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31.
针对多数企业在机械加工中都是采用人工排料的现状,提出了基于线性规划的计算机辅助排料算法,并建立了管材下料的数学模型,给出了求解所有合理下料方案的高效算法,以及求解该数学模型适合生产实际的快速算法,根据此算法下料能得到最优的结果,即能最大限度地提高原料利用率,有效降低企业生产成本。 相似文献
32.
Algorithms developed to solve linear programming (LP) problems and advances in computer speed have made large-scale LP problems solvable in time for implementation. Solving an LP is relatively easier than solving an MIP for modern production planning problems. In this study, we propose a heuristic iterative algorithm between LP solution phases and setup decision computations for solving these difficult MIP production planning problems. By utilizing the shadow price information provided by the LP solution of the previous iteration, the setup decision computation converts an MIP problem into an LP problem, which can be efficiently solved in the current iteration. Extensive experiments show that the proposed heuristic algorithm performs well. 相似文献
33.
针对10tex纯棉经纱和13texT65/C35涤棉经纱,选用5种浆料配方,在测定浆液和浆纱性能12项质量指标的基础上,运用浓缩映射法和功能评价值对实验数据进行处理,并进行上浆成本核算,综合分析优选出最佳的浆料配方.投产后,织造效率由82.4%提高到93.6%. 相似文献
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35.
Information system design and sizing constitute a complex, top-down process that tailors the technology architecture to application requirements. Practitioners usually tackle this top-down process by focusing on individual design aspects, such as data or specific applications, and by relying on their previous experiences to compare alternative architectural solutions. Acquisition costs are usually accounted for, but related operating and maintenance costs are often neglected or underestimated. The complexity of optimizing individual design problems leads researchers to avoid a global optimization perspective and, thus, the IS architecture is usually a result of the juxtaposition of multiple local optima.This paper takes an overall perspective on the cost minimization problem of information system design to achieve a better trade-off between cost and performance over the whole expected life of the technology architecture. A comprehensive design methodology is discussed as an integrating framework that accounts for all categories of costs, including design, implementation, maintenance, and operation, to achieve a globally cost-minimizing solution. 相似文献
36.
定宽压力机(SP)同步控制原理及调试 总被引:1,自引:0,他引:1
针对鞍钢1780机组引进的日本IHI开发的定宽大侧压新技术,对其侧压模块运动轨迹的高精度控制进行分析,并对其同步控制及调试进行了说明. 相似文献
37.
以GA301型浆纱机的恒张力卷绕系统为例,介绍了PUX3无级变速器的主要技术参数和作用原理.针对PUX3无级变速器在浆纱机运转中经常出现的机械故障进行分析,从安装和调整两方面讨论了卷绕张力的精确控制问题. 相似文献
38.
Yang Honghong Wu ZhimingDepartment of Automation Shanghai Jiaotong University Shanghai China 《机械工程学报(英文版)》2003,16(1):21-24
The capacitated lot sizing and scheduling probbm that involves in determining the production amounts and release dates for several items over a given planning horizon are given to meet dynamic order demand without incurring backloggings. Thi: problem considering overtime capacity is studied. The mathematical model is presented, and a genelic algorithm (GA) approach is developed to solve the problem. The initial solutions are generated after using heuristic method. Capacity balancing procedure is employed to stipulate the feasibility of the solutions. In addition, a technique based on Tabu search (TS) is inserted into the genetic algorithm to d;al with the scheduled overtime and help the convergence of algorithm. Computational simulation is conducted to test the efficiency of the proposed hybrid approach, which turns out to improve both the solution quality and execution speed. 相似文献
39.
A baseline-free quantitative sizing methodology utilizing ultrasonic guided waves for fatigue cracks under welded stiffeners in steel bridge decks has been developed. An inverse wavefield extrapolation-based formulation for obtaining the crack reflectivity and depth profile has been presented in the kernel of which, the presence of welded orthogonal stiffeners has been accounted for. Having conducted experiments on a test bridge deck subject to fatigue loading, it has been demonstrated that the crack profile can be estimated from the reflection coefficients obtained. In comparison with the reference measurements, the maximum crack depth estimation error turned out to be about 20%. 相似文献
40.
This paper presents a novel optimization method for sizing and design of stand alone photovoltaic systems. Loss of power supply probability analysis is set as a benchmark to determine all possible PV array and battery capacity. Then, the optimum design is proposed based on the lowest levelized cost of energy. The case study, with reference to Malaysia's meteorological data and typical load profile of rural area, has been simulated and compared to selected three past researches. 相似文献