Influence of habitat heterogeneity and bed surface complexity on benthic invertebrate diversity in a gravel‐bed river

Maintaining or restoring physical habitat diversity is a central tenet of sustainable river management, yet a link between habitat and ecological diversity in fluvial systems has long remained equivocal. The lack of consistent evidence partly reflects the problems of characterizing habitat in ways that are ecologically meaningful. This paper assesses the influence of habitat heterogeneity and complexity on macroinvertebrate assemblages in a mountain gravel‐bed river. With the use of 0.1‐m resolution data obtained from an acoustic Doppler current profiler, heterogeneity and complexity in hydraulic conditions and bed topography were characterized using 13 metrics applied to 30 areas, each 1 m², with an invertebrate sample collected from each area. Turnover of invertebrate taxa (i.e., β‐diversity) between sampled areas was rather limited, but observed differences in diversity were related significantly to several metrics of habitat heterogeneity. Invertebrate abundance was related to habitat diversity, patch size coefficient of variation, and patch size, whereas the Shannon diversity was related to the number of patches and patch size. None of the habitat complexity metrics accounted for a significant amount of observed variation in invertebrate communities between sampled areas. The paper demonstrates that high‐resolution data can help reveal relationships between habitat and benthic invertebrate diversity.     

“危机，什么危机？”

8月中旬当美国大型投资机构Sentinel停止投资者抽离资金时，它的理由是市场出现了“恐慌”。毫无疑问：近日全球市场剧烈震荡，导致金融界某些领域的危机感日益加剧。[第一段]     

Competence management in knowledge intensive organizations using consensual knowledge and ontologies

This article describes an architecture suitable for use in a competence management system for knowledge intensive organizations (KIOs). The underlying motivation for this work is to explore the practical problems of the use of codified knowledge in knowledge management systems (KMS) in KIOs. We explore some of the key issues associated with the use of tacit and codified knowledge in KMS, and describe an architecture based on an ontology-driven framework derived from collective and consensual knowledge that acts as a structure for a formal knowledge base. We describe, in outline, a prototype competence management system based on this architecture designed to support the management of competencies in a structured way. We conclude with some observations about our approach to the representation of knowledge in a KMS and its potential value to KIOs.     

The Cost of Environmental Constraints in Traffic Networks: Assessing the Loss of Optimality

Increasing numbers of hard environmental constraints are being imposed in urban traffic networks by authorities in an attempt to mitigate pollution caused by traffic. However, it is not trivial for authorities to assess the cost of imposing such hard environmental constraints. This leads to difficulties when setting the constraining values as well as implementing effective control measures. For that reason, quantifying the cost of imposing hard environmental constraints for a certain network becomes crucial. This paper first indicates that for a given network, such cost is not only related to the attribution of environmental constraints but also related to the considered control measures. Next, we present an assessment criterion that quantifies the loss of optimality under the control measures considered by introducing the environmental constraints. The criterion can be acquired by solving a bi-level programming problem with/without environmental constraints. A simple case study shows its practicability as well as the differences between this framework and other frameworks integrating the environmental aspects. This proposed framework is widely applicable when assessing the interaction of traffic and its environmental aspects.     

Categories of quantum and classical channels

We introduce a construction that turns a category of pure state spaces and operators into a category of observable algebras and superoperators. For example, it turns the category of finite-dimensional Hilbert spaces into the category of finite-dimensional C*-algebras and completely positive maps. In particular, the new category contains both quantum and classical channels, providing elegant abstract notions of preparation and measurement. We also consider nonstandard models that can be used to investigate which notions from algebraic quantum information theory are operationally justifiable.     

Repeatedly foldable AMOLED display

In this study, a 5.9‐inch foldable active‐matrix organic light emitting diode (AMOLED) display was developed. A folding test was performed repeatedly. The display survived the folding test (100,000 folds) with a curvature radius of 2 mm. To protect an organic light emitting diode (OLED) against moisture, inorganic passivation layers are provided on the upper and lower sides of the flexible display. Using our transfer technology, high density passivation layers can be obtained. The measured water vapor transmission rate of the layer is 7 × 10^?6 g/m²?day or less, which improves OLED reliability. With these techniques, we have developed a book‐type display, which is repeatedly foldable like a book, and a tri‐fold display including a display area, which is foldable in three.     

A Dimension‐reduced Pressure Solver for Liquid Simulations

This work presents a method for efficiently simplifying the pressure projection step in a liquid simulation. We first devise a straightforward dimension reduction technique that dramatically reduces the cost of solving the pressure projection. Next, we introduce a novel change of basis that satisfies free‐surface boundary conditions exactly, regardless of the accuracy of the pressure solve. When combined, these ideas greatly reduce the computational complexity of the pressure solve without compromising free surface boundary conditions at the highest level of detail. Our techniques are easy to parallelize, and they effectively eliminate the computational bottleneck for large liquid simulations.     

Adoption and use of Java generics

Support for generic programming was added to the Java language in 2004, representing perhaps the most significant change to one of the most widely used programming languages today. Researchers and language designers anticipated this addition would relieve many long-standing problems plaguing developers, but surprisingly, no one has yet measured how generics have been adopted and used in practice. In this paper, we report on the first empirical investigation into how Java generics have been integrated into open source software by automatically mining the history of 40 popular open source Java programs, traversing more than 650 million lines of code in the process. We evaluate five hypotheses and research questions about how Java developers use generics. For example, our results suggest that generics sometimes reduce the number of type casts and that generics are usually adopted by a single champion in a project, rather than all committers. We also offer insights into why some features may be adopted sooner and others features may be held back.