Temperature distributions in concrete box girders due to heat of concrete hydration

Based on heat transfer theory,a two-dimensional complex exponential function was used to compute heat of concrete hydration.A concrete box girder consisting of a single box with two cells used on Harbin Songpu Bridge was measured on site.The two coefficients in the complex exponential function were determined to best fit the field measured data.ABAQUS program was used to simulate the heat transfer and determine the temperature distribution in the concrete box girders during concrete setting.The calculated temperature distribution in the box girders were compared with the field measured data and good agreement was observed.The temperature distribution and gradient in the entire box section,webs and bottom slab were analyzed using the measured and calculated results during the course of concrete hydration.

Fatigue Performance of Orthotropic Steel Decks in Super-Wide Steel Box Girder Considering Transverse Distribution of Vehicle Load

This study presents an investigation on the fatigue analysis of four types of details on orthotropic steel decks(OSDs)for a cable-stayed super-wide steel box girder bridge based on finite-element analysis(FEA)with vehicle transverse distribution model(VTDM).A high-fidelity 3D FE model verified by the static load test is established to satisfy the fatigue analysis accuracy.The stress behavior of super-wide steel box girders under the vehicle load at different lane locations is investigated.Then,considering the effect of VTDM,the fatigue life analysis of four typical details is performed using the Miner cumulative damage rule.The results show that the vehicle transverse location has a great influence on the stress behavior of details with sharp influence surface,and the stress ranges in the outermost lane are larger than those in other lanes,indicating that the details of OSD in the outermost lane are prone to fatigue.The fatigue life analysis indicates that the diaphragm cutout is more prone to fatigue than other details,which should be carefully treated in bridge maintenance.

Average of Distribution and Remarks on Box-Splines

A class of generalized moving average operators is introduced, and the integral representations of an average function are provided. It has been shown that the average of Dirac δ distribution is just the well known box spline. Some remarks on box splines, such as their smoothness and the corresponding partition of unity, are made. The factorization of average operators is derived. Then, the subdivision algorithm for efficient computing of box splines and their linear combinations follows.

A NOTE ON THE RECURRENCE RELATIONS OF MULTIVARIATE TRUNCATED POWERS AND BOX SPLINES

This paper gives an additional definition to multivariate truncated power T(x|x1 ,…,xn) when the knots x1 ,…,xn do not span the whole space to which x1 ,…,xn belong. By which, together with the recurrence relation, the practical evaluation of T(x|x1,…,xn ) will be very convenient and efficient. The same discussion is also done to box splines.

A RESEARCH ON THE DISTRIBUTION OF SHUTTLES ON THE BOX LOOM

The figure of shuttle distribution one side of the loom has been used to show the convel-sion of shuttle in picking process.The characteristics of the figure have been analysed andused to introduce a simple method for shuttle starting distribution.

A Novel Black Box Based Behavioral Model of Power Amplifier for WCDMA Applications

In this paper, Black Box approach is presented for behavioral modeling of a non linear power amplifier with memory effects. Large signal parameters of a Motorola LDMOS power amplifier driven by a WCDMA signal were extracted while taking into considerations the power amplifier’s bandwidth. The proposed model was validated based on the simulated data. Some validation results are presented both in the time and frequency domains, using WCDMA signal.

Electric power generation technology of natural gas pressure reduction:Insights from black box-gray box hierarchical exergy analysis and evaluation method

Based on the“three box”exergy analysis model,a black box-gray box hierarchical exergy analysis and evaluation method is put forward in this paper,which is applied to evaluate the power generation technology of differential pressure produced by natural gas expansion.By using the exergy analysis theory,the black box-gray box hierarchical exergy analysis models of three differential pressure power generation technologies are established respectively.Firstly,the“black box”analysis models of main energy consuming equipment are established,and then the“gray box”analysis model of the total system is established.Based on the calculation results of exergy analysis indexes,the weak energy consumption equipment in the whole power generation process is accurately located.Taking a gas field in southwest China as an example,the comprehensive energy consumption evaluation of the three power generation technologies is carried out,and the technology with the best energy consumption condition among the three technologies is determined.Finally,the rationalization improvement measures are put forward from improving the air tightness,replacing the deflector and reducing the flow loss.

Basic Functions for Computational Implementation of the Box-Cox Symmetric Class of Distributions

A class of distributions called Box-Cox symmetric was proposed for random variables with asymmetric distributions. This class allows through its structure an interpretation of the parameters in terms of quantiles (in particular, the median), relative dispersion and skewness. This study presents the initial results of the computational development of basic functions of each of the distributions that make up the Box-Cox symmetric class. Four functions have been developed to compose a routine in software R up to now. These functions are related to random numbers generation, probability density function, cumulative distribution function, and quantile function associated to a given probability. Examples of implemented functions were presented. The gamlss routine was used to check the performance of developed functions.

A Neuro-Based Software Fault Prediction with Box-Cox Power Transformation

Software fault prediction is one of the most fundamental but significant management techniques in software dependability assessment. In this paper we concern the software fault prediction using a multilayer-perceptron neural network, where the underlying software fault count data are transformed to the Gaussian data, by means of the well-known Box-Cox power transformation. More specially, we investigate the long-term behavior of software fault counts by the neural network, and perform the multi-stage look ahead prediction of the cumulative number of software faults detected in the future software testing. In numerical examples with two actual software fault data sets, we compare our neural network approach with the existing software reliability growth models based on nonhomogeneous Poisson process, in terms of predictive performance with average relative error, and show that the data transformation employed in this paper leads to an improvement in prediction accuracy.

基于P-Box和CVaR并考虑灵活性的配电网区间优化方法

为实现高比例可再生能源配电系统的安全经济调度,提出了一种计及风电、光伏出力与负荷预测误差的不确定性和配电网灵活性调用能力的日前区间优化调度方法。为避免传统方法在描述不确定性时的信息丢失问题、传统区间方法的保守性以及区间截断方法的冒进性,该文基于概率盒理论与条件风险价值方法计算不确定性因素的区间边界。随后,基于灵活性资源的实时调整能力,建立调度计划的灵活性时段耦合约束,并建立线路传输灵活性越限约束,以提高所提方法在调度过程的适应性。以配电网综合运行成本最小为优化目标,采用遗传算法进行求解。最后,基于IEEE-33节点配电系统、某地区实际配电网以及美国PG&E 69节点的算例分析表明,所提出的区间提取方法及调度模型能在保证配电网满足传输容量约束的同时达到系统运行成本最优。

基于Box-Cox变换结合多种算法的风电机组数据预处理方法研究

由于弃风限电、环境干扰等因素的影响,SCADA系统采集的原始数据中会存在异常数据,对原始数据进行精确有效的数据预处理,是后续故障预警工作的基础;基于SCADA系统采集的数据,对风电机组运行数据的预处理方法进行改进和研究,提出了一种将Box-Cox变换与以正态分布为前提的异常值清洗算法相结合的方法,对原始数据进行预处理;运用Box-Cox变换分别与Bin算法、肖维勒准则、狄克逊准则和格拉布斯准则相结合的方法进行数据预处理,经过实例验证:肖维勒准则的算法简单且检测时间短,但是对于异常数据的清洗效果较差;狄克逊准则和格拉布斯准则对于异常数据的清洗效果较好,但是处理时间较长,对大型风电场海量数据,这种方法的实用性较差;相比于其他算法,Bin算法的优势较为明显。

Nest box selection and reproduction of European Rollers in Central Italy: a 7-year study

Background: Changes and increased mechanisation of agricultural practices have influenced the biodiversity composition of farmland habitats and caused a decline of bird communities in many European countries. The removal of shrubs and large trees rich in natural cavities, has also led to a drastic decrease in nest site availability for cavity-nesting bird species. Nest-boxes are a common conservation tool used to improve nest-site availability, and have helped to reverse declines in many endangered bird populations. Nonetheless to maximize the results of such interventions it is crucial to know where nest-boxes should be sited. The objective of this study was to investigate the effectiveness of the nest-box program for the European Roller (Coracias garrulus) population of Lazio region (Central Italy). More specifically, we focused on what landscape features were preferred (or avoided) in the process of nest box selection and how they influenced population’s breeding parameters. Particular attention was paid to identifying potential limitations and to provide management recommendations for future interventions. Methods: Using data from 70 nest boxes sited on power lines monitored over a 7-year period (representing 140 breeding attempts), we developed probability functions to evaluate if nest box location, in terms of distance from habitat resources and habitat composition and structure, had an effect on nest box occupancy and on the main reproductive parameters. Results: Nest boxes were more likely to be occupied if they were located near arable fields and in areas characterized by a higher amount of incoming solar radiation. Higher fledging success was associated with fallow fields and with a moderate/low habitat structural complexity. Higher breeding success was associated with solar radiation and with greater distance from urban areas. Conclusions: Our results highlight the importance of specific habitat variables in influencing nest occupancy, and show which drivers primarily affect species’ reproduction and persistence over time. Siting nest boxes in habitats where occupancy rate and fledging success is higher, such as in arable and fallow fields and on south-facing slopes where solar radiation is maximised, may help to extend the suitable habitat for rollers and facilitate its local expansion.

A hybrid storage technology for low power consumption and high I/O performance in an IPTV set-top box

A new method of prefetching data blocks from the NVCache to the page cache in main memory and cascading prefetching n-blocks from a hard disk to the NVCache together was proposed to reduce the spin-up frequency of a hybrid hard disk drive and thus enhance I/O performance.The proposed method consists of three steps:1) Analyzing the pattern of read requests in block units;2) Determining the number of blocks prefetched to the NVCache;3) Replacing blocks in the NVCache according to the block replacement policy.The proposed method can reduce the latency time of a hybrid hard disk and optimize the power consumption of an IPTV set-top box.Experimental results show that the proposed method provides better average response time compared to an existing adaptive multistream prefetching(AMP) method by 25.17%.It also reduces by 20.83% the average power consumption over that of the existing external caching in energy saving storage system(EXCES) method.

Dynamic inhomogeneous S-Boxes in AES: a novel countermeasure against power analysis attacks

Substitution boxes (S-Boxes) in advanced encryption standard (AES) are vulnerable to attacks bypower analysis.The general S-Boxes masking schemes in circuit level need to adjust the design flow andlibrary databases.The masking strategies in algorithm level view each S-Box as an independent moduleand mask them respectively,which are costly in size and power for non-linear characteristic of S-Boxes.The new method uses dynamic inhomogeneous S-Boxes instead of traditional homogeneous S-Boxes,andarranges the S-Boxes randomly.So the power and data path delay of substitution unit become unpre-dictable.The experimental results demonstrate that this scheme takes advantages of the circuit character-istics of various S-Box implementations to eliminate the correlation between crypto operation and power.Itneeds less extra circuits and suits resource constrained applications.

Analysis of the relation between organic products consumption and box schemes use in Alicante (Spain)

Box-schemes or organic food subscription plans consist on a regular delivery of a box of seasonal fruits and/or vegetables, preferably organic, cultivated in the vicinity at a specified point using subscription, The object of the present work is trying to examine whether there is a relationship between consumer knowledge about these short distribution channels and the consumption of organic products in the province of Alicante. A survey has been conducted among 400 usual food buyers in this Spanish province. It has been found that the consumption of organic products and the knowledge of such initiatives are linked. We recommend to companies that use this type of distribution channel to publicize its benefits.

德尔福汽车系统（中国）投资有限公司 Power Box混合动力系统

德尔福的混合动力Power Box是一个完备的、轻度混合动力系统，它包括混合动力控制器、牵引逆变器、DC／DC转换器、电池包及其控制器、电池断路和热量管理子系统。整套系统设计便于直接放置在车内，尤其是安装在后排座椅的后方，并且广泛适用于多种汽车平台和多种动力总成结构。另外，此系统可以兼容镍氢电池和锂离子电池。

基于Box-Cox幂转换模型的非正态过程能力分析

标准过程能力指数是基于过程输出服从正态分布的假设建立的。实际中存在大量不服从正态分布的过程输出,几何公差类质量特性就是其中一种。本文在数据转换方法基础上,基于Box-Cox幂转换模型进行偏态数据正态化来专门处理此类质量特性的过程能力指数计算。通过仿真研究了该方法在过程能力分析中的适用性和效果。仿真结果和案例分析显示,该方法计算简单、结果可靠。

基于Box算法的无功优化配置

Box算法是工程优化设计中一种重要的直接搜索算法 ,适用于无法给出目标函数显式数学表达式的优化问题求解。针对无功优化配置问题非线性、非连续性及目标函数与控制变量的隐式关系等特点 ,提出了基于 Box算法的无功优化配置模型及相应求解步骤 ,利用罚函数处理函数约束、重复迭代及采用贝斯—德拉姆洗牌与组合方法产生随机数均能改善收敛性。对 IEEE6,1 4和 30节点以及实际大规模系统的数字仿真结果表明 。

Box-Cox变换原理及其在财务比率正态分布中的作用

对上海深圳交易所1998～2002年1 100余家公司5 571份年报12个财务比率的综合研究揭示,绝大多数财务比率不服从正态分布且不易变换到接近正态.正态变换实证过程表明:原始财务比率数据经行业划分、剔除污染样本后再进行Box-Cox变换的的正态变换效率最高,可使绝大多数财务比率接近正态分布,但仍有少数比率无法正态化.

Box-Cox转换在估计危险因素平均暴露剂量中的应用

目的 :Box -Cox转换在估计危险因素平均暴露剂量中的应用。方法 :用Stata软件包进行数据的Box -Cox转换 ,并用转换后的数据计算暴露剂量算术平均数。结果 :大多数的氡子体暴露计量的数据不呈正态分布 ,只有约 2 1%的原始数据适合用算术平均数代表 ;Box -Cox转换后所有数据都可以计算出有代表性的氡子体暴露剂量平均水平。结论 :在估计环境危险因素的年平均暴露剂量时 ,若原始数据分布不呈正态或近似正态 ,应当先进行数据转换。Box -Cox转换是一种适用范围较广的数据转换方式 ,在估计放射性氡子体平均暴露剂量时 ,结果令人满意。