Abstract
A coordinated offering strategy between a wind farm and a reversible hydro plant can reduce wind power imbalances, improving the system efficiency whilst decreasing the total imbalances. A stochastic mixed integer linear model is proposed to maximize the profit and the future water value FWV of the system using Conditional Value at Risk (CVaR) for risk-hedging. The offer strategies analyzed are: (i) single wind-reversible hydro offer with a physical connection between wind and hydro units to store spare wind energy, and (ii) separate wind and reversible hydro offers without a physical connection between them. The effect of considering the FWV of the reservoirs is studied for several time horizons: one week (168 h) and one month (720 h) using an illustrative case study. Conclusions are duly drawn from the case study to show the impact of FWV in the results.

Abstract
For the integration of distributed generation (DG) units to the utility grid, voltage source converter (VSC) is the key technology. In order to realize high quality power injection, different control techniques have been adopted. However, the converter-based DG interface is subject to inevitable uncertainties, which adversely influence the performance of the controller. The interfacing impedance seen by the VSC may considerably vary in real distribution networks. It can be observed that the stability of the DG interface is highly sensitive to the impacts of interfacing impedance changes so that the controller cannot inject appropriate currents. To deal with the instability problem, this paper proposes an enhanced fractional order active sliding mode control scheme for integration of DG units to the utility grid, which is much less sensitive to interfacing impedance variations. A fractional sliding surface which demonstrates the desired dynamics of the system is developed and then the controller is designed in two phases: sliding phase and reaching phase to keep the control loop stable. The proposed controller takes a role to provide high quality power injection and ensures precise current tracking and fast response despite uncertainties. Theoretical analyses and simulation results are verified to study the performance and feasibility of the proposed control scheme.

Abstract

Abstract
In this study, we investigated the temperature behavior of phase-shifted long-period fiber gratings (PS-LPFGs) inscribed in two types of optical fiber: B/Ge and SMF28. The experiments were carried out from 5 to 305 K using a superconducting quantum interference device magnetometer. The average temperature sensitivity obtained of -0.43 nm/K for PS-LPFGs inscribed in the B/Ge fiber is one order of magnitude larger than for PS-LPFGs inscribed in the SMF28 fiber, in the 60-240 K range. Values ranging from -0.08 nm/K up to 0.2 nm/K were obtained in the 5-35 K temperature range, which are considerably better than previous results achieved for metal-coated FBGs and also for LPFGs inscribed in a similar B/Ge codoped fiber. Nevertheless, further work is required in order to correctly address sensor reliability.

Abstract
Given the growth in usage of online social networks, such as Facebook, YouTube, Instagram and Snapchat, which rely on videos and images (such as photos) to relay information between connections, new intuitive languages, though not yet formally recognized, have emerged. We also herein give the example of a new language we have created – the Business Narrative Modelling Language (BNML) – which communicates business perspectives based on pictorial representations, supported by the narrative. Currently, the concept of language is linked to the use of words. We foresee that such a definition of language will have to change to include other structured forms of communication, resorting and relying on graphics, also. We give examples of BNML representations, with regards to two case studies we have performed, based on face-to-face interviews and company visits. At ExpressGlass technology plays an important role, while at Yazaki Saltano a remarkable team effort between Toyota suppliers is made evident, to create innovation. © Universidad Alberto Hurtado, Facultad de Economía y Negocios.

Abstract