Loop headers in λ-calculus or CPS

The introduction of a loop header block facilitates the hoisting of loop-invariant code from a loop. In a -calculus intermediate representation, which has a notion of scope, this transformation is particularly useful. Loop headers with scope also solve a problem with in-line expansion of recursive functions or loops: if done naively, only the first iteration is inlined. A loop header can encapsulate the loop or recursion for better in-line expansion. This optimization improves performance by about 5% in Standard ML of New Jersey.     

考虑电-氢-热多能互补的微网多目标优化配置研究

氢储能具有储能容量大、储存时间长、清洁无污染、实现多种能源网络互联互补和协同优化等诸多优点,有望成为推动分布式能源发展和提升终端能源利用效率的重要支撑技术。为了提高独立型微网供电可靠性及可再生能源利用率,本文建立了考虑电-氢-热多能互补的独立微网多目标优化配置模型,并基于模拟退火的粒子群算法对目标问题进行求解。最后,通过东北某地独立微网优化配置算例,基于MATLAB平台验证了所提多能互补配置方案较传统电储能配置方案负荷失电率降低了3.18%,可再生能源利用率提高了8.37%,所提配置方案可有效促进可再生能源消纳,保证独立微网的供电可靠性。     

增材制造技术在电机中的应用综述

增材制造技术(即3D打印)因具有高设计自由度、高材料利用率、高成形效率和精度等优势,逐渐成为高效轻质高功率密度电机设计与制造的研究热点。该文旨在对3D打印电机的性能及其应用作系统性综述。首先,对3D打印电机的发展脉络进行简要概括。其次,分别对3D打印铁心、磁钢、绕组,以及散热和机械支撑结构的研究现状进行总结,并与传统工艺加工的样件进行性能对比。随后,介绍了适用于增材制造的结构设计方法——拓扑优化。最后,根据目前的研究情况归纳了3D打印电机未来的发展趋势和面临的挑战。     

机械结构相似度评价及可靠性预计研究

在用传统的相似产品法进行可靠性预计时,所选取的相似产品与评价对象之间差异较大,会造成预计结果的偏差较大。为解决这一问题,提出了一种基于"功能—运动—动作"结构化分解的可靠性预计新方法。通过明确产品的各大运动功能建立功能层,分析完成各功能的机械部件运动建立运动层,确定实现各机械部件运动的元动作运动单元建立元动作层,建立了可靠性预计的"功能—运动—元动作运动单元"层次模型。引入区间层次分析法,确定了"功能—运动—元动作运动单元"层次模型中各子代运动单元对父代运动单元的可靠性影响权重,并构建了由子代运动单元预计父代运动单元可靠性的数学模型。确定影响评价机械结构相似度的因素,构建了区间数综合评判云模型并选取与元动作运动单元相似的参考结构,以区间数综合评价云模型得出的相似度值修正参考结构的可靠性数据来预计元动作运动单元的可靠性。将元动作运动单元的可靠性预计值代入数学模型,层层预计父代运动单元的可靠性,从而得出整个产品的可靠性水平。最后以数控转台为例进行了分析,得出了可靠性预计值,并将该方法与传统方法进行了比较。结果表明,新的可靠性预计方法具有较好的可行性和较高的准确性。     

Optimization of correlated multi-response quality engineering by the upside-down normal loss function

Most of the published literature on robust design is basically concerned with a single response. However, the reality is that common industrial problems usually involve several quality characteristics, which are often correlated. Traditional approaches to multidimensional quality do not offer much information on how much better or worse a process is when finding optimal settings. Köksoy and Fan [Engineering Optimization 44 (8): 935–945] pointed out that the upside-down normal loss function provides a more reasonable risk assessment to the losses of being off-target in product engineering research. However, they only consider the single-response case. This article generalizes their idea to more than one response under possible correlations and co-movement effects of responses on the process loss. The response surface methodology has been adapted, estimating the expected multivariate upside-down normal loss function of a multidimensional system to find the optimal control factor settings of a given problem. The procedure and its merits are illustrated through an example.     

Formulation to obtain the most reliable aggregate mix with quantity and other constraints

The aggregate batch mixing problem determines the proportion (or relative masses) in which aggregate batches with different gradations are to be blended so as to achieve a target mix with a given gradation. As shown in previous studies, the gradation of a batch is not homogeneous and should be considered stochastic. Also, when batches are blended in the field there are random variations in the masses or proportions of individual batches in the mix. Assuming batch gradation and blend masses as stochastic implies that the notion of a mix (blend) satisfying the gradation of a target mix becomes stochastic. In such a framework, every mix has a reliability with which it satisfies the definition of the target mix. In addition, a mix is also required to satisfy various restrictions. This article presents an optimization formulation to determine the most reliable mix while satisfying restrictions on available quantity, budget, etc.     

液氦温区大型低温制冷系统的可靠性评估

针对改进Claude循环的大型氦低温制冷系统,以制冷量不足为顶事件建立了故障树模型。利用结构法对故障树模型进行定性分析,分析得到系统的最小割集为18个。利用来自不同数据库的部件失效率对故障树模型进行定量计算,得到了不同的结果,并分析其原因。对各部件的关键重要度进行了计算,以衡量各个部件对系统发生故障的贡献程度。并通过增加系统冗余部件和提高关键部件可靠度等措施,为提高系统可靠性找到了有效的解决途径。     

Reconstructing design parameters of a rectangular resonator via peak signal-to-noise ratio and global optimization algorithms

This article proposes an approach for reconstructing physical parameters of a sample in a rectangular resonator during microwave radiation, knowing a priori, its electric field distribution. The inverse problem was solved using two global optimization algorithms and the peak signal-to-noise ratio (PSNR) criterion. First, the Self-regulated Fretwidth Harmony Search algorithm (SFHS) identified suitable resonant frequencies for a given configuration. Next, the unified Particle Swarm Optimization (UPSO) optimized said configuration. Together, they became a maximization strategy of the PSNR through a dual optimization process. Results showed the ability of the approach for estimating the height of each sample block and the resonating frequency of the cavity. This process takes longer to finish as a higher PSNR is demanded (mainly due to the aforementioned dual optimization). Even so, it allows for more similar electric field distributions between both, the direct and inverse problems.     

数控机床操控器人机界面优化设计研究

目的控制器和显示器共同组成数控机床控制面板的整体界面,是机床接受与执行命令的交互平台。从人机交互角度,聚焦于控制器的界面布局进行优化设计。方法基于人机工程学理论的优化流程,采用现场访谈、现场观察等方法,将人机工程学的理论转化为具体考核指标。结论从人机工程学的研究角度出发,结合工业设计、用户体验设计学等内容,从功能区域分区、操纵器色彩设计等方面优化数控机床控制器的界面,提高系统整体效能及使用者满意度,为数控机床系统开发设计提供参考。     

Optimization of A-TIG process parameters using response surface methodology

In the present work, the influence of process parameters such as welding current (I), welding speed (S), and flux coating density (F) on different aspects of weld bead geometry for example depth of penetration (DOP), bead width (BW), depth to width ratio (D/W), and weld fusion zone area (WA) were investigated by using the central composite design (CCD). 9–12% Cr ferritic stainless steel (FSS) plates were welded using A-TIG welding. It was observed that all input variables have a direct influence on the DOP, BW, and D/W. However, flux coating density has no significant effect on WA. Mathematical models were generated from the obtained responses to predict the weld bead geometry. An optimized DOP, BW, D/W, and WA of 6.95?mm, 8.76?mm, 0.80, and 41.99?mm², respectively, were predicted at the welding current of 213.78 A, the welding speed of 96.22?mm/min, and the flux coating density of 1.99?mg/cm². Conformity test was done to check the practicability of the developed models. The conformity test results were in good agreement with the predicted values. Arc constriction and reversal in Marangoni convection were considered as major mechanisms for the deep and narrow weld bead during A-TIG welding.