核电站数字化反应堆保护系统停堆响应时间分析

为了评价出核电站数字化反应堆保护系统停堆响应的最大时间,根据数字化反应堆保护系统结构,分析出保护系统的响应过程须经过AI输入、IO总线通讯、CPU运算、网络通讯、DO输出处理。并基于DCS定周期扫描的运行方式,得出了各处理过程所需最大响应时间的计算方法,DCS停堆响应时间的评价值就是各部分最大响应时间的累加。最后提出了可缩短响应时间的改进方法。     

一种改进编码器角度解算过程的方法与实现

在机械电子一直是一个热门学科,其目的是通过软件控制机械操作来代替机械的哑巴解决方案。DS-25旋转电子编码器能够很好地与机械电子应用相匹配,其输出为两路标准的sine和cosine曲线,通过分析sine和cosine数值来计算编码器所对应的绝对角度位置。通过对DS-25的工作模式分析和实际应用情况提出角度解算的改进方案,该方案利用DS-25工作于粗略模式下测试到的角度值来推算精确模式下的信号周期,结合精确模式下测试到的角度值来计算编码器所对应的绝对角度。摒弃其原有的复杂查表过程进而节省电子表格的存储空间,在降低硬件成本的同时提升了软件灵活性。实验证明,算法的改进能够节省约2KB的存储空间,角度位置误差能控制在1‰以内。     

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。     

影视作品中“审丑”现象流行的原因——从王宝强的走红谈起

从王宝强走红影视圈的案例出发,讨论了当今影视作品中的"审丑"现象流行的原因。这种"丑",不涉及品德,而是单纯的外貌丑,而这种外貌丑又是相对的。认为"审丑"现象的产生主要基于观众的审美疲劳,时代导致审美趋向多元化,把审美的意义赋予丑的形象,丑星的现实生活基础等几个原因。另外指出这种类型的丑星需要对自己加以调整、提高演技才能在影视圈走得更久,否则会引起观众的"审丑疲劳",不过是昙花一现。     

Embedding a fault-free hamiltonian cycle in a class of faulty generalized honeycomb tori

Generalized honeycomb torus (GHT) is recognized as an attractive alternative to existing torus interconnection networks in parallel computing systems. Assume that m and d are integers with m ? 2 and d ? 8. This paper addresses the fault-tolerant hamiltonicity of GHT(m, 2d, d) with fault set F = {(w, y), (x, y)}, where w < x, w + y is even and x + y is odd. We show that such a faulty GHT is hamiltonian by presenting a systematic method for constructing a fault-free hamiltonian cycle. This result reveals another appealing feature of GHTs.     

有限长度LDPC码一种速率兼容删余算法

提出一种AWGN信道下有限长度RC-LDPC码的删余算法,该算法对规则及非规则LDPC码均有效。该删余算法基于一系列准则,其中一个重要准则是某个候选删除节点的具有低的近似环外消息度(ACE)的短环的数量。仿真结果表明,ACE对删余码的性能有很大的影响,该算法的性能比已有算法有进一步提高。     

减震油弹性模量及疲劳特性试验台设计与实现

油液的体积弹性模量以及疲劳特性参数是油液非常重要的物理参数,在液压系统中,直接影响系统的稳定性和动态品质.研究设计了弹性模量及疲劳特性参数测试试验台,基于弹性模量的定义对弹性模量进行测量计算,同时以专用车辆油气悬挂装置为对象,对悬挂内液压油疲劳特性参数进行测试,如:温度、粘度等.完成控制系统以及数据采集系统的设计,与上位机实时通讯,实现测试过程的自动化.     

Spatial frequencies in aesthetic website evaluations--explaining how ultra-rapid evaluations are formed

This study investigates how aesthetic website evaluations, especially those formed after very brief presentations, depend on visual information that is encoded in low- or high-spatial frequencies. A total of 92 participants took part in the experiment. The study used a 3 × 3 mixed design in which presentation time (50, 500 and 10000 ms) and spatial filtering (low-pass filtered, high-pass filtered and unfiltered stimuli) were manipulated. First, we replicate prior results from online studies of high- and low-spatial frequencies. Second, we confirm a prediction from neurocognitive models that only low-spatial frequencies are relevant to aesthetic judgements in ultra-rapid presentation modes. Third, we demonstrate that stimulus repetitions lead to an overestimation of the importance of ultra-rapid stimulus presentations. Taken together, our results highlight the utility of neurocognitive models of visual processing to explain the rapid aesthetic evaluation of websites. PRACTITIONER SUMMARY: Using neurocognitive models we present an approach to explain how aesthetic impressions are formed. We show that ultra-rapid judgements are connected with low- but not with high-spatial frequencies, which are neurologically processed in different visual pathways. Furthermore we identify possible methodological problems in previous studies of ultra-rapid website perception.     

Using Tabulated Information

Abstract

Different tabulation formats for currency conversion tables wore examined. It was found that most formats could be used equally well to make conversions bi-directionally, i.e. from A to B and from 13 to A. A fully redundant table, one that required no additional arithmetic operations, could be used more quickly than a schematic table, and in schematic tables it was more important to have each of the major units given directly rather than each of the minor units. A matrix, although fully redundant, was much more difficult to use than the corresponding table of lists. Many subjects clearly did not understand the principles of matrix format. Measures of incidental learning suggested that practice at using a table resulted in only slight knowledge of the content of the table, even though much of each table could be generated from a single rule     

A Continuum Mechanics Approach for Crack Initiation and Crack Growth Predictions

Very often, different approaches are used for crack initiation and crack growth predictions. The current article introduces a recently developed approach that can be used for the predictions of both crack initiation and crack propagation. A basic assumption is that both crack nucleation and crack growth are governed by the same fatigue damage mechanisms and a single fatigue damage criterion can model both stages. A rule is that any material point fails to form a fresh crack if the total accumulated fatigue damage reaches a limit. For crack initiation predictions, the stresses and strains are obtained either directly from experiments or though a numerical analysis. For the prediction of crack growth, the approach consists of two steps. Elastic‐plastic stress analysis is conducted to obtain the detailed stress‐strain responses. A general fatigue criterion is used to predict fatigue crack growth. Compact specimens made of 1070 steel were experimentally tested under constant amplitude loading with different R‐ratios and the overloading influence. The capability of the approach to predict both crack initiation and the crack growth under these loading conditions was demonstrated by comparing the predictions with the experimental observations.