Wind turbines are usually clustered in wind farms which causes the downstream turbines to operate in the turbulent wakes of upstream turbines. As turbulence is directly related to increased fatigue loads, knowledge of the turbulence in the wake and its evolution are important. Therefore, the main objective of this study is a comprehensive exploration of the turbulence evolution in the wind turbine’s wake to identify characteristic turbulence regions. For this, we present an experimental study of three model wind turbine wake scenarios that were scanned with hot-wire anemometry with a very high downstream resolution. The model wind turbine was exposed to three inflows: laminar inflow as a reference case, a central wind turbine wake, and half of the wake of an upstream turbine. A detailed turbulence analysis reveals four downstream turbulence regions by means of the mean velocity, variance, turbulence intensity, energy spectra, integral and Taylor length scales, and the Castaing parameter that indicates the intermittency, or gustiness, of turbulence. In addition, a wake core with features of homogeneous isotropic turbulence and a ring of high intermittency surrounding the wake can be identified. The results are important for turbulence modeling in wakes and optimization of wind farm wake control
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Aging diversity in organizations creates potential challenges, particularly for knowledge management, skills update and skills obsolescence. Intergenerational learning (IGL) involves knowledge building, innovation and knowledge transfer between generations within an organization (Ropes 2011). Serious games refer to the use of computer games in raising awareness about educational topics, acquiring new knowledge and skills by enabling learners to engage and participate in situations that would otherwise be impossible to experience (Corti 2006). Although learning with the use of serious games is similar to traditional learning in several cognitive respects, there are noted differences in the learning style and structure of learning using serious games. The success of learning using serious games lies in the actual involvement of a participant playing the game, which in turn, creates increased cognitive links with real-life situations allowing the individual to make relevant associations, to use mnemonic strategies with the facilitation of multi-dimensional educational aids (e.g., visual, auditory). Some of the beneficial aspects of learning with the use of serious games include the elevation of several cognitive skills, which are directly or indirectly implicated in the learning process. Among them are attention and visuo-spatial abilities, memory and motor skills. However, several barriers have been noted that fall into two general categories: a) health issues (e.g., cognitive strain, headaches) and b) psychological issues (e.g., social isolation, emotional disturbances). Since the training conditions are learner-centered and highly determined by the individual, there is increased need for evaluating the learning outcomes using specific success indicators. Examples of games that are designed to facilitate IGL are scarce, while there are no examples of IGL games in most EU countries. The purpose of this paper is to critically evaluate the current literature of theories on learning through serious games in adults and the elderly with reference to the cognitive mechanisms implicated, benefits and barriers in learning using new technologies in different generations. Secondly, this paper reviews the existence of serious games designed to facilitate IGL in Europe, as well as the characteristics of serious games in raising awareness that could be used to facilitate IGL. In doing so, specific focus is placed on the development of success indicators that determine the effectiveness of serious games on raising awareness on IGL.
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Pitch size varies in official soccer matches and differently sized pitches are adopted for tactical purposes in small-sided training games. Since interactive team behaviour emerges under constraints, the authors evaluate the effect of pitch size (task) manipulations on interactive team behaviour in small-sided soccer games. Four 4-a-side (plus goalkeepers) small-sided games were played: a reference game (30×20 m), length manipulation (24×20 m), width manipulation (30×16 m), and a combination (24×16 m). Using position data (100Hz), three measures quantifying the teams' interaction were calculated: longitudinal inter-team distance, lateral inter-team distance, and surface area difference. Means and standard deviations, correlations and coupling values were calculated. Running correlations were calculated over a 3-s window to evaluate interaction patterns. As expected, a shorter pitch results in smaller longitudinal inter-team distance, lateral inter-team distance decreased for narrow pitches, and smaller total playing area resulted in decreased surface area. Unanticipated, a crossover effect was present; length and width manipulations also triggered changes in lateral and longitudinal direction respectively. Inter-team distances and surface area difference differed significantly across conditions. Interaction patterns differed across conditions for all measures. So, highly tactically relevant, soccer teams seem to adapt their interactive behaviour according to pitch size in small-sided games. © 2013 Institute of Systems Science, Academy of Mathematics and Systems Science, CAS and Springer-Verlag Berlin Heidelberg.
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