The Empirical Bayes Estimation of the Location Parameter in Double-Exponential Family under the LINEX Loss Function

In this paper, we derive the Bayes estimator of the location parameter in double-exponential family under the LINEX loss function, and then construct the corresponding empirical Bayes estimator. It is shown that the empirical Bayes estimator is asymptotically optimal with convergence rate being , , where 1/2相似文献   

面向客户群的服务方案配置规则挖掘方法

产品/服务配置规则获取的主要方式是用数据挖掘技术从设计实例数据库中提取.客户化服务方案配置规则为服务功能需求和方案特征间的关联规则.考虑到常用关联规则挖掘算法Apriori具有运算复杂的缺点,提出基于PIETM(Principle of Inclusion—Exclusion and Transaction Mapping)算法的配置规则挖掘方法,考虑置信度和有趣度指标,提取强关联规则.针对配置实例数据库数据量较大时,配置规则挖掘的效率会降低且会产生大量冗余规则的问题,采用二元语义模型表达定性的服务功能需求,将同类客户群的功能需求进行合并,替换多样化的功能需求,减少规则的冗余.最后以一工程机械制造企业服务方案配置规则挖掘为例,验证了所提方法的有效性.     

Surface‐Tension‐Confined Microfluidics and Their Applications

This article is a brief overview of the emerging microfluidic systems called surface‐tension‐confined microfluidic (STCM) devices. STCM devices utilize surface energy that can control the movement of fluid droplets. Unlike conventional poly(dimethylsiloxane)‐based microfluidics which confine the movement of fluids by three‐dimensional (3D) microchannels, STCM systems provide two‐dimensional (2D) platforms for microfluidics. A variety of STCM devices have been prepared by various micro‐/nanofabrication strategies. Advantages of STCM devices over conventional microfluidics are significant reduction of energy consumption during device operation, facile introduction of fluids onto 2D microchannels without the use of a micropump, increased flow rate in a special type of STCM device, among others. Thus, STCM devices can be excellent alternatives for certain areas in microfluidics. In this Minireview, fabrication methods, operating modes, and applications of STCM devices are introduced.     

Two New Abietane Diterpenoids from the Roots of Tripterygium wilfordii Hook. f.

Two new abietane‐type diterpenoids, named triptobenzene R ( 1 ) and triptobenzene S ( 2 ), together with three known abietane‐type diterpenoids, triptophenolide ( 3 ), triptonodiol ( 4 ), and triptonoterpene methyl ether ( 5 ), were isolated from the roots of Tripterygium wilfordii Hook . f. Their structures and relative configurations were established by detailed spectral studies, including 1D‐ and 2D‐NMR (HSQC, HMBC, and NOESY), and HR‐ESI‐TOF‐MS, and by comparison with published data. Their absolute configurations were assigned by the CD technique, applied for the first time to abietane diterpenes from Tripterygium wilfordii. Compound 2 is the first abietane‐type norditerpenoid isolated from the genus Tripterygium.     

Synthesis and Crystal Structure of Two Succinato‐Bridged Macrocyclic Nickel(II) Complexes

Two dinuclear succinato‐bridged nickel(II) complexes [Ni(RR‐L)]₂(μ‐SA)(ClO₄)₂ ( 1 ) and [Ni(SS‐L)]₂(μ‐SA)(ClO₄)₂ ( 2 ) (L = 5, 5, 7, 12, 12, 14‐hexamethyl‐1, 4, 8, 11‐tetraazacyclotetradecane, SA = succinic acid) were synthesized and characterized by EA, Circular dichroism (CD), as well as IR and UV/Vis spectroscopy. Single crystal X‐ray diffraction analyses revealed that the Ni^II atoms display a distorted octahedral coordination arrangement, and the succinato ligand bridges two central Ni^II atoms in a bis bidentate fashion to form dimers in 1 and 2 . The monomers of {[Ni(RR‐L)]₂(μ‐SA)}²⁺ and {[Ni(SS‐L)]₂(μ‐SA)}²⁺ are connected by O–H ··· O and N–H ··· O hydrogen bonds into a 1D right‐handed and left‐handed helical chain along the b axis, respectively. The homochiral natures of 1 and 2 are confirmed by the results of CD spectroscopy.     

Investigation on ion movement in the fringe-field switching mode depending on resistivity of alignment layer and dielectric anisotropic sign of liquid crystal

Adsorption and desorption of ions at interface between liquid crystal and alignment layer in liquid crystal displays play a crucial role in residual direct current voltage associated with image sticking. In this article, the dependency of such adsorption and desorption of ions on resistivity of alignment layer and sign of liquid crystal dielectric anisotropy in the fringe-field liquid crystal cell has been investigated. Our studies show that the time constant of ions during adsorption and desorption depends upon resistivity and dielectric constant of liquid crystal and alignment layer, and most strongly influenced by the resistivity of alignment layer such that the one with lower resistivity in two orders shows much faster adsorption and desorption at the interface than that of the one with higher resistivity.