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1.
为提高大型公共建筑能耗的预测精度,提出一种基于灰色模型和最小二乘向量机方法(GM-LSSVM)的办公能耗预测模型.该方法结合灰色建模计算简单的特点,以及最小二乘支持向量机非线性拟合能力和泛化能力强的优势,充分发掘样本数据的规律,并以粒子群优化算法进行模型参数选择.根据福州某大型公共建筑能耗数据,通过本研究提出的方法建立预测模型,并与神经网络模型以及最小二乘支持向量机模型的预测结果进行比较,验证了该方法具备较高的预测精度和较强的泛化能力.  相似文献   

2.
首先分析讨论了两种基于信号到达时间的超宽带定位方法--最小二乘法和DFP算法,最小二乘定位方法计算简单,但在存在测距误差的情况下定位精度较低;DFP算法的定位结果通常与初值有关,还易陷入局部最优点.因此,作者提出了基于遗传算法的UWB(超宽带)定位方法,通过与前两种算法进行仿真分析和比较,表明该方法能有效提高定位精度.  相似文献   

3.
基于移动最小二乘法的轨迹拟合切线方位角计算   总被引:1,自引:0,他引:1  
基于移动最小二乘法,提出了轨迹切线方位角算法.利用实测数据验证了算法的可行性,并对算法关键参数(紧支系数与权函数)的设置进行了讨论.结果表明:该方法简单易行,适用于形状弯曲较小的轨迹;移动最小二乘法中的紧支系数应满足计算的需求,但不宜过大;权函数能提高拟合精度,但对轨迹切线方位角的精度几乎没有影响.  相似文献   

4.
针对生物医学中近红外光进行成像问题,简要描述了基于有限元法(FEM)的光学图像重建的过程,提出了光学重建逆问题的阻尼Gauss-Newton算法.该方法定义一个测量与预测数据间误差的目标函数,利用最小二乘问题的结构特点由目标函数一阶导数直接获得Hessian阵以确定下降方向,并在迭代求解中引入线性搜索以确定搜索步长,从而达到快速收敛.数值模拟结果证明该方法在实际应用中的优越性和可行性.  相似文献   

5.
提出了一种基于截断完全最小二乘法(TTLS)的生物发光断层成像(BLT)重建算法,并在扩展广义交叉验证(GCV)的基础上,设计了一种用于确定最佳截断水平的混合广义交叉验证方案(HGCV).与现有的只考虑测量噪声的重建算法不同,这种TTLS结合HGCV的重建算法可将模型离散、解剖结构获取以及光学参数测定中的误差与表面测量误差同时处理,仿真及物理仿体实验验证了该算法的有效性和鲁棒性.  相似文献   

6.
结合图像分割技术提出了一种用于数字全息显微成像的相位像差自动补偿算法.首先,采用最小二乘拟合算法对包含被测物体的解包裹相位图进行粗略的补偿,在此基础上,利用图像分割算法对其背景区域进行分割,获得不含被测物体的解包裹相位图.最后,对其进行最小二乘拟合从而实现相位像差的精确补偿.传统的数字全息显微技术需要通过手工检测背景区域来解决相位像差补偿的问题.然而,本文方法既不需要人工干预,也不需要光学设置的先验知识,即可实现相位像差的自动补偿.通过搭建的数字全息显微实验平台验证了所提算法的可行性和准确性.  相似文献   

7.
提出了基于全局最小二乘拟合的应用于二维图像的直线抽取算法.类似于一维数据曲线拟合的方法,通过引入叉分的手段,克服了二维图像数据非单值函数的困难(图像的y坐标作为x坐标的函数),实现了用最小二乘算法来全局地描述、提取二维图像中的直线.并提供了数值实验验证.  相似文献   

8.
为提高无GPS情况下的3维定位精度,提出基于惯性导航与UWB(超宽带技术)的联合定位算法.该算法将线性最小二乘法的航迹计算与定位点拟合进行融合,使用加权平均对信赖度因子进行权衡.为验证算法的有效性,设计了1套UWB与9轴惯性导航模块结合的软硬件平台.仿真和实际测试结果表明:该算法可将3维定位误差控制在20cm以内.  相似文献   

9.
针对模型不确定系统的连续时间广义预测控制,引入无穷时域的性能指标使闭环系统达到稳定.用递推最小二乘法估计系统的未知参数,在每个采样点基于估计的状态模型来计算控制输入.通过施加新的终端等式约束,将无穷时域性能指标的优化问题转化成可解的二次规划问题.利用后退时域性能指标的单调性证明,给出使连续时间广义预测控制达到闭环稳定的条件.仿真算例验证了算法的有效性.  相似文献   

10.
为了提高稀疏信道环境下同相/正交(I/Q)不平衡正交频分复用(OFDM)系统的性能,该文提出了一种低复杂度的门限时域最小二乘信道估计算法。该算法通过估计噪声方差确定合适的门限过滤信道响应采样点内的噪声以提高估计精度。仿真结果表明,该文算法估计精度与现有频域和时域最小二乘信道估计方法相比分别提升了6 d B、2 d B,逼近基于压缩感知的时域迭代收缩算法,且计算复杂度低于后者。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

15.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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