人工林经营过程密度最优控制研究

在连续状态动态规划方法建立的人工林种群密度决策模型的基础上，首次提出应用遗传算法优化人工林林分经营过程的间伐时间和主伐时间的最优组合方案，并阐明其数学模型和具体方法。杉木人工林经营过程的密度最优控制方案优化实例表明，用遗传算法优化能收到良好效果。优化结果表明，杉木人工林经营过程中以间伐两次为最优，第一次在１１～１２年，第二次在１５～１８年，而主伐年龄以２５年为最优。     

The concept of intrinsic value and transgenic animals

The creation of transgenic animals by means of modern techniques of genetic manipulation is evaluated in the light of different interpretations of the concept of intrinsic value. The zoocentric interpretation, emphasizing the suffering of individual, sentient animals, is described as an extension of the anthropocentric interpretation. In a biocentric or ecocentric approach the concept of intrinsic value first of all denotes independence of humans and a non-instrumental relation to animals. In the zoocentric approach of Bernard Rollin, genetic engineering is seen as a morally neutral tool, as long as the animal does not suffer as a result of it. Robert Colwell who defends an ecocentric ethic, makes a sharp distinction between wild animals and domesticated animals. Genetic manipulation of wild species is a serious moral issue, in contrast to genetic manipulation of domesticated species which is no problem at all for Colwell. Both authors do not take the species-specific nature (or telos) of domesticated animals seriously. When domestication is seen as a process between the two poles of the wild animal and the human construct (which can be patented), the technique of genetic manipulation can only be seen as a further encroachment upon the intrinsic value of animals. At the level of molecular biology, the concept of an animal's telos loses its meaning.     

A molecular genetic analysis of social structure, dispersal, and interpack relationships of the African wild dog (Lycaon pictus )

The African wild dog is a highly social, pack-living predator of the African woodland and savannah. The archetypal wild dog pack consists of a single dominant breeding pair, their offspring, and non-breeding adults who are either offspring or siblings of one of the breeding pair. Non-breeding adults cooperate in hunting, provisioning and the protection of young. From these observations follows the prediction that the genetic structure of wild dogs packs should resemble that of a multigenerational family, with all same-sexed adults and offspring within a pack related as sibs or half-sibs. Additionally, a higher kinship between females from neighboring packs should be evident if females tend to have small dispersal distances relative to males. We test these predictions through analysis of mitochondrial DNA control region sequences and 14 microsatellite loci in nine wild dog packs from Kruger National Park, Republic of South Africa. We show that as predicted, African wild dog packs generally consist of an unrelated alpha male and female, subdominant close relatives, and offspring of the breeding pair. Sub-dominant wild dogs occasionally reproduce but their offspring rarely survive to 1 year of age. Relatedness influences the timing and location of dispersal events as dispersal events frequently coincide with a change in pack dominance hierarchy and dispersers often move to areas with a high proportion of close relatives. Received: 22 February 1996 / Accepted after revision: 16 November 1996     

A genetic component to size in queens of the ant,<Emphasis Type="Italic"> Formica truncorum</Emphasis>

The genetic basis of morphological traits in social insects remains largely unexplored. This is even true for individual body size, a key life-history trait. In the social insects, the size of reproductive individuals affects dispersal decisions, so that small size in queens is often associated with reduced dispersal, and large size with long-range dispersal and independent colony founding. Worker size is connected to division of labour when workers specialize in certain tasks according to their size. In many species, variation in worker size has been shown to increase colony performance. In this study, we present the first evidence of an additive genetic component to queen size in ants, using maternal half sib analysis. We also compared intra-colony size variation in colonies with high (queen doubly mated) versus low (queen singly mated) genetic variability. We found a high and significant heritability (h²=0.51) for queen size in one of the two study years, but not in the other. Size variation among queens was greater in colonies headed by a doubly mated queen in one of the study years, but not in the other. This indicates that genetic factors can influence queen size, but that environmental factors may override these under some circumstances. The heritability for worker size was low (h²=0.09) and non-significant. Increased genetic diversity did not increase worker size variation in the colonies. Worker size appeared largely environmentally determined, potentially allowing colonies to adjust worker size ratios to current conditions.Communicated by J. Heinze     

Multiple-pattern parameter identification and uncertainty analysis approach for water quality modeling

This paper presents a multiple-pattern parameter identification and uncertainty analysis approach for robust water quality modeling using a neural network (NN) embedded genetic algorithm (GA). The modeling approach uses an adaptive NN–GA framework to inversely solve the governing equations in a water quality model for multiple parameter patterns, along with an alternating fitness method to maintain solution diversity. The procedure was demonstrated through a coupled 2D hydrodynamic and eutrophication model for Loch Raven Reservoir in Maryland. The inverse problem was formulated as a nonlinear optimization problem minimizing the degree of misfit (DOM) between model results and observed data. A set of NN models was developed to approximate the input-output response relationship of the Loch Raven Reservoir model and was incorporated into a GA framework in an adaptive fashion to search for near-optimal solutions minimizing the DOM. The numerical example showed that the adaptive NN–GA approach is capable of identifying multiple parameter patterns that reproduce the observed data equally well. The resulting parameter patterns were incorporated into the numerical model, and a multiple-pattern robust water quality modeling analysis, along with a compound margin of safety (CMOS) method, was proposed and applied to analyze the parameter pattern uncertainty.     

Simulation-based fault propagation analysis—Application on hydrogen production plant

Recently production of hydrogen from water through the Cu–Cl thermochemical cycle is developed as a new technology. The main advantages of this technology over existing ones are higher efficiency, lower costs, lower environmental impact and reduced greenhouse gas emissions. Considering these advantages, the usage of this technology in new industries such as nuclear and oil is increasingly developed. Due to hazards involved in hydrogen production, design and implementation of hydrogen plants require provisions for safety, reliability and risk assessment. However, very little research is done from safety point of view. This paper introduces fault semantic network (FSN) as a novel method for fault diagnosis and fault propagation analysis by using evolutionary techniques like genetic programming (GP) and neural networks (NN), to uncover process variables’ interactions. The effectiveness, feasibility and robustness of the proposed method are demonstrated on simulated data obtained from the simulation of hydrogen production process in Aspen HYSYS^®. The proposed method has successfully achieved reasonable detection and prediction of non-linear interaction patterns among process variables.     

自然灾害社会脆弱性评估研究——以上海市为例

基于投影寻踪聚类模型(PPC),结合基于实数编码的加速遗传算法(RAGA),对上海市进行了自然灾害社会脆弱性评估的尝试。结果表明:①灾害社会脆弱性最高的为崇明县,其次为宝山区和金山区;②灾害社会脆弱性最低的是黄埔区,其次是徐汇区和静安区;③总体而言,灾害脆弱性较低的地区集中于上海城市中心区,而城市边缘区的社会脆弱性一般较高。     

基于遗传算法的前馈神经网络火灾探测

分析了前馈神经网络火灾探测的基本原理;针对ＢＰ算法的缺陷,提出用遗传算法（ＧＡ）和ＢＰ相结合的一种方法,即：ＢＰ－ＧＡ算法;并把ＢＰ－ＧＡ算法用于火灾探测的模拟,结果表明：前馈神经网络是处理火灾信号的良好方法,ＢＰ－ＧＡ算法提高了网络的收剑性。     

First-trimester amniotic fluid and extraembryonic coelomic fluid acetylcholinesterase electrophoresis

Acetylcholinesterase (AChE) gel electrophoresis was performed on samples of amniotic fluid and extraembryonic coelomic fluid obtained by high resolution transvaginal ultrasound-guided amniocentesis from 38 women between 8 and 12 weeks of pregnancy. AChE was positive in 33 per cent (12/36) of the amniotic fluid samples; the percentage of positive results decreased as gestation advanced. AChE was positive in 32 per cent (9/28) of the extraembryonic coelomic fluid samples. In 81 per cent (21/26) of matched samples, the AChE results were identical in the two fluids. Amniotic fluid and extraembryonic coelomic fluid AChE electrophoresis cannot be used to diagnose neural tube defects prior to 12 weeks of gestation.     

Risk of amniocentesis and laboratory findings in a series of 1500 prenatal diagnoses

The experiences with 1500 midtrimester prenatal diagnoses are reported. Abnormal findings of amniotic fluid investigations led to 43 therapeutic abortions. In ± 30 percent of the chromosome anomalies diagnosed, the significance of the effect on fetal development was inconclusive. The outcomes of all pregnancies except one are known. Fetal loss and perinatal mortality involved 69 cases, 23 (33 percent) of which occurred within three weeks after amniocentesis. In these 23 cases there appeared to be a relationship between the degree of experience of the gynaecologist and fetal loss: 3·7 percent when this experience was limited to a maximum of 10 punctures diminishing to 0·3 percent with an experience of more than 50 punctures. It is concluded that the risk of an abortion due to amniocentesis decreases as the gynaecologist becomes more experienced with the puncture technique.