基于马尔可夫决策的钢铁产成品订单分配模型研究

物流订单分配是钢铁产成品销售过程中的重要环节,对销售过程的整体体验和全流程的良性循环起着至关重要的作用。在实际生产过程中,传统的人工分单模式已难以适应长时间维度的发展要求。为了充分考虑一个时间周期内销售的物流成本最低以及承运司机的收益较高,同时确保企业的长期收益,本文用多目标约束,建立马尔可夫决策模型,引入KM算法执行二分图匹配,基于司机收益最大化和企业成本最小的多目标优化,最大化钢铁商品总交易量为长期的最终目标,结合价值函数和多属性的多目标优化函数,形成车辆和货物的完整匹配决策。以钢铁企业的真实业务数据为例,对数据进行预处理后筛选合适特征进行模型训练并验证算法的正确性和可用性。结果表明,该模型相较于传统的订单分配方法,可以更好地解决钢铁企业在订单分配场景下的需求。

钢铁物流中基于D^(*)的路线规划算法

物流企业通过路径规划工作实现车辆巡径,以完成在工作场景中实时规划出便捷可靠的车辆工作路线。因此本文面向钢铁物流配送场景,设计一种基于改进D*的路径规划算法。算法对候选子节点进行约束以禁止车辆斜穿两个障碍物间的狭缝,并且引入拐点惩罚因子以避免规划出与理想路径偏差较大的路径,尽可能避免拐动行为。此算法可避免车辆的非必要转弯,提高大型装卸车辆配送效率和安全性。使用随机障碍物的方法进行仿真测试,仿真结果表明,该路径规划算法所设计出的路径安全性优于已有算法。本文旨在将此算法应用于钢铁物流配送中,以提升钢铁企业物流配送效率。

Is longer sevoflurane preconditioning neuroprotective in permanent focal cerebral ischemia?

Sevoflurane preconditioning has neuroprotective effects in the cerebral ischemia/reperfusion model. However, its influence on permanent cerebral ischemia remains unclear. In the present study, the rats were exposed to sevoflurane for 15, 30, 60, and 120 minutes, followed by induction of perma- nent cerebral ischemia. Results demonstrated that 30- and 60-minute sevoflurane preconditioning significantly reduced the infarct volume at 24 hours after cerebral ischemia, and 60-minute se- voflurane preconditioning additionally reduced the number of TUNEL- and caspase-3-positive cells in the ischemic penumbra. However, 120-minute sevoflurane preconditioning did not show evident neuroprotective effects. Moreover, 60-minute sevoflurane preconditioning significantly attenuated neurological deficits and infarct volume in rats at 4 days after cerebral ischemia. These findings in- dicated that 60-minute sevoflurane preconditioning can induce the best neuroprotective effects in rats with permanent cerebral ischemia through the inhibition of apoptosis.

Efficient Concurrent L1-Minimization Solvers on GPUs

Given that the concurrent L1-minimization(L1-min)problem is often required in some real applications,we investigate how to solve it in parallel on GPUs in this paper.First,we propose a novel self-adaptive warp implementation of the matrix-vector multiplication(Ax)and a novel self-adaptive thread implementation of the matrix-vector multiplication(ATx),respectively,on the GPU.The vector-operation and inner-product decision trees are adopted to choose the optimal vector-operation and inner-product kernels for vectors of any size.Second,based on the above proposed kernels,the iterative shrinkage-thresholding algorithm is utilized to present two concurrent L1-min solvers from the perspective of the streams and the thread blocks on a GPU,and optimize their performance by using the new features of GPU such as the shuffle instruction and the read-only data cache.Finally,we design a concurrent L1-min solver on multiple GPUs.The experimental results have validated the high effectiveness and good performance of our proposed methods.

Deformation Analysis and Fixture Design of Thin-walled Cylinder in Drilling Process Based on TRIZ Theory

Thin-walled cylindrical workpiece is easy to deform during machining and clamping processes due to the insufficient rigidi.Moreover,it’s also difficult to ensure the perpendicularity of flange holes during drilling process.In this paper,the element birth and death technique is used to obtain the axial deformation of the hole through finite element simulation.The measured value of the perpendicularity of the hole was compared with the simulated value to verify then the rationality of the simulation model.To reduce the perpendicularity error of the hole in the drilling process,the theory of inventive principle solution(TRIZ)was used to analyze the drilling process of thin-walled cylinder,and the corresponding fixture was developed to adjust the supporting surface height adaptively.Three different fixture supporting layout schemes were used for numerical simulation of drilling process,and the maximum,average and standard deviation of the axial deformation of the flange holes and their maximum hole perpendicularity errors were comparatively analyzed,and the optimal arrangement was optimized.The results show that the proposed deformation control strategy can effectively improve the drilling deformation of thin-walled cylindrical workpiece,thereby significantly improving the machining quality of the parts.

An Algorithm for Mining Gradual Moving Object Clusters Pattern From Trajectory Streams

The discovery of gradual moving object clusters pattern from trajectory streams allows characterizing movement behavior in real time environment,which leverages new applications and services.Since the trajectory streams is rapidly evolving,continuously created and cannot be stored indefinitely in memory,the existing approaches designed on static trajectory datasets are not suitable for discovering gradual moving object clusters pattern from trajectory streams.This paper proposes a novel algorithm of gradual moving object clusters pattern discovery from trajectory streams using sliding window models.By processing the trajectory data in current window,the mining algorithm can capture the trend and evolution of moving object clusters pattern.Firstly,the density peaks clustering algorithm is exploited to identify clusters of different snapshots.The stable relationship between relatively few moving objects is used to improve the clustering efficiency.Then,by intersecting clusters from different snapshots,the gradual moving object clusters pattern is updated.The relationship of clusters between adjacent snapshots and the gradual property are utilized to accelerate updating process.Finally,experiment results on two real datasets demonstrate that our algorithm is effective and efficient.

集中供热系统供暖建筑室温控制算法研究综述

将集中供热系统供暖建筑室温控制算法分为基于经典控制理论的室温控制算法、基于现代控制理论的室温控制算法进行综述,分析各种控制算法的研究进展、局限性及改进方向。基于经典控制理论的供暖建筑室温控制算法,虽然能在一定程度上改善集中供热室温控制效果,但仍然存在一些难以突破的局限性。基于现代控制理论的供暖建筑室温控制算法由经典控制理论发展而来,对供暖建筑室温控制效果和供热系统的节能性进行了极大的改进,是当前研究的热点。自适应控制和人工神经网络控制对模型的精度要求不高,适合非线性系统,理论研究证明二者能得到更优秀的控制效果,但需要在实际工程中进一步验证。

基于相关性分析小时热负荷影响因素研究

以大连某实验房间为研究对象,使用DeST能耗模拟软件建立实验房间模型并验证。使用DeST模型获得的小时热负荷模拟值分析小时热负荷影响因素。对室内设计温度及影响小时热负荷的时间因素、气象因素、室内热扰因素、历史负荷因素进行研究。通过相关系数法筛选出对该实验房间小时热负荷影响程度较大的影响因素,作为小时热负荷预测模型输入变量。研究结果表明,室内设计温度对小时热负荷的影响明显。时间因素类影响因素筛选过程中,应首先考虑影响因素与预测热负荷的时间尺度是否在相近的级别,时间尺度相差越大,相关性越小。传统的将太阳辐射热作为自由热而不计入负荷影响因素或简单考虑负荷修正系数的方法是不合理的。室内热扰因素能对小时热负荷产生较大影响,在负荷预测的过程中,需要将室内热扰因素考虑在内。预测时刻前第1h的小时热负荷与小时热负荷相关性最强,预测时刻前第2h的小时热负荷的相关性次之。对大连实验房间小时热负荷影响程度较大的影响因素包括室内设计温度、是否工作时间、室外干球温度、太阳辐照度、人员在室率、灯光使用率以及预测时刻前第1、2、24h的小时热负荷。