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911.
We introduce stochastic utilities such that utility of any fixed amount of interest is a stochastic process or random variable. Also, there exist stochastic (or random) subsistence and satiation levels associated with stochastic utilities. Then, we consider optimal consumption, life insurance purchase and investment strategies to maximize the expected utility of consumption, bequest and pension with respect to stochastic utilities. We use the martingale approach to solve the optimization problem in two steps. First, we solve the optimization problem with an equality constraint which requires that the present value of consumption, bequest and pension is equal to the present value of initial wealth and income stream. Second, if the optimization problem is feasible, we obtain the explicit representations of the replicating life insurance purchase and portfolio strategies. As an application of our general results, we consider a family of stochastic utilities which have hyperbolic absolute risk aversion (HARA).  相似文献   
912.
《Optimization》2012,61(2):283-289
An inventory system with unit demand, varying ordering levels and random lead times is considered in this paper. Ordering level is determined by the number of demands during last lead time. The ordering quantity will be such as to bring back the inventory level to S at the ordering epoch. No backlog is permitted. The time dependent probability distribution of the inventory level is obtained. Correlation between the number of demands during a lead time and the length of the next inventory dry period is obtained and it is illustrated by an example.  相似文献   
913.
We present a study on the performance of our iterative triples correction for the coupled cluster singles and doubles excitations (CCSDT-1a+d) method for computation of potential energy surface (PES), spectroscopic constants, and vibrational spectrum for the ground state (X1Σ+) BeMg, where the ostensible inadequacy of the CCSD and CCSD(T) methods is quite expected. We compare our results with those obtained using state-of-the-art multireference configuration interaction (MRCI) investigations reported earlier by Kerkines and Nicolaides. Our estimated dissociation energy (417.37 cm?1), equilibrium distance (3.285 Å), and vibrational frequency (82.32 cm?1) are in good agreement with recent results of advanced MRCI calculations for X1Σ+ BeMg PES, which exhibits a shallow well of 469.4 cm?1 with a minimum at 3.241 Å and a harmonic vibrational frequency of 85.7 cm?1. Very weakly bound nature of X1Σ+ BeMg is clearly reflected from these values. In accord with MRCI studies, a comparison of BeMg with iso-valence weakly bound ground-state species, Be2 and Mg2, suggests that its characteristics do not exhibit any resemblance to Be2 rather, it shows a close kinship to Mg2. The agreement of our derived vibrational levels with those obtained via the high-level MRCI calculations is very encouraging reflecting the potential of the suitably modified single-reference coupled cluster (SRCC) method, CCSDT-1a+d as a tool for the study of multireference van der Waals systems.  相似文献   
914.
陶小平  薛栋林  黎发志  闫锋 《光子学报》2012,41(11):1359-1364
相较于低轨卫星线阵扫描成像模式,地球静止轨道面阵成像的曝光时间相对更长,更容易受到平台颤振的影响而造成图像模糊.为了消除由平台颤振引起的像质退化,本文提出了基于分时积分亚像元融合的方法.由于地球静止轨道的凝视成像特性,相机观察区域在长时间内保持不变,因此分时短曝光可以获得多帧目标内容相同,但模糊尺度更低的短曝光图像.然后对多帧短曝光图像采用基于能量区域质心法的相位相关算法进行亚像元图像配准,计算相对偏移量并进行补偿,位移探测准确度可达0.1像元以内,满足卫星平台应用需求.再按亚像元偏移量对多帧图像进行融合,融合的过程可以提升由于曝光时间缩短而降低的单帧图像信噪比,最终可以获得图像清晰度更高、信噪比与原长曝光图像相当、信息辨识度更好的遥感图像.  相似文献   
915.
董嫣然  张树东  侯圣伟  程起元 《中国物理 B》2012,21(8):83104-083104
Potential energy curves(PECs) for the ground state(X 2 Σ +) and the four excited electronic states(A 2 Π,B 2 Π,C 2 Σ +,4 Π) of a BeH molecule are calculated using the multi-configuration reference single and double excited configuration interaction(MRCI) approach in combination with the aug-cc-pVTZ basis sets.The calculation covers the internuclear distance ranging from 0.07 nm to 0.70 nm,and the equilibrium bond length R e and the vertical excited energy T e are determined directly.It is evident that the X2Σ+,A2Π,B2Π,C2Σ+ states are bound and 4Π is a repulsive excited state.With the potentials,all of the vibrational levels and inertial rotation constants are predicted when the rotational quantum number J is set to be equal to zero(J = 0) by numerically solving the radial Schr¨odinger equation of nuclear motion.Then the spectroscopic data are obtained including the rotation coupling constant ω e,the anharmonic constant ωexe,the equilibrium rotation constant Be,and the vibration-rotation coupling constant αe.These values are compared with the theoretical and experimental results currently available,showing that they are in agreement with each other.  相似文献   
916.
高志福  彭秋和  王娜  邹志刚 《中国物理 B》2012,21(5):57109-057109
Once the energies of electrons near the Fermi surface obviously exceed the threshold energy of the inverse β decay,electron capture(EC) dominates inside the magnetar.Since the maximal binding energy of the 3 P 2 neutron Cooper pair is only about 0.048 MeV,the outgoing high-energy neutrons(E k(n) > 60 MeV) created by the EC can easily destroy the 3 P 2 neutron Cooper pairs through the interaction of nuclear force.In the anisotropic neutron superfluid,each 3 P 2 neutron Cooper pair has magnetic energy 2μ n B in the applied magnetic field B,where μ n = 0.966 × 10 23 erg.G 1 is the absolute value of the neutron abnormal magnetic moment.While being destroyed by the high-energy EC neutrons,the magnetic moments of the 3 P 2 Cooper pairs are no longer arranged in the paramagnetic direction,and the magnetic energy is released.This released energy can be transformed into thermal energy.Only a small fraction of the generated thermal energy is transported from the interior to the surface by conduction,and then it is radiated in the form of thermal photons from the surface.After highly efficient modulation within the star’s magnetosphere,the thermal surface emission is shaped into a spectrum of soft X-rays/γ-rays with the observed characteristics of magnetars.By introducing related parameters,we calculate the theoretical luminosities of magnetars.The calculation results agree well with the observed parameters of magnetars.  相似文献   
917.
Abstract

Deep Level Transient Spectroscopy (DLTS) was applied to nitrogen related deep electron trap 0.4 eV in green emitting diodes of GaP under hydrostatic pressure. The pressure coefficient of the level energy is determinated as equal -31 meV/kbar with respect to the valence band edge.  相似文献   
918.
Abstract

Point defects produced by neutron, electron or γ-ray irradiation were studied by electrical measurements. The defect levels were analyzed by DLTS technique. Annealing of radiation induced defects at about 260°C was obtained in 20 min isochronal annealings. Annealed fraction of the 260°C stage was obtained to be 85% in arsenic-doped crystals and independent of the species of irradiating particle. The value in antimony-doped and oxygen-doped specimens were 25 and 70%, respectively. The activation energy was found to be 1.6 eV and the annealing kinetics were first order. A tentative model for the defect responsible at the 260°C stage is a vacancy complex.  相似文献   
919.
A short survey on the radioisotope applications in the four European countries is given. This survey is based on the detailed report prepared by the group of 15 experts during their 70 day study tour organized by the International Atomic Energy Agency in Vienna, at the end of 1966. The purpose of the tour was the acquaintance with the application of radioisotopes and radiation in industry and research.Organization of industrial radioisotope work and basic forms of radioisotope applications are described.  相似文献   
920.
Analytical solutions for bending, buckling, and vibration analyses of thick rectangular plates with various boundary conditions are presented using two variable refined plate theory. The theory accounts for parabolic variation of transverse shear stress through the thickness of the plate without using shear correction factor. In addition, it contains only two unknowns and has strong similarities with the classical plate theory in many aspects such as equations of motion, boundary conditions, and stress resultant expressions. Equations of motion are derived from Hamilton’s principle. Closed-form solutions of deflection, buckling load, and natural frequency are obtained for rectangular plates with two opposite edges simply supported and the other two edges having arbitrary boundary conditions. Comparison studies are presented to verify the validity of present solutions. It is found that the deflection, stress, buckling load, and natural frequency obtained by the present theory match well with those obtained by the first-order and third-order shear deformation theories.  相似文献   
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