Optimisation algorithms for spatially constrained forest planning

We compared genetic algorithms, simulated annealing and hill climbing algorithms on spatially constrained, integrated forest planning problems. There has been growing interest in algorithms that mimic natural processes, such as genetic algorithms and simulated annealing. These algorithms use random moves to generate new solutions, and employ a probabilistic acceptance/rejection criterion that allows inferior moves within the search space. Algorithms for a genetic algorithm, simulated annealing, and random hill climbing are formulated and tested on a same-sample forest-planning problem where the adjacency rule is strictly enforced. Each method was randomly started 20 times and allowed to run for 10,000 iterations. All three algorithms identified good solutions (within 3% of the highest found), however, simulated annealing consistently produced superior solutions. Simulated annealing and random hill climbing were approximately 10 times faster than the genetic algorithm because only one solution needs to be modified at each iteration. Performance of simulated annealing was essentially independent of the starting point, giving it an important advantage over random hill climbing. The genetic algorithm was not well suited to the strict adjacency problem because considerable computation time was necessary to repair the damage caused during crossover.     

Seasonal polydomy and unicoloniality in a polygynous population of the red wood ant Formica truncorum

Ant colonies may have a single or several reproductive queens (monogyny and polygyny, respectively). In polygynous colonies, colony reproduction may occur by budding, forming multinest, polydomous colonies. In most cases, budding leads to strong genetic structuring within populations, and positive relatedness among nestmates. However, in a few cases, polydomous populations may be unicolonial, with no structuring and intra-nest relatedness approaching zero. We investigated the spatial organisation and genetic structure of a polygynous, polydomous population of Formica truncorum in Finland. F. truncorum shifts nest sites between hibernation and the reproductive season, which raises the following question: are colonies maintained as genetic entities throughout the seasons, or is the population unicolonial throughout the season? Using nest-specific marking and five microsatellite loci, we found a high degree of mixing between individuals of the population, and no evidence for a biologically significant genetic structuring. The nestmate relatedness was also indistinguishable from zero. Taken together, the results show that the population is unicolonial. In addition, we found that the population has undergone a recent bottleneck, suggesting that the entire population may have been founded by a very limited number of females. The precise causes for unicoloniality in this species remain open, but we discuss the potential influence of intra-specific competition, disintegration of recognition cues and the particular hibernation habits of this species.     

Effects of intracolony variability in behavioral development on plasticity of division of labor in honey bee colonies

There is a genetic component to plasticity in age polyethism in honey bee colonies, such that workers of some genotypes become precocious foragers more readily than do workers of other genotypes, in colonies lacking older bees. Using colonies composed of workers from two identifiable genotype groups, we determined that intracolony differences in the likelihood of becoming a precocious forager are a consequence of differences in rates of behavioral development that are also evident under conditions leading to normal development. An alternative hypothesis, that differences in the likelihood of becoming a precocious forager are due to differences in general sensitivity to altered colony conditions, was not supported. In three out of three trials, workers from the genotype group that was more likely to exhibit precocious foraging in single cohort colonies also foraged at relatively younger ages in colonies in which workers exhibited normal behavioral development. In contrast, in three out of three trials, workers from the genotype group that was more likely to exhibit precocious foraging in single-cohort colonies did not show disproportionately more overaged nursing in colonies in which workers exhibited delayed development. These results indicate that genotypic differences in plasticity in age-related division of labor are based on genotypic differences in rates of behavioral development.     

矿井通风网路的线性解算法及其程序设计

针对“京大二试算法”存在的不足——当已知矿井总风量时,“京大二试算法”的迭代格式是错误的,解算出的风量分配不合理,提出了矿井通风网络线性算法的数学模型.该通风网络算法是将支路特性方程变换为线性关系,则风网回路方程被线性化,就可以应用线性逼近法求解.该算法弥补了“京大二试算法”的缺陷,当已知矿井总风量时,解算出的风量值更接近真值,结果更加精确.介绍了线性算法数学模型的迭代格式及迭代精度问题,并编制了该线性算法的Matlab程序,程序简单,节省计算时间,给出了算法原理,并以实例进行计算,得到了令人满意的结果.     

Forest planning across Europe: the spatial scale,tools, andinter-sectoral integration in land-use planning

New approaches to forest planning are needed to support the transition of European forests to sustainable management. The aim of this study is to review forest planning systems already in place throughout Europe by exploring a set of case-study countries reflecting the main silvicultural schools of Western Europe, including Belgium, Finland, France, Italy, Portugal, and Slovenia.

A literature review and case-study data were used to assess the scale factors (vertical logic) as well as the relationships between forest planning and other environmental/land-use planning sectors (horizontal logic). The influence of EU policy on the development of forest planning is also discussed. As assessed using the vertical logic, the multi-scale and multi-topic planning approaches adopted in the countries studied here are highly heterogeneous. The horizontal logic shows that despite the importance of an inter-sectoral and harmonic relational framework between forest planning and the planning efforts of other sectors such as landscape and urban planning, the various plans are barely consistent with each other across the European countries studied here. Although interest is growing in the multi-functionality of forests, their sustainable management calls for the development of better integrated planning approaches across Europe.     

Referee analyses: A better approach than data validation

Data validation, as prescribed in guidance documents provided by the United States Environmental Protection Agency (EPA), yields legal evidence that an analytical laboratory has performed analyses according to predetermined specifications. This validation process, because it involves only the checking of procedural documentation, provides minimal information concerning the technical validity of the data. Unfortunately, in the minds of many, the performance of such a data validation has become synonymous with technical validity. A better approach is to implement a routine program of referee analyses. That is, submit a predetermined number of samples from the project to a second laboratory. A routine program of this type provides a self-checking and self-correcting mechanism for determining whether data are technically valid. Publication No. 3874, Environmental Sciences Division, ORNL. Managed by Martin-Marietta Energy Systems, Inc. for the US Department of Energy under Contract No. DE-AC05-840R21400.     

枣庄市医疗废物处理对策研究浅析

通过对医疗废物的危害和相关处理技术等问题的研究,提出枣庄市医疗废物处理对策的研究方案,为建立枣庄市医疗废物集中处理中心提供参考,可作为政府及相关业务主管部门的决策依据。     

GLOBAL WATER ISSUES AND THE WORLD WATER COUNCIL1

ABSTRACT: The key events and the process that led to the creation of the World Water Council on World Water Day 1996 are reviewed and its characteristics summarized. The development of this new organization is discussed in the context of the major global trends in water and water-related issues, viz. growing water scarcity with its links to limits on food production and demographic patterns. In response to the need to find solutions to these pressing water issues, the development of a Technical Program based on the deliberations of the founding member organizations and a number of short-term activities have been outlined to demonstrate the evolution of the Council in this first year of its existence. Given the importance of complementarity between the Council and the Global Water Partnership, an attempt has been made to articulate the mutually-reinforcing roles of the two organizations.     

A PROBABILISTIC BENEFIT-COST ANALYSIS OF A ZONING PROGRAM FOR FLOOD PLAINS1

ABSTRACT: Various techniques, one of which is zoning, are used to control the extent of flood damage. The benefit-cost analysis of zoning programs must take into account the random nature of flooding. This paper outlines a method for determining not only the expected value of the benefit-cost ratio, but also the probability of such a zoning program being profitable. It also presents an application of the method to the assessment of the Outaouais Regional Community zoning program.