Production process adapted design of thermoplastic-compatible piezoceramic modules

Fibre-reinforced polymers with thermoplastic matrix systems are suitable for a wide range of applications in the field of function-integrative lightweight structures ready for series production. The development of functional elements which are tailored to processes is therefore of increasingly significant importance. The thermoplastic-compatible piezoceramic modules under development are suitable for adhesive-free integration into fibre-reinforced thermoplastic structures using a welding process which is intrinsic to the manufacturing process. The continuous refinement of the novel module design and the corresponding manufacturing process (which is based on hot-pressing technology) is supported by the development of tailored coupled and physical nonlinear simulation models which facilitate module design and the analysis of functionality in terms of interactions between technical and technological parameters. Special attention is given to the definition of precise, function-specific manufacturing tolerances as well as the residual stresses caused by the various thermal expansion coefficients of the module components and the use thereof as a means of enhancing module performance.     

Impact localisation with FBG for a self-healing carbon fibre composite structure

We demonstrated the localisation of impacts in orthotropic carbon fibre reinforced polymer (CFRP) composite materials to within a few centimetres, using a sparse array of fibre Bragg grating (FBG) sensors. This type of sensor is easily embedded in composites permitting the development of structures with integrated sensing capability. Impact location was determined by measuring the differences in time-of-flight of ultrasonic Lamb waves at three surface-mounted sensors. An algorithm was developed taking into account the angle dependence of the optical fibre sensor sensitivity and the variation of Lamb waves propagation velocity with direction and wave mode. The performance of FBG sensors for impact localisation was compared to that of standard piezoelectric transducers (PZTs), which are already widely used for that purpose. The FBG-based system showed promising potential for a non-intrusive impact detection system applied to self-healing composite structures.     

Electrochromic interference filters fabricated from dense and porous tungsten oxide films

Smart windows offer an opportunity to reduce energy consumption. However, the use of multiple optical elements, such as low emittance coatings and electrochromic devices, is detrimental to the luminous transmittance of these high performance windows. Although the addition of antireflective coatings has helped to reduce this problem, some elements, such as high index of refraction materials still give rise to loss of light. We show that replacing the single WO₃ active coating, the main component of an electrochromic device, by an appropriately designed electrochromic interference filter can significantly increase the transmittance. This active filter is based on a stack of dense and porous WO₃ layers. We first study the effect of porosity on the physical and electrochromic properties of WO₃ prepared by radio frequency magnetron sputtering. We demonstrate that the overlying dense coating does not inhibit the coloration of the underlying porous coating. The best performing films are combined into a 27 layer quarter-wave interference filter which is shown to cycle between bleached and colored states, while providing attractive transmission. Finally, we discuss various filter designs which can increase the transmission of an electrochromic device in its bleached state, as well as the potential use of active filters for optical security devices possessing two levels of authentication.     

一种智慧城市平台部署思路的探讨

介绍了当前智慧城市平台部署面临的关键问题，对智慧城市平台部署步骤提出了建议，最后给出了智慧城市平台的建设模式和商业模式。     

The importance of instrumental,symbolic, and environmental attributes for the adoption of smart energy systems

The conceptual model on motivations to adopt sustainable innovations (Noppers et al., 2014) proved to be successful in explaining proxies of the adoption of sustainable innovations: positive evaluations of the utility (instrumental attributes), environmental impact (environmental attributes), and specifically the extent to which the innovation says something about a person (symbolic attributes) increased interest in and intention to adopt sustainable innovations. In this paper, we examined to what extent the evaluations of these three attributes can also explain the actual adoption of smart energy systems that facilitate sustainable energy use. Results showed that adopters of smart energy systems (who agreed to participate in a project in which these systems were tested) evaluated the symbolic attributes of these systems more positively than non-adopters (who did not participate in this project), while both groups did not differ in their evaluation of the instrumental and environmental attributes of smart energy systems. A logistic regression analysis indicated that only evaluations of the symbolic attributes explained actual adoption of smart energy systems. Policy could stress and enhance the symbolic attributes of sustainable innovations to encourage adoption.     

Robust control for voltage and transient stability of power grids relying on wind power

Common practice in stabilization of power grids is to refer to different stability categories (transient stability, voltage stability, rotor angle stability) and to address these by designing dedicated controllers separately based on models linearized around nominal operation points. Furthermore, the controllers of a generating unit contained in the grid are usually synthesized without considering other grid nodes. This work, in contrast, proposes a scheme for unified synthesis of controllers which conjunctively address rotor angle stability and voltage stability for grids containing synchronous generators as well as wind energy conversion systems based on doubly-fed induction generators. First, a procedure is proposed to describe the generating units by linear-parameter-varying (LPV) systems, in which fluctuations imposed by the grid or the wind are mapped into time-varying model parameters. For appropriate ranges of these parameters, decentralized robust controllers can be synthesized by semidefinite-programming, such that the power grid is stabilized for the considered fluctuations and disturbances. The effectiveness of the approach is demonstrated for a multi-bus benchmark system, where the grid oscillations are well damped and the LPV-controller stabilizes the grid after permanent changes.     

Consumer engagement: An insight from smart grid projects in Europe

This paper provides an insight into consumer engagement in smart grid projects in Europe. Projects analysed are those included in the catalogue annexed in the JRC Report “Smart Grid projects in Europe: lessons learned and current developments”. The analysis suggests an increase in the interest in consumer engagement projects at European level and a strong focus on the residential sector, and emphasises the key importance of public funding to support these projects. The study also reveals that projects involving consumers are characterised by the pursuit of two main objectives: gaining deeper knowledge of consumer behaviour (observing and understanding the consumer) and motivating and empowering consumers to become active energy customers (engaging the consumer). The paper reviews the main activities undertaken to obtain these objectives and highlights trends and developments in the field. Finally, the paper discusses obstacles to consumer engagement and the strategies adopted by the projects surveyed to tackle them, highlighting the need to build consumer trust and to design targeted campaigns taking into consideration different consumer segments. The conclusions are in line with findings and analyses presented in the literature and underscore the need for further research and action at European level.     

Intranet模式企业信息系统分析与设计

通过对比信息系统结构特点，该文提出了建立基于Intranet的企业信息系统的解决方案，并进行了详细的分析和探讨。     

The potential for segmentation of the retail market for electricity in Ireland

We estimate the gross margin that is earned from the supply of electricity to households in Ireland. Using half hourly electricity demand data, the system marginal price (also called the wholesale price) and the retail price of electricity, we analyse how the gross margin varies across customers with different characteristics. The wholesale price varies throughout the day, thus, the time at which electricity is used affects the gross margin. The main factor in determining gross margin, however, is the level of demand.The highest gross margins are earned from supplying customers that have the following characteristics: being aged between 46 and 55, having a household income of at least €75,000 per annum, being self-employed, having a third-level education, having a professional or managerial occupation, living in a household with seven or more people, living in a detached house, having at least five bedrooms or being a mortgage holder.An OLS regression shows that gross margin is partly explained by the energy conservation measures which are present in a household; the number of household members; the number of bedrooms; age; occupation; and accommodation-type.     

Adoption of three new types of computers in Taiwan: Tablet PCs,netbooks, and smart phones

Tablet PCs, netbooks, and smart phones are similar to one another in that they possess the basic functions of computers, but they differ in what functions they emphasize. Rogers’ diffusion of innovation model has been widely recognized as a powerful model for predicting technology adoption. This study adopted Rogers’ model to examine the adoption intentions of the three new types of computers. A telephone survey was conducted to collect data. This study made 1757 telephone calls, from which 1100 valid calls were obtained, representing a response rate of 62.61%. The data analysis demonstrates that the findings are generally congruent with the predictions of Rogers’ model. However, this study’s results also reveal one limitation of Rogers’ model, its pro-innovation bias, which explains why the diffusion of netbooks was incongruent with Rogers’ model.