This paper reviews the work carried out under the European ACTS KEOPS (KEys to Optical Packet Switching) project, centering on the definition, development and assessment of optical packet switching and routing networks capable of providing transparency to the payload bit rate. The adopted approach uses optical packets of fixed duration with low bit rate headers to facilitate processing at the network/node interfaces. The paper concentrates on the networking concepts developed in the KEOPS project through a description of the implementation issues pertinent to optical packet switching nodes and network/node interfacing blocks, and consideration of the network functionalities provided within the optical packet layer. The implementation, from necessity, relies on advanced optoelectronic components specifically developed within the project, which are also briefly described.

The nature of the force (T) response during and after steady lengthening has been investigated in tetanized single muscle fibres from Rana temporaria (4 °C; 2.15 μm sarcomere length) by determining both the intensity of the third order myosin meridional X‐ray reflection (IM3) and the stiffness (e) of a selected population of sarcomeres within the fibre. With respect to the value at the isometric tetanus plateau (T0), IM3 was depressed to 0.67 ± 0.04 during steady lengthening at ≈160 nm s−1 (T≈ 1.7) and recovered to 0.86 ± 0.05 during the 250 ms period of after‐stretch potentiation following the rapid decay of force at the end of lengthening (T≈ 1.3); under the same conditions stiffness increased to 1.25 ± 0.02 and to 1.12 ± 0.03, respectively. After subtraction of the contribution of myofilaments to the half‐sarcomere compliance, stiffness measurements indicated that (1) during lengthening the cross‐bridge number rises to 1.8 times the original isometric value and the average degree of cross‐bridge strain is similar to that induced by the force‐generating process in isometric conditions (2.3 nm), and (2) after‐stretch potentiation is explained by a residual larger cross‐bridge number. Structural data are compatible with mechanical data if the axial dispersion of attached heads is doubled during steady lengthening and recovers half‐way towards the original isometric value during after‐stretch potentiation.

No abstract

To address the urgent need for high-capacity, scalable and energy-efficient data center solutions, we propose a novel data center network architecture realized by combining broadcast-and-select approach with elastic channel spacing technology.\ud We demonstrate that the proposed architecture is able to scale efficiently with the number of servers and offers lower energy consumption at a competitive cost compared to the existing solutions

No abstract