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1.
本文讨论中立型大系统,获得了这类问题稳定性的一些充分判据,作为特殊情况,还得到了与[1-11]中相应的一些不同的结果.这些结果并不象文献[1]和[2]那样,要求a_(ii)的上界q_(ii)小于零. 相似文献
2.
Robert Fourer 《Mathematical Programming》1983,25(3):251-292
This and a companion paper consider how current implementations of the simplex method may be adapted to better solve linear
programs that have a staged, or ‘staircase’, structure. The preceding paper considered ‘inversion’ routines that factorize
the basis and solve linear systems. The present paper examines ‘pricing’ routines that compute reduced costs for nonbasic
variables and that select a variable to enter the basis at each iteration. Both papers describe extensive (although preliminary)
computer experiments, and can point to some quite promising results. For pricing in particular, staircase computation strategies
appear to offer modest but consistent savings; staircase selection strategies, properly chosen, may offer substantial savings
in number of iterations, time per iteration, or both. 相似文献
3.
Jonathan E. Spingarn 《Mathematical Programming》1985,32(2):199-223
A primal–dual decomposition method is presented to solve the separable convex programming problem. Convergence to a solution and Lagrange multiplier vector occurs from an arbitrary starting point. The method is equivalent to the proximal point algorithm applied to a certain maximal monotone multifunction. In the nonseparable case, it specializes to a known method, the proximal method of multipliers. Conditions are provided which guarantee linear convergence.This research was sponsored, in part, by the Air Force Office of Scientific Research under grant 80-0195. 相似文献
4.
Since the original work of Dantzig and Wolfe in 1960, the idea of decomposition has persisted as an attractive approach to large-scale linear programming. However, empirical experience reported in the literature over the years has not been encouraging enough to stimulate practical application. Recent experiments indicate that much improvement is possible through advanced implementations and careful selection of computational strategies. This paper describes such an effort based on state-of-the-art, modular linear programming software (IBM's MPSX/370). 相似文献
5.
Mingming Wang Dr. Jiale Ma Yahan Meng Dr. Jifei Sun Dr. Yuan Yuan Dr. Mingyan Chuai Na Chen Dr. Yan Xu Xinhua Zheng Prof. Zhenyu Li Prof. Wei Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(3):e202214966
Aqueous zinc-ion batteries (AZBs) show promises for large-scale energy storage. However, the zinc utilization rate (ZUR) is generally low due to side reactions in the aqueous electrolyte caused by the active water molecules. Here, we design a novel solvation structure in the electrolyte by introduction of sulfolane (SL). Theoretical calculations, molecular dynamics simulations and experimental tests show that SL remodels the primary solvation shell of Zn2+, which significantly reduces the side reactions of Zn anode and achieves high ZUR under large capacities. Specifically, the symmetric and asymmetric cells could achieve a maximum of ∼96 % ZUR at an areal capacity of 24 mAh cm−2. In a ZUR of ∼67 %, the developed Zn−V2O5 full cell can be stably cycled for 500 cycles with an energy density of 180 Wh kg−1 and Zn-AC capacitor is stable for 5000 cycles. This electrolyte structural engineering strategy provides new insight into achieving high ZUR of Zn anodes for high performance AZBs. 相似文献
6.
Andrzej Stankiewicz Farnaz Eghbal Sarabi Abdul Baubaid Peng Yan Hakan Nigar 《Chemical record (New York, N.Y.)》2019,19(1):40-50
The paper discusses the currents status and future perspectives of the utilization of microwaves, as a selective and locally controlled heating method, in heterogeneous catalytic flow reactors. Various factors related to the microwave‐catalyst interaction and the design of microwave‐assisted catalytic reactor systems are analyzed. The analysis clearly shows the superiority of the traveling‐wave systems over the mono‐mode and multi‐mode cavity‐based systems when it comes to the design and application of microwave flow reactors at relevant production scales. 相似文献
7.
小湾水电站饮水沟大规模倾倒破坏现象的工程地质研究 总被引:6,自引:0,他引:6
倾倒破坏是陡倾层状岩体一类主要的变形破坏形式,一般发育于地表临空面附近的坡体浅部。根据文献资料,前人研究的倾倒破坏体能保持其完整形态者规模并不大。小湾水电站左岸坝前高边坡由于其特殊地形地貌及其岩体结构条件,使得如此大规模的倾倒变形体能保持其完整形态至今。由于倾倒变形体紧邻大坝且地势较高,一旦失稳,将给小湾水电站的建设造成不可估量的损失。查明倾倒破坏堆积体规模及其岩体结构特征,为倾倒堆积体边坡支护方案选择及稳定性评价参数选取提供依据。更重要的是,揭示这类大规模的倾倒破坏表现特征及其形成条件,对认识复杂条件下岩石高边坡的变形破坏机理具有一定指导意义。本文通过细致的野外调查,揭示了一类发育深度较大的大规模倾倒变形破坏。通过对边坡的详细描述与记录,阐明了这类变形破坏发育的特征和空间展布,并对其形成机制作了简要的分析。 相似文献
8.
The solution of a large-scale linear, integer, or mixed integer programming problem is often facilitated by the exploitation
of special structure in the model. This paper presents heuristic algorithms for identifying embedded network rows within the
coefficient matrix of such models. The problem of identifying a maximum-size embedded pure network is shown to be among the
class of NP-hard problems. The polynomially-bounded, efficient algorithms presented here do not guarantee network sets of
maximum size. However, upper bounds on the size of the maximum network set are developed and used to show that our algorithms
identify embedded networks of close to maximum size. Computational tests with large-scale, real-world models are presented. 相似文献
9.
Global minimization of large-scale constrained concave quadratic problems by separable programming 总被引:4,自引:0,他引:4
The global minimization of a large-scale linearly constrained concave quadratic problem is considered. The concave quadratic part of the objective function is given in terms of the nonlinear variablesx R
n
, while the linear part is in terms ofy R
k. For large-scale problems we may havek much larger thann. The original problem is reduced to an equivalent separable problem by solving a multiple-cost-row linear program with 2n cost rows. The solution of one additional linear program gives an incumbent vertex which is a candidate for the global minimum, and also gives a bound on the relative error in the function value of this incumbent. Ana priori bound on this relative error is obtained, which is shown to be 0.25, in important cases. If the incumbent is not a satisfactory approximation to the global minimum, a guaranteed-approximate solution is obtained by solving a single liner zero–one mixed integer programming problem. This integer problem is formulated by a simple piecewise-linear underestimation of the separable problem.This research was supported by the Division of Computer Research, National Science Foundation under Research Grant DCR8405489.Dedicated to Professor George Dantzig in honor of his 70th Birthday. 相似文献
10.
Dr. Wenxu Yin Mengkai Li Wei Dong Prof. Dr. Xiaoyu Zhang Prof. Dr. Weitao Zheng 《Angewandte Chemie (International ed. in English)》2023,62(26):e202303462
Colloidal perovskite nanocrystals (NCs) have risen rapidly in luminescence efficiency and color purity. However, their high performance requires careful and complex pre-treatment of precursors and precise regulation of the reaction atmosphere; otherwise, their emission will be weak and broad. To overcome these limitations, we develop a facile ligand exchange method using a new type of bidentate ligand, which is obtained by reacting cheap sulfur with tributylphosphine (S-TBP). During ligand exchange, the double bond between P and S atoms breaks and a single bond is formed between them, after which S-TBP switches into a bidentate ligand and binds to a perovskite NC at two points. With short-chain S-TBP ligands that have high spatial position resistance, both NC spacing and surface ligand density can be reduced, thereby improving carrier injection and transport. On the NC surface after ligand exchange, halogen vacancies were substantially filled, leading to a PbSP (Pb, S, and P elements) component-dominated shell that greatly decreases trap density and enhances material stability. The resulting perovskite NCs are stable and bright with a photoluminescence quantum yield of ≈96 %, and an external quantum efficiency of 22 %. Note that our ligand-exchange strategy remains effective even when scaling up, which should accelerate commercialization. 相似文献