Rational function optimization using genetic algorithms

In the absence of either satellite ephemeris information or camera model, rational functions are introduced by many investigators as mathematical model for image to ground coordinate system transformation. The dependency of this method on many ground control points (GCPs), numerical complexity, particularly terms selection, can be regarded as the most known disadvantages of rational functions. This paper presents a mathematical solution to overcome these problems. Genetic algorithms are used as an intelligent method for optimum rational function terms selection. The results from an experimental test carried out over a test field in Iran are presented as utilizing an IKONOS Geo image. Different numbers of GCPs are fed through a variety of genetic algorithms (GAs) with different control parameter settings. Some initial constraints are introduced to make the process stable and fast. The residual errors at independent check points proved that sub-pixel accuracies can be achieved even when only seven and five GCPs are used. GAs could select rational function terms in such a way that numerical problems are avoided without the need to normalize image and ground coordinates.     

Extended larval development compensates for sublethal effects of fish predation in a mayfly population (Rhithrogena semicolorata, Ephemeroptera)

Many predation experiments in streams are carried out in enclosures. Hence, the relevance of their results to predict population dynamics is often unclear due to the relatively small spatial and temporal scale of the experiments. To enhance the transferability of experimental results on the ecosystem scale the impact of fish predators on a prey population was observed in a reach scale approach over 2 years in a natural stream. A 400-m reach inhabited by the small benthivorous fishes gudgeon (Gobio gobio) and stone loach (Barbatula barbatula) was compared with a fishless reference reach.It was shown that fish predation may affect the population of the grazing mayfly Rhithrogena semicolorata on the ecosystem scale. Although the larvae grew slower in the fish reach than in the fishless reach, the adults reached the same size and fecundity because they emerged 2–3 weeks later. By this compensation, the prey species avoided a reduction of their individual fecundity. On the other hand, the extended exposure to the fish predators resulted in an enhanced mortality and a reduced density of adult mayflies. Thus, there was obviously a trade-off between maximising fecundity and minimising mortality from fish predation.The observed differences were almost certainly caused be fish predation and not by natural differences of the reaches. This was concluded from results gained after eliminating all benthivorous fish from the former fish reach.With the help of scenario analyses based on our empirical data and simple model assumptions we could demonstrate that compensating the potential loss in fecundity by extending development time led to higher average fitness of the prey population than emerging at an earlier fixed time to avoid additional predation losses. Therefore, we concluded that this strategy was adaptive in the presence of benthivorous fish.     

An application of problem and product ontologies for the revision of beach nourishments

An ontological approach in GIS serves as a framework for the conceptualization of processes in the real world. In this paper, we examine an application in coastal change in the Netherlands, whereby beaches are subject to artificial nourishment to offset the effect of severe erosion. The use of ontologies helps to define two scenarios: S_I determined by the regulations from the Ministry for Public Works; S_II grounded on the abilities from an existing spatial dataset. A comparison between S_I and S_II shows that 72.8% of the objects suitable and unsuitable for nourishment are correctly classified. A higher overlap is found in areas where actual beach nourishments were carried out. Inaccuracies in attributes influence the determination of the objects. A sensitivity analysis applied to altitude illustrates a significant increase of objects suitable for nourishment for both scenarios, when altitude is decreased within the lower limit of the root mean square error for the 95% confidence interval. Moreover, the sensitivity of altitude shows that artificial boundaries for beach nourishment objects are not reasonable and consequently should be treated as vague objects.     

Offshore wind farms as productive sites or ecological traps for gadoid fishes? – Impact on growth,condition index and diet composition

With the construction of wind farms all across the North Sea, numerous artificial reefs are created. These windmill artificial reefs (WARs) harbour high abundances of fish species which can be attracted from elsewhere or can be the result of extra production induced by these wind farms. To resolve the attraction–production debate in suddenly altered ecosystems (cf. wind farms), the possible consequences of attraction should be assessed; thereby bearing in mind that ecological traps may arise. In this paper we investigated whether the wind farms in the Belgian part of the North Sea act as ecological traps for pouting and Atlantic cod. Length-at-age, condition and diet composition of fish present at the windmill artificial reefs was compared to local and regional sandy areas.Fish data from the period 2009–2012 were evaluated. Mainly I- and II-group Atlantic cod were present around the WARs; while the 0- and I-group dominated for pouting. For Atlantic cod, no differences in length were observed between sites, indicating that fitness was comparable at the WARs and in sandy areas. No significant differences in condition index were observed for pouting. At the WARs, they were slightly larger and stomach fullness was enhanced compared to the surrounding sandy areas. Also diet differed considerably among the sites. The outcome of the proxies indicate that fitness of pouting was slightly enhanced compared to the surrounding sandy areas. No evidence was obtained supporting the hypothesis that the WARs act as an ecological trap for Atlantic cod and pouting.     

Analysis of the extinction of the Late Cretaceous foraminifer Afrobolivina afra

Afrobolivina afra, a Late Cretaceous bolivinid foraminifer, became extinct in the Early Paleocene. It was succeeded by the smaller, morphologically similar species Afrobolivina africana. Morphological variation in A. afra was in part correlated with environmental factors showing a pattern of random fluctuations about long-term ecological trends. A gradual, persistent and unbroken environmental trend, related to a eustatic fall in sea-level, is significantly correlated with the morphological evolution of the species. The micro-biogeography of A. afra at the time it was approaching extinction is consistent with its having given rise to A. afracana allopatrically in a manner which can be described by a fold-catastrophe adaptive model. This mode predicts that A. afra should undergo quantum evolution to A. africana in a restricted area in a near-shore environment.However, detailed study of borehole material reveals an apparent parabolic increase in the overall size of A. afra prior to extinction and it is argued that as a result, A. africana cannot be the direct descendant of A. afra without there having been some “discontinuity” in the environment or evolutionary process. This suggests that the sudden replacement of a species by a smaller, morphologically similar form may not be a straightforward succession. The apparent parabolic increase in size of A. afra can be modelled by the fold catastrophe of Thom theory if interpreted as representing the initial phase of a form of adaptive quantum evolution in which a gradual environmental change causes a fitness peak to be absorbed into the flank of a higher peak.In terms of such a model, the absence of a larger descendant species suggests that A. afra could have been replaced by A. africana before the quantum threshold had been reached. A possible cause for this could be that the changes in the environment might have lowered the height of the fitness function in the vicinity of the peak for A. afra to below that of the peak for A. africana, or vice versa.     

垂直形变强度分析在地震预报中的应用

根据数学上曲面拟合度的概念定义－－平均垂直形变量，来定量分析研究地壳表面垂直形变的强度，这一量值同时值有系统分析性质一统计意义。采用５０－９０年代中国大陆趋势性的垂直移计算结果，并利用定方法研究了中国在陆垂直形变强度背景值的分布特征及其与地震危险性的关系；利用华北地区１９６５－１９８８年多期垂直形变资料，研究了１９７６年唐山７．８级大地震的前后华北地区垂直形变强度随时间变化的动态过程，得到了强震的     

基于灰色系统与线性回归方法的水质预测

以北京市石景山区某地地下水监测点多年监测数据为例,进行适宜性预测方法的验证。其中,总硬度灰色预测值的平均相对误差为2.62%比线性预测低5.65个百分点;溶解性总固体线性预测值的平均相对误差为2.33%比灰色预测低0.61个百分点,与通过拟合度R~2值大小选取的最优预测方法一致,表明通过拟合度R~2值大小来选取合理的预测方法是一种便捷、合理的技术手段。     

Spatio-temporal evaluation matrices for geospatial data

The global geospatial community is investing substantial effort in providing tools for geospatial data-quality information analysis and systematizing the criteria for geospatial data quality. The importance of these activities is increasing, especially in the last decade, which has witnessed an enormous expansion of geospatial data use in general and especially among mass users. Although geospatial data producers are striving to define and present data-quality standards to users and users increasingly need to assess the fitness for use of the data, the success of these activities is still far from what is expected or required. As a consequence, neglect or misunderstanding of data quality among users results in misuse or risks. This paper presents an aid in spatio-temporal quality evaluation through the use of spatio-temporal evaluation matrices (STEM) and the index of spatio-temporal anticipations (INSTANT) matrices. With the help of these two simple tools, geospatial data producers can systematically categorize and visualize the granularity of their spatio-temporal data, and users can present their requirements in the same way using business intelligence principles and a Web 2.0 approach. The basic principles and some examples are presented in the paper, and potential further applied research activities are briefly described.     

Sex dependent sexual reproduction strategies in a cyclic parthenogen—A case study from intermittent urban pond

The fitness of animals inhabiting highly unpredictable intermittent ponds depends on the effectiveness of the production of their resting stages. Daphnia living in such an environment produce sexual eggs as well as the males needed to fertilize them. We hypothesize that the strategy of permanent male presence should coexist with the synchronization of the production of males with that of sexual eggs. To test this hypothesis, we collected plankton samples from a model urban pond, two times a week, throughout the growing season. We analyzed in detail a number of environmental factors and the population dynamics of two Daphnia populations. The percentage of ephippial females and males periodically reached c.a. 50 % of the population. Depending on the moment of the growing season, this proportion was primarily influenced by population crowding, the richness of invertebrate predators in the habitat, extreme high temperatures and the occurrence of the autumnal photoperiod. Our results confirm the hypothesis that Daphnia produce simultaneously long-living males and males synchronized with receptive females. Additionally, we have shown that the number of resting eggs deposited by temporally-isolated populations varied significantly; thus the fitness of a particular genotype depends on the season and on the particular timing of its activation.     

台北健身俱乐部的演变与都市发展

都市不但是本土与跨国健身俱乐部聚集之所在,也是其宣传和散布生活美学的流行文化中心,更是其主要的市场,现今最新、规模最大且最具代表性的健身俱乐部旗舰店无不想尽办法挤身首要都市,其中选择性的在新兴消费中心掀起卡位战。都市不仅是地理空间,也是现代资本主义和消费主义的汇集地点,这个权力场驱动了健身产业的发展与转型,建构了健身意义内涵与实践的框架,以及健身地景的文化形式。本篇文章企图将健身产业的地景和都市发展之间的关系进行讨论,说明随着台北城市由戒严时期的战时首都、工业城市、投机城市、全球化城市,健身如何由都市空间上和以生产为主流的社会伦理中的双重边陲,成为进占都市中心的「企业」,并取代工业城市地景,成为全球化台北的生活风格地景。