Abstract
Most model checkers provide a useful simulation mode, that allows users to explore the set of possible behaviours by interactively picking at each state which event to execute next. Traditionally this simulation mode cannot take into consideration additional temporal logic constraints, such as arbitrary fairness restrictions, substantially reducing its usability for debugging the modelled system behaviour. Similarly, when a specification is false, even if all its counter-examples combined also form a set of behaviours, most model checkers only present one of them to the user, providing little or no mechanism to explore alternatives. In this paper, we present a simple on-the-fly verification technique to allow the user to explore the behaviours that satisfy an arbitrary temporal logic specification, with an interactive process akin to simulation. This technique enables a unified interface for simulating the modelled system and exploring its counter-examples. The technique is formalised in the framework of state/event linear temporal logic and a proof of concept was implemented in an event-based variant of the Electrum framework.

Abstract
The American NASA Apollo missions to the lunar surface, between 1969 and 1972 greatly increased the knowledge of the Moon as well as that of our own Earth’s age and origins. Part of the scientific research used geophysical techniques to help define the structure of the Moon, both deep and also regarding the near surface. One such experimentation that was carried out, on both Apollo 14 and Apollo 16, as part of the Apollo Lunar Seismic Experiment Package (ALSEP), was the Active Seismic Experiment (ASE). The ASE comprised of three geophones, planted at approximately 45m apart along a longitudinal line, that recorded signals from small explosive charges deployed at specific distances in between the geophones, The analysis resulted in a set of traveltimes, from source to receiver, that were later interpreted using the intercept time method. Since then the data set results were accepted. The development of traveltime tomographic techniques in the early 1990’s allows for models to have a more realistic appearance with both lateral variations of seismic velocity as well as increasing velocities with a certain gradient in depth. This is opposed to the sharp sudden increases of compressional wave velocity typical of the intercept time method’s assumption. Herein we will present a discussion as well as the results of the reinterpretation of the Apollo 14 and 16 ASE refraction traveltimes using traveltime tomography techniques. © SGEM2019.

Abstract
Optical waveguides directly written in fused silica using a femtosecond laser were characterized from 350 to 1750 nm to gain insight on the waveguide's loss mechanisms and their dependence on processing parameters, such as pulse energy, scan velocity, and annealing temperature. Two major loss mechanisms were identified. In the range of parameters tested, high pulse energy was seen to improve coupling losses at long wavelengths, while high scan velocity has a negative effect in both Rayleigh scattering and coupling losses at long wavelengths. Thermal annealing of the waveguides demonstrated an improvement of the Rayleigh scattering at a cost of higher coupling losses at long wavelengths. Wavelength independent Mie scattering was also observed, evolving negatively with pulse energy. A minimum Rayleigh scattering coefficient of approximate to 0.5 dB.cm(-1).mu m(4) (approximate to 0.08 dB.cm(-1).mu m(4) for thermally treated waveguides) together with a Mie scattering coefficient of approximate to 0.2-0.65 dB/cm are reported.

Abstract
The growth of intermittent renewable power generation has been drawing attention to the design of balancing markets. Portugal is an interesting case study because wind generation already accounts for a high fraction of demand (23% in 2012-2016), but still there are no economic incentives for efficient wind forecasting (wind balancing costs are passed to end consumers). We analyze the evolution of the balancing market from 2012 to 2016. Using actual market data, we find wind balancing costs around 2 euros per MWh of generated energy. One main reason for these low costs is the existence of a robust transmission grid, which allows for the compensation of positive with negative wind imbalances across the system. Nevertheless, the results suggest that final consumers could save several million euros per year if wind generators were made responsible for the economic cost of their imbalances, in line with other European markets.

Abstract
In this study, the operation of an energy system composed of a battery energy storage system (BESS) and a conventional generator to compensate the forecasting error of renewable power production has been analyzed. A scenario with low forecasting error and another with high forecasting error have been synthetically modeled and incorporated to a computational model of the energy system. The results obtained from a case study suggest that a low forecasting error could be compensated by a single BESS. However, a high forecasting error would require the installation of a controllable power source such as a conventional generator.

Abstract
Real-time monitoring of the power system by phasor measurement units (PMUs) leads to the development of such devices in a wide area measurement system (WAMS). However, the power system observability cannot be obtained by employing only PMUs. The communication infrastructure (CI) is a significant part of the WAMS that has to be optimally designed and implemented to collect data from PMUs and deliver them to control centers. In this paper, a novel hybrid wireless sensor network is proposed for the connection of PMUs throughout the system to enable convenient and low-cost communication media. The problem of observability in the communication system is checked along with the optimal placement of PMUs in the power system to reach full observability. A hybrid wireless sensor network including plug-in powered sensor nodes (PPSNs) and energy harvesting sensor nodes (EHSNs) is utilized for increasing the reliability of the communication system. In the proposed co-optimal PMU-sensor placement problem, the main objective is to minimize the total cost of PMU placement and the related communication system, considering full observability of the power system and CI. To achieve better results, the zero-injection bus (ZIB) effect and system observability redundancy index (SORI) are considered as a constraint in the objective function. A binary-coded genetic algorithm is used for solving the proposed mixed-objective optimization problem subject to different technical operating constraints. The proposed method is examined on IEEE 13-bus and IEEE 37-bus test feeder systems. The results show the applicability and effectiveness of the proposed method compared with the conventional methods in this subject area.