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61.
Conducting drop tests to investigate impact behavior and identify failure mechanisms of small-size electronic products is
generally expensive and time-consuming. Nevertheless, strict drop/impact performance criteria for hand-held electronic products
such as cellular phones play a decisive role in the design because they must withstand unexpected shocks. The design of product
durability on impact has heavily relied on the designer's intuition and experience. In this study, a reliable drop/impact
simulation for a cellular phone is carried out using the explicit code LS-DYNA. Subsequently globallocal experimental verification
is accomplished by means of high-speed photography and impact response measurement. Using this methodology, we predict potential
damage locations in a cellular phone and compare them with real statistical data. It is envisaged that development of a reliable
methodology of drop/impact simulation will provide us with a powerful and efficient vehicle for improvement of the design
quality and reduction of the product development cycle. 相似文献
62.
S. Park 《Acta Mathematica Hungarica》1998,81(1-2):155-161
A closed multimap T : X ? X having the KKM property has a fixed point whenever X is a compact convex set satisfying a certain topological condition. Our new result properly generalizes a known one due to W. K. Kim [4]. 相似文献
63.
In this paper we present numerical methods for computations of nonequilibrium hypersonic flow of air around bodies including chemical reaction effects and present numerical result of the flow over concave corners. We developed implicit finite difference method to overcome numerical difficulties associated with the lack of resolution behind the shock and near the body. Using our method we were able to find details of the flow properties near the shock and body and were able to continue the computation of the flow for a long distance from the corner of the body. 相似文献
64.
Perfect information two-person zero-sum markov games with imprecise transition probabilities 总被引:1,自引:0,他引:1
Hyeong Soo Chang 《Mathematical Methods of Operations Research》2006,64(2):335-351
Based on an extension of the controlled Markov set-chain model by Kurano et al. (in J Appl Prob 35:293–302, 1998) into competitive two-player game setting, we provide a model of perfect information two-person zero-sum Markov games with imprecise transition probabilities. We define an equilibrium value for the games formulated with the model in terms of a partial order and then establish the existence of an equilibrium policy pair that achieves the equilibrium value. We further analyze finite-approximation error bounds obtained from a value iteration-type algorithm and discuss some applications of the model. 相似文献
65.
The nucleation and grain growth of the Ge2Sb2Te5 (GST) thin films were studied using high voltage electron microscope operated at 1250 kV. As a result, we have found that 2 nm-sized nucleus forms as a cluster which atoms are arranged regularly at the stage of nucleation prior to the formation of grains having crystal structure. The high-resolution transmission electron microscopy study and fast-Fourier transformations revealed that coexistence of face-centered-cubic (FCC) and hexagonal structure occurs, and formation of twin defect is found in the hexagonal structure during the grain growth as the annealing temperature is increased. GST grain having the hexagonal structure grow from the surface, and the growth proceeded perpendicular to the [0 0 0 1], namely the path parallel to the (0 0 0 1) plane. Consequently, grain growth to a large-scale result in a lengthened shape. 相似文献
66.
N. Jiten Singh Adriana C. Olleta Anupriya Kumar Mina Park Hai-Bo Yi Indrajit Bandyopadhyay Han Myoung Lee P. Tarakeshwar Kwang S. Kim 《Theoretical chemistry accounts》2006,115(2-3):127-135
In earlier studies, the interactions of isolated ionic species with various solvents were investigated using ab initio calculations.
The ionic species investigated included cations (proton, hydronium, ammonium, and metal cations) and anions (single electron,
hydroxide, and halide anions). However in the present study, we investigate the interactions of these ionic species with the
solvent in the presence of other competing ionic species. We also elaborate on how the information obtained from these extensive
studies have been employed in designing and synthesizing various kinds of novel ionophores and receptors. 相似文献
67.
Nak-Jin Seong Young-Hun Jo Myung-Hwa Jung Soon-Gil Yoon 《Journal of magnetism and magnetic materials》2006
Epitaxial Ti0.97Co0.03O2:Sb0.01(TCO:Sb) films were deposited on R-Al2O3 (1 1 0 2) substrates at 500 °C in various deposition pressures by pulsed laser deposition. The solubility of cobalt within the films increases with decreasing deposition pressure at a deposition temperature of 500 °C. The TCO:Sb films deposited at 5×10−6 Torr exhibit a p-type anomalous Hall effect having a hole concentration of 6.1×1022/cm3 at 300 K. On the other hand, films deposited at 4×10−4 Torr exhibits an n-type anomalous Hall effect having an electron concentration of about 1.1×1021/cm3. p- or n-type DMS characteristics depends on the change of the structure of TCO:Sb films and the solubility of Co is possible by controlling the deposition pressure. 相似文献
68.
We study codes over the p-adic integers and correct errors in the existing literature. We show that MDS codes exist over the p-adics for all lengths, ranks and p. We show that self-dual codes exist over the 2-adics if and only if the length is a multiple of 8 and that self-dual codes
exist over the p-adics with p odd if and only if the length is 0 (mod 4) for p ≡ 3 (mod 4) and 0 (mod 2) for p ≡ 1 (mod 4). 相似文献
69.
Seoung-Soo Lee Ho-In Park Chung-Hyung Joh Song-Ho Byeon 《Journal of solid state chemistry》2007,180(12):3529-3534
Three different synthetic methods, the liquid phase process in HCl solution, the solvothermal reaction, and the surfactant-assisted solvothermal reaction, were explored to selectively control the particle shape and to enhance the luminescence intensity of the PbFCl-type red-emitting oxychloride phosphors LnOCl:Eu (Ln=La and Gd). The solvothermal pressure facilitated the low-temperature crystallization of the rod-shape particles for both Ln=La and Gd. It is noted that LaOCl:Eu nanorods show highly porous particle surface and quite low photoemission intensity. In contrast, the solvothermal synthesis could highly enhance the red-emission of GdOCl:Eu with no porous surface so as to be comparable to that of commercial Y2O3:Eu phosphor. An addition of surfactant material during solvothermal reaction yielded a rhomboidal-shape phosphor particles with no porous surface for both Ln=La and Gd. Interestingly, the elimination of surface porosity by using a surfactant significantly increased the emission intensity of LaOCl:Eu. It is proposed that the application of solvothermal technique for the synthesis of the PbFCl-type oxychloride phosphors is very effective to selectively control the particle shape and consequently to enhance the photoemission intensity if we use an appropriate surfactant material. 相似文献
70.
We consider a SA-SA' critical point in the presence of a symmetry-breaking external magnetic (electric) field with a positive magnetic (dielectric) anisotropy or a dislocation layer. Via a renormalization group analysis of the model hamiltonian, we show that the upper critical dimensions below which mean-field theory breaks down is dc = 2·5. Thus the SA-SA' transition in three dimensions becomes mean-field like in the presence of a symmetry-breaking field. We estimate the reduced temperature region where we can expect to see the mean field SA-SA' critical point in the presence of a magnetic field or a dislocation layer. 相似文献