Characterizations of geometric distribution and discrete IFR (DFR) distributions using order statistics

Let X be a discrete random variable the set of possible values (finite or infinite) of which can be arranged as an increasing sequence of real numbers a₁<a₂<a₃<…. In particular, a_i could be equal to i for all i. Let X_1n≦X_2n≦?≦X_nn denote the order statistics in a random sample of size n drawn from the distribution of X, where n is a fixed integer ≧2. Then, we show that for some arbitrary fixed k(2≦k≦n), independence of the event {X_kn=X_1n} and X_1n is equivalent to X being either degenerate or geometric. We also show that the montonicity in i of P{X_kn = X_1n | X_1n = a_i} is equivalent to X having the IFR (DFR) property. Let a_i = i and $\text{G(i) = P(X≧i), i = 1, 2, …}$. We prove that the independence of {X_2n ? X_1n ∈B} and X_1n for all i is equivalent to X being geometric, where B = {m} (B = {m,m+1,…}), provided G(i) = q^i?1, 1≦i≦m+2 (1≦i≦m+1), where 0<q<1.     

Three models of OPEC leadership and policy in the aftermath of Iran

Collapse of the Shah's regime has transformed Iran's attitude regarding oil production policy. The nature of OPEC leadership is changing as well. Three models examine the nature of this leadership inside OPEC: (1) the conventional price leadership model, (2) a model emphasizing a concept of egalitarian leadership, and (3) a team model composed of coalitions. The three models establish the limits within which OPEC leadership is exercised. A composite model drawing upon all three sets of results suggests that Saudi Arabia shapes cartel policy not by itself, but through a dominant coalition of states. For most of the period 1969–1978 this coalition has been stable. Following the unsettling changes of 1973, cooptation of Iran into the dominant coalition in 1974 was an important step in achieving a new level of stability. But during the turbulence of regime transformation in Iran, the nature of the governing coalition appears to have changed. One consequence may be that in the future Saudi Arabia will yield more willingly to arguments heard within OPEC on behalf of upwards price pressure, especially in an atmosphere of growing political isolation and overall tight supply.     

网絡协議TCP/IP

网络协议TCP/IP,分别相当于ISO/OSI参考模式中的第四层和第三层,源于美国国防部ARPANET的协议标准.目前,在高档微机工程工作站中得到广泛的应用,并成为工业界的一个“公认”标准. 本文介绍TCP/IP协议,并结合对B-NET(运行于16位微机DUAL系统83和UNIX系统V)中的TCP/IP的提取和分析,着重说明它们的接口及其执行过程机理.     

A ONE-SIDED TRIMMED MEAN ESTIMATOR FOR THE MEAN OF POSITIVELY SKEWED DISTRIBUTIONS

This article proposes estimating the mean of positively skewed distributions by a one-sided trimmed mean estimator, called the upper-mean, and uses it to assess soil contact exposures at sites with toxic contamination. An optimal upper-mean is found by maximising the probability of the estimator falling in a target range. Monte Carlo studies are conducted for several positively skewed distributions and for a distribution obtained from real data. The simulation results show that the upper-mean is a better estimator than the upper 95% confidence limit estimator currently used, because it is more probable that the estimator is covered by the target range.     

一类非线性滞后微分方程的振荡性

本文讨论了一阶非线性滞后型微分方程组■，（1）所有解振荡的充分条件，发展了文[1]的方法，并推广强化了文[1]的有关结论。     

WTO框架下会计国际化的中国困境与创新

本文通过分析WTO对各国会计制度的要求,探讨了WTO框架下中国会计国际化所带来的四大困境；并试图从制度变迁成本的角度,提出了以制度借鉴为主线的中国会计国际化创新战略的基本原则,进一步给出了中国会计国际化创新战略实施的路径设计图。文章认为,充分利用国际会计资源解决我国的现实问题,减少我国会计国际化变迁的成本,应该是后WTO时代中国会计国际化制度困境突破与创新的基本路径取向。     

论中国与印度贸易的前景与障碍

长久以来,中国和印度贸易量在较低水平上徘徊。但是从规模经济看,中印间存在发展双边贸易的巨大潜力。中国与印度应该努力扩大贸易,这有利于两个国家的产业竞争力的提高。     

A computational general equilibrium approach to the shadow pricing of trade restrictions and the adjustment of the exchange rate, with an application to Argentina

A general equilibrium model of an open economy in which there are ad valorem texes on domestic production and export activities, and import activities are subject to both tariffs and quotas is constructed. A domestic monetary asset, foreign exchange, and a corresponding nominal exchange rate are introduced and a numerical example of the model is constructed. The example is solved via the Scarf fixed point algorithm, first with taut quotas and then after having relaxed quotas. Various price indices are then used to guide programs designed to stabilize the trade balance against the quota liberalization. An empirical example, using Argentine data, is carried out to find the quota equivalent of a particular tariff.     

Distributional implications of changes in U.S. petroleum taxation

This article develops a methodology based on input-output relations for the evaluation of excise tax incidence. Since many excise taxes are levied on products that are used not only in final consumption but also as intermediate inputs in the production of other commodities, estimation of the tax burden by the conventional methodology of using direct final consumption may yield inadequate and perhaps misleading results. The input-output methodology developed in this article is applied to the case of the U.S. taxation of petroleum products and the empirical results are compared with similar ones obtained by the U.S. Congressional Budget Office.