Evolution of Tungsten Fiber-Reinforced Tungsten-Remarks on Production and Joining

Material issues pose a significant challenge for the design of future fusion reactors. These issues require new advanced materials to be developed. W-fiber-reinforced W-composite material (W _f/W) incorporates extrinsic toughening mechanisms increasing the resistance against failure and thus granting steps toward application in a future fusion reactor. W _f/W can be produced based on chemical vapor deposition or powder metallurgical routes. In this contribution, the efforts of upscaling the production of W _f/W will be reviewed based on recent results. In addition, the activities related to enabling large-scale production for new fusion applications are being studied. Herein, two main achievements are to be highlighted. First, an upscaled production is established to produce flat tile samples for joining tests on copper and steel, and second, a new method of joining W _f/W on copper is established and tested under high heat-flux conditions.     

Object-based approach to programming distributed systems

Two kinds of parallel computers exist: those with shared memory and those without. The former are difficult to build but easy to program. The latter are easy to build but difficult to program. In this paper we present a hybrid model that combines the best properties of each by simulating a restricted object-based shared memory on machines that do not share physical memory. In this model, objects can be replicated on multiple machines. An operation that does not change an object can then be done locally, without any network traffic. Update operations can be done using the reliable broadcast protocol described in the paper. We have constructed a prototype system, designed and implemented a new programming language for it, and programmed various applications using it. The model, algorithms, language, applications and performance will be discussed.     

Retrieval-based language model adaptation for handwritten Chinese text recognition

International Journal on Document Analysis and Recognition (IJDAR) - In handwritten text recognition, compared to human, computers are far short of linguistic context knowledge, especially...     

Dependability analysis of stand‐alone photovoltaic systems

Long‐term performance of PV stand‐alone systems is analysed in this work in terms of dependability. On one side, the quality of a PV system, the energy service supplied to the users, depends on the initial design and sizing and on the component ageing that progressively decreases the availability of supply on demand (energy reliability). On the other side, technical failures lead to system stoppage until repairing is performed (technical reliability), which is crucial in real rural electrification applications. All those factors are analysed together with the basis of an extended field, laboratory and bibliographic review work. Copyright © 2006 John Wiley & Sons, Ltd.