Reactive investment strategies

Asset liability management is a key aspect of the operation of all financial institutions. In this endeavor, asset allocation is considered the most important element of investment management. Asset allocation strategies may be static, and as such are usually assessed under asset models of various degrees of complexity and sophistication. In recent years attention has turned to dynamic strategies, which promise to control risk more effectively.In this paper we present a new class of dynamic asset strategy, which respond to actual events. Hence they are referred to as ‘reactive’ strategies. They cannot be characterized as a series of specific asset allocations over time, but comprise rules for determining such allocations as the world evolves. Though they depend on how asset returns and other financial variables are modeled, they are otherwise objective in nature.The resulting strategies are optimal, in the sense that they can be shown to outperform all other strategies of their type when no asset allocation constraints are imposed. Where such constraints are imposed, the strategies may be demonstrated to be almost optimal, and dramatically more effective than static strategies.     

Convolution product formula for associated homogeneous distributions on R

The set of Associated Homogeneous Distributions (AHDs) on R, ??′(R), consists of distributional analogues of power‐log functions with domain in R. This set contains the majority of the (one‐dimensional) distributions typically encountered in physics applications. In earlier work of the author it was shown that ??′(R) admits a closed convolution structure, provided that critical convolution products are defined by a functional extension process. In this paper, the general convolution product formula is derived. Convolution of AHDs on R is found to be associative, except for critical triple products. Critical products are shown to be non‐associative in a minimal and interesting way. Copyright © 2010 John Wiley & Sons, Ltd.     

个体投资治理污染的随机增长模型

本文研究了个体投资治理污染的随机增长模型.利用随机最优化的方法,得出了随机扰动、个体环保投资及环保技术对福利和经济增长的影响.对我国制定环保政策具有一定的积极作用.     

住宅房地产顾客感知价值评估

不同的顾客对同一住宅房地产的感知价值是不同的,购房决策主要取决于对住宅房地产的顾客感知价值.提出了住宅房地产顾客感知价值评估的质量功能配置逆过程法,在已知住宅房地产工程特性的条件下,确定顾客需求值.利用该方法,给出了评估住宅房地产的顾客感知价值的过程和数学模型,案例研究表明,方法能有效评估住宅房地产的顾客感知价值,帮助购房者选择住宅房地产项目.     

M/M/1/m系统算子的本征值特性(m=7,8)

研究了m=7,8时,M/M/1/m算子本征值特性:相应本征值的代数重为1;m=7,8时,相应的系统算子的非零本征值相互交替;m=8时的最大非零本征值比m=7时更靠近0点.这种特性延续了m=1,2,3,4,5,6时相应的特性.另外给出了m=7,8时,相应的p_0(t)图像.     

基于灰色理论的温州房价预测模型

以温州统计局有关房地产销售数据为分析对象,用销售总面积和销售总额折算成价格指标,采用灰色系统GM(1,1)建立数学模型对房屋价格指标进行分析和预测.基于投资回报周期和预期心理,对2007至2010年的房价作两次平移整理后再进行建模,效果更为理想.利用模型对.2011年上半年房价进行预测与市场行情吻合性程度高.     

Molecular-beacon-based tricomponent probe for SNP analysis in folded nucleic acids

Hybridization probes are often inefficient in the analysis of single‐stranded DNA or RNA that are folded in stable secondary structures. A molecular beacon (MB) probe is a short DNA hairpin with a fluorophore and a quencher attached to opposite sides of the oligonucleotide. The probe is widely used in real‐time analysis of specific DNA and RNA sequences. This study demonstrates how a conventional MB probe can be used for the analysis of nucleic acids that form very stable (T_m>80 °C) hairpin structures. Here we demonstrate that the MB probe is not efficient in direct analysis of secondary structure‐folded analytes, whereas a MB‐based tricomponent probe is suitable for these purposes. The tricomponent probe takes advantage of two oligonucleotide adaptor strands f and m. Each adaptor strand contains a fragment complementary to the analyte and a fragment complementary to a MB probe. In the presence of a specific analyte, the two adaptor strands hybridize to the analyte and the MB probe, thus forming a quadripartite complex. DNA strand f binds to the analyte with high affinity and unwinds its secondary structure. Strand m forms a stable complex only with the fully complementary analyte. The MB probe fluorescently reports the formation of the quadripartite associate. It was demonstrated that the DNA analytes folded in hairpin structures with stems containing 5, 6, 7, 8, 9, 11, or 13 base pairs can be detected in real time with the limit of detection (LOD) lying in the nanomolar range. The stability of the stem region in the DNA analyte did not affect the LOD. Analytes containing single base substitutions in the stem or in the loop positions were discriminated from the fully complementary DNA at room temperature. The tricomponent probe promises to simplify nucleic acid analysis at ambient temperatures in such applications as in vivo RNA monitoring, detection of pathogens, and single nucleotide polymorphism (SNP) genotyping by DNA microarrays.     

The entropic discriminant

The entropic discriminant is a non-negative polynomial associated to a matrix. It arises in contexts ranging from statistics and linear programming to singularity theory and algebraic geometry. It describes the complex branch locus of the polar map of a real hyperplane arrangement, and it vanishes when the equations defining the analytic center of a linear program have a complex double root. We study the geometry of the entropic discriminant, and we express its degree in terms of the characteristic polynomial of the underlying matroid. Singularities of reciprocal linear spaces play a key role. In the corank-one case, the entropic discriminant admits a sum of squares representation derived from the discriminant of a characteristic polynomial of a symmetric matrix.