黄土丘陵区地质灾害规模参数幂律相依性研究

对滑坡、崩塌和不稳定斜坡等地质灾害规模参数幂律相依性进行定量研究,拓展了规模参数之间幂律相依性的研究范围。研究结果发现:1地质灾害规模参数的幂律相依性不仅存在于体积与面积之间,而且存在于面积与长、面积与宽等参数之间;2幂指数可以作为间接反映区域地质灾害或者不同类型地质灾害的宏观特征表征谱;3体积与面积关系式的幂指数分布为不稳定斜坡>滑坡>崩塌;面积与长关系式的幂指数分布为崩塌>滑坡>不稳定斜坡。面积与宽关系式的幂指数的分布为滑坡>崩塌>不稳定斜坡。

区域崩塌和滑坡规模参数频率分布研究——以秦巴山地宁强县为例

基于假设提出崩塌和滑坡灾害长、宽和厚等规模参数频率分布呈负指数关系,并通过变换负指数关系提出面积和体积等规模参数频率分布简单而有效的计算公式。以秦巴山区宁强县为例,对所提出的公式进行验证。结果表明:(1)特大型和巨型滑坡、崩塌在控制滑坡、崩塌总面积和总体积中起着重要的作用;(2)崩塌、滑坡规模参数(长、宽和厚)频率分布符合更简单的指数关系,且用指数关系拟合的规模参数频率曲线不会产生"偏转效应",地质灾害参数不仅符合对数正态分布(Normal),而且符合对数韦伯(Weibull)和Logistic分布;(3)对于崩塌和滑坡面积与体积规模参数,其实质是长、宽和厚等参数的平方级和立方级,因此,对于其规模参数频率分布求解的一个简单的方法是对面积和体积开平方根和立方根后再用指数分布对其拟合,事实证明其确实呈现一种指数分布;(4)文中所提出的规模参数频率负指数分布,简捷而有效,便于推广应用。

思茅松短期纸浆林规模参数的研讨

1988年,我院受建设单位委托,承担了“思茅纸厂纸材资源及基地建设可行性研究。”经过调研后,对思茅松人工纸浆林合理规模及经营标准化问题有如下设想,简介如下:目前,世界人工林的发展,联合国粮农组织推荐了一些对策:其中短周期工业林,例如造纸林建设是个重点。

面向水文模拟的大规模多级并行参数率定框架

为了实现大尺度水文模拟中的参数率定,提出一种基于优化算法的大规模多级并行参数率定框架。首先利用MPI划分子通信域的技术,实现了多级并行处理框架,其次设计了基于对等模式的整体架构,以充分利用处理器资源,最后使用大量非阻塞式通信的方式优化了计算效率,减少了进程间等待。将该框架应用于HIMS水文模型的参数率定,试验结果表明,对等多级并行框架相对于主从并行框架具有更好的寻优效果,利用非阻塞式通信,在寻优效率上有所提升。该框架能够高效地利用大规模处理器且有效地缩短运行时间,提升了参数优化的整体效率,具有良好的扩展性。

参数搜索空间规模对遗传算法稳定性的影响

对基于基因池重组遗传算法的无限种群动力系统进行了分析,讨论了参数搜索空间规模对系统稳定性的影响.特别地,针对处理“大海捞针”函数时参数搜索空间规模与系统不动点的解析关系进行了刻画,证明当参数搜索空间规模较小时,系统只有一个接近最优的稳定不动点;随着参数搜索空间规模的扩大,当超过临界值时,会出现一个不稳定的随机不动点和另外一个稳定不动点;当参数搜索空间规模进一步扩大时,所有的不动点将最终消失.实验和分析进一步证明该理论结果在通常情况下也适用.

降低参数规模的卷积神经网络模型压缩方法

针对卷积神经网络模型参数规模越来越大导致难以在计算与存储资源有限的嵌入式设备上大规模部署的问题,提出一种降低参数规模的卷积神经网络模型压缩方法。通过分析发现,卷积层参数量与输入输出特征图数量以及卷积核大小有关,而全连接层参数数量众多且难以大幅减少。通过分组卷积减少输入输出特征图数量,通过卷积拆分减小卷积核大小,同时采用全局平均池化层代替全连接层的方法来解决全连接层参数数量众多的问题。将上述方法应用于LeNet5和AlexNet进行实验,实验结果表明通过使用组合压缩方法对LeNet5模型进行最大压缩后,参数规模可减少97%,识别准确率降低了不到2个百分点,而压缩后的AlexNet模型参数规模可减少95%,识别准确率提高了6.72个百分点,在保证卷积神经网络精度的前提下,可大幅减少模型的参数量。

应用于图像分割的卷积神经网络参数简化模型

在图像处理领域卷积神经网络普遍存在模型复杂、参数众多等问题,使得方法应用不便、时间开销不可控。针对这一问题,提出了一种混合规模的深度卷积神经网络,该网络架构基于扩展的卷积方法,以便在不同图像规模上采集到关键特征,并通过将深度特征紧密相连,从而控制参数的数量。实验结果表明,新方法可以在限制模型参数前提下达到相当高的准确率,并能有效降低过拟合的风险。

现代曲流河点坝定量模式探讨

利用卫星照片测量了全球27个典型现代曲流河点坝的规模参数,对曲流河点坝的沉积特征参数进行了半定量到定量的研究,建立了曲流河点坝的长度、宽度与河流满岸宽度之间的定量关系式,并探讨了应用于曲流河相储层研究的思路.

Combustion simulation and key parameter optimization for opposite axial piston engine in small-scale

As potential alternative power sources used in portable electric generators, opposite axial piston engines in small-scale were investigated to show their advantages in power density. A novel cylinder charge system was introduced, based on which a quasi-dimension model and a CFD(computational fluid dynamics) model were established. Comparison of those two models was carried out to validate the quasi-dimension model. Furthermore, optimal diameter of charge cylinder and speed were determined after evaluating the quasi-dimension model based on different parameters. High agreement between the quasi-dimension model and the CFD model validates the quasi-dimension model. Further studies show that the power of engine increases with the diameter of charge cylinder. However, a too big charge cylinder lowers the fuel efficiency instead. Taking economic influence into consideration the charge cylinder should be 1.4 times power cylinder, which could ensure the power density, volumetric efficiency and fuel economic at the same time. Axial piston engine running at 1.0×104 r/min could achieve a better overall performance. The maximal power of engine with optimal parameters is 0.82 k W, which fits the power need of the portable electric generators completely.

Optimization of Parameters for Melt Crystallization of p-Cresol

Laboratory-scale experiments were carried out to evaluate the influences of operational parameters on the melt crystallization efficiency for p-cresol purification.The optimal crystallization conditions were determined:dynamic pulsed aeration at 90 L·h-1 and the cooling rate of 0.6-0.8 ℃·min-1,followed by sweating at 0.2-0.3 ℃·min-1 for 40 min.Results also demonstrate that the melt crystallization efficiency is sensitive to feed concentration,which highlights this technology for separation and purification of high purity products.

一种轻量化手写数字的识别算法

在手写阿拉伯数字识别系统中,传统手写数字识别算法准确率不高。基于LeNet-5卷积神经网络算法,提出一种轻量化的卷积神经网络算法。利用全局平均池化算法代替原有的全连接层降低算法训练参数的规模;利用RELU函数代替tanh函数作为激活函数、增加BN层等方法来加速网络模型的收敛速度。利用MNIST手写数据集设计了验证实验,实验表明,改进后的算法不但训练参数规模只有LeNet-5训练参数规模的1/3,而且相较于LeNet-5改进后的算法准确率上升了约0.4%。由此证明该算法具备较高的应用及推广价值。

Experimental Investigation of Environmental Hydraulic Parameters for Dual Mixed Media Biofilter for Greywater Treatment

Laboratory scale model of DMMBF （dual mixed media biofilter） were designed and installed in AI-Mustansiriya University Environmental Hydraulic Lab. Experiments were conducted using two mixed layers through PVR column--2.2 m height and 300 mm diameter. The first mixed media filter of depth 640mm mixed of sand, rice husk and granular activated carbon. The percentage volume mix is 1：1：1. While the other mixed media of depth 740 mm, consisting of coal, crash porcelinaite, rock and granite with equally percentage volume. Fifty samples were collected during the experiments, which was spread over a period of forty two weeks. The obtained results indicate that when the flow loading raised from 0.15 L/min to 2.7 L/rain, the removal efficiency of BOD decreased 8%-11%, and the removal efficiency of COD deceased 3%-4%, while the removal efficiency of turbidity increased with the decreasing of hydraulic loading. The results showed that the removal efficiency of turbidity is more than 95% at the lower discharge （0.15 L/min）. Therefore, infiltration should be conservatively designed using low loading rates.

3D structure parameterization design and modeling for irregular structure of stope bottom

Stope mining design is a very important and complicated task in daily production design and technical management of an underground mine.Based on workface technology and human-computer interaction technology,this study introduces a method of 3D parametric design for the irregular structure of stope bottoms,and focuses on solving technical problems in surface modeling of stope bottom structure.Optimization of the minimum span length algorithm(MSLA) and the shortest path search algorithm(SPSA) is conducted to solve the problem of contour-line based instant modeling of stope bottom structures,which makes possible the 3D parametric design for irregular structure of stope bottom.Implementation process and relevant methods of the proposed algorithms are also presented.Feasibility and reliability of the proposed modeling method are testified in a case study.In practice,the proposed 3 D parameterization design method for irregular structure stope bottom proves to be very helpful to precise 3D parametric design.This method is capable of contributing to improved efficiency and precision of stope design,and is worthy of promotion.

Product-Library-Derived Specification Parameters in Building Information Models Augmentation

This paper conceptualizes a framework for bridging the BIM （building information modelling）-specifications divide through augmenting objects within BIM with specification parameters derived from a product library. We demonstrate how model information, enriched with data at various LODs （levels of development）, can evolve simultaneously with design and construction using different representation of a window object embedded in a wall as lifeeyele phase exemplars at different levels of granularity. The conceptual standpoint is informed by the need for exploring a methodological approach which extends beyond current limitations of current modelling platforms in enhancing the information content of BIM models. Therefore, this work demonstrates that BIM objects can be augmented with construction specification parameters leveraging product libraries.

Novel robust approach for constructing Mamdani-type fuzzy system based on PRM and subtractive clustering algorithm

A novel approach for constructing robust Mamdani fuzzy system was proposed, which consisted of an efficiency robust estimator(partial robust M-regression, PRM) in the parameter learning phase of the initial fuzzy system, and an improved subtractive clustering algorithm in the fuzzy-rule-selecting phase. The weights obtained in PRM, which gives protection against noise and outliers, were incorporated into the potential measure of the subtractive cluster algorithm to enhance the robustness of the fuzzy rule cluster process, and a compact Mamdani-type fuzzy system was established after the parameters in the consequent parts of rules were re-estimated by partial least squares(PLS). The main characteristics of the new approach were its simplicity and ability to construct fuzzy system fast and robustly. Simulation and experiment results show that the proposed approach can achieve satisfactory results in various kinds of data domains with noise and outliers. Compared with D-SVD and ARRBFN, the proposed approach yields much fewer rules and less RMSE values.

A comprehensive assessment of urban vulnerability and its spatial differentiation in China

The urban vulnerability poses a serious challenge to achieving sustainable devel- opment. With the concentration of the population and the economy, cities must manage the higher frequencies and risks of various hazards and are becoming more vulnerable. Re- search on the assessment and regulatory control of urban vulnerability is of great significance for both urbanization quality improvement and sustainable development in China or other countries in the world. Because of the complexity of cities and vulnerability concepts, existing studies have focused on different aspects of urban vulnerability. And the research content of urban vulnerability is scattered and relatively independent, leading to a lack of comparability among the research data and resulting in tremendous difficulties in summarizing the conclu- sions through comparison of independent research data. Therefore the goal of this study was to construct urban vulnerability index （UV/） from the perspective of sustainable development that could assess urban vulnerability comprehensively. In this study, we selected 10 subin- dexes involving 36 specific parameters from four aspects （resources, eco-environmental sys- tems, economics, and social development） to construct a comprehensive index system. We also established the standard values of measurements. Then we take 288 prefecture-level cities in China as a study area and evaluate its overall urban vulnerability and its spatial differentiation. Results indicate that urban vulnerability of China has a remarkable spatial differentiation of both ＂gradient distribution＂ and ＂clustered distribution＂; the extent of urban vulnerability corresponds to city size, the bigger the city, the lower its vulnerability; re- source-based cities are more vulnerable than comprehensive cities; a city＇s economic growth rate does not reflect the extent of its urban vulnerability. Further, we offer a few suggestions to cope with urban vulnerability in China.

New semidefinite programming relaxations for box constrained quadratic program

We establish in this paper optimal parametric Lagrangian dual models for box constrained quadratic program based on the generalized D.C.(difference between convex) optimization approach,which can be reformulated as semidefinite programming problems.As an application,we propose new valid linear constraints for rank-one relaxation.

Effects of foundation damage and water-level change on vibration modal parameters of gravity-type caisson structure

In this paper,the effects of foundation damage and water-level change on vibration characteristics of gravity-type caisson structure are examined by analyzing modal parameters extracted from output-only information.To achieve the objective,the following approaches are implemented.Firstly,vibration response analysis methods are selected to estimate power spectral density and modal parameters such as natural frequency,damping ratio and mode shape of a lab-scale caisson structural system.Secondly,vibration tests on the lab-scale caisson system are performed under a series of test scenarios which include three water-level changes and three damage levels.Thirdly,experimental modal parameters corresponding to the damaging cases as well as the water level cases are extracted by frequency domain decomposition method and stochastic subspace identification method.Finally,the effects of the water-level variation and foundation damage on the extracted modal parameters are examined to assess the feasibility of the vibration-based damage detection in gravity-type caisson structures under water-level uncertainty.

Rare Decay B_c → D_s *μ^+ μ^- in a Family Non-Universal Z′ Model

Using the form factors calculated in the three-point QCD sum rules, we calculate the new physics contri- butions to the physical observables of Bc→D;μ＋ μ- decay in a family non-universal Z＇ model. Under the consideration of three cases of the new physics parameters, we find that： （a） the Z＇ boson can provide large contributions to the differential decay rates; （b） the forward-backward asymmetry （FBA） can be increased by about 47%, 38%, and 110% at most in S1, S2, and extreme limR values （ELV）, respectively. In addition, the zero crossing can be shifted in all the cases; （c） when s 〉 0.08, the value Of PL can be changed from -1 in the Standard Model （SM） to -0.5 in S1, -0.6 in S2, and 0 in extreme limit values, respectively; （d） the new physics corrections to PT will decrease the SM prediction about 25% for the cases of S1 and S2, 100% for the case of ELV.