Threshold Estimation for Stochastic Processes with Small Noise

Consider a process satisfying a stochastic differential equation with unknown drift parameter, and suppose that discrete observations are given. It is known that a simple least squares estimator (LSE) can be consistent but numerically unstable in the sense of large standard deviations under finite samples when the noise process has jumps. We propose a filter to cut large shocks from data and construct the same LSE from data selected by the filter. The proposed estimator can be asymptotically equivalent to the usual LSE, whose asymptotic distribution strongly depends on the noise process. However, in numerical study, it looked asymptotically normal in an example where filter was chosen suitably, and the noise was a Lévy process. We will try to justify this phenomenon mathematically, under certain restricted assumptions.     

Some alternative bivariate Kumaraswamy models

In this article we discuss various strategies for constructing bivariate Kumaraswamy distributions. As alternatives to the Nadarajah et al. (2011) bivariate model, four different models are introduced utilizing a conditional specification approach, a conditional survival function approach, and an Arnold–Ng bivariate beta distribution construction approach. Distributional properties for such bivariate distributions are investigated. Parameter estimation strategies for the models are discussed, as are the consequences of fitting two of the models to a particular data set involving the proportion of foggy days at two different airports in Colombia.     

中国"十五"计划经济发展速度的引证

论证"十五"计划经济发展速度的前提是要正确分析和判断经济发展趋势、经济现象与经济规律的吻合程度,经济运行的工作质量和寻求解决问题的途径和办法。影响国内生产总值增长速度的因素有全社会固定资产投资总额、社会消费品零售总额、价格指数、进出口总额、实际利用外资、财政收入、居民储蓄和城镇居民人均可支配收入及农民人均纯收入八项。固定资产投资、消费品零售总额、进出口总额是经济增长可持续发展的关键因素,必须重视价格指数的正面影响,关注资本的投入量和资本的使用效率,关注财政投资对宏观调控能力的影响,增加城镇中低收入居民的可支配收入和增加农民收入是启动消费市场带动经济全面回升的重要步骤。     

傣泰民族起源与傣泰民族文化圈的形成新探

中国古代不存在一个可成其为民族的越人族体,泰人也不是越人演变而来的,傣泰民族在汉代以前的历史的追溯已无意义。傣泰民族可追溯的源流在汉代云南滇中,并随后向南迁移到今天的云南南部及东南亚一带。由于傣泰民族在长期的历史迁移与发展中保持了水稻种植、“勐-阪”制度与文化的复制模式,使傣泰民族的先民们能在长期的迁移过程中定居并壮大起来,从而在今天形成了一个傣泰民族居住的文化圈。傣泰民族文化圈是一个文化地理概念,基于共同的民族渊源关系,人们互相理解、宽容、合作、开展社会与经济的交流,共同促进民族与文化的发展,是当代理解傣泰民族文化的新思维。     

莱麦草染色体组分析及染色体变异的观察

通过对有丝分裂中期及减数分裂终变期染色体数目统计,形态、行为的观察,发现莱麦草染色体呈现广泛的变异：有丝分裂中期株内染色体数目在2n＝11──56内变化,含有本物种染色体数目2n＝28的细胞仅占统计数的27．8％。减数分裂终变期出现36％具非整倍性的花粉母细胞,染色体数除数目变异外还有结构变异如Robertson易位等。本文对该种进行了染色体组分析,确认其为同源四倍体。同时对该物种株内产生混倍性的原因,在物种进化上的意义进行了探讨。     

对《花东》480卜辞的释读

《花东》480版上,共有六条卜辞,涉及到的人物有祖甲、祖乙和妣庚;王、（武）丁、妇好;大子、子灵等。祭祀的种类有 、彡。瑞玉的种类有吉（圭）、珥。祭祀以外的事类有“在断,来狞自 ”、“在 ,来自 ”及嘉（ ）字不同于王卜辞中的“娩嘉”等内容。     

Ecosystem resilience, specialized adaptation and population decline: A modern Malthusian theory

The purpose of this article is to construct a theoretical framework characterizing the interactions among economic development, ecosystem equilibrium and possible population decline, and to discuss the population dynamics in the very long run. In our framework, economic activities bridge population and environment. On the one hand, human beings reform the environment through economic activities; on the other hand, economic activities decrease environmental resilience and increase the possibility of an environmental change in a discontinuous and irreversible pattern, as described in Arrow et al. (1995). Furthermore, a highly developed economy also causes over-specialization of human adaptation, which tends to exaggerate the impact of an environmental change on human population size. Received: 19 January 1999/Accepted: 3 July 1999