基于超拉普拉斯先验的图像非盲解卷积

自然图像梯度的重尾分布在去噪、去模糊以及超分辨率等问题中已经被证实是一个非常有效的先验。自然图像梯度的长尾分布可以极好地用超拉普拉斯(Hyper-Laplacian)分布模型化。基于空间变化点扩散函数提出了一种超拉普拉斯先验的图像快速非盲解卷积方法,对图像进行复原。该算法的优势就是引入空间变化点扩散函数,使用分步交替迭代最小化方法,通过查表法快速对图像去卷积求解。该方法的解卷积速度得到较大幅度的提升,而且对模糊图像有较好的复原效果,提高了图像的质量。     

基于用户间影响力度量的网络信任模型研究

为了解决完全依靠公钥证书体系为动态变化的网络环境提供信任支撑存在较大局限性的问题,需要在信任领域引入新技术。由于网络信任计算中的信任问题和社交网络中的用户影响力问题具有一定的相关性且属性认证、隐私交互等都是需要解决的问题,因此将用户影响力引入网络信任领域具有一定的可行性。基于上述理论,本文提出了一种基于用户间影响力的网络信任计算模型。首先,论述了模型的相关基础理论和模型构架;然后,研究其工作过程,分析设计信任算法;最后,将模型的各项性能与几种经典模型进行对比和测试并通过对模型参数对比的理论分析验证了模型的可行性、安全性和高效性等。     

机器类通信终端蜂窝网接入拥塞控制

针对网络接入拥塞问题,设计一套机器类通信终端蜂窝网接入拥塞控制方案。基于动态资源分配,利用机器类终端接入检测机制,控制蜂窝网机器类通信接入资源的数量及瞬时接入强度,以降低接入冲突率。     

Near ground wind characteristics during typhoon Meari: Turbulence intensities,gust factors,and peak factors

Journal of Central South University - Wind data were collected during the 2011 typhoon Meari at heights of 10, 20, 30, and 40 m above the ground using a 40 m high anemometer tower in the coastal...     

建筑施工过程碳排放量预测模型及应用研究

在明确碳排放量计算公式和碳排放因子的基础上,文章建立建筑施工过程中碳排放量预测模型,并对建筑施工过程中材料及机械设备使用情况进行实证分析,得出建筑面积与施工过程碳排放量存在显著的线性关系。最后通过实例对该碳排放量预测模型进行应用研究。     

异程管网热湿负荷分配次优解群及适应性

提出了一种基于次优解群统计分析的异程管网热湿负荷分配方法,采用变步长+随机走步的寻优计算方法,获得空调季不同负荷率下热湿负荷再分配的次优解群,分析次优解群的随机行为和统计规律,以此探索复杂变量约束下的冷冻水系统负荷分配的优化控制策略及其适应性。根据计算结果,在40%、60%、80%、100%这4种负荷率下末端人数次优解重叠率最高达到24%。研究表明,次优解群随机行为与管网热湿负荷分配策略存在相关性,离冷源侧越近,末端人数次优解重叠率越高,分配策略的负荷适应性越好,其权重越大。     

多分辨率分析和小波能量曲率的框架结构损伤识别

为研究运用多分辨率和小波包分析方法识别结构损伤的有效性,以三层混凝土框架结构为研究对象,分别建立不同损伤工况下的三维有限元数值模型,采用ANSYS程序进行动力时程分析,研究不同识别指标和输入信号的识别灵敏度以及其他因素对损伤识别结果的影响.分析结果表明:小波包能量曲率差法能够较好达到损伤识别的目的,输入信号使用加速度响应信号比速度和位移响应信号具有更好的识别效果;有限元模型网格划分、加速度时程响应信号的提取位置以及采样频率对损伤位置的识别有较大影响;有限元网格划分越密、加速度时程响应信号提取位置离损伤位置越近、采样频率越大,损伤位置识别越精确.     

卫星太阳翼板面水平展开试验方法

为减少卫星姿态翻转,确保卫星光学载荷指向精度,提出卫星太阳翼板面水平展开试验方法.采用多自由度配重悬挂法抵消太阳翼水平展开试验过程中的重力,开展运动学及动力学分析、试验误差分析,完成卫星太阳翼板面水平展开试验验证.试验结果表明:相比传统展开试验方法,能够更真实的模拟太阳翼在轨展开运动;对太阳翼配重质量偏差、太阳翼吊挂质心偏差及系统摩擦力控制要求高.验证模型和试验方法的正确性,满足卫星太阳翼展开试验要求.     

Effect of pore structures on the electrochemical performance of porous silicon synthesized from magnesiothermic reduction of biosilica

Two kinds of porous silicon(PS) were synthesized by magnesiothermic reduction of rice husk silica(RHS) derived from the oxidization of rice husks(RHs). One was obtained from oxidization/reduction at 500 ℃ of the unleached RHs, the other was synthesized from oxidization/reduction at 650 ℃ of the acidleached RHs. The structural difference of the above PS was compared: the former had a high pore volume(PV, 0.31 cm3/g) and a large specific surface area(SSA, 45.2 m~2/g), 138 % and 17 % higher than the latter, respectively. As anode materials for lithium ion batteries, the former had reversible capacity of 1 400.7 m Ah/g, 987 m Ah/g lower than the latter; however, after 50 cycles, the former had 64.5 % capacity retention(907 m Ah/g), which was 41.2 % higher than the latter(555.7 m Ah/g). These results showed that the electrochemical performance of PS was significantly affected by its pore structures, and low reduction temperature played the key role in increasing its porosity, and therefore improving its cycling performance.     

Aging behaviors of silicone rubber composite materials under outdoor environment

We investigated the aging effect on the chemical structure of silicone rubber composite materials under outdoor environment. The variations of low molecular weight siloxanes in silicone rubber were probed by gas chromatography-mass spectrometry during the degradation process. The experimental results indicate that a series of cyclic siloxanes exist in both the virgin and aged silicone rubber samples, while the additional low molecular weight siloxanes (hexamethyl cyclotrisiloxane) only appear in the aged samples. Meanwhile, the total amounts of low molecular weight siloxanes in the aged samples are much less than those in the virgin ones. The loss of low molecular weight siloxanes is induced by the chain scission and depolymerization.