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海水环境因素对网纹藤壶金星幼虫附着的影响机制

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中国腐蚀与防护学报 2024年第5期44卷 1316-1322页

作者：吴进怡柴柯李晓琳尚瑾李强吴耀华潍坊科技学院智能制造学院、山东省农机装备用材料工程高校特色实验室潍坊262700 广东腐蚀科学与技术创新研究院广州510530

网纹藤壶是广泛分布在中国各海域及世界许多海域的大型污损生物。通过藤壶培养及附着观察探索了不同海水环境因素对网纹藤壶金星幼虫在生物相容性极佳的钛合金表面和玻璃表面附着的影响,结果表明p H为8时金星幼虫在TC4钛合金表面的附着... 详细信息

网纹藤壶是广泛分布在中国各海域及世界许多海域的大型污损生物。通过藤壶培养及附着观察探索了不同海水环境因素对网纹藤壶金星幼虫在生物相容性极佳的钛合金表面和玻璃表面附着的影响,结果表明p H为8时金星幼虫在TC4钛合金表面的附着率及在TC4钛合金表面和玻璃表面的整体附着率达到最大值,分别为10%和76.7%;盐度为25‰时,整体附着率达最大值73.3%,盐度在(13~18)‰之间,TC4钛合金表面附着率达最大值6.67%;温度和海水流速对网纹藤壶金星幼虫附着的影响也极为显著,当温度为10℃时不附着,当温度为25℃时,整体附着率达50%,TC4钛合金表面附着率达10%;当海水流速为0时,金星幼虫附着率最高,流速达12 m/s时,金星幼虫在钛合金表面和玻璃表面均无法附着。上述环境因素对网纹藤壶金星幼虫附着的影响,可为海洋防污损策略提供依据。

关键词：网纹藤壶金星幼虫环境因素钛合金附着率

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维数发散乘积回归模型的M估计

应用概率统计 2024年第1期40卷 33-49页

作者：范瑞雅张曙光吴耀华西南科技大学数理学院绵阳621010 中国科学技术大学统计与金融系合肥230026

针对乘积回归模型,本文提出了非凹惩罚最小乘积相对误差的M估计(简称为惩罚MLPRE),该方法可有效处理高维样本量及参数维数随样本量增大而增大的稀疏乘积回归模型.基于一些正则条件,本文得到惩罚M-LPRE参数估计的相合性和渐近正态性等理... 详细信息

针对乘积回归模型,本文提出了非凹惩罚最小乘积相对误差的M估计(简称为惩罚MLPRE),该方法可有效处理高维样本量及参数维数随样本量增大而增大的稀疏乘积回归模型.基于一些正则条件,本文得到惩罚M-LPRE参数估计的相合性和渐近正态性等理论性质,通过数值模拟和实例分析,验证了惩罚M-LPRE准则的有效性.

关键词：惩罚LPRE M估计乘积回归模型

A Multi-stage Heuristic Algorithm for Matching Problem in the Modified Miniload Automated Storage and Retrieval System of E-commerce

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Chinese Journal of Mechanical Engineering 2016年第3期29卷 641-648页

作者： WANG Wenrui wu yaohua wu Yingying School of Transportation Engineering Shandong Jianzhu University School of Control Science and Engineering Shandong University

E-commerce, as an emerging marketing mode, has attracted more and more attention and gradually changed the way of our life. However, the existing layout of distribution centers can＇t fulfill the storage and picking demands of e-commerce sufficiently. In this paper, a modified miniload automated storage/retrieval system is designed to fit these new characteristics of e-commerce in logistics. Meanwhile, a matching problem, concerning with the improvement of picking efficiency in new system, is studied in this paper. The problem is how to reduce the travelling distance of totes between aisles and picking stations. A multi-stage heuristic algorithm is proposed based on statement and model of this problem. The main idea of this algorithm is, with some heuristic strategies based on similarity coefficients, minimizing the transportations of items which can not arrive in the destination picking stations just through direct conveyors. The experimental results based on the cases generated by computers show that the average reduced rate of indirect transport times can reach 14.36% with the application of multi-stage heuristic algorithm. For the cases from a real e-commerce distribution center, the order processing time can be reduced from 11.20 h to 10.06 h with the help of the modified system and the proposed algorithm. In summary, this research proposed a modified system and a multi-stage heuristic algorithm that can reduce the travelling distance of totes effectively and improve the whole performance of e-commerce distribution center.

关键词： e-commerce modified miniload automated storage/retrieval system matching problem multi-stage heuristic algorithm

ORDER-PICKING OPTIMIZATION FOR AUTOMATED PICKING SYSTEM WITH PARALLEL DISPENSERS

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Chinese Journal of Mechanical Engineering 2008年第6期21卷 25-29页

作者： wu yaohua ZHANG Yigong College of Control Science and Engineering Shandong University Jinan 250061 China

Based on the characteristics of parallel dispensers in automated picking system, an order-picking optimization problem is presented. Firstly, the working principle of parallel dispensers is introduced, which implies the time cost of picking each order is influenced by the order-picking sequence. So the order-picking optimization problem can be classified as a dynamic traveling salesman problem （TSP）. Then a mathematical model of the problem is established and an improved max-min ant system （MMAS） is adopted to solve the model. The improvement includes two aspects. One is that the initial assignment of ants depends on a probabilistic formula instead of a random deployment; the other is that the heuristic factor is expressed by the extra picking time of each order instead of the total. At last, an actual simulation is made on an automated picking system with parallel dispensers. The simulation results proved the optimization value and the validity of improvement on MMAS.

关键词： Automated picking system Parallel dispensers Max-min ant system

COMPRESSIBLE VIRTUAL WINDOW ALGORITHM IN PICKING PROCESS CONTROL OF AUTOMATED SORTING SYSTEM

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Chinese Journal of Mechanical Engineering 2008年第3期21卷 41-45页

作者： wu yaohua ZHANG Yigong wu Yingying School of Control Science and Engineering Shandong University Jinan 250061China

Compared to fixed virtual window algorithm （FVWA）, the dynamic virtual window algorithm （DVWA） determines the length of each virtual container according to the sizes of goods of each order, which saves space of virtual containers and improves the picking efficiency. However, the interval of consecutive goods caused by dispensers on conveyor can not be eliminated by DVWA, which limits a further improvement of picking efficiency. In order to solve this problem, a compressible virtual window algorithm （CVWA） is presented. It not only inherits the merit of DVWA but also compresses the length of virtual containers without congestion of order accumulation by advancing the beginning time of order picking and reasonably coordinating the pace of order accumulation. The simulation result proves that the picking efficiency of automated sorting system is greatly improved by CVWA.

关键词： Virtual window algorithm Dynamics Compressibility Picking efficiency

Storage Assignment Optimization in a Multi-tier Shuttle Warehousing System

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Chinese Journal of Mechanical Engineering 2016年第2期29卷 421-429页

作者： WANG Yanyan MOU Shandong wu yaohua School of Control Science and Engineering Shandong University Jinan 250061 China

The current mathematical models for the storage assignment problem are generally established based on the traveling salesman problem（TSP）,which has been widely applied in the conventional automated storage and retrieval system（AS/RS）.However,the previous mathematical models in conventional AS/RS do not match multi-tier shuttle warehousing systems（MSWS） because the characteristics of parallel retrieval in multiple tiers and progressive vertical movement destroy the foundation of *** this study,a two-stage open queuing network model in which shuttles and a lift are regarded as servers at different stages is proposed to analyze system performance in the terms of shuttle waiting period（SWP） and lift idle period（LIP） during transaction cycle time.A mean arrival time difference matrix for pairwise stock keeping units（SKUs） is presented to determine the mean waiting time and queue length to optimize the storage assignment problem on the basis of SKU *** decomposition method is applied to analyze the interactions among outbound task time,SWP,and *** ant colony clustering algorithm is designed to determine storage partitions using clustering *** addition,goods are assigned for storage according to the rearranging permutation and the combination of storage partitions in a 2D *** combination is derived based on the analysis results of the queuing network model and on three basic *** storage assignment method and its entire optimization algorithm method as applied in a MSWS are verified through a practical engineering project conducted in the tobacco *** applying results show that the total SWP and LIP can be reduced effectively to improve the utilization rates of all devices and to increase the throughput of the distribution center.

关键词： Multi-tier shuttle warehousing system storage assignment optimization open queuing network ant colony clustering algorithm

Sequential Estimate for Generalized Linear Models with Uncertain Number of Effective Variables

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Journal of Systems Science & Complexity 2015年第2期28卷 424-438页

作者： LU Haibo WANG Zhanfeng wu yaohua Department of Statistics and Finance University of Science and Technology of China

For the generalized linear model,the authors propose a sequential sampling procedure based on an adaptive shrinkage estimate of *** method can determine a minimum sample size under which effective variables contributing to the model are identified and estimates of regression parameters achieve the required *** authors prove that the proposed sequential procedure is asymptotically *** simulation studies show that the proposed method can save a large number of samples compared to the traditional sequential approach.

关键词： Confidence set generalized linear regression sequential sampling stopping rule

A Relative Error Estimation Approach for Multiplicative Single Index Model

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Journal of Systems Science & Complexity 2017年第5期30卷 1160-1172页

作者： WANG Zhanfeng CHEN Zimu wu yaohua Department of Statistics and Finance School of ManagementUniversity of Science and Technology of ChinaHefei 230026China

As an alternative to absolute error methods, such as the least square and least absolute deviation estimations, a product relative error estimation is proposed for a multiplicative single index regression model. Regression coefficients in the model are estimated via a two-stage procedure and their statistical properties such as consistency and normality are studied. Numerical studies including simulation and a body fat example show that the proposed method performs well.

关键词： Asymptotic properties least product relative error relative errors single index model

Selecting between Sequential Zoning and Simultaneous Zoning for Picker-to-parts Order Picking System Based on Order Cluster and Genetic Algorithm

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Chinese Journal of Mechanical Engineering 2011年第5期24卷 820-828页

作者： SHEN Changpeng wu yaohua ZHOU Chen School of Control Science and Engineering Shandong University Jinan 250061 China School of Industrial and Systems Engineering Georgia Institute of Technology Atlanta GA 30332 USA

The existing research of sequential zoning system and simultaneous zoning system mainly focuses on some optimization problems such as workload balance,product assignment and simulation for each system *** there is little research on comparative study between sequential zoning and simultaneous *** order to help the designers to choose the suitable zoning policy for picker-to-parts system reasonably and quickly,a systemic selection method is ***,both zoning and batching are order clustering,so the customer order sheet can be divided into many unit *** the time formulation in one-dimensional unit was defined,the time models for each zoning policy in two-dimensional space were established using filling curves and sequence models to link the one-dimensional unit *** consideration of ＂U＂ shaped dual tour into consideration,the subtraction value of order picking time between sequential zoning and simultaneous zoning was defined as the objective function to select the suitable zoning policy based on time *** it is convergent enough,genetic algorithm is adopted to find the optimal value of order picking *** the experimental study,5 different kinds of order/stock keeping unit（SKU） matrices with different densities d and quantities q following uniform distribution were created in order to test the suitability of sequential zoning and simultaneous zoning to different kinds of *** parameters setting,experimental orders inputting and iterative computations,the optimal order picking time for each zoning policy was *** observing whether the delta time between them is greater than 0 or not,the suitability of zoning policies for picker-to-parts system were *** significant effect of batch size b,zone number z and density d on suitability was also found by experimental *** proposed research provides a new method for selection between sequential zoning and simultaneous zoning for picker-to-parts syst

关键词： selecting sequential zoning simultaneous zoning order cluster genetic algorithm picker-to-parts