Development of industrial SFF system using dual laser and optimal process

Selective laser sintering (SLS) is currently recognized as a leading process in the new field of solid freeform fabrication (SFF). SLS extends the applications to machinery and automobiles due to various employing materials. In order to develop more elaborate and speedy system for fabricating large objects compared to existing SLS, this study employs a new selective dual-laser sintering (SDLS) process. It contains three-axis dynamic focusing scanner system for scanning large area instead of the existing fθ lens used in commercial SLS. The optimal fabrication parameters such as sintering temperature, laser beam power and layer thickness should be determined when sintering polymer and metal powder. In this paper, we will address methods for the effective laser scanning path generation, the suitable temperature and the accurate z-axis control. Also, experiments have been performed to evaluate the effect of fabrication parameters on process and to fabricate the various 3D objects using polymer.     

基于线性规划和遗传–粒子群算法的烧结配料多目标综合优化方法

针对钢铁企业二次配料工艺,本文采用将硫含量折算为可比成本,兼顾节能减排目标和配料成本,建立了二次配料多目标优化模型;提出了一种基于线性规划和遗传–粒子群算法（GA–PSO）的钢铁烧结配料优化方法.首先采用线性规划算法进行求解,若线性规划方法无法求得最优解,则采用GA–PSO算法进行搜索.该方法应用于某钢铁企业360m2生产线的＂配料优化与决策支持系统＂中,实际运行结果表明,该算法在保证烧结矿质量的前提下,能够有效地减少二氧化硫排放,降低配料成本.     

计及云边协同的综合能源系统双层优化

多区域互联的综合能源系统具备两大优势：区域内部多能互补与区域之间能量互济,本文针对综合能源系统设计了一种云边协同调控方法以兑现这两大优势。首先,本文设计了能量管理云平台-边缘控制器双层架构分别统筹子区域内和子区域间的能量流,子区域以预测控制方法(model predictive control, MPC)实现边缘控制器内部能量的实时调控。其次,基于所提双层架构设计了包括集中调控层-分布协同层的双层能量优化模型,集中调控层负责区域间能量互济以降低整个系统对外部配电网的能量需求,提高系统运行经济性;分布协同层负责控制区域内可控机组以降低实际运行工况与日前调度计划值的偏差,降低系统运行波动性。然后,研究了交替方向乘子法(alternating direction method of multipliers, ADMM)求解所提双层能量优化模型的具体步骤。最后,仿真验证了所提云边协同能量调控方法对多区域互联综合能源系统经济性与稳定性的改善作用。     

融合XGBoost和Multi-GRU的数据中心服务器能耗优化算法

随着云计算技术的快速发展,数据中心的数量大幅增加,随之而来的能源消耗问题逐渐成为一个研究热点.针对服务器能耗优化问题,提出了一种融合极限梯度提升(XGBoost)和多个门控循环单元(Multi-GRU)的数据中心服务器能耗优化(ECOXG)算法.首先利用Linux终端监控命令和功耗仪收集服务器各部件的资源占用信息和能耗...     

基于自适应粒子群算法的制造云服务组合研究

针对云制造系统中制造云服务组合的多目标规划问题,研究建立了问题模型并提出了求解方法。首先引入了网格制造模式的制造资源服务组合技术,探讨并描述了云制造模式中基于服务质量（QoS）的制造云服务组合过程;接着通过分析云制造模式下制造云服务的特征并基于制造领域知识,研究定义了制造云服务的八维QoS评估标准及计算表达式,推导出制造组合云服务的QoS表达,进而建立了制造云服务组合的多目标规划问题模型。最终设计了自适应粒子群算法来解决该多目标规划问题。仿真实验表明,该算法能有效并高效地解决该问题,且求解效率优于传统粒子群算法。     

车联网建模和统计性质分析及其路由策略综述

利用复杂网络理论和方法对通信网络进行建模、分析网络演化过程中的统计性质,进而指导路由策略优化,已经成为热点领域。分析了车联网建模、车联网统计性质分析、车联网路由策略优化,以及车联网路由协议设计等方面的研究现状,并提出从三个方面进行改进,分别是:采用有向加权图来描述车联网的拓扑结构;从车联网与移动自组织网络的统计性质差异入手,寻找影响车联网传输能力的关键统计性质;利用复杂网络,研究基于多输入多输出技术的多径路由(即同时利用多个信道、多条路径传输)优化策略。     

基于能量和均衡分簇的WSN自适应拓扑控制

无线传感器网络中基于分簇的拓扑控制方法容易将低能量节点误选为簇头而加速死亡,且在成簇过程中未考虑簇成员数量,会导致簇头负载过重。为此,提出一种基于能量和均衡分簇的自适应拓扑控制方法。在选择簇头时考虑节点的剩余能量,采用均衡化思想自适应构建簇成员。仿真实验结果表明,该方法能有效降低节点死亡速率,延长网络寿命,提高网络的服务性能。     

Using online textual data,principal component analysis and artificial neural networks to study business and innovation practices in technology-driven firms

In this paper we introduce a method that combines principal component analysis, correlation analysis, K-means clustering and self organizing maps for the quantitative semantic analysis of textual data focusing on the relationship between firms’ co-creation activities, the perception of their innovation and the articulation of the attributes of their product-enabled services. Principal component analysis was used to identify the components of firms’ value co-creation activities and service value attributes; correlation analysis was used to examine the relationship between the degree of involvement in specific co-creation activities, the online articulation of firms’ service value attributes and the perception of their innovativeness. K-means and self organizing map (SOM) are used to cluster firms with regards to their involvement in co-creation and new service development, and, additionally, as complementary tools for studying the relationship between co-creation and new service development.The results show that, first, there is a statistically significant relationship between firms’ degree of involvement in co-creation activities and the degree of articulation of their service value attributes; second, the relationship should be considered within the context of firms’ innovation activities; third, OS Software-driven firms are the best example in terms of co-creation and new product-enabled service development, i.e. the collaborative principles built in their customer participation platforms should be adopted by other (non-software) firms interested in enhancing their innovation capacity through involvement in co-creation and new product-enabled service development.