The Effect of Initial Inventories in a Two-Echelon System

A model in which jointly optimal stocks of material and finished products are to be chosen is reexamined. While it costs less to hold material, a certain percentage of the random demand not immediately satisfied by previously finished products is lost. We pay particular attention to the dependence of the optimal stocks on the initial ones, which assumes an interesting form. For example, if the stock of finished products is high but the combined stock is low, die quantity of material ordered depends on the stock of finished products.     

核壳型铁钴纳米复合材料的制备及其性能

采用多元醇还原工艺和自组装技术,在微米级Fe粉表面包覆纳米Co粒子,一步法制备了一种具有核壳结构的复合磁性微球,用SEM表征了其相组成和形貌,用VSM测试了磁滞回线,初步研究了磁学性能。结果表明:用该法制备的核壳型Fe/Co纳米复合材料表面包覆致密,其比饱和磁化强度和矫顽力介于微米铁粉和纳米钴粉之间。     

山东省胶东地区引黄调水工程倒虹吸设计

山东省胶东地区引黄调水工程是一项大型调水工程,倒虹吸是该调水工程中数量较多的一种河渠交叉建筑物.由于该工程远距离输水,水头紧张,分配给每座渠倒虹的设计水头都很少.因此,在大流量、小水头的设计条件下,渠倒虹过水断面必然较大.从倒虹吸的设计和计算等角度,对胶东供水倒虹吸进行了概要阐述,对于类似工程具有较好的参考价值.     

水动力学数学模型并行计算技术研究及实现

基于MPI(Message Passing Interface)消息传递实现了黄河二维水动力学数学模型的并行编程。以数据的分布存储作为区域划分的依据,实现了计算量的负载平衡;在全局网格和局部区域之间建立映射关系,并且在临界单元、进出口单元、共用节点等通过规约等进行特殊处理,一方面尽可能的减少通讯量,另一方面也避免消息的阻塞。采用曙光4000A系统的8个CPU进行计算的加速比达0.8,多CPU并行计算极大的提高了计算任务的容量,使得无法在单机上完成的巨量计算成为可能。     

叠前地震数据的规则化

本文通过对动校正前积分法DMO原理的探讨，在借鉴Canning(1996)提出的利用DMO实现三维数据规则化的方法和Biondi(1998)提出的三维叠前地震数据方位角校正方法的基础上，从方位角校正的角度入手，利用DMO和DMO^-1相结合的处理流程对地震数据进行规则化，以得到新的规则的观测系统下具有所需特定方位角的观测数据。此方法可用于解决叠前地震数据道插值、陆上地震勘探中不规则观测数据的规则化和海上地震勘探中的羽状现象校正等问题，可将已有地震观测数据转变为特定观测系统的叠前地震数据，以便于某些处理方法的应用。此方法原理简单并具有广泛的适用性。     

节水是拉动经济效益增长的有效途径

本文简要介绍朔里煤矿抓节水的工作思路、工作方法和取得的节水经济效果，充分说明节水也是拉动经济增长的有效途径。     

石家庄市室内氡及其子体浓度

本文报道了用双滤膜法对石家庄市室内空气中氡及其子体浓度的调查结果。47个房间室内氡年平均浓度为17.0Bq·m~(-3),氡子体平均浓度是7.14Bq·m~(-3)。氡及其子体浓度的日变化是清晨4—8时出现峰值。季节变化是夏秋季低,冬季高,全年的最低值出现在8月,最高值出现在11月。     

利用5A284型铣齿机加工转盘螺旋锥齿轮探讨

利用引进设备5A284苏联铣齿机加工石油钻机转盘螺旋锥齿轮，建立计算程序并进行调整计算，详述了遇到的问题及解决方法，使所加工的锥齿轮质量良好。     

想象热刺激和实际热刺激脑功能成像研究

本实验用功能性核磁共振成像技术（fMRI）对人想象热刺激和实际接受热刺激进行了研究。这是继想象冷刺激和实际接受冷刺激实验之后的另一个关于想象刺激与实际接受刺激的实验、实验结果发现想象热刺激与实际热刺激激活脑区既有相同之处也有不同之处。想象热刺激激活了初级体感区（SI）、左侧额上回、左侧额中回、运动区和扣带回。实际热刺激激活了初级体感区（SI）区、右侧额上回、右侧额中回、运动区。区别在于额叶和扣带回,这个结论与想象冷刺激和实际冷刺激实验的结论几乎相同,只是两种情况下在额叶的具体差别不同。     

COLOR VISION SYSTEM FOR RIPENESS INSPECTION OF OIL PALM ELAEIS GUINEENSIS

In checking harvesting discipline and quality control for oil palm fruits, color has presumably been an important guide to whether the oil content has reached a maximum where the fruit bunch is ready for cutting. However, establishing a single and harmonious standard base on color is a very contentious issue in the oil palm industry because of the subjective nature of the human vision of color. This was further complicated due to the lack of information on fruit color upon which to base a definite ripeness criterion. We demonstrated in this paper that this problem can be solved using machine vision technology. Methods used were to treat color in HSI (Hue, Saturation and Intensity) color space and applied multivariate discriminant analysis. These have proven to be highly effective for color evaluation and image processing. The vision system was trained to classify oil palms into four quality grades according to PORIM (Palm Oil Research Institute of Malaysia) inspection standards. These are the unripe, the underripe, the optimally ripe and the overripe classes. Depending upon the quality feature evaluated, misclassification by the vision system varied from 5 to 12% but averaged at about 8%. Machine vision disagreement ranged from 2 to 19%.