Orthogonal multipulse modulation for next-generation datacommunication links

Orthogonal multipulse modulation is demonstrated to allow ≈30 Gb/s real-time transmission over multimode fibre using an 850 nm VCSEL. The scheme eases considerably component bandwidth requirements compared with conventional NRZ modulation. © 2011 OSA.

The retrieval of structured design rationale for the re-use of design knowledge with an integrated representation

Design knowledge can be acquired from various sources and generally requires an integrated representation for its effective and efficient re-use. Though knowledge about products and processes can illustrate the solutions created (know-what) and the courses of actions (know-how) involved in their creation, the reasoning process (know-why) underlying the solutions and actions is still needed for an integrated representation of design knowledge. Design rationale is an effective way of capturing that missing part, since it records the issues addressed, the options considered, and the arguments used when specific design solutions are created and evaluated. Apart from the need for an integrated representation, effective retrieval methods are also of great importance for the re-use of design knowledge, as the knowledge involved in designing complex products can be huge. Developing methods for the retrieval of design rationale is very useful as part of the effective management of design knowledge, for the following reasons. Firstly, design engineers tend to want to consider issues and solutions before looking at solid models or process specifications in detail. Secondly, design rationale is mainly described using text, which often embodies much relevant design knowledge. Last but not least, design rationale is generally captured by identifying elements and their dependencies, i.e. in a structured way which opens the opportunity for going beyond simple keyword-based searching. In this paper, the management of design rationale for the re-use of design knowledge is presented. The retrieval of design rationale records in particular is discussed in detail. As evidenced in the development and evaluation, the methods proposed are useful for the re-use of design knowledge and can be generalised to be used for the retrieval of other kinds of structured design knowledge. © 2012 Elsevier Ltd. All rights reserved.

Optimization on the orthogonal group for independent component analysis

This paper derives a new algorithm that performs independent component analysis (ICA) by optimizing the contrast function of the RADICAL algorithm. The core idea of the proposed optimization method is to combine the global search of a good initial condition with a gradient-descent algorithm. This new ICA algorithm performs faster than the RADICAL algorithm (based on Jacobi rotations) while still preserving, and even enhancing, the strong robustness properties that result from its contrast. © Springer-Verlag Berlin Heidelberg 2007.

Orthogonal multipulse modulation for 64 Gigabit Fibre Channel

Real-time orthogonal multipulse modulation is demonstrated at 56 Gb/s with transmission over 500 m of single-mode fiber. Up to 2 dBo power budget advantage is predicted relative to alternatives such as PAM4. © 2013 OSA.

An integrated representation of the services provided by global water resources

Water is essential not only to maintain the livelihoods of human beings but also to sustain ecosystems. Over the last few decades several global assessments have reviewed current and future uses of water, and have offered potential solutions to a possible water crisis. However, these have tended to focus on water supply rather than on the range of demands for all water services (including those of ecosystems). In this paper, a holistic global view of water resources and the services they provide is presented, using Sankey diagrams as a visualisation tool. These diagrams provide a valuable addition to the spatial maps of other global assessments, as they track the sources, uses, services and sinks of water resources. They facilitate comparison of different water services, and highlight trade-offs amongst them. For example, they reveal how increasing the supply of water resources to one service (crop production) can generate a reduction in provision of other water services (e.g., to ecosystem maintenance). The potential impacts of efficiency improvements in the use of water are also highlighted; for example, reduction in soil evaporation from crop production through better farming practices, or the results of improved treatment and re-use of return flows leading to reduction of delivery to final sinks. This paper also outlines the measures needed to ensure sustainable water resource use and supply for multiple competing services in the future, and emphasises that integrated management of land and water resources is essential to achieve this goal. © 2013 Elsevier Ltd.