An Object-Oriented Transaction Model

In object-oriented database systems(OOBSs),the traditional transaction models are no longer suitable because of the difference between the object-oriented data model(OODM)and the conventional data models(e.g.relational data model).In this paper,transction models for advanced database applications are reviewed and their shortcomings are analyzed.Exchangeability of operations is proposed instead of commuativity and recoverability for using more semantics in transaction management.As a result,an object-oriented transaction model(in short,OOTM)is presented.It is not modeled for some special application,but directly based on object-oriented paradigms.A transaction is regarded as an interpretation of a metho.Each transaction(even subtransactions)keeps relative ACID(Atomicity,Consistency,Isolation,Durability)properties,therefore the special problems appearing in OOBSs such as“long transactions”,“visibility of inconsistent database state”can be solved.     

水煤浆中氮的测定方法研究

研究了用开式定氮法测定水煤浆中氮含量的方法 ,探讨了浆样量的确定和水煤浆固体试样以及浆体试样均匀性的检验方法 ;对于两种制取水煤浆试样方式 ,即可替代方式和重复测定方式的精确度进行了比较 .结果表明 :两种制样方法可以互相替代 ,且其差值在 99%的置信区间均小于同一实验室测定煤中氮的允许差 ,测定结果的重复性均与煤中氮测定的重复性一致 ,因此煤中氮的测定方法可以应用于水煤浆中氮的测定     

K-行正交矩阵及其可交换性

给出K-行正交矩阵的概念,并讨论K-行正交矩阵的行列式、可逆性、可交换性等问题,得出：K-行正交矩阵是行列对称矩阵;若干个K-行正交矩阵之和与其行转置矩阵可交换,若干个K-行正交矩阵之和与其列转置矩阵也可交换;若干个K-行正交矩阵之差与其行转置矩阵可交换,若干个K-行正交矩阵之差与其列转置矩阵也可交换等结论.     

Effects of Carbonate on Exchangeability and Bioavailability of Exogenous Neodymium in Soil

Ｉｔｈａｓｂｅｅｎｒｅｐｏｒｔｅｄｔｈａｔｔｒａｃｅｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓ (ＲＥＥｓ)ｐｌａｙａｎｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｉｎ ｃｒｅａｓｉｎｇｃｒｏｐｐｒｏｄｕｃｔｉｏｎ[1] .ＲＥＥｔｒａｃｅｅｌｅ ｍｅｎｔｆｅｒｔｉｌｉｚｅｒｓａｒｅａｐｐｌｉｅｄｉｎｍｏｒｅｔｈａｎ 3 33ｍｉｌｌｉｏｎｈｅｃｔａｒｅｉｎＣｈｉｎａｐｅｒｙｅａｒ[2 ] .ＡｇｒｅａｔａｍｏｕｎｔｏｆＲＥＥｆｅｒｔｉｌｉｚｅｒｓａｒｅＲＥＥ ａｍｍｏｎｉｕｍ ｂｉｃａｒｂｏｎａｔｅｃｏｍｐｏｕｎｄｆｅｒｔｉｌｉｚｅｒｓ …     

燃气互换性判定指数的计算

在对不同组分燃气混合气体互换性分析的基础上,结合美国燃气协会（Ａ．Ｇ．Ａ．）互换性判定指数,提出了燃气互换性判定电算化方法。     

铝荧光灯框架与盖板型材尺寸和偏差的设计

根据有关挤压工艺技术,结合生产实践和铝合金荧光灯具的安装使用要求,对其框架与盖板铝合金型材配合处有关尺寸及偏差的设定进行了介绍,并说明了配合处尺寸互换性的重要性。     

局部互换性测量在锥齿轮质量控制中的应用

提出了局部基准和局部互换性测量的概念及基本原理 ,介绍了局部互换性测量技术应用于批量生产汽车差速机构直锥齿轮副的关键工序质量控制的实例     

Assessing the Value of a Second Opinion: the Role and Structure of Exchangeability

This paper displays the productive role of the judgment of exchangeability and even conditional exchangeability that should replace the misleading assertion of independence of various experts' opinions regarding uncertain situations. The application is technically rather complicated, and a basic understanding of exchangeability in its simple applications is presumed. One component of the analysis is novel. It suggests how we might specify a likelihood function that allows us to learn about one exchangeable sequence of events from the outcomes of another exchangeable sequence. The substantive content of the the paper concerns the use of personal probabilities by two experts in assessing the sex of human skulls found in anthropological investigations. Although we initially value the two experts' assertions exchangeably, we learn to value one of the expert's assertions more than the other's. Moreover we identify precisely how much to value the elicitation from a second expert after we have already learned the assertion of the first. Valuation is based on a decision theoretic procedure assessing reduction in risk.     

按行可交换随机向量函数加权和的收敛性

因为可交换随机变量无限列的基本结构定理De-Finetti定理对可交换的有限列不成立,所以必须寻找另外的办法解决可交换随机变量有限列的渐近性质问题。通过选取适当的σ－代数,采用适当的矩条件和非正交性度量条件,利用逆鞅方法讨论了按行可交换随机向量三角阵列函数加权和收敛性,得到的按行可交换随机向量三角阵列函数加权的两个结论,分别推广了按行可交换随机变量大数定律的相应结果,可应用于可交换双变总体随机抽样统计量收敛性的研究中。     

数字化变电站IED互换性研究

受智能设备数据模型配置技术的限制,数字化变电站智能电子设备互换性还未能实现.在不改变 IEC61850 通信标准体系的前提下,提出了资源定义机制和基于需求激励的资源匹配机制,将 IED 的资源分为需求资源对象和生产资源对象.该定义机制在考虑 IED 拓扑关系的基础上,实现了变电站智能设备数据模型的自动配置,通过生产资源...