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31.
液化天然气(LNG)是天然气经脱硫、脱水等净化处理后,再经降温冷凝而成的液体状态的天然气。LNG的沸点取决于组成成分,通常情况下接近纯甲烷的沸点,即-162.15℃。其体积约为气体状态下天然气的1/625,具有巨大的储存和运输优势。由于其高效性、清洁性等优点,LNG已成为世界各国重点发展的能源项目,被公认为未来的理想能源。 相似文献
32.
Stelios Arvanitis 《时间序列分析杂志》2014,35(6):536-557
Indirect estimators usually emerge from two‐step optimization procedures. Each step in such a procedure may induce complexities in the asymptotic theory of the estimator. In this note, we are occupied with a simple example in which the estimator defined by the inversion of the binding function has a ‘discontinuous’ limit theory even in cases where the auxiliary one does not. This example lives in the framework of estimation of the MA (1) parameter. The ‘discontinuities’ involve the dependence of the rate of convergence on the parameter, the non‐continuity of the limit distribution w.r.t. the parameter and the estimator's non‐regularity. We are also occupied with a more complex example where the discontinuities occur because of complexities induced in any step of the defining procedure. We present some Monte Carlo evidence on the quality of the approximations from the limit distributions. Copyright © 2014 Wiley Publishing Ltd 相似文献
33.
Tendon-driven robot utilizes only tensile force (i.e. tension) for motion generation. Therefore, a redundant actuation is characteristically necessary, and then it yields the internal force among tendons. Given the internal force for balance at a desired posture, the musculoskeletal tendon-driven manipulator has the inherent possibility of point-to-point position control without any sensory feedback. However, the motion convergence is strongly governed by the arrangement of tendons.This study analyzes the mathematical conditions of convergence for this sensorless position control by use of a Lyapunov function. Subsequently, targeting the two-link musculoskeletal structure with six tendons, the sufficient conditions for the convergence at desired posture are further defined by employing an approximation of the tendon-length based on a Taylor expansion. Finally, the convergent conditions are verified through simulation and validated via experimental results. 相似文献
34.
We consider a micropolar fluid flow in a two-dimensional domain. We assume that the velocity field satisfies a non-linear slip boundary condition of friction type on a part of the boundary while the micro-rotation field satisfies non-homogeneous Dirichlet boundary conditions. We prove the existence and uniqueness of a solution. Then motivated by lubrication problems we assume that the thickness and the roughness of the domain are of order and we study the asymptotic behaviour of the flow as tends to zero. By using the two-scale convergence technique we derive the limit problem which is totally decoupled for the limit velocity and pressure on one hand and the limit micro-rotation on the other hand. Moreover we prove that , and are uniquely determined via auxiliary well-posed problems. 相似文献
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探讨了如何求解大型稀疏鞍点问题,给出了一种基于正定分裂的广义正定和反Hermitian分裂(GPSS)方法。该方法首先利用矩阵的正定分裂,构造出鞍点矩阵的2种分裂格式;然后利用这2种分裂格式构造出GPSS迭代;接着给出了迭代收敛的充要条件。最后进行了数值对比实验,实验结果表明,GPSS比正定和反Hermitian分裂(PSS)和Hermitian和反Hermitian分裂(HSS)方法更有效。 相似文献
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Tactic planning or master production scheduling focuses on time and spatial decomposition of the aggregate planning targets and forecasts, as well as, forecast and provision of needed resources. This process becomes extremely hard and time consuming with the increase of number of products, resources and periods considered. In face of such obstacles, this work shows a study of an Artificial Intelligence technique called Simulated Annealing applied to the optimization of production planning problem, more specifically, Master Production Scheduling. This work reviews some of the fundamental theory of simulated annealing, the methodology for master production scheduling calculation, the applicability of simulating annealing to planning problems, most important results and suggestions for further studies. 相似文献
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C-calculus was introduced by the first author as a technique for the analysis of complex hierarchical systems.2 It has been further applied as a versatile tool in pattern recognition.1,3 Our present aim is to exhibit a model for C-calculus, and deal with its convergence and filtering properties. 相似文献