二次凸规划的迭代解

线性互补问题的投影Jacobi松弛算法应用于求解不等式约束的二次规划问题,对称半正定的二次规划问题由K-T条件可以转化为P_0-矩阵的非对称线性互补问题(LCP),通过求解带扰动项的P-矩阵的非对称线性互补问题得到二次规划的最优解。最后给出一些数值结果。     

利用交替方向法求解H权重最近相关系数矩阵问题

由于计算H权重的半正定矩阵锥投影比较困难,目前求解带有H权重的最近相关系数矩阵问题的方法很少且比较复杂.考虑用交替方向法求解该问题,每次迭代只需求解一个有显式解的二次规划问题和一个不带权重的半正定矩阵锥投影,计算简单,易于实现.为提高计算速度,还考虑了改进的交替方向法.此外,通过数值实验对交替方向法与现有方法进行了比较,说明了交替方向法对解决带有H权重的最近相关系数矩阵问题的有效性.     

解二次规划的Lagrange方法

本文讨论解二次规划问题的 Lagrange 方法。我们分析了解正定二次规划和某些半正定二次规划的对偶算法,指出这些算法可以从 Lagrange 方法直接导出。此外我们还给岀了解不定二次规划的一个新的 Lagrange 算法。这一算法在投影矩阵为不定矩阵时,利用广义的 Cholesky 分解技术由 Lagrange 方程解得二次目标函数的负曲率方向,以此作为该步迭代寻查方向。算法还采用了有效集策略。     

求解约束最小二乘半正定规划问题的L-BFGS方法

对带等式和不等式约束的最小二乘半正定规划问题的求解进行了研究。在Slater约束规范条件下,对偶问题的最优解与原问题最优解相等。因此,考虑将最小二乘半正定规划问题转化为相应的对偶问题,通过求解对偶问题达到求解原问题的目的。针对最小二乘半正定规划问题的对偶问题,首先构造相应的二次模型,沿负梯度方向最小化该二次模型得到柯西点,在此基础上,利用积极约束技巧,划分积极约束集与非积极约束集,然后应用L-BFGS技巧对自由变量进行加速,从而求得对偶问题的最优解。最后,从理论上证明了算法的全局收敛性,并进行了初步的数值实验,将该算法与光滑化牛顿法作对比,结果表明该算法在计算时间上有一定的优势。     

一类特殊规划的求解算法

二次规划问题是一类重要的优化问题,是NP困难的.通过对已有算法的理解与分析,在假设原问题的Hessian矩阵正定的条件下,作者给出了求解二次规划问题的一种新算法,并讨论了算法的收敛性.     

线性约束下实二次型有定或不定性的一个判别算法

针对经济学中较为常见的判别线性约束下实二次型的正定性问题，研究了实对称矩阵的有关性质，提出了一个判别一般实对称矩阵是（半）正定、（半）负正定或不定矩阵有效而实用的算法，较好地民带线性约束与无约束的实二次型有定或不定性的判别问题，所述算法具有计算量小，数值计算稳定，易于编程实现等优点，最后给出计算实例。     

一种求解二次模型信赖域子问题的休恩算法

在Hessian矩阵正定的前提下,首先根据二次模型赖域子问题的精确求解方法的思想,得到了最优曲线的参数方程,进而根据参数方程建立了一种最优曲线的微分方程模型。针对此微分方程模型,运用求解微分方程的休恩方法构造了一条折线,从而用该折线代替最优曲线,提出了一种求解二次模型信赖域子问题的休恩算法。通过与切线单折线法的数值实验作比较,数值结果表明新算法比切线单折线法具有明显的优势。     

算子分裂法求解旋转坐标系下不可压黏性流动

提出了求解旋转坐标系下的不可压黏性流动问题的θ格式算子分裂算法．通过算子分裂，把不可压缩性、非线性和哥氏力占优三大耦合困难分割开来．采用亚网格尺度稳定化方法消除了Galerkin方法求解时由于不可压缩性和哥氏力占优所引发的数值振荡．结合最小二乘和共轭梯度法间接求解非线性子问题，排除了强对流作用所引发的数值振荡，避免了引入迎风格式离散对流项的必要性．同时该算法保证了迭代过程中有限元总刚度矩阵正定不变的特性，为求解线性方程组采用高效的求解器提供了可能．数值试验表明，该算法具有稳定性好、收敛速度快、计算精度高的特点．     

一种求解二次模型信赖域子问题的新算法

在Hessian矩阵正定的前提下,首先根据信赖域子问题精确求解方法的思想,得到了最优曲线的参数方程,进而建立了一种最优曲线的微分方程模型.针对此微分方程模型,运用中点公式构造了一条折线.从而用该折线代替最优曲线,提出了一种求解二次模型信赖域子问题的新算法.数值结果表明新算法比切线单折线法具有明显的优势.     

一种序列线性方程组滤子算法的全局收敛性

提出了一种不可行序列线性规划滤子方法,只需求解2个具有相同系数矩阵的线性方程组以得到搜索方向,在一定程度上克服了序列二次规划方法的缺点并提高了计算效率.算法中使用了χ-有效集.给出了该算法的全局收敛性证明,并给出了数值结果说明该算法的有效性.     

Markedness and its Interpretation in Language Use

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

Design and analysis of generic LBS application developing platform

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

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.     

On Tragic Consciousness In The Works By Ernest Hemingway

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.