An open expanding economy model

The authors extend the generalized von Neumann model they developed (with J. G. Kemeny) in 1956 to an open model by assuming that there are exogeneously determined export and import prices and that any amount can be exported or imported at these prices. The open model is then characterized by means of seven axioms. It is shown, by applying the theory of linear programming, that if four economically reasonable assumptions hold, the open model has at least one solution in which at least one good with positive export price is exported and at least one good with positive import price is imported. It is also shown that, in general, a continuum of expansion rates can be achieved by varying certain control variables. The choice of these expansion rates gives indirectly the choice of a suitable sub-economy and also determines the exports and imports of the economy. Other results and examples are discussed.     

Time-minimizing transportation problems

A method is given for finding those solutions of a transportation problem which minimize the total time necessary for transporting goods from the suppliers to the consumers. Several extensions of the model are presented.     

A solution for queues with instantaneous jockeying and other customer selection rules

This paper presents a general solution for the M/M/r queue with instantaneous jockeying and r > 1 servers. The solution is obtained in matrices in closed form without recourse to the generating function arguments usually used. The solution requires the inversion of two (Z^r?1) × (2^r?1) matrices. The method proposed is extended to allow different queue selection preferences of arriving customers, balking of arrivals, jockeying preference rules, and queue dependent selection along with jockeying. To illustrate the results, a problem previously published is studied to show how known results are obtained from the proposed general solution.     

YBa_2Cu_3O_x超导薄膜水解前后的XPS分析

本文用X射线光电子能谱(XPS)方法研究了在ZrO_2(100)单晶衬底上用固相反应法制备的YBa_2Cu_3O_x超导薄膜的表面状态,组成和各成份元素的结合能,特别是超导薄膜水解前后表面状态和组成的变化。     

新型智能化平直度测量装置

本文主要介绍了“智能化平直度测量仪”的结构和工作原理,它解决了在几何量计量中对平尺、平板、以及机床导轨等的自动检测及误差评定问题。工作效率提高近百倍。由于采用了分立式结构,该仪器还可以广泛地应用于形位误差、螺纹、齿轮等几何量计量领域,是一种实用的智能化测量仪器。     

高阶稠密矩阵的并行求逆与应用

采用基于列交换的Ｇａｕｓｓ－Ｊｏｒｄａｎ并行算法来解决空气动力学中超音速高阶面元法的稠密矩阵求逆问题,该方法采取了块循环数据分配方式,尤其对超立方体结构的并行机系统来说具有通讯优势。在４台ＳＧＩ工作站构成的２×２网格上进行的实验表明,对秩为１０００左右的矩阵可得到５７％～６４％的效率。     

振动非平衡喷管流场的数值研究

从非定常的基本方程出发,采用时间相关法,利用带有平滑项的ＭａｃＣｏｒｍａｃｋ格式对以氮气为实验气体的一维振动非平衡喷管流场进行了数值计算。分析了不同条件下振动非平衡对流场的影响,确定了支配振动非平衡的主要因素。计算结果表明,对于一些实际应用的喷管条件,振动非平衡具有较为显著的影响。