A Review of the Application of Meta-Heuristic Algorithms to 2D Strip Packing Problems

This paper is a review of the approachesdeveloped to solve 2D packing problems withmeta-heuristic algorithms. As packing tasks arecombinatorial problems with very large searchspaces, the recent literature encourages theuse of meta-heuristic search methods, inparticular genetic algorithms. The objective ofthis paper is to present and categorise thesolution approaches in the literature for 2Dregular and irregular strip packing problems.The focus is hereby on the analysis of themethods involving genetic algorithms. Anoverview of the methods applying othermeta-heuristic algorithms including simulatedannealing, tabu search, and artificial neuralnetworks is also given.     

引大总干渠先明峡倒虹吸水平管段复位施工方法

引大入秦工程总干渠先明峡倒虹吸管水平段钢管因温度变化引起上下游伸缩节的预留伸缩量发生了较大的变化,造成支承环的底座与支墩上的四氟滑块产生了较大错位,支墩出现了偏心受压,大部分四氟滑块出现断裂、脱胶和翘曲等破坏。通过水平管段支承环底座的摩阻力、伸缩节橡胶棒摩阻力计算,水平管段采用箱型定向滑动导轨和滑动钢球的复位措施、施工方法、步骤。采用该施工方法复位后,工程运行情况良好。     

无线传感器网络中基于树的动态多路径容错路由协议

多路径路由对无线传感器网络的负载均衡和容错能力等方面都有一定改善作用。在研究一些多路径路由算法的基础上,对分层的无线传感器网络路由进行探索,提出了一种基于树的动态多路径路由的生成方法,快速获得当前节点的主路径与备用路径。仿真结果表明,该方法可有效地均衡网络负载、减少时延、提高网络的可靠性。     

Modeling deterministic echo state network with loop reservoir

Echo state network (ESN),which efficiently models nonlinear dynamic systems,has been proposed as a special form of recurrent neural network.However,most of the proposed ESNs consist of complex reservoi...     

Predicting dam failure risk for sustainable flood retention basins: A generic case study for the wider Greater Manchester area

This study aims to provide a rapid screening tool for assessment of sustainable flood retention basins (SFRBs) to predict corresponding dam failure risks. A rapid expert-based assessment method for dam failure of SFRB supported by an artificial neural network (ANN) model has been presented. Flood storage was assessed for 110 SFRB and the corresponding Dam Failure Risk was evaluated for all dams across the wider Greater Manchester study area. The results show that Dam Failure Risk can be estimated by using the variables Dam Height, Dam Length, Maximum Flood Water Volume, Flood Water Surface Area, Mean Annual Rainfall (based on Met Office data), Altitude, Catchment Size, Urban Catchment Proportion, Forest Catchment Proportion and Managed Maximum Flood Water Volume. A cross-validation R² value of 0.70 for the ANN model signifies that the tool is likely to predict variables well for new data sets. Traditionally, dams are considered safe because they have been built according to high technical standards. However, many dams that were constructed decades ago do not meet the current state-of-the-art dam design guidelines. Spatial distribution maps show that dam failure risks of SFRB located near cities are higher than those situated in rural locations. The proposed tool could be used as an early warning system in times of heavy rainfall.     

华龙国际大厦混合结构构件及节点设计

论述了矩形钢管混凝土柱钢框架、混凝土核心筒结构在江西华龙国际大厦的应用，介绍了矩形钢管混凝土混合结构总体设计、节点大样及构造。     

聚乙烯钢塑复合管导热系数的测定

聚乙烯钢塑复合管是新一代替代传统管道的新型管材，其导热系数的测试及相关的数据目前还没有报导。本文利用一维、稳态传热的基本规律，采用相对简单易行、测试成本低、较能真实反映实际情况的测试装置，对成都某企业的聚乙烯钢塑复合管导热系数进行了测试，获取了较满意的测试结果，并对测试结果的准确性进行了分析。所采用的测试方法及所获取的数据，对相应的生产厂家、设计、施工单位具有一定的指导意义。     

鞍钢无缝钢管厂总体改造框架探讨

介绍了鞍钢无缝钢管厂发展的历程,阐述了必须对其进行技术改造的理由,提出了改造的具体原则及设想.     

VPN构建的一种设计思想

Internet的发展对安全问题的要求越来越高，网络安全日益受到重视。文章以虚拟专用网为主要研究对象，结合软件工程的一些开发思想，对虚拟专用网的构建做出了理论上的设计。文章分析了虚拟专用网目前所涉及的主要几大模型，具体构建了一种可行的VPN设计方案，同时结合软件工程，对VPN构建给出自行设计的一种模块结构图，并对各个模块结构给出了具体解释，今后的工作在于将模块具体细化运用到实践中。     

神经网络控制器用于永磁电机的伺服驱动

提出用一种遗传算法（ＧｅｎｅｔｉｃＡｌｇｏｒｉｔｈｍ，简称ＧＡ）训练的多层神经网络结构（ＮＮ），并把它用于交流直线永磁同步电动机（简称ＬＰＭＳＭ）的辩识与控制，使其运行在伺服驱动环境．ＮＮ可随时辩识被控系统的动态待性，而不需要ＬＰＭＳＭ的精确的数学模型．仿真结果令人满意