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Search Results: 1 - 10 of 275268 matches for " 张昆鹏 "
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基于SVAR模型对商品价格波动和居民消费关系的讨论
Discussion Based on the SVAR Model of Commodity Price Volatility and Consumer Relations
 [PDF]


E-Commerce Letters (ECL) , 2012, DOI: 10.12677/ECL.2012.13005
Abstract:

本文运用结构向量自回归(SVAR)模型,深入分析了2000年到2012年月度商品零售价格指数与居民消费价格指数二者之间的关系,进行了相应的单位根检验,在VAR模型的基础上做出SVAR模型,由此获得了该模型中两变量长期稳定的关系,分析得出,二者受自身前期影响较大,且上期商品零售价格对于居民消费价格有明显的正相关影响(影响系数为0.44)。并在此基础上建立了脉冲响应函数,继而做出了(SVAR)模型的脉冲响应函数分析。

This paper tries to analyse the relationship between the retail price index and consumer price index with the structural vector auto regression (SVAR) model when it was 2000 to 2012 monthly. With the VAR model we have the unit root test, in which we get the long-term stable relationship between two variables in the model analysis. With their own pre-impact, the retail price has a significantly positive effect on the consumer price (which affects coefficient of 0.44). On this basis, with the establishment of the impulse response function we make (SVAR) model impulse response function analysis.

 

基于丁克问题的人口结构预测
Research of the Population Structure Prediction Based on Dink Problem
 [PDF]

刘欢, 方巧,
Aging Research (AR) , 2014, DOI: 10.12677/ar.2014.11002
Abstract:
人口的增长是引起世界各国普遍关注的问题。随着社会的发展,科技的进步,人们的生活节奏在逐步加快,人才之间的竞争也在愈演愈烈,这些使得越来越多的人不愿意在业余时间为子女操心操劳,而要集中精力为自身的存在与发展拼搏,加之,养育孩子的经济负担越来越重,所以“丁克”家庭的数目也越来越多。因此许多学者担心:丁克家庭的大量出现,加剧了人口老龄化问题。本文首先采用一元回归对丁克人口进行预测,然后使用预测的丁克数据运用人口移算的方法对总人口进行预测,并分析人口结构,认为我国老龄化现象日益明显。
The population growth is causing widespread concern around the world. With social development and technological advances, people gradually accelerate pace of life, and talent competition is becoming intensively, which makes more and more people not willing to worry about their children in their spare time, but to concentrate on their own existence and development. In addition, the economic burden of raising a child is getting heavier and heavier, so the number of “DINK” family is also increasing. Many scholars are worried that “DINK” families have exacerbated the aging of population. First this paper uses simple regression to predict the population of dink. Based on the predicted dink data, we use the method of demographic shift operator to predict the total population and analyze the demographic structure, which shows that the aging phenomenon has become increasingly evident.
混合离散差分进化算法在单机批处理调度中的应用
明玺,
中国管理科学 , 2010,
Abstract: ?本文研究单机批处理调度问题,批处理机有批次容量限制,批处理时间由每个批次所含作业中的最长作业处理时间决定。每个作业具有不同的大小、处理时间、提前拖期惩罚权重,所有作业具有公共交货期,且交货期无限晚。目标函数为最小化所有作业的加权提前拖期惩罚之和。该问题已被证明为NP难题,本研究找到了其最优解具有的一些性质,在此基础上利用它们提出了一种动态规划(DP)与差分进化(DE)算法相结合的混合离散差分进化(HDDE)算法来求解该问题,通过与传统的遗传算法、模拟退火算法和迭代贪婪算法进行对比,HDDE算法显示了更加强大的全局搜索能力。
鱼雷热动力技术的发展综述
陈兵?,峰?,
推进技术 , 2011,
Abstract: 概括地介绍目前世界上各国的先进鱼雷热动力系统以及发展前景,根据鱼雷总体对热动力系统的要求,从推进剂、发动机以及减振降噪三个方面总结了鱼雷热动力系统的研究特点。
混凝土徐变对柔性车体列车-桥梁系统动力响应影响分析
Analysis of concrete creep’s influence on dynamic response of train-bridge system with flexible car-body

,夏禾,
- , 2017, DOI: 10.11860/j.issn.1673-0291.2017.06.018
Abstract: 摘要 为了解决高速铁路混凝土简支梁桥徐变引起桥上轨道结构发生附加变形,进而影响桥上列车运营品质的问题,建立了柔性车体列车-桥梁系统动力分析模型,并以高速铁路常见跨度32 m和24 m预应力混凝土简支梁为例,分析了混凝土徐变对桥上CRTS III型无砟轨道结构附加变形的影响特点,并进一步研究了轨道结构附加变形对桥上列车运行安全性及平稳性的影响规律.研究结果表明:延长铺轨时间可有效防止混凝土桥梁工后徐变引起的轨道结构附加变形量超出规范限值;梁体徐变下挠情况会使梁端区域的轨道结构出现凸起折角,列车通过这一折角时轮对动轴重会急剧减小,可能出现“轮轨分离”;梁体徐变对运行舒适性指标的影响远大于对运行安全性指标的影响,同时,忽略车体柔性会低估梁体徐变对车辆运行舒适性的影响.
Abstract:The creep of simply-supported concrete beam on high-speed railway will induce additional deformation of the track structure and affect train operation quality. A train-bridge system which takes car-body flexibility into consideration is therefore established. Taking the 32 m and 24 m simply-supported prestressed concrete beams, which are the common span beams, on high-speed railway as a study case, the additional deformation of CRTS III ballastless slab track induced by concrete creep and its effect on the safety and comfort of vehicles running through the deformed bridge are studied. The calculation results show that prolonging the track construction time can effectively prevent additional deformation of track structure induced by creep from exceeding code limit. The creep deflection makes the convex angles appear around beam end of the track structure, when a wheel goes through the convex angle, the wheel-rail force will decrease sharply, which could even induce wheel-rail separation. The influence of creep on the comfort index is far greater than that on the safety index, and the influence of creep on the vehicle operation comfort could be underestimated when ignoring car-body flexibility.
基于供需分析的城市绿地空间布局优化——以南京市为例
,徐建刚,翔**
应用生态学报 , 2013,
Abstract: 城市绿地具有生态服务和社会服务两种主要功能,这两种服务水平的高低取决于供需关系.而绿地的供给和需求不仅指数量上,还包括空间分布,因此单纯的绿化指标或可达性水平都不能完全体现城市绿地的真实服务水平.本文从供需分析的角度,在arcgis平台下,利用均匀度指数和可达范围内人均享有公共绿地达标率考察了南京城市绿地的生态服务和社会服务在空间上的需求和供给,最终得出了南京市各区绿地系统的生态和社会服务水平.结果表明:东部地区绿地数量上富余,但缺乏高可达性公共绿地,社会服务水平中等;老城地区绿地缺乏,特征绿地分布不均匀,绿地生态和社会服务水平低;河西地区绿地社会服务水平高,但生态绿地较少且分布不均,生态服务水平低;南部、北部均存在绿地不足、分布不均、高可达性公共绿地少的问题.
加气混凝土与普通混凝土黏结界面剪切性能试验
孙静,建伟,
- , 2017, DOI: 10.11918/j.issn.0367-6234.201603037
Abstract: 密肋复合墙体是由钢筋混凝土肋构成的框格与内嵌轻质加气混凝土砌块组成, 是密肋复合墙结构的主要承力构件.由于密肋复合墙体特殊的制作工艺, 在混凝土肋与加气混凝土砌块相接触的位置处形成一黏结界面, 而此类黏结界面的性能目前仍不明确, 为此, 有必要在材料层次上对加气混凝土砌块与普通混凝土黏结界面性能进行研究.本文以密肋复合墙结构为研究背景, 采用棱柱体剪切试验的方法测定加气混凝土砌块与普通混凝土黏结界面性能, 分析黏结界面倾斜角度对试件的破坏形态和界面强度的影响.结果表明, 当倾斜角较小时, 试件发生界面剪切破坏, 而倾斜角增大, 试件趋向于发生轻质加气混凝土砌块材料破坏;根据试验数据拟合出τn关于σn的二次界面破坏包络线方程, 并分析界面变形特性, 提出界面切应力-滑移位移特征曲线, 为密肋复合墙结构构件层次和结构层次力学性能的研究提供理论和数值计算依据
Multi-ribbed wall structure (MRWs) is composed of densely distributed ribbed frames, including ribbed beams and columns, and autoclaved aerated concrete (AAC) is filled inside the ribbed frames. Because of the special production process, there is a bonded interface of which property is still undefined between ribbed frames and infilled AAC. To study the properties of bonded interface of ordinary concrete and AAC, the experimental study is necessary on the material level. On the background of multi-ribbed composite wall structure, the slant shear test was used to measure the bonded interface properties of ordinary concrete and AAC. This paper analyzed the influence of bonded interface joint angle to interfacial strength and proposed the failure envelope of bonded interface. Based on test results, the equation between τn and σn of the bond failure envelope is fitted which provides a valuable basis of theoretical and numerical solutions for mechanical properties of multi-ribbed composite wall structures
基于可变形部件模型的遥感影像船只检测方法
绍明,,,王建梅
- , 2017, DOI: 10.11908/j.issn.0253-374x.2017.12.021
Abstract: 提出了一种基于混合可变形部件模型的船只检测方法.该方法采用基于梯度方向直方图(HOG)特征的可变形部件模型(DPM)来描述船只,在HOG特征金字塔空间通过滑窗方式检测目标.基于HOG特征的DPM不具有方向不变性,因此根据船只目标特点,分别从模型训练阶段和目标检测阶段进行改进.在模型训练阶段,为了减少模板数量,将所有船只样本旋转到相同方向进行参数学习;在目标检测阶段,将兴趣区旋转至特定方向后进行模板匹配,实现遥感影像上任意方向的船只检测.利用该方法在高分二号光学遥感影像上进行船只检测,实验结果表明此方法可以有效检测船只.
A method of ship detection in high resolution remote sensing images using mixture of deformable part models(DPMs) is proposed in this paper. The method is robust to size difference by constructing multi scale histogram of oriented gradients (HOG) feature pyramids. Deformable part models are introduced to deal with the deformation of the key parts of ships. And a sliding window detection strategy is adopted to separate the clustered ships. Considering that HOG features are orientation sensitive, improved training and detection methods are also proposed. In the training phase, all the samples are rotated to the same direction for parameter learning to reduce the number of templates. In the detection phase, the regions of interest are rotated to a specific direction to implement template matching. The experiments of ship detection in GaoFen 2 high resolution remote sensing images are carried out. It is shown that the proposed method is effective
城市绿地系统生态服务效能评价及优化研究——以淮安生态新城为例
王洪威,徐建刚,,,王振波
环境科学学报 , 2012,
Abstract: 通过运用生态服务效能指数的概念,选择5种指标因子(吸收二氧化硫量、吸收热量、蒸腾水量、涵养水源量、滞尘降尘量)构建了淮安生态新城绿地系统生态服务效能评估模型,并运用全排列多边形图示指标法,针对"现状条件"、"概念规划"、"控制性详细规划"、"理想状态"4种情景下的绿地系统进行了生态服务效能评价与预测.结果表明,4种不同的土地利用方式下,绿地系统生态服务效能综合指数分别为0.24、0.56、0.70和0.89,生态服务效能逐步改善.研究结果进一步表明,在"概念规划"和"控制性详细规划"两种情景下,应使城市绿地系统面积大于1200hm2,采用复合式绿地结构并调整林地与草地面积的比例达到7∶3,同时应保证本地植物指数大于70%,研究结果可为生态城市建设提供一定的参考.
温度对采后桃果实内酯类香气生物合成的调控
席万,,梁莉,申济源,徐昌杰,
园艺学报 , 2011,
Abstract:
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