Realisation of linear time-varying systems

In this paper, the realisation problem of linear multi-input multi-output, time-varying systems is studied. The approach, based on the theory of non-commutative polynomial rings, yields explicit and simple formulas for computation of the state coordinates as well as for state equations in observable canonical form. The formulas are based on (left) Euclidean polynomial division.     

城市轨道交通工程施工测量中注意问题及应对措施

城市轨道交通包括地铁、轻轨等。现城市轨道交通公司（业主）一般建立了由业主管理、第三方测量的单位，试图阐述城市轨道交通工程中施工测量注意的问题，并对难点、重点及应对措施做了探讨。     

试论工程进度控制管理及影响进度问题研究

建筑工程的管理工作随着建筑业的发展越来越受到重视。在工程项目管理工作中，对工程进度的控制与管理是其中重要的内容之一。为使工程能够按时完工，相关负责人员对工程进度的监控管理工作就必须做到位，对影响工程进度的因素要及时进行排除。     

Two-staged guillotine cut,two-dimensional bin packing optimisation with flexible bin size for steel mother plate design

This paper looks into the steel mother plate design problem. A slab, which is an intermediate work in process, is subsequently rolled into a mother plate with the specific dimensions of thickness, length, and width. The mother plate is then cut into customer order plates. As a slab is rolled into a mother plate through a series of horizontal and vertical rolling processes, different-sized mother plates can be generated from a single-slab type. This flexibility allows for the size of a mother plate to be determined according to the order plates assigned to it. Furthermore, when the order plates are cut from a mother plate, a guillotine cut is required to reduce the production cost. The steel mother plate design problem involves the placing of order plates on the mother plates in a guillotine cut pattern and determining the sizes of the mother plates with the objective of minimising the number of slabs; thus it may be considered as a two-staged guillotine cut, two-dimensional bin packing problem with flexible bin size. This paper introduces the problem, presents several mathematical models, and proposes an iterative two-phase heuristic method consisting of several algorithms to solve the problem. Computational results for the benchmark problems show the effectiveness of the proposed method.     

建筑施工企业科技创新工作探讨

建筑施工企业在政府政策的支持下,科技创新工作取得进展,与此同时企业要认真分析,总结经验,调整科技战略,制定更有利于科技创新持续开展的机制,切实发挥科技创新工作的实效。     

A Physarum-inspired optimization algorithm for load-shedding problem

Load-shedding is an intentional reduction approach which can maintain the stability of a microgrid system effectively. Recent studies have shown that a load-shedding problem can be solved by formulating it as a 0/1 knapsack problem (KP). Although approximate solutions of 0/1 KP can be given by ant colony optimization (ACO) algorithms, adopting them requests a delicate consideration of the robustness, convergence rate and premature convergence. This paper proposes a new kind of Physarum-based hybrid optimization algorithm, denoted as PM-ACO, based on the critical paths reserved feature of Physarum-inspired mathematical (PM) model. Through adding additional pheromone to those important items selected by the PM model, PM-ACO improves the selection probability of important items and emerge a positive feedback process to generate optimal solutions. Comparing with other 0/1 KP solving algorithms, our experimental results demonstrate that PM-ACO algorithms have a stronger robustness and a higher convergence rate. Moreover, PM-ACO provides adaptable solutions for the load-shedding problem in a microgrid system.     

对于岩土工程勘察中的技术问题与措施探究

本文针对岩土勘察工程技术上近几年频繁出现的问题进行了分析与探讨,并提出应对的措施和方法,希望为以后的勘探工作做好基础和预防。     

建筑电气工程常见问题分析

本文对建筑工程中的电气工程进行了分析,并针对设计阶段和施工阶段的常见问题提出了相应的解决对策。     

Optimization of casting process based on the theory of inventive problem solving

Optimization of casting process involves the adjustment of parameters as well as the improvement of process schemes and measures. This paper proposes a new method based on the Theory of Inventive Problem Solving (TRIZ) for casting process optimization, and realizes the idea of applying TRIZ to optimize the casting process of a magnesium alloy intake manifold. By this method, the casting process is optimized so as to remove the shrinkage pores. The successful optimization of casting process demonstrates the feasibility of the proposed method.     

The Selective Fixing Algorithm for the closest string problem

A hybrid heuristic algorithm based on integer linear programming is proposed for the closest string problem (CSP). The algorithm takes a rough feasible solution in input and iteratively selects variables to be fixed at their initial value until the number of free variables is small enough for the remaining problem to be solved to optimality by an ILP solver. The new solution can then be used as input for another iteration of the algorithm and this approach is repeated a predefined number of times. The procedure is denoted as Selective Fixing Algorithm (SFA). SFA has first been tested on standard instances available from the literature, which is denoted as rectangular having string length larger than the number of strings. Then, this approach has also been tested on the so-called square instances (having string length equal to the number of strings) and rectangular inverse instances (having string length smaller than the number of strings). Computational experiments indicate that SFA globally outperforms the state-of-the-art heuristics.