Abstract
Solving nesting problems or irregular strip packing problems is to position polygons on a fixed width and unlimited length strip, obeying polygon integrity containment constraints and non-overlapping constraints, in order to minimize the used length of the strip. To ensure non-overlapping, we use separation lines, i.e., straight lines that separate polygons. We present a nonlinear programming model that considers free rotations of the polygons and of the separation lines. This model uses a considerable smaller number of variables than the few other approaches proposed in the literature. We use the nonlinear programming solver IPOPT (an algorithm of interior points type), which is part of COIN-OR. Computational tests were run using established benchmark instances and the results were compared with the ones obtained with other methodologies in the literature that use free rotations. © 2018 Brazilian Operations Research Society.

Abstract
The Portuguese business structure is essentially composed of small and medium-sized enterprises (SMEs), which, despite their size, generate employment and contribute to the increase of national income. In many of these companies, some of them having less than ten employees, management and operational functions are often carried out by the entrepreneur. In addition, the entrepreneur does not always have technical knowledge in management, nor do they have the available time (since they have various responsibilities within the company) to develop and implement a management strategy that allows the enterprise to remain in the market while adopting a more conscious, consistent and sustained orientation. Within the scope of the Operational Program for Competitiveness and Internationalization - Portugal 2020, the Balanced ScoreCard (BSC) strategic management instrument was developed and implemented in several companies and sectors of the Portuguese economy. This instrument was crucial in initiating a process of strategic thinking which, quite possibly, would not have happened in such a short time horizon. This research work analyses through an essentially qualitative research the way the BSC instrument was developed and implemented. Another objective is to understand the main advantages of its use and its main application constraints. The data was gathered through a semi-structured interview developed for the owners of four Portuguese SMEs in the northern region Portugal, targeted under the abovementioned programme framework. The results demonstrate the instrument was essential for the development of a structured strategic thinking, as well as for a better performance and, consequently, to the improvement of the competitiveness of the targeted companies. The results also show the instrument had to be adapted and simplified and its implementation has to involve all the employees of the enterprises.

Abstract
Aggregated management of distributed energy resources (DERs) is an emerging topic mainly with simulation based investigation of the developed approaches. On the other hand, field tests can provide important insights on the path to wide deployment. Most of the works take into account aggregated DERs as a single entity and do not get into details about how to allocate a desired management target among them. This study focuses on management of different types of DERs as a group to reach aggregation targets through two field-testing scenarios. Active power management scenario investigates management of a DER group for an hour long period by allocating an overall target proportional to DERs energy storage capacities. Varying PV panel, wind turbine and residential consumer power profiles were also included in the testing scenario as a challenge to determine set points for manageable devices. Reactive power management case equally distributes aggregation targets among available DERs, comparing relative management performances in 4 consecutive periods. Management performances of individual DERs and the whole group were evaluated, highlighting management accuracy and possible challenges in the field.

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Abstract
The concept of urban mobility development needs to be somehow reconsidered towards planning and implementing transports in a more sustainable, inclusive and integrated manner. It urges to monitor and evaluate the sustainable development of the cities based on a triple bottom line dimension - economic, social and environmental; as well as on the main indicators, including the ones regarding the cities context and particularities. Hence, the definition of sustainability indicators and the associated index is a major tool towards gaining higher visibility of the current state of mobility and to establish goals and milestones to attain the desired sustainability. According to the Viana do Castelo case study, a description of the city and of the existents transports is presented, and Sustainable Urban Mobility Plan guidelines are also proposed. In this paper, a set of sustainability indicators are defined with balanced distribution by the sustainability dimensions, according to the benchmarking analysis and the Viana do Castelo' characteristics - including the ones regarding the historic city center. These sustainability indicators enable the development of an evolutive sustainable profile, provide knowledge to the redesign of sustainable urban policies in the Viana do Castelo city and in the Alto Minho Region context.

Abstract