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排序方式: 共有1100条查询结果,搜索用时 15 毫秒
1.
This paper reviews some recent blockchain‐based applications for information capture, distribution and preservation. As part of that review, this paper examines two key concerns with current blockchain designs for accounting and supply chain transactions: data independence and multiple semantic models for the same information distribution problem. Blockchain applications typically integrate database, application and presentation tiers all in the same ledger. This results in a general inability to query information in the ledger and other concerns. Further, since most applications appear to be private blockchain applications, there is a concern of agents needing to accommodate multiple blockchains depending on who their trading partners are and what they request. Finally, this paper uses a distributed database to design a ‘blockchain‐like’ system for virtual organizations.  相似文献   
2.
We give an example of a subspace K of     such that     , where     denotes the closure with respect to convergence in probablity. On the other hand, the cone   C ≔ K − L +  is dense in   L   with respect to the weak-star topology  σ( L , L 1)  . This example answers a question raised by I. Evstigneev. The topic is motivated by the relation of the notion of no arbitrage and the existence of martingale measures in Mathematical Finance.  相似文献   
3.
本文通过在电子商务环境下封中国现代物流业现状和问题的研究,得出中国应当通过电子商务的契机推动现代物流企业的网络化、信息化、标准化运营,实现物流业规模化发展,以提高中国现代物流业在全球的竞争力。  相似文献   
4.
关丽  孙宏英 《物流科技》2007,30(10):76-78
第三方物流企业作为一种新型行业,企业的发展已越来越受到企业内部控制薄弱瓶颈的制约.借鉴企业内部控制理论最新成果——企业风险管理框架(ERM)八要素理论建立和完善第三方物流企业内部控制,对该行业做优做强有着深刻的现实意义。  相似文献   
5.
We introduce a new method for proving large-deviation principles (LDPs). This method amounts to "mixing" a collection of LDPs with a sequence of probability measures that obeys itself an LDP. As an illustration, we construct from empirical measures a sequence of capacity-valued maps that can be considered as an indexed collection of LDPs. The index 1 coincides with Sanov's theorem. By taking a Poisson mixture we establish a new connection with Cramér's theorem.  相似文献   
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7.
This paper extends the mean-variance analysis and the two-fund separation theorem to a market with some constraints, such as, the incompleteness, prohibition of short-selling, and partial information, with stochastic interest rate, and with stochastic volatility for risky assets. By maximizing a quadratic utility of terminal wealth, we show that the efficient frontier for the problem is a straight line in the mean-standard-deviation diagram. The quadratic utility function exhibits mean-variance efficiency. Our results apply to portfolios of claims in a single period, multiperiod, and continuous time.  相似文献   
8.
对于密绕载流无限长螺线管,管外的磁场是否严格为零与管外磁场和管内磁场相比是否可以忽略不计,这是两个完全不同的问题。  相似文献   
9.
Conditional probability distributions seem to have a bad reputation when it comes to rigorous treatment of conditioning. Technical arguments are published as manipulations of Radon–Nikodym derivatives, although we all secretly perform heuristic calculations using elementary definitions of conditional probabilities. In print, measurability and averaging properties substitute for intuitive ideas about random variables behaving like constants given particular conditioning information.
One way to engage in rigorous, guilt-free manipulation of conditional distributions is to treat them as disintegrating measures—families of probability measures concentrating on the level sets of a conditioning statistic. In this paper we present a little theory and a range of examples—from EM algorithms and the Neyman factorization, through Bayes theory and marginalization paradoxes—to suggest that disintegrations have both intuitive appeal and the rigor needed for many problems in mathematical statistics.  相似文献   
10.
济南市物流产业现状分析及对策研究   总被引:1,自引:0,他引:1  
荆刚  陈建岭  张强 《物流科技》2004,27(2):42-45
本文介绍了近年来济南市物流产业发展的现状,分析了济南市物流产业已经取得的成绩和存在的问题。并提出了相应的解决措施。  相似文献   
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