柴油机装配质量控制

柴油机装配是柴油机制造过程中最重要、也是最后一道工序。柴油机能否保证其良好的性能和可观的经济性,装配工作的质量在很大程度上是决定性的,这意味着最终的结果取决于装配的结果。这也要求企业在装配过程中必须对柴油机进行质量控制,确保产品质量能够达到相应的标准。因此,为了提高装配质量,有必要对装配过程中所采用的工艺进行探索和分析,并在深入了解后提出相应的质量控制方案。     

基于图论的飞机典型装配工艺数据挖掘方法

为实现飞机装配指令编制的快速化、智能化,提出基于图论的飞机典型装配工艺数据挖掘方法。该方法将停用词表和分隔数组两个约束引入语义分词法完成装配工艺指令的分词处理,并以装配工艺特征向量结构化地表达分词后的装配工艺指令。将装配工艺特征向量映射为单向有序链,以此构建装配工艺图。通过定义装配工艺图的节点支持度和边支持度,给出了典型装配工艺挖掘方法。以某型飞机的平尾装配工艺为例,在多个支持度下验证了方法的有效性。     

基于3DVIA Composer的三维装配作业指导书编制技术研究

随着数字化技术的发展,装配工艺三维化成为一种必然趋势。利用3DVIA Composer软件直接依据产品MBD数模,通过工艺图解编制和装配动画制作能够方便、快捷地进行三维装配作业指导书的制作,并能够将三维工艺发布到装配现场指导车间工人完成产品装配。     

现代船用柴油机智能故障诊断系统的研究

现代船用柴油机是机一电．液等各种子系统组成的大型机电设备,结构复杂决定了对其故障进行诊断的困难性。基于目前发展较快的船用柴油机故障诊断技术及较成熟的专家系统与人工神经网络理论,对专家系统和BP神经网络的融合方法在船用柴油机故障诊断方面的应用进行了有益的探讨,并提出了利用专家系统和BP神经网络的融合方法建立的船用柴油机神经网络故障诊断专家系统基本结构。     

基于3DVIA Composer的三维装配作业指导书编制技术研究

<正>随着数字化技术的发展,装配工艺三维化成为一种必然趋势。利用3DVIA Composer软件直接依据产品MBD数模,通过工艺图解编制和装配动画制作,能够方便、快捷地进行三维装配作业指导书的制作,并能够将三维工艺发布到装配现场指导车间工人完成产品装配。     

面向三维装配工艺系统的CATIA模型信息提取与应用

三维装配工艺系统是CAPP发展的一个热门趋势,其基础数据主要来源于三维CAD系统模型信息．针对汽车等行业常用的CATIA三维模型装配信息提取的关键技术与难点,介绍如何深入应用CAA二次开发技术,提取装配信息并应用于三维装配工艺系统,编制装配工艺．     

柴油机故障诊断专家系统

本文讨论了柴油机故障诊断专家系统的总体结构。着重讨论其知识库结构，推理方法，利用该专家系统，装入领域知识的相应规则集，即可用于不同型号，不同用途柴油机的故障诊断，此专家系统采用C语言编写。     

基于RPO/E的虚拟装配、运动仿真与装配动画

通过零件三维模型的生成和对零件虚拟装配和运动仿真的分析,可大大减少设计周期;通过装配动画的设计和制作,可提高装配工艺编制效率,并指导工人装配,从而提高产品制造质量。以齿轮泵为例介绍了RPO/E软件中的虚拟装配、运动仿真和装配动画的操作思路和具体方法。     

专家系统在工业企业中的应用

本文是对国内外应用专家系统，尤其是工业企业中的应用专家系统的最新研究进展进行跟踪性研究，从而进一步探索专家系统在工业企业中的应用前景，文章首先简要介绍了专家系统的基础，然后跟踪研究了工业企业界最热门的专家系统研究开发的最新进展，包括智能决策系统，专家计划系统，专家调度系统以及智能工艺规定编制系统，最后提出了作者的几点看法。     

基于知识的装配机器人选型专家系统的研制

装配机器人的迅速发展，使装配机器人选型变得越来越重要。本文根据装配机器人进行装配业的特点，主要探讨了装配机器人选型专家系统中知识表示、推理方法以及装配知识的获取等问题。     

Remote sensing of soil salinity: potentials and constraints

Soil salinity caused by natural or human-induced processes is a major environmental hazard. The global extent of primary salt-affected soils is about 955 M ha, while secondary salinization affects some 77 M ha, with 58% of these in irrigated areas. Nearly 20% of all irrigated land is salt-affected, and this proportion tends to increase in spite of considerable efforts dedicated to land reclamation. This requires careful monitoring of the soil salinity status and variation to curb degradation trends, and secure sustainable land use and management. Multitemporal optical and microwave remote sensing can significantly contribute to detecting temporal changes of salt-related surface features. Airborne geophysics and ground-based electromagnetic induction meters, combined with ground data, have shown potential for mapping depth of salinity occurrence. This paper reviews various sensors (e.g. aerial photographs, satellite- and airborne multispectral sensors, microwave sensors, video imagery, airborne geophysics, hyperspectral sensors, and electromagnetic induction meters) and approaches used for remote identification and mapping of salt-affected areas. Constraints on the use of remote sensing data for mapping salt-affected areas are shown related to the spectral behaviour of salt types, spatial distribution of salts on the terrain surface, temporal changes on salinity, interference of vegetation, and spectral confusions with other terrain surfaces.As raw remote sensing data need substantial transformation for proper feature recognition and mapping, techniques such as spectral unmixing, maximum likelihood classification, fuzzy classification, band ratioing, principal components analysis, and correlation equations are discussed. Lastly, the paper presents modelling of temporal and spatial changes of salinity using combined approaches that incorporate different data fusion and data integration techniques.     

Integration | Innovation | Inclusion: Values,Variables and the Design of Human Environments

Complexity, complication, contradiction, consumption, confusion, delusion, depression. Opportunity, inspiration, ingenuity, compassion, wisdom. Our world is perplexing, our times are fast moving, and our choices are many. To find an appropriate path is a daunting yet vital challenge that confronts us as individuals, as communities, and as a civilization. How sustainable is our world? How reasonable are our behaviors? The present article is a collection of thoughts on a series of intertwined issues related to the contemporary world, its environmental dimensions, and their present-day problems. The goal is to survey the landscape through a lens of Environmental Design, to provide some perspectives, to raise some questions, and to explore systems, beliefs, and values informing and influencing actions. It is important to consider how people's belief systems influence, inform, and shape actions. This holds true in realms political, spiritual, and cultural. It also proves relevant in the ways in which we imagine, design, develop, and construct our buildings, cities, spaces, and places.

Appropriate solutions to some of our most daunting problems will arise through the concerted efforts, open dialogue, and collective wisdom of the wide array of stakeholders, professionals, politicians, decision makers, and citizens (both engaged and disenfranchised) who have the will and wherewithal to make a difference and to make the world safer, healthier, and better. It seems vital for us to critically examine, and question, our belief systems and their connections to the ways we define, refine, and realize progress. Architecture and Environmental Design, in both a philosophical and a practical sense, reflect as well as form greater aspirations, directions, and events of our times.     

区块链+物联网在农产品溯源中的应用研究

近年来,农产品安全问题日益严峻,传统的农产品追溯体系面临公信力缺失、监管困境和扩展性问题,农产品质量安全追溯迫在眉睫。随着区块链技术不断发展,其具有的分布式、去中心化、不可篡改、可追溯等特性在改善农产品溯源系统数据安全性、透明性等方面发挥着重要作用,并受到了各个行业的广泛关注。在简述可追溯性和追溯系统概念的基础上,介绍物联网和区块链技术,并探讨了当前国内外学者将区块链和物联网框架融合应用到农产品溯源中的一些相关研究,同时阐述了溯源系统在物联网与区块链结合下带来的安全、可靠、透明等好处及面临可扩展性、效率问题、资源浪费等挑战,最后对当前农产品溯源体系建设提出建议以及未来的研究方向。     

面向大尺寸货物运送的吊车控制方法综述

随着现代化工业和基础设施建设的飞速发展,面向大尺寸货物运送的吊车系统以其高负载能力、低成本的显著优势广泛应用于集装箱搬运、风机安装、飞机机翼机身移动、水轮发电机转子安装、海上钻井平台搭建等诸多重要领域。然而,相对于传统的点质量单摆吊车系统,面向大尺寸货物运送的吊车系统具有更高的欠驱动程度、更强的状态耦合性和更加复杂的非线性,给大尺寸货物高效、安全的运送控制带来严峻挑战。本文首先简单阐述了面向大尺寸货物运送吊车系统不同吊装形式的建模、优势和缺点;然后,详细介绍了点质量双摆吊车系统、分布式质量双摆吊车系统和多吊车协同运送系统控制的研究现状;最后,对面向大尺寸货物运送吊车系统控制的研究现状进行概括,并对可能存在的关键问题和未来的研究方向进行了讨论和展望。     

Expert system verification and validation: a survey and tutorial

Assuring the quality of an expert system is critical. A poor quality system may make costly errors resulting in considerable damage to the user or owner of the system, such as financial loss or human suffering. Hence verification and validation, methods and techniques aimed at ensuring quality, are fundamentally important. This paper surveys the issues, methods and techniques for verifying and validating expert systems. Approaches to defining the quality of a system are discussed, drawing upon work in both computing and the model building disciplines, which leads to definitions of verification and validation and the associated concepts of credibility, assessment and evaluation. An approach to verification based upon the detection of anomalies is presented, and related to the concepts of consistency, completeness, correctness and redundancy. Automated tools for expert system verification are reviewed. Considerable attention is then given to the issues in structuring the validation process, particularly the establishment of the criteria by which the system is judged, the need to maintain objectivity, and the concept of reliability. This is followed by a review of validation methods for validating both the components of a system and the system as a whole, and includes examples of some useful statistical methods. Management of the verification and validation process is then considered, and it is seen that the location of methods for verification and validation in the development life-cycle is of prime importance.     

区块链分片技术综述

区块链作为分布式账本的关键技术之一,其去中心化、可匿名、不可篡改的特性受到学术界和工业界的青睐,被广泛应用于金融、数字货币、公共服务等领域。分片技术作为区块链扩容的主流方式之一,能够在不降低区块链去中心化程度的同时实现高性能的链上扩容,从而解决区块链可拓展性不足以及吞吐量较低的问题。介绍近年来出现的分片技术以及相关协议,总结分片技术的关键理论与方法,从分片配置、重配置、片内共识协议、跨片共识协议、状态存储等方面对分片技术方案进行对比,归纳不同分片方案在网络分片、交易分片、状态分片等设计中存在的优势和不足。同时,阐述一些经典分片技术在性能和实现方式上的特点,对许可区块链和无许可区块链、片内共识协议、跨片共识协议、准入性方案、状态分片方式等进行分析和概述。在此基础上,从分片内、分片间以及系统层级的角度总结分片技术当前所面临的困境和挑战,并对该领域的发展前景及未来研究方向加以展望。     

Survival analysis of a neotropical rainforest using multitemporal satellite imagery

We present results of an analysis of deforestation at a UNESCO Biosphere Reserve, the Parque National Yasuní, located in the rainforests of eastern Ecuador using multitemporal Landsat TM and ETM+ satellite imagery. Using survival analysis, we assessed both current and future trends in deforestation rates, and investigated the impact of spatial, cultural, and economic factors on deforestation. These factors included the distance from roads, rivers, research facilities, oil facilities, markets and towns, and land ownership by colonists, native inhabitants, and an oil company. We found the annual rate of deforestation is currently only 0.11%, but that this rate is increasing with time and, assuming that the trend of increasing rate of forest loss continues, we would predict that by 2063, 50% of the forest within 2 km of an oil access road will be lost to unhindered colonization and anthropogenic conversion. The Quechua colonists are associated with areas of the highest rate of deforestation, followed by the native Huaorani and the lowest region of deforestation was in areas occupied by a local oil company. By far, the strongest predictor of where deforestation is predicted to occur was proximity to the road. Proximity to research sites, oil facilities, market, and rivers significantly decreases deforestation rates, and proximity to towns significantly increases deforestation rates.     

联邦开发过程中的校核、验证与确认（VV＆A）

对联邦的VV＆A不仅能够使每一步的工作得到跟踪和衡量,还使每一步能够减少多余的工作量,巩固需要加强的工作,明确开发人员的角色和职责,从而使人力、时间、资金等资源得到更加有效率的利用,仿真的结果变得更加可预测和准确,在很大程度上减少了编程的风险.联邦成员描述了仿真模型的各对象类、交互类、相关的属性、参数等信息,而联邦是各联邦成员的有机集成,构成具有特定功能的仿真系统.因此,联邦成员的正确性是联邦正确性的前提,决定了仿真系统的成败.在VV＆A的过程中,最好采用一些自动化工具以便于工作,同时要根据具体仿真系统的实际情况来确定VV＆A所需要作的工作.     

On Belief and the Making of All Things Beautiful and Sublime: Creation by Ordinance and Destruction by Chaos

This is a study of beauty as a construct and a property of structural composition. I examine alternate possibilities of structural compositions, linguistics, or material arguments that beauty, impossible in utter chaos, might not be definitely found in order, but the latter is essential thereto. A distinction is also made between complex systems of order found in nature, often qualified as organic—the seemingly free and flowing forms found in formal sophistication beyond simple geometrical reduction—and the absence of order as pure chaos. Beauty is examined through order from historical linguistic, perceptual, and systemic constructivist perspectives, along with the sublime and the harmonious. Linguistically, order is a term of convergence of the seemingly disparate streams of significance of rank—in society, religion, and the belief in collective constants—and ornament is a term of bearing beauty and enhancement of taste that emanates from within the structure and should not be reduced to superficial application. I cite costume, including accessories of weaponry, as moments of proximity between style, purpose, utility, and the collective as semiotic bearer of meaning in culture and social order.     

一种基于对象信息的MIS自适应生成器

为解决MIS在开发和运行过程中因需求频繁变更所带来的开发和维护的工作量上升问题,提出一种新的MIS软件基础模块自适应生成管理器。通过信息化管理MIS的版本、用户与权限、系统结构、系统模块、对象信息、通用视图元素、通用业务逻辑元素和通用数据访问方式,并基于通用的界面层基础元素、业务逻辑层基础元素、数据访问层基础元素和对象信息自适应生成或重构MIS软件基础模块的数据库、交互界面、业务逻辑、数据交互部分和软件内部结构,以达到动态构建和管理MIS软件基础模块,实现基础模块信息化和系统对自身信息化、自动化管理的目的。通过将该生成器技术实现并实际应用于MIS开发,验证其能够较好地应对MIS基础模块的快捷构建与变更,有效降低MIS开发与维护的工作量。该生成器较好地解决了MIS软件基础模块快速构建与重构问题,能较好地应对MIS在开发和运行过程中的频繁变更。