船体结构设计中的生产工艺性问题分析

船舶工业是高度复杂的系统工程,涉及众多技术领域和工艺流程。船体结构设计是整个船舶设计和建造过程中的关键环节,其质量和工艺性直接影响到船舶的性能、安全性和经济性。因此,在船体结构设计阶段,设计人员需要充分考虑生产工艺性问题,提高船舶建造效率、降低成本、保证质量。基于此,本文从船体结构设计角度出发,通过对船体结构设计流程和性能要求的概述,以及对生产工艺性问题的分析和解决措施的探讨,为船体结构设计与建造工作提供指导。

安徽非物质文化遗产生产性保护问题研究

生产性保护从一种原始的民间自发的非物质文化遗产传承保护方式被提升为国家倡导和支持的非遗保护与传承模式迄今已有十年,在这十年的摸索实践中,安徽非遗生产性保护获得了阶段性成果,也提出了许多亟待解决的问题。课题组在深入调研的基础上,对如何解决我省非遗生产性保护中存在的问题提出了对策建议。

某公司630T开卷落料线安装调试及效率提升方法

本文介绍了某公司导入630T开卷落料线基本技术情况,并对设备安装调试过程进行阐述,分析安装完成后存在的生产性问题及其解决对策,归纳和总结了本生产线生产效率的提升方法。

Genetic Algorithm Based on Duality Principle for Bilevel Programming Problem in Steel-making Production

Steel-making and continuous/ingot casting are the key processes of modern iron and steel enterprises. Bilevel programming problems(BLPPs) are the optimization problems with hierarchical structure. In steel-making production, the plan is not only decided by the steel-making scheduling, but also by the transportation equipment.This paper proposes a genetic algorithm to solve continuous and ingot casting scheduling problems. Based on the characteristics of the problems involved, a genetic algorithm is proposed for solving the bilevel programming problem in steel-making production. Furthermore, based on the simplex method, a new crossover operator is designed to improve the efficiency of the genetic algorithm. Finally, the convergence is analyzed. Using actual data the validity of the proposed algorithm is proved and the application results in the steel plant are analyzed.

An Improved Genetic Algorithm for Solving the Mixed⁃Flow Job⁃Shop Scheduling Problem with Combined Processing Constraints

The flexible job-shop scheduling problem(FJSP)with combined processing constraints is a common scheduling problem in mixed-flow production lines.However,traditional methods for classic FJSP cannot be directly applied.Targeting this problem,the process state model of a mixed-flow production line is analyzed.On this basis,a mathematical model of a mixed-flow job-shop scheduling problem with combined processing constraints is established based on the traditional FJSP.Then,an improved genetic algorithm with multi-segment encoding,crossover,and mutation is proposed for the mixed-flow production line problem.Finally,the proposed algorithm is applied to the production workshop of missile structural components at an aerospace institute to verify its feasibility and effectiveness.

Improvement of Lagrangian relaxation performance for open pit mines constrained long-term production scheduling problem

Constrained long-term production scheduling problem(CLTPSP) of open pit mines has been extensively studied in the past few decades due to its wide application in mining projects and the computational challenges it poses become an NP-hard problem.This problem has major practical significance because the effectiveness of the schedules obtained has strong economical impact for any mining project.Despite of the rapid theoretical and technical advances in this field,heuristics is still the only viable approach for large scale industrial applications.This work presents an approach combining genetic algorithms(GAs) and Lagrangian relaxation(LR) to optimally determine the CLTPSP of open pit mines.GAs are stochastic,parallel search algorithms based on the natural selection and the process of evolution.LR method is known for handling large-scale separable problems; however,the convergence to the optimal solution can be slow.The proposed Lagrangian relaxation and genetic algorithms(LR-GAs) combines genetic algorithms into Lagrangian relaxation method to update the Lagrangian multipliers.This approach leads to improve the performance of Lagrangian relaxation method in solving CLTPSP.Numerical results demonstrate that the LR method using GAs to improve its performance speeding up the convergence.Subsequently,highly near-optimal solution to the CLTPSP can be achieved by the LR-GAs.

A linear programming model for long-term mine planning in the presence of grade uncertainty and a stockpile

The complexity of an open pit production scheduling problem is increased by grade uncertainty. A method is presented to calculate the cost of uncertainty in a production schedule based on deviations from the target production. A mixed integer linear programming algorithm is formulated to find the min- ing sequence of blocks from a predefined pit shell and their respective destinations, with two objectives： to maximize the net present value of the operation and to minimize the cost of uncertainty. An efficient clustering technique reduces the number of var/ables to make the problem tractable. Also, the parameters that control the importance of uncertainty in the optimization problem are studied. The minimum annual mining capacity in presence of grade uncertainty is assessed. The method is illustrated with an oil sand deposit in northern Alberta.

The Reconcilability Between Islamic and the Conventional Banking

Tensions between Western and Islamic traditions are very fierce in evidence currently. Many see the two systems as irreconcilable and the conflict between the two as inevitable （Huntingdon ＆ Berger, 2002）. This paper argues if reconcilability between Islam and the West exists in the field of finance and if the two systems can co-evolve in a mutually productive way, then, the author can be optimistic about the ability of the two systems to co-exist. Clearly, they involve different attitudes, but this paper argues on the basis of significant compatibility issues that these are resolvable under the tradition of tolerance that has existed in Western and Islamic societies. The context chosen for this analysis is finance which is central to global capitalism and is an area in which key differences of principle and practice exist between Islam and the West.

The Performance of Continuous Rotifer （Brachionus Pficatilis） Culture System for Ornamental Fish Production

Rotifers are considered as one of the most important prey organisms in the culture of altricial fish larvae. However, high density rotifer culture is often problematic due to water quality problems which results in frequent crashes. In the present study, the performance of a small-scale, continuous system was evaluated for culturing rotifers, Brachionus plicatilis, using concentrated nonviable green algae, Nannochloropsis oculeataas feed in a 160 L tank for a period of 90 days. The system configuration was simple and major components consisted of a protein skimmer and a pure oxygen delivery system. Although egg ratio increased from 3% on day 1 to 21.8% and 39.3% on days 7 and 9, respectively, rotifer growth was slow at start up and resulted in fluctuations in total number of rotifers between days 19-41. Rotifer densities remained 〈 400 until day 51 but increased at higher rates reaching 900 individuals/mL on day 55, 1,620 on day 60 and 2,127 on day 70. Rotifer density reached a maximum of 2,188 individuals/mL on day 85. Once the rotifer density exceeded 1,500 individuals/mL （day 60）, periodical harvesting （a total of 16 harvest events） produced a total of 369,920,000 rotifers corresponding to a daily production of 12,330,667 individuals/day during the next 30 days until the experiment was terminated at day 90. As a result of periodic harvesting, water makeup and continuous protein skimming, total settleable solids and NH3-N levels remained low and ranged between 4-22 mL/L and 0.4-2.2 mg/L, respectively. The authors＇ findings indicated that this inexpensive culture system can be successfully used for small-scale marine or freshwater ornamental fish production. Further work is required to minimize lag period at start-up and increase the production potential and yield by better management of suspended solids.