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101.
为提高企业核心竞争力以应对市场竞争需要,引进了Oracle ERP管理系统,通过需求分析、系统规划,方案设计、系统实现等实施过程,在企业中建立了扁平化管理、运营组织模式,同时通过对ERP系统的生产管理模块进行深层次开发,实现了生产计划的高级排产及生产过程的精益化管理,达到了信息流与物流的统一。 相似文献
102.
Teemu J. Ikonen Keijo Heljanko Iiro Harjunkoski 《American Institute of Chemical Engineers》2022,68(6):e17656
Periodic rescheduling is an iterative method for real-time decision-making on industrial process operations. The design of such methods involves high-level when-to-schedule and how-to-schedule decisions, the optimal choices of which depend on the operating environment. The evaluation of the choices typically requires computationally costly simulation of the process, which—if not sufficiently efficient—may result in a failure to deploy the system in practice. We propose the continuous control parameter choices, such as the re-optimization frequency and horizon length, to be determined using surrogate-based optimization. We demonstrate the method on real-time rebalancing of a bike sharing system. Our results on three test cases indicate that the method is useful in reducing the computational cost of optimizing an online algorithm in comparison to the full factorial sampling. 相似文献
103.
Oswaldo Andrés-Martínez Luis A. Ricardez-Sandoval 《American Institute of Chemical Engineers》2022,68(5):e17665
In the pursuit of integrated scheduling and control frameworks for chemical processes, it is important to develop accurate integrated models and computational strategies such that optimal decisions can be made in a dynamic environment. In this study, a recently developed switched system formulation that integrates scheduling and control decisions is extended to closed-loop operation embedded with nonlinear model predictive control (NMPC). The resulting framework is a nested online scheduling and control loop that allows to obtain fast and accurate solutions as no model reduction is needed and no integer variables are involved in the formulations. In the outer loop, the integrated model is solved to calculate an optimal product switching sequence such that the process economics is optimized, whereas in the inner loop, an NMPC implements the scheduling decisions. The proposed scheme was tested on two multi-product continuous systems. Unexpected large disturbances and rush orders were handled effectively. 相似文献
104.
针对带有阻塞限制的不相关并行机混合流水车间调度问题,以最小化最长完工时间为目标,依据不同的建模思想,建立了求解该问题的4个混合整数线性规划(MILP)模型;鉴于混合整数线性规划不适合求解中大规模问题,提出了一种改进的回溯搜索算法以求解中大规模问题,在该算法中,引入了轮盘赌选择策略以及变邻域搜索算法,以提高算法的收敛速度以及局部搜索能力。最后,对所提MILP模型以及算法进行了对比分析,通过对具体实例的求解验证了所提MILP模型以及算法的有效性及优越性。 相似文献
105.
Linlin Yang Ignacio E. Grossmann Jeremy Manno 《American Institute of Chemical Engineers》2014,60(10):3490-3501
There are four key aspects for water use in hydraulic fracturing, including source water acquisition, wastewater production, reuse and recycle, and subsequent transportation, storage, and disposal. Water use life cycle is optimized for wellpads through a discrete‐time two‐stage stochastic mixed‐integer linear programming model under uncertain availability of water. The objective is to minimize expected transportation, treatment, storage, and disposal cost while accounting for the revenue from gas production. Assuming freshwater sources, river withdrawal data, location of wellpads, and treatment facilities are given, the goal is to determine an optimal fracturing schedule in coordination with water transportation, and its treatment and reuse. The proposed models consider a long‐time horizon and multiple scenarios from historical data. Two examples representative of the Marcellus Shale play are presented to illustrate the effectiveness of the formulation, and to identify optimization opportunities that can improve both the environmental impact and economical use of water. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3490–3501, 2014 相似文献
106.
Refinery scheduling with varying crude: A deep belief network classification and multimodel approach 下载免费PDF全文
Xiaoyong Gao Chao Shang Yongheng Jiang Dexian Huang Tao Chen 《American Institute of Chemical Engineers》2014,60(7):2525-2532
In model‐based refinery scheduling, the varying composition of the crude being refined is a major challenge, especially for those reaction processes. A classification based, multimodel approach is proposed to handle the frequently varying crude. The idea is to build a scheduling model for each type of feed crude, and the type can be determined using an online classifier. The recently emerged deep belief network is introduced to develop the classifier, which provides more accurate classification than the traditional neural network. The proposed method is demonstrated through modeling a fluidized catalytic cracking unit (the mostly affected by varying crude), and then the scheduling of a refinery that was carefully simulated to mimic the actual operation of a refinery in northern China. The results reveal that the multimodel approach is effective in handling varying crude. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2525–2532, 2014 相似文献
107.
Inventory pinch based,multiscale models for integrated planning and scheduling‐part II: Gasoline blend scheduling 下载免费PDF全文
Pedro A. Castillo Castillo Vladimir Mahalec 《American Institute of Chemical Engineers》2014,60(7):2475-2497
Integration of planning and scheduling optimizes simultaneous decisions at both levels, thereby leading to more efficient operation. A three‐level discrete‐time algorithm which uses nonlinear models and integrates planning and detailed scheduling is introduced: first level optimizes nonlinear blend models via multiperiod nonlinear programming (NLP), where period boundaries are initially determined by the inventory pinch points; second level uses fixed recipes (from the first level) in a multiperiod mixed‐integer linear program to determine first an optimal production plan and then to optimize an approximate schedule which minimizes the total number of switches in blenders and swing tanks; third level computes detailed schedules that adhere to inventory constraints computed in the approximate schedule. If inventory infeasibilities appear at the second or the third level, the first‐level periods are subdivided and blend recipes are reoptimized. Algorithm finds the same or better solutions and is substantially faster than previously published full‐space continuous‐time model. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2475–2497, 2014 相似文献
108.
Integration of scheduling and control for batch processes using multi‐parametric model predictive control 下载免费PDF全文
Jinjun Zhuge Marianthi G. Ierapetritou 《American Institute of Chemical Engineers》2014,60(9):3169-3183
Integration of scheduling and control results in Mixed Integer Nonlinear Programming (MINLP) which is computationally expensive. The online implementation of integrated scheduling and control requires repetitively solving the resulting MINLP at each time interval. (Zhuge and Ierapetritou, Ind Eng Chem Res. 2012;51:8550–8565) To address the online computation burden, we incorporare multi‐parametric Model Predictive Control (mp‐MPC) in the integration of scheduling and control. The proposed methodology involves the development of an integrated model using continuous‐time event‐point formulation for the scheduling level and the derived constraints from explicit MPC for the control level. Results of case studies of batch processes prove that the proposed approach guarantees efficient computation and thus facilitates the online implementation. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3169–3183, 2014 相似文献
109.
基于现有数字化矿山应用现状及煤炭公司级安全生产调度与集约化管理需求,提出了基于煤炭集团公司安全生产综合信息系统平台,作为矿井数字化矿山信息化部分业务内容在公司层面的系统集成与向上延伸扩展与综合应用。平台的建设为集团公司综合调度提供了信息化支撑,使得各级调度管理人员能够分级分责快速获取作业现场安全生产运营数据信息,实现协同调度指挥与现代化集团集约化管控模式,减少重复性投资,提高企业的核心竞争力。 相似文献
110.
Cover Picture: Time‐Dependent Diaryl Ether Inhibitors of InhA: Structure–Activity Relationship Studies of Enzyme Inhibition,Antibacterial Activity,and in vivo Efficacy (ChemMedChem 4/2014) 下载免费PDF全文