成电8010分布式計算机之特点

成电8010是基于单板机开发成功的分布式微机过程控制系统。该系统的性能特点是任务的动态调度、机间合作、优美降级和资源分享等。这些特点使其应用非常成功。本文就是对这些性能特点作相应的分析和介绍。     

A Tighter Extra-Resource Analysis of Online Deadline Scheduling

This paper is concerned with online algorithms for scheduling jobs with deadlines on a single processor. It has been known for long that unless the system is underloaded, no online scheduling algorithm can be 1-competitive, i.e., matching the performance of the optimal offline algorithm. Nevertheless, recent work has revealed that some online algorithms using a moderately faster processor (or extra processors) can guarantee very competitive performance Kalyanasundaram and Pruhs, 2000 or even be 1-competitive Koo et al., 2002; Lam and To, 2001. This paper takes a further step to investigate online scheduling algorithms with an even higher performance guarantee (i.e., better than 1-competitive algorithms) and in particular, presents an extra-resource analysis of the earliest-deadline-first strategy (EDF) with respect to such a higher performance guarantee.A preliminary version of this paper has been accepted by The Australian Theory Symposium on Computing, 2004.This research was supported in part by Hong Kong RGC Grant HKU-7024/01E.     

Scheduling Truck Arrivals at an Air Cargo Terminal

We consider the scheduling of truck arrivals at an air cargo terminal. By coordinating arrivals of cargo delivery trucks with outbound flight departure schedules, some of the shipments can be transferred directly to the departing flights, while others will be stored at the terminal's storage facility and incur extra handling and storage costs. The objective is to obtain a feasible schedule so as to minimize the total cost of operations. We formulate the problem as a time‐indexed integer program and show that, even with limited number of unloading docks at the terminal, the problem is non‐trivial (NP‐hard in the strong sense). Our solution method includes an exact solution procedure to determine an optimal unloading sequence for the shipments carried by each truck, together with a Lagrangian relaxation‐based heuristic for assigning trucks to truck docks and determining truck arrival times. We conducted computational experiments to test the performance of our solution method. Computational results show that our method can generate near‐optimal solutions efficiently. Our simulation results indicate that the scheduling approach proposed in this paper has the potential to generate significant cost savings over a first‐come, first‐served approach currently used at the air cargo terminal that we observed.     

Intelligent Procedures for Intra‐Day Updating of Call Center Agent Schedules

For nearly all call centers, agent schedules are typically created several days or weeks before the time that agents report to work. After schedules are created, call center resource managers receive additional information that can affect forecasted workload and resource availability. In particular, there is significant evidence, both among practitioners and in the research literature, suggesting that actual call arrival volumes early in a scheduling period (typically an individual day or week) can provide valuable information about the call arrival pattern later in the same scheduling period. In this paper, we develop a flexible and powerful heuristic framework for managers to make intra‐day resource adjustment decisions that take into account updated call forecasts, updated agent requirements, existing agent schedules, agents' schedule flexibility, and associated incremental labor costs. We demonstrate the value of this methodology in managing the trade‐off between labor costs and service levels to best meet variable rates of demand for service, using data from an actual call center.     

中国当代多民族文学共同体发展格局素描

如果我们必须用一个等式来表现中国当代文学的本质特征,那么,它不是1+55=56,而是56=1。虽然在漫长历史进程中汉族文学与少数民族文学之间一直有一道无形的"万里长城"分割出相对隔绝的两个世界,但这改变不了多民族人民相互依存、多民族文化相互习染、多民族文学相互纠缠的历史事实。中国当代多民族文学共同体已经形成,中国文学的发展现实逼迫我们对多民族文学互动交融发展的事实作出及时反应,因此,学理构建和观点更新迫在眉睫。     

民族杂居地区乡村文化振兴与共同体重建的耦合——基于文化共生视角的分析

文化振兴是全面推进乡村振兴战略的题中应有之义,乡村共同体是乡村振兴的内生动力,乡村文化振兴的推动机制与乡村共同体的重建机制是同构的耦合。在民族杂居地区的两个村落案例中,从文化共生理论视角来看,是将传统文化与现代文化、民族文化与外来文化构成融合共生的内在动力贯穿于乡村共同体之中,从而激活了村民的内生发展动力,使乡村共同体得到复兴。目前在人口规模化常态化流动背景下,诸多因素给乡村共同体带来挑战,应利用乡村文化振兴和乡村共同体重建的耦合实践向度,以互惠共生文化传承乡村伦理,以组织引领多元主体协同参与,以公共文化激活公众集体意识,以利益共生助力乡村文化振兴,从而实现乡村的全面振兴和发展。     

考虑实时预倒箱的出口箱堆场多场桥调度优化

在出口集装箱堆场的实际作业过程中，倒箱是制约场桥作业效率的瓶颈之一。为提高出口箱堆场的作业效能，减少船舶装船作业时间，采用实时预倒来降低倒箱的影响，研究出口箱堆场多场桥调度优化问题。考虑待提箱作业次序固定、场桥间保持安全距离及不可跨越的现实约束，兼顾内集卡的等待上限，侧重场桥作业过程中的实时预倒箱，构建了以带惩罚因子的内集卡总等待时间最少为目标的混合整数线性规划模型。基于问题自身的特点设计了混合和声模拟退火算法，得出了各场桥的行走路径与实时预倒箱方案。在算例实验中，通过与不考虑实时预倒箱的方案、FCFS方案以及下界进行对比，验证了考虑实时预倒箱的场桥调度模型及算法的有效性，为集装箱码头出口箱堆场的场桥调度提供参考。     

赛珍珠《大地》叙事空间的置遣谫论

赛珍珠的《大地》虽然是用传统叙事写法创作的小说,但仍带有明显的叙事空间化的倾向,体现了时空维度的统一。小说以王龙一家所居村庄为基点空间,同时又设置了附近的城镇和南方大城市两个外缘空间。三大空间都具有表征人物性格、助推情节发展和突显主题思想等多种功能。三大空间都蕴含着地理、社会、文化、心理等方面因素,都由场域、场景和场面三个层次构成,并都表现出实在性、主体性和能动性三大特征。深厚的生活积累和谙熟中国小说写法是作者得以充分发挥空间叙事的长处并圆满完成故事讲述宗旨的决定性前提。