监测技术和传感器技术的快速发展,使得在工程实践中不仅能够获取系统的退化数据,还能得到大量的系统运行环境监测数据,从而使得数据驱动寿命预测中基于协变量的方法得到了广泛应用.本文根据系统运行环境中协变量数据的不同变化规律,将基于协变量方法的可靠性评估模型分为:固定协变量模型、时变协变量模型和随机协变量模型,并分别讨论了各模型的发展现状.最后,讨论了协变量处理中存在的一些挑战及未来的研究方向.     

Probabilistic landslide hazard mapping using GIS and remote sensing data at Boun,Korea

The aim of this study is to evaluate the hazard of landslides at Boun, Korea, using a Geographic Information System (GIS) and remote sensing. Landslide locations were identified in the Boun area from interpretation of aerial photographs and field surveys. The topographic, soil, forest, geologic, lineament and land cover data were collected, processed and constructed into a spatial database using GIS and remote sensing data. The factors that influence landslide occurrence, such as slope, aspect and curvature of the topography, were calculated from the topographic database. Texture, material, drainage and effective soil thickness were extracted from the soil database, and type, age, diameter and density of timber were extracted from the forest database. The lithology was extracted from the geological database and lineaments were detected from Indian Remote Sensing (IRS) satellite images. The land cover was classified based on the Landsat Thematic Mapper (TM) satellite image. Landslide hazard areas were analysed and mapped, using the landslide-occurrence factors, by the probability–likelihood ratio method. The results of the analysis were verified using actual landslide location data. The validation results showed satisfactory agreement between the hazard map and the existing data on landslide locations.     

新型高线性度分段激磁式扭矩传感器的研究

扭矩的准确测量对实现机械设备的自动控制有着重要的作用,为此,设计了一种新型分段激磁的高线性度扭矩传感器。传感器的激磁绕组为分段式,传感器转轴受到扭矩作用时,输出绕组经过电磁耦合输出与负载扭矩呈正比关系的感应电势,并找到了传感器输出特性呈较高度线性时,激磁线圈与输出线圈的匝数比的范围约为0.56~0.59。推导了传感器的输出特性,构建了传感器的数学模型。最后采用扭转试验机对传感器进行了标定,实验结果表明传感器的灵敏度约为1.05 m V/(N·m),重复性误差约为±0.38%,非线性误差约为±0.26%,迟滞误差约为±0.37%。     

An intelligent simulation system for earthquake disaster assessment

This paper presents an intelligent simulation system for an earthquake disaster assessment system based on a development platform of a Geographic Information System (GIS) and Artificial Intelligence (AI). This system is designed to identify the weakness of the structure and infrastructure system in pre-earthquake conditions, quickly assess earthquake damage and make an intelligent emergency response for the public and government during the earthquake and post-earthquake. The system includes the following functions: intelligent seismic hazard assessment, earthquake damage and loss evaluation, optimizing emergency response and post-earthquake recovering plan. The principle, design criteria, structure, functions and test results of this system are described in this paper. Based on its functional characteristics, this system is composed of four parts: an information database, analytical modules, an intelligent decision-making sub-system and a friendly user interface. There are 132 coverages and 78 analytical modules included in the information database and analytical modules. With this system, seismic disaster mitigation strategies can be verified during a pre-earthquake, and be executed at the time of an earthquake and post-earthquake; the earthquake resisting capacities for an entire city and all of its communities can be greatly enhanced. To check its reliability and its efficiency, this system has been tested based on a scenario earthquake event in one city, and the related results have also been given in this paper. At the present, this system has been installed and used in Daqing City, China. After running for almost 10 years, this system has successfully been used in rehearsing of seismic disaster mitigation and post-earthquake emergency response. Simultaneously, an optimizing aseismic retrofitting plan in Daqing City has been executed based on results from this system.