首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
An integrated batch planning mathematical model based on multi-object optimization is proposed to solve the orderly and efficient flow of material between different working stations in iron and steel enterprises, where production technology constraints, material variations and coupling between steelmaking-continuous casting and hot rolling are analyzed first. According to the requirements of the hot rolling steel strip contracts, the integrated batch planning is divided into sub-plans of rolling plan, casting plan and furnace plan which are independent and coupling to each other, forming rolling plan and furnace plan simultaneously to influence casting plan. Heuristic method based on modified co-evolutionary algorithm is advanced to resolve this problem. The results of simulation and analysis in an iron and steel plant for strip steel production shows that it is feasible to provide effective guidance for integrated batch plan making.  相似文献   

2.
To realize efficient operation, the production organization constraints of ironmaking/steelmaking interface, desulphorization basic oxygen furnace and decarburization basic oxygen furnace, refining equipment and casting/rolling interface of typical steel production process A are analyzed. Order planning model of iron and steel enterprises considering production organization constraints is established. The scheduling compact and coordination and the optimization of commissioning date of different production lines are fully considered in the model. Then, the model is solved by tabu search. Finally, three different sizes of actual production contracts which are randomly selected from the steel plant A are simulated. The results prove the presented model and algorithm can harmonize and optimize the production effectively and also realize the process running efficiently.  相似文献   

3.
Considering the uncertainty and complexity of production planning and scheduling in steel making and continuous casting, an optimal simulation model is built. Based on the analysis of the logistics in steelmaking process, the casting plan is regarded as the global goal, and the procedural information is taken into account, as well as the local evolution rule that abstracted from scheduling rule. To simulate transferring of materials in the process, the state of operation sites are updated as a result of the global goals, process information and local rule. The goal directed simulation is carried out based on the self organization evolution mechanism. Finally, an optimal integrated production plan is made by a continuous simulation evolution. A simulation case for eight hours production plan shows that the model is valid and efficient.  相似文献   

4.
Aiming at multi type and batch production system with flexible process, an optimization method for input plan based on Witness simulation is proposed. The scientific problem researched is described. Aiming at the characteristics of multi type and batch production with flexible process, the simulation logic is designed. Taking Witness as simulation platform, the simulation model combining input plan with scheduling for multi type and batch production is constructed. The effectiveness of the method is tested by simulation examination.  相似文献   

5.
Using precise design principle, a multi-objective programming mathematical model of the BOF-Caster matched is established for single production line in the steelmaking plant of all plate and strip, according to the segmentation of steel grade and product specification of product mix. Objectives of the model have less investment, less difference between production capacity of the converter and continuous caster, higher operating rate of converter and higher level of weighted average casting speed. The model is solved by the improved delaminating sequence method. Then, the overall configuration method of BOF-continuous casting in the steelmaking plant is proposed through integrating single production lines. According to the production outline of a new large steel plant, the result of the model shows that the configuration scheme of the steelmaking workshop of the steel plant is a better design scheme.  相似文献   

6.
Reasonable production planning effectively ensures smooth operation. According to the analysis of the characteristics of steelmaking-continuous casting production process, a production planning method for steelmaking - continuous casting process based on time backward inference method and process simulation is presented. Production plan meeting certain criteria is rapidly gained by time backward inference method, and is regarded as input of simulation model in steelmaking process. Considering time randomicity in production process and transporting equipment restriction, production plan meeting more restrictive conditions, such as no equipment conflict, continuous casting, and etc, is acquired through simulating. It assures that the plan is carried out in practice. The instance demonstrates the feasibility of the method.  相似文献   

7.
The characteristics of the knowledge discovery for basic oxygen furnace(BOF) steelmaking are analyzed by using the Rough Set Theory. The production data of BOF steelmaking are preprocessed by using the methods of data withdrawal, standardization, discretization and so on. The main influencing factors of steelmaking production are set as the knowledge discovery property. The endpoint control objectives of BOF steelmaking are used as the decision attribute of knowledge discovery. Then the knowledge discovery model of BOF steelmaking based on rough set theory is established, which makes the automation of the production knowledge discovery, access and rule extraction come true. The model is tested by using the production data of 210 t BOF, and takes the temperature variation of smelting endpoint as the decision attribute. The results show that the influencing factors, such as silicon content, iron ore weight, oxygen consumption and so on, are of very importance to the endpoint temperature of molten steel. Besides, the rules of molten steel temperature extracted by the model vary with current converter steelmaking process, which proves the validity of the model.  相似文献   

8.
In order to realize optimization of production organization and put forward a reasonable calculation model for the turnover number of steel ladle, the turnover process and time of steel ladle are analyzed with steel ladle of Q steelmaking plant. Gantt charts of steel ladle turnover for single casting schedule and double casting schedule are drawn. Calculation model for turnover number of steel ladle is put forward by analyzing the relationship between casting schedule and the turnover time of steel ladle, and the accuracy of the model is verified by simulation method. Researches show that the turnover number of steel ladle can be reduced 1-2 by adjusting cast starting time, and have significance for the optimization of steel ladle production organization.  相似文献   

9.
9种鹤类DNA条形码的研究   总被引:1,自引:1,他引:0  
为了研究9种鹤类的DNA条形码,采用DNA条形码鸟类通用引物扩增中国4种鹤类(22个个体)的线粒体细胞色素C氧化酶亚基I(COI)基因。从GenBank及BOLD Systems下载13条鹤类的COI基因序列,对35条COI序列进行分析,构建NJ树和MP树,探讨DNA条形码对鹤类的识别和鉴定。结果显示,丹顶鹤群体中,除D1和B18号个体外,均被归为同一类群;白鹤群体中,编号为AY567881的个体与黑鹤划为同一类群;其余鹤类的系统发育分析结果均与形态学分类结果相同。由于丹顶鹤样本均取自沈阳森林野生动物园,所以是同一物种或是近缘物种杂交的可能性最大;白鹤较大的种内差异则可能是地理位置或是其他原因。  相似文献   

10.
Aiming at the scheduling problem for jit delivery under the pulling type production, an optimal method for flexible job-shop scheduling problem (FJSP) based on demand time window is proposed. According to the demand time window of every workpiece, an optimal model for FJSP is constructed to maximize the average membership degree based on the completion time for every workpiece.Then, a tabu search algorithm based on multi-stage hybrid mutation is proposed and designed.To improve the convergence of the algorithm, inverse order mutation and gene segment swap mutation are used to find a good original solution, upon which gene swap mutation is used to find the optimal solution. The effectiveness of the proposed method is validated by applying to a multi-type and small-batch production manufacturing workshop.  相似文献   

11.
增强城乡统筹协调发展能力 突出解决“三农”问题   总被引:2,自引:0,他引:2  
从不同层面描述了城乡差距、形成城乡关系失衡的危机意识。必须认识城乡统筹是生产关系必须适应生产力发展这一规律的必然体现,是资源优化配置的客观要求;造成城乡分化的主要原因是由于中国长期实行的城乡二元经济结构政策造成的;城乡统筹协调发展的国际经验值得借鉴;打破城乡分割体制、实现城乡关系平等、协调、融合、发展是增强城乡统筹协调发展能力、突出解决“三农”问题的主要措施。  相似文献   

12.
In this paper, the water model method is used to optimize the flow behavior of asymmetrical five streams L-type tundish in a steelmaking plant. The results show that the optimization plan is set up with turbulence suppressor T+ vice guide wall D2+ main guide wall with three holes (D1a) which consists of top two holes with 25° inclination and one hole with 30° inclination below. With this plan, the time which the colorants reach to the outlets increases, the difference of response time in all outlets decreases, the peak concentration of the RTD reduces, the existence time of high concentration liquid steel extends, and the ratio of dead zone in each streams reduces.  相似文献   

13.
To deal with the complexity problems of design tasks decomposition and allocation in the process of product collaborative innovation, a task decomposition model based on mapping level function, structure and task and fuzzy search and matching collaborative partners is proposed by considering the dependencies between the design tasks and the design capacity constraints of innovative subjects. Then on the basis of studying the classification and attributes of design resource, a design resources allocation model with resource use threshold is established to compensate the lack of resource allocation by the priority strategy for design tasks, and the simulation modeling for task-resource allocation based on the time colored Petri net is carried out. Finally, a product collaborative innovation design R & D case of a certain brand phone is imported to verify the effectiveness of the proposed model.  相似文献   

14.
Cropping fields often have poor-performing patches. In an attempt to increase production on poor patches, farmers may apply additional fertiliser or ameliorants without economic or scientific justification. Improved understanding of the extent and causes of poor performance, management options, potential crop yield and economic benefits can give farmers the tools to consider management change. This paper presents an approach to integrating farmer knowledge, precision agriculture tools and crop simulation modelling to evaluate management options for poor-performing patches.We surveyed nine cropping fields in Western Australia and showed that (1) farmers have good understanding of the spatial extent and rank performance of poor-performing areas, when compared to NDVI or yield maps, (2) there is a wide range of physical and chemical soil constraints to crop yield in such patches, some of which can be ameliorated to raise yield potential, and others where crop inputs such as fertiliser can be better matched to low yield potential.Management options for poor-performing patches were evaluated through simulation analysis by removal of constraints to rooting to varying extents, and hence plant available water capacity. These examples show that if the constraint is mis-diagnosed then the potential benefits from amelioration can be overstated. In many cases constraints, often associated with physical limitations such as shallow available rooting depth or light-texture cannot be ameliorated or are uneconomic to ameliorate. In such cases the best intervention may be to lower crop inputs to better match the water-limited yield potential of such poor-performing areas.This research integrated farmer knowledge and spatial data to define yield zones in which targeted soil sampling and crop simulation were then used to determine yield potential and particular constraints to that potential. The economic costs and benefits of differential zone management were examined under a range of husbandry scenarios and, importantly, the sensitivity of economic gain to mis-diagnosis or errors in defining the zones was tested. This approach provided farmers with a robust and credible method for making decisions about spatial management of their fields.  相似文献   

15.
By analyzing the inherent uncertainties, discrete uncertainties and external environmental uncertainties, a dual-feedback control strategy and the dynamic scheduling method are proposed to solve the dynamic scheduling problem of vehicle air-conditioning assembly shop under uncertainty. Considering the reentrant constraint, equipment capacity constraint, and time discrete constraint etc., the multi-objective scheduling model of vehicle air-conditioning assembly shop is set up,taken the earliness/tardiness, process time, production cost and quality loss as optimization objectives. According to the characteristic of the model, sectional chromosome encoding, crossover operator and mutation operator are designed to prevent the generation of illegal solutions and improve efficiency of the algorithm. An example is given to prove the feasibility and validity of the approach.  相似文献   

16.
Based on the definition about the idea of Flexible Manufacture Systems(FMS), a three dimensional systematic views to represent the concept of the FMS production planning and scheduling problem is presented firstly. Next,a four-layer framework model of FMS' s production scheduling problem is put forward. Then, the operations research models and techniques in the static and dynamic scheduling of FMS operation are systematically analyzed, and the existing difficulties are pointed out. Finally,a brief introduction about the trend of using other approaches,such as artificial intelligence (AI) and artificial neural network (ANN), to solve the FMS planning and scheduling problems is given.  相似文献   

17.
This paper presents a dynamic hybrid substructure synthetic method for tower crane dynamic analysis. This method employs the transfer matrix method and the flexibility degree method respectively to formulate the vibration mathematical models of the tower body and tower top system substructures in the hoisting luffing plane. Based on the motion of the substructures in the interface and the dynamic harmonize condition, the frequency equations are established. Then the program is designed according to the mathematical models and firstly applied to the dynamic analysis of the QTZ63 tower crane in the construction site and the parameter identification of attached device and tower body. The test results show that the value calculated by the above method is quite approximate to the instrument measured value, which can meet the engineering requirements. Further study has found that , for the flexible long-distance attached tower crane, the method that introduces dynamic load coefficient for statics analysis of tower cranes is unprecise enough since there exist errors.This paper suggests to conduct site test and identification of the rigidity coefficient of attached device of the tower crane for the accident prevention of tower crane collapse by timely take measures.  相似文献   

18.
Wheat yield and protein content are spatially variable because of inherent spatial variability of factors affecting the yield at field scale. In Mediterranean environments, yield variability is often caused by the irregular weather pattern, particularly rainfall and by position on the landscape. The objective of this study was to determine the effects of landscape position and rainfall on spatial variability of wheat yield and protein in a rolling terrain field of Southern Italy, and to propose stable management areas through simulation modelling and georesistivity imaging in rolling landscape. The study was carried out in Southern Italy, during 2 years of wheat monoculture; extensive soil properties and in-season plant measurements were measured. This study showed that soil water content was the main factor affecting spatial variation of yield for both years. The interactions between rainfall, topography and soil attributes increase the chances to observe yield variability among years. The principal component analysis demonstrated that for both years, soil water content explained most of the variability. The crop simulation model provided excellent results when compared with measured data with root mean square error of 0.2 t ha−1. The simulated cumulative probability function showed that the model was able to confirm the yield temporal stability of three different zones.  相似文献   

19.
平房仓粮堆温度时空分布的基本统计特征分析   总被引:3,自引:0,他引:3  
在以2h等间隔不间断采样,采集了聊城1栋储藏小麦的和铜梁1栋储藏稻谷的平房仓近2年的粮情监测数据,在此基础上对平房仓粮堆温度分布的统计特征进行分析,得出平房仓粮堆温度时空变化的一些基本规律,并就其对传感器布局的影响进行了讨论。认为可以通过对最大温差变化点的跟踪分析,找到粮温异常点,并建议:①提供任意两次检测之间的温差,特殊标注其中10%的最大温差,并将其列入粮情检测系统标准;②加大现有设备的检测频率,以弥补现有检测点布局的不足。  相似文献   

20.
It has been verified that the ICA can isolate sources from multi channel magnetoencephalography (MEG) signals. Based on the route of constrained ICA (cICA), this paper achieves a new solution of MEG inverse problem called functional source separation (FSS) by adding a functional constraint to the cost function of a basic ICA model. Source activity is obtained by applying this method to one MEG signal dataset under a self paced finger tapping task. The result is proved effective by calculating correlation coefficients between the weight vectors of function source separation method and the spatial filter coefficients of SAM method. It is found that finger tapping related functional source was localized in motor cortex of precentral gyrus. At the same time, the temporal and frequency information provided by FSS method could be a basis of exploring cortical control timing mechanisms associated with finger movements and extracting time frequency characteristics of the functional source.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号