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1.
通过引入可信性方法和Yager熵约束,建立以方差-混合熵(VHE)为风险度量的投资组合优化模型,通过上海证券交易所数据对均值-方差-混合熵模型(MVHEM)、均值-方差模型(MVM)和均值-混合熵(MHEM)模型进行实证比较分析。结果表明,本文所构建的模型可以较好地均衡方差和混合熵在风险控制方面的作用,Yager熵约束的引入可以进一步增强模型的稳定性,在控制风险水平的条件下实现了相对更高的累计收益。  相似文献   

2.
用方差和熵共同度量投资风险,并且考虑交易费用的影响,提出一种基于交易费用的均值-方差-熵的投资组合模型,并进一步讨论了熵在投资组合模型中所起的作用.通过对相关案例的求解与分析,验证了该模型的可行性及有效性.  相似文献   

3.
在分析马科维茨的均值方差模型及威廉·夏普的单一指数模型的基础上:将熵的概念引入到证券投资的风险度量中,提出一种新的投资组合模型,并进行了实证研究  相似文献   

4.
为研究社保基金最优投资组合问题,在借鉴现代投资组合理论的基础上,从证券投资组合理论的风险度量着手,用条件在险价值(Conditional Value at Risk,CVaR)和熵来共同度量风险,提出新的风险度量模型:均值-CVaR-熵模型。在保证投资组合收益率的前提下,以 CVaR 和叉熵函数的线性组合为最小目标函数,在险价值(Value at Risk,VaR)为约束条件,构建考虑交易成本和政策约束下不允许卖空的基于均值 CVaR 熵的社保基金投资组合模型,探讨社保基金的投资方式及投资比例的分配问题,并利用实际数据求得该模型的最优解及各资产的分配比例。结果表明多元化投资是我国社保基金投资实现保值增值目的的必然选择。  相似文献   

5.
投资组合分散风险能力的度量及应用   总被引:7,自引:0,他引:7  
用信息论中熵的概念度量投资组合对风险的分散能力,提出了最大熵和最大广义熵投资组合的概念,并与Markowitz的均值一方差理论进行了比较,同时做了数值模拟。表明了熵投资组合的可行性。  相似文献   

6.
比较以方差为风险构建的均值-方差模型、以半方差为风险构建的均值-半方差模型、以绝对离差为风险构建的均值-离差模型可知,在同等收益水平下以半方差为风险最符合投资者心理的结论.引入熵构建均值-半方差-熵模型.实例分析结果表明,新模型能更全面地考虑股票市场中各种可能的不确定因素,在收益达到一定水平的基础上,为投资者提供更安全的投资方案.  相似文献   

7.
证券投资问题的传统研究方法中,一般假定用于度量证券组合投资风险的方差阵为正定矩阵,且不考虑证券投资中不可回避的交易费,我们将条件放宽为方差阵为非负定且考虑交易费,对证券组合投资模型进行研究。  相似文献   

8.
通过引入可信性偏度及模糊流动性约束,分别建立了同时满足随机不确定和模糊不确定情形下的均值-方差-偏度-正弦熵(M-V-S-SE)的投资组合模型和带有模糊流动性约束的均值-方差-偏度-正弦熵(M-V-S-L-SE)投资组合优化模型。然后运用马尔科夫方法求解模糊收益率,利用上海证券交易所数据进行实证研究。结果表明:模糊流动性约束的引入使得模型更加稳定,在提高收益、控制风险等方面更具有优势。  相似文献   

9.
证券投资组合优化问题的实质就是有限的资产在具有不同风险收益特性的证券之间的优化配置问题.本文在马克维茨投资组合的均值一方差模型框架下,提出改进的证券投资组合优化模型,即以VAR作为风险度量工具和以RAROC作为目标优化函数的投资组合优化模型.从理论上讲该模型更符合投资工具的风险收益规律,同时采用遗传算法求解也保证了该模型在投资实践中应用的有效性.该模型和求解方法的有效性在上证A股市场的实证研究中得到了验证.  相似文献   

10.
为了更全面的研究各类方差阵下的证券组合投资模型,在分析非负定方差阵下的证券组合投资模型[1]的基础上,利用线性代数的二次型及对称阵的相关理论知识,提出了非正定方差阵下证券组合投资模型的改进方法,使得模型中的方差阵最终转化成正定阵.此模型对于研究协方差矩阵为非正定的证券组合投资模型的最优投资比列系数有一定的参考价值.  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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